#KeepItReal: discursive constructions of authenticity in South African consumer culture
- Authors: Plüg, Simóne Nikki
- Date: 2019
- Subjects: Consumer behavior Consumers' preferences -- South Africa Brand choice -- South Africa Marketing -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64973 , vital:28641
- Description: Writers as diverse as Oscar Wilde (1915), Matthew Arnold (1960), Erich Fromm (1997) and a proliferation of contemporary self-help gurus, variously assert that it is preferable for people to focus on “being”, or to value “who you are”, instead of emphasising “having” or the material possessions you have acquired. These discourses assert that individuals content with “being” are happier and more fulfilled than those involved in the constant (and alienating) motion of acquiring material goods as representations of themselves (de Botton, 2004; Fromm, 1997; James, 2007). This thesis provides an in-depth critical exploration of one of these ideal “ways of being”: authenticity. It does not seek to discover what authenticity is in an empirical sense, nor to define what it should be in a normative sense, but to map the cultural work done by changing and often contradictory discourses of personal authenticity. More specifically, this study uses a qualitative research design, social constructionist theoretical framework, and discourse analytic method to critically discuss the discursive constructions of subject authenticity in South African brand culture. The sample consisted of (1.) ten marketing campaigns of several large, mainstream brands, which were popular in South Africa from 2015 to 2017, and (2.) fifteen smaller South African “craft” brands popular in the “artisanal” context. The analysis is presented in two distinct, but interrelated, sections (namely, Selling Stories and Crafting Authenticity), where the relevant discourses of authenticity for each data set are explored in depth. Through this analysis the thesis provides a critical discussion of the ways in which these discourses of authenticity work to produce and maintain, (or challenge and subvert), subject positions, ideologies, and power relations that structure contemporary South African society.
- Full Text:
- Date Issued: 2019
A classification of large wetlands in Africa’s elevated drylands based on their formation, structure, and hydrological functioning using Earth Observation (EO) data and Geographic Information System (GIS)
- Authors: Lidzhegu, Zwidofhelangani
- Date: 2020
- Subjects: Wetlands -- Africa -- Classification , Wetlands -- Africa -- Research , Wetlands -- Africa -- Monitoring , Topographical surveying -- Africa , Hydrological surveys == Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142668 , vital:38100
- Description: Due to wetland inaccessibility and limited wetland geomorphological studies, there is limited information on the geomorphological origin and hydrological functioning of different types of wetlands in Africa’s elevated drylands. As a result, there is limited information for the development of a comprehensive wetland classification system that classifies wetlands based on long-term geomorphic processes that determine their formation and shape, their structure and hydrological functioning. Therefore, the current study was designed to classify large wetlands in Africa’s elevated drylands based on processes that determine their formation, and shape their structure and hydrological functioning using remote sensing and Geographic Information System (GIS) techniques. Although wetlands perform a number of hydrological functions including groundwater recharge and water purification, the current study focuses mainly on their flood attenuation function. Detailed analysis of topographic information was undertaken using Shuttle Radar Topographic Mission (SRTM) elevations measured at the scale of 30 m x 30 m. LandsatLook and Google Earth images, tectonic as well as geological data were used as supplementary data for developing an understanding of the origin, structure and hydrological characteristics of wetlands. The Principal Component Analysis (PCA) of wetland environmental variables was used to identify and explain wetland heterogeneity. The results of the study showed that fluvial processes, tectonic history and the evolution of Africa’s landscape played a fundamental role in the formation and evolution of wetlands. This study demonstrates a wide range of processes that contribute to wetland formation, structure and functioning. At one extreme it is clear that tectonic processes may be primarily responsible for the creation of basins that host wetlands. At another extreme, wetlands may be structured primarily by fluvial processes. At a third extreme are wetlands that superficially appear to be structured by fluvial processes, but which have their structures modified by gradual rising of the base level at their distal ends, either through marginal uplift adjacent to rift valleys, or through aggradation of a floodplain that blocks a tributary valley. Overall, the classification of wetlands considered in this study can be summarised into four distinct groupings, with two of these divided further into two groupings each: (1) Tectonic basins with little or no indication of fluvial development (Bahi and Wembere wetlands), (2) Tectonic basins evolving towards a wetland with a structure increasingly shaped by fluvial characteristics (Usangu wetland), (3) Fluvially modified valleys with a local base level at the toe of the wetland such as a resistant lithology or a tectonic control that limits the rate of incision of easily weathered and eroded lithologies, leading to valley widening and longitudinal slope reduction, which are of two distinct types: (a) With a catchment on Kalahari Group sediment that is transported fluvially as bedload, and therefore with no prominent alluvial ridge or backwater depressions (Upper Zambezi and Barotse wetlands), (b) With a catchment that produces abundant fine sediment that is deposited as overbank sediments, leading to channel migration via meandering and to the construction of an elevated alluvial ridge (Lufira wetland), (4) Fluvially modified basins with evidence of gradual elevation of the base level at the toe of the wetland, which are of two types: (a) Tectonic marginal rift valley uplift such that they behave more as depression wetlands rather than as wetlands shaped by fluvial processes (Kafue and Luapula wetlands), (b) Tributary valley wetlands blocked by aggradation of the trunk valley (Lukanga wetland). In conclusion, although few geomorphological studies have been conducted on southern African wetlands because of their inaccessibility, Africa’s surface topography and its historical evolution, as well as aridity, provide an opportunity for illustrating the important role that the long-term tectonic, geological and geomorphological processes play in determining wetland origin, structure and dynamics. GIS methodology and Earth Observation (EO) data on the other hand, provide a practical means for acquiring information on inaccessible and hard to traverse wetland systems. A novel cut-and-fill approach for delineating wetlands from a Digital Elevation Model (DEM) was presented as another way in which GIS methodology and Earth Observation (EO) data can provide practical means for assessing inaccessible and hard to traverse wetland systems.
