The ecology and management of the large carnivore guild on Shamwari Game Reserve, Eastern Cape
- Authors: O'Brien, John William
- Date: 2013
- Subjects: Cheetah -- Behavior -- South Africa -- Shamwari Game Reserve Shamwari Game Reserve (South Africa) Carnivora -- South Africa -- Shamwari Game Reserve Wildlife conservation -- South Africa -- Shamwari Game Reserve Game reserves -- Management -- South Africa -- Shamwari Game Reserve Lion -- Behavior -- South Africa -- Shamwari Game Reserve Lion -- Ecology -- South Africa -- Shamwari Game Reserve African wild dog -- Ecology -- South Africa -- Shamwari Game Reserve Cheetah -- Ecology -- South Africa -- Shamwari Game Reserve Lion -- Food -- South Africa -- Shamwari Game Reserve Lion -- Food -- South Africa -- Shamwari Game Reserve Cheetah -- Food -- South Africa -- Shamwari Game Reserve African wild dog -- Behavior -- South Africa -- Shamwari Game Reserve African wild dog -- Food -- South Africa -- Shamwari Game Reserve Leopard -- Behavior -- South Africa -- Shamwari Game Reserve Leopard -- Ecology -- South Africa -- Shamwari Game Reserve Leopard -- Food --South Africa -- Shamwari Game Reserve
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5609 , http://hdl.handle.net/10962/d1002604
- Description: Shamwari Game Reserve was the first enclosed conservation area in the Eastern Cape Province of South Africa to reintroduce free ranging lions, cheetahs, leopards and wild dogs back into their historic range. At that time (2000 – 2001), little information was available on the ecology and behaviour of these predators in the habitats of the Eastern Cape, and management decisions were based on assumptions and unfounded comparisons with extant populations but from quite different habitats. The aim of this study was therefore to obtain a better understanding of the feeding ecology and space use of the predator guild, and the carrying capacity of Shamwari Game Reserve to enable more informed management decisions. In addition, the reserve is a photographic based tourism venture and understanding both the ecological and financial sustainability of the predator guild was important. The diets of the predators were similar to those reported in other studies; larger predators killed a greater range of prey species than did smaller predators and a small number of prey species made up the majority of the kills. The larger predators had a higher mean kill mass than the smaller species and prey selection was influenced by prey size, prey abundance and prey habitat preference, and risk associated with hunting the species. Diet was flexible and responded to natural and management induced changes in prey abundance. There was a considerable overlap in space use by the lions, cheetahs and leopards with their core areas being centred on and around the Bushmans River. Space use was driven by resource distribution and landscape attributes, and by the presence of other predators of the same or different species. The long term viability of wild dog within the reserve was explored and the results confirmed that there was neither the required space nor the ecological processes and the wild dogs were removed from the reserve. A carrying capacity of the reserve for the predator guild was determined using the Maximum Sustainable Yield method to assess the potential prey species off take and a resultant density of 3.3 to 6.6 lion female equivalent units per 10 000 ha was established. The natural carrying capacity of the reserve with respect to predators will not sustain the tourism objectives and consequently prey supplementation was necessary to maintain predator density at levels high enough to sustain tourism. Under these conditions the large predator guild is still sustainable financially although careful, responsible management is needed to provide ecological sustainability.
- Full Text:
- Date Issued: 2013
- Authors: O'Brien, John William
- Date: 2013
- Subjects: Cheetah -- Behavior -- South Africa -- Shamwari Game Reserve Shamwari Game Reserve (South Africa) Carnivora -- South Africa -- Shamwari Game Reserve Wildlife conservation -- South Africa -- Shamwari Game Reserve Game reserves -- Management -- South Africa -- Shamwari Game Reserve Lion -- Behavior -- South Africa -- Shamwari Game Reserve Lion -- Ecology -- South Africa -- Shamwari Game Reserve African wild dog -- Ecology -- South Africa -- Shamwari Game Reserve Cheetah -- Ecology -- South Africa -- Shamwari Game Reserve Lion -- Food -- South Africa -- Shamwari Game Reserve Lion -- Food -- South Africa -- Shamwari Game Reserve Cheetah -- Food -- South Africa -- Shamwari Game Reserve African wild dog -- Behavior -- South Africa -- Shamwari Game Reserve African wild dog -- Food -- South Africa -- Shamwari Game Reserve Leopard -- Behavior -- South Africa -- Shamwari Game Reserve Leopard -- Ecology -- South Africa -- Shamwari Game Reserve Leopard -- Food --South Africa -- Shamwari Game Reserve
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5609 , http://hdl.handle.net/10962/d1002604
- Description: Shamwari Game Reserve was the first enclosed conservation area in the Eastern Cape Province of South Africa to reintroduce free ranging lions, cheetahs, leopards and wild dogs back into their historic range. At that time (2000 – 2001), little information was available on the ecology and behaviour of these predators in the habitats of the Eastern Cape, and management decisions were based on assumptions and unfounded comparisons with extant populations but from quite different habitats. The aim of this study was therefore to obtain a better understanding of the feeding ecology and space use of the predator guild, and the carrying capacity of Shamwari Game Reserve to enable more informed management decisions. In addition, the reserve is a photographic based tourism venture and understanding both the ecological and financial sustainability of the predator guild was important. The diets of the predators were similar to those reported in other studies; larger predators killed a greater range of prey species than did smaller predators and a small number of prey species made up the majority of the kills. The larger predators had a higher mean kill mass than the smaller species and prey selection was influenced by prey size, prey abundance and prey habitat preference, and risk associated with hunting the species. Diet was flexible and responded to natural and management induced changes in prey abundance. There was a considerable overlap in space use by the lions, cheetahs and leopards with their core areas being centred on and around the Bushmans River. Space use was driven by resource distribution and landscape attributes, and by the presence of other predators of the same or different species. The long term viability of wild dog within the reserve was explored and the results confirmed that there was neither the required space nor the ecological processes and the wild dogs were removed from the reserve. A carrying capacity of the reserve for the predator guild was determined using the Maximum Sustainable Yield method to assess the potential prey species off take and a resultant density of 3.3 to 6.6 lion female equivalent units per 10 000 ha was established. The natural carrying capacity of the reserve with respect to predators will not sustain the tourism objectives and consequently prey supplementation was necessary to maintain predator density at levels high enough to sustain tourism. Under these conditions the large predator guild is still sustainable financially although careful, responsible management is needed to provide ecological sustainability.
- Full Text:
- Date Issued: 2013
Afro-communitarianism and the nature of reconciliation
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Date Issued: 2013
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Date Issued: 2013
High performance nonwovens in technical textile applications
- Ogunleye, Christopher Olarinde
- Authors: Ogunleye, Christopher Olarinde
- Date: 2013
- Subjects: Nonwoven fabrics , Textile fabrics -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10356 , http://hdl.handle.net/10948/d1021011
- Description: The aim of this research was to establish the optimum processing conditions and parameters for producing nonwoven fabrics best suited for application in disposable and protective wear for surgical gowns, drapes and laboratory coats. Carded and crosslapped webs, of three basic weights (80, 120, and 150g/m2), from greige (unscoured and unbleached) cotton, viscose and polyester fibres, were hydroentangled, using three different waterjet pressures (60, 100 and 120 bars), on a Fleissner Aquajet hydroentanglement machine. An antibacterial agent (Ruco-Coat FC 9005) and a fluorochemical water repellent agent (Ruco Bac-AGP), were applied in one bath using the pad-dry-cure technique, to impart both antibacterial and water repellent properties to the fabrics, SEM photomicrographs indicating that the finished polymers were evenly dispersed on the fabric surface. The effect of waterjet pressure, fabric weight and type and treatment on the structure of the nonwoven produced, was evaluated by measuring the relevant characteristics of the fabrics. As expected, there was an interrelationship between fabric weight, thickness, and density, the fabric thickness and mass density increasing with fabric weight. An increase in waterjet pressure decreased the fabric thickness and increased the fabric density. The water repellent and antibacterial treatment increased the fabric weight and thickness. The antimicrobial activity of the fabrics was assessed by determining the percentage reduction in Staphylococcus aureus and Escherichia coli bacteria population. The maximum percent reduction at 24hrs contact time for both bacteria ranged from 99.5 to 99.6 percent for all the fabric types. The standard spray test ratings for the three treated fabrics ranged from 80-90 percent, whereas that of the untreated water repellent fabric was zero, while the contact angles for all the fabric types exceeded 90 degrees, indicating good resistance to wetting. It was found that the tensile strength of the fabric in the cross-machine direction was higher than that in the machine direction, for both the treated and untreated fabrics, with the tensile strengths in both the MD and CD of the treated fabrics were greater than that of the untreated fabrics, the reverse being true for the extension at break. An increase in waterjet pressure increased the tensile strength but decreased the extension at break, for both the treated and untreated fabrics. The finishing treatment decreased the mean pore size of all the fabrics, the mean pore size decreasing with an increase in fabric weight and waterjet pressure. An increase in waterjet pressure and fabric weight decreased the air and water vapour permeability, as did the finishing treatment, although the differences were not always statistically significant. The polyester fabrics had the highest water and air permeability. Hence low weight fabrics of 80 g/m2, which were hydroentangled at low water jet pressures of 60 bars, were suitable for use in this study due to their higher air and water vapour permeability as well as higher pore size distribution. These group of fabrics thus meet the requirements for surgical gowns, drapes, nurses’ uniforms and laboratory coats.
- Full Text:
- Date Issued: 2013
- Authors: Ogunleye, Christopher Olarinde
- Date: 2013
- Subjects: Nonwoven fabrics , Textile fabrics -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10356 , http://hdl.handle.net/10948/d1021011
- Description: The aim of this research was to establish the optimum processing conditions and parameters for producing nonwoven fabrics best suited for application in disposable and protective wear for surgical gowns, drapes and laboratory coats. Carded and crosslapped webs, of three basic weights (80, 120, and 150g/m2), from greige (unscoured and unbleached) cotton, viscose and polyester fibres, were hydroentangled, using three different waterjet pressures (60, 100 and 120 bars), on a Fleissner Aquajet hydroentanglement machine. An antibacterial agent (Ruco-Coat FC 9005) and a fluorochemical water repellent agent (Ruco Bac-AGP), were applied in one bath using the pad-dry-cure technique, to impart both antibacterial and water repellent properties to the fabrics, SEM photomicrographs indicating that the finished polymers were evenly dispersed on the fabric surface. The effect of waterjet pressure, fabric weight and type and treatment on the structure of the nonwoven produced, was evaluated by measuring the relevant characteristics of the fabrics. As expected, there was an interrelationship between fabric weight, thickness, and density, the fabric thickness and mass density increasing with fabric weight. An increase in waterjet pressure decreased the fabric thickness and increased the fabric density. The water repellent and antibacterial treatment increased the fabric weight and thickness. The antimicrobial activity of the fabrics was assessed by determining the percentage reduction in Staphylococcus aureus and Escherichia coli bacteria population. The maximum percent reduction at 24hrs contact time for both bacteria ranged from 99.5 to 99.6 percent for all the fabric types. The standard spray test ratings for the three treated fabrics ranged from 80-90 percent, whereas that of the untreated water repellent fabric was zero, while the contact angles for all the fabric types exceeded 90 degrees, indicating good resistance to wetting. It was found that the tensile strength of the fabric in the cross-machine direction was higher than that in the machine direction, for both the treated and untreated fabrics, with the tensile strengths in both the MD and CD of the treated fabrics were greater than that of the untreated fabrics, the reverse being true for the extension at break. An increase in waterjet pressure increased the tensile strength but decreased the extension at break, for both the treated and untreated fabrics. The finishing treatment decreased the mean pore size of all the fabrics, the mean pore size decreasing with an increase in fabric weight and waterjet pressure. An increase in waterjet pressure and fabric weight decreased the air and water vapour permeability, as did the finishing treatment, although the differences were not always statistically significant. The polyester fabrics had the highest water and air permeability. Hence low weight fabrics of 80 g/m2, which were hydroentangled at low water jet pressures of 60 bars, were suitable for use in this study due to their higher air and water vapour permeability as well as higher pore size distribution. These group of fabrics thus meet the requirements for surgical gowns, drapes, nurses’ uniforms and laboratory coats.
