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Exploring youth unemployment through entrepreneurship education: a case study of Biziniz in the box in Newcastle

  • Authors: Ndlovu, Bonginkosi Siphelele
  • Date: 2024-04
  • Subjects: Youth -- Employment -- South Africa -- KwaZulu Natal , Entrepreneurship -- South Africa -- KwaZulu Natal , Economic development -- South Africa -- KwaZulu Natal
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63386 , vital:73267
  • Description: Youth unemployment is a long-standing social and economic issue in South Africa. One possible drive behind the ever-increasing rate of youth unemployment is the school curriculum that is still tainted by the so-called “bantu education” which is training learners to be job seekers rather than job creators. Government-led initiatives have served to empower the youth through capacity-building projects and financial assistance. One such example is the Bizniz in the Box initiative. Using a qualitative research methodology, and by examining Bizniz in the Box as a case study, this study sought to explore the types of methods, strategies, and outcomes that the Bizniz in the Box initiative used and produced, along with its role in imparting entrepreneurship knowledge and skill to its participants. Through such strategies, the study aimed also to find the possible role the government could have in the imparting of entrepreneurship education. By employing Vygotsky’s Activity Theory (1978) and drawing extensively on Paulo Freire’s Pedagogy of the Oppressed (1970), the study seeks to make recommendations on how government initiatives could critically engage with school curricula and the ways in which government intervention and initiatives can aid school teachers that are ill-trained to impart entrepreneurship skill and knowledge, which is vital to abate the problem of youth unemployment. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2024
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  • Date Issued: 2024-04

Facilitating language communication in English using “VFL” in English second language (ESL) primary school science classrooms

  • Authors: Kemp, Hermione
  • Date: 2024-04
  • Subjects: Science -- Study and teaching , Science -- Study and teaching -- Methodology , Communication -- Study and teaching
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10948/63985 , vital:73635
  • Description: Many classrooms across South Africa have teachers and learners who are English Second Language (ESL) speakers. As a result, teaching and learning becomes a challenge, especially in science education. Science has its own language, which has concepts, terminology, definitions and more that teachers and learners are expected to engage with. The language issues seem to weigh heavier on the learners’ scale as they are learning the Language of Learning and Teaching (LOLT), while they are learning science. Likewise, science teachers face their own challenges in that they are trying to teach the language of science while their learners are still in the process of learning the English language. Therefore, this research study addresses the issue of using language as a resource rather than seeing it as a challenge so that it can enhance the learners’ ability to engage with science concepts. In doing so, this study introduces a group of teachers to using VFL to teach science education through a Community of Practice. Through the use of qualitative methods such as questionnaires, video-recorded lessons and a focus group interview discussion, this study explores how VFL enhance the communication of ESL primary school science classrooms. The vehicles that were used in this study are drama, poetry, visual art, stories, and music. This study adds to the conversation around using the arts to teach science as well as the benefits thereof. One of the findings was that the learners were able to recall scientific content. Multilingual classrooms are the order of the day; therefore, language issues will be present. The teachers shared the same domain in this study within the COP. This space enhanced the opportunity for the teachers to create a community, where they were able to learn, share and grow from one another. Thus, this study encouraged teachers to step out of their comfort zone and to restructure how they teach science by including VFL. Therefore, VFL are a platform for teachers to see themselves as change agents. , Thesis (DPhil) -- Faculty of Education, School of Postgraduate education, 2024
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  • Date Issued: 2024-04

Factors affecting learning of English as a second language in South African schools

  • Authors: Notshulwana, Lamla Augustin
  • Date: 2024-04
  • Subjects: English language -- Study and teaching -- Foreign speakers , Second language acquisition , English language - Study and teaching (Secondary)
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63440 , vital:73359
  • Description: The aim of this study was to identify the factors that are affecting the learning of English as a second language in South African schools. Although many South African learners are not fluent or native speakers of the English language, they are required to learn the content of their subjects in English. This is because there is a lack of resources in South Africa to teach other languages and English is seen as the language that grants access to better education and job opportunities, and it is the language that is used to communicate worldwide. The input, output, interaction and sociocultural theories were used to inform the theoretical framework of the study. This study used both qualitative and quantitative methods in order to answer the research question. The participants for this study consisted of individuals who matriculated in South Africa within the period of the past five years and were taught English as a second language. The participants were approached through social media platforms. One hundred participants responded to the questionnaire and 14 were interviewed. The methods of conducting interviews and distributing questionnaires were used to help the researcher to gain a better understanding of the topic. The findings of this study indicate that there are still teachers in South African schools who are not well qualified or proficient in the English language. In addition, learners face a variety of challenges in learning English as a second language. These challenges are found not only within the school context but also outside of school. The learners’ external environment also influences their learning of English as a second language. These external influences include overcrowding at schools, lack of resources such as libraries or books, and parents who are not involved in their children’s learning of English. Being proficient in L1 is important in order develop L2 because a learner can use their L1 skills to learn L2. There are also affective factors such as motivation, confidence and anxiety that play a role in in learning a second language. One of the reasons that some learners perform better than others when it comes to learning English is because of the motivation and self-confidence that they possess. Anxiety related to learning English as a second language is seen as a threat to an individual’s self-concept. This is because learners might find it difficult to communicate well in a language they have not learnt completely. Learners need to be encouraged to achieve their best level in their English skills so that their learning outcomes can be improved. Also, in order for the literacy rate of poor performing schools in South Africa to be improved, teachers should be trained to teach the English language better, parents need to be involved actively in their children’s learning of English as a second language and the Department of Basic Education needs to develop programmes and a policy that puts emphasis on the use of English as a LoLT. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2024
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  • Date Issued: 2024-04

From Clown Prince to critical phenomenon: Fashioning the Joker as a nomadic war machine

