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
- Full Text:
- Date Issued: 2024-04
- 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
- Full Text:
- 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
- Full Text:
- Date Issued: 2024-04
- 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
- Full Text:
- Date Issued: 2024-04
Reasonable accommodation for persons with disabilities at the workplace
- Authors: Addae, Charles Kwadwo
- Date: 2024-04
- Subjects: Employment Equity Act 55 of 1998 , Disability rights , Disability in the work place
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/66140 , vital:74420
- Description: In recent years, there has been a growing recognition of the importance of inclusivity and equal opportunities for individuals with disabilities in the workplace. This thesis aims to contribute to this discourse by examining the issue of reasonable accommodation for disabled employees, with a specific focus on the South African context. The International Labour Organisation (ILO) and the United Nations (UN) Convention on the Rights of Persons with Disabilities provide important frameworks for promoting inclusivity and equal opportunities for disabled individuals in employment. These global standards emphasise the need for reasonable accommodation, which refers to the adjustments and modifications made to the work environment or job duties to enable disabled employees to perform their tasks effectively. In South Africa, the Employment Equity Act 55 of 1998 (EEA) and the Labour Relations Act 66 of 1995 (LRA) serve as the legal framework for addressing disability rights in the workplace. These acts outline the obligations of employers to provide reasonable accommodation and protect disabled employees from discrimination. By analysing the specific provisions within the EEA and LRA, this research aims to gain insights into how South Africa addresses and implements reasonable accommodation measures. By synthesizing the perspectives of the ILO, the UN Convention, and the South African legal framework, this study aims to provide a comprehensive understanding of the challenges, successes, and potential areas for improvement in achieving workplace inclusivity for individuals with disabilities. It will examine the barriers that disabled employees face in accessing reasonable accommodation, such as attitudinal barriers, lack of awareness, and financial constraints. Additionally, it will explore the strategies and initiatives that have been successful in promoting inclusivity and equal opportunities for disabled individuals in the South African workplace. , Thesis (MSc) -- Faculty of Law, Department of Mercantile law, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Addae, Charles Kwadwo
- Date: 2024-04
- Subjects: Employment Equity Act 55 of 1998 , Disability rights , Disability in the work place
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/66140 , vital:74420
- Description: In recent years, there has been a growing recognition of the importance of inclusivity and equal opportunities for individuals with disabilities in the workplace. This thesis aims to contribute to this discourse by examining the issue of reasonable accommodation for disabled employees, with a specific focus on the South African context. The International Labour Organisation (ILO) and the United Nations (UN) Convention on the Rights of Persons with Disabilities provide important frameworks for promoting inclusivity and equal opportunities for disabled individuals in employment. These global standards emphasise the need for reasonable accommodation, which refers to the adjustments and modifications made to the work environment or job duties to enable disabled employees to perform their tasks effectively. In South Africa, the Employment Equity Act 55 of 1998 (EEA) and the Labour Relations Act 66 of 1995 (LRA) serve as the legal framework for addressing disability rights in the workplace. These acts outline the obligations of employers to provide reasonable accommodation and protect disabled employees from discrimination. By analysing the specific provisions within the EEA and LRA, this research aims to gain insights into how South Africa addresses and implements reasonable accommodation measures. By synthesizing the perspectives of the ILO, the UN Convention, and the South African legal framework, this study aims to provide a comprehensive understanding of the challenges, successes, and potential areas for improvement in achieving workplace inclusivity for individuals with disabilities. It will examine the barriers that disabled employees face in accessing reasonable accommodation, such as attitudinal barriers, lack of awareness, and financial constraints. Additionally, it will explore the strategies and initiatives that have been successful in promoting inclusivity and equal opportunities for disabled individuals in the South African workplace. , Thesis (MSc) -- Faculty of Law, Department of Mercantile law, 2024
- Full Text:
- Date Issued: 2024-04
Exploring the views of selected, unafflicted women from Walvis bay and Windhoek, Namibia, regarding intimate partner killing and its effect on their well-being.
- Authors: Amadhila,Luise Utuhole
- Date: 2024-04
- Subjects: Intimate partner violence , Gender-based violence , Post-traumatic stress disorder in women
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/63653 , vital:73575
- Description: Intimate Partner Killing (IPK), popularly known as passion killing in certain regions, such as in southern parts of Africa, Europe, and America, and also referred to as intimate partner homicide, is a global concern. In Namibia, the rate at which men take the lives of their intimate partners due to failed romantic relationships has sparked apprehension within the communities. This study delves into the perspectives of unafflicted women in Namibia, shedding light on the broader impact of intimate partner killing on female well-being. Using a qualitative approach, the study conducted face-to-face, semi-structured interviews with 14 participants. Grounded theory was applied to analyse the collected data and form categories from it. The data were transcribed and analysed using codes, thematic analysis, and interpretation. The theoretical frameworks intersectionality theory, social feminist theory, structuralist theory and systems theory underpin this study. The findings reveal that intimate partner killing severely affects women’s mental health, leading to vicarious trauma characterised by fear and anxiety. Participants reported difficulty experiencing positive emotions in their romantic relationships due to the pervasive uncertainty of this growing issue. Intimate partner killing leaves women feeling scared, unsafe, and traumatised, often prompting them to exercise extreme caution in their relationships to avoid becoming victims themselves. Symptoms such as feeling unsafe, scared, and traumatised align with post-traumatic stress and generalised anxiety. The study recommends implementing policy interventions and stringent laws in Namibia to prevent or discourage men from resorting to violence against their loved ones. Moreover, establishing assistance centres staffed with social work and mental health professionals is crucial to counselling and supporting women experiencing post-traumatic stress and anxiety resulting from intimate partner violence. , Thesis (PhD) -- Faculty of Health Sciences, School of behavioural Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Amadhila,Luise Utuhole
- Date: 2024-04
- Subjects: Intimate partner violence , Gender-based violence , Post-traumatic stress disorder in women
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/63653 , vital:73575
- Description: Intimate Partner Killing (IPK), popularly known as passion killing in certain regions, such as in southern parts of Africa, Europe, and America, and also referred to as intimate partner homicide, is a global concern. In Namibia, the rate at which men take the lives of their intimate partners due to failed romantic relationships has sparked apprehension within the communities. This study delves into the perspectives of unafflicted women in Namibia, shedding light on the broader impact of intimate partner killing on female well-being. Using a qualitative approach, the study conducted face-to-face, semi-structured interviews with 14 participants. Grounded theory was applied to analyse the collected data and form categories from it. The data were transcribed and analysed using codes, thematic analysis, and interpretation. The theoretical frameworks intersectionality theory, social feminist theory, structuralist theory and systems theory underpin this study. The findings reveal that intimate partner killing severely affects women’s mental health, leading to vicarious trauma characterised by fear and anxiety. Participants reported difficulty experiencing positive emotions in their romantic relationships due to the pervasive uncertainty of this growing issue. Intimate partner killing leaves women feeling scared, unsafe, and traumatised, often prompting them to exercise extreme caution in their relationships to avoid becoming victims themselves. Symptoms such as feeling unsafe, scared, and traumatised align with post-traumatic stress and generalised anxiety. The study recommends implementing policy interventions and stringent laws in Namibia to prevent or discourage men from resorting to violence against their loved ones. Moreover, establishing assistance centres staffed with social work and mental health professionals is crucial to counselling and supporting women experiencing post-traumatic stress and anxiety resulting from intimate partner violence. , Thesis (PhD) -- Faculty of Health Sciences, School of behavioural Sciences, 2024
- Full Text:
- 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
- Full Text:
- Date Issued: 2024-04
- 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
