Ecological consequences of non-native fish invasion in Eastern Cape headwater streams
- Authors: Ellender, Bruce Robert
- Date: 2014
- Subjects: Fishery management -- South Africa -- Eastern Cape Fishes -- Conservation -- South Africa Introduced fishes -- South Africa -- Eastern Cape Introduced organisms
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/69065 , vital:29380
- Description: The introduction, spread and concomitant impacts of non-native species are a global problem. Fish are among the most widely introduced vertebrate groups, with their impacts affecting multiple levels of organisation- from individuals, populations and communities, to entire ecosystems. In South Africa, the largest perceived threat to range-restricted endemic headwater stream fishes is said to be invasion by non-native fishes, however, as is the case elsewhere, invasive impacts are often a case of risk perception rather than actual risk analysis. Two range-restricted headwater species, the Eastern Cape redfin Pseudobarbus afer and the Border barb Barbus trevelyani are redlisted by the International Union for the Conservation of Nature (IUCN) as ‘Endangered’, primarily due to invasion by non-native fishes. To investigate invasions in South Africa, and provide a quantitative estimate of the impact of non-native fishes on the two imperilled endemics, P. afer and B. trevelyani, the overall aims of this thesis were to: (A) Provide a literature review on non-native fish invasions in South Africa; (B) Using two case studies on the headwaters of the perennial Keiskamma and episodic Swartkops River systems, investigate the naturalisation-invasion continuum to provide a holistic view of the invasion process in these variable environments. The specific thesis objectives were: (1) Reviewing current knowledge of invasive impacts of non-native fishes in South Africa; (2) Investigating invasibility of headwater stream environments by non-native fishes; (3) Determining the establishment success of non-native fishes, (4) Assessing the spatial and temporal impacts of invasion; (5) Understanding mechanisms responsible for non-native fish impacts; (6) Investigating the threat of non-native fish invasion on the genetic diversity of two the two headwater fishes, P. afer and B. trevelyani. Results from the literature review of fish invasions (Chapter 1) showed that South Africa has a long history of non-native fish introductions, spanning two and a half centuries. Currently, 55 species have been introduced or translocated. Many of these introduced species have become fully invasive (36%). Their impacts also span multiple levels of biological organisation. There was a general paucity of studies on fish invasions (38 studies), however, of those conducted, reviewed studies placed emphases on invasive impacts (25 studies) and the transport, introduction, establishment and spread stages of the invasion process were largely ignored. The two study systems, the Swartkops and Keiskamma Rivers, were heavily invaded and numbers of introduced species surpassed that of natives (Chapter 2, 3 and 5). Headwater streams had varying invasibility and a number of non-native species were successfully established (Chapter 2, 3, 5 and 6). The remainder of the invasions were casual incursions into headwater streams from source populations in mainstream and impoundment environments which were invasion hotspots. Irrespective of establishment, four predatory invaders (largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss) impacted heavily on native fish communities (Chapter 3, 4 and 5). Two broad types of invasion were documented, top down invasion by non-native O. mykiss and S. trutta and upstream invasion by M. salmoides and M. dolomieu (Chapter 3 and 5). Their impacts included changes in community structure, extirpation from invaded stream reaches resulting in contracted distribution, and isolation and fragmentation of native fish populations. The impacts of non-native predatory fishes were particularly acute for P. afer and B. trevelyani. Where non-native predatory fish occurred, P. afer and B. trevelyani had been extirpated (Chapter 3 and 5). As a result both native species exhibited contracted distributions (>20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.
- Full Text:
- Date Issued: 2014
Effect of diet and sex-sorting on growth and gonad development in farmed South African abalone, Haliotis midae
- Authors: Ayres, Devin William Philip
- Date: 2014
- Subjects: Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalone culture -- South Africa , Abalones -- Physiology -- South Africa , Abalones -- South Africa -- Growth , Abalones -- Feeding and feeds -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5357 , http://hdl.handle.net/10962/d1010856 , Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalone culture -- South Africa , Abalones -- Physiology -- South Africa , Abalones -- South Africa -- Growth , Abalones -- Feeding and feeds -- South Africa
- Description: Abalone, Haliotis midae, farmers in South Africa that feed formulated diets reported a periodic drop in abalone growth during periods of increased gonad development. A large drop in abalone biomass was noticed after presumed spawning events. This study was aimed to determine the effect of diet and sex-sorting on gonad development in abalone. Experiments were conducted on a commercial abalone farm from July 2012 to the end of June 2013. Isonitrogenous and isoenergetic diets were formulated with two protein sources. A fishmeal and soybean meal (S-diet) diet and a fishmeal only (F-diet) diet were fed to abalone (50 - 70 g abalone⁻¹) over 12 months. Weight and length gain, gonad bulk index (GBI), visceral index (%) and meat mass index (%) were determined monthly and seasonally. A histological study on the female gonads was conducted. This study also included an experiment to test the effect of sex-sorting (70 - 80 g abalone⁻¹) on growth and body composition with treatments including males (M), females (F) and equal numbers of males and females (MF). Weight gain and length gain were faster in S-diet-fed abalone (RM-ANOVA, F ₍₁, ₁₆₎ = 7.77, p = 0.01; F ₍₁, ₆₉₎ = 49.9, p < 0.001, respectively). Gonad development was significantly affected by the inclusion of soybean meal with S-diet-fed abalone showing higher GBI-values than F-diet-fed abalone (RM-ANOVA, F ₍₁, ₃₃)= 16.22, p = 0.0003). Male abalone had higher GBI-values than females (RM-ANOVA, F ₍₁, ₃₃₎ = 39.87, p < 0.0001). There was no significant difference in average feed conversion ratio (FCR) between diets over time (RM-ANOVA, F ₍₁, ₂₁₎ = 0.008, p = 0.97). However, average FCR-values were significantly highest between November 2012 and March 2013, the presumed spawning season. The visceral mass (gut and gonad) as a proportion of whole mass (visceral index, %) was significantly higher in abalone fed the S-diet (RM-ANOVA; F ₍₁, ₆₉₎ = 68.06, p < 0.0001). There was no difference in meat mass index (%) between diets for both male and female abalone (RM-ANOVA; F ₍₇, ₂₄₈₎ = 0.80, p = 0.60; F ₍₇, ₂₄₁₎ = 1.7, p = 0.11,respectively). Meat mass index significantly decreased from September 2012 to February 2013 coinciding with the period of high GBI-values. The distribution of oocyte maturity stages differed between diets. The majority of oocytes within S-diet-fed abalone were fully mature stage 8 oocytes compared to a majority of stage 7 oocytes in F-diet-fed abalone. Histology corroborated peaks in GBI-values for abalone fed both diets. There was no significant difference in growth, GBI, visceral index (%) and meat mass index (%) between abalone sorted into monosex and mixed-sex populations. Thus, the presence of the opposite sex did not have an effect on growth and gonad mass in H. midae. The phytoestrogens daidzin, glycitin, genistin, daidzein, glycitein and genistein were present in soybean meal and only traceable amounts were found in the F-diet. This study provided evidence that soybean meal present in formulated feed affected growth and gonad development in H.midae. The difference in the distribution of the maturity stages of oocytes was affected by diet. Sex-sorting abalone into monosex and mixed-sex populations had no influence on weight and length gain and gonad development.