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- Date Issued: 2020
A combined modelling approach for simulating channel–wetland exchanges in large African river basins
- Authors: Makungu, Eunice J
- Date: 2020
- Subjects: Watersheds -- Africa , Watershed management -- Africa , Water resources development -- Africa -- International cooperation , Floodplain management -- Africa , Wetland ecology -- Simulation methods -- Africa , Wetland management -- Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/123288 , vital:35424
- Description: In Africa, many large and extensive wetlands are hydrologically connected to rivers, and their environmental integrity, as well as their influence on downstream flow regimes, depends on the prevailing channel–wetland exchange processes. These processes are inherently complex and vary spatially and temporally. Understanding channel–wetland exchanges is therefore, indispensable for the effective management of wetlands and the associated river basins. However, this information is limited in most of the river basins containing large wetlands in Africa. Furthermore, it is important to understand the links between upstream and downstream flow regimes and the wetland dynamics themselves, specifically where there are water resource developments that may affect these links (upstream developments), or be affected by them (downstream developments). Hydrological modelling of the entire basin using basin-scale models that include wetland components in their structures can be used to provide the information required to manage water resources in such basins. However, the level of detail of wetland processes included in many basin-scale models is typically very low and the lack of understanding of the wetland dynamics makes it difficult to quantify the relevant parameters. Detailed hydraulic models represent the channel-wetland exchanges in a much more explicit manner, but require relatively more data and time resources to establish than coarser scale hydrological models. The main objective of this study was, therefore, to investigate the use of a detailed hydraulic wetland model to provide a better understanding of channel–wetland exchanges and wetland dynamics, and to use the results to improve the parameterisation of a basin-scale model. The study focused on improving the water resource assessments modelling of three data-scarce African river basins that contain large wetlands: the floodplains of the Luangwa and Upper Zambezi River basins and the Usangu wetland in the Upper Great Ruaha River basin. The overall objective was achieved through a combined modelling approach that uses a detailed high-resolution LISFLOOD-FP hydraulic model to inform the structure and parameters of the GW Pitman monthly hydrological model. The results from the LISFLOOD-FP were used to improve the understanding of the channel–wetland exchange dynamics and to establish the wetland parameters required in the GW Pitman model. While some wetland parameters were directly quantified from the LISFLOOD-FP model results, others, which are highly empirical, were estimated by manually calibrating the GW Pitman wetland sub-model implemented in excel spreadsheets containing the LISFLOOD-FP model results. Finally, the GW Pitman model with the inclusion of the estimated wetland parameters was applied for each basin and the results compared to the available downstream observed flow data. The two models have been successfully applied in southern Africa, with the GW Pitman model being one of the most widely applied hydrological models in this region. To address the issue of data scarcity, during setup of these models, the study mainly relied on the global datasets which clearly adds to the overall uncertainty of the modelling approach. However, this is a typical situation for most of the data scarce regions of the continent. A number of challenges were, however, faced during the setup of the LISFLOOD-FP, mainly due to the limitations of the data inputs. Some of the LISFLOOD-FP data inputs include boundary conditions (upstream and downstream), channel cross-sections and wetland topography. In the absence of observed daily flows to quantify the wetland upstream boundary conditions, monthly flow volumes simulated using the GW Pitman monthly model (without including the wetland sub-model) were disaggregated into daily flows using a disaggregation sub-model. The simulated wetland inflows were evaluated using the observed flow data for downstream gauging stations that include the wetland effects. The results highlighted that it is important to understand the possible impacts of each wetland on the downstream flow regime during the evaluations of the model simulation results. Although the disaggregation approach cannot be validated due to a lack of observed data, it at least enables the simulated monthly flows to be used in the daily time step hydraulic model. One of the recommendations is that improvements are required in gauging station networks to provide more observed information for the main river and the larger tributary inflows into these large and important wetland systems. Even a limited amount of newly observed data would be helpful to reduce some of the uncertainties in the combined modelling approach. The SRTM 90 m DEM (used to represent wetland topography) was filtered to reduce local variations and noise effects (mainly vegetation bias), but there were some pixels that falsely affect the inundation results, and the recently released vegetation-corrected DEMs are suggested to improve the simulation results. Channel cross-section values derived from global datasets should be examined because some widths estimated from the Andreadis et al. (2013) dataset were found to be over-generalised and did not reflect widths measured using high-resolution Google Earth in many places. There is an indication that channel cross-sections digitised from Google Earth images can be successfully used in the model setup except in densely vegetated swamps where the values are difficult to estimate, and in such situations, field measured cross-section data are required. Small channels such as those found in the Usangu wetland could play major role in the exchange dynamics, but digitising them all was not straightforward and only key ones were included in the model setup. Clearly, this inevitably introduced uncertainties in the simulated results, and future studies should consider applying methods that simplify extractions of most of these channels from high-resolution images to improve the simulated results. The study demonstrated that the wetland and channel physical characteristics, as well as the seasonal flow magnitude, largely influence the channel–wetland exchanges and wetland dynamics. The inundation results indicated that the area–storage and storage–inflow relationships form hysteretic curves, but the shape of these curves vary with flood magnitude and wetland type. Anticlockwise hysteresis curves were observed in both relationships for the floodplains (Luangwa and Barotse), whereas there appears to be no dominant curve type for the Usangu wetlands. The lack of well-defined hysteretic relationships in the Usangu could be related to some of the difficulties (and resulting uncertainties) that were experienced in setting up the model for this wetland. The storage–inflow relationships in all wetlands have quite complex rising limbs due to multiple flow peaks during the main wet season. The largest inundation area and storage volume for the Barotse and Usangu wetlands occurred after the peak discharge of the wet season, a result that is clearly related to the degree of connectivity between the main channel and those areas of the wetlands that are furthest away from the channel. Hysteresis effects were found to increase with an increase in flood magnitudes and temporal variations in the wetland inflows. Overall, hysteresis behaviour is common in large wetlands and it is recommended that hysteresis curves should be reflected in basin-scale modelling of large river basins with substantial wetland areas. At a daily time scale, inflow–outflow relationships showed a significant peak reduction and a delayed time to peak of several weeks in the Barotse and Usangu wetlands, whereas the attenuation effects of the Luangwa floodplain are minimal. To a large extent, the LISFLOOD-FP results provided useful information to establish wetland parameters and assess the structure of Pitman wetland sub-model. The simple spreadsheet used to estimate wetland parameters did not account for the wetland water transfers from the upstream to the next section downstream (the condition that is included in the LISFLOOD-FP model) for the case when the wetlands were distributed across more than one sub-basin. It is recommended that a method that allows for the upstream wetland inflows and the channel inflows should be included in the spreadsheet. The same is true to the Pitman model structure, and a downstream transfer of water can be modelled through return flows to the channel. The structure of the wetland sub-model was modified to allow an option for the return flows to occur at any time during the simulation period to provide for types of wetlands (e.g. the Luangwa) where spills from the channel and drainage back to the channel occur simultaneously. The setup of the GW Pitman model with the inclusion of wetland parameters improved the simulation results. However, the results for the Usangu wetlands were not very satisfactory and the collection of additional field data related to exchange dynamics is recommended to achieve improvements. The impacts of the Luangwa floodplain on the flow regime of the Luangwa River are very small at the monthly time scale, whereas the Barotse floodplain system and the Usangu wetlands extensively regulate flows of the Zambezi River and the Great Ruaha River, respectively. The results highlighted the possibilities of regionalising some wetland parameters using an understanding of wetland physical characteristics and their water exchange dynamics. However, some parameters remain difficult to quantify in the absence of site-specific information about the water exchange dynamics. The overall conclusion is that the approach implemented in this study presents an important step towards the improvements of water resource assessments modelling for research and practical purposes in data-scarce river basins. This approach is not restricted to the two used models, as it can be applied using different model combinations to achieve similar study purpose.
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- Date Issued: 2020
A comparative analysis of the use of participatory practices by indigenous trusts and mainstream development NGOs in Zvimba Communal Area Zimbabwe
- Authors: Mbanje, Bowden Bolt
- Date: 2020
- Subjects: Caritas Zimbabwe , Zvimba Community Share Ownership Trust (ZvCSOT) , Non-governmental organizations -- Zimbabwe -- Zvimba District , Community development -- Zimbabwe -- Zvimba District , Rural development -- Zimbabwe -- Zvimba District , Zvimba Communal Land (Zimbabwe)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167099 , vital:41437
- Description: This thesis compares the extent to which participatory practices have been used by Caritas Zimbabwe, a mainstream NGO, and the Zvimba Community Share Ownership Trust (ZvCSOT), an indigenous Trust, in Zvimba District, Zimbabwe. Participatory development initiatives are common practice in NGO and government development work in Zimbabwe. The thesis begins with a discussion of two aspects of participatory development (PD). Firstly, PD is discussed in relation to decentralization processes where central government transfers administrative and financial authority to sub-national government units in order to enhance the participation of rural communities in development interventions. Secondly, PD is discussed in relation to the increased role of NGOs in development work. During the 1980s and 1990s, shifts in development thinking resulted in NGOs being perceived as important actors who could attend to the development gaps left by an economically incapacitated state. Both NGOs and sub-national government units were seen to be closer to rural communities and so were thought to be in a better position to enhance the participation of these communities in meaningful development projects. An analysis of the practices of the NGO and CSOT under consideration in this study shows that while there has been much rhetorical commitment to participation, community participation in the development interventions of the NGO and the CSOT is inadequate. In introducing and implementing development interventions, there has been a tendency by both the NGO and CSOT to give priority to organizational preferences over local needs. While recognizing the participatory efforts made by mainstream development NGOs (Caritas in particular) and indigenous Trusts (Zvimba Community Share Ownership Trust in particular) in Zimbabwe, this thesis also considers the impact of other factors on participatory development initiatives. A major observation from the study is that in as much as we expect genuine participatory approaches which include grassroots communities’ inputs from the project’s conceptualization all the way to its evaluation, the challenge is that the elites at the higher level (central government and donor offices) have their own development preferences and interests while the elites at the lower levels (local government and NGO offices) also have their own priorities and needs. Consequently, local communities tend to be confined to implementing development projects foisted on them by elites at the higher level as well as those at the lower level. Worse still, the study shows that elites at the lowest level (community) sometimes hijack or take advantage of the imposed projects. Participation has been stalled by elites at various levels of the participatory development ladder. Thus, unless power imbalances are seriously addressed at all levels, participatory development will remain elusive.