- Full Text:
- Date Issued: 2013
Application of bidentate N,N'-donor extractants in the hydrometallurgical separation of base metals from an acidic sulfate medium
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Date Issued: 2013
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Date Issued: 2013
Synthesis, characterisation and biological activity of 2-(methylthiomethyl)anilines, 2-(methylthio)anilines, their Schiff-base derivatives and metal(II) (Co, Ni, Cu) complexes
- Olalekan, Temitope Elizabeth
- Authors: Olalekan, Temitope Elizabeth
- Date: 2013
- Subjects: Aniline , Schiff bases , Ligands , Nuclear magnetic resonance spectroscopy , Chelates , X-ray crystallography , Antimalarials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4562 , http://hdl.handle.net/10962/d1020868
- Description: A series of 31 sulfur-nitrogen donor ligands and 64 metal(II) complexes have been investigated. The thiomethylated aniline ligands 2–(methylthiomethyl)aniline 2MT and 2–(methylthio)aniline 2MA were synthesized with their substituted derivatives (-Me, -MeO, -Cl, -Br, -NO2) to serve as chelating agents. These ligands behave as bidentate ligands with SN donor group with Co(II), Ni(II) and Cu(II). The Co(II) and Ni(II) complexes have the ML2Cl2 molecular formula while the Cu(II) complexes formed with MLCl2 stoichiometry where L is the bidentate ligand. The ligands and their metal(II) complexes have been characterized by elemental analysis and with spectroscopic techniques. The trend observed in the NMR spectra and IR frequencies of the thiomethylated compounds shows there is a significant difference between the 2MT and 2MA series as a result of sulfur lone pairs extending the conjugation of the aromatic ring in the case of the latter. The effect of the position and electronic nature of ring substituent on the NMR shifts of the amine protons is discussed. The 6- and 5-membered chelate complexes formed by the 2MT and 2MA ligands respectively do not show significant diversity in their spectroscopic properties. From the elemental analysis for the Co(II) and Ni(II) complexes, their compositions reveal 1:2 M:L stoichiometry with 2 chlorine atoms from the respective metal salts. In addition, the spectroscopic data are largely indicative of tetragonally distorted structures for these solid complexes. The X-ray crystallography data reveal the Cu(II) complexes exist as square pyramidal dimers and with long Cu–Cl equitorial bonds fit into the tetragonally distorted octahedral structure. The electrolytic nature of Co(II) and Cu(II) complexes in DMF were found to be similar, they behave as non electrolytes in contrast to Ni(II) complexes which are 1:1 electrolytes. The electronic spectra of these metal(II) complexes were found to be different for both their solid forms and in solutions of DMF and DMSO and this has been discussed. The thiomethylated aniline ligands possess the amine and thioether groups which are present in many known biologically active compounds, hence the biological activity of the ligands and their metal complexes were tested against three strains of bacteria and one fungus. The methoxy-substituted derivatives were found to possess better inhibitory activity and this was similarly reflected in the metal(II) complexes. The activity of the complexes can be said to be in the order, Cu(II) > Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.
- Full Text:
- Date Issued: 2013
- Authors: Olalekan, Temitope Elizabeth
- Date: 2013
- Subjects: Aniline , Schiff bases , Ligands , Nuclear magnetic resonance spectroscopy , Chelates , X-ray crystallography , Antimalarials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4562 , http://hdl.handle.net/10962/d1020868
- Description: A series of 31 sulfur-nitrogen donor ligands and 64 metal(II) complexes have been investigated. The thiomethylated aniline ligands 2–(methylthiomethyl)aniline 2MT and 2–(methylthio)aniline 2MA were synthesized with their substituted derivatives (-Me, -MeO, -Cl, -Br, -NO2) to serve as chelating agents. These ligands behave as bidentate ligands with SN donor group with Co(II), Ni(II) and Cu(II). The Co(II) and Ni(II) complexes have the ML2Cl2 molecular formula while the Cu(II) complexes formed with MLCl2 stoichiometry where L is the bidentate ligand. The ligands and their metal(II) complexes have been characterized by elemental analysis and with spectroscopic techniques. The trend observed in the NMR spectra and IR frequencies of the thiomethylated compounds shows there is a significant difference between the 2MT and 2MA series as a result of sulfur lone pairs extending the conjugation of the aromatic ring in the case of the latter. The effect of the position and electronic nature of ring substituent on the NMR shifts of the amine protons is discussed. The 6- and 5-membered chelate complexes formed by the 2MT and 2MA ligands respectively do not show significant diversity in their spectroscopic properties. From the elemental analysis for the Co(II) and Ni(II) complexes, their compositions reveal 1:2 M:L stoichiometry with 2 chlorine atoms from the respective metal salts. In addition, the spectroscopic data are largely indicative of tetragonally distorted structures for these solid complexes. The X-ray crystallography data reveal the Cu(II) complexes exist as square pyramidal dimers and with long Cu–Cl equitorial bonds fit into the tetragonally distorted octahedral structure. The electrolytic nature of Co(II) and Cu(II) complexes in DMF were found to be similar, they behave as non electrolytes in contrast to Ni(II) complexes which are 1:1 electrolytes. The electronic spectra of these metal(II) complexes were found to be different for both their solid forms and in solutions of DMF and DMSO and this has been discussed. The thiomethylated aniline ligands possess the amine and thioether groups which are present in many known biologically active compounds, hence the biological activity of the ligands and their metal complexes were tested against three strains of bacteria and one fungus. The methoxy-substituted derivatives were found to possess better inhibitory activity and this was similarly reflected in the metal(II) complexes. The activity of the complexes can be said to be in the order, Cu(II) > Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.
- Full Text:
- Date Issued: 2013
Polymer based electrospun nanofibers as diagnostic probes for the detection of toxic metal ions in water
- Authors: Ondigo, Dezzline Adhiambo
- Date: 2013
- Subjects: Heavy metals , Nanofibers , Nanoparticles , Colorimetric analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4557 , http://hdl.handle.net/10962/d1018261
- Description: The thesis presents the development of polymer based electrospun nanofibers as diagnostic probes for the selective detection of toxic metal ions in water. Through modification of the chemical characteristics of nanofibers by pre- and post-electrospinning treatments, three different diagnostic probes were successfully developed. These were the fluorescent pyridylazo-2-naphthol-poly(acrylic acid) nanofiber probe, the colorimetric probe based on glutathione-stabilized silver/copper alloy nanoparticles and the colorimetric probe based on 2-(2’-Pyridyl)-imidazole functionalized nanofibers. The probes were characterized by Fourier transform infrared spectroscopy (FTIR), Energy dispersive x-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The fluorescent nanofiber probe was developed towards the determination of Ni²⁺. Covalently functionalized pyridylazo-2-naphthol-poly(acrylic acid) polymeric nanofibers were employed. The solid state Ni²⁺ probe exhibited a good correlation between the fluorescence intensity and nickel concentration up to 1.0 mg/mL based on the Stern-Volmer mechanism. The detection limit of the nanofiber probe was found to be 0.07 ng/mL. The versatility of the fluorescent probe was demonstrated by affording a simple, rapid and selective detection of Ni²⁺ in the presence of other competing metal ions by direct analysis without employing any sample handling steps. For the second part of the study, a simple strategy based on the in-situ synthesis of the glutathione stabilized silver/copper alloy nanoparticles (Ag/Cu alloy NPs) in nylon 6 provided a fast procedure for fabricating a colorimetric probe for the detection of Ni²⁺ in water samples. The electrospun nanofiber composites responded to Ni²⁺ ions but did not suffer any interference from the other metal ions. The effect of Ni²⁺ concentration on the nanocomposite fibers was considered and the “eye-ball” limit of detection was found to be 5.8 μg/mL. Lastly, the third probe was developed by covalently linking an imidazole derivative; 2-(2′-Pyridyl)-imidazole (PIMH) to Poly(vinylbenzyl chloride) (PVBC) and nylon 6 nanofibers by post-electrospinning treatments using a wet chemical method and graft copolymerization technique, respectively. The post-electrospinning modifications of the nanofibers were achieved without altering their fibrous morphology. The color change to red-orange in the presence of Fe²⁺ for both the grafted nylon 6 (white) and the chemically modified PVBC (yellow) nanofibers was instantaneous. The developed diagnostic probes exhibited the desired selectivity towards the targeted metal ions.
- Full Text:
- Date Issued: 2013
- Authors: Ondigo, Dezzline Adhiambo
- Date: 2013
- Subjects: Heavy metals , Nanofibers , Nanoparticles , Colorimetric analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4557 , http://hdl.handle.net/10962/d1018261
- Description: The thesis presents the development of polymer based electrospun nanofibers as diagnostic probes for the selective detection of toxic metal ions in water. Through modification of the chemical characteristics of nanofibers by pre- and post-electrospinning treatments, three different diagnostic probes were successfully developed. These were the fluorescent pyridylazo-2-naphthol-poly(acrylic acid) nanofiber probe, the colorimetric probe based on glutathione-stabilized silver/copper alloy nanoparticles and the colorimetric probe based on 2-(2’-Pyridyl)-imidazole functionalized nanofibers. The probes were characterized by Fourier transform infrared spectroscopy (FTIR), Energy dispersive x-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The fluorescent nanofiber probe was developed towards the determination of Ni²⁺. Covalently functionalized pyridylazo-2-naphthol-poly(acrylic acid) polymeric nanofibers were employed. The solid state Ni²⁺ probe exhibited a good correlation between the fluorescence intensity and nickel concentration up to 1.0 mg/mL based on the Stern-Volmer mechanism. The detection limit of the nanofiber probe was found to be 0.07 ng/mL. The versatility of the fluorescent probe was demonstrated by affording a simple, rapid and selective detection of Ni²⁺ in the presence of other competing metal ions by direct analysis without employing any sample handling steps. For the second part of the study, a simple strategy based on the in-situ synthesis of the glutathione stabilized silver/copper alloy nanoparticles (Ag/Cu alloy NPs) in nylon 6 provided a fast procedure for fabricating a colorimetric probe for the detection of Ni²⁺ in water samples. The electrospun nanofiber composites responded to Ni²⁺ ions but did not suffer any interference from the other metal ions. The effect of Ni²⁺ concentration on the nanocomposite fibers was considered and the “eye-ball” limit of detection was found to be 5.8 μg/mL. Lastly, the third probe was developed by covalently linking an imidazole derivative; 2-(2′-Pyridyl)-imidazole (PIMH) to Poly(vinylbenzyl chloride) (PVBC) and nylon 6 nanofibers by post-electrospinning treatments using a wet chemical method and graft copolymerization technique, respectively. The post-electrospinning modifications of the nanofibers were achieved without altering their fibrous morphology. The color change to red-orange in the presence of Fe²⁺ for both the grafted nylon 6 (white) and the chemically modified PVBC (yellow) nanofibers was instantaneous. The developed diagnostic probes exhibited the desired selectivity towards the targeted metal ions.