  • Authors: Goldmann, Talya
  • Date: 2024-04
  • Subjects: Joker -- (Fictitious character) , Comic books, strips, etc. -- United States -- History and criticism , Literature and society -- United States
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62769 , vital:72941
  • Description: Based on the original clown prince of crime in the DC comic books, the Joker is one of the most notorious villains in cinematic history. He originated in the comic book Batman #1 (Finger, 1940) over eighty years ago, and he remains a prominent character across a myriad of media platforms. In film and television, the Joker has appeared in major and minor roles in approximately nine animated series, eighteen animated films, six live-action series, and five live-action films. Indeed, multiple roles, actors, and decades after the character’s first debut in the Batman television series (1966), the Joker continues to be well-received and sought-after, insofar as every time a new Joker is announced, the character garners more intensive publicity and the film as a whole becomes highly anticipated. Thus, what started as a simple clownish character in the role of a minor villain in Batman (1966), has evolved into a multi-faceted villain so captivating that he has recently earned his own stand-alone films, namely Todd Phillips’ Joker (2019), and the sequel, Joker Folie à Deux (2024) – where he is no longer the antagonist, but now the protagonist. In this research, firstly, key features of the Deleuzoguattarian schema relevant to this study will be presented, before capitalism – as the context of Batman’s Gotham – is considered through a Deleuzoguattarian lens. This study will delve into what makes the beloved Joker so extraordinary along with the aesthetic features associated with his meteoric rise to fame. In this regard, what will be theorized is that the Joker constitutes an example of a Deleuzean nomadic war machine: that is, a critical character who borrows aspects of the State Apparatus and then twists and shapes them into weapons through which he questions and mocks society for its authoritarian and ideological flaws, and with which he exposes its conceptual and ethical blind spots. In this way, he acts like a mirror, reflecting what is wrong with society, and by implication, with the human ‘nature’ – not only in the fictional world of Gotham, but also in the contemporary era created therein. More specifically, discourse analysis and film analysis will be used here, to engage critically with the Joker’s persona in relation to the changing contexts in which the various films were made, in order to trace the development of the character through a Deleuzoguattarian lens. As will be discussed, Phillips’ Joker (2019) signals the deterritorialization of the Joker from the ambit of Batman’s influence, and opens up the possibility for his further deterritorialization as an increasingly mobile and nomadic catalyst of critical thinking beyond even Gotham itself. Then, thirdly, an in-depth analysis on the five key cinematic Jokers will be completed in terms of the characters’ historical contexts, character backgrounds, and aesthetics. And thereafter, the deterritorializing ‘line of flight’ already underway – as by Phillips’ Joker (2019) – will be continued through the creative media production component of this study, which will entail the conceptualization, design and illustration of three new Joker manifestations, each of which will reflect critically upon failing systems in South African society across select time periods, and how these failing systems have contributed to the collective trauma of marginalized groups of people. The first South African Joker manifestation, set in the 1980s, will reflect upon the faltering political infrastructure during the Apartheid era. The second Joker manifestation, set in the early 2000s, will encapsulate the repercussions of the post-Apartheid neoliberal economic landscape. And the third Joker manifestation, set in the 2010s, will draw attention to sociocultural collapse particularly in the space of gender-based violence and sexual assault. Thus, the creation of these Jokers will act as an exploration of trauma, insofar as the tragedy and pain caused by the above-mentioned failing systems will manifest physically through their character designs. In terms of this, and in keeping with the dynamics of appropriation and inflection that are definitive of nomadic war machines, here focus will fall on how their character aesthetics pose critical questions about relevant issues in the South Africa. On account of this, although this research is by definition situated within the spectacle/performance paradigm, it also runs counter to the largely apolitical orientation of creative media production that occurs therein, through its emphasis, instead, on how such creative media production can also entail critical thought that is aimed at thematizing socio-cultural and politico-economic issues and the trauma that they create; thus, this creative media component aims to encourage a more trauma-aware society through art. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2023
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  • Date Issued: 2024-04

Grade 12 literary writing: Perceptions and practices of educators and learners in an English Home Language classroom

  • Authors: Krause, Sade
  • Date: 2024-04
  • Subjects: Creative writing -- Study and teaching , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , English language -- Study and teaching -- South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63122 , vital:73188
  • Description: This study sought to understand perceptions and practices of the literary writing abilities of educators1 and learners of Grade 12 at a high school in Gqeberha, Eastern Cape. Evidence reveals these abilities to be poor. Interviews with educators in the English Home Language Department at the selected school aimed to gain insight into their approaches to teaching literary writing as well as their comprehension and methods of implementation of the Curriculum Assessment Policy Statement’s guidelines for the teaching of the literary essay. Focus group discussions were held with the predominantly isiXhosa or Afrikaans-speaking learners to gauge whether their identities as isiXhosa and Afrikaans speakers in the English Home Language classroom affect their perceptions of the literary texts they have to read and write about. Lastly, an analysis of the learners’ literary essays provided a window into the translation of writing techniques taught and learned. The study found that literary essay writing and literature study lessons contributed to the alienation learners experienced. Learners’ varying learning styles are not prioritised for literature study and literary essay writing. The educators’ selected approach is partly due to the overloaded curriculum which does not equip teachers with the information and skills to execute lessons which lead to effective acquisition of literary writing skills. The CAPS’s flawed premises of the nature of language and lack of support of educators’ teaching of the literary essay perpetuates the subjugation of learners. A framework is suggested to create access to academic writing skills for the learners. , Thesis (MA) -- Faculty of Humanities, Language, Media and Communication, 2024
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  • Date Issued: 2024-04

Herpetofaunal diversity and affiliations of the Okavango River Basin, with specific focus on the Angolan headwaters

  • Authors: Conradie, Werner
  • Date: 2024-04
  • Subjects: Water conservation -- Okavango River Delta , Watersheds -- Okavango River -- Angola , Biodiversity -- Angola
  • Language: English
  • Type: Doctorate theses , text
  • Identifier: http://hdl.handle.net/10948/63667 , vital:73576
  • Description: Although Africa is reputed to possess some of the richest herpetofaunal diversities in the world, a number of areas remain poorly documented and thus inadequately conserved. One such area in particular is the south-eastern part of Angola. Angola endured a long struggle for independence with a protracted civil war that lasted for nearly three decades, leaving the status of the country’s biodiversity in turmoil. Over the past two decades, Angola has become more accessible for biodiversity surveys, opening up new opportunities to document these previously poorly studied areas and help conserve its biodiversity. South-eastern Angola is the water source of the world-renowned Okavango Delta. However very little is known about the biodiversity, diversity status and conservation significance of the headwaters supplying the largest inland delta in the world. To address this bias in sampling and to investigate the conservation importance of the region, a series of rapid biodiversity surveys of the Angolan Okavango River Basin were conducted between 2012 and 2019. This study contributed over 2150 individual records of amphibians and reptiles, representing 88 reptile and 43 amphibian species. At least 15 species were added to the growing country checklist, with the south-eastern region of Angola now comprising 113 reptile species and 51 amphibian species. Because of this study, the area is now one of the most species-rich and well-studied areas in Angola. This study provided the first genetic data for 26 species, and sequences containing Angolan specimens for the first time were generated for 80 species, of which 23 species have originally been described from Angola. Maximum likelihood and Bayesian inference analyses, supported by species delimitation analyses, were utilised to validate specific species statuses. This allowed for the description of five new species of snake, one gecko and two frogs for Angola. The material further contributed to the description of a new genus of snakes. Numerous undescribed and potentially cryptic species were identified, long-lasting taxonomic issues were resolved, and various taxonomic adjustments were emphasised. Further contributions of the material include assisting in the revision of targeted Angolan amphibian and reptile groups as well as large-scale phylogenetic studies across Africa. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
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  • Date Issued: 2024-04