- Full Text:
- Date Issued: 2020
A computational analysis to decipher the pathways of stability, uncoating and antigenicity of human enterovirus capsids
- Authors: Ross, Caroline Jane
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/114788 , vital:34035 , 10.21504/10962/114788
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
A constructivist deconstruction of post-apartheid South Africa’s trade negotiation strategies: the politics of development and global value chains
- Authors: Pillay, Morgenie
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64731 , vital:28596
- Description: Expected release date-May 2020
- Full Text:
- Date Issued: 2015
A critical analysis of the de-peasantisation process in Nepal with specific reference to the role of state land policies since the 1950s
- Authors: Basnet, Jagat
- Date: 2020
- Subjects: Land tenure -- Nepal , Land reform -- Law and legislation -- Nepal , Nepal -- Politics and government , Peasants -- Nepal -- Economic conditions , Panchayat -- Nepal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/138716 , vital:37667
- Description: The principal objective of this thesis is to offer a critical analysis of the process of de-peasantisation in Nepal since 1950, with a particular focus on the capitalist neo-liberal restructuring of the economy beginning in the early 1990s. The analysis begins by tracing the legacy of feudal land practices and landholdings from the pre-1950 Rana and Shah dynasties. It was under these feudal dynasties that economic and political institutions of extraction first emerged, leading to a landlord-peasant agrarian economy in which peasants (often as tenants/sharecroppers and smallholders) were subordinate to the power nexus between feudal landlords and the ruling dynasties. After 1950, a window of democratic opening was soon interrupted by the formation of the party-less Panchayat system, which lasted from 1960 to 1990. In 1964, a major land reform measure was enacted under the Lands Act, with the goal of enhancing the security and livelihood of the peasantry. However, this process was met with significant resistance by feudal landlords, and actually led to deepening insecurity and the loss of land by peasants, with farmers belonging to lower castes and indigenous groups experiencing this with a greater degree of intensity. The overall result of this period was the beginnings of what is referred to in this study as de-peasantisation. This line of analysis shows that the institutions of extraction remained firmly in place even after the reforms of this period. Finally, the neo-liberal period, which was marked by land titling, the marketisation of land, and the commercialisation of agriculture, represents the late entry of capitalism into Nepal. This period saw the deepening and widening of the process of de-peasantisation, including further loss of peasants’ access to land and a general turn to wage-labour. In this regard, despite propagating the slogan ‘land to the tillers’, the major political parties in Nepal (including the Maoist party) have failed to defend the interests of the peasantry. Some progressive civil society groups have recently sought to do better, but there is also evidence of peasant organisations themselves seeking to resist and oppose the de-peasantisation effects of neo-liberal restructuring. This thesis thus considers the form and extent of de-peasantisation in Nepal, and some responses to it, over an extended period. A broad Marxist-based political economy perspective has been adopted in pursuing the principal thesis objective, but one which argues that there is a symbiotic relationship between economic and political power, such that the latter is not reducible to the former. The thesis draws upon original fieldwork in twenty districts of Nepal, including through the use of a survey, interviews, observations, case studies, and focus group discussions, thus combining both quantitative and qualitative research methods. Based on this fieldwork, it becomes clear that (i) there are major social, economic, and political forces behind the processes of de-peasantisation in the studied districts (and in Nepal more broadly), and that (ii) the Nepali peasantry is becoming increasingly landless, or land-short, and subject to processes of proletarianisation.
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- Date Issued: 2020
A critical analysis of the establishment, conceptualisation, design and curriculum component selection of Master of Education programmes at selected Tanzanian universities
- Authors: Ramadhan, Maryam Khamis
- Date: 2018
- Subjects: Master of education degree Tanzania , Universities and colleges Curricula Tanzania , Universities and colleges Evaluation , Teacher effectiveness Tanzania , Master of education degree , Educational change Tanzania , Secondary school teachers Tanzania , Pedagogical content knowledge Tanzania , Universities and colleges Administration , Critical realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62214 , vital:28139
- Description: There is a dearth of research on how the design and curriculum of a Master of Education (MEd) qualification for university-based teacher educators of prospective secondary school teachers may or may not contribute to the problem of poor secondary school learning outcomes in Tanzania. This qualitative study analyses the establishment, conceptualisation, design and curriculum components of selected MEd programmes with the purpose of identifying and explaining the conditions enabling and/or constraining the development of quality teacher educators. The research used a case study design to investigate how and why particular knowledge is privileged in two MEd programmes at two Tanzanian universities with a view to probing the relevance of the knowledge to teacher educators professional roles and practices. The study used critical realism as an under-labourer to investigate power structures and the generative and causal mechanisms underlying the two MEd programmes. The study draws on aspects of Bernstein’s theory as analytical tools to explain what emerges from the data. The data was collected from interviews, document analysis and observation, and analysed using thematic analysis, abductive and retroductive modes of inference. The research revealed and explains how underlying structural and agential mechanisms have shaped the establishment, conceptualisation and curriculum design of the two MEd programmes. The findings revealed a strong relationship between constraints, including the lack of appropriate MEd design team and the inadequacy of resources and facilities, and the quality of MEd graduates. Such constrains are possible mechanisms associated with the agential actions of the top administrators affect the relevance and appropriateness of the MEd curriculum components, the effective lecturers transmission and students acquisition of knowledge and skills. The research also explored how underlying mechanisms shaped the selection of course content and the privileging of certain types of teacher knowledge. These mechanisms include programme entry qualification, curriculum arrangement of core and elective courses, the lack of awareness of the knowledge and skills requisite for teacher educators’ specialisation, and the absence of recontextualisation principles to guide appropriate selection and recontextualisation of the relevant teacher educator’s courses. There is evidence that both MEd programmes have insufficient pedagogical knowledge and lack large components of academic content knowledge of teaching. An emphasis on individual disciplinary education courses with strong boundaries between modules and topics, aimed at developing specific education specialisations, results in teacher educator professional knowledge being less developed. Furthermore the accumulation and repetition of inappropriate knowledge has resulted in these programmes being weak regions for teacher educators’ professional fields of practice. This has implications for the quality of the secondary school teacher professional development courses on which these MEd graduates teach. It raises questions about the quality of the secondary school teachers being produced, and the extent to which this is contributing to the disappointing performance of Tanzanian schooling. The study generates insights into the mechanisms and conditions constraining the development of quality teacher educators. These conditions include the domination of higher education by customer demand, weak university regulatory systems, and the autonomy of university administration in terms of programme approval and other academic operations. Some administrators and lecturers showed an understanding of what would enable quality teacher educator development in the MEd programme. The findings of the research may help to strengthen and enhance quality assurance in the Master of Education programmes for teacher educators in Tanzania in ways that help develop quality secondary school teachers and improve school learning outcomes.
