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An exploration of the prior conceptual understanding of measurement of first year national certificate (vocational) Engineering students

  • Authors: Vale, Pamela
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/8033 , vital:21337
  • Description: Measurement is acknowledged to be a critical component in mathematics education and is particularly important for vocational Engineering students, for whom this is a key skill required in the workplace. The goal of this research was to explore the existing measurement conceptualisations of vocational Engineering students at the outset of their course, as evident in their engagement with mediated measurement tasks. The focus on students’ prior knowledge in measurement, was for the value that this awareness holds in understanding the learning needs of the students. Students participated in five measurement tasks. Four took the form of dynamically assessed task-based interviews, and the fifth was a written test assessing what they had learned during their Mathematics classes. Domains of measurement that were assessed in these tasks included length, area, surface area, volume and flow rate. The interviewer took the role of mediator and students were assessed according to the number of moments of mediation and the degree of mediation required to successfully complete the task. Students’ responsiveness to this mediation provided insight as to their conceptualisations of the measurements relevant to the task. This research was exploratory in nature and adopted an open and flexible approach to the data analysis. Critical incidents were identified and coded according to the mediation offered and the actions of the students during the measuring activity. This allowed patterns to emerge that revealed stable and emerging conceptualisations that related to embodied and symbolic aspects of measurement. Evidence was found that for many of these students the link between the embodied and symbolic aspects of the concept was broken. This insight allowed suggestions to be formulated about how better to facilitate these students’ learning of measurement.
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An historical perspective on the evolution of the United States internal revenue code from 1981-2001

  • Authors: Johnson, Ryan A
  • Date: 2017
  • Subjects: United States -- Economic conditions -- 1981-2001 , Income tax -- Law and legislation -- United States , Internal revenue law -- United States , Taxtion -- Law and legislation -- United States , United States. Economic Recovery Tax Act of 1981 , United States. Tax Reform Act of 1986 , United States. Omnibus Budget Reconciliation Act of 1993 , United States. Economic Growth and Tax Relief Reconciliation Act of 2001
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/7384 , vital:21251
  • Description: The purpose of this study was to identify and analyse in an historical context the major changes to the United States’ Internal Revenue Code during the period 1981-2001. This qualitative study relied on historical and legal interpretative approaches to better understand the political forces, personalities, and interactions that helped shape the legislative changes during this time period. The study focused on deep analysis of primary sources that best illuminated the latent narrative of four major tax actions: The Economic Recovery Tax Act of 1981, the Tax Reform Act of 1986, The Omnibus Budget Reconciliation Act of 1993, and The Economic Growth and Tax Relief Reconciliation Act of 2001. Archives, periodicals, and political rhetoric were examined in order to help shape the historical narrative. In addition, this study sought to identify major trends and paradigm shifts in the way United States tax policy was formed during the time period examined. The study identified several key trends that emerged in United States’ tax policy during this period: the use of budget deficits as political tools; factors associated with accomplishing tax reform; gaps between political rhetoric of individual politicians and their political action; and the virtual disappearance of a political middle ground in United States budget politics. The study concluded by noting the economic and political significance of budget deficits and stressing the need for fundamental changes in voter responsibility in helping achieve lasting, broad-based tax reform and budgetary responsibility in the United States.
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An investigation into the effect of an Extensive Reading Programme on bilingual Grade 3 learners’ reading attitudes in two primary schools in Grahamstown

  • Authors: Nkomo, Sibhekinkosi Anna
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD , text
  • Identifier: http://hdl.handle.net/10962/7723 , vital:21289
  • Description: The focus of this study is to explore formative intervention of a bilingual Extensive Reading Programme (ERP) in two Grade 3 classes in Grahamstown, South Africa. ERP involves access to large quantities of reading materials for pleasure and to reading opportunities (Bamford & Day, 2002; Krashen 2004). The current focus on measurable reading achievement in clearly defined areas such as vocabulary, fluency and comprehension has resulted in reduced attention towards the affective component in relation to literacy development, and links attitudes to reading success. This study helps to fill this gap by examining the effect of an ERP on the reading attitudes of Grade 3 learners. The study draws on Cultural Historical Activity Theory (CHAT) to make sense of learning and social change through mediation, scaffolding, interaction and collaboration learning. The ERP is located within a broad framework of literacy and incorporates a balanced reading approach implemented in an informal reading setting so as to motivate, encourage and nurture reading for enjoyment. This formative intervention used expansive learning cycles to develop a responsive ERP that was implemented and evaluated to investigate its effects on learners’ reading attitude. There were three phases (pre-, during- and post- intervention) that were designed over 31 weeks where rich, qualitative data was collected from questionnaires, observations, learners’ drawings and interviews. To make sense of this data, concepts from CHAT such as contradictions, expansive learning, double stimulation, transformative agency and sustainability were used (Engestrom & Sannino, 2010; Haapasaari & Kerosuo, 2015; Saninno, 2015). In addition, Mathewson’s (1994) reading attitude model addressed the attitudinal aspects of the study whilst a multimodal social semiotic perspective (Kress & Van Leeuwen, 1996) was used to analyse learners’ drawings. The findings of this study demonstrate the effectiveness of combining top-down and bottom-up reading methodologies. In both research sites there was appreciable change in the number of books learners read. Learners also began to volunteer to read and participated in book talks. Through access to a variety of reading materials and reading opportunities, learners demonstrated agency, criticising some ERP practices and modelling new ways, thus claiming and sustaining the reading programme. Being provided with a safe, informal learning context where reading was presented as a social activity, learners gained confidence, engaged in meaningful discussions and improved their self- esteem. Finally, learners continue to access these resources even beyond the research programme.
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Analysis of a foundational biomedical curriculum: exploring cumulative knowledge-building in the rehabilitative health professions

