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Evaluating the potential of monometallic and bimetallic nanomaterials as horseradish peroxidase mimetics

- Mvango, Sindisiwe

Authors: Mvango, Sindisiwe
Date: 2017
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/65134 , vital:28694
Description: This study presents the synthesis of citrate-capped gold nanoparticles (cit-AuNPs), copper oxide nanoparticles (CuONPs), glutathione-capped gold nanoparticles (GSH-AuNPs), 4- aminothiophenol-capped gold nanoparticles (4-ATP-AuNPs), 4-mercapto benzoic acid- capped gold nanoparticles (4-MBA-AuNPs) and copper oxide gold nanoalloys (CuO-Au nanoalloys). Microscopy and spectroscopy techniques were used to confirm the successful synthesis of these nanoparticles. The synthesized nanoparticles were studied their potential applications as horseradish peroxidase (HPR) enzyme mimetics and for the detection of glucose. The cit-AuNPs and GSH-AuNPs exhibited peroxidase-like activity towards hydrogen peroxide (H2O2) with high Michaelis-Menten (Km) values of 61.5 mM and 30.8 mM, respectively. The other nanoparticles, that is, 4-ATP-AuNPs, CuONPs and CuO-Au nanoalloys gave lower Km values of 4.74 mM, 1.92 mM and 4.05 mM, respectively. The obtained Km values were comparable to those of HRP enzymes which ranged from 0.214 - 3.70 mM with 4-ATP-AuNPs and CuO-Au nanoalloys slightly higher. These values were within the reasonable experimental values of the HRP enzyme. The studies showed that the gold nanoparticles had low adsorptive efficiency towards H2O2 compared to the copper-based nanoparticles (CuONPs and CuO-Au nanoalloys). The CuO-Au nanoalloys also showed the synergistic effect between the gold and copper nanoparticles with extended linear concentration range for the quantification of H2O2. The mechanism of catalysis was confirmed using UV-vis spectroscopy and electron paramagnetic resonance (EPR) in that the generation of reactive oxygen species was observed. The use of 1,3-diphenylisobenzofuran (DPBF) as radical quencher and 5,5- dimethyl-1-pyrroline N-oxide (DMPO) as a radical scavenger confirmed the production of reductive reactive oxygen species using UV-vis and EPR studies. The rate of production of reactive oxygen species in the gold-based nanoparticles was small compared to the copper-based nanoparticles, that is CuONPs and CuO-Au (bimetallic) nanoalloys. The synthesized nanoparticles were further studied their potential use in the colorimetric detection of glucose. The copper-based nanomaterials, CuONPs and CuO-Au nanoalloys, were excellent towards detection of glucose, with a limit of detection (LoD) of 9.34 pM for CuONPs and 6.75 pM for CuO-Au nanoalloys. The linear concentration (LCR) range of CuONPs was 0 to 70 pM and for CuO-Au nanoalloys the LCR was 0.0 - 30 pM. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
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Date Issued: 2017

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Outcome and impact assessment in the comprehensive evaluation of rural ICT projects in developing countries

- Mtkoko, Hafeni Tulimewawa Wilhelmina Lyatenda

Authors: Mtkoko, Hafeni Tulimewawa Wilhelmina Lyatenda
Date: 2017
Subjects: Uncatalogued
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/64483 , vital:28548 , DOI 10.21504/10962/64483
Description: Despite existing literature that indicates that Information and communication technologies (ICTs) act as tools for social change and development, there is still limited empirical evidence that demonstrates this. An outcome and impact assessment based on a comprehensive (holistic) evaluation is deemed appropriate at a time when many ICT4D programmes fail to effectively demonstrate their impact towards rural development. A comprehensive evaluation is one that incorporates the evaluation of the need, design, implementation, outcome and impact, efficiency, and scalability of a programme. These stages make up the different domains of an evaluation lifecycle. The following study aims to develop an outcome and impact assessment framework for ICT4D programmes. It forms part of continuous research associated with the development of a rural ICT Comprehensive Evaluation framework. A theoretical approach, using Design Science and Weick’s theorizing process, was applied to investigate the development of a framework (design artefact) for outcome and impact assessment of ICT4D programmes. The theorizing process analysed existing outcome and impact assessment frameworks from social programmes, information systems/technology programmes, and ICT4D programmes. The output of the theorizing process proposes five critical themes of outcome and impact assessment of rural ICT4D programmes that should be assessed. These themes include: Strategic Value, Most Significant Change, Empowerment, Livelihoods, and Sustainability. To assess its utility, the framework was implemented in the Siyakhula Living Lab and Information and Communication Technology for Rural Education (ICT4RED) projects in South Africa. Through the application of the framework in real life ICT4D contexts, the lessons learned contributed to its revision and enhancement. The proposed framework aims to guide evaluators through the assessment of outcomes and impacts in ICT4D programmes. It provides a foundation and justification for the selected outcome and impact assessment themes that contribute to a comprehensive evaluation. An outcome and impact assessment that is informed by: baseline; needs assessment; programme theory assessment; and process assessment data, provides ICT4D evaluators and project stakeholders with meaningful outcome and impact feedback. Having such an approach to outcome and impact assessment ensures that the evaluation process is seen more holistically as part of the ICT4D project as a whole. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2017
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Date Issued: 2017

