List of Titles

Bayesian inference for Cronbach's alpha

Authors: Izally, Sharkay Ruwade
Date: 2025-04-03
Subjects: Bayesian inference , Bayesian statistical decision theory , Cronbach's alpha , Confidence distribution , Probability matching , Jeffreys prior , Random effects model
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479919 , vital:78380 , DOI 10.21504/10962/479919
Description: Cronbach’s alpha is used as a measure of reliability in fields like education, psychology and sociology. The reason for the popularity of Cronbach’s alpha is that it is computationally simple. Only the sample size and the variance components are needed and it can be computed for continuous as well as binary data. Cronbach’s alpha has been studied extensively using maximum likelihood estimation. Since Cronbach’s alpha is a function of the variance components, this often results in negative estimates of the variance components when the maximum likelihood method is considered as a method of estimation. In the field of Bayesian statistics, the parameters are random variables, and this can alleviate some of the problems of estimating negative variance estimates that often occur when the frequentist approach is used. The Bayesian approach also incorporates loss functions that considers the symmetry of the distribution of the parameters being estimated and adds some flexibility in obtaining better estimates of the unknown parameters. The Bayesian approach often results in better coverage probabilities than the frequentist approach especially for smaller sample sizes and it is therefore important to consider a Bayesian analysis in the estimation of Cronbach’s alpha. The reference and probability matching priors for Cronbach’s alpha will be derived using a one-way random effects model. The performance of these two priors will be compared to that of the well-known Jeffreys prior and a divergence prior. A simulation study will be considered to compare the performance of the priors, where the coverage rates, average interval lengths and standard deviations of the interval lengths will be computed. A second simulation study will be considered where the mean relative error will be compared for the various priors using the squared error, the absolute error and the linear in exponential (LINEX) loss functions. An illustrative example will also be considered. The combined Bayesian estimation of more than one Cronbach’s alpha will also be considered for m experiments with equal α but possibly different variance components. It will be shown that the reference and the probability-matching priors are the same. The Bayesian theory and results will be applied to two examples. The intervals for the combined model are however much shorter than those of the individual models. Also, the point estimates of the combined model are more accurate than those of the individual models. It is further concluded that the posterior distribution of α for the combined model becomes more important as the number of samples and models increase. The reference and probability matching priors for Cronbach’s alpha will be derived using a three-component hierarchical model. The performance of these two priors will be compared to that of the well-known Jeffreys prior and a divergence prior. A simulation study will be v vi considered to compare the performance of the priors, where the coverage rates, average interval lengths and standard deviations of the interval lengths will be computed. Two illustrative examples will also be considered. Statistical control limits will be obtained for Cronbach’s alpha in the case of a balanced one-way random effects model. This will be achieved by deriving the predictive distribution of a future Cronbach’s alpha. The unconditional posterior predictive distribution will be determined using Monte Carlo simulation and the Rao-Blackwell procedure. The predictive distribution will be used to obtain control limits and to determine the run-length and average run-length. Cronbach’s alpha will be estimated for a general covariance matrix using a Bayesian approach and comparing these results to the asymptotic frequentist interval valid under a general covariance matrix framework. Most of the results used in the literature require the compound symmetry assumption for analyses of Cronbach’s alpha. Fiducial and posterior distributions will be derived for Cronbach’s alpha in the case of the bivariate normal distribution. Various objective priors will be considered for the variance components and the correlation coefficient. One of the priors considered corresponds to the fiducial distribution. The performance of these priors will be compared to an asymptotic frequentist interval often used in the literature. A simulation study will be considered to compare the performance of the priors and the asymptotic interval, where the coverage rates and average interval lengths will be computed. , Thesis (PhD) -- Faculty of Science, Statistics, 2025
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Date Issued: 2025-04-03

Bridging cultures in science education: leveraging lesson study approach for indigenous knowledge integration in a township school

Authors: Mayana, Xolani Justice
Date: 2025-04-03
Subjects: Science Study and teaching (Secondary) South Africa , Traditional knowledge , Lesson study , Participatory action research , Professional learning communities , Sociocultural perspective , Pedagogical content knowledge
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480084 , vital:78395 , DOI 10.21504/10962/480084
Description: The South African Curriculum Assessment and Policy Statement (CAPS) encourages science teachers to use culturally responsive pedagogies in their teaching. This should be done by integrating Indigenous Knowledge (IK) in science teaching to make it accessible and relevant to learners. However, the policy falls short of giving clear details on how this ought to be done. For instance, the school textbooks hardly contain any IK and there are few or no readily available teaching resources either. To complicate matters, many science teachers have not been trained on how to integrate IK into science teaching. As a result, most of them do not integrate any IK during their science lessons. It is against this backdrop that this study aimed to leverage the use of a Lesson Study approach when working with science teachers on how to integrate IK to mediate learning of the topics of waves and sound and redox reactions in a township school. Underpinned by the indigenous research and transformative paradigms, a qualitative case study approach in a form of participatory action research was adopted. Six science teachers from a township school, five Indigenous Knowledge Custodians1 (IKCs), one critical friend (isiXhosa and English teacher from the same school) and three university lecturers and a school principal from Zambia who conducted various workshops, and I were the participants in this study. Qualitative data was generated using interviews (semi-structured and stimulated recall interviews), document analysis, workshop discussions, observations (participatory and classroom observations) and journal reflections. Vygotsky’s sociocultural theory, Shulman’s pedagogical content knowledge, specifically Topic-specific Pedagogical Content Knowledge (TSPCK) and Ogunniyi’s Contiguity Argumentation Theory (CAT) were used as complementary theoretical frameworks. A thematic approach to data analysis was employed to come up with sub-themes and themes. The main findings of the study revealed that through collaboration with Indigenous Knowledge Custodians and tapping into their cultural heritage the integration of IK into science lessons was possible. Thus, this study showed that leveraging the use of a Lesson Study approach when working with science teachers on how to integrate IK to mediate learning of the topics of waves and sound and redox reactions in a township school, shifted the science teachers’ Zone of Proximal Development and Pedagogical Content Knowledge positively. Also, this study revealed that the integration of IK promotes learner talk or argumentation. Moreover, the use of isiXhosa our home language proved to be an invaluable cultural tool for effective communication in this study. The study thus recommends that transformational professional learning communities (PLCs) be established in township schools and that teachers should work in collaboration with IKCs to learn about IK which could be integrated into other science topics. Furthermore, the study recommends that teachers should be trained in document analysis and how to use the TSPCK components to unpack the curriculum. This might help the teachers to understand the curriculum needs better, plan better, and hopefully teach better. Thus, the contention of this study is that teacher preparedness is inextricably linked to learner achievement. , Thesis (PhD) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Bridging traditions: mobilising indigenous knowledge and marine biodiversity conservation to support learner talk and sense-making in Grade 11 Life Sciences

Authors: Sibanda, Aswad
Date: 2025-04-03
Subjects: Life sciences Study and teaching (Secondary) South Africa , Marine biodiversity conservation South Africa , Ethnoscience South Africa , Pedagogical content knowledge , Cultural-historical activity theory , Sensemaking
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/480007 , vital:78388
Description: The Curriculum Assessment Policy and Statement (CAPS) document mandates that science teachers should integrate learners’ Indigenous Knowledge (IK) into their classrooms. However, many South African teachers, like those in Namibia, seem to struggle with this integration due to insufficient pedagogical content knowledge, leading to minimal IK integration and hence poor science performance. This issue suggests that science curricula seem to lack clarity on integrating IK. It is against this backdrop that I was motivated to mobilise marine Indigenous Knowledge to support Grade 11 Life Sciences learners from a township school to talk and make sense of marine biodiversity conservation. A qualitative case study research design was used as it permits the grouping of detailed information essential to making sense of the anticipated responses of the participants. This study was informed by Vygotsky’s sociocultural theory and Cultural-Historical Activity Theory (CHAT). It was conducted at a township school in the Eastern Cape, South Africa. Forty-five Grade 11 Life Sciences learners, two Indigenous Knowledge Custodians (IKCs) who grew up in marine environments and a local fisherman were participants in this study. Additionally, I asked one science teacher to be a critical friend. Data sets were gathered using a group activity, focus group interviews (sharing circles), observations (participatory and lesson observations), stimulated recall interviews and learners’ reflections. The sociocultural theory was used as a lens to find out how learners learn through social interactions and how learning takes place in a sociocultural context. I augmented this theory with CHAT as an analytical framework. The CHAT provided an analytical lens to understand how community involvement and IKC interventions supported learner talk and sense making of the content and facilitated meaningful learning. The main findings of the study revealed that during the IKCs’ presentations, learners were able to identify science concepts embedded in the Indigenous Knowledge of marine biodiversity conservation. The findings further revealed that the presentations stimulated learner talk and improved sense making among learners regarding marine biodiversity conservation and related concepts. The study recommends that teachers should leverage IKCs’ cultural heritage by inviting them into classrooms to make science more relevant, accessible and meaningful for learners. , Thesis (MEd) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Bushmeat hunting and use by rural communities living adjacent to indigenous forests in the Eastern Cape

