Cognitive justice and environmental learning in South African social movements
- Authors: Burt, Jane Caroline
- Date: 2021-04
- Subjects: Transformative learning , Water security -- South Africa , Environmental education -- South Africa , EEASA (Organization) , Civil society -- South Africa , Water justice , Cognitive justice
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174437 , vital:42477 , http://dx.doi.org/10.21504/10962/174437
- Description: This thesis by publication is an applied study into transformative learning as an emancipatory practice for water justice. It is guided by the core research question: How can cognitively just learning be an activist practice in social movements working towards water justice? To address this question, I use the applied critical realist approach which makes use of three moments of moral reasoning which are very similar to the approach adopted in the learning intervention that is the focus of this research. These three moments are: Diagnose, Explain, Act – sometimes known as the DEA model (Bhaskar, 2008, 243; Munnik & Price, 2015). The research object is the Changing Practice course for community-based environmental and social movements. The course was developed and studied over seven years, starting from the reflexive scholarship of environmental learning in South Africa, particularly the adult learning model of working together/working away developed through the Environmental Education Association of Southern Africa in partnership with the Environmental Learning Research Centre at Rhodes University (Lotz-Sisitka & Raven, 2004). We (the facilitators/educators) ran the Changing Practice course three times (2012-2014; 2014-2016; 2016-2018), in which I generated substantive data which forms the empirical base on which this study was developed. We found the concept of cognitive justice (Visvanathan, 2005; de Sousa Santos, 2016) to be a powerful mobilizing concept with which to carry out emancipatory research and learning, in three ways. First, it brought together a group of researchers, activists and practitioners from different organizations to work on how to strengthen the role of civil society in monitoring government water policy and practice (Wilson et al., 2016). Second, within the Changing Practice course itself, it became a principle for guiding learning design and pedagogy as well as a way of engaging in dialogue with the participants around the politics of knowledge, exclusion and inclusion in knowledge production, systems of oppression and multiple knowledges (Wilson et al., 2016; Burt et al., 2018). Thirdly, the participants’ change projects (the applied projects undertaken during the ‘working away’ phase between course modules), allowed participants to draw on different knowledge systems, which they learnt to do in the ‘working together’ modules, and to address cognitive justice concerns linked to environmental justice. The change projects also challenged our learning pedagogy by raising contradictions in the course’s approach to learning that needed to be transformed in order for our pedagogy to be more cognitively just. Throughout this thesis I argue that the work of cognitive justice deepens the connections between people, institutions and structures, particularly in relation to transformative learning. Our intention was to identify and critique structures and ideologies that perpetuated oppressive relations, and then to identify and enact the work needed towards transforming these relations. This is why I often refer to cognitive justice as a solidarity and mobilizing concept, and I use the term cognitive justice praxis to mean the reflection and actions that are needed to enact cognitive just learning. The facilitators and participants of the Changing Practice course worked to remove the layered effects of oppression both in the practice of water justice and in the learning process itself. We worked, however imperfectly, with a caring, collectively-held ethic towards each other and the world. Using the DEA model I applied the critical realist dialectic to analyse contradictions and generate explanations through four articles as reflexive writing projects (See Part 2 of this thesis). I used the critical realist dialectic both to reveal contradictions, investigate how these contradictions have come to be, and to generate alternative explanations and action to absent them. Through this research I identified four essential mechanisms for cognitively just environmental learning: care work, co-learning, reflexivity and an interdisciplinary approach to learning scholarship as learning praxis. The essential elements that made the Changing Practice course so effective were the working together/working away design, the encouraging of participants to make the change project something they were passionate about, and the situating and grounding of the Changing Practice course within a social movement network. We were able to show that for academic scholarship to contribute meaningfully to cognitively just learning praxis, it needs to be collaborative and reflexive, and start from the embodied historical and contextual experience of learning as experienced and understood by participants on the course. This demanded an interdisciplinary approach to work with contradictions in learning practice, one that could take into consideration different knowledges and knowledge practices beyond professional disciplines. Both social movement communities and scholarly communities have valuable knowledge to offer each other. As argued in article one, rather than a lack of knowledge, what more often limits our emancipatory action are factors that prevent us from coming closer together. (Burt et al, 2018) This research revealed that social movement learning towards water justice is multi-level care work, the four levels being: individual psychology, our relations with others, our relations with structures such as our social movements, and our relations with the planet. When such care work attains self- reflexivity, practice-reflexivity, co-learning and collective scholarship, it is able to absent the contradictions that inhibit cognitive justice. This thesis is a record of our attempts to learn how to achieve this.
- Full Text:
- Date Issued: 2021-04
- Authors: Burt, Jane Caroline
- Date: 2021-04
- Subjects: Transformative learning , Water security -- South Africa , Environmental education -- South Africa , EEASA (Organization) , Civil society -- South Africa , Water justice , Cognitive justice
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174437 , vital:42477 , http://dx.doi.org/10.21504/10962/174437
- Description: This thesis by publication is an applied study into transformative learning as an emancipatory practice for water justice. It is guided by the core research question: How can cognitively just learning be an activist practice in social movements working towards water justice? To address this question, I use the applied critical realist approach which makes use of three moments of moral reasoning which are very similar to the approach adopted in the learning intervention that is the focus of this research. These three moments are: Diagnose, Explain, Act – sometimes known as the DEA model (Bhaskar, 2008, 243; Munnik & Price, 2015). The research object is the Changing Practice course for community-based environmental and social movements. The course was developed and studied over seven years, starting from the reflexive scholarship of environmental learning in South Africa, particularly the adult learning model of working together/working away developed through the Environmental Education Association of Southern Africa in partnership with the Environmental Learning Research Centre at Rhodes University (Lotz-Sisitka & Raven, 2004). We (the facilitators/educators) ran the Changing Practice course three times (2012-2014; 2014-2016; 2016-2018), in which I generated substantive data which forms the empirical base on which this study was developed. We found the concept of cognitive justice (Visvanathan, 2005; de Sousa Santos, 2016) to be a powerful mobilizing concept with which to carry out emancipatory research and learning, in three ways. First, it brought together a group of researchers, activists and practitioners from different organizations to work on how to strengthen the role of civil society in monitoring government water policy and practice (Wilson et al., 2016). Second, within the Changing Practice course itself, it became a principle for guiding learning design and pedagogy as well as a way of engaging in dialogue with the participants around the politics of knowledge, exclusion and inclusion in knowledge production, systems of oppression and multiple knowledges (Wilson et al., 2016; Burt et al., 2018). Thirdly, the participants’ change projects (the applied projects undertaken during the ‘working away’ phase between course modules), allowed participants to draw on different knowledge systems, which they learnt to do in the ‘working together’ modules, and to address cognitive justice concerns linked to environmental justice. The change projects also challenged our learning pedagogy by raising contradictions in the course’s approach to learning that needed to be transformed in order for our pedagogy to be more cognitively just. Throughout this thesis I argue that the work of cognitive justice deepens the connections between people, institutions and structures, particularly in relation to transformative learning. Our intention was to identify and critique structures and ideologies that perpetuated oppressive relations, and then to identify and enact the work needed towards transforming these relations. This is why I often refer to cognitive justice as a solidarity and mobilizing concept, and I use the term cognitive justice praxis to mean the reflection and actions that are needed to enact cognitive just learning. The facilitators and participants of the Changing Practice course worked to remove the layered effects of oppression both in the practice of water justice and in the learning process itself. We worked, however imperfectly, with a caring, collectively-held ethic towards each other and the world. Using the DEA model I applied the critical realist dialectic to analyse contradictions and generate explanations through four articles as reflexive writing projects (See Part 2 of this thesis). I used the critical realist dialectic both to reveal contradictions, investigate how these contradictions have come to be, and to generate alternative explanations and action to absent them. Through this research I identified four essential mechanisms for cognitively just environmental learning: care work, co-learning, reflexivity and an interdisciplinary approach to learning scholarship as learning praxis. The essential elements that made the Changing Practice course so effective were the working together/working away design, the encouraging of participants to make the change project something they were passionate about, and the situating and grounding of the Changing Practice course within a social movement network. We were able to show that for academic scholarship to contribute meaningfully to cognitively just learning praxis, it needs to be collaborative and reflexive, and start from the embodied historical and contextual experience of learning as experienced and understood by participants on the course. This demanded an interdisciplinary approach to work with contradictions in learning practice, one that could take into consideration different knowledges and knowledge practices beyond professional disciplines. Both social movement communities and scholarly communities have valuable knowledge to offer each other. As argued in article one, rather than a lack of knowledge, what more often limits our emancipatory action are factors that prevent us from coming closer together. (Burt et al, 2018) This research revealed that social movement learning towards water justice is multi-level care work, the four levels being: individual psychology, our relations with others, our relations with structures such as our social movements, and our relations with the planet. When such care work attains self- reflexivity, practice-reflexivity, co-learning and collective scholarship, it is able to absent the contradictions that inhibit cognitive justice. This thesis is a record of our attempts to learn how to achieve this.
- Full Text:
- Date Issued: 2021-04
Exploring learners’ proficiency in stoichiometry and attitudes towards science through Process Oriented Guided Inquiry Learning (POGIL) intervention
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
An investigation into the mediation of the representation of gender roles in God of women : a critical discourse analysis of pedagogic practices in selected Namibian schools
- Nghikefelwa, Josephine Mwasheka
- Authors: Nghikefelwa, Josephine Mwasheka
- Date: 2021
- Subjects: Nyati, Sifiso. God of women , Stereotypes (Social psychology) in literature , Women in literature , English literature -- Study and teaching (Secondary) -- Namibia , Women's rights in literature , Women's rights -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172389 , vital:42195 , 10.21504/10962/172389
- Description: This is a qualitative study designed to investigate the role of pedagogical practices in the mediation of stereotypical gender representations in the drama God of Women by Sifiso Nyathi (1998). This drama is one of the literature setworks for Grade 9 English Second Language learners in Namibian Secondary schools. Fairclough’s (2012) Critical Discourse Analysis was used as a research design, as well as the conceptual and analytical framework. The analysis of this drama by teachers during the teaching and learning process, pedagogic practices they employ, learners’ engagement in classroom activities, and the nature of comments that teachers write on students’ assignment, based on God of Women, formed part of the unit of analysis. The study explored teachers’ pedagogical practices during English Literature teaching to gain insight into whether and how teachers shape learners’ engagement with literature to promote critical thinking. Focus on the mediation process (‘teacher talks around the text’) concerned a close analysis of teachers’ engagement with the text during lessons. Semi-structured interviews, classroom observation and documentary evidence were used to generate data. The research site and study participants were purposively sampled.
- Full Text:
- Date Issued: 2021
- Authors: Nghikefelwa, Josephine Mwasheka
- Date: 2021
- Subjects: Nyati, Sifiso. God of women , Stereotypes (Social psychology) in literature , Women in literature , English literature -- Study and teaching (Secondary) -- Namibia , Women's rights in literature , Women's rights -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172389 , vital:42195 , 10.21504/10962/172389
- Description: This is a qualitative study designed to investigate the role of pedagogical practices in the mediation of stereotypical gender representations in the drama God of Women by Sifiso Nyathi (1998). This drama is one of the literature setworks for Grade 9 English Second Language learners in Namibian Secondary schools. Fairclough’s (2012) Critical Discourse Analysis was used as a research design, as well as the conceptual and analytical framework. The analysis of this drama by teachers during the teaching and learning process, pedagogic practices they employ, learners’ engagement in classroom activities, and the nature of comments that teachers write on students’ assignment, based on God of Women, formed part of the unit of analysis. The study explored teachers’ pedagogical practices during English Literature teaching to gain insight into whether and how teachers shape learners’ engagement with literature to promote critical thinking. Focus on the mediation process (‘teacher talks around the text’) concerned a close analysis of teachers’ engagement with the text during lessons. Semi-structured interviews, classroom observation and documentary evidence were used to generate data. The research site and study participants were purposively sampled.
