Case-based research on the fedup model for self-help housing
- Authors: Qumbisa, Nolwazi
- Date: 2023-12
- Subjects: Community participation , Human settlements , Informal settlements
- Language: English
- Type: doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/62199 , vital:72007
- Description: In South Africa, the government subsidises the building of starter homes to meet the demand for housing for people with lower incomes. However, it is necessary for the state to revise its efforts to meet the demand for housing in the country. Self-help housing is a model that can be used as an alternative to state housing subsidies. The present research study investigates the essential aspects of sustainable self-help housing in the central region of South Africa. The present study aimed to address the central research topic by eliciting responses from participants: How can self-help provision become sustainable in the central region of South Africa? In response to the question, an effective self-help housing support model was developed, the aim of which is to outline how self-help housing projects could be improved. The literature findings demonstrate the potential of this model as a viable alternative to the existing housing delivery mechanism in South Africa. This assertion is supported by a study of self-help housing trajectories and an examination of relevant South African housing policies. However, there has been a lack of emphasis on the simplification of current models to accommodate the needs of implementers, government entities, and beneficiaries of self-help housing initiatives. This study aimed to address the highlighted gaps by utilising a qualitative methodology and drawing upon the data obtained. The data collection techniques included semi-structured interviews, structured observations, and focus-group discussions. A total of 25 semi-structured interviews were conducted with key stakeholders in human settlements, while the focus-group discussions involved 50 participants. A total of 5 focus group discussions were conducted with each group consisting of 10 participants. Moreover, the researcher conducted a document analysis, observations, and questionnaire survey. The data collected were analysed thematically. The results revealed that there are still challenges with implementing self-help housing. Moreover, the results are attributed mainly to a mismatch of the roles and responsibilities and not understanding the Enhanced People’s Housing Process (EPHP) policy. The principal contribution of the thesis is that housing policies, programmes and sector plans must encourage beneficiaries to play an active role. This study found that weak or unclear project vi specifications lead to contractor misunderstandings or discrepancies in housing project implementation, resulting in poor-quality work or delays. The conventional contractor-driven housing-delivery model also has issues like poor construction, corruption and mismanagement, profit-driven contractors, high contractor rates, project delays/incomplete projects, illegal occupation of incomplete projects, riots and disputes, ineffective project specifications, and beneficiary disengagement. In this study, it is demonstrated how a positive social impact on housing could be the outcome of an improved self-help approach. Consequently, the research suggests the adoption of an effective self-help housing support model, which may effectively address the challenges posed by informal settlements while enhancing the execution of self-help housing projects. The model has the potential to make contemporary contributions to the public housing policy model in South Africa. This study contributes to the broader discourse on sustainable housing alternatives, providing insights into the various obstacles, potential advantages, and recommended strategies within the realm of selfhelp housing. The study's qualitative approach facilitated a comprehensive examination of the lived experiences and viewpoints of diverse stakeholders. This yielded valuable insights that can inform policymakers, practitioners, and communities in their efforts to improve the sustainability of self-help housing solutions in the central region of South Africa. , Thesis (PhD) -- Engineering, Built Environment and Technology, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Qumbisa, Nolwazi
- Date: 2023-12
- Subjects: Community participation , Human settlements , Informal settlements
- Language: English
- Type: doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/62199 , vital:72007
- Description: In South Africa, the government subsidises the building of starter homes to meet the demand for housing for people with lower incomes. However, it is necessary for the state to revise its efforts to meet the demand for housing in the country. Self-help housing is a model that can be used as an alternative to state housing subsidies. The present research study investigates the essential aspects of sustainable self-help housing in the central region of South Africa. The present study aimed to address the central research topic by eliciting responses from participants: How can self-help provision become sustainable in the central region of South Africa? In response to the question, an effective self-help housing support model was developed, the aim of which is to outline how self-help housing projects could be improved. The literature findings demonstrate the potential of this model as a viable alternative to the existing housing delivery mechanism in South Africa. This assertion is supported by a study of self-help housing trajectories and an examination of relevant South African housing policies. However, there has been a lack of emphasis on the simplification of current models to accommodate the needs of implementers, government entities, and beneficiaries of self-help housing initiatives. This study aimed to address the highlighted gaps by utilising a qualitative methodology and drawing upon the data obtained. The data collection techniques included semi-structured interviews, structured observations, and focus-group discussions. A total of 25 semi-structured interviews were conducted with key stakeholders in human settlements, while the focus-group discussions involved 50 participants. A total of 5 focus group discussions were conducted with each group consisting of 10 participants. Moreover, the researcher conducted a document analysis, observations, and questionnaire survey. The data collected were analysed thematically. The results revealed that there are still challenges with implementing self-help housing. Moreover, the results are attributed mainly to a mismatch of the roles and responsibilities and not understanding the Enhanced People’s Housing Process (EPHP) policy. The principal contribution of the thesis is that housing policies, programmes and sector plans must encourage beneficiaries to play an active role. This study found that weak or unclear project vi specifications lead to contractor misunderstandings or discrepancies in housing project implementation, resulting in poor-quality work or delays. The conventional contractor-driven housing-delivery model also has issues like poor construction, corruption and mismanagement, profit-driven contractors, high contractor rates, project delays/incomplete projects, illegal occupation of incomplete projects, riots and disputes, ineffective project specifications, and beneficiary disengagement. In this study, it is demonstrated how a positive social impact on housing could be the outcome of an improved self-help approach. Consequently, the research suggests the adoption of an effective self-help housing support model, which may effectively address the challenges posed by informal settlements while enhancing the execution of self-help housing projects. The model has the potential to make contemporary contributions to the public housing policy model in South Africa. This study contributes to the broader discourse on sustainable housing alternatives, providing insights into the various obstacles, potential advantages, and recommended strategies within the realm of selfhelp housing. The study's qualitative approach facilitated a comprehensive examination of the lived experiences and viewpoints of diverse stakeholders. This yielded valuable insights that can inform policymakers, practitioners, and communities in their efforts to improve the sustainability of self-help housing solutions in the central region of South Africa. , Thesis (PhD) -- Engineering, Built Environment and Technology, 2023
- Full Text:
- Date Issued: 2023-12
Characterization of the coastal Aquifer of Gqeberha, South Africa : Developing a conceptual understanding
- Authors: Vandala, Bamanye
- Date: 2023-12
- Subjects: Aquifers -- South Africa -- Port Elizabeth , Groundwater ecology , Hydrogeology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62710 , vital:72932
- Description: The aquifer systems in Gqeberha are poorly understood due to a lack of groundwater studies within the area, and this is particularly the case for the coastal aquifer of Gqeberha. Amidst the water crisis the city is currently facing, groundwater has become crucial, with over 1000 boreholes reportedly drilled in the coastal area, most of which are residential. This has resulted in the need to conduct more groundwater studies in the area and in Nelson Mandela Bay. This study presents a detailed hydrogeological characterization of the coastal aquifer of Gqeberha. This was achieved through the use of different techniques, which include field mapping, geophysics, hydrochemistry, and pumping test analysis. The work was done on the coastal seeps of the Algoa Group Formation and the fractured aquifer of the Peninsula Formation. The results through mapping indicated an abundance of folds, faults, and fractures which all have implications for groundwater flow. The majority of fractures are striking in the NE-SW and NW-SE directions. The pumping test analysis also indicated fractal flow with significant matrix flow resulting in a dual porosity system up to at least 200m in depth. The transmissivity and storativity values range from 6.78 – 44.5 m2/day and 0.0172 – 0.0325, respectively. This is highly dependent on the fracture interconnectivity, which varies across the area and is higher at shallow depths, as suggested by the geophysical profiles. Geophysical profiles indicate that the contact between the Algoa Group Formations and the Peninsula Formation results in coastal seeps due to the difference in hydraulic conductivities. The hydrochemical analysis suggests that the seeps generally have Na-Cl and Ca-Mg-Cl water types. The groundwater in the eastern area has a Ca-HCO3 water type, and the groundwater in the western region has a Ca-Mg-Cl water type, with the Chelsea-Noordhoek Fault system separating the two groundwater signatures. Groundwater at greater depths has a Na-Cl water type with higher TDS values. The chemical signatures seen are due to external factors, which include sea sprays, anthropogenic activities, rock-water processes, and possibly connate water in the Peninsula Formation aquifer. The findings of this study offer valuable insights into the present conditions of the aquifer in Gqeberha. This research serves as a foundational study that can provide a baseline for future hydrogeological investigations in the area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Vandala, Bamanye
- Date: 2023-12
- Subjects: Aquifers -- South Africa -- Port Elizabeth , Groundwater ecology , Hydrogeology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62710 , vital:72932
- Description: The aquifer systems in Gqeberha are poorly understood due to a lack of groundwater studies within the area, and this is particularly the case for the coastal aquifer of Gqeberha. Amidst the water crisis the city is currently facing, groundwater has become crucial, with over 1000 boreholes reportedly drilled in the coastal area, most of which are residential. This has resulted in the need to conduct more groundwater studies in the area and in Nelson Mandela Bay. This study presents a detailed hydrogeological characterization of the coastal aquifer of Gqeberha. This was achieved through the use of different techniques, which include field mapping, geophysics, hydrochemistry, and pumping test analysis. The work was done on the coastal seeps of the Algoa Group Formation and the fractured aquifer of the Peninsula Formation. The results through mapping indicated an abundance of folds, faults, and fractures which all have implications for groundwater flow. The majority of fractures are striking in the NE-SW and NW-SE directions. The pumping test analysis also indicated fractal flow with significant matrix flow resulting in a dual porosity system up to at least 200m in depth. The transmissivity and storativity values range from 6.78 – 44.5 m2/day and 0.0172 – 0.0325, respectively. This is highly dependent on the fracture interconnectivity, which varies across the area and is higher at shallow depths, as suggested by the geophysical profiles. Geophysical profiles indicate that the contact between the Algoa Group Formations and the Peninsula Formation results in coastal seeps due to the difference in hydraulic conductivities. The hydrochemical analysis suggests that the seeps generally have Na-Cl and Ca-Mg-Cl water types. The groundwater in the eastern area has a Ca-HCO3 water type, and the groundwater in the western region has a Ca-Mg-Cl water type, with the Chelsea-Noordhoek Fault system separating the two groundwater signatures. Groundwater at greater depths has a Na-Cl water type with higher TDS values. The chemical signatures seen are due to external factors, which include sea sprays, anthropogenic activities, rock-water processes, and possibly connate water in the Peninsula Formation aquifer. The findings of this study offer valuable insights into the present conditions of the aquifer in Gqeberha. This research serves as a foundational study that can provide a baseline for future hydrogeological investigations in the area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Chemical analysis and biological activities of crude extracts and essential oil of selected medicinal plants from the Eastern Cape, South Africa, and Volta Region of Ghana
- Authors: Agbo, Irene Adzo
- Date: 2023-12
- Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62431 , vital:72728
- Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Agbo, Irene Adzo
- Date: 2023-12
- Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62431 , vital:72728
- Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Effects of annealing on the structural and optical properties of nanostructured TiO2
- Talla, Assane, Urgessa, Zelalem
- Authors: Talla, Assane , Urgessa, Zelalem
- Date: 2023-12
- Subjects: Titanium dioxide , Nanostructured materials , Nanotubes
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62655 , vital:72907
- Description: In this thesis, the structural, morphological and optical properties of titanium dioxide (TiO2) are investigated. Titanium dioxide (TiO2) nanotubes are prepared by anodic oxidation of titanium foil. The as-anodised samples are thermally annealed at various temperatures in nitrogen, air, oxygen and vacuum. The purpose is to study how the annealing conditions affect the properties of the nanostructures, including the anatase to rutile phase transformation. In all annealing atmospheres, except in vacuum, the dominant phase is found to be anatase when annealing is performed up to 600 oC. Above 700 oC the rutile phase becomes dominant. The anatase phase is stable above 600 oC in vacuum and does not evolve significantly up to 900 oC. The morphologies of the tubes tend to deteriorate with increased annealing temperature, in nitrogen, air and oxygen atmospheres, due to sintering effects. However, the integrity of the nanotubes is maintained up to 900 oC in vacuum. The photoluminescence (PL) spectra suggest mainly the presence of oxygen vacancies and self-trapped excitons, with respective emission bands around 2.5 eV and 2.3 eV. The results show that both the annealing temperature and atmosphere strongly influence the crystalline and optical properties of the TiO2 nanotubes. In addition, the phase transformation from anatase to rutile for samples annealed in an oxygen-rich environment is investigated in detail. Complementary structural information obtained from transmission electron microscopy and Raman analysis for oxygen-annealed samples reveals that the nucleation of the rutile phase starts from the titanium substrate and then propagates along the tubes. The results provide suitable annealing conditions to control the phase content and morphology of anodic TiO2 nanotubes. The PL characteristics of bulk crystalline anatase TiO2, namely virgin and hydrogen-annealed at 600 oC for 1 h, are studied. The low temperature PL spectra at 5.5 K shows near band edge (NBE) emissions with two dominant lines ascribed to shallow donor bound exciton and possibly free to bound recombination. The two main transitions are assisted by optical phononmodes. Temperature-dependent PL measurements performed on these anatase crystals reveal that the donor bound exciton is stable below 90 K. Hydrogen trapped in oxygen vacancies is proposed to be the shallow donor. In addition, two activation processes are involved for the thermal quenching of donor bound excitons. The total activation energy is found to correlate well with the localisation energy of the bound exciton. Site-selective PL spectra obtained from anodic TiO2 tubes reveals that the luminescence of the nanostructures depends on the morphology. The result shows unusual near-band edge emission (NBE) for these structures, which is rarely observed in indirect band gap TiO2. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Talla, Assane , Urgessa, Zelalem
