Biological activities and mechanisms of action of two ethnobotanically selected South African medicinal plants on some bacteria associated with gastrointestinal infections
- Olajuyigbe, Olufunmiso Olusola https://orcid.org/0000-0002-7889-0416
- Authors: Olajuyigbe, Olufunmiso Olusola https://orcid.org/0000-0002-7889-0416
- Date: 2012-08
- Subjects: Medicinal plants , Herbs -- Therapeutic use , Gastrointestinal system
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25439 , vital:64249
- Description: In this study, 36 plant species representing 24 families were found to be commonly used for the treatment of a variety of gastrointestinal disorders in Eastern Cape, South Africa. The family Fabaceae had the highest number of species. Out of these, 47.06percent were used in the treatment of dysentery alone while 46.15percent were used in the treatment of diarrhoea. Acacia mearnsii De Wild and Ziziphus mucronata subsp. mucronata Willd were selected for this research because they are extensively used in folkloric medicine in South Africa and there was lack of scientific reports that documented their biological activities. The phytochemical screening, antioxidant activities, in vitro antimicrobial activities, cytotoxicity, the synergistic potentials and mechanisms of actions of these plants were investigated. The phytochemical screening and the antioxidant activities of the two species showed that the quantity of the phenolic compounds, flavonoids and proanthocyanidins detected differ significantly in the various extracts. Of the aqueous, acetone, ethanolic and methanolic extracts of A. mearnsii, the ethanolic extract had the highest flavonoids while the acetone extract had the highest phenolic contents. The proanthocyanidins were highest in the methanol extract while aqueous extracts had the least phytochemicals. Aqueous extract showed the least ferric reducing power but methanol extract indicated the highest reducing power. The reducing power of the extracts was lower than those obtained from the reference standard such as butylated hydroxytoluene (BHT), rutin and ascorbic acid. 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) diammonium salt showed that ethanol extract exhibited the highest antioxidant activity at the highest concentration tested. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay indicated that ethanol extract had the highest radical scavenging activity at the lowest concentration and the activities of all the extracts decreased with increase in their concentrations. In Z. mucronata subsp. mucronata, the phenolics were significantly higher than the flavonoids and proanthocyanidin contents in all the extracts investigated. The ethanol extract had the highest antioxidant activity, followed by the acetone extract while the aqueous extract was the least active. Reacting with ABTS, the 50percent inhibitory concentrations (IC50) were (0.0429 ± 0.04 mg/ml) for aqueous, (0.0317 ± 0.04 mg/ml) for acetone and (0.0306 ± 0.04 mg/ml) for ethanol extracts while they inhibited DPPH radical with 50percent inhibitory concentration (IC50) values of 0.0646 ± 0.02 mg/ml (aqueous), 0.0482 ± 0.02 mg/ml (acetone) and 0.0422 ± 0.03 mg/ml (ethanol). The investigation showed that a positive linear correlation existed between the total phenolic content and antioxidant activity of the extracts and that these plants have strong antioxidant property and free radical scavenging capability. The in vitro antibacterial activities of Acacia mearnsii and Z. mucronata subsp. mucronata showed that their minimum inhibitory concentrations ranged between 0.039 mg/ml and 1.25 mg/ml. With the exception of acetone extract of A. mearnsii having MICs greater than 1.0 mg/ml for Enterococcus faecalis ATCC 29212 and Bacillus subtilis KZN, all other isolates had MICs less than 0.7 mg/ml. In all the bacteria treated with Z. mucronata subsp. mucronata extracts, Enterobacter cloacae ATCC 13047 had MIC greater than 1 mg/ml in methanol extract, Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 6538 had MICs greater than 1 mg/ml in acetone extract while all other isolates were highly susceptible to the different extracts of Z. mucronata subsp. mucronata and had MICs less than 0.7 mg/ml. While aqueous extract was as active as the alcoholic extracts in A. mearnsii, that of Z. mucronata had no effect. The ethanol extracts exhibited the highest degree of antibacterial activity in both plants. This study, also, showed that the antifungal activity of A. mearnsii ranging 0.3125 – 5.0 mg/ml was higher than those of the different extracts of Z. mucronata subsp. mucronata ranging 1.25 – 10.0 mg/ml. It is evident from the results of the brine shrimp lethality assay that the crude extracts of A. mearnsii with the LC50 equaled 112.36 µg/ml and having the highest levels of toxicity (100percent) death at 500 μg/ml was non toxic (LC50 > 100 μg/ml) while the LC50 for Z. mucronata subsp. mucronata equaled 90.27 µg/ml indicated a low level of toxicity. The effects of combining the crude extracts of these plants with eight antibiotics were investigated by means of checkerboard and agar diffusion methods. On using the methanol extract of A. mearnsii, the agar diffusion assay showed that extract-kanamycin combination had zones of inhibition ≥ 20 ± 1.0 mm in all the bacteria tested (100percent), followed by extract chloramphenicol (90percent) > extract-ciprofloxacin = extract-tetracycline (70percent) > extract amoxicillin (60percent) > extract-nalidixic acid (50percent) > extract-erythromycin (40percent) > extract metronidazole (20percent). The checkerboard showed synergistic interaction (61.25percent), additivity/indifference (23.75percent) and antagonistic (15percent) effects. I, therefore, concluded that the antibacterial potentials of the antibiotics were improved and combining natural products with antibiotic could be a potential source of resistance-modifying agents useful against multi-drug resistant bacteria. The influences of these extracts on the ultrastructures, elemental components, protein and lipid leakages of five different bacteria were determined as the possible mechanisms of action of the extracts investigated. The scanning electron microscopy indicated varied ultrastructural changes in the morphology of bacterial cells treated with the extracts. The X-ray microanalysis showed significant differences between the elemental contents of extract-treated and untreated bacteria while lipids and proteins were leaked to a great extent from the extract-treated bacterial strains in comparison with the untreated ones. The possible mechanisms of action of the extracts may include inhibition of a significant step in peptidoglycan assembly, inhibition of metabolic processes, disruption of cell wall and cell membranes resulting in the efflux of lipid and protein in all the bacteria tested. The possible mechanism of action involved in the lipid and protein leakages in the bacterial cells could be attributed to lipid peroxidation and protein oxidation owing to the antioxidant activities of the extracts that were active beyond the protective levels. I concluded that the morphological changes and the observed leakages showed rapid killing, significant membrane depolarization resulting in leakages and efflux of disintegrated cellular materials. In general, this study has justified the ethnotherapeutic importance of A. mearnsii and Z. mucronata subsp. mucronata in the treatment of microbial infections by indicating the possible mechanisms of action of the crude extracts on the tested bacteria. , Thesis (PhD) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012-08
- Authors: Olajuyigbe, Olufunmiso Olusola https://orcid.org/0000-0002-7889-0416
- Date: 2012-08
- Subjects: Medicinal plants , Herbs -- Therapeutic use , Gastrointestinal system
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25439 , vital:64249
- Description: In this study, 36 plant species representing 24 families were found to be commonly used for the treatment of a variety of gastrointestinal disorders in Eastern Cape, South Africa. The family Fabaceae had the highest number of species. Out of these, 47.06percent were used in the treatment of dysentery alone while 46.15percent were used in the treatment of diarrhoea. Acacia mearnsii De Wild and Ziziphus mucronata subsp. mucronata Willd were selected for this research because they are extensively used in folkloric medicine in South Africa and there was lack of scientific reports that documented their biological activities. The phytochemical screening, antioxidant activities, in vitro antimicrobial activities, cytotoxicity, the synergistic potentials and mechanisms of actions of these plants were investigated. The phytochemical screening and the antioxidant activities of the two species showed that the quantity of the phenolic compounds, flavonoids and proanthocyanidins detected differ significantly in the various extracts. Of the aqueous, acetone, ethanolic and methanolic extracts of A. mearnsii, the ethanolic extract had the highest flavonoids while the acetone extract had the highest phenolic contents. The proanthocyanidins were highest in the methanol extract while aqueous extracts had the least phytochemicals. Aqueous extract showed the least ferric reducing power but methanol extract indicated the highest reducing power. The reducing power of the extracts was lower than those obtained from the reference standard such as butylated hydroxytoluene (BHT), rutin and ascorbic acid. 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) diammonium salt showed that ethanol extract exhibited the highest antioxidant activity at the highest concentration tested. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay indicated that ethanol extract had the highest radical scavenging activity at the lowest concentration and the activities of all the extracts decreased with increase in their concentrations. In Z. mucronata subsp. mucronata, the phenolics were significantly higher than the flavonoids and proanthocyanidin contents in all the extracts investigated. The ethanol extract had the highest antioxidant activity, followed by the acetone extract while the aqueous extract was the least active. Reacting with ABTS, the 50percent inhibitory concentrations (IC50) were (0.0429 ± 0.04 mg/ml) for aqueous, (0.0317 ± 0.04 mg/ml) for acetone and (0.0306 ± 0.04 mg/ml) for ethanol extracts while they inhibited DPPH radical with 50percent inhibitory concentration (IC50) values of 0.0646 ± 0.02 mg/ml (aqueous), 0.0482 ± 0.02 mg/ml (acetone) and 0.0422 ± 0.03 mg/ml (ethanol). The investigation showed that a positive linear correlation existed between the total phenolic content and antioxidant activity of the extracts and that these plants have strong antioxidant property and free radical scavenging capability. The in vitro antibacterial activities of Acacia mearnsii and Z. mucronata subsp. mucronata showed that their minimum inhibitory concentrations ranged between 0.039 mg/ml and 1.25 mg/ml. With the exception of acetone extract of A. mearnsii having MICs greater than 1.0 mg/ml for Enterococcus faecalis ATCC 29212 and Bacillus subtilis KZN, all other isolates had MICs less than 0.7 mg/ml. In all the bacteria treated with Z. mucronata subsp. mucronata extracts, Enterobacter cloacae ATCC 13047 had MIC greater than 1 mg/ml in methanol extract, Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 6538 had MICs greater than 1 mg/ml in acetone extract while all other isolates were highly susceptible to the different extracts of Z. mucronata subsp. mucronata and had MICs less than 0.7 mg/ml. While aqueous extract was as active as the alcoholic extracts in A. mearnsii, that of Z. mucronata had no effect. The ethanol extracts exhibited the highest degree of antibacterial activity in both plants. This study, also, showed that the antifungal activity of A. mearnsii ranging 0.3125 – 5.0 mg/ml was higher than those of the different extracts of Z. mucronata subsp. mucronata ranging 1.25 – 10.0 mg/ml. It is evident from the results of the brine shrimp lethality assay that the crude extracts of A. mearnsii with the LC50 equaled 112.36 µg/ml and having the highest levels of toxicity (100percent) death at 500 μg/ml was non toxic (LC50 > 100 μg/ml) while the LC50 for Z. mucronata subsp. mucronata equaled 90.27 µg/ml indicated a low level of toxicity. The effects of combining the crude extracts of these plants with eight antibiotics were investigated by means of checkerboard and agar diffusion methods. On using the methanol extract of A. mearnsii, the agar diffusion assay showed that extract-kanamycin combination had zones of inhibition ≥ 20 ± 1.0 mm in all the bacteria tested (100percent), followed by extract chloramphenicol (90percent) > extract-ciprofloxacin = extract-tetracycline (70percent) > extract amoxicillin (60percent) > extract-nalidixic acid (50percent) > extract-erythromycin (40percent) > extract metronidazole (20percent). The checkerboard showed synergistic interaction (61.25percent), additivity/indifference (23.75percent) and antagonistic (15percent) effects. I, therefore, concluded that the antibacterial potentials of the antibiotics were improved and combining natural products with antibiotic could be a potential source of resistance-modifying agents useful against multi-drug resistant bacteria. The influences of these extracts on the ultrastructures, elemental components, protein and lipid leakages of five different bacteria were determined as the possible mechanisms of action of the extracts investigated. The scanning electron microscopy indicated varied ultrastructural changes in the morphology of bacterial cells treated with the extracts. The X-ray microanalysis showed significant differences between the elemental contents of extract-treated and untreated bacteria while lipids and proteins were leaked to a great extent from the extract-treated bacterial strains in comparison with the untreated ones. The possible mechanisms of action of the extracts may include inhibition of a significant step in peptidoglycan assembly, inhibition of metabolic processes, disruption of cell wall and cell membranes resulting in the efflux of lipid and protein in all the bacteria tested. The possible mechanism of action involved in the lipid and protein leakages in the bacterial cells could be attributed to lipid peroxidation and protein oxidation owing to the antioxidant activities of the extracts that were active beyond the protective levels. I concluded that the morphological changes and the observed leakages showed rapid killing, significant membrane depolarization resulting in leakages and efflux of disintegrated cellular materials. In general, this study has justified the ethnotherapeutic importance of A. mearnsii and Z. mucronata subsp. mucronata in the treatment of microbial infections by indicating the possible mechanisms of action of the crude extracts on the tested bacteria. , Thesis (PhD) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012-08
Bioprospecting for amylases, cellulases and xylanases from ericoid associated fungi, their production and characterisation for the bio-economy
- Authors: Adeoyo, Olusegun Richard
- Date: 2018
- Subjects: Mycorrhizal fungi , Hydrolases , Ericaceae South Africa , Ericaceae Molecular aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64327 , vital:28533
- Description: South Africa is one of the most productive areas for ericaceous plants with about 850 identified species in the Cape Floral Region. The Albany Centre of Endemism where all fungi used in this study were isolated from, falls within this region. Ericaceous plants interact with some fungi via an association called the ericoid mycorrhizal (ERM) association. All fungi used in this study were isolated from roots of six ericaceous plants; Erica cerinthoides, Erica demissa, Erica chamissonis, Erica glumiflora, Erica caffra and Erica nemorosa. Fungal enzymes are known to play a significant role in the food, brewing, detergent, pharmaceutical and biofuel industries. The enzyme industry is among the major sectors of the world, and additional novel sources are being explored from time to time. This study focussed on amylases (amyloglucosidase, AMG), cellulases (endoglucanase) and xylanases (endo-1,4-P-xylanase) production from ERM fungal isolates. Out of the fifty-one (51), fungal isolates screened, ChemRU330 (Leohumicola sp.), EdRU083 and EdRU002 were among the fungi that had the highest activities of all the enzymes. They were tested for the ability to produce amylases and cellulases under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28°C in a modified Melin-Norkrans (MMN) liquid medium. Cellulase specific activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and ChemRU330, respectively, was produced at an optimal pH of 5.0. For amylase, ChemRU330 had the highest specific activity of 1.11 U/mg protein while EdRU083 and EdRU02 had a specific activity of 0.80 and 0.92 U/mg protein, respectively, at the same pH with corresponding biomass yield of 113, 125 and 97 mg/50 ml, respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone, while NaFe-EDTA and cobalt inhibited enzyme activity. ChemRU330 was selected to determine the consistency and amount of amylase, cellulase and xylanase formed after several in vitro subculturing events. AMG and endo-1,4-P-xylanase were found to have the most consistent production throughout the study period. The AMG was stable at 45oC (pH 5.0), retaining approximately 65% activity over a period of 24 h. The molecular mass of AMG and endo-1,4-P-xylanase were estimated to be 101 kDa and 72 kDa, respectively. The Km and kcat were 0.38 mg/ml and 70 s-1, respectively, using soluble starch (AMG). For endo-1,4-P-xylanase, the Km and Vmax were 0.93 mg/ml and 8.54 U/ml, respectively, using beechwood xylan (endo-1,4-P-xylanase) as substrate. Additionally, crude extracts of five root endophytes with unique morphological characteristics were screened for antibacterial properties and was followed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). L. incrustata (ChemRU330) and Chaetomium sp. extracts exhibited varying degrees of inhibition against two Gram-positive and Gram-negative bacteria. The crude extract of L. incrustata was the most effective which was found to inhibit Staphylococcus aureus (MIC: 1 mg/ml), Bacillus subtilis (MIC: 2 mg/ml) and Proteus vulgaris (MIC: 16 mg/ml). The L. incrustata displayed potential for antibacterial production and could be considered as an additional source of new antimicrobial agents in drug and food preservation. Also, the three isolates used for enzyme production were identified to genus and species levels, i.e., Leohumicola incrustata (ChemRU330), Leohumicola sp. (EdRU083) and Oidiodendron sp. (EdRU002) using both ITS and Cox1 DNA regions. The molecular analysis results indicated that these ERM mycorrhizal fungi were similar to those successfully described by some researchers in South Africa and Australia. Therefore, this study opens new opportunities for exploring ERM fungal biomolecules for the bio-economy. The promising physicochemical properties, starch and xylan hydrolysis end- products, and being non-pathogenic make AMG and endo-1,4-P-xylanase potential candidates for future applications as additives in the food industry for the production of glucose, glucose syrups, high-fructose corn syrups, and as well as the production of bioethanol. Finally, the findings of this study revealed that it is possible to produce hydrolytic enzymes from ERM fungi in vitro using chemically defined media. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Adeoyo, Olusegun Richard
