Integration of clinical legal education with procedural law modules
- Authors: Welgemoed, Marc
- Date: 2021-12
- Subjects: Law -- Study and teaching (Clinical education) , Procedure law
- Language: English
- Type: Doctoral theses , Thesis
- Identifier: http://hdl.handle.net/10948/56123 , vital:55571
- Description: This research evaluates the role that Clinical Legal Education (CLE) can and should play in the teaching and learning of procedural law modules, ie Civil Procedure, Criminal Procedure and the Law of Evidence. It is argued that the doctrine of transformative constitutionalism provides a sound theoretical basis for the integration of CLE in the teaching and learning of procedural law modules in that there is a constitutional imperative on law schools to train law graduates, who are ready for entry into legal practice, as far as adequate theoretical knowledge and practical skills are concerned. This research provides an indication of how the integration of CLE with procedural law modules can improve the appreciation of the values of the Constitution of the Republic of South Africa 108 of 1996 by law graduates. Graduates will learn the importance of advancing social and procedural justice when rendering legal services to members of the public. Furthermore, graduates will be equipped with valuable graduate attributes required for legal practice. The conclusion of this research is that an integrated teaching and learning methodology, in relation to procedural law modules, will result in producing better law graduates for legal practice. The result of this will be that future legal practitioners, who can serve the public in a professional, ethical and accountable manner as envisaged by the Legal Practice Act 28 of 2014, immediately after graduating from law schools, will be produced. , Thesis (LLD) -- Faculty of Law, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Welgemoed, Marc
- Date: 2021-12
- Subjects: Law -- Study and teaching (Clinical education) , Procedure law
- Language: English
- Type: Doctoral theses , Thesis
- Identifier: http://hdl.handle.net/10948/56123 , vital:55571
- Description: This research evaluates the role that Clinical Legal Education (CLE) can and should play in the teaching and learning of procedural law modules, ie Civil Procedure, Criminal Procedure and the Law of Evidence. It is argued that the doctrine of transformative constitutionalism provides a sound theoretical basis for the integration of CLE in the teaching and learning of procedural law modules in that there is a constitutional imperative on law schools to train law graduates, who are ready for entry into legal practice, as far as adequate theoretical knowledge and practical skills are concerned. This research provides an indication of how the integration of CLE with procedural law modules can improve the appreciation of the values of the Constitution of the Republic of South Africa 108 of 1996 by law graduates. Graduates will learn the importance of advancing social and procedural justice when rendering legal services to members of the public. Furthermore, graduates will be equipped with valuable graduate attributes required for legal practice. The conclusion of this research is that an integrated teaching and learning methodology, in relation to procedural law modules, will result in producing better law graduates for legal practice. The result of this will be that future legal practitioners, who can serve the public in a professional, ethical and accountable manner as envisaged by the Legal Practice Act 28 of 2014, immediately after graduating from law schools, will be produced. , Thesis (LLD) -- Faculty of Law, 2021
- Full Text:
- Date Issued: 2021-12
A proposed framework for the development of urban agriculture in South African cities
- Authors: Brown, Nicola Jayne
- Date: 2021-04
- Subjects: Urban agriculture -- South Africa , Sustainable development -- South Africa , Food security -- Climatic factors -- South Africa , Resilience (Ecology)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/174413 , vital:42475
- Description: While climate change and rapid urbanisation are impacting our cities and existing infrastructure, population growth and resource scarcity are placing unprecedented pressure on our food systems. In light of such challenges and the Sustainable Development Goals, resilient solutions are being sought to move both urban development and food production towards a more sustainable future. In this context, Urban Agriculture (UA) has been identified as a possible mechanism to complement rural food production with many associated social, economic and environmental benefits for urban communities. Some of these benefits include increased food system resilience, better urban environmental management, circular and productive reuse of urban wastes, employment opportunities, reduced food miles and the promotion of social inclusivity. Through a sustainable food system lens and underpinned by Resilience Theory, this research study sets out to investigate and explore the considerations for UA development. The research study reviews UA literature to identify and analyse the common challenges which act as barriers to implementation, as well as the current or potential opportunities which could be leveraged to drive UA development. The insights gained from literature on UA and UA development frameworks; and the data gathered from qualitative interviews with experts working in UA-related fields in South Africa (SA), were used to build a conceptual framework for UA development in SA. The conceptual framework developed is intended to be used as a guide for local municipalities, urban planners, urban farmers, urban communities and UA support organisations in their approach to developing UA initiatives. The findings from this research study reveal that UA development in SA involves numerous actors at both provincial and municipal levels; and within private institutions, businesses, universities, farmer organisations and society. The findings also reveal that UA currently occurs at many levels in SA, with each level drawing a particular range of participants due to the various social, economic and/or environmental features of the initiative. Along with challenges associated with land access, the lack of UA-related knowledge, the threat of theft, vandalism and soil contamination (to name a few); a lack of understanding of how agriculture can fit into urban spaces was found to be a major obstacle. The findings suggest that this lack of understanding has led to an under-realisation of the full potential of UA in South African towns and cities; and an inability to incentivise and optimise the development of UA. Considering the findings derived from the investigation, the study proposes five major considerations for UA development in SA, all of which are unpacked in the conceptual framework. The study concludes by making recommendations for UA decision-makers and UA organisations to consider for future developments.
