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Biological control initiatives against Lantana camara L. (Verbenaceae) in South Africa : an assessment of the present status of the programme, and an evaluation of Coelocephalapion camarae Kissinger (Coleoptera: Brentidae) and Falconia intermedia (Distant) (Heteroptera: Miridae), two new candidate natural enemies for release on the weed

  • Authors: Baars, Jan-Robert
  • Date: 2003
  • Subjects: Lantana camara Lantana camera -- South Africa Biological pest control agents -- South Africa Beetles -- South Africa Hemiptera -- South Africa Weeds -- Biological control -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5647 , http://hdl.handle.net/10962/d1005329
  • Description: Lantana camara (lantana), a thicket-forming shrub, a number of different varieties of which were introduced into South Africa as ornamental plants but which has become a serious invasive weed. Conventional control measures for lantana are expensive and ineffective and it has therefore been targeted for biological control since 1961. To date, eleven biological control agent species have become established on lantana in South Africa. However, most agents persist at low densities and only occasionally impact plant populations. Three species regularly cause significant damage, but only reach sufficiently high numbers by midsummer after populations crash during the winter. Overall, the impact of the biological control programme on the weed is negligible and this has been ascribed to the poor selection of agents for release, the accumulation of native parasitoids, differences in insect preference for different varieties of the weed and variable climatic conditions over the weed’s range. This study suggests that the importance of varietal preferences has been over-estimated. A predictive bioclimatic modelling technique showed that most of the agents established in South Africa have a wide climatic tolerance and that the redistribution and importation of new climatypes of these agents will not improve the level of control. Additional agents are required to improve the biocontrol in the temperate conditions, and also to increase damage in the sub-tropical areas where most of the agents are established and where the weed retains its leaves year round. New candidate agents that possess biological attributes that favour a high intrinsic rate of increase, a high impact per individual and that improve the synchrony between the weed and the agent in climatic conditions that promote the seasonal leaflessness of plants should receive prior consideration. A survey in Jamaica indicated that additional biological control agents are available in the region of origin but that care should be taken to prioritise the most effective agents. The various selection systems currently available in weed biocontrol produce contradictory results in the priority assigned to candidate agents and a new selection system is proposed. The biology and host range of two new candidate natural enemies, the leaf-galling weevil, Coelocephalapion camarae and the leaf-sucking mirid, Falconia intermedia were investigated for the biocontrol of lantana. The studies indicated that these have considerable biocontrol potential, in that the weevil has a wide climatic tolerance and has the potential to survive the host leaflessness typical of temperate conditions, while the mirid has a high intrinsic rate of increase, and the potential for several generations a year. Both agents caused a high level of damage to the leaves, with the weevil galling the vascular tissue in the leaf-petiole and the mirid causing chlorotic speckling of the leaves. During laboratory trials both agents accepted indigenous species in the genus Lippia. However, under multiple choice conditions these agents showed a significant and strong oviposition preference for lantana. A risk assessment and post release field trials indicated that F. intermedia is likely to attack some Lippia species in the presence of lantana, but the levels of damage are predicted to be relatively low. A possible low incidence of damage to indigenous species was considered a justifiable ‘trade-off’ for the potentially marked impact on L. camara. Preference and performance studies on the two candidate agents suggested that most of the South African lantana varieties are suitable host plants. The mirid preferred certain varieties in multiple choice experiments, but this is unlikely to affect its impact under field conditions. Permission for release was accordingly sought for both species. Finally, the challenges facing the biological control programme and the potential for improving the control of L. camara in South Africa are considered.
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  • Date Issued: 2003

Visual narratives of division in contemporary Palestinian art and social space

  • Authors: Baasch, Rachel Mary
  • Date: 2017
  • Subjects: Art, Palestinian Arab , Art, Palestinian Arab -- Political aspects , Art and society -- Palestine
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/41770 , vital:25132
  • Description: This study analyses artworks by contemporary Palestinian artists that respond to visual narratives of division in social space from a perspective grounded in a South African context. The state of Israel is built on Historic Palestine. Political Zionism has created an ideological narrative of division that positions people of the Jewish faith as the rightful heirs to the land on which Palestinians have lived for centuries. In order to execute their vision of an exclusively Jewish nation state, the founding pioneers of political Zionism colonised and ethnically cleansed Historic Palestine, establishing Israel in 1948. To sustain the exclusive claim to Palestinian land, Israel has divided the space and the people in it at every possible level. The greatest testament to these efforts is the Israeli apartheid wall and checkpoint security system that can be described as a monumental visual narrative of division. With each second that passes, Israel claims more Palestinian land and expands on existing fences, walls and barriers. It is no secret that the Occupied Palestinian Territories are rapidly transforming into open-air prisons. Israel has stolen the Palestinian horizon line and replaced it with a concrete wall that blocks out light, vision and optimism. Within the shadows of these conflicted, traumatised sites of division, Palestinian artists seek openings, cracks and loopholes that signal the possibility for physical and psychological transgression of these seemingly impenetrable structures of division. I have developed a creative methodology that can be understood through the metaphor of ‘looking with the skin’ as a way to identify and analyse visual narratives of division and artistic responses to sites of division in Palestinian social space. Looking with the skin combines aspects of participant observation (specifically the emphasis on engaged fieldwork) from the discipline of Anthropology with the method of visual analysis from the discipline of Art History. In my application of this method through primary fieldwork conducted within the Occupied Palestinian West Bank Territory from 2013 and 2014, I have learnt that Israel’s colonisation, military occupation and system of apartheid directly impacts the ability of Palestinian artists to make and disseminate their work as well as the choice of content within their artwork. The artworks analysed in this thesis by the artists Khaled Jarrar, Y ael Bartana, Larissa Sansour, Hasan Darahgmeh, Fareh Saleh and Emily Jacir can be positioned in relation to artworks by artists based within a South African context, namely Thando Mama, Serge Alain Nitegeka and Doung Anwar Jahangeer. In this thesis I present a combination of my own photographic documentation of sites of division with the West Bank OPT in relation to the specific artworks made by the artists mentioned above. In my analysis of the photographic documentation and the artists’ work I highlight similarities, parallels, threads and intersecting narratives that connect different artists to one another and to the sites of division they are responding to within their artistic practice. This study carves a small conceptual pathway through ideological and physical walls from South Africa to Palestine through the study of contemporary art and visual culture.
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  • Date Issued: 2017

'Environmental policy to community action': methodology and approaches in community-based environmental education programmes in Uganda