- Full Text:
- Date Issued: 2018
A critical realist exploration of the culture of resistance in educational technology integration practices at a South African university
- Authors: Tshuma, Nompilo
- Date: 2019
- Subjects: Critical realism , Educational technology -- South Africa , Education, Higher -- Effect of technological innovations on -- South Africa , College teachers -- South Africa , College teaching -- Sociological aspects -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72318 , vital:30033
- Description: This thesis seeks to address a number of troubling concerns related to research and practice in the field of educational technology in South African higher education. Firstly, educational technology research has been criticised for a lack of theoretical rigour resulting in perspectives that are tightly focused mostly on practice but fail to adequately interrogate the socio-political complexities of integrating educational technology. Secondly, while research in the field has been criticised for failing to adequately contextualise the study of educational technology, it also fails to interrogate the impact of colonial legacies and Western-developed technologies on integration practices. Thirdly, there seems to be a disconnect between academics’ practices and choices with educational technology, and the expectations and assumptions of educational technologists. As such, this thesis predominantly follows inductive reasoning where literature and theory are applied to the empirical situation retrospectively in order to avoid the potential influences and biases of mostly Western-driven discourses on educational technology integration practices. Critical realism is used to ‘underlabour’ this study. This meta-theory asserts that there are multiple perspectives of an independent reality, and the work of research is to use these perspectives to draw closer to an understanding of that reality. As such, it allows me to interrogate my perspectives firstly, and secondly those of my research participants, about factors that constrain educational technology integration in the South African context through the use of theory (abstract concepts) and data (research participants’ multiple perspectives). However, critical realism is somewhat cautious in how to access this reality. Therefore, a critical ethnographic epistemology is employed to strengthen critical realism’s aim of accessing knowledge. A critical epistemology emphasises exposing hidden power structures, value judgements as well as self-knowledge and reflexivity. The thesis thus shows how a critical realist ontology could be complemented by a critical ethnographic methodology, particularly in critically-orientated research that has an emancipatory focus which seeks to uncover the socio-political context within which educational technology practices take place. A key argument is that critical realism can be employed as an ontological underlabourer for critical research because of: 1) its immanent critique of traditionally-accepted philosophies, 2) its emphasis on critique of our knowledge claims and value judgements, 3) its insistence that knowledge of the social world necessarily precedes emancipation, and 4) its different conceptions of power (oppressive power and transformatory power). This critical ethnographic research is conducted in a South African university with eight female academics. Data collection is in the form of interviews, observations and reflections, as well as informal and work-related interactions. At each data collection moment, I have had to be reflexively aware of my positionality as an educational technologist, the impact of a colonially-motivated methodology and an ethically-aware approach that seeks to put the needs of the research participants first. Critical ethnography’s meaning-making and critical realism’s abduction and retroduction are used to analyse and make sense of the data. In my attempt to contextualise the study’s findings, I first uncover structural forces and their impact on the academic role before attempting to correlate this with educational technology practices. The study’s findings point to two main structural forces in the socio-political context of South African higher education: the teaching/research tension and the elevation of one dominant culture. In terms of the teaching/research tension, the female academics in this study have to balance the urgent teaching function with the valued research function. They struggle to find this balance because of ambiguous messages from different structures, their passion for teaching, oppressive departmental dynamics and the pressures of their career trajectory. The elevation of one dominant culture is demonstrated through both oppressive cultural practices and untransformed curricula. The study shows that academics mitigate these structural constraints mostly through subtle every day resistance that seeks to mitigate their effect on both the academics and, where applicable, their students. Archer’s morphogenetic/morphostatic cycle is used retrospectively, in response to fieldwork, to conceptualise why this resistance comes about. A resistance framework developed using Archer is then used to understand educational technology choices and practices. The results of the research show that while academics are often pictured as resistant to technology as a response to different barriers, they actually often employ technology to resist structural forces. That is, with this thesis I show that there is a focus on resistance with technology rather than resistance to technology. The study shows how the research participants resist structural forces (teaching tension and dominant culture) by using technology to create safe and responsive learning spaces. As such, this thesis challenges educational technologists to re-think the way they support academics by recommending support strategies that acknowledge both the structural forces in the South African higher education context, as well as the culture of resistance, both of which impact academics’ educational technology choices and practices.
- Full Text:
- Date Issued: 2019
A critique of language policy and implementation strategies used in selected institutions of higher learning in South Africa
- Authors: Somlata, Zakhile
- Date: 2018
- Subjects: Language policy South Africa , Translanguaging (Linguistics) , Language and education South Africa , Language and languages Study and teaching South Africa , Education, Higher South Africa , Multilingualism South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62571 , vital:28208
- Description: This thesis evaluated the language policy implementation strategies used in selected universities of South Africa. The Constitution of the Republic of South African (1996) recognises eleven official languages, namely: English, Afrikaans, isiNdebele, isiXhosa, isiZulu, Sesotho, Setswana, SiSwati, Sepedi, Tshivenda and Xitsonga. These official languages should enjoy the parity of esteem in all domains. The language practices are very important in the education of students at all levels of education but this study focuses on the language policy implementation in universities. Most universities of South Africa have their language policies but the dilemma is on the implementation of those language policies. The overarching aim of this study is to evaluate how university use language policy for access and success of the students and to assess the language policy implementation strategies, monitoring and evaluation. The language is central to the success of the students and this study further investigated to what extent are the universities use the linguistic repertoires of the students in their education. This study is rooted in orientations of language planning: Language as problem, language as right and language as resource (Ruiz, 1984). This thesis employed a mixed methods approach (qualitative and quantitative method) with convergent parallel design. The data was collected from eleven universities of South Africa and the participants in each university were the "Key informants" (experts and insiders) which