- Full Text:
- Date Issued: 2014
Electrospun fiber based colorimetric probes for aspartate aminotransferase and I7ß-estradiol
- Authors: Pule, Bellah Oreeditse
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54869 , vital:26623
- Description: Fabrication, characterization and application of electrospun polymer composite based colorimetric probes are presented in this thesis. The first part of the thesis involved the development of a protocol for in situ reduction of gold trication (Au³+) into metallic gold atoms with sodium borohydride. The prepared PS-Au NPs showed an SPR band at 542 nm. Furthermore the absorbance of the colloidal Au NPs in polystyrene exhibited a good linear correlation (r2 = 0.9934) to E2 concentration in the range 5 to 50 ppb. The lowest naked eye detection limit was found to be 0.5 ppb and could further be easily monitored by UV-vis spectrophotometer. Upon interaction with E2 Au NPs aggregated to give nanoparticle clusters, confirmed through TEM analysis. Different concentrations of Au NPs were found to have a significant effect on the conductivity of the PS-Au NPs solution. At low concentrations of Au NPs (0.002, 0.015 and 0.025% w/v) PS-Au NPs solution could be electrospun without clogging. The FE-SEM images showed a non-beaded morphology of PS-Au NPs composite fibers. Upon interaction of the colorimetric probe strips with various E2 concentrations it was observed that with increasing E2 concentrations (50 ng/ml to 1000 µg/ml) the colour of the probe changed gradually from white to shades of pink and eventually to shades of blue at higher E2 concentrations. The visible cut-off concentration was 100 ng/ml. The second component of the thesis focussed on the development of diazonium dye-nylon 6 colorimetric probe for aspartate aminotransferase. At optimal pH 7.4 the enzyme was stable, highly active and catalyzed a reaction that was susceptible to detailed kinetic analysis by continuous optical methods. The KM values for L-aspartate, a- ketoglutarate and oxaloacetate were 2.60, 0.59 and 0.066 mM, respectively. On the basis of these KM values the solid-state colorimetric probe was developed. A colour change occurred when an electrospun dye-N 6 probes were exposed to visibly detectable concentrations of oxaloacetate, an AST-catalyzed reaction product. While monitoring AST activity at 530 run, a linear relation was obtained between oxaloacetate concentrations ranging from 0.4 - 7.4 µg/ml. Naked eye detection limit of 2.4 µg/ml oxalaoacetate equivalence of 10 times the normal AST activity was attained. The colorimetric probe was in addition, tested against co-substrates aspartate, ketoglutarate and a variety of other compounds such as alanine, pryruvate, as well as glutamic, malaic and succinic acids known to interfere with AST activity. Each compound elicited a distinct and unambiguous colour change upon interaction with the colorimetric probe. Further X-ray powder diffraction (XRD), duNouy ring tensiometer, Brunauer- Emmett- Teller (BET) and energy dispersive X-ray spectroscopy (EDS/EDX) characterization confirmed composition and stability of the colorimetric probes. Colorimetric probes developed in this thesis are relatively cost effective, simple and "rugged" for measurement of analytes with visual detection without sample pretreatment in matrices, such as plasma and dairy effluents. The probes warrant further investigation as they have shown potential and offer a promising solid-state platform for both clinical diagnostics and environmental monitoring.
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- Date Issued: 2014
Electrospun fibre based colorimetric probes for biological molecules
- Authors: Mudabuka, Boitumelo
- Date: 2014
- Subjects: Nanofibers , Vitamin C , Dopamine
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4535 , http://hdl.handle.net/10962/d1016354
- Description: The thesis reports the use of electrospun nanofibres as a platform for the development of colorimetric probes. Three colorimetric probes in the form of electrospun nanofibre test strips were developed for the selective detection of ascorbic acid and dopamine because they are crucial biomolecules for physiological processes in human metabolism and usually coexist in biological samples. The simultaneous detection of the biomolecules is very important as their abnormal concentration levels would lead to diseases such as Parkinson's and schizophrenia. Different methods of incorporating detector agents into the nanofibre were exploited for the detection of the biomolecules. The methods included physical incorporation of nanoparticles, covalent bonding of ligand/dyes through surface modification of the fibres. The first colorimetric test strip for ascorbic acid was based on copper-gold alloy nanoparticles prepared in-situ and hosted in nylon6. The test strip showed selectivity in detecting ascorbic acid in the pH range 2 – 7. The suitability of fibres in hosting copper-gold alloy nanoparticles for the colorimetric detection of ascorbic acid was investigated using nylon6, poly(vinyl benzyl chloride)-styrene and cellulose acetate based test strips. All the test strips exhibited leaching and the nylon6 based test strip was found to be thermally stable up to 60 ˚C. The colorimetric performance of the test strips was maintained and neither was colour decay exhibited after 10 months of storage in a shelf. The test strip achieved an eye-ball limit of detection of 1.76 x10-2 mg L-1 and its suitability was demonstrated by the determination of ascorbic acid in fruit juices, urine, serum, and vitamin C tablets. The second colorimetric test strip for ascorbic acid and dopamine employed prussian blue synthesised in-situ in nylon6. Ascorbic acid turned the deep blue test strip to light blue at pH 3, and a faded navy blue colour at a pH range of 6 - 7 while dopamine changed the strip to purple at the same pH range. The versatility of the test strip was demonstrated by detecting ascorbic acid in commercial fruit juices as well as by detecting ascorbic acid as well as dopamine in fortified urine. The eye-ball detection limit of the Prussian blue test strip for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The third method involved a covalent approach, where poly(vinylbenzyl chloride) nanofibers were post functionalised with 2-(2′-pyridyl)-imidazole and iron(III) for the selective detection of ascorbic acid and dopamine. The eye-ball detection limit for ascorbic acid and dopamine was 17.6 mg L-1 and 18.9 mg L-1, respectively. The test strip was selective for dopamine, but the detection of ascorbic acid suffered from interference by glutathione. The application of the test strips was nevertheless demonstrated by the detection of ascorbic acid in fruit juices and dopamine in fortified urine. The developed test strips employing the three approaches were applied without sample pre-treatment and use of supporting equipment.
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- Date Issued: 2014
Electrospun nanofibers as solid phase extraction sorbents and support for alkylphenols colorimetric probes
- Authors: Tancu, Yolanda
- Date: 2014
- Subjects: Nanofibers , Electrospinning , Extraction (Chemistry) , Sorbents , Phenols , Colorimetry , Transmission electron microscopy , High resolution spectroscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4486 , http://hdl.handle.net/10962/d1012997
- Description: The thesis reports on fabricating alternative solid phase extraction (SPE) sorbents and colorimetric probes based on electrospun nanofibers for alkylphenols (APs). Hydroxyl methylated styrene [poly(co-styrene-CH₃OH)] and 3-oxobutanoate styrene [poly(co-styrene-OCOCH₃COCH₃)] copolymers were synthesized and fabricated into sorbent materials by electro-spinning/spraying. The fabricated morphologies consisting of bead free fibers, beaded fibers and particles were evaluated as SPE sorbents using batch experiments. Electropun fibers proved to be better sorbents as they exhibited extraction efficiency that exceeded 95% compared to 60% for beaded fibers and 40% for particles. In view to reduce sample and solvent volumes, smooth fibers were packed into pipette tips as SPE devices that yielded quantitative recoveries of APs from spiked wastewater samples. Recoveries ranged from 70% to 125% with LOD of 0.008, 0.01 and 0.1 μg mL⁻¹ for 4-tert octylphenol (4-t-OP), 4-octylphenol (4-OP) and 4-nonylphenol (4-NP) respectively, when using high performance liquid chromatography-fluorescence detector (HPLC-FLD). Furthermore, amino functionalised polydiacetylene polymers (PDAs), citrate capped gold (AuNPs) and silver nanoparticles (AgNPs) were evaluated as colorimetric probes for visual detection of APs. In colloidal studies, AuNPs probe showed a colour change from wine red to green upon introduction of analyte. UV-vis spectroscopy revealed the shifting of the surface plasmon resonance (SPR) peak from 525 nm to 729 nm induced by aggregation of AuNPs. For AgNPs probe, a colour change was observed from yellowish green to brown. Transmission electron microscopy (TEM) studies showed growth of AgNPs. A presumed oxidation of the analyte, forming an absorbing compound at 279 nm in both AgNPs and PDAs probes was also observed. For PDAs probe the colour change was from purple to pink. Concentrations as low as 30 μg mL⁻¹ were detectable in all colloidal based probes. Further colorimetric investigations were conducted with electrospun AuNPs-nylon 6 fiber mat. A colour change from purplish red to navy blue at concentrations of 1000 μg mL⁻¹ was observed. Electrospun AgNPs –nylon 6 fiber mat did not show a distinct colour change. High resolution scanning electron microscopy (HRSEM) revealed the analyte inducing the assembly of AuNPs and AgNPs as they covered the surface of the nanofiber mat. Electrospun nanofibers are a platform for analysis and thus tuning their chemistry will lead to sensitive and selective methods