IL-4/ IL-13 directed microglial activation and differentiation in response to LPS-induced neuroinflammation

  • Authors: Ackerdien, Shiraz
  • Date: 2024-04
  • Subjects: Inflammation , Inflammation -- Treatment , Anti-inflammatory agents
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63606 , vital:73554
  • Description: Microglia activation is a common hallmark of neuroinflammation that occurs during pathogen invasion or lipopolysaccharide (LPS)-induced inflammation. A neuroinflammatory response is elicited by the release of proinflammatory cytokines which stimulates microglia in an autocrine manner to be polarized into classically activated, pro-inflammatory M1 cells. Prolonged exposure to the inflammatory response can have disastrous effects on the central nervous system (CNS). However, microglia can alternatively be polarized into the activated M2 anti-inflammatory phenotype, but the exact molecular mechanism mediating this phenotypic switch remains poorly understood. Studies have shown that interleukin (IL)-4 can induce the M2 phenotype and activate the signal transducer and activator of the transcription 6 (STAT6) signalling pathway that in turn provokes a beneficial Th2 immune response. Since IL-4 and IL-13 share a common IL-4 receptor alpha (IL-4Rα) chain, it is possible that alternative microglia differentiation and its anti-inflammatory action also involve IL-13. This study aimed to investigate how IL-13 and STAT6 signalling orchestrates the microglial response and differentiation associated with LPS-induced inflammation. Furthermore, the molecular mechanisms that relieve LPS-induced neuroinflammation and neural protection through IL-13-enhanced BDNF signalling were also investigated. C8-B4 microglial cells were induced with LPS to exhibit an M1 pro-inflammatory phenotype or stimulated with IL-4 and/or IL-13 to exhibit an M2 anti-inflammatory microglial phenotype. The cell viability following LPS, IL-4, and/ or IL-13 exposure was determined. The LPS-induced neuroinflammatory response and the anti-inflammatory response induced by IL-4 and IL-13 which promotes STAT-6 signalling were determined by measuring TNFα, IL-1β, and BDNF protein concentrations using ELISA assays. The polarising effects of LPS and IL-4/IL-13 cytokines were also examined via changes in the expression of Iba-1, CD206, CD86, and STAT-6 determined by immunofluorescence analysis. These changes were further investigated by quantifying the mRNA transcripts of TNFα, IL-1 β, Arg-1, CD206, IL-4R, and STAT-6 and BDNF using qRT-PCR. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
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  • Date Issued: 2024-04

Implementation of the world health organization surgical safety checklist in the operating room in a private hospital in the Nelson Mandela Bay Municipality

  • Authors: Obeng, Emelia
  • Date: 2024-04
  • Subjects: World Health Organization , Operating room nursing , Preoperative care
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63517 , vital:73384
  • Description: The World Health Organisation Surgical Safety Checklist (WHO SSC) was developed to improve teamwork among healthcare professionals and ensure consistent use of safety processes in the operating room (Abbott et al., 2018: 147). The WHO SSC has successfully reduced common and avoidable surgical errors relating to nerve cutting, among others (Jain et al., 2018:7). However, the implementation of the WHO SSC has not been widely acknowledged in South Africa due to specific barriers (Koopman, 2018: 20; Sauls, 2019: 15). To this end, the aim of this study was two-fold: (i) to determine the factors that contribute to the implementation of the WHO SSC among operating room healthcare professionals and (ii) to develop a contextually appropriate process implementation guide that may be used to facilitate utilisation of the WHO SSC in a private operating room healthcare facility. A non-experimental descriptive quantitative approach underpinned by positivism and a descriptive exploratory survey was used to study the factors contributing to implementing the WHO SSC. A self-reported questionnaire was used as the method for data collection. Purposive sampling was adopted by selecting all the 130 operating room staff directly involved in completing the WHO SSC. All 130 respondents completed and returned the questionnaire. Data were analysed using the Statistical Package Software for the Social Sciences (SPSS) Version 28.0 for Windows (IBM Corp, 2021). The study described four factors (i.e. awareness, relative advantage, complexity, and usability) contributing to the implementation of the WHO SSC. The analysis revealed a significant inter-relationship between two factors (i.e. relative advantage and awareness) and characteristics of the operating room healthcare professionals (regarding highest qualification, current age and work experience). The study’s main contribution to the existing body of knowledge is the proposed process-oriented implementation guide, including a readiness assessment template for effective implementation of the WHO SSC. It is recommended that good knowledge of the WHO SSC should be created by making operating room healthcare professionals aware of the arrangements and interventions by the private hospital to implement the WHO SSC. , Thesis (MCur) -- Faculty of Health Sciences, School of Clinical care & medicinal sciences , 2024
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  • Date Issued: 2024-04

Investigating the anti-inflammatory effect of blueberry-AuNP on microglial cells and obese rat brains

  • Authors: Ngwato, Anacia
  • Date: 2024-04
  • Subjects: Anti-inflammatory agents , Brain -- Anatomy , Brain -- Physiology
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64266 , vital:73670
  • Description: Nanotoxicology is a field of study that investigates how nanomaterials interact with biological systems. It focuses on understanding the correlation between the physicochemical properties of nanomaterials, such as size and stability, and their potential toxic effects. Gold nanoparticles (AuNPs), for instance, have a variety of applications in the biological sciences. Therefore, there is a great deal of attention given to evaluating their toxicity to ensure their safe and effective use in biological systems. Anti-inflammatory AuNPs have shown to be a desirable application in obesity treatments since obesity is associated with systematic inflammation. Thus, the study aimed to evaluate the anti-inflammatory effect of BE-AuNPs on C8-B4 microglial cell lines and, to validate the results, the grey matter of brain tissue of obese rats treated with BE-AuNPs. Following the synthesis and characterization of BE-AuNPs, C8-B4 microglial cells were treated with the BE-AuNPs and were evaluated through MTT, HRTEM imaging, qPCR, and ROS. LPS was used to activate the cells. Concentration-dependent toxicity of BE-AuNPs and cellular uptake was observed. The qPCR results showed that the BE-AuNPs decreased the LPS-induced inflammation in the cells. The BE-AuNPs were shown to reduce ROS in inflammatory conditions in the cells. Rat brain tissue analysis through qPCR and ROS demonstrated that BE-AuNPs reduce HFD-induced inflammation and had no ROS effects on the brain, respectively. Thus, leading to a conclusion the BE-AuNPs used in this study are anti-inflammatory. , Thesis (MSc) -- Faculty of Science, Biomolecular & Chemical Sciences, 2024
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  • Date Issued: 2024-04

