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Just stories?: Epistemic (in)justice and everyday resistance in the digital stories of family literacy practices by Grade 1-5 workers at a South African University

  • Authors: Viedge, Jane Margaret
  • Date: 2023-10-13
  • Subjects: Digital storytelling , Family literacy programs , Epistemic injustice , Epistemic justice , Communication for social change , Fricker, Miranda
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/432308 , vital:72860
  • Description: This thesis sets out to establish in what ways digital storytelling (DST) revealed instances of epistemic (in)justices inherent in the family literacy intervention experiences of four Black, working-class parents employed at a South African University1. Additionally, it explores how DST might be used by the participants (self-labelled the Storytelling Family Literacy - SFL Advocates) to correct any harm done. The context for the research is based on the deep-rooted harms of Bantu education in which Black South Africans were denied equal access to resources such as literacy practices. I investigated these aims by using the theories of DST, Communication for Social Change (C4SC) and epistemic (in)justice. As a participatory media practice supporting communications in marginalised communities, DST’s broad purpose is to assist these communities in telling stories of their lived experiences in ways that change dominant and, therefore, unchallenged views about them (Servaes & Malikhao 2014). In facilitating DST workshops with the SFL Advocates, I searched for evidence of epistemic (in)justice to enhance our (all stakeholders) understanding of their literacy experiences in ways that addressed their credibility status as ‘knowers’ (Fricker, 2007). Viewed through this lens, utilising DST provided a mechanism for understanding the impact of social interventions in a university setting that aimed to correct past injustices. The process involved online and face-to-face workshops with the participants during the Covid-19 Lockdown. The online format hampered data collection processes, and I resorted to face-to-face interactions for the workshops and interviews. These interactions were distinctly different from those I had experienced with participants in previous workshops, and they became a key focus in my analysis. Using narrative inquiry with critical realist and interpretive analysis techniques to interrogate the data, I discovered DST has both weaknesses and strengths as a C4SC communication tool. My findings revealed participants who, in the moment of leading their children and communities through the family literacy intervention, could claim to have redressed epistemic harms from the legacy of Apartheid education. However, by reflecting on this moment, the participants brought to light an epistemic harm that had been previously left unspoken: their sense of restored credibility as knowledge-bearers during the intervention was deeply shaken when the programme ended because they felt abandoned by the university. Therefore, the epistemic (in)justice lens unveiled hidden injustices that curtailed the participants’ ability to participate fully in the DST workshops. They described suffering the effects of pernicious and arbitrary acts of epistemic injustice at the hands of the University. Their participation in my workshops was erratic, and their stories were incomplete. As a result, I experienced difficulty analysing what I perceived as a lack of data. Moreover, despite my independent researcher status, my positionality as participant-observer was problematic as the participants may have perceived me as representative of the University and its institutional power. I responded to the problematic data by including a new theoretical framework in my analysis: the theory of everyday resistance (Vinthagen & Johansson, 2013). Combined with epistemic (in)justice theory and Vivienne’s ideas of using DST for everyday activism, I theorised how the participants negotiated their expressions of identity in epistemically unjust spaces. To put institutional epistemic injustice in perspective in the context of the University, I drew on Fricker’s three models of epistemic justice that enable fair and free conditions for marginalised workers to communicate for social change. , Thesis (MA) -- Faculty of Humanities, Journalism and Media Studies, 2023
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  • Date Issued: 2023-10-13

Kant and the experience of skepticism: rranscendental arguments, skepticism, and a version of the problem of the justification of foundational assumptions

  • Authors: Grecia, Hadley
  • Date: 2023-10-13
  • Subjects: Kant, Immanuel, 1724-1804 , Transcendental argument , Deductive reasoning , Skepticism , Foundationalism (Theory of knowledge)
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/425078 , vital:72207
  • Description: Immanuel Kant is a key thinker in the History of Western Philosophy whose ideas continue to fascinate contemporary English-speaking academic philosophers. One such idea is Kant's conception of transcendental arguments. Although these arguments do not originate in Kant's philosophy, Kant's conception of them occupies a special place in the English-speaking literature on the topic. A growing trend in this literature is to claim that Kant's transcendental arguments are unique because they aim to achieve an anti-skeptical end through deductive means. I call the basic assumption behind readings of transcendental arguments like these the deductive/anti-skeptical assumption. This assumption claims that deduction is the best means to achieve an anti-skeptical end. In this thesis, I argue that accepting this assumption is one way to misinterpret transcendental arguments because—even though it seems compelling at first blush—it must be false. The resultant twist is that transcendental arguments cannot be deductive, which, in turn, means that understanding that Kant's transcendental arguments are not deductive in nature is itself no small detail for understanding the version of Kant's 'not-deductive' solution to skepticism developed here. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2023
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  • Date Issued: 2023-10-13

Kenyan comedy: transmogrifying stereotypes and fashioning a ‘Kenyanness’ of aesthetic escapism

  • Authors: Lumasia, Patrick Chesi
  • Date: 2023-10-13
  • Subjects: Comedy in popular culture Kenya , Stereotypes (Social psychology) , Kenyans Attitudes , Kenyans Humor , Escapism , Aesthetics in popular culture
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432477 , vital:72874 , DOI 10.21504/10962/432477
  • Description: Despite the proliferation of stereotypes in Kenyan comedy, little research exists to show the two intersect to shape a peculiar notion of ‘Kenyanness’. Indeed, Kenyan comedy, besides reproducing and playing on the quotidian and the historical, is heavily invested with ethnic and gender stereotypes that reflect the Kenyan milieu as it intersects with the global. This comedy is oftentimes seen by some critics as detrimental to Kenyan society because it supposedly shapes and reinforces ethnic and/or gender relations in the country. However, this study contends that Kenyan comedy is open to multiple interpretations and meaning contestations that are not necessarily clear to the comedians and audiences due to the asymmetry that abounds between the production and consumption ends of the comedy’s spectrum. The comedy is therefore ambivalent. This research seeks to demonstrate that Kenyan comedy—as a form of entertainment and critique of society—does not seek to fix and reify Kenyan identities. Instead, the comedy frees these identities from the presumed vice-hold, constricting world of stereotypes by disrupting the linearity of the stereotypes, thereby unsettling the hierarchical structure of hegemonic ideology embedded in them through postmodern humour: a form of humour amenable to postmodern sensibilities. To this end, the comedy offers Kenyans momentary escape into a comedic utopia, through which, they address pertinent issues affecting their nationhood, even as they endeavor to fashion a ‘Kenyanness’ of aesthetic escapism that is celebratory of the country’s rich socio-cultural diversity. The study employs Jörg Schweinitz’s (2011) stereotype theory and the postpositivist realist theory of identity in its study of stand-up, scripted episodic and topical comedy as transposed on to YouTube. Specifically, the thesis considers: the Churchill Show (2012 – 2022) that aired on NTV; 2012–2022; The Real Househelps of Kawangware (2014–2021) on KTN/NTV; Auntie Boss (2016–2021) on NTV; The Wicked Edition and The Trending Trend Talkers (2014–). , Thesis (PhD) -- Faculty of Humanities, Literary Studies in English, 2023
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  • Date Issued: 2023-10-13

Labour law and non-standard employment: case studies of selected workplaces in Makhanda

  • Authors: Mini, Sifanelwa
  • Date: 2023-10-13
  • Subjects: Non-standard employment South Africa Makhanda , Job security , Labor market South Africa , Labor laws and legislation South Africa , Work-life balance South Africa , Temporary employment South Africa , Collective bargaining South Africa
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/425171 , vital:72216
  • Description: While precarious and poorly-regulated forms of employment are on the increase worldwide, the patterns vary significantly over time and space. This study sought to understand employees’ perceptions of non-standard employment (NSE), the reasons why employers resort to NSE and why they use particular types of NSE. In addition, the research explored how labour law protections for NSE are applied in particular workplaces. Drawing on the regulation approach, which provides a conceptual framework to explain changes in production and employment relationships under specific spatio-temporal conditions, this study focused on three companies in Makhanda. Furthermore, this study employed a qualitative research method to explore the employees’ perceptions on non-standard work. This was done by using an interpretive approach to explore how workers experience NSE and how Eastern Cape citizens in Makhanda navigate the scourge of unemployment and exploitation in the labour market. Moreover, the research investigated how employees experience the efficacy of their employment rights in the workplace. The employment rights observed in the study include (among others) leave, contract of employment and collective bargaining; all of which are provisions in the Labour Relations Act. The findings in the study do validate the use of NSE as a ‘tool’ to curb high unemployment. However, the study finds that the positive result of job creation does not signify job security for non-standard workers, instead beneath the rhetoric of job creation and investment, lies hidden the exploitation of vulnerable groups of citizens and extension of precarious forms of employment. This is because businesses engage in economic competition locally and globally. Therefore, in order to successfully compete against other, employer’s cut on labour expenses by adopting a “race to the bottom,” the effect of which is paying employees below the minimum wage. Moreover, this study opposes the argument that NSE is a stepping stone to permanent employment. The conditions which prevail in NSE are distinctly different from those in the Standard Employment Relationship (SER), making it difficult for employees to transition to a new labour market. The latter is more aligned with the heterodox approach than it is to the orthodox approach to labour market. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
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  • Date Issued: 2023-10-13

Lady Die

  • Authors: Jephtas, Veronique Bianca
  • Date: 2023-10-13
  • Subjects: Creative writing (Higher education) South Africa , Kaaps , Books Reviews , South African fiction 21st century , Diaries Authorship
  • Language: Afrikaans
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424928 , vital:72194
  • Description: My tesis is geskryf in Kaaps en incorporate veskillende streeksvariante vannie taal. Die gedigte is hoofsaaklik innie dialek en ytie perspektief vannie spreker, Pamela geskryf. Tematies issie fokus die seksualiteit ennie inner workings vanne jong, bruinvrou wat haa feminine power probee assert in ’n patriarchal en invasive wêreld. Die bundel illustreer hierdie constant shifting power dynamics dee Pamela en haa vier boyfriends se vehoudings te examine. Wat vorm betref gebryk ek aspekte vannie zuihitsu, spesifiek die free movement tussen genre en styles: veskillende dele vannie bundel is geskryf as prose, poetry en kort, losstaande gedagtes. Ek kies die skryfstyl wattie narrative van oomblik tot oomblik die beste onnersteun, en beperk nie myself tot een consistent vorm nie ––oek kenmerkend van zuihitsu. Literêre invloede virrie teks is The Pillow Book dee Makura no Sōshi. Meer kontemporêre invloede is Kathy Acker, Marie Calloway, Nathan Trantraal en Ronelda S. Kamfer. Acker virrie manier wat sy identiteit illustreer, amper soese collage constructed yt seemingly unrelated stukkies teks en experiences; Calloway vi haa detached en unromanticised skrywe oo sex en vehoudings; Trantraal en Kamfer virrie manier waarop hulle universal stories vetel in ’n taal wat tightly bound is aan ’n baie spesifieke geography. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
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  • Date Issued: 2023-10-13

Learning to make a difference: Small-scale women farmers in social learning spaces for climate action

  • Authors: Chanyau, Ludwig
  • Date: 2023-10-13
  • Subjects: Social learning South Africa Amathole District Municipality , Value creation , Environmental education South Africa Amathole District Municipality , Climatic changes Study and teaching South Africa Amathole District Municipality , Communities of practice , Crops and climate South Africa Amathole District Municipality , Women farmers South Africa Amathole District Municipality , Farms, Small South Africa , Agricultural ecology South Africa
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/402944 , vital:69908 , DOI 10.21504/10962/402944
  • Description: How do women farmers in Africa learn about climate change? What is quality climate change learning for farmers? How do farmers interface new knowledge with their long-held and trusted traditional knowledge? How do we evaluate learning at farm level and beyond? Using Okoli’s theory mining review, I untangled a tripartite knot of social learning literature to find Social Learning Theory (SLT) suitable for a study to explore my practical and scholarly curiosity as reflected in the above questions. Wenger’s theory of Social Learning emerged as the most appropriate for my research. The second phase of my study explored the climate change learning and practice terrain for small-scale women farmers, analysing the connection between learning, practice, and the resultant value in two case study areas, municipalities in the Amathole District of the Eastern Cape Province of South Africa. In addition to a paper on SLT mining review that unravels and chooses between the strands of social learning, the two case studies resulted in three articles that responded to the study’s objectives and the research questions. The thesis is introduced and synthesised through five 'book-end' chapters, as well as through these four articles. What were my findings? In the first case study, in the drought-stricken Raymond Mhlaba Municipality, I gathered the data through individual semi-structured interviews with farmers, extension officers and representatives of the involved organisations. I also conducted a group interview with farmers and analysed documents to supplement interview data. I analysed the data using concepts of Communities of Practice (CoP) and SLT to map out the learning and practice landscape. I discovered a constellation of CoPs interconnected by the shared drive for adaptive water management. The constellation is made up of tertiary institutions, government departments, non-governmental organisations and farmers of varying experiences and competencies, with women emerging as the more proactive gender, and state-led extension services being willing but overstretched and under-resourced. SLT effectively traced the apparent fragmented learning within and outside the CoPs and the sudden and extensive shifts in the CoP boundaries, especially in the context of COVID-19 pandemic lockdowns and the increased adoption of digital learning platforms. Despite the richness and diversity brought by the emergent new learning networks that involve participants in the province and further afield, the adoption of digital learning platforms worsened the existing generational digital divide among farmers. iii In the second case study, in the water scarce Buffalo City Metropolitan Municipality, I adopted the Value Creation Framework (VCF) to conduct an ethnographic evaluation that used semi-structured interviews, participant observation and document analysis of the learning experiences of women farmers in a social movement on agroecology. I found that the farmer-centred learning approach of the movement has created value for the farmers involved, evidenced by the adoption of agroecology by over 2700 members (including new urban farmers who are occupying open spaces typically used as dumpsites). The learning approach has facilitated expansive learning, enhanced resource mobilisation, new collaborations, partnerships, and seed sharing networks. Additionally, it necessitated context-appropriate and transformative changes to intersectional justice issues associated with historical inequalities in access to land and water and gender discrimination, leading to improved practices, new access to markets and improved quality yields. These are examples of immediate, potential, applied, realised, orienting, enabling and transformative as well as strategic value, as defined by the VCF. In reflecting on how women farmers learn in these social learning spaces I elucidate the learning impact pathways and local contextual influences in shifting CoP boundaries, domains, and practices during the climate crisis as it intersects with other compounding factors. I generated insights that could be useful for stakeholders in the agricultural (extension) sector to build better pathways for emancipatory and empowering expansive social learning in contexts characterised by resource constraints, but also by strong women-led agency. Such learning could make a difference and cushion small-scale farming from collapse especially in times of unprecedented changes. The agroecology movement and associated communities of practice explored in this study create transformative social learning spaces that are able to respond to climate change, and hence a model that state-led extension might want to adopt in other resource-constrained contexts. , Thesis (PhD) -- Faculty of Education, Education, 2023
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  • Date Issued: 2023-10-13

Leverage points for meaningful participatory governance: lessons from the Tsitsa River catchment, South Africa

  • Authors: Fry, Anthony St Leger
  • Date: 2023-10-13
  • Subjects: Watershed management South Africa Eastern Cape Citizen participation , Political participation South Africa , Twelve leverage points , Transdisciplinarity , Socio-ecological system
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/431714 , vital:72798 , DOI 10.21504/10962/431714
  • Description: South Africa underwent the renowned transition into a representative multiracial democracy in 1994. While there has been notable progress in many developmental aspects of South African society, many inherited dilemmas persist, and myriad novel ones are emerging. In land and water governance, the nascent institutions do not reflect the visions laid out in the pioneering and substantive legislation, policies, and guidelines generated in the post-1994 period. Unaddressed dilemmas include widespread failures in local water governance, persistent inequality of access to land and water, poor or non-existent service delivery in rural areas, underdeveloped institutions for integrated and inclusive water resource management, and pernicious divisions between institutions. Overcoming these challenges, which are embedded in complex social-ecological systems across South Africa, will require the collaborative effort of diverse actors from different levels and sectors of society. So how do we foster meaningful participation in ways that are not tyrannical, tokenistic, or manipulative? How do we build local institutions that make sense in the broader political system and in the lives of rural residents? How do we support institutions that meaningfully include diverse voices and enable tangible development outcomes? This thesis explores these questions as part of the Tsitsa Project, a transdisciplinary landscape management project working in the Tsitsa River Catchment (TsRC) in the rural parts of the Eastern Cape province of South Africa. Based on the valuable water resources, severe ecosystem degradation, overlapping traditional and democratic governance systems, and impoverished population, the TsRC is a worthwhile candidate for in-depth study paired with innovative efforts towards systemic development. The single place-based case study approach drew on systems thinking within an evolving transdisciplinary methodology. Qualitative data were collected through extended fieldwork and analysed through an adaptive and iterative approach. Governance mapping elucidated the multiple levels of governance, and a systemic analysis explored meaningful participation at the local level through causal diagramming and observation-based narratives. From the findings, a synthetic analysis identified high leverage points to enable participatory governance interventions to have more sustained impacts. Governance manifestations in the TsRC generally align with existing descriptions of the fractures and associated dilemmas across South Africa, with the added complexities of being a rural landscape in which democratic and traditional governance systems overlap and interact. Local participatory institutions need to endure the broader instability and dysfunction. Interventions must, therefore, be oriented towards trust building and shared understanding while using more practical interventions that provide tangible outcomes, enable in-practice capacity development, and support platforms for all actors to experience and practice meaningful participation together. This thesis aims to unearth the lessons that one small rural catchment might hold for the governance of complex, contested land and for water governance contexts more broadly. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2023
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  • Date Issued: 2023-10-13

Lifting the veil on the "Untouchable": a study of Muslims living with HIV in Durban, South Africa

  • Authors: Shaik, Shabnam
  • Date: 2023-10-13
  • Subjects: AIDS (Disease) Religious aspects Islam , HIV infections Religious aspects Islam , AIDS (Disease) (Islamic law) South Africa , Muslims South Africa Durban , Traditional medicine South Africa , Integrative medicine
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432518 , vital:72877 , DOI 10.21504/10962/432519
  • Description: HIV and AIDS has been prominently studied, by both biomedical and social scientists, since the 1980s. Despite the extensive research that has emerged globally, Muslims have largely been absent in much of the discourse on HIV and AIDS. While the disease is said to be under control in many parts of the world, hidden populations pose a risk to increase in prevalence. Muslims living with HIV are one such hidden population and are only recently gaining representation in studies on HIV and AIDS. Quantitative studies reflect a sharp increase in HIV prevalence in countries with significant Muslim populations, however, more in-depth qualitative studies are needed to garner an understanding of the nature of the disease among Muslims. Muslims have a long history in South Africa, beginning with indentured slavery in Natal (now KwaZulu-Natal) in 1860. There are no specific HIV and AIDS prevention campaigns directed at Muslims in Durban, KwaZulu-Natal, South Africa. Muslims in Durban do not regard HIV is a significant concern for them due to religious doctrine, which they believe if followed will keep them safe from infection. My findings suggest that there is cause for concern over the spread of HIV and AIDS amongst Muslims in Durban. The hidden nature of the disease in the Muslim community has created challenges to curbing the spread of the disease due to the concealment of its presence and the marginalisation of Muslims living with HIV and AIDS. This study conceptualises the HIV and AIDS lived experience amongst Muslims in Durban, South Africa, and uncovers the social and cultural context of the disease. The qualitative study used life histories with ten Muslims living with HIV and semi-structured and unstructured interviews with ten caregivers, five health care professionals and two religious leaders to gain a detailed understanding of the lived experiences of Muslims in Durban. Through the lenses of Purity and Danger, Stigma and Spoilt Identity, and Social Death, this study found that religion [Islam] and its strong moral code influences understandings and perceptions of HIV and AIDS which, in turn affects diagnosis, treatment, care, social identity, and the social well-being of Muslims living with HIV who face stigma, discrimination, shame, and ostracisation from their own community. This study highlights the gaps in the literature on Muslims living with HIV and by providing insight into the lives of participants, the study draws attention to the plight of Muslims living with HIV and AIDS (MLWHIV) and encourages more qualitative studies to be conducted so that a multifaceted understanding of Muslims living with HIV can be created. , Thesis (PhD) -- Faculty of Humanities, Anthropology, 2023
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  • Date Issued: 2023-10-13

Liposomal formulations of metallophthalocyanines-nanoparticle conjugates for hypoxic photodynamic therapy and photoelectrocatalysis

  • Authors: Nwahara, Nnamdi Ugochinyere
  • Date: 2023-10-13
  • Subjects: Liposomes , Photochemotherapy , Phthalocyanines , Photoelectrochemistry , Cancer Treatment
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432159 , vital:72847 , DOI 10.21504/10962/432159
  • Description: This thesis investigates new strategies to enhance the efficacy of photodynamic therapy (PDT) under hypoxic conditions using in-vitro cancer cell models. Phthalocyanines are chosen as viable photosensitizer complexes owing to the favourable absorption properties. To this end, this thesis reports on the synthesis and photophysicochemical properties of various zinc and silicon phthalocyanines (Pcs). To afford better photophysicochemical properties, the reported Pcs were conjugated to different nanoparticles (NPs) through chemisorption as well as amide bond formation to yield Pc-NP conjugates. All the studied Pcs showed relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yields. The various mechanisms for hypoxic response include (i) Type I PDT, (ii) PDT coupled with oxygen-independent therapy and (iii) in-situ oxygen generation using catalase-mimicking nanoparticles which serve to supplement in-vitro oxygen concentrations using MPcs or MPc-NPs conjugates. The mechanisms were assessed using electrochemical, computational techniques and catalase mimicking experiments. The as-synthesised Pcs or Pc-NPs were subjected to liposomal loading before PDT studies which led to enhanced biocompatibility and aqueous dispersity. The in-vitro dark cytotoxicity tests and photodynamic therapy activities of the fabricated Pc-liposomes and Pc-NPs-liposomes on either Henrietta Lacks (HeLa) or Michigan Cancer Foundation-7 (MCF-7) breast cancer cells are presented herein. This work further showed that folic acid (FA) functionalization of liposomes could be exploited for active drug delivery and herein led to an almost 3-fold increase in drug uptake vs non-FA functionalised liposomes in accordance with folate receptor (FR) expression levels between HeLa and MCF-7 cells. The in-vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates were accessed using MCF-7 and HeLa cell lines. The various mechanisms; (i) Type I PDT, (ii) PDT coupled with oxygen -independent therapy and (iii) in-situ oxygen generation using catalase-mimicking nanoparticles were shown to adequately compensate for the otherwise attenuation of PDT activity under hypoxia. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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  • Date Issued: 2023-10-13

Liquidity shocks and capital market efficiency in South Africa

  • Authors: Matapuri, Dexter Tinotenda Kushinga
  • Date: 2023-10-13
  • Subjects: Liquidity (Economics) , Stock exchanges South Africa , Insolvency , Securities South Africa , Capital market South Africa , Investments, Foreign
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/419610 , vital:71659
  • Description: Financial markets are dynamic in nature. As such, one way to keep up with their plethora of variables is to conduct research and seek understanding on how they all work together. Understanding financial market mechanics is the key to achieving and maintaining efficient capital markets. The goal of many economies is to have efficient capital markets mainly because they entail economic growth. One of the common avenues here being foreign direct investments. Therefore, over the years, a lot of financial economics research has been conducted on how best to attain financial market development which ultimately yields capital market efficiency. The opposite is also true. This research therefore set out to study the impact of liquidity shocks on capital market efficiency, more specifically stock market efficiency. As such, the overarching research goal was to determine the link between liquidity shocks and stock market efficiency in South Africa. Furthermore, the research also tested whether there is a homogenous impact exerted by liquidity shocks on the JSE Financial 15, JSE Industrial 25 and JSE Resource 20 indices. The arguments and thus conclusions of the research were constructed based on existing theories such as the Efficient Market hypothesis, Behavioural Finance and the Adaptive Market Hypothesis. Literature and existing empirical evidence related to the topic were also analysed and used for the same purpose. Econometric methods used to achieve these research goals include the time series and panel ARDL, impulse response and variance decomposition tests and the Granger Causality tests. The research found that liquidity shocks do impact stock market efficiency in South Africa in both the short run and long run. The direction of the impact was noted to vary with time and dependent on the liquidity shock proxy. Key findings here were that liquidity shocks lower JSE All-Share index efficiency in the short run thus allowing market participants to beat the market in the initial phases of a liquidity shock. Adding on, it was also found that illiquidity shocks lower efficiency for the JSE Financial 15 and Industrial 25 indices in the short run. In the long run, stock market efficiency is enhanced no matter the source of the shock. As such, the research recommended that regulatory policies should focus on liquidity shocks in the short run for the JSE All-Share index and on illiquidity shocks in the short run for the Financial 15 and Industrial 25 indices. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
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  • Date Issued: 2023-10-13

M3: Mining Mini-Halos with MeerKAT

  • Authors: Trehaeven, Keegan Somerset
  • Date: 2023-10-13
  • Subjects: Physics , Astronomy , Galaxies Clusters , Extragalactic astronomy , Astrophysics , MeerKAT
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424754 , vital:72181
  • Description: This work aims to showcase the MeerKAT telescope’s capabilities and related calibration and imaging software in studying the emission of radio mini-halos. These diffuse radio synchrotron sources surround a Brightest Cluster Galaxy (BCG) in relatively relaxed clusters out to a few 100 kpc in size. They are difficult to image because of their relatively low surface brightness and small angular size. Hence, they could not be studied in great detail by previous generations of radio telescopes and much about their nature, particularly the exact production mechanism, is not yet fully understood. Thus, for the first time, MeerKAT observed a sample of five galaxy clusters to investigate the central radio mini-halo in each. Studying these sources requires the deepest images generated from the data and the effective subtraction of any projected sources obscuring or contaminating the underlying diffuse emission. Therefore, I describe the data reduction used to create third-generation calibrated, primary beam corrected, point source subtracted Stokes I L-band continuum images of these clusters. For first- and second-generation calibration, I use the CARACal pipeline, which implements software optimised explicitly for MeerKAT data. For third-generation calibration, I use the faceted approach of killMS and DDFacet, and then I perform visibility-plane point source subtraction to disentangle the compact and diffuse emissions. I then measured the size, flux density, in-band spectral properties, and radio power of the central mini-halos. I present the first new mini-halo detection by MeerKAT (MACS J2140.2-2339, Trehaeven et al. accepted), the first spectral index maps of these mini-halos, which show very interesting distributions, and a ∼100 kpc II southern extension to the ACO 3444 mini-halo previously unseen in archival VLA data. Thereafter, I present a multi-wavelength case study for two complementary mini-halos from our sample and show via a radio-to-X-ray spatial correlation test that they might be caused by different particle (re)-acceleration mechanisms. Through these initial science results, I have shown that future observations of radio mini-halos with MeerKAT are an exciting prospect that can lead to a better understanding of the fundamental physics behind these sources. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
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  • Date Issued: 2023-10-13

Macroplastics in the environment: are they suitable habitats for macroinvertebrates in riverine systems?

  • Authors: Ali, Andrew Abagai
  • Date: 2023-10-13
  • Subjects: Macroplastics , Aquatic invertebrates South Africa Eastern Cape , Experimental ecology , Plastic scrap , Environmental degradation , Functional ecology , Biotic communities
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424153 , vital:72128
  • Description: Emerging pollutants, such as plastics are threat to freshwater ecosystems, and may negatively impact riverine systems. They can modify riverine habitats and affect aquatic organism distribution and composition. Knowledge of how macroplastics alter riverine habitat heterogeneity, and their effects on macroinvertebrate assemblage structure is sparse, especially in Africa. This study examines the effect of hydraulic biotopes on the colonisation, establishment and succession patterns of macroinvertebrates on macroplastic and natural substrates based on the taxonomic and trait-based approach. Four experimental sites from minimally impacted upper reaches of the Buffalo, Kat, Kowie, and Swartkops Rivers in the Eastern Cape of South Africa were selected for the deployment of plastic substrates. Plastics materials, including polyethylene terephthalate (PET) bottles and natural substrate composed of stone and vegetation, were used to formulate three substrate groups: Group 1: 100% natural substrates (NS), Group 2: 50% natural substrates and 50% plastic material (NP), and Group 3: 100% plastic materials (PD). These substrates were placed in litter bags of equal dimension (25 cm by 35 cm, with 2.5 cm mesh) and deployed randomly in three hydraulic biotopes (pools, riffles, runs) over a period of 180 days (October 2021 to April 2022). A total of 216 substrate bags, 54 bags per substrate were deployed per site in the four experimental sites. Twelve bags from each substrate group were retrieved at an interval of 30 days beginning on day 30 after deployment, and analysed for the establishment of macroinvertebrate communities. Based on composite hydraulic biotope data, Simpson index was significantly higher (P < 0.05) for macroinvertebrate assemblage structure on the 50% and 100% macroplastic substrate groups compared to natural substrates. With the exception of Tabanidae, Glossosomatidae, and Psephenidae, all macroinvertebrate taxa recorded showed non-significant positive correlations with all three substrate groups. However, Tabanidae, Glossosomatidae, and Psephenidae showed significant positive correlation with the 100% natural substrates, 50% plastic substrates and 100% plastic substrates, respectively. The parsimony analysis reveal that, within 30 days, all substrate groups underwent similar succession, with high abundance of pioneer taxa which increased on days 60 and 90, and then decreased from days 120 to 180. For the the pool biotope, Shannon and Simpson indices were significantly higher (P < 0.05) for the macroinvertabrates collected over the natural substates compared with those collected on the macroplastic substrate groups. However, in the riffle and run biotopes, all diversity indices were similar for all substrate groups and no statistically significant difference was observed. Statistically significant higher values for taxonomic richness, diversity, and evenness were found on day 30 to 90 for the riffle biotopes, and day 30 to 60 for the run biotopes. The run biotope presented temporal statistical significant variability in taxonomic composition with different macroinvertebrate communities recorded on days 30 and 60 compared with days 90 to 180. However, in pools and riffles, no temporal variation was observed in the taxonomic composition of macroinvertebrates on all three substrate groups. The trait-based fuzzy correspondence analysis revealed differential spatial-temporal distribution of macroinvertebrate traits on all three substrate group. The early colonisers i.e. day 30 – 60, were dominated by group of taxa characterised by medium (>10 – 20 mm) and large (20 > 40) body size, flat body, collector-gatherers, free-living, and predators. The late colonisers, collected mainly on day 150 and 180 were dominated by taxa with a preference for high flow velocity (0.3 - 0.6 m/s), permanent attachment, and filter-feeding mode. Traits such as oval and flat body shape, medium body size (>10 - 20 mm), skating and clinging/climbing mobility, temporal attachment, shredders, predators, prey, and plastron and spiracle respiration showed positive correlation with the 100% macroplastic substrates. Filter feeding, crawling, permanent attachment, a preference for fast velocity (0.3-0.6 m/s), and coarse particle organic matter were positively correlated with the 50% macroplastic substrates. Overall, the results provided critical insights on the impact of macroplastics on the assemblage structure of biological communities by acting as suitable habitats in stream ecosystems. The study elucidated the role of traits of aquatic organisms in mediating the colonisation of plastics substrates, providing insights into the impact of plastics proliferation on riverine ecosystem functioning. Furthermore, the finding provides a baseline insight into the influence of hydraulic biotopes on the colonisation and establishment of macroinvertebrates on macroplastic acting as artificial riverine habitat. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
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  • Date Issued: 2023-10-13

Maintaining the façade: the disconnect between policy and practice in heritage resources management in Makhanda, South Africa

  • Authors: Dlongolo, Zandile Nombulelo
  • Date: 2023-10-13
  • Subjects: Heritage management , Urban development , Cultural property South Africa Makhanda , Cultural resources management , Heritage tourism
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424576 , vital:72165
  • Description: Cultural heritage is globally acknowledged as having the potential to contribute to positive economic, environmental, political, and social impacts (Graham, 2002). In the South African context, cultural heritage management is rooted in colonial and apartheid narratives that mark a large part of the country's history. Post-apartheid transformation processes have driven new approaches to managing heritage to represent the shared collective narrative of a democratic South Africa. This transformation includes the formation of the three-tiered South African heritage management system by the National Heritage Resources Agency (NHRA) in 1999 and a rethinking of what heritage constitutes and whose heritage matters. Despite the extensive cultural heritage resources in the country, literature concerning the management of these assets in the context of the urban environment and urban planning and management is limited (Donaldson, 2001; Donaldson et al., 2013; Buchanan & Donaldson, 2021; Kruger & Donaldson, 2021). This research explores the built environment heritage resources in Makhanda (formerly Grahamstown) in the Eastern Cape province. Makhanda possesses a rich and varied cultural heritage landscape, including over 70 Provincial Heritage Resources in the form of built environment heritage. The case study provides a perfect laboratory for investigating the various threats and opportunities in the local context that severely affect heritage management. The research used a mixed-method approach to generate data. Primary data were collected through a field survey of built environment heritage resources, semi-structured interviews, and focus groups. Secondary data sources comprised government policy documents, by-laws, reports, research papers and newspaper articles. In the localised context, findings illustrated several challenges affecting local heritage management, centring mainly on the balance between heritage resource management and overall urban management. Findings identified challenges included a poor acknowledgement of the nuances in local history, questions on the effectiveness of legislation, governance and management issues, conflicting demands for social services and urban development, and building maintenance. Heritage resources are acknowledged as a potential tool to meet the local community's needs, and opportunities for developing the heritage sector were also identified. These suggestions include information sharing and cooperation between the municipality, community and various role players, community education, tourism product development, institutional development through skills development, the incorporation of intangible heritage, and the acknowledgement of more inclusive forms of cultural heritage. Overall, the findings indicate that the disconnection in heritage management, urban management practices, and municipal dysfunction in Makhanda threatens the built environment heritage and the local sense of place. The study argues that for local heritage management to succeed, there needs to be a balanced approach to heritage management and urban management through improvements in stakeholder relationships, governance, institutional capacity, knowledge sharing and community involvement in decision-making processes. , Thesis (MSc) -- Faculty of Science, Geography, 2023
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  • Date Issued: 2023-10-13

Marine plastic pollution impacts on ecosystem services and livelihoods in South Africa: a review and stakeholder perceptions

  • Authors: Yose, Papama
  • Date: 2023-10-13
  • Subjects: Marine ecology South Africa , Marine plastic pollution , Ecosystem services , Multi-stakeholder process , Marine biodiversity conservation
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424743 , vital:72180
  • Description: Marine plastic pollution is one of the major environmental problems globally, with adverse impacts on marine ecosystem services, functions and benefits and people. Yet, compared to plastic pollution impacts on terrestrial ecosystems, the impacts of plastic waste on marine ecosystems are little studied and poorly understood in South Africa. In response, research interest on the ecological and economic impacts of marine plastic pollution has grown rapidly but socio-cultural impacts remain poorly conceptualized and little understudied. This trend is arguably driven by the dominance of a quantitative paradigm which is arguably inadequate to respond to dynamic socio-cultural issues and contexts. Further, in South Africa, marine ecosystems are used by diverse groups of people ranging from subsistence users, tourism operators, commercial fishers and recreational users, meaning that addressing marine plastic pollution requires a multi-stakeholder approach. However, few studies explore the perceptions of diverse stakeholders regarding marine plastic pollution, its impacts and potential interventions. Against this background, the objective of the thesis are twofold: (a) to argue for a more nuanced understanding of marine plastic pollution impacts on human well-being in order to strengthen conceptualization of impacts that goes beyond direct and quantitatively measured impacts (ecological, health and economic) but considers the socio-cultural dimensions of impacts (lifestyle disruptions, mental health costs and cultural and heritage impacts), and (b) examine stakeholders’ perceptions of marine plastic pollution, its impacts and potential interventions in South Africa. Drawing on case studies, this study provides a working definition of the socio-cultural impacts of marine plastic pollution and a conceptual framework for categorizing the impacts. It highlights three dimensions of the socio-cultural impacts of marine plastic pollution (lifestyle, mental health, and cultural and heritage impacts). It also illustrates connections between marine ecosystems and marine-based livelihood activities with the social and cultural dimensions of human wellbeing to show the links between marine environments and socio-cultural contexts. Concerning stakeholder perceptions, the study showed a tendency to associate marine plastic pollution with immediate, noticeable and easily quantifiable ecological impacts such as entanglement and ingestion of marine organisms, economic impacts and social impacts (e.g., loss of aesthetic appeal). However, secondary impacts such as loss of marine biodiversity and social impacts such as human health, were largely unknown. Moreover, there was heterogeneity in perceptions of marine plastic pollution impacts among the stakeholder groups. Prospective studies researching marine plastic pollution impacts should consider divergent and diverse perceptions of different stakeholders to capture the real costs of marine plastic pollution. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
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  • Date Issued: 2023-10-13

Mechanisms conditioning the implementation of an integrated quality assurance and enhancement approach at a South African University of Technology

  • Authors: Mabote, Ntele Emily
  • Date: 2023-10-13
  • Subjects: Quality assurance , Tshwane University of Technology , Transformative learning , Critical realism , Social realism , Quality (Philosophy)
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/431576 , vital:72787 , DOI 10.21504/10962/431576
  • Description: Literature related to quality in higher education argues that achieving an integrated approach which balances improvement and accountability in a single quality assurance (QA) system, is not easy. In response to the literature, I decided to conduct a realist study to identify mechanisms that can enable or constrain the implementation of an integrated approach in a single quality assurance system at the Tshwane University of Technology (TUT). The scope of my study was limited to teaching and learning as one of the University’s core functions. An integrated approach encouraged a deliberate focus and attention on transformative learning and teaching. The main research question, “what mechanisms enable or constrain the implementation of an integrated approach to quality assurance and enhancement at the Tshwane University of Technology,” underpinned this study. I used Bhaskar’s critical realist philosophy as an underlabourer for the study and Archer’s social realism as an analytical framework to enable me to seek answers to the research questions. The study took the form of a case study at TUT. Data was generated through document analysis and thirty-five semi-structured interviews with agents from across the various levels and campuses of TUT. In keeping with a social realist study, I used Archer’s concept of analytical dualism to analyse structure, culture, and agency separately, and their interplay. My findings indicated that compliance and accountability are related cultural mechanisms and were dominant in the University’s cultural system. This signalled a strong emphasis on quality assurance (QA) rather than quality enhancement (QE). In addition, the findings showed that the University has established sufficient structural and agential enablements to assure the quality of learning and teaching. However, there is a need to integrate transformative cultural mechanisms into the University’s QA system. Furthermore, there were limited structural, cultural, and agential enablements to encourage enhancement. In this regard, I recommended mechanisms that should be in place for an integrated QA and QE approach to be successful at TUT. My main argument is that an institutional context that encourages structural, cultural, and agential QA and QE mechanisms to work in tandem can enable an integrated QA and QE approach. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2023
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  • Date Issued: 2023-10-13

Mega-churches and the neo-Pentecostalisation of South Africa’s black middle class

  • Authors: Ngoma, Amuzweni Lerato
  • Date: 2023-10-13
  • Subjects: Megachurch , Charismatic Movement , Pentecostalism South Africa , Middle class Black people South Africa , Bourdieu, Pierre, 1930-2002 , Habitus (Sociology) , Social capital (Sociology)
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432422 , vital:72869 , DOI 10.21504/10962/432422
  • Description: This thesis argues that the presence and expansion of South African neo-Pentecostal Charismatic Churches (neo-PCCs) and mega-churches holds significant political economy consequences. Methodologically, the thesis is anchored on digital and in-person ethnography, life history and in-depth interviews. The central argument of this thesis is that neo-PCCs and mega-churches are holding spaces for societal change. The symbolic capital of neo-PCCs and mega-churches and the neo-Pentecostalised habitus, which is co-produced by middle-classes acts as a conduit that facilitates social transitions of political and economic orders. Indeed, religion emerges as a transition mechanism as Durkheim argued for France. It has helped South African social groups to extricate themselves from racist discourses, foster non-racialism and build empowered, somewhat deracialised modern middle-class discourses and tastes. White and Black middle classes have co-produced neo-Pentecostal habiti in the post-apartheid era, that have first, built dispositions for neoliberal capital democracy from apartheid capitalism, second as a middle classing and elite making mechanism and field, third as a stabilising, consolidating and upward strategy of social reproduction. In this way, neo-PCCs and the Black middle class have significantly affected the post-apartheid social formation by producing dispositions that uphold financialised neoliberal capitalism. Significantly, accumulated cultural capital is an indispensable resource in initiating and building post-apartheid institutions. As in the neo-PCC field, it has been pastors, prophets and bishops that have demonstrated the capability to accumulate, transubstantiate and maintain cultural capital that has made their churches comparatively durable social institutions. In a political economy context of state-capture and corruption, a post-GFC-and-COVID-19 milieu characterised by the absence of economic growth, rising unemployment, business closure and ever-increasing interest rates that affect indebted middle-class households and the poor alike, the mega-churches studied herein and their neo-Pentecostalised Black middle class adherents expressed an intense dislike for South African politicians across party lines, and especially the poor performance of the African National Congress-dominated state. So that it is possible that mega-churches and their leaders will outlive many new political parties and independents in the same way that they have outlived post-1994 political parties such as the New National Party, Agang South Africa and the Independent Democrats. Much like the buffer Black middle class that was promoted by the apartheid state as a project of reforming apartheid in the 1970s, whose political activism was pragramatically disengaged, this will likely continue, unless if, generally the post-apartheid Black middle classes shift their sociality from in-ward looking-enclaved social anxiety. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
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  • Date Issued: 2023-10-13

Movement ecology of a West African sciaenid fish, Argyrosomus coronus, in southern Angola

  • Authors: Parkinson, Matthew Cameron
  • Date: 2023-10-13
  • Subjects: Argyrosomus coronus Benguela Current Geographical distribution , Underwater acoustic telemetry , Fisheries Benguela Current , Fish populations , Spatio-temporal dynamics , Spatial ecology
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432203 , vital:72851 , DOI 10.21504/10962/432203
  • Description: Argyrosomus coronus is a large sciaenid species with a primary distribution between Cape Frio, in Namibia, and Luanda, in Angola, where it exists as a panmictic stock. Early juveniles (< 300 mm TL) occur on muddy offshore substrata (50–80 m deep) and at one year of age they recruit into the inshore zone. Adults are thought to predominantly occur inshore. Spawning occurs in the species during late spring. The species is heavily targeted by the recreational, subsistence, artisanal and commercial fisheries as juveniles through to adults and there are signs of population decline with declines in catch per unit effort (CPUE) and maximum size. A basic understanding of their movement ecology has emerged from previous studies, based on conventional tagging (mark-recapture) and CPUE monitoring from a shore-based recreational fishery. Juveniles were thought to be resident, with larger fish undertaking long distance migration southward in the austral summer and returning during the austral winter. In addition to the fishery-related threats faced by the species, the southern Angolan region has been identified to be an ocean warming hotspot, and this has been linked to a southward distribution shift and the recent hybridisation of A. coronus with its congener A. inodorus, in Namibia. This study aims to expand the knowledge of the movement ecology of A. coronus and to interrogate our current understanding of the movement patterns of the species using passive acoustic telemetry. Passive acoustic receivers were deployed at three study sites, Flamingo, where all tagging occurred, which lies ~ 200 km north of the Angolan border with Namibia, is a relatively exposed stretch of coastline; Tombua Bay, which lies 30 km south of Flamingo, is a small, sheltered natural embayment; and Baia dos Tigres, which lies 100 km south of Tombua Bay, is a sheltered lagoon in the lee of an island ~ 10 km from the mainland. Tagging occurred in two batches, one year apart. In the first batch, sub-adults (n = 3) and adults (n = 17) were tagged and monitored for two years. In the second batch, juveniles (n = 7) and sub-adults (n = 3) were tagged and monitored for one year. The first objective of this thesis (Chapter 3) was to examine the spatio-temporal dynamics of A. coronus at a regional-level (across study sites, to investigate the prevalence of the longshore migration), and at a local-level (within a study site), and to categorise the movement behaviour of juveniles, sub-adults and adults. Traditional seasons were not used in this thesis, as the study region alternates between ‘warm’ periods (up to ~ 26 °C mean daily water temperature), when Angola Current water covers the area, and ‘cold’ periods (down to ~ 15 °C mean daily water temperature), when Benguela Current water covers the area. A high degree of residency of tagged fish to the Flamingo study site, where tagging was conducted, was found, with juveniles and sub-adults never being detected outside of the Flamingo study site. Five adults (29 %) were detected haphazardly for between one and 36 days at Tombua Bay, following which they were typically detected again at the Flamingo study site. No fish were ever detected at the southernmost site, Baia dos Tigres, suggesting that none migrated to Namibia. Within the Flamingo study site, adults were found to group at the inshore mid-region of the study site during ‘cold’ periods, dispersing again during ‘warm’ periods, when there was a concomitant offshore shift in their area use. This explained the absence of the species from catches in the shore-based recreational fishery during ‘warm’ periods. These results challenge previous migration hypotheses for the species. Therefore, longshore return migrations which were evident from previously conducted conventional tagging, are probably not the norm for the species, but likely occur at a low frequency. The species exhibited a high degree of residency to their tagging site, despite the drastic seasonal changes in water temperatures and station-keeping was the dominant behaviour across all life stages. The constrained area-use noted in this study, relative to the known distribution of the species, suggests that A. coronus exists as a metapopulation, consisting of a network of subpopulations interconnected by gene flow that is most likely facilitated during their pelagic egg and larval phase. The second objective of this thesis was to examine the group formation observed at the Flamingo study site during ‘cold’ periods (Chapter 4). While this grouping of individuals was found to be correlated with water temperature, it was unlikely to be a causal relationship, as the water temperature was not dissimilar to adjacent areas. The area where individuals were concentrated is known to frequently attract large shoals of their dominant prey, Sardinella aurita. While the timing of this group formation aligns with a pre-spawning period, no studies have assessed the existence of local spawning. A. coronus were, however, likely utilising an abundant prey source, during the important pre-spawning period, in order to build up energy reserves. Group formation is a common feature of sciaenids, but literature on the subject is restricted to spawning congregations. Fish are not only more vulnerable to capture during these periods but may also be disturbed during these potentially important social periods. The third objective of this thesis was to investigate the presence of sociality in the species (Chapter 5). Evidence for sociality during and outside the seasonal group formation was explored using network analyses. There was evidence for sociality, with several groups, characterized by co-locations among individuals, identified. While these groups were fluid through time, there was evidence of persistent sociality, with two individuals in particular being consistently co-located over the entire study period. Due to the persistent nature of sociality, group foraging is suggested as an explanation for this, with anecdotal evidence of coordinated hunting supporting this. Acoustic telemetry vastly improved the knowledge of the movement ecology of A. coronus. Despite their panmictic population genetic structure, they were found to be largely resident, likely occurring as a metapopulation across their distribution, with egg and larval dispersal likely the primary mechanism for maintaining panmixia. Evidence for sociality was also found, which was previously unexplored in the species. The persistent nature of social groupings throughout the year, suggests that it may be linked with group foraging and is supported by anecdotal evidence of coordinated hunting by the species. While this study highlights the value of acoustic telemetry in studying movement ecology, it also shows the importance of drawing on multiple methods to fully understand a species’ spatial ecology, including mark-recapture, population genetics, and fishery catch and effort data. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
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  • Date Issued: 2023-10-13

Native-range studies on insect herbivores associated with African Lovegrass (Eragrostis curvula) in South Africa: prospects for biological control in Australia

  • Authors: Yell, Liam Dougal
  • Date: 2023-10-13
  • Subjects: Weeping lovegrass Biological control Australia , Tetramesa , Biological pest control agents , Efficacy , Host specificity , Environmental risk assessment
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424446 , vital:72154
  • Description: Eragrostis curvula (Schrad.) Nees. (African Lovegrass) is an African native species of grass that was intentionally introduced for pasture in Australia. It has since escaped cultivation and has become widespread and highly invasive. Eragrostis curvula has been recorded in every state and territory in Australia where it has altered fire regimes, disrupted nutrient cycles and can reduce livestock carrying capacity by up to 50%. The Centre for Biological Control at Rhodes University and the New South Wales Department of Primary Industries have been working in collaboration to identify and screen herbivorous insects as biological control agents for E. curvula in Australia. Native-range surveys were conducted between 2021 and 2022 on E. curvula at twenty-two sites across South Africa to identify herbivorous natural enemies associated with it. Species accumulation curves were generated to ensure adequate sampling was performed to identify all the insects associated with E. curvula. Twenty-nine non-target grass species were surveyed simultaneously to determine the field-host range of the natural enemies associated with the target weed. Herbivorous natural enemies were prioritised as possible biological control agents against E. curvula in Australia based on field-host range, predicted efficacy and climatic suitability. Four insect species were consistently found on E. curvula, two of which were herbivorous, as well as a parasitoid and a detritivore. Species accumulation curves show that the insect community was adequately sampled in South Africa. The two herbivorous insects were identified to the lowest taxonomic level using COI barcoding. Both species are undescribed phytophagous wasps in the genus Tetramesa (Hymenoptera: Eurytomidae). Because Tetramesa species have been shown to be host specific and highly damaging in previous biological control programs for other invasive grass weeds, we assessed their suitability as candidate biological control agents for use on E. curvula in Australia. Both Tetramesa species (“sp. 4” and “sp. 5”) were found on several native congeners under field conditions in South Africa. Congeneric South African-native non-target grass species were used as phylogenetic proxies to assess the risk posed to Australian native Eragrostis species. This highlighted three non-target Australian native Eragrostis species, namely: E. parviflora (R. Br.) Trin., E. leptocarpa Benth. fl., and E. trachycarpa Benth., that are at risk of being attacked by the two candidate agents based on their phylogenetic proximity to E. curvula. Predicted efficacy trials were conducted at five long-term repeat survey sites and revealed that Tetramesa sp. 4 does not reduce the probability of E. curvula tiller survival or reproduction, while Tetramesa sp. 5 does not reduce the probability of tiller reproduction but does increase the probability of tiller survival. This result was unexpected and may be a plant compensatory response to herbivory. The sites where both Tetramesa species were collected in South Africa are climatically similar to the invaded range of E. curvula in Australia, and as such, the Tetramesa spp. are likely to be suitably adapted to the climate where they would be released in Australia. These results suggest that both Tetramesa species associated with E. curvula may have too broad a host range to be used as biological control agents in Australia. However, further quarantine-based host-range assessments on Australian native Eragrostis species are recommended to confirm this. The field-based methods used in this study have reduced the number of insect and plant species that host-range assessments will be required to be performed on, thus preventing wasted resources. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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  • Date Issued: 2023-10-13

Natural Language Processing with machine learning for anomaly detection on system call logs

  • Authors: Goosen, Christo
  • Date: 2023-10-13
  • Subjects: Natural language processing (Computer science) , Machine learning , Information security , Anomaly detection (Computer security) , Host-based intrusion detection system
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424699 , vital:72176
  • Description: Host intrusion detection systems and machine learning have been studied for many years especially on datasets like KDD99. Current research and systems are focused on low training and processing complex problems such as system call returns, which lack the system call arguments and potential traces of exploits run against a system. With respect to malware and vulnerabilities, signatures are relied upon, and the potential for natural language processing of the resulting logs and system call traces needs further experimentation. This research looks at unstructured raw system call traces from x86_64 bit GNU Linux operating systems with natural language processing and supervised and unsupervised machine learning techniques to identify current and unseen threats. The research explores whether these tools are within the skill set of information security professionals, or require data science professionals. The research makes use of an academic and modern system call dataset from Leipzig University and applies two machine learning models based on decision trees. Random Forest as the supervised algorithm is compared to the unsupervised Isolation Forest algorithm for this research, with each experiment repeated after hyper-parameter tuning. The research finds conclusive evidence that the Isolation Forest Tree algorithm is effective, when paired with a Principal Component Analysis, in identifying anomalies in the modern Leipzig Intrusion Detection Data Set (LID-DS) dataset combined with samples of executed malware from the Virus Total Academic dataset. The base or default model parameters produce sub-optimal results, whereas using a hyper-parameter tuning technique increases the accuracy to within promising levels for anomaly and potential zero day detection. , Thesis (MSc) -- Faculty of Science, Computer Science, 2023
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  • Date Issued: 2023-10-13

Octa carboxy metal (II) phthalocyanine covalent films as pH sensitive electrochemical sensor for neurotransmitters

  • Authors: Moyo, Iphithuli
  • Date: 2023-10-13
  • Subjects: Phthalocyanines , Thin films , Neurotransmitters , Carboxylic acids
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/424525 , vital:72161
  • Description: Octa acyl chloride metallophthalocyanines of cobalt (CoOAClPc) and iron (FeOAClPc) were synthesized and characterized using spectroscopic and electrochemical techniques. The metallophthalocyanines were fabricated as thin films onto phenylethylamine (PEA) pre-grafted Au electrode following a covalent amide reaction. The spectroscopic and electrochemical characterization confirmed the modification of the bare Au with PEA monolayer thin film (Au-PEA) and the covalent immobilization of MOAClPc to yield Au-PEA-MOAClPc (where M is Co and Fe). The acyl chloride functional groups were hydrolyzed forming pH sensitive thin films of terminal carboxylic acid (-COOH) functional groups (Au-PEA-MOCAPc). The Au-PEA-MOCAPc electrode exhibited pH selectivity and sensitivity properties towards the negatively charged [Fe(CN)6]3-/4- and positively charged [Ru(NH3)6]2+/3+ redox probes. The Au-PEA-MOCAPc electrodes were studied for their electrocatalytic and electroanalytical properties towards the detection of catecholamine neurotransmitters; dopamine (DA), epinephrine (EP) and norepinephrine (NOR). The electrodes were further investigated in the screening of ascorbic and uric acids by means of pH sensitive functional groups. The modification process exhibited good reproducibility. Excellent electrocatalytic and electroanalytical properties were observed. The limits of detection (LOD) determined using 3σ/m was found to be 64 nM, 0.22 μM and 0.17 μM for DA, EP and NOR respectively using Au-PEA-CoOCAPc. For Au-PEA-FeOCAPc, the LOD was found to 0.24 μM, 0.45 μM and 0.34 μM for DA, EP and NOR respectively. The Au-PEA-MOCAPc electrodes screened off the strong interferents, ascorbic and uric acid. The Au-PEA-FeOCAPc electrode was evaluated for its potential application in real sample analysis using new born calf serum, and it showed excellent percentage recoveries. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
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  • Date Issued: 2023-10-13
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