- Full Text:
- Date Issued: 2024-04
Exploring senior phase teachers’ use of Kahoot! Gamification as a formative assessment tool to scaffold mathematical understanding
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Kahoot! Algebra by DragonBox , Mathematics Computer-assisted instruction , Pedagogical content knowledge , Mathematics Study and teaching (Secondary) South Africa , Gamification , Educational technology , Mathematics teachers Training of South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Kahoot! Algebra by DragonBox , Mathematics Computer-assisted instruction , Pedagogical content knowledge , Mathematics Study and teaching (Secondary) South Africa , Gamification , Educational technology , Mathematics teachers Training of South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
Exploring 3d printing of brass instruments: a comparative study of French horn mouthpieces
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2024
- Full Text:
- Date Issued: 2024-04
Using Building Information Modelling to initiate criticality to promote built environment student collaboration at the Nelson Mandela University
- Authors: Basson, Jean-Pierre
- Date: 2024-04
- Subjects: Building information modeling -- South Africa , Architectural design -- Computer simulation , Buildings -- Computer-aided design
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64470 , vital:73736
- Description: Architectural, engineering, and construction education is fragmented, and there is no collaboration between disciplines during an architectural design project in the design studio. There is a lack of co-creation of knowledge in an interdisciplinary collaborative environment where students use critical reasoning, self-reflection, and critical action, essential skills required to become 21st century global citizens. Therefore, students from the built environment are being prepared contrary to the highly collaborative nature of the industry they are entering upon graduation. The purpose of this study is thus to determine whether adopting a digital interdisciplinary collaborative Building Information Modelling (BIM) environment in which architectural design projects promote criticality in undergraduate exit-level students. A cohort comparison study was used as a method to collect qualitative data. The 2022 cohort used the traditional design process, whereas the 2023 cohort used the BIM process, which supported interdisciplinary collaboration. Both cohorts engaged in a project and student narrative self-reflection essay. Fourteen students from the 2022 and 2023 cohorts participated in the study. The work was analysed using three cycles of coding. The first cycle focused on linguistic acts, followed by the second cycle that looked for evidence of critical reasoning, self-reflection, and action. The third cycle was based on the Habersian validity claims of truth, comprehension, and sincerity. The work of both cohorts was analysed, and findings included the following: relationships; information; emotional reasoning, and digital environment. Based on the research findings, it can be concluded that the BIM process as teaching strategy promotes a higher level of criticality in students than the traditional design process. In conclusion, this research not only contributes to promoting criticality improvement in students but also enriches the existing body of knowledge relative to BIM adoption in AEC education. Moreover, it offers practical guidance for educators to assess and enhance students' critical thinking skills, ultimately advancing the field of interdisciplinary education in the digital era. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Basson, Jean-Pierre
- Date: 2024-04
- Subjects: Building information modeling -- South Africa , Architectural design -- Computer simulation , Buildings -- Computer-aided design
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64470 , vital:73736
- Description: Architectural, engineering, and construction education is fragmented, and there is no collaboration between disciplines during an architectural design project in the design studio. There is a lack of co-creation of knowledge in an interdisciplinary collaborative environment where students use critical reasoning, self-reflection, and critical action, essential skills required to become 21st century global citizens. Therefore, students from the built environment are being prepared contrary to the highly collaborative nature of the industry they are entering upon graduation. The purpose of this study is thus to determine whether adopting a digital interdisciplinary collaborative Building Information Modelling (BIM) environment in which architectural design projects promote criticality in undergraduate exit-level students. A cohort comparison study was used as a method to collect qualitative data. The 2022 cohort used the traditional design process, whereas the 2023 cohort used the BIM process, which supported interdisciplinary collaboration. Both cohorts engaged in a project and student narrative self-reflection essay. Fourteen students from the 2022 and 2023 cohorts participated in the study. The work was analysed using three cycles of coding. The first cycle focused on linguistic acts, followed by the second cycle that looked for evidence of critical reasoning, self-reflection, and action. The third cycle was based on the Habersian validity claims of truth, comprehension, and sincerity. The work of both cohorts was analysed, and findings included the following: relationships; information; emotional reasoning, and digital environment. Based on the research findings, it can be concluded that the BIM process as teaching strategy promotes a higher level of criticality in students than the traditional design process. In conclusion, this research not only contributes to promoting criticality improvement in students but also enriches the existing body of knowledge relative to BIM adoption in AEC education. Moreover, it offers practical guidance for educators to assess and enhance students' critical thinking skills, ultimately advancing the field of interdisciplinary education in the digital era. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
Mindsets of change agents for development: a case study of the Sundays River Valley, Eastern Cape
- Bezuidenhout, Theo Gerhardus
- Authors: Bezuidenhout, Theo Gerhardus
- Date: 2024-04
- Subjects: Social change , Sustainable development -- South Africa , Well-being , Economic development -- Social aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64874 , vital:73937
- Description: Societal development in underdeveloped areas is a process of enhancing and improving the quality of life in communities, with a focus on meeting their social, economic, environmental, and political needs. Despite ideological efforts and growing interest in movements, mobilisations and communities promoting social change, little research has been done on the mindsets of change agents. Margaret Archer’s (1988), Morphogenetic Approach to social development has been used in this case as a theoretical framework emphasising that social change and development occur through interactions between individuals and their social environments. This approach focusses on the importance of feedback loops, where changes in the environment and the reactions of individuals to these changes both influence and are influenced by one another. Through reflective learning, semistructured interviews and document analysis, the dissertation explored research questions concerning different perspectives of change agents in the Sundays River Valley. The theories examined provide options of theoretical frameworks which can be used to assess and evaluate the work and role of change agents to participate in societal development. This is important in the Sundays River Valley context as, up to now, there has been no shortage or lack of development plans and policies for the area. Rather, what has been absent is the theoretical frameworks to provide the context and meaning for change agents to participate in societal development and occupy their role in the various development plans and policies. Collaborative development and participation acknowledge that solving complex social problems requires the efforts of multiple organisations, individuals, and generations. To enable societal development requires social trust and cooperation of multiple stakeholders, including government, community members, businesses, development agencies, non-governmental organisations and educational institutions. , Thesis (MA) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism , 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Bezuidenhout, Theo Gerhardus
- Date: 2024-04
- Subjects: Social change , Sustainable development -- South Africa , Well-being , Economic development -- Social aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64874 , vital:73937