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- Date Issued: 2014
Electrospun sorbents for solid phase extraction (SPE) and colorimetric detection of pesticides
- Authors: Gulamussen, Noor Jehan
- Date: 2014
- Subjects: Sorbents , Electrospinning , Extraction (Chemistry) , Colorimetry , Pesticides , Water -- Pesticide content -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4501 , http://hdl.handle.net/10962/d1013241
- Description: The thesis presents the evaluation of polysulfone sorbents for solid phase extraction (SPE) and the development of colorimetric probes for pesticides analysis in water. Through electrospraying and electrospinning techniques, different morphologies of sorbents (particles, beaded fibers and bead-free fibers) were fabricated. The sorbents were morphologically characterized by scanning electron microscopy. Adsorption capacities of sorbents were evaluated by conducting recoveries studies for model pesticides; atrazine, chlorpyrifos and DDT using batch and column SPE modes. Better recovery results were achieved by employing the batch mode of fibers, as values ranged from 98 to 105percent. Further sorbent evaluation was conducted using breakthrough experiments and static experiments. The breakthrough studies indicated that 1700 μL was the sample volume that could be percolated with no breakthrough of the analyte that correspond to a concentration of 150 mg/g of sorbent that can be extracted without any loss of analyte. From static studies, quantities of each model compound adsorbed into the fiber at the equilibrium time were evaluated. The adsorbed atrazine was 65, chlorpyrifos 250 and DDT 400 mg/g of sorbent. Kinetic studies suggested retention mechanism following pseudo first and second order model observed by high correlation coefficients (> 0. 96), demonstrating the fiber affinity to retain both polar and non-polar compounds opening a possibility to be used as sorbent for sample preparation of different classes of pesticides in water. For the second part of the study simple strategies for colorimetric sensing based on silver nanoparticles and polivinylpyrrolidone capped nanoparticles were developed, respectively for atrazine and chlorpyrifos detection. The limits of detection of the methods were 3.32 and 0.88 mg/L for atrazine and chlorpyrifos respectively. The applicability of the probe in real samples was demonstrated by the recoveries studies of tap water varying from 94 to 104 percent. The versatility of the probe was demonstrated by affording a simple, rapid and selective detection of atrazine and chlorpyrifos in the presence of other pesticides by direct analysis without employing any sample handling steps. Attempt to incorporate the probes in a solid support was achieved by using nylon 6 as solid support polymer proving to be fast and useful for on-site detection.
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- Date Issued: 2014
Empathy in the time of ecological apartheid : a social sculpture practice-led inquiry into developing pedagogies for ecological citizenship
- Authors: McGarry, Dylan Kenneth
- Date: 2014
- Subjects: Education -- Philosophy , Social learning , Environmental education , Arts in education
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1985 , http://hdl.handle.net/10962/d1013154
- Description: Considering the ecological crisis and the increased disconnection between human beings and nature, this study attempts to find the social and aesthetic educational response needed for developing ecological citizenship for the 21st century. In this transdisciplinary study I articulate what at first seems a clumsy attempt to enable the capacities of the embodied ecological citizen, and which later emerges as an alchemical ‘social sculpture’ approach to learning that expands the range of capacities available to the citizen and the citizen’s immediate community. This learning bridges the gap between purely biocentric and technocentric forms of education, and addresses the ambiguity of concepts and forms of action such as ‘sustainability’. My primary focus is enabling both communal and personal forms of agency: new ways of 'doing’ and 'being' in the world as it changes radically. I argue that this demands constantly reflecting on and engaging without understanding, place and perception of the problems we see. Attending to a call for the importance of complex learning processes, that deepens our understanding of sustainability, and the need for methodological and pedagogical approaches to accessible forms of learning socially in the era of climate change and environmental degradation, this study offers a particular insight into the education of an ecological citizen. In particular I examine a form of learning that enables individuals to explore relationships between themselves and their ecologies (both physical and social), and that encourages personal forms of knowing so that each person’s values can be cultivated within the experience and intuitive expression from both inner and outer realities. Central to my research focus is addressing the difficulties inherent in ‘ecological apartheid’, which is defined as a growing separation of relationships that include the human being’s relationship with the natural world, as well as disconnections experienced within one’s own inner and outer capacities. Subsequently I investigate forms of learning that encourage agency that most appropriately enable citizens to respond personally to both inner and outer forms of disconnection. ‘Personal’ and ‘relational agency’ are defined and investigated through an initial twelve-month collaborative participatory contextual profiling exploratory research period in South Africa (phase A), where I explore various forms of multiple-genre creative social learning practice that develop an accessible set of methodologies and pedagogies for the ecological citizen. Through this exploratory research, I place significance in the relatively unknown field of social sculpture, which I investigate through a self-made apprenticeship with Shelley Sacks, an expert in the field. This is documented through a rigorous ethnographic inquiry over a period of 18 months. Following this I undertake another two-year collaborative, practice-based research study across South Africa (phase B: 17 towns, with a total of 350 citizens) and eventually abroad (United Kingdom, Germany, USA and Belgium).The focus of this study was the implementation of a collaboratively developed citizen learning practice entitled Earth Forum developed by Shelley Sacks as a progression from her work “Exchange Values: voices of insivible lives” and my collaboative exploration into Earth Forum and its further development draws heavily from social sculpture methods obtained during the apprenticeship, and applied in 36 different incidences. I further explore the efficacy of this practice in enabling and expanding the capacities of participants, particularly those that encourage the development of personal and relational agency. This was achieved through a pedagogical development and expansion period (phase C). A primary finding through the iterative phase (phase D) was the value of imaginal contemplation, attentive listening, and empathy as capacities that enable an ecological citizen’s overall capability. I ascribed this to Nussbaum and Sen’s (1993) capability theory and the need to enable the articulation and implementation of a citizen’s valued ‘beings and doings’. Through this iterative phase, specific attention is given to listening and intuitive capacities in enabling personal and relational agency, and specifically I observed the fundamental role of imagination in this form of learning. Particularly valuable for the educational contribution of this study is the pedagogical development of the Earth Forum practice that enables an accessible, socially constructed form of learning. This contributes specifically to exploring ‘how’ social learning is undertaken, and I argue that an aesthetic approach to learning is vital for the education of the ecological citizen. I carefully describe how one can conduct collaborative practice-based research that utilises creative connective practice in agency development. This collaborative approach, with regard to learning socially and capacity development for ecological citizenship (that focuses its attention on addressing ecological apartheid and separateness), is articulated through a multiple-genred text. I found that empathetic capacity in ecological citizen education is relatively unexplored, and within listening and as well in empathy theory, that the role of imagination in listening and empathy development, requires greater attention. I attempt to reveal how connective practice considers aesthetic form and shape in expanding capacities of human beings, and introduce novel expanded forms of developing pedagogies that encourage personal and relational agency in the context of ecological apartheid from the artsbased field of social sculpture. Finally, I aim in this study to share the potential value found in social sculpture theory and practice into the field of environmental education and social learning through a reflection on the current context of education and social learning, and its potential enrichment via social sculpture processes.