- Full Text:
- Date Issued: 2021
Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021
Defended subjectivity in service-learning:a psychosocial analysis of students’ talk about service-learning in psychology
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
- Full Text:
- Date Issued: 2021
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
- Full Text:
- Date Issued: 2021
Design patterns and software techniques for large-scale, open and reproducible data reduction
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
- Full Text:
- Date Issued: 2021
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
- Full Text:
- Date Issued: 2021
Elucidating Tuta absoluta (Meyrick) invasion and enhancing its management in Eastern Africa : spread, socio-ecological impacts, and potential of a newly imported larval parasitoid for classical biological control Eastern in Africa
- Aigbedion-Atalor, Pascal Osabhahiemen
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021
Evaluation of metallophthalocyanine functionalized photocatalytic asymmetric polymer membranes for pollution control and antimicrobial activity
- Mafukidze, Donovan Musizvinoda Chidyamurimi
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
How art-as-therapy supports participants with a diagnosis of schizophrenia : a phenomenological investigation
- Authors: Mitchell, Julia L G
- Date: 2021
- Subjects: Schizophrenia -- Treatment , Schizophrenia -- Treatment -- South Africa -- Case studies , Art Therapy , Art Therapy -- South Africa -- Case studies , Stormberg Hospital (Eastern Cape, South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172157 , vital:42171 , 10.21504/10962/172157
- Description: Although art therapy is recommended in management programmes for individuals with a diagnosis of schizophrenia, calls have been made for more detailed explanations as to how artmaking is working. This study responds to those calls by considering the artmaking experiences of 15 mental health users with a diagnosis of schizophrenia, resident at a forensic, mental health facility in South Africa. A phenomenological approach was chosen because of its focus on lived experiences, suited to explore the embodied and pre-reflective experience of studio-based artmaking. Dialogical and narrative understandings were subsequently incorporated to account for more reflective aspects of the artmaking experience. Two main participant descriptions of artmaking, centring on feeling at home and on doing something meaningful, guided the phenomenological lifeworld method in analysing the data (interviews, artworks and field observations in art groups and exhibitions), along selected dimensions of lived experience, namely embodiment, temporality, spatiality, sociality and selfhood. These findings lend support to new phenomenological research which suggests that artmaking intersects with disrupted abilities for perceptual engagement underlying manifestations of schizophrenia symptomology. This research supports assertions that artmaking has the potential to support the minimal sense of self and expand possibilities for renewed embodied and more reflective meaning-making. Explanations of findings centred around the distinct artistic style of each participant, as well as their artworks which revealed individual lifeworlds including a variety of self-positions. The inherent properties of the completed artworks also provided possibilities for renewed experiences of sociality. Additional support for the findings is drawn from recent research in the fields of early neurodevelopmental trauma, and trauma research findings within the art therapy field.
- Full Text:
- Date Issued: 2021
- Authors: Mitchell, Julia L G
- Date: 2021
- Subjects: Schizophrenia -- Treatment , Schizophrenia -- Treatment -- South Africa -- Case studies , Art Therapy , Art Therapy -- South Africa -- Case studies , Stormberg Hospital (Eastern Cape, South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172157 , vital:42171 , 10.21504/10962/172157
- Description: Although art therapy is recommended in management programmes for individuals with a diagnosis of schizophrenia, calls have been made for more detailed explanations as to how artmaking is working. This study responds to those calls by considering the artmaking experiences of 15 mental health users with a diagnosis of schizophrenia, resident at a forensic, mental health facility in South Africa. A phenomenological approach was chosen because of its focus on lived experiences, suited to explore the embodied and pre-reflective experience of studio-based artmaking. Dialogical and narrative understandings were subsequently incorporated to account for more reflective aspects of the artmaking experience. Two main participant descriptions of artmaking, centring on feeling at home and on doing something meaningful, guided the phenomenological lifeworld method in analysing the data (interviews, artworks and field observations in art groups and exhibitions), along selected dimensions of lived experience, namely embodiment, temporality, spatiality, sociality and selfhood. These findings lend support to new phenomenological research which suggests that artmaking intersects with disrupted abilities for perceptual engagement underlying manifestations of schizophrenia symptomology. This research supports assertions that artmaking has the potential to support the minimal sense of self and expand possibilities for renewed embodied and more reflective meaning-making. Explanations of findings centred around the distinct artistic style of each participant, as well as their artworks which revealed individual lifeworlds including a variety of self-positions. The inherent properties of the completed artworks also provided possibilities for renewed experiences of sociality. Additional support for the findings is drawn from recent research in the fields of early neurodevelopmental trauma, and trauma research findings within the art therapy field.
- Full Text:
- Date Issued: 2021
In marketing, it’s either you have it or you don’t : a study of knowledge and knowers legitimated in the marketing diploma curriculum in South Africa
- Authors: Ncube, Kevin
- Date: 2021
- Subjects: Marketing -- Study and teaching (Higher) -- Curricula , Marketing -- Study and teaching (Higher) -- South Africa , Vocational qualifications -- South Africa , Education, Higher -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172230 , vital:42178 , 10.21504/10962/172230
- Description: This study was undertaken in the South African higher education system in which the differentiation of institutions still reflects racial inequalities from the country’s history of colonial apartheid. As an educator in an institutional type referred to as Universities of Technology, I had become increasingly concerned about who succeeds, how they succeed, who fails, and who drops out. The South Africa education system broadly suffers from low student retention and high drop out with lower success rates mostly affecting Black students. By the end of apartheid in 1994, Black students had been entering Technikons en masse and were the dominant student group in these institutions which changed designation to Universities of Technology in 2005. Technikons offered programmes with a stronger technological and vocational orientation focusing on qualifications directly linked to the job market. They did not offer postgraduate programmes and today, Universities of Technology still produce little research. These institutions also battle with a far lower throughput rate than Traditional Universities and a higher graduate unemployment rate. This has led to a call for better theorised accounts of applied knowledge to replace unhelpful common-sense understandings. There was thus a call in the literature for studies, such as this one, that focused on the nature of knowledge in a diploma curriculum. Furthermore, the field of Marketing is under-researched. The field of Marketing has been characterised as having a weak theoretical foundation and as appropriating knowledge from other fields without growth of the field per se. In Marketing, importance is placed on the possession of a broad spectrum of general knowledge, rather than specialised accounts of the field. The study sought to examine the following research questions: 1) What kind of knowledge is privileged in the Marketing diploma? 2) How does the positioning of actors in the field of Marketing education impact on the choice and structure of knowledge privileged in the curriculum? The study was undertaken mainly through the use of interviews to explore academics’ perspectives on what is valued in the Marketing curriculum. Thirty-one academics from 11 institutions participated in the study. I also analysed course guides and other documentation related to the curriculum. The study analysed the organising of knowledge in the Marketing curriculum. To do this, the study drew on Legitimation Code Theory and in particular the tools of Specialisation and Semantics. These tools allowed the analysis of data to establish the basis on which it is specialised from other fields and the extent to which the field is contextually or conceptually coherent. The data demonstrated that academics who lecture in Marketing entered Marketing education from a diverse range of disciplines. The data also confirmed, in line with the literature, that the field of Marketing draws from multiple disciplines and fields for the purposes of serving the world of work. In Bernsteinian terms the nature of the Marketing curriculum is identified as a ‘region’. However, the data also demonstrated that the field of Marketing serves a heterogenous world of work characterised by constant changes which do not seem to allow a stable development of the field. The field of Marketing was thus portrayed as a region tending towards a generic, raising questions about the reliability of its knowledge base. The nature of generics often leads to an openness which is associated with instability, a weaker autonomy, and an inability to differentiate the field from others with further implications that knowledge in the curriculum is likely to be unsettled. One of the key findings was that while there was significant focus on knowledge, this was not the main basis on which success is achieved. Despite the ample evidence of knowledge in the Marketing curriculum, there was little agreement as to what constituted that knowledge, the actual nature of that knowledge was not settled, broadly agreed upon, nor particularly complex, drawing as it did on ‘everyday’ understandings of the world. The data revealed that there was little evidence that the knowledge was particularly specialised nor that it allowed for cumulative acquisition of ‘powerful knowledge’. Rather, the knowledges in the field of Marketing were characterised by a horizontal knowledge structure consisting of a set of languages acquired separately. The knowledges were based on different and sometimes even contradictory assumptions and thus presented few opportunities to integrate previous theories to build a more powerful knowledge structure. The knowledges tended to be context specific as opposed to being abstract or conceptual. There are social justice implications for fields in which the acquirer is only afforded context specific knowledges and as such has to acquire an endless series of low-level knowledges. They are not given access to powerful knowledge characterised by induction into a system of meaning which enables a more meaningful engagement with the complex world and thinking the not yet thought. In such instances, the education arguably does not provide access to the kind of specialised knowledge which allows for powerful meaning making in the world. The study calls for a strengthening of the epistemic spine of the Marketing diploma to provide access to more abstract, principled knowledge. A major finding was that most of the lecturers’ responses focused on the need for being a particular kind of knower to be successful in Marketing. The kind of person valued in Marketing was portrayed as possessing a particular personality and natural talent which were rarely seen as dependent on the knowledge acquired during the diploma, but rather on the dispositions that students brought. The respondents also mostly raised concerns that most of the students enrolled in Marketing did not to have the requisite ‘Marketing personalities’. Students were expected to be from a particular social class intimated through reference to their backgrounds, the schools they went to, their access to technologies, and the geographical regions they came from. They were expected to bring a particular language competency. Social class and language were arguably also used as coded reference to racial category, and this was more explicitly indicated by some respondents. The dominance of the knower in the data revealed that in Marketing, “you either have it or you don’t” indicating a strong view that Marketers are born with the necessary inherent characteristics of “confidence and people-skills” or belong to the social group that develops them. The implications were that if you do not have it, there is nothing one can do to get . This particular finding raises serious social justice issues on access and success in Marketing. If there is nothing that can be done to develop these characteristics, allowing such people into Marketing is setting them up for failure. On the other hand, denying access based on birth and social grouping raises concerns of the justice in the societies we live in. The study calls for an explicit engagement with the assumptions about the knower’s dispositions. While it was consistently evident that such dispositions were key to the specialisation of the field, the assumption that students either had these dispositions or lacked them is a social injustice and raises a number of unanswerable and painful questions given the racially differentiated success rates. The study concludes by calling for academics to explicitly curriculate for the target dispositions so that students are exposed to the value of these dispositions and given opportunities to engage with them.