- Description: Societal development in underdeveloped areas is a process of enhancing and improving the quality of life in communities, with a focus on meeting their social, economic, environmental, and political needs. Despite ideological efforts and growing interest in movements, mobilisations and communities promoting social change, little research has been done on the mindsets of change agents. Margaret Archer’s (1988), Morphogenetic Approach to social development has been used in this case as a theoretical framework emphasising that social change and development occur through interactions between individuals and their social environments. This approach focusses on the importance of feedback loops, where changes in the environment and the reactions of individuals to these changes both influence and are influenced by one another. Through reflective learning, semistructured interviews and document analysis, the dissertation explored research questions concerning different perspectives of change agents in the Sundays River Valley. The theories examined provide options of theoretical frameworks which can be used to assess and evaluate the work and role of change agents to participate in societal development. This is important in the Sundays River Valley context as, up to now, there has been no shortage or lack of development plans and policies for the area. Rather, what has been absent is the theoretical frameworks to provide the context and meaning for change agents to participate in societal development and occupy their role in the various development plans and policies. Collaborative development and participation acknowledge that solving complex social problems requires the efforts of multiple organisations, individuals, and generations. To enable societal development requires social trust and cooperation of multiple stakeholders, including government, community members, businesses, development agencies, non-governmental organisations and educational institutions. , Thesis (MA) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism , 2024
- Full Text:
- Date Issued: 2024-04
A model for speech-driven lesson summary generation in a noisy educational environment
- Authors: Blunt, Phillip John
- Date: 2024-04
- Subjects: Automatic speech recognition , Speech processing systems , Educational technology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64500 , vital:73741
- Description: The application of Automatic Speech Recognition (ASR) technology for generating lesson transcripts and closed captions in the classroom has shown to improve the learning experience of people in disadvantaged student groups. This dissertation proposes a concept model for applying ASR technology in the educational environment for lesson transcription or closed captioning. The model aims further to bolster students’ secondary contact with the lesson content using keyword identification and subsequent association to generate a summary of the educator’s key points with reference to known course content material. To reinforce this concept, three core theoretical areas are discussed in this work, namely the existing applications of ASR technology in the classroom, the prominent machine-learning solutions that are capable of performing ASR, either for keyword spotting or for continuous speech recognition, and finally, the speech enhancement techniques used to mitigate the negative effects of environmental noise in the educational space. After a groundwork investigation into these three core theoretical areas, an initial model was created for incorporating an ASR system into the educational environment using the speech of the educator to drive the process of generating the lesson summary. After analysis for prototype development, the feasibility of developing a keyword-spotting system using South African speech data to train a machine-learning model revealed a number of challenges. Hence, it was decided that it would be more appropriate to implement a cloud-based ASR solution to establish proof of concept in a prototype system. In addition, the advent of a cloud-based ASR solution meant that a more reliable lesson transcript could be generated and, as a result, the direction of this work could move towards exploiting the utility provided by lesson transcription to generate a meaningful lesson summary. An initial prototype implementation was then developed based on the initial model using a cloud-based ASR approach. The final model presented in this work makes use of keyword identification in the transcription process, in collaboration with a course content database to identify known, educator-defined keyword terms during a lesson that are tied to relevant course content items for the specified lesson. As the model or prototype was improved and adapted, its counterpart was modified appropriately, ensuring that each reflected both the theoretical and practical aspects of the other. After a series of improvement cycles, a final version of the model was ascertained, supported by a performance evaluation of an acceptable prototype system. Ultimately, the prototype proved capable of generating a lesson summary, presented to students to bolster secondary contact with lesson content. This lesson summary provides students with a lesson transcript, but also helps them to monitor educator-defined keyword terms, their prevalence as communicated in the lesson by the educator, and their associations with educator-defined sections of course content. The prototype was developed with a modular approach so that its speech recognition component was interchangeable between CMU’s Sphinx and Google Cloud’ Speech-to-Text speech recognition systems, both accessed via a cloud-based programming library. In addition to the ASR module, noise injection, cancellation and reduction were also introduced to the prototype as a speech enhancement module to demonstrate the effects of noise on the prototype. The prototype was tested using different configurations of speech recognition- and speech enhancement techniques to demonstrate the change in accuracy of lesson summary generation. Proof of concept was established using the Google Cloud Continuous Speech Recognition System, which prevailed over CMU’s Sphinx and enabled the prototype to achieve 100,00% accuracy in keyword identification and subsequent association on noise-free speech, contrasted with a 96,93% accuracy in keyword identification and subsequent association on noise-polluted speech when applying noise cancellation. , Thesis (MIT) -- Faculty of Engineering, the Built Environment, and Technology, School of Information Technology, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Blunt, Phillip John
- Date: 2024-04
- Subjects: Automatic speech recognition , Speech processing systems , Educational technology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64500 , vital:73741
- Description: The application of Automatic Speech Recognition (ASR) technology for generating lesson transcripts and closed captions in the classroom has shown to improve the learning experience of people in disadvantaged student groups. This dissertation proposes a concept model for applying ASR technology in the educational environment for lesson transcription or closed captioning. The model aims further to bolster students’ secondary contact with the lesson content using keyword identification and subsequent association to generate a summary of the educator’s key points with reference to known course content material. To reinforce this concept, three core theoretical areas are discussed in this work, namely the existing applications of ASR technology in the classroom, the prominent machine-learning solutions that are capable of performing ASR, either for keyword spotting or for continuous speech recognition, and finally, the speech enhancement techniques used to mitigate the negative effects of environmental noise in the educational space. After a groundwork investigation into these three core theoretical areas, an initial model was created for incorporating an ASR system into the educational environment using the speech of the educator to drive the process of generating the lesson summary. After analysis for prototype development, the feasibility of developing a keyword-spotting system using South African speech data to train a machine-learning model revealed a number of challenges. Hence, it was decided that it would be more appropriate to implement a cloud-based ASR solution to establish proof of concept in a prototype system. In addition, the advent of a cloud-based ASR solution meant that a more reliable lesson transcript could be generated and, as a result, the direction of this work could move towards exploiting the utility provided by lesson transcription to generate a meaningful lesson summary. An initial prototype implementation was then developed based on the initial model using a cloud-based ASR approach. The final model presented in this work makes use of keyword identification in the transcription process, in collaboration with a course content database to identify known, educator-defined keyword terms during a lesson that are tied to relevant course content items for the specified lesson. As the model or prototype was improved and adapted, its counterpart was modified appropriately, ensuring that each reflected both the theoretical and practical aspects of the other. After a series of improvement cycles, a final version of the model was ascertained, supported by a performance evaluation of an acceptable prototype system. Ultimately, the prototype proved capable of generating a lesson summary, presented to students to bolster secondary contact with lesson content. This lesson summary provides students with a lesson transcript, but also helps them to monitor educator-defined keyword terms, their prevalence as communicated in the lesson by the educator, and their associations with educator-defined sections of course content. The prototype was developed with a modular approach so that its speech recognition component was interchangeable between CMU’s Sphinx and Google Cloud’ Speech-to-Text speech recognition systems, both accessed via a cloud-based programming library. In addition to the ASR module, noise injection, cancellation and reduction were also introduced to the prototype as a speech enhancement module to demonstrate the effects of noise on the prototype. The prototype was tested using different configurations of speech recognition- and speech enhancement techniques to demonstrate the change in accuracy of lesson summary generation. Proof of concept was established using the Google Cloud Continuous Speech Recognition System, which prevailed over CMU’s Sphinx and enabled the prototype to achieve 100,00% accuracy in keyword identification and subsequent association on noise-free speech, contrasted with a 96,93% accuracy in keyword identification and subsequent association on noise-polluted speech when applying noise cancellation. , Thesis (MIT) -- Faculty of Engineering, the Built Environment, and Technology, School of Information Technology, 2024
- Full Text:
- Date Issued: 2024-04
Defining and regulating de facto and shadow directors: lessons from New Zealand
- Authors: Botha, Bernardus Hermanus
- Date: 2024-04
- Subjects: Business law , Companies Act 71 of 2008. , Company Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63059 , vital:73182
- Description: The term ‘director’ is commonly limited to those persons who have been validly appointed as directors. These directors are referred to as de jure directors. However, this is not the only type of director found in practical corporate settings. There are also those who have not been validly appointed as a director, who nonetheless act as directors and who are held out by companies as such. These persons are known as de facto directors. An individual who has not been validly appointed as a director, who is not held out by a company as such, but who still exercises some measure of control over the affairs of a company, is known as a shadow director. The existence of de facto and shadow directors is not peculiar to South Africa. New Zealand has seen fit to regulate de facto and shadow directors and has done so for over 70 years. Owing to the ambiguous wording of the definition of ‘director’ contained in the Companies Act, there is uncertainty whether the current definition in the Companies Act 71 of 2008 extends to de facto and shadow directors. This uncertainty resulted in the non-regulation of these forms of directorship. The Act only applies to those individuals who fall within the definition of ‘director’. The practical effect of this is the absence of clear avenues of accountability to those who occupy a position of power within a company without being appointed as a de jure director. Considering this, the core objectives of this research are to illustrate the far-reaching consequences of the non-regulation of de facto and shadow directors and how this problem may be remedied. , Thesis (LLM) -- Faculty of Law
- Full Text:
- Date Issued: 2024-04
- Authors: Botha, Bernardus Hermanus
- Date: 2024-04
- Subjects: Business law , Companies Act 71 of 2008. , Company Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63059 , vital:73182
- Description: The term ‘director’ is commonly limited to those persons who have been validly appointed as directors. These directors are referred to as de jure directors. However, this is not the only type of director found in practical corporate settings. There are also those who have not been validly appointed as a director, who nonetheless act as directors and who are held out by companies as such. These persons are known as de facto directors. An individual who has not been validly appointed as a director, who is not held out by a company as such, but who still exercises some measure of control over the affairs of a company, is known as a shadow director. The existence of de facto and shadow directors is not peculiar to South Africa. New Zealand has seen fit to regulate de facto and shadow directors and has done so for over 70 years. Owing to the ambiguous wording of the definition of ‘director’ contained in the Companies Act, there is uncertainty whether the current definition in the Companies Act 71 of 2008 extends to de facto and shadow directors. This uncertainty resulted in the non-regulation of these forms of directorship. The Act only applies to those individuals who fall within the definition of ‘director’. The practical effect of this is the absence of clear avenues of accountability to those who occupy a position of power within a company without being appointed as a de jure director. Considering this, the core objectives of this research are to illustrate the far-reaching consequences of the non-regulation of de facto and shadow directors and how this problem may be remedied. , Thesis (LLM) -- Faculty of Law
- Full Text:
- Date Issued: 2024-04
Self-attentive vision in evolutionary robotics
- Authors: Botha, Bouwer
- Date: 2024-04
- Subjects: Evolutionary robotics , Robotics , Neural networks (Computer science)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63628 , vital:73566
- Description: The autonomy of a robot refers to its ability to achieve a task in an environment with minimal human supervision. This may require autonomous solutions to be able to perceive their environment to inform their decisions. An inexpensive and highly informative way that robots can perceive the environment is through vision. The autonomy of a robot is reliant on the quality of the robotic controller. These controllers are the software interface between the robot and environment that determine the actions of the robot based on the perceived environment. Controllers are typically created using manual programming techniques, which become progressively more challenging with increasing complexity of both the robot and task. An alternative to manual programming is the use of machine learning techniques such as those used by Evolutionary Robotics (ER). ER is an area of research that investigates the automatic creation of controllers. Instead of manually programming a controller, an Evolutionary Algorithms can be used to evolve the controller through repeated interactions with the task environment. Employing the ER approach on camera-based controllers, however, has presented problems for conventional ER methods. Firstly, existing architectures that are capable of automatically processing images, have a large number of trained parameters. These architectures over-encumber the evolutionary process due to the large search space of possible configurations. Secondly, the evolution of complex controllers needs to be done in simulation, which requires either: (a) the construction of a photo-realistic virtual environment with accurate lighting, texturing and models or (b) potential reduction of the controller capability by simplifying the problem via image preprocessing. Any controller trained in simulation also raises the inherent concern of not being able to transfer to the real world. This study proposes a new technique for the evolution of camera-based controllers in ER, that aims to address the highlighted problems. The use of self-attention is proposed to facilitate the evolution of compact controllers that are able to evolve specialized sets of task-relevant features in unprocessed images by focussing on important image regions. Furthermore, a new neural network-based simulation approach, Generative Neuro-Augmented Vision (GNAV), is proposed to simplify simulation construction. GNAV makes use of random data collected in a simple virtual environment and the real world. A neural network is trained to overcome the visual discrepancies between these two environments. GNAV enables a controller to be trained in a simple simulated environment that appears similar to the real environment, while requiring minimal human supervision. The capabilities of the new technique were demonstrated using a series of real-world navigation tasks based on camera vision. Controllers utilizing the proposed self-attention mechanism were trained using GNAV and transferred to a real camera-equipped robot. The controllers were shown to be able to perform the same tasks in the real world. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Botha, Bouwer
- Date: 2024-04
- Subjects: Evolutionary robotics , Robotics , Neural networks (Computer science)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63628 , vital:73566
- Description: The autonomy of a robot refers to its ability to achieve a task in an environment with minimal human supervision. This may require autonomous solutions to be able to perceive their environment to inform their decisions. An inexpensive and highly informative way that robots can perceive the environment is through vision. The autonomy of a robot is reliant on the quality of the robotic controller. These controllers are the software interface between the robot and environment that determine the actions of the robot based on the perceived environment. Controllers are typically created using manual programming techniques, which become progressively more challenging with increasing complexity of both the robot and task. An alternative to manual programming is the use of machine learning techniques such as those used by Evolutionary Robotics (ER). ER is an area of research that investigates the automatic creation of controllers. Instead of manually programming a controller, an Evolutionary Algorithms can be used to evolve the controller through repeated interactions with the task environment. Employing the ER approach on camera-based controllers, however, has presented problems for conventional ER methods. Firstly, existing architectures that are capable of automatically processing images, have a large number of trained parameters. These architectures over-encumber the evolutionary process due to the large search space of possible configurations. Secondly, the evolution of complex controllers needs to be done in simulation, which requires either: (a) the construction of a photo-realistic virtual environment with accurate lighting, texturing and models or (b) potential reduction of the controller capability by simplifying the problem via image preprocessing. Any controller trained in simulation also raises the inherent concern of not being able to transfer to the real world. This study proposes a new technique for the evolution of camera-based controllers in ER, that aims to address the highlighted problems. The use of self-attention is proposed to facilitate the evolution of compact controllers that are able to evolve specialized sets of task-relevant features in unprocessed images by focussing on important image regions. Furthermore, a new neural network-based simulation approach, Generative Neuro-Augmented Vision (GNAV), is proposed to simplify simulation construction. GNAV makes use of random data collected in a simple virtual environment and the real world. A neural network is trained to overcome the visual discrepancies between these two environments. GNAV enables a controller to be trained in a simple simulated environment that appears similar to the real environment, while requiring minimal human supervision. The capabilities of the new technique were demonstrated using a series of real-world navigation tasks based on camera vision. Controllers utilizing the proposed self-attention mechanism were trained using GNAV and transferred to a real camera-equipped robot. The controllers were shown to be able to perform the same tasks in the real world. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-04