- Date: 2023-12
- Subjects: Titanium dioxide , Nanostructured materials , Nanotubes
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62655 , vital:72907
- Description: In this thesis, the structural, morphological and optical properties of titanium dioxide (TiO2) are investigated. Titanium dioxide (TiO2) nanotubes are prepared by anodic oxidation of titanium foil. The as-anodised samples are thermally annealed at various temperatures in nitrogen, air, oxygen and vacuum. The purpose is to study how the annealing conditions affect the properties of the nanostructures, including the anatase to rutile phase transformation. In all annealing atmospheres, except in vacuum, the dominant phase is found to be anatase when annealing is performed up to 600 oC. Above 700 oC the rutile phase becomes dominant. The anatase phase is stable above 600 oC in vacuum and does not evolve significantly up to 900 oC. The morphologies of the tubes tend to deteriorate with increased annealing temperature, in nitrogen, air and oxygen atmospheres, due to sintering effects. However, the integrity of the nanotubes is maintained up to 900 oC in vacuum. The photoluminescence (PL) spectra suggest mainly the presence of oxygen vacancies and self-trapped excitons, with respective emission bands around 2.5 eV and 2.3 eV. The results show that both the annealing temperature and atmosphere strongly influence the crystalline and optical properties of the TiO2 nanotubes. In addition, the phase transformation from anatase to rutile for samples annealed in an oxygen-rich environment is investigated in detail. Complementary structural information obtained from transmission electron microscopy and Raman analysis for oxygen-annealed samples reveals that the nucleation of the rutile phase starts from the titanium substrate and then propagates along the tubes. The results provide suitable annealing conditions to control the phase content and morphology of anodic TiO2 nanotubes. The PL characteristics of bulk crystalline anatase TiO2, namely virgin and hydrogen-annealed at 600 oC for 1 h, are studied. The low temperature PL spectra at 5.5 K shows near band edge (NBE) emissions with two dominant lines ascribed to shallow donor bound exciton and possibly free to bound recombination. The two main transitions are assisted by optical phononmodes. Temperature-dependent PL measurements performed on these anatase crystals reveal that the donor bound exciton is stable below 90 K. Hydrogen trapped in oxygen vacancies is proposed to be the shallow donor. In addition, two activation processes are involved for the thermal quenching of donor bound excitons. The total activation energy is found to correlate well with the localisation energy of the bound exciton. Site-selective PL spectra obtained from anodic TiO2 tubes reveals that the luminescence of the nanostructures depends on the morphology. The result shows unusual near-band edge emission (NBE) for these structures, which is rarely observed in indirect band gap TiO2. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Effects of fire on architecture and composition of canopy shrubs in subtropical dune thicket of the southeastern Cape Floristic Region
- Strydom, Tiaan, Grobler, Adriaan
- Authors: Strydom, Tiaan , Grobler, Adriaan
- Date: 2023-12
- Subjects: Plant ecology -- Research , Plant communities -- South Africa , Browsing (Animal behavior)
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62632 , vital:72899
- Description: Disturbance, such as fire and megaherbivory, is a pervasive phenomenon globally and has different effects on the flora and vegetation of different ecosystems. The Cape Floristic Region (CFR) of South Africa includes the distinctive Subtropical Thicket biome, which occurs as interrupted blocks that are not exposed to fire, but also as mosaics with the fire-prone vegetation of the Fynbos biome, especially on coastal dunes where thicket species are exposed to fire. Subtropical Dune Thicket (hereafter thicket) thus co-occurs with Fynbos, capable of supporting intense fires that can lead to thicket shrub defoliation and mortality. Thicket also experiences disturbance from meso- and megaherbivores that causes defoliation and mortality of shrubs. The aim of this study was to investigate the resilience of thicket shrub species to varying disturbance levels from fire and browsing to understand what drives thicket persistence in a fire-prone landscape. Firstly, I established the architectural traits of thicket species in long unburnt and post-fire contexts and investigated the relationships between these traits and the survival, resprouting ability and persistence of thicket shrubs. In mature thicket, I identified three distinct architectural guilds, namely hedge formers, lateral spreaders, and vertical growers. In post-fire thicket I identified three resprouting architectures, namely weak resprouters, moderate resprouters and strong resprouters. There was no strong relationship between the unburnt and post-fire resprouting architectures. Secondly, I compared thicket species and architectural composition in patches of landscape that experience different levels of fire exposure to assess the potential effect of fire frequency on determining thicket structure. I recognised three thicket vegetation units, each with a distinct structure and each corresponding to the level of fire exposure in the landscape. The first unit, forest-thicket, is exposed to low levels of fire frequency (> 100 years) and harbours forest species, many of which were vertical growers. The second unit, thicket, is exposed to moderate levels of fire frequency (50-100 years) and is dominated by lateral spreaders. The last unit, fynbos-thicket, is exposed to high levels of fire frequency (10-50 years) and here hedge-forming shrubs dominate the canopy cover. Forest-thicket and fynbos-thicket had a diverse set of shrub species with many being restricted to their respective vegetation type, whereas thicket had a lower diversity with no unique shrub species. , Thesis (DPhil) -- Faculty of Science, School of Natural Resource Management, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Strydom, Tiaan , Grobler, Adriaan
- Date: 2023-12
- Subjects: Plant ecology -- Research , Plant communities -- South Africa , Browsing (Animal behavior)
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62632 , vital:72899
- Description: Disturbance, such as fire and megaherbivory, is a pervasive phenomenon globally and has different effects on the flora and vegetation of different ecosystems. The Cape Floristic Region (CFR) of South Africa includes the distinctive Subtropical Thicket biome, which occurs as interrupted blocks that are not exposed to fire, but also as mosaics with the fire-prone vegetation of the Fynbos biome, especially on coastal dunes where thicket species are exposed to fire. Subtropical Dune Thicket (hereafter thicket) thus co-occurs with Fynbos, capable of supporting intense fires that can lead to thicket shrub defoliation and mortality. Thicket also experiences disturbance from meso- and megaherbivores that causes defoliation and mortality of shrubs. The aim of this study was to investigate the resilience of thicket shrub species to varying disturbance levels from fire and browsing to understand what drives thicket persistence in a fire-prone landscape. Firstly, I established the architectural traits of thicket species in long unburnt and post-fire contexts and investigated the relationships between these traits and the survival, resprouting ability and persistence of thicket shrubs. In mature thicket, I identified three distinct architectural guilds, namely hedge formers, lateral spreaders, and vertical growers. In post-fire thicket I identified three resprouting architectures, namely weak resprouters, moderate resprouters and strong resprouters. There was no strong relationship between the unburnt and post-fire resprouting architectures. Secondly, I compared thicket species and architectural composition in patches of landscape that experience different levels of fire exposure to assess the potential effect of fire frequency on determining thicket structure. I recognised three thicket vegetation units, each with a distinct structure and each corresponding to the level of fire exposure in the landscape. The first unit, forest-thicket, is exposed to low levels of fire frequency (> 100 years) and harbours forest species, many of which were vertical growers. The second unit, thicket, is exposed to moderate levels of fire frequency (50-100 years) and is dominated by lateral spreaders. The last unit, fynbos-thicket, is exposed to high levels of fire frequency (10-50 years) and here hedge-forming shrubs dominate the canopy cover. Forest-thicket and fynbos-thicket had a diverse set of shrub species with many being restricted to their respective vegetation type, whereas thicket had a lower diversity with no unique shrub species. , Thesis (DPhil) -- Faculty of Science, School of Natural Resource Management, 2023
- Full Text:
- Date Issued: 2023-12
Effects of selected natural flavonoids on an optimized insulin resistance induction model on myotubes and hepatocytes in vitro
- Authors: Van de Venter, Ruben
- Date: 2023-12
- Subjects: Flavonoid , Insulin resistance , Myotubes and hepatocytes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63049 , vital:73085
- Description: Introduction: As the third largest life-threatening non-communicable disease, further research to improve T2DM treatment remains pivotal. The approved insulin sensitizing agents, metformin and thiazolidinediones, although effective, have an array of adverse effects. This leads to the growing need for safer insulin sensitizing agents. Aims: To induce insulin resistance, an insulin resistance induction (IRI) model consisting of palmitic acid (PA), fructose, and dexamethasone (DEX), was optimized. The model was utilized to compare the insulin sensitizing efficacy of chrysin, apigenin, luteolin, and quercetin. The most effective flavonoid was extrapolated based on the hydroxylation hypothesis and relevant SAR. The flavonoid was combined with metformin to evaluate potential insulin sensitizing synergism. Methods: C3A hepatocytes and L6 myotubes were exposed to the IRI models: IR1, IR2, and OIR, for 24 and 48h. Morphological features indicative of insulin resistance were monitored through high-content analysis (HCA). Thereafter, cells were exposed to OIR and concurrently treated with the selected flavonoids. Cytotoxicity, oxidative stress (OS), mitochondrial content, mitochondrial membrane potential (MMP), and lipid accumulation, were once again evaluated through HCA. Subsequently, quercetin was combined with metformin (QM); insulin resistant conditions established through OIR exposure, and QM administered as prophylaxis. The efficacy of QM was determined through changes in phosphorylated-Akt, glucose uptake, and gluconeogenesis. Results: IR1 and IR2 demonstrated excessive potency, whereas OIR consistently generated insulin resistant C3A/L6 cells by increasing OS (↑14%/20%), lipid accumulation (0.7-fold/1.5-fold), and decreasing MMP (↓4%/6%). Of the selected flavonoids, quercetin was most effective at ameliorating each of these parameters. Furthermore, QM demonstrated potential insulin sensitizing synergism, as it improved Akt phosphorylation (Thr308: ↑31%/↑17%; Ser473: ↑29%), glucose uptake (↑10%/ 5%), and suppressed hepatic gluconeogenesis (15↓%) more effectively compared to monotherapy. Conclusions: OIR is an effective model for the induction of complete early-stage insulin resistance in myotubes and hepatocytes. Quercetin demonstrates exceptional antidiabetic activity due its unique expression of hydroxyl groups. Lastly, QM, comparative to monotherapy, improves insulin sensitivity with enhanced efficacy. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Van de Venter, Ruben
- Date: 2023-12
- Subjects: Flavonoid , Insulin resistance , Myotubes and hepatocytes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63049 , vital:73085
- Description: Introduction: As the third largest life-threatening non-communicable disease, further research to improve T2DM treatment remains pivotal. The approved insulin sensitizing agents, metformin and thiazolidinediones, although effective, have an array of adverse effects. This leads to the growing need for safer insulin sensitizing agents. Aims: To induce insulin resistance, an insulin resistance induction (IRI) model consisting of palmitic acid (PA), fructose, and dexamethasone (DEX), was optimized. The model was utilized to compare the insulin sensitizing efficacy of chrysin, apigenin, luteolin, and quercetin. The most effective flavonoid was extrapolated based on the hydroxylation hypothesis and relevant SAR. The flavonoid was combined with metformin to evaluate potential insulin sensitizing synergism. Methods: C3A hepatocytes and L6 myotubes were exposed to the IRI models: IR1, IR2, and OIR, for 24 and 48h. Morphological features indicative of insulin resistance were monitored through high-content analysis (HCA). Thereafter, cells were exposed to OIR and concurrently treated with the selected flavonoids. Cytotoxicity, oxidative stress (OS), mitochondrial content, mitochondrial membrane potential (MMP), and lipid accumulation, were once again evaluated through HCA. Subsequently, quercetin was combined with metformin (QM); insulin resistant conditions established through OIR exposure, and QM administered as prophylaxis. The efficacy of QM was determined through changes in phosphorylated-Akt, glucose uptake, and gluconeogenesis. Results: IR1 and IR2 demonstrated excessive potency, whereas OIR consistently generated insulin resistant C3A/L6 cells by increasing OS (↑14%/20%), lipid accumulation (0.7-fold/1.5-fold), and decreasing MMP (↓4%/6%). Of the selected flavonoids, quercetin was most effective at ameliorating each of these parameters. Furthermore, QM demonstrated potential insulin sensitizing synergism, as it improved Akt phosphorylation (Thr308: ↑31%/↑17%; Ser473: ↑29%), glucose uptake (↑10%/ 5%), and suppressed hepatic gluconeogenesis (15↓%) more effectively compared to monotherapy. Conclusions: OIR is an effective model for the induction of complete early-stage insulin resistance in myotubes and hepatocytes. Quercetin demonstrates exceptional antidiabetic activity due its unique expression of hydroxyl groups. Lastly, QM, comparative to monotherapy, improves insulin sensitivity with enhanced efficacy. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Establishment of a high-content neurodegenerative disease model screening platform
- Authors: Swanepoel, Bresler
- Date: 2023-12
- Subjects: Molecular neurobiology , Nervous system -- Diseases , Nervous system -- Degeneration
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62644 , vital:72906
- Description: The identification of viable therapeutic targets and new treatments for central nervous system disorders, especially neurodegenerative diseases, remain major challenges in the field of drug discovery. Over the past few years there has been a steady decline in the turnaround time of current screening processes to yield viable drugs. Therefore, an increasing need exists for better technologies, protocols, and the screening of larger libraries. High-throughput screening provides the best solution to this problem and has become a key part in the drug discovery and development process. Likewise, high-content analysis has gained popularity over the past few years and is suitable for high-throughput screening. The aim of this study was to establish a comprehensive in vitro neuroprotective screening platform incorporating high throughput screening, using Parkinson’s disease as the neurodegenerative disease of interest. To evaluate the success of this platform, the neuroprotective potential of two mushrooms (Hericium erinaceus and Phlebopus sudanicus), two plants (Lippia javanica and Myrothamnus flabellifolia) and two seaweeds (Eucheuma denticulatum and Kappaphycus alvarezii) were investigated. Aqueous and ethanolic extracts of the selected natural products were evaluated across 21 parameters associated with four hallmarks of neurodegeneration: acquiring senescence, acquiring cell death, neuroinflammation and altered metabolism/cell survival. Based on the effects of these selected natural products on the 21 parameters, their potential mechanisms of action were elucidated. In addition to this, the natural products were scored under each of these therapeutic targets in an attempt to identify the most suitable animal models for future studies. The scoring system indicated that animal models investigating anti-senescence ability would be more suited for extracts of H. erinaceus, P. sudanicus and E. denticulatum whereas studies investigating the prevention of cell death would be more suited for extracts of E. denticulatum, L. javanica and K. alvarezii. Likewise, models based on neuroinflammation would be best suited for extracts of H. erinaceus, E. denticulatum and L. javanica while studies examining altered metabolism/cell survival would be best suited to extracts of H. erinaceus, E. denticulatum, K. alvarezii and M. flabellifolia. Considering the pleiotropic nature of the selected natural products, models that can combine these therapeutic targets could be of great interest. 6-OHDA proved to be capable of inducing favourable effects, in all the parameters investigated, with regard to a neurodegenerative state. However, it is known to have some disadvantages when it comes to pathological features such as the lack of the ability to induce Lewy body formation. Choosing the correct inducer remains a daunting task and no model, whether cell-based or animal-based, exists yet in which all the features of neurodegenerative diseases have been successfully replicated. The limitations of the current models, however, does not mean that they do not produce valuable insights. This is especially true if the mechanism of action for a specific compound or natural product is unknown. Animal models are still indispensable for the validation and interpretation of the results obtained from cell models with particular importance to toxicity. Therefore, this study assessed the best studied extract with the highest overall score for its toxicity using a zebrafish larvae-based model. Assessment of the toxicity of H. erinaceus revealed that both aqueous and ethanolic extracts resulted in death at the highest concentrations. This was supported by the results obtained in the in vitro cytotoxicity screening. In conclusion, this highlighted the importance of using physiologically relevant concentrations and supported the translational value of the current cell-based screening model to animal models and possibly humans. The findings of the present study suggest that a scoring system, which categorizes the different activities of selected natural products into distinct groups, can be a useful tool to improve the translatability of in vitro results to animal models. Furthermore, the current study arguably provides the most comprehensive neuroprotective screening platform in existence. Future research can look at expanding the platform through incorporation of additional parameters based on other hallmarks of neurodegeneration, not covered in this study, including protein folding and aggregation, altered epigenetics and the examination of other neuronal markers such as the involvement of astrocytes, oligodendrocytes, and microglia. In addition to this, future research can make use of more sophisticated cell models such as differentiated, human induced pluripotent stem cells and three-dimensional cultures. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Swanepoel, Bresler
- Date: 2023-12
- Subjects: Molecular neurobiology , Nervous system -- Diseases , Nervous system -- Degeneration
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62644 , vital:72906
- Description: The identification of viable therapeutic targets and new treatments for central nervous system disorders, especially neurodegenerative diseases, remain major challenges in the field of drug discovery. Over the past few years there has been a steady decline in the turnaround time of current screening processes to yield viable drugs. Therefore, an increasing need exists for better technologies, protocols, and the screening of larger libraries. High-throughput screening provides the best solution to this problem and has become a key part in the drug discovery and development process. Likewise, high-content analysis has gained popularity over the past few years and is suitable for high-throughput screening. The aim of this study was to establish a comprehensive in vitro neuroprotective screening platform incorporating high throughput screening, using Parkinson’s disease as the neurodegenerative disease of interest. To evaluate the success of this platform, the neuroprotective potential of two mushrooms (Hericium erinaceus and Phlebopus sudanicus), two plants (Lippia javanica and Myrothamnus flabellifolia) and two seaweeds (Eucheuma denticulatum and Kappaphycus alvarezii) were investigated. Aqueous and ethanolic extracts of the selected natural products were evaluated across 21 parameters associated with four hallmarks of neurodegeneration: acquiring senescence, acquiring cell death, neuroinflammation and altered metabolism/cell survival. Based on the effects of these selected natural products on the 21 parameters, their potential mechanisms of action were elucidated. In addition to this, the natural products were scored under each of these therapeutic targets in an attempt to identify the most suitable animal models for future studies. The scoring system indicated that animal models investigating anti-senescence ability would be more suited for extracts of H. erinaceus, P. sudanicus and E. denticulatum whereas studies investigating the prevention of cell death would be more suited for extracts of E. denticulatum, L. javanica and K. alvarezii. Likewise, models based on neuroinflammation would be best suited for extracts of H. erinaceus, E. denticulatum and L. javanica while studies examining altered metabolism/cell survival would be best suited to extracts of H. erinaceus, E. denticulatum, K. alvarezii and M. flabellifolia. Considering the pleiotropic nature of the selected natural products, models that can combine these therapeutic targets could be of great interest. 6-OHDA proved to be capable of inducing favourable effects, in all the parameters investigated, with regard to a neurodegenerative state. However, it is known to have some disadvantages when it comes to pathological features such as the lack of the ability to induce Lewy body formation. Choosing the correct inducer remains a daunting task and no model, whether cell-based or animal-based, exists yet in which all the features of neurodegenerative diseases have been successfully replicated. The limitations of the current models, however, does not mean that they do not produce valuable insights. This is especially true if the mechanism of action for a specific compound or natural product is unknown. Animal models are still indispensable for the validation and interpretation of the results obtained from cell models with particular importance to toxicity. Therefore, this study assessed the best studied extract with the highest overall score for its toxicity using a zebrafish larvae-based model. Assessment of the toxicity of H. erinaceus revealed that both aqueous and ethanolic extracts resulted in death at the highest concentrations. This was supported by the results obtained in the in vitro cytotoxicity screening. In conclusion, this highlighted the importance of using physiologically relevant concentrations and supported the translational value of the current cell-based screening model to animal models and possibly humans. The findings of the present study suggest that a scoring system, which categorizes the different activities of selected natural products into distinct groups, can be a useful tool to improve the translatability of in vitro results to animal models. Furthermore, the current study arguably provides the most comprehensive neuroprotective screening platform in existence. Future research can look at expanding the platform through incorporation of additional parameters based on other hallmarks of neurodegeneration, not covered in this study, including protein folding and aggregation, altered epigenetics and the examination of other neuronal markers such as the involvement of astrocytes, oligodendrocytes, and microglia. In addition to this, future research can make use of more sophisticated cell models such as differentiated, human induced pluripotent stem cells and three-dimensional cultures. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Evaluating antidiabetic properties of selected African medicinal plants in a cell-based model
- Sirkhotte, Saeedah, Reddy, Shanika
- Authors: Sirkhotte, Saeedah , Reddy, Shanika
- Date: 2023-12
- Subjects: Medicinal plants -- South Africa , Insulin resistance , Gluconeogenesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62600 , vital:72827
- Description: The World Health Organisation lists diabetes as one of the major non-communicable diseases affecting the world, and its prevalence is expected to increase rapidly. Type II diabetes mellitus (T2DM) is characterised by insulin resistance and impaired blood glucose control. T2DM is of growing concern within South Africa, with 10.8% of the population currently diagnosed. The popularity, as well as availability, of traditional plant-based medicine in South Africa, might provide a solution. Antidiabetic potential is commonly tested by in vitro assays, however the methods to test this potential via gluconeogenesis are limited. This project aimed to optimise an in vitro hepatic gluconeogenesis model. In addition, this project aimed to determine the antidiabetic properties of Prunus africana, Hypoxis stellipilis, and Eriocephalus africanus by in vitro analysis. These properties were examined in human hepatoma cells (C3A cell line) and rat pancreatic cells (INS1 cell line) and methods included: cytotoxicity analysis, Amplex® red glucose oxidase assay, antibody staining, gene expression analysis by RT-qPCR, oxidative stress analysis, and calcium signaling for insulin release. Insulin resistance was successfully induced by exposing C3A hepatocarcinoma cells to a combination treatment of 50 μM dexamethasone, 1.25 mM fructose and 0.125 mM palmitic acid for a period of three days. Thereafter, gluconeogenesis was assessed using the Amplex® red glucose oxidase assay. The established model was effective in inducing insulin resistance and upregulating gluconeogenesis. Of the tested plant extracts, H. stellipilis showed the most potential as an antidiabetic treatment. It had low toxicity, significantly decreased hepatic glucose production and reduced the amount of phosphoenolpyruvate carboxykinase (PCK) and well as PCK gene expression, and reduced lipid content and reactive oxygen species (ROS) in the C3A cell line. H. stellipilis increased calcium signalling in INS1 rat insulinoma cells, however there was a decrease in expression of genes for insulin and glucose transporter 2 after 6 hr exposure. H. stellipilis appears be beneficial as an antidiabetic treatment. Although antidiabetic studies have been done on other Hypoxis species, this is the first study on the effects of H. stellipilis on gluconeogenesis and diabetes. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Sirkhotte, Saeedah , Reddy, Shanika
- Date: 2023-12
- Subjects: Medicinal plants -- South Africa , Insulin resistance , Gluconeogenesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62600 , vital:72827
- Description: The World Health Organisation lists diabetes as one of the major non-communicable diseases affecting the world, and its prevalence is expected to increase rapidly. Type II diabetes mellitus (T2DM) is characterised by insulin resistance and impaired blood glucose control. T2DM is of growing concern within South Africa, with 10.8% of the population currently diagnosed. The popularity, as well as availability, of traditional plant-based medicine in South Africa, might provide a solution. Antidiabetic potential is commonly tested by in vitro assays, however the methods to test this potential via gluconeogenesis are limited. This project aimed to optimise an in vitro hepatic gluconeogenesis model. In addition, this project aimed to determine the antidiabetic properties of Prunus africana, Hypoxis stellipilis, and Eriocephalus africanus by in vitro analysis. These properties were examined in human hepatoma cells (C3A cell line) and rat pancreatic cells (INS1 cell line) and methods included: cytotoxicity analysis, Amplex® red glucose oxidase assay, antibody staining, gene expression analysis by RT-qPCR, oxidative stress analysis, and calcium signaling for insulin release. Insulin resistance was successfully induced by exposing C3A hepatocarcinoma cells to a combination treatment of 50 μM dexamethasone, 1.25 mM fructose and 0.125 mM palmitic acid for a period of three days. Thereafter, gluconeogenesis was assessed using the Amplex® red glucose oxidase assay. The established model was effective in inducing insulin resistance and upregulating gluconeogenesis. Of the tested plant extracts, H. stellipilis showed the most potential as an antidiabetic treatment. It had low toxicity, significantly decreased hepatic glucose production and reduced the amount of phosphoenolpyruvate carboxykinase (PCK) and well as PCK gene expression, and reduced lipid content and reactive oxygen species (ROS) in the C3A cell line. H. stellipilis increased calcium signalling in INS1 rat insulinoma cells, however there was a decrease in expression of genes for insulin and glucose transporter 2 after 6 hr exposure. H. stellipilis appears be beneficial as an antidiabetic treatment. Although antidiabetic studies have been done on other Hypoxis species, this is the first study on the effects of H. stellipilis on gluconeogenesis and diabetes. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Evaluation of the antidiabetic potential, safety and efficacy of selected natural products using zebrafish larvae and in vitro bioassays
- Reddy, Shanika, Dambuza, Ntokozo
- Authors: Reddy, Shanika , Dambuza, Ntokozo
- Date: 2023-12
- Subjects: Traditional medicine -- Research -- South Africa , Medicinal plants -- South Africa -- Research , Insulin resistance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62575 , vital:72825
- Description: Abstract. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Reddy, Shanika , Dambuza, Ntokozo
- Date: 2023-12
- Subjects: Traditional medicine -- Research -- South Africa , Medicinal plants -- South Africa -- Research , Insulin resistance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62575 , vital:72825
- Description: Abstract. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Evidence of Late Holocene extreme marine wave event (tsunami) deposits along the South African coast and implications for coastal zone management
- Authors: Mfikili, Athi Nkosibonile
- Date: 2023-12
- Subjects: Tsunamis -- South Africa , Coasts -- Risk assessment , Sediments (Geology)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62517 , vital:72811
- Description: Although extreme marine wave events such as tsunamis and storm surges have always been part of human existence, their impact on ever-growing coastal population of the world’s coast was highlighted by the recent catastrophic events over the past three decades. Although in situ observations and eyewitness accounts have improved our ability to record and interpret wave inundation by modern extreme marine events, records documenting inundation by pre-historic and historical events are relatively sparse to provide reasonable information on their distribution, magnitude and frequency intervals in most parts of the world. Owing to consequences these natural coastal hazards have on coastal population and infrastructure of the world’s coast, onshore sedimentary deposits preserved in the geological records have been extensively utilized by scientists worldwide to reconstruct the record of pre-historic and historical events and establish the recurrence interval of future events. Although studies investigating inundation of past tsunami has increased worldwide over the past two decades, research on extreme marine inundation has received little attention along the South African coast, despite known inundation by recent events and potential source mechanisms. Therefore, the aim of this study is to investigate sedimentary evidence of past tsunamis and related extreme marine wave events (i.e., storm surges) preserved in the recent geological archive of several coastal environments along the South African coast. The Swartkops, Kabeljous, Kromme and Keurbooms estuaries located in log-spiral bays along the south-east coast and sheltered coastal systems of the Berg Estuary and Verlorenvlei as well as coastal lowlands of the Dwarskersbos on the west coast were selected as the study sites. The sediment cores were collected from these coastal environments and identification of extreme marine wave inundation was based on the recognition of distinct anomalous sand layers. To characterise sediment transport and reconstruct provenance source origin of the deposits, a combination of sedimentological (i.e., grain size distribution), exoscopy (i.e., quartz grain surface microtextures) and micropaleontological (i.e., foraminiferal assemblages) proxies were utilized. Furthermore, age estimation of the deposits was determined using a combination of radiocarbon (14C) and radiometric (137Cs and 210Pb) dating methods.Evidence of coastal flooding by high-energy marine wave events is found preserved in the stratigraphic records of Swartkops and Kabeljous estuaries along the south-east coast and lowlands of Dwarskersbos on the west coast in the form of anomalous sand deposits (layers). The anomalous deposits of Swartkops and Kabeljous estuaries generally consist of gravel-sized shell fragments often with a sharp erosive contact suggesting deposition by a highly energetic marine wave event. Although the preservation varies between cores, a maximum of three anomalous sand depositional layers are preserved in the Swartkops whereas only a single layer in the Kabeljous Estuary with a basal layer of calcrete deposits. 210Pb and 14C dating, constrain the ages of the younger deposits (i.e., the uppermost layer) at Swartkops between 1770-1804 AD and 339-3 cal. BP (1611-1947 cal. AD), respectively. Although these ages span over a wide period, they are interpreted to represent evidence of one of the historical tsunamis generated in the subduction zones of the Indian Ocean e.g., 1762 AD and 1797 AD events generated by 8.8 and 8.0 Mw earthquakes in the Arakan and Sunda Subduction Zones, respectively. Furthermore, the deposits could also represent geological evidence of the 1833 Mentawai events whereas evidence of 1883 Krakatau tsunami is not disregarded, since this event reportedly inundated Algoa Bay. On the other hand, the 14C dating constrain the ages of the second anomalous deposits between 1526-1253 cal. BP (424-697 cal. AD), whereas the older anomalous deposits preserved in the deeper sections of the Swartkops cores as well as the backwater channel of the Kabeljous Estuary are constrained to have been deposited around 4000 cal. BP. Although there is no known locally documented extreme marine wave event during this period, these deposits are interpreted to represent late and mid-Holocene tsunamis associated with mega-thrust subduction zones of the Indian Ocean whereas local submarine landslide generated event are also not disregarded entirely. On the west coast, three anomalous deposits representing extreme marine wave inundation are preserved in the coastal lowlands of the Dwarskersbos. Although the general sedimentary features and thickness vary between the deposits, the first anomalous deposits in the uppermost section of the cores consist of medium sand with scattered shell fragments whereas, the third anomalous deposits in the deeper section of the cores are generally coarser with gravel-sized shell fragments and sharp erosive basal contacts. By contrast, the second anomalous deposits consist of three successive sub-layers of yellow sand with variable sedimentary features and these layers represent successive wave inundation events. Although the sedimentary characteristics of these sub-layers varies, it was noted that the lowermost layers consist of coarser and less well sorted sediments often with basal erosive contact, suggesting that the first wave was more energetic than the two-succeeding waves. Furthermore, calibrated 14C dated shell fragments from the first and second anomalous deposits yielded ‘post-bomb’ ages suggesting deposition after 1950 AD. Given their position within the stratigraphic records, the two deposits are interpreted to represent first geological evidence of the 2008 west coast and 1969 Dwarskersbos events, respectively. On the other hand, the 14C dated shell fragments constrain the deposition of the third anomalous deposits between 315-0 cal. BP (1635-11950 cal. AD) and 358-0 cal. BP (1592-1950 cal. AD), respectively. The third anomalous deposits are interpreted to the 07 April 1620 event, which was described as ‘Two startling thunderclaps’ near Robben Island. Although initially associated to earthquakes, there are no records of an earthquake during this period, therefore, we postulate that the 1620 event could have been a similar event to that of 2008 that inundated the west coast region and/or an unknown event. While it is acknowledged that the absence of reliable source mechanisms poses a great challenge in the reconstruction of extreme marine wave events inundation along the south-east coast, the findings of exoscopy and micropaleontological analyses suggest that the deposits were transported to their depositional environments, although resultant microtextural features and occurrence of individual foraminiferal species and their taphonomical conditions is dependent on coastal setting. The south-east coast deposits consist of highly diverse foraminiferal assemblages, which are dominated by marine and marginal-marine taxa with relatively low abundances of estuarine-brackish species and variable taphonomical conditions. Furthermore, the mechanical-induced features such as percussion marks, fresh surfaces with sharp edges were still preserved on quartz grain surface of the Swartkops deposits, despite dominance by chemical-induced features such as dissolution. By contrast, grain surface microtextural signatures of the Dwarskersbos deposits are dominated by mechanical features such as fresh surfaces and v-percussion marks. Furthermore, the foraminiferal assemblages of the Dwarskersbos deposits consist of exclusively marine and marginal-marine species, suggesting that the sediments were sourced from shallow water environments as well as the adjacent beach. It was further noted that the foraminiferal tests of these deposits consist of higher abundance of corroded and fragmented tests indicating deposition by high-energy conditions. , Thesis (D.Phil) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Mfikili, Athi Nkosibonile
- Date: 2023-12
- Subjects: Tsunamis -- South Africa , Coasts -- Risk assessment , Sediments (Geology)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62517 , vital:72811
- Description: Although extreme marine wave events such as tsunamis and storm surges have always been part of human existence, their impact on ever-growing coastal population of the world’s coast was highlighted by the recent catastrophic events over the past three decades. Although in situ observations and eyewitness accounts have improved our ability to record and interpret wave inundation by modern extreme marine events, records documenting inundation by pre-historic and historical events are relatively sparse to provide reasonable information on their distribution, magnitude and frequency intervals in most parts of the world. Owing to consequences these natural coastal hazards have on coastal population and infrastructure of the world’s coast, onshore sedimentary deposits preserved in the geological records have been extensively utilized by scientists worldwide to reconstruct the record of pre-historic and historical events and establish the recurrence interval of future events. Although studies investigating inundation of past tsunami has increased worldwide over the past two decades, research on extreme marine inundation has received little attention along the South African coast, despite known inundation by recent events and potential source mechanisms. Therefore, the aim of this study is to investigate sedimentary evidence of past tsunamis and related extreme marine wave events (i.e., storm surges) preserved in the recent geological archive of several coastal environments along the South African coast. The Swartkops, Kabeljous, Kromme and Keurbooms estuaries located in log-spiral bays along the south-east coast and sheltered coastal systems of the Berg Estuary and Verlorenvlei as well as coastal lowlands of the Dwarskersbos on the west coast were selected as the study sites. The sediment cores were collected from these coastal environments and identification of extreme marine wave inundation was based on the recognition of distinct anomalous sand layers. To characterise sediment transport and reconstruct provenance source origin of the deposits, a combination of sedimentological (i.e., grain size distribution), exoscopy (i.e., quartz grain surface microtextures) and micropaleontological (i.e., foraminiferal assemblages) proxies were utilized. Furthermore, age estimation of the deposits was determined using a combination of radiocarbon (14C) and radiometric (137Cs and 210Pb) dating methods.Evidence of coastal flooding by high-energy marine wave events is found preserved in the stratigraphic records of Swartkops and Kabeljous estuaries along the south-east coast and lowlands of Dwarskersbos on the west coast in the form of anomalous sand deposits (layers). The anomalous deposits of Swartkops and Kabeljous estuaries generally consist of gravel-sized shell fragments often with a sharp erosive contact suggesting deposition by a highly energetic marine wave event. Although the preservation varies between cores, a maximum of three anomalous sand depositional layers are preserved in the Swartkops whereas only a single layer in the Kabeljous Estuary with a basal layer of calcrete deposits. 210Pb and 14C dating, constrain the ages of the younger deposits (i.e., the uppermost layer) at Swartkops between 1770-1804 AD and 339-3 cal. BP (1611-1947 cal. AD), respectively. Although these ages span over a wide period, they are interpreted to represent evidence of one of the historical tsunamis generated in the subduction zones of the Indian Ocean e.g., 1762 AD and 1797 AD events generated by 8.8 and 8.0 Mw earthquakes in the Arakan and Sunda Subduction Zones, respectively. Furthermore, the deposits could also represent geological evidence of the 1833 Mentawai events whereas evidence of 1883 Krakatau tsunami is not disregarded, since this event reportedly inundated Algoa Bay. On the other hand, the 14C dating constrain the ages of the second anomalous deposits between 1526-1253 cal. BP (424-697 cal. AD), whereas the older anomalous deposits preserved in the deeper sections of the Swartkops cores as well as the backwater channel of the Kabeljous Estuary are constrained to have been deposited around 4000 cal. BP. Although there is no known locally documented extreme marine wave event during this period, these deposits are interpreted to represent late and mid-Holocene tsunamis associated with mega-thrust subduction zones of the Indian Ocean whereas local submarine landslide generated event are also not disregarded entirely. On the west coast, three anomalous deposits representing extreme marine wave inundation are preserved in the coastal lowlands of the Dwarskersbos. Although the general sedimentary features and thickness vary between the deposits, the first anomalous deposits in the uppermost section of the cores consist of medium sand with scattered shell fragments whereas, the third anomalous deposits in the deeper section of the cores are generally coarser with gravel-sized shell fragments and sharp erosive basal contacts. By contrast, the second anomalous deposits consist of three successive sub-layers of yellow sand with variable sedimentary features and these layers represent successive wave inundation events. Although the sedimentary characteristics of these sub-layers varies, it was noted that the lowermost layers consist of coarser and less well sorted sediments often with basal erosive contact, suggesting that the first wave was more energetic than the two-succeeding waves. Furthermore, calibrated 14C dated shell fragments from the first and second anomalous deposits yielded ‘post-bomb’ ages suggesting deposition after 1950 AD. Given their position within the stratigraphic records, the two deposits are interpreted to represent first geological evidence of the 2008 west coast and 1969 Dwarskersbos events, respectively. On the other hand, the 14C dated shell fragments constrain the deposition of the third anomalous deposits between 315-0 cal. BP (1635-11950 cal. AD) and 358-0 cal. BP (1592-1950 cal. AD), respectively. The third anomalous deposits are interpreted to the 07 April 1620 event, which was described as ‘Two startling thunderclaps’ near Robben Island. Although initially associated to earthquakes, there are no records of an earthquake during this period, therefore, we postulate that the 1620 event could have been a similar event to that of 2008 that inundated the west coast region and/or an unknown event. While it is acknowledged that the absence of reliable source mechanisms poses a great challenge in the reconstruction of extreme marine wave events inundation along the south-east coast, the findings of exoscopy and micropaleontological analyses suggest that the deposits were transported to their depositional environments, although resultant microtextural features and occurrence of individual foraminiferal species and their taphonomical conditions is dependent on coastal setting. The south-east coast deposits consist of highly diverse foraminiferal assemblages, which are dominated by marine and marginal-marine taxa with relatively low abundances of estuarine-brackish species and variable taphonomical conditions. Furthermore, the mechanical-induced features such as percussion marks, fresh surfaces with sharp edges were still preserved on quartz grain surface of the Swartkops deposits, despite dominance by chemical-induced features such as dissolution. By contrast, grain surface microtextural signatures of the Dwarskersbos deposits are dominated by mechanical features such as fresh surfaces and v-percussion marks. Furthermore, the foraminiferal assemblages of the Dwarskersbos deposits consist of exclusively marine and marginal-marine species, suggesting that the sediments were sourced from shallow water environments as well as the adjacent beach. It was further noted that the foraminiferal tests of these deposits consist of higher abundance of corroded and fragmented tests indicating deposition by high-energy conditions. , Thesis (D.Phil) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Experiences of mothers who are on tuberculosis treatment While caring for their children in Nelson Mandela Bay health district
- Authors: Mwadiwa, Chiedza
- Date: 2023-12
- Subjects: Caring experiences -- Nelson Mandela Bay , Tuberculosis treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62935 , vital:73071