- Full Text:
- Date Issued: 2021
- Authors: Ncube, Kevin
- Date: 2021
- Subjects: Marketing -- Study and teaching (Higher) -- Curricula , Marketing -- Study and teaching (Higher) -- South Africa , Vocational qualifications -- South Africa , Education, Higher -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172230 , vital:42178 , 10.21504/10962/172230
- Description: This study was undertaken in the South African higher education system in which the differentiation of institutions still reflects racial inequalities from the country’s history of colonial apartheid. As an educator in an institutional type referred to as Universities of Technology, I had become increasingly concerned about who succeeds, how they succeed, who fails, and who drops out. The South Africa education system broadly suffers from low student retention and high drop out with lower success rates mostly affecting Black students. By the end of apartheid in 1994, Black students had been entering Technikons en masse and were the dominant student group in these institutions which changed designation to Universities of Technology in 2005. Technikons offered programmes with a stronger technological and vocational orientation focusing on qualifications directly linked to the job market. They did not offer postgraduate programmes and today, Universities of Technology still produce little research. These institutions also battle with a far lower throughput rate than Traditional Universities and a higher graduate unemployment rate. This has led to a call for better theorised accounts of applied knowledge to replace unhelpful common-sense understandings. There was thus a call in the literature for studies, such as this one, that focused on the nature of knowledge in a diploma curriculum. Furthermore, the field of Marketing is under-researched. The field of Marketing has been characterised as having a weak theoretical foundation and as appropriating knowledge from other fields without growth of the field per se. In Marketing, importance is placed on the possession of a broad spectrum of general knowledge, rather than specialised accounts of the field. The study sought to examine the following research questions: 1) What kind of knowledge is privileged in the Marketing diploma? 2) How does the positioning of actors in the field of Marketing education impact on the choice and structure of knowledge privileged in the curriculum? The study was undertaken mainly through the use of interviews to explore academics’ perspectives on what is valued in the Marketing curriculum. Thirty-one academics from 11 institutions participated in the study. I also analysed course guides and other documentation related to the curriculum. The study analysed the organising of knowledge in the Marketing curriculum. To do this, the study drew on Legitimation Code Theory and in particular the tools of Specialisation and Semantics. These tools allowed the analysis of data to establish the basis on which it is specialised from other fields and the extent to which the field is contextually or conceptually coherent. The data demonstrated that academics who lecture in Marketing entered Marketing education from a diverse range of disciplines. The data also confirmed, in line with the literature, that the field of Marketing draws from multiple disciplines and fields for the purposes of serving the world of work. In Bernsteinian terms the nature of the Marketing curriculum is identified as a ‘region’. However, the data also demonstrated that the field of Marketing serves a heterogenous world of work characterised by constant changes which do not seem to allow a stable development of the field. The field of Marketing was thus portrayed as a region tending towards a generic, raising questions about the reliability of its knowledge base. The nature of generics often leads to an openness which is associated with instability, a weaker autonomy, and an inability to differentiate the field from others with further implications that knowledge in the curriculum is likely to be unsettled. One of the key findings was that while there was significant focus on knowledge, this was not the main basis on which success is achieved. Despite the ample evidence of knowledge in the Marketing curriculum, there was little agreement as to what constituted that knowledge, the actual nature of that knowledge was not settled, broadly agreed upon, nor particularly complex, drawing as it did on ‘everyday’ understandings of the world. The data revealed that there was little evidence that the knowledge was particularly specialised nor that it allowed for cumulative acquisition of ‘powerful knowledge’. Rather, the knowledges in the field of Marketing were characterised by a horizontal knowledge structure consisting of a set of languages acquired separately. The knowledges were based on different and sometimes even contradictory assumptions and thus presented few opportunities to integrate previous theories to build a more powerful knowledge structure. The knowledges tended to be context specific as opposed to being abstract or conceptual. There are social justice implications for fields in which the acquirer is only afforded context specific knowledges and as such has to acquire an endless series of low-level knowledges. They are not given access to powerful knowledge characterised by induction into a system of meaning which enables a more meaningful engagement with the complex world and thinking the not yet thought. In such instances, the education arguably does not provide access to the kind of specialised knowledge which allows for powerful meaning making in the world. The study calls for a strengthening of the epistemic spine of the Marketing diploma to provide access to more abstract, principled knowledge. A major finding was that most of the lecturers’ responses focused on the need for being a particular kind of knower to be successful in Marketing. The kind of person valued in Marketing was portrayed as possessing a particular personality and natural talent which were rarely seen as dependent on the knowledge acquired during the diploma, but rather on the dispositions that students brought. The respondents also mostly raised concerns that most of the students enrolled in Marketing did not to have the requisite ‘Marketing personalities’. Students were expected to be from a particular social class intimated through reference to their backgrounds, the schools they went to, their access to technologies, and the geographical regions they came from. They were expected to bring a particular language competency. Social class and language were arguably also used as coded reference to racial category, and this was more explicitly indicated by some respondents. The dominance of the knower in the data revealed that in Marketing, “you either have it or you don’t” indicating a strong view that Marketers are born with the necessary inherent characteristics of “confidence and people-skills” or belong to the social group that develops them. The implications were that if you do not have it, there is nothing one can do to get . This particular finding raises serious social justice issues on access and success in Marketing. If there is nothing that can be done to develop these characteristics, allowing such people into Marketing is setting them up for failure. On the other hand, denying access based on birth and social grouping raises concerns of the justice in the societies we live in. The study calls for an explicit engagement with the assumptions about the knower’s dispositions. While it was consistently evident that such dispositions were key to the specialisation of the field, the assumption that students either had these dispositions or lacked them is a social injustice and raises a number of unanswerable and painful questions given the racially differentiated success rates. The study concludes by calling for academics to explicitly curriculate for the target dispositions so that students are exposed to the value of these dispositions and given opportunities to engage with them.
- Full Text:
- Date Issued: 2021
Investigating grade R teacher institutional identity presented in policy and expressed through narrative in a time of transition
- Authors: Long, Roxanne
- Date: 2021
- Subjects: Early childhood education -- South Africa , Early childhood education -- Government policy -- South Africa , Child development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171346 , vital:42051 , 10.21504/10962/171346
- Description: This study investigated Grade R (reception year) teacher institutional identity presented in policy and expressed through teacher narratives. The study was conducted in the context of a major national policy transition that involved the physical and contextual shift of Grade R out of the Early Childhood Development sector and into the formal schooling sector. This study highlighted the way in which this shift has resulted in mixed policy messages, which have implications for Grade R teachers’ institutional identities and learning trajectories across their landscapes of practice. The thesis begins by exploring the South African Education context in general as well as the Early Childhood Development context in particular. In order to understand the institutional identities of Grade R teachers as both storied by others (in policy) and by themselves, the study conducted a documentary analysis of policy relating to Grade R teachers and Grade R teacher narrative expressions of their identities. The methodological approach of the study involved a qualitative approach, drawing on grounded theory analytical techniques to closely examine policy documents and teacher generated data gathered through interviews and questionnaires. The study was guided by a sociocultural perspective and drew on three key sociocultural theorists whose work provided complementary perspectives on teacher identity. Sfard and Prusak’s (2005) operationalization of identity as narratives was used to define the unit of analysis for the study (i.e. identities as stories). Gee’s (2000) definition and conceptualization of institutional identity was supplemented with Wenger-Trayner, Fenton-O'Creevy, Hutchinson, Kubiak, and Wenger-Trayner’s (2015) notion of identity as journeying across landscapes of practice. This complementary framing allowed for focused and detailed analysis of policy documents and Grade R teacher identity stories. The study addresses the research gap of an under-representation of identity research in early childhood teacher education and particularly in the South African context. This study is significant as it is the first study of its kind to explore the importance of identity formation for Grade R teachers as newcomers to the formal schooling landscape. Findings from the policy analysis point to mixed messages moving across a spectrum of descriptors from the not yet qualified ‘mothers and ‘caregivers’ to qualified ‘specialised’ educators. These descriptors have implications for the differentiated roles and responsibilities (institutional identity) of Grade R teachers. The findings from teacher identity narratives highlighted tension in the navigation of the policy promoted institutional identities. Teacher narratives pointed to vastly contrasting experiences of teachers with specialised and qualified institutional teacher identities to those with not yet qualified institutional identities. For the former, there were high levels of confidence in their job security and in terms of recognition received from others. For the latter, however, there was vulnerability in terms of the stability of their jobs and remuneration as well as low levels of recognition from others. The study draws on the findings from the analysis to suggest recommendations for Grade R policy, Grade R teacher education (both inservice and pre-service); as well as Grade R professional development initiatives.
- Full Text:
- Date Issued: 2021
- Authors: Long, Roxanne
- Date: 2021
- Subjects: Early childhood education -- South Africa , Early childhood education -- Government policy -- South Africa , Child development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171346 , vital:42051 , 10.21504/10962/171346
- Description: This study investigated Grade R (reception year) teacher institutional identity presented in policy and expressed through teacher narratives. The study was conducted in the context of a major national policy transition that involved the physical and contextual shift of Grade R out of the Early Childhood Development sector and into the formal schooling sector. This study highlighted the way in which this shift has resulted in mixed policy messages, which have implications for Grade R teachers’ institutional identities and learning trajectories across their landscapes of practice. The thesis begins by exploring the South African Education context in general as well as the Early Childhood Development context in particular. In order to understand the institutional identities of Grade R teachers as both storied by others (in policy) and by themselves, the study conducted a documentary analysis of policy relating to Grade R teachers and Grade R teacher narrative expressions of their identities. The methodological approach of the study involved a qualitative approach, drawing on grounded theory analytical techniques to closely examine policy documents and teacher generated data gathered through interviews and questionnaires. The study was guided by a sociocultural perspective and drew on three key sociocultural theorists whose work provided complementary perspectives on teacher identity. Sfard and Prusak’s (2005) operationalization of identity as narratives was used to define the unit of analysis for the study (i.e. identities as stories). Gee’s (2000) definition and conceptualization of institutional identity was supplemented with Wenger-Trayner, Fenton-O'Creevy, Hutchinson, Kubiak, and Wenger-Trayner’s (2015) notion of identity as journeying across landscapes of practice. This complementary framing allowed for focused and detailed analysis of policy documents and Grade R teacher identity stories. The study addresses the research gap of an under-representation of identity research in early childhood teacher education and particularly in the South African context. This study is significant as it is the first study of its kind to explore the importance of identity formation for Grade R teachers as newcomers to the formal schooling landscape. Findings from the policy analysis point to mixed messages moving across a spectrum of descriptors from the not yet qualified ‘mothers and ‘caregivers’ to qualified ‘specialised’ educators. These descriptors have implications for the differentiated roles and responsibilities (institutional identity) of Grade R teachers. The findings from teacher identity narratives highlighted tension in the navigation of the policy promoted institutional identities. Teacher narratives pointed to vastly contrasting experiences of teachers with specialised and qualified institutional teacher identities to those with not yet qualified institutional identities. For the former, there were high levels of confidence in their job security and in terms of recognition received from others. For the latter, however, there was vulnerability in terms of the stability of their jobs and remuneration as well as low levels of recognition from others. The study draws on the findings from the analysis to suggest recommendations for Grade R policy, Grade R teacher education (both inservice and pre-service); as well as Grade R professional development initiatives.
- Full Text:
- Date Issued: 2021
Kuntanshi yamikalile (The Future): speculative nonconformity in the works of Zambian visual artists
- Authors: Mulenga,Andrew Mukuka
- Date: 2021
- Subjects: Future in art , Africa -- In art , Art, Zambian , Art, African , Artists -- Zambia , Nyandoro, Gareth
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172203 , vital:42175 , 10.21504/10962/172203
- Description: In recent years, select African visual artists practising on the continent as well as in its diaspora have increasingly been attracted to themes that explore, portray or grapple with Africa’s future. Along with this increasing popularity of the ‘future’ or indeed ‘African futuristic’ themes by visual artists, such themes have also attracted academic consideration among various scholars, resulting primarily in topics described as ‘African Futurism’ or Afrofuturism. These are topics that may be used to disrupt what some scholars – across disciplines and in various contexts – have highlighted as the persistent presumptive notions that portray Africa as a hinterland (Hassan 1999; Sefa Dei, Hall and Goldin Rosenberg 2000; Simbao 2007; Soyinka-Airewele and Edozie 2010; Moyo 2013; Keita, L. 2014; Green 2014; Serpell 2016). This study makes an effort to critique certain aspects of ‘African Art History’ with regard to the representation of Africa, and raises the following question: How can an analysis of artistic portrayals of ‘the future’ portrayed in the works of select contemporary Zambian artists be used to critique the positioning of Africa as ‘backward’, an occurrence at the intersection of a dualistic framing of tradition versus modern. Furthermore, how can this be used to break down this dichotomy in order to challenge lingering perceptions of African belatedness? The study analyses ways in which this belatedness is challenged by the juxtaposition of traditional, contemporary and futuristic elements by discussing a series of topics and debates associated to African cultures and technology that may be deemed disconnected from the contemporary lived experiences of Africans based on the continent. The study acknowledges that there is no singular ‘African Art History’ that one can talk of and there have been various shifts in how it has been perceived. I argue that while currently the African art history that is written in the West does not simplistically position Africa as backward as it may have done in the past, there appear to be moments of a hangover of this perception (Lamp 1999:4). What started out as a largely Western scholarly discourse of African art history occurred in about the 1950s and the journal African Arts started in the 1960s. Even before contemporary African art became a big thing in the 1990s for the largely US- and Europe-based discourses there were many discussions in the US about how the ‘old’ art history tended to freeze time and that this was not appropriate (Drewal 1991 et al). In order to advance the discourse on contemporary African visual arts I present critical analyses of the select works of Zambian artists to develop interpretations of the broader uses of the aforementioned themes. The evidence that supports the core argument of this research is embedded in the images discussed throughout this dissertation. The artists featured in the study span several decades including artists who were active from the 1960s to the 1980s, such as Henry Tayali and Akwila Simpasa, as well as artists who have been practising since the 1980s, such as Chishimba Chansa and William Miko and those that are more current and have been producing work from the early 1990s and 2000s, such as Zenzele Chulu, Milumbe Haimbe, Stary Mwaba, Isaac Kalambata and Roy Jethro Phiri.