Authors: Martins, Vusumzi
Date: 2025-04-03
Subjects: Wildlife as food South Africa Eastern Cape , Forests and forestry South Africa , Hunting South Africa , Local ecological knowledge , Forest management South Africa , Sustainability , Social ecology
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479930 , vital:78381 , DOI 10.21504/10962/479930
Description: The use of forest wild species directly contributes to the well-being of billions of people globally and is particularly important to people living in vulnerable situations. Rural, indigenous communities have harvested a variety of timber and non-timber forest products (NTFPs) for millennia and still do to date. For these people, forests provide many products and benefits such as food, medicine, fuelwood and a source of income from trade in these items. In South Africa, a large number of studies have investigated the harvesting and use of NTFPs, highlighting their importance to rural and urban communities. Additionaly, the hunting of wild mammals occurs throughout the Afro-temperate forests of South Africa. Yet, no comprehensive study has been conducted on the hunting and use of wild forest mammals in the region. I sought to investigate the motivations, extent and impact of local hunting in the indigenous forests of the Eastern Cape. I hypothesize that in the region hunting is not a primary source of nutrition or income, but it continues to hold cultural significance, reflecting deep-rooted traditions within these communities. Understanding bushmeat hunting and use in the region is key to guiding sustainable management and assessing the need for policy adjustments. The current study firstly provides a detailed evaluation of NTFPs harvesting and use, highlighting the livelihood benefits associated with bushmeat hunting by investigating bushmeat hunting patterns and consumption by rural communities surrounding forest patches in the Eastern Cape province, South Africa. Here bushmeat hunting refers to the informal hunting of wild mammals by rural communities, primarily for subsistence consumption. While often organised and small-scale, it is shaped by local ecological knowledge, cultural traditions, and resource availability. The practice occurs within a complex illegal and socio-economic landscape, where access to alternative protein sources, conservation regulations, and historical land-use patterns influence its prevalence and significance. To assess NTFP harvesting and bushmeat hunting, 12 villages at different proximities to forests were selected around the province. Using a quantitative approach in the form of guided, semi-structured interviews, data on the extraction and use of NTFPs, bushmeat hunting, frequency of bushmeat consumption, general protein consumption and food security of each household were solicited. Only 16% of the households attested to hunting in the 12 months prior to the survey, with all these households including an active hunter. Though 64% of the interviewed head of households mentioned that they had consumed bushmeat in the past year, these were mostly men, only 12% percent mentioned that the hunter in the household brought their catch home and consumed the meat with their families. Hunters mostly consumed their catch with other hunters, non-hunting males and young boys. Hence the study concluded that bushmeat consumption was not an important livelihood strategy nor food source of rural people but instead plays a significant social and cultural role in the region. I also provide comprehensive insights into bushmeat hunting practices in the province. Though conducting in-depth questionnaire surveys with self-identifying hunters from the 12 villages I was able to determine the motivations, methods and perceptions behind bushmeat hunting. A total of 147 hunter interviews were conducted. All the interviewees were male, with a mean age of 32 ± 9 years. The primary motivations behind bushmeat hunting were culture (40%), sport/competition (33%) and recreational purposes (20%). Contrary to hunting in the tropics, only 4% mentioned that they hunt for income. Most of the hunters (44%) used mixed hunting methods. This involved setting up or checking snares whilst hunting with dogs and sticks, 27% only used dogs and sticks and 17% only used snares. Hunters reported ten mammal species caught in forests of the Eastern Cape in the last 12 months. Bushbuck (Tragelaphus scriptus), Common duiker (Sylvicapra grimmia) and Cape porcupine (Hystrix africaeaustralis) were the most hunted species. All the hunters acknowledged that hunting was an illegal activity and if caught they could be arrested. The study further presents a thorough assessment of forest mammal species diversity under hunting pressure. Evidence suggests that higher hunting occurs in communal land forests compared to forests on protected or privately owned land. Hence, data on species richness and abundance within fenced protected forests and neighbouring unfenced communal forests was acquired using a mixed-methods approach in the form of ecological line transects and local ecological knowledge (LEK) surveys. The line transects revealed a mean mammal species richness of 7.6 ±1.3 in the protected forests, 5.3 ±1.4 in the Afromontane communal forests and 3.3 ±1.6 in the Coastal communal forests. The Afromontane and Coastal communal forests had a mean species abundance of 12.1 ± 5.4 and 6.5 ± 5.0, per forest respectively, whilst the protected forests had a mean species abundance of 18.0 ± 7.0. During the LEK surveys hunters from villages close to the forests reported more species (8.9 ±1.7) than those from far villages (7.3 ± 1.2). The regular forest users reported a mean species richness of 5.5 ± 1.2 and the local experts from the protected forests reporting a mean species richness of 13.4 ± 0.7. The study demonstrates the importance of mixed-methods approach in wildlife research and sustainable natural resource use. The current study clearly shows that protected areas support higher biodiversity and that local forest users’ knowledge aligns well with ecological data. Lastly, I present a social-ecological assessment of bushmeat hunting in the forests of the Eastern Cape. The use of traditional biological sustainability indices have proved inadequate for measuring the impact of bushmeat hunting because sustainability is treated as a static, binary question, thus ignoring stochastic processes, the inherent variability of natural systems, and the complexity of hunting systems. I hence used a combination of social and ecological methods to gain insights on how the offtake of forest mammal species affected species density in the communal forests of the Eastern Cape and also how this influenced hunting practices and behaviour. The density estimates of the hunted mammal fauna in the communal forests was significantly less (50%) than in the protected forests in the region. Also, the density estimates for the five most hunted mammal species in the communal forests were significantly lower (15%) than density estimates reported in the literature. Additionally, participatory hunter interviews revealed a decline in catch per unit effort and harvest rates over the past 10 years. This decline resulted in changes in the hunting strategies and patterns of many hunters. I argue that bushmeat hunting systems should be regarded as social-ecological systems in which the animal populations are not the only focus. Instead, understanding the complex and dynamic relationships between the hunting ground, its resources, the stakeholders, and the different exogenous drivers of change that affect these components yields a better interpretation of sustainability. The current study contributes to the growing knowledge of bushmeat hunting and use in the country and also provides novel findings on the sustainability of bushmeat hunting in the forests of the Eastern Cape. Here I provide an all-inclusive appraisal of bushmeat hunting and use by rural communities living adjacent to biodiversity-rich indigenous forests. The study provides in-depth insights on household bushmeat use, hunting practices and motivations of hunters and the effect of hunting on mammalian forest fauna. Furthermore, the study provides a novel approach to determining the sustainability of bushmeat hunting by using mixed social and ecological methods. The study can be used as a model for other studies assessing bushmeat hunting elsewhere in the country. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2025
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Date Issued: 2025-04-03

Creating access to powerful knowledge in accounting education: a case study of pedagogies used in an accountancy diploma

Authors: West, Janét
Date: 2025-04-03
Subjects: Accounting Study and teaching South Africa , Educational change , Knowledge, Theory of , Critical thinking , Semantics
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480062 , vital:78393 , DOI 10.21504/10962/480062
Description: Students enter universities to obtain a qualification that they believe will enhance their chances of employment and thereby a better future. But the World Economic Forum states that the world of work is changing so fast that 75% of companies are not prepared for the pace at which their industries are changing. The field of accounting, and accounting education in particular, is facing significant challenges as accountants change from being ‘number crunchers’ to engaging business partners. There is also a decrease in the demand for accountants, at the same time as increasing complaints that accounting graduates are unprepared for their work. These contextual challenges raise the question of ‘What can higher education institutions do to prepare students for a future of rapid change and uncertainty, specifically within the field of accounting?’ This study argues that epistemological access to powerful knowledge is essential for creating lifelong learners that can adapt to change. The study draws on Legitimation Code Theory (LCT) to visualise the powerful knowledge that students require access to in two thirdyear modules within a Diploma of Accounting. This is followed by an analysis of the pedagogies used in the two modules and how access to powerful knowledge is enabled (or hindered) through the pedagogical practices. Data include lecturer observations, course documents and interviews. The study found that there are significant differences between the knowledge structures of the modules, despite them being part of the same discipline. Furthermore, through the analysis I was able to identify key patterns in the pedagogies that enable access to powerful knowledge as well as pedagogical approaches that may constrain access to powerful knowledge. The findings of this study can help accounting lecturers as well as lecturers in similar disciplines to consider how their pedagogical practices enable epistemological access to the target powerful knowledge of their discipline. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2025
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Date Issued: 2025-04-03

Developing the behaviours that we value in physics knowers through implementing aspects of the Investigative Science Learning Environment (ISLE) approach in a South African high school

