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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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
- Full Text:
- Date Issued: 2017
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
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
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.
- Full Text:
- Date Issued: 2017
Evidence for a biological control-induced regime shift between floating and submerged invasive plant dominance in South Africa
- Authors: Strange, Emily Frances
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/32448 , vital:24044
- Description: South Africa has a long history battling the establishment and spread of invasive floating macrophytes. The negative consequences of these are costly both economically and ecologically. They form dense mats on the water's surface that deplete resources such as light and oxygen to the submerged community, which creates anoxic conditions, reduces biodiversity and limits access to freshwater. The past thirty years of South African invasive plant research and the implementation of nationwide biological control programmes has led to widespread control of these species in many degraded systems. Such initiatives are aimed at restoring access to potable freshwater and increasing native biodiversity. However, in recent years, where there has been a decline in floating invasive plant populations, an increase in the establishment and spread of submerged invasive plant species has been observed. Species such as Brazilian waterweed (Egeria densa (Planch.) (Hydrocharitaceae)) and Eurasian watermilfoil (Myriophyllum spicatum (L.) (Haloragaceae)) have been recorded in South African freshwater systems, posing significant threats to aquatic ecosystems. This thesis proposes that the biological control of floating invasive plants, which occurs in numerous dams and rivers nationwide, is the catalyst of a regime shift from floating invasive to submerged invasive plant dominance. Regime shifts are large and often sudden changes in the key structure and functioning of ecosystems, and studies into their occurrence and driving mechanisms broadens understanding of community structures and can guide effective resource management. In order to explore the existence of this new regime shift, a multi-platform approach using controlled experiments and ecological modelling techniques was employed. A model system was created consisting of a floating invasive (Pistia stratiotes L. (Araceae)), a submerged invasive (E. densa) and an ecologically analogous submerged native plant species (Lagarosiphon major (Ridl.) Moss (Hydrocharitaceae)). A suite of experiments was conducted to explore the interactions between the floating and submerged plants under varying regimes of floating plant biological control and levels of nutrient loading. These experiments revealed a competitive advantage of the invasive E. densa over the native L. major that increased by 86% under heavy nutrient loading. The relative growth rate and accumulated biomass of E. densa was significantly higher for plants grown in the presence of biologically controlled P. stratiotes (compared to insect free plants). This demonstrates a high capacity for the invasive E. densa to capitalise on resources made newly available through the biological control of the floating plants. In contrast, the native L. major fared poorly when grown in the presence of the floating P. stratiotes, regardless of applied biological control measures. The experimental observations were then used to parameterise a mathematical model, built to provide a holistic understanding of the individually assessed interactions which work together as the driving mechanisms underpinning the newly identified regime shift. This thesis utilised a multi-platform approach to build the first body of evidence in support of a newly recognised regime shift between floating invasive and submerged invasive plant dominance, as driven by biological control. The results indicate that a reduction in the nutrient loading of South Africa's freshwater systems will reduce negative impacts of submerged invasive macrophytes, whilst increasing system resilience against future invasion. The evidence presented has the potential to better inform management of South Africa's freshwater systems and highlights the importance of integrating multi-trophic interactions when considering future invasive plant management. This research also opens up a multitude of possibilities for studies into submerged plant invasion mechanisms and resilience of native macrophyte communities in South Africa, and further afield.