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- Date Issued: 2014
Enabling cumulative knowledge-building through teaching: a legitimation code theory analysis of pedagogic practice in law and political science
- Authors: Clarence, Sherran
- Date: 2014
- Subjects: Law -- Study and teaching (Higher) -- South Africa Political science -- Study and teaching (Higher) -- South Africa Education, Higher -- South Africa College teaching -- South Africa Knowledge, Theory of Social realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1966 , http://hdl.handle.net/10962/d1011763
- Description: Much current research and practice in teaching and learning in higher education tends to overfocus on social aspects of education; on how rather than what students are learning. Much of this research and practice is influenced by constructivism, which has a relativist stance on knowledge, generally arguing, contra positivism, that knowledge is constructed in socio-historical contexts and largely inseparable from those who construct it and from issues of power. This leads to a confusion of knowledge with knowing, and knowledge is thus obscured as an object of study because it is only seen or understood as knowing or as a subject of learning and teaching. This ‘knowledge-blindness’ (Maton 2013a: 4) is problematic in higher education because knowledge and knowing are two separate parts of educational fields, and while they need to be brought together to provide a whole account of these fields, they also need to be analysed and understood separately to avoid blurring necessary boundaries and to avoid confusing knowledge itself with how it can be known. Being able to see and analyse knowledge as an object with its own properties and powers is crucial for both epistemological access and social inclusion and justice, because knowledge and knowledge practices are at the heart of academic disciplines in universities. Social realism offers an alternative to the dilemma brought about by constructivism’s tendency towards knowledge-blindness. Social realism argues that it is possible to see and analyse both actors within social fields of practice as well as knowledge as something that is produced by these actors but also about more than just these actors and their practices; thus knowledge can be understood as emergent from these practices and fields but not reducible to them (Maton & Moore 2010). Social realism, drawing from Roy Bhaskar’s critical realist philosophy (1975, 2008), is intent on looking at the real structures and mechanisms that lie beneath appearances and practices in order to understand the ways in which these practices are shaped, and change over time. Legitimation Code Theory is a realist conceptual framework that has, as its central aim, the uncovering and analysis of organising principles that shape and change intellectual and education fields of production and reproduction of knowledge. In other words, the conceptual tools Legitimation Code Theory offers can enable an analysis of both knowledge and knowers within relational social fields of practice by enabling the analysis of the ways in which these fields, such as academic disciplines, are organised and how knowledge and knowing are understood in educational practice. This study draws on social realism more broadly and Legitimation Code Theory specifically to develop a relatively novel conceptual and explanatory framework within which to analyse and answer its central question regarding how to enable cumulative knowledge building through pedagogic practice. Using qualitative data from two academic disciplines, Law and Political Science, which was analysed using a set of conceptual and analytical tools drawn from Legitimation Code Theory, this study shows that the more nuanced and layered accounts of pedagogy that have been generated are able to provide valuable insights into what lecturers are doing as they teach in terms of helping students to acquire, use and produce disciplinary and ‘powerful’ knowledge (Young 2008b). Further, the study demonstrates that the organising principles underlying academic disciplines have a profound effect on how the role of the knower and the place or purpose of knowledge is understood in pedagogy and this affects how the pedagogy is designed and enacted. This study has argued that if we can research pedagogy rigorously using tools that allow us to see the real mechanisms and principles influencing and shaping it, and if we can reclaim the role of disciplinary knowledge as a central part of the pedagogic relationship between lecturer and students, then we can begin to see how teaching both enables and constrains cumulative learning. Further, we can change pedagogy to better enable cumulative learning and greater epistemological access to disciplinary knowledge and related practices for greater numbers of students. The study concludes by suggesting that the conceptual tools offered by Legitimation Code Theory can provide academic lecturers with a set of tools that can begin to enable them to 'see' and understand their own teaching more clearly, as well as the possible gaps between what they are teaching and what their students are learning. This study argues that a social realist approach to the study of pedagogy such as the one used here can begin not only to enable changes in pedagogy aimed at filling these gaps but also begin to provide a more rigorous theoretical and practical approach to analysing, understanding and enacting pedagogic practice. This, in turn, can lead to more socially just and inclusive student learning and epistemic and social access to the powerful knowledge and ways of knowing in their disciplines.
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- Date Issued: 2014
Establishing a formulation design space for a generic clobetasol 17- propionate cream using the principles of quality by design
- Authors: Fauzee, Ayeshah Fateemah Beebee
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:20983 , http://hdl.handle.net/10962/5868
- Description: The pharmaceutical industry is global, is highly regulated and is able to achieve reasonable product quality but at high cost with maximum effort. Numerous challenges face the pharmaceutical industry and include a shrinking research pipeline, less innovation, outsourcing, investments, increasing research and development costs, long approval times, growth of the generic industry, failure to understand or analyze manufacturing failure and wastage as high at fifty percent for some pharmaceutical products. An efficient and flexible pharmaceutical sector should be able to consistently produce high quality pharmaceutical products at a reduced cost with minimal waste. As a result, Food and Drug Administration (FDA) and other agencies such as the International Conference on Harmonization (ICH) have embraced a “Quality by Design” (QbD) paradigm and this has become the “desired state” so as to shift manufacturing from being empirical to a science, engineering, and risk based approach. QbD is a systematic approach for the development of high quality pharmaceutical dosage forms that begins with predefined objectives based on the premise that quality must be built into and not tested into a product. QbD together with the establishment of a design space for dosage forms is a fairly new concept and there is limited published data on QbD concepts that report the entire process of identifying Critical Quality Attributes (CQA), design of a formulation and manufacturing process to meet product CQA, understanding the impact of material attributes and process parameters on product CQA, identification and controlling sources of variability in materials and processes that affect the CQA of a product and finally establishing, evaluating and testing a design space using both in vitro and in vivo approaches to assure that a product of consistent quality can always be produced. The objective of these studies was to implement a QbD approach to establish a design space for the development and manufacture of a safe, effective, stable generic formulation containing 0.05% w/w clobetasol 17-propionate (CP) that had similar in vitro and in vivo characteristics to an innovator product, Dermovate® (Sekpharma® Pty Ltd, Sandton, Gauteng, RSA). Such a product would pose a minimal risk of failure when treating severe skin disorders such as seborrhoeic dermatitis, extreme photodermatitis and/or severe psoriasis in HIV/AIDS patients in Southern Africa.
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- Date Issued: 2014
Evaluating the post-implementation effectiveness of selected household water treatment technologies in rural Kenya
- Authors: Onabolu, Boluwaji
- Date: 2014
- Subjects: Water-supply, Rural -- Kenya , Sanitation, Rural -- Kenya , Sanitation, Household -- Kenya , Drinking water -- Purification -- Kenya , Drinking water -- Microbiology -- Kenya , Health behavior -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6045 , http://hdl.handle.net/10962/d1013145
- Description: Water, sanitation and hygiene-related diseases are responsible for 7% of all deaths and 8% of all disability adjusted live years (DALYs), as well as the loss of 320 million days of productivity in developing countries. Though laboratory and field trials have shown that household water treatment (HWT) technologies can quickly improve the microbiological quality of drinking water, questions remain about the effectiveness of these technologies under real-world conditions. Furthermore, the value that rural communities attach to HWT is unknown, and it is not clear why, in spite of the fact that rural African households need household water treatment (HWT) most, they are the least likely to use them. The primary objective of this multi-level study was to assess the post-implementation effectiveness of selected HWT technologies in the Nyanza and Western Provinces of Kenya. The study was carried out in the rainy season between March and May, 2011 using a mixed method approach. Evidence was collected in order to build a case of evidence of HWT effectiveness or ineffectiveness in a post-implementation context. A quasi-experimental design was used first to conduct a Knowledge, Attitudes and Practices (KAP) survey in 474 households in ten intervention and five control villages (Chapter 3). The survey assessed the context in which household water treatment was being used in the study villages to provide real-world information for assessing the effectiveness of the technologies. An interviewer-administered questionnaire elicited information about the water, sanitation and hygiene-related KAP of the study communities. A household water treatment (HWT) survey (Chapter 4) was carried out in the same study households and villages as the KAP study, using a semi-structured questionnaire to gather HWT adoption, compliance and sustained use-related information to provide insight into the perceived value the study households attach to HWT technologies, and their likelihood of adoption of and compliance with these technologies. The drinking water quality of 171 (one quarter of those surveyed during KAP) randomly selected households was determined and tracked from source to the point of use (Chapter 5). This provided insights into HWT effectiveness by highlighting the need for HWT (as indicated by