- Full Text:
- Date Issued: 2021-04
- Authors: Brown, Nicola Jayne
- Date: 2021-04
- Subjects: Urban agriculture -- South Africa , Sustainable development -- South Africa , Food security -- Climatic factors -- South Africa , Resilience (Ecology)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/174413 , vital:42475
- Description: While climate change and rapid urbanisation are impacting our cities and existing infrastructure, population growth and resource scarcity are placing unprecedented pressure on our food systems. In light of such challenges and the Sustainable Development Goals, resilient solutions are being sought to move both urban development and food production towards a more sustainable future. In this context, Urban Agriculture (UA) has been identified as a possible mechanism to complement rural food production with many associated social, economic and environmental benefits for urban communities. Some of these benefits include increased food system resilience, better urban environmental management, circular and productive reuse of urban wastes, employment opportunities, reduced food miles and the promotion of social inclusivity. Through a sustainable food system lens and underpinned by Resilience Theory, this research study sets out to investigate and explore the considerations for UA development. The research study reviews UA literature to identify and analyse the common challenges which act as barriers to implementation, as well as the current or potential opportunities which could be leveraged to drive UA development. The insights gained from literature on UA and UA development frameworks; and the data gathered from qualitative interviews with experts working in UA-related fields in South Africa (SA), were used to build a conceptual framework for UA development in SA. The conceptual framework developed is intended to be used as a guide for local municipalities, urban planners, urban farmers, urban communities and UA support organisations in their approach to developing UA initiatives. The findings from this research study reveal that UA development in SA involves numerous actors at both provincial and municipal levels; and within private institutions, businesses, universities, farmer organisations and society. The findings also reveal that UA currently occurs at many levels in SA, with each level drawing a particular range of participants due to the various social, economic and/or environmental features of the initiative. Along with challenges associated with land access, the lack of UA-related knowledge, the threat of theft, vandalism and soil contamination (to name a few); a lack of understanding of how agriculture can fit into urban spaces was found to be a major obstacle. The findings suggest that this lack of understanding has led to an under-realisation of the full potential of UA in South African towns and cities; and an inability to incentivise and optimise the development of UA. Considering the findings derived from the investigation, the study proposes five major considerations for UA development in SA, all of which are unpacked in the conceptual framework. The study concludes by making recommendations for UA decision-makers and UA organisations to consider for future developments.
- Full Text:
- Date Issued: 2021-04
An exploration of working with grade 11 life sciences educators on the use of Virtual Lab to mediate learning of energy transformations
- Authors: Shambare, Brian
- Date: 2021-04
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Energy conversion -- Study and teaching , Educational technology -- South Africa -- Eastern Cape , Teaching -- Aids and devices , Virtual Lab
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/174388 , vital:42473
- Description: The Department of Basic Education (DBE) examiners’ diagnostic reports for 2012-2019 indicate that National Senior Certificate (NSC) learners mostly perform poorly in examination questions based on scientific investigations. The low performance by learners in these questions has been attributed to the failure by teachers to effectively mediate the learning of scientific concepts due to lack of science laboratories or poorly resourced laboratories in most rural schools. As a result, most learners are finding that scientific concepts are decontextualized and hence abstract. Thus, this study explored making use of Virtual Lab to mediate learning of scientific investigations using the topic Energy transformations. The study was located within an interpretive paradigm and a qualitative case study approach was employed. The study was conducted in four different rural schools in the Joe Gqabi district and seven Grade 11 Life Sciences teachers participated. Data was generated using semi-structured questionnaires, semi-structured interviews, lesson observation, workshop discussions, and journal reflections. The study was informed by Vygotsky’s (1978) Socio-Cultural Theory (SCT) as the theoretical framework, and Thompson and Mishra’s (2006) Technological Pedagogical Content Knowledge (TPACK) as the analytical framework. The results of this study showed that most educators have a positive predisposition towards the integration of Information and Communication Technologies (ICT) in their practice. The study found that using the Virtual Lab to teach Life Sciences has several benefits such as safe environment for conducting experiments; convenience and accessibility; positive teacher and learner attitudes and improvement on learner performance; elimination of physical limitations of a real lab; and availability top-class lab equipment and up-to-date reagents. The study also revealed some shortcomings that were associated with the use of the Virtual Lab. These are; lack of lab partner and peer-learning; and lack of direct supervision by a more knowledgeable facilitator. This study concluded that using the Virtual Lab enhances the quality of teaching scientific experiments in the selected under-resourced rural secondary schools. The study recommends the adoption of the Virtual Lab as a viable alternative to the conventional lab.