  • Authors: De Bie, Gabrielle
  • Date: 2017
  • Subjects: Medical education -- Curricula , Human anatomy -- Study and teaching -- Curricula , Physiology -- Study and teaching -- Curricula , Occupational therapy -- Study and teaching -- Curricula , Physical therapy -- Study and teaching -- Curricula , Medical rehabilitation -- Study and teaching -- Curricula , Knowledge, Theory of
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/18617 , vital:22361
  • Description: This study was motivated by the researcher's experience that students in the rehabilitative health professional programmes were finding it difficult to access fundamental knowledge upon which their professional practices and clinical contexts are based. An important focus of the research was the extent to which cumulative knowledge-building was impacted after the foundational biomedical curriculum became an interdisciplinary programme. The study explored whether the organisation of the interdisciplinary foundational curriculum served the fundamental needs of the professions, and whether, as a matter of social justice, students' access to powerful knowledge was enabled by the form that the fundamental curriculum assumed. This curriculum study at a particular Faculty of Health Sciences foregrounds the structuring, organisation and differentiation of disciplinary knowledge, and reflects a twenty year period that included not only transitions in professional education but also extensive transformation in, and a different approach to, health delivery. At the institution, physiology and anatomy, the biomedical sciences basic to the health professions, underwent disciplinary merging and subsequent altered positioning in curricula. Medicine opted for a problem-based learning approach whereas the rehabilitation health sciences did not. Legitimation Code Theory (LCT) provided the means for analysis of the extent to which interdisciplinary organisation in the foundational curriculum for Physiotherapy and Occupational Therapy enabled integrative, cumulative building of knowledge for professional and clinical contexts. Specialisation and Semantics dimensions of Legitimation Code Theory were used to reveal the principles underpinning practices, contexts and dispositions of Anatomy and Physiology at the Faculty of Health Sciences over a twenty year period post democratisation in South Africa (1994 - 2013). Disciplinary positioning in curriculum prior- and post-merger, were compared and contrasted. LCT were used to characterise the distinctiveness of Physiotherapy and Occupational Therapy at the university including the kind of knowledge and the kind of knower that specialises the different professions, and what is valorised and legitimated for each kind of professional. Semantic gravity was used to explore the expected knowledge recontextualisations in diverse and complex clinical settings for each of the professions. Registered professionals who are clinical educators as well as curriculum designers for clinical studies were interviewed. Profession-specific course outlines were further data sources. The biomedical disciplines Anatomy and Physiology were characterised for their measures of distinction and their respective knowledge-knower structures. Analysis traced each discipline from its strongly classified form in autonomous curricula when there were separate learner-cohorts for physiotherapists and occupational therapists, to post-merger when the disciplines were framed as human biology in an integrated foundational curriculum for a joint cohort of students. Curricular documents for the twenty year period were analysed quantitatively and qualitatively to establish the positioning of Physiology and Anatomy before and after the disciplines merged to a single course of Human Biology. Teaching staff were interviewed for their understanding of what specialises the physiological and anatomical components of the Human Biology curriculum, what they considered as powerful knowledge for the professions, and who they envisaged as the ideal student-knower exiting the basic sciences platform to enter more advanced clinical studies. The degree of context-dependence for meaning-making in the different disciplinary domains and the condensation of meanings inherent in the respective practices and contexts, were analysed. The thesis argues that following the merger Anatomy is preferentially legitimated as powerful knowledge at the expense of Physiology; that the ideal of disciplinary integration is not reached, and that the segmental organisation and structuring of the curriculum negatively impacted on cumulative knowledge-building and application of professional knowledge in the clinical arena. After the merger the disciplines lost their shape, and in particular the hierarchical knowledge structure of Physiology collapsed. By not having access to the necessary disciplinary knowledge structures and their associated practices, students' ability for scaffolding and integrating knowledge into the clinical arena was constrained. The organisation of the current Human Biology curriculum does not facilitate cumulative learning, and in so doing may not contribute to the envisaged graduate professional who is required to practice within a complex and demanding healthcare work environment. The significance of this study conveys that interdisciplinary programmes should be carefully considered, and there is an added imperative in the health professions which ultimately realise treatment of patients. If, aside from interdisciplinary teaching, there are also merged cohorts of participant students, then a sound understanding of the epistemic requirements of each profession is required. Those involved in curriculum development in various fields need to take these recommendations into account to enable cumulative learning and enable epistemological access to powerful knowledge for an increasingly diverse student body.
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Apparent digestibility coefficients of feed ingredients and essential amino acid requirements of dusky kob (Argyrosomus japonicus)

  • Authors: Adesola, Abidemi Adejoke
  • Date: 2017
  • Subjects: Amino acids in animal nutrition , Fishes -- Feeding and feeds , Argyrosomus japonicus , Argyrosomus , Argyrosomus japonicus -- Nutrition , Argyrosomus -- Nutrition , Argyrosomus japonicus -- Feeding and feeds , Argyrosomus -- Feeding and feeds
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/32140 , vital:24014
  • Description: Important to the evaluation of potential feed ingredients for inclusion in fish diets should be their digestibility and amino acid requirement so that feeds can be formulated on a digestible basis rather than a gross nutrient basis. This thesis established techniques for faecal collection, the validity of digestibility markers, it determined apparent digestibility coefficients for various novel feed ingredients, and it established the optimal lysine requirement for Argyrosomus japonicus, which was used to estimate each of the essential amino acid requirements by using the ideal protein concept. There were no significant differences in dry matter apparent digestibility coefficients when faeces were collected by stripping (77.0 %), dissection (80.1 %) or settlement (83.5 %). Faecal collection by the settlement method produced the most reliable digestibility data. Apparent digestibility coefficients for dry matter, crude protein and energy calculated using acid-insoluble ash were higher (84.0 %, 93.2 % and 93.0 %, respectively) than those using chromic oxide (55.7 %, 79.1 % and 78.2 %) and titanium dioxide (58.6 %, 79.7 % and 80.5 %). The magnitude of variation in digestibility coefficients obtained using acid-insoluble ash was always lower than that obtained with the other markers. Therefore, acid-insoluble ash was preferred as a dietary marker. Using the above protocol, protein and amino acid digestibility of some animal and plant protein ingredients were evaluated in a series of experiments. The first trial compared the apparent digestibility coefficients of some animal products included as single protein source in the test diets. Apparent protein digestibility values were 84.5 %, 83.8 %, 85.8 % and 83.1 % for fishmeal-prime, fishmeal-standard, poultry meal and pork meal, respectively. Apparent digestibility coefficients for poultry meal were comparable to those of fishmeal, which indicate its potential as a substitute for fishmeal in the diets of A. japonicus. The second trial determined the apparent coefficients of plant and animal protein sources included at 30 % into a practical reference diet (70 %). Apparent protein digestibility ranged from 92.4 % in sunflower meal to 85.5 % in corn gluten meal. Soybean meal is a promising feed ingredient in A. japonicus due to the high apparent digestibility of its protein (92.0 %) and essential amino acid digestibility (mean average 91.4 %). A fundamental assumption in fish feed formulation is that the digestibility of nutrients is additive, i.e., digestibility of a nutrient in one ingredient does not interact with the digestibility of the same nutrient in another ingredient. In the third trial, additivity of feed ingredients was tested using pork meal and poultry meal. The results indicate that the apparent digestibility coefficient of animal protein ingredients could be calculated from compound diets to accurately determine protein and amino acid digestibility in A. japonicus, and possibly other carnivorous fish species. Dietary essential amino acid requirements were determined for juvenile A. japonicus in two trials. A dose-response study was conducted using crystalline lysine to determine the optimal requirement of dietary lysine for A. japonicus. Optimal dietary lysine was estimated at 31.7 g kg-¹ dry diet, corresponding to 73.5 g kg-¹ of dietary protein, based on specific growth rate and broken-line segmented regression analyses. Dietary requirements for other essential amino acids ranged from 22 g kg-¹ (histidine) to 71 g kg-¹ (leucine) crude protein. The results of the present study provided a research tool that could be used to assess and verify the conclusions of earlier dietary work on A. japonicus and in further studies to develop least cost diet formulations for this species. The study also adds to the knowledge of the nutritional requirements of A. japonicus by providing information on the digestibility of plants and animal protein ingredients. It also contributes to future dietary research for this species because this study determines, for the first time, the most suitable methods for investigating the digestibility of raw materials for A. japonicus.
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Biotic and abiotic factors promoting the development and proliferation of water hyacinth (eichhornia crassipes (Mart.) Solms-Laub.) in the Wouri Basin (Douala-Cameroon) and environs, with implications for its control