source water quality) and the effect of the study households’ KAP on drinking water quality (as indicated by the stored water quality). Physico-chemical and microbiological water quality of the nineteen improved and unimproved sources used by the study households was determined, according to the World Health Organisation guidelines. The microbiological quality of 291 water samples in six intervention and five control villages was determined from source to the point-of-use (POU) using the WHO and Sphere Drinking Water Quality Guidelines. An observational study design was then used to assess the post-implementation effectiveness of the technologies used in 37 households in five intervention villages (Chapter 6). Three assessments were carried out to determine the changes in the microbiological quality of 107 drinking water samples before treatment (from collection container) and after treatment (from storage container) by the households. The criteria used to assess the performance of the technologies were microbial efficacy, robustness and performance in relation to sector standards. A Quantitative Microbial Risk Assessment (QMRA) was then carried out in the HWT effectiveness study households to assess the technologies’ ability to reduce the users’ exposure to and probability of infection with water-borne pathogens (Chapter 7). The KAP survey showed that the intervention and control communities did not differ significantly in 18 out of 20 socio-economic variables that could potentially be influenced by the structured manner of introducing HWT into the intervention villages. The majority of the intervention group (IG) and the control group (CG) were poor or very poor on the basis of household assets they owned. The predominant level of education for almost two-thirds of the IG and CG respondents was primary school (completed and non-completed). Though very few were unemployed in IG (8.07%) and CG (14.29%), the two groups of respondents were predominantly engaged in subsistence farming — a low income occupation. With regard to practices, both groups had inadequate access to water and sanitation with only one in two of the households in both IG and CG using improved water sources as their main drinking water source in the non-rainy season. One in ten households in both study groups possessed an improved sanitation facility, though the CG was significantly more likely to practice open defecation than the IG. The self-reported use of soap in both study groups was mainly for bathing and not for handwashing after faecal contact with adult or child faeces. Despite the study groups' knowledge about diarrhoea, both groups showed a disconnection between their knowledge about routes of contamination and barriers to contamination. The most frequent reason for not treating water was the perceived safety of rain water in both the IG and CG. , The HWT adoption survey revealed poor storage and water-handling practices in both IG and CG, and that very few respondents knew how to use the HWT technologies correctly: The IG and CG were similar in perceived value attached to household water treatment. All HWT technologies had a lower likelihood of adoption compared to the likelihood of compliance indicators in both IG and CG. The users’ perceptions about efficacy, time taken and ease of use of the HWT technologies lowered the perceived value attached to the technologies. The assessment of the drinking water quality used by the study communities indicated that the improved sources had a lower geometric mean E. coli and total coliform count than the unimproved sources. Both categories of sources were of poor microbiological quality and both exceeded the Sphere Project (2004) and the WHO (2008) guidelines for total coliforms and E. Coli respectively The study communities’ predominant drinking water sources, surface water and rainwater were faecally contaminated (geometric mean E. coli load of 388.1±30.45 and 38.9±22.35 cfu/100 ml respectively) and needed effective HWT. The improved sources were significantly more likely than the unimproved sources to have a higher proportion of samples that complied with the WHO drinking water guidelines at source, highlighting the importance of providing improved water sources. The lowest levels of faecal contamination were observed between the collection and storage points which coincided with the stage at which HWT is normally applied, suggesting an HWT effect on the water quality. All water sources had nitrate and turbidity levels that exceeded the WHO stipulated guidelines, while some of the improved and unimproved sources had higher than permissible levels of lead, manganese and aluminium. The water source category and the mouth type of the storage container were predictive of the stored water quality. The active treater households had a higher percentage of samples that complied with WHO water quality guidelines for E. coli than inactive treater households in both improved and unimproved source categories. In inactive treater households, 65% of storage container water samples from the improved sources complied with the WHO guidelines in comparison to 72% of the stored water samples in the active treater households. However the differences were not statistically significant. The HWT technologies did not attain sector standards of effective performance: in descending order, the mean log10 reduction in E. coli concentrations after treatment of water from unimproved sources was PUR (log₁₀ 2.0), ceramic filters (log₁₀ 1.57), Aquatab (log₁₀ 1.06) and Waterguard (log₁₀ 0.44). The mean log10 reduction in E. coli after treatment of water from improved sources was Aquatab (log₁₀ 2.3), Waterguard (log₁₀ 1.43), PUR (log₁₀ 0.94) and ceramic filters (log₁₀ 0.16). The HWT technologies reduced the user’s daily exposure to water-borne pathogens from both unimproved and improved drinking water sources. The mean difference in exposure after treatment of water from unimproved sources was ceramic filter (log₁₀ 2.1), Aquatab (log₁₀ 1.9), PUR (log₁₀ 1.5) and Waterguard (log₁₀ 0.9), in descending order. The mean probability of infection with water-borne pathogens (using E.coli as indicator) after consumption of treated water from both improved and unimproved sources was reduced in users of all the HWT technologies. The difference in reduction between technologies was not statistically significant. The study concluded that despite the apparent need for HWT, the study households’ inadequate knowledge, poor attitudes and unhygienic practices make it unlikely that they will use the technologies effectively to reduce microbial concentrations to the standards stipulated by accepted drinking water quality guidelines. The structured method of HWT promotion in the intervention villages had not resulted in more hygienic water and sanitation KAP in the IG compared to the CG, or significant differences in likelihood of adoption and compliance with the assessed HWT technologies. Despite attaching a high perceived value to HWT, insufficient knowledge about how to use the HWT technologies and user concerns about factors such as ease of use, accessibility and time to use will impact negatively on adoption and compliance with HWT, notwithstanding their efficacy during field trials. Even though external support had been withdrawn, the assessed HWT technologies were able improve the quality of household drinking water and reduce the exposure and risk of water-borne infections. However, the improvement in water quality and reduction in risk did not attain sector guidelines, highlighting the need to address the attitudes, practices and design criteria identified in this study which limit the adoption, compliance and effective use of these technologies. These findings have implications for HWT interventions, emphasising the need for practice-based behavioural support alongside technical support.
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- Date Issued: 2014
Examining the nature of the relationship between learners' conceptual understanding and their mathematical dispositions in the context of multiplication
- Authors: Ndongeni, Siviwe Lungelwa
- Date: 2014
- Subjects: Multiplication -- Study and teaching (Elementary) -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa , Problem solving in children , Multiplication -- Ability testing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1987 , http://hdl.handle.net/10962/d1013217
- Description: The focus of this study is to explore three key aspects of learners’ multiplicative proficiency: the nature of learners’ conceptual understanding of multiplication, the nature of learners’ numeracy dispositions (in the context of learning multiplication), and the relationship between conceptual understanding and productive dispositions in the context of multiplication. The study used a qualitative case study approach to gather rich data in relation to these. In the study a purposively selected sample of six Grade 4 learners was used from the same school: two high, two average, and two low performers. Kilpatrick, Swafford, and Findell (2001) define conceptual understanding as a functional grasp of mathematical ideas and its significant indicator is being able to represent mathematical situations in different ways and knowing how different representations can be useful for different purposes. They then refer to productive disposition as the ‘tendency to see sense in mathematics, to perceive it as both useful and worthwhile, to believe that steady effort in learning mathematics pays off, and to see oneself as an effective learner and doer of mathematics’ (p.131). Individual interviews were conducted using Wright, et al.’s (2006) instrument for exploring the nature of students’ conceptual understanding of multiplication. Wright, et al. (2006) argue that the topics of multiplication and division build on the students’ knowledge of addition and subtraction, and also multiplication and division provide foundational knowledge for topics such as fractions, ratios, proportion and percentage, all of which are core and essential areas of mathematical learning typically addressed in the primary or elementary grades. Researchers agree that learners have to be exposed to various strategies so that they are able to see that there is a difference between additive reasoning and multiplicative reasoning. In order to classify learners’ conceptual understanding of multiplication an analysis of the data was done and learners were allocated levels according to the Wright, et al. (2006) levels of achievement. For the classification of learner dispositions, the data was analysed in terms of the elements of productive disposition as defined by Kilpatrick, et al. (2001) and Carr and Claxton (2002). The key findings of the study indicate that for conceptual understanding most of the learners depended on using concrete materials in solving multiplication and they also used basic strategies and methods. The findings for productive dispositions were that most of the learners saw themselves as competent in doing multiplication but the aspect of sense making and steady effort was less developed. The findings for the relationship between conceptual understanding and productive disposition were that both strands have a mutual relationship in which one helped the other to develop.