- Full Text:
- Date Issued: 2021-04
- Authors: Shambare, Brian
- Date: 2021-04
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Energy conversion -- Study and teaching , Educational technology -- South Africa -- Eastern Cape , Teaching -- Aids and devices , Virtual Lab
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/174388 , vital:42473
- Description: The Department of Basic Education (DBE) examiners’ diagnostic reports for 2012-2019 indicate that National Senior Certificate (NSC) learners mostly perform poorly in examination questions based on scientific investigations. The low performance by learners in these questions has been attributed to the failure by teachers to effectively mediate the learning of scientific concepts due to lack of science laboratories or poorly resourced laboratories in most rural schools. As a result, most learners are finding that scientific concepts are decontextualized and hence abstract. Thus, this study explored making use of Virtual Lab to mediate learning of scientific investigations using the topic Energy transformations. The study was located within an interpretive paradigm and a qualitative case study approach was employed. The study was conducted in four different rural schools in the Joe Gqabi district and seven Grade 11 Life Sciences teachers participated. Data was generated using semi-structured questionnaires, semi-structured interviews, lesson observation, workshop discussions, and journal reflections. The study was informed by Vygotsky’s (1978) Socio-Cultural Theory (SCT) as the theoretical framework, and Thompson and Mishra’s (2006) Technological Pedagogical Content Knowledge (TPACK) as the analytical framework. The results of this study showed that most educators have a positive predisposition towards the integration of Information and Communication Technologies (ICT) in their practice. The study found that using the Virtual Lab to teach Life Sciences has several benefits such as safe environment for conducting experiments; convenience and accessibility; positive teacher and learner attitudes and improvement on learner performance; elimination of physical limitations of a real lab; and availability top-class lab equipment and up-to-date reagents. The study also revealed some shortcomings that were associated with the use of the Virtual Lab. These are; lack of lab partner and peer-learning; and lack of direct supervision by a more knowledgeable facilitator. This study concluded that using the Virtual Lab enhances the quality of teaching scientific experiments in the selected under-resourced rural secondary schools. The study recommends the adoption of the Virtual Lab as a viable alternative to the conventional lab.
- Full Text:
- Date Issued: 2021-04
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
Economic impact of climate change on maize production in the Free State Province, South Africa
- Authors: Johnson, Richard Cowper
- Date: 2021-04
- Subjects: Corn -- Climatic factors -- South Africa -- Free State , Climatic changes -- Economic aspects -- South Africa -- Free State , Climate change mitigation -- South Africa -- Free State , Agriculture -- Economic aspects -- South Africa -- Free State
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/174365 , vital:42471
- Description: Higher concentrations of CO2 in the atmosphere is a major influence on climate change globally. Climate change is caused by greenhouse gases trapping too much heat from the sun in the atmosphere and thus, altering the climate through a rise in global surface temperatures and changing precipitation patterns. CO2 is the most prominent greenhouse gas found in the atmosphere and it is reported that by the turn of the century the CO2 concentration levels will have doubled if the current rate of emissions continues. However, the increase in atmospheric levels of the gas has been found to increase the capacity of maize plants and their water use efficiency to achieve higher yields through CO2 fertilisation. Simulation experiments conducted by the Rhodes University Botany Department found that the effect of elevated levels of CO2 of double the current concentration offsets the negative effects of drought on maize. A case study was conducted on commercial maize farmers in two regions of the Free State province in South Africa to estimate the economic impact of climate change on maize production. Although production is increasing in the province, adaptation to the changing climate is key to the sustainability of production. There is a trade-off between the negative effects of higher CO2 levels changing the climate and the positive effect of CO2 fertilisation. As predicted, the economic impact of climate change is the disruption of farming practices and the increase in costs of production as a result of adapting to climate change. Using a gross margin analysis, the study found that the larger maize farmers who benefit from economies of scale are able to adapt and grow their production whilst the smaller farmers are being pushed out of the market.