  • Authors: Voukeng, Sonia Nadege Kenfack
  • Date: 2017
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/7644 , vital:21281
  • Description: The Wouri River, situated in the Wouri Basin, is one of the main rivers of the Littoral Region in the city of Douala in Cameroon. It is a source of income and food for the population living around these areas. Since the 1990s, the fishing, transportation, irrigation and sand extraction activities have been impeded by the invasion of aquatic plants, specifically water hyacinth (Eichhornia crassipes [Mart.] Solms-Laubach: Pontederiaceae). Introduced in 1997 to the shore of Lake Chad, water hyacinth has invaded almost 114 ha of the Wouri Basin. Furthermore, Douala, the economic capital of the Cameroon and location for more than 70% of the country’s industries, uses the Wouri River and its tributaries to deposit its effluent and waste, which has worsened the problem of water hyacinth. This thesis examined the ecological and socio-economic impacts of water hyacinth in the Wouri Basin and its possible control. An increase in the nutrients in the water has provided water hyacinth with appropriate conditions for its fast growth during both the rainy and dry seasons. The availability of nutrients in these areas is enhanced by the constant, daily tidal fluctuation of water, providing enough water to the plant for easy nutrient uptake. A survey of the impacts of water hyacinth on aquatic plant communities in the Wouri Basin showed that this plant is able to out-compete native species. Assessment of the impact of water hyacinth on the abundance and diversity of plant communities indicated that at some invaded sites, 65% of the vegetation consisted of water hyacinth. Species found in association with water hyacinth with a high level of abundance-dominance were Pistia stratiotes L. (Araceae) (another invader), Commelina benghalensis L. (Commelinaceae) and Echinochloa pyramidalis (Lam.) Hitchc. & Chase (Poaceae). This component of the study also showed that habitats rich in water hyacinth were poor in diversity, while habitats without water hyacinth were rich in diversity, thus raising awareness of the importance of monitoring invasive aquatic weeds along the Wouri Basin, and of implementing correct control management of all invasive aquatic weeds. Communities living along the invaded rivers are well aware of the range of problems caused by the weed; because as the rivers and water bodies used for fishing, transportation, and sand extraction are progressively invaded by the weed, the riparian population is the first to feel the impact. The impact on people has been noticeable, with an increase in diseases, such as malaria, cholera, diarrhoea, typhoid, filariasis, schistosomiasis, scabies and yellow fever increasing the need for a medicine and hospitalization. Economic losses due to the management of invasive aquatic weeds were recorded, and the Ministry of Environment spent an estimated US$1 200 000 between 2010 and 2015 to manage this scourge. In 2016, an amount of US$160 000 was transferred to these regions to manage invasive aquatic weeds, especially water hyacinth, although manual clearing is still the only method used to control this weed. Isolation of fungi from diseased water hyacinth plants in the Wouri Basin revealed several fungal species, most of which have been isolated from water hyacinth species in water bodies elsewhere, which showed a higher diversity during the dry season than during the rainy season. These fungi included Acremonium zonatum (Sawada). W. Gams (Hypocreaceae), Alternaria eichhorniae Nag Raj & Ponnappa (Pleosporaceae), Chaetomium sp., Colletotrichum sp., Curvularia pallescens Boedjin (Pleosporaceae), Curvalaria sp., Epicoccum nigrum Link (Pleosporaceae), Fusarium sp., Pithomyces chartarum fBerk. & M. A. Curtis) M. B. Ellis (Montagnulaceae), to a lesser extent Myrothecium roridum Tode ex Fr. (Incertae sedis) and Nigrospora sp. Although never released in Cameroon, arthropod biological control agents (Neochetina eichhorniae Warner (Coleoptera, Curculionidae) and N. bruchi Hustache (Coleoptera, Curculionidae)) were present, but their populations were relatively low. The slow spread of the insect population was explained by several factors, among them the tidal fluctuation of water, which has an impact on the population growth of the weevils. Whilst adults may be able to survive tidal fluctuations, larvae are severely impacted by them, contributing to the slow success of biological control. In this study, a significant increase in pathogen-induced disease severity and incidence was noted when Neochetina eichhorniae weevils were present, possibly because larvae tunnelling on the petiole created openings for the penetration of fungal spores. This study highlights the negative impacts of water hyacinth, on the environment, people, and thus economy of Cameroon. The presence of biological control agents and pathogens offers Cameroon the possibility of initiating and properly implementing the biological control option, or an integrated management solution, to manage water hyacinth in the Wouri Basin, and in the rest of Cameroon.
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Changes in household food security, nutrition and food waste along an agro-ecological gradient and the rural-urban continuum in mid-sized South African towns

  • Authors: Chakona, Gamuchirai
  • Date: 2017
  • Subjects: Food security -- South Africa , Women -- South Africa -- Nutritiona , Urban women -- South Africa -- Nutrition , Rural women -- South Africa -- Nutrition , Wild foods -- South Africa , Food supply -- South Africa , Malnutrition in children -- South Africa , Grants-in-aid -- South Africa , Household ecology -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/6484 , vital:21127
  • Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. Most poor communities are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversities and food security of women of reproductive age between 15-49 years, households and communities along the rural-urban continuum in three mid-sized towns situated along an agro-ecological gradient in South Africa. A 48-hour dietary recall was performed across two seasons (twice in summer and once in winter) and focus group discussions were held to gather all information including food abundance, seasons of food scarcity as well as coping strategies which households employ during periods of food shocks. Households were further asked to quantify any type of food waste that they could have generated in the previous 48 hours. Nutritional status of children under the age of five in all three towns was also measured using height-for-age (HAZ) and mid-upper arm circumference (MUAC) as indicators of stunting and wasting respectively. The household surveys were conducted with 554 women randomly selected in rural, peri-urban and urban locations of Richards Bay, Dundee and Harrismith. For nutritional status, the sample consisted of 216 children who were randomly selected from the sampled households in rural, peri-urban and urban locations of the study sites. Household Dietary Diversity Scores (HDDS) and Women’s Dietary Diversity Scores (WDDS) were calculated from the food items consumed by each household and each woman over a two-day period, respectively. Household food access was also measured for each household using Household Food Insecurity Access Scale (HFIAS). The mean WDDS and HDDS for the wettest site of Richards Bay (3.8±0.29 and 8.44±1.72, respectively) was significantly higher than at Dundee (3.4±0.30 and 7.76±1.63, respectively) and Harrismith (3.5±0.27 and 7.83±1.59, respectively) which were not different from one another. The mean HFIAS for Dundee (9.39±7.13) was significantly higher than that in Richards Bay (5.57±6.98) and Harrismith (6.43±6.59) which were not significantly different from one another. Dietary diversity scores were also significantly higher in urban locations than in peri-urban and rural ones whilst HFIAS was significantly lower in the urban locations than peri-urban and rural locations. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith where the majority of the population was purchasing most of their food. The majority of Richards Bay households were involved in subsistence agriculture and also produced a surplus for sale, as well as collecting wild foods, which improved food security, unlike Dundee and Harrismith. Food insecurity was higher in rural and peri-urban areas compared to urban areas. In all towns, food was always available throughout the year but was beyond the reach of many households. In urban areas food was readily available and only limited by access, whereas rural populations have limited access to affordable food and face higher prices. The peri-urban populations were more food insecure because of high levels of poverty, unemployment and lack of access/entitlements to land. Periurban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. Household dietary diversity was significantly negatively correlated with household food access, that is households with low HDDS had higher HFIAS scores. Due to high levels of food insecurity, a greater percentage of children under the age of five years were stunted (35 %) and wasted (18 %). There were no significant differences in stunting along the agro-ecological gradient, along the rural-urban continuum and sex of child. However, significant differences were observed in child wasting along the agro-ecological gradient with Harrismith having more wasted children than the other two towns, which were not significantly different from each other. Significant differences were also observed between MUAC and sex of child where male children had higher MUAC than females. Wasting was significantly negatively associated with HDDS, with children from households with low HDDS tending to have large MUAC thus showing an inverse association among HDDS and obesity. However, further studies are needed to confirm this finding. In general food insecurity was closely associated with low wealth, food expenditure, large household size and limited access to land. The study did not find any significant role in the use of wild foods and social grants in improving food security for those households who were consuming wild foods and those receiving social grants. Although a greater percentage of households were food insecure, significant amounts of unprepared food (495±179 g per household) were wasted in Richards Bay alone in 48 hours mainly because the food had passed the best before date or had visibly gone bad. The amount of food waste was closely significantly negatively associated with household size. In general, the prevalence of food insecurity and wasting followed the agro-ecological gradient, with households in Richards Bay where the area.
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Chinese aid and African agency since 2000: examining the cases of Zimbabwe, Angola and Ghana