- Full Text:
- Date Issued: 2013
A critical analysis of the grammar of isiXhosa as used in the Revised Union version of the Bible
- Oosthuysen, Jacobus Christiaan
- Authors: Oosthuysen, Jacobus Christiaan
- Date: 2013
- Subjects: Bible -- Xhosa -- Revised Union -- 1942 Xhosa language -- Grammar -- Research Xhosa language -- Texts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3555 , http://hdl.handle.net/10962/d1001625
- Description: This study provides a description and critical analysis of the grammatical structure of isiXhosa as used in the Revised Union Version of the Bible, published in 1942 and republished in 1975. This translation records what was regarded as proper isiXhosa at the beginning of the 20th century, reflecting the consensus inter alia of prominent isiXhosa writers, such as W.B. Rubusana, J.H. Soga, C. Koti, Y. Mbali and D. D. T. Jabavu, who served on the committee that produced the revision. In this study isiXhosa is described in its own right, without approaching it with preconceived ideas derived from other languages. That is to say this is a phenomenological analysis describing the grammatical structures of isiXhosa as they present themselves to the analyst. It is comprehensive, with no structure being overlooked or being described in such a manner that it complicates an understanding of other structures. In the first chapter the context of the research and a brief outline of the historical growth in understanding the structure of isiXhosa are set out and the goals and the method followed in this study are described. In the following chapters the findings of this study are presented. The initial focus is on isiXhosa phonology and the orthography used to put it to writing. Then isiXhosa morphology and syntax is set out. Initially the substantives, i.e. the nouns and pronouns in their distinctive classes and forms, and how they are qualified, receive attention. Then the predicates are explored, i.e. the verbs and copulatives, as linked to the substantives with concords, and reflecting various moods, tenses, actualities and aspects. Finally attention is given to ideophones and interjections and words that can be grouped together as adverbs, conjunctions, avoidance words and numerals. In the concluding chapter consideration is given to the question of whether this study has in fact achieved the aim of setting out a description of the structure of isiXhosa based solely on the language itself, free of preconceived ideas, and attention is drawn to insights gained in respect of the true nature of the isiXhosa grammatical structures, such as, for example, the variable prefix qualificative nouns, traditionally referred to as adjectives. This study is therefore a revisionist study in the sense that it reinvents isiXhosa as a language in its own right, free from Western influenced perspectives.
- Full Text:
- Date Issued: 2013
- Authors: Oosthuysen, Jacobus Christiaan
- Date: 2013
- Subjects: Bible -- Xhosa -- Revised Union -- 1942 Xhosa language -- Grammar -- Research Xhosa language -- Texts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3555 , http://hdl.handle.net/10962/d1001625
- Description: This study provides a description and critical analysis of the grammatical structure of isiXhosa as used in the Revised Union Version of the Bible, published in 1942 and republished in 1975. This translation records what was regarded as proper isiXhosa at the beginning of the 20th century, reflecting the consensus inter alia of prominent isiXhosa writers, such as W.B. Rubusana, J.H. Soga, C. Koti, Y. Mbali and D. D. T. Jabavu, who served on the committee that produced the revision. In this study isiXhosa is described in its own right, without approaching it with preconceived ideas derived from other languages. That is to say this is a phenomenological analysis describing the grammatical structures of isiXhosa as they present themselves to the analyst. It is comprehensive, with no structure being overlooked or being described in such a manner that it complicates an understanding of other structures. In the first chapter the context of the research and a brief outline of the historical growth in understanding the structure of isiXhosa are set out and the goals and the method followed in this study are described. In the following chapters the findings of this study are presented. The initial focus is on isiXhosa phonology and the orthography used to put it to writing. Then isiXhosa morphology and syntax is set out. Initially the substantives, i.e. the nouns and pronouns in their distinctive classes and forms, and how they are qualified, receive attention. Then the predicates are explored, i.e. the verbs and copulatives, as linked to the substantives with concords, and reflecting various moods, tenses, actualities and aspects. Finally attention is given to ideophones and interjections and words that can be grouped together as adverbs, conjunctions, avoidance words and numerals. In the concluding chapter consideration is given to the question of whether this study has in fact achieved the aim of setting out a description of the structure of isiXhosa based solely on the language itself, free of preconceived ideas, and attention is drawn to insights gained in respect of the true nature of the isiXhosa grammatical structures, such as, for example, the variable prefix qualificative nouns, traditionally referred to as adjectives. This study is therefore a revisionist study in the sense that it reinvents isiXhosa as a language in its own right, free from Western influenced perspectives.
- Full Text:
- Date Issued: 2013
M-health user experience framework for the public healthcare sector
- Authors: Ouma, Stella
- Date: 2013
- Subjects: Communication in public health , Public health -- South Africa , Wireless communication systems in medical care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9827 , http://hdl.handle.net/10948/d1020793
- Description: The public healthcare sectors within developing nations face a lot of challenges because of constrained resources available to them. The South African public healthcare sector is no different. Although it serves the majority of the South African population, most of the financial resources are directed towards the private sector, which serves very few individuals when compared to the public healthcare sector. Apart from that, other challenges that the National Department of Health has to deal with include the lack of sufficiently trained healthcare employees who can work on the different levels of the public healthcare sector, as well as the burden of diseases such as HIV and Aids, tuberculosis and other chronic diseases. In order to improve service delivery, the National Department of Health is introducing Information and Communications Technology interventions that can increase efficiency and reduce costs, thereby improving the quality of service delivery. This research delivers an m-health application user experience framework to be proposed to the National Department of Health in South Africa, in order to assist in scaling up of m-health applications. The m-health applications that can benefit the South African population if scaled up successfully include those that can be used in remote data collection, treatment and compliance, accessing patients records, remote monitoring, communication and training for healthcare workers and applications that can be used for education and awareness. The study focused on three domains: the Human-Computer Interaction domain, public healthcare domain and Health Informatics domain. The proposed framework was realized by investigating mobile user experience components, mobile health requirements and the South African public healthcare domain components that contribute to the m-health user experience framework. This research was conducted through the interpretivist philosophy. Due to the exploratory nature of the study, an application of qualitative methodology was used. The conceptual theoretical framework was validated through a single case study approach by m-health user experience experts, who reside in South Africa. Data were analysed inductively. An m-health user experience framework was provided at the end of the study. An m-health user experience framework can assist the National Department of Health to look into design issues, address m-health requirements and put the domain needs in place, thus enabling the Department to successfully scale up implementations of m-health applications nationwide.
- Full Text:
- Date Issued: 2013
- Authors: Ouma, Stella
- Date: 2013
- Subjects: Communication in public health , Public health -- South Africa , Wireless communication systems in medical care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9827 , http://hdl.handle.net/10948/d1020793
- Description: The public healthcare sectors within developing nations face a lot of challenges because of constrained resources available to them. The South African public healthcare sector is no different. Although it serves the majority of the South African population, most of the financial resources are directed towards the private sector, which serves very few individuals when compared to the public healthcare sector. Apart from that, other challenges that the National Department of Health has to deal with include the lack of sufficiently trained healthcare employees who can work on the different levels of the public healthcare sector, as well as the burden of diseases such as HIV and Aids, tuberculosis and other chronic diseases. In order to improve service delivery, the National Department of Health is introducing Information and Communications Technology interventions that can increase efficiency and reduce costs, thereby improving the quality of service delivery. This research delivers an m-health application user experience framework to be proposed to the National Department of Health in South Africa, in order to assist in scaling up of m-health applications. The m-health applications that can benefit the South African population if scaled up successfully include those that can be used in remote data collection, treatment and compliance, accessing patients records, remote monitoring, communication and training for healthcare workers and applications that can be used for education and awareness. The study focused on three domains: the Human-Computer Interaction domain, public healthcare domain and Health Informatics domain. The proposed framework was realized by investigating mobile user experience components, mobile health requirements and the South African public healthcare domain components that contribute to the m-health user experience framework. This research was conducted through the interpretivist philosophy. Due to the exploratory nature of the study, an application of qualitative methodology was used. The conceptual theoretical framework was validated through a single case study approach by m-health user experience experts, who reside in South Africa. Data were analysed inductively. An m-health user experience framework was provided at the end of the study. An m-health user experience framework can assist the National Department of Health to look into design issues, address m-health requirements and put the domain needs in place, thus enabling the Department to successfully scale up implementations of m-health applications nationwide.
- Full Text:
- Date Issued: 2013
Microcystin enhances the fitness of microcystin producing cyanobacteria at high light intensities by either preventing or retarding photoinhibition
- Authors: Phelan, Richard Reginald
- Date: 2013
- Subjects: Microcystins , Microcystis , Cyanobacterial toxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10354 , http://hdl.handle.net/10948/d1020957
- Description: Several genera of cyanobacteria produce microcystin, a monocyclic peptide, with a unique chemical structure. To date, there have been over a 100 different structural variants of microcystin which have been identified. Microcystin production is affected by numerous environmental factors. However, the primary modulating factor for intracellular microcystin quota is the intracellular N:C ratio. No clearly defined biological role has been described for microcystin. Proposed roles for microcystin include defence against plankton grazers, metal chelation, an infochemical and a protectant against oxidative stress. There is sufficient evidence to support a biological role for microcystin in photosynthesis: microcystin is predominantly located in the thylakoid membranes, the microcystin gene cluster is differentially expressed as a function of light and a growth advantage for the microcystin producer in saturating light intensities. The purpose of this study is to investigate a possible biological role for microcystin in preventing photoinhibition and thus explaining the growth advantage observed in toxin-producers over non-toxin-producers. The uptake of exogenous microcystin was observed in Synechocystis PCC 6803 which was internalized and located in the thylakoid membranes and caused the inhibition of photosynthesis. Microcystin variants and increasing concentrations of microcystin-LR had no effect on the fluidity of the thylakoid membranes. The exposure of thylakoid membranes from Synechocystis PCC 6803 to physiologically relevant concentrations of different microcystin variants resulted in the inhibition of photosystem II activity but not photosystem I activity. The inhibition of photosystem II was variant dependent and concentration dependent for microcystin-LR and microcystin-RR. Chlorophyll a fluorescence data showed that photosystem II inhibition was caused by the inhibition of the oxygen evolving complex. Furthermore, a completion study revealed that the microcystin-producing Microcystis PCC 7806 had a competitive advantage over the non-microcystin producing ΔmcyA mutant of Microcystis PCC 7806 at high light intensities. The data indicates that microcystin protects the toxin-producer by either retarding or preventing photoinhibition and thus identifying the first data supported function for microcystin in cyanobacteria.
- Full Text:
- Date Issued: 2013
- Authors: Phelan, Richard Reginald
- Date: 2013
- Subjects: Microcystins , Microcystis , Cyanobacterial toxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10354 , http://hdl.handle.net/10948/d1020957
- Description: Several genera of cyanobacteria produce microcystin, a monocyclic peptide, with a unique chemical structure. To date, there have been over a 100 different structural variants of microcystin which have been identified. Microcystin production is affected by numerous environmental factors. However, the primary modulating factor for intracellular microcystin quota is the intracellular N:C ratio. No clearly defined biological role has been described for microcystin. Proposed roles for microcystin include defence against plankton grazers, metal chelation, an infochemical and a protectant against oxidative stress. There is sufficient evidence to support a biological role for microcystin in photosynthesis: microcystin is predominantly located in the thylakoid membranes, the microcystin gene cluster is differentially expressed as a function of light and a growth advantage for the microcystin producer in saturating light intensities. The purpose of this study is to investigate a possible biological role for microcystin in preventing photoinhibition and thus explaining the growth advantage observed in toxin-producers over non-toxin-producers. The uptake of exogenous microcystin was observed in Synechocystis PCC 6803 which was internalized and located in the thylakoid membranes and caused the inhibition of photosynthesis. Microcystin variants and increasing concentrations of microcystin-LR had no effect on the fluidity of the thylakoid membranes. The exposure of thylakoid membranes from Synechocystis PCC 6803 to physiologically relevant concentrations of different microcystin variants resulted in the inhibition of photosystem II activity but not photosystem I activity. The inhibition of photosystem II was variant dependent and concentration dependent for microcystin-LR and microcystin-RR. Chlorophyll a fluorescence data showed that photosystem II inhibition was caused by the inhibition of the oxygen evolving complex. Furthermore, a completion study revealed that the microcystin-producing Microcystis PCC 7806 had a competitive advantage over the non-microcystin producing ΔmcyA mutant of Microcystis PCC 7806 at high light intensities. The data indicates that microcystin protects the toxin-producer by either retarding or preventing photoinhibition and thus identifying the first data supported function for microcystin in cyanobacteria.
- Full Text:
- Date Issued: 2013
Exploring interventions for participation of emerging farmers in the Eastern Cape ostrich-industry supply chain
- Authors: Pittaway, Timothy
- Date: 2013
- Subjects: Farmers -- South Africa -- Eastern Cape , Ostrich products industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10596 , http://hdl.handle.net/10948/d1021008
- Description: The changing agricultural environment (dualistic agricultural landscape, land reform programme, market liberalisation and globalisation) has caused emerging ostrich farmers to become increasingly isolated. Governmental agriculture reforms and public sector interventions have been insufficient to address all the challenges faced by rural ostrich farmers in the Eastern Cape. Participation in the ostrich supply chain for emerging farmers in the Eastern Cape is currently unsustainable as a result of avian influenza, control and registration protocols for ostriches (VPN04), structural barriers in marketing, technical constraints and a lack of market participation. People in the rural areas of the Eastern Cape are challenged by inferior infrastructure, poor site conditions, low earnings, poor access to health services and unreliable water sources. The marginal conditions and prevalent complexities in which agriculture is practised require costly resource intervention. Intensive ostrich production necessitates continuous genetic improvement, methodical record keeping, intensive egg incubation methods and highmaintenance chick rearing and ostrich handling while minimising feed costs throughout this process. Rural farmers have not embraced ostrich farming in the same way as they have done with other livestock farming because it does not offer the anthropological functions that traditional livestock farming provides. The ostrich supply chain requires a wide range of activities to bring products to the final consumer. The worth of ostrich production lies mainly in the higher returns which are achieved only through the export markets. Today the ostrich industry has become vulnerable to market cannibalism, a lack of market development, unregulated numbers of ostriches and recurring international meat bans. The deregulation of the ostrich single-channel marketing system had a substantial effect on the value chain on which farmers depended for market access and market protection. As the majority of ostrich products are being exported to the European Union, the role of intermediary agencies is becoming an important factor influencing entry into the high-end markets. This agent structure that represents the South African ostrich industry is vital for the distribution, market penetration and regulation of the ostrich products. The ostrich leather, which is today the main product line, is primarily used for luxury goods and is susceptible to economic downturn and over-supply. The ostrich meat industry has been severely influenced by outbreaks of avian influenza and processors now pre-heat the meat in order to maintain export. However, this preheating meat facility is only for export produce and available to farmers who conform to VPN04 and have officially registered farms. The relevant South African government departments played a crucial role in identifying avian influenza outbreaks and liaising with the European Union about avian influenza isolation strategies. No previous studies have been conducted on the participation of emerging farmers in the Eastern Cape ostrich-industry supply chain and on the interventions required to address the multiple constraints and forces in this sector. This led to a study with research emphasis on the required capacity for supply-chain participation and the supporting mechanisms that would be required for emerging ostrich farmers to integrate successfully into this supply chain. An exploratory research approach was chosen for the investigation, as no earlier research has been undertaken that could serve as a source of reliable data or reference. A triangulation research methodology using both the quantitative and the qualitative approach was applied. The qualitative research entailed an interpretive approach associated with using grounded theory and content analysis for interpreting data. The comparative case study design was the main qualitative research instrument for the multiple-case studies on emerging ostrich farmers in the Eastern Cape. The study was undertaken at five different sites, namely, the Peddie Ostrich Programme, the Rockhurst Ostrich Programme, the Hlumani Co-operative farm, the Zamukwanda Ostrich farm near Pearston and the Mimosadale Ostrich farm. The quantitative methods were applied to capture all the measurable components and representations of the stakeholders and participants, through interviews, questionnaires and focus group interviews. The quantitative study also included an experimental instrument to measure the capacity of emerging farmer programmes for supply chain participation. It was found that the main driver for three of the case studies pertained to land ownership and that ostrich farming was incidental and only seen as means of activity for income. These three humanitarian farming projects had limited capacity for intensive management requirements for ostrich farming. It was found that the VPN04 bio-security protocols and disease control require a higher level of record keeping for EU markets and is prohibitively expensive for poor rural emerging farmers. The study established that the emerging ostrich farming programmes contributed value to the industry and government rural development in land redistribution programmes, vehicles for reduction of poverty and job creation in the rural areas and by acting as out-grower programmes for commercial farmers. The researcher’s observation is that through strategic interventions the programmes have potential to become commercial players in the industry. The following interventions were recommended from this study: Feasibility study of programmes and review of location selection before initiation. Providing supportive interventions for programme start-ups; Improved selection of programme beneficiaries; Improved structure of emerging farmers’ co-operatives; On-going and appropriate training for emerging ostrich farmers; The role of government and mentors needs to be defined; Reducing feed costs; Establishing programmes linkages to informal markets and facilitating increased self-consumption; Developing new export markets; Alternative finance for the no-income months; Alternative marketing channels to export markets; Representation of emerging farmers in the ostrich-industry leadership structures.
- Full Text:
- Date Issued: 2013
- Authors: Pittaway, Timothy
- Date: 2013
- Subjects: Farmers -- South Africa -- Eastern Cape , Ostrich products industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10596 , http://hdl.handle.net/10948/d1021008
- Description: The changing agricultural environment (dualistic agricultural landscape, land reform programme, market liberalisation and globalisation) has caused emerging ostrich farmers to become increasingly isolated. Governmental agriculture reforms and public sector interventions have been insufficient to address all the challenges faced by rural ostrich farmers in the Eastern Cape. Participation in the ostrich supply chain for emerging farmers in the Eastern Cape is currently unsustainable as a result of avian influenza, control and registration protocols for ostriches (VPN04), structural barriers in marketing, technical constraints and a lack of market participation. People in the rural areas of the Eastern Cape are challenged by inferior infrastructure, poor site conditions, low earnings, poor access to health services and unreliable water sources. The marginal conditions and prevalent complexities in which agriculture is practised require costly resource intervention. Intensive ostrich production necessitates continuous genetic improvement, methodical record keeping, intensive egg incubation methods and highmaintenance chick rearing and ostrich handling while minimising feed costs throughout this process. Rural farmers have not embraced ostrich farming in the same way as they have done with other livestock farming because it does not offer the anthropological functions that traditional livestock farming provides. The ostrich supply chain requires a wide range of activities to bring products to the final consumer. The worth of ostrich production lies mainly in the higher returns which are achieved only through the export markets. Today the ostrich industry has become vulnerable to market cannibalism, a lack of market development, unregulated numbers of ostriches and recurring international meat bans. The deregulation of the ostrich single-channel marketing system had a substantial effect on the value chain on which farmers depended for market access and market protection. As the majority of ostrich products are being exported to the European Union, the role of intermediary agencies is becoming an important factor influencing entry into the high-end markets. This agent structure that represents the South African ostrich industry is vital for the distribution, market penetration and regulation of the ostrich products. The ostrich leather, which is today the main product line, is primarily used for luxury goods and is susceptible to economic downturn and over-supply. The ostrich meat industry has been severely influenced by outbreaks of avian influenza and processors now pre-heat the meat in order to maintain export. However, this preheating meat facility is only for export produce and available to farmers who conform to VPN04 and have officially registered farms. The relevant South African government departments played a crucial role in identifying avian influenza outbreaks and liaising with the European Union about avian influenza isolation strategies. No previous studies have been conducted on the participation of emerging farmers in the Eastern Cape ostrich-industry supply chain and on the interventions required to address the multiple constraints and forces in this sector. This led to a study with research emphasis on the required capacity for supply-chain participation and the supporting mechanisms that would be required for emerging ostrich farmers to integrate successfully into this supply chain. An exploratory research approach was chosen for the investigation, as no earlier research has been undertaken that could serve as a source of reliable data or reference. A triangulation research methodology using both the quantitative and the qualitative approach was applied. The qualitative research entailed an interpretive approach associated with using grounded theory and content analysis for interpreting data. The comparative case study design was the main qualitative research instrument for the multiple-case studies on emerging ostrich farmers in the Eastern Cape. The study was undertaken at five different sites, namely, the Peddie Ostrich Programme, the Rockhurst Ostrich Programme, the Hlumani Co-operative farm, the Zamukwanda Ostrich farm near Pearston and the Mimosadale Ostrich farm. The quantitative methods were applied to capture all the measurable components and representations of the stakeholders and participants, through interviews, questionnaires and focus group interviews. The quantitative study also included an experimental instrument to measure the capacity of emerging farmer programmes for supply chain participation. It was found that the main driver for three of the case studies pertained to land ownership and that ostrich farming was incidental and only seen as means of activity for income. These three humanitarian farming projects had limited capacity for intensive management requirements for ostrich farming. It was found that the VPN04 bio-security protocols and disease control require a higher level of record keeping for EU markets and is prohibitively expensive for poor rural emerging farmers. The study established that the emerging ostrich farming programmes contributed value to the industry and government rural development in land redistribution programmes, vehicles for reduction of poverty and job creation in the rural areas and by acting as out-grower programmes for commercial farmers. The researcher’s observation is that through strategic interventions the programmes have potential to become commercial players in the industry. The following interventions were recommended from this study: Feasibility study of programmes and review of location selection before initiation. Providing supportive interventions for programme start-ups; Improved selection of programme beneficiaries; Improved structure of emerging farmers’ co-operatives; On-going and appropriate training for emerging ostrich farmers; The role of government and mentors needs to be defined; Reducing feed costs; Establishing programmes linkages to informal markets and facilitating increased self-consumption; Developing new export markets; Alternative finance for the no-income months; Alternative marketing channels to export markets; Representation of emerging farmers in the ostrich-industry leadership structures.
- Full Text:
- Date Issued: 2013
Postcolonial monuments and public sculpture in Zimbabwe
- Authors: Samwanda, Biggie
- Date: 2013 , 2013-10-10
- Subjects: Benhura, Dominic, 1968- -- Criticism and interpretation Madebe, Adam -- Criticism and interpretation Postcolonialism and the arts Monuments -- Zimbabwe Public sculpture -- Zimbabwe Art -- Political aspects -- Zimbabwe Collective memory in art -- Zimbabwe Old Bulawayo (Zimbabwe) National Heroes Acre (Zimbabwe)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2447 , http://hdl.handle.net/10962/d1006825
- Description: The study critically examines public art in postcolonial Zimbabwe‘s cities of Harare and Bulawayo. In a case by case approach, I analyse the National Heroes Acre and Old Bulawayo monuments, and three contemporary sculptures – Dominic Benhura‘s Leapfrog (1993) and Adam Madebe‘s Ploughman (1987) and Looking into the future (1985). I used a qualitative research methodology to collect and analyse data. My research design utilised in-depth interviews, observation, content and document analysis, and photography to gather nuanced data and these methods ensured that data collected is validated and/or triangulated. I argue that in Zimbabwe, monuments and public sculpture serve as the necessary interface of the visual, cultural and political discourse of a postcolonial nation that is constantly in transition and dialogue with the everyday realities of trying to understand and construct a national identity from a nest of sub-cultures. I further argue that monuments and public sculpture in Zimbabwe abound with political imperatives given that, as visual artefacts that interlace with ritual performance, they are conscious creations of society and are therefore constitutive of that society‘s heritage and social memory. Since independence in 1980, monuments and public sculpture have helped to open up discursive space and dialogue on national issues and myths. Such discursive spaces and dialogues, I also argue, have been particularly animated from the late 1990s to the present, a period in which the nation has engaged in self-introspection in the face of socio-political change and challenges in the continual process of imagining the Zimbabwean nation. Little research focusing on postcolonial public art in Zimbabwe has hitherto been undertaken. This study addresses gaps in this literature while also providing a spring board from which future studies may emerge. , Microsoft� Word 2010 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2013
- Authors: Samwanda, Biggie
- Date: 2013 , 2013-10-10
- Subjects: Benhura, Dominic, 1968- -- Criticism and interpretation Madebe, Adam -- Criticism and interpretation Postcolonialism and the arts Monuments -- Zimbabwe Public sculpture -- Zimbabwe Art -- Political aspects -- Zimbabwe Collective memory in art -- Zimbabwe Old Bulawayo (Zimbabwe) National Heroes Acre (Zimbabwe)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2447 , http://hdl.handle.net/10962/d1006825
- Description: The study critically examines public art in postcolonial Zimbabwe‘s cities of Harare and Bulawayo. In a case by case approach, I analyse the National Heroes Acre and Old Bulawayo monuments, and three contemporary sculptures – Dominic Benhura‘s Leapfrog (1993) and Adam Madebe‘s Ploughman (1987) and Looking into the future (1985). I used a qualitative research methodology to collect and analyse data. My research design utilised in-depth interviews, observation, content and document analysis, and photography to gather nuanced data and these methods ensured that data collected is validated and/or triangulated. I argue that in Zimbabwe, monuments and public sculpture serve as the necessary interface of the visual, cultural and political discourse of a postcolonial nation that is constantly in transition and dialogue with the everyday realities of trying to understand and construct a national identity from a nest of sub-cultures. I further argue that monuments and public sculpture in Zimbabwe abound with political imperatives given that, as visual artefacts that interlace with ritual performance, they are conscious creations of society and are therefore constitutive of that society‘s heritage and social memory. Since independence in 1980, monuments and public sculpture have helped to open up discursive space and dialogue on national issues and myths. Such discursive spaces and dialogues, I also argue, have been particularly animated from the late 1990s to the present, a period in which the nation has engaged in self-introspection in the face of socio-political change and challenges in the continual process of imagining the Zimbabwean nation. Little research focusing on postcolonial public art in Zimbabwe has hitherto been undertaken. This study addresses gaps in this literature while also providing a spring board from which future studies may emerge. , Microsoft� Word 2010 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2013
Examining emergent active learning processes as transformative praxis : the case of the schools and sustainability professional development programme
- Authors: Schudel, Ingrid Joan
- Date: 2013 , 2013-09-20
- Subjects: Active learning -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Student-centered learning -- Research -- South Africa -- Eastern Cape Environmental education -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Environmental education -- Curricula -- South Africa -- Eastern Cape Competency-based education -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1891 , http://hdl.handle.net/10962/d1006079
- Description: This is a study on the nature of learning, particularly the emergence of active learning processes in the case of an environmental education teacher professional development programme – the Eastern Cape Border-Kei cohort of the 2008 Schools and Sustainability Course. This was a part-time, one-year course supporting teachers to qualify, strengthen and deepen opportunities for environmental learning in the South African curriculum. An active learning framework (O’Donoghue, 2001) promoting teaching and learning with information, enquiry, action and reporting/reflection dimensions was integrated into the Schools and Sustainability course design to support these environmental learning opportunities. In this study, the notion of active learning is elaborated as a situated, action-oriented, deliberative and co-engaged approach to teaching and learning, and related to Bhaskar’s (1993) notion of transformative praxis. The study used a nested case study design, considering the case of six Foundation Phase teachers in six primary schools within the Border-Kei Schools and Sustainability cohort. Interviews, observations (of workshops and lesson plan implementation in classrooms) and document review of teacher portfolios (detailing course activities, lesson plans, learners’ work and learning and teaching support materials) were used to generate the bulk of the data. A critical realist theory underpinning the methodology enables a view of agency as emergent from social structures and mechanisms as elaborated in Archer’s (1998b) model of morphogenesis and Bhaskar’s (1993) model of four-planar being. The critical realist methodology also enables a view of emergent active learning processes as open-ended, responsive to particular potential, but dependent on contingencies (such as learning and teaching support materials, tools and methodologies). The analysis of emergent active learning processes focuses particularly on Bhaskar’s (1993) ontological-axiological chain (MELD schema) as a tool for analysing change. The MELD schema highlights1M ontological questions of what is (with emphasis on structures and generative mechanisms) and what could be (real, but non-actualised possibilities). It enables reflection on what mediating and interactive agential processes either reproduce what is or have the potential to transform what is to what could be (2E). Thirdly, the MELD schema enables reflection on what should be – this is the 3L “axiological moment” (Bhaskar, 1993: 9) where questions of values and ethics in relation to the holistic whole are raised. Finally, the schema raises questions (4D) of what can be, with ontologically grounded, context-sensitive and expressively veracious considerations. The study describes the agency of course tutors, teachers and learners involved in the Schools and Sustainability course, as emergent from a social-ecological context of poverty and inequality, and from an education system with a dual transformative and progressive intent (Taylor, 1999). It uses a spiral approach to cluster-based teacher professional development (Janse van Rensburg & Mhoney, 2000) focusing on the development of autonomous (Bernstein, 1990) and reflexive teachers. With teachers well-disposed and qualified to fill a variety of roles in the classroom, these generative structures and mechanisms had the power to drive active learning processes with potential for manifestation as transformative praxis. Through the analysis of the active learning processes emergent from this context, the study shows that the manifestation of transformative praxis was contingent on relational situated learning, value-based reflexive deliberations, and an action-orientation with an emphasis on an iterative relationship between learning and doing. These findings enable a reframing of an interest in action in response to environmental issue and risk, to an interest in the processes that led up to that action. This provides a nuanced vision of active learning that does not judge an educational process by its outcome. Instead, it can be judged by the depth of the insights into absences (2E), the ability to guide moral deliberations on totality (3L), and by the degree of reality congruence (1M) in the lead up to the development of transformative agency (4D). The study also has a methodological interest. It contributes to educational and social science research in that it applies dialectical critical realist philosophy to a concrete context of active learning enquiry in environmental education. It reports on the value of the onto-axiolgical chain in describing a diachronic, emergent and open-ended process; in providing ontological grounding for analysis (1M); in understanding relationality in situated learing processes (2E); in focusing on value-based reflexive learning (3L) and in understanding transformative learning as “tensed socio-spatialising process” (Bhaskar, 1993: 160) where society is emergent from a stratified ontology, and agency and change are open-ended and flexible processes not wholly determined by the social structures from which they emerge (4D). Considering the knowledge interests defined in the 2011 South African Minimum Requirements for Teacher Education (South Africa. Department of Higher Education and Training, 2011) and the Curriculum Assessment Policy Statements (CAPS) which were implemented in South Africa from 2012 (in a phased approach), the study concludes with recommendations for exploring environmental learning in the CAPS. The study proposes working with a knowledge-focused curriculum focusing on the exploration and deepening of foundational environmental concepts, developing relational situated learning processes for meaningful local application of knowledge, supporting transformative praxis through the “unity of theory and practice in practice” (Bhaskar, 1993: 9), and implementing a spiral approach to cluster-based teacher professional development.
- Full Text:
- Date Issued: 2013
- Authors: Schudel, Ingrid Joan
- Date: 2013 , 2013-09-20
- Subjects: Active learning -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Student-centered learning -- Research -- South Africa -- Eastern Cape Environmental education -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Environmental education -- Curricula -- South Africa -- Eastern Cape Competency-based education -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1891 , http://hdl.handle.net/10962/d1006079
- Description: This is a study on the nature of learning, particularly the emergence of active learning processes in the case of an environmental education teacher professional development programme – the Eastern Cape Border-Kei cohort of the 2008 Schools and Sustainability Course. This was a part-time, one-year course supporting teachers to qualify, strengthen and deepen opportunities for environmental learning in the South African curriculum. An active learning framework (O’Donoghue, 2001) promoting teaching and learning with information, enquiry, action and reporting/reflection dimensions was integrated into the Schools and Sustainability course design to support these environmental learning opportunities. In this study, the notion of active learning is elaborated as a situated, action-oriented, deliberative and co-engaged approach to teaching and learning, and related to Bhaskar’s (1993) notion of transformative praxis. The study used a nested case study design, considering the case of six Foundation Phase teachers in six primary schools within the Border-Kei Schools and Sustainability cohort. Interviews, observations (of workshops and lesson plan implementation in classrooms) and document review of teacher portfolios (detailing course activities, lesson plans, learners’ work and learning and teaching support materials) were used to generate the bulk of the data. A critical realist theory underpinning the methodology enables a view of agency as emergent from social structures and mechanisms as elaborated in Archer’s (1998b) model of morphogenesis and Bhaskar’s (1993) model of four-planar being. The critical realist methodology also enables a view of emergent active learning processes as open-ended, responsive to particular potential, but dependent on contingencies (such as learning and teaching support materials, tools and methodologies). The analysis of emergent active learning processes focuses particularly on Bhaskar’s (1993) ontological-axiological chain (MELD schema) as a tool for analysing change. The MELD schema highlights1M ontological questions of what is (with emphasis on structures and generative mechanisms) and what could be (real, but non-actualised possibilities). It enables reflection on what mediating and interactive agential processes either reproduce what is or have the potential to transform what is to what could be (2E). Thirdly, the MELD schema enables reflection on what should be – this is the 3L “axiological moment” (Bhaskar, 1993: 9) where questions of values and ethics in relation to the holistic whole are raised. Finally, the schema raises questions (4D) of what can be, with ontologically grounded, context-sensitive and expressively veracious considerations. The study describes the agency of course tutors, teachers and learners involved in the Schools and Sustainability course, as emergent from a social-ecological context of poverty and inequality, and from an education system with a dual transformative and progressive intent (Taylor, 1999). It uses a spiral approach to cluster-based teacher professional development (Janse van Rensburg & Mhoney, 2000) focusing on the development of autonomous (Bernstein, 1990) and reflexive teachers. With teachers well-disposed and qualified to fill a variety of roles in the classroom, these generative structures and mechanisms had the power to drive active learning processes with potential for manifestation as transformative praxis. Through the analysis of the active learning processes emergent from this context, the study shows that the manifestation of transformative praxis was contingent on relational situated learning, value-based reflexive deliberations, and an action-orientation with an emphasis on an iterative relationship between learning and doing. These findings enable a reframing of an interest in action in response to environmental issue and risk, to an interest in the processes that led up to that action. This provides a nuanced vision of active learning that does not judge an educational process by its outcome. Instead, it can be judged by the depth of the insights into absences (2E), the ability to guide moral deliberations on totality (3L), and by the degree of reality congruence (1M) in the lead up to the development of transformative agency (4D). The study also has a methodological interest. It contributes to educational and social science research in that it applies dialectical critical realist philosophy to a concrete context of active learning enquiry in environmental education. It reports on the value of the onto-axiolgical chain in describing a diachronic, emergent and open-ended process; in providing ontological grounding for analysis (1M); in understanding relationality in situated learing processes (2E); in focusing on value-based reflexive learning (3L) and in understanding transformative learning as “tensed socio-spatialising process” (Bhaskar, 1993: 160) where society is emergent from a stratified ontology, and agency and change are open-ended and flexible processes not wholly determined by the social structures from which they emerge (4D). Considering the knowledge interests defined in the 2011 South African Minimum Requirements for Teacher Education (South Africa. Department of Higher Education and Training, 2011) and the Curriculum Assessment Policy Statements (CAPS) which were implemented in South Africa from 2012 (in a phased approach), the study concludes with recommendations for exploring environmental learning in the CAPS. The study proposes working with a knowledge-focused curriculum focusing on the exploration and deepening of foundational environmental concepts, developing relational situated learning processes for meaningful local application of knowledge, supporting transformative praxis through the “unity of theory and practice in practice” (Bhaskar, 1993: 9), and implementing a spiral approach to cluster-based teacher professional development.
- Full Text:
- Date Issued: 2013
A study of maximum and minimum operators with applications to piecewise linear payoff functions
- Authors: Seedat, Ebrahim
- Date: 2013
- Subjects: Options (Finance) Piecewise linear topology Geometry, Affine Riesz spaces Lattice theory Algebra, Boolean Pricing , Max and min operators
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:931 , http://hdl.handle.net/10962/d1001457
- Description: The payoff functions of contingent claims (options) of one variable are prominent in Financial Economics and thus assume a fundamental role in option pricing theory. Some of these payoff functions are continuous, piecewise-defined and linear or affine. Such option payoff functions can be analysed in a useful way when they are represented in additive, Boolean normal, graphical and linear form. The issue of converting such payoff functions expressed in the additive, linear or graphical form into an equivalent Boolean normal form, has been considered by several authors for more than half-a-century to better-understand the role of such functions. One aspect of our study is to unify the foregoing different forms of representation, by creating algorithms that convert a payoff function expressed in graphical form into Boolean normal form and then into the additive form and vice versa. Applications of these algorithms are considered in a general theoretical sense and also in the context of specific option contracts wherever relevant. The use of these algorithms have yielded easy computation of the area enclosed by the graph of various functions using min and max operators in several ways, which, in our opinion, are important in option pricing. To summarise, this study effectively dealt with maximum and minimum operators from several perspectives
- Full Text:
- Date Issued: 2013
- Authors: Seedat, Ebrahim
- Date: 2013
- Subjects: Options (Finance) Piecewise linear topology Geometry, Affine Riesz spaces Lattice theory Algebra, Boolean Pricing , Max and min operators
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:931 , http://hdl.handle.net/10962/d1001457
- Description: The payoff functions of contingent claims (options) of one variable are prominent in Financial Economics and thus assume a fundamental role in option pricing theory. Some of these payoff functions are continuous, piecewise-defined and linear or affine. Such option payoff functions can be analysed in a useful way when they are represented in additive, Boolean normal, graphical and linear form. The issue of converting such payoff functions expressed in the additive, linear or graphical form into an equivalent Boolean normal form, has been considered by several authors for more than half-a-century to better-understand the role of such functions. One aspect of our study is to unify the foregoing different forms of representation, by creating algorithms that convert a payoff function expressed in graphical form into Boolean normal form and then into the additive form and vice versa. Applications of these algorithms are considered in a general theoretical sense and also in the context of specific option contracts wherever relevant. The use of these algorithms have yielded easy computation of the area enclosed by the graph of various functions using min and max operators in several ways, which, in our opinion, are important in option pricing. To summarise, this study effectively dealt with maximum and minimum operators from several perspectives
- Full Text:
- Date Issued: 2013
Investigation into causes of service delivery protests in municipalities :a case study of Nelson Mandela Bay Municipality
- Authors: Shaidi, Elisante Walter
- Date: 2013
- Subjects: Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8245 , http://hdl.handle.net/10948/d1011153 , Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Description: This study investigates the causes of the service delivery protests in South African municipalities that occurred between 2005 to 2013. In a sense, the recent widespread service delivery protests which, in many instances, have turned violent, have sounded an alarm that cannot be ignored. The study is premised on the fact that no political democracy can survive and flourish if the mass of its people remain in poverty, and in a state of inequality and unemployed without tangible prospects for a better life. In this regard, the presence of service delivery protests, especially violent ones, is a threat to South Africa’s young democracy and its sustainability. This study is based on the assumption that the Nelson Mandela Bay Metropolitan Municipality, like other municipalities in South Africa, could be confronted with the possibility of further violent service delivery protests if the current causes were not scientifically investigated and solutions found. The study adopted a hypothesis with a view that South African municipalities could succeed in rendering effective public services if matters of poor public participation, corruption, service delivery inhibiting systemic factors, a cumbersome legislative environment, political infighting, poor intergovernmental fiscal regime and the low capacity of municipalities were adequately addressed. The study proposed to provide a brief literature review on the emergence of service delivery protests against the backdrop of a theoretical investigation on the new local government developmental mandate. The empirical survey and research methodology employed in the study is described, followed by the operationalisation of the survey questionnaire used for gathering field data. The research findings of the empirical survey are then statistically analysed, interpreted and reported. Some of the findings on the causes of service delivery protests includes slow pace of service delivery, especially in the delivery of sustainable human settlements, poor public participation and other underpinning systemic factors. Recommendations flowing from, inter alia, the results of the empirical study, are presented on how the existing status quo can be changed to enhance service delivery and development. If adopted, these recommendations will enable the Nelson Mandela Bay Municipality, as a development agent, to fulfil its developmental mandate thereby addressing the causes of the service delivery protests currently facing it.
- Full Text:
- Date Issued: 2013
- Authors: Shaidi, Elisante Walter
- Date: 2013
- Subjects: Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8245 , http://hdl.handle.net/10948/d1011153 , Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Description: This study investigates the causes of the service delivery protests in South African municipalities that occurred between 2005 to 2013. In a sense, the recent widespread service delivery protests which, in many instances, have turned violent, have sounded an alarm that cannot be ignored. The study is premised on the fact that no political democracy can survive and flourish if the mass of its people remain in poverty, and in a state of inequality and unemployed without tangible prospects for a better life. In this regard, the presence of service delivery protests, especially violent ones, is a threat to South Africa’s young democracy and its sustainability. This study is based on the assumption that the Nelson Mandela Bay Metropolitan Municipality, like other municipalities in South Africa, could be confronted with the possibility of further violent service delivery protests if the current causes were not scientifically investigated and solutions found. The study adopted a hypothesis with a view that South African municipalities could succeed in rendering effective public services if matters of poor public participation, corruption, service delivery inhibiting systemic factors, a cumbersome legislative environment, political infighting, poor intergovernmental fiscal regime and the low capacity of municipalities were adequately addressed. The study proposed to provide a brief literature review on the emergence of service delivery protests against the backdrop of a theoretical investigation on the new local government developmental mandate. The empirical survey and research methodology employed in the study is described, followed by the operationalisation of the survey questionnaire used for gathering field data. The research findings of the empirical survey are then statistically analysed, interpreted and reported. Some of the findings on the causes of service delivery protests includes slow pace of service delivery, especially in the delivery of sustainable human settlements, poor public participation and other underpinning systemic factors. Recommendations flowing from, inter alia, the results of the empirical study, are presented on how the existing status quo can be changed to enhance service delivery and development. If adopted, these recommendations will enable the Nelson Mandela Bay Municipality, as a development agent, to fulfil its developmental mandate thereby addressing the causes of the service delivery protests currently facing it.
- Full Text:
- Date Issued: 2013
Electrocatalytic detection of pesticides with electrodes modified with nanoparticles of phthalocyanines and multiwalled carbon nanotubes
- Authors: Siswana, Msimelelo Patrick
- Date: 2013
- Subjects: Phthalocyanines Pesticides Electrocatalysis Electrochemistry Nanotubes Nanoparticles Transmission electron microscopy Scanning electron microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4282 , http://hdl.handle.net/10962/d1002613
- Description: Three types of electrodes: carbon paste electrodes modified with nanoparticles of metallophthalocyanines (MPcNP-CPEs, M = Mn, Fe, Ni, Co), basal plane pyrolytic graphite electrodes modified with iron or nickel phthalocyanine nanoparticles and multiwalled carbon nanotube composites (FePcNP/MWCNT-BPPGE or NiPcNP/MWCNT-BPPGE),and basal plane pyrolytic graphite electrodes modified with multiwalled carbon nanotubes and electropolymerized metal tetra-aminophthalocyanines (poly-MTAPc-MWCNT-BPPGE), where M is Mn, Fe, Ni or Co, were prepared. Electrochemical characterizations showed that faster electron transfer kinetics occurred at the NiPcNP/MWCNT-BPPGE than at the FePcNP/MWCNT-BPPGE surface. SEM and electrochemical characterizations of poly-MTAPc-MWCNT-BPPGE showed that MTAPc had been deposited on the MWCNTBPPGE surface, and that the poly-CoTAPc-MWCNT-BPPGE exhibited the fastest electron transfer kinetics of all the poly-MTAPc-MWCNT-BPPGEs. Using amitrole and asulam as test analytes, electrochemical experiments showed that, amongst the CPEs, the FePcNP-CPE and NiPcNP-CPE displayed the most electrocatalytic behavior towards amitrole and asulam oxidation, respectively, and further experiments were done to obtain the electrochemical parameters associated with these electrodes and the corresponding analytes. Although, the FePcNP/MWCNT- BPPGE displayed electrocatalytic behavior towards amitrole oxidation in comparison with the bare BPPGE, it was less electrocatalytic than the FePcNP-CPE in terms of detection potential. The NiPcNP/MWCNT-BPPGE displayed the same detection potential as the NiPcNP-CPE. The poly-FeTAPc-MWCNT-BPPGE exhibited the most electrocatalytic behavior towards amitrole, of all the electrodes investigated, and the poly-CoTAPc-MWCNT-BPPGE displayed the best electrocatalytic behavior towards asulam, amongst the poly-MTAPc-MWCNT-BPPGEs.
- Full Text:
- Date Issued: 2013
- Authors: Siswana, Msimelelo Patrick
- Date: 2013
- Subjects: Phthalocyanines Pesticides Electrocatalysis Electrochemistry Nanotubes Nanoparticles Transmission electron microscopy Scanning electron microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4282 , http://hdl.handle.net/10962/d1002613
- Description: Three types of electrodes: carbon paste electrodes modified with nanoparticles of metallophthalocyanines (MPcNP-CPEs, M = Mn, Fe, Ni, Co), basal plane pyrolytic graphite electrodes modified with iron or nickel phthalocyanine nanoparticles and multiwalled carbon nanotube composites (FePcNP/MWCNT-BPPGE or NiPcNP/MWCNT-BPPGE),and basal plane pyrolytic graphite electrodes modified with multiwalled carbon nanotubes and electropolymerized metal tetra-aminophthalocyanines (poly-MTAPc-MWCNT-BPPGE), where M is Mn, Fe, Ni or Co, were prepared. Electrochemical characterizations showed that faster electron transfer kinetics occurred at the NiPcNP/MWCNT-BPPGE than at the FePcNP/MWCNT-BPPGE surface. SEM and electrochemical characterizations of poly-MTAPc-MWCNT-BPPGE showed that MTAPc had been deposited on the MWCNTBPPGE surface, and that the poly-CoTAPc-MWCNT-BPPGE exhibited the fastest electron transfer kinetics of all the poly-MTAPc-MWCNT-BPPGEs. Using amitrole and asulam as test analytes, electrochemical experiments showed that, amongst the CPEs, the FePcNP-CPE and NiPcNP-CPE displayed the most electrocatalytic behavior towards amitrole and asulam oxidation, respectively, and further experiments were done to obtain the electrochemical parameters associated with these electrodes and the corresponding analytes. Although, the FePcNP/MWCNT- BPPGE displayed electrocatalytic behavior towards amitrole oxidation in comparison with the bare BPPGE, it was less electrocatalytic than the FePcNP-CPE in terms of detection potential. The NiPcNP/MWCNT-BPPGE displayed the same detection potential as the NiPcNP-CPE. The poly-FeTAPc-MWCNT-BPPGE exhibited the most electrocatalytic behavior towards amitrole, of all the electrodes investigated, and the poly-CoTAPc-MWCNT-BPPGE displayed the best electrocatalytic behavior towards asulam, amongst the poly-MTAPc-MWCNT-BPPGEs.