- Full Text:
- Date Issued: 2021
- Authors: Mulenga,Andrew Mukuka
- Date: 2021
- Subjects: Future in art , Africa -- In art , Art, Zambian , Art, African , Artists -- Zambia , Nyandoro, Gareth
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172203 , vital:42175 , 10.21504/10962/172203
- Description: In recent years, select African visual artists practising on the continent as well as in its diaspora have increasingly been attracted to themes that explore, portray or grapple with Africa’s future. Along with this increasing popularity of the ‘future’ or indeed ‘African futuristic’ themes by visual artists, such themes have also attracted academic consideration among various scholars, resulting primarily in topics described as ‘African Futurism’ or Afrofuturism. These are topics that may be used to disrupt what some scholars – across disciplines and in various contexts – have highlighted as the persistent presumptive notions that portray Africa as a hinterland (Hassan 1999; Sefa Dei, Hall and Goldin Rosenberg 2000; Simbao 2007; Soyinka-Airewele and Edozie 2010; Moyo 2013; Keita, L. 2014; Green 2014; Serpell 2016). This study makes an effort to critique certain aspects of ‘African Art History’ with regard to the representation of Africa, and raises the following question: How can an analysis of artistic portrayals of ‘the future’ portrayed in the works of select contemporary Zambian artists be used to critique the positioning of Africa as ‘backward’, an occurrence at the intersection of a dualistic framing of tradition versus modern. Furthermore, how can this be used to break down this dichotomy in order to challenge lingering perceptions of African belatedness? The study analyses ways in which this belatedness is challenged by the juxtaposition of traditional, contemporary and futuristic elements by discussing a series of topics and debates associated to African cultures and technology that may be deemed disconnected from the contemporary lived experiences of Africans based on the continent. The study acknowledges that there is no singular ‘African Art History’ that one can talk of and there have been various shifts in how it has been perceived. I argue that while currently the African art history that is written in the West does not simplistically position Africa as backward as it may have done in the past, there appear to be moments of a hangover of this perception (Lamp 1999:4). What started out as a largely Western scholarly discourse of African art history occurred in about the 1950s and the journal African Arts started in the 1960s. Even before contemporary African art became a big thing in the 1990s for the largely US- and Europe-based discourses there were many discussions in the US about how the ‘old’ art history tended to freeze time and that this was not appropriate (Drewal 1991 et al). In order to advance the discourse on contemporary African visual arts I present critical analyses of the select works of Zambian artists to develop interpretations of the broader uses of the aforementioned themes. The evidence that supports the core argument of this research is embedded in the images discussed throughout this dissertation. The artists featured in the study span several decades including artists who were active from the 1960s to the 1980s, such as Henry Tayali and Akwila Simpasa, as well as artists who have been practising since the 1980s, such as Chishimba Chansa and William Miko and those that are more current and have been producing work from the early 1990s and 2000s, such as Zenzele Chulu, Milumbe Haimbe, Stary Mwaba, Isaac Kalambata and Roy Jethro Phiri.
- Full Text:
- Date Issued: 2021
Lipid nanocarriers : a novel approach to delivering ophthalmic clarithromycin
- Authors: Makoni, Pedzisai Anotida
- Date: 2021
- Subjects: Clarithromycin , Nanomedicine , Nanostructures , Antibiotics , Eye -- Diseases -- Treatment , Ocular pharmacology , Ophthalmic drugs , Karatitis -- Chemotherapy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171678 , vital:42109 , 10.21504/10962/171678
- Description: The feasibility of incorporating clarithromycin (CLA) into innovative solid lipid nanoparticles (SLN) and nanostructured lipi d carriers (NLC) using hot emulsification ultrasonication (HEUS) was investigated. This approach was investigated in an attempt to address the shortcomings associated with the use of lyophilized parenteral formulations administered via the ocular route suc h as toxic reactions, intolerance and patient discomfort due to frequent insti llation of topical solutions of CLA. In particular, sustained release approaches to delivery may enhance precorneal retention, increase ocular availability and permit dose reduction or use of a longer dosing frequency when treating ocular non - tuberculous m ycobacterial (NTM) keratitis infections. This approach may potentially improve the delivery of CLA to the eye, thereby addressing some or all of the unmet clinical needs described vide infra . Prior to initiating pre - formulation, formulation development a nd optimization studies of CLA - loaded SLN and/or NLC, Design of Experiments (DoE), specifically a Central Composite Design (CCD) was used in conjunction with Response Surface Methodology (RSM) to develop and optimize a suitable method for the quantitative determination of CLA in pharmaceutical formulations and for monitoring CLA release from SLN and/or NLC in vitro . A simple, accurate, precise, sensitive and stability - indicating reversed phase - high performance liquid chromatography (RP - HPLC) method with ele ctrochemical (EC) detection was developed, validated and optimized for the in vitro analysis of CLA loaded SLN and/or NLC formulations. Pre - formulation studies were undertaken to investigate the thermal stability of CLA and bulk lipids to facilitate the s election of lipid excipients for the manufacture of nanocarriers in addition to establishing compatibility of CLA with the excipients. It was established that CLA was thermostable up to a temperature of approximately 300 °C thereby indicating that HEUS cou ld be used for the manufacture of CLA - loaded SLN and/or NLC. Lipid screening revealed that CLA i s, in general, poorly soluble in solid and liquid lipids however a combination of stearic acid (SA) and Transcutol ® HP (THP) exhibited the best dissolution pote ntial for CLA of all lipids tested . Stearic acid appears to exist as polymorphic form B prior to exposure to heat however occurs as the form C polymorph following heating at 85 °C for one hour. The best ratio for the mixture of SA and THP for the manufactu re of CLA - NLC ii was an 80:20 ( w/w ) ratio of SA: THP as the two lipids are miscible in this ratio and exhibited the greatest dissolution potential for CLA. Furthermore, an investigation of binary mixtures of CLA/SA and SA/Transcutol ® HP, in addition to eutect ic mixtures of CLA, SA and Transcutol ® HP, revealed no obvious interaction between CLA and the lipids selected for the production of the nanocarriers. Due to the relatively high solubility of CLA in THP in comparison to SA, NLC are likely to exhibit a hig her loading capacity (LC) and encapsulation efficiency (EE) for CLA than SLN. Consequently the feasibility of incorporating CLA (10% w/w ) into NLC was investigated and evaluation of the production of SLN was not undertaken as the production of these might not result in the manufacture of a delivery technology with a high EE and LC for CLA. Tween ® 20 was used as the surfactant as it is readily available, exhibits little or no cytotoxicity and is relatively cheap. Polyethylene glycol (PEG) was used as a coati ng polymer to impart muco - adhesive properties the formulated CLA - NLC. Response surface methodology (RSM) in conjunction with DoE, specifically a Box - Behnken Design (BBD) used as a screening design was used to identify a formulation composition which would produce a product that would meet the pre - defined target critical quality attributes (CQA) for the nanoparticles viz. particle size (PS) in the nano - range, polydispersity index (PDI) < 0.5, Zeta Potential (ZP) ≥ ± 30 mV, and EE > 80%. The formulation composition identified was subsequently used for the optimization of the manufacturing parameters viz. sonication time and amplitude, using a Central Composite Design (CCD) . The LC and EE, in vitro CLA release, cytotoxicity, osmolarity, pH, degree of crystallinity and lipid modification, elemental analysis and surface morphology of the optimized batch was investigated and mon itored to ensure that CLA - loaded NLC, of the desirable quality, had been produced. On the day of manufacture the mean PS and PDI of the optimized CLA - loaded NLC formulation adjusted to physiological osmolarity (250 – 450 mOsm/kg) was 461.9 ± 40.16 nm and 0. 523 ± 0.104, respectively. The ZP for the optimized NLC generated on the day of manufacture using HPLC grade water as the dispersion medium was - 20.5 ± 4.82 mV. The pH and osmolarity of the optimized CLA - loaded NLC formulation was 7.76 ± 0.01 and 316 ± iii 2 m Osm/Kg, respectively and the EE was 88.62 ± 0.23 %. The optimized NLC exhibited a decreased crystallinity in comparison to the bulk lipid materials. DSC, WAXS and FT - IR revealed that CLA was molecularly dispersed in the nanocarriers. The optimized CLA - load ed NLC exhibited muco - adhesive properties, when tested under stationary conditions using laser doppler anemometry (LDA). The optimized formulation also exhibited sustained release of CLA over 24 hours during in vitro release testing and CLA release was bes t described using the Baker - Lonsdale model . The cumulative % CLA released over 24 hours was 56.13 ± 0.23% and mass balance analysis revealed 41.38 ± 0.02% CLA had been retained in the NLC. In vitro cytotoxicity testing revealed that the optimized CLA - NLC w ere less cytotoxic to HeLa cells when compared to CLA alone and further confirmed that the lipids and excipients used in these studies were of GRAS status . Stability studies revealed that the EE reduced over 28 days by 14.42% and 5.14% when stored at 4 °C and 22 °C , respectively. In addition, the particle size increased from the nm to μm range for samples stored at 22 °C. The findings are a good starting point but require further optimization to ensure prolongation of stability. In addition , the technology requires additional developmental studies and a powder for reconstitution for use as a single - dose considered as single dose packaging may be a solution to the compromised formulation stability observed in these studies. The CLA - NLC produced in these stu dies exhibit sound product attributes which serve as a useful foundation for the novel delivery of antibiotics to the eye. The results suggest that the optimized NLC have the potential to enhance precorneal retention and increase ocular availability of CLA , which in turn may be useful to reduce the required dose and dosing frequency when administering CLA as a reconstituted solution to treat susceptible organisms that infect ocular tissues.