- Description: Women and mothers have an important role to play as caregivers of their children. However, mothers are often faced with challenges with fulfilling this important role. Many women value the caring role as a mother over other areas of their lives, and for ill women, such as those with tuberculosis (TB) and those on TB treatment, it can be difficult to relinquish maternal responsibility. Indeed, many mothers in South Africa and other low- and middle-income countries develop TB during pregnancy and postpartum because their immune systems are compromised. For a mother who is chronically ill, carrying out a mother’s caregiving role presents a range of challenges. However, few studies have addressed this problem or explored the experiences of such mothers. The purpose of the study was to understand the experiences of mothers who are on TB treatment while caring for their children in order to establish their support needs and thereby develop recommendations to assist CHWs, nurses and nurse managers at primary healthcare (PHC) clinics to provide optimum care to such women. The Socio-Ecological model was used as the theoretical lens to explore the phenomenon under investigation. A qualitative, exploratory-descriptive research design was identified as most suited to respond to the research question. Purposive sampling was used to select both the participants and the clinics in the Nelson Mandela Bay Health District (NMBHD) for the purpose of this study. The population was mothers on TB treatment caring for their children (aged five years or younger) who were attending either one of the two of the largest PHC clinics in Sub-district C in the NMBH. Altogether ten mothers on TB treatment caring for their children took part in individual semi-structured interviews conducted telephonically. Ethical clearance was obtained from Nelson Mandela University and permission was obtained from the Department of Health (DoH), district office, operational managers at the respective clinics, and the participants involved in the study. Trustworthiness was enhanced by ensuring credibility, transferability, dependability, and confirmability. Ethical principles were upheld throughout the course of this study namely respect for persons, beneficence and justice. All interviews were recorded and transcribed, and the data was analysed using Tesch’s method of data analysis to identify the themes. Three themes came out of the data, namely: Theme 1: Mothers expressed having to navigate a range of physical and psychosocial challenges while caring for their v children; Theme 2: Mothers struggled to perform motherly roles while on TB treatment; Theme 3: Mothers described their relationships with their family, community members and clinic health practitioners. The experiences of the participants were described using direct quotations from the interviews followed by a literature control used to verify the participants’ experiences. Thereafter, the findings were used to develop recommendations to optimise the care and support of mothers on TB treatment who are caring for their children. Four recommendations were developed: Recommendation 1: Prepare and support mothers with TB to care for themselves and their children; Recommendation 2: Assist CHWs and nurses to care and support mothers with TB and their children; Recommendation 3: Prepare and support family members to support mothers with TB and their children and Recommendation 4: Educate community members regarding the needs of mothers with TB. There is limited existing research on mothers who are on TB treatment while caring for their children. This research study helped to fill this gap, particularly in an urban Eastern Cape context. The findings illustrated mothers’ physical and psychosocial challenges, as well their role-related challenges and finally the challenges related to the various spousal, family, community and clinic relationships that influence their experience of caring for their child while on TB treatment. , Thesis (MA) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Mwadiwa, Chiedza
- Date: 2023-12
- Subjects: Caring experiences -- Nelson Mandela Bay , Tuberculosis treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62935 , vital:73071
- Description: Women and mothers have an important role to play as caregivers of their children. However, mothers are often faced with challenges with fulfilling this important role. Many women value the caring role as a mother over other areas of their lives, and for ill women, such as those with tuberculosis (TB) and those on TB treatment, it can be difficult to relinquish maternal responsibility. Indeed, many mothers in South Africa and other low- and middle-income countries develop TB during pregnancy and postpartum because their immune systems are compromised. For a mother who is chronically ill, carrying out a mother’s caregiving role presents a range of challenges. However, few studies have addressed this problem or explored the experiences of such mothers. The purpose of the study was to understand the experiences of mothers who are on TB treatment while caring for their children in order to establish their support needs and thereby develop recommendations to assist CHWs, nurses and nurse managers at primary healthcare (PHC) clinics to provide optimum care to such women. The Socio-Ecological model was used as the theoretical lens to explore the phenomenon under investigation. A qualitative, exploratory-descriptive research design was identified as most suited to respond to the research question. Purposive sampling was used to select both the participants and the clinics in the Nelson Mandela Bay Health District (NMBHD) for the purpose of this study. The population was mothers on TB treatment caring for their children (aged five years or younger) who were attending either one of the two of the largest PHC clinics in Sub-district C in the NMBH. Altogether ten mothers on TB treatment caring for their children took part in individual semi-structured interviews conducted telephonically. Ethical clearance was obtained from Nelson Mandela University and permission was obtained from the Department of Health (DoH), district office, operational managers at the respective clinics, and the participants involved in the study. Trustworthiness was enhanced by ensuring credibility, transferability, dependability, and confirmability. Ethical principles were upheld throughout the course of this study namely respect for persons, beneficence and justice. All interviews were recorded and transcribed, and the data was analysed using Tesch’s method of data analysis to identify the themes. Three themes came out of the data, namely: Theme 1: Mothers expressed having to navigate a range of physical and psychosocial challenges while caring for their v children; Theme 2: Mothers struggled to perform motherly roles while on TB treatment; Theme 3: Mothers described their relationships with their family, community members and clinic health practitioners. The experiences of the participants were described using direct quotations from the interviews followed by a literature control used to verify the participants’ experiences. Thereafter, the findings were used to develop recommendations to optimise the care and support of mothers on TB treatment who are caring for their children. Four recommendations were developed: Recommendation 1: Prepare and support mothers with TB to care for themselves and their children; Recommendation 2: Assist CHWs and nurses to care and support mothers with TB and their children; Recommendation 3: Prepare and support family members to support mothers with TB and their children and Recommendation 4: Educate community members regarding the needs of mothers with TB. There is limited existing research on mothers who are on TB treatment while caring for their children. This research study helped to fill this gap, particularly in an urban Eastern Cape context. The findings illustrated mothers’ physical and psychosocial challenges, as well their role-related challenges and finally the challenges related to the various spousal, family, community and clinic relationships that influence their experience of caring for their child while on TB treatment. , Thesis (MA) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Experiences of psychological practitioners when working with Isixhosa speaking minors in the Eastern Cape.
- Authors: Matushe, Masakhane
- Date: 2023-12
- Subjects: language barriers -- Eastern Cape , Psychological practitioner
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62884 , vital:73062
- Description: Language barriers continue to pose challenges in education and the health sector where psychological assessments and tests are administered in a language that is different from that of the client. The implication this has on the interpretations of test-taker scores may be bias against those whose first language is not English or Afrikaans, which are two of the primary languages majority of the tests currently used in the South Africa are normed against. This study aimed to explore the implications of the current language repertoires on test-taker performance. This was achieved through exploring the experiences of psychological practitioners who use English language psychological tests on isiXhosa speaking child clients in the Eastern Cape. The methodology followed an exploratory-descriptive, qualitative design, adopting Lincoln and Guba's model of trustworthiness. The researcher employed a qualitative method with an exploratory-descriptive research design, and participants were recruited by utilizing a purposive sampling strategy. Thematic analysis was used as a means of data analysis,and the following themes emerged and were discussed: The use of translators & interpreters, and the challenges thereof; practitioner’s own language proficiencies and limitations; cultutral influence and langaage exposure of clients; Adaptation as well as revision of decolonization of testing measures; and training psychological practitioners. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Matushe, Masakhane
- Date: 2023-12
- Subjects: language barriers -- Eastern Cape , Psychological practitioner
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62884 , vital:73062
- Description: Language barriers continue to pose challenges in education and the health sector where psychological assessments and tests are administered in a language that is different from that of the client. The implication this has on the interpretations of test-taker scores may be bias against those whose first language is not English or Afrikaans, which are two of the primary languages majority of the tests currently used in the South Africa are normed against. This study aimed to explore the implications of the current language repertoires on test-taker performance. This was achieved through exploring the experiences of psychological practitioners who use English language psychological tests on isiXhosa speaking child clients in the Eastern Cape. The methodology followed an exploratory-descriptive, qualitative design, adopting Lincoln and Guba's model of trustworthiness. The researcher employed a qualitative method with an exploratory-descriptive research design, and participants were recruited by utilizing a purposive sampling strategy. Thematic analysis was used as a means of data analysis,and the following themes emerged and were discussed: The use of translators & interpreters, and the challenges thereof; practitioner’s own language proficiencies and limitations; cultutral influence and langaage exposure of clients; Adaptation as well as revision of decolonization of testing measures; and training psychological practitioners. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Exploring culturally adapted psychological interventions for mental illness in South Africa: A scoping review
- Authors: Mbatha, Andiswa
- Date: 2023-12
- Subjects: Cultural Adaptation , Evidence-Based Treatments
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62898 , vital:73065
- Description: Culturally appropriate interventions are crucial for its universal applicability. Although it is well documented that mental health practitioners need to consider cultural factors when working with clients, there is a paucity of research concerning culturally adapted psychological treatments within South Africa. Mental Health practitioners use borrowed Westernised methods of psychological interventions, whose effectiveness has been proven to work on people with different values and belief systems from those of South Africa. This study sought to map the literature on culturally adapted psychological interventions in the South African context. The main research question of the study is: “According to the literature, what are the culturally adapted psychological interventions available for use in the South African context?” Employing the scoping review methodology, published literature was sourced from various electronic databases. The data is presented in a table format using the thematic framework. The study found that out of 250 records that were retrieved, we identified nine articles describing four distinct interventions in treating three mental illnesses in South Africa. Cognitive behaviour therapy (n = 3), behaviour activation (n=2) mindfulness-based stress reduction (n=2) interpersonal therapy (n=1) and Motivational interviewing (n=1) surfaced as culturally adapted psychological interventions to treat people with depression, trauma and substance use disorder. Improvement in symptoms was a common result of all therapies. The potential benefit of the study is to provide recommendations that will inform further research and clinical practice. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Mbatha, Andiswa
- Date: 2023-12
- Subjects: Cultural Adaptation , Evidence-Based Treatments
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62898 , vital:73065
- Description: Culturally appropriate interventions are crucial for its universal applicability. Although it is well documented that mental health practitioners need to consider cultural factors when working with clients, there is a paucity of research concerning culturally adapted psychological treatments within South Africa. Mental Health practitioners use borrowed Westernised methods of psychological interventions, whose effectiveness has been proven to work on people with different values and belief systems from those of South Africa. This study sought to map the literature on culturally adapted psychological interventions in the South African context. The main research question of the study is: “According to the literature, what are the culturally adapted psychological interventions available for use in the South African context?” Employing the scoping review methodology, published literature was sourced from various electronic databases. The data is presented in a table format using the thematic framework. The study found that out of 250 records that were retrieved, we identified nine articles describing four distinct interventions in treating three mental illnesses in South Africa. Cognitive behaviour therapy (n = 3), behaviour activation (n=2) mindfulness-based stress reduction (n=2) interpersonal therapy (n=1) and Motivational interviewing (n=1) surfaced as culturally adapted psychological interventions to treat people with depression, trauma and substance use disorder. Improvement in symptoms was a common result of all therapies. The potential benefit of the study is to provide recommendations that will inform further research and clinical practice. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Exploring the psychological and emotional understanding of Amagqirha within the Eastern Cape province, South Africa
- Authors: Ncapayi, Abongile
- Date: 2023-12
- Subjects: traditional healers , Indigenous Knowledge , Cultural religion
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62947 , vital:73074
- Description: Indigenous knowledge systems influence mental health understanding and treatments. Amongst the Xhosa’s (amaXhosa), a person may receive a ‘calling’ from the ancestors, usually associated with symptoms that would be characterized as a mental illness. However, the symptoms experienced during the calling, usually dissipate once training has been received. One of the categories within traditional healers are amagqirha, also known as diviners. These are individuals who receive the ‘calling’. Thereafter, they undergo extensive training and become blessed with clairvoyant “powers” to divine and act as mediators between the living and the dead. This study aimed to explore the psychological and emotional understanding of amagqirha of the Xhosa culture, within the Eastern Cape, South Africa. In doing so, the study centralizes the experiences of individuals within cultural spaces, allowing for commentary on the psychological and emotional understanding of the amagqirha. Furthermore, this study focused on the work that amagqirha do in communities and how this ultimately affects them. This study sought to understand the experiences and perceptions of the individuals who are affected by this ‘calling’. The researcher employed a qualitative method with an exploratory-descriptive research design. Ten participants were recruited by utilizing a purposive snowball sampling strategy. Data was collected using a semi-structured interview due to the sensitivity of the demographic of the study. Ethics were adhered to. Additionally, trustworthiness was guided by Lincoln and Guba’s (1985) four constructs: credibility, dependability, transferability, and confirmability. Thematic analysis was used as a means of data analysis, as presented by Braun and Clarke (2006). The themes identified were: The collateral damage/profuse repercussions cast upon by the ancestors due to inaction (either by them or those that case before them), the severity of the emotional and psychological effects is equally prevalent prior and during their journey of vi ubugqirha, methods that may assist in alleviating the emotional and psychological symptoms, understanding of mental health, awareness of their own mental health status, and help-seeking (psychological services). The main findings suggested that there is a general understanding of the term ‘mental health’ amongst amagqirha. Additionally, the findings revealed that amagqirha experienced emotional and psychological symptoms/effects, prior to and during the journey of ubugqirha - these were due to the lack of understanding and fear. Furthermore, the findings suggesting that amagqirha embarked on various help-seeking measures, i.e., seeking psychological services or leaning into seeking guidance from their ancestors. However, they were met with barriers as well, i.e., finding a mental health practitioner with awareness on African spirituality, and dealing with the stigma that comes with help-seeking. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Ncapayi, Abongile
