Surface properties and electrocatalytic applications of metallophthalocyanines confined on electrode surfaces
- Authors: Akinbulu, Isaac Adebayo
- Date: 2011
- Subjects: Phthalocyanines Electrochemistry Electrocatalysis Pesticides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4365 , http://hdl.handle.net/10962/d1005030
- Description: New cobalt (13, 16 19 and 22), manganese (14, 17, 20 and 23) and iron (15, 18, 21 and 24)phthalocyanine complexes were synthesized and characterized. The UV-Vis spectral properties of the complexes were typical of the nature of central metal and position of substituent on the Pc ligand. Their electrochemical behaviors were signatures of the central metals, with varying influences of the nature and position of substituents. Nanocomposite of complex 18 and single walled carbon nanotubes (SWCNTs) (SWCNT-18)was fabricated. Formation of this nano-composite was confirmed by infrared (IR)spectroscopy, X-ray diffraction (XRD) spectroscopy and transmission electron microscopy (TEM). Self-assembled monolayers (SAMs) of SWCNT-18, complexes 13-15, and 20 were electropolymerized on glassy carbon electrodes (GCE). Complex 14 was also electrodeposited on GCE. Surface properties of the SAMs were consistent with the molecular feature of the substituent and the nature of central metal in the adsorbed species, while those of the MnPc modified GCEs were dependent on point of substitution and number of substituent. The SAM-modified gold electrodes were used for the electrocatalytic oxidation of the carbamate insecticide, carbofuran. Amplification of the current signal of the insecticide, at more energetically feasible oxidation potentials, on the SAM-modified gold electrodes, relative to bare gold electrode,justified electrocatalysis. There was enhanced sensitivity (attributed to the presence of SWCNT) of the SWCNT-18-SAM-modified gold electrode towards carbofuran, relative to the signals observed on the other SAMs. Current response of the insecticide,bendiocarb, was also intensified, at more favorable oxidation potentials, on the MnPc (14 and 17) modified GCEs, relative to the response on bare GCE, substantiating electrocatalysis. Also, catalysis of the oxidation of the herbicide, bentazon, was observed on polymeric film of complex 20. The current response of the herbicide on this film was better than that observed on bare GCE. Electrocatalysis of the analytes, on the respective modified electrodes, occurred via closely related mechanisms.
- Full Text:
- Authors: Akinbulu, Isaac Adebayo
- Date: 2011
- Subjects: Phthalocyanines Electrochemistry Electrocatalysis Pesticides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4365 , http://hdl.handle.net/10962/d1005030
- Description: New cobalt (13, 16 19 and 22), manganese (14, 17, 20 and 23) and iron (15, 18, 21 and 24)phthalocyanine complexes were synthesized and characterized. The UV-Vis spectral properties of the complexes were typical of the nature of central metal and position of substituent on the Pc ligand. Their electrochemical behaviors were signatures of the central metals, with varying influences of the nature and position of substituents. Nanocomposite of complex 18 and single walled carbon nanotubes (SWCNTs) (SWCNT-18)was fabricated. Formation of this nano-composite was confirmed by infrared (IR)spectroscopy, X-ray diffraction (XRD) spectroscopy and transmission electron microscopy (TEM). Self-assembled monolayers (SAMs) of SWCNT-18, complexes 13-15, and 20 were electropolymerized on glassy carbon electrodes (GCE). Complex 14 was also electrodeposited on GCE. Surface properties of the SAMs were consistent with the molecular feature of the substituent and the nature of central metal in the adsorbed species, while those of the MnPc modified GCEs were dependent on point of substitution and number of substituent. The SAM-modified gold electrodes were used for the electrocatalytic oxidation of the carbamate insecticide, carbofuran. Amplification of the current signal of the insecticide, at more energetically feasible oxidation potentials, on the SAM-modified gold electrodes, relative to bare gold electrode,justified electrocatalysis. There was enhanced sensitivity (attributed to the presence of SWCNT) of the SWCNT-18-SAM-modified gold electrode towards carbofuran, relative to the signals observed on the other SAMs. Current response of the insecticide,bendiocarb, was also intensified, at more favorable oxidation potentials, on the MnPc (14 and 17) modified GCEs, relative to the response on bare GCE, substantiating electrocatalysis. Also, catalysis of the oxidation of the herbicide, bentazon, was observed on polymeric film of complex 20. The current response of the herbicide on this film was better than that observed on bare GCE. Electrocatalysis of the analytes, on the respective modified electrodes, occurred via closely related mechanisms.
- Full Text:
Synthesis and evaluation of novel HIV-1 enzyme inhibitors
- Olomola, Temitope Oloruntoba
- Authors: Olomola, Temitope Oloruntoba
- Date: 2011
- Subjects: HIV infections -- Treatment HIV infections -- Chemotherapy HIV (Viruses) Enzyme inhibitors AZT (Drug) Reverse transcriptase Proteolytic enzymes Ligands Psoralens Resorcinol
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4369 , http://hdl.handle.net/10962/d1005034
- Description: This study has involved the design, synthesis and evaluation of novel HIV-1 enzyme inhibitors accessed by synthetic elaboration of Baylis-Hillman adducts. Several series of complex coumarin-AZT and cinnamate ester-AZT conjugates have been prepared, in high yields, by exploiting the click reaction between appropriate Baylis-Hillman derived precursors and azidothymidine (AZT), all of which have been fully characterised using spectroscopic techniques. These conjugates, designed as potential dual-action HIV-1 inhibitors, were tested against the appropriate HIV-1 enzymes, i.e. HIV-1 reverse transcriptase and protease or HIV-1 reverse transcriptase and integrase. A number of the ligands have exhibited % inhibition levels and IC50 values comparable to drugs in clinical use, permitting their identification as lead compounds for the development of novel dual-action inhibitors. In silico docking of selected ligands into the active sites of the respective enzymes has provided useful insight into binding conformations and potential hydrogen-bonding interactions with active-site amino acid residues. A series of furocoumarin carboxamide derivatives have been synthesised in four steps starting from resorcinol and these compounds have also been tested for HIV-1 integrase inhibition activity. The structures of unexpected products isolated from Aza-Baylis-Hillman reactions of N-tosylaldimines have been elucidated by spectroscopic analysis, and confirmed by single crystal X-ray analysis. A mechanism for what appears to be an unprecedented transformation has been proposed. Microwave-assisted SeO₂ oxidation of Baylis-Hillman-derived 3-methylcoumarins has provided convenient and efficient access to coumarin-3-carbaldehydes, and a pilot study has revealed the potential of these coumarin-3-carbaldehydes as scaffolds for the construction of tricyclic compounds. The HCl-catalysed reaction of tert-butyl acrylate derived Baylis-Hillman adducts has been shown to afford 3-(chloromethyl)coumarins and α-(chloromethyl)cinnamic acids, the Zstereochemistry of the latter being established by X-ray crystallography. ¹H NMR-based experimental kinetic and DFT-level theoretical studies have been undertaken to establish the reaction sequence and other mechanistic details. Base-catalysed cyclisation on the other hand, has been shown to afford 2H-chromene rather than coumarin derivatives.
- Full Text:
- Authors: Olomola, Temitope Oloruntoba
- Date: 2011
- Subjects: HIV infections -- Treatment HIV infections -- Chemotherapy HIV (Viruses) Enzyme inhibitors AZT (Drug) Reverse transcriptase Proteolytic enzymes Ligands Psoralens Resorcinol
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4369 , http://hdl.handle.net/10962/d1005034
- Description: This study has involved the design, synthesis and evaluation of novel HIV-1 enzyme inhibitors accessed by synthetic elaboration of Baylis-Hillman adducts. Several series of complex coumarin-AZT and cinnamate ester-AZT conjugates have been prepared, in high yields, by exploiting the click reaction between appropriate Baylis-Hillman derived precursors and azidothymidine (AZT), all of which have been fully characterised using spectroscopic techniques. These conjugates, designed as potential dual-action HIV-1 inhibitors, were tested against the appropriate HIV-1 enzymes, i.e. HIV-1 reverse transcriptase and protease or HIV-1 reverse transcriptase and integrase. A number of the ligands have exhibited % inhibition levels and IC50 values comparable to drugs in clinical use, permitting their identification as lead compounds for the development of novel dual-action inhibitors. In silico docking of selected ligands into the active sites of the respective enzymes has provided useful insight into binding conformations and potential hydrogen-bonding interactions with active-site amino acid residues. A series of furocoumarin carboxamide derivatives have been synthesised in four steps starting from resorcinol and these compounds have also been tested for HIV-1 integrase inhibition activity. The structures of unexpected products isolated from Aza-Baylis-Hillman reactions of N-tosylaldimines have been elucidated by spectroscopic analysis, and confirmed by single crystal X-ray analysis. A mechanism for what appears to be an unprecedented transformation has been proposed. Microwave-assisted SeO₂ oxidation of Baylis-Hillman-derived 3-methylcoumarins has provided convenient and efficient access to coumarin-3-carbaldehydes, and a pilot study has revealed the potential of these coumarin-3-carbaldehydes as scaffolds for the construction of tricyclic compounds. The HCl-catalysed reaction of tert-butyl acrylate derived Baylis-Hillman adducts has been shown to afford 3-(chloromethyl)coumarins and α-(chloromethyl)cinnamic acids, the Zstereochemistry of the latter being established by X-ray crystallography. ¹H NMR-based experimental kinetic and DFT-level theoretical studies have been undertaken to establish the reaction sequence and other mechanistic details. Base-catalysed cyclisation on the other hand, has been shown to afford 2H-chromene rather than coumarin derivatives.