- Full Text:
- Date Issued: 2021
- Authors: Makoni, Pedzisai Anotida
- Date: 2021
- Subjects: Clarithromycin , Nanomedicine , Nanostructures , Antibiotics , Eye -- Diseases -- Treatment , Ocular pharmacology , Ophthalmic drugs , Karatitis -- Chemotherapy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171678 , vital:42109 , 10.21504/10962/171678
- Description: The feasibility of incorporating clarithromycin (CLA) into innovative solid lipid nanoparticles (SLN) and nanostructured lipi d carriers (NLC) using hot emulsification ultrasonication (HEUS) was investigated. This approach was investigated in an attempt to address the shortcomings associated with the use of lyophilized parenteral formulations administered via the ocular route suc h as toxic reactions, intolerance and patient discomfort due to frequent insti llation of topical solutions of CLA. In particular, sustained release approaches to delivery may enhance precorneal retention, increase ocular availability and permit dose reduction or use of a longer dosing frequency when treating ocular non - tuberculous m ycobacterial (NTM) keratitis infections. This approach may potentially improve the delivery of CLA to the eye, thereby addressing some or all of the unmet clinical needs described vide infra . Prior to initiating pre - formulation, formulation development a nd optimization studies of CLA - loaded SLN and/or NLC, Design of Experiments (DoE), specifically a Central Composite Design (CCD) was used in conjunction with Response Surface Methodology (RSM) to develop and optimize a suitable method for the quantitative determination of CLA in pharmaceutical formulations and for monitoring CLA release from SLN and/or NLC in vitro . A simple, accurate, precise, sensitive and stability - indicating reversed phase - high performance liquid chromatography (RP - HPLC) method with ele ctrochemical (EC) detection was developed, validated and optimized for the in vitro analysis of CLA loaded SLN and/or NLC formulations. Pre - formulation studies were undertaken to investigate the thermal stability of CLA and bulk lipids to facilitate the s election of lipid excipients for the manufacture of nanocarriers in addition to establishing compatibility of CLA with the excipients. It was established that CLA was thermostable up to a temperature of approximately 300 °C thereby indicating that HEUS cou ld be used for the manufacture of CLA - loaded SLN and/or NLC. Lipid screening revealed that CLA i s, in general, poorly soluble in solid and liquid lipids however a combination of stearic acid (SA) and Transcutol ® HP (THP) exhibited the best dissolution pote ntial for CLA of all lipids tested . Stearic acid appears to exist as polymorphic form B prior to exposure to heat however occurs as the form C polymorph following heating at 85 °C for one hour. The best ratio for the mixture of SA and THP for the manufactu re of CLA - NLC ii was an 80:20 ( w/w ) ratio of SA: THP as the two lipids are miscible in this ratio and exhibited the greatest dissolution potential for CLA. Furthermore, an investigation of binary mixtures of CLA/SA and SA/Transcutol ® HP, in addition to eutect ic mixtures of CLA, SA and Transcutol ® HP, revealed no obvious interaction between CLA and the lipids selected for the production of the nanocarriers. Due to the relatively high solubility of CLA in THP in comparison to SA, NLC are likely to exhibit a hig her loading capacity (LC) and encapsulation efficiency (EE) for CLA than SLN. Consequently the feasibility of incorporating CLA (10% w/w ) into NLC was investigated and evaluation of the production of SLN was not undertaken as the production of these might not result in the manufacture of a delivery technology with a high EE and LC for CLA. Tween ® 20 was used as the surfactant as it is readily available, exhibits little or no cytotoxicity and is relatively cheap. Polyethylene glycol (PEG) was used as a coati ng polymer to impart muco - adhesive properties the formulated CLA - NLC. Response surface methodology (RSM) in conjunction with DoE, specifically a Box - Behnken Design (BBD) used as a screening design was used to identify a formulation composition which would produce a product that would meet the pre - defined target critical quality attributes (CQA) for the nanoparticles viz. particle size (PS) in the nano - range, polydispersity index (PDI) < 0.5, Zeta Potential (ZP) ≥ ± 30 mV, and EE > 80%. The formulation composition identified was subsequently used for the optimization of the manufacturing parameters viz. sonication time and amplitude, using a Central Composite Design (CCD) . The LC and EE, in vitro CLA release, cytotoxicity, osmolarity, pH, degree of crystallinity and lipid modification, elemental analysis and surface morphology of the optimized batch was investigated and mon itored to ensure that CLA - loaded NLC, of the desirable quality, had been produced. On the day of manufacture the mean PS and PDI of the optimized CLA - loaded NLC formulation adjusted to physiological osmolarity (250 – 450 mOsm/kg) was 461.9 ± 40.16 nm and 0. 523 ± 0.104, respectively. The ZP for the optimized NLC generated on the day of manufacture using HPLC grade water as the dispersion medium was - 20.5 ± 4.82 mV. The pH and osmolarity of the optimized CLA - loaded NLC formulation was 7.76 ± 0.01 and 316 ± iii 2 m Osm/Kg, respectively and the EE was 88.62 ± 0.23 %. The optimized NLC exhibited a decreased crystallinity in comparison to the bulk lipid materials. DSC, WAXS and FT - IR revealed that CLA was molecularly dispersed in the nanocarriers. The optimized CLA - load ed NLC exhibited muco - adhesive properties, when tested under stationary conditions using laser doppler anemometry (LDA). The optimized formulation also exhibited sustained release of CLA over 24 hours during in vitro release testing and CLA release was bes t described using the Baker - Lonsdale model . The cumulative % CLA released over 24 hours was 56.13 ± 0.23% and mass balance analysis revealed 41.38 ± 0.02% CLA had been retained in the NLC. In vitro cytotoxicity testing revealed that the optimized CLA - NLC w ere less cytotoxic to HeLa cells when compared to CLA alone and further confirmed that the lipids and excipients used in these studies were of GRAS status . Stability studies revealed that the EE reduced over 28 days by 14.42% and 5.14% when stored at 4 °C and 22 °C , respectively. In addition, the particle size increased from the nm to μm range for samples stored at 22 °C. The findings are a good starting point but require further optimization to ensure prolongation of stability. In addition , the technology requires additional developmental studies and a powder for reconstitution for use as a single - dose considered as single dose packaging may be a solution to the compromised formulation stability observed in these studies. The CLA - NLC produced in these stu dies exhibit sound product attributes which serve as a useful foundation for the novel delivery of antibiotics to the eye. The results suggest that the optimized NLC have the potential to enhance precorneal retention and increase ocular availability of CLA , which in turn may be useful to reduce the required dose and dosing frequency when administering CLA as a reconstituted solution to treat susceptible organisms that infect ocular tissues.
- Full Text:
- Date Issued: 2021
Prioritising biological control agents for release against Sporobolus pyramidalis and Sporobolus natalensis (Poaceae) in Australia
- Authors: Sutton, Guy Frederick
- Date: 2021
- Subjects: Grasses -- Diseases and pests , Bruchophagus , Wasps , Alien plants -- Biological control -- Australia , Sporobolus -- Biological control -- Africa , Sporobolus -- Biological control -- Australia , Insects as biological pest control agents -- Australia , Insects as biological pest control agents -- Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172445 , vital:42201 , 10.21504/10962/172445
- Description: Sporobolus pyramidalis Beauv. and S. natalensis (Steud.) Th. Dur. and Schinz. (giant rat’s tail grass) (Poaceae), invade rangelands and pastures in eastern Australia, costing the livestock industry approximately AUS$ 60 million per annum in grazing losses. Mechanical and chemical control options are costly and largely ineffective. Biological control is viewed as the most promising control option, however this management strategy has largely been avoided for grasses, due to their perceived lack of suitably host-specific and damaging natural enemies. In this thesis, the prospects for using biological control against S. pyramidalis and S. natalensis in Australia was assessed, in light of these potential challenges. Climate matching models were used to identify high-priority geographic regions within the plants’ native distributions to survey for potential biological control agents. High-priority regions to perform surveys were identified by modelling the climatic suitability for S. pyramidalis and S. natalensis in sub-Saharan Africa (i.e. their potential native ranges’), and climatic compatibility with regions where biological control is intended in Australia. High-priority regions for S. pyramidalis included: (1) coastal East Africa, ranging from north-eastern South Africa to Uganda, including south-eastern DRC, (2) some parts of West Africa, including inland regions of the Ivory Coast and western Nigeria, (3) northern Angola and (4) eastern Madagascar, and for S. natalensis included: (1) eastern South Africa, (2) eastern Zimbabwe, (3) Burundi, (4) central Ethiopia and (5) central Madagascar. Prospective control agents collected from these regions have the highest probability of establishing and proliferating in Australia, if released. In surveys of the insect assemblages on S. pyramidalis and S. natalensis in the climatically-matched region of eastern South Africa fifteen insect herbivores associated with the grasses were identified. Insect feeding guild, geographic distributions, and seasonal abundances suggest that three stem-boring phytophagous wasps, Tetramesa sp. 1, Tetramesa sp. 2 and Bruchophagus sp. 1 (Hymenoptera: Eurytomidae), have potential as control agents. Species accumulation curves indicated that additional surveys in South Africa are unlikely to yield additional potential control agents. Field host-range surveys of 47 non-target grass species in South Africa showed that Tetramesa sp. 1, Tetramesa sp. 2, and Bruchophagus sp. 1, were only recorded from S. pyramidalis and S. natalensis. Integrating field host-range with phylogenetic relationships between plant species indicated that no native Australian Sporobolus species or economic crops and pastures are expected to be attacked by these wasps. All three wasp species are predicted to be suitably host-specific for release in Australia. Three other endophagous herbivores attacked non-target native African Sporobolus species that share a close phylogenetic relationship to native Australian Sporobolus species, and therefore, demonstrate considerable risk of non-target damage. These species should not be considered as potential control agents. Under native-range, open-field conditions, Tetramesa sp. 1 caused an approximately 5-fold greater reduction in plant survival and reproductive output than Tetramesa sp. 2 and Bruchophagus sp. 1. Tetramesa sp. 1 in combination with Tetramesa sp. 2 did not significantly increase the level of damage, while Bruchophagus sp. 1 may decrease the efficiency of Tetramesa sp. 1, if released in combination. Tetramesa 1 is therefore the most promising candidate agent. Prioritising potential agents using predicted efficacy allowed otherwise equally suitable prospective agents to be prioritised in a strategic manner. Prioritising which natural enemies to target as biological control agents is a complex task. Field host range and damage assessments in the native range may provide more realistic data than typical studies performed under artificial conditions in a laboratory or quarantine. Moreover, it could assist practitioners in prioritising the most suitable agent(s) at the earliest stage in the programme as possible. This study demonstrated that grasses are suitable targets for biological control as they can harbour host-specific and damaging natural enemies.
- Full Text:
- Date Issued: 2021
- Authors: Sutton, Guy Frederick
- Date: 2021
- Subjects: Grasses -- Diseases and pests , Bruchophagus , Wasps , Alien plants -- Biological control -- Australia , Sporobolus -- Biological control -- Africa , Sporobolus -- Biological control -- Australia , Insects as biological pest control agents -- Australia , Insects as biological pest control agents -- Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172445 , vital:42201 , 10.21504/10962/172445
- Description: Sporobolus pyramidalis Beauv. and S. natalensis (Steud.) Th. Dur. and Schinz. (giant rat’s tail grass) (Poaceae), invade rangelands and pastures in eastern Australia, costing the livestock industry approximately AUS$ 60 million per annum in grazing losses. Mechanical and chemical control options are costly and largely ineffective. Biological control is viewed as the most promising control option, however this management strategy has largely been avoided for grasses, due to their perceived lack of suitably host-specific and damaging natural enemies. In this thesis, the prospects for using biological control against S. pyramidalis and S. natalensis in Australia was assessed, in light of these potential challenges. Climate matching models were used to identify high-priority geographic regions within the plants’ native distributions to survey for potential biological control agents. High-priority regions to perform surveys were identified by modelling the climatic suitability for S. pyramidalis and S. natalensis in sub-Saharan Africa (i.e. their potential native ranges’), and climatic compatibility with regions where biological control is intended in Australia. High-priority regions for S. pyramidalis included: (1) coastal East Africa, ranging from north-eastern South Africa to Uganda, including south-eastern DRC, (2) some parts of West Africa, including inland regions of the Ivory Coast and western Nigeria, (3) northern Angola and (4) eastern Madagascar, and for S. natalensis included: (1) eastern South Africa, (2) eastern Zimbabwe, (3) Burundi, (4) central Ethiopia and (5) central Madagascar. Prospective control agents collected from these regions have the highest probability of establishing and proliferating in Australia, if released. In surveys of the insect assemblages on S. pyramidalis and S. natalensis in the climatically-matched region of eastern South Africa fifteen insect herbivores associated with the grasses were identified. Insect feeding guild, geographic distributions, and seasonal abundances suggest that three stem-boring phytophagous wasps, Tetramesa sp. 1, Tetramesa sp. 2 and Bruchophagus sp. 1 (Hymenoptera: Eurytomidae), have potential as control agents. Species accumulation curves indicated that additional surveys in South Africa are unlikely to yield additional potential control agents. Field host-range surveys of 47 non-target grass species in South Africa showed that Tetramesa sp. 1, Tetramesa sp. 2, and Bruchophagus sp. 1, were only recorded from S. pyramidalis and S. natalensis. Integrating field host-range with phylogenetic relationships between plant species indicated that no native Australian Sporobolus species or economic crops and pastures are expected to be attacked by these wasps. All three wasp species are predicted to be suitably host-specific for release in Australia. Three other endophagous herbivores attacked non-target native African Sporobolus species that share a close phylogenetic relationship to native Australian Sporobolus species, and therefore, demonstrate considerable risk of non-target damage. These species should not be considered as potential control agents. Under native-range, open-field conditions, Tetramesa sp. 1 caused an approximately 5-fold greater reduction in plant survival and reproductive output than Tetramesa sp. 2 and Bruchophagus sp. 1. Tetramesa sp. 1 in combination with Tetramesa sp. 2 did not significantly increase the level of damage, while Bruchophagus sp. 1 may decrease the efficiency of Tetramesa sp. 1, if released in combination. Tetramesa 1 is therefore the most promising candidate agent. Prioritising potential agents using predicted efficacy allowed otherwise equally suitable prospective agents to be prioritised in a strategic manner. Prioritising which natural enemies to target as biological control agents is a complex task. Field host range and damage assessments in the native range may provide more realistic data than typical studies performed under artificial conditions in a laboratory or quarantine. Moreover, it could assist practitioners in prioritising the most suitable agent(s) at the earliest stage in the programme as possible. This study demonstrated that grasses are suitable targets for biological control as they can harbour host-specific and damaging natural enemies.