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- Date Issued: 2014
Exploration for sediment-hosted copper mineralization in Kaponda Prospect, Central African Copperbelt, Democratic Republic of Congo
- Authors: Kabunda, Ghislain Mwape
- Date: 2014
- Subjects: Copper mines and mining -- Central African Copperbelt (Congo and Zambia) , Sedimentation -- Central African Copperbelt (Congo and Zambia) , Prospecting -- Central African Copperbelt (Congo and Zambia) , Geological mapping -- Central African Copperbelt (Congo and Zambia) , Geochemistry -- Central African Copperbelt (Congo and Zambia) , Induced polarization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5061 , http://hdl.handle.net/10962/d1013129
- Description: The Kaponda Prospect represents a surface of 915.8 km² located at about 10 km south of the town of Lubumbashi and 33km NW of Kasumbalesa in the Democratic Republic of Congo (DRC). It lies within Neoproterozoic sedimentary rocks of the Katangan Supergroup in the Central African Copperbelt (CACB). In this province, copper mineralization occurs at different stratigraphic level with different associated alteration. Mineralization is of multistage origin from synsedimentary, diagenetic to post orogenic. Since the discovery of the CACB in the early 20th century, several exploration techniques have been used to delineate Cu deposits. A review and application of these methods including remote sensing, geological mapping, geochemical and geophysical surveys, and drilling, gives an insight of their effectiveness and limitation before analyzing their results from the Kaponda Prospect. The geology and structure of the Prospect is represented by a series of two NW trending disharmonic tight anticlines, locally domal, with cores occupied by either Roan Group or “Grand Conglomerat” Formation. These anticlines are separated by an open syncline made of Kundelungu rocks. Two mains direction of faults are recognized, the NW and NE trending structures. The latter direction are normal transfer faults which can serve as conduit for mineralization. They are related to the late orogenic extension of the Lufilian belt. However NE trending faults are believed to be associated to the climax of Lufilian folding or represents synsedimentary intergrowth faults. Exploration approach for sediment-hosted Cu within Kaponda Prospect, take into account the integration of all information derived from different techniques. Remote sensing is used as aid to geology. Landsat and Google earth images show lineaments that corresponds to lithostratigraphy boundary and domal anticline. Geological mapping identified reduced horizons which can potentially host mineralization, whereas analysis of structure measurements reveals the geometry of fold and direction of its axial plane and hinge. Statistical methods such as the main + 2 standard deviation, the frequency histogram and probability plot, together with experiential method are used to constrain and define Cu and Co thresholds values in soil samples. It appears that in this region, log-probability plot and histogram methods combined with spatial representation and the experience of the region, are the best practice to constrain and separate geochemical background from anomaly data. Ground and airborne magnetic, and radiometric images show specific signatures which map alteration and particularly lithostratigraphy such as “Roan” Group, “Grand Conglomerat” unit, “Nguba” cap carbonates and “Kundelungu” siliciclastic units. Analysis of faults interpreted from geophysical maps identified three major directions: E-W, NE-SW and NW-SE. The E-W faults are also interpreted as normal transfer faults such NE-SW structures, consistent with regional geological map. Although pole-dipole array of induced polarization (IP) survey was directly targeting disseminated Cu sulphide, its results suffer in responding to graphitic rocks and barren pyrite. Only relative small chargeable bodies need to be tested in drilling follow-up. A total of 15 targets have been generated through re-interpretation and integration of both geological mapping and remote sensing, geochemical and geophysical data, as well as existing drilling. Specific recommendations of follow-up works are advised for each type of target.
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- Date Issued: 2014
Exploratory study : how do Somali shop owners (SSO) succeed in running businesses in Soweto : a South African perspective
- Authors: Mokitlane, Ofentse Clifford
- Date: 2014
- Subjects: Business enterprises, Foreign -- South Africa , Small business -- Management , Small business -- South Africa , Foreign workers -- South Africa , Employment in foreign countries , Entrepreneurship -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:842 , http://hdl.handle.net/10962/d1015653
- Description: This is a qualitative study which seeks to understand how Somali shop owners run successful businesses in the township of Soweto in South Africa. This research report has three sections, namely (1) the academic paper which comprises a shortened literature review, the research method, findings, and the discussion; (2) an extended literature review and (3) the research methodology. It is important to mention that these three sections are related and not necessarily stand-alone sections. Despite the hostilities faced by the Somali shop owners from the host communities in South Africa, it is notable that they are successful, small-sized entrepreneurs in most townships of South Africa (SA). Previous research on Somalis has predominantly focused on their assimilation into the societies in their host countries, and on how they are led into self-employment because of the unfavourable labour markets in the host country. In this vein, there is a need to understand how they run successful businesses in the townships of SA. This study seeks to answer the following research question: How Do Somali Shop Owners Succeed in Running Businesses in Soweto, South Africa (SA)? In pursuit of answers to the above research question, this study was confined to three locations in Soweto, namely Orlando West, Chiawelo and Rockville which have a relatively high number of Somali entrepreneurs who have been in operation for longer than three years. This qualitative study explored the multiple perspectives of reality of Somali shop owners. Purposively, 14 Somali shop owners were identified initially using purposive sampling. Subsequently, theoretical sampling was used to identify Somali shop owners who were interviewed regarding how they successfully run their businesses in the locations of Orlando West, Chiawelo and Rockville in the township of Soweto. A total of eighteen semi-structured, in-depth and face-to-face interviews were conducted with these shop owners as a means of gathering data to the point of saturating their perspectives. Data collection ceased when new perspectives were no longer evident as interviewees were being repetitive. Open-coding and constant comparison was used to analyse the data. The findings of the study show that ethnicity plays a predominant role in the success of the Somali shop owners. The intra-ethnic networks and trust-based support systems are pivotal to how Somali shop owners run successful businesses in Soweto. The key findings manifested showed that various forms of support came from Somali communities, family and fellow countrymen which were also central to their success. Another key finding showed that Somali shop owners run their businesses by complementing, rather than predominantly competing with the other local businesses, which ultimately differentiates them in this way. The study also revealed that responsiveness to local customer needs by enhancing the value of their business to the locality is also characteristic of how Somali shop owners build customer loyalty. This study contributes to our understanding of how Somali entrepreneurs conduct successful businesses in a hostile host country. The findings have implications for business development training and programmes which support immigrant entrepreneurs. The findings may also be extended to inform how business development programmes would be designed to equally support local entrepreneurs.
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- Date Issued: 2014
Exploratory study of the enablers and challenges of a social entrepreneur : case of Dr Govender in the Gelvandale community, Port Elizabeth, South Africa
- Authors: Mfeketho, Chuma Nqabase Masechaba
- Date: 2014
- Subjects: Famhealth Medipark (Port Elizabeth, South Africa) , Businesspeople -- South Africa -- Port Elizabeth , Social entrepreneurship -- South Africa -- Port Elizabeth , Nonprofit organizations -- South Africa -- Port Elizabeth , Social responsibility of business -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth , Social capital (Sociology) -- South Africa -- Port Elizabeth , Success in business -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:851 , http://hdl.handle.net/10962/d1017519
- Description: Social entrepreneurs seek to create social value in various ways in the community. Notably, they encounter not only enabling factors but also face and attempt to deal with a variety of challenges in their endeavor to start and run social ventures. This academic paper adopts a single case study approach with the aims to explore challenges and attempts to deal with them, as well as enablers, in how Dr Govender sought to create social value within the community of Gelvandale in Port Elizabeth in South Africa. Famhealth Medipark was chosen because it is unique and has been considered as an example of successful social entrepreneurship in Port Elizabeth. In the light of this, there has not been any previous study particularly focusing on its challenges and enablers in adding social value in the community through a multi-disciplinary venture. This research is valuable as it builds our understanding of how social entrepreneurs create social value. This qualitative study uses a single case study to focus on incidents of challenges and enabling factors as experienced, recollected and expressed by Dr Govender as a social entrepreneur. A variety of data, such as interview data collected through sampling incidents in nine in-depth initial and follow-up interviews, documents, audio documentaries and emails, were used. Open coding and constant comparison was used to analyze data and induce themes. Findings depict that Dr Govender as a social entrepreneur was propelled by four enablers: (1) strong enthusiasm to create positive change in others within a community, (2) network to resources, (3) a nurturing world view, and (4) consistent self-sacrifice. Dr Govender also revealed that he faced four types of challenges in setting up and operating Famhealth Medipark (FHM) as a vehicle with the sole purpose of creating and adding social value to the community of Gelvandale. Predominantly, (1) limitation of finance, (2) overwhelming effect of multiple roles, (3) negative effects of the non-accredited status of the care-giver training programme, and (4) the predominance of a destructive mindset entrenched within the Gelvandale community were key challenges he faced and attempted to deal with in setting up and operating a social venture to ultimately create social value. Although other types of data have been used, the predominant reliance on primary data collected through in-depth interviews is one of the major limitations of this qualitative study. However, this qualitative and exploratory study provides insights into our understanding of not only challenges encountered by social entrepreneurs but also the various drivers that sustain their social mission. Recommendations were then made, based on the findings from the research conducted.