  • Authors: Babikwa, Daniel J
  • Date: 2004
  • Subjects: Environmental education -- Uganda -- Case studies Education and state -- Uganda Community development -- Uganda -- Case studies Sustainable development -- Uganda -- Case studies Environmental policy -- Uganda -- Case studies
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1518 , http://hdl.handle.net/10962/d1003400
  • Description: This research was conducted in Luwero, a rural district in central Uganda, over a period of three years, half of which entailed fulltime engagement in a participatory action research process with VEDCO, an indigenous NGO. The study focuses on the educational processes involved in the translation of Uganda's environmental policy into action at community level. It looks at community-based education and development activities run by VEDCO among smallholder farmers. The study addressed four objectives. For the first objective I developed a conceptual framework through a review of theories informing education in general and environmental education, adult education, community education, and community development in particular. The second objective was to conduct a situational analysis to identify contextual issues related to policy implementation at community level. The third objective was to engage in a participatory action research process with the NGO in the farming community in response to the identified contextual issues, and the fourth was to explore and comment on environmental education methods used within a community context. PRA techniques, interviews, and other participatory data collection methods were used to generate the data. The study reveals contradictions that limit NGO capacity to make appropriate use of participatory education processes in implementing policy-related training at community level. Elements in the National Plan for the Modernisation of Agriculture, for example, conflicted with the principle of sustainable development underlying the policy. VEDCO itself was changing from a social-welfare-oriented organisation into a commercial enterprise pursuing economic goals, which conflicted with its social goals. The capitalist development ideology of the donor was being adopted by VEDCO, which contradicted the goals of people-centred development. This was exacerbated by VEDCO's dependency on donor funds for its activities. Contextual issues like people's history; poverty, gender and inconsistent land policies further complicated the policy implementation processes. There were also inconsistencies in the epistemological assumptions and didactic approaches evident in the implementation. The study shows that the intended emancipatory education processes are more often supplanted by technicist methodologies. Thus, it exposes the underlying historical, ideological and epistemological tensions and contradictions within the field of education, particularly in relation to the `paradigmatic' orientations (neo-classical, liberal and socially critical/emancipatory) outlined in the literature. Conclusions are made at two levels: in relation to the study goals, of examining policy implementation at community level and in terms of the study's contribution to the understanding of current education theory in the context of sustainable development among communities.
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  • Date Issued: 2004

A comprehensive approach to scalability assessment of ICTD projects : a case study of ICT4RED

  • Authors: Baduza, Gugulethu Qhawekazi
  • Date: 2021-04
  • Subjects: To be added
  • Language: English
  • Type: thesis , text , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/178435 , vital:42939
  • Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
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  • Date Issued: 2021-04

Sedimentary, geochemical and geophysical study of the Ecca group, Karoo supergroup and its hydrocarbon potential in the Eastern Cape Province, South Africa

  • Authors: Baiyegunhi, Christopher
  • Date: 2017
  • Subjects: Sediments (Geology) -- South Africa -- Eastern Cape Sedimentology -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10353/4881 , vital:28658
  • Description: The Ecca Group of Karoo Supergroup is a sedimentary rock sequence that deposited between the Late Carboniferous (Dwyka Group) and the Late Permian-Middle Triassic (Beaufort Group). The Ecca Group investigated in this study is situated in the Eastern Cape Province of South Africa and it comprises mainly of shales, mudstones, siltstones and sandstones. The Ecca Group sequence contains considerable carbon content and suitable thickness to make it an ideal target for shale gas exploration. Previous studies put more emphasis on the geology and stratigraphy of the Ecca Group, this study revised the stratigraphy, and put new insight on the petrography, depositional processes, sedimentary facies, provenance, paleoweathering, tectonic setting, subsidence rates and history, electrical resistivity, source rock characteristics and diagenesis of the potentially feasible sandstone and mudrock reservoir rocks of the Ecca Group. Based on the lithological features, sedimentary structures and facies characteristics, the stratigraphy of the Prince Albert, Whitehill, Collingham and Fort Brown Formations of the Ecca Group is now subdivided into two informal members each, i.e. Lower Member and Upper Member. Furthermore, the Ripon Formation is now subdivided into three informal members. Each member has been asigned a lithological name. The grain size parameters show that most of the Ecca Group sandstones are very fine to fine grained, poorly to moderately well sorted, mostly near-symmetrical and mesokurtic in grain-size distribution. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under deep marine environment for Prince Albert, Whitehill and Collingham Formations, shallow marine environment for Ripon Formation, while the Fort Brown Formation is lacustrine-deltaic deposits. Modal composition analysis and petrography studies revealed that the detrital components of the sandstones are dominated by monocrystalline quartz, feldspar and lithic fragments. The sandstones are compositionally and texturally immature and can be classified as feldspathic wacke and lithic wacke. The provenance analysis revealed plutonic and metamorphic terrains as the main source rocks with minor debris derived from recycled sedimentary rocks. The detrital modal compositions of these sandstones are related to back arc to island and continental margin of tectonic setting. Based on the detailed sedimentological analyses of outcrop and borehole data, fourteen lithofacies were identified and seven facies associations (FAs) were recognised. The facies associations are: FA 1: Shale and mudstones intercalated with siltstones, FA 2: Carbonaceous shale, mudstone with subordinate chert and sandstone, FA 3: Mudstones rhythmite with thin bedded mudstone and lenticular siltstone, FA 4: Greyish medium bedded sandstone intercalated with laminated mudstone, FA 5: Dark-grey medium to thick bedded mudstone and siltstone, FA 6: Thin to medium bedded sandstone alternated with thin bedded carbonaceous mudstone, and FA 7: Varved mudstone rhythmite intercalated with siltstone and minor sandstone. Sedimentological characteristics of the identified facies associations indicate four deposition environments, namely, deep marine basin, turbidite, shallow marine and lacustrine environments, which constitute a gradually regression sequence as a result of sea-level dropping and shallowing of the basin during the developmental processes. Geochemical analysis of the Ecca mudrocks and sandstones revealed that the rocks are of quartzose sedimentary provenance, suggesting that they were derived from a cratonic interior or recycled orogen. The petrography and geochemistry of the sandstones indicated that the source areas are composed of plutonic and metamorphic rocks with a minor component from sedimentary rocks. The geochemical diagrams and indices of weathering suggested that the granitic source rocks underwent moderate to high degree of chemical weathering. The tectonic setting discrimination diagrams support passive continental margin setting of the provenance.
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  • Date Issued: 2017

Inter-individual variability and phenotypic plasticity : the effect of the environment on the biogeography, population structure, ecophysiology and reproduction of the sandhoppers Talorchestia capensis and Africorchestia quadrispinosa