- Full Text:
Synthesis of novel inhibitors of 1-Deoxy-D-xylulose-5-phosphate reductoisomerase as potential anti-malarial lead compounds
- Authors: Mutorwa, Marius Kudumo
- Date: 2011
- Subjects: Antimalarials -- Development Plasmodium falciparum Malaria -- Chemotherapy Drug development Lead compounds Phosphonates Phosphonic acids Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4372 , http://hdl.handle.net/10962/d1005037
- Description: This research has focused on the development of novel substrate mimics as potential DXR inhibitors of 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), an essential enzyme in the mevalonate-independent pathway for the biosynthesis of isoprenoids in Plasmodium falciparum. DXR mediates the isomerisation and reduction of 1-deoxy-D-xylulose-5-phosphate (DOXP) into 2C-methyl-D-erithrytol 4-phosphate (MEP) and has been validated as an attractive target for the development of novel anti-malarial chemotherapeutic agents. Reaction of various amines with specially prepared 4-phosphonated crotonic acid in the presence of the peptide coupling reagent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), has afforded a series of amido-phosphonate esters in moderate to good yields (48% - 73%) which, using a RuCl₃/CeCl₃/NaIO₄ catalyst system, have been dihydroxylated to furnish the dihydroxy-amido phosphonate ester pro-drugs; subsequent hydrolysis under microwave irradiation has afforded the corresponding phosphonic acids. A second series of potential inhibitors viz., 3-substituted aniline-derived phosphonate esters, their corresponding phosphonic acids and mono-sodium salts, have also been successfully synthesised. In these compounds, the essential functional groups are separated by one, two, three or four methylene groups, Deprotonation of the 3-substituted aniline substrates, followed by reaction with the appropriate ω-chloroalkanoyl chloride produced the ω-chloroamide intermediates, which were subjected to the Michaelis-Arbuzov reaction to afford the diethyl phosphonate esters in moderate to good yields (48% - 74%). Microwave-assisted TMSBrmediated cleavage of the phosphonate esters furnished the phosphonic acids, neutralisation of which afforded the mono-sodium salts. Furan-derived phosphate esters and phosphonic acids have been prepared as conformationally-restricted DOXP analogues. Functionalization at C-5 of the trityl-protected furan was achieved using the Vilsmeier-Haack formylation and Friedel-Crafts acylation reactions and, following de-tritylation, phosphorylation and oximation, using hydroxylamine hydrochloride, the novel oxime derivatives have been isolated as a third series of potential DXR inhibitors in very good yields (87% - 96%). Finally, in order to exploit an additional binding pocket in the PƒDXR active site, a series of N-benzylated phosphoramidic derivatives were obtained in seven steps from the starting material, diethyl phosphoramidate. The known inhibitors, fosmidomycin and its acetyl derivative FR900098, were also successfully synthesised as standards for STD-NMR binding and inhibition assays. In all, over 200 compounds (136 novel) have been prepared and appropriately characterised using 1-and 2-D NMR and IR spectroscopic analysis and, where necessary, HRMS or combustion analysis. Saturation Transfer Difference (STD) protein-NMR experiments, undertaken using selected compounds, have revealed binding of most of the ligands examined to EcDXR. Computersimulated docking studies have also been used to explore the preferred ligand-binding conformations and interactions between the ligands and essential DXR active-site residues, while DXR-enzyme inhibition assays of selected synthesised ligands have revealed certain patterns of inhibitory activity.
- Full Text:
- Authors: Mutorwa, Marius Kudumo
- Date: 2011
- Subjects: Antimalarials -- Development Plasmodium falciparum Malaria -- Chemotherapy Drug development Lead compounds Phosphonates Phosphonic acids Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4372 , http://hdl.handle.net/10962/d1005037
- Description: This research has focused on the development of novel substrate mimics as potential DXR inhibitors of 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), an essential enzyme in the mevalonate-independent pathway for the biosynthesis of isoprenoids in Plasmodium falciparum. DXR mediates the isomerisation and reduction of 1-deoxy-D-xylulose-5-phosphate (DOXP) into 2C-methyl-D-erithrytol 4-phosphate (MEP) and has been validated as an attractive target for the development of novel anti-malarial chemotherapeutic agents. Reaction of various amines with specially prepared 4-phosphonated crotonic acid in the presence of the peptide coupling reagent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), has afforded a series of amido-phosphonate esters in moderate to good yields (48% - 73%) which, using a RuCl₃/CeCl₃/NaIO₄ catalyst system, have been dihydroxylated to furnish the dihydroxy-amido phosphonate ester pro-drugs; subsequent hydrolysis under microwave irradiation has afforded the corresponding phosphonic acids. A second series of potential inhibitors viz., 3-substituted aniline-derived phosphonate esters, their corresponding phosphonic acids and mono-sodium salts, have also been successfully synthesised. In these compounds, the essential functional groups are separated by one, two, three or four methylene groups, Deprotonation of the 3-substituted aniline substrates, followed by reaction with the appropriate ω-chloroalkanoyl chloride produced the ω-chloroamide intermediates, which were subjected to the Michaelis-Arbuzov reaction to afford the diethyl phosphonate esters in moderate to good yields (48% - 74%). Microwave-assisted TMSBrmediated cleavage of the phosphonate esters furnished the phosphonic acids, neutralisation of which afforded the mono-sodium salts. Furan-derived phosphate esters and phosphonic acids have been prepared as conformationally-restricted DOXP analogues. Functionalization at C-5 of the trityl-protected furan was achieved using the Vilsmeier-Haack formylation and Friedel-Crafts acylation reactions and, following de-tritylation, phosphorylation and oximation, using hydroxylamine hydrochloride, the novel oxime derivatives have been isolated as a third series of potential DXR inhibitors in very good yields (87% - 96%). Finally, in order to exploit an additional binding pocket in the PƒDXR active site, a series of N-benzylated phosphoramidic derivatives were obtained in seven steps from the starting material, diethyl phosphoramidate. The known inhibitors, fosmidomycin and its acetyl derivative FR900098, were also successfully synthesised as standards for STD-NMR binding and inhibition assays. In all, over 200 compounds (136 novel) have been prepared and appropriately characterised using 1-and 2-D NMR and IR spectroscopic analysis and, where necessary, HRMS or combustion analysis. Saturation Transfer Difference (STD) protein-NMR experiments, undertaken using selected compounds, have revealed binding of most of the ligands examined to EcDXR. Computersimulated docking studies have also been used to explore the preferred ligand-binding conformations and interactions between the ligands and essential DXR active-site residues, while DXR-enzyme inhibition assays of selected synthesised ligands have revealed certain patterns of inhibitory activity.
- Full Text:
Systematics, morphology, phylogeny and historical biogeography of the Mayfly family Prosopistomatidae (Ephemeroptera: Insecta) of the world
- Barber-James, Helen Margaret
- Authors: Barber-James, Helen Margaret
- Date: 2011
- Subjects: Mayflies Mayflies -- Classification Mayflies -- Morphology Mayflies -- Phylogeny Mayflies -- Geographical distribution Ephemeridae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5785 , http://hdl.handle.net/10962/d1005473
- Description: The diversity, classification and historical biogeography of the mayfly family Prosopistomatidae are explored. First, the higher classification of the Ephemeroptera is reviewed, focussing on the phylogenetic placement of the Prosopistomatidae relative to other mayfly families. All relevant literature from 1762 to 2010 is synthesized. Baetiscidae are established as the probable sister lineage of Prosopistomatidae, the two constituting the superfamily Baetiscoidea. Next, qualitative morphological variation within the Prosopistomatidae is reviewed and revised, emphasizing nymphs because imaginal specimens are few. The labium and associated structures and the hypopharynx of nymphs, and the highly-derived wing venation of the imaginal stages, are re-interpreted. The structure of the male tarsal claws changes considerably between subimago and imago, which, together with deeply scalloped ridges on male imaginal forelegs and unusual pits on the female thorax, are interpreted as providing an unusual mating mechanism. These structures provide morphological characters for species definition and phylogenetic analyses. Two approaches to species delimitation are explored. First, morphometric variation is analysed using Principal Component Analysis, revealing groupings that can be interpreted as species, although there is some overlap between them. Discriminant Function Analysis shows that head width and carapace shape have the most value in identifying nymphs of different species. The carapace of Prosopistoma nymphs is shown to grow allometrically and gradually, in contrast with that of Baetisca, indicating a difference in early ontogeny. Second, an Artificial Neural Network algorithm applied to nymphal morphological characters accurately identified species. This computer-driven artificial intelligence method has power to provide future easy-to-use electronic identification aids. Phylogenetic analysis of nymphal morphology using the parsimony method shows two clades of Prosopistomatidae, one sharing characters with the type species, Prosopistoma variegatum and the other predominating in Africa, although also occurring in Asia; these clades are named the “P. variegatum” and “African” clades, respectively. Parsimony analysis of adult morphology supports these two clades, but supertree analysis obscures the relationships, nesting the “P. variegatum” lineage within the other clade. Preliminary molecular phylogenetic analysis of the 16S rRNA, (mitochondrial) 18S rRNA and Histone-3 genes using Bayesian Inference methods does not support the two clades shown by morphology. Instead, there is a strong relationship between the European species and one African species, with the single Asian representative being most distantly related. These results are limited by lack of fresh material, patchy taxon sampling, and problems with finding suitable primers. A molecular clock program, BEAST, calibrated using fossils, suggests divergence times for the oldest crown-group Prosopistoma clade, represented by the Asian P. wouterae, of about 131 Ma, with the youngest species, the African P. crassi, of 1.21 Ma. Stem-group relationships are analysed using parsimony analysis, focussing on wing characters of the Baetiscoidea, other extant mayfly lineages, and extinct stem-group lineages. This suggests that the Baetiscoidea diverged from main-line Ephemeroptera earlier than any other extant mayfly lineage. This approach expands upon ideas hinted at by earlier scientists. Finally, historical biogeographical analysis of the distribution of known Baetiscoidea s.s. stem-group fossils implies a once Pangean distribution of the lineage. Changing palaeo-climate, catastrophic extinction events and plate tectonic movements in relation to the distribution of crown-group species are reviewed. Other approaches to historical biogeography that build on both morphological and molecular phylogenies are used to interpret disperalist and vacarianist arguments. Distribution patterns of eight unrelated freshwater organisms which share a similar distribution pattern are compared, assuming that shared patterns indicate similar historic biogeographic processes. The distribution of recent Prosopistoma species is seen to be the product of evolution resulting from both vicariance and dispersal. In conclusion, this thesis encompasses a variety of disciplines. It successfully recognises new characters and distinguishes previously unknown species. It uses new approaches to delimiting species and known methods to determine phylogeny from several angles. The analysis of stem-group relationships offers an insight into possible early lineage splitting within Ephemeroptera. Interpretation of historical biogeography allows for both a Gondwanan origin of Prosopistomatidae, with rafting of species on the Deccan plate to Asia, and for subsequent dispersal from Asia down to Australia and across to Europe, and possibly back to Africa.