- Date: 2023-12
- Subjects: traditional healers , Indigenous Knowledge , Cultural religion
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62947 , vital:73074
- Description: Indigenous knowledge systems influence mental health understanding and treatments. Amongst the Xhosa’s (amaXhosa), a person may receive a ‘calling’ from the ancestors, usually associated with symptoms that would be characterized as a mental illness. However, the symptoms experienced during the calling, usually dissipate once training has been received. One of the categories within traditional healers are amagqirha, also known as diviners. These are individuals who receive the ‘calling’. Thereafter, they undergo extensive training and become blessed with clairvoyant “powers” to divine and act as mediators between the living and the dead. This study aimed to explore the psychological and emotional understanding of amagqirha of the Xhosa culture, within the Eastern Cape, South Africa. In doing so, the study centralizes the experiences of individuals within cultural spaces, allowing for commentary on the psychological and emotional understanding of the amagqirha. Furthermore, this study focused on the work that amagqirha do in communities and how this ultimately affects them. This study sought to understand the experiences and perceptions of the individuals who are affected by this ‘calling’. The researcher employed a qualitative method with an exploratory-descriptive research design. Ten participants were recruited by utilizing a purposive snowball sampling strategy. Data was collected using a semi-structured interview due to the sensitivity of the demographic of the study. Ethics were adhered to. Additionally, trustworthiness was guided by Lincoln and Guba’s (1985) four constructs: credibility, dependability, transferability, and confirmability. Thematic analysis was used as a means of data analysis, as presented by Braun and Clarke (2006). The themes identified were: The collateral damage/profuse repercussions cast upon by the ancestors due to inaction (either by them or those that case before them), the severity of the emotional and psychological effects is equally prevalent prior and during their journey of vi ubugqirha, methods that may assist in alleviating the emotional and psychological symptoms, understanding of mental health, awareness of their own mental health status, and help-seeking (psychological services). The main findings suggested that there is a general understanding of the term ‘mental health’ amongst amagqirha. Additionally, the findings revealed that amagqirha experienced emotional and psychological symptoms/effects, prior to and during the journey of ubugqirha - these were due to the lack of understanding and fear. Furthermore, the findings suggesting that amagqirha embarked on various help-seeking measures, i.e., seeking psychological services or leaning into seeking guidance from their ancestors. However, they were met with barriers as well, i.e., finding a mental health practitioner with awareness on African spirituality, and dealing with the stigma that comes with help-seeking. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Exploring university level admissions decision-making based on access testing and undergraduate admissions variables
- Authors: Oakes, Elizabeth
- Date: 2023-12
- Subjects: decision-making , Social-Judgement Theory , Cognitive-Continuum TheoryLens Model Equation
- Language: English
- Type: Doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/62969 , vital:73078
- Description: Decision-making is an essential everyday cognitive function. How people go about making judgements and decisions is difficult to pin down. The reason for this lies in the inherent nature of decision-making, which is uncertain and variable because decision-making is a human cognitive process that is context-dependent. However, the body of research on judgement and decision-making (JDM) is concerned with describing what people are 'actually' thinking, when they make decisions or judgements. This study applied the descriptive theories of the Social-Judgement Theory (SJT) and the Cognitive-Continuum Theory (CCT), in order to understand decision-making in an undergraduate, entry-level admission decision-making context, in which decision-makers used access testing and school results, to make admission decisions at Nelson Mandela University. The sample consisted of four consultants from the Centre for Access Assessment and Research (CAAR) who volunteered to participate in the study. While the sample was small, it was nonetheless deemed to be adequate as 57% of the consultants at CAAR were included in the sample. Using the SJT methodological approach, an experiment was conducted to mirror the real-life context of decision-making at CAAR. As CAAR consultants were used to test, and school results being presented on a profile when they made decisions, a sample of 120 of these was drawn from a repository, with 60 of them requiring decisions for degree admission (to B Com Accounting) and 60 for diploma admission (to the Diploma in Accountancy). Ten degree and 10 diploma profiles were duplicated to check for consistency in decision-making. As SJT suggests restricting the number of cues used, a process was instituted to identify the cues perceived to be used most frequently to make decisions at CAAR. This resulted in 5 cues being included on the cue profile. In Phase 1 of the experiment the CAAR consultants made admission decisions using a familiar cue profile in terms of how the information was presented visually and numerically. In phase 2 the information was presented using a different visual format, which was more closely aligned to the intuitive decision-making mode that most consultants used. A 2 x 2 within-subjects experimental design was thus employed with two independent variables, namely, profile type and program type. Descriptive statistics and correlational and regression analyses were used to describe the judgement policies of the consultants in terms of the time taken, the difficulty ratings, and the cue use and its importance). The indices of the Lens Model Equation (LME) of SJT were used to describe the decision-achievement levels, and the Task-Continuum Index (TCI) was computed to describe which cognitive modes were used. xvii The results revealed that decision-makers have unique, varied, and changeable judgement policies, with regard to the time taken, the perception of difficulty, and the decision outcomes and had a tendency to rely more on the school results, while the regression models derived indicated that test results made a stronger contribution to the decision outcome. The consultants found degree decisions easier than diploma decisions, and the consultants perceived the contribution and weighting of the cues somewhat differently, once the format of the cue profile had changed in Phase 2, although they made decisions more quickly in Phase 2. The decision-makers also displayed individualised patterns of decision achievement that differed for degree and diploma programs. Furthermore, in terms of the cognitive mode, decision-makers were thinking quasi-rationally and they largely used the cognitive modes of computer modelling or expert judgement. Thus, by synergistically using the two theories of JDM, the researcher was able to determine baseline information for understanding decision- making in an admission context. Furthermore, suggestions were made in terms of the nature of the feedback and training that could be provided to decision-makers to enhance their future decision-making. Suggestions were also made regarding how the methodology used and findings of this study could be applied in other contexts, such as when training students in psychological assessment. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Oakes, Elizabeth
- Date: 2023-12
- Subjects: decision-making , Social-Judgement Theory , Cognitive-Continuum TheoryLens Model Equation
- Language: English
- Type: Doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/62969 , vital:73078
- Description: Decision-making is an essential everyday cognitive function. How people go about making judgements and decisions is difficult to pin down. The reason for this lies in the inherent nature of decision-making, which is uncertain and variable because decision-making is a human cognitive process that is context-dependent. However, the body of research on judgement and decision-making (JDM) is concerned with describing what people are 'actually' thinking, when they make decisions or judgements. This study applied the descriptive theories of the Social-Judgement Theory (SJT) and the Cognitive-Continuum Theory (CCT), in order to understand decision-making in an undergraduate, entry-level admission decision-making context, in which decision-makers used access testing and school results, to make admission decisions at Nelson Mandela University. The sample consisted of four consultants from the Centre for Access Assessment and Research (CAAR) who volunteered to participate in the study. While the sample was small, it was nonetheless deemed to be adequate as 57% of the consultants at CAAR were included in the sample. Using the SJT methodological approach, an experiment was conducted to mirror the real-life context of decision-making at CAAR. As CAAR consultants were used to test, and school results being presented on a profile when they made decisions, a sample of 120 of these was drawn from a repository, with 60 of them requiring decisions for degree admission (to B Com Accounting) and 60 for diploma admission (to the Diploma in Accountancy). Ten degree and 10 diploma profiles were duplicated to check for consistency in decision-making. As SJT suggests restricting the number of cues used, a process was instituted to identify the cues perceived to be used most frequently to make decisions at CAAR. This resulted in 5 cues being included on the cue profile. In Phase 1 of the experiment the CAAR consultants made admission decisions using a familiar cue profile in terms of how the information was presented visually and numerically. In phase 2 the information was presented using a different visual format, which was more closely aligned to the intuitive decision-making mode that most consultants used. A 2 x 2 within-subjects experimental design was thus employed with two independent variables, namely, profile type and program type. Descriptive statistics and correlational and regression analyses were used to describe the judgement policies of the consultants in terms of the time taken, the difficulty ratings, and the cue use and its importance). The indices of the Lens Model Equation (LME) of SJT were used to describe the decision-achievement levels, and the Task-Continuum Index (TCI) was computed to describe which cognitive modes were used. xvii The results revealed that decision-makers have unique, varied, and changeable judgement policies, with regard to the time taken, the perception of difficulty, and the decision outcomes and had a tendency to rely more on the school results, while the regression models derived indicated that test results made a stronger contribution to the decision outcome. The consultants found degree decisions easier than diploma decisions, and the consultants perceived the contribution and weighting of the cues somewhat differently, once the format of the cue profile had changed in Phase 2, although they made decisions more quickly in Phase 2. The decision-makers also displayed individualised patterns of decision achievement that differed for degree and diploma programs. Furthermore, in terms of the cognitive mode, decision-makers were thinking quasi-rationally and they largely used the cognitive modes of computer modelling or expert judgement. Thus, by synergistically using the two theories of JDM, the researcher was able to determine baseline information for understanding decision- making in an admission context. Furthermore, suggestions were made in terms of the nature of the feedback and training that could be provided to decision-makers to enhance their future decision-making. Suggestions were also made regarding how the methodology used and findings of this study could be applied in other contexts, such as when training students in psychological assessment. , Thesis (Ma) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Field mapping and geochemistry of lower Jurassic sediments and volcanics of the upper Karoo supergroup near Ha Mosi, Lesotho mountains
- Authors: Valashiya, Khaya
- Date: 2023-12
- Subjects: Sediments (Geology) -- South Africa -- karoo basin , Geochemistry , Geological mapping
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62687 , vital:72925
- Description: Geological mapping in the Lesotho-Drakensberg Mountains spans over 100 years with du Toit and Stockley being the major contributors to the published maps and to the understanding of emplacement of the Karoo Large Igneous Province (KLIP) in the countries of South Africa and Lesotho. Despite the detailed previous work, there remains limited data on paleoenvironmental changes at the contact between the sedimentary and volcanic sequences of the upper Karoo Supergroup. This study aims to map the lithostratigraphic boundaries, volcano-sedimentary facies and faults near Ha Mosi in southern Lesotho. A total 48 rock samples were collected for petrography, XRF and ICP-MS analyses. The new results were used to characterize the local chemostratigraphy and to propose new regional correlations across Lesotho and South Africa. In this thesis, eight lithostratigraphic units were defined with a total thickness of 550 m. The first two units (Units 1 and 2) comprise massive and bedded sandstones, interpreted as possible floodplain and ephemeral lacustrine deposits; these are ascribed to the upper Stormberg Group. These units are unconformably overlain by locally preserved thin basaltic (Unit 3) flows that are characterised by high Zr/Nb and Zr/Y ratios; and low Ti/Zr and P/Zr ratios similar to the Golden Gate Unit of the Drakensberg Group. The lava flows are overlain by bedded sandstone ascribed to Unit 4 and volcaniclastic breccia ascribed to Units 5 and 6. Unit 6 consists of a monolithic breccia that is composed of angular sandstone clasts similar to those of the underlying Stormberg Group. The monolithic breccia transitions upwards into a massive megaclastic clast-supported volcanic breccia, which consists of angular to sub-rounded basaltic and doleritic boulders. Petrified wood fragments are found within the megaclastic breccia, indicating the presence of vegetation during deposition and enhanced preservation. Unit 6 laterally grades into Unit 5, which is characterised by poorly bedded breccia composed of angular sandstone, mudstone clasts with minor basaltic and doleritic clasts and, breccia intraclasts. The breccia units are often associated with reworked sediments interpreted to be deposited by fluvial systems. The breccia is conformably overlain by basaltic lava flows (Unit 8) characterised by high Ti/Zr and P/Zr ratios and moderate to low Zr/Y and Zr/Nb ratios compared to the Unit 3 lavas and is similar to that of the Sani Pass Unit of the Drakensberg Group. The basaltic sequences in the Ha Mosi studied area preserve both pahoehoe textures and pillow lavas, indicating subaerial and subaqueous volcanism. The studied lithologies are intruded by gabbro and dolerites of the Karoo Dolerite Suite at 183 Ma. This stratigraphy records the transition from sedimentation in the Karoo Basin through to a dominantly volcanic succession, which has importance in terms of the Toarcian extinction at ca. 182 Ma. Mapped faults and associated fractures are orientated predominantly NW-SE with the hanging walls moved maximum 80 m to the south. The different dykes and fault structures possibly relate to the Weddel Triple Junction that developed during the Early Jurassic break up of Gondwana, between 200 and 180 Ma. The mapped lavas show that the magma source was a chemically heterogenous mantle that was subjected to different degrees of partial melting, with the introduction of small-scale chemical heterogeneities. The geodynamic setting is comparable to the Afar Triangle of north-east Africa where active tectonics created a large-scale NW-SE orientated fault system in response to crustal thinning and rifting. In both the Afar and Lesotho, vertical movements created lowlands that allow for the preservation of volcanic breccia and basalts with pillow lavas. These findings show that existing geological models in the Drakensberg-Lesotho Mountains can be improved upon detailed field mapping and geochemistry. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Valashiya, Khaya