  • Authors: Baldanzi, Simone
  • Date: 2014
  • Subjects: Phenotypic plasticity -- Research -- Africa, Southern Talitridae -- Research -- Africa, Southern Amphipoda -- Research -- Africa, Southern Climatic changes -- Environmental aspects -- Africa, Southern Marine biology -- Africa, Southern Adaptation (Biology) -- Africa, Southern
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5846 , http://hdl.handle.net/10962/d1011447
  • Description: Climatic envelope models focus on the climatic variables affecting species or species assemblages, and are important tools to investigate the effect of climate change on their geographical ranges. These models have largely been proposed in order to make successful predictions on species‘ persistence, determining which variables are likely to induce range expansion, contraction, or shifting. More recent models, including the ability and the cost for individuals to respond promptly to an environmental stimulus, have revealed that species may express phenotypic plasticity able to induce adaptation to the new environment. Consequently, understanding how species evolve to a changing climate is fundamental. From this perspective, investigating intraspecific responses to an environmental variable may contribute to better understanding and prediction of the effect of climate change on the geographical range and evolution of species, particularly in the case of widespread species. In this context, the present study aimed at establishing how environmental variables (focussing mainly on temperature) may have contributed to shape the spatial distribution, physiology, reproductive biology and connectivity of two species of Southern African sandhoppers (Talorchestia capensis and Africorchestia quadrispinosa, Amphipoda, Talitridae). Most of the work was carried out on T. capensis, due to its widespread spatial distribution. A first investigation of the biogeography of T. capensis and A. quadrispinosa, revealed that, for both species, spatial patterns of abundance, size and sex ratio were not explained by the Abundant Centre Hypothesis (greater abundance at the core of a spatial range), but rather guided by bio-physical forces. Precisely, the abundance of sandhoppers was driven by the morphodynamic state of the beach, salinity and temperatures, with strong differentiation among sites that reflected local environmental conditions. In support of these findings, strong population structure in the genetics of T. capensis was found (three main groups) when investigating its phylogeography and genetic connectivity. Although such defined structure may suggests cryptic speciation, the concomitant within-population variation in the COX1 region of mtDNA, also highlighted the importance of individual genetic variability. High individual variability was also found in the response of T. capensis to temperature, both in its physiology (thermal plasticity) and its reproductive biology (maternal effects). Since temperature is one of the main variables affecting the coastal marine systems of southern Africa and the metabolism of animals in general, its effect on the physiology and reproduction of T. capensis was therefore investigated. Thermal responses to increasing/decreasing temperatures were assessed for separated populations of T. capensis. Individual variability was reported in the oxygen consumption of T. capensis in response to temperature (high variation around the means, especially for increasing temperatures). Among population differences in thermal sensitivity were significantly correlated with air temperature variability experienced over the past 23 years, highlighting the importance of historical temperature fluctuations to the current thermal physiology of these sandhoppers. Temperature also had an important effect on the reproductive plasticity of T. capensis. Different temperatures induced mothers to adjust the size of their offspring (i.e. egg size), with larger eggs produced at lower temperatures. Interestingly, females showed strongly significant among individual variation in the size of the eggs. Given the importance of understanding rapid responses of organisms to climate change and considering the fundamental role played by phenotypic plasticity in evolution, the overall study revealed the significance of individual plasticity and variability in response to the environment and highlighted its importance. Particularly, studying the thermal physiology of separated populations and understanding within population reproductive plasticity in response to temperature, helped to clarify how differences among individual responses have important consequences at the population level, possibly explaining the widespread distribution of T. capensis.
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  • Date Issued: 2014

Exploring transformative social learning and sustainability in community based irrigation scheme contexts in Mozambique

  • Authors: Baloi, Aristides
  • Date: 2017
  • Subjects: Social learning -- Mozambique , Irrigation -- Social aspects -- Mozambique , Water resources development -- Mozambique , Sustainable agriculture -- Mozambique , Community development -- Mozambique
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/50154 , vital:25963
  • Description: This study set out to examine transformative social learning and sustainability in the context of community-based irrigation systems in Mozambique. These irrigation systems are socio-ecological in nature. The history of irrigation systems in Mozambique can be described in two periods: pre-Independence period (mainly the colonial period) and the post-Independence period from 1975 onwards. Most recently, the Mozambique Government has introduced a policy which supports community-based irrigation system implementation and management via irrigation associations in a move to support a shift from rain-fed farming practices to irrigation-supported farming practices amongst smallholder farmers. It is this shift in the object of activity that this study focusses on. It does this by studying learning process in the constituted irrigation associations, examining whether such learning is transformative and sustainability oriented or not, and how such learning can be further expanded and supported. Learning may occur in socio-ecological systems, but whether that learning enables transformation and sustainability of irrigation systems and the constituted associations is as yet under-explored in the Mozambique context and in the context of Education for Sustainable Development in southern Africa. The aim of this research was therefore to understand transformative social learning within the development of sustainable irrigation practices in the context of irrigation associations and new agrarian policy development in Mozambique. To examine transformative social learning in sustainable irrigation system practices (including management practices), the study worked with three research goals, which also formed phases of the study’s design: GOAL 1: Examine how and what transformative social learning has (or has not) emerged in existing activity systems to date (Phase 1: Activity System Analysis). GOAL 2: Examine how transformative social learning could emerge through expansive learning processes (Phase 2: Identification of contradictions and new solution modelling through Developmental Work Research and Change Laboratories). GOAL 3: Identify what opportunities exist for ongoing transformative social learning (Phase 3: Identification of absences and ongoing dialectical transformation possibilities). The study draws on theories of Social Learning, Transformative Learning and Cultural Historical Activity Theory’s (CHAT) expansive learning and formative interventionist research framework to develop insights into the learning processes. It works especially with third generation Cultural Historical Activity Theory which provides a theory of expansive social learning and collective transformative agency formation, which I deemed most appropriate for the need to understand the transformation of farmers’ activities in a collective formation such as an irrigation association. The study involved identification and examination of interacting activity systems, contradictions or dissonances in two case studies of community-based irrigation system development via the respective associations. It involved identifying existing learning, as well as engaging in formative intervention research to expand learning in two case study sites: namely the Macubulane and Massaca Irrigation Associations, located near Maputo, Mozambique in the Inkomati and Umbeluzi river basins. The Macubulane community practices a monocropping system of sugar cane plantations using sprinkler irrigation methods and the Massaca community practices a mixed cropping system growing vegetables using mainly gravity or furrow irrigation methods. The study uses a qualitative research approach and is underlaboured by Dialectical Critical Realism which allowed for a deeper probing of ontology and transformative praxis, and transformative learning. The study used methods which included in-depth interviews, change laboratory workshops, document analysis and focus group interviews with farmers and subjects in associated activity systems. Analysis involved activity system analysis, identification of contradictions, modeling of solutions, transformative agency analysis, as well as analysis of real and nominal absences and generative mechanisms as recommended in dialectical critical realism. I used inductive, abductive and retroductive modes of inference, relying on the latter to identify further potential for transformative learning. The study demonstrates that within the associations, transformative social learning is taking place as farmers seek to address problems and contradictions. This learning leads to the creation of new agency and capabilities by ensuring good yields and continuous improvement of management practices and social status. Learning operates through formal mediation in the irrigation system of workplace-based operation, maintenance and crop management practices (i.e. through workplace learning). Social learning occurs through collective engagement with the constraints that the association faces while applying new knowledge, introducing new technology, in the process of administration and planning of irrigation activities. Expansive learning is possible when mediated actively through formative interventions in change laboratory workshops. All three types of learning were found to be present and possible in the context of the two irrigation scheme contexts. The main study findings are that transformative social learning is a collective object-driven process in the context of a transforming object (from rain-fed to sustainable community-based irrigation scheme farming in this study), that can be explained from the level of generative mechanisms and associated real absences that shape nominal absences and contradictions within and between activity systems. These induce, and have potential to induce, transformative learning in irrigation systems, including the emergence of transformative agency via learning through workplace-based, wider social learning, and expansive learning interaction processes amongst subjects in interacting activity systems. Absenting absences is also crucial for extending the potential of transformative learning in irrigation associations. The study further shows how critical realism helps to interpret learning processes and how it strengthens the empirical findings obtained from qualitative analysis. A key outcome of the study is a model that frames conceptualisation of transformative social learning in irrigation systems. The model and the insights gained into farmers learning around the transformation of the object of activity explored in this study have implications for wider curriculum and policy development interventions. The study therefore also makes recommendations for curriculum development and policy implementation intervention. The curriculum development recommendations are not at the level of making recommendations for new courses only, but frame how the design of new courses should take into account the wider processes of learning and change associated with the transformation of an object of activity as articulated in the study. It recommends an approach that allows for in-field engagement with contradictions and the absenting of absences (a problem-based type of curriculum) that will also allow for conceptual development and understanding of the changing object of activity (i.e. community-based irrigation scheme practice and management). The main policy recommendation made from the study is to invest more in farmer support and farmers’ learning so that they can transition from rain-fed agriculture to sustainable irrigation scheme development and management via their associations. The research contributes to knowledge production on irrigation practices; considering that substantial understandings were generated through analysis of communal irrigation scheme practice and management and its implications, especially from a transformative learning perspective. As shown in this study, transformative social learning theories are still not well understood in the context of irrigation system development, and this study has contributed knowledge to this field. The study contributes towards understanding of sustainability learning in irrigation associations in terms of concepts and practices. The study offers a model for transformative social learning in irrigation scheme development and suggests an expanded curriculum for community-based irrigation association practice and management. Overall, the study contributes to an understanding of transformative, sustainability oriented learning processes as support for the emergence of community-based irrigation associations. Additionally, the study has added perspectives on how to frame transformative social learning from a CHAT and critical realist perspective in Education for Sustainable Development. The study also contributes to a growing body of scholarship in southern Africa which seeks to develop expansive, transformative social learning approaches in response to concerns experienced by communities who are reliant on natural resources and the environment for their livelihoods and well-being, and who are also seeking to emerge out of poverty.
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  • Date Issued: 2017