An in vitro evaluation of the anti-breast cancer activity of Nigella sativa extracts and its bioactive compound in combination with curcumin
- Authors: Botha, Susanna Gertruida
- Date: 2024-04
- Subjects: Herbs -- Therapeutic use , Radiation-protective agents , Breast -- Cancer -- Treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63639 , vital:73571
- Description: Breast cancer constitutes 23% of all cancers in South African females. Curcumin and Nigella sativa have anti-cancer, anti-metastatic and antioxidant-properties and may be effective against breast cancer. This study focused on the effect of N. sativa extracts or thymoquinone and curcumin, individually and in combination, on breast cancer cells. An MTT assay showed that curcumin reduced cell viability by 50% (IC50) at 18 ± 2.63 μg/mL and thymoquinone (TQ) at 5 ± 0.95 μg/mL against the MDA-MB-231 cells. The IC50 values for curcumin and TQ were 35 ± 6.98 μg/mL and 4 ± 0.96 μg/mL against the MCF-7 cells, respectively. The IC50 value for the NSBE was determined to be 350 ± 55 μg/mL. The IC50 value of NSAE did not fall within the selected concentration range. Synergism was noted for combinations of NSBE with curcumin, and combinations of TQ with curcumin, against both MCF-7 and MDA-MB-231 cells. Two synergistic combinations per treatment per cell line, as determined by the combination index analysis, were chosen for further investigation. The combinations and individual treatments tested against the MCF-10A cells, were not significant, except for NSBE80:CURC20 combination. Curcumin had the most significant anti-oxidant activity; however, no link was noted between the anti-oxidant activity and the cytotoxicity of the combinations. The combination treatments induced apoptosis more effectively than the individual treatments. Caspase-3 dependent apoptosis was noted for NSBE10:CURC90 and TQ80:CURC20 combinations against the MDA-MB-231 cells, and the TQ60:CURC40 combination against the MCF-7 cells. The individual and combined treatments effectively reduced MDA-MB-231 cell adhesion to fibronectin, but not all reduced the cell adhesion to laminin. Based on these results, the combinations of curcumin with TQ or NSBE, have promising anticancer benefits against breast cancer. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Botha, Susanna Gertruida
- Date: 2024-04
- Subjects: Herbs -- Therapeutic use , Radiation-protective agents , Breast -- Cancer -- Treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63639 , vital:73571
- Description: Breast cancer constitutes 23% of all cancers in South African females. Curcumin and Nigella sativa have anti-cancer, anti-metastatic and antioxidant-properties and may be effective against breast cancer. This study focused on the effect of N. sativa extracts or thymoquinone and curcumin, individually and in combination, on breast cancer cells. An MTT assay showed that curcumin reduced cell viability by 50% (IC50) at 18 ± 2.63 μg/mL and thymoquinone (TQ) at 5 ± 0.95 μg/mL against the MDA-MB-231 cells. The IC50 values for curcumin and TQ were 35 ± 6.98 μg/mL and 4 ± 0.96 μg/mL against the MCF-7 cells, respectively. The IC50 value for the NSBE was determined to be 350 ± 55 μg/mL. The IC50 value of NSAE did not fall within the selected concentration range. Synergism was noted for combinations of NSBE with curcumin, and combinations of TQ with curcumin, against both MCF-7 and MDA-MB-231 cells. Two synergistic combinations per treatment per cell line, as determined by the combination index analysis, were chosen for further investigation. The combinations and individual treatments tested against the MCF-10A cells, were not significant, except for NSBE80:CURC20 combination. Curcumin had the most significant anti-oxidant activity; however, no link was noted between the anti-oxidant activity and the cytotoxicity of the combinations. The combination treatments induced apoptosis more effectively than the individual treatments. Caspase-3 dependent apoptosis was noted for NSBE10:CURC90 and TQ80:CURC20 combinations against the MDA-MB-231 cells, and the TQ60:CURC40 combination against the MCF-7 cells. The individual and combined treatments effectively reduced MDA-MB-231 cell adhesion to fibronectin, but not all reduced the cell adhesion to laminin. Based on these results, the combinations of curcumin with TQ or NSBE, have promising anticancer benefits against breast cancer. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
An implementation model: photovoltaic application for sustainable energy in South Africa
- Authors: Bukula, Mvuleni
- Date: 2024-04
- Subjects: Energy development -- South Africa , Renewable energy sources -- South Africa , Sustainable engineering -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64511 , vital:73743
- Description: South African electrical grid faces significant risks that the state produced electricity supply from electricity network to premises for consumption will not meet the electricity demand. Certain sectors of the economy and essential social services such as the hospitals, the telecommunications networks, and water companies are heavily impacted on by load management, through load shedding by rotating power outages or reducing power consumption from primary sources until demand decreases. Eskom, as the major electricity supplier in South Africa's aging infrastructure, with declining reliability, substandard quality coal and large gaps between generating capacity and demand, leaves the country vulnerable to electricity blackouts. The consequences of such power outages are devastating, but no single technology solution can meet the demand. Localised backup solutions such as solar power and battery backup limit the risk of power outages and provide power security during the periods of load shedding. Quantitative research method is pursued as a systematic survey to collect quantitative data by means of sampling and submitting online survey questionnaires. After receiving the data, statistical techniques were performed through structural equation modeling to analyse the structural relationship between the measured variables and the underlying variables. This research focuses on photovoltaic applications as a means of harnessing solar energy to convert solar energy into electricity. Solar panels consist of photovoltaic cells made of semiconductors or materials that respond to the action of photons of light. Energy availability to all can promote economic development and human well-being. Without the improvements in energy efficiency and development costs of new energy technologies such as photovoltaics, the global energy system will come under even more pressure. Therefore, changes in the global trend towards a decentralised low-carbon energy system are inevitable to ensure affordable, reliable and sustainable energy access for all. This research seeks to contribute to the present challenges that are facing South Africa’s electricity supply industry by increasing the energy mix of renewable energy as compared to the fossil fuel-based electricity supply. , Thesis (DPhil) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Bukula, Mvuleni
- Date: 2024-04
- Subjects: Energy development -- South Africa , Renewable energy sources -- South Africa , Sustainable engineering -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64511 , vital:73743
- Description: South African electrical grid faces significant risks that the state produced electricity supply from electricity network to premises for consumption will not meet the electricity demand. Certain sectors of the economy and essential social services such as the hospitals, the telecommunications networks, and water companies are heavily impacted on by load management, through load shedding by rotating power outages or reducing power consumption from primary sources until demand decreases. Eskom, as the major electricity supplier in South Africa's aging infrastructure, with declining reliability, substandard quality coal and large gaps between generating capacity and demand, leaves the country vulnerable to electricity blackouts. The consequences of such power outages are devastating, but no single technology solution can meet the demand. Localised backup solutions such as solar power and battery backup limit the risk of power outages and provide power security during the periods of load shedding. Quantitative research method is pursued as a systematic survey to collect quantitative data by means of sampling and submitting online survey questionnaires. After receiving the data, statistical techniques were performed through structural equation modeling to analyse the structural relationship between the measured variables and the underlying variables. This research focuses on photovoltaic applications as a means of harnessing solar energy to convert solar energy into electricity. Solar panels consist of photovoltaic cells made of semiconductors or materials that respond to the action of photons of light. Energy availability to all can promote economic development and human well-being. Without the improvements in energy efficiency and development costs of new energy technologies such as photovoltaics, the global energy system will come under even more pressure. Therefore, changes in the global trend towards a decentralised low-carbon energy system are inevitable to ensure affordable, reliable and sustainable energy access for all. This research seeks to contribute to the present challenges that are facing South Africa’s electricity supply industry by increasing the energy mix of renewable energy as compared to the fossil fuel-based electricity supply. , Thesis (DPhil) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
Credit accessibility and enabling policies for SMMEs in King Sabata Dalindyebo Local Municipality South Africa
- Authors: Busakwe, Lomso
- Date: 2024-04
- Subjects: Credit -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Small business -- Management -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64884 , vital:73938
- Description: Small, medium and micro enterprises contribute significantly to the economy, approximately 34% to South Africa’s Gross Domestic Product. They also play a vital role in the economy as drivers for reducing unemployment. In a modern transforming globe, small, medium and micro enterprises depend on funding. Categorically, credit in South Africa is limited to small, medium and micro enterprises from banks, this has to do with the credit histories, policies and collateral. The issue of policies that make it convenient for Small, medium and micro enterprises to obtain loans have proven to be difficult. These policies aspects have verified to be specifically difficult for regulations meant to increase asset-based total lending. The aim of the study was to assesses the role, adequacy and gaps of current policies to enhance credit accessibility by SMMEs in the KSDLM. The following research objectives are pursued: to identify the challenges faced by small businesses in the KSDLM, specifically from a credit access perspective; to identify the role of policies in assisting SMMEs to access credit for their small businesses in the KSDLM; to identify the policy gaps that hinder access to credit by SMMEs in the KSDLM; to draft a policy framework that enhances access to credit by SMMEs. A mixed method approach was adopted in this study. A questionnaire for quantitative approach, as well as an interview schedule for qualitative approach, was used to collect data. A sample of 145 small, medium, and micro enterprises, as well as 5 financial institutions, was utilised for the study. The study revealed numerous challenges that are hindering small, medium and micro enterprises from accessing credit and they are compliant, lack of proper record keeps, poor adjustment to technology, collateral and stability. Most small, medium and micro enterprises mentioned are facing challenges in accessing credit owing to the policies that are in place that do not cater for all their challenges and shortcomings. The study recommend that the Government can provide financial assistance to small businesses through grants, loans, tax incentives, and subsidies. These initiatives can reduce the financial burden on small businesses, allowing them to invest in growth, innovation and sustainability. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Busakwe, Lomso
- Date: 2024-04
- Subjects: Credit -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Small business -- Management -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64884 , vital:73938
- Description: Small, medium and micro enterprises contribute significantly to the economy, approximately 34% to South Africa’s Gross Domestic Product. They also play a vital role in the economy as drivers for reducing unemployment. In a modern transforming globe, small, medium and micro enterprises depend on funding. Categorically, credit in South Africa is limited to small, medium and micro enterprises from banks, this has to do with the credit histories, policies and collateral. The issue of policies that make it convenient for Small, medium and micro enterprises to obtain loans have proven to be difficult. These policies aspects have verified to be specifically difficult for regulations meant to increase asset-based total lending. The aim of the study was to assesses the role, adequacy and gaps of current policies to enhance credit accessibility by SMMEs in the KSDLM. The following research objectives are pursued: to identify the challenges faced by small businesses in the KSDLM, specifically from a credit access perspective; to identify the role of policies in assisting SMMEs to access credit for their small businesses in the KSDLM; to identify the policy gaps that hinder access to credit by SMMEs in the KSDLM; to draft a policy framework that enhances access to credit by SMMEs. A mixed method approach was adopted in this study. A questionnaire for quantitative approach, as well as an interview schedule for qualitative approach, was used to collect data. A sample of 145 small, medium, and micro enterprises, as well as 5 financial institutions, was utilised for the study. The study revealed numerous challenges that are hindering small, medium and micro enterprises from accessing credit and they are compliant, lack of proper record keeps, poor adjustment to technology, collateral and stability. Most small, medium and micro enterprises mentioned are facing challenges in accessing credit owing to the policies that are in place that do not cater for all their challenges and shortcomings. The study recommend that the Government can provide financial assistance to small businesses through grants, loans, tax incentives, and subsidies. These initiatives can reduce the financial burden on small businesses, allowing them to invest in growth, innovation and sustainability. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
Exploring cultural context and masculine ideals: implications for male mental health help-seeking in South Africa
- Authors: Bux, Shezadia
- Date: 2024-04
- Subjects: Mental health counseling , Masculinity -- South Africa , Men -- Mental health
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69604 , vital:77961
- Description: The pervasive underdiagnosis and undertreatment of mental health issues among males, exacerbated by societal expectations of masculinity, represent a significant public health concern. This study addresses the critical gap in understanding how sociocultural constructs of masculinity influence mental health help-seeking behaviours among males in South Africa, a context marked by high rates of crime, violence, substance abuse, and male suicides. Adopting a qualitative research approach, this study conducted in-depth interviews with 12 participants, employing convenience and snowball sampling techniques to achieve data saturation. Thematic analysis was utilised to systematically identify and interpret patterns of meaning within the data, focusing on participants' understandings of mental health, the impact of sociocultural constructions of masculinity on their help-seeking behaviours, and the barriers they encounter. The findings illuminate the profound impact of sociocultural constructs of masculinity on male mental health help-seeking behaviours, revealing significant barriers rooted in societal stigma, traditional masculinity norms, and a lack of tailored mental health services. The study also introduces a conceptual model illustrating the influences on mental health acknowledgement and help-seeking behaviour among males in South Africa, underscored by a reflective analysis of exploring male emotional well-being. This study highlights the urgent need for culturally sensitive mental health care interventions that address the unique challenges faced by men in South African communities. By challenging societal norms and advocating for improved mental health awareness and services tailored to men, this research contributes to the broader discourse on gender, mental health, and social change, offering insights for researchers, policymakers, and practitioners aiming to enhance male mental health outcomes. , Thesis (MA) -- Faculty of Health Science, School of School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Bux, Shezadia
- Date: 2024-04
- Subjects: Mental health counseling , Masculinity -- South Africa , Men -- Mental health
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69604 , vital:77961
- Description: The pervasive underdiagnosis and undertreatment of mental health issues among males, exacerbated by societal expectations of masculinity, represent a significant public health concern. This study addresses the critical gap in understanding how sociocultural constructs of masculinity influence mental health help-seeking behaviours among males in South Africa, a context marked by high rates of crime, violence, substance abuse, and male suicides. Adopting a qualitative research approach, this study conducted in-depth interviews with 12 participants, employing convenience and snowball sampling techniques to achieve data saturation. Thematic analysis was utilised to systematically identify and interpret patterns of meaning within the data, focusing on participants' understandings of mental health, the impact of sociocultural constructions of masculinity on their help-seeking behaviours, and the barriers they encounter. The findings illuminate the profound impact of sociocultural constructs of masculinity on male mental health help-seeking behaviours, revealing significant barriers rooted in societal stigma, traditional masculinity norms, and a lack of tailored mental health services. The study also introduces a conceptual model illustrating the influences on mental health acknowledgement and help-seeking behaviour among males in South Africa, underscored by a reflective analysis of exploring male emotional well-being. This study highlights the urgent need for culturally sensitive mental health care interventions that address the unique challenges faced by men in South African communities. By challenging societal norms and advocating for improved mental health awareness and services tailored to men, this research contributes to the broader discourse on gender, mental health, and social change, offering insights for researchers, policymakers, and practitioners aiming to enhance male mental health outcomes. , Thesis (MA) -- Faculty of Health Science, School of School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Organisational citizenship behaviour (OCB) in the South African transport state-owned enterprises