comprised of member of Executive Management, a member of the Institutional Language Committee and a language lecturer; and a cohort of forty third year students. The Key informants participated in the qualitative data collection through the structured interviews. The forty third year students participated in the quantitative data collected through survey questionnaires. The language policy documents of the universities were also sampled to get a better understanding of the real language practices and the language policy. The thematic analysis was used to analyse transcripts that were developed from the interviews, data from the students was analysed through descriptive and inferential analyses with Statistical Package for the Social Sciences (SPSS) as a statistical test and document analysis was used to analyse the language policies; The findings show that universities have commitment to access of the students to institutions of Higher Education. The success of the students is being thwarted by the monolingual approach where most of the universities use English only as the medium of instruction. The monolingual approach negatively affects the academic success and excellent academic performance of the majority of students. The findings show that there is high demand from the students that the course materials should be provided in African languages. All selected universities have their language policy which is something positive but most of them are outdated because they need to be reviewed at least after five years. The findings demonstrate that most universities lack the language policy implementation plans. The nonexistence of the language policy implementation plan adversely affects the implementation of the language policy. The study recommends that universities should provide the learning resources in African languages to meet the demands of the students. To maximise the success, students should be examined in any official languages of the university. The language policy implementation plans should be developed urgently so as to improve language policy implementation in universities. , Le thesisi iphonononge iindlela zokusetyenziswa komgaqo-nkqubo wolwimi kwiiyunivesithi ezichongiweyo zaseMzantsi Afrika. Umgaqo-siseko waseMzantsi Afrika (1996) athathela ingqalelo iilwimi ezisemthethweni ezilishumi elinanye, isiNgesi, isiBhulu, isiNdebele, isiXhosa, isiZulu, Sesotho, Setswana, Sepedi, SiSwati, Tshivenda neXitsonga. Ezi lwimi zisemthethweni zifanele ukuba zisetyenziswe ngokulinganayo kuzo zonke iinkalo. Ukusetyenziswa kweelwimi kubalulekile kakhulu kwimfundo yabantwana kuwo onke amanqanaba emfundo kodwa olu phando lugxile ekusetyenzisweni komgaqo-nkqubo wolwimi kwiiyunivesithi. Uninzi lweeyunivesithi zinayo imigaqo-nkqubo yolwimi kodwa ingxaki isekusetyenzisweni kwaloo migaqo-nkqubo yolwimi. Ezona njongo zolu phando kukuphonononga ukuba iiyunivesithi ziyisebenzisa njani na imigaqo-nkqubo yolwimi ukuze abafundi bafikelele kwaye baphumelele ezifundweni kwakhona nokugocagoca izicwangciso zokusetyenziswa komgaqo-nkqubo wolwimi nokuhlola ukusebenza kwezo zicwangciso. Ulwimi ngundoqo kwimpumelelo yabafundi kwaye umyinge wokusetyenziswa kweelwimi zabafundi ekufundeni kwabo kuthe kwaphandwa. Esi sifundo sisekelwe kwiindlela zocwangciso-lwimi: Ulwimi njengengxaki, ulwimi njengelungelo nolwimi njengesixhobo (Ruiz, 1984). Le thesisi esebenzise indlela yophando entlantlu-mbini (eyobunjani neyobungakanani) kunye noyilo lwendibaniso kokunxuseneyo. Idatha yathi yaqokelelwa kwiiyunivesithi ezilishumi elinanye eMzantsi Afrika kwaye abathabathi nxaxheba babandakanya ilungu lesigqeba solawulo, ilungu lekomiti yeelwimi eyunivesithi nomhlohli wolwimi; kunye nabafundi abakunyaka wesithathu kwizifundo zabo kwiyunivesithi nganye. Idatha yaqokelelwa kubadlulisi-lwazi abaphambili beeyunivesithi ngodliwano-ndlebe oluqingqiweyo. Abafundi abalishumi elinesine bathi bathabathi inxaxheba kuqokelelo lwedatha ngokuthi bagcwalise uludwe lwemibuzo eyayicwangcisiwe. Umaxwebhu omgaqo-nkqubo wolwimi athi achongwa ukuze kubekho ukuqondakala phakathi kokusetyenziswa kolwimi kunye nokumgaqo-nkqubo wolwimi. Uhlalutyo ngokomxholo lwathi lwasetyenziswa ukuhlalutya ulwazi olwabhalwayo luvela kudliwano-ndlebe olwashicilelwayo, idatha eyayisuka kubafundi yathi yahlalutywa ngokusebenzisa uhlalutyo ngokwenkcazelo nangokuthelekelela kunye neStatistical Pakage for Social Sciences (SPSS) njengesixhobo senkcukacha-manani kwaye uhlalutyo loxwebhu lwathi lwasetyenziswa ukuhlalutya imigaqo-nkqubo yolwimi. Iziphumo zibonakalisa ukuba iiyunivesithi zizibophelele ekufikelelekeni kwabafundi kumaziko emfundo ephakamileyo. Impumelelo yabafundi ithi ithityazwe kukusetyenziswa kolwimi olunye apho uninzi lweeyunivesithi zisebenzisa isiNgesi kuphela njengolwimi lokufunda nokufundisa. Ukusetyenziswa kolwimi olunye kuthi kuchaphazela gwenxa impumelelo yabafundi nokuqhuba ngcono ezifundweni. Iziphumo zibonakalisa ukuba kukho imfuno emmandla kubafundi yokuba izixhobo zokufunda nokufundisa zifumaneke nangeelwimi zesiNtu. Inyathelo elihle lelokuba zonke iiyunivesithi ezichongiweyo zinayo imigaqo-nkqubo yolwimi kodwa imigaqo-nkqubo yolwimi emininzi midala kuba ifanelwe ukuba iphononongwe emva kweminyaka emihlanu ubuncinane. Iziphumo zibonakalisa ukuba iiyunivesithi azinazo izicwangciso zokusetyenziswa kwemigaqo-nkqubo yolwimi. Ukungabikho kwesicwangciso sokusetyenziswa komgaqo-nkqubo wolwimi kuchaphazela gwenxa ukusetyenziswa kwawo. Olu phando lundulula ukuba iiyunivesithi zifanele ukuba zibonelele ngezixhobo zokufunda nokufundisa ezingeelwimi zesiNtu ukukhawulelana neemfuno zabafundi. Ukwandisa impumelelo, abafundi kufanele ukuba bavavanywe ngalo naluphi na ulwimi olusemthethweni lweyunivesithi. Izicwangciso zokusetyenziswa komgaqo-nkqubo wolwimi zifanele ukuba ziveliswe njengenyewe engxamisekileyo ukuze kuphuculwe ukusetyenziswa kwemigaqo- nkqubo yolwimi kwiiyunivesithi.
- Full Text:
- Date Issued: 2018
A development method for deriving reusable concurrent programs from verified CSP models
- Authors: Dibley, James
- Date: 2019
- Subjects: CSP (Computer program language) , Sequential processing (Computer science) , Go (Computer program language) , CSPIDER (Open source tool)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72329 , vital:30035
- Description: This work proposes and demonstrates a novel method for software development that applies formal verification techniques to the design and implementation of concurrent programs. This method is supported by a new software tool, CSPIDER, which translates machine-readable Communicating Sequential Processes (CSP) models into encapsulated, reusable components coded in the Go programming language. In relation to existing CSP implementation techniques, this work is only the second to implement a translator and it provides original support for some CSP language constructs and modelling approaches. The method is evaluated through three case studies: a concurrent sorting array, a trialdivision prime number generator, and a component node for the Ricart-Agrawala distributed mutual exclusion algorithm. Each of these case studies presents the formal verification of safety and functional requirements through CSP model-checking, and it is shown that CSPIDER is capable of generating reusable implementations from each model. The Ricart-Agrawala case study demonstrates the application of the method to the design of a protocol component. This method maintains full compatibility with the primary CSP verification tool. Applying the CSPIDER tool requires minimal commitment to an explicitly defined modelling style and a very small set of pre-translation annotations, but all of these measures can be instated prior to verification. The Go code that CSPIDER produces requires no intervention before it may be used as a component within a larger development. The translator provides a traceable, structured implementation of the CSP model, automatically deriving formal parameters and a channel-based client interface from its interpretation of the CSP model. Each case study demonstrates the use of the translated component within a simple test development.