Investigation of the host potential of compounds derived from tartaric acid, succinic acid and 1,4-cyclohexanedioic acid

  • Authors: Adam, Muhammad Ameen
  • Date: 2024-04
  • Subjects: Chemical reactions , Chemistry, Organic , Bacteriology
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63617 , vital:73562
  • Description: The present investigation considered the host behaviour of three compounds, namely (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (H1), 1,1,4,4-tetraphenyl-1,4-butanediol (H2) and cyclohexane-1,4-diylbis(diphenylmethanol) (H3) in various guest mixtures. These host compounds were readily synthesized by means of Grignard addition reactions on the diesters of tartaric acid, succinic acid and 1,4-cyclohexanedioic acid. The guest mixtures included cyclopentanone, cyclohexanone, cycloheptanone and cyclooctanone, γ-butyrolactone, 2-pyrrolidone, N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, and pyridine, 2-methylpyridine, 3-methylpyridine and 4-methylpyridine. Crystals of (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (H1) were grown from cyclopentanone (5-ONE), cyclohexanone (6-ONE), cycloheptanone (7-ONE) and cyclooctanone (8-ONE,) producing 1:1 host:guest complexes in each instance. Thermal analysis showed the thermal stabilities of these complexes to be in the order 6-ONE > 7-ONE > 8-ONE > 5-ONE which correlated exactly with results from binary guest/guest competition experiments, where 6-ONE was always preferred by H1, while 5-ONE was consistently disfavoured. Single crystal X-ray diffraction (SCXRD) analyses demonstrated that each guest compound was retained in the crystals by means of a hydrogen bond with an alcohol moiety of the host compound. Furthermore, preferred guests 6- and 7-ONE produced crystals with greater densities than guests less favoured (5- and 8-ONE). A conformational analysis of the guest geometries in the four complexes with H1 revealed that the low energy guest conformers were present. The host selectivity for 6- and 7-ONE was proposed to be due to the improved molecular packing in the crystals of the complexes containing these two guest compounds, observed from their higher crystal densities. Hirshfeld surface analyses were not useful in explaining the preference of H1 for 6-ONE relative to 7-ONE (these types of analyses were not possible for the 5-ONE and 8-ONE-containing inclusion compounds due to the nature and degree of disorder present in the guest molecules). H1 was also crystallized from γ-butyrolactone (GBL), 2-pyrrolidone (NP), N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP), and 1H-NMR spectroscopy revealed that all but GBL were included. The host compound was also presented with these guest solvents in various mixtures, and it was observed that NMP was an extremely favoured guest solvent, followed by NEP and NP, with GBL being consistently disfavoured in every experiment. It was therefore shown that in certain instances, H1 may serve as an alternative tool for separating some of these mixtures through host-guest chemistry strategies. The hydrogen bonding motifs present in each of the successfully formed complexes were extensively investigated through SCXRD analysis, as was the thermal behaviour of these complexes. In the latter instance, the peak temperature of the endotherm (from the DSC trace) representing the guest release was greater for the inclusion compound with favoured NMP (145.5 °C) relative to the complexes with NP (139.8 °C) and NEP (120.5 °C). Host compounds H2 and H3 were revealed to have the ability to include each of pyridine (PYR), 2-methylpyridine (2MP), 3-methylpyridine (3MP) and 4-methylpyridine (4MP). H2 displayed selective behaviour for 3MP and 4MP when presented with mixtures of these guest compounds, whilst H3 preferred PYR. In the latter case, this PYR-containing inclusion compound was also the more stable one (the guest release onset temperature was highest, Ton 66.0 °C). It was demonstrated that H2 has the ability to separate very many binary mixtures of these pyridines on a practical platform, since K (the selectivity coefficient) values were 10 or greater in many instances. However, unfortunately, the more difficult-to-separate mixtures containing 3MP and 4MP cannot be purified or separated by employing H2 and supramolecular chemistry strategies. H3 was also shown to be a likely candidate for binary guest separations in very many of the guest solutions considered here, where K was also 10 or greater, and even infinity in many cases. SCXRD demonstrated that 2MP, 3MP and 4MP were retained in the crystals of their complexes by means of classical hydrogen bonds with the host compound. Satisfyingly, this hydrogen bond between 2MP and H2 (3.0213(18) Å) was significantly longer than that between this host compound and both disorder components of 3MP (2.875(2) and 2.825(9) Å) and that between H2 and 4MP (2.8458(13) Å). This observation explains the affinity of H2 for both 3MP and 4MP, and why 2MP was disfavoured. The results of thermal experiments did not wholly concur with observations from the guest/guest competition experiments. Hirshfeld surface analyses were also conducted but were not entirely conclusive with respect to explaining the host selectivity behaviour. In the case of H3, SCXRD analyses revealed that favoured PYR experienced a classical hydrogen bond with the host compound that was statistically significantly shorter (2.795(2) Å, 165°) than those between the other guest compounds and H3. Additionally, this guest compound was the only one to be involved in a (host)C−H···π(guest) interaction (2.91 Å, 139°) and also a non-classical hydrogen bond with the host compound ((host)C−H···N−C(guest), 2.77 Å (144°)). Finally, Hirshfeld surface analyses showed also that preferred PYR experienced a greater percentage of C···H/H···C (33.1%) and H···N/N···H (11.1%) interactions compared with the complexes with 2MP, 3MP and 4MP. However, it is not clear whether these Hirshfeld observations explain the affinity of H3 for PYR. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
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  • Date Issued: 2024-04

Investigation of the synthesis and characterisation of spiro orthocarbonates and heterocyclic orthocarbonates