- Full Text:
- Date Issued: 2021
Probing the binding sites of novel 2-substituted imidazole-4,5-dicarboxylic acids : Towards new imidazole-based drugs
- Authors: Clark, Candyce Raine
- Date: 2021
- Subjects: Heterocyclic compounds Coordination compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50848 , vital:42957
- Description: A series of benzimidazole and imidazole-4,5-dicarboxylic acids were prepared using known and adapted protocols. Novel ligands synthesised in this study include 2-tert-butyl-benzimidazole, 2-tert-butyl-imidazole-4,5-dicarboxylic acid, an intermediate in the synthesis of 1,2- bis(2-benzimidazyl)-1,2,-dihydroxyethane and 2-(2-hydroxyphenyl)-benzimidazole with a salicylic acid co-crystallisate. All ligands prepared were reacted with metal salt solutions in order to prepare metal coordination compounds. Complexes with Cu(II), Ag(I), Mn(II), Ni(II) and Cd(II) ions and 2-phenyl-imidazole-4,5-dicarboxylic acid were prepared, as well as Cu(II) and Mn(II) with 2-trifluoro-methyl-imidazole-4,5-dicarboxylic acid and Cu(II) ions with 2-(2- hydroxyphenyl)-benzimidazole. The ligands and complexes were characterised by means of single-crystal X-ray diffraction studies, NMR analysis, UV spectrophotometric analysis and IR spectroscopy. DFT studies were carried out for selected ligands in order to provide theoretical values for comparison. Antimicrobial studies were performed on some of the ligands and complexes and these results show promise for the future development of new imidazole-based drugs.
- Full Text:
- Date Issued: 2021
- Authors: Clark, Candyce Raine
- Date: 2021
- Subjects: Heterocyclic compounds Coordination compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50848 , vital:42957
- Description: A series of benzimidazole and imidazole-4,5-dicarboxylic acids were prepared using known and adapted protocols. Novel ligands synthesised in this study include 2-tert-butyl-benzimidazole, 2-tert-butyl-imidazole-4,5-dicarboxylic acid, an intermediate in the synthesis of 1,2- bis(2-benzimidazyl)-1,2,-dihydroxyethane and 2-(2-hydroxyphenyl)-benzimidazole with a salicylic acid co-crystallisate. All ligands prepared were reacted with metal salt solutions in order to prepare metal coordination compounds. Complexes with Cu(II), Ag(I), Mn(II), Ni(II) and Cd(II) ions and 2-phenyl-imidazole-4,5-dicarboxylic acid were prepared, as well as Cu(II) and Mn(II) with 2-trifluoro-methyl-imidazole-4,5-dicarboxylic acid and Cu(II) ions with 2-(2- hydroxyphenyl)-benzimidazole. The ligands and complexes were characterised by means of single-crystal X-ray diffraction studies, NMR analysis, UV spectrophotometric analysis and IR spectroscopy. DFT studies were carried out for selected ligands in order to provide theoretical values for comparison. Antimicrobial studies were performed on some of the ligands and complexes and these results show promise for the future development of new imidazole-based drugs.
- Full Text:
- Date Issued: 2021
The application of human factors and ergonomics (HFE) to community-sport organisations in resource scarce contexts: a case study of grassroots football in Makana, Eastern Cape
- Authors: Bennett, Ryan
- Date: 2021
- Subjects: Makana Local Football Association (South Africa) , Human engineering , Soccer teams -- South Africa -- Makhanda -- Management , Soccer -- Management -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172412 , vital:42198 , 10.21504/10962/172412
- Description: Background: Modern Human Factors and Ergonomics (HFE) focuses on the optimisation of complex socio-technical systems and has been challenged to contribute to broader societal issues. An example is within grassroots football organisations in resource-scarce areas such as Makana, South Africa. Through embedded participatory approaches, the research problem was co-constructed: To investigate the socio-technical system of the Makana Local Football Association (LFA). Method: A useful complex system modelling tool is that of Cognitive Work Analysis (CWA), with its 5 phases used to identify constraints and affordances. Three perspectives were adopted for the application of an adapted (to suit participant characteristics) CWA to the Makana LFA: 1) how work is prescribed by the governing body SAFA, 2) how subject matter experts (SME) disclose its current functioning, and 3) how SMEs imagine it could function. Five SMEs attended 12 three-hour workshops to complete the latter two perspectives. Results: The composite work domain analysis between work as prescribed and work as disclosed identified significant mismatches between how policymakers envision the system and how SMEs report its functioning. Key differences in perspectives included the fundamental purpose of the Makana LFA, while only four of 22 functions operate within the Makana LFA. Participants also identified key affordances for the LFA such as reorientation as a community sports organisation. Discussion: Comparison between perspectives indicated four mismatches. 1) SAFA views the LFA as the foundation of the talent identification and development infrastructure of South African football. SMEs view it as a community centred organisation. 2) A lack of human capacity is evident at the community level of Makana football. 3) Funding and assets are absent at this grassroots level. 4) The LFA relies on other stakeholders, but these relationships are not formalised. Policymakers, therefore, have a lack of knowledge of the contextual challenges faced by LFA administrators. It is recommended that SAFA view the LFA as a community sport organisation, focusing on improving human capacity, increasing funding, and formalising stakeholder networks. Furthermore, conceptual models from CWA provide explicit socio-technical system redesign recommendations. Conclusion: Large mismatches between the organising body SAFA and the actual functioning of the LFA significantly hinder the effective management and running of football at a grassroots level in resource-scarce contexts in South Africa. The perspectives approach to CWA was useful in elucidating the constraints and affordances of the Makana LFA socio-technical system and informing redesign opportunities. Systems HFE methodology is therefore well placed to contribute to broader societal issues within resources scarce contexts such as football in Makana. Furthermore, the philosophical underpinnings of systems based HFE were successful in the development of sustainable participatory research within the South African grassroots football context.
- Full Text:
- Date Issued: 2021
- Authors: Bennett, Ryan
- Date: 2021
- Subjects: Makana Local Football Association (South Africa) , Human engineering , Soccer teams -- South Africa -- Makhanda -- Management , Soccer -- Management -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172412 , vital:42198 , 10.21504/10962/172412
- Description: Background: Modern Human Factors and Ergonomics (HFE) focuses on the optimisation of complex socio-technical systems and has been challenged to contribute to broader societal issues. An example is within grassroots football organisations in resource-scarce areas such as Makana, South Africa. Through embedded participatory approaches, the research problem was co-constructed: To investigate the socio-technical system of the Makana Local Football Association (LFA). Method: A useful complex system modelling tool is that of Cognitive Work Analysis (CWA), with its 5 phases used to identify constraints and affordances. Three perspectives were adopted for the application of an adapted (to suit participant characteristics) CWA to the Makana LFA: 1) how work is prescribed by the governing body SAFA, 2) how subject matter experts (SME) disclose its current functioning, and 3) how SMEs imagine it could function. Five SMEs attended 12 three-hour workshops to complete the latter two perspectives. Results: The composite work domain analysis between work as prescribed and work as disclosed identified significant mismatches between how policymakers envision the system and how SMEs report its functioning. Key differences in perspectives included the fundamental purpose of the Makana LFA, while only four of 22 functions operate within the Makana LFA. Participants also identified key affordances for the LFA such as reorientation as a community sports organisation. Discussion: Comparison between perspectives indicated four mismatches. 1) SAFA views the LFA as the foundation of the talent identification and development infrastructure of South African football. SMEs view it as a community centred organisation. 2) A lack of human capacity is evident at the community level of Makana football. 3) Funding and assets are absent at this grassroots level. 4) The LFA relies on other stakeholders, but these relationships are not formalised. Policymakers, therefore, have a lack of knowledge of the contextual challenges faced by LFA administrators. It is recommended that SAFA view the LFA as a community sport organisation, focusing on improving human capacity, increasing funding, and formalising stakeholder networks. Furthermore, conceptual models from CWA provide explicit socio-technical system redesign recommendations. Conclusion: Large mismatches between the organising body SAFA and the actual functioning of the LFA significantly hinder the effective management and running of football at a grassroots level in resource-scarce contexts in South Africa. The perspectives approach to CWA was useful in elucidating the constraints and affordances of the Makana LFA socio-technical system and informing redesign opportunities. Systems HFE methodology is therefore well placed to contribute to broader societal issues within resources scarce contexts such as football in Makana. Furthermore, the philosophical underpinnings of systems based HFE were successful in the development of sustainable participatory research within the South African grassroots football context.
- Full Text:
- Date Issued: 2021
The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials
- Authors: Mpeta, Lekhetho Simon
- Date: 2021
- Subjects: Phthalocyanines , Nanostructured materials , Electrocatalysis , Nanoparticles , Environmental chemistry , Electrodes , Organic wastes -- Purification
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172191 , vital:42174 , 10.21504/10962/172191
- Description: Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.
- Full Text:
- Date Issued: 2021
- Authors: Mpeta, Lekhetho Simon
- Date: 2021
- Subjects: Phthalocyanines , Nanostructured materials , Electrocatalysis , Nanoparticles , Environmental chemistry , Electrodes , Organic wastes -- Purification
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172191 , vital:42174 , 10.21504/10962/172191
- Description: Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.