  • Authors: Chipaike, Ronald
  • Date: 2017
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/59151 , vital:27442
  • Description: Restricted access-thesis embargoed for 2 years
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Colonisation and succession of fishes in Lake Liambezi, a shallow ephemeral floodplain lake in Southern Africa

  • Authors: Peel, Richard Anthony
  • Date: 2017
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/65211 , vital:28707
  • Description: Expected release date-May 2019
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Combined in silico approaches towards the identification of novel malarial cysteine protease inhibitors

  • Authors: Musyoka, Thommas Mutemi
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/4488 , vital:20679
  • Description: Malaria an infectious disease caused by a group of parasitic organisms of the Plasmodium genus remains a severe public health problem in Africa, South America and parts of Asia. The leading causes for the persistence of malaria are the emergence of drug resistance to common antimalarial drugs, lack of effective vaccines and the inadequate control of mosquito vectors. Worryingly, accumulating evidence shows that the parasite has developed resistant to the current first-line treatment based on artemisinin. Hence, the identification and characterization of novel drug targets and drugs with unique mode of action remains an urgent priority. The successful sequencing and assembly of genomes from several Plasmodium species has opened an opportune window for the identification of new drug targets. Cysteine proteases are one of the major drug targets to be identified so far. The use of cysteine protease inhibitors coupled with gene manipulation studies has defined specific and putative roles of cysteine proteases which include hemoglobin degradation, erythrocyte rupture, immune evasion and erythrocyte invasion, steps which are central for the completion of the Plasmodium parasite life cycle. In an aim to discover potential novel antimalarials, this thesis focussed on falcipains (FPs), a group of four papain-like cysteine proteases from Plasmodium falciparum. Two of these enzymes, FP-2 and FP-3 are the major hemoglobinases and have been validated as drug targets. For the successful elimination of malaria, drugs must be safe and target both human and wild Plasmodium infective forms. Thus, an incipient aim was to identify protein homologs of these two proteases from other Plasmodium species and the host (human). From BLASTP analysis, up to 16 FP-2 and FP-3 homologs were identified (13 plasmodial proteases and 3 human cathepsins). Using in silico characterization approaches, the intra and inter group sequence, structural, phylogenetic and physicochemical differences were determined. To extend previous work (MSc student) involving docking studies on the identified proteins using known FP-2 and FP-3 inhibitors, a South African natural compound and its ZINC analogs, molecular dynamics and binding free energy studies were performed to determine the stabilities and quantification of the strength of interactions between the different protein-ligand complexes. From the results, key structural elements that regulate the binding and selectivity of non-peptidic compounds onto the different proteins were deciphered. Interaction fingerprints and energy decomposition analysis identified key residues and energetic terms that are central for effective ligand binding. This research presents novel insight essential for the structure-based molecular drug design of more potent antimalarial drugs.
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Crime and punishment Mzansi style: an exploration of the discursive production of criminality and popular justice in South Africa’s Daily Sun

  • Authors: Boshoff, Priscilla
  • Date: 2017
  • Subjects: Daily Sun (South Africa) , Tabloid newpapers -- South Africa , Crime in mass media , Justice in mass media , Police in mass media , Newpapers -- South Africa , Newpapers -- Objectivity -- South Africa , Women -- Violence against -- South Africa -- Press coverage , Witchcraft -- South Africa -- Press coverage , Police -- South Africa -- Press coverage
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/44419 , vital:25406
  • Description: The highly popular South African tabloid the Daily Sun, established post-apartheid in 2002, is known for its sensationalist and controversial reporting of black township life. Read by over five million black working class readers, much of its reporting concerns the crimes experienced by them and their struggles for justice. The extraordinarily high rate of violent crime in township areas for which South Africa became infamous during the 1980s did not decrease as much as hoped after the political transition in 1994 and crime overshadowed the first decades of the new administration, adding to the frustrations generated by the slow pace of social and economic reform. Part of the Daily Sun’s success can be attributed to how, around these linked concerns, it fashions for its readers a particular discursive world, Sunland. It is the phatic relationship that the tabloid maintains between itself and its readers which forms the foundation upon which this textual study rests. In approaching the tabloid’s representations of crime I draw on cultural criminological understandings of crime as culture and the formative relationship in this regard between crime and the media. As a preeminent site of cultural production in contemporary society, the media contribute to the ongoing definition of what constitutes crime, who is criminal and what counts as justice. This constructivist approach is congruent with Foucault’s notions of discourse and the subject, and I argue that the various competing discourses about crime and justice which appear in the paper establish a set of subjectivities with which its readers may identity. The thesis explores the rhetorical and discursive means by which such subject positions are constructed within the ‘grid of intelligibility’ created by the Daily Sun’s reportage, and using the spatial metaphor of the ‘map’ I trace the contours of the Daily Sun’s domain with regard to crime and popular justice. To this end, the approach taken is a qualitative one which draws eclectically on a variety of interpretive methods, including semiotic, narrative and discourse analysis. Using these, I map the relations between People’s Justice, the police, gender relations and witchcraft crimes, four areas chosen from a broad thematic content analysis of the complete set of editions from 2011. I show how these are not discreet but co-constructed areas within the coverage, drawing their meaning mutually from a range of conflictual relationships derived from the conditions of post-apartheid social life.
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Data compression, field of interest shaping and fast algorithms for direction-dependent deconvolution in radio interferometry

  • Authors: Atemkeng, Marcellin T
  • Date: 2017
  • Subjects: Radio astronomy , Solar radio emission , Radio interferometers , Signal processing -- Digital techniques , Algorithms , Data compression (Computer science)
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/6324 , vital:21089
  • Description: In radio interferometry, observed visibilities are intrinsically sampled at some interval in time and frequency. Modern interferometers are capable of producing data at very high time and frequency resolution; practical limits on storage and computation costs require that some form of data compression be imposed. The traditional form of compression is simple averaging of the visibilities over coarser time and frequency bins. This has an undesired side effect: the resulting averaged visibilities “decorrelate”, and do so differently depending on the baseline length and averaging interval. This translates into a non-trivial signature in the image domain known as “smearing”, which manifests itself as an attenuation in amplitude towards off-centre sources. With the increasing fields of view and/or longer baselines employed in modern and future instruments, the trade-off between data rate and smearing becomes increasingly unfavourable. Averaging also results in baseline length and a position-dependent point spread function (PSF). In this work, we investigate alternative approaches to low-loss data compression. We show that averaging of the visibility data can be understood as a form of convolution by a boxcar-like window function, and that by employing alternative baseline-dependent window functions a more optimal interferometer smearing response may be induced. Specifically, we can improve amplitude response over a chosen field of interest and attenuate sources outside the field of interest. The main cost of this technique is a reduction in nominal sensitivity; we investigate the smearing vs. sensitivity trade-off and show that in certain regimes a favourable compromise can be achieved. We show the application of this technique to simulated data from the Jansky Very Large Array and the European Very Long Baseline Interferometry Network. Furthermore, we show that the position-dependent PSF shape induced by averaging can be approximated using linear algebraic properties to effectively reduce the computational complexity for evaluating the PSF at each sky position. We conclude by implementing a position-dependent PSF deconvolution in an imaging and deconvolution framework. Using the Low-Frequency Array radio interferometer, we show that deconvolution with position-dependent PSFs results in higher image fidelity compared to a simple CLEAN algorithm and its derivatives.
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Demobilisation and the civilian reintegration of women ex-combatants in post-apartheid South Africa: the aftermath of transnational guerrilla girls, combative mothers and in- betweeners in the shadows of a late twentieth-century war

  • Authors: Magadla, Siphokazi
  • Date: 2017
  • Subjects: South Africa. National Defence Force , Umkhonto we Sizwe (South Africa) -- Demobilization , Azanian People's Liberation Army -- Demobilization , Amabutho Self-Defence Unit -- Demobilization , South Africa. Army -- Women , Women soldiers -- South Africa , Government, Resistance to -- South Africa -- History , Women veterans -- South Africa -- History , Women veterans -- South Africa -- Interviews
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/41775 , vital:25133
  • Description: This study examines the state assisted demobilisation and civilian reintegration of women excombatants in post-apartheid South Africa. The study is based on life history interviews conducted with 36 women who fought for Umkhonto we Sizwe (MK), Azanian People’s Liberation Army (APLA) and Amabutho Self-Defence Unit. There is agreement across the literature that the armed struggle against apartheid falls within the category of guerilla warfare, fought in multiple terrains, that blur conventional distinctions of civilian and combatant, homefront and battlefront, as well as the domestic and transnational. Located within feminist International Relations theory, the study argues that the formal process that led to the integration of statutory and non-statutory forces to form the South African National Defence Force, which facilitated the demobilisation process, was framed in ways that did not reflect the unconventional nature of the armed struggle against apartheid. The few women who participated in this process were the transnationally trained combatants of MK and APLA. The majority of women who participated in the multiple and overlapping sites of the domestic and international apartheid battlefront were left out of this process. It is argued that women’s roles in the armed struggle were shaped by various factors, such as age, space and period of struggle. Three categories, guerilla girls, combative mothers and the in-betweeners, are introduced in order to demonstrate the different spaces from within which women fought, and the methods they used, all of which were central to the success of the People’s War strategy. In this regard, the venerated transnationally trained woman combatant, like their male counterpart, is argued to be an exception, as the majority of women were thrust into the armed struggle without military training. Furthermore, it is argued that conservative feminist readings of black women’s relationship with nationalism in the anti-apartheid struggle have misrecognised and undermined women’s combatant contributions, by inscribing their forms of resistance as maternal, and outside the war effort. The study shows that the majority of women combatants have transitioned to civilian life without formal state recognition and assistance. The erasure of women’s role as combatants also means that they are excluded from the current legislative framework facilitated by the Department of Military Veterans to support the welfare of former combatants. As such, the study builds on Jacklyn Cock’s (1991) pioneering study on war and gender in South Africa; it is the first study that exclusively focuses on women ex-combatants’ experiences in postapartheid South Africa.
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Development and assessment of ketoconazole intravaginal thermosetting hydrogel formulations

  • Authors: Ramanah, Ashmita
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/5198 , vital:20785
  • Description: Imidazole compounds are commonly used as antifungal therapies and ketoconazole was the first broad spectrum orally active azole identified and registered. However, the risks of hepatotoxicity and drug interactions following systemic delivery and absorption of ketoconazole outweigh the therapeutic benefits and ketoconazole was therefore discontinued as first line systemic antifungal therapy in many countries. Although not yet banned in South Africa, the South African Medicine Formulary has ceased to recommend the use of ketoconazole for systemic treatment. Topical use of ketoconazole is, however, regarded as safe following extensive human use as low systemic absorption occurs following topical administration. Vulvo-vaginal candidiasis is a yeast infection that affects a large number of women, some of whom present with several infections annually. The topical treatment options for vulvo-vaginal candidiasis include the use of vaginal tablets, capsules, ovules and creams administered as a single dose or one to three times daily for three to fourteen days either alone or in combination with another dosage form depending on the regimen. Administration of the dose nightly is recommended for most vaginal creams and ovule formulation due to leakage and the uncomfortable feel of the dosage form if administered during the day. A thermosetting gel that remains in the vagina following administration and prolongs the release of ketoconazole from a once daily dose would be a useful addition to the arsenal for intra-vaginal antifungal therapy. Thermosetting gels would be more comfortable to administer as the gel would set in a form similar to naturally occurring mucous in the vagina and, if formulated with a low pH, irritation of the sensitive and fissured tissue would be minimised. A further benefit would be that once set the gel would loosely take on the anatomical shape of the vagina. A simple, precise, accurate, reproducible and sensitive stability-indicating reversed phase-high performance liquid chromatographic method using ultraviolet detection for the quantitation of ketoconazole was developed and validated. The method was specific and was applied to the determination of ketoconazole in commercial and experimental formulations in addition to samples from degradation studies and in vitro release testing. Product performance characteristics of commercial products were investigated with the goal to provide a strategy for the development of a novel intra vaginal gel in the shortest possible time. Characterisation of Xolegel®, Kez® shampoo and Ketazol® cream included an evaluation of pH, viscosity and assay, in addition to spectroscopic and thermal analysis, to identify ideal characteristics of topical products that could be used as targets during formulation development of the gel. An in vitro release method was developed and validated for precision and accuracy and the in vitro release profiles of commercial ketoconazole products were compared using analysis of variance, model dependent and independent approaches. Ketoconazole release data from test gel manufactured during formulation development were investigated to obtain information about the relationship between formulation content and drug release. Poloxamers marketed as Pluronic® and Lutrol® are synthetic non-ionic tri-block copolymers that consist of hydrophobic propylene oxide and hydrophilic polyethylene oxide blocks, which in solution interact to exhibit thermo-reversible behaviour. In situ forming hydrogels consisting of poloxamers, more specifically poloxamer 407, are activated following a temperature stimulus and undergo a sol to gel transition. This approach was used to produce a thermosetting vaginal gel that would exhibit a long residence time in the vagina with an associated enhancement of therapeutic efficacy. Ketoconazole- excipient compatibility was investigated during preformulation studies using spectroscopic and thermal analysis to enable the selection of excipients best suited for the production of a novel dosage form prior to formulation development activities. No obvious interactions between ketoconazole and excipient were observed and ketoconazole was found in an amorphous form when in combination with polysorbate 80 and poloxamers. A two-level factorial design was used to produce solvent systems with different amounts of polysorbate 80, citric acid and ethanol to identify a vehicle in which ketoconazole exhibited optimum solubility and at a pH that would be least irritating to the vaginal mucosa with a low content of excipients. The optimised vehicle consisted of 4% m/v citric acid, 1.5% v/v polysorbate 80 and 9.5% v/v ethanol made up to 50 g with citrate-phosphate buffer adjusted to pH 5.0, resulted in a vehicle of pH of 3.5 in which 71.41 mg of ketoconazole was dissolved per mL. A Central Composite Design was used to evaluate compositions for the modulation of viscosity of the thermosetting dosage form such that it was a liquid at 22 °C that rapidly formed a stiff gel when heated to 37 °C (intra-vaginal temperature) using different amounts of the poloxamer grades 407, 188 and 237. Thermosetting gels containing 2% m/v ketoconazole were manufactured using specifications generated using the Central Composite Design and the viscosity at 22 °C and 37 °C, solution to gel transition time, potency and ketoconazole release at 24, 48 and 72 hours investigated. Contour and three-dimensional response surface plots and mathematical relationships with target ranges set for responses were identified and with the aid of Central Composite Design the optimisation of a desirable thermosetting gel was achieved. The optimised composition included 16% m/v poloxamer 407, 10% m/v poloxamer 188 and 6% m/v poloxamer 237 in the gel that was used as the basis for further optimisation studies. The low ketoconazole release for ketoconazole observed indicated that the poloxamers had formed a gel matrix that sustained the release of ketoconazole and would therefore ensure that once daily administration of the gel was possible. The sol-gel transition test may be used as a simple and cheap alternative to viscosity testing for thermosetting formulations when expensive viscometers and rheometers are unavailable and was successfully used for this purpose.Ketoconazole is photolabile and is prone to degradation in aqueous solutions. The hydrophobic core of micelles formed in these dosage forms are believed to shield ketoconazole molecules and improve stability in aqueous solutions and acidic gels. The thermosetting gel optimised for poloxamer content was subjected to a further Central Composite Design in which sodium metabisulphite content and vehicle pH were investigated. The length of storage was used as a numeric variable and storage condition as a categoric variable at two levels to monitor the stability of the gels. The formulations were investigated at sample times of 0, 1, 2, 4 and 8 weeks at 5 °C, 25 °C and 40 °C. The use of a Central Composite Design facilitated an understanding of the interactions between input variables and their impact on the responses analysed including ketoconazole content, release at 24, 48 and 72 hours, gel pH and viscosity at 22 °C and 37 °C. Design of Experiments may be used as a rapid cost effective tool for an overall assessment of the stability of novel topical dosage forms. However, a more thorough assessment of stability may be required for product registration. Ketoconazole was found to be unstable in the acidic thermosetting gels despite the addition of antioxidant. The gels in liquid form at 5 °C and 25 °C have a low number of micelles for ketoconazole incorporation and therefore additional optimisation studies would be required to enhance the shelf-life of this product.
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Differentiating engagement of opportunity identification: a grounded theory study of Chinese immigrant entreprenuers

  • Authors: Ndoro, Tinashe Tsungai Raphael
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/5568 , vital:20942
  • Description: The aim of this study was to develop a substantive grounded theory describing how Chinese immigrant entrepreneurs who own and operate small retail businesses in the Eastern Cape province of South Africa identify opportunities in the business environment. The substantive grounded theory was developed using the prescripts of grounded theory proposed by Strauss and Corbin (1990). In this respect, a substantive grounded theory called differentiating engagement of opportunity identification was developed from a sample of 41 qualitative interviews conducted with Chinese immigrant entrepreneurs. The study found that Chinese immigrant entrepreneurs identified various opportunities (startup, sales, operational, relational) in the business environment through their dynamic interactions and relationships with different stakeholders. These stakeholders mainly included family members, local employees and customers. The Chinese immigrant entrepreneurs displayed two interactional processes in their interactions with stakeholders, namely engaging in and disengaging from interactions. These interactional processes enabled the Chinese immigrant entrepreneurs to identify opportunities and operate their small businesses in the business environment. Assumptions held about the interactions and relationships with stakeholders in the host community were central to the interactional processes displayed by the Chinese immigrant entrepreneurs. As they operated their small businesses, the Chinese immigrant entrepreneurs would engage in interactions with customers who were perceived as favourable (approachable). From these interactions with favourable (approachable) customers, the Chinese immigrant entrepreneurs were able to identify opportunities (gaining customer insight of opportunity), whereas they would disengage from interactions with customers perceived as unfavourable (unapproachable). In this respect, they would delegate their local employees (actions of delegation in business) with the responsibility of interacting with unfavourable and hostile customers. Additionally, the Chinese immigrant entrepreneurs would engage in interactions with local employees to gain insight into local indigenous products and identify opportunities in the host community. In order to identify other opportunities (operational, relational), the Chinese immigrant entrepreneurs would disengage from interactions with local employees and engage in interactions with other stakeholders such as family members. The varying differentiated interactions and relationships established by the Chinese immigrant entrepreneurs with different stakeholders created a relational context which enabled the identification of opportunities in the host environment. Thus, the findings of the present study and the substantive grounded theory developed (differentiating engagement of opportunity identification) are discussed from the perspective of social capital, social exchange theory and Chinese cultural values. Finally, the theory developed in the present study contributes to the understanding of the processes of how social capital and relationships contribute to the process of identifying opportunities and operating a small business by immigrant entrepreneurs within a host environment.
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Discursive constructions of quality assurance: the case of the Zimbabwe Council for Higher Education