Authors: Cobbing, Kathleen Margaret
Date: 2025-04-03
Subjects: Science Study and teaching (Secondary) South Africa , Knowledge, Theory of , Reflective learning , Critical thinking , Action research in education
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479874 , vital:78375 , DOI 10.21504/10962/479874
Description: Situated in Physics Education Research, this study focused on physics learning through the Investigative Science Learning Environment (ISLE) approach. The ISLE approach is underpinned by the belief that students should learn physics through doing physics, and that all aspects of the learning experience should seek to enhance student well-being. The ISLE approach was introduced in the physics classrooms of two, well-resourced, independent South African high schools. Physics provides a context in which to develop behaviours that assist learning and that promote a learning-orientated mindset. Physics students need to be able to (i) actively engage to facilitate learning, (ii) connect the domains of a problem to construct a coherent knowledge structure, (iii) transfer their understanding of a concept to a new context, and (iv) grapple with concepts and problems. These behaviours, which are valued in physics students, should be modelled through activities so that students can be trained to adopt these practices. The Specialization dimension of Legitimation Code Theory (LCT) was used as the analytical framework for this study and translation devices were developed and used to code the activities in terms of the behaviours that they value. Both quantitative and qualitative data were collected in a mixed methods approach, and inductively determined codes were thematically analysed. The ISLE activities, as well as activities that were developed, based on ISLE principles, were found to legitimate the behaviours that we value in physics knowers. The student experience of the ISLE approach demonstrated the development of these behaviours for many students, although there remained a strong emphasis on performance. Activities that model all four of the valued behaviours were particularly effective. , Thesis (PhD) -- Faculty of Humanities, Physics and Electronics, 2025
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Date Issued: 2025-04-03

Enhancing Grade 12 physical sciences teachers’ pedagogical content knowledge to teach work, energy, and power bilingually in the Eastern Cape

Authors: Mapfumo, Alfred Khumbulani
Date: 2025-04-03
Subjects: Science Study and teaching (Secondary) South Africa , Pedagogical content knowledge , Translanguaging (Linguistics) , Professional learning communities , Social learning
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480073 , vital:78394 , DOI 10.21504/10962/480073
Description: South Africa has been performing very poorly in consecutive Trends in International Mathematics and Science Study (TIMSS) in Science and Mathematics, where it has been ranked last among all participating countries. Similarly, in the recent National Senior Certificate examinations (2017–2023), the percentage of candidates who scored at least 40% in Physical Sciences ranged from 39% to 51%. This points to a possible problem in the teaching and learning of Physical Sciences in schools. On close analysis, the question on the topic of Work, Energy, and Power, in particular, is usually one of the most poorly answered in the Physics paper of the Physical Sciences examination. Some South African studies have concluded that there is poor mastery of the energy concept in the Further Education and Training Phase by both learners and teachers. Against this backdrop, this formative interventionist study sought to support Grade 12 Physical Sciences teachers in co-developing and enacting exemplar lessons on Work, Energy and Power that incorporate everyday and home language through pedagogical translanguaging and transknowledging. The five teachers from township and rural schools and I formed a Professional Learning Community (PLC) to co-develop lessons later enacted by the teachers. The study was underpinned by an interpretivist paradigm and complemented by the critical theory paradigm. A qualitative case study research design was employed. Data were gathered using semi-structured interviews, document analysis, workshops, lesson observations and participant-teacher reflections. Vygotsky’s sociocultural theory was my theoretical framework, while Mavhunga and Rollnick’s five components of Topic-Specific Pedagogical Content Knowledge were used as an analytical lens. An inductive-deductive approach to data analysis was used. This study demonstrated how teachers in a PLC can work together to develop their individual pedagogical content knowledge in particular practice areas. The PLC created lesson plans that guided their use of pedagogical translanguaging techniques, such as code-switching, code-mixing, translation, and versioning of scientific terminology, to facilitate learning. In addition, the PLC created an IsiXhosa glossary for concepts related to Work, Energy, and Power. The study’s main contribution is that teachers involved in this study displayed transformative agency through co-constructing their pedagogical content knowledge (PCK) for pedagogical translanguaging. The study thus recommends that if the goal of improving epistemological access for learners who are learning Physical Sciences in a second language is to be realised, in-service teachers should be capacitated to apply pedagogical translanguaging, which brings about transknowledging using PLCs such as the one-formed for this study. , Thesis (PhD) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Enhancing the effectiveness of the Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) sterile insect technique release programme

Authors: Githae, Michael Mathenge
Date: 2025-04-03
Subjects: False codling moth , Cryptophlebia leucotreta , Insect sterilization , Pests Integrated control , Insect populations , Parasitism , Fruit Diseases and pests
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479897 , vital:78377 , DOI 10.21504/10962/479897
Description: The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is a key phytosanitary pest in the South African citrus industry. Due to its cryptic nature and its endemic presence in sub-Saharan Africa with a wide array of host plants, and eradication is not possible. However, the sterile insect technique (SIT) has been incorporated into an Area-Wide Integrated Pest Management (AW-IPM) programme to induce widespread population suppression. The successful implementation of the SIT programme required a series of well-researched phases, with one key phase being the determination of an effective overflooding ratio, previously established at 10:1. Despite this, various studies of T. leucotreta SIT programmes have reported higher release ratios than 10:1 in orchards, necessitating an investigation into their efficacy. This thesis aimed to understand the effects of higher release ratios, different combinations of sterile and fertile T. leucotreta of both sexes, compatibility of SIT and the egg parasitoid Trichogrammatoidea cryptophlebiae, and the pre-release mating levels during production and release stages to improve the effectiveness of the T. leucotreta SIT programme. This study initially investigated the impact of different ratios of sterile and fertile adults on fruit damage, sterile male competitiveness, and population growth in laboratory cages using Washington Navel oranges. Sterilised to fertile T. leucotreta adults at ratios of 0:1 (control), 10:1, 20:1, 40:1, and 60:1 were placed inside insect-rearing cages and allowed to mate, oviposit and infest the fruit. Treatment cages receiving sterile T. leucotreta produced significantly fewer damaged fruit, larval entries, and F1 adults compared to the control. The number of damaged fruit, larval entries, and F1 adults negatively correlated with the increase in the overflooding ratio of sterile to fertile T. leucotreta. Control cages had significantly higher fecundity and fertility compared to treatment cages. The 60:1 ratio exhibited the lowest per generation rate of increase (<1× from the parental [P1] to the F1 generation) compared to the 10:1 ratio (current release ratio). The effects of different combinations of both treated (T) and untreated (U) male (M) and female (F) adult T. leucotreta: UM×UF (control), TM×UF, UM×TF, TM×TF, and UM×UF×TM×TF on fruit damage, mating competitiveness, and per-generation rate of increase were tested. The treatments were housed in insect-rearing cages containing Navel oranges and allowed to mate, oviposit, and infest the fruit. Treatment cages with both treated male and female T. leucotreta had significantly fewer damaged fruit, larval entries, and emerged F1 adults compared to the control cages, except for the UM×UF×TM×TF combination. Similarly, control cages and UM×UF×TM×TF treatments had significantly Higher fecundity and fertility compared to other treatments. The TM×UF combination exhibited the lowest rate of increase per generation (<0.57× from the parental [P1] to F1 generation). A field cage study was conducted to evaluate the effects of various overflooding ratios and different combinations of sterile and fertile male and female T. leucotreta. However, the results were limited, and inconclusive due to collection of insufficient data, as the fruit infestation level was low. This could be attributed to the low quality of the moths released or effects of environmental variables on the moths. A laboratory study explored the susceptibility of T. leucotreta eggs resulting from various pairings of sterile and fertile moths to parasitism by Trichogrammatoidea cryptophlebiae. The ratios of sterile to fertile T. leucotreta used were: 0:1, 10:1, 20:1, 40:1, and 60:1. The resulting eggs were then exposed to T. cryptophlebiae for parasitism, and the parasitism rates of newly laid (24 h), 48 h and 72 h old eggs were evaluated. Overall, eggs from all ratios were suitable for T. cryptophlebiae development and acceptable for oviposition. Significantly higher number of parasitised eggs were recorded between the control (0:1) and ratios 40:1 and 60:1 at 48 h old eggs. Additionally, a higher proportion of flying T. cryptophlebiae emerged across the ratios, with a higher proportion of female-to-male sex ratio. Pre-release mating levels were studied during the production and release stages, divided into three stages: moth eclosion, irradiation, and release. A significantly higher number of spermatophores and percentages of mated female T. leucotreta were recorded at the eclosion and irradiation stages in January. Similarly, in May, a significantly higher number of spermatophores and percentages of mated female T. leucotreta were recoded post-irradiation and release stages in the Sundays River Valley region (SRV). Overall results indicated more spermatophores and percentages of mated female T. leucotreta at the irradiation and release stages in the SRV region. In conclusion, the study demonstrated that a release ratio exceeding 40:1 and different combinations of sterile and fertile T. leucotreta, especially the TM×UF combination, has a suppressive effect against T. leucotreta and integrating SIT with T. cryptophlebiae, shows potential for enhancing the effectiveness of the T. leucotreta SIT programme. Additionally, the mating competitiveness of sterile insects in dual-sex releases can be improved by controlling the level of pre-release matings. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2025
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Date Issued: 2025-04-03