- Full Text:
- Authors: Barber-James, Helen Margaret
- Date: 2011
- Subjects: Mayflies Mayflies -- Classification Mayflies -- Morphology Mayflies -- Phylogeny Mayflies -- Geographical distribution Ephemeridae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5785 , http://hdl.handle.net/10962/d1005473
- Description: The diversity, classification and historical biogeography of the mayfly family Prosopistomatidae are explored. First, the higher classification of the Ephemeroptera is reviewed, focussing on the phylogenetic placement of the Prosopistomatidae relative to other mayfly families. All relevant literature from 1762 to 2010 is synthesized. Baetiscidae are established as the probable sister lineage of Prosopistomatidae, the two constituting the superfamily Baetiscoidea. Next, qualitative morphological variation within the Prosopistomatidae is reviewed and revised, emphasizing nymphs because imaginal specimens are few. The labium and associated structures and the hypopharynx of nymphs, and the highly-derived wing venation of the imaginal stages, are re-interpreted. The structure of the male tarsal claws changes considerably between subimago and imago, which, together with deeply scalloped ridges on male imaginal forelegs and unusual pits on the female thorax, are interpreted as providing an unusual mating mechanism. These structures provide morphological characters for species definition and phylogenetic analyses. Two approaches to species delimitation are explored. First, morphometric variation is analysed using Principal Component Analysis, revealing groupings that can be interpreted as species, although there is some overlap between them. Discriminant Function Analysis shows that head width and carapace shape have the most value in identifying nymphs of different species. The carapace of Prosopistoma nymphs is shown to grow allometrically and gradually, in contrast with that of Baetisca, indicating a difference in early ontogeny. Second, an Artificial Neural Network algorithm applied to nymphal morphological characters accurately identified species. This computer-driven artificial intelligence method has power to provide future easy-to-use electronic identification aids. Phylogenetic analysis of nymphal morphology using the parsimony method shows two clades of Prosopistomatidae, one sharing characters with the type species, Prosopistoma variegatum and the other predominating in Africa, although also occurring in Asia; these clades are named the “P. variegatum” and “African” clades, respectively. Parsimony analysis of adult morphology supports these two clades, but supertree analysis obscures the relationships, nesting the “P. variegatum” lineage within the other clade. Preliminary molecular phylogenetic analysis of the 16S rRNA, (mitochondrial) 18S rRNA and Histone-3 genes using Bayesian Inference methods does not support the two clades shown by morphology. Instead, there is a strong relationship between the European species and one African species, with the single Asian representative being most distantly related. These results are limited by lack of fresh material, patchy taxon sampling, and problems with finding suitable primers. A molecular clock program, BEAST, calibrated using fossils, suggests divergence times for the oldest crown-group Prosopistoma clade, represented by the Asian P. wouterae, of about 131 Ma, with the youngest species, the African P. crassi, of 1.21 Ma. Stem-group relationships are analysed using parsimony analysis, focussing on wing characters of the Baetiscoidea, other extant mayfly lineages, and extinct stem-group lineages. This suggests that the Baetiscoidea diverged from main-line Ephemeroptera earlier than any other extant mayfly lineage. This approach expands upon ideas hinted at by earlier scientists. Finally, historical biogeographical analysis of the distribution of known Baetiscoidea s.s. stem-group fossils implies a once Pangean distribution of the lineage. Changing palaeo-climate, catastrophic extinction events and plate tectonic movements in relation to the distribution of crown-group species are reviewed. Other approaches to historical biogeography that build on both morphological and molecular phylogenies are used to interpret disperalist and vacarianist arguments. Distribution patterns of eight unrelated freshwater organisms which share a similar distribution pattern are compared, assuming that shared patterns indicate similar historic biogeographic processes. The distribution of recent Prosopistoma species is seen to be the product of evolution resulting from both vicariance and dispersal. In conclusion, this thesis encompasses a variety of disciplines. It successfully recognises new characters and distinguishes previously unknown species. It uses new approaches to delimiting species and known methods to determine phylogeny from several angles. The analysis of stem-group relationships offers an insight into possible early lineage splitting within Ephemeroptera. Interpretation of historical biogeography allows for both a Gondwanan origin of Prosopistomatidae, with rafting of species on the Deccan plate to Asia, and for subsequent dispersal from Asia down to Australia and across to Europe, and possibly back to Africa.
- Full Text:
Teaching reading in Rukwangali in four Grade 3 Namibian classrooms : a case study
- Authors: Siyave, Theresia Nerumbu
- Date: 2011
- Subjects: Reading (Elementary) -- Namibia Reading teachers -- Training of -- Namibia Kwangali language -- Study and teaching (Elementary) -- Namibia Literacy -- Study and teaching (Elementary) -- Namibia Native language and education -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1798 , http://hdl.handle.net/10962/d1003683
- Description: This study aims to explore four grade 3 teachers’ understanding of teaching reading in Rukwangali, a home language in Namibia in Kavango region and to observe the strategies they use as well as the activities they set for their learners. During my School Based Studies (SBS), I noticed that learners were not reading with understanding. My interest was also stimulated by a study carried out in Namibia that found that the literacy levels for Namibian learners were poor compared to those of other African countries. This is a qualitative case study carried out within an interpretive paradigm. It seeks to understand the meaning that people attached to human actions. I selected the participants purposefully and in terms of convenience, as all three schools selected are situated in Rundu, the town in which I work as a college lecturer. The research tools I employed were semi-structured interviews, document analysis, classroom observation, and stimulated recall discussions on the lessons I observed. I used a variety of methods to triangulate data and enhance validity. This study reveals that teachers use multiple methods to teach reading. These methods include phonics and syllabification to help struggling learners to decode difficult and long (polysyllabic) words and the look-and-say method for whole word recognition and meaning making at word and sentence level. In addition, they also use the thematic approach to teaching and learning to expand learners’ vocabulary and enhance their understanding of the texts they read and to make their lessons learnercentred. However, the problems of language, lack of reading books written in Rukwangali and large class sizes constrain the teachers from teaching in a more learner-centred way. Therefore, the study gives some tentative recommendations to remedy this situation.
- Full Text:
- Authors: Siyave, Theresia Nerumbu
- Date: 2011
- Subjects: Reading (Elementary) -- Namibia Reading teachers -- Training of -- Namibia Kwangali language -- Study and teaching (Elementary) -- Namibia Literacy -- Study and teaching (Elementary) -- Namibia Native language and education -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1798 , http://hdl.handle.net/10962/d1003683
- Description: This study aims to explore four grade 3 teachers’ understanding of teaching reading in Rukwangali, a home language in Namibia in Kavango region and to observe the strategies they use as well as the activities they set for their learners. During my School Based Studies (SBS), I noticed that learners were not reading with understanding. My interest was also stimulated by a study carried out in Namibia that found that the literacy levels for Namibian learners were poor compared to those of other African countries. This is a qualitative case study carried out within an interpretive paradigm. It seeks to understand the meaning that people attached to human actions. I selected the participants purposefully and in terms of convenience, as all three schools selected are situated in Rundu, the town in which I work as a college lecturer. The research tools I employed were semi-structured interviews, document analysis, classroom observation, and stimulated recall discussions on the lessons I observed. I used a variety of methods to triangulate data and enhance validity. This study reveals that teachers use multiple methods to teach reading. These methods include phonics and syllabification to help struggling learners to decode difficult and long (polysyllabic) words and the look-and-say method for whole word recognition and meaning making at word and sentence level. In addition, they also use the thematic approach to teaching and learning to expand learners’ vocabulary and enhance their understanding of the texts they read and to make their lessons learnercentred. However, the problems of language, lack of reading books written in Rukwangali and large class sizes constrain the teachers from teaching in a more learner-centred way. Therefore, the study gives some tentative recommendations to remedy this situation.
- Full Text:
Teaching struggling adolescent readers in Namibia : a case study
- Authors: Simanga, Elizabeth Miyaze
- Date: 2011
- Subjects: Reading (Secondary) -- Namibia Reading comprehension -- Study and teaching (Secondary) -- Namibia Reading -- Remedial teaching -- Namibia Reading teachers -- Training of -- Namibia Second language acquisition -- Namibia English language -- Study and teaching -- Foreign speakers -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1876 , http://hdl.handle.net/10962/d1005639
- Description: Though research has been conducted on many issues since Namibia's independence in 1990, none of these studies has investigated how English Second Language (ESL) teachers teach and support struggling adolescent readers (SARs) to read. Utilising qualitative research techniques such as classroom observations, semi-structured interviews and document analysis, this case study looked at strategies, methods, and resources used by five ESL secondary school teachers to teach SARs to read in two regions in Namibia, Caprivi and Otjozondjupa regions. Two of the five participants were male teachers. The presence of SARs in the classes observed was established by using informal methods such as the ESL teachers' experience (Caprivi region), while a sample of questions from PIRLS 2001 (Mullis, Martin, Gonzalez, & Kennedy (2003) was compiled to form a test used in the Otjozondjupa region. The findings show that despite undergoing initial teacher training and majoring in English, the five ESL secondary school teachers were not trained to teach SARs either how to read or how to support them. In addition, the study found that there was a shortage of reading materials in all five selected schools.
- Full Text:
- Authors: Simanga, Elizabeth Miyaze
- Date: 2011
- Subjects: Reading (Secondary) -- Namibia Reading comprehension -- Study and teaching (Secondary) -- Namibia Reading -- Remedial teaching -- Namibia Reading teachers -- Training of -- Namibia Second language acquisition -- Namibia English language -- Study and teaching -- Foreign speakers -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1876 , http://hdl.handle.net/10962/d1005639
- Description: Though research has been conducted on many issues since Namibia's independence in 1990, none of these studies has investigated how English Second Language (ESL) teachers teach and support struggling adolescent readers (SARs) to read. Utilising qualitative research techniques such as classroom observations, semi-structured interviews and document analysis, this case study looked at strategies, methods, and resources used by five ESL secondary school teachers to teach SARs to read in two regions in Namibia, Caprivi and Otjozondjupa regions. Two of the five participants were male teachers. The presence of SARs in the classes observed was established by using informal methods such as the ESL teachers' experience (Caprivi region), while a sample of questions from PIRLS 2001 (Mullis, Martin, Gonzalez, & Kennedy (2003) was compiled to form a test used in the Otjozondjupa region. The findings show that despite undergoing initial teacher training and majoring in English, the five ESL secondary school teachers were not trained to teach SARs either how to read or how to support them. In addition, the study found that there was a shortage of reading materials in all five selected schools.
- Full Text:
Testing the existence and direction of "spill-over" of mussel recruits beyond the boundaries of marine protected areas
- Authors: Ludford, Adam
- Date: 2011
- Subjects: Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5786 , http://hdl.handle.net/10962/d1005474 , Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Description: Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.
- Full Text:
- Authors: Ludford, Adam
- Date: 2011
- Subjects: Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5786 , http://hdl.handle.net/10962/d1005474 , Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Description: Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.