- Date: 2018
- Subjects: Mycorrhizal fungi , Hydrolases , Ericaceae South Africa , Ericaceae Molecular aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64327 , vital:28533
- Description: South Africa is one of the most productive areas for ericaceous plants with about 850 identified species in the Cape Floral Region. The Albany Centre of Endemism where all fungi used in this study were isolated from, falls within this region. Ericaceous plants interact with some fungi via an association called the ericoid mycorrhizal (ERM) association. All fungi used in this study were isolated from roots of six ericaceous plants; Erica cerinthoides, Erica demissa, Erica chamissonis, Erica glumiflora, Erica caffra and Erica nemorosa. Fungal enzymes are known to play a significant role in the food, brewing, detergent, pharmaceutical and biofuel industries. The enzyme industry is among the major sectors of the world, and additional novel sources are being explored from time to time. This study focussed on amylases (amyloglucosidase, AMG), cellulases (endoglucanase) and xylanases (endo-1,4-P-xylanase) production from ERM fungal isolates. Out of the fifty-one (51), fungal isolates screened, ChemRU330 (Leohumicola sp.), EdRU083 and EdRU002 were among the fungi that had the highest activities of all the enzymes. They were tested for the ability to produce amylases and cellulases under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28°C in a modified Melin-Norkrans (MMN) liquid medium. Cellulase specific activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and ChemRU330, respectively, was produced at an optimal pH of 5.0. For amylase, ChemRU330 had the highest specific activity of 1.11 U/mg protein while EdRU083 and EdRU02 had a specific activity of 0.80 and 0.92 U/mg protein, respectively, at the same pH with corresponding biomass yield of 113, 125 and 97 mg/50 ml, respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone, while NaFe-EDTA and cobalt inhibited enzyme activity. ChemRU330 was selected to determine the consistency and amount of amylase, cellulase and xylanase formed after several in vitro subculturing events. AMG and endo-1,4-P-xylanase were found to have the most consistent production throughout the study period. The AMG was stable at 45oC (pH 5.0), retaining approximately 65% activity over a period of 24 h. The molecular mass of AMG and endo-1,4-P-xylanase were estimated to be 101 kDa and 72 kDa, respectively. The Km and kcat were 0.38 mg/ml and 70 s-1, respectively, using soluble starch (AMG). For endo-1,4-P-xylanase, the Km and Vmax were 0.93 mg/ml and 8.54 U/ml, respectively, using beechwood xylan (endo-1,4-P-xylanase) as substrate. Additionally, crude extracts of five root endophytes with unique morphological characteristics were screened for antibacterial properties and was followed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). L. incrustata (ChemRU330) and Chaetomium sp. extracts exhibited varying degrees of inhibition against two Gram-positive and Gram-negative bacteria. The crude extract of L. incrustata was the most effective which was found to inhibit Staphylococcus aureus (MIC: 1 mg/ml), Bacillus subtilis (MIC: 2 mg/ml) and Proteus vulgaris (MIC: 16 mg/ml). The L. incrustata displayed potential for antibacterial production and could be considered as an additional source of new antimicrobial agents in drug and food preservation. Also, the three isolates used for enzyme production were identified to genus and species levels, i.e., Leohumicola incrustata (ChemRU330), Leohumicola sp. (EdRU083) and Oidiodendron sp. (EdRU002) using both ITS and Cox1 DNA regions. The molecular analysis results indicated that these ERM mycorrhizal fungi were similar to those successfully described by some researchers in South Africa and Australia. Therefore, this study opens new opportunities for exploring ERM fungal biomolecules for the bio-economy. The promising physicochemical properties, starch and xylan hydrolysis end- products, and being non-pathogenic make AMG and endo-1,4-P-xylanase potential candidates for future applications as additives in the food industry for the production of glucose, glucose syrups, high-fructose corn syrups, and as well as the production of bioethanol. Finally, the findings of this study revealed that it is possible to produce hydrolytic enzymes from ERM fungi in vitro using chemically defined media. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
Cape Fold Ecoregion fish community ecology and responses to stressors
- Authors: Broom, Casey Jay
- Date: 2022-10-14
- Subjects: Cyprinidae South Africa Western Cape , Freshwater fishes South Africa Western Cape , Cyprinidae Habitat South Africa Western Cape , Food chains (Ecology) , Restoration ecology South Africa Western Cape , Riparian restoration South Africa Western Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365644 , vital:65772 , DOI https://doi.org/10.21504/10962/365644
- Description: Freshwater fishes are in global decline and fish as a group are the most imperilled of all vertebrates. Freshwater systems are among the most threatened globally, largely owing to their comparatively high species and habitat diversity while occupying a minute fraction of the Earth’s surface. In South Africa, invasion by non-native fishes has had a devastating effect on freshwater systems across the country. Numerous other stressors and anthropogenic impacts continue to impact these systems, including habitat degradation, water abstraction and global change effects. In general, South African freshwater systems are under-studied and there is a lack of baseline biological and ecological studies on many freshwater fish species. The Cape Fold Ecoregion (CFE) of South Africa is a particularly vulnerable region, with many range-restricted species and highly fragmented native fish ranges following high invasion rates. Within the CFE, the Olifants-Doring River System (ODRS) is of primary concern owing to the high endemism and imperilled status of its freshwater fish species. The Rondegat River in the ODRS is of notable conservation value, as it hosts populations of important endemic CFE species. This river is unique, being the site of the first alien fish eradication programme of its kind in South Africa. Thus the Rondegat River, and in particular its imperilled cyprinid assemblage, is used here as a case study of the responses and community dynamics of recovering freshwater fish species. The members of this cyprinid assemblage are Sedercypris calidus, Pseudobarbus phlegethon and Labeobarbus seeberi. Sedercypris calidus and L. seeberi are listed by the International Union for the Conservation of Nature (IUCN) as “Near-Threatened”, while P. phlegethon is listed as “Endangered”. Understanding the dynamics and responses to understudied vulnerable fish communities in the wake of restoration efforts was the overarching goal of this thesis. The first chapter served as a review of current knowledge of the CFE, the Rondegat River, the myriad stressors that have impacted on or are projected to affect this region, and the freshwater fish species on which those stressors act. My first investigations served as an extension of the existing Rondegat River monitoring programme, making use of remote underwater video (RUV) data to assess relative abundance and habitat associations of the focal species (Chapter 2). A relatively limited spatial range of P. phlegethon was established, which was suggested to be a result of relatively highly specialised habitat requirements and sensitivity to disturbance. Sedercypris calidus was confirmed as a relatively more abundant and ubiquitous species across the length of the Rondegat River, sharing much of the lower and middle reaches with L. seeberi. I sought to use experimental trials of functional response, as a proxy for feeding performance, across representative temperatures and relevant prey types, in the spatially overlapping S. calidus and L. seeberi (Chapter 3). Labeobarbus seeberi generally outcompeted S. calidus across temperature treatments and prey types. The ecomorphology and diet of all three species were used to construct trophic profiles, which suggested that there was a high degree of feeding capacity overlap between L. seeberi and S. calidus, while P. phlegethon diverged from the other two species (Chapter 4). Gut content suggested that all three species overlapped broadly in diet. This indicated that the realised trophic niche of these species is similar, despite some morphological specialisation. I then used RUV data to investigate in-situ feeding behaviours, with the aim to disentangle the nuances of community dynamics and mechanisms of coexistence in the cyprinid assemblage (Chapter 5). I found that, despite the higher feeding performance of L. seeberi (Chapter 3) and its overlaps in diet and feeding capacity with S. calidus (Chapter 4), S. calidus is able to mitigate competitive pressures through foraging mode switching and exploitation of allochthonous food inputs. Evidence for further habitat and prey selectivity in Pseudobarbus phlegethon was gathered based on dependence on complex habitats and pool refugia for the majority of its feeding, supporting this species as a headwater specialist; alongside signals of its spatial and habitat use patterns (Chapter 2). While S. calidus and L. seeberi were found to be less habitat-specific than P. phlegethon, caution was noted in the potential for ongoing stressors, such as habitat destruction, loss of river connectivity and global change effects, to impact on the reproductive success of these two species. Stressors affecting the habitats and sensitive invertebrate taxa upon which all three species depend continue to threaten the Rondegat system, highlighting the need to maintain ecosystem integrity through conservation interventions. There remains significant scope to maintain restoration efforts in the Rondegat River and other river systems of the CFE, through direct conservation actions, enhanced community awareness, indigenous riparian vegetation restoration and involvement of local stakeholders in various conservation-centred activities. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Broom, Casey Jay
- Date: 2022-10-14
- Subjects: Cyprinidae South Africa Western Cape , Freshwater fishes South Africa Western Cape , Cyprinidae Habitat South Africa Western Cape , Food chains (Ecology) , Restoration ecology South Africa Western Cape , Riparian restoration South Africa Western Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365644 , vital:65772 , DOI https://doi.org/10.21504/10962/365644
- Description: Freshwater fishes are in global decline and fish as a group are the most imperilled of all vertebrates. Freshwater systems are among the most threatened globally, largely owing to their comparatively high species and habitat diversity while occupying a minute fraction of the Earth’s surface. In South Africa, invasion by non-native fishes has had a devastating effect on freshwater systems across the country. Numerous other stressors and anthropogenic impacts continue to impact these systems, including habitat degradation, water abstraction and global change effects. In general, South African freshwater systems are under-studied and there is a lack of baseline biological and ecological studies on many freshwater fish species. The Cape Fold Ecoregion (CFE) of South Africa is a particularly vulnerable region, with many range-restricted species and highly fragmented native fish ranges following high invasion rates. Within the CFE, the Olifants-Doring River System (ODRS) is of primary concern owing to the high endemism and imperilled status of its freshwater fish species. The Rondegat River in the ODRS is of notable conservation value, as it hosts populations of important endemic CFE species. This river is unique, being the site of the first alien fish eradication programme of its kind in South Africa. Thus the Rondegat River, and in particular its imperilled cyprinid assemblage, is used here as a case study of the responses and community dynamics of recovering freshwater fish species. The members of this cyprinid assemblage are Sedercypris calidus, Pseudobarbus phlegethon and Labeobarbus seeberi. Sedercypris calidus and L. seeberi are listed by the International Union for the Conservation of Nature (IUCN) as “Near-Threatened”, while P. phlegethon is listed as “Endangered”. Understanding the dynamics and responses to understudied vulnerable fish communities in the wake of restoration efforts was the overarching goal of this thesis. The first chapter served as a review of current knowledge of the CFE, the Rondegat River, the myriad stressors that have impacted on or are projected to affect this region, and the freshwater fish species on which those stressors act. My first investigations served as an extension of the existing Rondegat River monitoring programme, making use of remote underwater video (RUV) data to assess relative abundance and habitat associations of the focal species (Chapter 2). A relatively limited spatial range of P. phlegethon was established, which was suggested to be a result of relatively highly specialised habitat requirements and sensitivity to disturbance. Sedercypris calidus was confirmed as a relatively more abundant and ubiquitous species across the length of the Rondegat River, sharing much of the lower and middle reaches with L. seeberi. I sought to use experimental trials of functional response, as a proxy for feeding performance, across representative temperatures and relevant prey types, in the spatially overlapping S. calidus and L. seeberi (Chapter 3). Labeobarbus seeberi generally outcompeted S. calidus across temperature treatments and prey types. The ecomorphology and diet of all three species were used to construct trophic profiles, which suggested that there was a high degree of feeding capacity overlap between L. seeberi and S. calidus, while P. phlegethon diverged from the other two species (Chapter 4). Gut content suggested that all three species overlapped broadly in diet. This indicated that the realised trophic niche of these species is similar, despite some morphological specialisation. I then used RUV data to investigate in-situ feeding behaviours, with the aim to disentangle the nuances of community dynamics and mechanisms of coexistence in the cyprinid assemblage (Chapter 5). I found that, despite the higher feeding performance of L. seeberi (Chapter 3) and its overlaps in diet and feeding capacity with S. calidus (Chapter 4), S. calidus is able to mitigate competitive pressures through foraging mode switching and exploitation of allochthonous food inputs. Evidence for further habitat and prey selectivity in Pseudobarbus phlegethon was gathered based on dependence on complex habitats and pool refugia for the majority of its feeding, supporting this species as a headwater specialist; alongside signals of its spatial and habitat use patterns (Chapter 2). While S. calidus and L. seeberi were found to be less habitat-specific than P. phlegethon, caution was noted in the potential for ongoing stressors, such as habitat destruction, loss of river connectivity and global change effects, to impact on the reproductive success of these two species. Stressors affecting the habitats and sensitive invertebrate taxa upon which all three species depend continue to threaten the Rondegat system, highlighting the need to maintain ecosystem integrity through conservation interventions. There remains significant scope to maintain restoration efforts in the Rondegat River and other river systems of the CFE, through direct conservation actions, enhanced community awareness, indigenous riparian vegetation restoration and involvement of local stakeholders in various conservation-centred activities. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Cape Vultures (Gyps coprotheres) and the threat of wind farms: a race to extinction?