  • Authors: Chidindi, Joseph
  • Date: 2017
  • Subjects: Zimbabwe Council for Higher Education -- Evaluation , Education, Higher -- Zimbabwe , Universities and colleges -- Evaluation -- Zimbabwe
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/7800 , vital:21299
  • Description: Quality assurance is on the contemporary agenda in higher education and has been prioritised across the globe. It has been conspicuous through the emergence of numerous quality assurance bodies, and in Zimbabwe, where this study takes place, the government has constituted the Zimbabwe Council for Higher Education. This study aims to identify the discourses drawn on by academics and those working within Zimbabwe Council for Higher Education to construct the roles and processes of external quality assurance practices in universities in Zimbabwe. The study was grounded on the premise that external quality assurance processes in higher education can vary according to their contextual environment. Fairclough’s Critical Discourse Analysis as a method driven theory not only provided a methodology, a way of collecting and analysing my data, but it was also a substantive theory, which provided a particular way of understanding the world through discourse. Fairclough’s Critical Discourse Analysis is grounded in a Critical Realist view of the social world that enabled generalisations about the effect discourse was having on the phenomenon of interest: quality assurance in higher education. One-to-one and group interviews were used to yield exploratory, descriptive and explanatory data. To corroborate and augment data from interviews, key documents related to quality assurance in universities in Zimbabwe and obtained from the Zimbabwe Council for Higher Education were analysed. There were a number of profound discourses that emerged in the research study. There was a discourse of ‘control’ in which Zimbabwe Council for Higher Education put in place compliance mechanisms, setting minimum requirements for universities to offer ‘credible’ higher education. There was a discourse of ‘power struggle’ in which universities endeavoured to maintain their institutional autonomy in response to what was perceived as Zimbabwe Council for Higher Education’s requirement of compliance. In the context of higher education in Zimbabwe, an important implication of the study was evident in the discourse of ‘gold standard’ of quality assurance which assumed that quality entails a generic best practice but which fails to take context into account. While a generic ‘global’ notion of best practice in quality assurance was dominant in the discourses of quality identified in this study, there were other discourses that focused on what quality might look like within the resource constraints of the context. The study highlighted the importance of collegiality between quality assurance organisations and universities to realise success of quality assurance intentions.
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Drawing on principles of Dance Movement Therapy practice in a South African water research context

  • Authors: Copteros, Athina
  • Date: 2017
  • Subjects: Water-supply -- Management -- South Africa , Dance therapy , Movement therapy , Dance therapy -- South Africa , Movement therapy -- South Africa , Interdisciplinary research , Interdisciplinary approach to knowledge , Environmental education , Environmental education -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/50759 , vital:26024
  • Description: Research that draws on principles of Dance Movement Therapy in a South African water research context has not been done before. In order to initiate this exploration, culturally relevant themes from professional training in the United Kingdom were identified that could be developed in the context of trans-disciplinary water resource management research in South Africa. Hermeneutic phenomenology provided the methodological framing for this study. Interpretative Phenomenological Analysis was used to discover culturally relevant themes based on the recorded perceptions of the phenomenon of the training while it was taking place. The themes of: ‘awareness of power and difference'; ‘therapeutic adaptability'; ‘safety and ownership' and ‘connecting with the environment' emerged as overriding themes. Influences from Artistic Inquiry informed the inclusion of a creative embodied response to the themes that emerged. These themes then informed the application of some relevant principles of Dance Movement Therapy practice within a trans-disciplinary complex social-ecological systems researcher group. Eight members of the group participated in the study. They represented a range of academic research roles, genders and backgrounds. They reflected on their experience of an introductory session and five Dance Movement Therapy based sessions in semi-structured interviews. Using Interpretative Phenomenological Analysis, four themes were identified that capture the quality of the participants' shared experience of the phenomenon: ‘community engagement'; ‘embodiment'; ‘individual and group identity' and ‘integration'. Based on the integration of themes, it is concluded that principles of Dance Movement Therapy have a contribution to make. Core tenets of Dance Movement Therapy such as: inclusion of body and emotion; healing from trauma through embodiment; group processes held with safety and acceptance; and a deep level of connection to self, each other and the wider ecology, address some of the basic challenges of trans-disciplinary complex social ecological systems research practice. Through researchers experiencing principles of DMT practice for themselves and reflecting on their experience, it is possible that their embodied knowledge and reflections will influence and inform their engagement with communities in the future.
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Ecosystem services in a biosphere reserve context: identification, mapping and valuation

  • Authors: Ntshane, Basane Claire
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/4536 , vital:20686
  • Description: Despite their contribution to human well-being, ecosystem services (ES) are being destroyed by anthropogenic activities, taken for granted and often compromised during land use decision making. The question that often arises is, what value do ES have compared to other undertakings that are economically robust, such as mining? The vision of the Millenium Ecosystem Assessment (MA) was a world in which natural assets (including ES) are appreciated and integrated into decision-making. The biodiversity strategy of the Convention on Biological Diversity (CBD) also concerns the integration of natural assets into decision making. Responding to challenges facing ES and their mainstreaming into decision-making has been constrained by lack of data and requires new tools and approaches. Integrating natural assets into decision-making is very important for South Africa (SA), where ES have been a crucial part of human systems for decades, and also because of the country’s commitment to the implementation of the CBD's biodiversity strategy. With the aim of incorporating ES into decision-making in an integrated way, this study was conducted in two biosphere reserves (BRs), Vhembe and Waterberg, in Limpopo Province, SA. The aims of the study were the identification, mapping and valuation of ES following an integrated approach. In order to achieve these aims, the study attempted to address four key objectives: (1) to assess and evaluate the status of mapping and valuation of ES in SA, (2) to identify and quantify ES and their indicators, (3) to investigate and analyse the impact of land use/cover (LU/LC) change to ES and (4) to conduct valuation of selected ES. Two separate literature reviews were undertaken to assess and evaluate the status of mapping and valuation of ES in SA, thus addressing study objective 1. Both reviews detected a significant research gap with regard to mapping and valuation of supporting services in SA. To identify ES and indicators provided by the two BRs and to assess the impact of LU/LC change and its effect on ES, a participatory scenario planning process was conducted under three different scenarios, namely ecological development, social development and economic development. It became clear that LU issues were diverse in nature and affected ES in a number of ways and that there were always trade-offs in the choice of LU. For example, yields of ES were best in the ecological development scenario and were affected negatively, together with agricultural commodity production, in the social development and economic development scenarios. A mapping exercise was undertaken to illustrate the spatial distribution of ES supply and demand, involving five ES and 15 indicators using existing datasets and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) mapping tool, again addressing objective 2 of the study. Carbon storage and habitat quality were assessed, modelled and quantified and their values provided in biophysical terms using InVEST modelling tools, thus addressing objective 4 of the study. High quantities of carbon storage and high habitat quality were recorded in natural areas and low quantities were recorded in managed systems (cultivated, urban and plantation areas). InVEST was again applied to conduct an economic valuation of two provisioning ES, timber and firewood, by determining their net present values, attempting to address objective 4 of the study. Results revealed that, at 12% discount rate, the net present value (NPV) for timber production accounted for R23 317/ha in VBR and R57 304/ha in WBR. However, at lower discount rates (4 and 7%), the NPVs for timber were negative in VBR and positive in WBR. With regard to firewood production, the NPVs were negative against all three discount rates in both study areas. I conclude by proposing a four-step integrated approach that can aid the successful incorporation of ES into decision-making: (1) maintain a balance between the social, economic and ecological aspects when making decisions on ES, (2) strive for an evidence- based approach to decision-making (use quantities and values), (3) apply integrated approaches (methods and techniques) to quantification and valuation, and (4) communicate all steps along the way. The results of this study will serve as a baseline for integration of ES into decision-making in SA.
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Ellipsis in the vP domain in Mandarin and Xhosa