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An unsung dialogue: music, society and the history of The Flames

- Park, Duncan Keith

Authors: Park, Duncan Keith
Date: 2016
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/193645 , vital:45376
Description: This research aims to examine the relationship between music and social conditions within the context of apartheid. The focus area is the city of Durban, specifically 1960-1970. A case study of the multi-racial Durban-based band, The Flames (1963 – 1972) will be used to rigorously assess the extent to which social conditions and music can affect each other in both directions. This will also be the first coherent and historical narrative of the band, The Flames. As such, the thesis aims to make an original contribution to this field of music history, while it will provide the very first academic discussion of The Flames. , Thesis (MA) -- Faculty of Humanities, History, 2016
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Date Issued: 2016

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Behaviour and trophic ecology of oceanic triggerfish (Canthidermis maculata) and rainbow runner (Elagatis bipinnulata) associated with floating objects in the open ocean

- Forget, Fabien Rocky Gilbert

Authors: Forget, Fabien Rocky Gilbert
Date: 2016
Subjects: Uncatalogued
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/193531 , vital:45340
Description: The oceanic triggerfish (Canthidermis maculata) and rainbow runner (Elagatis bipinnulata) are epipelagic species that commonly associate with floating objects throughout the world’s tropical oceans. Besides tunas, these two species often form the bulk of the aggregation and are major non-target species (bycatch) incidentally captured at fish aggregation devices (FADs) by tropical tuna purse seiners. Despite being abundant, little is known about their basic biology, ecology and associative behavior with floating objects. This thesis aims to address knowledge gaps in their associative behavior and ecology at floating objects and attempts to explore potential bycatch mitigation methods. Acoustic telemetry was used to characterise several aspects of the two species’ behavior at floating objects. Fish were captured and tagged at drifting FADs in the core of the western Indian Ocean tuna fishing grounds. Prolonged remote observations were obtained through satellite linked receivers which provided fine-scale data on the behavior of oceanic triggerfish (n= 46 919 cumulated observation days) and rainbow runner (n= 24 538 cumulated observation days). The two species remained associated with the same floating object for periods extending up to several months. The mean residence time estimated using a survival analysis was 65 days for oceanic triggerfish and 94 days for rainbow runner. A distinct diel pattern in association was observed; the two species were closely associated to the FAD during the night and increased their home range during the day while performing short excursions (oceanic triggerfish mean: 2.0 hours ±1.6 SD; rainbow runner mean: 2.4 hours ±2.2 SD) away from the FAD. Similarly, distinct patterns in the vertical movements and locomotory activity (measured using accelerometer tags) were observed as the two species increased their vertical movements and activity levels during the day. Generally, their vertical movements were largely restricted to the mixed layer (< 60 m). At night, the two species remained close to the surface (0-5 m) where they appear to be in a resting state. An interesting behavioural switch in activity levels and vertical distribution was observed for oceanic triggerfish which coincided with a change in the environment as the FAD drifted close to a cold-core cyclonic eddy. Ambient light appears to be the key stimulus triggering the observed diel behavioural patterns. species-specific vulnerability for target species, skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares), bigeye tuna (Thunnus obesus) and non-target species, including silky shark (Carcharhinus falciformis), oceanic triggerfish, and rainbow runner, to the purse seine fishing gear were investigated. Hourly presence rates at FADs over 24 hours were examined to assess whether the capture rate of non-target species could be reduced at specific times during the day. Silky sharks displayed a similar associative pattern to that of targeted tunas. Moreover, the vulnerability of both target and non-target species were close to the maximum during the period of behavioural transitions at sunrise when the majority of the fishing sets are made. As such, a change in set time in the western Indian Ocean does not appear to be a feasible method to reduce capture rates of non-target species. Stomach content and stable isotope analysis were conducted on oceanic triggerfish (stomach n = 152, isotope n = 65) and rainbow runner (stomach n = 156, isotope n = 71) incidentally captured individuals at FADs by purse seiners. Typical FAD-associated prey items represented a minor component of their diet as they predominantly foraged on zooplankton and micronekton in the water column, suggesting that oceanic triggerfish and rainbow runner do not associate to floating objects for direct trophic advantages. Overlap in their dietary and isotopic niches indicates an intermediate level of competition. Overall, the spatial and trophic ecology of both species are remarkably similar and prolonged associations with FADs indicates that floating objects play a significant ecological role in the pelagic environment for the two species. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2016
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Date Issued: 2016