- Date: 2023-12
- Subjects: Sediments (Geology) -- South Africa -- karoo basin , Geochemistry , Geological mapping
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62687 , vital:72925
- Description: Geological mapping in the Lesotho-Drakensberg Mountains spans over 100 years with du Toit and Stockley being the major contributors to the published maps and to the understanding of emplacement of the Karoo Large Igneous Province (KLIP) in the countries of South Africa and Lesotho. Despite the detailed previous work, there remains limited data on paleoenvironmental changes at the contact between the sedimentary and volcanic sequences of the upper Karoo Supergroup. This study aims to map the lithostratigraphic boundaries, volcano-sedimentary facies and faults near Ha Mosi in southern Lesotho. A total 48 rock samples were collected for petrography, XRF and ICP-MS analyses. The new results were used to characterize the local chemostratigraphy and to propose new regional correlations across Lesotho and South Africa. In this thesis, eight lithostratigraphic units were defined with a total thickness of 550 m. The first two units (Units 1 and 2) comprise massive and bedded sandstones, interpreted as possible floodplain and ephemeral lacustrine deposits; these are ascribed to the upper Stormberg Group. These units are unconformably overlain by locally preserved thin basaltic (Unit 3) flows that are characterised by high Zr/Nb and Zr/Y ratios; and low Ti/Zr and P/Zr ratios similar to the Golden Gate Unit of the Drakensberg Group. The lava flows are overlain by bedded sandstone ascribed to Unit 4 and volcaniclastic breccia ascribed to Units 5 and 6. Unit 6 consists of a monolithic breccia that is composed of angular sandstone clasts similar to those of the underlying Stormberg Group. The monolithic breccia transitions upwards into a massive megaclastic clast-supported volcanic breccia, which consists of angular to sub-rounded basaltic and doleritic boulders. Petrified wood fragments are found within the megaclastic breccia, indicating the presence of vegetation during deposition and enhanced preservation. Unit 6 laterally grades into Unit 5, which is characterised by poorly bedded breccia composed of angular sandstone, mudstone clasts with minor basaltic and doleritic clasts and, breccia intraclasts. The breccia units are often associated with reworked sediments interpreted to be deposited by fluvial systems. The breccia is conformably overlain by basaltic lava flows (Unit 8) characterised by high Ti/Zr and P/Zr ratios and moderate to low Zr/Y and Zr/Nb ratios compared to the Unit 3 lavas and is similar to that of the Sani Pass Unit of the Drakensberg Group. The basaltic sequences in the Ha Mosi studied area preserve both pahoehoe textures and pillow lavas, indicating subaerial and subaqueous volcanism. The studied lithologies are intruded by gabbro and dolerites of the Karoo Dolerite Suite at 183 Ma. This stratigraphy records the transition from sedimentation in the Karoo Basin through to a dominantly volcanic succession, which has importance in terms of the Toarcian extinction at ca. 182 Ma. Mapped faults and associated fractures are orientated predominantly NW-SE with the hanging walls moved maximum 80 m to the south. The different dykes and fault structures possibly relate to the Weddel Triple Junction that developed during the Early Jurassic break up of Gondwana, between 200 and 180 Ma. The mapped lavas show that the magma source was a chemically heterogenous mantle that was subjected to different degrees of partial melting, with the introduction of small-scale chemical heterogeneities. The geodynamic setting is comparable to the Afar Triangle of north-east Africa where active tectonics created a large-scale NW-SE orientated fault system in response to crustal thinning and rifting. In both the Afar and Lesotho, vertical movements created lowlands that allow for the preservation of volcanic breccia and basalts with pillow lavas. These findings show that existing geological models in the Drakensberg-Lesotho Mountains can be improved upon detailed field mapping and geochemistry. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Finite difference methods for Burgers-Huxley equation and biofilm formation
- Authors: Tijani, Yusuf Olatunji
- Date: 2023-12
- Subjects: Burgers equation , Terrestrial heat flow , Applied mathematics
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62732 , vital:72934
- Description: In this thesis, we constructed some versions of finite difference scheme for the Burgers-Huxley equation and for a set of partial differential equations (PDEs) arising in biofilm formation. The Burgers-Huxley equation serves as a fundamental model that describes the interaction between reaction mechanisms, convection effects, and diffusion transport. It has applications in the study of wave mechanics, population dynamics, physiology, fluid mechanics to list but a few. The study of biofilm formation is becoming increasingly important due to micro-organisms (i.e. bacteria) forming a protected mode from the host defense mechanism which may result in alteration in the host gene transcription and growth rate. Applications can be found useful in the treatment of bacterial infections, contamination of foods and water quality. We designed two nonstandard finite difference and two exponential finite difference schemes for the Burgers-Huxley equation. Numerical experiments with six cases and in three different regimes were studied. We show that the nonstandard scheme preserves the properties of the continuous equation which include positivity and boundedness. The stability region of the explicit exponential scheme was obtained and we outlined the algorithm for the implicit exponential scheme. The performance of the four schemes are compared in regard to absolute error, relative error, L1 and L∞ norms. For a singularly perturbed Burgers-Huxley equation, a novel nonstandard finite difference technique is constructed. It is demonstrated numerically that the NSFD scheme outperforms the classical scheme by comparing maximum pointwise errors and rate of convergence. We then solved the 2D Burgers-Huxley equation using four novel nonstandard finite difference schemes (NSFD1, NSFD2, NSFD3 and NSFD4). The numerical profiles from NSFD1 and NSFD2 exhibit some deviation from the exact profile. Our quest for a better performing scheme led to the modification of NSFD1 using the remainder effect technique. NSFD4 was designed by employing the time splitting approach. All the schemes preserve the properties of the continuous model (positivity and boundedness). The performance of all the schemes are analysed. We construct three nonstandard finite difference schemes for the equations modelling biomass equation and coupled substrate-biomass system of equations respectively. We checked the accuracy of our scheme by the conservation of physical properties (positivity, boundedness, biofilm formation and annihilation) since an analytical solution is not available. We show the instability, lack of conservation of physical properties by the classical scheme. Our proposed scheme shows good performance when compared with other results in the literature. The results here give more insight into the benefits of the nonstandard finite difference approximations. , Thesis (DPhil) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics , 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Tijani, Yusuf Olatunji
- Date: 2023-12
- Subjects: Burgers equation , Terrestrial heat flow , Applied mathematics
- Language: English
- Type: Doctorial theses , text
- Identifier: http://hdl.handle.net/10948/62732 , vital:72934
- Description: In this thesis, we constructed some versions of finite difference scheme for the Burgers-Huxley equation and for a set of partial differential equations (PDEs) arising in biofilm formation. The Burgers-Huxley equation serves as a fundamental model that describes the interaction between reaction mechanisms, convection effects, and diffusion transport. It has applications in the study of wave mechanics, population dynamics, physiology, fluid mechanics to list but a few. The study of biofilm formation is becoming increasingly important due to micro-organisms (i.e. bacteria) forming a protected mode from the host defense mechanism which may result in alteration in the host gene transcription and growth rate. Applications can be found useful in the treatment of bacterial infections, contamination of foods and water quality. We designed two nonstandard finite difference and two exponential finite difference schemes for the Burgers-Huxley equation. Numerical experiments with six cases and in three different regimes were studied. We show that the nonstandard scheme preserves the properties of the continuous equation which include positivity and boundedness. The stability region of the explicit exponential scheme was obtained and we outlined the algorithm for the implicit exponential scheme. The performance of the four schemes are compared in regard to absolute error, relative error, L1 and L∞ norms. For a singularly perturbed Burgers-Huxley equation, a novel nonstandard finite difference technique is constructed. It is demonstrated numerically that the NSFD scheme outperforms the classical scheme by comparing maximum pointwise errors and rate of convergence. We then solved the 2D Burgers-Huxley equation using four novel nonstandard finite difference schemes (NSFD1, NSFD2, NSFD3 and NSFD4). The numerical profiles from NSFD1 and NSFD2 exhibit some deviation from the exact profile. Our quest for a better performing scheme led to the modification of NSFD1 using the remainder effect technique. NSFD4 was designed by employing the time splitting approach. All the schemes preserve the properties of the continuous model (positivity and boundedness). The performance of all the schemes are analysed. We construct three nonstandard finite difference schemes for the equations modelling biomass equation and coupled substrate-biomass system of equations respectively. We checked the accuracy of our scheme by the conservation of physical properties (positivity, boundedness, biofilm formation and annihilation) since an analytical solution is not available. We show the instability, lack of conservation of physical properties by the classical scheme. Our proposed scheme shows good performance when compared with other results in the literature. The results here give more insight into the benefits of the nonstandard finite difference approximations. , Thesis (DPhil) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics , 2023
- Full Text:
- Date Issued: 2023-12
Functional traits and potential physical drivers of offshore benthic epifauna on the west and south coast of South Africa
- Van Stavel, Jordan, Morris, Tamaryn
- Authors: Van Stavel, Jordan , Morris, Tamaryn
- Date: 2023-12
- Subjects: Marine ecology , Marine biology -- South Africa , Oceanography -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62698 , vital:72931
- Description: Offshore benthic ecosystems (> 200 m depth) are challenging to access and remain poorly studied globally. Epifaunal invertebrates comprise a critical trophic level in benthic ecosystems and can serve as indicators of the overall health and functioning. There is limited knowledge of South Africa’s offshore marine environment and benthic ecosystem functioning due to limitations in funding, resources, and the lack of suitable science-based monitoring tools which are vital for sustainable management into the future. The aim of this research was to improve the understanding of epifaunal functioning as well as their potential physical drivers in 13 South African offshore biogeographic ecotypes. The objectives of this study were threefold: 1) to investigate the functional composition of benthic epifauna from 13 biogeographic ecotypes, 2) to quantify the Functional Diversity (FD) associated with epifaunal traits between the different assemblages (i.e. biogeographic ecotypes), and 3) to evaluate the relationship between physical variables and epifaunal functional traits at the biogeographic ecotype level. Biological trait-based approaches were applied to a subset of 80 benthic epifaunal species collected from 909 offshore stations along the west and south coasts of South Africa. Nine biological traits (associated with life history, morphology and behavioural characteristics exhibited by each species) were classified into 39 modalities and weighted with biomass. Community Weighted Means (CWMs) were used to evaluate the benthic epifaunal functional trait composition of the 13 biogeographic ecotypes. Functional composition across the 13 ecotype assemblages on the west and south coast appeared to be dominated by species with similar trait compositions, such as large, long-lived, surface crawling/burrowing/filter-feeding epifauna with medium to no mobility, however, their percentage of contribution to trait expression (CWMs) was higher on the west coast. Functional diversity indices (alpha and beta) showed higher overall FD for west coast ecotypes, with most ecotypes on the continental shelf (except slopes and canyons) being significantly different (p<0.05) from ecotypes on the south coast. The global RLQ (three-table co-inertia) test did not reveal a significant relationship between biomass and physical variables or between biomass and traits (p>0.05). The fourth-corner method was used to test the significance of individual traitenvironment relationships. The fourth-corner results were similar overall to the RLQ analysis, revealing that three physical variables (temperature, depth, and fluorescence) were significantly correlated to two trait modalities belonging to the feeding mode filter-feeders (FM1) and scavengers (FM5). Scavengers were positively correlated with depth and negatively with temperature, while filter-feeders were positively correlated with fluorescence levels. This indicated that the presence of scavenging epifauna increased with a decrease in temperature and an increase in depth. While a positive significant correlation between filter-feeders and fluorescence suggested their potential tolerance or preference for environmental conditions with high levels of fluorescence. This research was the first such study to explore the functional composition and diversity of benthic epifauna and their relationship with potential physical drivers in offshore west and south coast benthic biogeographic ecotypes of South Africa. The application of new tools to quantify the functional diversity of epifauna as indicators of ecosystem health, and their potential physical drivers. This provided a platform on which to advance our understanding of benthic communities and the roles they play in ecosystem functioning under changing environments. Functional trait-based approaches such as those applied in this study can provide us with vital information on the relationship between biodiversity, ecosystem functioning, and physical drivers. Environmental stressors and changing climate patterns threaten to impact marine ecosystems and their functioning. Benthic epifauna are especially sensitive to changes in their environment and these fluctuations could potentially lead to the loss of certain benthic functionality, altering the thresholds these ecosystems have to response to disturbances. This undermines the stability of these ecosystems which can have ripple effects on the health of these ecosystems and their ability to provide the ecosystem services humans dependent on. Having suitable tools to track current and predict future changes will therefore be vital to inform management and conservation strategies for sustainable ocean utilisation. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Van Stavel, Jordan , Morris, Tamaryn
- Date: 2023-12
- Subjects: Marine ecology , Marine biology -- South Africa , Oceanography -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62698 , vital:72931