Evaluating social effects of arable field abandonment in communal areas of South Africa

Authors: Pokwana, Sihle
Date: 2025-04-03
Subjects: Arable land , Land abandonment , Livelihood , Rural conditions , Food security South Africa , Land cover , South Africa Economic conditions
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479941 , vital:78382 , DOI 10.21504/10962/479941
Description: The phenomenon of arable field abandonment, a complex and multifaceted aspect of land use dynamics, has become a subject of increasing significance in rural landscapes. Across diverse geographic contexts, the abandonment of once-cultivated fields is indicative of transformative shifts in agricultural practices, reflecting the interplay of numerous socio-economic, environmental, and cultural factors. The abandonment of arable fields in the former homelands of the Eastern Cape and KwaZulu-Natal poses a multifaceted challenge with significant social implications. Historically, agriculture has been central to these regions, yet recent trends show a shift from traditional field cultivation to alternative practices such as garden cultivation or complete cessation. This shift has heightened vulnerability to food insecurity, hunger, and poverty, particularly as high unemployment levels exacerbate the situation. Moreover, the intricate relationships between humans and their surrounding ecosystems is also affected. Therefore, understanding the drivers of arable field abandonment at the community or household level can reveal localised factors that differ from broader, generalised drivers identified in previous studies. Additionally, examining the diverse impacts on these communities is crucial for developing targeted interventions that address their specific needs and enhance resilience. This study investigates arable field abandonment in specific villages of Gotyibeni and Melani in the Eastern Cape and Manqorholweni and Mawane, in KwaZulu-Natal. Using the Driving forces, Pressures, State, Impacts, and Responses (DPSIR) framework as a conceptual framework uncovers the driving factors, pressures, state, impacts and responses of this phenomenon in these rural villages. The study’s main aim was to assess the social effects of arable field abandonment in the selected study areas. The main objective is to determine how livelihoods, social relationships, and living conditions within and between households have changed following the cessation of field cultivation. The study also employed several specific objectives: first, to identify trends in field cultivation within the study areas; second, to analyse the drivers contributing to arable field abandonment in the villages; third, to examine the impact of field abandonment on the elderly population over the past 50 years; and fourth, to investigate the level of youth engagement in agriculture, including how the abandonment of arable fields affects their participation and perceptions of agriculture as a livelihood. To achieve the objectives the study employed mixed research methods that combine satellite imagery analysis, household surveys, oral history interviews with elders, most of whom had stopped farming, and youth focus group discussions. Landsat 7 Satellite imagery with a 15-meter spatial resolution was sourced from the South African Space Agency (SANSA) for the four study areas. The temporal coverage spanned from 1972 to 2020, with considerations for image usability based on resolution. Unfortunately, many earlier images were deemed unusable due to low resolution, particularly affecting Gotyibeni, where clear images only became available from 2013, therefore for this village the focus was on two decades. Arable fields, residential areas, homestead gardens, grasslands, and shrublands were classified. Change detection utilised a post-classification approach, comparing land cover categories between the early and late 2000s. A change detection matrix and statistics were generated using a ha/year formula, enabling the quantification of land cover changes. Image analysis employed ArcGIS 10.8.1 software for mapping and classification, involving georeferencing, signature file creation, maximum likelihood classification, and conversion from raster to vector formats for area calculations. For the LULC change matrix, an intersection analysis in ArcGIS overlaid data from different time points, and a pivot table in Excel organised resulting data. A focus on arable land changes, particularly conversions to other land uses, was crucial, as the study is investigating the level of arable field abandonment in these areas, understanding how much arable land has been converted or remained unchanged provides a clear indication of the extent of abandonment. To understand driving forces of arable field abandonment, a semi-structured questionnaire was developed based on the Driving forces, Pressures, States, Impacts, and Responses (DPSIR) framework. The questionnaires were administered through household interviews conducted in the four study villages. Sections of the questionnaire covered household involvement in cropping, perceptions of land use change, abandonment of field cultivation, and socio-economic demographics. Sampling involved a random selection of 20% of total households in each village, with data analysis performed using Statistical Package for Social Sciences (SPSS). Chi-square tests and Kruskal-Wallis analysis were employed to assess differences between villages. A second questionnaire specifically targeting households that had abandoned field cultivation was also done. Ninety-seven interviews were conducted to evaluate economic, health, socio-cultural and environmental impacts from respondents that indicated to have ceased field cultivation. Data analysis through SPSS utilised descriptive statistics and chi-square tests to identify statistically significant differences between villages. Oral histories were collected from elderly individuals in each village from a sample size of 15 individuals who were previous cultivators of fields, selected with the assistance of a village leader. The selected elders provided qualitative insights into historical and contemporary experiential aspects of village life. The focus was on changes in village relations, the environment, generational values, and traditional farming practices in each village. Youth-focused group discussions were organised with 30 young people in the village between the ages of 18-35, covering topics such as youth goals, the importance of field cultivation, and perceptions of the future. Both the oral histories and focus group discussions conducted in the local languages, were tape-recorded, transcribed, and subjected to content analysis to identify and interpret themes and patterns. The approach involved coding sentences, grouping codes into sub-themes, and further organising them into categories and subcategories. The LULC change results showed a consistent trend of significant arable land reduction across all villages, accompanied by a notable increase in grassland cover. Manqorholweni experienced the most significant loss of these arable fields. This finding was further supported by the household interviews which revealed 100% abandonment of fields in this village. Grasslands emerged as the dominant land cover in all villages, overtaking arable fields and homestead gardens. Regarding field abandonment, 76% of households across villages left fields unused for over 19 years due to reasons including lack of fencing, animal damage to crops, and financial constraints, despite recognising the socio-economic importance of field cultivation. Respondents expressed interest in returning to cultivation if the state would assist with fencing materials and costs. Concerns such as loss of cultural identity due to field abandonment were raised, especially in Manqorholweni, Mawane, and Melani. Homestead gardens were identified as a compensating strategy, with 78% of respondents actively maintaining them, although LULC change results indicated a decline, except in Mawane. Field cultivation revealed gender, age, and educational disparities, with non-cropping households having more female heads, individuals above 55, and higher proportions with only primary education. Households that abandoned field cultivation reported a decline in economic stability, with 97% experiencing less stable household economic circumstances. Unemployment was prevalent, with over 70% relying on social grants, creating financial challenges for 76% lacking sufficient cash. Limited off-farm formal employment (20%) was observed, while remittances played a minor role, this resulted in insufficient monthly income, affecting 94% of respondents. Dietary diversity declined, and reliance on store-bought food led to health concerns. Field abandonment impacted family dynamics, altering power relationships and reducing interaction, also heightened by COVID-19, affecting cultural identity and community cohesion. Youth across villages were not currently engaged in field cultivation or farming but expressed interest in revitalising agriculture. They recognised the socio-economic significance of agriculture and highlighted the importance of capital, resources, and government support. Challenges for youth involvement included lack of information, absence of agricultural advisors, and disparities in access to credit. Lack of support from elders and limited sharing of agricultural knowledge further hindered youth's ability to initiate farming projects. In conclusion, this study highlights the significant issue of arable field abandonment in rural areas of the Eastern Cape and KwaZulu-Natal, reflecting broader socio-economic and environmental transformations. The consistent reduction in arable land across the studied villages, coupled with the rise in grassland cover, underscores a critical shift from traditional agricultural practices to alternative land uses. The abandonment of fields has had profound impacts on community livelihoods, leading to decreased economic stability, reduced dietary diversity, and weakened social and cultural ties. The findings reveal a clear need for targeted interventions to address the specific challenges faced by these communities, particularly regarding food security and economic resilience. To address the challenges of arable field abandonment, it is crucial to implement a multi-faceted support program. This should include providing essential resources such as fencing, irrigation systems, and agricultural tools to facilitate field cultivation. Additionally, engaging and supporting youth in agriculture through training, access to advisors, and financial aid is vital to revitalise interest in farming. Strengthening social safety nets by enhancing financial support systems can mitigate economic challenges faced by affected households. Furthermore, initiating cultural and educational programs to preserve traditional farming knowledge while integrating modern practices will help maintain cultural identity and community cohesion. These measures are key to improving resilience and livelihoods in the context of field abandonment. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2025
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Date Issued: 2025-04-03

Exploring academics’ experiences of the research ethical clearance process: a case study of a South African university