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Catchment and River Management in Graduate Teacher Education: A Case Study of Student Teacher Learning and Teaching in the Upper uThukela Valley, KwaZulu-Natal
- Authors: Heath, Gavin Edward Craig
- Date: 2021-10-29
- Subjects: Geography Study and teaching (Higher) South Africa KwaZulu-Natal , Watershed management Study and teaching (Higher) South Africa KwaZulu-Natal , Pedagogical content knowledge , Environmental education South Africa KwaZulu-Natal , Teacher effectiveness South Africa KwaZulu-Natal , Curriculum and Assessment Policy Statement (CAPS)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190635 , vital:45012 , 10.21504/10962/190635
- Description: This study developed as a progressive focus on a design research process towards the inclusion of new environmental knowledge in teacher education. It is centred on the clarification of pedagogical content knowledge for the teaching of catchment and river management in Geography teacher education. The study was developed as a design research case study with three phases or iterations of experiential engagement and data collection during the teaching of Postgraduate Certificate in Education students at the University of KwaZulu-Natal where I lecture Geography Education. The study’s iterative design was developed around pedagogical content knowledge refinement with curriculum knowledge analysis (phase 1) that was followed by lecture delivery and analysis (phase 2) and analysis of student engagement during fieldwork, and on teaching practice in rural classroom contexts (phase 3). Data and insights were generated across the successive stages of knowledge differentiation and teaching and learning interactions over time, and included reflection with students involved in the lectures, fieldwork and teaching practice programme. The analytical work covered a review of trajectories in new environmental knowledge, social-ecological systems, sustainability competencies, practice architecture and fieldwork pedagogy. This was done using three research lenses, namely social-ecological systems, social learning and practice architectures. All the design research and review processes served to develop, clarify and refine pedagogical content knowledge for sustainability-oriented teacher education. Thus the study conformed to the tenets of design-based research that was centred on clarification and review of pedagogical content knowledge that was carried into phases two and three. Research was focused at the nexus of pedagogical content knowledge and sustainability concerns that is necessary for the teaching of catchment and river basin management within a social-ecological systems perspective for integrated water resources management in South Africa and globally. The findings informed an illustrative model on how the research was carried out. Six design research insights and principles conclude the study and encapsulate the contribution it makes to new knowledge on how teacher education practice can be progressively aligned with new content knowledge teaching and the teaching of sustainability concerns. Specific findings in the form of six research insights indicated that the fieldworkbased teaching practice experience proved a successful learning crucible to develop sustainability competences. The cohort of student teachers passed their fieldwork teaching practice despite inadequate covering of foundational concepts in school and university. The teaching of a catchment management strategy case study was valuable in all three phases of research. A multi-contextual teaching and learning environment was successfully negotiated and navigated by the student teachers. The present Curriculum and Assessment Policy Statement does not speak to the reality on the ground, particularly in deep rural environments. A compulsory virtual Geography teacher training experience is recommended. Lastly, varied and broad responses to the noted multi-contextual challenges are needed in order to prepare and equip student teachers for the demands of the new environmental knowledge in the curriculum. Based on the groundwork provided by this study, there is scope for further research especially regarding the varied and broad responses to this new environmental knowledge in the curriculum. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Heath, Gavin Edward Craig
- Date: 2021-10-29
- Subjects: Geography Study and teaching (Higher) South Africa KwaZulu-Natal , Watershed management Study and teaching (Higher) South Africa KwaZulu-Natal , Pedagogical content knowledge , Environmental education South Africa KwaZulu-Natal , Teacher effectiveness South Africa KwaZulu-Natal , Curriculum and Assessment Policy Statement (CAPS)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190635 , vital:45012 , 10.21504/10962/190635
- Description: This study developed as a progressive focus on a design research process towards the inclusion of new environmental knowledge in teacher education. It is centred on the clarification of pedagogical content knowledge for the teaching of catchment and river management in Geography teacher education. The study was developed as a design research case study with three phases or iterations of experiential engagement and data collection during the teaching of Postgraduate Certificate in Education students at the University of KwaZulu-Natal where I lecture Geography Education. The study’s iterative design was developed around pedagogical content knowledge refinement with curriculum knowledge analysis (phase 1) that was followed by lecture delivery and analysis (phase 2) and analysis of student engagement during fieldwork, and on teaching practice in rural classroom contexts (phase 3). Data and insights were generated across the successive stages of knowledge differentiation and teaching and learning interactions over time, and included reflection with students involved in the lectures, fieldwork and teaching practice programme. The analytical work covered a review of trajectories in new environmental knowledge, social-ecological systems, sustainability competencies, practice architecture and fieldwork pedagogy. This was done using three research lenses, namely social-ecological systems, social learning and practice architectures. All the design research and review processes served to develop, clarify and refine pedagogical content knowledge for sustainability-oriented teacher education. Thus the study conformed to the tenets of design-based research that was centred on clarification and review of pedagogical content knowledge that was carried into phases two and three. Research was focused at the nexus of pedagogical content knowledge and sustainability concerns that is necessary for the teaching of catchment and river basin management within a social-ecological systems perspective for integrated water resources management in South Africa and globally. The findings informed an illustrative model on how the research was carried out. Six design research insights and principles conclude the study and encapsulate the contribution it makes to new knowledge on how teacher education practice can be progressively aligned with new content knowledge teaching and the teaching of sustainability concerns. Specific findings in the form of six research insights indicated that the fieldworkbased teaching practice experience proved a successful learning crucible to develop sustainability competences. The cohort of student teachers passed their fieldwork teaching practice despite inadequate covering of foundational concepts in school and university. The teaching of a catchment management strategy case study was valuable in all three phases of research. A multi-contextual teaching and learning environment was successfully negotiated and navigated by the student teachers. The present Curriculum and Assessment Policy Statement does not speak to the reality on the ground, particularly in deep rural environments. A compulsory virtual Geography teacher training experience is recommended. Lastly, varied and broad responses to the noted multi-contextual challenges are needed in order to prepare and equip student teachers for the demands of the new environmental knowledge in the curriculum. Based on the groundwork provided by this study, there is scope for further research especially regarding the varied and broad responses to this new environmental knowledge in the curriculum. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Characterisation of communal rangeland degradation and evaluation of vegetation restoration techniques in the Eastern Cape, South Africa
- Authors: Lesoli, 'Mota Samuel
- Date: 2011-12
- Subjects: Communal rangelands , Grazing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24316 , vital:62624
- Description: This study assessed the social factors influencing poor communal rangeland management, which are assumed to result in rangeland degradation. This was followed by, examination of biophysical characteristics of rangeland degradation in communal areas. To relate social factors featuring in communal rangeland management with rangeland degradation, biophysical factors influencing livestock grazing distribution patterns were studied. To establish the solution to communal rangeland degradation, rangeland restoration techniques were evaluated. The study was conducted at Amakhuze Tribal Authority (ATA) (S32o 38´, E26o56, 763 - 1500 m.a.s.l) composed of six villages and Phandulwazi Agricultural High School (S32o 39´ and E26o 55´, 747 m.a.s.l). Focus group discussions were conducted in six villages and questionnaire surveys in four randomly selected villages to assess social factors influencing communal rangeland degradation. Communal rangeland degradation biophysical characteristics were assessed. Biophysical factors affecting livestock grazing distribution pattern were examined through direct field observations for 12 months. Restoration techniques were evaluated on 26 plots. The social factors influencing communal rangeland management include lack of skills on rangeland management for farmers, lack of individual/community obligation on grazing management, lack of effective policies and/or poor enforcement accompanied by lack of effective institutions governing rangeland utilisation and management. Communal rangelands were more (χ 2 = 2612.07, df = 26, p < 0.01) degraded compared with controlled grazing areas. Within the communal rangelands, land degradation was higher at the low-lying areas, compared to foothills, midslopes, and mountaintop (crest). Rangeland degradation in communal areas was characterised by poor forage productivity and poor vegetation cover , higher soil unconfined compressive strength (UCS) (4.5 kg/cm2) with low hydraulic conductivity (5.21 x 10-3) and physical soil loss characteristics such presence of terracettes, pedestals, rills and gullies. Grazing distribution was higher at valley bottom (r2 = 0.404, p < 0.001), low altitude (r2 = -0.007, p < 0.001), closer to water points (r2 = -0.001, p < 0.001), and on grassland vegetation (r2 = 0.620, p < 0.001). Introduction of seedlings with microcatchment combined with brushpack promoted (p < 0.05) higher number of tillers (13), leaves (42) and reduced seedling mortality (10.4percent). T. triandra produced higher (p < 0.05) number of tillers (12) and leaves (39) but low number of inflorescence (0.7) with higher mortality rates (25.3percent) compared to P. dilatatum. Where plant propagules were introduced as seeds, use of microcatchment promoted higher seed germination (F = 38.84, p < 0.05) and maintained higher plant density (F = 37.43, p < 0.05). E. curvula seeds attained higher germination rate and maintained higher plant density compared to D. eriantha and P. Maximum. Use of microcatchment, brushpack, and water spreading system promoted soil water retention. It is important that any interventions aimed at improving communal rangeland management, controlling rangeland degradation in the communal areas, or restoring degraded rangelands to consider the social factors driving rangeland management and biophysical factors influencing grazing distribution pattern. Rangeland restoration techniques for communal areas should be centred on their ability to collect and retain water to promote restoration performance of introduced plant propagules. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-12
- Authors: Lesoli, 'Mota Samuel
- Date: 2011-12
- Subjects: Communal rangelands , Grazing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24316 , vital:62624
- Description: This study assessed the social factors influencing poor communal rangeland management, which are assumed to result in rangeland degradation. This was followed by, examination of biophysical characteristics of rangeland degradation in communal areas. To relate social factors featuring in communal rangeland management with rangeland degradation, biophysical factors influencing livestock grazing distribution patterns were studied. To establish the solution to communal rangeland degradation, rangeland restoration techniques were evaluated. The study was conducted at Amakhuze Tribal Authority (ATA) (S32o 38´, E26o56, 763 - 1500 m.a.s.l) composed of six villages and Phandulwazi Agricultural High School (S32o 39´ and E26o 55´, 747 m.a.s.l). Focus group discussions were conducted in six villages and questionnaire surveys in four randomly selected villages to assess social factors influencing communal rangeland degradation. Communal rangeland degradation biophysical characteristics were assessed. Biophysical factors affecting livestock grazing distribution pattern were examined through direct field observations for 12 months. Restoration techniques were evaluated on 26 plots. The social factors influencing communal rangeland management include lack of skills on rangeland management for farmers, lack of individual/community obligation on grazing management, lack of effective policies and/or poor enforcement accompanied by lack of effective institutions governing rangeland utilisation and management. Communal rangelands were more (χ 2 = 2612.07, df = 26, p < 0.01) degraded compared with controlled grazing areas. Within the communal rangelands, land degradation was higher at the low-lying areas, compared to foothills, midslopes, and mountaintop (crest). Rangeland degradation in communal areas was characterised by poor forage productivity and poor vegetation cover , higher soil unconfined compressive strength (UCS) (4.5 kg/cm2) with low hydraulic conductivity (5.21 x 10-3) and physical soil loss characteristics such presence of terracettes, pedestals, rills and gullies. Grazing distribution was higher at valley bottom (r2 = 0.404, p < 0.001), low altitude (r2 = -0.007, p < 0.001), closer to water points (r2 = -0.001, p < 0.001), and on grassland vegetation (r2 = 0.620, p < 0.001). Introduction of seedlings with microcatchment combined with brushpack promoted (p < 0.05) higher number of tillers (13), leaves (42) and reduced seedling mortality (10.4percent). T. triandra produced higher (p < 0.05) number of tillers (12) and leaves (39) but low number of inflorescence (0.7) with higher mortality rates (25.3percent) compared to P. dilatatum. Where plant propagules were introduced as seeds, use of microcatchment promoted higher seed germination (F = 38.84, p < 0.05) and maintained higher plant density (F = 37.43, p < 0.05). E. curvula seeds attained higher germination rate and maintained higher plant density compared to D. eriantha and P. Maximum. Use of microcatchment, brushpack, and water spreading system promoted soil water retention. It is important that any interventions aimed at improving communal rangeland management, controlling rangeland degradation in the communal areas, or restoring degraded rangelands to consider the social factors driving rangeland management and biophysical factors influencing grazing distribution pattern. Rangeland restoration techniques for communal areas should be centred on their ability to collect and retain water to promote restoration performance of introduced plant propagules. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-12
Characterisation of two novel ferrocenyl benzoxazines as in vitro triple-negative breast cancer inhibitors
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Characterization of bioflocculants produced by consortia of three marine bacteria belonging to the genera bacillus and cobetia previously isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa
- Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Authors: Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Date: 2013
- Subjects: Water -- Purification -- Flocculation , Water quality management , Flocculation
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24454 , vital:62804
- Description: The bioflocculant-producing potentials of three marine bacteria isolated from the sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99 percent, 99 percent, and 98 percent similarity to Cobetia sp. L222, Bacillus sp. A-5A, and Bacillus sp. HXG-C1 respectively and the sequence was deposited in GenBank as Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert (accession number JF799092, JF799093, and HQ537128 respectively). Cultivation condition studies for Cobetia sp. OAUIFE revealed that bioflocculant production was optimal with an inoculum size of 2 percent (v/v), initial pH of 6.0, Mn2+ as the metal ion, and glucose as the carbon source. Metal ions, including Na+, K+, Li+, Ca2+and Mg2+ stimulated bioflocculant production resulting in flocculating activity of above 90 percent. This crude bioflocculant is thermally stable, with about 78 percent of its flocculating activity remaining after heating at 100 oC for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide. FTIR analysis revealed the presence of methoxyl, hydroxyl, and carboxyl - groups in the compound bioflocculant and SEM micrograph of the bioflocculant revealed a crystal-linear structure. On the other hand, bioflocculant production by Bacillus sp. MAYA was optimal when glucose (95.6 percent flocculating activity) and ammonium nitrate (83.3 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 2 percent (v/v); initial pH 6; and Ca2+ as coagulant aid. Chemical analysis of the purified bioflocculant shows that it is composed of uronic acid, neutral sugar and protein. FTIR analysis also revealed the presence of methoxyl, hydroxyl, carboxyl and amino- groups in this bioflocculant. The bioflocculant is thermostable with about 65.6 percent residual flocculating activity retained after heating the bioflocculant at 100 oC for 25 min. However bioflocculant production by Bacillus sp. Gilbert was optimal when sodium carbonate (95.2 percent flocculating activity) and potassium nitrate (76.6 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 3 percent (v/v); initial pH 9; and Al3+ as cation. The crude bioflocculant retained 44.2 percent residual flocculating activity after heating at 100 oC for 15 min. FTIR analysis reveals the presence of hydroxyl, carboxyl and methylene - groups in the compound bioflocculant. SEM micrograph of the bioflocculant revealed an amorphous compound. The consortia of these bacteria strains also produced bioflocculants with high flocculating activities which were highly efficient in removing turbidity and chemical oxygen demand (COD) from brewery wastewater, diary wastewater and river water. The bioflocculants from the consortia seemed better than traditional flocculants such as alum . The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE and Bacillus sp. MAYA showed that this extracellular bioflocculant, composed of 66percent uronic acid and 31percent protein and an optimum flocculation (90 percent) of kaolin suspension, when the dosage concentration was 0.8 mg/ml, under weak alkaline pH of 8, and Ca2+ as a coagulant aid. The bioflocculant is thermally stable, with a high residual flocculating activity of 86.7 percent, 89.3 percent and 87.0 percent after heating at 50 oC, 80 oC and 100 oC for 25 min respectively. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl functional groups. Scanning electron microscopy (SEM) image revealed a crystal-linear spongy-like bioflocculant structure and EDX analysis of the purified bioflocculant showed that the elemental composition in mass proportion of C,N,O,S and P was 6.67:6.23:37.55:0.38:4.42 (percent w/w). However, the characteristics of the bioflocculant produced by the consortium of Cobetia sp OAUIFE and Bacillus sp. Gilbert showed an optimum flocculation (90 percent) of kaolin suspension when the dosage concentration was 0.2 mg/ml, under neutral pH of 7, and Ca2+ as a coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl and carbonyl functional groups. Scanning electron microscopy (SEM) image revealed an amorphous morphology. On the other hand the bioflocculant produced by the consortium of Bacillus sp. MAYA and Bacillus sp. Gilbert showed similar characteristic with the bioflocculant from the consortium of Cobetia sp. OAUIFE and Bacillus sp. Gilbert except for Al3+ being the preferred coagulant aid. The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert showed an optimum flocculation (87 percent) of kaolin suspension when the dosage concentration was 1.0 mg/ml. Under strong alkaline pH of 12, flocculating activity reached (95 percent) when Al3+ was the coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl and phosphoryl functional groups. Scanning electron microscopy (SEM) image revealed a flaky amorphous morphological structure. Due to the excellent COD and turbidity removal efficiencies of the bioflocculants produced by the consortia, these make those attractive candidates for use in water and wastewater treatment. , Thesis (PhD) -- Faculty of Science and Agriculture, 2013
- Full Text:
- Date Issued: 2013
- Authors: Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Date: 2013
- Subjects: Water -- Purification -- Flocculation , Water quality management , Flocculation
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24454 , vital:62804
- Description: The bioflocculant-producing potentials of three marine bacteria isolated from the sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99 percent, 99 percent, and 98 percent similarity to Cobetia sp. L222, Bacillus sp. A-5A, and Bacillus sp. HXG-C1 respectively and the sequence was deposited in GenBank as Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert (accession number JF799092, JF799093, and HQ537128 respectively). Cultivation condition studies for Cobetia sp. OAUIFE revealed that bioflocculant production was optimal with an inoculum size of 2 percent (v/v), initial pH of 6.0, Mn2+ as the metal ion, and glucose as the carbon source. Metal ions, including Na+, K+, Li+, Ca2+and Mg2+ stimulated bioflocculant production resulting in flocculating activity of above 90 percent. This crude bioflocculant is thermally stable, with about 78 percent of its flocculating activity remaining after heating at 100 oC for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide. FTIR analysis revealed the presence of methoxyl, hydroxyl, and carboxyl - groups in the compound bioflocculant and SEM micrograph of the bioflocculant revealed a crystal-linear structure. On the other hand, bioflocculant production by Bacillus sp. MAYA was optimal when glucose (95.6 percent flocculating activity) and ammonium nitrate (83.3 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 2 percent (v/v); initial pH 6; and Ca2+ as coagulant aid. Chemical analysis of the purified bioflocculant shows that it is composed of uronic acid, neutral sugar and protein. FTIR analysis also revealed the presence of methoxyl, hydroxyl, carboxyl and amino- groups in this bioflocculant. The bioflocculant is thermostable with about 65.6 percent residual flocculating activity retained after heating the bioflocculant at 100 oC for 25 min. However bioflocculant production by Bacillus sp. Gilbert was optimal when sodium carbonate (95.2 percent flocculating activity) and potassium nitrate (76.6 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 3 percent (v/v); initial pH 9; and Al3+ as cation. The crude bioflocculant retained 44.2 percent residual flocculating activity after heating at 100 oC for 15 min. FTIR analysis reveals the presence of hydroxyl, carboxyl and methylene - groups in the compound bioflocculant. SEM micrograph of the bioflocculant revealed an amorphous compound. The consortia of these bacteria strains also produced bioflocculants with high flocculating activities which were highly efficient in removing turbidity and chemical oxygen demand (COD) from brewery wastewater, diary wastewater and river water. The bioflocculants from the consortia seemed better than traditional flocculants such as alum . The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE and Bacillus sp. MAYA showed that this extracellular bioflocculant, composed of 66percent uronic acid and 31percent protein and an optimum flocculation (90 percent) of kaolin suspension, when the dosage concentration was 0.8 mg/ml, under weak alkaline pH of 8, and Ca2+ as a coagulant aid. The bioflocculant is thermally stable, with a high residual flocculating activity of 86.7 percent, 89.3 percent and 87.0 percent after heating at 50 oC, 80 oC and 100 oC for 25 min respectively. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl functional groups. Scanning electron microscopy (SEM) image revealed a crystal-linear spongy-like bioflocculant structure and EDX analysis of the purified bioflocculant showed that the elemental composition in mass proportion of C,N,O,S and P was 6.67:6.23:37.55:0.38:4.42 (percent w/w). However, the characteristics of the bioflocculant produced by the consortium of Cobetia sp OAUIFE and Bacillus sp. Gilbert showed an optimum flocculation (90 percent) of kaolin suspension when the dosage concentration was 0.2 mg/ml, under neutral pH of 7, and Ca2+ as a coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl and carbonyl functional groups. Scanning electron microscopy (SEM) image revealed an amorphous morphology. On the other hand the bioflocculant produced by the consortium of Bacillus sp. MAYA and Bacillus sp. Gilbert showed similar characteristic with the bioflocculant from the consortium of Cobetia sp. OAUIFE and Bacillus sp. Gilbert except for Al3+ being the preferred coagulant aid. The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert showed an optimum flocculation (87 percent) of kaolin suspension when the dosage concentration was 1.0 mg/ml. Under strong alkaline pH of 12, flocculating activity reached (95 percent) when Al3+ was the coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl and phosphoryl functional groups. Scanning electron microscopy (SEM) image revealed a flaky amorphous morphological structure. Due to the excellent COD and turbidity removal efficiencies of the bioflocculants produced by the consortia, these make those attractive candidates for use in water and wastewater treatment. , Thesis (PhD) -- Faculty of Science and Agriculture, 2013
- Full Text:
- Date Issued: 2013
Characterization of termite Trinervitermes trinervoides metagenome-derived glycoside hydrolases, the formulation of synergistic core enzyme sets for effective sweet sorghum and corncob saccharification, and their potential industrial applications
- Authors: Mafa, Mpho Stephen
- Date: 2019
- Subjects: Termites , Metagenomics , Glucosides , Hydrolases , Enzymes , Feedstock
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/72414 , vital:30044 , DOI https://doi.org/10.21504/10962/72414
- Description: The current study investigated the biochemical properties of endo-glucanase (GH5E), exo-glucanase (GH5D), xylanase (GH5H) and endo-glucanase/xylanase (GH45), derived from the hindgut bacterial symbionts of a termite (Trinervitermes trinervoides) for their potential role in the biotechnology industry. All these enzymes, except GH5D, exhibited activities on cellulosic and xylan-rich polymeric substrates, which only displayed activity on p-nitrophenyl cellobioside. GH5D, GH5E, GH5H and GH45 enzymes retained more than 80% of their activities at pH 5.5 and also retained more than 80% of their activities at 40ºC. Furthermore, these enzymes were thermostable at 37ºC for 72 hours. GH5E, GH5H and GH45 were generally stable over a range of metal-ion. The kinetic parameters for GH5E were 5.68 mg/ml (KM) and 34.36 U/mg protein (Vmax). GH5D activity did not follow classical Michaelis-Menten kinetics, suggesting product inhibition. GH5H displayed KM values of 5.53, 95.03 and 2.10 mg/ml and Vmax values of 112.36, 144.45 and 180.32 U/mg protein on beechwood xylan, CMC, and xyloglucan, respectively. GH45 displayed a KM of 6.94 mg/ml and a Vmax of 12.30 U/mg protein on CMC. GH5D [cellobiohydrolase (CBH)] and a commercial CBHII (GH6) enzyme outperformed a commercial CBHI (GH7) enzyme when these enzymes hydrolysed β-glucan. GH5D and CBHII also displayed a higher degree of synergy on β-glucan but failed to show synergy on Avicel. We therefore concluded that GH5D and CBHII are β-glucan-specific cellobiohydrolases. The corncob (CC) and sweet sorghum bagasse (SSB) substrates were pretreated with lime, NaOH and NaClO2. Subsequent to pretreatment, these substrates were used to investigate if GH5D, GH5E, GH5H and GH45 could operate in synergy. Results revealed that out of 12 possible core enzyme sets constructed, only two (referred to as CES-E and CES-H) displayed higher activities on pretreated CC or SSB. Simultaneous synergy was generally the most effective mode of synergy during hydrolysis of alkaline pretreated SSB and CC samples by both CES-E and CES-H. Both core enzyme sets did not display synergy on oxidative pretreated substrates. These findings suggest that lime and NaOH are more effective pretreatments for CC and SSB substrates. We used PRotein Interactive MOdeling (PRIMO) software to demonstrate that GH5D protein structure is an (α/β)8 barrel with a tunnel-like active site. Enzymes with this type of protein structure are able to perform transglycosylation, a process in which GH5D produced methyl, ethyl and propyl cellobiosides. We concluded that the GH5D, GH5E, GH5H and GH45 enzymes possess novel biochemical properties and that they form synergy during the hydrolysis of complex substrates (SSB and CC). GH5D transglycosylation could be used to produce novel biodegradable chemicals with special properties (e.g. anti-microbial properties). In conclusion, our findings suggest that GH5D, GH5E, GH5H and GH45 can potentially be used to improve biorefinery processes. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2019
- Full Text:
- Date Issued: 2019
- Authors: Mafa, Mpho Stephen
- Date: 2019
- Subjects: Termites , Metagenomics , Glucosides , Hydrolases , Enzymes , Feedstock
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/72414 , vital:30044 , DOI https://doi.org/10.21504/10962/72414
- Description: The current study investigated the biochemical properties of endo-glucanase (GH5E), exo-glucanase (GH5D), xylanase (GH5H) and endo-glucanase/xylanase (GH45), derived from the hindgut bacterial symbionts of a termite (Trinervitermes trinervoides) for their potential role in the biotechnology industry. All these enzymes, except GH5D, exhibited activities on cellulosic and xylan-rich polymeric substrates, which only displayed activity on p-nitrophenyl cellobioside. GH5D, GH5E, GH5H and GH45 enzymes retained more than 80% of their activities at pH 5.5 and also retained more than 80% of their activities at 40ºC. Furthermore, these enzymes were thermostable at 37ºC for 72 hours. GH5E, GH5H and GH45 were generally stable over a range of metal-ion. The kinetic parameters for GH5E were 5.68 mg/ml (KM) and 34.36 U/mg protein (Vmax). GH5D activity did not follow classical Michaelis-Menten kinetics, suggesting product inhibition. GH5H displayed KM values of 5.53, 95.03 and 2.10 mg/ml and Vmax values of 112.36, 144.45 and 180.32 U/mg protein on beechwood xylan, CMC, and xyloglucan, respectively. GH45 displayed a KM of 6.94 mg/ml and a Vmax of 12.30 U/mg protein on CMC. GH5D [cellobiohydrolase (CBH)] and a commercial CBHII (GH6) enzyme outperformed a commercial CBHI (GH7) enzyme when these enzymes hydrolysed β-glucan. GH5D and CBHII also displayed a higher degree of synergy on β-glucan but failed to show synergy on Avicel. We therefore concluded that GH5D and CBHII are β-glucan-specific cellobiohydrolases. The corncob (CC) and sweet sorghum bagasse (SSB) substrates were pretreated with lime, NaOH and NaClO2. Subsequent to pretreatment, these substrates were used to investigate if GH5D, GH5E, GH5H and GH45 could operate in synergy. Results revealed that out of 12 possible core enzyme sets constructed, only two (referred to as CES-E and CES-H) displayed higher activities on pretreated CC or SSB. Simultaneous synergy was generally the most effective mode of synergy during hydrolysis of alkaline pretreated SSB and CC samples by both CES-E and CES-H. Both core enzyme sets did not display synergy on oxidative pretreated substrates. These findings suggest that lime and NaOH are more effective pretreatments for CC and SSB substrates. We used PRotein Interactive MOdeling (PRIMO) software to demonstrate that GH5D protein structure is an (α/β)8 barrel with a tunnel-like active site. Enzymes with this type of protein structure are able to perform transglycosylation, a process in which GH5D produced methyl, ethyl and propyl cellobiosides. We concluded that the GH5D, GH5E, GH5H and GH45 enzymes possess novel biochemical properties and that they form synergy during the hydrolysis of complex substrates (SSB and CC). GH5D transglycosylation could be used to produce novel biodegradable chemicals with special properties (e.g. anti-microbial properties). In conclusion, our findings suggest that GH5D, GH5E, GH5H and GH45 can potentially be used to improve biorefinery processes. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2019
- Full Text:
- Date Issued: 2019
Characterization of Trypanosoma brucei Sti1 and its interactions with Trypanosoma brucei Hsp83 and human Hsp90
- Authors: Jamabo, Miebaka
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422629 , vital:71963 , DOI 10.21504/10962/422629
- Description: Neglected tropical diseases continue to pose global concern due to their impact on health and socio-economic status of developing countries in sub-Saharan Africa. African trypanosomiasis is one of the neglected tropical diseases caused by the kinetoplastid flagellate parasite Trypanosoma brucei (T. brucei). The disease is fatal if untreated and the toolbox to combat the disease has been plagued with many difficulties such as drug resistance, toxic chemotherapeutics, and cumbersome drug delivery processes. In recent years, the disease has received attention from organizations such as the Drugs for Neglected Diseases initiative (DNDi) in partnership with WHO as well as academia and industry to provide alternatives to the existing drugs as part of a targeted approach to eliminate human African trypanosomiasis by 2030. The life cycle of the T. brucei parasite requires that it transitions between a cold-blooded vector (the tsetse fly) and a human host. To survive this extreme environmental change and maintain its infectious cycle, the parasite has evolved an arsenal of tools which include a strong immune evasion technique and a robust molecular chaperone system. Heat shock protein 90 (Hsp90) is one of the most abundant eukaryotic molecular chaperones that has been extensively studied in many organisms. It is indispensable for maintaining proteostasis in some organisms and its inhibition is currently being explored as a drug target for cancer and other parasitic diseases. In T. brucei, cytosolic Hsp90 is specifically referred to as Hsp83 due to variations in the sizes amongst different orthologues. Hsp90 is present in high levels in all stages of the T. brucei cell cycle both constitutively and on exposure to stress. To function in the cell, Hsp90 is dependent on co-chaperones, one of which can be found in most organisms, namely, the stress-inducible protein 1 (Sti1). The Hsp90-Sti1 interaction was shown to be crucial for growth in the intracellular kinetoplastid parasite, Leishmania donovani. However, this partnership has not been explored in the extracellular parasite T. brucei. To analyse the interaction of Hsp90 with Sti1 in T. brucei, this study combined in silico, in vitro and in vivo tools. In silico analyses of the Hsp90 complement in T. brucei revealed the presence of twelve putative Hsp90 genes, ten of which code for the cytosolic protein and are arranged in tandem in a head to tail fashion on the same chromosome. One gene each was found for the mitochondrial and ER paralogues of Hsp90, similar to all other species analysed. Eight putative co-chaperones specific to T. brucei were also discovered: six tetratricopeptide repeat domain (TPR) containing co-chaperones and two non-TPR containing co-chaperones. Structural and evolutionary analysis also confirmed that the domains were conserved across the species analysed. T. brucei Sti1 (TbSti1), T. brucei cytosolic Hsp90 (TbHsp83) and human cytosolic Hsp90 (hHsp90) were heterologously overproduced in E. coli and purified using nickel affinity chromatography. With specific antibodies, the expression and localization of the proteins were confirmed. TbSti1 showed strong affinity to the Hsp90s in the nanomolar range, with higher affinity for hHsp90 compared to TbHsp83. TbHsp83 and hHsp90 showed typical chaperone properties by suppressing the aggregation of thermolabile substrate MDH at equimolar concentrations and both chaperones had potent ATP hydrolysis activity. TbSti1, on the other hand, showed no MDH suppression activity and did not affect the ATP hydrolysis activity of TbHsp83 or hHsp90. Ex-vivo experiments using HeLa CRISPR Hop knockout (KO) human cell lines transfected with pcDNA3.1(+)HA-TbSti1 revealed TbSti1 also localized to the cytoplasm. The transfected cells showed a distinct fibroblast-like morphology which was different from the circular morphology seen in the Hop KO untransfected and wild type untransfected cells. Finally, co-immunoprecipitation studies revealed that TbSti1 co-immunoprecipitated with hHsp90. These results show the first characterization of the TbHsp83-TbSti1 partnership in T. brucei. The strong association between both proteins suggests a functional role for this partnership in T. brucei and could provide an updated context for understanding Trypanosome brucei biology. , Thesis (PhD) -- Faculty of Science, Biotechnology and Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Jamabo, Miebaka