- Full Text:
Textual representations of migrants and the process of migration in selected South African media a combined critical discourse analysis and corpus linguistics study
- Authors: Crymble, Leigh
- Date: 2011
- Subjects: Immigrants in mass media -- South Africa Mass media and foreign workers -- South Africa Refugees -- Press coverage -- South Africa Xenophobia in mass media -- South Africa Critical discourse analysis Corpora (Linguistics) Sunday Times (Johannesburg, South Africa) City Press (Johannesburg, South Africa) Mail & Guardian
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2342 , http://hdl.handle.net/10962/d1002624
- Description: South Africa has long been associated with racial and ethnic issues surrounding prejudice and discrimination and despite a move post-1994 to a democratic ‘rainbow nation’ society, the country has remained plagued by unequal power relations. One such instance of inequality relates to the marginalisation of migrants which has been realised through xenophobic attitudes and actions, most notably the violence that swept across the country in 2008. Several reasons have been suggested in an attempt to explain the cause of the violence, including claims that migrants are taking ‘our jobs and our women’, migrants are ‘illegal and criminal’ and bringing ‘disease and contamination’ with them from their countries of origin. Although widely accepted that many, if not all, of these beliefs are based on ignorance and hearsay, these extensive generalisations shape and reinforce prejudiced ideologies about migrant communities. It is thus only when confronted with evidence that challenges this dominant discourse, that South Africans are able to reconsider their views. Williams (2008) suggests that for many South Africans, Africa continues to be the ‘dark continent’ that is seen as an ominous, threatening force of which they have very little knowledge. For this reason, anti-immigrant sentiment in a South African context has traditionally been directed at African foreigners. In this study I examine the ways in which African migrants and migrant communities, as well as the overall processes of migration, are depicted by selected South African print media: City Press, Mail & Guardian and Sunday Times. Using a combined Corpus Linguistics and Critical Discourse Analysis approach, I investigate the following questions: How are migrants and the process of migration into South Africa represented by these established newspapers between 2006 and 2010? Are there any differences or similarities between these representations? In particular, what ideologies regarding migrants and migrant communities underlie these representations? My analysis focuses on the landscape of public discourse about migration with an exploration of the rise and fall of the terminologies used to categorise migrants and the social implications of these classifications. Additionally, I analyse the expansive occurrences of negative representations of migrants, particularly through the use of ‘othering’ pronouns ‘us’ versus ‘them’ and through the use of metaphorical language which largely depicts these individuals as en masse natural disasters. I conclude that these discursive elements play a crucial role in contributing to an overall xenophobic rhetoric. Despite subtle differences between the three newspapers which can be accounted for based on their political persuasions and agendas, it is surprising to note how aligned these publications are with regard to their portrayal of migrants. With a few exceptions, this representation positions these individuals as powerless and disenfranchised and maintains the status quo view of migrants as burdens on the South African economy and resources. Overall, the newspaper articles contribute to mainstream dominant discourse on migrants and migration with the underlying ideology that migrants are responsible for the hardships suffered by South African citizens. Thus, this study contributes significantly to existing bodies of research detailing discourse on migrants and emphasises the intrinsic links between language, ideology and society.
- Full Text:
- Authors: Crymble, Leigh
- Date: 2011
- Subjects: Immigrants in mass media -- South Africa Mass media and foreign workers -- South Africa Refugees -- Press coverage -- South Africa Xenophobia in mass media -- South Africa Critical discourse analysis Corpora (Linguistics) Sunday Times (Johannesburg, South Africa) City Press (Johannesburg, South Africa) Mail & Guardian
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2342 , http://hdl.handle.net/10962/d1002624
- Description: South Africa has long been associated with racial and ethnic issues surrounding prejudice and discrimination and despite a move post-1994 to a democratic ‘rainbow nation’ society, the country has remained plagued by unequal power relations. One such instance of inequality relates to the marginalisation of migrants which has been realised through xenophobic attitudes and actions, most notably the violence that swept across the country in 2008. Several reasons have been suggested in an attempt to explain the cause of the violence, including claims that migrants are taking ‘our jobs and our women’, migrants are ‘illegal and criminal’ and bringing ‘disease and contamination’ with them from their countries of origin. Although widely accepted that many, if not all, of these beliefs are based on ignorance and hearsay, these extensive generalisations shape and reinforce prejudiced ideologies about migrant communities. It is thus only when confronted with evidence that challenges this dominant discourse, that South Africans are able to reconsider their views. Williams (2008) suggests that for many South Africans, Africa continues to be the ‘dark continent’ that is seen as an ominous, threatening force of which they have very little knowledge. For this reason, anti-immigrant sentiment in a South African context has traditionally been directed at African foreigners. In this study I examine the ways in which African migrants and migrant communities, as well as the overall processes of migration, are depicted by selected South African print media: City Press, Mail & Guardian and Sunday Times. Using a combined Corpus Linguistics and Critical Discourse Analysis approach, I investigate the following questions: How are migrants and the process of migration into South Africa represented by these established newspapers between 2006 and 2010? Are there any differences or similarities between these representations? In particular, what ideologies regarding migrants and migrant communities underlie these representations? My analysis focuses on the landscape of public discourse about migration with an exploration of the rise and fall of the terminologies used to categorise migrants and the social implications of these classifications. Additionally, I analyse the expansive occurrences of negative representations of migrants, particularly through the use of ‘othering’ pronouns ‘us’ versus ‘them’ and through the use of metaphorical language which largely depicts these individuals as en masse natural disasters. I conclude that these discursive elements play a crucial role in contributing to an overall xenophobic rhetoric. Despite subtle differences between the three newspapers which can be accounted for based on their political persuasions and agendas, it is surprising to note how aligned these publications are with regard to their portrayal of migrants. With a few exceptions, this representation positions these individuals as powerless and disenfranchised and maintains the status quo view of migrants as burdens on the South African economy and resources. Overall, the newspaper articles contribute to mainstream dominant discourse on migrants and migration with the underlying ideology that migrants are responsible for the hardships suffered by South African citizens. Thus, this study contributes significantly to existing bodies of research detailing discourse on migrants and emphasises the intrinsic links between language, ideology and society.
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The contribution made by Mr Justice EF Watermeyer to South African tax jurisprudence
- Authors: Thackwell, Robert Colin
- Date: 2011
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:881 , http://hdl.handle.net/10962/d1001635
- Description: The objective of this thesis is to highlight the colossal contributions made by the late Justice Watermeyer to South African tax jurisprudence. His contributions are viewed from a practical application point of view as well as from a statutory interpretative perspective. The style and technique with which he delivered his judgments are also considered to be a contribution in their own right. The core of this thesis is the analysis of seven of Justice Watermeyer‟s most influential judgments. The development and application of the principle or principles developed in each of these seven judgments is then traced chronologically through case law up until recent judgments. It is most notable that each and every phrase contained in section 11(a) of the Income Tax Act has been interpreted by Justice Watermeyer. These interpretations are still viewed as correct statements of the applicable law and will continue to be referred to on a regular basis given the fact that section 11(a) is one of the most widely contested provisions in the Income Tax Act. Several references to his approach to statutory interpretation are made through the course of the case analyses. Whilst significant evidence of a purposive oriented approach to interpretation appears in some judgments, such evidence is lacking in others. An absolute or conclusive submission in terms of his approach to statutory interpretation is not sufficiently supported. His style of judgment is also referred to and commented on, with particular focus placed on his use of illustrative examples. The contribution to South African tax law by Justice Watermeyer is found to be nothing short of enormous. He was and continues to be influential with respect to section 11(a),the definition of gross income in section 1, common law principles of tax avoidance as well as the interpretation of statutory laws of tax avoidance. It is anticipated that some of his interpretations with respect to statutory rules of tax avoidance will be referred to when the relatively new anti-avoidance provisions become the subject of litigation.
- Full Text:
- Authors: Thackwell, Robert Colin
- Date: 2011
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:881 , http://hdl.handle.net/10962/d1001635
- Description: The objective of this thesis is to highlight the colossal contributions made by the late Justice Watermeyer to South African tax jurisprudence. His contributions are viewed from a practical application point of view as well as from a statutory interpretative perspective. The style and technique with which he delivered his judgments are also considered to be a contribution in their own right. The core of this thesis is the analysis of seven of Justice Watermeyer‟s most influential judgments. The development and application of the principle or principles developed in each of these seven judgments is then traced chronologically through case law up until recent judgments. It is most notable that each and every phrase contained in section 11(a) of the Income Tax Act has been interpreted by Justice Watermeyer. These interpretations are still viewed as correct statements of the applicable law and will continue to be referred to on a regular basis given the fact that section 11(a) is one of the most widely contested provisions in the Income Tax Act. Several references to his approach to statutory interpretation are made through the course of the case analyses. Whilst significant evidence of a purposive oriented approach to interpretation appears in some judgments, such evidence is lacking in others. An absolute or conclusive submission in terms of his approach to statutory interpretation is not sufficiently supported. His style of judgment is also referred to and commented on, with particular focus placed on his use of illustrative examples. The contribution to South African tax law by Justice Watermeyer is found to be nothing short of enormous. He was and continues to be influential with respect to section 11(a),the definition of gross income in section 1, common law principles of tax avoidance as well as the interpretation of statutory laws of tax avoidance. It is anticipated that some of his interpretations with respect to statutory rules of tax avoidance will be referred to when the relatively new anti-avoidance provisions become the subject of litigation.
- Full Text:
The critical natural capital of the Buffalo City Municipality, South Africa : harnessing local action for biodiversity conservation
- Authors: Hagen, Brett
- Date: 2011
- Subjects: Natural resources -- South Africa -- Buffalo City , Biodiversity conservation -- South Africa -- Buffalo City , Ecosystem services -- South Africa -- Buffalo City , Nature conservation -- South Africa -- Buffalo City , Environmental protection -- South Africa -- Buffalo City , Environmental degradation -- South Africa -- Buffalo City , Restoration ecology -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4753 , http://hdl.handle.net/10962/d1007075 , Natural resources -- South Africa -- Buffalo City , Biodiversity conservation -- South Africa -- Buffalo City , Ecosystem services -- South Africa -- Buffalo City , Nature conservation -- South Africa -- Buffalo City , Environmental protection -- South Africa -- Buffalo City , Environmental degradation -- South Africa -- Buffalo City , Restoration ecology -- South Africa -- Buffalo City
- Description: Globally, ecosystems provide services of almost twice the value of global gross national product (Costanza et al., 2006). The Buffalo City Municipality (BCM), South Africa contains biodiversity of national and international importance (Pierce, 2003; Pierce et al., 2005). Despite this, the municipality continues to experience loss of both urban and rural biodiversity (Buffalo City Municipality, 2006a). This study sought to determine the status of biodiversity, and the potential for ecosystem services to contribute to conservation, within the BCM. Biodiversity features, including ecosystem type, species of special concern and biodiversity processes, were identified and mapped using a GIS to produce a biodiversity priority index for the BCM. Current transformation status was then mapped to determine the level of ecosystem degradation within the BCM. Priority biodiversity areas as well as individual biodiversity features were spatially overlain against current transformation status and protected areas and analysed using a GIS to determine the level of degradation and protection of BCM biodiversity. In total 3.5 % of total BCM biodiversity was protected. Of the 24 ecosystem types, 11 (45%) had less than 1% under protection, while 16 (67%) had less than five percent protected. Not restorable areas, thus completely lost to biodiversity conservation, comprised just less than a quarter of the total BCM area while un-impacted areas comprised just 12.3%. Twenty five ecosystem services were identified as being provided by intact natural ecosystems within the BCM. The natural capital providing these services was identified and mapped to produce an ecosystem service index (ESI) using a GIS. This ecosystem service index and the biodiversity priority index were overlain to determine their level of correlation. Overall ESI correlation with priority biodiversity was weak although several individual ecosystem services, including carbon sequestration, showed correlation. Using the above data layers an implementation plan and conservation framework was proposed to assist the coordination of local conservation action within the BCM. It is concluded that ecosystem services are a potentially useful tool for conservationists at the local level seeking to ensure that biodiversity has relevance to and receives protection from broader society.