- Authors: Calvert, Candice
- Date: 2024-04
- Subjects: Organizational behavior -- South Africa , Government business enterprises -- South Africa , Government ownership -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64896 , vital:73944
- Description: The transport sector is critically important for economic growth and sustainability of a country and therefore requires carefully crafted strategical policies aimed at social enhancements. Employees who are employed in the major South African transport sector’s State-Owned Enterprises (SOEs) carry the responsibility of providing quality and effective services, thus, they are executing the mandate of the National Department of Transport (NDoT). Therefore, their willingness to contribute positively to the goals of the sector, is critically important. Extra-roles and positive behaviours displayed by employees ensure that organisations gain competitive advantage over competitors. These special behaviours are documented in literature as organisational citizenship behaviours (OCB). OCB is referred to as voluntary positive behaviours displayed by employees, which benefit the organisation and improve the overall performance of employees and the organisation but are not recognised by the reward system of the organisation. The scarcity of literature pertaining to OCB in SOEs and in particular, the transport sector globally indicates that OCB is not entrenched in organisational cultures in this sector. The primary objective of this study is to investigate the views of management and employees regarding the influential factors and the outcomes of OCB in South Africa’s major SOEs in the transport sector. A hypothetical model and a questionnaire were developed to establish the influential factors of OCB and its outcomes on the performance of South Africa’s major transport SOEs. Eight independent variables (leadership styles, organisational culture, management support, personal importance, transparency, job autonomy, employee trust and organisational commitment), the intervening variable (organisational citizenship behaviour) and the dependent variables (employee performance and employee retention) were investigated. Primary data was collected by means of electronic questionnaires, which were distributed to five provinces via a QuestionPro link that was emailed to the contact person nominated by the HR department of the two major transport SOEs. Hard copies of the questionnaire were also physically distributed to prospective participants by the researcher. Non-probability sampling was used, specifically convenience sampling technique. The study targeted 500 respondents and 318 questionnaires were usable which amounts to a response rate of 64%. The reliability of the measuring instrument was determined by means of Cronbach’s alpha coefficient and the construct validity was tested using exploratory factor analysis (EFA). Content validity for the measuring instrument was validated by experts in the fields of organisational behaviour and change management, prior to the distribution of the questionnaire to participants. EFA, descriptive statistics, multiple regression analysis and correlation analysis were determined. A STATISTICA computer programme 14.0 was used. The results of the study showed that OCB, which was tested as a seven-dimensional construct, namely, altruism, sportsmanship, loyalty, individual initiative, civic virtue, courtesy, and self-development, was perceived by respondents as two constructs, namely, OCB-selflessness (OCB-S) (altruism, sportsmanship, individual initiative, courtesy and self-development) and OCB-reliability (OCB-R) (civic virtue and loyalty). The empirical results revealed that personal importance is significantly related to OCB-S, but is not significantly related to OCB-R. Furthermore, the findings showed that transparency is not significantly related to OCB-S, however, there is a significant positive relationship between transparency and OCB-R. It was also found that job autonomy is not significantly related to OCB-S, and has a significant negative relationship with OCB-R. In addition, the research findings showed that employee trust and organisational commitment are significantly related to both OCB-S and OCB-R. OCB-S and OCB-R were found to be significantly related to employee performance and employee retention. This study contributed to the body of knowledge in the fields of organisational behaviour and human resources. Furthermore, the study will contribute to policy makers and management within the transport sector of South Africa and globally in order to develop policies and devise strategies to combat negative workplace environments, stimulate service delivery, and improve the competitive advantage of the organisation and the economic sustainability in the transport sector globally, through employee performance and employee retention. , Thesis (DBA) -- Faculty of Business and Economic Sciences, Business School, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Calvert, Candice
- Date: 2024-04
- Subjects: Organizational behavior -- South Africa , Government business enterprises -- South Africa , Government ownership -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/64896 , vital:73944
- Description: The transport sector is critically important for economic growth and sustainability of a country and therefore requires carefully crafted strategical policies aimed at social enhancements. Employees who are employed in the major South African transport sector’s State-Owned Enterprises (SOEs) carry the responsibility of providing quality and effective services, thus, they are executing the mandate of the National Department of Transport (NDoT). Therefore, their willingness to contribute positively to the goals of the sector, is critically important. Extra-roles and positive behaviours displayed by employees ensure that organisations gain competitive advantage over competitors. These special behaviours are documented in literature as organisational citizenship behaviours (OCB). OCB is referred to as voluntary positive behaviours displayed by employees, which benefit the organisation and improve the overall performance of employees and the organisation but are not recognised by the reward system of the organisation. The scarcity of literature pertaining to OCB in SOEs and in particular, the transport sector globally indicates that OCB is not entrenched in organisational cultures in this sector. The primary objective of this study is to investigate the views of management and employees regarding the influential factors and the outcomes of OCB in South Africa’s major SOEs in the transport sector. A hypothetical model and a questionnaire were developed to establish the influential factors of OCB and its outcomes on the performance of South Africa’s major transport SOEs. Eight independent variables (leadership styles, organisational culture, management support, personal importance, transparency, job autonomy, employee trust and organisational commitment), the intervening variable (organisational citizenship behaviour) and the dependent variables (employee performance and employee retention) were investigated. Primary data was collected by means of electronic questionnaires, which were distributed to five provinces via a QuestionPro link that was emailed to the contact person nominated by the HR department of the two major transport SOEs. Hard copies of the questionnaire were also physically distributed to prospective participants by the researcher. Non-probability sampling was used, specifically convenience sampling technique. The study targeted 500 respondents and 318 questionnaires were usable which amounts to a response rate of 64%. The reliability of the measuring instrument was determined by means of Cronbach’s alpha coefficient and the construct validity was tested using exploratory factor analysis (EFA). Content validity for the measuring instrument was validated by experts in the fields of organisational behaviour and change management, prior to the distribution of the questionnaire to participants. EFA, descriptive statistics, multiple regression analysis and correlation analysis were determined. A STATISTICA computer programme 14.0 was used. The results of the study showed that OCB, which was tested as a seven-dimensional construct, namely, altruism, sportsmanship, loyalty, individual initiative, civic virtue, courtesy, and self-development, was perceived by respondents as two constructs, namely, OCB-selflessness (OCB-S) (altruism, sportsmanship, individual initiative, courtesy and self-development) and OCB-reliability (OCB-R) (civic virtue and loyalty). The empirical results revealed that personal importance is significantly related to OCB-S, but is not significantly related to OCB-R. Furthermore, the findings showed that transparency is not significantly related to OCB-S, however, there is a significant positive relationship between transparency and OCB-R. It was also found that job autonomy is not significantly related to OCB-S, and has a significant negative relationship with OCB-R. In addition, the research findings showed that employee trust and organisational commitment are significantly related to both OCB-S and OCB-R. OCB-S and OCB-R were found to be significantly related to employee performance and employee retention. This study contributed to the body of knowledge in the fields of organisational behaviour and human resources. Furthermore, the study will contribute to policy makers and management within the transport sector of South Africa and globally in order to develop policies and devise strategies to combat negative workplace environments, stimulate service delivery, and improve the competitive advantage of the organisation and the economic sustainability in the transport sector globally, through employee performance and employee retention. , Thesis (DBA) -- Faculty of Business and Economic Sciences, Business School, 2024