- Full Text:
- Date Issued: 2017
Evolving an efficient and effective off-the-shelf computing infrastructure for schools in rural areas of South Africa
- Authors: Siebörger, Ingrid Gisélle
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/14557 , vital:21938
- Description: Upliftment of rural areas and poverty alleviation are priorities for development in South Africa. Information and knowledge are key strategic resources for social and economic development and ICTs act as tools to support them, enabling innovative and more cost effective approaches. In order for ICT interventions to be possible, infrastructure has to be deployed. For the deployment to be effective and sustainable, the local community needs to be involved in shaping and supporting it. This study describes the technical work done in the Siyakhula Living Lab (SLL), a long-term ICT4D experiment in the Mbashe Municipality, with a focus on the deployment of ICT infrastructure in schools, for teaching and learning but also for use by the communities surrounding the schools. As a result of this work, computing infrastructure was deployed, in various phases, in 17 schools in the area and a “broadband island” connecting them was created. The dissertation reports on the initial deployment phases, discussing theoretical underpinnings and policies for using technology in education as well various computing and networking technologies and associated policies available and appropriate for use in rural South African schools. This information forms the backdrop of a survey conducted with teachers from six schools in the SLL, together with experimental work towards the provision of an evolved, efficient and effective off-the-shelf computing infrastructure in selected schools, in order to attempt to address the shortcomings of the computing infrastructure deployed initially in the SLL. The result of the study is the proposal of an evolved computing infrastructure model for use in rural South African schools.
- Full Text:
- Date Issued: 2017
Exploring and expanding situated cognition in teaching science concepts: the nexus of indigenous knowledge and Western modern science
- Authors: Mukwambo, Muzwangowenyu
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/8382 , vital:21389
- Description: Certain teaching and learning strategies are appropriate in the context of exposing learners to modern science in situated cognition (SC) - the theory that posits that knowing is inseparable from doing - during, for example, visits to industrial operations. The distance and cost of travel, however, excludes most rural teachers and their learners from such SC exposure to Science and technology in industrial settings. To fill this gap between knowledge and practice in the curriculum experience for rural schools, this research investigated the extent to which a SC approach could be used in relation to indigenous knowledge practices (IKP) that have relevance to science teaching for rural science teachers. The study was conducted in three schools in the Zambezi Region of Namibia whereby six science teachers participated in the study. Also, to generate data from the community, the study included Indigenous community members as participants. Only three selected members from the community participated as representatives of the whole community. Essentially, the study explored and expanded possibilities for rural school teachers to use IKP as sites of SC in relation to concepts of pressure in particular and other science concepts. The research thus studied teaching practices as activity systems related to concepts in the school curriculum and the activity system of Indigenous community members. The patterns, regularities and irregularities provided the framing which was used to view SC through the lens of IKP. This framing of SC within the school curriculum was explored using cultural historical activity theory (CHAT) and Engestrom’s expansive learning cycle (ELC). The study was organized into two phases; exploration and the expansive phase. In the exploration phase, interviews, community analysis, document analysis, brainstorming, reflections and audiovisual evidence were used to generate data. The expansive stage used brainstorming, reflections, and interviews, an experimental test, audio-visual evidence, and interviews. Inductive and abductive modes of inference were used to come up with explanations of the research questions. Explanations proceeded using the frameworks of socio-cultural theory and social realism. Some findings from the data generated from the exploration phase revealed that science teachers in the schools studied do not always engage in a SC approach on account of a lack of Western modern science (WMS) resources and factors related to economic marginalization of the learners. Data generated in the same phase revealed that science teachers can engage the SC approach through embracing indigenous knowledge practices (IKP) reflecting Science whereby they can apprentice learners. Some of the other findings from the expansive learning phase show that science teachers in under-resourced schools can engage the SC approach if IK practices are used as mediational tools which can be used as models, icons/symbols, vocabulary, patterns, case studies and practical activities anchored in IKP. From the findings obtained the contribution which the study made was to come up with some methods of infusing indigenous knowledge systems in science teaching. The trend in research related to IK is more aligned to policies rather than how IK can be usefully used for the benefit of science teaching. As the study only looked into the IKP reflecting Science which the participating teachers brainstormed, it provides an insight into how and which other IK practices can be woven into WMS to encourage social transformation accommodative of Afrocentric world views which allows scientific literacy to be achieved.