- Full Text:
- Date Issued: 2019
A dynamics based analysis of allosteric modulation in heat shock proteins
- Authors: Penkler, David Lawrence
- Date: 2019
- Subjects: Heat shock proteins , Molecular chaperones , Allosteric regulation , Homeostasis , Protein kinases , Transcription factors , Adenosine triphosphatase , Cancer -- Chemotherapy , Molecular dynamics , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115948 , vital:34273
- Description: The 70 kDa and 90 kDa heat shock proteins (Hsp70 and Hsp90) are molecular chaperones that play central roles in maintaining cellular homeostasis in all organisms of life with the exception of archaea. In addition to their general chaperone function in protein quality control, Hsp70 and Hsp90 cooperate in the regulation and activity of some 200 known natively folded protein clients which include protein kinases, transcription factors and receptors, many of which are implicated as key regulators of essential signal transduction pathways. Both chaperones are considered to be large multi-domain proteins that rely on ATPase activity and co-chaperone interactions to regulate their conformational cycles for peptide binding and release. The unique positioning of Hsp90 at the crossroads of several fundamental cellular pathways coupled with its known association with diverse oncogenic peptide clients has brought the molecular chaperone under increasing interest as a potential anti-cancer target that is crucially implicated with all eight hallmarks of the disease. Current orthosteric drug discovery efforts aimed at the inhibition of the ATPase domain of Hsp90 have been limited due to high levels of associated toxicity. In an effort to circumnavigate this, the combined focus of research efforts is shifting toward alternative approaches such as interference with co-chaperone binding and the allosteric inhibition/activation of the molecular chaperone. The overriding aim of this thesis was to demonstrate how the computational technique of Perturbation response scanning (PRS) coupled with all-atom molecular dynamics simulations (MD) and dynamic residue interaction network (DRN) analysis can be used as a viable strategy to efficiently scan and accurately identify allosteric control element capable of modulating the functional dynamics of a protein. In pursuit of this goal, this thesis also contributes to the current understanding of the nucleotide dependent allosteric mechanisms at play in cellular functionality of both Hsp70 and Hsp90. All-atom MD simulations of E. coli DnaK provided evidence of nucleotide driven modulation of conformational dynamics in both the catalytically active and inactive states. PRS analysis employed on these trajectories demonstrated sensitivity toward bound nucleotide and peptide substrate, and provided evidence of a putative allosterically active intermediate state between the ATPase active and inactive conformational states. Simultaneous binding of ATP and peptide substrate was found to allosterically prime the chaperone for interstate conversion regardless of the transition direction. Detailed analysis of these allosterically primed states revealed select residue sites capable of selecting a coordinate shift towards the opposite conformational state. In an effort to validate these results, the predicted allosteric hot spot sites were cross-validated with known experimental works and found to overlap with functional sites implicated in allosteric signal propagation and ATPase activation in Hsp70. This study presented for the first time, the application of PRS as a suitable diagnostic tool for the elucidation and quantification of the allosteric potential of select residues to effect functionally relevant global conformational rearrangements. The PRS methodology described in this study was packaged within the Python programming environment in the MD-TASK software suite for command-line ease of use and made freely available. Homology modelling techniques were used to address the lack of experimental structural data for the human cytosolic isoform of Hsp90 and for the first time provided accurate full-length structural models of human Hsp90α in fully-closed and partially-open conformations. Long-range all-atom MD simulations of these structures revealed nucleotide driven modulation of conformational dynamics in Hsp90. Subsequent DRN and PRS analysis of these MD trajectories allowed for the quantification and elucidation of nucleotide driven allosteric modulation in the molecular chaperone. A detailed PRS analysis revealed allosteric inter-domain coupling between the extreme terminals of the chaperone in response to external force perturbations at either domain. Furthermore PRS also identified several individual residue sites that are capable of selecting conformational rearrangements towards functionally relevant states which may be considered to be putative allosteric target sites for future drug discovery efforts Molecular docking techniques were employed to investigate the modulation of conformational dynamics of human Hsp90α in response to ligand binding interactions at two identified allosteric sites at the C-terminal. High throughput screening of a small library of natural compounds indigenous to South Africa revealed three hit compounds at these sites: Cephalostatin 17, 20(29)-Lupene-3β isoferulate and 3'-Bromorubrolide F. All-atom MD simulations on these protein-ligand complexes coupled with DRN analysis and several advanced trajectory based analysis techniques provided evidence of selective allosteric modulation of Hsp90α conformational dynamics in response to the identity and location of the bound ligands. Ligands bound at the four-helix bundle presented as putative allosteric inhibitors of Hsp90α, driving conformational dynamics in favour of dimer opening and possibly dimer separation. Meanwhile, ligand interactions at an adjacent sub-pocket located near the interface between the middle and C-terminal domains demonstrated allosteric activation of the chaperone, modulating conformational dynamics in favour of the fully-closed catalytically active conformational state. Taken together, the data presented in this thesis contributes to the understanding of allosteric modulation of conformational dynamics in Hsp70 and Hsp90, and provides a suitable platform for future biochemical and drug discovery studies. Furthermore, the molecular docking and computational identification of allosteric compounds with suitable binding affinity for allosteric sites at the CTD of human Hsp90α provide for the first time “proof-of-principle” for the use of PRS in conjunction with MD simulations and DRN analysis as a suitable method for the rapid identification of allosteric sites in proteins that can be probed by small molecule interaction. The data presented in this section could pave the way for future allosteric drug discovery studies for the treatment of Hsp90 associated pathologies.
- Full Text:
- Date Issued: 2019
A gendered analysis of conditional cash based transfers: a case study of Puntland Technical Vocational Skills Training Programme, Somalia
- Authors: Chitombi, Rumbidzai
- Date: 2020
- Subjects: Puntland Technical Vocational Skills Training Programme , Transfer payments -- Somalia -- Case studies , Economic assistance, Domestic -- Somalia , Economic development -- Social aspects -- Somalia , Women -- Somalia -- Social conditions
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167335 , vital:41469
- Description: As part of the worldwide development system, conditional cash transfer (CCT) programmes have become an increasingly popular policy and development approach in seeking to address poverty, especially in developing countries. Under the CCT programmes, beneficiaries are given assistance in the form of either cash or cash vouchers after fulfilling certain obligations of the development programme, such as attending training, enacting proper health care, or ensuring regular school attendance of children. The programmes have been described as a ‘double-edged sword’ since they aim to address poverty and, at the same time, reduce reliance on government largesse. In this regard, they are seen as potentially effective, and more empowering, alternatives to more traditional social assistance programmes whereby poor people receive welfare assistance in the form of ‘in kind’ and ‘unconditional’ assistance, receiving this as either food or shelter commodities, and without having to meet any conditions in doing so. This ‘traditional’ way of assisting poor people has largely been criticised for creating a dependency syndrome amongst the beneficiaries. In certain cases, CCT programmes focus specifically on women, either in receiving the cash transfer or in meeting the conditions attached to the programme, or both. In this context, considerable debate exists in the scholarly literature about the effects of such CCT programmes on the situation and status of women, specifically in terms of possibly empowering women. While some scholars claim that these programmes enhance the human and financial assets of women, others argue that focusing specifically on women, and as care-givers within households, tends to reproduce gender-based inequalities and subordination. Since gender equality and female empowerment are now key issues in global development spheres, and at national levels, this thesis aims to contribute to literature on the effects of CCTs on gender and women’s empowerment. This is pursued by way of a gendered perspective on CCTs as a development methodology for empowering women with reference to Somalia, using the Puntland Technical Vocational Skills Training programme as a case study. This programme focused, in the main, on internally-displaced people in Somalia, with a particular emphasis on women in meeting the programme conditions (i.e. participating in a training programme) and in being the cash recipients. The study used both quantitative and qualitative approaches for data collection and analysis, focusing on sixty selected beneficiaries who participated in the Puntland Technical Vocational skills training programme in Somalia from 2013. The thesis examines the prevailing structures (including cultural dynamics and socio-economic factors) in Somalia which lead to women’s subordination, notably in the light of significant internal displacement because of war and conflict and the emergence of internally-displaced camps. On this basis, from a gendered perspective, there is a critical appraisal of the manner in which the Puntland CCT programme affected women’s subordinate status, including how it may have led to the restructuring of gendered relations at both household and community levels. In offering this appraisal with reference to the Puntland programme, the thesis argues that women’s subordination and, by extension, women’s empowerment, is multi-faceted, and that continuity and change along the dimensions of subordination is often uneven and contradictory. Further, as also demonstrated in the Puntland case study, women’s subordination (as a social totality) is not a totalising system, such that women regularly make use of gaps in the system as opportunities to enhance their well-being without confronting the totality of the system.