- Full Text:
- Date Issued: 2024-04
The role of environmental factors, vegetation type, and community knowledge, attitude, and practices on schistosomiasis intermediate host snails’ distribution in the Nelson Mandela Bay water bodies
- Authors: Campbell, Prince Samkelo
- Date: 2024-04
- Subjects: Schistosoma -- Nelson Mandela Bay Municipality (South Africa) , Schistosomiasis -- Nelson Mandela Bay Municipality (South Africa) , Schistosomiasis -- Prevention -- Nelson Mandela Bay Municipality (South Africa) , Tropical medicine
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63813 , vital:73615
- Description: Schistosomiasis, often known as bilharzia, is a parasitic water-borne disease caused by trematode flatworms of the genus Schistosoma. In 76 endemic countries, including 46 in Africa, over 800 million individuals are at risk of contracting the disease. This study examined the influence of water physicochemical properties, vegetation type and community knowledge, attitudes and practices (KAP) on the distribution and habitat preference of schistosomiasis intermediate host snails in the communities of Kariega and Kwa Nobuhle, in Nelson Mandela Bay. Methods. A quantitative cross-sectional research design approach was employed in this study. Data for the water physicochemical properties was collected over different seasons over a 9-month period. Eight sampling sites were selected based on their proximity to residential areas. A simple dip method was used for surface water samples and measurements done using a Bante 900P multiparameter meter, Macherey Nagel PF-12 plus, and hardness meter. A 300 μm mesh scoop net on a metal frame was used to capture snails. At each sample site, the predominant plant species were gathered and transported to experts in the Botany Department at Nelson Mandela University for identification. The composition and percentage cover of vegetation were visually estimated and documented. A structured questionnaire was used to elicit responses from 380 participants for the pre- and post-intervention KAP study, using the interview format. Data was analysed using R software (version 4.3.1) and Microsoft Office 365 Excel (2019 version). Results. Freshwater snails were found in all eight water bodies studied; however, schistosomiasis intermediate host snails were only found in three of them while the prevailing species in the study sites were Physa snails. There was no correlation between the number of snails and turbidity (r=-0.070). However, a negative and weak correlation existed between snails and DO (r=-0.185), hardness (r=-0.210), pH (r=-0.235), TDS (r=-0.236), EC (r=-0.240), salinity (r=-0.242), and temperature (r=-0.273). There was also a negative correlation between snails and vegetation coverage (r=-0.127). Of the 380 study participants, only 8.7% were aware of the disease pre-intervention. The paired samples t-test results demonstrate a difference (7.2 ± 2.5) in knowledge scores, and the improvement in knowledge levels post-intervention is statistically significant (p<0.001). Conclusion. The study discovered an abundance of Physa snails; considering their biological characteristics and ability to endure, these snails could potentially serve as a biological control agent in locations where the , Thesis (MSc) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Campbell, Prince Samkelo
- Date: 2024-04
- Subjects: Schistosoma -- Nelson Mandela Bay Municipality (South Africa) , Schistosomiasis -- Nelson Mandela Bay Municipality (South Africa) , Schistosomiasis -- Prevention -- Nelson Mandela Bay Municipality (South Africa) , Tropical medicine
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63813 , vital:73615
- Description: Schistosomiasis, often known as bilharzia, is a parasitic water-borne disease caused by trematode flatworms of the genus Schistosoma. In 76 endemic countries, including 46 in Africa, over 800 million individuals are at risk of contracting the disease. This study examined the influence of water physicochemical properties, vegetation type and community knowledge, attitudes and practices (KAP) on the distribution and habitat preference of schistosomiasis intermediate host snails in the communities of Kariega and Kwa Nobuhle, in Nelson Mandela Bay. Methods. A quantitative cross-sectional research design approach was employed in this study. Data for the water physicochemical properties was collected over different seasons over a 9-month period. Eight sampling sites were selected based on their proximity to residential areas. A simple dip method was used for surface water samples and measurements done using a Bante 900P multiparameter meter, Macherey Nagel PF-12 plus, and hardness meter. A 300 μm mesh scoop net on a metal frame was used to capture snails. At each sample site, the predominant plant species were gathered and transported to experts in the Botany Department at Nelson Mandela University for identification. The composition and percentage cover of vegetation were visually estimated and documented. A structured questionnaire was used to elicit responses from 380 participants for the pre- and post-intervention KAP study, using the interview format. Data was analysed using R software (version 4.3.1) and Microsoft Office 365 Excel (2019 version). Results. Freshwater snails were found in all eight water bodies studied; however, schistosomiasis intermediate host snails were only found in three of them while the prevailing species in the study sites were Physa snails. There was no correlation between the number of snails and turbidity (r=-0.070). However, a negative and weak correlation existed between snails and DO (r=-0.185), hardness (r=-0.210), pH (r=-0.235), TDS (r=-0.236), EC (r=-0.240), salinity (r=-0.242), and temperature (r=-0.273). There was also a negative correlation between snails and vegetation coverage (r=-0.127). Of the 380 study participants, only 8.7% were aware of the disease pre-intervention. The paired samples t-test results demonstrate a difference (7.2 ± 2.5) in knowledge scores, and the improvement in knowledge levels post-intervention is statistically significant (p<0.001). Conclusion. The study discovered an abundance of Physa snails; considering their biological characteristics and ability to endure, these snails could potentially serve as a biological control agent in locations where the , Thesis (MSc) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
The determinants of foreign direct investment inflows into South Africa
- Authors: Campher, Renate
- Date: 2024-04
- Subjects: Investments, Foreign -- South Africa , Economic development -- South Africa , South Africa -- Foreign economic relations
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64907 , vital:73958
- Description: Through mechanisms such as knowledge transfer and productivity spillovers, foreign direct investment (FDI) is viewed as a critical driver of growth in developing economies. The flow of FDI into a country can benefit both the investing entity and the host government. This study employed ordinary least square (OLS) regression to examine the factors that determine FDI in South Africa using time series data from 1996 to 2021. The results demonstrate that gross domestic product (GDP), institutional quality, trade openness, the regulatory environment, and the real effective exchange rate (REER) all have positive effects on FDI flows into South Africa. To sustain and promote FDI inflows, the government of South Africa must ensure that the country remains attractive for investment by better promoting good governance, creating jobs to increase growth, maintaining free and fair elections in 2024, forging alliances with trading partners outside of Africa, speeding up all policy processes that may hinder the inflow of FDI, and decreasing government debt. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Campher, Renate
- Date: 2024-04
- Subjects: Investments, Foreign -- South Africa , Economic development -- South Africa , South Africa -- Foreign economic relations
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64907 , vital:73958
- Description: Through mechanisms such as knowledge transfer and productivity spillovers, foreign direct investment (FDI) is viewed as a critical driver of growth in developing economies. The flow of FDI into a country can benefit both the investing entity and the host government. This study employed ordinary least square (OLS) regression to examine the factors that determine FDI in South Africa using time series data from 1996 to 2021. The results demonstrate that gross domestic product (GDP), institutional quality, trade openness, the regulatory environment, and the real effective exchange rate (REER) all have positive effects on FDI flows into South Africa. To sustain and promote FDI inflows, the government of South Africa must ensure that the country remains attractive for investment by better promoting good governance, creating jobs to increase growth, maintaining free and fair elections in 2024, forging alliances with trading partners outside of Africa, speeding up all policy processes that may hinder the inflow of FDI, and decreasing government debt. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- 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
- Full Text:
- Date Issued: 2024-04
- 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
- Full Text:
- Date Issued: 2024-04