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- Date Issued: 2014
Exploring teaching proficiency in geometry of selected effective mathematics teachers in Namibia
- Authors: Stephanus, Gervasius Hivengwa
- Date: 2014
- Subjects: Mathematics -- Study and teaching (Secondary) -- Namibia , Geometry -- Study and teaching (Secondary) -- Namibia , Effective teaching -- Namibia , Mathematics teachers -- Education (Secondary) -- Namibia , Education, Secondary -- Namibia , Mathematics teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1976 , http://hdl.handle.net/10962/d1013012
- Description: Quality mathematics education relies on effective pedagogy which offers students appropriate and rich opportunities to develop their mathematical proficiency (MP) and intellectual autonomy in learning mathematics. This qualitative case study aimed to explore and analyse selected effective mathematics teachers' proficiency in the area of geometry in five secondary schools in five different Namibia educational regions. The sample was purposefully selected and comprised five mathematics teachers, identified locally as being effective practitioners by their peers, Education Ministry officials and the staff of the University of Namibia (UNAM). The schools where the selected teachers taught were all high performing Namibian schools in terms of students' mathematics performance in the annual national examinations. The general picture of students' poor performance in mathematics in Namibia is no different to other sub-Saharan countries and it is the teachers who unfortunately bear the brunt of the criticism. There are, however, beacons of excellence in Namibia and these often go unnoticed and are seldom written about. It is the purpose of this study to focus on these high achievers and analyse the practices of these teachers so that the rest of Namibia can learn from their practices and experience what is possible in the Namibian context. The mathematical content and context focus of this study was geometry. This qualitative study adopted a multiple case study approach and was framed within an interpretive paradigm. The data were collected through individual questionnaires, classroom lesson observations and in-depth open-ended and semi-structured interviews with the participating teachers. These interviews took the form of post lesson reflective and stimulated recall analysis sessions. An adapted framework based on the Kilpatrick, Swafford and Findell's (2001) five strands of teaching for MP was developed as a conceptual and analytical lens to analyse the selected teachers' practice. The developed coding and the descriptive narrative vignettes of their teaching enabled a qualitative analysis of what teachers said contributed to their effectiveness and how they developed MP in students. An enactivist theoretical lens was used to complement the Kilpatrick et al.'s (2001) analytical framework. This enabled a deeper analysis of teacher teaching practice in terms of their embodied mathematical knowledge, actions and interactions with students. procedural fluency (PF) and productive disposition (PD), were addressed regularly by all five participating teachers. Evidence of addressing either the development of students' strategic competence (SC) or adaptive reasoning (AR) appeared rarely. Of particular interest in this study was that the strand of PD was the glue that held the other four strands of MP together. PD was manifested in many different ways in varying degrees. PD was characterised by a high level of content knowledge, rich personal experience, sustained commitment, effective and careful preparation for lessons, high expectations of themselves and learners, collegiality, passion for mathematics and an excellent work ethic. In addition, the teachers' geometry teaching practices were characterised by making use of real-world connections, manipulatives and representations, encouraging a collaborative approach and working together to show that geometry constituted a bridge between the concrete and abstract. The findings of the study have led me, the author, to suggest a ten (10) principles framework and seven (7) key interrelated factors for effective teaching, as a practical guide for teachers. This study argues that the instructional practices enacted by the participating teachers, who were perceived to be effective, aligned well with practices informed by the five strands of the Kilpatrick et al.'s (2001) model and the four concepts of autopoesis, co-emergence, structural determinism and embodiment of the enactivist approach. The study concludes with recommendations for effective pedagogical practices in the teaching of geometry, and opportunities for further research.
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- Date Issued: 2014
Exploring the fertiliser potential of biosolids from algae integrated wastewater treatment systems
- Authors: Mlambo, Patricia Zanele
- Date: 2014
- Subjects: Sewage disposal plants , Sewage sludge as fertilizer , Algae -- Biotechnology , Sewage -- Purification -- Anaerobic treatment , Plant regulators , Biofertilizers , Microalgae -- Biotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5957 , http://hdl.handle.net/10962/d1013342
- Description: High rate algae oxidation ponds (HRAOP) for domestic wastewater treatment generate biosolids that are predominantly microalgae. Consequently, HRAOP biosolids are enriched with minerals, amino acids, nutrients and possibly contain plant growth regulator (PGR)-like substances, which makes HRAOP biosolids attractive as fertiliser or PGR. This study investigated HRAOP biosolids as a starting material for a natural, cost-effective and readily-available eco-friendly organic fertiliser and/or PGRs. Various HRAOP extract formulations were prepared and their effect on plant growth and development was evaluated using selected bioassays. Initial screening included assessing the effect on change in specific leaf area, radish cotyledon expansion as an indicator of PGR-like activity, and seed germination index (GI). More detailed studies on fertiliser efficacy and PGR-like activity utilised bean (Phaseolus vulgaris) and tomato (Solanum lycopersicum) plants. Combined effects of sonicated (S) and 40% v/v methanol (M) extract (5:1 SM) had impressive plant responses, comparable to Hoagland solution (HS). Other potentially fertiliser formulations included 0.5% M, 1% M, 2.5% S and 5% S formulations. The 5:1 SM and 5% S showed greater PGR-like activity, promoting cotyledon expansion by 459 ± 0.02% and 362 ± 0.01%, respectively. GI data showed that none of the formulations negatively impacted germination. Further investigation showed that the 5% S formulation increased leaf length, width and area by 6.69 ± 0.24, 6.21 ± 0.2 mm and 41.55 ± 0.2 mm². All formulated fertiliser extracts had no adverse effect on chlorophyll content and plant nutrient balance as indicated by C:N (8-10:1) ratio. In addition, plants appeared to actively mobilise nutrients to regions where needed as evidenced by a shift in shoot: root ratio depending on C, N and water availability. Furthermore, 5% S caused a 75% increase in tomato productivity and had no effect on bean productivity. Whereas, 5:1 SM and 1% M formulation improved bean pod production by 33.3% and 11%, respectively but did not affect tomato production. Harvest index (HI) however indicated a 3% reduction in tomato productivity with 5:1 SM and little or no enhancement in bean productivity with both 5:1 SM and 5% S treatments. Bean plants treated with 5:1 SM and 5% S produced larger fruits, which could be an indication of the presence of a PGR effect. Overall, HRAOP biosolids extracts prepared and investigated in this study demonstrated both fertiliser characteristics and PGR-like activity with performances comparable and in some cases exceeding that of commercial products. However additional research is needed to confirm presence of PGR-like activities and fertiliser efficacy.
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- Date Issued: 2014
Exports and economic growth in South Africa
- Authors: Feddersen, Maura
- Date: 2014
- Subjects: Exports -- South Africa Economic development -- South Africa Unemployment -- South Africa Poverty -- South Africa Income distribution -- South Africa Investments -- South Africa Saving and investment -- South Africa South Africa -- Economic conditions South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1087 , http://hdl.handle.net/10962/d1012029
- Description: Various studies conclude that accelerated economic growth and development are necessary in South Africa to make a significant contribution towards reducing high levels of unemployment, inequality and poverty. Moreover, in theories of economic growth the export sector is frequently accorded a special role in encouraging faster economic growth, which is often supported by empirical evidence. Nonetheless, a question that remains unresolved is whether higher export growth leads to higher economic growth in South Africa and what particular role exports may play within the overall economic growth process of the country. This study applies Johansen’s cointegration procedure, impulse response functions, variance decomposition analysis and Granger causality tests to shed light on the channels through which export growth may impact South Africa’s economic growth rate. Quarterly time series data ranging from 1975q1 to 2012q4 is employed in the study’s empirical tests. The empirical results lend support to the idea that the role of exports in the economic growth process fundamentally lies in their ability to encourage investment and capital formation. While export growth supports higher economic growth in the short-run, it does not have the same effect in the long-run. Nonetheless, with export growth supporting faster capital formation in South Africa, and capital formation, in turn, significantly increasing economic growth in the long-run, the impetus to growth stemming from exports has been found to lie in the channel to capital formation. On the basis of the empirical results, not only are exports a critical requirement of higher investment, but they are also anticipated to play a prominent role in lifting the balance of payments constraint that would make investment-led growth possible in the first place. Overall, a strategy of export-led growth that does not explicitly emphasise the export-capital-growth connection is likely to fall short of reflecting the dynamics contained within the exports-growth relationship in South Africa.
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- Date Issued: 2014
Fabrication, characterization and application of phthalocyanine-magnetite hybrid nanofibers
- Authors: Modisha, Phillimon Mokanne
- Date: 2014
- Subjects: Nanofibers , Nanoparticles , Magnetite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4500 , http://hdl.handle.net/10962/d1013223
- Description: Magnetic nanoparticles comprising magnetite (Fe3O4) were functionalized with 3-aminopropyl-triethoxysilane forming amino functionalized magnetite nanoparticles (AMNPs). The amino group allows for conjugation with zinc octacarboxyphthalocyanine (ZnOCPc) or zinc tetracarboxyphthalocyanine (ZnTCPc) via the carboxyl group to form an amide bond. A reduced aggregation of ZnTCPc is observed after conjugation with AMNPs. The thermal stability, conjugation, morphology and the sizes of the nanoparticles and their conjugates were confirmed using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and Powder X-ray diffractometry (PXRD), respectively. The covalent linkage of AMNPs to ZnOCPc or ZnTCPc resulted in improvement in the photophysical behavior of the phthalocyanines. Improvement in the triplet quantum yield (ΦT), singlet oxygen quantum yield (ΦΔ), triplet lifetime (τT) and singlet oxygen lifetime (τΔ) of the ZnOCPc or ZnTCPc were observed, hence improving the photosensitizers efficiency. The conjugates comprising of zinc octacarboxyphthalocyanine (ZnOCPc) and AMNPs were electrospun into fibers using polyamide-6 (PA-6). This was used for the photodegradation of Orange-G and compared with ZnOCPc-AMNPs in suspension. For ZnOCPc-AMNPs in suspension, it is noteworthy that the catalyst can be easily recovered using an external magnetic field. The singlet oxygen generation increases as we increase the fiber diameter by increasing the ZnOCPc concentration. The singlet oxygen quantum yield is higher for PA-6/ZnOCPc-AMNPs nanofibers when compared to PA-6/ZnOCPc. The rate of degradation of Orange-G increased with an increase in the singlet oxygen quantum yield. Moreover, the kinetic analysis showed that the photodecomposition of Orange-G is a first-order reaction according to the Langmuir-Hinshelwood model.
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- Date Issued: 2014
Facilitating and renegotiating Afrikaans youth identities: Die Antwoord phenomenon
- Authors: Meintjes, Stephané Ruth
- Date: 2014
- Subjects: Die Antwoord , Die Antwoord -- I Fink U Freeky , Identity (Psychology) -- Social aspects , Afrikaner nationalism , Afrikaners -- Ethnic identity , Afrikaners -- Psychology , South Africa -- Race relations , Music, Influence of -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3538 , http://hdl.handle.net/10962/d1015655
- Description: This thesis reports on a project which investigated how young native, Afrikaans-speaking Rhodes University students responded to the musical outfit Die Antwoord and to their music video “I Fink U Freeky”. The study attempted to establish how a selected group of Afrikaans-speaking students consisting of Whites, Coloureds and Blacks interpret the work of Die Antwoord as well as their own Afrikaans identity. The purpose of the study was to interrogate the relationship between artistic media, citizenship and belonging to a particular group. The thesis reports on the ways in which interviewees in the group discussions responded to notions of identity, whiteness, class, race, hybridity and creolization registered in the music video which was used to prompt the discussions. Finally the thesis reports on findings regarding the relationship between citizenship and the artistic media. The enormous change in the socio-political position of Afrikaans-speakers in the post -1994 dispensation provides the social context of the study. The project utilised qualitative research and a reception study of the music was undertaken by means of focus group discussions in order to arrive at thick descriptions in an attempt to understand the contextual behaviour of the participants. It was postulated that Die Antwoord provides a discursive site within which audiences could generate their own innovative meanings regarding being Afrikaans. While there was no clear indication that the identities of the participants was constructed by the media, the video prompted discussions regarding identity and provided evidence that media texts are capable of stimulating an interrogation of identities. It emerged that all participants, while abandoning some aspects of Afrikaans culture, strongly embraced and highly valued the language. Participants did not regard race as an important aspect of citizenship. Vociferous discussions regarding class demonstrated how media texts can influence citizenship. Discussions about hybridization and creolization demonstrated how the media can challenge received conceptions regarding citizenship. Responses provided evidence that the media could stimulate new forms of citizenship and contribute to the inclusion of previously excluded subjects. The research findings clearly demonstrate links between artistic media, citizenship and belonging to a group of Afrikaanses rather than Afrikaners. Post- 1994 young Afrikaans-speakers in this study provided clear evidence that they are exploring new and alternative ways of being Afrikaans.
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- Date Issued: 2014
Factors influencing ecological sustainability in the ostrich industry in the Little Karoo, South Africa
- Authors: Wheeler, Anita
- Date: 2014
- Subjects: Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4259 , http://hdl.handle.net/10962/d1011741 , Ostrich farms -- South Africa -- Little Karoo , Land degradation -- South Africa -- Little Karoo , Land use -- South Africa -- Little Karoo , Land degradation -- Environmental aspects -- South Africa -- Little Karoo , Conservation of natural resources -- South Africa -- Little Karoo , Sustainable development -- South Africa -- Little Karoo , Sustainable agriculture -- South Africa -- Little Karoo
- Description: The Little Karoo, situated in the Succulent Karoo biome of South Africa, has been heavily transformed by land use, and only 8.6% of the remaining natural vegetation is considered to be intact. There is ample evidence that the main cause of degradation is the overstocking of ostriches, an industry that has been the major economic driver of the area for more than 150 years. The ostrich stocking rate currently recommended is 22 ha.ostrich⁻¹. A literature review was used to examine the evidence, assumptions and rationale on which recommended and actually implemented stocking rates for ostriches are based. No experimental evidence using ostriches was found that supported the recommended stocking rate as either ecologically or economically sustainable. From the literature, there appears to be a wide gap between what are considered to be economically and ecologically sustainable stocking rates, with the implication that these two aims may be impossible to reconcile when practicing ostrich farming on natural veld. A comparison of recommended with actual stocking rates among land managers in the Little Karoo showed that all land managers far exceeded the recommended agricultural stocking rate of 22.8 ha.ostrich⁻¹. However, the stocking rates reported by land managers to the South African Ostrich Business Chamber were found to accurately reflect actual numbers determined when whole flocks had to be slaughtered after an outbreak of avian influenza. The recommended stocking rate appeared to be irrelevant to ostrich flock breeders and there appeared to be a trade-off between profitable ostrich farming and sustainable land-use practices. This study also investigated the attitudes and behaviour of ostrich farmers. It was found that environmental attitude is most likely the most important characteristic of a land manager to ensure positive conservation behaviour. This characteristic was most prominent in younger land managers with larger farms. The last component of the study integrated the context and complexity of the long term social, economic and ecological sustainability of this industry through the development of a logic model. The results showed a general lack of linkages between industry elements which impact on achieving sustainability targets. Greater collaboration between industry role-players, organized agriculture and conservation organizations is required to find a balance between utilization and conservation in the ostrich industry.
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- Date Issued: 2014