  • Authors: Cuthbertson, Jarryd Pierre
  • Date: 2024-04
  • Subjects: Chemistry, Analytic , Analytical chemistry , Chemistry
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63678 , vital:73578
  • Description: A series of mostly asymmetrical spiro orthocarbonates and heterospirocyclic derivatives of orthocarbonic acid was synthesized from 2,2-dichlorobenzodioxole and a number of difunctional reagents. A systematic study of the size of the chelate rings formed around the spirocentric carbon atom was conducted by selecting representative samples of aliphatic and aromatic diols. The feasibility and scope of potential starting materials used was expanded by reacting DCBD successfully with thiols. Molecular structures of these compounds were confirmed using diffraction studies on single crystals. All compounds were analyzed using multinuclear NMR. DFT calculations performed on the compounds allowed for the development of equations that can accurately predict 13C chemical shifts of SOCs. Furthermore, the experimental NMR spectroscopy gave rise to an increment shift system for the 13C NMR shifts allowing for further assignment of carbon atom positions in compounds with multiple possible bonding patterns. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
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  • Date Issued: 2024-04

Learners’ understanding of their linguistic resources as a basis for learning natural sciences

  • Authors: Thorne, Rochelle Eugenia
  • Date: 2024-04
  • Subjects: Linguistic analysis (Linguistics) , Science -- Study and teaching -- Methodology , Science -- Study and teaching (Elementary)
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10948/64049 , vital:73646
  • Description: With eleven official languages, South Africa is known for its multilingual environment. Despite this, the country's educational system heavily favours English and Afrikaans. Despite the varied linguistic backgrounds of learners, English continues to be used as the Language of Learning and Teaching (LoLT), which raises questions regarding fair access to education. Within the context of South Africa's constitution and policy frameworks, particularly the Language in Education Policy (LiEP), this study aims to investigate how group work activities in a Natural Sciences classroom can give learners an opportunity to mobilise their multilingual repertoires. Three formerly Afrikaans-medium high schools in the Northern Areas of Gqeberha, were the sites for this research which focuses on Grade Nine Natural Sciences learners. Through the use of both quantitative and qualitative methods such as questionnaires, classroom observations, and focus groups, the study explores how learners make use of their language resources to navigate science instruction in English. The results contest the idea that languages are distinct entities and show that learners use language interchangeably as a learning tool, a practice known as translanguaging. Group work becomes an important space in which learners exercise agency in language selection, enabling the link of dialogical, multilingual, and cultural responses. Sociocultural theory offers insights into group work relationships and provides the theoretical foundation for understanding how learners use language to understand scientific topics. Building on Gibbons' mode continuum (2003), which maps the shifts in discourse in classroom contexts from every day talk at the “here and now” to more specialized talk, the study also explored an expanded continuum which aimed at clarifying the nuances of language and cognitive progression among learners working in collaborative groups. This study adds to the conversation about language ideologies by recognising the ideologies of inclusion, access and identity which informed learners’ thinking and attitudes to language choice in education. Thus, the study emphasises the importance of a sophisticated comprehension of multilingual repertoires in the classroom. In order to better accommodate the changing linguistic patterns of multilingual learners, the study recommends re-evaluating language policies and encouraging educators to exploit the potential of group work to develop understanding of scientific concepts. , Thesis (DPhil) -- Faculty of Education, School of Post Graduate Education, 2024
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  • Date Issued: 2024-04

Lion and leopard diet and dispersal in human-dominated landscapes

  • Authors: Forbes, Ryan Edward
  • Date: 2024-04
  • Subjects: Carnivora -- South Africa , Carnivorous animals -- Conservation , Carnivorous animals -- Ecology
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63766 , vital:73596
  • Description: Terrestrial carnivore population declines are driven by habitat loss and fragmentation, prey-depletion, persecution, and retaliatory killings. Population strongholds now centre on protected areas, that face increasing human pressure, resulting in population isolation, declining prey populations, and livestock intrusion. I therefore aimed to investigate dispersal and connectivity, and diets of lions (Panthera leo) and leopards (P. pardus) in response to human-use and wildlife density gradients in the Greater Limpopo Transfrontier Conservation Area (GLTCA). Firstly, I investigated dispersal and connectivity for these carnivores across the GLTCA, using single nucleotide polymorphisms. I present evidence that in the prey-depleted Mozambique portion of the GLTCA, lion and leopard dispersal distances are higher compared with the prey-abundant Kruger National Park (KNP). I also provide the first evidence for long-range dispersal in female lions. Despite evidence for connectivity occurring across the GLTCA, I recorded population structuring across the region for both carnivores, likely due to habitat fragmentation by human activities in the Mozambique portion of the GLTCA. I then assessed carnivore diet responses to prey depletion and livestock availability by comparing lion and leopard diets in the prey-abundant/livestock-absent KNP (South Africa), with the prey-depleted/livestock-abundant Limpopo National Park (LNP, Mozambique), using scat analyses. Lions and leopards downshifted their prey size selection in LNP relative to KNP. Despite both carnivores expanding their dietary niche breadths in LNP relative to KNP, diet overlap did not differ between sites. This suggests that even when prey is depleted, lions and leopards can partition food resources, which likely limits competition. Despite cattle (Bos taurus) being the most abundant ungulate in LNP, lions and leopards strongly avoided cattle, supporting the notion that carnivores can perceive the risk of hunting livestock and modulate their foraging behaviour to reduce human-carnivore conflict. Should my findings reflect general patterns in carnivore dispersal and diet responses to human-use and wildlife gradients, then carnivore conservation initiates across their range should focus on prey population rehabilitation, improved livestock husbandry practices, the establishment of effective dispersal corridors and improved human-tolerance towards large carnivores. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
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  • Date Issued: 2024-04

Mathematical modelling of the tumour treatment with chemotherapy

  • Authors: Nyaweni, Fundile Sindy
  • Date: 2024-04
  • Subjects: Mathematical models , Mathematics , Chemotherapy
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64289 , vital:73672
  • Description: In this study, a cancer disease model incorporating predator-prey dynamics between immune cells and tumor cells, as well as competition between tumor cells and normal cells, is formulated in an attempt to understand the interaction dynamics that govern the complex interplay within the tumor microenvironment. Mathematical analysis is employed to derive conditions for the boundedness of solutions and to discuss disease thresholds such as the basic reproduction number, R0. Equilibrium points are identified, and stability conditions for the system are derived. Sensitivity analysis is used to assess uncertainties in the parameters of the model, specifically their impact on R0. Numerical simulations are conducted, utilizing the Runge-Kutta scheme to solve the model. Furthermore, optimal control (OC) techniques are applied to examine the role of chemotherapy in enhancing tumor cell elimination and minimizing adverse effects on immune cells and normal cells. The improved model, incorporating normal cells, anticancer drugs, and immune cells, allows for a more comprehensive analysis of the dynamic interactions within the biological system. The optimal control is determined using the forward-backward sweep numerical method. The numerical simulation is carried out in MATLAB to validate and complement the analytical findings. The results indicate that a low concentration of the drug leads to a prolonged period for tumor clearance. Conversely, a higher drug concentration results in quicker tumor clearance, albeit with adverse effects on normal and effector cells. The OC identifies when to stop the treatment once the tumor clears. Furthermore, OC facilitates the regeneration of normal and immune cells beyond treatment, in contrast to a control scenario without optimization. The findings highlight the importance of early detection and careful chemotherapy dosage selection for effective and personalized cancer treatment strategies. , Thesis (MSc) -- Faculty of Science, School Computer Science, Mathematics, Physics and Statistics, 2024
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  • Date Issued: 2024-04