- Description: Offshore benthic ecosystems (> 200 m depth) are challenging to access and remain poorly studied globally. Epifaunal invertebrates comprise a critical trophic level in benthic ecosystems and can serve as indicators of the overall health and functioning. There is limited knowledge of South Africa’s offshore marine environment and benthic ecosystem functioning due to limitations in funding, resources, and the lack of suitable science-based monitoring tools which are vital for sustainable management into the future. The aim of this research was to improve the understanding of epifaunal functioning as well as their potential physical drivers in 13 South African offshore biogeographic ecotypes. The objectives of this study were threefold: 1) to investigate the functional composition of benthic epifauna from 13 biogeographic ecotypes, 2) to quantify the Functional Diversity (FD) associated with epifaunal traits between the different assemblages (i.e. biogeographic ecotypes), and 3) to evaluate the relationship between physical variables and epifaunal functional traits at the biogeographic ecotype level. Biological trait-based approaches were applied to a subset of 80 benthic epifaunal species collected from 909 offshore stations along the west and south coasts of South Africa. Nine biological traits (associated with life history, morphology and behavioural characteristics exhibited by each species) were classified into 39 modalities and weighted with biomass. Community Weighted Means (CWMs) were used to evaluate the benthic epifaunal functional trait composition of the 13 biogeographic ecotypes. Functional composition across the 13 ecotype assemblages on the west and south coast appeared to be dominated by species with similar trait compositions, such as large, long-lived, surface crawling/burrowing/filter-feeding epifauna with medium to no mobility, however, their percentage of contribution to trait expression (CWMs) was higher on the west coast. Functional diversity indices (alpha and beta) showed higher overall FD for west coast ecotypes, with most ecotypes on the continental shelf (except slopes and canyons) being significantly different (p<0.05) from ecotypes on the south coast. The global RLQ (three-table co-inertia) test did not reveal a significant relationship between biomass and physical variables or between biomass and traits (p>0.05). The fourth-corner method was used to test the significance of individual traitenvironment relationships. The fourth-corner results were similar overall to the RLQ analysis, revealing that three physical variables (temperature, depth, and fluorescence) were significantly correlated to two trait modalities belonging to the feeding mode filter-feeders (FM1) and scavengers (FM5). Scavengers were positively correlated with depth and negatively with temperature, while filter-feeders were positively correlated with fluorescence levels. This indicated that the presence of scavenging epifauna increased with a decrease in temperature and an increase in depth. While a positive significant correlation between filter-feeders and fluorescence suggested their potential tolerance or preference for environmental conditions with high levels of fluorescence. This research was the first such study to explore the functional composition and diversity of benthic epifauna and their relationship with potential physical drivers in offshore west and south coast benthic biogeographic ecotypes of South Africa. The application of new tools to quantify the functional diversity of epifauna as indicators of ecosystem health, and their potential physical drivers. This provided a platform on which to advance our understanding of benthic communities and the roles they play in ecosystem functioning under changing environments. Functional trait-based approaches such as those applied in this study can provide us with vital information on the relationship between biodiversity, ecosystem functioning, and physical drivers. Environmental stressors and changing climate patterns threaten to impact marine ecosystems and their functioning. Benthic epifauna are especially sensitive to changes in their environment and these fluctuations could potentially lead to the loss of certain benthic functionality, altering the thresholds these ecosystems have to response to disturbances. This undermines the stability of these ecosystems which can have ripple effects on the health of these ecosystems and their ability to provide the ecosystem services humans dependent on. Having suitable tools to track current and predict future changes will therefore be vital to inform management and conservation strategies for sustainable ocean utilisation. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Honouring the Dead: The Psychological Consequences of the COVID-19 Lockdown Restrictions on Burial Practices and Rituals, amongst AmaXhosa from the Eastern Cape, South Africa
- Authors: Sibam-Twalo, Zimkhitha
- Date: 2023-12
- Subjects: Death and burial , COVID-19 Lockdown
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63005 , vital:73081
- Description: Honouring the dead is upheld in religions and cultures across the world and embedded in rituals and rites of passage that must be adhered to. In many instances, religio-cultural beliefs synthesise or overlap, creating a mutual influence on the person. These religio-cultural rituals are symbolic and important for the living, but they are also equally important for the dead in order to ensure that their souls are returned to the source of their belief system. The COVID-19 lockdown restrictions in South Africa altered death ceremonies and rituals by limiting social gatherings to 50 people to ensure safety protocols like mask wearing and physical distancing. Additionally, family members were prohibited from interacting with the deceased’s body, including performing rituals like washing and dressing, to prevent virus spread. The resultant psychological consequences of these changes to burial practices have not been fully explored in the South African context, and given the importance rituals play, it becomes important to understand them. Studying the psychological consequences of the changes provided insights into individuals’ grief and loss coping in the absence of traditional burial rituals and practices. This is aimed at assisting with the development of interventions for mental health and well-being in future crises. The study explored the psychological consequences of COVID-19 lockdown restrictions on AmaXhosa burial practices and rituals in the Eastern Cape Province of South Africa. AmaXhosa have a rich cultural heritage that places great significance on death and burial rituals. These rituals serve as a way to honour and remember the deceased, provide closure for the bereaved, and maintain social cohesion within the community. The absence of these rituals during the COVID-19 lockdown had consequences for the AmaXhosa’s psychological and religio-cultural well-being. The exploration of their experiences was thus important because it shed light on the importance of these rituals and will help devise innovative ways to address their psychological needs during times of loss. The study utilised a qualitative method, conducting interviews with AmaXhosa aged 18 and older. Participants , Thesis (PhD) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Sibam-Twalo, Zimkhitha
- Date: 2023-12
- Subjects: Death and burial , COVID-19 Lockdown
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63005 , vital:73081
- Description: Honouring the dead is upheld in religions and cultures across the world and embedded in rituals and rites of passage that must be adhered to. In many instances, religio-cultural beliefs synthesise or overlap, creating a mutual influence on the person. These religio-cultural rituals are symbolic and important for the living, but they are also equally important for the dead in order to ensure that their souls are returned to the source of their belief system. The COVID-19 lockdown restrictions in South Africa altered death ceremonies and rituals by limiting social gatherings to 50 people to ensure safety protocols like mask wearing and physical distancing. Additionally, family members were prohibited from interacting with the deceased’s body, including performing rituals like washing and dressing, to prevent virus spread. The resultant psychological consequences of these changes to burial practices have not been fully explored in the South African context, and given the importance rituals play, it becomes important to understand them. Studying the psychological consequences of the changes provided insights into individuals’ grief and loss coping in the absence of traditional burial rituals and practices. This is aimed at assisting with the development of interventions for mental health and well-being in future crises. The study explored the psychological consequences of COVID-19 lockdown restrictions on AmaXhosa burial practices and rituals in the Eastern Cape Province of South Africa. AmaXhosa have a rich cultural heritage that places great significance on death and burial rituals. These rituals serve as a way to honour and remember the deceased, provide closure for the bereaved, and maintain social cohesion within the community. The absence of these rituals during the COVID-19 lockdown had consequences for the AmaXhosa’s psychological and religio-cultural well-being. The exploration of their experiences was thus important because it shed light on the importance of these rituals and will help devise innovative ways to address their psychological needs during times of loss. The study utilised a qualitative method, conducting interviews with AmaXhosa aged 18 and older. Participants , Thesis (PhD) -- Faculty of Health Science, 2023
- Full Text:
- Date Issued: 2023-12
Insights into the relative abundance, demographics and behaviour of sea turtles along the east coast of South Africa
- Authors: dos Santos, Natalie Aida
- Date: 2023-12
- Subjects: Sea turtles -- Conservation -- South Africa , Sea turtles -- South Africa , Photogrammetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62495 , vital:72778
- Description: Sea turtles are ecologically important species that have endured a history of overexploitation. Combined with their long, complex life cycles and ongoing anthropogenic pressures, they remain conservation-dependent. Conservation efforts worldwide focus on sea turtle nesting beach protection, however, comprehensive management strategies require an understanding of their lives at sea which are often spent in distant waters. This understanding is hindered by the relative challenges of in-water studies. South Africa has also focused research and conservation efforts on nesting adult female loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea), largely overlooking the species or age classes remaining at sea. Green turtles (Chelonia mydas), hawksbills (Eretmochelys imbricata) and non-breeding loggerheads are frequently stranded and rehabilitated by aquaria, and observed by recreational divers on reefs, suggesting year-round residency along the country’s entire seaboard. Recent technological advancements in photo-identification methods for sea turtles, underwater photography and internet connectivity allowing even recreational divers to become citizen scientists now place us on the verge of an exciting opportunity to unravel the cryptic in-water ecology of these species. The overall aim of this study was to conduct the first assessment of relative abundance, demographics, distribution, and behaviour of sea turtles on reefs within the iSimangaliso and Aliwal Shoal Marine Protected Areas (MPAs) on the east coast of South Africa. A robust photo-identification database was established from research dives, voluntourism and citizen science contributions over a two-year period. From 1057 sightings in the two MPAs, a total of 227 individual sea turtles were identified constituting three species (green turtles: n = 120; hawksbills: n = 46; loggerheads: n = 61). Their relative abundance was proportional to the overall sizes of the South West Indian Ocean (SWIO) populations (green turtles > hawksbills > loggerheads > leatherbacks). However, sightings per unit effort (SPUE) showed that loggerheads were more prevalent than hawksbills in iSimangaliso, likely due to its proximity to this loggerhead rookery. Reefs supported mixed size aggregations with juvenile to adult-sized green turtles (straight carapace lengths, SCLs of 44.9–99.2 cm), whilst hawksbills were mostly juveniles or subadults (SCL range: 37.4–73.4 cm) and loggerheads were mostly adult-sized (SCL range: 66.9–81 cm). Adult sex ratios were slightly female-biased but not significantly different from 1:1. The longest minimum residence periods recorded for individual subadult green and hawksbill turtles (676 and 675 days respectively) and adult-sized loggerheads (621 days) were suggestive of residency. Resident sea turtle activities were typical; they wereobserved foraging, resting, cleaning and interacting year-round, whilst only loggerheads and leatherbacks were observed in breeding behaviour (e.g., patrolling and mating) just after the seasonal arrival of transient individuals. This study thus reveals that the east coast of South Africa hosts regionally important resident and transient sea turtle aggregations with some of the highest SPUE results recorded for the region. This first attempt at monitoring foraging grounds using a variety of techniques and stakeholder groups can serve as the baseline assessment for future work and the foundation for a long-term in-water monitoring programme, allowing for expansion along the entire coastline. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: dos Santos, Natalie Aida
- Date: 2023-12
- Subjects: Sea turtles -- Conservation -- South Africa , Sea turtles -- South Africa , Photogrammetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62495 , vital:72778
- Description: Sea turtles are ecologically important species that have endured a history of overexploitation. Combined with their long, complex life cycles and ongoing anthropogenic pressures, they remain conservation-dependent. Conservation efforts worldwide focus on sea turtle nesting beach protection, however, comprehensive management strategies require an understanding of their lives at sea which are often spent in distant waters. This understanding is hindered by the relative challenges of in-water studies. South Africa has also focused research and conservation efforts on nesting adult female loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea), largely overlooking the species or age classes remaining at sea. Green turtles (Chelonia mydas), hawksbills (Eretmochelys imbricata) and non-breeding loggerheads are frequently stranded and rehabilitated by aquaria, and observed by recreational divers on reefs, suggesting year-round residency along the country’s entire seaboard. Recent technological advancements in photo-identification methods for sea turtles, underwater photography and internet connectivity allowing even recreational divers to become citizen scientists now place us on the verge of an exciting opportunity to unravel the cryptic in-water ecology of these species. The overall aim of this study was to conduct the first assessment of relative abundance, demographics, distribution, and behaviour of sea turtles on reefs within the iSimangaliso and Aliwal Shoal Marine Protected Areas (MPAs) on the east coast of South Africa. A robust photo-identification database was established from research dives, voluntourism and citizen science contributions over a two-year period. From 1057 sightings in the two MPAs, a total of 227 individual sea turtles were identified constituting three species (green turtles: n = 120; hawksbills: n = 46; loggerheads: n = 61). Their relative abundance was proportional to the overall sizes of the South West Indian Ocean (SWIO) populations (green turtles > hawksbills > loggerheads > leatherbacks). However, sightings per unit effort (SPUE) showed that loggerheads were more prevalent than hawksbills in iSimangaliso, likely due to its proximity to this loggerhead rookery. Reefs supported mixed size aggregations with juvenile to adult-sized green turtles (straight carapace lengths, SCLs of 44.9–99.2 cm), whilst hawksbills were mostly juveniles or subadults (SCL range: 37.4–73.4 cm) and loggerheads were mostly adult-sized (SCL range: 66.9–81 cm). Adult sex ratios were slightly female-biased but not significantly different from 1:1. The longest minimum residence periods recorded for individual subadult green and hawksbill turtles (676 and 675 days respectively) and adult-sized loggerheads (621 days) were suggestive of residency. Resident sea turtle activities were typical; they wereobserved foraging, resting, cleaning and interacting year-round, whilst only loggerheads and leatherbacks were observed in breeding behaviour (e.g., patrolling and mating) just after the seasonal arrival of transient individuals. This study thus reveals that the east coast of South Africa hosts regionally important resident and transient sea turtle aggregations with some of the highest SPUE results recorded for the region. This first attempt at monitoring foraging grounds using a variety of techniques and stakeholder groups can serve as the baseline assessment for future work and the foundation for a long-term in-water monitoring programme, allowing for expansion along the entire coastline. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12