Modelling parallel and distributed virtual reality systems for performance analysis and comparison

  • Authors: Bangay, Shaun Douglas
  • Date: 1997
  • Subjects: Virtual reality Computer simulation
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4657 , http://hdl.handle.net/10962/d1006656
  • Description: Most Virtual Reality systems employ some form of parallel processing, making use of multiple processors which are often distributed over large areas geographically, and which communicate via various forms of message passing. The approaches to parallel decomposition differ for each system, as do the performance implications of each approach. Previous comparisons have only identified and categorized the different approaches. None have examined the performance issues involved in the different parallel decompositions. Performance measurement for a Virtual Reality system differs from that of other parallel systems in that some measure of the delays involved with the interaction of the separate components is required, in addition to the measure of the throughput of the system. Existing performance analysis approaches are typically not well suited to providing both these measures. This thesis describes the development of a performance analysis technique that is able to provide measures of both interaction latency and cycle time for a model of a Virtual Reality system. This technique allows performance measures to be generated as symbolic expressions describing the relationships between the delays in the model. It automatically generates constraint regions, specifying the values of the system parameters for which performance characteristics change. The performance analysis technique shows strong agreement with values measured from implementation of three common decomposition strategies on two message passing architectures. The technique is successfully applied to a range of parallel decomposition strategies found in Parallel and Distributed Virtual Reality systems. For each system, the primary decomposition techniques are isolated and analysed to determine their performance characteristics. This analysis allows a comparison of the various decomposition techniques, and in many cases reveals trends in their behaviour that would have gone unnoticed with alternative analysis techniques. The work described in this thesis supports the Performance Analysis and Comparison of Parallel and Distributed Virtual Reality systems. In addition it acts as a reference, describing the performance characteristics of decomposition strategies used in Virtual Reality systems.
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  • Date Issued: 1997

Nonlinear optical responses of phthalocyanines in the presence of nanomaterials or when embedded in polymeric materials

  • Authors: Bankole, Owolabi Mutolib
  • Date: 2017
  • Subjects: Phthalocyanines , Phthalocyanines -- Optical properties , Alkynes , Triazoles , Nonlinear optics , Photochemistry , Complex compounds , Amines , Mercaptopyridine
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/45794 , vital:25548
  • Description: This work describes the synthesis, photophysical and nonlinear optical characterizations of alkynyl Pcs (1, 2, 3, 8 and 9), 1,2,3-triazole ZnPc (4), mercaptopyridine Pcs (5, 6 and 7) and amino Pcs (10 and 11). Complexes 1, 2, 4, 7, 8, 9 and 11 were newly synthesized and characterized using techniques including 1H-NMR, MALDI-TOF, UV-visible spectrophotometry, FTIR and elemental analysis. The results of the characterizations were in good agreement with their molecular structures, and confirmed the purity of the new molecules. Complex 10 was covalently linked to pristine graphene (GQDs), nitrogen- doped (NGQDs), and sulfur-nitrogen co-doped (SNGQDs) graphene quantum dots; gold nanoparticles (AuNPs); poly(acrylic acid) (PAA); Fe3O4@Ag core-shell and Fe3O4- Ag hybrid nanoparticles via covalent bonding. Complex 11 was linked to Agx Auy alloy nanoparticles via NH2-Au and/or Au-S bonding, 2 and 3 were linked to gold nanoparticles (AuNPs) via clicked reactions. Evidence of successful conjugation of 2, 3, 10 and 11 to nanomaterials was revealed within the UV-vis, EDS, TEM, XRD and XPS spectra. Optical limiting (OL) responses of the samples were evaluated using open aperture Z-scan technique at 532 nm and 10 ns radiation in solution or when embedded in polymer mixtures. The analyses of the Z-scan data for the studied samples did fit to a two-photon absorption mechanism (2PA), but the Pcs and Pc-nanomaterial or polymer composites also possess the multi-photon absorption mechanisms aided by the triplet-triplet population to have reverse saturable absorption (RSA) occur. Phthalocyanines doped in polymer matrices showed larger nonlinear absorption coefficients (ßeff), third-order susceptibility (Im [x(3)]) and second-order hyperpolarizability (y), with an accompanying low intensity threshold (Ium) than in solution. Aggregation in DMSO negatively affected NLO behaviour of Pcs (8 as a case study) at low laser power, and improved at relatively higher laser power. Heavy atom-substituted Pcs (6) enhanced NLO and OL properties than lighter atoms such as 5 and 7. Direct relationship between enhanced photophysical properties and nonlinear effects favoured by excited triplet absorption of the 2, 3, 10 and 11 in presence of nanomaterials was established. Major factor responsible for the enhanced nonlinearities of 10 in the presence of NGQDs and SNGQDs were fully described and attributed to the surface defects caused by the presence of heteroatoms such as nitrogen and sulfur. The studies showed that phthalocyanines-nanomaterial composites were useful in applications such as optical switching, pulse compressor and laser pulse narrowing.
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  • Date Issued: 2017

Neuropharmacological interactions in the rat pineal gland a study of antidepressant drugs