- Full Text:
- Date Issued: 2017
Exploring change-oriented learning, competencies and agency in a regional teacher professional development programme's change projects
- Authors: Mandikonza, Caleb
- Date: 2017
- Subjects: SADC Regional Environmental Education Programme Environmental education -- Africa, Southern Education -- Africa, Southern , International Certificate in Environmental Education , Environmental education -- Africa, Southern , Teachers, Training of -- Africa, Southern , Education -- Philosophy , Mediated learning experience , Vygotskiĭ, L. S. (Lev Semenovich), 1896-1934
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4410 , vital:20660
- Description: This aim of this study was to explore the mediatory role of the Rhodes University (RU) / Southern African Development Community (SADC) International Certificate in Environmental Education course in developing capacity for reflexive mainstreaming of environment and sustainability education in teacher education in southern Africa. This course was a change-oriented intervention to support capacity and agency for mainstreaming environmental education across many sectors of education. The discourse of the course included environmental education and education for sustainable development and for this study this was referred to as environment and sustainability education (ESE). Environment and sustainability education is a developing notion in southern Africa and the SADC Regional Environmental Education Programme (REEP) was set up to support capacity for mainstreaming ESE. ESE was one of the responses taken by the SADC region to respond to prevalent environment and sustainability issues across the region. This study focused, in general, on establishing the mediatory roles of the reflexive mediatory tool, the change project in the course. More specifically, the research explores the mediatory role of course interventions and activities that were used to develop understanding of and to frame the change project in fostering agentially motivated changed practice in the teacher education sector. Drawing on realist social theory, which is a form of critical realism, especially the work of Margaret Archer, the study used the principle of emergence to interpret changes in the course participants' practices. The study was framed using the research question: How do mediated actions in a regional professional development programme and the workplace influence Environment and Sustainability (ESE) competencies, practice, learning and agency in Teacher Education for Sustainable Development (TESD) change projects? The following sub-questions refined the study: • What mediated actions on the course influence ESE competences, practice, learning and agency on the professional development programme? • How do these identified mediated actions influence ESE competences, practice and learning on the professional development programme? • What mediated actions in workplaces influence ESE competences, practice, learning and agency in the change projects in teacher education institutions? • How do these identified mediated actions in workplaces influence ESE competences, practices and mediated actions in the workplace? Notions of practice, agency, reflexivity, competences and capabilities were used to sensitise explanations of features emergent from course interactions; the process of analysis was under-laboured by the theoretical lens of critical realism and realist social theory. Mediation theory was used to explain the role of interventions across the course. The study used a case study approach with three cases of teacher educators from two institutions in two southern African countries. Data were generated through document analysis of course portfolios, semi-structured interviews with research participants, observations of participants during their teaching and through group discussions in a change management workshop to establish features that emerged from the course and change project interactions. The principle of emergence recognises that any interactions result in new features of characteristics that are different from the original. In this case, the study investigated those features shown by participants after being exposed to the course's mediatory tools. In order to describe the cases, a narrative approach was used. The study was conducted at the interface of the United Nations Decade of Education for Sustainable Development (UNDESD) and the Global Action Plan for Education for Sustainable Development, therefore the outcomes have implications for capacity development for ESE during and beyond the Global Action Plan for Education for Sustainable Development. The key finding is that capacity development for ESE needs to foreground reflexive engagement with one's own practice for it to be meaningful and relevant. The change project provided course participants with the opportunity to engage with their own practice and particularly their competences and capabilities through its mediatory tools. Course participants showed emergent properties that were evidence of expanded zones of proximal development (ZPD) in competences, capabilities and agency. The study illustrates that meaningful learning happens when immersed in context and when learners are able to make connections between concepts, practices and experiences (their praxis). The study also illustrates that capacity building creates opportunities for practitioners to expand their repertoire through the course activities. Some of the course activities stimulated, enhanced and gave impetus to their agency or double morphogenesis for them to continue to expand that repertoire by trying and retrying changes in practice that they value on their own and in communities of practice. Capacity development courses need to be structured to involve a variety of mediatory activities as some of these are relevant and are valued for different teacher education contexts. The study also shows how knowledge and understanding of classical Vygotskian mediation can be used to frame and structure courses for developing the ZPD retrospectively and how the repertoire which forms the ZPD has potential to be expanded and to keep expanding, whether at individual level or in community with others, as an object in the post-Vygotskian mediation process. The change project provides the starting point, the vehicle and momentum to teacher educators to critique and to reflexively transform competences or aspects of their practice that they value. The study showed that capacity development through the change project generated momentum for potentially morphogenetic changes in teacher education practice. The course initiated interactions at the phase T2-T3 that disrupted teacher educators' habitus. On-course phase activities such as assignments, lectures, discussions, practical tasks, excursions and regional knowledge exchange groups contributed smaller morphogenetic cycles to the main cycle. Reflexive engagement with one's own practice becomes a useful tool for building capacity for scaling capacity for mainstreaming ESE during and after the Global Action programme for ESD. Contributions of the study therefore go beyond the SADC region to contribute insights into capacity development for ESD in similar conditions of teacher education across the world.
- Full Text:
- Date Issued: 2017
Exploring transformative social learning and sustainability in community based irrigation scheme contexts in Mozambique
- Authors: Baloi, Aristides
- Date: 2017
- Subjects: Social learning -- Mozambique , Irrigation -- Social aspects -- Mozambique , Water resources development -- Mozambique , Sustainable agriculture -- Mozambique , Community development -- Mozambique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50154 , vital:25963
- Description: This study set out to examine transformative social learning and sustainability in the context of community-based irrigation systems in Mozambique. These irrigation systems are socio-ecological in nature. The history of irrigation systems in Mozambique can be described in two periods: pre-Independence period (mainly the colonial period) and the post-Independence period from 1975 onwards. Most recently, the Mozambique Government has introduced a policy which supports community-based irrigation system implementation and management via irrigation associations in a move to support a shift from rain-fed farming practices to irrigation-supported farming practices amongst smallholder farmers. It is this shift in the object of activity that this study focusses on. It does this by studying learning process in the constituted irrigation associations, examining whether such learning is transformative and sustainability oriented or not, and how such learning can be further expanded and supported. Learning may occur in socio-ecological systems, but whether that learning enables transformation and sustainability of irrigation systems and the constituted associations is as yet under-explored in the Mozambique context and in the context of Education for Sustainable Development in southern Africa. The aim of this research was therefore to understand transformative social learning within the development of sustainable irrigation practices in the context of irrigation associations and new agrarian policy development in Mozambique. To examine transformative social learning in sustainable irrigation system practices (including management practices), the study worked with three research goals, which also formed phases of the study’s design: GOAL 1: Examine how and what transformative social learning has (or has not) emerged in existing activity systems to date (Phase 1: Activity System Analysis). GOAL 2: Examine how transformative social learning could emerge through expansive learning processes (Phase 2: Identification of contradictions and new solution modelling through Developmental Work Research and Change Laboratories). GOAL 3: Identify what opportunities exist for ongoing transformative social learning (Phase 3: Identification of absences and ongoing dialectical transformation possibilities). The study draws on theories of Social Learning, Transformative Learning and Cultural Historical Activity Theory’s (CHAT) expansive learning and formative interventionist research framework to develop insights into the learning processes. It works especially with third generation Cultural Historical Activity Theory which provides a theory of expansive social learning and collective transformative agency formation, which I deemed most appropriate for the need to understand the transformation of farmers’ activities in a collective formation such as an irrigation association. The study involved identification and examination of interacting activity systems, contradictions or dissonances in two case studies of community-based irrigation system development via the respective associations. It involved identifying existing learning, as well as engaging in formative intervention research to expand learning in two case study sites: namely the Macubulane and Massaca Irrigation Associations, located near Maputo, Mozambique in the Inkomati and Umbeluzi river basins. The Macubulane community practices a monocropping system of sugar cane plantations using sprinkler irrigation methods and the Massaca community practices a mixed cropping system growing vegetables using mainly gravity or furrow irrigation methods. The study uses a qualitative research approach and is underlaboured by Dialectical Critical Realism which allowed for a deeper probing of ontology and transformative praxis, and transformative learning. The study used methods which included in-depth interviews, change laboratory workshops, document analysis and focus group interviews with farmers and subjects in associated activity systems. Analysis involved activity system analysis, identification of contradictions, modeling of solutions, transformative agency analysis, as well as analysis of real and nominal absences and generative mechanisms as recommended in dialectical critical realism. I used inductive, abductive and retroductive modes of inference, relying on the latter to identify further potential for transformative learning. The study demonstrates that within the associations, transformative social learning is taking place as farmers seek to address problems and contradictions. This learning leads to the creation of new agency and capabilities by ensuring good yields and continuous improvement of management practices and social status. Learning operates through formal mediation in the irrigation system of workplace-based operation, maintenance and crop management practices (i.e. through workplace learning). Social learning occurs through collective engagement with the constraints that the association faces while applying new knowledge, introducing new technology, in the process of administration and planning of irrigation activities. Expansive learning is possible when mediated actively through formative interventions in change laboratory workshops. All three types of learning were found to be present and possible in the context of the two irrigation scheme contexts. The main study findings are that transformative social learning is a collective object-driven process in the context of a transforming object (from rain-fed to sustainable community-based irrigation scheme farming in this study), that can be explained from the level of generative mechanisms and associated real absences that shape nominal absences and contradictions within and between activity systems. These induce, and have potential to induce, transformative learning in irrigation systems, including the emergence of transformative agency via learning through workplace-based, wider social learning, and expansive learning interaction processes amongst subjects in interacting activity systems. Absenting absences is also crucial for extending the potential of transformative learning in irrigation associations. The study further shows how critical realism helps to interpret learning processes and how it strengthens the empirical findings obtained from qualitative analysis. A key outcome of the study is a model that frames conceptualisation of transformative social learning in irrigation systems. The model and the insights gained into farmers learning around the transformation of the object of activity explored in this study have implications for wider curriculum and policy development interventions. The study therefore also makes recommendations for curriculum development and policy implementation intervention. The curriculum development recommendations are not at the level of making recommendations for new courses only, but frame how the design of new courses should take into account the wider processes of learning and change associated with the transformation of an object of activity as articulated in the study. It recommends an approach that allows for in-field engagement with contradictions and the absenting of absences (a problem-based type of curriculum) that will also allow for conceptual development and understanding of the changing object of activity (i.e. community-based irrigation scheme practice and management). The main policy recommendation made from the study is to invest more in farmer support and farmers’ learning so that they can transition from rain-fed agriculture to sustainable irrigation scheme development and management via their associations. The research contributes to knowledge production on irrigation practices; considering that substantial understandings were generated through analysis of communal irrigation scheme practice and management and its implications, especially from a transformative learning perspective. As shown in this study, transformative social learning theories are still not well understood in the context of irrigation system development, and this study has contributed knowledge to this field. The study contributes towards understanding of sustainability learning in irrigation associations in terms of concepts and practices. The study offers a model for transformative social learning in irrigation scheme development and suggests an expanded curriculum for community-based irrigation association practice and management. Overall, the study contributes to an understanding of transformative, sustainability oriented learning processes as support for the emergence of community-based irrigation associations. Additionally, the study has added perspectives on how to frame transformative social learning from a CHAT and critical realist perspective in Education for Sustainable Development. The study also contributes to a growing body of scholarship in southern Africa which seeks to develop expansive, transformative social learning approaches in response to concerns experienced by communities who are reliant on natural resources and the environment for their livelihoods and well-being, and who are also seeking to emerge out of poverty.
- Full Text:
- Date Issued: 2017