- Full Text:
- Authors: Hagen, Brett
- Date: 2011
- Subjects: Natural resources -- South Africa -- Buffalo City , Biodiversity conservation -- South Africa -- Buffalo City , Ecosystem services -- South Africa -- Buffalo City , Nature conservation -- South Africa -- Buffalo City , Environmental protection -- South Africa -- Buffalo City , Environmental degradation -- South Africa -- Buffalo City , Restoration ecology -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4753 , http://hdl.handle.net/10962/d1007075 , Natural resources -- South Africa -- Buffalo City , Biodiversity conservation -- South Africa -- Buffalo City , Ecosystem services -- South Africa -- Buffalo City , Nature conservation -- South Africa -- Buffalo City , Environmental protection -- South Africa -- Buffalo City , Environmental degradation -- South Africa -- Buffalo City , Restoration ecology -- South Africa -- Buffalo City
- Description: Globally, ecosystems provide services of almost twice the value of global gross national product (Costanza et al., 2006). The Buffalo City Municipality (BCM), South Africa contains biodiversity of national and international importance (Pierce, 2003; Pierce et al., 2005). Despite this, the municipality continues to experience loss of both urban and rural biodiversity (Buffalo City Municipality, 2006a). This study sought to determine the status of biodiversity, and the potential for ecosystem services to contribute to conservation, within the BCM. Biodiversity features, including ecosystem type, species of special concern and biodiversity processes, were identified and mapped using a GIS to produce a biodiversity priority index for the BCM. Current transformation status was then mapped to determine the level of ecosystem degradation within the BCM. Priority biodiversity areas as well as individual biodiversity features were spatially overlain against current transformation status and protected areas and analysed using a GIS to determine the level of degradation and protection of BCM biodiversity. In total 3.5 % of total BCM biodiversity was protected. Of the 24 ecosystem types, 11 (45%) had less than 1% under protection, while 16 (67%) had less than five percent protected. Not restorable areas, thus completely lost to biodiversity conservation, comprised just less than a quarter of the total BCM area while un-impacted areas comprised just 12.3%. Twenty five ecosystem services were identified as being provided by intact natural ecosystems within the BCM. The natural capital providing these services was identified and mapped to produce an ecosystem service index (ESI) using a GIS. This ecosystem service index and the biodiversity priority index were overlain to determine their level of correlation. Overall ESI correlation with priority biodiversity was weak although several individual ecosystem services, including carbon sequestration, showed correlation. Using the above data layers an implementation plan and conservation framework was proposed to assist the coordination of local conservation action within the BCM. It is concluded that ecosystem services are a potentially useful tool for conservationists at the local level seeking to ensure that biodiversity has relevance to and receives protection from broader society.
- Full Text:
The democratisation of art CAP as an alternative art space in South Africa
- Authors: Lochner, Eben
- Date: 2011
- Subjects: Arts and society -- South Africa Democracy and the arts -- South Africa Art -- Political aspects -- South Africa Apartheid and art -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2409 , http://hdl.handle.net/10962/d1002205
- Description: While formal arts education was inaccessible to many during Apartheid, community-based centres played a significant role in the training of previously disadvantaged artists. By engaging in a socio-political critique of the history of South African art, this thesis argues that even though alternative art spaces are often marginalised, they remain essential to the diversification and democratisation of contemporary South African art today with its re-entry into the international art scene. According to Lize van Robbroeck (2004:52), “some of the fundamental ideals of community arts need to be revised to enrich, democratize and diversify [South Africa's] cultural practice.” The aim of my Thesis is to investigate this statement in relation to the contribution the Community Arts Project (CAP) in Cape Town (1977-2003). CAP and other art centres have played an indispensable role in the establishment of black artists and in producing a locally reflective artistic practice in South Africa, even into the 21st century. Through researching the changes the organisation underwent between the 1980s and 1990s, the ways in which such art centres constantly need to respond to the changing sociopolitical landscape around them become clear. Within South Africa these centres were seen to play a significant part in the liberation struggle and then later in nation building. While these centres were well supported by foreign donors in the late 1980s, such funding was withdrawn in 1991 and the majority of art centres collapsed, illustrating to some degree that the training of artist was not valued outside the context of the struggle against apartheid. By interviewing key people and by reading documentation stored at the Manuscripts and Archives department of UCT I have discovered some of the different benefits and hindrances of working in community art centres both during and after Apartheid. This thesis argues that these centres still play a vital role in contributing to the development of South Africa's local art practice and should not be relegated to the sideline.
- Full Text:
- Authors: Lochner, Eben
- Date: 2011
- Subjects: Arts and society -- South Africa Democracy and the arts -- South Africa Art -- Political aspects -- South Africa Apartheid and art -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2409 , http://hdl.handle.net/10962/d1002205
- Description: While formal arts education was inaccessible to many during Apartheid, community-based centres played a significant role in the training of previously disadvantaged artists. By engaging in a socio-political critique of the history of South African art, this thesis argues that even though alternative art spaces are often marginalised, they remain essential to the diversification and democratisation of contemporary South African art today with its re-entry into the international art scene. According to Lize van Robbroeck (2004:52), “some of the fundamental ideals of community arts need to be revised to enrich, democratize and diversify [South Africa's] cultural practice.” The aim of my Thesis is to investigate this statement in relation to the contribution the Community Arts Project (CAP) in Cape Town (1977-2003). CAP and other art centres have played an indispensable role in the establishment of black artists and in producing a locally reflective artistic practice in South Africa, even into the 21st century. Through researching the changes the organisation underwent between the 1980s and 1990s, the ways in which such art centres constantly need to respond to the changing sociopolitical landscape around them become clear. Within South Africa these centres were seen to play a significant part in the liberation struggle and then later in nation building. While these centres were well supported by foreign donors in the late 1980s, such funding was withdrawn in 1991 and the majority of art centres collapsed, illustrating to some degree that the training of artist was not valued outside the context of the struggle against apartheid. By interviewing key people and by reading documentation stored at the Manuscripts and Archives department of UCT I have discovered some of the different benefits and hindrances of working in community art centres both during and after Apartheid. This thesis argues that these centres still play a vital role in contributing to the development of South Africa's local art practice and should not be relegated to the sideline.
- Full Text:
The demography and population dynamics of a re-introduced black rhinoceros population on the Great Fish River Reserve, Eastern Cape Province
- Authors: Fike, Bradley Robin
- Date: 2011
- Subjects: Black rhinoceros -- South Africa -- Great Fish River Valley , Population biology -- South Africa -- Great Fish River Valley , Black rhinoceros -- Habitat -- South Africa -- Great Fish River Valley , Black rhinoceros -- Adaptation -- South Africa -- Great Fish River Valley , Black rhinoceros -- Ecology -- South Africa -- Great Fish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5948 , http://hdl.handle.net/10962/d1020869
- Description: The re-introduction of black rhinoceros onto the Great Fish River Reserve in the Eastern Cape, following the species absence for over a century, created an opportunity to study this species in the thicket biome, and in particular the succulent thicket of the Great Fish River valley. The thicket biome is quite different from the habitats in which other extant populations of these animals are found and where studies of their demography have been undertaken. Data collection occurred from May 1986, with the arrival of the first four animals to December 2008, when the population was estimated to be 144 individuals. A variety of monitoring techniques were used including direct ground observations, aerial helicopter census, aerial monitoring by microlight aircraft, camera traps and opportunistic observations, each with its own advantages and disadvantages. The combination of methods and effort has resulted in the population being recognized as completely known with up to 97% of the animals being located at least once per year with a mean frequency of sightings of 11.5 per animal per year. In 2008, the population was about 20% juvenile, 36% sub-adult and 44% adult with a female biased sex ratio of 1.3 females per male. Mean age at first birth was about 80 months and this increased significantly with increasing density of black rhinoceroses. Mean intercalf interval was about 28 months and 41% of adult females gave birth each year. Mortality rates were low for juveniles, higher for sub-adults and higher for males than females. There was a weak but significant positive effect of density on male mortality. Population growth rate was about 10% and was not significantly affected by density. These results suggest that this population is beginning to show the first indications of density dependant constraints and that harvesting should be implemented in order to maintain the productive tempo. A secondary goal of the Management Plan will then be realized as the population functions as a donor to establish founder populations elsewhere within the Diceros bicornis minor range.
- Full Text:
- Authors: Fike, Bradley Robin
- Date: 2011
- Subjects: Black rhinoceros -- South Africa -- Great Fish River Valley , Population biology -- South Africa -- Great Fish River Valley , Black rhinoceros -- Habitat -- South Africa -- Great Fish River Valley , Black rhinoceros -- Adaptation -- South Africa -- Great Fish River Valley , Black rhinoceros -- Ecology -- South Africa -- Great Fish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5948 , http://hdl.handle.net/10962/d1020869
- Description: The re-introduction of black rhinoceros onto the Great Fish River Reserve in the Eastern Cape, following the species absence for over a century, created an opportunity to study this species in the thicket biome, and in particular the succulent thicket of the Great Fish River valley. The thicket biome is quite different from the habitats in which other extant populations of these animals are found and where studies of their demography have been undertaken. Data collection occurred from May 1986, with the arrival of the first four animals to December 2008, when the population was estimated to be 144 individuals. A variety of monitoring techniques were used including direct ground observations, aerial helicopter census, aerial monitoring by microlight aircraft, camera traps and opportunistic observations, each with its own advantages and disadvantages. The combination of methods and effort has resulted in the population being recognized as completely known with up to 97% of the animals being located at least once per year with a mean frequency of sightings of 11.5 per animal per year. In 2008, the population was about 20% juvenile, 36% sub-adult and 44% adult with a female biased sex ratio of 1.3 females per male. Mean age at first birth was about 80 months and this increased significantly with increasing density of black rhinoceroses. Mean intercalf interval was about 28 months and 41% of adult females gave birth each year. Mortality rates were low for juveniles, higher for sub-adults and higher for males than females. There was a weak but significant positive effect of density on male mortality. Population growth rate was about 10% and was not significantly affected by density. These results suggest that this population is beginning to show the first indications of density dependant constraints and that harvesting should be implemented in order to maintain the productive tempo. A secondary goal of the Management Plan will then be realized as the population functions as a donor to establish founder populations elsewhere within the Diceros bicornis minor range.