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Islamic compliant short term insurance: an exploratory study to develop an Islamic compliant insurance model within a South African context

- Jeeva, Shakir

Authors: Jeeva, Shakir
Date: 2016
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/193633 , vital:45375
Description: In a world where there is ever increasing risks to be mitigated, either by choice or due to the law of the country, an insurance instrument is the most popular risk mitigation tool. However, from an Islamic perspective, Muslims have certain parameters to adhere to due to the laws and boundaries as set out in the Quraan, as well as the teachings of the final prophet, Prophet Muhammed (Peace Be Upon Him). This has relevance in this context as, according to Islam, the conventional insurance models are in contravention of certain Islamic laws as they contain elements which are not acceptable in the Muslim faith. Therefore, the Islamic insurance models, or Takaful models, have removed the impermissible elements of usury, speculation, and uncertainty, which are all contained in the current conventional insurance models. By removing these impermissible elements from the insurance model, the Takaful model is acceptable for Muslims to use as a risk mitigation tool. The primary aim of the study sought to propose a short term Islamic compliant insurance model within a South African framework. The secondary aims were to ascertain the Islamic requirements for an Islamic insurance model, how these requirements fit into an insurance model, to then compare and contrast the differences between conventional insurance and Islamic insurance and, lastly, to explore awareness and attitudes towards Islamic insurance. Therefore, from the above, a proposed short term Islamic insurance model was developed within a South African context which conforms to the laws and boundaries of Islam, making this insurance model permissible to use as a Takaful tool. Additionally, semi structured interviews were conducted with certain research participants, using purposive sampling, to examine the attitudes and knowledge of the Muslim community towards the Takaful model within a South African context. It was concluded that while the majority of the research participants understand the Takaful model and the significance of this, they have chosen to use the conventional insurance offerings due to the fact that they were unaware of other Takaful alternatives, or due to the fact that the Takaful alternative was out-priced when compared to the conventional insurance offerings. It was therefore concluded that while there is a need for Takaful offerings within South Africa, this must be done in conjunction with additional marketing, education and competitive pricing for potential clients to consider this as an insurance option. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2016
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Date Issued: 2016

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Human FN1 is regulated by the heat-shock response

- Dhanani, Karim Colin Hassan

Authors: Dhanani, Karim Colin Hassan
Date: 2015
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/193487 , vital:45336
Description: Heat shock protein 90 (Hsp90) and heat shock factors (HSFs) are known to be involved in the epigenetic regulation of several fundamental oncogenic genes. Fibronectin (FN) is an extracellular matrix (ECM) glycoprotein which plays key roles in cell adhesion and migration. Hsp90 binds directly to FN and Hsp90 inhibition has been shown to regulate FN protein levels and matrix formation. Where inhibition of Hsp90 with a C-terminal inhibitor (novobiocin) induced the loss of FN matrix, treatment with an N-terminal inhibitor (geldanamycin) increased FN matrix levels. GA treatment induced a strong dose and time dependent increase in FN1 promoter activity and increased total FN mRNA respectively. By contrast, NOV showed no increase in the promoter activity and no change in the expression of FN mRNA. As GA is known to induce the stress response, we investigated the relationship between the cell stress machinery and the transcriptional regulation of FN. Three putative heat shock elements (HSEs) were identified in the FN1 promoter. The loss of two of the three identified putative HSEs resulted in a loss in the basal transcriptional activity of the FN1 promoter in our reporter model. This was in addition to the loss of the induction of transcriptional activity with GA treatment observed with the full-length promoter. Binding of HSF1 to one of the putative HSEs, which was identified as potentially functional from the truncation analysis, was confirmed using ChIP. The occupancy of this HSE by HSF1 was shown to increase with GA treatment. These data support the hypothesis that FN1 is a functional HSF1 target gene. The 5' promoter regions of seven additional ECM protein encoding genes were analysed and mRNA levels were detected by quantitative RT-PCR upon treatment with GA. Collagen 4 _2 and laminin _3 mRNA were found to increase in the presence of GA, whereas collagen 4 _3 and osteopontin showed no change. Similarly to FN1, these data indicate that a subset of ECM genes may be under the regulation of the HSF1 mediated heat-shock response. This may have implications for our understanding of ECM dynamics in cancer, where the clinical application of Hsp90 inhibitors is intended. Additionally, our data provide a poten- tial underpinning for the role of the HSF1 mediated heat-shock response in several fibrotic and metabolic stress related pathologies. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2015
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Date Issued: 2015