  • Authors: Banoo, Shabir
  • Date: 1992
  • Subjects: Antidepressants -- Research , Pineal gland -- Research
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3744 , http://hdl.handle.net/10962/d1003222 , Antidepressants -- Research , Pineal gland -- Research
  • Description: The rat pineal gland provides a convenient model for investigating nor adrenergic receptor neurotransmission and the effects of various drugs on these processes in health and disease. The effect of a variety of antidepressant drugs on rat pineal gland function following acute and chronic administration is described. Antidepressants from several different classes increase melatonin synthesis in rat pineal gland cultures when administered acutely. This effect appears to be mediated by noradrenaline acting on postsynaptic β-adrenoceptors. Activation of these receptors, in turn, activates the enzyme serotonin N-acetyltransferase via a cyclic adenosine monophosphate (cAMP) second messenger system. Serotonin N-acetyltransferase catalyses the rate-limiting conversion of serotonin to melatonin. Blockade of postsynaptic β-adrenoceptors prevents the antidepressant-induced increase in melatonin synthesis. The possibility that atypical antidepressants as well as those that selectively inhibit serotonin reuptake may increase melatonin synthesis via a β-adrenoceptor mechanism is discussed. In contrast, however, antidepressants from different classes have variable effects on rat pineal gland function when administered repeatedly. Chronic treatment with antidepressants that selectively inhibit noradrenaline reuptake appear to down-regulate the β-adrenoceptor system while, simultaneously, increasing melatonin output. Atypical antidepressants and those that selectively inhibit serotonin reuptake appear to be without these effects when administered repeatedly. The pineal gland of normal rats may therefore not represent a suitable model for evaluating the biochemical effects of chronic antidepressant treatment. In an attempt to investigatc pineal gland function in rats with "model depression" , antidepressants were administered to chronically reserpinized rats. Treatment with reserpine produced an increase in the density of pineal β-adrenoceptors. In addition, pineal cyclic AMP accumulation and N-acetyltransferase activity were increased in reserpinized rats following exogenous catecholamine stimulation. Reserpine, by depleting intraneuronal catecholamine stores, prevented the nocturnal induction of N-acetyltransferase activity and reduced the synthesis of melatonin in pineal gland cultures. A variety of antidepressants, irrespective of their acute pharmacological actions, reversed these effects when administered chronically to resepinized rats. Acute antidepressant administration was not associated with a reversal of the reserpine-induced effects. These findings provide additional evidence against the hypothesis that antidepressant drugs act by reducing noradrenergic neurotransmission and casts doubt on the importance of β-adrenoceptor down-regulation in the mechanism of antidepressant action. The possibility that the pineal gland of the reserpinized rat may represent an alternative model for evaluating antidepressant therapies is discussed.
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  • Date Issued: 1992

The development of a concept of psychological well-being

  • Authors: Bar-On, Reuven
  • Date: 1988
  • Subjects: Mental health -- Psychological aspects Personality
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2928 , http://hdl.handle.net/10962/d1002437
  • Description: This thesis focuses on the development of an operational and theoretically eclectic concept of psychological well-being. A comprehensive research strategy was employed to examine various personality factors thought to be components of psychological health (i.e., the basis of the proposed concept). The general approach involved four major phases: (1) the clustering of various variables and identification of underlying key factors purported to be related to psychological health based on the writer's clinical experience and review of the mental health literature, (2) the formulation of an ~ priori concept of psychological well-being based on the operational definition of those factors, (3) the construction of an inventory designed to examine the proposed concept, and (4) the interpretation of the results and their implications for the development of the overall concept based on the examination of the factorial structure, validity and reliability of the inventory. The"a posteriori concept" evolved out of this process. The results of the present study indicate that the most valid and reliable factorial components of psychological well-being are self regard,interpersonal relationship, independence, problem-solving, assertiveness,reality testing, stress tolerance, self-actualization and happiness; social responsibility and flexibility emerged as questionable components of the a posteriori concept. The inventory which was designed to study the concept was successful in significantly differentiating various levels of psychological health. This way of conceptualizing and assessing psychological well-being has potential applicability for mental health practitioners and researchers.
  • Full Text:
  • Date Issued: 1988

Financial development in the SADC: growth and cross-country spatial spill-over effects

  • Authors: Bara, Alex
  • Date: 2017
  • Subjects: Economic development -- South Africa Economic assistance -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/14950 , vital:27943
  • Description: This study was prompted by the prevailing imbalance in financial development across SADC countries, which is not consistent with the linkages and interconnectedness of financial systems of these economies. South Africa is the most financially developed country in Africa, yet it is surrounded by economies with relatively small and underdeveloped financial systems, contrary to the spatial proximity theory in finance. The study performed a number of empirical estimations in respect of the spatiality of financial development, motivated by the intention to assess the growth and spatial spill-over effects of financial development in SADC. The study provides new information in spatial spill-over dynamics of financial development, which could inform policy development particularly in view of the on-going financial integration in the SADC region. The study also contributes to regional economic development in SADC from a finance perspective. The analysis was performed using annual data for all the 15 SADC countries, spanning for the period 1985 to 2014. Using the Generalised Method of Moments approach, the study finds that financial development does not support economic growth in SADC. Financial reforms were found to be insufficient to drive growth. A bi-directional causality between financial development and economic growth was established with causality being strong when flowing from economic growth to financial development. The extended Aghion, Howitt and Mayer-Foulkes Model, estimated by an Autoregressive Distributive Lag approach, established that financial innovation has a positive relation to economic growth in SADC, particularly in the long-run. There is no causality, in either direction, between financial innovation and economic growth in both the short and long-run. The Spatial Durbin Model reveals a presence of positive spatial effects on financial development in the region and that proximity to South Africa yields consistent effects of spatial externality in money markets and inconsistent spatial externality in credit markets. The monetary union has no influence on spatial dynamics of financial development in SADC. The generalised impulse response analysis of a Bayesian VAR model indicate that shocks in South Africa’s financial sector has positive, but constrained and in some cases weak, financial spill-over effects on both economic growth and financial development of other SADC countries. The study established, using the Herfindahl-Hirschman Index, a high level of financial market concentration for SADC, cantered in South Africa, and a fair distribution when South Africa is excluded. Dynamic panel models established that financial market concentration reduces financial development in SADC. South Africa’s financial development has mixed and opposing effects on financial market concentration in SADC. The findings also show that international finance has a positive, but currently weak, effect on financial development in SADC and countries with international financial centres contribute more to financial development than countries without. Proximity to South Africa creates huge potential for increasing financial development in SADC through spill-overs and more benefits of spatial proximity are realised in the long-run. Given the strong spatial effects in money markets and significant positive spill-overs in credit markets in the region, countries closer to South Africa need to link their money and credit markets to the South African markets and possibly benchmark to the Rand so as to benefit from proximity and spill-overs from South Africa. The results also suggest that SADC countries need to capitalise on their proximity to South Africa to enhance financial development by promoting economic growth, financial innovation, opening and diversification of financial sectors and linkages to global financial markets. Financial innovation supports financial inclusion, cross-border flows of funds, remittances and trade in SADC and has effects of enabling integration with developed markets and facilitating economic activity. Opening financial sectors enhances diversification of financial systems, increases competition and efficiency. To enhance access to international finance, the study suggests the creation of information centres in South Africa with SADC countries as economic hinterlands, commercialisation of solutions to SADC countries financial challenges, financial integration and support for deepening of financial systems in these countries. Strengthening economic growth could also increase financial development given a strong demand-following causality. The major challenge, however, is that some of the SADC countries have underdeveloped and highly concentrated financial systems characterised by high financial intermediation inefficiencies, high financial exclusion, weak financial infrastructure and regulations. Consequently, countries suffer financial leakages, are not receptive to spatial externalities and financial spill-overs from South Africa and often generate financial spillbacks to South Africa. SADC countries should, however, first address the issue of financial exclusion, financial infrastructure and regulation as well as efficiency in the financial markets. The SADC countries need mechanisms to attract financial development from South Africa to benefit from positive spill-overs and instruments to deal with negative externalities of financial shocks in South Africa. Overall, there is potential for increased financial development in SADC by consolidating absorption of positive financial spill-overs and externalities of proximity to South Africa -particularly in the medium to long term. Heterogeneity among SADC countries and the varying levels of financial development, however, dictates that the region should promote financial integration in order to enhance development of underdeveloped financial systems through spatial spill-over gains.
  • Full Text:
  • Date Issued: 2017

Modelling the hydrological responses to changes in land use and cover in the Malaba River Catchment, Eastern Uganda

  • Authors: Barasa, Bernard
  • Date: 2014
  • Subjects: Hydrologic models -- Uganda , Runoff -- Uganda
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:10670 , http://hdl.handle.net/10948/d1020153
  • Description: Hydrological responses vary from one catchment to another, depending on the nature of land use and cover changes. Modelling the hydrological responses to changes in land use and cover at different catchment spatial scales was the major focus of this study. This study assessed the hydrological responses attributed to changes in land use and extreme weather events resulting into increased sediment loading/concentration, rainfall-runoff generation/volume, streamflow fluctuation and modification of the river channel in the Malaba River Catchment, Eastern Uganda. The hydrological responses were assessed using hydrological models (IHACRES, SCS CN, and SHETRAN) to examine the effect of land use on soil physio-chemical properties susceptibility to rainfall-runoff generation and volume, frequency and severity of extreme weather events, changes in streamflow variations, sediment loading/concentration and river channel morphology. The preliminary study results showed that the frequency of extreme weather events reduced from 4-10 to 1-3 years over the catchment. The performance of the IHACRES model with a Nash-Sutcliffe Efficiency (NSE) of 0.89 showed that streamflow comparatively corresponded with the results obtained the drought indices in predicting the recorded events of severe drought (2005) and flood (1997). Changes in land use and cover types showed that the highest change in the gain of land was experienced from the agricultural land use (36.7 percent), and tropical forest (regeneration) (2.2 percent). The biggest losses in land were experienced in the wetlands (24.6 percent) and bushland and thickets (15.3 percent) land cover types. The SHETRAN model calibrated period had a NSE of 0.78 and 0.81 in the validation period showed satisfactory fits between the measured and simulated streamflow. The agricultural land use (crop growing) had a higher influence on the rainfall-runoff generation and increase in the streamflow than the tropical forest, and bushland cover types in the simulated period. Similarly, the curve number model estimated a comparatively higher surface rainfall-runoff volume generated from the agricultural land use (crop growing) (71,740 m3) than in the bushlands and thickets (42,872 m3) from a rainstorm followed by the tropical forest cover type. This was also reflected in the lower rates of saturated hydraulic conductivity from the agricultural land use (crop growing). The study also showed that human-induced sediment loading due to gold mining activities contributed a much higher impact on the concentration of suspended sediments and streamflow than sediments from rainfall-runoff from the sampled streams. The main contributor of human-induced sediments to the Malaba River were Nankuke River (130.6kg/annum), followed by Omanyi River (70.6kg/annum), and Nabewo River (66.8kg/annum). Human-induced sediment loading had a profound impact on the streamflow variations both in the dry and wet seasons from the sampled tributaries. Lastly, in regard to the effect of land use and cover types on the river channel morphology, tree plantation (cohesion=12, angle of internal friction=27) and bushland and thickets (cohesion=14, angle of internal friction=22) cover types had the most stable river banks compared to the wetland and agricultural land use and cover types that exhibited higher levels of sediment concentration.
  • Full Text:
  • Date Issued: 2014

Systematics, morphology, phylogeny and historical biogeography of the Mayfly family Prosopistomatidae (Ephemeroptera: Insecta) of the world

  • Authors: Barber-James, Helen Margaret
  • Date: 2011
  • Subjects: Mayflies Mayflies -- Classification Mayflies -- Morphology Mayflies -- Phylogeny Mayflies -- Geographical distribution Ephemeridae
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5785 , http://hdl.handle.net/10962/d1005473
  • Description: The diversity, classification and historical biogeography of the mayfly family Prosopistomatidae are explored. First, the higher classification of the Ephemeroptera is reviewed, focussing on the phylogenetic placement of the Prosopistomatidae relative to other mayfly families. All relevant literature from 1762 to 2010 is synthesized. Baetiscidae are established as the probable sister lineage of Prosopistomatidae, the two constituting the superfamily Baetiscoidea. Next, qualitative morphological variation within the Prosopistomatidae is reviewed and revised, emphasizing nymphs because imaginal specimens are few. The labium and associated structures and the hypopharynx of nymphs, and the highly-derived wing venation of the imaginal stages, are re-interpreted. The structure of the male tarsal claws changes considerably between subimago and imago, which, together with deeply scalloped ridges on male imaginal forelegs and unusual pits on the female thorax, are interpreted as providing an unusual mating mechanism. These structures provide morphological characters for species definition and phylogenetic analyses. Two approaches to species delimitation are explored. First, morphometric variation is analysed using Principal Component Analysis, revealing groupings that can be interpreted as species, although there is some overlap between them. Discriminant Function Analysis shows that head width and carapace shape have the most value in identifying nymphs of different species. The carapace of Prosopistoma nymphs is shown to grow allometrically and gradually, in contrast with that of Baetisca, indicating a difference in early ontogeny. Second, an Artificial Neural Network algorithm applied to nymphal morphological characters accurately identified species. This computer-driven artificial intelligence method has power to provide future easy-to-use electronic identification aids. Phylogenetic analysis of nymphal morphology using the parsimony method shows two clades of Prosopistomatidae, one sharing characters with the type species, Prosopistoma variegatum and the other predominating in Africa, although also occurring in Asia; these clades are named the “P. variegatum” and “African” clades, respectively. Parsimony analysis of adult morphology supports these two clades, but supertree analysis obscures the relationships, nesting the “P. variegatum” lineage within the other clade. Preliminary molecular phylogenetic analysis of the 16S rRNA, (mitochondrial) 18S rRNA and Histone-3 genes using Bayesian Inference methods does not support the two clades shown by morphology. Instead, there is a strong relationship between the European species and one African species, with the single Asian representative being most distantly related. These results are limited by lack of fresh material, patchy taxon sampling, and problems with finding suitable primers. A molecular clock program, BEAST, calibrated using fossils, suggests divergence times for the oldest crown-group Prosopistoma clade, represented by the Asian P. wouterae, of about 131 Ma, with the youngest species, the African P. crassi, of 1.21 Ma. Stem-group relationships are analysed using parsimony analysis, focussing on wing characters of the Baetiscoidea, other extant mayfly lineages, and extinct stem-group lineages. This suggests that the Baetiscoidea diverged from main-line Ephemeroptera earlier than any other extant mayfly lineage. This approach expands upon ideas hinted at by earlier scientists. Finally, historical biogeographical analysis of the distribution of known Baetiscoidea s.s. stem-group fossils implies a once Pangean distribution of the lineage. Changing palaeo-climate, catastrophic extinction events and plate tectonic movements in relation to the distribution of crown-group species are reviewed. Other approaches to historical biogeography that build on both morphological and molecular phylogenies are used to interpret disperalist and vacarianist arguments. Distribution patterns of eight unrelated freshwater organisms which share a similar distribution pattern are compared, assuming that shared patterns indicate similar historic biogeographic processes. The distribution of recent Prosopistoma species is seen to be the product of evolution resulting from both vicariance and dispersal. In conclusion, this thesis encompasses a variety of disciplines. It successfully recognises new characters and distinguishes previously unknown species. It uses new approaches to delimiting species and known methods to determine phylogeny from several angles. The analysis of stem-group relationships offers an insight into possible early lineage splitting within Ephemeroptera. Interpretation of historical biogeography allows for both a Gondwanan origin of Prosopistomatidae, with rafting of species on the Deccan plate to Asia, and for subsequent dispersal from Asia down to Australia and across to Europe, and possibly back to Africa.
  • Full Text:
  • Date Issued: 2011

An investigation into Grade R teachers' experiences of implementing numeracy in Grade R

  • Authors: Barnard, Elna
  • Date: 2011
  • Subjects: Teachers -- South Africa -- Attitudes Numeracy -- Study and teaching (Elementary) -- South Africa Teachers -- Training of -- South Africa Mathematics teachers -- In-service training -- South Africa Early childhood education -- South Africa -- History Early childhood education -- South Africa -- Political aspects
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1855 , http://hdl.handle.net/10962/d1004529
  • Description: This research study investigates how selected Grade R teachers implement numeracy in their classrooms, based on their experiences, personal beliefs and perceptions. This study adopts the view that a teacher's practice is not only informed on what she believes about her learners, but also on how she organises her classroom environment and her own teaching practice. However, the teacher cannot be divorced from the political and historical background of Early Childhood Development (ECD), as these factors have an impact on her numeracy implementation. Integrated in this research study is thus not only a comprehensive historical analysis of the historical and political background of ECD, but also an in-depth look at the complex curriculum road the Grade R teacher had to travel over the past twelve years. The aim of this case study is to understand and describe what is happening in Grade R classrooms when numeracy is implemented, as well as identifying possible barriers which Grade R teachers may experience in implementing numeracy. The author utilized an adapted Interactive Qualitative Analysis Framework to explore Grade R teachers' views and experiences. Open-ended focus group interviews were used to develop a framework for individual interviews. This interview framework guided the data collection of nine audio-video tapes of classroom activities and nine semi-structured individual interviews. Analysis of the individual interviews revealed each teacher's understanding as well as her perceptions and needs regarding the implementation of numeracy in her classroom. The transcriptions of the individual interviews were compared to the audio-video tapes of what happened in each classroom. This was done in order to determine whether the teachers' practices were consistent with what they said in the interviews. Paradoxes and inconsistencies were documented. The historical and political analysis of ECD illustrates the complex development of ECD in South Africa over the last few decades. It therefore also highlights and brings to the fore the complex journey that Grade R teachers had to navigate in adapting their practice to ever changing curriculum requirements. The empirical results show that there are inconsistencies between what selected teachers know and believe, and what they are implementing. However, "silent themes" which did not come to the fore in the focus group or individual interviews, were identified in the audiovideo tapes of classroom activities. Also, many "silent themes" indicate that there are numerous concerns, such as lack of proficiency in bridging the gap between theory and practice, regarding the implementation of numeracy in Grade R. It was found that many of the selected Grade R teachers struggle to implement numeracy in their classrooms, as they lack the skills and support to teach numeracy in a Grade R context.
  • Full Text:
  • Date Issued: 2011

The relationship between servant leadership, workplace trust, work engagement and workplace wellbeing

  • Authors: Barnard, Patrick Christian
  • Date: 2017
  • Subjects: Work environment -- Psychological aspects Organizational behavior , Psychology, Industrial Leadership
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/14532 , vital:27740
  • Description: Globalization has had a profound impact on the business environment of organizations and on the lives of employees in most countries. Previously sheltered markets were suddenly opened up to intense international competition. Organizations had to improve the efficient and effective utilization of resources to retain and gain market shares. Even organizations which are still prospering today in the face of serious competition, cannot be sure of continued success in the next financial year. Astute owners and managers are acutely aware of the need to continually and consciously seek the competitive edge for their businesses. Market forces exert continuous pressure on organizations and their employees to increase performance to keep up with ever rising demands. Concurrently there are rising pressures from civil society, easily mobilized through social media, for organizational leaders to be more ethical, moral and socially responsible. Employers are currently expected to not only take care of the wellbeing of their employees, but also the wellbeing of the communities in which they operate. The challenge is clearly to find a business model that can increase individual and organizational performance, while at the same time create high levels of wellbeing for employees and thereby creating a spill-over effect to influence the wellbeing of their social environment positively. To this end, the literature was reviewed to identify constructs which could provide a solid ethical and moral managerial foundation, increase performance and create high levels of wellbeing at the same time. Servant Leadership, Workplace Trust, Work Engagement and Workplace Wellbeing were identified as constructs which could fulfill these requirements. As measurement lies at the heart of scientific endeavour, the selection of appropriate measuring instruments was considered to be equally important. The Servant Leadership Survey (Van Dierendonck and Nuijten, 2011), the Workplace Trust Survey (Ferres, 2001), the Utrecht Work Engagement Scale (Schaufeli et al, 2002) and the Work Wellbeing Questionnaire (Parker and Hyett, 2011) were selected as the most suitable instruments. These instruments are deemed to measure the constructs thoroughly through a combined total of 114 items and 18 dimensions. Three primary aims were identified for the study namely, determining the configurational portability of the instruments, investigating the relationships between the variables to determine their direct and sequential effect on wellbeing and establishing whether structural models of the findings could be built. The main findings indicate that each of the variables explain significant proportions of the variance in Work Wellbeing directly as well as indirectly through their effect on the other variables of the study. It seems that these variables contribute to fostering a psycho-organizational climate conducive to increased wellbeing.
  • Full Text:
  • Date Issued: 2017

An empirical phenomenological investigation of procrastinating behaviour

  • Authors: Barratt, Neal Anthony
  • Date: 2010
  • Subjects: Procrastination Self-actualization (Psychology) Cognitive psychology
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2929 , http://hdl.handle.net/10962/d1002438
  • Description: A qualitative empirical phenomenological study was undertaken to determine the self-experience of procrastinating behaviour. Five students each gave an account of an occasion when they procrastinated. The resultant protocols were analysed and the Situated Structure of each individual’s experience was reported. From these, the General Structure of procrastinating behaviour was determined. A further, novel step was added to the standard methodology, whereby ‘themes’ were extracted from participant protocols and a ‘Composite Reality’ of everyday-life procrastination was rendered. Participants’ accounts suggest they are concerned the results of intellectual tasks they undertake will be seen as equivalent to their quality of being-as-an-individual: poor work results will be interpreted by important-others as evidence of participants’ poor quality of self – which is to be avoided. This study suggests that procrastination is a ploy used by individuals to avoid criticism, by deflecting assessment of their capacity to complete a task well, to instead, what they are capable of when only a limited time is available. Conclusions drawn by the important-others of participants’ true ability are thereby confounded. The results achieved in the phenomenological study were compared with others originating from various quantitative studies, and considerable overlap was found. The experiential richness of the phenomenological results point to a worthwhile methodological strategy for future procrastination research.
  • Full Text:
  • Date Issued: 2010

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.
  • Full Text:
  • Date Issued: 2020

Critical assessment of corruption in municipalities and its impact in service delivery : case study Buffalo City Metropolitan Municipality

  • Authors: Basopu, Price Mike
  • Date: 2016
  • Subjects: Misconduct in office -- South Africa -- Eastern Cape Corruption -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10353/1558 , vital:27445
  • Description: Many African countries including Africa South have been experiencing many challenges such as corruption, fraud and misaprpriation of fund in this new democratic dispensation. In this regard, the municipalities are viewed as the most affected institutions, with the Eastern Cape Province identified as culprit number one engaging in corrupt activities. There are a number of contributing factors, as attributed in the study, but most prevalent among these are capacity issues in most of these municipalities, with fewer personnel and less capacity. Challenges of corruption in municipalities are perpetrated mainly by municipal officials, councilors and members of the public. This study, identified corruption as one of the challenges facing municipalities in the Eastern Cape. It involves both the achievements and limitations that have been experienced; and indeed, there are still numerous issues to be addressed and accomplished. It discusses some critical issues such as how corruption has been the mother of the day in South Africa and its effect on the public sector in general. Inadditon, misappropriation of public resources and corruption immersed the nation as a whole into a greater challenge rather than focusing on service delivery issues. There are situations, within municipalities, where the majority of senior officials, who may be in possession of valuable information, are always under suspension. The findings of the study also show that all the municipalities operating in this new democaticatic dispensation have not been able to prepare a transparent annual financial year report at the end of the year. In fact, the majority of them always obtain disclaimer or adverse reports from the Office of Auditor-General (AG), despite numerous attempts and interventions by the AG‟s office and the Provincial Treasury to rectify the situation. The challenges of leadership crises in some of these municipalities, both administratively and politically have been critically examined. The findings show that between 2012 and 2015 financial years, some of these municipalities have been without full-time Accounting Officers; people were only seconded or in acting capacity, and some of them were under adminisistration, which is section 139 (c) of the constitution. There were numerous attempts of interventions by the national leadership of the ANC in the ANC regional structures which in many instances were the root cause of the problems or divisions, as well as in municipalities where in Buffalo City Metro and Nelson Mandela Metro respectively there were leadership changes or redeployments. The issue of corruption in the municipalities is compromising and impact negatively in the service delivery. It can be concluded that municipalities are characterized by a number of instances of corruption perpetrated mainly by municipal officials, councilors and members of society. Bribery, fraud, nepotism, and systematic corruption are some of the forms of corruption that take place in municipalities in South Africa. There are systems in place to fight corruption, but the reality is that they are very weak and ineffective. The anti-corruption strategies put in municipalities have general functioned poorly hence the prevailing the situation. There is glaring non-compliance with the Municipal Finance Management Act (MFMA), the Treasury Regulations and their own Procurement Procedures and Procurement Policies. It is evident that despite the achievement by an ANC led government for almost over 21 years of democracy, there remain many political and administrative challenges especial in municipalities. The fundamental question need to be posed and address therefore is, how best these challenges can be addressed and turn around service delivery to a tangible outcome. The Constitution of the Republic of South Africa provides for the promotion and maintenance of a high standard of professional ethics in the public service. Public resources are vulnerable to abuse by unscrupulous elements, both inside and outside government and therefore requires careful monitoring and control. The existing legislative framework is solid but fragmented and requires review and consolidation to improve its efficiency. To achieve that government requires an approach that is developmental in nature. Governance should be able to take control of the organization’s systems and at the same time adaptable to the environment in a way strengthens the capacity to achieve goals.
  • Full Text:
  • Date Issued: 2016

Development of molecularly imprinted polymer based solid phase extraction sorbents for the selective cleanup of food and pharmaceutical residue samples

  • Authors: Batlokwa, Bareki Shima
  • Date: 2012
  • Subjects: Sorbents -- Research Nanofibers -- Research Aflatoxins -- Research Electrospinning -- Research Extraction (Chemistry) -- Research
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4309 , http://hdl.handle.net/10962/d1004967
  • Description: This thesis presents the development of chlorophyll, cholic acid, aflatoxin B1 molecularly imprinted polymer (MIP) particles and cholic acid MIP nanofibers for application as selective solid phase extraction (SPE) sorbents. The particles were prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The AFB1 MIP particles were compared with an aflatoxin specific immunoextraction sorbent in cleaning-up and pre-concentrating aflatoxins from nut extracts. They both recorded high extraction efficiencies (EEs) of > 97 % in selectively extracting the aflatoxins (AFB1, AFB2, AFG1 and AFG2). High reproducibility marked by the low %RSDs of < 1% and low LODs of ≤ 0.02 ng/g were calculated in all cases. The LODs were within the monitoring requirements of the European Commission. The results were validated with a peanut butter certified reference material. The chlorophyll MIP on the other hand selectively removed chlorophyll that would otherwise interfere during pesticide residue analysis (PRA) from > 0.6 to <0.09 Au in green plants extracts. The extracted chlorophyll was removed to far below the level of ≥ 0.399 Au that is usually associated with interference during PRA. Furthermore, the MIP demonstrated better selectivity by removing only chlorophyll (> 99%) in the presence of planar pesticides than the currently employed graphitized carbon black (GCB) that removed both the chlorophyll (> 88%) and planar pesticides (> 89%). For the interfering cholic acid during drug residue analysis, cholic acid MIP electrospun nanofibers demonstrated to be more sensitive and possessing higher loading capacity than the MIP particles. 100% cholic acid was removed by the nanofibers from standard solutions relative to 80% by the particles. This showed that the nanofibers have better performance than the micro particles and as such have potential to replace the particle based SPE sorbents that are currently in use. All the templates were optimally removed from the prepared MIPs by employing a novel pressurized hot water extraction template removal method that was used for the first time in this thesis. The method employed only water, an environmentally friendly solvent to remove templates to ≥ 99.6% with template residual bleeding of ≤ 0.02%.
  • Full Text:
  • Date Issued: 2012
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