- Full Text:
- Date Issued: 2021
“Munhu wese ihama yako (everyone is your relative)”: Ubuntu and the social inclusion of students with disabilities at South African universities
- Authors: Chiwandire, Desire
- Date: 2021
- Subjects: College students with disabilities -- Education -- South Africa , Inclusive education -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170578 , vital:41938 , 10.21504/10962/170578
- Description: Background: During apartheid, South African students with disabilities (SWDs) were educated in special schools and taught an inferior curriculum. Black learners with disabilities were discriminated against on grounds of both race and disability. Following South Africa’s first democratic election in 1994, the African National Congress (ANC) government put in place arrange of new laws to address the educational and other needs of those disadvantaged under apartheid, including persons with disabilities (PWDs). The South African government is a signatory of the 2006 United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) which has resulted in the country assuming obligations to promote inclusive education for ASWDs. However, research (see, for instance, Chiwandire & Vincent 2019; Chiwandire 2019; Mutanga 2019; Majoko & Phasha 2018; Mutanga et al. 2018; Mutanga 2017a; Chiwandire 2017; Israel 2017) has shown that SWDs continue to fare differently in comparison to their non-disabled peers in terms of participation in education with the likelihood of success. Higher education institutions (HEIs) have thus been urged to create conducive environments for the academic inclusion of SWDs with particular attention being paid to lecturers employing inclusive instructional strategies as well as flexible curricula, if they are to ensure the equal opportunity for academic success of SWDs in the regular classroom setting. The focus, to date, on academic inclusion, while important, has meant that issues relating to the social inclusion of SWDs have received minimal attention. Purpose: To date, there is a dearth of South African studies which have investigated the social inclusion needs of SWDs on South African campuses. Although a number of studies have given voice to the perspectives of SWDs and lecturers, with respect to their experiences in relation to matters of academic inclusion in South African higher education (HE), few have focused on Disability Unit Staff Members(DUSMs) who are pivotal to ensuring fair and equitable policies and practices for SWDs in HEIs. Disability Studies (DS) as a field has been criticised for being dominated by voices from the Global North, which fail to consider or effectively theorise Global South disability experiences in a contextually relevant way. The thesis argues that the failure to recognise the value of diversity and to treat SWDs as valued and welcomed participants in South African HEIs partly stems from policy, practice and relationships being informed by the Western individualist paradigm that prizes individual achievement and success rather than cooperation and mutuality. The African philosophy of Ubuntu, which stresses values of communalism, hospitality and respect for human dignity is offered here as an alternative starting point for achieving genuinely inclusive campuses. Methods: In-depth face-to-face qualitative interviews were conducted with 40 participants, most of whom were, at the time of being interviewed, Heads of Disability Units and DUSMs based at 10 different universities in four of South Africa’s nine provinces. Data were coded and analysed using Braun & Clarke’s (2006) method of inductive and deductive thematic analysis. Results: The findings of this study indicate that South African campuses are ableist spaces in which the social needs of SWDs are not prioritised. The thesis argues that in order for campuses to become genuinely inclusive, South African campuses ought to seek to inculcate in their members the values of the African worldview Ubuntu, in contrast to the dominant Western individualist orthodoxy. SWDs are being excluded and denied a sense of belonging and equal participation despite universities giving lip service to embracing such inclusive education-oriented values as co-operative learning. Non-disabled students steeped in Western individualism, which affirms the solitary pursuit of individual success rather than the value of interdependence and diversity, end up marginalising SWDs who are seen as less capable. DUSMs addressing the needs of SWDs through an ableist/Western individualist lens are not challenging unfair practices which are impairing the dignity of SWDs, particularly students with physical disabilities who are being forced to “fit into” oppressive inaccessible built environments on campuses. These DUSMs may unwittingly re-inscribe ableist assumptions that normalise discrimination against SWDs. Conclusions and Recommendations: Ubuntu values offer a starting point for building mutual respect and interdependence between SWDs and their non-disabled peers. The thesis finds however that as was the case in traditional African communities, which embraced the values of Ubuntu, acts of leadership are required if Ubuntu’s values of human dignity, mutual respect and acceptance are to be fostered on campuses. In a range of important ways, the dignity of SWDs is not respected at HEIs in South Africa. This includes, for example, such practical matters as the inaccessibility of toilets to wheelchair users and the lack of appropriate signage for blind students. Disrespectful attitudes and assumptions about SWDs on the part of non-disabled university members also result in SWDs’ human dignity being impaired. Ubuntu’s value of hospitality stresses the importance of promoting relations of group solidarity and interdependence between SWDs and their non-disabled peers. Both academic inclusion-oriented programmes and the promotion of a wide range of social activities, involving both SWDs and non-disabled students, can play an important role in cultivating the formation of long-term fruitful and respectful friendships between SWDs and non-disabled students. An enabling classroom environment alone is not enough to holistically address the social inclusion needs of SWDs. South African HEIs that embrace the Ubuntu values of communalism, human dignity and hospitality will be in a position to respect the needs of SWDs as “whole persons”. Amongst other things, this requires DUSMs to be fully empowered to make important decisions regarding vital matters such as disability inclusion, and it necessitates university management to relinquish their power, so that they may work collaboratively with DUSMs and SWDs, all on equal footing, to ensure that HE funding allocation, policy and planning also prioritises the social needs of SWDs.
- Full Text:
- Date Issued: 2021
- Authors: Chiwandire, Desire
- Date: 2021
- Subjects: College students with disabilities -- Education -- South Africa , Inclusive education -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170578 , vital:41938 , 10.21504/10962/170578
- Description: Background: During apartheid, South African students with disabilities (SWDs) were educated in special schools and taught an inferior curriculum. Black learners with disabilities were discriminated against on grounds of both race and disability. Following South Africa’s first democratic election in 1994, the African National Congress (ANC) government put in place arrange of new laws to address the educational and other needs of those disadvantaged under apartheid, including persons with disabilities (PWDs). The South African government is a signatory of the 2006 United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) which has resulted in the country assuming obligations to promote inclusive education for ASWDs. However, research (see, for instance, Chiwandire & Vincent 2019; Chiwandire 2019; Mutanga 2019; Majoko & Phasha 2018; Mutanga et al. 2018; Mutanga 2017a; Chiwandire 2017; Israel 2017) has shown that SWDs continue to fare differently in comparison to their non-disabled peers in terms of participation in education with the likelihood of success. Higher education institutions (HEIs) have thus been urged to create conducive environments for the academic inclusion of SWDs with particular attention being paid to lecturers employing inclusive instructional strategies as well as flexible curricula, if they are to ensure the equal opportunity for academic success of SWDs in the regular classroom setting. The focus, to date, on academic inclusion, while important, has meant that issues relating to the social inclusion of SWDs have received minimal attention. Purpose: To date, there is a dearth of South African studies which have investigated the social inclusion needs of SWDs on South African campuses. Although a number of studies have given voice to the perspectives of SWDs and lecturers, with respect to their experiences in relation to matters of academic inclusion in South African higher education (HE), few have focused on Disability Unit Staff Members(DUSMs) who are pivotal to ensuring fair and equitable policies and practices for SWDs in HEIs. Disability Studies (DS) as a field has been criticised for being dominated by voices from the Global North, which fail to consider or effectively theorise Global South disability experiences in a contextually relevant way. The thesis argues that the failure to recognise the value of diversity and to treat SWDs as valued and welcomed participants in South African HEIs partly stems from policy, practice and relationships being informed by the Western individualist paradigm that prizes individual achievement and success rather than cooperation and mutuality. The African philosophy of Ubuntu, which stresses values of communalism, hospitality and respect for human dignity is offered here as an alternative starting point for achieving genuinely inclusive campuses. Methods: In-depth face-to-face qualitative interviews were conducted with 40 participants, most of whom were, at the time of being interviewed, Heads of Disability Units and DUSMs based at 10 different universities in four of South Africa’s nine provinces. Data were coded and analysed using Braun & Clarke’s (2006) method of inductive and deductive thematic analysis. Results: The findings of this study indicate that South African campuses are ableist spaces in which the social needs of SWDs are not prioritised. The thesis argues that in order for campuses to become genuinely inclusive, South African campuses ought to seek to inculcate in their members the values of the African worldview Ubuntu, in contrast to the dominant Western individualist orthodoxy. SWDs are being excluded and denied a sense of belonging and equal participation despite universities giving lip service to embracing such inclusive education-oriented values as co-operative learning. Non-disabled students steeped in Western individualism, which affirms the solitary pursuit of individual success rather than the value of interdependence and diversity, end up marginalising SWDs who are seen as less capable. DUSMs addressing the needs of SWDs through an ableist/Western individualist lens are not challenging unfair practices which are impairing the dignity of SWDs, particularly students with physical disabilities who are being forced to “fit into” oppressive inaccessible built environments on campuses. These DUSMs may unwittingly re-inscribe ableist assumptions that normalise discrimination against SWDs. Conclusions and Recommendations: Ubuntu values offer a starting point for building mutual respect and interdependence between SWDs and their non-disabled peers. The thesis finds however that as was the case in traditional African communities, which embraced the values of Ubuntu, acts of leadership are required if Ubuntu’s values of human dignity, mutual respect and acceptance are to be fostered on campuses. In a range of important ways, the dignity of SWDs is not respected at HEIs in South Africa. This includes, for example, such practical matters as the inaccessibility of toilets to wheelchair users and the lack of appropriate signage for blind students. Disrespectful attitudes and assumptions about SWDs on the part of non-disabled university members also result in SWDs’ human dignity being impaired. Ubuntu’s value of hospitality stresses the importance of promoting relations of group solidarity and interdependence between SWDs and their non-disabled peers. Both academic inclusion-oriented programmes and the promotion of a wide range of social activities, involving both SWDs and non-disabled students, can play an important role in cultivating the formation of long-term fruitful and respectful friendships between SWDs and non-disabled students. An enabling classroom environment alone is not enough to holistically address the social inclusion needs of SWDs. South African HEIs that embrace the Ubuntu values of communalism, human dignity and hospitality will be in a position to respect the needs of SWDs as “whole persons”. Amongst other things, this requires DUSMs to be fully empowered to make important decisions regarding vital matters such as disability inclusion, and it necessitates university management to relinquish their power, so that they may work collaboratively with DUSMs and SWDs, all on equal footing, to ensure that HE funding allocation, policy and planning also prioritises the social needs of SWDs.
- Full Text:
- Date Issued: 2021
A best practice guideline for screening and managing chorioamnionitis
- Authors: Du Plessis, Allison Herlene
- Date: 2020
- Subjects: Bacterial diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46374 , vital:39575
- Description: Due to the complex nature of chorioamnionitis, women are often misdiagnosed, undiagnosed or only diagnosed after birth when it is too late to prevent maternal and neonatal complications. A lack of a comprehensive best practice guidelinefor screening and managing women withchorioamnionitis resultsin delayed treatment and management that could minimise maternal and neonatal complications. Saving Babiesreported that unexplained intra-uterine deathsremained the main primary (obstetric) cause of death for babies with a weight above 1000g (24.4%of all deaths). Of these unexplained uterine deaths, 33% are of normal birth weight (>2500g), and,therefore,most likely term gestation. Saving Babies further reported that 22.9% of all live births in South Africa was premature and 22.8% of birthswere unexplained intra-uterine deaths. Prematurity is one major complication of chorioamnionitis. When susceptibility for chorioamnionitis is considered during early pregnancy, it is possible to intervene and prevent or even reduce the incidences and complications of chorioamnionitis.A qualitative research study was conducted in three phases. In Phase One(Part One), a theoretically constructed patient scenario of chorioamnionitis was presented to ten midwives,and semi-structured individual interviews were done to elicit information regarding how they screen for and manage chorioamnionitis. In Phase One(Part Two), experienced medical practitioners in the field of obstetrics and gynaecology were individually interviewed, also using semi-structured individual interviewsto gain their views regarding chorioamnionitis as a contributing factor to maternal morbidity and mortality. Qualitative findings in Phase Oneindicated that there is a general lack of knowledge regarding chorioamnionitis among midwives, resulting ininadequate screening, misdiagnosis and mismanagement of the condition. Experienced medical practitioners confirmed that chorioamnionitis is underdiagnosed, misdiagnosed or undiagnosed and underreported,and they hold views that it is difficult to treat and control pregnancy-related infections according to current practice.An integrative literature review was conductedin Phase Twoand literature regarding diagnostic biomarkers, screening options to diagnose chorioamnionitis and management of chorioamnionitis were extracted. After evidence synthesisofPhase Oneand Phase Twodata, a best practice guidelinefor screening and managing viiwomen withchorioamnionitiswas developed usingthe National Institute for Health and Clinical Excellence guideline development approach in Phase Three. The purpose of the best practice guideline for screening and managing women with chorioamnionitis was to provide a guideline onhow to manage women who are at risk and those who present with signs and symptoms of chorioamnionitis at any stage during their pregnancy. Five recommendations were made that involve screening for chorioamnionitisand causative factors, biomarkers to diagnose chorioamnionitis, management of chorioamnionitis that includes pharmacological and non-pharmacological management, and health education to women.Ethics for this research study were guided by the ethical principles and guidelines of the Belmont Report. The trustworthiness of this research study was adopted from Ravitch and Carl,and was based on criticality, reflexivity, collaboration, and rigour. An independent coder and reviewer wereto verify the data that were included in the best practice guideline. Expert reviewersappraised the best practice guidelineusing Appraisal of Guidelines for Research and Evaluation II tools.