Out of place: an analysis of place as a contributor to the complexities of my “coloured” identity in Malabar, Gqeberha

  • Authors: Flowers, Victoria
  • Date: 2024-04
  • Subjects: Colored people (South Africa) -- Race identity , Ethnicity in art -- South Africa -- Port Elizabeth , Modernism (Art)
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62780 , vital:72954
  • Description: Coloured identity has been a historical point of contestation in South Africa because Colouredness is assumed as “an inbred quality that arises automatically from miscegenation while instrumentalists share the essentialist premise that coloured identity is something negative and undesirable but blame it on the racism and the exploitative practices of the ruling white minority” (Adhikari, 2009: 15). This archaic belief attributed to racial mixture has now become redundant, due to the emergence of new hybridised Coloured identities that factor other ethnic and cultural groups as well as internal and external elements into their conception. The role of Place in the formation of Coloured identities is at the core of this fine arts based enquiry. This study is located in Malabar, Gqeberha which was established after the forced removals onset by the Group Areas Act of 1950 and the displacement of residents from South End. Additionally, it considers specific locations significant in their linkages to hybridised peoples, and how the place and individuals have been influenced by historical legacies of colonisation and apartheid. These are examined to consider their function in contextualising contemporary lived experiences of Coloured identity within the community of Malabar and its effect on artistic practice through autoethnographic research. Through this autoethnographic and reflexive study and the accompanying empirical research process, I critically examine and explore my Coloured identity as part of being-in-the-world (Heidegger, 1962). This ‘being’ is multifaceted as a result of the significance of Place in South Africa and how it has shaped my perception of how and where I have a sense of being and belonging. , Thesis (MA) -- Faculty of Humanities, School Visual and Performing Arts, 2023
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  • Date Issued: 2024-04

Photocatalytic reduction of CO2 into green fuels on microspherical nanocomposites comprising of CdS, TiO2, ZnFe2O4 semiconductors and heterojunctions

  • Authors: Mudau, Rendani Julian
  • Date: 2024-04
  • Subjects: Heterojunctions , Chemistry, Inorganic , Nanochemistry
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64214 , vital:73665
  • Description: Human anthropogenic activities have led to an increase in CO2 levels resulting in global warming. There is a need to reduce CO2 levels in the atmosphere by capturing the gas and converting the captured CO2 into fuels. Photocatalytic conversion of CO2 into valuable products via photoreduction is a promising technique to reduce carbon dioxide using sunlight and water. Redox reactions between CO2 and water using photocatalysts offer an effective method of lowering CO2, which has detrimental effects on the environment. This dissertation reports the synthesis and characterization of five photochemical catalysts comprising of CdS, TiO2, ZnFe2O4 semiconductors and heterojunctions and their use as photocatalysts for the photocatalytic reduction of CO2 into green fuels. Mott−Schottky plot of TiO2, CdS and CdS/TiO2 confirmed the formation of n-type, n-type, and n-n type material respectively. The band gap of TiO2, CdS, and CdS/TiO2 obtained were 3.21,2.24, 2.04 eV, respectively, the combination of TiO2 and CdS resulted in the lowering of band gap energy which is favourable for photocatalytic reduction studies. XRD of TiO2, CdS and CdS/TiO2 provided relevant information about the various phase reflections of the photocatalysts, it also supported reports confirming the increase in crystallite size of TiO2 anatase phase upon calcination. Chemical environment of the various photocatalysts, such as Ti2p1/2, Ti2p3/2, O1s, Cd3d3/2, Cd3d5/2, S2p1/2 and S2p3/2 were observed in TiO2, CdS and CdS/TiO2. BET surface area of TiO2, CdS and CdS/TiO2 was also observed to be 2.9243, 4.0605, and 9.8450 m2g, respectively. Photocatalytic reduction of CO2 resulted in formic acid, formaldehyde, acetic acid, carbon monoxide, ethanol, and methanol after 12 h. Modification of CdS with TiO2 to form CdS/TiO2 produced high yield of formic acid (217.7 μmol/g) compared to CdS (8.7 μmol/g) and TiO2 (122.5 μmol/g). CdS had high yield of formaldehyde (20.4 μmol/g) and ethanol (57.8 μmol/g) compared to TiO2 (12.9, 3.6 μmol/g of formaldehyde and ethanol, respectively) and CdS/TiO2 (19.7 μmol/g and there was no detection of ethanol). TiO2 shows high yield of methanol (145.2 μmol/g) and is the only catalysts that produced carbon monoxide (52.2 μmol/g) compared to CdS (87.8 μmol/g of methanol) and CdS/TiO2 (50.2 μmol/g of methanol). A detailed elucidation of the various products was reported by means of nuclear magnetic resonance (NMR) spectrometer. ZnFe2O4 and CdS/TiO2/ZnFe2O4 were characterized and employed for photocatalytic reduction of CO2 in water. XRD and XPS confirmed the presence Fe (2+) and Fe (3+) in tetrahedral/octahedral and Zn (2+) in tetrahedral on ZnFe2O4 and CdS/TiO2. CdS/TiO2/ZnFe2O4 presented a lowered band gap of 1.98 eV due to the presence of ZnFe2O4 while the band gap of ZnFe2O4 obtained is 1.95 eV. The Mott-Schottky plots confirmed the conduction (2.81 and 2.59 eV) and valence band (–0.86 and –6.1 eV) of ZnFe2O4 and CdS/TiO2/ZnFe2O4 together with their junctions, respectively. ZnFe2O4 and CdS/TiO2/ZnFe2O4 are p-type and p-n type junctions, respectively. Photocatalytic reduction of CO2 under visible light for 12 h using CdS/TiO2/ZnFe2O4 hollow microspheres nanocomposites produced methanol (182.1 μmol/g), formic acid (1.9 μmol/g), formaldehyde (9.5 μmol/g), ethanol (67.1 μmol/g), and oxalic acid (38.9 μmol/g). Amongst the synthesized catalysts, CdS/TiO2/ZnFe2O4 produced high yield of methanol, ethanol, and oxalic acid. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
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  • Date Issued: 2024-04