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If I Stay Right Here

- Ngamlana, Chwayita

Authors: Ngamlana, Chwayita
Date: 2015
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/193498 , vital:45337
Description: My novella concerns the dynamics of a relationship between two girls. It shows the heterosexual‐like nature of the relationship rather than dwelling on the pressures on lesbians from society as a whole. At its core is the raw emotion and passion of the relationship, which is at the same time toxic, destructive and volatile because of their class differences and other insecurities. The work is influenced by the grit, openness, and innovation of several contemporary writers. , Thesis (MA) -- Faculty of Humanities, Institute for the Study of English in Africa, 2015
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Date Issued: 2015

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Modification and application of the decentralised wastewater treatment technology for greywater treatment to reduce water needs

- Ngqwala, Nosiphiwe Patience

Authors: Ngqwala, Nosiphiwe Patience
Date: 2015
Subjects: Uncatalogued
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/193509 , vital:45338
Description: Water is a scarce resource that is being acknowledged as a limiting factor to further social- economic growth and development. Demand for freshwater is increasing with corresponding increases in human population, industrial and agricultural activities. Alternative sources, such as greywater and rainwater are often polluted. Though greywater can be used for non-potable purposes, such as irrigation, it still requires some measures of treatment to improve its quality. To improve on greywater quality to facilitate its reuse, decentralised wastewater treatment technologies carry a great potential as complementary and alternative means of wastewater management particularly in peri-urban areas. Five research goals are addressed in this thesis: (i) to monitor the performance of Fly Ash Lime Filter Tower (FLFT) in the treatment of greywater; (ii) to modify the Fly Ash Lime Filter Tower in the treatment of greywater in order to reduce the pH of the greywater, and improved on the reduction of chemical oxygen demand (COD) and coliform counts; (iii) to investigate the potential of the reuse of greywater for irrigation; (iv) to undertake a techno analysis of the FLFT system for commercial use; and (v) to evaluate the use of hydrogen-sulphide (H2S) test kit to monitor faecal contamination of various water sources using a multidisciplinary approach. The modification of the FLFT indicated good treatment efficiency, reducing the concentrations of COD, chlorides, nitrates, ammonia and sulphate by 82.6%, 60.4%, 72.9%, 60.5%, and 53.9%, respectively; while the average pH was at 8.3. Greywater contains nutrients that are beneficial to the growth of most plants. Growth variables included biomass, stem height, number of leaves and number of vegetables harvested. Soil analysis showed no effects of the treated greywater on soil physico-chemical and microbial quality with bulk density 2.0g/cm3, average pH 7.4, total phosphorus 0.16mg/L 8, faecal coliform 0.3 CFU/100 ml. The tomatoes had high biomass and dry weight (150 g; 33g) than beetroot (35 g; 15 g). Crops irrigated with greywater significantly grew faster compared with those irrigated with tap water. The community approach highlighted the value of knowledge management in greywater reuse. It highlighted the importance of creating an institutional knowledge in water management using the H2S kit. The techno-economic analysis was used to evaluate key factors and the activities that are relevant to develop a sustainable FLFT in order to gain insights into the possibility of developing, and incorporating a business model framework to support decision making in value creation and value capturing during the research and the scaling up of the system. By this, a long term perspective to accomplish sustainable FLFT service businesses can be achieved. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2015
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Date Issued: 2015

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The reform of world order?: BRICS in an Interpolar world

- Phyllis, Yvonne

Authors: Phyllis, Yvonne
Date: 2015
Subjects: Uncatalogued
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/193520 , vital:45339
Description: International relations has recently seen new developments which are unpredictable and in their infant stage. The causes of these developments are plentiful, the consequences stemming from waning unipolarity to the emergence of new fora creating their own spaces. Whatever the case, international relations is not as it was in the period just after the Cold War. As a result, the terms of global governance established after 1990 have come under serious scrutiny. This transition has the makings of a new world order, an interpolar world order. This study asserts that we no longer live in a unipolar world, nor do we live in a world which can only be described as multipolar. It makes the argument that although multipolarity is a crucial element of the world, it only offers a partial description of today’s order. The study asserts that it is interpolarity which is closest in accounting for today’s world. Not only does it describe the world as multipolar, it also describes it as interdependent. To this end, the study provides a detailed account of what is meant by an interpolar world order and how differently it explains international events. It also provides an account of factors which can develop in an interpolar world. One of these includes allowing room for emerging powers to create their own spaces in efforts of avoiding co-option while continuing to realise the importance of operating within a context of continuity. This means that emerging countries create their own spaces but they also realise the importance of working with already established regimes such as the G20. BRICS (Brazil, Russia, India, China and South Africa) is used as a case study to indicate one of the new developments afforded by an interpolar order-the emergence of new fora. The study asserts that although BRICS is rife with internal dissimilarities, it has indicated some degree of political will in one aspect; that is; advocating for the reform of the terms of global governance, advocating for more representative forms of global governance. The study thus explores factors of a world whose contours are gradually changing but which are unpredictable and in flux. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2015
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Date Issued: 2015

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