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422629 , vital:71963 , DOI 10.21504/10962/422629
- Description: Neglected tropical diseases continue to pose global concern due to their impact on health and socio-economic status of developing countries in sub-Saharan Africa. African trypanosomiasis is one of the neglected tropical diseases caused by the kinetoplastid flagellate parasite Trypanosoma brucei (T. brucei). The disease is fatal if untreated and the toolbox to combat the disease has been plagued with many difficulties such as drug resistance, toxic chemotherapeutics, and cumbersome drug delivery processes. In recent years, the disease has received attention from organizations such as the Drugs for Neglected Diseases initiative (DNDi) in partnership with WHO as well as academia and industry to provide alternatives to the existing drugs as part of a targeted approach to eliminate human African trypanosomiasis by 2030. The life cycle of the T. brucei parasite requires that it transitions between a cold-blooded vector (the tsetse fly) and a human host. To survive this extreme environmental change and maintain its infectious cycle, the parasite has evolved an arsenal of tools which include a strong immune evasion technique and a robust molecular chaperone system. Heat shock protein 90 (Hsp90) is one of the most abundant eukaryotic molecular chaperones that has been extensively studied in many organisms. It is indispensable for maintaining proteostasis in some organisms and its inhibition is currently being explored as a drug target for cancer and other parasitic diseases. In T. brucei, cytosolic Hsp90 is specifically referred to as Hsp83 due to variations in the sizes amongst different orthologues. Hsp90 is present in high levels in all stages of the T. brucei cell cycle both constitutively and on exposure to stress. To function in the cell, Hsp90 is dependent on co-chaperones, one of which can be found in most organisms, namely, the stress-inducible protein 1 (Sti1). The Hsp90-Sti1 interaction was shown to be crucial for growth in the intracellular kinetoplastid parasite, Leishmania donovani. However, this partnership has not been explored in the extracellular parasite T. brucei. To analyse the interaction of Hsp90 with Sti1 in T. brucei, this study combined in silico, in vitro and in vivo tools. In silico analyses of the Hsp90 complement in T. brucei revealed the presence of twelve putative Hsp90 genes, ten of which code for the cytosolic protein and are arranged in tandem in a head to tail fashion on the same chromosome. One gene each was found for the mitochondrial and ER paralogues of Hsp90, similar to all other species analysed. Eight putative co-chaperones specific to T. brucei were also discovered: six tetratricopeptide repeat domain (TPR) containing co-chaperones and two non-TPR containing co-chaperones. Structural and evolutionary analysis also confirmed that the domains were conserved across the species analysed. T. brucei Sti1 (TbSti1), T. brucei cytosolic Hsp90 (TbHsp83) and human cytosolic Hsp90 (hHsp90) were heterologously overproduced in E. coli and purified using nickel affinity chromatography. With specific antibodies, the expression and localization of the proteins were confirmed. TbSti1 showed strong affinity to the Hsp90s in the nanomolar range, with higher affinity for hHsp90 compared to TbHsp83. TbHsp83 and hHsp90 showed typical chaperone properties by suppressing the aggregation of thermolabile substrate MDH at equimolar concentrations and both chaperones had potent ATP hydrolysis activity. TbSti1, on the other hand, showed no MDH suppression activity and did not affect the ATP hydrolysis activity of TbHsp83 or hHsp90. Ex-vivo experiments using HeLa CRISPR Hop knockout (KO) human cell lines transfected with pcDNA3.1(+)HA-TbSti1 revealed TbSti1 also localized to the cytoplasm. The transfected cells showed a distinct fibroblast-like morphology which was different from the circular morphology seen in the Hop KO untransfected and wild type untransfected cells. Finally, co-immunoprecipitation studies revealed that TbSti1 co-immunoprecipitated with hHsp90. These results show the first characterization of the TbHsp83-TbSti1 partnership in T. brucei. The strong association between both proteins suggests a functional role for this partnership in T. brucei and could provide an updated context for understanding Trypanosome brucei biology. , Thesis (PhD) -- Faculty of Science, Biotechnology and Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-03-31
Chemical analysis of selected Eastern Cape medicinal plants
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Climate for changing lenses: Reconciliation through site-specific, media arts-based environmental education on the water and climate change nexus in South Africa and Canada
- Authors: Van Borek, Sarah
- Date: 2021-10-29
- Subjects: Environmental education South Africa , Environmental education Canada , Climatic changes in art , Water-supply Climatic factors , Decolonization , Reconciliation South Africa , Curriculum change , Traditional ecological knowledge
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192754 , vital:45260 , 10.21504/10962/192754
- Description: This study took place in the context of a growing racialised global water crisis and increasing demands worldwide for transforming higher education at institutions of ongoing settler colonialism. It presents a conceptualisation of what education, research and activism can look like and unfolded inside a doctoral research project that expands what doctoral education can look like. Using a media arts-based praxis process, I developed a relational model of university curriculum –site-specific, media arts-based, environmental education –with potential to cultivate relations (human and nonhuman) towards reconciliation while contributing to justice at the water-climate change nexus. My aim as a settler-ally was to expand my teaching and curriculum practices, thereby also offering curriculum transformation inspiration to others. My research was rooted in my concept of reconciliation as a practice towards thriving together, where the ‘together’ was inclusive of both humans and nonhumans. The curriculum engaged students in de/re/constructing water narratives through making site-specific videos focused on local water bodies. Decolonising artistic approaches known as slow media and soundscape recording were strategically incorporated into audio/video mapping assignments where students observed water aesthetics in ways that shifted their perceptions about water and entities entangled with it. Students met with Knowledge Keepers (Indigenous and non-Indigenous people from outside the academy with existing relationships to water bodies). A photovoice methodology was used in these meetings with Knowledge Keepers to reconfigure traditional film director-subject power relations. Guest lecturers from non-traditional backgrounds contributed diverse perspectives. Ecomotricity was incorporated, whereby students were in deliberate movement in/with water bodies through canoeing together. The curriculum culminated in a public screening/education event where resulting videos, interspersed with educational games facilitated by students, surfaced emotions, knowledge co-production and new synergies amongst the event’s temporary community. Through two iterations of the curriculum, where I co-designed and taught a course called Making Waveforms, one in Vancouver, Canada and one in Cape Town, South Africa, I explored the primary research question: How can a relational site specific, media arts-based university environmental education curriculum cultivate students’ relational sensibilities and abilities oriented towards reconciliation of diverse peoples and ecosystems in South Africa and Canada? Iterating the curriculum across these two contexts allowed me to assess which aspect(s)of the curriculum may have been applicable across these and other contexts. By using mixed methods of data collection and sharing throughout the research journey, I explored the sub-questions: a) How is reconciliation understood currently by university students in South Africa and Canada? and b) How can a relational site-specific, media arts-based university environmental education curriculum and my PhD methodologies (PhD-by-publication, website, and participatory approaches to podcasting, video making, and song creation), contribute to decolonising higher education, and thereby further contribute to reconciliation of diverse peoples and ecosystems in South Africa and Canada? Integral to my praxis process, I undertook a PhD-by-publication that involved writing four academic journal articles, with each paper presenting a key stage in the process. The papers, all of which have been submitted to peer-reviewed academic journals, form part of this thesis and can be found in the Appendices. The course was originally developed around Donati’s (2011) relational sociology and Gergen’s (2009) relational education theory. Throughout my praxis process, I expanded my theoretical influences as called for by the research and teaching practice. The journey behind my first PhD paper, (Towards) Sound research practice: Podcast-building as modeling relational sensibilities at the water-climate change nexus in Cape Town, began when I officially started my doctoral studies in early 2018. The paper was co-authored with a fellow PhD scholar from Rhodes University’s Environmental Learning Research Centre (ELRC), Anna James. It presents an experimental arts-based methodology we co-developed for doing contextual profiling by building a socially-engaged podcast series, called Day One, to explore the lived experiences of the Cape Town water crisis of 2018. It includes my initial tool of analysis for exploring how the curriculum might cultivate relational sensibilities and abilities towards reconciliation. The podcast pedagogy offered opportunities to develop some relational learning processes. The analytical tool was developed from cross-referencing reconciliation and relational educational theories. This paper also incorporated theories in relational solidarity and social movement learning. The podcast episodes included personal narratives that, in turn, revealed diverse ideologies and polarisations in the water situation. Working with the audio medium highlighted possibilities for creating and shifting affective relations. Recording and editing soundscapes of waterbodies began explorations of the agential qualities of water. These were foundational dynamics to explore in building the reconciliation curriculum. The paper is published in the International Journal of New Media, Technology, and the Arts (2019, Volume14, Issue1). My second PhD paper, A media arts-based praxis process of building towards a relational model of curriculum oriented towards reconciliation through water justice, presents my methodology for and analysis of a pilot course I co-designed and taught at the Emily Carr University of Art + Design (ECUAD) in Vancouver, Canada in 2018. This course served as contextual profiling around the water situation in Vancouver. The course was offered in partnership with a science-based environmental non-profit called the David Suzuki Foundation and an Indigenous-led post-secondary school called the Native Education College. The course’s public event was hosted at the Beaty Biodiversity Museum. At this stage, I was introduced to Cree/Métis filmmaker, Gregory Coyes, and his Indigenous cinematic narrative approach known as Slow Media. Integrating slow media into video mapping assignments presented exciting possibilities for shifting views and valuing of water. This was the stage at which my concept of reconciliation expanded to explicitly include nonhumans. I applied my initial analytical tool to the curriculum here, which revealed the three most prominent relational sensibilities and abilities towards reconciliation cultivated by students through the course: (1) knowledge ecologies; (2) a hopeful social imaginary; and (3) embodied ways of knowing. I began to make connections between the curriculum and Mi’kmaq elder Albert Marshall’s concept of ‘Two-Eyed-Seeing’, and expanded the notion to ‘Three-Eyed-Seeing’ to include artistic approaches. Deeply inspired by Bekerman and Zembylas’s (2012) Teaching Contested Narratives, I began to see the growing importance of the narrative aspects of reconciliation education. The paper is published in the University of Pretoria’s Journal of Decolonising Disciplines (2021, Volume 1, Issue 2). My third PhD paper, Water as artist-collaborator: Posthumanism and reconciliation in relational media arts-based education, presents a 2019 iteration of the curriculum at ECUAD in Vancouver, and illustrates my shift to include posthuman theories in my analysis. This course was offered in affiliation with the David Suzuki Foundation, and in collaboration with the Native Education College. The culminating public event was hosted by the Beaty Biodiversity Museum. Decentring the human in this data analysis better supported my research and curricular aims. The strong technoculture of the media arts-based curriculum fits well with many posthuman concepts. This posthuman reading of the course and data enabled me to see what changes were emerging through student-water-technology intra-actions, and how these supported relations towards reconciliation as well as water justice. Most notable of these changes was the emergence of water’s agential qualities, specifically of water as becoming collaborator in artistic/knowledge co-production, where students think with water. I argued this contributes to reconciliation by decentring the human, enabling relations in which power is more equal, and where there are greater possibilities for mutual responsibility between related entities. This is where I developed the concept of audio/video as relational texts, supporting the creating and shifting of affective relations more than the monumentalised verbal/written knowledge of traditional universities. This is also where I realised that relational work towards reconciliation would require engaging with the hidden curriculum of institutions. The paper is published in the journal Reconceptualizing Educational Research Methodology (2021, Volume 12, Issue 1), as part of a special issue on Posthuman Conceptions of Change in Empirical Educational Research. My fourth PhD paper, originally entitled Making waveforms: Implicit knowledge representation through video water narratives as decolonising practice towards reconciliation in South Africa’s higher education, presents an analysis of the 2019 iteration of the curriculum in South Africa. I co-designed and led a course called Making Waveforms at the University of Cape Town’s Future Water Institute (FWI) in collaboration with Rhodes University. The course was co-designed/facilitated with FWI’s Research Fellow Amber Abrams, who also co-authored this paper. The course’s public event was hosted by a non-profit organisation called the Tshisimani Centre for Activist Education. This paper explored the ways that non-verbalisable, implicit learning –understood as part of many non-Euro/Western ways of knowing– takes place in the Making Waveforms course and how this influenced water-specific climate behaviours while contributing to decolonised reconciliation practice for higher education institutions. Drawing on theories of implicit and explicit knowledge, we first showed how implicit learning primarily took place through: 1) site-specific audio/video mapping of water bodies; 2) meetings with Knowledge Keepers; and 3) an interactive public screening event. We highlighted how this non-verbalisable learning produced feelings of empathy for diverse peoples and waterways, as well as aesthetic appreciation of water, and how this can contribute to more response-able water behaviours. This, we argued, supported the valuing of implicit knowledge within a traditional educational setting, thereby pluralising knowledge, and was key to reconciliation/decolonisation in higher education. Iterating the curriculum for the South African context emphasised the importance of context-specificity of the course overall, and also of the relational work embedded in the curriculum. This paper is under review by the University of Toronto’s journal Curriculum Inquiry (CI). Following receipt of CI's internal review process, the title of the paper has since been updated to Non-verbalisable, implicit knowledge through cellphilms as decolonised reconciliation practice towards response-able water behaviours in South Africa. Through reflective analysis of my four papers, I developed a concept for an Anatomy of Decoloniz/sed Curriculum consisting of five key parts: 1) relationality; 2) multimodality; 3) narratives/counter-narratives; 4) context-specificity; and 5) unhidden curriculum. Four meta reflections have been included in this thesis, each corresponding with one of the four papers, and presented chronologically