  • Authors: Ma, Xiujie
  • Date: 2017
  • Subjects: Grammar, Comparative and general -- Ellipsis , Chinese lanaguage -- Ellipsis , Chinese lanaguage -- Grammar, Comparative -- Xhosa , Xhosa lanaguage -- Ellipsis , Xhosa lanaguage -- Grammar, Comparative -- Chinese
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/43105 , vital:25266
  • Description: This thesis provides a unified analysis of ellipsis in the vP domain in two typologically different languages, Mandarin and Xhosa from a generative perspective. It starts with the V-stranding Verb Phrase Ellipsis (VPE) assumption and shows that Mandarin and Xhosa do not have V-stranding VPE. The evidence for this is that in both languages, the constituents that remain in vP obligatorily are not allowed to be deleted, whereas the ones that can/must move out of vP can be deleted. The deleted constituents display the characteristics of PF-deletion, i.e. they have an internal syntactic structure. Based on the parallel between movement and ellipsis of the vP-internal constituents, I propose the Ellipsis EPP Hypothesis to account for ellipsis in the vP domain. The Hypothesis predicts that there is an Ellipsis Phrase at the left periphery of vP. The EP bears an Ellipsis-EPP (EEPP) feature, which must be satisfied. Maximal phrases in the c-command domain of EP are all potential candidates for satisfying the EEPP feature by moving to [Spec, EP]. However, only the phrases that are allowed to move out of vP can move to [Spec, EP] as EP is located above vP. Moreover, the movement to [Spec, EP] is subject to the syntactic and semantic restrictions in structure-building in that ellipsis is one operation in the course of structure-building and the derivation will continue after ellipsis takes place. The EEPP feature renders an XP in the specifier phonetically empty and syntactically frozen; therefore, a constituent will be deleted as soon as it moves to [Spec, EP]. The Hypothesis is schematically represented below. The Ellipsis EPP Hypothesis adequately accounts for the ellipsis of various vP-internal constituents - NPs, DPs, infinitive complements and CP complements - in both Mandarin and Xhosa. At the same time, it reveals the reasons why vP is precluded from being elided in these two languages. In Mandarin vP moves to [Spec, AspPi] to check the uninterpretable [asp] feature and in Xhosa vP moves to [Spec, FocP] to realize the focus; consequently, vP may not move to [Spec, EP] for ellipsis.
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Estuary-dependency and multiple habitat connectivity of juvenile leervis lichia amia (pisces: carangidae) and the factors influencing their movements

  • Authors: Murray, Taryn Sara
  • Date: 2017
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/4477 , vital:20676
  • Description: Estuaries are highly productive ecosystems that provide an important nursery function to many marine-spawning fish species. While in estuaries, the juveniles of estuary-associated fishes are exposed to frequent, abrupt changes in environmental conditions and, as such, utilise movement as a strategy to cope with the changing conditions. Therefore, to gain a better understanding of the importance of estuaries (i.e. estuary-dependency) to estuary-associated species, knowledge on their movement patterns within estuaries, the links between habitats, and the environmental and cyclical processes driving these movements, is necessary. Lichia amia, commonly known as leervis or garrick in southern Africa, is an over-exploited, estuary-dependent fishery species targeted by coastal recreational and subsistence fishers, as well as spearfishers, throughout its South African distribution. Aspects of its biology and life history have been assessed; however, knowledge on its movement behaviour is limited to a single conventional dart tagging study, which described large-scale coastal movements of juvenile, sub-adult and adult leervis. As such, little is known about area use and movement patterns within estuaries, or the degree of connectivity between estuarine and marine habitats. Therefore, the aim of this study, using conventional dart tagging and passive acoustic telemetry methods, was to assess the role of estuarine nursery habitats in the life cycle of the leervis by examining area use patterns and movement behaviour within estuaries, investigating the degree of habitat connectivity, and determining the drivers (cyclical rhythms and environmental variables) of estuarine use and connectivity. A dedicated conventional mark-recapture study on juvenile leervis within the Swartkops Estuary revealed a high level of estuarine fidelity (philopatry) suggesting that estuaries are important nursery habitats. However, movement distances increased with increasing fish length, with some fish also being recaptured in the neighbouring marine environment. These results provided evidence of an ontogenetic habitat shift, with smaller fish remaining in the estuary for extended periods and larger individuals undertaking more extensive movements. Complementary passive acoustic telemetry studies were conducted in the Kowie and Goukou estuaries, spaced 620 km apart, to assess area use, movement patterns, residency and multiple habitat connectivity of juvenile leervis. These telemetry studies showed varying levels of residency within the tagging estuaries, and seasonal variation in area use. The lengths of estuary used by leervis tagged in the Kowie Estuary generally decreased with the onset of austral winter, while fish tagged in the Goukou Estuary generally moved into the marine environment. Despite tagged individuals spending on average 56% and 38% of the total monitoring periods within the Kowie and Goukou estuaries, respectively, fish displayed high levels of multiple habitat connectivity, with 71% and 76% of Kowie and Goukou fish, respectively, visiting adjacent marine and estuarine environments. A total of 11 different neighbouring habitats (estuaries and ports) were visited by Kowie fish, while fish tagged in the Goukou Estuary only visited four adjacent habitats. These differences in connectivity could be attributed to the proximity of many more estuaries to the Kowie Estuary compared to the Goukou Estuary. Estuarine movements by acoustically tagged leervis in both estuaries followed a strong diel but a much weaker tidal pattern. A number of environmental variables significantly influenced estuarine movements and marine excursions (including river inflow, photoperiod and moon phase). However, water temperature (river and sea) had the most significant effects on these movements, with decreasing winter river temperatures coincident with a downstream shift in mean daily position of fish tagged in the Kowie Estuary, and movement into the marine environment from the Goukou Estuary. Interestingly, the area use patterns of juvenile leervis tagged in the Kowie and Goukou estuaries were different, predominantly using limited portions of each estuary. Kowie fish spent more time in the mouth region and lower reaches, while Goukou fish spent more time in the lower and middle reaches of the estuary. Therefore, should no-take Estuarine Protected Areas be implemented, inter-estuary differences would need to be considered to determine the most effective stretches of estuary to close to provide maximum protection for leervis. This study provided new information on the movement behaviour of juvenile leervis, the degree to which juveniles depend on estuaries as nursery areas, and the cyclical rhythms and environmental factors influencing their movements. The study therefore contributes considerably to our understanding of the role of estuaries in the life history of leervis, and provides essential information for the improved management of this over-exploited species.
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