- Full Text:
- Date Issued: 2020
- Authors: Du Plessis, Allison Herlene
- Date: 2020
- Subjects: Bacterial diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46374 , vital:39575
- Description: Due to the complex nature of chorioamnionitis, women are often misdiagnosed, undiagnosed or only diagnosed after birth when it is too late to prevent maternal and neonatal complications. A lack of a comprehensive best practice guidelinefor screening and managing women withchorioamnionitis resultsin delayed treatment and management that could minimise maternal and neonatal complications. Saving Babiesreported that unexplained intra-uterine deathsremained the main primary (obstetric) cause of death for babies with a weight above 1000g (24.4%of all deaths). Of these unexplained uterine deaths, 33% are of normal birth weight (>2500g), and,therefore,most likely term gestation. Saving Babies further reported that 22.9% of all live births in South Africa was premature and 22.8% of birthswere unexplained intra-uterine deaths. Prematurity is one major complication of chorioamnionitis. When susceptibility for chorioamnionitis is considered during early pregnancy, it is possible to intervene and prevent or even reduce the incidences and complications of chorioamnionitis.A qualitative research study was conducted in three phases. In Phase One(Part One), a theoretically constructed patient scenario of chorioamnionitis was presented to ten midwives,and semi-structured individual interviews were done to elicit information regarding how they screen for and manage chorioamnionitis. In Phase One(Part Two), experienced medical practitioners in the field of obstetrics and gynaecology were individually interviewed, also using semi-structured individual interviewsto gain their views regarding chorioamnionitis as a contributing factor to maternal morbidity and mortality. Qualitative findings in Phase Oneindicated that there is a general lack of knowledge regarding chorioamnionitis among midwives, resulting ininadequate screening, misdiagnosis and mismanagement of the condition. Experienced medical practitioners confirmed that chorioamnionitis is underdiagnosed, misdiagnosed or undiagnosed and underreported,and they hold views that it is difficult to treat and control pregnancy-related infections according to current practice.An integrative literature review was conductedin Phase Twoand literature regarding diagnostic biomarkers, screening options to diagnose chorioamnionitis and management of chorioamnionitis were extracted. After evidence synthesisofPhase Oneand Phase Twodata, a best practice guidelinefor screening and managing viiwomen withchorioamnionitiswas developed usingthe National Institute for Health and Clinical Excellence guideline development approach in Phase Three. The purpose of the best practice guideline for screening and managing women with chorioamnionitis was to provide a guideline onhow to manage women who are at risk and those who present with signs and symptoms of chorioamnionitis at any stage during their pregnancy. Five recommendations were made that involve screening for chorioamnionitisand causative factors, biomarkers to diagnose chorioamnionitis, management of chorioamnionitis that includes pharmacological and non-pharmacological management, and health education to women.Ethics for this research study were guided by the ethical principles and guidelines of the Belmont Report. The trustworthiness of this research study was adopted from Ravitch and Carl,and was based on criticality, reflexivity, collaboration, and rigour. An independent coder and reviewer wereto verify the data that were included in the best practice guideline. Expert reviewersappraised the best practice guidelineusing Appraisal of Guidelines for Research and Evaluation II tools.
- Full Text:
- Date Issued: 2020
A classification of large wetlands in Africa’s elevated drylands based on their formation, structure, and hydrological functioning using Earth Observation (EO) data and Geographic Information System (GIS)
- Authors: Lidzhegu, Zwidofhelangani
- Date: 2020
- Subjects: Wetlands -- Africa -- Classification , Wetlands -- Africa -- Research , Wetlands -- Africa -- Monitoring , Topographical surveying -- Africa , Hydrological surveys == Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142668 , vital:38100
- Description: Due to wetland inaccessibility and limited wetland geomorphological studies, there is limited information on the geomorphological origin and hydrological functioning of different types of wetlands in Africa’s elevated drylands. As a result, there is limited information for the development of a comprehensive wetland classification system that classifies wetlands based on long-term geomorphic processes that determine their formation and shape, their structure and hydrological functioning. Therefore, the current study was designed to classify large wetlands in Africa’s elevated drylands based on processes that determine their formation, and shape their structure and hydrological functioning using remote sensing and Geographic Information System (GIS) techniques. Although wetlands perform a number of hydrological functions including groundwater recharge and water purification, the current study focuses mainly on their flood attenuation function. Detailed analysis of topographic information was undertaken using Shuttle Radar Topographic Mission (SRTM) elevations measured at the scale of 30 m x 30 m. LandsatLook and Google Earth images, tectonic as well as geological data were used as supplementary data for developing an understanding of the origin, structure and hydrological characteristics of wetlands. The Principal Component Analysis (PCA) of wetland environmental variables was used to identify and explain wetland heterogeneity. The results of the study showed that fluvial processes, tectonic history and the evolution of Africa’s landscape played a fundamental role in the formation and evolution of wetlands. This study demonstrates a wide range of processes that contribute to wetland formation, structure and functioning. At one extreme it is clear that tectonic processes may be primarily responsible for the creation of basins that host wetlands. At another extreme, wetlands may be structured primarily by fluvial processes. At a third extreme are wetlands that superficially appear to be structured by fluvial processes, but which have their structures modified by gradual rising of the base level at their distal ends, either through marginal uplift adjacent to rift valleys, or through aggradation of a floodplain that blocks a tributary valley. Overall, the classification of wetlands considered in this study can be summarised into four distinct groupings, with two of these divided further into two groupings each: (1) Tectonic basins with little or no indication of fluvial development (Bahi and Wembere wetlands), (2) Tectonic basins evolving towards a wetland with a structure increasingly shaped by fluvial characteristics (Usangu wetland), (3) Fluvially modified valleys with a local base level at the toe of the wetland such as a resistant lithology or a tectonic control that limits the rate of incision of easily weathered and eroded lithologies, leading to valley widening and longitudinal slope reduction, which are of two distinct types: (a) With a catchment on Kalahari Group sediment that is transported fluvially as bedload, and therefore with no prominent alluvial ridge or backwater depressions (Upper Zambezi and Barotse wetlands), (b) With a catchment that produces abundant fine sediment that is deposited as overbank sediments, leading to channel migration via meandering and to the construction of an elevated alluvial ridge (Lufira wetland), (4) Fluvially modified basins with evidence of gradual elevation of the base level at the toe of the wetland, which are of two types: (a) Tectonic marginal rift valley uplift such that they behave more as depression wetlands rather than as wetlands shaped by fluvial processes (Kafue and Luapula wetlands), (b) Tributary valley wetlands blocked by aggradation of the trunk valley (Lukanga wetland). In conclusion, although few geomorphological studies have been conducted on southern African wetlands because of their inaccessibility, Africa’s surface topography and its historical evolution, as well as aridity, provide an opportunity for illustrating the important role that the long-term tectonic, geological and geomorphological processes play in determining wetland origin, structure and dynamics. GIS methodology and Earth Observation (EO) data on the other hand, provide a practical means for acquiring information on inaccessible and hard to traverse wetland systems. A novel cut-and-fill approach for delineating wetlands from a Digital Elevation Model (DEM) was presented as another way in which GIS methodology and Earth Observation (EO) data can provide practical means for assessing inaccessible and hard to traverse wetland systems.
- Full Text:
- Date Issued: 2020
- Authors: Lidzhegu, Zwidofhelangani
- Date: 2020
- Subjects: Wetlands -- Africa -- Classification , Wetlands -- Africa -- Research , Wetlands -- Africa -- Monitoring , Topographical surveying -- Africa , Hydrological surveys == Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142668 , vital:38100
- Description: Due to wetland inaccessibility and limited wetland geomorphological studies, there is limited information on the geomorphological origin and hydrological functioning of different types of wetlands in Africa’s elevated drylands. As a result, there is limited information for the development of a comprehensive wetland classification system that classifies wetlands based on long-term geomorphic processes that determine their formation and shape, their structure and hydrological functioning. Therefore, the current study was designed to classify large wetlands in Africa’s elevated drylands based on processes that determine their formation, and shape their structure and hydrological functioning using remote sensing and Geographic Information System (GIS) techniques. Although wetlands perform a number of hydrological functions including groundwater recharge and water purification, the current study focuses mainly on their flood attenuation function. Detailed analysis of topographic information was undertaken using Shuttle Radar Topographic Mission (SRTM) elevations measured at the scale of 30 m x 30 m. LandsatLook and Google Earth images, tectonic as well as geological data were used as supplementary data for developing an understanding of the origin, structure and hydrological characteristics of wetlands. The Principal Component Analysis (PCA) of wetland environmental variables was used to identify and explain wetland heterogeneity. The results of the study showed that fluvial processes, tectonic history and the evolution of Africa’s landscape played a fundamental role in the formation and evolution of wetlands. This study demonstrates a wide range of processes that contribute to wetland formation, structure and functioning. At one extreme it is clear that tectonic processes may be primarily responsible for the creation of basins that host wetlands. At another extreme, wetlands may be structured primarily by fluvial processes. At a third extreme are wetlands that superficially appear to be structured by fluvial processes, but which have their structures modified by gradual rising of the base level at their distal ends, either through marginal uplift adjacent to rift valleys, or through aggradation of a floodplain that blocks a tributary valley. Overall, the classification of wetlands considered in this study can be summarised into four distinct groupings, with two of these divided further into two groupings each: (1) Tectonic basins with little or no indication of fluvial development (Bahi and Wembere wetlands), (2) Tectonic basins evolving towards a wetland with a structure increasingly shaped by fluvial characteristics (Usangu wetland), (3) Fluvially modified valleys with a local base level at the toe of the wetland such as a resistant lithology or a tectonic control that limits the rate of incision of easily weathered and eroded lithologies, leading to valley widening and longitudinal slope reduction, which are of two distinct types: (a) With a catchment on Kalahari Group sediment that is transported fluvially as bedload, and therefore with no prominent alluvial ridge or backwater depressions (Upper Zambezi and Barotse wetlands), (b) With a catchment that produces abundant fine sediment that is deposited as overbank sediments, leading to channel migration via meandering and to the construction of an elevated alluvial ridge (Lufira wetland), (4) Fluvially modified basins with evidence of gradual elevation of the base level at the toe of the wetland, which are of two types: (a) Tectonic marginal rift valley uplift such that they behave more as depression wetlands rather than as wetlands shaped by fluvial processes (Kafue and Luapula wetlands), (b) Tributary valley wetlands blocked by aggradation of the trunk valley (Lukanga wetland). In conclusion, although few geomorphological studies have been conducted on southern African wetlands because of their inaccessibility, Africa’s surface topography and its historical evolution, as well as aridity, provide an opportunity for illustrating the important role that the long-term tectonic, geological and geomorphological processes play in determining wetland origin, structure and dynamics. GIS methodology and Earth Observation (EO) data on the other hand, provide a practical means for acquiring information on inaccessible and hard to traverse wetland systems. A novel cut-and-fill approach for delineating wetlands from a Digital Elevation Model (DEM) was presented as another way in which GIS methodology and Earth Observation (EO) data can provide practical means for assessing inaccessible and hard to traverse wetland systems.
- Full Text:
- Date Issued: 2020