- Full Text:
- Date Issued: 2020
A holistic approach in understanding the effects of dietary protein sources on the growth and reproductive development of farmed abalone, Haliotis midae
- Authors: Wu, Yu
- Date: 2020
- Subjects: Abalones -- Nutrition , Abalones -- Reproduction , Abalones -- Growth , Abalone culture , Haliotis midae -- Nutrition , Haliotis midae -- Reproduction , Haliotis midae -- Growth , Haliotis midae fisheries
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167719 , vital:41506
- Description: The combination of fishmeal and soya in the formulated feed of farmed South African abalone, Haliotis midae, not only improved abalone growth, but also the sustainability of the compound diets by reducing the reliance on fishmeal. However, the presence of soya produced larger gonads compared to those of abalone fed kelp or single-source protein diets. There is an increasing drive to control sexual maturation and reduce undesirable spawning events in farmed abalone. However, the reasons for the reported effects of soya inclusion on the reproductive development of farmed H. midae remain unresolved. The aim of this research was to use a combination of techniques to contribute to the understanding of the relationship between growth, reproductive and nutritional physiology of farmed H. midae fed diets of varying protein sources. These techniques included stable isotope analysis (SIA), fatty acid analysis, gonad histological assessments and haemolymph sexsteroid hormone analysis. The objectives were to examine the allocation of protein and nutritional components to somatic and reproductive tissues. This study also included the first attempt to investigate the role that sex steroid hormones play during gametogenesis. Abalone (40 – 50 g abalone-1) were fed one of four diets: either a single-source protein-based diet, i.e., (1) fishmeal-only (FM) or (2) soya-only (S), or a combination diet of (3) fishmeal-soya (FM S) or (4) fishmeal-sunflower meal (FM SM). Sampling occurred in 45-day intervals over one year. Dietary protein source had an effect on the growth of abalone, with enhancements in growth linked to the combination of fishmeal and a plant-protein source. The fishmeal ingredient was the most utilised protein source throughout the temporal changes in protein allocation into somatic and reproductive tissue, followed by soya and then sunflower meal. The mean whole- body mass of abalone was significantly influenced by an interaction between time and dietary treatment, with average whole-body mass changing differently over time between treatments (RM-ANOVA, F(24, 96) = 2.13, p = 0.005). Overall, abalone that were fed FM S had higher mean whole-body mass values than abalone that were fed the single-protein based diets, while abalone that were fed FM SM were similar to animals from all dietary treatments (RMANOVA, F(3, 12) = 5.75, p = 0.01). Male abalone had significantly higher gonad bulk index (GBI) values compared to females (RM-ANOVA, F(1, 24) = 49.03, p < 0.001) and this was independent of dietary treatment. Within each sex, female abalone fed the FM S diet (15.92 ± 1.88 mm3 g-1) had significantly higher GBI values than abalone fed S (9.76 ± 1.08 mm3 g-1), while abalone fed FM (11.96 ± 1.71 mm3 g-1) and FM SM (11.90 ± 0.80 mm3 g-1) were similar to abalone from all other dietary treatments (Tukey’s HSD, p < 0.05). Male abalone fed the FM S (21.59 ± 2.10 mm3 g-1) and FM SM diet (19.30 ± 2.63 mm3 g-1) had similar GBI values and they were significantly higher than in abalone fed the S diet (14.74 ± 1.27 mm3 g-1), while abalone fed FM S had significantly higher GBI values than abalone that consumed the FM diet (15.08 ±1.63mm3 g-1) ( Tukey’s HSD, p < 0.05). Although sunflower meal was poorly utilised, it produced similar overall growth to abalone that were fed the FM S diets. Yet, feed conversion ratio values were significantly lower for abalone fed FM S (1.30 ± 0.13) compared to those in the other three treatments, with ratios ranging from 1.65 – 1.72 over the one-year. The fatty acid compositions of the somatic and gonadal tissues were similar between treatments (PERMANOVA, p = 0.21), while fatty acid composition was influenced by sampling day, tissue type and abalone sex (PERMANOVA, p < 0.05). The essential fatty acids (EFAs) eicosadienoic acid and a-linolenic acid were present in abalone tissue, but they were not detected in the diets, suggesting the important role that an alternate food source (e.g. farmed abalone also had access to diatoms) may have played and the ability that H. midae may have in converting long-chain polyunsaturated fatty acids from C18 precursors. A change in the abundance of EFAs in the gonad tissue during highest and lowest GBI values suggested that arachidonic, eicosapentaenoic, g-linolenic and linoleic acid were important in females, while eicosapentaenoic, eicosadienoic and a-linolenic acid were important for male reproductive development. Dietary protein sources had an effect on the frequency distribution of maturity stages, where females that were fed FM S produced more ripe gonads and more males that were fed FM SM contained testes that showed signs of ripeness over the one-year study. Although dietary protein influenced the sex steroid concentrations in females and males, exhibiting fluctuations throughout the one-year period, no distinct pattern linked to gametogenesis were observed. The results from this study illustrate: (1) the importance of conducting laboratory studies when implementing SIA and mixing models in aquaculture nutrition; (2) conducting nutritional studies on mature, grow-out abalone; and (3) assessing the importance of naturally occurring diatoms in their diet and their contribution to growth and reproduction. The novel contribution of this research towards abalone nutritional physiology, the implications of these findings to industry as well as potential considerations for future studies were addressed.
- Full Text:
- Date Issued: 2020
A multi-threading software countermeasure to mitigate side channel analysis in the time domain
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
A novel, improved throughput bioassay for determining the delative speed of antimalarial drug action using fluorescent vitality probes
- Authors: Laming, Dustin
- Date: 2020
- Subjects: Plasmodium falciparum , Malaria -- Treatment -- Africa , Antimalarials , Malaria vaccine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/139902 , vital:37810
- Description: Malaria is one of the most prevalent diseases in Africa and Plasmodium falciparum is widely accepted as the most virulent of the malaria parasite species, with a fatality rate of 15 – 20 % of reported cases of infection. While various treatments have been accepted into early stage clinical trials, there has been little progress towards a proven vaccine. Pending a long-term solution, endemic countries rely heavily on the development of innovative drugs that are not only efficacious but are also quick acting. Traditional methods of evaluating antimalarial killing speeds via morphological assessments are inherently flawed by tedious, subjective interpretations of the heterogenous parasite morphology encountered in routine parasite culture conditions. This has led to the introduction of alternative assay formats to determine how rapidly compounds act on parasites in vitro: a parasite reduction ratio (PRR) assay that measures the recovery of parasite cultures from drug exposure; determining the shift in IC50 values of compounds when dose-response assays are carried out for different time periods; a bioluminescence relative rate of kill (BRRoK) assay that compares the extent to which compounds reduce firefly luciferase activity in transgenic parasites. Recent whole cell in vitro screening efforts have resulted in the generation of chemically diverse compound libraries such as the Medicines for Malaria Venture’s Pathogen Box, which houses 125 novel compounds with in vitro antiplasmodial activity. Assessing the relative killing speeds of these compounds would aid prioritizing fast-acting compounds that can be exploited as starting points for further development. This study aimed to develop a bioassay using the calcein-acetoxymethyl and propidium iodide fluorescent vitality probes, which would allow the relative speed of drug action on Plasmodium falciparum malaria parasites to be assessed and ranked in relation to each other using a quantitative, improved throughput approach. Initially applied to human (HeLa) cells, the assay was used to compare the relative speeds of action of 3 potential anti-cancer compounds by fluorescence microscopy. Subsequently adapted to P. falciparum, the assay was able to rank the relative speeds of action of standard antimalarials by fluorescence microscopy and two flow cytometry formats. Application of a multiwell flow cytometer increased throughput and enabled the assessment of experimental compounds, which included a set of artemisinin analogs and 125 antimalarial compounds in the MMV Pathogen Box. The latter culminated in the identification of five rapidly parasiticidal compounds in relation to the other compounds in the library, which may act as benchmark references for future studies and form the basis of the next generation of fast acting antimalarials that could be used to combat modern, resistant malaria.