Photoluminescence and electroluminescence imaging of PV devices

  • Authors: Roodt, Roelof Petrus
  • Date: 2024-04
  • Subjects: Photoluminescence , Biosensors
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64333 , vital:73676
  • Description: Luminescence imaging has become a particularly useful and valuable tool for the characterisation of photovoltaic devices. This study entailed the design, construction, and optimisation of a system for the electroluminescence (EL) and photoluminescence (PL) imaging of various solar cell devices. The system can perform EL and PL imaging of solar cells of different cell technologies and materials systems, including Si, perovskite, and triple-junction concentrator solar cells. This required appropriate electrical power supplies for carrier injection for EL imaging and optical excitation for PL imaging. The different materials systems also required wavelength appropriate filters for PL imaging. In addition, the system utilized a temperature-controlled sample stage and was placed in a chamber for environmental control and isolation of UV radiation from laboratory. In addition to optimization of imaging conditions, luminescence images need to be optimized to facilitate detailed analysis and the application of appropriate algorithms to extract device parameters and hence generate device parameter images of the devices under investigation. For EL imaging, two power supplies were used to inject current into the solar cells. The reason for the two power supplies is that the first power supply had a current range of ± 1 A and an applied voltage capability of ± 21 V. This was used for the smaller solar cells. It was also convenient to use as the power supply could also measure the injected current and applied voltage and digitally store it with the images. For the larger solar cells, a second power supply was utilized, which could inject current into the samples in the range of ± 12 A at an applied voltage of ± 40 V. To measure the current and voltage of the power supply provided, two digital multimeters were utilized. For acquiring images, the same camera was used for EL and PL imaging. The sensor used in the camera is a silicon CMOS sensor. For PL imaging, four light emitting diode (LED) boards, consisting out of sixty-four LED’s, per board, of four different wavelengths, were used to optically excite the solar cells. The four wavelengths emitted by the LED’s were chosen to match the bandgaps of the different solar cell devices investigated. The LEDs were powered with a multi-channel constant voltage power supply, where the current could be varied. The Si solar cell is a 156 x 156 mm commercial solar cell. The perovskite solar module is a 40 x 40 mm module, which consists out of six cells connected in series. The triple-junction concentrator solar cell has a dimension of 10 x 10 mm which consists of three junctions staked on top of one another. These three layers consist of indium gallium phosphate (InGaP), indium gallium arsenide (InGaAs) and germanium (Ge). To capture EL and PL images of these various solar cell devices, filters of specific wavelengths were placed in front of the camera to isolate the light generated by the different devices. In addition to isolating the luminescence observed from the solar cells, an image correction procedure was adapted from literature, to be applicable to acquiring luminescence images of these various solar cells. As there are a range of factors which influence the quality and clarity of the luminescence images, i.e., chromatic aberration, diffraction, and absorption depth, to name a few, the wavelength dependency of these factors was investigated. This was done by acquiring a point spread function (PSF) for each of these devices and then using these PSF's together with a deconvolution algorithm to correct the luminescence images. The PSF was acquired by fitting a point source emission image to a function that includes exponential and Gaussian terms. The point source image was obtained by placing a black piece of vinyl with a pinhole in it over the solar cell. To communicate with all the various devices and to acquire images at various intensities a LABVIEW program was written. This was used then used to control the power supplies, digital multimeters, camera, and the LED's. This allowed for the user to specify at what points along the current-voltage (I-V) curve data points needed to be measured together with the luminescence images captured. For PL imaging the intensity of the LED's was then also adjusted according to user specified values. The system was utilised to acquire EL images of the Si solar cell, EL and PL images of the perovskite solar cell and EL images of the InGaP and InGaAs layers in the triple-junction concentrator solar cell. With the correction procedure utilised in this study, it was seen that the image quality and clarity improved, compared to the conventional way of capturing luminescence images. These statements are supported by the results obtained for the series resistance maps of the Si solar cell and the perovskite solar module, as the series resistance maps obtained from the corrected luminescence images have less noise and more detail compared to the results from the raw luminescence images. From the EL images captured for the two layers of the triple junction concentrator, it was clear that the intensity profile of the two layers is different, as the intensity for the InGaP layers was that the device had bright edges and darker intensity on the interior where exactly the opposite was observed for the InGaAs layer, having a bright interior and darker edges. This is most likely due to the opto-electric coupling of these layers withing the triple junction solar cell. For the series resistance images obtained for the Si solar cell, it is observed that at lower carrier injection, the series resistance is lower compared to higher carrier injection levels. This result can also be influenced by the increase in cell temperature with the increase in injected carriers. The series resistance maps obtained from the perovskite EL images shows an interesting result. As the perovskite solar cell has degraded, three of the six cells have optically inactive regions, showing lower luminescence intensities. The series resistance of the other three cells are much lower compared to these cells that have inactive regions under low injection conditions. As the injection level increases, it is seen that the series resistance values of five of the six cells become comparable to one another. With regards to the PSF, it was found that using a bandpass filter in front of the lens reduced to amount of spreading observed from a single point source across the detector. Furthermore, there is a strong wavelength dependency in the PSF as the severity increased with increase in the emission wavelength of the solar cells under investigation.In this study an opto-electrical characterisation system was constructed to acquire PL and EL images of various solar cell technologies. In addition to this, a range of factors that influence the quality of these images were investigated and used in the image correction procedure to correct the images for all these cell technologies. It was shown that the correction procedure works for all three of the technologies investigated in this study, and all these factors showed a strong wavelength dependency. These corrected luminescence images together with current-voltage (I-V) data was then used to determine characteristic parameters of a one-diode model of the various PV devices. This was not only achieved, but it also clearly indicated that all the correction procedures need to be considered to obtain a clear and accurate representation of the actual PV device. This has a major influence on the understanding and improvement of these PV devices. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
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  • Date Issued: 2024-04

Preparation and Investigation of coumarin-based chemosensors towards sensing of ions using UV studies in aqueous systems

  • Authors: Kotze, Tyla
  • Date: 2024-04
  • Subjects: Chemistry, Analytic , Water chemistry , Ionic solutions , Aquatic ecology , Geochemistry
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64116 , vital:73654
  • Description: Humanity's unrelenting expansion has shown little regard for the environment, and this has resulted in tons of toxic heavy metal cations and anions being released into the environment through industrial, agricultural, electronic, and mining dumping. The release of these toxic heavy metals can cause diseases and sometimes lead to death, especially in third-world countries with low-income that reside in informal settlements, who suffer the most. Furthermore, the release of these toxins eventually finds their way back into the environment through bioaccumulation in fish, plants and animals. Although there is an ever need for the growth of these industries; low-cost, sensitive, selective, and organic-based sensors is a positive step forward in highlighting the need for environmental restoration and remediation, whilst striving to avoid unnecessary disease and death through this development. In this project, coumarin-based chemosensors for the detection of cationic and anionic species in aqueous and organic media are described. This project involves the synthesis of six different coumarin-based ether derivatives (E2-E5) and coumarin-based ester derivatives (H1-H2). FT-IR, 1H NMR and 13C NMR were used to confirm the structures of all sensors. The abilities of these novel compounds as chemosensors for detection of cations and anions were investigated using UV-vis analysis. These compounds displayed a favourable interaction with Fe2+ and Fe3+ ions with an increase in absorbance. Ether derivatives E2-E5 did not display any degree of selectivity or sensitivity towards the chosen anions. It was found that in the presence of FeCl2, sensors H1 and H2 displayed a degree of selectivities and further investigations were therefore carried out. From the titration experiments, the limit of detection, limit of quantification and association constants were determined. Job’s plot analyses were performed to determine the binding ratios, which was supported by Benesi-Hildebrand studies. The binding ratio between the sensors and metal cations during complexation was found to be 1:1. Reversibility studies were carried out using EDTA to determine whether the sensors could be reused. Molecular Modelling studies were used to determine the most preferred binding sites. Lastly, real-life application screenings were also run to determine if the sensors will be able to be used in real-life scenarios. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
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  • Date Issued: 2024-04

Prevalence of red blood cell alloantibodies in healthy blood donors: A retrospective study

  • Authors: Bada, Thandolwethu Sarafina
  • Date: 2024-04
  • Subjects: Blood--Transfusion , Blood donors , Red blood cell alloantibodies
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63688 , vital:73586
  • Description: Background: Blood transfusion is one of the essential supporting therapies in the management of patients and all efforts must be geared towards ensuring greater blood safety. There are studies on the prevalence of red blood cell alloantibodies in numerous transfused patients. However, no research has been done on the population of healthy first-time donors in South Africa who donates blood for transfusion. Red blood cell alloantibodies may be present in the donated units and potentially lead to transfusion reactions or to decreased survival of transfused RBCs. Therefore, it is necessary to know the prevalence of alloantibodies in donors and the clinical significance. Aims and objectives: The aim of this study is to determine the prevalence and identity of red blood cell alloantibodies in healthy first-time blood donors in the South African population, as well as to identify them, with the goal of improving blood safety and transfusion support for patients. Materials and methods: This retrospective and observational study investigates healthy first-time blood donors in the South African population over a five-year period, from January 2015 to December 2019. ABO typing and Rh typing were performed using the fully automated immunohaematology analyser BECKMAN COULTER PK7300 (Danaher Corporation, Brea, California). Erytra Eflexis automated system (8-column DG Gel cards) (Diagnostic Grifols, Barcelona, Spain) was used for antibody screening and antibody identification was performed using the RBC 11 Identisera Diana panel sheet. Approval was obtained from the Ethics Committees of Nelson Mandela University, South African National Blood Services and Western Province Blood Services prior to commencement of the study. Results: A total of 497 711 healthy first-time donors, consisting of 209 604 (42%) males and 288 107 (58%) females, were evaluated for irregular antibodies. The maximum number of donors belonged to the age group 18 to 29. Antibody screening results were positive in 849 donors from the entire population investigated, and 603 were RBC alloantibodies with an overall prevalence of 0.12%. The most frequent RBC alloantibody identified was anti-M from the MNS blood group systems, being present in 129 blood donors. Conclusion: The prevalence of RBC alloantibodies in the donor population in the study was 0.12% (603/497 711). As the inclusion criteria was limited, larger studies examining at all donors (first-time and repeated donations) are needed to determine the actual prevalence of alloantibodies in the population of South African donors. , Thesis (MHSc) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
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  • Date Issued: 2024-04

Quantifying the impact of the spatio-temporal variability of land use/land cover on surface run-off generation and groundwater recharge in the luvuvhu river catchment area as a study area

  • Authors: Ramuhovhi, Dakalo Ndivhuwo Stella
  • Date: 2024-04
  • Subjects: Remote sensing , Geographic information systems , Groundwater flow
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/64322 , vital:73675
  • Description: Assessing the spatio-temporal dynamics of land use land cover (LULC) change on hydrological response is vital for catchment sustainability and developing proper management strategies. The study aimed to assess the spatiotemporal effects and implications of LULC dynamics on surface runoff in the Luvuvhu River Catchment, Limpopo Province, using the Soil and Water Assessment Tool (SWAT) model. Satellite images of Landsat 5-thematic mapper and Landsat 8 operational land imager for the years 1990 and 2021 were used to explore the characteristics of LULC for this study by adopting the maximum likelihood (ML) supervised classification method. Five LULC classes were classified in this study; namely, water, built-up area, bare surface, dense vegetation, and sparse vegetation. The classification results show good accuracy values in the range of 76% (1990) and 84% (2021) with overall kappa of 63.8% and 72.8% for 1990 and 2021, respectively. For the purpose of this study, integration of geospatial technique and SWAT model were configured to operate at a monthly time interval over a span of 34 years, specifically from 1979 to 2013 to simulate surface runoff. The SWAT simulation process was executed using a digital elevation model, soil, LULC, and weather data. The analysis of LULC for 1990 and 2021 runoff modelling, it was found that, the runoff depth increased gradually from 3249 mm to 5162.5 mm during 1990 and 2021 LULC change, respectively. The R2, ENS, PBIAS, and RSR values for the calibration and the validation were 0.81 and 0.76, and 0.72 and 0.68, 0.64 and 0.58, 0.54 and 0.63 respectively. These values indicate good correlation between the observed and simulated stream flow data Therefore, suitable and timely management measures must be taken by policy decision-makers to enable sustainable development and to protect the catchment’s natural resources in order to reduce the severity of the changes. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
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  • Date Issued: 2024-04
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