- Full Text:
- Date Issued: 2013
A contribution to the theory of prime modules
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
Fixed points of single-valued and multi-valued mappings with applications
- Authors: Stofile, Simfumene
- Date: 2013
- Subjects: Fixed point theory Mappings (Mathematics) Coincidence theory (Mathematics) Metric spaces Uniform spaces Set-valued maps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5397 , http://hdl.handle.net/10962/d1002960
- Description: The relationship between the convergence of a sequence of self mappings of a metric space and their fixed points, known as the stability (or continuity) of fixed points has been of continuing interest and widely studied in fixed point theory. In this thesis we study the stability of common fixed points in a Hausdorff uniform space whose uniformity is generated by a family of pseudometrics, by using some general notations of convergence. These results are then extended to 2-metric spaces due to S. Gähler. In addition, a well-known theorem of T. Suzuki that generalized the Banach Contraction Principle is also extended to 2-metric spaces and applied to obtain a coincidence theorem for a pair of mappings on an arbitrary set with values in a 2-metric space. Further, we prove the existence of coincidence and fixed points of Ćirić type weakly generalized contractions in metric spaces. Subsequently, the above result is utilized to discuss applications to the convergence of modified Mann and Ishikawa iterations in a convex metric space. Finally, we obtain coincidence, fixed and stationary point results for multi-valued and hybrid pairs of mappings on a metric space.
- Full Text:
- Date Issued: 2013
- Authors: Stofile, Simfumene
- Date: 2013
- Subjects: Fixed point theory Mappings (Mathematics) Coincidence theory (Mathematics) Metric spaces Uniform spaces Set-valued maps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5397 , http://hdl.handle.net/10962/d1002960
- Description: The relationship between the convergence of a sequence of self mappings of a metric space and their fixed points, known as the stability (or continuity) of fixed points has been of continuing interest and widely studied in fixed point theory. In this thesis we study the stability of common fixed points in a Hausdorff uniform space whose uniformity is generated by a family of pseudometrics, by using some general notations of convergence. These results are then extended to 2-metric spaces due to S. Gähler. In addition, a well-known theorem of T. Suzuki that generalized the Banach Contraction Principle is also extended to 2-metric spaces and applied to obtain a coincidence theorem for a pair of mappings on an arbitrary set with values in a 2-metric space. Further, we prove the existence of coincidence and fixed points of Ćirić type weakly generalized contractions in metric spaces. Subsequently, the above result is utilized to discuss applications to the convergence of modified Mann and Ishikawa iterations in a convex metric space. Finally, we obtain coincidence, fixed and stationary point results for multi-valued and hybrid pairs of mappings on a metric space.
- Full Text:
- Date Issued: 2013
Climate variability and climate change in water resources management of the Zambezi River basin
- Authors: Tirivarombo, Sithabile
- Date: 2013
- Subjects: Water resources development -- Zambezi River Watershed Climatic changes -- Zambezi River Watershed Water-supply -- Zambezi River Watershed Water-supply -- Political aspects -- Africa, Southern Water rights -- Africa, Southern Water security -- Africa, Southern Rain and rainfall -- Africa, Southern Rainfall probabilities -- Africa, Southern Food security -- Africa, Southern Drought forecasting -- Africa, Southern Watersheds -- Africa, Southern Water supply -- Measurement -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6024 , http://hdl.handle.net/10962/d1002955
- Description: Water is recognised as a key driver for social and economic development in the Zambezi basin. The basin is riparian to eight southern African countries and the transboundary nature of the basin’s water resources can be viewed as an agent of cooperation between the basin countries. It is possible, however, that the same water resource can lead to conflicts between water users. The southern African Water Vision for ‘equitable and sustainable utilisation of water for social, environmental justice and economic benefits for the present and future generations’ calls for an integrated and efficient management of water resources within the basin. Ensuring water and food security in the Zambezi basin is, however, faced with challenges due to high variability in climate and the available water resources. Water resources are under continuous threat from pollution, increased population growth, development and urbanisation as well as global climate change. These factors increase the demand for freshwater resources and have resulted in water being one of the major driving forces for development. The basin is also vulnerable due to lack of adequate financial resources and appropriate water resources infrastructure to enable viable, equitable and sustainable distribution of the water resources. This is in addition to the fact that the basin’s economic mainstay and social well-being are largely dependent on rainfed agriculture. There is also competition among the different water users and this has the potential to generate conflicts, which further hinder the development of water resources in the basin. This thesis has focused on the Zambezi River basin emphasising climate variability and climate change. It is now considered common knowledge that the global climate is changing and that many of the impacts will be felt through water resources. If these predictions are correct then the Zambezi basin is most likely to suffer under such impacts since its economic mainstay is largely determined by the availability of rainfall. It is the belief of this study that in order to ascertain the impacts of climate change, there should be a basis against which this change is evaluated. If we do not know the historical patterns of variability it may be difficult to predict changes in the future climate and in the hydrological resources and it will certainly be difficult to develop appropriate management strategies. Reliable quantitative estimates of water availability are a prerequisite for successful water resource plans. However, such initiatives have been hindered by paucity in data especially in a basin where gauging networks are inadequate and some of them have deteriorated. This is further compounded by shortages in resources, both human and financial, to ensure adequate monitoring. To address the data problems, this study largely relied on global data sets and the CRU TS2.1 rainfall grids were used for a large part of this study. The study starts by assessing the historical variability of rainfall and streamflow in the Zambezi basin and the results are used to inform the prediction of change in the future. Various methods of assessing historical trends were employed and regional drought indices were generated and evaluated against the historical rainfall trends. The study clearly demonstrates that the basin has a high degree of temporal and spatial variability in rainfall and streamflow at inter-annual and multi-decadal scales. The Standardised Precipitation Index, a rainfall based drought index, is used to assess historical drought events in the basin and it is shown that most of the droughts that have occurred were influenced by climatic and hydrological variability. It is concluded, through the evaluation of agricultural maize yields, that the basin’s food security is mostly constrained by the availability of rainfall. Comparing the viability of using a rainfall based index to a soil moisture based index as an agricultural drought indicator, this study concluded that a soil moisture based index is a better indicator since all of the water balance components are considered in the generation of the index. This index presents the actual amount of water available for the plant unlike purely rainfall based indices, that do not account for other components of the water budget that cause water losses. A number of challenges were, however, faced in assessing the variability and historical drought conditions, mainly due to the fact that most parts of the Zambezi basin are ungauged and available data are sparse, short and not continuous (with missing gaps). Hydrological modelling is frequently used to bridge the data gap and to facilitate the quantification of a basin’s hydrology for both gauged and ungauged catchments. The trend has been to use various methods of regionalisation to transfer information from gauged basins, or from basins with adequate physical basin data, to ungauged basins. All this is done to ensure that water resources are accounted for and that the future can be well planned. A number of approaches leading to the evaluation of the basin’s hydrological response to future climate change scenarios are taken. The Pitman rainfall-runoff model has enjoyed wide use as a water resources estimation tool in southern Africa. The model has been calibrated for the Zambezi basin but it should be acknowledged that any hydrological modelling process is characterised by many uncertainties arising from limitations in input data and inherent model structural uncertainty. The calibration process is thus carried out in a manner that embraces some of the uncertainties. Initial ranges of parameter values (maximum and minimum) that incorporate the possible parameter uncertainties are assigned in relation to physical basin properties. These parameter sets are used as input to the uncertainty version of the model to generate behavioural parameter space which is then further modified through manual calibration. The use of parameter ranges initially guided by the basin physical properties generates streamflows that adequately represent the historically observed amounts. This study concludes that the uncertainty framework and the Pitman model perform quite well in the Zambezi basin. Based on assumptions of an intensifying hydrological cycle, climate changes are frequently expected to result in negative impacts on water resources. However, it is important that basin scale assessments are undertaken so that appropriate future management strategies can be developed. To assess the likely changes in the Zambezi basin, the calibrated Pitman model was forced with downscaled and bias corrected GCM data. Three GCMs were used for this study, namely; ECHAM, GFDL and IPSL. The general observation made in this study is that the near future (2046-2065) conditions of the Zambezi basin are expected to remain within the ranges of historically observed variability. The differences between the predictions for the three GCMs are an indication of the uncertainties in the future and it has not been possible to make any firm conclusions about directions of change. It is therefore recommended that future water resources management strategies account for historical patterns of variability, but also for increased uncertainty. Any management strategies that are able to satisfactorily deal with the large variability that is evident from the historical data should be robust enough to account for the near future patterns of water availability predicted by this study. However, the uncertainties in these predictions suggest that improved monitoring systems are required to provide additional data against which future model outputs can be assessed.
- Full Text:
- Date Issued: 2013
- Authors: Tirivarombo, Sithabile
- Date: 2013
- Subjects: Water resources development -- Zambezi River Watershed Climatic changes -- Zambezi River Watershed Water-supply -- Zambezi River Watershed Water-supply -- Political aspects -- Africa, Southern Water rights -- Africa, Southern Water security -- Africa, Southern Rain and rainfall -- Africa, Southern Rainfall probabilities -- Africa, Southern Food security -- Africa, Southern Drought forecasting -- Africa, Southern Watersheds -- Africa, Southern Water supply -- Measurement -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6024 , http://hdl.handle.net/10962/d1002955
- Description: Water is recognised as a key driver for social and economic development in the Zambezi basin. The basin is riparian to eight southern African countries and the transboundary nature of the basin’s water resources can be viewed as an agent of cooperation between the basin countries. It is possible, however, that the same water resource can lead to conflicts between water users. The southern African Water Vision for ‘equitable and sustainable utilisation of water for social, environmental justice and economic benefits for the present and future generations’ calls for an integrated and efficient management of water resources within the basin. Ensuring water and food security in the Zambezi basin is, however, faced with challenges due to high variability in climate and the available water resources. Water resources are under continuous threat from pollution, increased population growth, development and urbanisation as well as global climate change. These factors increase the demand for freshwater resources and have resulted in water being one of the major driving forces for development. The basin is also vulnerable due to lack of adequate financial resources and appropriate water resources infrastructure to enable viable, equitable and sustainable distribution of the water resources. This is in addition to the fact that the basin’s economic mainstay and social well-being are largely dependent on rainfed agriculture. There is also competition among the different water users and this has the potential to generate conflicts, which further hinder the development of water resources in the basin. This thesis has focused on the Zambezi River basin emphasising climate variability and climate change. It is now considered common knowledge that the global climate is changing and that many of the impacts will be felt through water resources. If these predictions are correct then the Zambezi basin is most likely to suffer under such impacts since its economic mainstay is largely determined by the availability of rainfall. It is the belief of this study that in order to ascertain the impacts of climate change, there should be a basis against which this change is evaluated. If we do not know the historical patterns of variability it may be difficult to predict changes in the future climate and in the hydrological resources and it will certainly be difficult to develop appropriate management strategies. Reliable quantitative estimates of water availability are a prerequisite for successful water resource plans. However, such initiatives have been hindered by paucity in data especially in a basin where gauging networks are inadequate and some of them have deteriorated. This is further compounded by shortages in resources, both human and financial, to ensure adequate monitoring. To address the data problems, this study largely relied on global data sets and the CRU TS2.1 rainfall grids were used for a large part of this study. The study starts by assessing the historical variability of rainfall and streamflow in the Zambezi basin and the results are used to inform the prediction of change in the future. Various methods of assessing historical trends were employed and regional drought indices were generated and evaluated against the historical rainfall trends. The study clearly demonstrates that the basin has a high degree of temporal and spatial variability in rainfall and streamflow at inter-annual and multi-decadal scales. The Standardised Precipitation Index, a rainfall based drought index, is used to assess historical drought events in the basin and it is shown that most of the droughts that have occurred were influenced by climatic and hydrological variability. It is concluded, through the evaluation of agricultural maize yields, that the basin’s food security is mostly constrained by the availability of rainfall. Comparing the viability of using a rainfall based index to a soil moisture based index as an agricultural drought indicator, this study concluded that a soil moisture based index is a better indicator since all of the water balance components are considered in the generation of the index. This index presents the actual amount of water available for the plant unlike purely rainfall based indices, that do not account for other components of the water budget that cause water losses. A number of challenges were, however, faced in assessing the variability and historical drought conditions, mainly due to the fact that most parts of the Zambezi basin are ungauged and available data are sparse, short and not continuous (with missing gaps). Hydrological modelling is frequently used to bridge the data gap and to facilitate the quantification of a basin’s hydrology for both gauged and ungauged catchments. The trend has been to use various methods of regionalisation to transfer information from gauged basins, or from basins with adequate physical basin data, to ungauged basins. All this is done to ensure that water resources are accounted for and that the future can be well planned. A number of approaches leading to the evaluation of the basin’s hydrological response to future climate change scenarios are taken. The Pitman rainfall-runoff model has enjoyed wide use as a water resources estimation tool in southern Africa. The model has been calibrated for the Zambezi basin but it should be acknowledged that any hydrological modelling process is characterised by many uncertainties arising from limitations in input data and inherent model structural uncertainty. The calibration process is thus carried out in a manner that embraces some of the uncertainties. Initial ranges of parameter values (maximum and minimum) that incorporate the possible parameter uncertainties are assigned in relation to physical basin properties. These parameter sets are used as input to the uncertainty version of the model to generate behavioural parameter space which is then further modified through manual calibration. The use of parameter ranges initially guided by the basin physical properties generates streamflows that adequately represent the historically observed amounts. This study concludes that the uncertainty framework and the Pitman model perform quite well in the Zambezi basin. Based on assumptions of an intensifying hydrological cycle, climate changes are frequently expected to result in negative impacts on water resources. However, it is important that basin scale assessments are undertaken so that appropriate future management strategies can be developed. To assess the likely changes in the Zambezi basin, the calibrated Pitman model was forced with downscaled and bias corrected GCM data. Three GCMs were used for this study, namely; ECHAM, GFDL and IPSL. The general observation made in this study is that the near future (2046-2065) conditions of the Zambezi basin are expected to remain within the ranges of historically observed variability. The differences between the predictions for the three GCMs are an indication of the uncertainties in the future and it has not been possible to make any firm conclusions about directions of change. It is therefore recommended that future water resources management strategies account for historical patterns of variability, but also for increased uncertainty. Any management strategies that are able to satisfactorily deal with the large variability that is evident from the historical data should be robust enough to account for the near future patterns of water availability predicted by this study. However, the uncertainties in these predictions suggest that improved monitoring systems are required to provide additional data against which future model outputs can be assessed.
- Full Text:
- Date Issued: 2013
The application of the Rome Statute of the International Criminal Court to illegal natural resource exploitation in the Congo conflic
- Authors: Tsabora, James
- Date: 2013 , 2013-03-27
- Subjects: International criminal law -- Congo (Democratic Republic) Criminal procedure (International law) Natural resources -- Law and legislation -- Congo (Democratic Republic)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3665 , http://hdl.handle.net/10962/d1002612
- Description: This thesis explores the phenomenon of illegal natural resource exploitation in conflict zones and the application of international criminal law, particularly the Rome Statute of the International Criminal Court to combat the roblem. Contemporary African conflicts, such as the Democratic Republic of Congo conflict explored as a case study herein, have become increasingly distinguishable by the tight connection between war and various forms of illegal natural resource exploitation, particularly targeting valuable and precious mineral resources. With their incidence being highest in Africa, wars funded by illegally exploited natural resources have gradually become one of the greatest threats to regional peace and human security on the African continent. The Congo conflict clearly demonstrated the problematic nature and impact of illegal natural resource exploitation and the widespread human, economic and political costs associated with this phenomenon. This thesis is based on the initial assumption that the quest by conflict actors to profit from war through illegal natural resource exploitation activities is at the centre of the commission of serious human rights violations as well as the complexity and longevity of African conflicts. Developments in international criminal law, culminating in the adoption of the Rome Statute and the establishment of the International Criminal Court, have given impetus to the argument that any group of conflict actors should be subjected to the individual criminal responsibility regime of this legal framework. A further underlying assumption of this thesis is therefore that international criminal law can constrain the acts and conduct defined in this thesis as illegal natural resource exploitation activities since they constitute war crimes under the Rome Statute framework. However, despite illustrating the illegal resource exploitation activities of various state and non-state actors, this thesis is confined to an application of the Rome Statute based international criminal liability regime against members of armed rebel groups involved in such acts. In exploring these issues, this work examines international criminal law institutions and the relevance of international criminal justice in addressing particular phenomena prevalent during African armed conflicts. It further provides the stage to assess the potential of international criminal law in safeguarding natural resources for the benefit of African societies perennially exposed to the depredations of natural resource financed warfare. , Microsoft� Office Word 2007 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2013
- Authors: Tsabora, James
- Date: 2013 , 2013-03-27
- Subjects: International criminal law -- Congo (Democratic Republic) Criminal procedure (International law) Natural resources -- Law and legislation -- Congo (Democratic Republic)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3665 , http://hdl.handle.net/10962/d1002612
- Description: This thesis explores the phenomenon of illegal natural resource exploitation in conflict zones and the application of international criminal law, particularly the Rome Statute of the International Criminal Court to combat the roblem. Contemporary African conflicts, such as the Democratic Republic of Congo conflict explored as a case study herein, have become increasingly distinguishable by the tight connection between war and various forms of illegal natural resource exploitation, particularly targeting valuable and precious mineral resources. With their incidence being highest in Africa, wars funded by illegally exploited natural resources have gradually become one of the greatest threats to regional peace and human security on the African continent. The Congo conflict clearly demonstrated the problematic nature and impact of illegal natural resource exploitation and the widespread human, economic and political costs associated with this phenomenon. This thesis is based on the initial assumption that the quest by conflict actors to profit from war through illegal natural resource exploitation activities is at the centre of the commission of serious human rights violations as well as the complexity and longevity of African conflicts. Developments in international criminal law, culminating in the adoption of the Rome Statute and the establishment of the International Criminal Court, have given impetus to the argument that any group of conflict actors should be subjected to the individual criminal responsibility regime of this legal framework. A further underlying assumption of this thesis is therefore that international criminal law can constrain the acts and conduct defined in this thesis as illegal natural resource exploitation activities since they constitute war crimes under the Rome Statute framework. However, despite illustrating the illegal resource exploitation activities of various state and non-state actors, this thesis is confined to an application of the Rome Statute based international criminal liability regime against members of armed rebel groups involved in such acts. In exploring these issues, this work examines international criminal law institutions and the relevance of international criminal justice in addressing particular phenomena prevalent during African armed conflicts. It further provides the stage to assess the potential of international criminal law in safeguarding natural resources for the benefit of African societies perennially exposed to the depredations of natural resource financed warfare. , Microsoft� Office Word 2007 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2013
Politics, polemics and practice: a history of narratives about, and responses to, AIDS in South Africa, 1980-1995
- Authors: Tsampiras, Carla
- Date: 2013
- Subjects: AIDS (Disease) -- Government policy -- South Africa AIDS (Disease) -- Political aspects -- South Africa -- History AIDS (Disease) -- South Africa -- Public opinion -- History AIDS (Disease) -- Social aspects -- South Africa -- History South Africa -- Politics and government -- 20th century African National Congress Health Policy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2517 , http://hdl.handle.net/10962/d1001653
- Description: The ongoing urgency of addressing AIDS in South Africa has kept academics and activists focussed primarily on the immediate crises of AIDS ‘in the present’. This thesis, covering the period 1980 – 1995, examines narratives about, and responses to, AIDS ‘in the past’ and explores the interplay between these narratives and elites in medical and political communities trying to address AIDS during a period of political transition. The thesis begins by examining the hegemonic medico-scientific narratives about AIDS that featured in the South African Medical Journal, an important site of enquiry as AIDS was primarily conceived of as a ‘medical issue’. The SAMJ narratives, which often relied on constructed ‘AIDS avatars’, framed understandings of the syndrome and influenced responses to it by medical and political communities. The first community that the thesis explores is the African National Congress (ANC) in exile, which had to address AIDS in exile communities and prepare health strategies for ‘the new South Africa’. Secondly, the thesis analyses government responses to AIDS and argues that four phases of response can be identified. These phases were characterised by minimum concerns about obtaining information and providing health advice; efforts to gather infection data while exploiting political and public fear; attempts to extend health education and (belatedly) encourage broader engagement; and finally, consultative, democratic ideals. The thesis then examines the National Medical and Dental Association (NAMDA) a progressive medical organisation that worked with the ANC on influential health (and AIDS) strategies. NAMDA members ‘crossed over’ between various medical and political communities and both reinforced and challenged hegemonic AIDS narratives. Finally, the thesis moves from the abstract, via the practical, to the personal and concludes with a detailed account of the experiences of two sexuality activists at the intersections of these communities and narratives. By focussing on these medical and political communities, and analysing the relationships between these communities, the existing AIDS narratives, and individuals, the thesis also reveals the constructions of morality, ‘race’, gender, and sexuality that infused them. In doing this it shows how polemic and politics combined to influence practical responses to, and personal experiences of, AIDS.
- Full Text:
- Date Issued: 2013
- Authors: Tsampiras, Carla
- Date: 2013
- Subjects: AIDS (Disease) -- Government policy -- South Africa AIDS (Disease) -- Political aspects -- South Africa -- History AIDS (Disease) -- South Africa -- Public opinion -- History AIDS (Disease) -- Social aspects -- South Africa -- History South Africa -- Politics and government -- 20th century African National Congress Health Policy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2517 , http://hdl.handle.net/10962/d1001653
- Description: The ongoing urgency of addressing AIDS in South Africa has kept academics and activists focussed primarily on the immediate crises of AIDS ‘in the present’. This thesis, covering the period 1980 – 1995, examines narratives about, and responses to, AIDS ‘in the past’ and explores the interplay between these narratives and elites in medical and political communities trying to address AIDS during a period of political transition. The thesis begins by examining the hegemonic medico-scientific narratives about AIDS that featured in the South African Medical Journal, an important site of enquiry as AIDS was primarily conceived of as a ‘medical issue’. The SAMJ narratives, which often relied on constructed ‘AIDS avatars’, framed understandings of the syndrome and influenced responses to it by medical and political communities. The first community that the thesis explores is the African National Congress (ANC) in exile, which had to address AIDS in exile communities and prepare health strategies for ‘the new South Africa’. Secondly, the thesis analyses government responses to AIDS and argues that four phases of response can be identified. These phases were characterised by minimum concerns about obtaining information and providing health advice; efforts to gather infection data while exploiting political and public fear; attempts to extend health education and (belatedly) encourage broader engagement; and finally, consultative, democratic ideals. The thesis then examines the National Medical and Dental Association (NAMDA) a progressive medical organisation that worked with the ANC on influential health (and AIDS) strategies. NAMDA members ‘crossed over’ between various medical and political communities and both reinforced and challenged hegemonic AIDS narratives. Finally, the thesis moves from the abstract, via the practical, to the personal and concludes with a detailed account of the experiences of two sexuality activists at the intersections of these communities and narratives. By focussing on these medical and political communities, and analysing the relationships between these communities, the existing AIDS narratives, and individuals, the thesis also reveals the constructions of morality, ‘race’, gender, and sexuality that infused them. In doing this it shows how polemic and politics combined to influence practical responses to, and personal experiences of, AIDS.
- Full Text:
- Date Issued: 2013