- Full Text:
- Date Issued: 2020
A personality-based surveillance model for Facebook apps
- Authors: Van der Schyff, Karl Izak
- Date: 2020
- Subjects: Facebook (Electronic resource) , Electronic surveillance -- Psychological aspects , Online social networks -- Psychological aspects , Social media -- Psychological aspects , Personality
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145534 , vital:38447
- Description: The surveillance of data through the use of Facebook Apps is an ongoing and persistent problem that impacts millions of users. Nonetheless, limited research has been conducted investigating to what extent a Facebook user’s personality influences their awareness of such surveillance practices. Thus, to understand this situation better, the current study inductively developed four propositions from secondary data sources as part of a detailed content analysis. Spanning three search and analysis phases the content analysis led to the development of the research model. Guided by the propositions and research questions, a questionnaire was developed based on the relevant constructs prescribed by the Theory of Planned Behaviour. This questionnaire was used, and a total of 651 responses were collected from Facebook users over the age of 18 years old and residing in the United States of America. Primary data took place at both a univariate and multivariate level with a specific focus on the development of a structural model. Interpretation of the structural model revealed that out of all the Big Five personality traits, Conscientiousness exhibited the strongest relationship with information security awareness followed by Openness to Experience and Neuroticism, respectively. The results further indicated that the model constructs based on attitude, social norms and awareness significantly influenced the intended use of Facebook Apps. The study also contributes by indicating which personality traits are most vulnerable to Facebook App surveillance. For example, it was found that individuals high in Conscientiousness are the least vulnerable with individuals high in Extraversion being the most vulnerable. Since the results indicate that not all the personality traits are significantly related to the model constructs, additional factors may contribute to App surveillance in this context. Concerning this, factors such as user apathy, information privacy, privacy concerns, control and Facebook dependency are discussed as a means to argue why this might be the case.
- Full Text:
- Date Issued: 2020
A physiological study on a commercial reef fish to quantify the relationship between exploitation and climate change resilience
- Authors: Duncan, Murray Ian
- Date: 2019
- Subjects: Chrysoblephus laticeps -- Climatic factors , Chrysoblephus laticeps -- Physiology , Sparidae -- South Africa -- Climatic factors , Reef fishes -- South Africa -- Climatic factors , Fish populations -- South Africa -- Climatic factors , Fish populations -- Measurement , Fish populations -- Monitoring , Fisheries -- South Africa -- Environmental aspects , Ocean temperature -- Physiological effect -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76541 , vital:30599
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
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- Date Issued: 2019
A psychobiographical study of Temple Grandin
- Authors: Wannenburg, Nicola
- Date: 2018
- Subjects: Grandin, Temple , Psychology Biographical methods , Psychoanalysis , Autistic women United States Biography , Women animal specialists United States Biography , Developmental psychology , Erikson, Erik H (Erik Homburger), 1902-1994
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57358 , vital:26877
- Description: Psychobiographical researchers methodically formulate life histories and interpret them by means of psychological theories. The research typically focuses on exemplary and completed lives. The cases that are studied are usually of individuals who are of particular interest to society as a result of excelling in their particular fields, be they to benefit or detriment of society. Temple Grandin was chosen for this study using purposive sampling as she meets the psychobiographical requirement of being an extraordinary individual. As an individual with autism Grandin faced many challenges growing up. Despite a difficult and absent beginning, Grandin developed into a stable and scientifically creative adult who contributes to society. She excels as an animal scientist and designer of humane livestock handling facilities and has an international reputation for her contribution to the livestock industry and animal welfare. The primary aim of this study is to describe and interpret the life of Temple Grandin through Erikson’s (1950/1973) theory of psychosocial development. A mixed method approach (Yin, 2006) was employed for the conduction of this study. The overarching data processing and analysis guidelines for this study were provided by Miles and Huberman (1994, 2002a, 2002b). The conduction of the processing and analysis of data was aided by Alexander’s (1988, 1990) method of asking the data questions as well as an integration of Yin’s (2014) time series analysis with Erikson’s (1950/1973) triple bookkeeping approach. This study contributes to the development of psychobiographical research in South Africa as well as to personality and developmental theory.
- Full Text:
- Date Issued: 2018
A review of Climate-Smart system innovations in two Agricultural Colleges in the North West Province of South Africa
- Authors: Van Staden, Wilma
- Date: 2018
- Subjects: Crops and climate South Africa North-West , Sustainable agriculture South Africa North-West , Agriculture Environmental aspects South Africa North-West , Agricultural colleges Curricula South Africa , Agricultural innovations , Agricultural ecology South Africa North-West
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63426 , vital:28410
- Description: This study was centred on the Agricultural Innovation System in the North West Province, South Africa as a response to climate change. The study developed during a time when Climate-Smart Agriculture emerged in policy and was developed as a strategic agricultural innovation process in response to changes in climate that increased food insecurity. The Agricultural Colleges embedded in the agricultural system realised that they were teaching students without a clear provision for climate change and therefore needed to initiate climate responsive innovations to comply with the Climate-Smart strategy that had been proposed by the provincial authorities. This provided the context for the study to track and support the innovation process of transitioning towards Climate-Smart responsive curriculum and learning practices within the system. A theoretical framework for the study was developed using a Cultural Historical Activity Theory perspective. This allowed the researcher to approach the research process as two case studies of innovation within the Agricultural Innovation System of the North West Province. The study developed as an iterative process of innovation support and tracking. At the early stages of the research process, data were generated through document analysis and a survey completed by the research participants at the preliminary consultative workshop. The contextual data allowed the researcher to begin to develop a clear contextual profile for both case studies. The consultative workshops were held to orientate the research around the central problems and challenges related to curriculum alignment with provincial Climate-Smart Agricultural policies. The methodology thereafter was developed as an iterative process of successive intervention-innovation workshops where the participating staff in each college reviewed their curriculum with the support of a Climate-Smart Innovation Tool. This tool was developed as a mediating resource for participants to undertake intervention work towards curriculum innovation in their context. The historical analysis from the two consultative workshops and the data derived from the initial use of the Climate-Smart Innovation Tool was used to model the activity systems in the respective colleges and the provincial system. This analysis enabled the researcher to scope how the system was currently functioning and how it had changed over time. During the workshops, curriculum innovations were reviewed and a fuller picture of the challenges of system innovation emerged, especially from a curriculum innovation vantage point. This system analysis was used to analyse emergent tensions and contradictions within the system and to build a picture of the complexities of participating staff initiating innovations towards Climate-Smart responsiveness in the colleges and within the Agricultural Innovation System. During the review and tracking of the supported innovation process the Climate-Smart Innovation Tool was developed into online sub-tools where either Departments or individual lecturers could review and track their own Climate-Smart responsiveness. The tool was shown to be a useful tool for surfacing contradictions, and identifying absences, and thus for charting out the start of reflexive learning and change processes needed for introducing climate responsive knowledge into the system. The study reveals that catalysing of curriculum and learning system innovation aligned with wider innovations in the agricultural innovation system requires specific tools, time and the understanding of the importance of micro-level innovation. The innovations within the system revealed the significance of allowing for time and processes that facilitate ‘ascending’ from the abstract concept of Climate-Smart Agriculture into more concrete curriculum processes. The curriculum review tool developed for this study served as an important double stimulation tool, along with activity system mapping, and ongoing refinement and clarification of the object of Climate-Smart Agriculture and associated contradictions and action plans for climate smart responsiveness in the college context. The tools and processes that were developed during this study, assisting in the emergence of micro-level innovation of the curriculum and learning system. The barriers and processes hampering curriculum and learning innovation within the system were identified. The study concludes with the recommendations on how a Climate-Smart innovation process might best be supported with reflexive tools within a curriculum and learning system during a time of institutional flux.
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- Date Issued: 2018