- Full Text:
The design and synthesis of multidentate N-heterocyclic carbenes as metathesis catalyst ligands
- Authors: Truscott, Byron John
- Date: 2011
- Subjects: Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4304 , http://hdl.handle.net/10962/d1004962 , Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Description: This study has focused on the design and preparation of bi– and tridentate N–Heterocyclic Carbene (NHC) ligands in order to investigate the effect of a multidentate approach to the formation, stability and catalytic activity of coordination complexes. Chapters 1 – 3 provide background information of relevant catalysis, carbene and coordination chemistry, followed by previous work performed within our research group. In Chapter 4 attention is given to the synthetic aspects of the research conducted, comprising two distinct approaches to the preparation of unsymmetrical saturated and unsaturated NHCs. Firstly, an investigation of the saturated NHC ligands yielded three novel, unsymmetrical pro–ligands, viz., two halopropyl imidazolinium salts and a bidentate hydroxypropyl imidazolinium salt. Secondly, eight imidazolium salts have been generated, including a hydroxypropyl analogue and novel decyl and tridentate malonyl derivatives. These compounds were prepared using microwave–assisted methodology for the alkylation of N– mesitylimidazole – an approach that drastically reduced reaction times (from 8 hours – 7 days to ca. 0.5 – 2 hours) and facilitated isolation of the imidazolium salts. Many of the compounds prepared in this study are novel and were fully characterized using HRMS and 1– and 2–D NMR analysis. Coordination studies using a selection of the prepared pro–ligands afforded an alkoxy–NHC silver derivative and four novel Ru–complexes, viz., Grubbs II–type Ru–complexes containing:– chloropropyl imidazolinylidene; propenyl imidazolylidene; and bidentate alkoxypropyl imidazolylidene ligands. Furthermore, a well–defined benzyl mesitylimidazolylidene Ru–complex has been isolated, which exhibited good stability in air. DFT–level geometry–optimization studies, using the Accelrys DMol3 package have given valuable insights into the likely geometries of the prepared and putative catalysts.
- Full Text:
- Authors: Truscott, Byron John
- Date: 2011
- Subjects: Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4304 , http://hdl.handle.net/10962/d1004962 , Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Description: This study has focused on the design and preparation of bi– and tridentate N–Heterocyclic Carbene (NHC) ligands in order to investigate the effect of a multidentate approach to the formation, stability and catalytic activity of coordination complexes. Chapters 1 – 3 provide background information of relevant catalysis, carbene and coordination chemistry, followed by previous work performed within our research group. In Chapter 4 attention is given to the synthetic aspects of the research conducted, comprising two distinct approaches to the preparation of unsymmetrical saturated and unsaturated NHCs. Firstly, an investigation of the saturated NHC ligands yielded three novel, unsymmetrical pro–ligands, viz., two halopropyl imidazolinium salts and a bidentate hydroxypropyl imidazolinium salt. Secondly, eight imidazolium salts have been generated, including a hydroxypropyl analogue and novel decyl and tridentate malonyl derivatives. These compounds were prepared using microwave–assisted methodology for the alkylation of N– mesitylimidazole – an approach that drastically reduced reaction times (from 8 hours – 7 days to ca. 0.5 – 2 hours) and facilitated isolation of the imidazolium salts. Many of the compounds prepared in this study are novel and were fully characterized using HRMS and 1– and 2–D NMR analysis. Coordination studies using a selection of the prepared pro–ligands afforded an alkoxy–NHC silver derivative and four novel Ru–complexes, viz., Grubbs II–type Ru–complexes containing:– chloropropyl imidazolinylidene; propenyl imidazolylidene; and bidentate alkoxypropyl imidazolylidene ligands. Furthermore, a well–defined benzyl mesitylimidazolylidene Ru–complex has been isolated, which exhibited good stability in air. DFT–level geometry–optimization studies, using the Accelrys DMol3 package have given valuable insights into the likely geometries of the prepared and putative catalysts.
- Full Text:
The development and assessment of a fixed dose combination tablet of Ranitidine and Metronidazole
- Authors: King'ori, Loti David
- Date: 2011 , 2011-04-07
- Subjects: Ulcers -- Treatment , Ranitidine -- Evaluation , Metronidazole -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3858 , http://hdl.handle.net/10962/d1013359
- Description: The oral route of drug administration is convenient since it is acceptable to most patients and the manufacturing processes used to produce tablets and capsules are relatively simple when compared to those used to manufacture other types of dosage forms. Metronidazole (MTZ) and Ranitidine (RTD) have been used in combination, as part of triple therapy for the treatment of ulcers. However the use of large numbers of tablets and long duration of therapy makes adherence to drug treatment challenging for patients. Therefore the formulation of a fixed dose combination (FDC) of MTZ and RTD may improve patient adherence to therapy and consequently may reduce morbidity and mortality due to ulcers. A stability indicating HPLC method for the simultaneous analysis of MTZ and RTD was developed and validated according to the International Conference on Harmonization (ICH) guidelines. The method was sensitive, selective, precise, accurate and linear.Preformulation studies were performed on the active pharmaceutical ingredients (API) alone and in combination with potential excipients. Differential scanning calorimetry (DSC) studies revealed a potential interaction between MTZ and RTD, however the interaction was not apparent following IR analysis of the same samples. DSC analyses of the API in combination with potential excipients revealed that the compounds were compatible with most materials with the exception of a binary mixture of RTD and Dibasic calcium phosphate (DCP) that exhibited a potential interaction. Thermal gravimetric analysis (TGA) of MTZ and RTD revealed that both compounds exhibited thermal stability. The Carrs Index (CI) and Hausner Ratio (HR) values of MTZ and RTD indicated that both compounds exhibited poor flow and compressibility properties, whereas the CI and HR values for (Microcrystalline cellulose) MCC and DCP indicated better flowability and compressibility characteristics.Direct compression and wet granulation processes were assessed to identify a suitable method of manufacture of FDC tablets of MTZ and RTD. The blends were evaluated using bulk and tapped density and the resultant tablets were evaluated for weight uniformity, crushing strength, tensile strength and disintegration time. The wet granulation method of manufacture produced tablets that showed acceptable pharmacotechnical properties: this approach was therefore used as the method of manufacture of FDC tablets of MTZ and RTD. Tablet formulations comprised of API, viz. MTZ and RTD and different compositions of MCC, DCP, Sodium starch glycolate (SSG) and Croscarmellose sodium (CCS), were manufactured in order to screen for an appropriate diluent and disintegrant composition for use in response surface studies. Assays of tablet content and in vitro drug release were undertaken using the validated HPLC method. Tablets in which MCC and CCS were used appeared to produce better assay and dissolution results as compared to those manufactured using DCP and SSG. Consequently a formulation comprised of MCC and CCS was selected and used in studies in which the effect(s) of level two formulation and composition changes as described in the Scale and Post Approval Changes for Immediate Release (SUPAC-IR) Guidelines on tablet disintegration and in vitro release were assessed. A Box-Behnken statistical design was used for the investigation of the effect of input factors, viz. CCS, (Polyvinyl pyrollidone K30) PVP-K30 and magnesium stearate on measured responses, viz. disintegration time and percent drug release in 10 minutes (Q10). CCS appeared to have an inverse linear relationship on disintegration time and a linear relationship with the Q10 for MTZ and RTD, whereas PVP-K30 and magnesium stearate appeared to have an antagonistic effect on the measured responses. Furthermore CCS and magnesium stearate exhibited an interaction that had an agonistic effect on the Q10 value for RTD. A numerical optimization approach was used to predict a formulation composition that would produce tablets that exhibited a disintegration time and Q10 values for MTZ and RTD that fell within the constraints set in our laboratory. The resultant model was found to be accurate and had a percent prediction error of < 5% for all measured response variables.FDC tablets of MTZ and RTD have been successfully produced. The disintegration of the tablet and dissolution of the API were within compendial specifications and the tablets are of suitable quality and have the potential to be further investigated to reduce the pill burden in the treatment of ulcers.
- Full Text:
- Authors: King'ori, Loti David
- Date: 2011 , 2011-04-07
- Subjects: Ulcers -- Treatment , Ranitidine -- Evaluation , Metronidazole -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3858 , http://hdl.handle.net/10962/d1013359
- Description: The oral route of drug administration is convenient since it is acceptable to most patients and the manufacturing processes used to produce tablets and capsules are relatively simple when compared to those used to manufacture other types of dosage forms. Metronidazole (MTZ) and Ranitidine (RTD) have been used in combination, as part of triple therapy for the treatment of ulcers. However the use of large numbers of tablets and long duration of therapy makes adherence to drug treatment challenging for patients. Therefore the formulation of a fixed dose combination (FDC) of MTZ and RTD may improve patient adherence to therapy and consequently may reduce morbidity and mortality due to ulcers. A stability indicating HPLC method for the simultaneous analysis of MTZ and RTD was developed and validated according to the International Conference on Harmonization (ICH) guidelines. The method was sensitive, selective, precise, accurate and linear.Preformulation studies were performed on the active pharmaceutical ingredients (API) alone and in combination with potential excipients. Differential scanning calorimetry (DSC) studies revealed a potential interaction between MTZ and RTD, however the interaction was not apparent following IR analysis of the same samples. DSC analyses of the API in combination with potential excipients revealed that the compounds were compatible with most materials with the exception of a binary mixture of RTD and Dibasic calcium phosphate (DCP) that exhibited a potential interaction. Thermal gravimetric analysis (TGA) of MTZ and RTD revealed that both compounds exhibited thermal stability. The Carrs Index (CI) and Hausner Ratio (HR) values of MTZ and RTD indicated that both compounds exhibited poor flow and compressibility properties, whereas the CI and HR values for (Microcrystalline cellulose) MCC and DCP indicated better flowability and compressibility characteristics.Direct compression and wet granulation processes were assessed to identify a suitable method of manufacture of FDC tablets of MTZ and RTD. The blends were evaluated using bulk and tapped density and the resultant tablets were evaluated for weight uniformity, crushing strength, tensile strength and disintegration time. The wet granulation method of manufacture produced tablets that showed acceptable pharmacotechnical properties: this approach was therefore used as the method of manufacture of FDC tablets of MTZ and RTD. Tablet formulations comprised of API, viz. MTZ and RTD and different compositions of MCC, DCP, Sodium starch glycolate (SSG) and Croscarmellose sodium (CCS), were manufactured in order to screen for an appropriate diluent and disintegrant composition for use in response surface studies. Assays of tablet content and in vitro drug release were undertaken using the validated HPLC method. Tablets in which MCC and CCS were used appeared to produce better assay and dissolution results as compared to those manufactured using DCP and SSG. Consequently a formulation comprised of MCC and CCS was selected and used in studies in which the effect(s) of level two formulation and composition changes as described in the Scale and Post Approval Changes for Immediate Release (SUPAC-IR) Guidelines on tablet disintegration and in vitro release were assessed. A Box-Behnken statistical design was used for the investigation of the effect of input factors, viz. CCS, (Polyvinyl pyrollidone K30) PVP-K30 and magnesium stearate on measured responses, viz. disintegration time and percent drug release in 10 minutes (Q10). CCS appeared to have an inverse linear relationship on disintegration time and a linear relationship with the Q10 for MTZ and RTD, whereas PVP-K30 and magnesium stearate appeared to have an antagonistic effect on the measured responses. Furthermore CCS and magnesium stearate exhibited an interaction that had an agonistic effect on the Q10 value for RTD. A numerical optimization approach was used to predict a formulation composition that would produce tablets that exhibited a disintegration time and Q10 values for MTZ and RTD that fell within the constraints set in our laboratory. The resultant model was found to be accurate and had a percent prediction error of < 5% for all measured response variables.FDC tablets of MTZ and RTD have been successfully produced. The disintegration of the tablet and dissolution of the API were within compendial specifications and the tablets are of suitable quality and have the potential to be further investigated to reduce the pill burden in the treatment of ulcers.