Authors: Manqele, Siyanda Mabutho Dominic
Date: 2025-04-03
Subjects: Research Moral and ethical aspects , Graduate students Control South Africa , Compliance , Trust , Community engagement
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/480029 , vital:78390
Description: This study explores the experiences of academics regarding the research ethical clearance process at a South African university, aiming to identify key challenges and opportunities for improvement. The rationale behind this investigation stems from the increasing emphasis on ethical considerations in research, alongside the potential barriers that may hinder academics from navigating the clearance process effectively. The research questions focus on understanding the perceptions of academic staff concerning compliance, trust in the ethical review process, and the role of education and community engagement in facilitating ethical research practices. Utilising qualitative research methods approach, this study employed thematic analysis alongside qualitative methods, involving semi-structured interviews with 14 academic staff members from six faculties, all possessing a minimum of five years of experience in research and postgraduate supervision. The thematic analysis revealed several critical themes, including compliance challenges, trust and mistrust in the ethical clearance process, the necessity of education and awareness, and the significance of community engagement in fostering a supportive research environment. The findings indicate that compliance with ethical standards is often perceived as burdensome, leading to frustration among academics. Trust issues emerged, highlighting a perceived disconnect between researchers and the ethical review board, which can undermine the integrity of the clearance process. The study underscores the importance of enhancing education and awareness regarding ethical guidelines, suggesting that targeted training programmes could improve understanding and adherence among researchers. Community engagement also emerged as a vital element, with recommendations for fostering collaborative relationships between the university and local communities to enhance ethical research practices. The implications of this study point toward the necessity for universities to reevaluate their ethical clearance processes, promoting transparency, trust, and collaboration. By addressing the identified challenges and fostering a culture of ethical research, universities can support their academics in conducting research that is not only compliant but also socially responsible. Future research could further explore the perspectives of ethical review board members to gain a comprehensive understanding of the ethical clearance landscape. , Thesis (MEd) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2025
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Date Issued: 2025-04-03

Exploring Foundation Phase pre-service teachers’ mathematical pedagogical content knowledge for teaching additive mental mathematics strategies

Authors: Kumm, Marisa Luisa
Date: 2025-04-03
Subjects: Pedagogical content knowledge , Mathematics Study and teaching (Primary) South Africa , Pre-service teacher education , Student teachers South Africa , Addition Study and teaching (Elementary) , Number concept Study and teaching (Elementary)
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/480018 , vital:78389
Description: Poor learner performance in mathematics remains a concern in South African primary and secondary education according to continuous national and international assessments. Many learners fall behind in the early grades without being provided the opportunity to establish a solid foundational number sense. This is an essential requirement to progress into the higher grades. Addressing the challenges of number sense in the Foundation Phase is mandatory. This study aimed to investigate third-year Foundation Phase pre-service teachers’ content knowledge and pedagogical content knowledge of their additive reasoning strategies (a key aspect of number sense) at a private teacher education institution, guided by the question: What content knowledge and pedagogical content knowledge do third-year Foundation Phase pre-service teachers have of additive reasoning mental mathematics strategies? Several researchers have identified the need to develop pre-service teachers’ mathematical content knowledge and pedagogical content knowledge. This study was guided by Shulman’s (1986) constructs of teacher knowledge. This qualitative, descriptive study, which formed part of the Mental Mathematics – Work Integrated Learning (MM-WIL) programme, collected data from an interpretivist perspective. The information for this study was gathered from participants who agreed to be part of the study. The study collected data through pre- and post-intervention questionnaires that had two parts. The first part assessed pre-service teachers’ methods of solving four basic additive reasoning calculations (that lent themselves to using the strategies of bridging through ten, jump strategy, and rounding and adjusting). The second part of the questionnaire asked pre-service teachers to describe these strategies and how they would teach them, with the aim of understanding their additive reasoning skills and ability to use and teach these mental strategies. Key findings are that many pre-service teachers do not have the content knowledge to solve basic calculations using efficient methods. These are skills that they are required to teach in the Foundation Phase classroom. The findings in this study highlight the urgent need to address the weak content knowledge, pedagogical content knowledge and inefficient unit based counting methods of many pre-service teachers to improve learners’ development and fundamental understanding of numbers that allows for flexible and efficient calculation. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2025
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Date Issued: 2025-04-03

Exploring organisational learning in water resource protection: activity system analysis of social learning among resource directed measures role-players in South Africa

Authors: Thwala, Mmaphefo Doreen
Date: 2025-04-03
Subjects: Social learning , Organizational learning , Soft systems methodology , Water-supply Management , Cultural-historical activity theory
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480117 , vital:78398 , DOI 10.21504/10962/480117
Description: Globally, there are policy and practice efforts to mainstream inclusive education in different sub-fields of education. Part of the efforts have focused on investigating and finding practical mechanisms for the mainstreaming process in teacher education. Anecdotally, Education for Sustainable Development (ESD), with its focus on transformative education, collaborative learning, the community of practice and the whole institution approach, has the potential to mainstream inclusive education in teacher education practices if grounded in sociocultural realities rather than mere ideological framing. This situation is related to the need for more transformative capabilities for teacher educators to prepare teachers for inclusive pedagogical proficiency. However, in a southern African context, the outlook of the potential of pedagogical proficiency from the nexus of inclusive education, ESD and teacher education is disjointed. As such, this study focused on investigating the mainstreaming of inclusive education in teacher education practice for pedagogical proficiency through ESD Change Projects in Southern Africa, examining cases from Malawi, Tanzania and Eswatini. The study intended to gain an understanding of inclusive education and ESD in these countries, identify areas for strengthening inclusive education in teacher education practice, collaborate with teacher educators to develop strategies for mainstreaming inclusive education, and generate indicators for monitoring and evaluating inclusive education in teacher education contexts. The study used Urie Bronfenbrenner’s bioecological theory of human development and Lev Vygotsky’s sociocultural theory of learning as theoretical and analytical frameworks. The study also employed Roy Bhaskar’s critical realism philosophy as an underlabourer or a meta-theoretical framework. The study further adapted the Vygotsky-informed Engestrom’s expansive learning as a methodological torch. Together, these frameworks were used to analyse selected Change Projects within Sustainability Starts with Teachers (SST) programme, which focused on ESD capacity building in teacher educators from 11 southern African countries. In this regard, the research utilised a qualitative nested case study design. A formative interventionist research approach supported the cases in Malawi, Tanzania and Eswatini, with the study selecting SST Change Projects dealing with inclusive education through an initial scoping questionnaire. Data were generated through 12 in-depth interviews, nine workshops (involving 24 participants), document reviews, observations and reflective journals. Thematic ii analysis, employing a critical realist approach with abductive and retroductive reasoning, guided the reflexive presentation and discussion of research findings. The research findings revealed a common understanding of inclusive education as providing equal educational opportunities, ESD as supporting sustainable development, and teacher education as skill development. The research findings also highlighted the influence of teacher educators’ biopsychosocial characteristics on their perceptions of inclusive education, ESD and teacher education. Areas requiring improvement in teacher education systems included resources, attitude change, financing, cooperation, collaboration and leadership. Strategies for mainstreaming inclusive education in teacher education practice for pedagogical proficiency included curriculum implementation, policy shift, contextualisation and interactive systems. Monitoring and evaluation in all three cases focused on teaching practice, assessment, feedback tools, forums and curriculum implementation, but the absence of specific indicators for monitoring and evaluation was evident. These findings suggest multi-layered and complex implications for policy formulation, implementation practices and future research. Therefore, this thesis argues that, in a southern Africa context, the potential of pedagogical proficiency from the nexus of inclusive education, ESD and teacher education involves considering biopsychosocial characteristics to facilitate the capabilities of teacher educators. This situation necessitates utilising inclusivity mechanisms in pre-service teacher training grounded in biosocial and psychocultural realities of the region’s educational challenges. Consequently, this thesis proffers the Sustainable Inclusive Pedagogical Proficiency Process (SIP3) model as a framework to actualise the nexus of inclusive education, ESD and teacher education, and bring into focus its pedagogical proficiency potential which eventually helps with the mainstreaming process in teacher education practice via ESD. The study reported in this thesis contributes to international theory and practice development for inclusivity and ESD in teacher education practice, provides indicators for monitoring inclusive quality education in teacher education practice, and introduces a contextual dynamics model for comparative education research. The thesis is structured in eight chapters, introducing the study context, addressing literature gaps, presenting the theoretical framework, detailing research design, exploring specific cases in Malawi, Tanzania and Eswatini, discussing the research findings and its implications, and concluding with recommendations for change and future research. , Thesis (PhD) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Exploring pedagogical translanguaging practices used by ESL primary school teachers to enhance reading comprehension

Authors: Mufori, Selma Ndagwedhapo
Date: 2025-04-03
Subjects: English as a second or foreign language , Translanguaging (Linguistics) , Reading comprehension , Reading comprehension Study and teaching Namibia , Fourth grade (Education) Namibia
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/479985 , vital:78386 , https://doi.org/10.21504/RUR.28955792.v1
Description: Namibia has decided to use English as the transitional language and medium of instruction for Grade 4, even though learners have been performing poorly in English Second Language (ESL). Despite various interventions being recommended to address this issue, there has been little success. One teaching approach that experienced ESL teachers may use to enhance reading comprehension is pedagogical translanguaging. However, there is a lack of research exploring the use of this approach in Namibian primary schools, particularly in Grade 4. To address this gap, this study was conducted to investigate the pedagogical translanguaging practices employed by Grade 4 ESL primary school teachers in Namibia to improve reading comprehension. A qualitative exploratory case study oriented to an interpretivist paradigm was conducted. Purposive sampling was used to select five Grade 4 ESL teachers from the Oshikoto region for the study. Data were collected using simulated recall interviews, non-participant observation and document analysis. The data were analysed using an inductive thematic framework. The study showed that using simplified language, gestures, and pictures helped ESL teachers communicate with their learners and improve reading comprehension. The use of visual aids such as picture-rich texts, drawings, sketches and concrete materials (realia) also helped Grade 4 ESL learners in their reading comprehension. This visual support helped in vocabulary acquisition and reinforced the meaning of words through associations with images, leading to a better understanding of the language. The study also found that including drawings and sketches in reading lessons added a layer of pedagogical depth that aligned with learners' cultural backgrounds. This helped teachers to engage with their learners more deeply and promoted a sense of cultural inclusivity in the ESL classroom. The study found that teachers use Oshindonga, the learners’ mother tongue, to communicate with those who struggle with English or find it challenging to understand ESL texts. The study revealed that when teachers encouraged learners to use their mother tongue, they became more active and asked questions for clarity. Moreover, the study revealed that code-switching and language brokering, where Grade 4 emergent ESL learners and the ESL teacher translate or interpret using both the learners' native language and ESL, helped increase learner engagement and comprehension. The findings suggest that using translanguaging practices can enhance comprehension, support learners with special needs and assist in the overall learning and understanding of ESL. Furthermore, the study concluded that Grade 4 ESL teachers employ translanguaging procedures in an unplanned manner, perceiving the use of the mother tongue as a spontaneous action carried out when circumstances require it. This study recommends incorporating translanguaging into the official language policy and the National Curriculum for Basic Education as a means of instruction in ESL classrooms. This official endorsement would guarantee the integration of translanguaging across schools and support consistent language learning. The formalisation and endorsement of translanguaging in the official language policy would prove its success and encourage ESL teachers to utilise it. , Thesis (MEd) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Exploring the development of computational thinking among pre-service teachers using visual programming: an interventionist case study

Authors: Sepula, Chikondi
Date: 2025-04-03
Subjects: Computational thinking , Visual programming (Computer science) , Sociocultural perspective , Problem solving , Scratch (Computer program language) , Student teachers South Africa
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/479996 , vital:78387
Description: Due to its cognitive effect on learners, computational thinking (CT) has gained significant attention and has been increasingly integrated into primary and secondary education worldwide. The integration of CT into educational curricula offers several benefits, including improved learning outcomes, enhanced problem-solving abilities, and the development of skills necessary for the digital landscape of the 21st century. Recognizing these benefits, South Africa introduced CT in primary schools in 2023 through a dedicated subject, coding and robotics. However, teacher upskilling remains a major challenge, as many teachers lack the necessary skills to teach this subject effectively. This problem is particularly pronounced at the foundational phase, where delivering similar content to young learners presents additional pedagogical complexities. Thus, this study explored the development of CT skills with visual programming among foundational phase pre-service teachers. Situated within the interpretive paradigm, a qualitative case study methodology was employed, owing to its effectiveness in exploring contextual factors and complexities that influence human experiences. The study involved 49 first-year pre-service teachers in an Introduction to Technology module at Rhodes University. Purposive sampling was used to select the foundational phase pre-service teachers at Rhodes University. Data was collected using CT reflective tool, semi-structured interviews, focus-group discussions, and reflective journals. This study was grounded in Vygotsky’s sociocultural theory (SCT) to understand and mediate the development of CT through visual programming. It utilized the “Code, Connect, Create” professional development (PD) model as a structured teacher training approach for CT development through visual programming. Additionally, the “Use, Modify, Create” pedagogical model was implemented as a CT framework specific to visual programming to guide and regulate pedagogical decisions during the intervention. Brennan and Resnick’s 3D CT framework was employed to identify and analyse the CT concepts and skills incorporated in the study. Thematic analysis, which involved coding was used to generate themes from qualitative data to address the research questions. Results indicated that visual programming approach enhances CT by fostering interest, creativity, and collaboration. Key enablers included contextualised project-based learning, a clear rationale for CT, and prior programming exposure. Conversely, lack of a clear CT rationale, prior programming experience, and the multimedia nature of Scratch were identified as hindrances. The study concluded that visual programming effectively enhances CT among foundational phase pre-service teachers and recommended its early integration into their training programs to enhance CT skills. , Thesis (MEd) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Follow the yellow flag road : advancing the biological control of a global wetland invader, and a case study on ecosystem recovery

Authors: Minuti, Gianmarco
Date: 2025-04-03
Subjects: Aquatic plants , Invasive plants Biological control , Iris pseudacorus , Azolla filiculoides , Aphthona nonstriata , Host specificity
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479908 , vital:78378 , DOI 10.21504/10962/479908
Description: Global change is accelerating habitat degradation and extinction rates, disproportionately affecting freshwater ecosystems. Biological invasions, a core component of global change, have been recognized as a major driver of this phenomenon. Invasive alien aquatic plants (IAAPs) are a prime example, disrupting ecological dynamics and hindering the economic and social activities that depend upon freshwater ecosystems. The best approach to managing IAAPs is preventing their introduction and taking swift action when infestations are detected. Unfortunately, most IAAPs are only recognized after they have spread, making eradication difficult and requiring expensive, ongoing management through manual, mechanical, or chemical means, which become less effective as infestations grow. In this regard, a sustainable alternative against IAAPs is provided by classical biological control. This method lays on the assumption that invasive species have been introduced in an environment which is free from their natural enemies, and that such release allowed them to redirect their resources towards growth and reproduction. Accordingly, weed biocontrol involves introducing one such enemy - a so-called biocontrol agent - to regulate the population of the plant, ideally reducing its density below a critical threshold, minimizing its impacts. Biocontrol programs must follow stringent protocols in order to a) ensure the selection of the most appropriate agents; b) guarantee their establishment and effectiveness in controlling their target; c) minimize the risks involved with their release; and d) monitor their impacts after they have been released. This thesis is composed of two parts, focusing on pre-release studies (Part I, Chapters 1-4) and post-release evaluations (Part II, Chapter 5), respectively. Part I explores the biological control of Iris pseudacorus L. (Iridaceae) – yellow flag – a Eurasian plant that has invaded temperate wetlands worldwide. The first step consisted of conducting field surveys across the native range of the weed, which led to the selection of three candidate biocontrol agents. As a second step, bioclimatic niche modelling was used to forecast the current and future suitability of the weed and its prospective agents. These models helped to identify areas most at risk of invasion and predict how climate change might affect biocontrol efficacy, showing differing impacts in the Northern and Southern Hemispheres. Further, a scoring system was developed to prioritize non-target plants for host-specificity testing, focusing on species within the family Iridaceae. Most taxa prioritized are native to the Americas, South Africa and eastern Asia, highlighting the importance of collaboration across regions when dealing with global invaders with complex phylogeographic distributions. Finally, a germination study confirmed that I. pseudacorus seeds from Argentina germinate more than Belgian seeds, especially in absence of cold stratification, suggesting increased performances of invasive populations and an adaptation to warmer temperatures. Nonetheless, impact assessments conducted on one of the three biocontrol agents demonstrated that it could cause juvenile mortality, suggesting it may effectively reduce seedling recruitment, though further research on agents targeting reproductive structures is recommended. Part II of the thesis addresses an often understudied aspect of post-release evaluations: ecosystem recovery following biological control. To do so, a case study is presented, investigating the biological control of water fern, Azolla filiculoides Lamb. (Salviniaceae), in Belgium. The results of this study are used to discuss the shortcomings of different experimental designs, the lack of baseline data in invasion ecology, and the intricacies of defining and quantifying ecosystem recovery in light of legacy effects and context-dependency. , Wereldwijde verandering versnelt de degradatie van habitats en de uitstervingscijfers, met een onevenredige impact op zoetwaterecosystemen. Biologische invasies, een kernonderdeel van klimaatverandering, worden erkend als een belangrijke drijvende kracht achter dit fenomeen. Invasieve uitheemse waterplanten (IAAPs) zijn een duidelijk voorbeeld, omdat ze ecologische dynamiek verstoren en economische en sociale activiteiten belemmeren die afhankelijk zijn van zoetwaterecosystemen. De beste aanpak voor het beheer van IAAPs is het voorkomen van hun introductie en het nemen van snelle maatregelen bij het detecteren van besmettingen. Helaas worden de meeste IAAPs pas herkend nadat ze zich hebben verspreid, wat uitroeiing moeilijk maakt en dure, voortdurende beheersing vereist door handmatige, mechanische of chemische middelen, die minder effectief worden naarmate besmettingen toenemen. In dit opzicht biedt klassieke biologische bestrijding een duurzaam alternatief tegen IAAPs. Deze methode berust op de veronderstelling dat invasieve soorten zijn geïntroduceerd in een omgeving die vrij is van hun natuurlijke vijanden, waardoor ze hun middelen konden richten op groei en reproductie. Bijgevolg omvat onkruidbestrijding het introduceren van een dergelijke vijand - een zogenaamde biocontrole-agent - om de populatie van de plant te reguleren, idealiter door de dichtheid ervan onder een kritische drempel te verlagen en zo de impact ervan te minimaliseren. Biocontroleprogramma's moeten strikte protocollen volgen om a) de selectie van de meest geschikte agens te waarborgen; b) hun vestiging en effectiviteit bij het beheersen van hun doel te garanderen; c) de risico's van hun vrijlating te minimaliseren; en d) hun impact na vrijlating te monitoren. Dit proefschrift bestaat uit twee delen, gericht op respectievelijk pre-release studies (Deel I, Hoofdstukken 1-4) en post-release evaluaties (Deel II, Hoofdstuk 5). Deel I onderzoekt de biologische bestrijding van Iris pseudacorus L. (Iridaceae) - gele lis - een Euraziatische plant die gematigde moeraslanden wereldwijd heeft gekoloniseerd. De eerste stap bestond uit het uitvoeren van veldonderzoeken in het inheemse verspreidingsgebied van het onkruid, wat leidde tot de selectie van drie kandidaat-biocontroleagenten. Als tweede stap werd bioklimatisch nis-modelleren gebruikt om de huidige en toekomstige geschiktheid van het onkruid en zijn potentiële agens te voorspellen. Deze modellen hielpen gebieden met het grootste risico op invasie te identificeren en voorspelden hoe klimaatverandering de effectiviteit van biocontrole zou kunnen beïnvloeden, met verschillende effecten op het noordelijk en zuidelijk halfrond. Daarnaast werd een scoresysteem ontwikkeld om niet-doelplanten te prioriteren voor host-specifieke tests, met de nadruk op soorten binnen de familie Iridaceae. De prioritaire taxa zijn inheems in Amerika, Zuid-Afrika en Oost-Azië, wat het belang van samenwerking tussen regio’s onderstreept bij het omgaan met mondiale invasieve soorten met complexe fylogeografische verspreiding. Ten slotte bevestigde een kiemingsstudie dat I. pseudacorus zaden uit Argentinië meer kiemen dan Belgische zaden, vooral bij afwezigheid van koude stratificatie, wat wijst op verhoogde prestaties van invasieve populaties en aanpassing aan warmere temperaturen. Nochtans toonden effectbeoordelingen van een van de drie biocontroleagens aan dat deze de mortaliteit van juvenielen kon veroorzaken, wat suggereert dat het effectief kan zijn bij het verminderen van de zaailingrekrutering. Toch wordt verder onderzoek naar agenten die zich richten op reproductieve structuren aanbevolen. Deel II van het proefschrift behandelt een vaak onderbelicht aspect van post-release evaluaties: ecosysteemherstel na biologische bestrijding. Om dit te realiseren wordt een casestudy aangeboden over de biologische bestrijding van watervaren, Azolla filiculoides Lamb. (Salviniaceae), in België. De resultaten van deze studie worden gebruikt voor de bespreking van de tekortkomingen van verschillende experimentele ontwerpen, het gebrek aan basisgegevens in invasie-ecologie en de complexiteit van het definiëren en kwantificeren van ecosysteemherstel in het licht van nalatenschapseffecten en contextafhankelijkheid. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2025
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Date Issued: 2025-04-03

Investigating the basis of legitimation of English literary studies: a case study of a curriculum at a South African University

Authors: Knoetze, Retha
Date: 2025-04-03
Subjects: Knowledge, Theory of , Critical thinking , English literature Study and teaching (Higher) South Africa , Neoliberalism South Africa , Critical literacy , Transformative learning
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480050 , vital:78392 , DOI 10.21504/10962/480050
Description: This study explored the kinds of knowledge, ways of knowing and ways of being that are valued in English literary studies. It did so by providing an analysis of what was needed to succeed in a specific English literary studies curriculum. The study used the Specialisation dimension of Legitimation Code Theory (LCT) to investigate what is legitimated in an English literature curriculum at the University of South Africa (UNISA) across three years of undergraduate study. The purpose of this analysis was twofold. Firstly, it aimed to make the academic literacy practices of English literary studies more explicit in order to inform pedagogy intended to enable epistemological and ontological access to the discipline. Secondly, the study aimed to facilitate critiques of the curriculum from a social justice perspective by finding ways to make the basis for legitimacy (the ways of being and knowing that are valued) in the curriculum more explicit to both the academics and the students. The study found that English literary studies, as practised at UNISA, was underpinned by what LCT refers to as a ‘cultivated gaze’. This aligns with the findings of previous LCT studies that looked at English literary studies using the dimension of Specialisation. A discipline that is underpinned by a cultivated gaze requires students to exhibit a specific disposition that develops through immersion in the field over an extended period in order to be considered a legitimate knower. The study also found that two orientations within the cultivated gaze were legitimated in the curriculum: an aesthetic orientation and a socio-critical orientation. This finding adds to the previous research because it helps us to better understand the kinds of dispositions that are valued in English literary studies and how these dispositions are cultivated over time. In addition, the study found that neoliberal factors such as massification, managerialism and academic casualisation caused misalignments between the intended curriculum and the practices employed to teach and assess the curriculum. This placed particular limitations on one of the aims of the curriculum which was to cultivate a socially oriented criticality. This finding has implications for how we teach Humanities curricula that aim to develop critical citizens. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2025
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Date Issued: 2025-04-03

Investigating the mainstreaming of inclusive education in Teacher Education Practice for Pedagogical Proficiency through Education for Sustainable Development Change Projects in Southern Africa

Authors: Souza, Ben
Date: 2025-04-03
Subjects: Inclusive education South Africa , Education for sustainable development , Teachers Training of South Africa , Teacher effectiveness , Critical realism , Social learning , Bioecological model
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/480106 , vital:78397 , DOI 10.21504/10962/480106
Description: Globally, there are policy and practice efforts to mainstream inclusive education in different sub-fields of education. Part of the efforts have focused on investigating and finding practical mechanisms for the mainstreaming process in teacher education. Anecdotally, Education for Sustainable Development (ESD), with its focus on transformative education, collaborative learning, the community of practice and the whole institution approach, has the potential to mainstream inclusive education in teacher education practices if grounded in sociocultural realities rather than mere ideological framing. This situation is related to the need for more transformative capabilities for teacher educators to prepare teachers for inclusive pedagogical proficiency. However, in a southern African context, the outlook of the potential of pedagogical proficiency from the nexus of inclusive education, ESD and teacher education is disjointed. As such, this study focused on investigating the mainstreaming of inclusive education in teacher education practice for pedagogical proficiency through ESD Change Projects in Southern Africa, examining cases from Malawi, Tanzania and Eswatini. The study intended to gain an understanding of inclusive education and ESD in these countries, identify areas for strengthening inclusive education in teacher education practice, collaborate with teacher educators to develop strategies for mainstreaming inclusive education, and generate indicators for monitoring and evaluating inclusive education in teacher education contexts. The study used Urie Bronfenbrenner’s bioecological theory of human development and Lev Vygotsky’s sociocultural theory of learning as theoretical and analytical frameworks. The study also employed Roy Bhaskar’s critical realism philosophy as an underlabourer or a meta-theoretical framework. The study further adapted the Vygotsky-informed Engestrom’s expansive learning as a methodological torch. Together, these frameworks were used to analyse selected Change Projects within Sustainability Starts with Teachers (SST) programme, which focused on ESD capacity building in teacher educators from 11 southern African countries. In this regard, the research utilised a qualitative nested case study design. A formative interventionist research approach supported the cases in Malawi, Tanzania and Eswatini, with the study selecting SST Change Projects dealing with inclusive education through an initial scoping questionnaire. Data were generated through 12 in-depth interviews, nine workshops (involving 24 participants), document reviews, observations and reflective journals. Thematic ii analysis, employing a critical realist approach with abductive and retroductive reasoning, guided the reflexive presentation and discussion of research findings. The research findings revealed a common understanding of inclusive education as providing equal educational opportunities, ESD as supporting sustainable development, and teacher education as skill development. The research findings also highlighted the influence of teacher educators’ biopsychosocial characteristics on their perceptions of inclusive education, ESD and teacher education. Areas requiring improvement in teacher education systems included resources, attitude change, financing, cooperation, collaboration and leadership. Strategies for mainstreaming inclusive education in teacher education practice for pedagogical proficiency included curriculum implementation, policy shift, contextualisation and interactive systems. Monitoring and evaluation in all three cases focused on teaching practice, assessment, feedback tools, forums and curriculum implementation, but the absence of specific indicators for monitoring and evaluation was evident. These findings suggest multi-layered and complex implications for policy formulation, implementation practices and future research. Therefore, this thesis argues that, in a southern Africa context, the potential of pedagogical proficiency from the nexus of inclusive education, ESD and teacher education involves considering biopsychosocial characteristics to facilitate the capabilities of teacher educators. This situation necessitates utilising inclusivity mechanisms in pre-service teacher training grounded in biosocial and psychocultural realities of the region’s educational challenges. Consequently, this thesis proffers the Sustainable Inclusive Pedagogical Proficiency Process (SIP3) model as a framework to actualise the nexus of inclusive education, ESD and teacher education, and bring into focus its pedagogical proficiency potential which eventually helps with the mainstreaming process in teacher education practice via ESD. The study reported in this thesis contributes to international theory and practice development for inclusivity and ESD in teacher education practice, provides indicators for monitoring inclusive quality education in teacher education practice, and introduces a contextual dynamics model for comparative education research. The thesis is structured in eight chapters, introducing the study context, addressing literature gaps, presenting the theoretical framework, detailing research design, exploring specific cases in Malawi, Tanzania and Eswatini, discussing the research findings and its implications, and concluding with recommendations for change and future research. , Thesis (PhD) -- Faculty of Education, Secondary and Post School Education, 2025
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Date Issued: 2025-04-03

Mainstreaming equitable decision-making under uncertainty at the Water User Association level using a reallocation model in the Western Cape, South Africa

Authors: Xoxo, Beauten Sinetemba
Date: 2025-04-03
Subjects: Water-supply Management , Water-supply South Africa Western Cape , Right to water South Africa Western Cape , Water Distribution , Water resources development South Africa Western Cape , Uncertainty (Information theory) , Hydrology Statistical methods
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479963 , vital:78384 , DOI 10.21504/10962/479963
Description: This thesis demonstrates how uncertainty can be explicitly incorporated into equitable decision-making in ungauged basins to support fair water reallocation strategies among conflicting uses and reduce vulnerability to water shortages. First, a methodological framework is developed to collect the required socio-economic data. Second, a role-playing game (RPG) is developed in collaboration with stakeholders to increase awareness and assess the implications of different allocation strategies and stakeholder actions. Thirdly, a reallocation decision-support system (Water-Sharing Tool) with dam storage and uncertainty is tested to inform strategic water planning under dry conditions. The study was carried out in collaboration with stakeholders in the upper reaches of the Koue Bokkeveld, Western Cape, South Africa. The study area is a winter rainfall area with commercial farming activities targeting the domestic and cross-border markets. Irrigation from numerous farm dams and run-of-river extraction compete with in-stream environmental protection targets for streamflow. The study area can be described as resource-poor in terms of institutional capacity, with water management decisions taken individually at a farm level. The key water users are the environment, farmers, lifestyle farmers (residents), and weekenders. The farmer group has three sub-groups: corporate-owned farms, family-owned commercial farms, and downstream less well-resourced farmers. Results from the user risk profiles show that the least influential actors reside downstream and are more vulnerable to water shortages, which could be attributed to upstream developments and their productivity-driven nature. The thesis pulls together the socio-economic data, the information contributed by the stakeholders during the RPG, uncertain natural runoff estimates, and water demands. It evaluates these using the Water Sharing Model to map water users’ vulnerability under four different management strategies and assesses equitable reallocation outcomes of the proposed strategies to different users. The magnitude and frequency of decision risks and the underlying uncertainty in the water supply are quantified. As expected, results suggest peak risks during months with the lowest streamflow, with negative implications for fruit production in the catchment. Results also showed the negative supply effects of upstream infrastructure development on downstream users and ecosystems. Game results with the farmers suggested different crop choices in dry periods between upstream and downstream farmers. Downstream farmers were surprisingly more willing to forego their dry season entitlements under water-sharing strategies that resulted in serious production losses upstream, prioritising social stability over their own profits. Farmers reflected on the game as an educational tool to enhance system understanding. The study confirms that decision-makers' understanding of the implications of water allocation decisions and the surrounding uncertainty is critical to meeting justice/fairness objectives. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2025
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Date Issued: 2025-04-03

New insights on classical radio galaxies from MeerKAT and uGMRT

Authors: Legodi, Portia Potasi
Date: 2025-04-03
Subjects: Radio galaxies , MeerKAT , Giant Metrewave Radio Telescope , Radio sources (Astronomy) , Radio interferometers
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479886 , vital:78376 , DOI 10.21504/10962/479886
Description: The morphology of low and high-power sources has been the subject of a classification method for over four decades, leading to a comprehensive understanding of extragalactic radio sources. The morphological classification of radio galaxies is again a hot topic. This project aims to revisit the current classification scheme for classical radio galaxies and investigate the properties and origin of the new filamentary features which are becoming standard within and outside the radio lobes and which are suggestive of so far unexplored interactions between the radio plasma and the external medium. This thesis presents high-resolution and sensitivity studies of the nature of ten known radio galaxies: three FRIs (4C -03.43, 3C 403.1, 3C 198), three FRIIs (3C 105, 3C 227, 3C 445), tailed radio sources (CGCG046-067, NGC7503) and the FR0s (SDSS J 09157+1331, SDSS J 1120+0407). The total sample was selected from the 4C catalogue with well-defined criteria. To this aim, we are using the μJy sensitivity offered by the combination of uGMRT and MeerKAT in a frequency range from 500−1712 MHz. The radio images present several new morphological features in the radio emission at a ∼4′′ −10′′ angular resolution. Our radio maps validate the morphological classification. The sources exhibit remarkable features that raise new questions regarding the complex interaction between radio plasma emitted by host galaxies and the surrounding medium through which the jet propagates. The wealth of morphological details includes, for example, the detection of filaments in the emission from the lobes, the existence of diffuse emission beyond the hotspots, and multiple knot-like structures along the jet spine in some sources in the sample. Detailed descriptions of the overall radio structures are presented. We derived the equipartition parameters for each source in the sample, and after fitting their integrated spectrum, we estimated their global radiative ages. We find a broad range of radiative ages, i.e. 40.19−242.85 Myr. We derived in-band spectral index imaging for a few radio galaxies in the sample. This allowed us to make some preliminary considerations on the origin of the various radio features. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2025
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Date Issued: 2025-04-03

Physiological responses of savanna grasses, encroaching, and non-encroaching tree saplings to changing water availability and elevated atmospheric CO2

Authors: Singili, Edith Joana
Date: 2025-04-03
Subjects: Uncatalogued
Language: English
Type: Academic theses , Doctoral theses , text
Identifier: http://hdl.handle.net/10962/479952 , vital:78383
Description: Access restricted. Expected release in 2027. , Thesis (PhD) -- Faculty of Science, Botany, 2025
Full Text:
Date Issued: 2025-04-03

Showing items 41 - 60 of 30891

Bayesian inference for Cronbach's alpha

Bridging cultures in science education: leveraging lesson study approach for indigenous knowledge integration in a township school

Bridging traditions: mobilising indigenous knowledge and marine biodiversity conservation to support learner talk and sense-making in Grade 11 Life Sciences

Bushmeat hunting and use by rural communities living adjacent to indigenous forests in the Eastern Cape

Creating access to powerful knowledge in accounting education: a case study of pedagogies used in an accountancy diploma

Developing the behaviours that we value in physics knowers through implementing aspects of the Investigative Science Learning Environment (ISLE) approach in a South African high school

Enhancing Grade 12 physical sciences teachers’ pedagogical content knowledge to teach work, energy, and power bilingually in the Eastern Cape

Enhancing the effectiveness of the Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) sterile insect technique release programme

Evaluating social effects of arable field abandonment in communal areas of South Africa

Exploring academics’ experiences of the research ethical clearance process: a case study of a South African university

Exploring Foundation Phase pre-service teachers’ mathematical pedagogical content knowledge for teaching additive mental mathematics strategies

Exploring organisational learning in water resource protection: activity system analysis of social learning among resource directed measures role-players in South Africa

Exploring pedagogical translanguaging practices used by ESL primary school teachers to enhance reading comprehension

Exploring the development of computational thinking among pre-service teachers using visual programming: an interventionist case study

Follow the yellow flag road : advancing the biological control of a global wetland invader, and a case study on ecosystem recovery

Investigating the basis of legitimation of English literary studies: a case study of a curriculum at a South African University

Investigating the mainstreaming of inclusive education in Teacher Education Practice for Pedagogical Proficiency through Education for Sustainable Development Change Projects in Southern Africa

Mainstreaming equitable decision-making under uncertainty at the Water User Association level using a reallocation model in the Western Cape, South Africa

New insights on classical radio galaxies from MeerKAT and uGMRT

Physiological responses of savanna grasses, encroaching, and non-encroaching tree saplings to changing water availability and elevated atmospheric CO2