- Full Text:
- Date Issued: 2021-04
- Authors: Johnson, Richard Cowper
- Date: 2021-04
- Subjects: Corn -- Climatic factors -- South Africa -- Free State , Climatic changes -- Economic aspects -- South Africa -- Free State , Climate change mitigation -- South Africa -- Free State , Agriculture -- Economic aspects -- South Africa -- Free State
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/174365 , vital:42471
- Description: Higher concentrations of CO2 in the atmosphere is a major influence on climate change globally. Climate change is caused by greenhouse gases trapping too much heat from the sun in the atmosphere and thus, altering the climate through a rise in global surface temperatures and changing precipitation patterns. CO2 is the most prominent greenhouse gas found in the atmosphere and it is reported that by the turn of the century the CO2 concentration levels will have doubled if the current rate of emissions continues. However, the increase in atmospheric levels of the gas has been found to increase the capacity of maize plants and their water use efficiency to achieve higher yields through CO2 fertilisation. Simulation experiments conducted by the Rhodes University Botany Department found that the effect of elevated levels of CO2 of double the current concentration offsets the negative effects of drought on maize. A case study was conducted on commercial maize farmers in two regions of the Free State province in South Africa to estimate the economic impact of climate change on maize production. Although production is increasing in the province, adaptation to the changing climate is key to the sustainability of production. There is a trade-off between the negative effects of higher CO2 levels changing the climate and the positive effect of CO2 fertilisation. As predicted, the economic impact of climate change is the disruption of farming practices and the increase in costs of production as a result of adapting to climate change. Using a gross margin analysis, the study found that the larger maize farmers who benefit from economies of scale are able to adapt and grow their production whilst the smaller farmers are being pushed out of the market.
- 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
Reminiscing In Tempo : Ubangulo
- Authors: Tutani, Zodwa
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , South African poetry (English) -- 21st century , South African poetry (English) -- History and criticism , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/174376 , vital:42472
- Description: My thesis is a collection of poems that focuses on black mothering and motherhood, within the context of the Eastern Cape’s violent history, its oppressive patriarchal cultural traditions and religious structures. Drawing from my own experiences, my poems explore what Toni Morrison calls the historical ‘wounds’ of black women which are transferred to their daughters within everyday spaces like the kitchen and the lounge, through objects like tea cups, chair backs and the various foods that every black girl needs to be able to prepare in order to be ‘marriagable’, and how these continue to hurt and emotionally disfigure us. I also draw influence from Saidiya Hartman, Christina Sharpe and Tina Campt on black lives and the effects of slavery within their daily existences. And I am inspired by the intimacy and care with which Tadeusz Rosewicz writes about his relationship with his mother in Mother Departs and Sandra Cisneros’ use of interconnected vignettes to engage childhood, culture and community within marginalized space. Stylistically I am influenced by the structural innovations in Fred Moten’s The Little Edges and the dreamy landscape in the poetry of Federico Garcia Lorca. My collection includes prose and lyrical poetry, combining more formal sound and rhythmic structures with free verse, to bring to life motherhood and the narratives we carry from childhood into our adult lives.
- Full Text:
- Date Issued: 2021-04
- Authors: Tutani, Zodwa
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , South African poetry (English) -- 21st century , South African poetry (English) -- History and criticism , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/174376 , vital:42472
- Description: My thesis is a collection of poems that focuses on black mothering and motherhood, within the context of the Eastern Cape’s violent history, its oppressive patriarchal cultural traditions and religious structures. Drawing from my own experiences, my poems explore what Toni Morrison calls the historical ‘wounds’ of black women which are transferred to their daughters within everyday spaces like the kitchen and the lounge, through objects like tea cups, chair backs and the various foods that every black girl needs to be able to prepare in order to be ‘marriagable’, and how these continue to hurt and emotionally disfigure us. I also draw influence from Saidiya Hartman, Christina Sharpe and Tina Campt on black lives and the effects of slavery within their daily existences. And I am inspired by the intimacy and care with which Tadeusz Rosewicz writes about his relationship with his mother in Mother Departs and Sandra Cisneros’ use of interconnected vignettes to engage childhood, culture and community within marginalized space. Stylistically I am influenced by the structural innovations in Fred Moten’s The Little Edges and the dreamy landscape in the poetry of Federico Garcia Lorca. My collection includes prose and lyrical poetry, combining more formal sound and rhythmic structures with free verse, to bring to life motherhood and the narratives we carry from childhood into our adult lives.
- Full Text:
- Date Issued: 2021-04
Ultraprecision Diamond Turning of Monocrystalline Germanium
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
Accelerated implementations of the RIME for DDE calibration and source modelling
- Authors: Van Staden, Joshua
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration , Radio astronomy -- Data processing , Radio inferometers -- Data processing , Radio inferometers -- Calibration -- Data processing
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172422 , vital:42199
- Description: Second- and third-generation calibration methods filter out subtle effects in interferometer data, and therefore yield significantly higher dynamic ranges. The basis of these calibration techniques relies on building a model of the sky and corrupting it with models of the effects acting on the sources. The sensitivities of modern instruments call for more elaborate models to capture the level of detail that is required to achieve accurate calibration. This thesis implements two types of models to be used in for second- and third-generation calibration. The first model implemented is shapelets, which can be used to model radio source morphologies directly in uv space. The second model implemented is Zernike polynomials, which can be used to represent the primary beam of the antenna. We implement these models in the CODEX-AFRICANUS package and provide a set of unit tests for each model. Additionally, we compare our implementations against other methods of representing these objects and instrumental effects, namely NIFTY-GRIDDER against shapelets and a FITS-interpolation method against the Zernike polynomials. We find that to achieve sufficient accuracy, our implementation of the shapelet model has a higher runtime to that of the NIFTY-GRIDDER. However, the NIFTY-GRIDDER cannot simulate a component-based sky model while the shapelet model can. Additionally, the shapelet model is fully parametric, which allows for integration into a parameterised solver. We find that, while having a smaller memory footprint, our Zernike model has a greater computational complexity than that of the FITS-interpolated method. However, we find that the Zernike implementation has floating-point accuracy in its modelling, while the FITS-interpolated model loses some accuracy through the discretisation of the beam.
- Full Text:
- Date Issued: 2021
- Authors: Van Staden, Joshua
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration , Radio astronomy -- Data processing , Radio inferometers -- Data processing , Radio inferometers -- Calibration -- Data processing
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172422 , vital:42199
- Description: Second- and third-generation calibration methods filter out subtle effects in interferometer data, and therefore yield significantly higher dynamic ranges. The basis of these calibration techniques relies on building a model of the sky and corrupting it with models of the effects acting on the sources. The sensitivities of modern instruments call for more elaborate models to capture the level of detail that is required to achieve accurate calibration. This thesis implements two types of models to be used in for second- and third-generation calibration. The first model implemented is shapelets, which can be used to model radio source morphologies directly in uv space. The second model implemented is Zernike polynomials, which can be used to represent the primary beam of the antenna. We implement these models in the CODEX-AFRICANUS package and provide a set of unit tests for each model. Additionally, we compare our implementations against other methods of representing these objects and instrumental effects, namely NIFTY-GRIDDER against shapelets and a FITS-interpolation method against the Zernike polynomials. We find that to achieve sufficient accuracy, our implementation of the shapelet model has a higher runtime to that of the NIFTY-GRIDDER. However, the NIFTY-GRIDDER cannot simulate a component-based sky model while the shapelet model can. Additionally, the shapelet model is fully parametric, which allows for integration into a parameterised solver. We find that, while having a smaller memory footprint, our Zernike model has a greater computational complexity than that of the FITS-interpolated method. However, we find that the Zernike implementation has floating-point accuracy in its modelling, while the FITS-interpolated model loses some accuracy through the discretisation of the beam.
- Full Text:
- Date Issued: 2021
An evaluation of co-management practices: A case of a South African platinum mine management and the local community
- Authors: Matsimela, Tebogo Mapipi
- Date: 2021
- Subjects: Mines and mineral resource -- Management -- South Africa , Mines and mineral resource -- Management -- Social aspects , Mines and mineral resource -- Management -- Moral and ethical aspects , Platinum mines and mining -- Management -- South Africa -- Case studies , Corporate governance -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/171874 , vital:42134
- Description: A vast body of literature reveals the paradigm shift of South Africa’s economy from an agricultural community to an industrial economy. Elbra (2013) illustrated that South African mining host communities viewed that mineral endowments have become a “resource curse” instead of a driver of local economic development for the benefit of the community. To understand the mining and community conflict and their subsequent complexities, the Marikana massacre in August 2012 must be revisited (Bell, 2016). The problems may be broadly summarised as a lack of stakeholder engagement and inclusivity. Studies involving stakeholder management and co-management focused on the identification of stakeholders and their management. The research evaluated the co-management practices between mine management and a local community. It considered the challenges that emanated from the co-management practices. The primary focus of this research has been to evaluate the co-management features between the mine management and the local community and to identify the challenges associated with co-management from a mine management perspective. Furthermore, the research attempted to find effective co-management practices between the mine management and the local community which may be used to improve the partnership. Armitage, Berkes and Doubleplay (2007) recognised that in facilitating effective co-management, the commitment towards fulfilling good governance and accountability was paramount in ensuring that the rights and obligations of both private and public actors were achieved. However, Ran and Qi (2018) acknowledged that such partnerships were not immune to challenges because the poor implementation of co-management features like power-sharing could collapse a co-management partnership. This study aimed to evaluate the current co-management practices from the mine management’s perspective. A literature search revealed the range of co-management features that explained the different use of practices. The features included co-management and power sharing, co-management and institution building, co-management and trust and social capital, co-management as a process, co-management and problem solving, and co-management and governance. The study evaluated the co-management features between the mine management and the local community, identified the current challenges associated with co-management from a mine management perspective and attempted to make recommendations on effective co-management practices between the mine management and a local community. A qualitative case study method was employed. This method allowed the researcher to evaluate multifaceted matters which may have been investigated in the past but not inconsiderable detail (Baxter and Jack, 2008). Data was sampled using purposive sampling. This was because the population sample was chosen according to their roles and responsibilities and their involvement in the co-management between the mine management and the local community. Data was collected through semi-structured interviews and document analyses. The findings of the research were derived from a range of company documents. Thematic analysis was employed to understand the practices of co-management which underpinned the co-management partnership between the mine management and the local community. It was found that there was a positive relationship between the literature study and the response from the mine management. The shared responsibilities emerged out of a dialogue characterised by deliberation and negotiations between the mine management and the stakeholders. Berkes (2009), asserted that co-management bore a resemblance to the process of the sharing of ideas of how responsibilities could be better shared and that it emanated from a process of deliberation and negotiation. Furthermore, if the evolution of the co-management partnership was not managed carefully, it could pose a risk to the partnership itself. It was acknowledged by the research respondents that there were complications involved in having the community as a shareholder in the mine, but equally, the community showed an appreciation of being involved in building a sustainable mine. The model of sustainable partnership emphasised that any viable partnership should adopt this model to achieve a sustainable performance (Thomson and Boutilier, 2011). This research showed that the co-management practices between the mine management and the local community concurred with the findings of Zvarivadza (2018). Trust and transparency between mine management and the community could go a long way in ensuring that the mine fulfilled its legal responsibilities in the local community where the mine is located.
- Full Text:
- Date Issued: 2021
- Authors: Matsimela, Tebogo Mapipi
- Date: 2021
- Subjects: Mines and mineral resource -- Management -- South Africa , Mines and mineral resource -- Management -- Social aspects , Mines and mineral resource -- Management -- Moral and ethical aspects , Platinum mines and mining -- Management -- South Africa -- Case studies , Corporate governance -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/171874 , vital:42134
- Description: A vast body of literature reveals the paradigm shift of South Africa’s economy from an agricultural community to an industrial economy. Elbra (2013) illustrated that South African mining host communities viewed that mineral endowments have become a “resource curse” instead of a driver of local economic development for the benefit of the community. To understand the mining and community conflict and their subsequent complexities, the Marikana massacre in August 2012 must be revisited (Bell, 2016). The problems may be broadly summarised as a lack of stakeholder engagement and inclusivity. Studies involving stakeholder management and co-management focused on the identification of stakeholders and their management. The research evaluated the co-management practices between mine management and a local community. It considered the challenges that emanated from the co-management practices. The primary focus of this research has been to evaluate the co-management features between the mine management and the local community and to identify the challenges associated with co-management from a mine management perspective. Furthermore, the research attempted to find effective co-management practices between the mine management and the local community which may be used to improve the partnership. Armitage, Berkes and Doubleplay (2007) recognised that in facilitating effective co-management, the commitment towards fulfilling good governance and accountability was paramount in ensuring that the rights and obligations of both private and public actors were achieved. However, Ran and Qi (2018) acknowledged that such partnerships were not immune to challenges because the poor implementation of co-management features like power-sharing could collapse a co-management partnership. This study aimed to evaluate the current co-management practices from the mine management’s perspective. A literature search revealed the range of co-management features that explained the different use of practices. The features included co-management and power sharing, co-management and institution building, co-management and trust and social capital, co-management as a process, co-management and problem solving, and co-management and governance. The study evaluated the co-management features between the mine management and the local community, identified the current challenges associated with co-management from a mine management perspective and attempted to make recommendations on effective co-management practices between the mine management and a local community. A qualitative case study method was employed. This method allowed the researcher to evaluate multifaceted matters which may have been investigated in the past but not inconsiderable detail (Baxter and Jack, 2008). Data was sampled using purposive sampling. This was because the population sample was chosen according to their roles and responsibilities and their involvement in the co-management between the mine management and the local community. Data was collected through semi-structured interviews and document analyses. The findings of the research were derived from a range of company documents. Thematic analysis was employed to understand the practices of co-management which underpinned the co-management partnership between the mine management and the local community. It was found that there was a positive relationship between the literature study and the response from the mine management. The shared responsibilities emerged out of a dialogue characterised by deliberation and negotiations between the mine management and the stakeholders. Berkes (2009), asserted that co-management bore a resemblance to the process of the sharing of ideas of how responsibilities could be better shared and that it emanated from a process of deliberation and negotiation. Furthermore, if the evolution of the co-management partnership was not managed carefully, it could pose a risk to the partnership itself. It was acknowledged by the research respondents that there were complications involved in having the community as a shareholder in the mine, but equally, the community showed an appreciation of being involved in building a sustainable mine. The model of sustainable partnership emphasised that any viable partnership should adopt this model to achieve a sustainable performance (Thomson and Boutilier, 2011). This research showed that the co-management practices between the mine management and the local community concurred with the findings of Zvarivadza (2018). Trust and transparency between mine management and the community could go a long way in ensuring that the mine fulfilled its legal responsibilities in the local community where the mine is located.
- Full Text:
- Date Issued: 2021
An exploratory case study on the barriers, challenges and benefits of sustainability reporting by small and medium enterprises (SMEs) in South Africa
- Authors: Mhlope, Veliswa
- Date: 2021
- Subjects: Small business -- South Africa -- Case studies , Sustainable development reporting -- South Africa -- Case studies , Social responsibility of business , Environmental responsibility -- South Africa , Environmental reporting -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/172018 , vital:42149
- Description: SMEs in South Africa and other developing countries have been slow to take up sustainability reporting. This qualitative study is aimed to study the challenges and barriers faced by SMEs, together with the potential benefits for SMEs participating in this type of reporting. It also makes recommendations about how SMEs can participate in and benefit from sustainability reporting. The study shows that indeed there are several challenges in terms of getting involved in sustainability reporting for SMEs. On the other hand, the research finds that the SMEs who are already participating in sustainability reporting can show the benefits of engaging in sustainability reporting and that these benefits far outweigh the challenges. The participating SMEs are also able to show that they have attained a competitive advantage as a result of engaging in sustainability reporting. If, however, sustainability reporting is to become entrenched into SMEs, a few changes need to take place to address challenges such as lack of information about sustainability reporting and its benefits, lack of regulations and more importantly, lack of awareness about sustainable development. As the South African government begins to respond to issues such as climate change, skills development and good governance, it will become necessary for them to introduce regulations to manage this risk. It is also highly possible that in the next few years, reporting will become a regulatory requirement that SMEs will be forced to comply with to continue to do business. The SMEs who are already practising sustainability practices will benefit from being first movers. Those SMEs who start sooner rather than later will already have the internal resources and capabilities to take advantage of the legislative environment. They will have a head start over their rivals in terms of gaining competitive advantage.
- Full Text:
- Date Issued: 2021
- Authors: Mhlope, Veliswa
- Date: 2021
- Subjects: Small business -- South Africa -- Case studies , Sustainable development reporting -- South Africa -- Case studies , Social responsibility of business , Environmental responsibility -- South Africa , Environmental reporting -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/172018 , vital:42149
- Description: SMEs in South Africa and other developing countries have been slow to take up sustainability reporting. This qualitative study is aimed to study the challenges and barriers faced by SMEs, together with the potential benefits for SMEs participating in this type of reporting. It also makes recommendations about how SMEs can participate in and benefit from sustainability reporting. The study shows that indeed there are several challenges in terms of getting involved in sustainability reporting for SMEs. On the other hand, the research finds that the SMEs who are already participating in sustainability reporting can show the benefits of engaging in sustainability reporting and that these benefits far outweigh the challenges. The participating SMEs are also able to show that they have attained a competitive advantage as a result of engaging in sustainability reporting. If, however, sustainability reporting is to become entrenched into SMEs, a few changes need to take place to address challenges such as lack of information about sustainability reporting and its benefits, lack of regulations and more importantly, lack of awareness about sustainable development. As the South African government begins to respond to issues such as climate change, skills development and good governance, it will become necessary for them to introduce regulations to manage this risk. It is also highly possible that in the next few years, reporting will become a regulatory requirement that SMEs will be forced to comply with to continue to do business. The SMEs who are already practising sustainability practices will benefit from being first movers. Those SMEs who start sooner rather than later will already have the internal resources and capabilities to take advantage of the legislative environment. They will have a head start over their rivals in terms of gaining competitive advantage.
- Full Text:
- Date Issued: 2021
An exploratory study of psychologists’ perceptions of the phenomenon currently understood as ‘borderline personality disorder’
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
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
An online information security Aaareness model: the disclosure of personal data
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
Asymmetric price transmission: an empirical analysis of the relationship between UG-2 chrome ore, charge chrome, nickel and Chinese domestic 304 stainless steel cold rolled coil
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- 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
Development and calidation of the psychometric properties underpinning the Kwaito Music Attitude and Perception Scale (KMP)
- Authors: Williams, Akhona
- Date: 2021
- Subjects: Kwaito-music Attitude and Perception , Chronbach's alpha , Kwaito (Music) , Psychotherapy and music -- South Africa , Problem youth -- Rehabilitation -- South Africa , Attitude (Psychology) -- Testing -- South Africa , Perception -- Testing -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172478 , vital:42208
- Description: Music holds a privileged position in enhancing therapeutic well-being, supporting life skills development in youth and adolescents, and shaping cultural identities. As such, music has been closely related to youth culture, especially as it pertains to youth rehabilitation and identity formation. Studies (e.g., Duffy and Fuller, 2000; Miranda et al, 2013; Strayhorn, 2011; Tomasello, 2016) highlight the value of utilising music in youth rehabilitation, and acknowledge the intrinsic value of music to facilitate psychological and social change for individuals who would not otherwise benefit from psycho-education, or other didactic modes of youth rehabilitation. That said, Tyson (2005) developed the RAP music scale to psychometrically validate the underlying constructs of youth’ attitudes and perception of rap music in the United States of America, in order to use the instrument for music-based youth rehabilitation programs. The development of the RAP music scale informed the creation and validation of the Kwaito-music Attitude and Perception (KMP) Scale, the subject of my Masters thesis. Following suggestions from Morrison (2014), my study sought to psychometrically validate the properties of the Kwaito-music Attitude and Perception (KMP) Scale. The KMP was found to be a reliable measure of kwaito music attitudes and perception amongst a sample of South African youth who listen to this genre of music. The internal consistency of the questionnaire revealed a Cronbach’s α (Alpha) value of 0.820. Limitations of the project including reduced factor extraction and sample size constrains are discussed. It is envisioned that results from this study will find resonance with youth-community programs, and rehabilitation projects utilising music as a medium of healing amongst South African youth.
- Full Text:
- Date Issued: 2021
- Authors: Williams, Akhona
- Date: 2021
- Subjects: Kwaito-music Attitude and Perception , Chronbach's alpha , Kwaito (Music) , Psychotherapy and music -- South Africa , Problem youth -- Rehabilitation -- South Africa , Attitude (Psychology) -- Testing -- South Africa , Perception -- Testing -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172478 , vital:42208
- Description: Music holds a privileged position in enhancing therapeutic well-being, supporting life skills development in youth and adolescents, and shaping cultural identities. As such, music has been closely related to youth culture, especially as it pertains to youth rehabilitation and identity formation. Studies (e.g., Duffy and Fuller, 2000; Miranda et al, 2013; Strayhorn, 2011; Tomasello, 2016) highlight the value of utilising music in youth rehabilitation, and acknowledge the intrinsic value of music to facilitate psychological and social change for individuals who would not otherwise benefit from psycho-education, or other didactic modes of youth rehabilitation. That said, Tyson (2005) developed the RAP music scale to psychometrically validate the underlying constructs of youth’ attitudes and perception of rap music in the United States of America, in order to use the instrument for music-based youth rehabilitation programs. The development of the RAP music scale informed the creation and validation of the Kwaito-music Attitude and Perception (KMP) Scale, the subject of my Masters thesis. Following suggestions from Morrison (2014), my study sought to psychometrically validate the properties of the Kwaito-music Attitude and Perception (KMP) Scale. The KMP was found to be a reliable measure of kwaito music attitudes and perception amongst a sample of South African youth who listen to this genre of music. The internal consistency of the questionnaire revealed a Cronbach’s α (Alpha) value of 0.820. Limitations of the project including reduced factor extraction and sample size constrains are discussed. It is envisioned that results from this study will find resonance with youth-community programs, and rehabilitation projects utilising music as a medium of healing amongst South African youth.
- 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