- Full Text:
The development and implementation of a mental toughness training programme for young cricketers
- Authors: Pattison, Stuart
- Date: 2011
- Subjects: Cricket -- Psychological aspects -- South Africa -- Grahamstown , Cricket -- Training -- South Africa -- Grahamstown , Cricket players -- Mental health -- South Africa -- Grahamstown , Mental discipline , Toughness (Personality trait) , Success -- Psychological aspects , Personal coaching -- South Africa -- Grahamstown , School sports -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3037 , http://hdl.handle.net/10962/d1002546 , Cricket -- Psychological aspects -- South Africa -- Grahamstown , Cricket -- Training -- South Africa -- Grahamstown , Cricket players -- Mental health -- South Africa -- Grahamstown , Mental discipline , Toughness (Personality trait) , Success -- Psychological aspects , Personal coaching -- South Africa -- Grahamstown , School sports -- South Africa -- Grahamstown
- Description: Modern research being conducted on Mental Toughness is now shifting away from efforts aimed at developing definitions for the construct and instead moving toward efforts at understanding its development. This particular research study focuses on the development and implementation of a Mental Toughness programme designed specifically for, and tailored exclusively to, the needs of schoolboy cricket at Kingswood College in Grahamstown, Eastern Cape. The programme development was an intricate process and the research procedure was guided by the Organisational Development Process model. Data from a focus group as well as various individual interviews were integrated with currently existing Mental Toughness literature and theory to devise this particular Mental Toughness programme. The programme entails educating the athletes on six specific mental skills and incorporates elements of practical application as well as awareness of the importance and influence of Mental Toughness and mental training in a sporting sphere. The programme took the form of mental skills workshops held over a three week period. An analysis was conducted post-programme to document the experience of the athletes as a result of exposure to the programme. Results drawn from the array of analysis procedures were used to help identify the level of success of the Mental Toughness intervention as well as help validify current Mental Toughness models. In addition to highlighting the benefits as a result of the programme experience, various recommendations were drawn in order to shed light on the programme limitations and assist future researchers with understanding the intricacies behind better and more efficient programme implementation.
- Full Text:
- Authors: Pattison, Stuart
- Date: 2011
- Subjects: Cricket -- Psychological aspects -- South Africa -- Grahamstown , Cricket -- Training -- South Africa -- Grahamstown , Cricket players -- Mental health -- South Africa -- Grahamstown , Mental discipline , Toughness (Personality trait) , Success -- Psychological aspects , Personal coaching -- South Africa -- Grahamstown , School sports -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3037 , http://hdl.handle.net/10962/d1002546 , Cricket -- Psychological aspects -- South Africa -- Grahamstown , Cricket -- Training -- South Africa -- Grahamstown , Cricket players -- Mental health -- South Africa -- Grahamstown , Mental discipline , Toughness (Personality trait) , Success -- Psychological aspects , Personal coaching -- South Africa -- Grahamstown , School sports -- South Africa -- Grahamstown
- Description: Modern research being conducted on Mental Toughness is now shifting away from efforts aimed at developing definitions for the construct and instead moving toward efforts at understanding its development. This particular research study focuses on the development and implementation of a Mental Toughness programme designed specifically for, and tailored exclusively to, the needs of schoolboy cricket at Kingswood College in Grahamstown, Eastern Cape. The programme development was an intricate process and the research procedure was guided by the Organisational Development Process model. Data from a focus group as well as various individual interviews were integrated with currently existing Mental Toughness literature and theory to devise this particular Mental Toughness programme. The programme entails educating the athletes on six specific mental skills and incorporates elements of practical application as well as awareness of the importance and influence of Mental Toughness and mental training in a sporting sphere. The programme took the form of mental skills workshops held over a three week period. An analysis was conducted post-programme to document the experience of the athletes as a result of exposure to the programme. Results drawn from the array of analysis procedures were used to help identify the level of success of the Mental Toughness intervention as well as help validify current Mental Toughness models. In addition to highlighting the benefits as a result of the programme experience, various recommendations were drawn in order to shed light on the programme limitations and assist future researchers with understanding the intricacies behind better and more efficient programme implementation.
- Full Text:
The development and technologizing of selected Sepedi ICT terminology
- Authors: Magagane, Raesetja Linah
- Date: 2011
- Subjects: Northern Sotho language -- Terms and phrases Northern Sotho language -- Terminology Northern Sotho language -- Computer-assisted instruction Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3581 , http://hdl.handle.net/10962/d1002156
- Description: It is my wish that the Sepedi language speakers, through the development and technologization of certain Sepedi ICT terminology, are able to operate a computer in their own language, and implement the new developed and technologized ICT terminology (technologization). The pupils and students at their various institutions should be made comfortable in using the developed and technologized Sepedi language terminology. In the long run the Sepedi language speakers should be ensured access to the web in order to find information about Sepedi language, culture and terms in disciplines such as ICT. It is recommended in this thesis that higher learning institutions offer bursaries to students to develop all South African languages in such a manner that they can be used in all high status functions.
- Full Text:
- Authors: Magagane, Raesetja Linah
- Date: 2011
- Subjects: Northern Sotho language -- Terms and phrases Northern Sotho language -- Terminology Northern Sotho language -- Computer-assisted instruction Communication -- Technological innovations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3581 , http://hdl.handle.net/10962/d1002156
- Description: It is my wish that the Sepedi language speakers, through the development and technologization of certain Sepedi ICT terminology, are able to operate a computer in their own language, and implement the new developed and technologized ICT terminology (technologization). The pupils and students at their various institutions should be made comfortable in using the developed and technologized Sepedi language terminology. In the long run the Sepedi language speakers should be ensured access to the web in order to find information about Sepedi language, culture and terms in disciplines such as ICT. It is recommended in this thesis that higher learning institutions offer bursaries to students to develop all South African languages in such a manner that they can be used in all high status functions.
- Full Text:
The development of an in vitro system for the production of drug metabolites using microsomal enzymes from bovine liver
- Authors: Morrison, Roxanne
- Date: 2011
- Subjects: Drugs -- Metabolism , Xenobiotics -- Metabolism , Metabolites , Drugs -- Testing , Toxicity testing -- In vitro , Doping in horse racing -- Control -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4087 , http://hdl.handle.net/10962/d1007698 , Drugs -- Metabolism , Xenobiotics -- Metabolism , Metabolites , Drugs -- Testing , Toxicity testing -- In vitro , Doping in horse racing -- Control -- Research
- Description: Drug metabolism is a specialised subset of xenobiotic metabolism, pertaining to the breakdown and elimination of pharmaceutical drugs. The enzymes involved in these pathways are the cytochrome P450 family of isozymes. Metabolism is an important factor in determining the pharmacological effects of drugs. The main aim of this study was to develop a system whereby the major metabolites of drugs can be produced in vitro. An in vitro system was developed and optimised using commercially prepared microsomes from rat liver and coumarin (by monitoring its conversion to 7-hydroxycoumarin) as a model. The optimum running conditions for the incubations were 50 μM coumarin, 50 μg protein/ml microsomes, 1 mM NADP⁺, 5 mM G6P and 1U/ml G6PDH incubated for 30 minutes at 38℃. The HPLC method for the detection of coumarin and 7-hydroxycoumarin was also validated with respect to linearity, reproducibility, precision, accuracy and lower limits of detection and quantification. The system developed was then tested using microsomes prepared from fresh bovine liver on these ten drugs of interest in doping control in horse racing: diazepam, nordiazepam, oxazepam, promazine, acepromazine, chlorpromazine, morphine, codeine, etoricoxib and lumiracoxib. The bovine liver microsomes were prepared using differential centrifugation and had activity on a par with the commercial preparations. This in vitro system metabolised the drugs and produced both phase I and II metabolites, similar to those observed in humans and horses in vivo. For example, the major metabolites of the benzodiazepine drug, diazepam, nordiazepam, temazepam and oxazepam as well as the glucuronidated phase II products were all found after incubations with the bovine liver microsomes. The metabolism of the drugs was also investigated in silico using the computational procedure, MetaSite. MetaSite was able to successfully predict known metabolites for most of the drugs studied. Differences were observed from the in vitro incubations and this is most likely due to MetaSite using only human cytochrome P450s for analysis.
- Full Text:
- Authors: Morrison, Roxanne
- Date: 2011
- Subjects: Drugs -- Metabolism , Xenobiotics -- Metabolism , Metabolites , Drugs -- Testing , Toxicity testing -- In vitro , Doping in horse racing -- Control -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4087 , http://hdl.handle.net/10962/d1007698 , Drugs -- Metabolism , Xenobiotics -- Metabolism , Metabolites , Drugs -- Testing , Toxicity testing -- In vitro , Doping in horse racing -- Control -- Research
- Description: Drug metabolism is a specialised subset of xenobiotic metabolism, pertaining to the breakdown and elimination of pharmaceutical drugs. The enzymes involved in these pathways are the cytochrome P450 family of isozymes. Metabolism is an important factor in determining the pharmacological effects of drugs. The main aim of this study was to develop a system whereby the major metabolites of drugs can be produced in vitro. An in vitro system was developed and optimised using commercially prepared microsomes from rat liver and coumarin (by monitoring its conversion to 7-hydroxycoumarin) as a model. The optimum running conditions for the incubations were 50 μM coumarin, 50 μg protein/ml microsomes, 1 mM NADP⁺, 5 mM G6P and 1U/ml G6PDH incubated for 30 minutes at 38℃. The HPLC method for the detection of coumarin and 7-hydroxycoumarin was also validated with respect to linearity, reproducibility, precision, accuracy and lower limits of detection and quantification. The system developed was then tested using microsomes prepared from fresh bovine liver on these ten drugs of interest in doping control in horse racing: diazepam, nordiazepam, oxazepam, promazine, acepromazine, chlorpromazine, morphine, codeine, etoricoxib and lumiracoxib. The bovine liver microsomes were prepared using differential centrifugation and had activity on a par with the commercial preparations. This in vitro system metabolised the drugs and produced both phase I and II metabolites, similar to those observed in humans and horses in vivo. For example, the major metabolites of the benzodiazepine drug, diazepam, nordiazepam, temazepam and oxazepam as well as the glucuronidated phase II products were all found after incubations with the bovine liver microsomes. The metabolism of the drugs was also investigated in silico using the computational procedure, MetaSite. MetaSite was able to successfully predict known metabolites for most of the drugs studied. Differences were observed from the in vitro incubations and this is most likely due to MetaSite using only human cytochrome P450s for analysis.