according to the stage of the praxis process with which they correspond. In these meta reflections, I applied Kolb’s (1984) Experiential Learning Cycle model for reflective writing, based on the premise that through experiences we can expand our understanding, and included four key stages: 1) concrete experience; 2) reflective observation; 3) abstract conceptualisation; and 4) active experimentation. For the concrete experience, I provided a thick description of my process in writing the paper, as well as aspects of the phase in my praxis process that was the focus of the paper, not included in but relevant to the paper. For the reflective observation, I identified any aspects of the experience that were new to me and which therefore presented opportunities for me to learn. For the abstract conceptualisation, I critically analysed my concrete experience and reflective observation to determine which, if any, of the five key parts of the Anatomy of Decoloniz/sed Curriculum that I outline in my introduction relate to this phase of my PhD praxis process. For the active experimentation, I made conclusions about the extent to which this phase of my PhD embraced decoloniality in practice, and built on this new understanding to make recommendations for myself and others committed to the decolonial project as part of my contribution to knowledge. These meta reflections also invite readers to follow my personal narrative of becoming-with water, meaning my transformation from being water illiterate to embracing a ‘watershed mind’ (Wong,2011). Multimodality, which I propose as a key part of an Anatomy of Decoloniz/sed Curriculum, is embedded in the representational aspects of this thesis. The courses I co-designed and taught as part of this project resulted in the creation of 20 short student films. My contextual profiling involved a podcast methodology that was ongoing throughout my study, as a model of decolonised research-communication-education-action at the water-climate change nexus. This methodology resulted in the creation of four Day One podcast episodes, co-produced with a PhD colleague, Anna James. Some of these episodes are available in all three main languages of Cape Town (Xhosa, Afrikaans, and English). I evolved the podcast methodology in a later stage of my praxis process as a form of member checking with contributors involved in various stages and aspects of the research. Once the four papers were written, I created a series of four short videos called In the Flow, with each video representing a translation of one of the four papers. I invited various contributors of the research project to either watch one or more of the In the Flow videos and/or read one or more of the academic papers, and then to respond in a Zoom call with me. The responses were then shared publicly in a series of seven Climate for Changing Lenses podcast episodes. Parts of these are included in a final song/music video called Please Don’t Blow It. A Climate for Changing Lenses website was created to host all of this multimedia content that forms part of this thesis. A link to this website is provided in the Introduction section of this thesis. My research contributes to the advancement of knowledge in the areas of relational and reconciliation pedagogy, decolonising higher education, arts-based teaching, learning and research methodologies and the water-climate change nexus. My praxis process provided a relational model of reconciliation curriculum that has been tried and tested in two international contexts: Canada and South Africa. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Van Borek, Sarah
- Date: 2021-10-29
- Subjects: Environmental education South Africa , Environmental education Canada , Climatic changes in art , Water-supply Climatic factors , Decolonization , Reconciliation South Africa , Curriculum change , Traditional ecological knowledge
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192754 , vital:45260 , 10.21504/10962/192754
- Description: This study took place in the context of a growing racialised global water crisis and increasing demands worldwide for transforming higher education at institutions of ongoing settler colonialism. It presents a conceptualisation of what education, research and activism can look like and unfolded inside a doctoral research project that expands what doctoral education can look like. Using a media arts-based praxis process, I developed a relational model of university curriculum –site-specific, media arts-based, environmental education –with potential to cultivate relations (human and nonhuman) towards reconciliation while contributing to justice at the water-climate change nexus. My aim as a settler-ally was to expand my teaching and curriculum practices, thereby also offering curriculum transformation inspiration to others. My research was rooted in my concept of reconciliation as a practice towards thriving together, where the ‘together’ was inclusive of both humans and nonhumans. The curriculum engaged students in de/re/constructing water narratives through making site-specific videos focused on local water bodies. Decolonising artistic approaches known as slow media and soundscape recording were strategically incorporated into audio/video mapping assignments where students observed water aesthetics in ways that shifted their perceptions about water and entities entangled with it. Students met with Knowledge Keepers (Indigenous and non-Indigenous people from outside the academy with existing relationships to water bodies). A photovoice methodology was used in these meetings with Knowledge Keepers to reconfigure traditional film director-subject power relations. Guest lecturers from non-traditional backgrounds contributed diverse perspectives. Ecomotricity was incorporated, whereby students were in deliberate movement in/with water bodies through canoeing together. The curriculum culminated in a public screening/education event where resulting videos, interspersed with educational games facilitated by students, surfaced emotions, knowledge co-production and new synergies amongst the event’s temporary community. Through two iterations of the curriculum, where I co-designed and taught a course called Making Waveforms, one in Vancouver, Canada and one in Cape Town, South Africa, I explored the primary research question: How can a relational site specific, media arts-based university environmental education curriculum cultivate students’ relational sensibilities and abilities oriented towards reconciliation of diverse peoples and ecosystems in South Africa and Canada? Iterating the curriculum across these two contexts allowed me to assess which aspect(s)of the curriculum may have been applicable across these and other contexts. By using mixed methods of data collection and sharing throughout the research journey, I explored the sub-questions: a) How is reconciliation understood currently by university students in South Africa and Canada? and b) How can a relational site-specific, media arts-based university environmental education curriculum and my PhD methodologies (PhD-by-publication, website, and participatory approaches to podcasting, video making, and song creation), contribute to decolonising higher education, and thereby further contribute to reconciliation of diverse peoples and ecosystems in South Africa and Canada? Integral to my praxis process, I undertook a PhD-by-publication that involved writing four academic journal articles, with each paper presenting a key stage in the process. The papers, all of which have been submitted to peer-reviewed academic journals, form part of this thesis and can be found in the Appendices. The course was originally developed around Donati’s (2011) relational sociology and Gergen’s (2009) relational education theory. Throughout my praxis process, I expanded my theoretical influences as called for by the research and teaching practice. The journey behind my first PhD paper, (Towards) Sound research practice: Podcast-building as modeling relational sensibilities at the water-climate change nexus in Cape Town, began when I officially started my doctoral studies in early 2018. The paper was co-authored with a fellow PhD scholar from Rhodes University’s Environmental Learning Research Centre (ELRC), Anna James. It presents an experimental arts-based methodology we co-developed for doing contextual profiling by building a socially-engaged podcast series, called Day One, to explore the lived experiences of the Cape Town water crisis of 2018. It includes my initial tool of analysis for exploring how the curriculum might cultivate relational sensibilities and abilities towards reconciliation. The podcast pedagogy offered opportunities to develop some relational learning processes. The analytical tool was developed from cross-referencing reconciliation and relational educational theories. This paper also incorporated theories in relational solidarity and social movement learning. The podcast episodes included personal narratives that, in turn, revealed diverse ideologies and polarisations in the water situation. Working with the audio medium highlighted possibilities for creating and shifting affective relations. Recording and editing soundscapes of waterbodies began explorations of the agential qualities of water. These were foundational dynamics to explore in building the reconciliation curriculum. The paper is published in the International Journal of New Media, Technology, and the Arts (2019, Volume14, Issue1). My second PhD paper, A media arts-based praxis process of building towards a relational model of curriculum oriented towards reconciliation through water justice, presents my methodology for and analysis of a pilot course I co-designed and taught at the Emily Carr University of Art + Design (ECUAD) in Vancouver, Canada in 2018. This course served as contextual profiling around the water situation in Vancouver. The course was offered in partnership with a science-based environmental non-profit called the David Suzuki Foundation and an Indigenous-led post-secondary school called the Native Education College. The course’s public event was hosted at the Beaty Biodiversity Museum. At this stage, I was introduced to Cree/Métis filmmaker, Gregory Coyes, and his Indigenous cinematic narrative approach known as Slow Media. Integrating slow media into video mapping assignments presented exciting possibilities for shifting views and valuing of water. This was the stage at which my concept of reconciliation expanded to explicitly include nonhumans. I applied my initial analytical tool to the curriculum here, which revealed the three most prominent relational sensibilities and abilities towards reconciliation cultivated by students through the course: (1) knowledge ecologies; (2) a hopeful social imaginary; and (3) embodied ways of knowing. I began to make connections between the curriculum and Mi’kmaq elder Albert Marshall’s concept of ‘Two-Eyed-Seeing’, and expanded the notion to ‘Three-Eyed-Seeing’ to include artistic approaches. Deeply inspired by Bekerman and Zembylas’s (2012) Teaching Contested Narratives, I began to see the growing importance of the narrative aspects of reconciliation education. The paper is published in the University of Pretoria’s Journal of Decolonising Disciplines (2021, Volume 1, Issue 2). My third PhD paper, Water as artist-collaborator: Posthumanism and reconciliation in relational media arts-based education, presents a 2019 iteration of the curriculum at ECUAD in Vancouver, and illustrates my shift to include posthuman theories in my analysis. This course was offered in affiliation with the David Suzuki Foundation, and in collaboration with the Native Education College. The culminating public event was hosted by the Beaty Biodiversity Museum. Decentring the human in this data analysis better supported my research and curricular aims. The strong technoculture of the media arts-based curriculum fits well with many posthuman concepts. This posthuman reading of the course and data enabled me to see what changes were emerging through student-water-technology intra-actions, and how these supported relations towards reconciliation as well as water justice. Most notable of these changes was the emergence of water’s agential qualities, specifically of water as becoming collaborator in artistic/knowledge co-production, where students think with water. I argued this contributes to reconciliation by decentring the human, enabling relations in which power is more equal, and where there are greater possibilities for mutual responsibility between related entities. This is where I developed the concept of audio/video as relational texts, supporting the creating and shifting of affective relations more than the monumentalised verbal/written knowledge of traditional universities. This is also where I realised that relational work towards reconciliation would require engaging with the hidden curriculum of institutions. The paper is published in the journal Reconceptualizing Educational Research Methodology (2021, Volume 12, Issue 1), as part of a special issue on Posthuman Conceptions of Change in Empirical Educational Research. My fourth PhD paper, originally entitled Making waveforms: Implicit knowledge representation through video water narratives as decolonising practice towards reconciliation in South Africa’s higher education, presents an analysis of the 2019 iteration of the curriculum in South Africa. I co-designed and led a course called Making Waveforms at the University of Cape Town’s Future Water Institute (FWI) in collaboration with Rhodes University. The course was co-designed/facilitated with FWI’s Research Fellow Amber Abrams, who also co-authored this paper. The course’s public event was hosted by a non-profit organisation called the Tshisimani Centre for Activist Education. This paper explored the ways that non-verbalisable, implicit learning –understood as part of many non-Euro/Western ways of knowing– takes place in the Making Waveforms course and how this influenced water-specific climate behaviours while contributing to decolonised reconciliation practice for higher education institutions. Drawing on theories of implicit and explicit knowledge, we first showed how implicit learning primarily took place through: 1) site-specific audio/video mapping of water bodies; 2) meetings with Knowledge Keepers; and 3) an interactive public screening event. We highlighted how this non-verbalisable learning produced feelings of empathy for diverse peoples and waterways, as well as aesthetic appreciation of water, and how this can contribute to more response-able water behaviours. This, we argued, supported the valuing of implicit knowledge within a traditional educational setting, thereby pluralising knowledge, and was key to reconciliation/decolonisation in higher education. Iterating the curriculum for the South African context emphasised the importance of context-specificity of the course overall, and also of the relational work embedded in the curriculum. This paper is under review by the University of Toronto’s journal Curriculum Inquiry (CI). Following receipt of CI's internal review process, the title of the paper has since been updated to Non-verbalisable, implicit knowledge through cellphilms as decolonised reconciliation practice towards response-able water behaviours in South Africa. Through reflective analysis of my four papers, I developed a concept for an Anatomy of Decoloniz/sed Curriculum consisting of five key parts: 1) relationality; 2) multimodality; 3) narratives/counter-narratives; 4) context-specificity; and 5) unhidden curriculum. Four meta reflections have been included in this thesis, each corresponding with one of the four papers, and presented chronologically according to the stage of the praxis process with which they correspond. In these meta reflections, I applied Kolb’s (1984) Experiential Learning Cycle model for reflective writing, based on the premise that through experiences we can expand our understanding, and included four key stages: 1) concrete experience; 2) reflective observation; 3) abstract conceptualisation; and 4) active experimentation. For the concrete experience, I provided a thick description of my process in writing the paper, as well as aspects of the phase in my praxis process that was the focus of the paper, not included in but relevant to the paper. For the reflective observation, I identified any aspects of the experience that were new to me and which therefore presented opportunities for me to learn. For the abstract conceptualisation, I critically analysed my concrete experience and reflective observation to determine which, if any, of the five key parts of the Anatomy of Decoloniz/sed Curriculum that I outline in my introduction relate to this phase of my PhD praxis process. For the active experimentation, I made conclusions about the extent to which this phase of my PhD embraced decoloniality in practice, and built on this new understanding to make recommendations for myself and others committed to the decolonial project as part of my contribution to knowledge. These meta reflections also invite readers to follow my personal narrative of becoming-with water, meaning my transformation from being water illiterate to embracing a ‘watershed mind’ (Wong,2011). Multimodality, which I propose as a key part of an Anatomy of Decoloniz/sed Curriculum, is embedded in the representational aspects of this thesis. The courses I co-designed and taught as part of this project resulted in the creation of 20 short student films. My contextual profiling involved a podcast methodology that was ongoing throughout my study, as a model of decolonised research-communication-education-action at the water-climate change nexus. This methodology resulted in the creation of four Day One podcast episodes, co-produced with a PhD colleague, Anna James. Some of these episodes are available in all three main languages of Cape Town (Xhosa, Afrikaans, and English). I evolved the podcast methodology in a later stage of my praxis process as a form of member checking with contributors involved in various stages and aspects of the research. Once the four papers were written, I created a series of four short videos called In the Flow, with each video representing a translation of one of the four papers. I invited various contributors of the research project to either watch one or more of the In the Flow videos and/or read one or more of the academic papers, and then to respond in a Zoom call with me. The responses were then shared publicly in a series of seven Climate for Changing Lenses podcast episodes. Parts of these are included in a final song/music video called Please Don’t Blow It. A Climate for Changing Lenses website was created to host all of this multimedia content that forms part of this thesis. A link to this website is provided in the Introduction section of this thesis. My research contributes to the advancement of knowledge in the areas of relational and reconciliation pedagogy, decolonising higher education, arts-based teaching, learning and research methodologies and the water-climate change nexus. My praxis process provided a relational model of reconciliation curriculum that has been tried and tested in two international contexts: Canada and South Africa. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Clinical governance implementation challenges in the Department of Health, Mpumalanga, South Africa
- Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Authors: Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Date: 2022-09
- Subjects: Clinical competence , Health services administration
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27275 , vital:66532
- Description: Clinical governance (CG) is the system through which health authorities are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which clinical excellence flourishes. South Africa is one of the countries where CG has not been successfully implemented. This study sought to explore the CG implementation challenges in the Mpumalanga province, South Africa. The study objectives included the seven pillars of CG. The study was a qualitative and exploratory, using purposive sampling technique to select study participants. A total of twenty-two (22) individuals were selected for the study. Semi-structured interviews were used for data collection. Each interview was transcribed verbatim by the researcher. Confidentiality was ensured through the coding of interviewee names. The content analysis technique was used for data analysis, using the study objectives as themes. The study found general lack of understanding of the concept of CG, poor performance of clinical audits, sub-standard clinical performance and effectiveness, poor clinical risk management, poor patient and public involvement in patient care, lack of evidence-based practice and research, inadequate training and development of healthcare workers, and sub-standard health information management across the department. The researcher recommends that the CG policy be prioritised by the Mpumalanga DOH, that systems be put in place to facilitate policy implementation, and that the departmental staff establishments at all levels, prioritise healthcare professionals in key leadership positions. In conclusion, there are numerous challenges that confront the Mpumalanga Department of Health regarding the implementation of clinical governance, requiring urgent attention. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-09
- Authors: Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Date: 2022-09
- Subjects: Clinical competence , Health services administration
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27275 , vital:66532
- Description: Clinical governance (CG) is the system through which health authorities are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which clinical excellence flourishes. South Africa is one of the countries where CG has not been successfully implemented. This study sought to explore the CG implementation challenges in the Mpumalanga province, South Africa. The study objectives included the seven pillars of CG. The study was a qualitative and exploratory, using purposive sampling technique to select study participants. A total of twenty-two (22) individuals were selected for the study. Semi-structured interviews were used for data collection. Each interview was transcribed verbatim by the researcher. Confidentiality was ensured through the coding of interviewee names. The content analysis technique was used for data analysis, using the study objectives as themes. The study found general lack of understanding of the concept of CG, poor performance of clinical audits, sub-standard clinical performance and effectiveness, poor clinical risk management, poor patient and public involvement in patient care, lack of evidence-based practice and research, inadequate training and development of healthcare workers, and sub-standard health information management across the department. The researcher recommends that the CG policy be prioritised by the Mpumalanga DOH, that systems be put in place to facilitate policy implementation, and that the departmental staff establishments at all levels, prioritise healthcare professionals in key leadership positions. In conclusion, there are numerous challenges that confront the Mpumalanga Department of Health regarding the implementation of clinical governance, requiring urgent attention. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-09
Clinical governance implementation challenges in the Department of Health, Mpumalanga, South Africa
- Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Authors: Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Date: 2022-09
- Subjects: Clinical competence , Evidence-based medicine , Health services administration
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23600 , vital:58194
- Description: Clinical governance (CG) is the system through which health authorities are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which clinical excellence flourishes. South Africa is one of the countries where CG has not been successfully implemented. This study sought to explore the CG implementation challenges in the Mpumalanga province, South Africa. The study objectives included the seven pillars of CG. The study was a qualitative and exploratory, using purposive sampling technique to select study participants. A total of twenty-two (22) individuals were selected for the study. Semi-structured interviews were used for data collection. Each interview was transcribed verbatim by the researcher. Confidentiality was ensured through the coding of interviewee names. The content analysis technique was used for data analysis, using the study objectives as themes. The study found general lack of understanding of the concept of CG, poor performance of clinical audits, sub-standard clinical performance and effectiveness, poor clinical risk management, poor patient and public involvement in patient care, lack of evidence-based practice and research, inadequate training and development of healthcare workers, and sub-standard health information management across the department. The researcher recommends that the CG policy be prioritised by the Mpumalanga DOH, that systems be put in place to facilitate policy implementation, and that the departmental staff establishments at all levels, prioritise healthcare professionals in key leadership positions. In conclusion, there are numerous challenges that confront the Mpumalanga Department of Health regarding the implementation of clinical governance, requiring urgent attention. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-09
- Authors: Maduna, Patrick Hawkins https://orcid.org/0000-0002-4926-1661
- Date: 2022-09
- Subjects: Clinical competence , Evidence-based medicine , Health services administration
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23600 , vital:58194
- Description: Clinical governance (CG) is the system through which health authorities are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which clinical excellence flourishes. South Africa is one of the countries where CG has not been successfully implemented. This study sought to explore the CG implementation challenges in the Mpumalanga province, South Africa. The study objectives included the seven pillars of CG. The study was a qualitative and exploratory, using purposive sampling technique to select study participants. A total of twenty-two (22) individuals were selected for the study. Semi-structured interviews were used for data collection. Each interview was transcribed verbatim by the researcher. Confidentiality was ensured through the coding of interviewee names. The content analysis technique was used for data analysis, using the study objectives as themes. The study found general lack of understanding of the concept of CG, poor performance of clinical audits, sub-standard clinical performance and effectiveness, poor clinical risk management, poor patient and public involvement in patient care, lack of evidence-based practice and research, inadequate training and development of healthcare workers, and sub-standard health information management across the department. The researcher recommends that the CG policy be prioritised by the Mpumalanga DOH, that systems be put in place to facilitate policy implementation, and that the departmental staff establishments at all levels, prioritise healthcare professionals in key leadership positions. In conclusion, there are numerous challenges that confront the Mpumalanga Department of Health regarding the implementation of clinical governance, requiring urgent attention. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-09
Co-generating a people-centred approach to addressing student hunger at a South African university
- Authors: Mansvelt, Natalie
- Date: 2021-04
- Subjects: Food security -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51309 , vital:43262
- Description: While considerable progress has been made regarding access to higher education in South Africa for previously excluded and disadvantaged students, great challenges are experienced in terms of student well-being. One of the key factors contributing to students’ ability to complete their studies successfully is food-related challenges. Various programmes have been introduced at institutions of higher education to assist and support students who lack funds for food. However, these programmes are characteristic of the welfarist model, as it is often based on needs, short-term by nature, and dependent on external resources. Furthermore, it reduces students to the role of passive beneficiaries. This research answers the question of how student hunger can be addressed through co-generating a people-centred approach at one higher education institution in South Africa. The study was underpinned by Sen’s capabilities approach to enable a theoretical understanding of the issue of student hunger. Additionally, Korten’s people-centred development provided the value base of the study to place students at the centre of the problem-solving process. An approach to student hunger that would be participative, student-centred, and enhancing nutritional capabilities was invited. Situated within the critical paradigm, I employed the participatory action research design to facilitate a process whereby students critically questioned the issue of hunger and took action to address the issue. Eight students from various study fields volunteered to co-research the issue of student hunger. Over the period of one year, we generated data using different methods (including photovoice, community self-survey, workshops, purposeful group discussions, focus group discussions, and my reflective notes). We applied cyclical processes to plan, implement, and reflect on actions intended to address student hunger. Through a combination of collaborative and individual processes of data analysis, we responded to four subquestions through four phases, which culminated in the co-construction of a people-centred approach to student hunger. Students’ conceptualisations of student hunger revealed two types: hunger of the stomach and hunger of the mind. The cyclical relationship between the two types infers that nutritional well-being is not achieved adequately when students have the means to acquire food. Choices regarding the utilisation of the available means also need consideration. The findings revealed that students apply the conscientisation framework in the ways that they plan to address student hunger. Applying value-driven processes, actions entailed physical dialogues with groups of people. The approach developed in this study offers strategies for the stakeholders who attend to student hunger, to collaborate and make contributions towards comprehensively resolving the complex issue. It primarily could be useful to institutions of higher education as the suggested coordinators of a collaborative structure. A second part of the developed approach puts forward a strategy to address the financial capabilities of students. The study contributes a consideration to constraints that stem from students’ mindsets and adoption of a prevailing culture that maintains student hunger. This demonstrates that resolutions to addressing student hunger might be more effective and sustainable if the context, views and participation of people experiencing the hunger are considered. , Thesis (PhD) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mansvelt, Natalie
- Date: 2021-04
- Subjects: Food security -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51309 , vital:43262
- Description: While considerable progress has been made regarding access to higher education in South Africa for previously excluded and disadvantaged students, great challenges are experienced in terms of student well-being. One of the key factors contributing to students’ ability to complete their studies successfully is food-related challenges. Various programmes have been introduced at institutions of higher education to assist and support students who lack funds for food. However, these programmes are characteristic of the welfarist model, as it is often based on needs, short-term by nature, and dependent on external resources. Furthermore, it reduces students to the role of passive beneficiaries. This research answers the question of how student hunger can be addressed through co-generating a people-centred approach at one higher education institution in South Africa. The study was underpinned by Sen’s capabilities approach to enable a theoretical understanding of the issue of student hunger. Additionally, Korten’s people-centred development provided the value base of the study to place students at the centre of the problem-solving process. An approach to student hunger that would be participative, student-centred, and enhancing nutritional capabilities was invited. Situated within the critical paradigm, I employed the participatory action research design to facilitate a process whereby students critically questioned the issue of hunger and took action to address the issue. Eight students from various study fields volunteered to co-research the issue of student hunger. Over the period of one year, we generated data using different methods (including photovoice, community self-survey, workshops, purposeful group discussions, focus group discussions, and my reflective notes). We applied cyclical processes to plan, implement, and reflect on actions intended to address student hunger. Through a combination of collaborative and individual processes of data analysis, we responded to four subquestions through four phases, which culminated in the co-construction of a people-centred approach to student hunger. Students’ conceptualisations of student hunger revealed two types: hunger of the stomach and hunger of the mind. The cyclical relationship between the two types infers that nutritional well-being is not achieved adequately when students have the means to acquire food. Choices regarding the utilisation of the available means also need consideration. The findings revealed that students apply the conscientisation framework in the ways that they plan to address student hunger. Applying value-driven processes, actions entailed physical dialogues with groups of people. The approach developed in this study offers strategies for the stakeholders who attend to student hunger, to collaborate and make contributions towards comprehensively resolving the complex issue. It primarily could be useful to institutions of higher education as the suggested coordinators of a collaborative structure. A second part of the developed approach puts forward a strategy to address the financial capabilities of students. The study contributes a consideration to constraints that stem from students’ mindsets and adoption of a prevailing culture that maintains student hunger. This demonstrates that resolutions to addressing student hunger might be more effective and sustainable if the context, views and participation of people experiencing the hunger are considered. , Thesis (PhD) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Coastal urban climate change adaptation and disaster risk reduction assessment: the case of East London city, South Africa
- Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Code of conduct for learners: A strategy for enhancing positive discipline in selected township schools in Durban, KwaZulu-Natal
- Zondo, Sindiswa Silindokuhle
- Authors: Zondo, Sindiswa Silindokuhle
- Date: 2022-03
- Subjects: School discipline
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21711 , vital:51744
- Description: Dealing with misbehaving learners remains a significant challenge for teachers in South African schools. As the use of corporal punishment and other punitive measures to deal with misbehaving learners is now illegal, alternative positive disciplinary measures have been put in place. The prohibition of negative disciplinary measures has left teachers feeling powerless and frustrated, not knowing how to manage learner behaviour, despite the fact that they are the viable agents tasked with ensuring that positive disciplinary measures are implemented in schools. This study sought to examine how best a code of conduct for learners can be used to enhance positive discipline in schools. To that end, the study offers insights into how positive disciplinary measures may be used, in dealing with learner indiscipline. This is a qualitative study, underpinned by the interpretivist paradigm. The study employed a phenomenological design as a strategy for data collection, to examine how a code of conduct for learners can be used to enhance positive discipline in selected township schools. As this is a qualitative study concerned more with the depth than the breadth of information, the researcher deemed it necessary to focus on two schools, to obtain deep insight into the participants’ lived experiences. Two schools, in Pinetown in Durban, participated in the study. Interviews, observations and document reviews were used as data-collection instruments. In each school, interviews were conducted with the school principal, teacher representatives serving on the school governing board, disciplinary committee members, and members of the representative council for learners. Disciplinary hearings and disciplinary committee meetings were observed, and documents of relevance to the study were reviewed. The findings, as reported on here, revealed that the code of conduct is the most important strategy that schools can use to enhance positive discipline. Other strategies in enhancing positive discipline include the use of a research-based positive classroom management approach; positive reinforcement; integrating community support services; modelling good behaviour; parental involvement; preventive, supportive and corrective discipline; detention; communication (incorporating professionalism and cooperation); the creation of an environment conducive to teaching and learning; and the withdrawal or withholding of privileges. The findings further revealed that positive discipline is an alternative to negative disciplinary measures, such as corporal punishment in schools. Teachers are expected to comply with, and adhere to, disciplinary policies, and to assist learners in unlearning bad behaviours and developing the necessary life skills, values, and attitudes. The participants’ understanding of the use of a code of conduct for positive discipline successfully assisted them, as teachers, in dealing with misbehaving learners, and, in turn, in developing learners’ positive self-control and self-esteem, helping them to become responsible citizens, and courageous and respectful learners, not only in the school environment, but also as members of society at large. The research findings also revealed that many participants believed using a code of conduct (positive discipline) to enhance positive behaviour was a waste of time, and ineffective. As the findings indicate, learners were found to become impervious or immune to positive disciplinary measures put in place to assist them with behavioural problems. The findings also revealed that the ineffectiveness of such a code in enhancing positive discipline could be attributed to the fact that the teachers themselves were not, to a certain degree, fully trained with regard to positive disciplinary measures. A lack of parental support and teacher professionalism, the continued use of (the prohibited) corporal punishment, poor communication, a lack of stakeholder involvement in formulating codes of conduct, a lack of positive modelling and power struggles were found to impede the use of a code of conduct to enhance positive discipline in schools. Based on the research findings, the study recommends that schools ensure that there is a sufficiently detailed code of conduct to assist teachers in addressing learners’ bad behaviour. There should also be advocacy from the Department of Basic Education, for support programmes to be put in place to assist teachers with alternative ways of enhancing positive discipline in the classroom. Awareness of how teachers are to be upskilled as regards positive disciplinary strategies, active parental involvement, and increased support for teachers, are amongst the recommendations. Ultimately, the researcher concluded that the code of conduct was a strategy that schools can use to enhance positive discipline. To this end, teachers must adhere to that code (and other positive disciplinary measures), for positive discipline to flourish in schools. , Thesis (PhD) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-03
- Authors: Zondo, Sindiswa Silindokuhle
- Date: 2022-03
- Subjects: School discipline
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21711 , vital:51744
- Description: Dealing with misbehaving learners remains a significant challenge for teachers in South African schools. As the use of corporal punishment and other punitive measures to deal with misbehaving learners is now illegal, alternative positive disciplinary measures have been put in place. The prohibition of negative disciplinary measures has left teachers feeling powerless and frustrated, not knowing how to manage learner behaviour, despite the fact that they are the viable agents tasked with ensuring that positive disciplinary measures are implemented in schools. This study sought to examine how best a code of conduct for learners can be used to enhance positive discipline in schools. To that end, the study offers insights into how positive disciplinary measures may be used, in dealing with learner indiscipline. This is a qualitative study, underpinned by the interpretivist paradigm. The study employed a phenomenological design as a strategy for data collection, to examine how a code of conduct for learners can be used to enhance positive discipline in selected township schools. As this is a qualitative study concerned more with the depth than the breadth of information, the researcher deemed it necessary to focus on two schools, to obtain deep insight into the participants’ lived experiences. Two schools, in Pinetown in Durban, participated in the study. Interviews, observations and document reviews were used as data-collection instruments. In each school, interviews were conducted with the school principal, teacher representatives serving on the school governing board, disciplinary committee members, and members of the representative council for learners. Disciplinary hearings and disciplinary committee meetings were observed, and documents of relevance to the study were reviewed. The findings, as reported on here, revealed that the code of conduct is the most important strategy that schools can use to enhance positive discipline. Other strategies in enhancing positive discipline include the use of a research-based positive classroom management approach; positive reinforcement; integrating community support services; modelling good behaviour; parental involvement; preventive, supportive and corrective discipline; detention; communication (incorporating professionalism and cooperation); the creation of an environment conducive to teaching and learning; and the withdrawal or withholding of privileges. The findings further revealed that positive discipline is an alternative to negative disciplinary measures, such as corporal punishment in schools. Teachers are expected to comply with, and adhere to, disciplinary policies, and to assist learners in unlearning bad behaviours and developing the necessary life skills, values, and attitudes. The participants’ understanding of the use of a code of conduct for positive discipline successfully assisted them, as teachers, in dealing with misbehaving learners, and, in turn, in developing learners’ positive self-control and self-esteem, helping them to become responsible citizens, and courageous and respectful learners, not only in the school environment, but also as members of society at large. The research findings also revealed that many participants believed using a code of conduct (positive discipline) to enhance positive behaviour was a waste of time, and ineffective. As the findings indicate, learners were found to become impervious or immune to positive disciplinary measures put in place to assist them with behavioural problems. The findings also revealed that the ineffectiveness of such a code in enhancing positive discipline could be attributed to the fact that the teachers themselves were not, to a certain degree, fully trained with regard to positive disciplinary measures. A lack of parental support and teacher professionalism, the continued use of (the prohibited) corporal punishment, poor communication, a lack of stakeholder involvement in formulating codes of conduct, a lack of positive modelling and power struggles were found to impede the use of a code of conduct to enhance positive discipline in schools. Based on the research findings, the study recommends that schools ensure that there is a sufficiently detailed code of conduct to assist teachers in addressing learners’ bad behaviour. There should also be advocacy from the Department of Basic Education, for support programmes to be put in place to assist teachers with alternative ways of enhancing positive discipline in the classroom. Awareness of how teachers are to be upskilled as regards positive disciplinary strategies, active parental involvement, and increased support for teachers, are amongst the recommendations. Ultimately, the researcher concluded that the code of conduct was a strategy that schools can use to enhance positive discipline. To this end, teachers must adhere to that code (and other positive disciplinary measures), for positive discipline to flourish in schools. , Thesis (PhD) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-03
Code of conduct for learners: A strategy for enhancing positive discipline in selected township schools in Durban, KwaZulu-Natal
- Zondo, Sindiswa Silindokuhle
- Authors: Zondo, Sindiswa Silindokuhle
- Date: 2022-03
- Subjects: School discipline
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21736 , vital:51747
- Description: Ddeleting thos one delete 2 , Thesis (PhD) -- Faculty of Education, 2022
- Full Text: false
- Date Issued: 2022-03
- Authors: Zondo, Sindiswa Silindokuhle
- Date: 2022-03
- Subjects: School discipline
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21736 , vital:51747
- Description: Ddeleting thos one delete 2 , Thesis (PhD) -- Faculty of Education, 2022
- Full Text: false
- Date Issued: 2022-03
Collegial leadership roles of teachers to manage curriculum reform in primary schools In Limpopo, South Africa
- Authors: Kgohlo, Piet Maphodisa
- Date: 2015-01
- Subjects: Limpompo (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53349 , vital:45143
- Description: The purpose of this study was to investigate the collegial leadership roles of teachers in managing the challenges of the implementation of the CAPS curriculum in primary schools in Limpopo. Four hundred and ninety-two teachers participated in this quantitative study. The findings of this study revealed that the majority of teachers in the intermediate phase of primary schooling in Limpopo lack competence in content subjects such as mathematics, NSTECH and English as the language of teaching and learning. The findings further revealed that the lack of facilities such as libraries, media centres and computers, teacher development and support and infrastructure such as classrooms contributed to teachers’ low competencies in the use of resources to manage the challenges of the implementation of CAPS. In addition, the findings revealed that the majority of teachers experienced high levels of tobephobia. Furthermore, the findings revealed that teachers showed symptoms of stress, anxiety, tension, unhappiness, depression, pessimism and uncertainty in managing the challenges of the implementation of CAPS. However, the findings also revealed that collegial teaming is a potent strategy that could be used to reinforce the in-service training that fails to equip teachers with the requisite knowledge and skills to face up to the challenges of managing the implementation of CAPS. This research explored a new area of managing curriculum change by making use of collegial teaming to develop teachers’ professional competencies. It makes a significant contribution to the existing body of knowledge of implementing curriculum reforms in disadvantaged schools. , Thesis (PhD) -- Faculty of Humanities, Primary School Education: Intermediate Phase, 2015.
- Full Text:
- Date Issued: 2015-01
- Authors: Kgohlo, Piet Maphodisa
- Date: 2015-01
- Subjects: Limpompo (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53349 , vital:45143
- Description: The purpose of this study was to investigate the collegial leadership roles of teachers in managing the challenges of the implementation of the CAPS curriculum in primary schools in Limpopo. Four hundred and ninety-two teachers participated in this quantitative study. The findings of this study revealed that the majority of teachers in the intermediate phase of primary schooling in Limpopo lack competence in content subjects such as mathematics, NSTECH and English as the language of teaching and learning. The findings further revealed that the lack of facilities such as libraries, media centres and computers, teacher development and support and infrastructure such as classrooms contributed to teachers’ low competencies in the use of resources to manage the challenges of the implementation of CAPS. In addition, the findings revealed that the majority of teachers experienced high levels of tobephobia. Furthermore, the findings revealed that teachers showed symptoms of stress, anxiety, tension, unhappiness, depression, pessimism and uncertainty in managing the challenges of the implementation of CAPS. However, the findings also revealed that collegial teaming is a potent strategy that could be used to reinforce the in-service training that fails to equip teachers with the requisite knowledge and skills to face up to the challenges of managing the implementation of CAPS. This research explored a new area of managing curriculum change by making use of collegial teaming to develop teachers’ professional competencies. It makes a significant contribution to the existing body of knowledge of implementing curriculum reforms in disadvantaged schools. , Thesis (PhD) -- Faculty of Humanities, Primary School Education: Intermediate Phase, 2015.
- Full Text:
- Date Issued: 2015-01
Colonial displacements and African coping strategies: The experience of BaTonga of Binga, Zimbabwe, 1956-2008
- Authors: Dhodho, Codelia Govha
- Date: 2022-10-14
- Subjects: Tonga (Zambezi people) Refugees , Subsistence farming Zambezi River Valley , Hunger Zambezi River Valley , Food security Zambezi River Valley , Adaptability (Psychology) , Food relief Zambezi River Valley , Non-governmental organizations , Kariba Dam (Zambia and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327642 , vital:61139 , DOI 10.21504/10962/327642
- Description: This study examines the challenges faced by BaTonga in livelihood reconstruction after involuntary displacement and resettlement from the Zambezi valley to pave way for the Kariba dam reservoir. It shows how they were forcibly evicted without compensation because of the racist policies of Southern Rhodesia. Their resettlement into an arid region infested with marauding elephants, malaria and tsetse fly undermined their complex livelihoods and eroded their self-sufficiency, but the study argues that they were active and resilient agents who adopted complex coping strategies. It shows how they had to adapt to dry-land farming and counter the effects of wildlife which plundered their crops and managed to secure the harvest in the drought-prone region. The study shows that although they adopted precarious livelihoods, they managed to survive under extreme circumstances for decades without any external assistance until the coming of NGOs who began to distribute free food from 1982. It argues that prolonged distribution of emergence food aid may not have been necessary, but its coming for almost three decades largely served political interests of both the NGOs and their governments. This perpetuated poverty as BaTonga also manipulated its distribution as a coping strategy against fragile livelihoods. This caused dependency which further plunged them into chronic food insecurity because they abandoned their traditional coping strategies. The study argues that both the colonial and postcolonial government as well as NGOs failed to address the root causes of livelihood insecurity in Binga for the five decades under study. It is therefore the contention of this study that the problem of food insecurity in Binga was not only an issue of recurring drought but was deeply rooted and pervasive due to multiple complex factors which made it difficult for the people to establish sustainable food production after displacement. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Dhodho, Codelia Govha
- Date: 2022-10-14
- Subjects: Tonga (Zambezi people) Refugees , Subsistence farming Zambezi River Valley , Hunger Zambezi River Valley , Food security Zambezi River Valley , Adaptability (Psychology) , Food relief Zambezi River Valley , Non-governmental organizations , Kariba Dam (Zambia and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327642 , vital:61139 , DOI 10.21504/10962/327642
- Description: This study examines the challenges faced by BaTonga in livelihood reconstruction after involuntary displacement and resettlement from the Zambezi valley to pave way for the Kariba dam reservoir. It shows how they were forcibly evicted without compensation because of the racist policies of Southern Rhodesia. Their resettlement into an arid region infested with marauding elephants, malaria and tsetse fly undermined their complex livelihoods and eroded their self-sufficiency, but the study argues that they were active and resilient agents who adopted complex coping strategies. It shows how they had to adapt to dry-land farming and counter the effects of wildlife which plundered their crops and managed to secure the harvest in the drought-prone region. The study shows that although they adopted precarious livelihoods, they managed to survive under extreme circumstances for decades without any external assistance until the coming of NGOs who began to distribute free food from 1982. It argues that prolonged distribution of emergence food aid may not have been necessary, but its coming for almost three decades largely served political interests of both the NGOs and their governments. This perpetuated poverty as BaTonga also manipulated its distribution as a coping strategy against fragile livelihoods. This caused dependency which further plunged them into chronic food insecurity because they abandoned their traditional coping strategies. The study argues that both the colonial and postcolonial government as well as NGOs failed to address the root causes of livelihood insecurity in Binga for the five decades under study. It is therefore the contention of this study that the problem of food insecurity in Binga was not only an issue of recurring drought but was deeply rooted and pervasive due to multiple complex factors which made it difficult for the people to establish sustainable food production after displacement. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14