- Full Text:
The development of isiZulu as an academic language for the teaching of fundamental concepts in economics
- Authors: Makhatini, Freedom Nkanyiso
- Date: 2011
- Subjects: Zulu language -- Study and teaching (Higher) -- South Africa African languages -- Study and teaching (Higher) -- South Africa Economics -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3589 , http://hdl.handle.net/10962/d1002164
- Description: This thesis looks at language as the medium of all our ideas and sentiments. The thesis represents a position statement regarding the development of isiZulu as an academic language. The field of Economics is used to merely illustrate and support the points that are being made in this work. It is argued that each language is viewed as the means of expression of the cultural heritage of its people, and it remains a reflection of cultural groups who speak that particular language. It is a fact that indigenous African Languages have been, for obvious reasons, blatantly understudied during the apartheid years in South Africa (Rudwick 2004). Languages have market value and the desirability of English as the most important global language today has an effect in most Black learners in South Africa. The study examined the development of indigenous African languages, isiZulu in particular, in Zululand University where ninety percent of students and lecturers are isiZulu first language speakers, and came to a conclusion that there is an urgent need for Black South African students to learn academic subjects through their mother tongues. This would help them in thorough understanding and interpretation of analytic text presented in a foreign language such as English. The study advocates that isiZulu, which is the mother-tongue of many students at the University of Zululand, should be a language for upward mobility to these students, but as the situation stands, isiZulu becomes a neglected or marginalised language since it is not the normal medium of instruction and it is not used for effective communication in their education system.
- Full Text:
- Authors: Makhatini, Freedom Nkanyiso
- Date: 2011
- Subjects: Zulu language -- Study and teaching (Higher) -- South Africa African languages -- Study and teaching (Higher) -- South Africa Economics -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3589 , http://hdl.handle.net/10962/d1002164
- Description: This thesis looks at language as the medium of all our ideas and sentiments. The thesis represents a position statement regarding the development of isiZulu as an academic language. The field of Economics is used to merely illustrate and support the points that are being made in this work. It is argued that each language is viewed as the means of expression of the cultural heritage of its people, and it remains a reflection of cultural groups who speak that particular language. It is a fact that indigenous African Languages have been, for obvious reasons, blatantly understudied during the apartheid years in South Africa (Rudwick 2004). Languages have market value and the desirability of English as the most important global language today has an effect in most Black learners in South Africa. The study examined the development of indigenous African languages, isiZulu in particular, in Zululand University where ninety percent of students and lecturers are isiZulu first language speakers, and came to a conclusion that there is an urgent need for Black South African students to learn academic subjects through their mother tongues. This would help them in thorough understanding and interpretation of analytic text presented in a foreign language such as English. The study advocates that isiZulu, which is the mother-tongue of many students at the University of Zululand, should be a language for upward mobility to these students, but as the situation stands, isiZulu becomes a neglected or marginalised language since it is not the normal medium of instruction and it is not used for effective communication in their education system.
- Full Text:
The discoursal construction of female physical identity in selected works in children's literature
- Authors: Hunt, Sally Ann
- Date: 2011 , 2013-09-20
- Subjects: Rowling, J K -- Criticism and interpretation Lewis, C S (Clive Staples), 1898-1963 -- Criticism and interpretation Girls in literature Girls -- Identity Human body in literature Gender identity in literature Sex role in literature Children's stories, English -- History and criticism Young women in literature Women in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2377 , http://hdl.handle.net/10962/d1005965
- Description: This thesis reports on an analysis of the discursive construction of female and male physical identity in children’s literature and explicitly combines corpus linguistic methods with a critical discourse approach. Based on three novels from each of the Chronicles of Narnia and the Harry Potter series, it shows clear gendering of body parts, not only in terms of the purely quantitative preferences for certain body parts to be associated with one or other gender, but in terms of discourse prosody, or the uses to which the body parts are put. Human body parts in these series are mostly used in the following four ways, all of which show differences in realisation in terms of gender: · to describe individuals, physically, in order to distinguish one from the other; · to convey emotion, unintentionally as well as consciously; · for physical interaction between people and · for interaction with the world more broadly: responses to danger and agency, i.e. the ability to act on the world and the nature of what is achieved. The use of body parts by characters to express emotion and act agentively on the world is revealed to be strongly gendered in the two series. I characterise the most prominent patterns in terms of the bodily products blood, sweat and tears, of which the last is strongly connected to female characters, who are generally associated with emotion. The other two, referring to active participation in fighting and injury, as well as agency, are almost exclusively reserved for males, with female characters rendered unable to act on the physical world as a result of overwhelming feelings. The females’ response to danger suggests stereotyped discourses of inequality which see women and girls as requiring protection and being physically incapable. Thus gender is still a particularly salient aspect in these widely-read examples of children’s literature, despite plots which appear to be fairly positive towards women. The strength of the inclusion of a corpus approach in this study lies in its capacity to reveal objective, and often fairly covert, trends in language use. These in turn enrich the critical analysis of discourses in these influential texts, which facilitates social change through linguistic analysis.
- Full Text:
- Authors: Hunt, Sally Ann
- Date: 2011 , 2013-09-20
- Subjects: Rowling, J K -- Criticism and interpretation Lewis, C S (Clive Staples), 1898-1963 -- Criticism and interpretation Girls in literature Girls -- Identity Human body in literature Gender identity in literature Sex role in literature Children's stories, English -- History and criticism Young women in literature Women in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2377 , http://hdl.handle.net/10962/d1005965
- Description: This thesis reports on an analysis of the discursive construction of female and male physical identity in children’s literature and explicitly combines corpus linguistic methods with a critical discourse approach. Based on three novels from each of the Chronicles of Narnia and the Harry Potter series, it shows clear gendering of body parts, not only in terms of the purely quantitative preferences for certain body parts to be associated with one or other gender, but in terms of discourse prosody, or the uses to which the body parts are put. Human body parts in these series are mostly used in the following four ways, all of which show differences in realisation in terms of gender: · to describe individuals, physically, in order to distinguish one from the other; · to convey emotion, unintentionally as well as consciously; · for physical interaction between people and · for interaction with the world more broadly: responses to danger and agency, i.e. the ability to act on the world and the nature of what is achieved. The use of body parts by characters to express emotion and act agentively on the world is revealed to be strongly gendered in the two series. I characterise the most prominent patterns in terms of the bodily products blood, sweat and tears, of which the last is strongly connected to female characters, who are generally associated with emotion. The other two, referring to active participation in fighting and injury, as well as agency, are almost exclusively reserved for males, with female characters rendered unable to act on the physical world as a result of overwhelming feelings. The females’ response to danger suggests stereotyped discourses of inequality which see women and girls as requiring protection and being physically incapable. Thus gender is still a particularly salient aspect in these widely-read examples of children’s literature, despite plots which appear to be fairly positive towards women. The strength of the inclusion of a corpus approach in this study lies in its capacity to reveal objective, and often fairly covert, trends in language use. These in turn enrich the critical analysis of discourses in these influential texts, which facilitates social change through linguistic analysis.
- Full Text:
The disempowering faces of the flexible firm: a case study of Gaborone Private Hospital
- Authors: Makorie, Theona Tariro
- Date: 2011
- Subjects: Gaberone Private Hospital -- Employees , Gaberone Private Hospital -- Personnel management , Gaberone Private Hospital -- Management , Nursing services -- Administration , Nurses -- Employment -- Botswana , Nursing -- Law and legislation -- Botswana , Hospitals -- Medical staff -- Botswana , Hospitals -- Administration -- Botswana
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3352
- Description: The purpose of the study was to investigate the ways in which the practice of t the Flexible Firm Model (FFM) disempowered the non-citizen professional nurses at Gaborone Private Hospital (GPH) in Gaborone, Botswana. GPH is a member of the Life Health care group of private hospitals based in South Africa. This study sought to probe the manner in which the practice of FFM influenced the employment relationship for non-citizen professional nurses. It also sought to examine the impact of the nature of the employment relationship on career development and representation and participation. Both qualitative and quantitative research methodologies were applied. Questionnaires were used to collect quantitative data. Thirty-five questionnaires were issued out to professional nursing staff and thirty-three responses were received. The response rate was ninety-four percent. The qualitative research data consisted of twelve in-depth interviews with professional nurses, the human resources manager , a professional nurse agency owner and a private clinic co-owner. Document analysis in the form of labour legislation, employee guides and employment contracts was used to validate data collected from the in-depth interviews. The results from the questionnaire revealed that an overwhelming majority of the professional nurses were Non-Citizens' dependent contractors. Although just under half of the participants held two or more previous contracts with GPH, an overwhelming majority had never been promoted. In addition, none of the participants were affiliated to the Botswana Nurses Association (BNA), the local equivalency of a professional nursing trade union. The in-depth interviews disclosed a sense of helplessness at their perceived disempowerment within the employment relationship, a poor career development and weak representation and participation. This study concluded that disempowerment at GPH was manifested through worker representation and participation and in effective skill upgrade. These forms of disempowerment were made worse by the global professional nurse shortage and maladministration of avail able human resources. Effective use of human resources and continued education could be employed to circumvent the adverse results of disempowerment.
- Full Text:
- Authors: Makorie, Theona Tariro
- Date: 2011
- Subjects: Gaberone Private Hospital -- Employees , Gaberone Private Hospital -- Personnel management , Gaberone Private Hospital -- Management , Nursing services -- Administration , Nurses -- Employment -- Botswana , Nursing -- Law and legislation -- Botswana , Hospitals -- Medical staff -- Botswana , Hospitals -- Administration -- Botswana
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3352
- Description: The purpose of the study was to investigate the ways in which the practice of t the Flexible Firm Model (FFM) disempowered the non-citizen professional nurses at Gaborone Private Hospital (GPH) in Gaborone, Botswana. GPH is a member of the Life Health care group of private hospitals based in South Africa. This study sought to probe the manner in which the practice of FFM influenced the employment relationship for non-citizen professional nurses. It also sought to examine the impact of the nature of the employment relationship on career development and representation and participation. Both qualitative and quantitative research methodologies were applied. Questionnaires were used to collect quantitative data. Thirty-five questionnaires were issued out to professional nursing staff and thirty-three responses were received. The response rate was ninety-four percent. The qualitative research data consisted of twelve in-depth interviews with professional nurses, the human resources manager , a professional nurse agency owner and a private clinic co-owner. Document analysis in the form of labour legislation, employee guides and employment contracts was used to validate data collected from the in-depth interviews. The results from the questionnaire revealed that an overwhelming majority of the professional nurses were Non-Citizens' dependent contractors. Although just under half of the participants held two or more previous contracts with GPH, an overwhelming majority had never been promoted. In addition, none of the participants were affiliated to the Botswana Nurses Association (BNA), the local equivalency of a professional nursing trade union. The in-depth interviews disclosed a sense of helplessness at their perceived disempowerment within the employment relationship, a poor career development and weak representation and participation. This study concluded that disempowerment at GPH was manifested through worker representation and participation and in effective skill upgrade. These forms of disempowerment were made worse by the global professional nurse shortage and maladministration of avail able human resources. Effective use of human resources and continued education could be employed to circumvent the adverse results of disempowerment.
- Full Text: