The economic implications of trade policy reform in South Africa for the automotive industry in the Eastern Cape Province
- Authors: Onyango, Donald Otieno
- Date: 2000
- Subjects: Automobile industry and trade -- South Africa -- Eastern Cape , South Africa -- Commercial policy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:936 , http://hdl.handle.net/10962/d1002669 , Automobile industry and trade -- South Africa -- Eastern Cape , South Africa -- Commercial policy
- Description: South Africa is no longer a pariah state and has been fully integrated into the global family of nations. With the country’s accession to multilateral agreements like the World Trade Organization (WTO), there has been pressure on the government to abandon its hitherto protectionist trade regime in favour of free and fair trade. Trade liberalisation has had profound implications for the country’s manufacturing sector in general, and the automotive industry in particular, which has seen tariff protection radically slashed and import restrictions greatly eased. Not only has the market share of domestic producers fallen, but increases in exports have to date not matched those of imports. As a result there has been a deterioration in the sector’s balance of trade and a reduction in employment levels, at a time when the country desperately needs to create new jobs. Recent developments, however, suggest that this scenario may be set to change. The thesis applies orthodox neoclassical and heterodox approaches to trade policy to an assessment of the likely economic impact of trade liberalisation on the automotive industry in the Eastern Cape, and by extension nationally. The thesis argues that reliance on orthodox trade theory to inform the direction of trade policy, especially in a developing country context, is unlikely to bring about an adequate increase in the level of exports and employment. This is because liberalisation of the import regime is likely to increase import levels without necessarily stimulating export levels, a scenario which serves to negate the presupposed benefits of liberalisation. The study uses information from surveys conducted on both motor vehicle assemblers and component manufacturing firms to investigate the effect of trade liberalisation on the sector in the Province and finds that, by and large, the motor assemblers have not fared as badly as expected and have in fact positioned themselves to export more vehicles and components. The components sector has had to contend with increased competition from cheaper imports. The thesis, while acknowledging that, as far as possible, free trade is an optimal position, nonetheless argues that governments still have an important role to play in the promotion of industrialisation. The scope of government intervention should, however, be limited to selective interventions which are aimed at counteracting market failure and facilitating innovation and the diffusion of technological know-how. The thesis argues that institution of supply side measures, such as the encouragement of research and development (R&D), skills development and industrial training, is necessary for sustained growth in the manufacturing sector to be realised. The thesis also finds that, contrary to expectations, the liberalisation of the automotive sector has not had the desired effects. Despite an increase in the value of automotive exports and an overall trend towards reduced net foreign exchange usage, employment levels are on the decline. The thesis also finds that without major export initiatives by both motor vehicle assemblers and component manufacturers, the future of the industry will be placed in jeopardy, especially with reduced protection and incentives.
- Full Text:
- Date Issued: 2000
- Authors: Onyango, Donald Otieno
- Date: 2000
- Subjects: Automobile industry and trade -- South Africa -- Eastern Cape , South Africa -- Commercial policy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:936 , http://hdl.handle.net/10962/d1002669 , Automobile industry and trade -- South Africa -- Eastern Cape , South Africa -- Commercial policy
- Description: South Africa is no longer a pariah state and has been fully integrated into the global family of nations. With the country’s accession to multilateral agreements like the World Trade Organization (WTO), there has been pressure on the government to abandon its hitherto protectionist trade regime in favour of free and fair trade. Trade liberalisation has had profound implications for the country’s manufacturing sector in general, and the automotive industry in particular, which has seen tariff protection radically slashed and import restrictions greatly eased. Not only has the market share of domestic producers fallen, but increases in exports have to date not matched those of imports. As a result there has been a deterioration in the sector’s balance of trade and a reduction in employment levels, at a time when the country desperately needs to create new jobs. Recent developments, however, suggest that this scenario may be set to change. The thesis applies orthodox neoclassical and heterodox approaches to trade policy to an assessment of the likely economic impact of trade liberalisation on the automotive industry in the Eastern Cape, and by extension nationally. The thesis argues that reliance on orthodox trade theory to inform the direction of trade policy, especially in a developing country context, is unlikely to bring about an adequate increase in the level of exports and employment. This is because liberalisation of the import regime is likely to increase import levels without necessarily stimulating export levels, a scenario which serves to negate the presupposed benefits of liberalisation. The study uses information from surveys conducted on both motor vehicle assemblers and component manufacturing firms to investigate the effect of trade liberalisation on the sector in the Province and finds that, by and large, the motor assemblers have not fared as badly as expected and have in fact positioned themselves to export more vehicles and components. The components sector has had to contend with increased competition from cheaper imports. The thesis, while acknowledging that, as far as possible, free trade is an optimal position, nonetheless argues that governments still have an important role to play in the promotion of industrialisation. The scope of government intervention should, however, be limited to selective interventions which are aimed at counteracting market failure and facilitating innovation and the diffusion of technological know-how. The thesis argues that institution of supply side measures, such as the encouragement of research and development (R&D), skills development and industrial training, is necessary for sustained growth in the manufacturing sector to be realised. The thesis also finds that, contrary to expectations, the liberalisation of the automotive sector has not had the desired effects. Despite an increase in the value of automotive exports and an overall trend towards reduced net foreign exchange usage, employment levels are on the decline. The thesis also finds that without major export initiatives by both motor vehicle assemblers and component manufacturers, the future of the industry will be placed in jeopardy, especially with reduced protection and incentives.
- Full Text:
- Date Issued: 2000
The effect of 6-Methoxy-2-Benzoxazolinone (6-MBOA) on indoleamine regulation and its possible role in depression
- Authors: Tanda, Sindiswa Eunice
- Date: 2000
- Subjects: Tryptophan -- Physiological effect , Tryptophan -- Therapeutic use , Antidepressants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3912 , http://hdl.handle.net/10962/d1003971 , Tryptophan -- Physiological effect , Tryptophan -- Therapeutic use , Antidepressants
- Description: Tryptophan is an essential amino acid that is obtained from the diet. Approximately 98 % of ingested tryptophan is metabolized by the enzyme tryptophan 2,3-dioxygenase (TDO). The metabolism of tryptophan by TDO is an important determinant of tryptophan bioavailability to the brain for serotonin (5-HT) biosynthesis, an essential amine in affective disorders such as depression. Studies done on circadian rhythmicity of the enzyme activity have shown that, TDO activity is high during the scoto-phase (dark-phase), which is attributable to the de novo enzyme synthesis that occurs during this phase. 6-Methoxy-2-benzoxazolinontr-(6-MBOA), a structural analogue of melatonin (aMT) was shown to inhibit TDO activity in both the photo-phase (light-phase) and the scoto-phase with greater potency during the light-phase. Further studies were directed at demonstrating the effects of 6-MBOA on the brain tryptophan hydroxylase (TH) activity, which is a rate limiting enzyme in 5-HT biosynthesis and subsequently on 5-HT levels. The findings showed that, 6-MBOA induces TH activity with a concomitant rise in brain 5-HT levels. The blockade of 5-HT re-uptake into the presynaptic neuron leads to an increase in 5-HT available for the stimulatory action of 5-HT receptors. An attempt to establish whether the administration of 6-MBOA would block the binding of 5-HT to receptors on the synaptosomal membrane showed that 6-MBO A only inhibits the binding of 5 -HT at specific concentrations. In view of the positive effects imposed by 6-MBOA on brain 5-HT levels, urinary 5-hydroxyindole acetic acid (5-HIAA) excretion was measured before and after treatment with 6-MBOA. 5-HIAA excretion was found to be significantly increased after 6-MBOA treatment. Extensive research on the biosynthesis of pineal metabolites has been conducted in the past two decades. The pineal metabolites are synthesized from the precursor tryptophan. In order to obtain an overall picture of the effect of6-MBOA on pineal indole metabolism, an organ culture technique was employed. The results obtained showed that although 6-MBOA administration to rats caused a significant increase in aMT production, there was an insignificant increase in NAS production. This is an immediate precursor of aMT. Other pineal indoles were not affected at all by 6-MBOA administration. Furthermore, the production of pineal NAS and aMT showed an inter-individual variation with some animals producing very high, some very low and some produced average levels of these two metabolites in both photo and scoto-phase experiments. A study undertaken to investigate the circadian rhythm in endogenous aMT production using the competitive ELISA technique showed a clear pattern with high levels of aMT produced during the dark-phase and low levels ofaMT produced during the light-phase. Furthermore, the administration of6-MBOA to rats lead to a significant rise in endogenous aMT production.
- Full Text:
- Date Issued: 2000
- Authors: Tanda, Sindiswa Eunice
- Date: 2000
- Subjects: Tryptophan -- Physiological effect , Tryptophan -- Therapeutic use , Antidepressants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3912 , http://hdl.handle.net/10962/d1003971 , Tryptophan -- Physiological effect , Tryptophan -- Therapeutic use , Antidepressants
- Description: Tryptophan is an essential amino acid that is obtained from the diet. Approximately 98 % of ingested tryptophan is metabolized by the enzyme tryptophan 2,3-dioxygenase (TDO). The metabolism of tryptophan by TDO is an important determinant of tryptophan bioavailability to the brain for serotonin (5-HT) biosynthesis, an essential amine in affective disorders such as depression. Studies done on circadian rhythmicity of the enzyme activity have shown that, TDO activity is high during the scoto-phase (dark-phase), which is attributable to the de novo enzyme synthesis that occurs during this phase. 6-Methoxy-2-benzoxazolinontr-(6-MBOA), a structural analogue of melatonin (aMT) was shown to inhibit TDO activity in both the photo-phase (light-phase) and the scoto-phase with greater potency during the light-phase. Further studies were directed at demonstrating the effects of 6-MBOA on the brain tryptophan hydroxylase (TH) activity, which is a rate limiting enzyme in 5-HT biosynthesis and subsequently on 5-HT levels. The findings showed that, 6-MBOA induces TH activity with a concomitant rise in brain 5-HT levels. The blockade of 5-HT re-uptake into the presynaptic neuron leads to an increase in 5-HT available for the stimulatory action of 5-HT receptors. An attempt to establish whether the administration of 6-MBOA would block the binding of 5-HT to receptors on the synaptosomal membrane showed that 6-MBO A only inhibits the binding of 5 -HT at specific concentrations. In view of the positive effects imposed by 6-MBOA on brain 5-HT levels, urinary 5-hydroxyindole acetic acid (5-HIAA) excretion was measured before and after treatment with 6-MBOA. 5-HIAA excretion was found to be significantly increased after 6-MBOA treatment. Extensive research on the biosynthesis of pineal metabolites has been conducted in the past two decades. The pineal metabolites are synthesized from the precursor tryptophan. In order to obtain an overall picture of the effect of6-MBOA on pineal indole metabolism, an organ culture technique was employed. The results obtained showed that although 6-MBOA administration to rats caused a significant increase in aMT production, there was an insignificant increase in NAS production. This is an immediate precursor of aMT. Other pineal indoles were not affected at all by 6-MBOA administration. Furthermore, the production of pineal NAS and aMT showed an inter-individual variation with some animals producing very high, some very low and some produced average levels of these two metabolites in both photo and scoto-phase experiments. A study undertaken to investigate the circadian rhythm in endogenous aMT production using the competitive ELISA technique showed a clear pattern with high levels of aMT produced during the dark-phase and low levels ofaMT produced during the light-phase. Furthermore, the administration of6-MBOA to rats lead to a significant rise in endogenous aMT production.
- Full Text:
- Date Issued: 2000
The effect of load carriage on selected metabolic and perceptual responses of military personnel
- Authors: Ramabhai, Leena I
- Date: 2000
- Subjects: Marching -- Physiological aspects , Military art and science , Marching -- Psychological aspects , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5111 , http://hdl.handle.net/10962/d1005189
- Description: Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.
- Full Text:
- Date Issued: 2000
- Authors: Ramabhai, Leena I
- Date: 2000
- Subjects: Marching -- Physiological aspects , Military art and science , Marching -- Psychological aspects , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5111 , http://hdl.handle.net/10962/d1005189
- Description: Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.
- Full Text:
- Date Issued: 2000
The evolution of the Brosterlea Volcanic Complex, Eastern Cape, South Africa
- Authors: Surtees, Grant Bradley
- Date: 2000
- Subjects: Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4944 , http://hdl.handle.net/10962/d1005556 , Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Description: Detailed field mapping (Map, Appendix B) has been conducted in and around the boundaries of a 14x18km, volcanic complex 35km northeast of Molteno in the Eastern Cape Province, South Africa. The structure is interpreted as a subsidence structure, and is filled with two volcaniclastic breccias, numerous lava flows, a number of sedimentary facies, and lies on a base of Clarens Formation overlying Elliot Formation rocks. This is an important study because 'widespread, voluminous fields of basaltic breccias are very rare (see Hanson and Elliot, 1996) and this is the first time that this type of volcanic complex and its deposits have been described. Detailed analyses of the two volcaniclastic breccias revealed changes in colour, clast types, clast sizes, and degree of alteration over relatively short distances both vertically and laterally within a single breccia unit. The variation in clast sizes implies a lack of sorting of the breccias. The lower of the two volcaniclastic breccias fills the subsidence structure, and outcrops between the Stormberg sedimentary sequence and the overlying Drakensberg basalts and was produced from phreatomagmatic eruptions signalling the start of the break-up of Gondwanaland in the mid-Jurassic. The upper volcaniclastic breccia is interbedded with the flood basalts and is separated from the lower breccia by up to 100m of lava flows in places, it is finer-grained than the lower volcaniclastic breccia, and it extends over 10km south, and over 100km north from the volcanic complex. The upper breccia is inferred to have been transported from outside the study area, from a source presumably similar to the subsidence structure in the volcanic complex. The pyroclastic material forming the upper breccia was transported to the subsidence structure as a laharic debris flow, based on its poorly sorted, unwelded and matrix-supported appearance. However, both breccias are unlikely to have been derived from epiclastic reworking of lava flows as they contain glass shards which are atypical of those derived from the autoclastic component of lava flows. The breccias are therefore not "secondary" lahars. There is also no evidence of any palaeotopographic highs from which the breccias could have been derived as gravity-driven flows. Based on the occurrence of three, 1m thick lacustrine deposits, localised peperite, fluvial reworking of sandstone and breccia in an outcrop to the south of the subsidence structure, and channel-lags encountered only in the upper units of the Clarens Formation and only within the subsidence structure, the palaeoenvironment inferred for the subsidence structure is one of wet sediment, possibly a shallow lake, in a topographic depression fed by small streams. Magmatic intrusions below the subsidence structure heated the water-laden, partly consolidated Clarens Formation sandstones, causing the circulation of pore fluid which resulted in the precipitation of minerals forming pisoliths in the sandstones. Intruding magma mixed, nonexplosively, with the wet, unconsolidated sediments near the base of the Clarens Formation (at approximately 100m below the surface), forming fluidal peperite by a process of sediment fluidisation where magma replaces wet sediment and cools slowly enough to prevent the magma fracturing brittly. Formation of fluidal peperite may have been a precursor to the development of FCIs (Fuel Coolant Interactions) (Busby-Spera and White, 1987). The breccias may represent the products of FCIs and may be the erupted equivalents of the peperites, suggesting a possible genetic link between the two. The peperites may have given way to FCI eruptions due to a number of factors including the drying out of the sediments and/or an increase in the volume of intruded magma below the subsidence structure which may have resulted in a more explosive interaction between sediment and magma. Phreatic activity fragmented and erupted the Clarens Formation sandstone, and stream flows reworked the angular sandstone fragments, pisoliths and sand grains into channelised deposits. With an increase in magmatic activity below the subsidence structure, phreatic activity became phreatomagmatic. The wet, partly consolidated Clarens Formation, and underlying, fully consolidated Elliot Formation sediments were erupted and fragmented. Clasts and individual grains of these sediments were redeposited with juvenile and non-juvenile basaltic material probably by a combination of back fall, where clasts erupted into the air fell directly back into the structure, and backflow where material was erupted out of the structure, but immediately flowed back in as lahars. This material formed the lower volcaniclastic breccia. A fault plane is identified along the southwestern margin of the subsidence structure, and is believed to continue up the western margin to the northwestern corner. A large dolerite body has intruded along the inferred fault plane on the western margin of the structure, and may be related to the formation of the lower volcaniclastic breccia, either directly through fluidisation of wet sediment during its intrusion, or as a dyke extending upwards from a network of sill-like intrusions below the subsidence structure. Geochemical analysis of the Drakensberg basalt lava flows by Mitchell (1980) and Masokwane (1997) revealed four distinct basalt types; the Moshesh's Ford, the Tafelkop, the Roodehoek, and the Vaalkop basalts. Basalt clasts sampled from the lower volcaniclastic breccia were shown to belong to the Moshesh's Ford basalt type which does not outcrop in situ within the subsidence structure. This implies that the Moshesh's Ford basalts were emplaced prior to the formation of the lower volcaniclastic breccia, and may have acted as a "cap-rock" over the system, allowing pressure from the vaporised fluids, heated by intruding basalt, to build up. The Moshesh's Ford basalt type was erupted prior to the resultant phreatomagmatic events forming the lower volcaniclastic breccia.
- Full Text:
- Date Issued: 2000
- Authors: Surtees, Grant Bradley
- Date: 2000
- Subjects: Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4944 , http://hdl.handle.net/10962/d1005556 , Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Description: Detailed field mapping (Map, Appendix B) has been conducted in and around the boundaries of a 14x18km, volcanic complex 35km northeast of Molteno in the Eastern Cape Province, South Africa. The structure is interpreted as a subsidence structure, and is filled with two volcaniclastic breccias, numerous lava flows, a number of sedimentary facies, and lies on a base of Clarens Formation overlying Elliot Formation rocks. This is an important study because 'widespread, voluminous fields of basaltic breccias are very rare (see Hanson and Elliot, 1996) and this is the first time that this type of volcanic complex and its deposits have been described. Detailed analyses of the two volcaniclastic breccias revealed changes in colour, clast types, clast sizes, and degree of alteration over relatively short distances both vertically and laterally within a single breccia unit. The variation in clast sizes implies a lack of sorting of the breccias. The lower of the two volcaniclastic breccias fills the subsidence structure, and outcrops between the Stormberg sedimentary sequence and the overlying Drakensberg basalts and was produced from phreatomagmatic eruptions signalling the start of the break-up of Gondwanaland in the mid-Jurassic. The upper volcaniclastic breccia is interbedded with the flood basalts and is separated from the lower breccia by up to 100m of lava flows in places, it is finer-grained than the lower volcaniclastic breccia, and it extends over 10km south, and over 100km north from the volcanic complex. The upper breccia is inferred to have been transported from outside the study area, from a source presumably similar to the subsidence structure in the volcanic complex. The pyroclastic material forming the upper breccia was transported to the subsidence structure as a laharic debris flow, based on its poorly sorted, unwelded and matrix-supported appearance. However, both breccias are unlikely to have been derived from epiclastic reworking of lava flows as they contain glass shards which are atypical of those derived from the autoclastic component of lava flows. The breccias are therefore not "secondary" lahars. There is also no evidence of any palaeotopographic highs from which the breccias could have been derived as gravity-driven flows. Based on the occurrence of three, 1m thick lacustrine deposits, localised peperite, fluvial reworking of sandstone and breccia in an outcrop to the south of the subsidence structure, and channel-lags encountered only in the upper units of the Clarens Formation and only within the subsidence structure, the palaeoenvironment inferred for the subsidence structure is one of wet sediment, possibly a shallow lake, in a topographic depression fed by small streams. Magmatic intrusions below the subsidence structure heated the water-laden, partly consolidated Clarens Formation sandstones, causing the circulation of pore fluid which resulted in the precipitation of minerals forming pisoliths in the sandstones. Intruding magma mixed, nonexplosively, with the wet, unconsolidated sediments near the base of the Clarens Formation (at approximately 100m below the surface), forming fluidal peperite by a process of sediment fluidisation where magma replaces wet sediment and cools slowly enough to prevent the magma fracturing brittly. Formation of fluidal peperite may have been a precursor to the development of FCIs (Fuel Coolant Interactions) (Busby-Spera and White, 1987). The breccias may represent the products of FCIs and may be the erupted equivalents of the peperites, suggesting a possible genetic link between the two. The peperites may have given way to FCI eruptions due to a number of factors including the drying out of the sediments and/or an increase in the volume of intruded magma below the subsidence structure which may have resulted in a more explosive interaction between sediment and magma. Phreatic activity fragmented and erupted the Clarens Formation sandstone, and stream flows reworked the angular sandstone fragments, pisoliths and sand grains into channelised deposits. With an increase in magmatic activity below the subsidence structure, phreatic activity became phreatomagmatic. The wet, partly consolidated Clarens Formation, and underlying, fully consolidated Elliot Formation sediments were erupted and fragmented. Clasts and individual grains of these sediments were redeposited with juvenile and non-juvenile basaltic material probably by a combination of back fall, where clasts erupted into the air fell directly back into the structure, and backflow where material was erupted out of the structure, but immediately flowed back in as lahars. This material formed the lower volcaniclastic breccia. A fault plane is identified along the southwestern margin of the subsidence structure, and is believed to continue up the western margin to the northwestern corner. A large dolerite body has intruded along the inferred fault plane on the western margin of the structure, and may be related to the formation of the lower volcaniclastic breccia, either directly through fluidisation of wet sediment during its intrusion, or as a dyke extending upwards from a network of sill-like intrusions below the subsidence structure. Geochemical analysis of the Drakensberg basalt lava flows by Mitchell (1980) and Masokwane (1997) revealed four distinct basalt types; the Moshesh's Ford, the Tafelkop, the Roodehoek, and the Vaalkop basalts. Basalt clasts sampled from the lower volcaniclastic breccia were shown to belong to the Moshesh's Ford basalt type which does not outcrop in situ within the subsidence structure. This implies that the Moshesh's Ford basalts were emplaced prior to the formation of the lower volcaniclastic breccia, and may have acted as a "cap-rock" over the system, allowing pressure from the vaporised fluids, heated by intruding basalt, to build up. The Moshesh's Ford basalt type was erupted prior to the resultant phreatomagmatic events forming the lower volcaniclastic breccia.
- Full Text:
- Date Issued: 2000
The experience of multi-cultural communication within a South African organization
- Authors: Lesch, Anthea M
- Date: 2000
- Subjects: Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3008 , http://hdl.handle.net/10962/d1002517 , Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Description: This research study was conducted in an attempt to explore the experience of multicultural communication within a South African organization. To this end employees, representing both Black and White culture, within a South African organization in the throes of transformation, were accessed. A model of managing diversity, focussing on the personal, interpersonal and organizational levels, was utilized in an attempt to uncover the nature of the experience of multi-cultural communication within Company X. A qualitative research design, and more specifically the case study method was employed in this study. Consistent with the case study approach a number of data sources were accessed. The primary data source consisted of a 3-stage interview process. Other data sources included documentary sources and company publications. By accessing multiple data sources, the researcher attempted to gain a holistic understanding of the experience of multi-cultural communication. It was found that the societal context of our post-Apartheid society exercises a profound influence on multi-cultural communication. Under Apartheid cultural separation was promoted. Diverse peoples thus have little common basis for interaction and view each other with skepticism and distrust. This exercises an effect on the personal and organizational levels of the managing diversity model. Influences at the personal level relate to the cultural paradigms of the individuals which provide the rules governing interactions and affect judgements of acceptable and unacceptable behaviours. Issues at the organizational level relate to its structures and policies which are still based on the “white is right ideology”. These issues, in turn, affect the interpersonal level of managing diversity, i.e., where the interactions occur, causing “communication short circuits” within the process of multi-cultural communication. In order to deal with failed multi-cultural communication, the individuals have developed a number of coping strategies. The results of the study indicate that both the organization and its employees share a responsibility for creating an environment that will facilitate effective multi-cultural communication.
- Full Text:
- Date Issued: 2000
- Authors: Lesch, Anthea M
- Date: 2000
- Subjects: Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3008 , http://hdl.handle.net/10962/d1002517 , Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Description: This research study was conducted in an attempt to explore the experience of multicultural communication within a South African organization. To this end employees, representing both Black and White culture, within a South African organization in the throes of transformation, were accessed. A model of managing diversity, focussing on the personal, interpersonal and organizational levels, was utilized in an attempt to uncover the nature of the experience of multi-cultural communication within Company X. A qualitative research design, and more specifically the case study method was employed in this study. Consistent with the case study approach a number of data sources were accessed. The primary data source consisted of a 3-stage interview process. Other data sources included documentary sources and company publications. By accessing multiple data sources, the researcher attempted to gain a holistic understanding of the experience of multi-cultural communication. It was found that the societal context of our post-Apartheid society exercises a profound influence on multi-cultural communication. Under Apartheid cultural separation was promoted. Diverse peoples thus have little common basis for interaction and view each other with skepticism and distrust. This exercises an effect on the personal and organizational levels of the managing diversity model. Influences at the personal level relate to the cultural paradigms of the individuals which provide the rules governing interactions and affect judgements of acceptable and unacceptable behaviours. Issues at the organizational level relate to its structures and policies which are still based on the “white is right ideology”. These issues, in turn, affect the interpersonal level of managing diversity, i.e., where the interactions occur, causing “communication short circuits” within the process of multi-cultural communication. In order to deal with failed multi-cultural communication, the individuals have developed a number of coping strategies. The results of the study indicate that both the organization and its employees share a responsibility for creating an environment that will facilitate effective multi-cultural communication.
- Full Text:
- Date Issued: 2000
The geomorphological impacts of impoundments, with particular reference to tributary bar development on the Keiskamma River, Eastern Cape
- Authors: McGregor, Gillian Kathleen
- Date: 2000
- Subjects: Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4835 , http://hdl.handle.net/10962/d1005510 , Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Description: The primary aim of this research was to develop and test a conceptual model of the geomorphological impacts of river regulation, based on a review of relevant international literature. It was motivated by the fact that there is very little local information on the topic, and it was intended that the model might provide a starting point for assessing the impact of impoundments on South African river systems. At present most research in South Africa on the impact of impoundments is undertaken from an ecological perspective. In order to manage our water resources sustainably it is necessary to have a better understanding of our river systems. South Africa is characterised by a variable climatic regime and, in order to supply water to the various user sectors of the nation, dams have to be larger than elsewhere in the world, to trap most of the mean annual runoff and provide a reliable water store (Alexander, 1985). South African dams have been designed to reduce the variability of a naturally variable regime. The impact of flow regulation in dryland rivers has been described as 'ecologically catastrophic at every level.' It is therefore hardly surprising that the impact of these dams on the natural functioning of rivers is substantial. The conceptual model showed that there are many responses to river impoundment, which are varied and complex, both in time and space. Responses or secondary impacts depended on the nature and degree of the primary impact or process alteration, on the sediment and flow regime of the river. High flows were affected in all cases and low flows were affected in most cases. The simplest form of change was Petts' (1979) concept of 'accommodation' of the regulated flow within the existing channel form. More complex responses occUrred where the channel perimeter was unstable, or where tributaries introduced fresh sediment loads. The river could adjust its long profile, cross sectional area and substrate composition by aggradation or degradation. The conceptual model was used in the Building Block Methodology to predict impoundment impacts at Instream Flow Requirement workshops on the Berg, Komati and Bivane rivers. It was also used in assessing the impact of the Sandile Dam on the Keiskamma river. Tributary junctions were identified as likely sites of change, and the morphology of bars at these junctions was investigated. Due to the number of variables affecting the sediment and flow regime in the system, and due to the fact that the primary impacts were not substantial, it was not possible to come to any decisive conclusions. It would seem that the dam is well located in the catchment, and, because the water is not heavily utilised, the secondary impacts are not great. The conceptual model was found to be a useful basic tool which might contribute to a better understanding of our river systems, and ultimately to improved sustainable resource management.
- Full Text:
- Date Issued: 2000
- Authors: McGregor, Gillian Kathleen
- Date: 2000
- Subjects: Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4835 , http://hdl.handle.net/10962/d1005510 , Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Description: The primary aim of this research was to develop and test a conceptual model of the geomorphological impacts of river regulation, based on a review of relevant international literature. It was motivated by the fact that there is very little local information on the topic, and it was intended that the model might provide a starting point for assessing the impact of impoundments on South African river systems. At present most research in South Africa on the impact of impoundments is undertaken from an ecological perspective. In order to manage our water resources sustainably it is necessary to have a better understanding of our river systems. South Africa is characterised by a variable climatic regime and, in order to supply water to the various user sectors of the nation, dams have to be larger than elsewhere in the world, to trap most of the mean annual runoff and provide a reliable water store (Alexander, 1985). South African dams have been designed to reduce the variability of a naturally variable regime. The impact of flow regulation in dryland rivers has been described as 'ecologically catastrophic at every level.' It is therefore hardly surprising that the impact of these dams on the natural functioning of rivers is substantial. The conceptual model showed that there are many responses to river impoundment, which are varied and complex, both in time and space. Responses or secondary impacts depended on the nature and degree of the primary impact or process alteration, on the sediment and flow regime of the river. High flows were affected in all cases and low flows were affected in most cases. The simplest form of change was Petts' (1979) concept of 'accommodation' of the regulated flow within the existing channel form. More complex responses occUrred where the channel perimeter was unstable, or where tributaries introduced fresh sediment loads. The river could adjust its long profile, cross sectional area and substrate composition by aggradation or degradation. The conceptual model was used in the Building Block Methodology to predict impoundment impacts at Instream Flow Requirement workshops on the Berg, Komati and Bivane rivers. It was also used in assessing the impact of the Sandile Dam on the Keiskamma river. Tributary junctions were identified as likely sites of change, and the morphology of bars at these junctions was investigated. Due to the number of variables affecting the sediment and flow regime in the system, and due to the fact that the primary impacts were not substantial, it was not possible to come to any decisive conclusions. It would seem that the dam is well located in the catchment, and, because the water is not heavily utilised, the secondary impacts are not great. The conceptual model was found to be a useful basic tool which might contribute to a better understanding of our river systems, and ultimately to improved sustainable resource management.
- Full Text:
- Date Issued: 2000
The implementation of a core architecture for geophysical data acquisition
- Authors: Heasman, Ray Edward
- Date: 2000
- Subjects: Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5471 , http://hdl.handle.net/10962/d1005256 , Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Description: This thesis describes the design, development and implementation of the core hardware and software of a modular data acquisition system for geophysical data collection. The primary application for this system is the acquisition and realtime processing of seismic data captured in mines. This system will be used by a commercial supplier of seismic instrumentation, ISS International, as a base architecture for the development of future products. The hardware and software has been designed to be extendable and support distributed processing. The IEEE-1394 High Performance Serial Bus is used to communicate with other CPU modules or peripherals. The software includes a pre-emptive multitasking microkernel, an asynchronous mailbox-based message passing communications system, and a functional IEEE-1394 protocol stack. The reasons for the end design and implementation decisions are given, and the problems encountered in the development of this system are described. A critical assessment of the match between the requirements for the project and the functionality of the implementation is made.
- Full Text:
- Date Issued: 2000
- Authors: Heasman, Ray Edward
- Date: 2000
- Subjects: Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5471 , http://hdl.handle.net/10962/d1005256 , Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Description: This thesis describes the design, development and implementation of the core hardware and software of a modular data acquisition system for geophysical data collection. The primary application for this system is the acquisition and realtime processing of seismic data captured in mines. This system will be used by a commercial supplier of seismic instrumentation, ISS International, as a base architecture for the development of future products. The hardware and software has been designed to be extendable and support distributed processing. The IEEE-1394 High Performance Serial Bus is used to communicate with other CPU modules or peripherals. The software includes a pre-emptive multitasking microkernel, an asynchronous mailbox-based message passing communications system, and a functional IEEE-1394 protocol stack. The reasons for the end design and implementation decisions are given, and the problems encountered in the development of this system are described. A critical assessment of the match between the requirements for the project and the functionality of the implementation is made.
- Full Text:
- Date Issued: 2000
The implications of the introduction of outcomes based education in the natural sciences curriculum at Cape College of Education: the assessment of perceptions of squatter camp teachers in Khayelitsha towards the outcomes based education
- Authors: Booi, Kwanele
- Date: 2000
- Subjects: Competency-based education -- South Africa Competency-based education -- Evaluation Competency-based education -- South Africa -- Khayelitsha -- Evaluation Physical sciences -- Study and teaching -- Evaluation Life sciences -- Study and teaching -- Evaluation Cape College of Education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1569 , http://hdl.handle.net/10962/d1003451
- Description: 1. This pilot study is a survey of practices of natural sciences educators at Cape College of Education to establish if they reflect the conceptual development, development of skills, change of attitudes and values that are the pillars of the Outcomes Based Education (OBE). Their approaches of lecturing have been assessed to determine if they incorporate investigative approaches based on social constructivism, the theory underpinning Curriculum 2005. The status of science education in the college has been analyzed to establish whether the curriculum can adapt itself to the specifications of the new curriculum. It has been concluded that the educators at Cape College of Education need to be empowered about strategies that will help them function along the principles embracing Curriculum 2005 specifications. The educators have shown not to be ready to practice social constructivism and the assessment strategies incorporated in their programmes do not embrace a variety of approaches that will enable their learners to develop conceptually, skill wise and enable them to develop change in attitudes and values. Investigative approaches to practical work appear to be lacking in the college teaching/learning and this also indicates that Curriculum 2005 will take time to be properly implemented at Cape College of Education. 2. This study is based on the practices of science educators in the squatter-camp school in Khayelitsha, a densely populated area for blacks near Cape Town. Teachers at Vuselela primary school were interviewed about their teaching assessment strategies to establish whether they incorporate a learner centred approach, which is the necessity for the Outcomes Based Education approach. Also some of the lessons they taught were observed in order to find out whether they validate what transpired from the interviews through a process of triangulation. It has become evident that the teachers are to some extent aware of the changes the education system is going through in South Africa. It also became clear from the study that the teachers are still lacking expertise as to how to practice along the lines of Curriculum 2005, the South African version of Outcomes Based Education (OBE). They also showed that they are keen to learn and practice OBE even though more opportunities need to be created for their epistemological empowerment as well as empowerment on the content of science.
- Full Text:
- Date Issued: 2000
- Authors: Booi, Kwanele
- Date: 2000
- Subjects: Competency-based education -- South Africa Competency-based education -- Evaluation Competency-based education -- South Africa -- Khayelitsha -- Evaluation Physical sciences -- Study and teaching -- Evaluation Life sciences -- Study and teaching -- Evaluation Cape College of Education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1569 , http://hdl.handle.net/10962/d1003451
- Description: 1. This pilot study is a survey of practices of natural sciences educators at Cape College of Education to establish if they reflect the conceptual development, development of skills, change of attitudes and values that are the pillars of the Outcomes Based Education (OBE). Their approaches of lecturing have been assessed to determine if they incorporate investigative approaches based on social constructivism, the theory underpinning Curriculum 2005. The status of science education in the college has been analyzed to establish whether the curriculum can adapt itself to the specifications of the new curriculum. It has been concluded that the educators at Cape College of Education need to be empowered about strategies that will help them function along the principles embracing Curriculum 2005 specifications. The educators have shown not to be ready to practice social constructivism and the assessment strategies incorporated in their programmes do not embrace a variety of approaches that will enable their learners to develop conceptually, skill wise and enable them to develop change in attitudes and values. Investigative approaches to practical work appear to be lacking in the college teaching/learning and this also indicates that Curriculum 2005 will take time to be properly implemented at Cape College of Education. 2. This study is based on the practices of science educators in the squatter-camp school in Khayelitsha, a densely populated area for blacks near Cape Town. Teachers at Vuselela primary school were interviewed about their teaching assessment strategies to establish whether they incorporate a learner centred approach, which is the necessity for the Outcomes Based Education approach. Also some of the lessons they taught were observed in order to find out whether they validate what transpired from the interviews through a process of triangulation. It has become evident that the teachers are to some extent aware of the changes the education system is going through in South Africa. It also became clear from the study that the teachers are still lacking expertise as to how to practice along the lines of Curriculum 2005, the South African version of Outcomes Based Education (OBE). They also showed that they are keen to learn and practice OBE even though more opportunities need to be created for their epistemological empowerment as well as empowerment on the content of science.
- Full Text:
- Date Issued: 2000
The interpretation of ABET placement tests in the recognition of prior learning
- Authors: Blunt, Sandra Viki
- Date: 2000
- Subjects: English language -- Ability testing , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1582 , http://hdl.handle.net/10962/d1003464
- Description: This thesis analyses the way in which placement testing is being interpreted in Adult Basic Education and Training (ABET). The thesis examines whether the placement tests used in the case study were valid in terms of whether their contents were relevant and authentic with regard to what English second language speakers could reasonably be expected to know. Adult learners have differing English second language knowledge depending on the different contexts in which they have learned their second language. This thesis investigates the implications of the different contexts and different language needs of adult learners for the testing of English as a second language for placement purposes in ABET programmes. The thesis examined two placement tests to determine how the recognition of prior second language learning was being interpreted and how the interpretation affected the validity of the tests. Learners= perceptions of the assessment process and test content were elicited in order to determine whether a policy of transparency had been followed in the implementation of the assessment. It was also established what the goals of the organisation were in implementing an ABET programme. This research suggests that placement testing should be viewed holistically; in other words, the goals of the organisation and the level of transparency affect the validity of the placement test. The conclusions were that the placement tests were inauthentic since their contents excluded certain vital aspects of real life performance, namely, that related to the work context. The research revealed that if the placement testing process and the ABET programme are integrated into the culture of the organisation and if employees are remunerated when they have passed the different levels in the programme, the programme is likely to achieve a fair measure of success. Recommendations are that literacy should be viewed as based on a variety of contexts and uses and that therefore tests should be tailored to suit each particular organisation and should contain workrelated content. Furthermore, multiple methods of assessment should be considered.
- Full Text:
- Date Issued: 2000
- Authors: Blunt, Sandra Viki
- Date: 2000
- Subjects: English language -- Ability testing , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1582 , http://hdl.handle.net/10962/d1003464
- Description: This thesis analyses the way in which placement testing is being interpreted in Adult Basic Education and Training (ABET). The thesis examines whether the placement tests used in the case study were valid in terms of whether their contents were relevant and authentic with regard to what English second language speakers could reasonably be expected to know. Adult learners have differing English second language knowledge depending on the different contexts in which they have learned their second language. This thesis investigates the implications of the different contexts and different language needs of adult learners for the testing of English as a second language for placement purposes in ABET programmes. The thesis examined two placement tests to determine how the recognition of prior second language learning was being interpreted and how the interpretation affected the validity of the tests. Learners= perceptions of the assessment process and test content were elicited in order to determine whether a policy of transparency had been followed in the implementation of the assessment. It was also established what the goals of the organisation were in implementing an ABET programme. This research suggests that placement testing should be viewed holistically; in other words, the goals of the organisation and the level of transparency affect the validity of the placement test. The conclusions were that the placement tests were inauthentic since their contents excluded certain vital aspects of real life performance, namely, that related to the work context. The research revealed that if the placement testing process and the ABET programme are integrated into the culture of the organisation and if employees are remunerated when they have passed the different levels in the programme, the programme is likely to achieve a fair measure of success. Recommendations are that literacy should be viewed as based on a variety of contexts and uses and that therefore tests should be tailored to suit each particular organisation and should contain workrelated content. Furthermore, multiple methods of assessment should be considered.
- Full Text:
- Date Issued: 2000
The isolation and partial characterization of a2-antiplasmin and plasminogen from ostrich plasma
- Authors: Thomas, Adele René
- Date: 2000
- Subjects: Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11080 , http://hdl.handle.net/10948/274 , http://hdl.handle.net/10948/d1005751 , Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Description: This study reports the isolation, purification and partial characterisation of the ostrich serpin, a2AP, as well as its target enzyme, ostrich plasmin, in its active and inactive proenzyme, viz. plasminogen, forms. Three different procedures were undertaken to isolate and purify ostrich a2AP. The first one involved L-lysine-Sepharose chromatography, ammonium sulfate fractionation, ion-exchange chromatography on Toyopearl Super-Q 650S, and ostrich plasminogen-Sepharose affinity chromatography. The second procedure replaced the latter chromatographic step with gel filtration on Sephadex G-200 and hydroxylapatite chromatography, while the third one employed instead the theoretically more efficient LBSI-Sepharose chromatographic step. The third procedure yielded purified ostrich a2AP, but the degree of purity and yield were relatively low. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and ostrich plasmin was obtained by the urokinase-activation of the purified ostrich plasminogen Ostrich a2AP revealed an Mr of 77-84 K and two isoelectric forms of pI 3.85 and 6.18. Nterminal sequence analysis showed ostrich a2AP to have only 2 out of 11 residues in common with both those of human and bovine a2AP. Ostrich a2AP showed the largest inhibitory effects on ostrich plasmin, followed by comm. bovine chymotrypsin, trypsin and plasmin, in that order, and it appeared to be a much less potent plasmin inhibitor than bovine aprotinin, but a much more potent one than the synthetic inhibitors, DFP and EACA. Ostrich plasminogen showed an Mr of 92 K and multiple isoelectric forms (~7) in the pI range 6.01-9.18, with a major one of pI 6.01. It showed a total of 775 amino acid residues and its N-terminal sequence showed ~53 percent identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin revealed an Mr of 78 K, two isoelectric forms of pI 4.07 and 6.01, and a total of 638 amino acid residues. N-terminal sequence analysis showed that 2-4 residues are identical to the 5 of human, cat, dog, rabbit, and ox plasmins. The pH and temperature optima of ostrich plasmin were determined as 8.0 and 40 oC, respectively. The thermodynamic and kinetic parameters of ostrich plasmin were computed, and plasmin was shown to prefer Lys to Arg residues in the S1 position. In conclusion, ostrich a2AP, plasminogen and plasmin showed definite similarities to their mammalian counterparts, but there were also significant differences.
- Full Text:
- Date Issued: 2000
- Authors: Thomas, Adele René
- Date: 2000
- Subjects: Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11080 , http://hdl.handle.net/10948/274 , http://hdl.handle.net/10948/d1005751 , Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Description: This study reports the isolation, purification and partial characterisation of the ostrich serpin, a2AP, as well as its target enzyme, ostrich plasmin, in its active and inactive proenzyme, viz. plasminogen, forms. Three different procedures were undertaken to isolate and purify ostrich a2AP. The first one involved L-lysine-Sepharose chromatography, ammonium sulfate fractionation, ion-exchange chromatography on Toyopearl Super-Q 650S, and ostrich plasminogen-Sepharose affinity chromatography. The second procedure replaced the latter chromatographic step with gel filtration on Sephadex G-200 and hydroxylapatite chromatography, while the third one employed instead the theoretically more efficient LBSI-Sepharose chromatographic step. The third procedure yielded purified ostrich a2AP, but the degree of purity and yield were relatively low. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and ostrich plasmin was obtained by the urokinase-activation of the purified ostrich plasminogen Ostrich a2AP revealed an Mr of 77-84 K and two isoelectric forms of pI 3.85 and 6.18. Nterminal sequence analysis showed ostrich a2AP to have only 2 out of 11 residues in common with both those of human and bovine a2AP. Ostrich a2AP showed the largest inhibitory effects on ostrich plasmin, followed by comm. bovine chymotrypsin, trypsin and plasmin, in that order, and it appeared to be a much less potent plasmin inhibitor than bovine aprotinin, but a much more potent one than the synthetic inhibitors, DFP and EACA. Ostrich plasminogen showed an Mr of 92 K and multiple isoelectric forms (~7) in the pI range 6.01-9.18, with a major one of pI 6.01. It showed a total of 775 amino acid residues and its N-terminal sequence showed ~53 percent identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin revealed an Mr of 78 K, two isoelectric forms of pI 4.07 and 6.01, and a total of 638 amino acid residues. N-terminal sequence analysis showed that 2-4 residues are identical to the 5 of human, cat, dog, rabbit, and ox plasmins. The pH and temperature optima of ostrich plasmin were determined as 8.0 and 40 oC, respectively. The thermodynamic and kinetic parameters of ostrich plasmin were computed, and plasmin was shown to prefer Lys to Arg residues in the S1 position. In conclusion, ostrich a2AP, plasminogen and plasmin showed definite similarities to their mammalian counterparts, but there were also significant differences.
- Full Text:
- Date Issued: 2000
The measurement of genetic diversity in mycobacterium tuberculosis using random amplified polymorphic DNA profiling
- Authors: Richner, Sharon M
- Date: 2000
- Subjects: Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4008 , http://hdl.handle.net/10962/d1004068 , Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis has caused a resurgence in pulmonary disease in both developed and developing countries in recent times, particularly amongst people infected with the human immunodeficiency virus. The disease has assumed epidemic proportions in South Africa and in the Eastern Cape Province in particular. Of further concern is the isolation of increasing numbers of multiply drug resistant strains. Knowledge of the genetic capability of this organism is essential for the successful development of novel antibiotics and vaccines in an attempt to bring the global pandemic under control. Measurement of the genetic diversity of the organism may significantly contribute to such knowledge, and is of vital importance in monitoring epidemics and in improving treatment and control of the disease. This will entail answering a number of questions related to the degree of genetic diversity amongst strains, to the difference between urban and rural strains, and between drug resistant and drug sensitive strains, and to the geographical distribution of strains. In order to establish such baseline information, RAPD profiling of a large population of isolates from the western and central regions of the Eastern Cape Province was undertaken. A smaller number of drug resistant strains from a small area of KwaZulu-Natal were also analysed, with a view to establishing the genetic difference between strains from the two provinces. Cluster analysis, analysis of molecular variance and Geographical Information Systems technology were used to analyse the RAPD profiles generated. An unexpectedly high degree of genetic diversity was detected in strains from both provinces. While no correlation was seen between genetic diversity and either urban-rural situation or geographical location, a small degree of population structure could be correlated with drug resistance in the Eastern Cape. Furthermore, a significant degree of population structure was detected between strains from the two provinces, although this was still within the parameters for conspecific populations. Future work is necessary to further characterise strains from rural areas of both provinces, as well as from the eastern region of the Eastern Cape in an attempt to pinpoint the cause of the separation of the provincial populations.
- Full Text:
- Date Issued: 2000
- Authors: Richner, Sharon M
- Date: 2000
- Subjects: Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4008 , http://hdl.handle.net/10962/d1004068 , Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis has caused a resurgence in pulmonary disease in both developed and developing countries in recent times, particularly amongst people infected with the human immunodeficiency virus. The disease has assumed epidemic proportions in South Africa and in the Eastern Cape Province in particular. Of further concern is the isolation of increasing numbers of multiply drug resistant strains. Knowledge of the genetic capability of this organism is essential for the successful development of novel antibiotics and vaccines in an attempt to bring the global pandemic under control. Measurement of the genetic diversity of the organism may significantly contribute to such knowledge, and is of vital importance in monitoring epidemics and in improving treatment and control of the disease. This will entail answering a number of questions related to the degree of genetic diversity amongst strains, to the difference between urban and rural strains, and between drug resistant and drug sensitive strains, and to the geographical distribution of strains. In order to establish such baseline information, RAPD profiling of a large population of isolates from the western and central regions of the Eastern Cape Province was undertaken. A smaller number of drug resistant strains from a small area of KwaZulu-Natal were also analysed, with a view to establishing the genetic difference between strains from the two provinces. Cluster analysis, analysis of molecular variance and Geographical Information Systems technology were used to analyse the RAPD profiles generated. An unexpectedly high degree of genetic diversity was detected in strains from both provinces. While no correlation was seen between genetic diversity and either urban-rural situation or geographical location, a small degree of population structure could be correlated with drug resistance in the Eastern Cape. Furthermore, a significant degree of population structure was detected between strains from the two provinces, although this was still within the parameters for conspecific populations. Future work is necessary to further characterise strains from rural areas of both provinces, as well as from the eastern region of the Eastern Cape in an attempt to pinpoint the cause of the separation of the provincial populations.
- Full Text:
- Date Issued: 2000
The nature and control of organic compounds in soda ash evaporate production
- Masemola, Patricia Mmoniemang
- Authors: Masemola, Patricia Mmoniemang
- Date: 2000
- Subjects: Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3902 , http://hdl.handle.net/10962/d1003961 , Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Description: Solar evaporite systems are man-managed ecosystems which are highly vulnerable to biological,physical and chemical disturbances. The problems encountered in such systems are in many cases found to be associated with the microbial ecology and the design of the system. This project focussed on investigating the nature of organic compounds contaminating soda ash produced at a solar evaporite production system located at Sua Pan in Botswana. Several years after the plant was commissioned, problems, including accumulation of total organic carbon (TOC) and discolouration of the soda ash product were encountered. The salt produced also retained high moisture content and was coloured pink. These phenomena impacted severely on the economic performance of the enterprise. This study was aimed at determining the origin and fate of these organic compounds within the system in order to elucidate the nature of the problem and also to conceptualise a remediation strategy suitable to reducing its impact. This was achieved by analysis of both dialysed and solvent extracts of the influent brine (well-brine), brine in the ponds (T-brine) and the bicarbonate filter cake. Although complete identification of the organic compounds isolated was not undertaken in this study, spectroscopic analysis of compounds isolated, by UV, IR, NMR and MS, strongly indicated that fulvic acids, a component of the influent well-brine organics, contribute to the organic contamination of the final product. Part of this component, however, is degraded during the ponding process. It was shown that an extracellular polysaccharide (EPS) produced by Dunaliella. spp., which proliferates in the evaporation ponds, contributes in a major way to the accumulation of TOC in the system. This was demonstrated by relating the sugar profile of carbohydrates isolated from the pond brine and final product, being arabinose, xylose, 2-o-methyl hexose, mannose, glucose and galactose. Studies reported show that EPS production was enhanced when algal cultures were exposed to stress conditions of high illumination, increasing salinity and temperature, and nitrogen limitation. Studies undertaken for the development of a remediation process for this system have shown that nutrient stripping and bacterial systems could be applied to deal with the dissolved TOC fraction, whereas adsorption systems could deal with the particulate fractions. Algal systems showed most potential for the removal of nutrients in the influent well-brine compared to chemical processes.Complete removal of ammonium and phosphorus removal efficiencies of pproximately 50% were achieved in an unoptimised pilot-scale Dunaliella-based HRAP. While similar effects were demonstrated for chemical processes, some economic constraints were noted. The potential of halophilic bacterial systems for the degradation of organic compounds in brine was also demonstrated. The limitations on the performance of such systems, associated with the low metabolic diversity, and poor immobilisation of physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product.halobacteria, however, were noted. Although physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product. Apart from a description of the microbial ecology of the ponds and the identification of major contributions to the TOC of the final product, a number of remediation strategies were evaluated and are described. These include chemical and biological stripping of nutrients sustaining microbial TOC production in the ponds, and also biological and physico-chemical processes for their removal once formed. Future studies to undertake the further development of these proposals has been described
- Full Text:
- Date Issued: 2000
- Authors: Masemola, Patricia Mmoniemang
- Date: 2000
- Subjects: Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3902 , http://hdl.handle.net/10962/d1003961 , Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Description: Solar evaporite systems are man-managed ecosystems which are highly vulnerable to biological,physical and chemical disturbances. The problems encountered in such systems are in many cases found to be associated with the microbial ecology and the design of the system. This project focussed on investigating the nature of organic compounds contaminating soda ash produced at a solar evaporite production system located at Sua Pan in Botswana. Several years after the plant was commissioned, problems, including accumulation of total organic carbon (TOC) and discolouration of the soda ash product were encountered. The salt produced also retained high moisture content and was coloured pink. These phenomena impacted severely on the economic performance of the enterprise. This study was aimed at determining the origin and fate of these organic compounds within the system in order to elucidate the nature of the problem and also to conceptualise a remediation strategy suitable to reducing its impact. This was achieved by analysis of both dialysed and solvent extracts of the influent brine (well-brine), brine in the ponds (T-brine) and the bicarbonate filter cake. Although complete identification of the organic compounds isolated was not undertaken in this study, spectroscopic analysis of compounds isolated, by UV, IR, NMR and MS, strongly indicated that fulvic acids, a component of the influent well-brine organics, contribute to the organic contamination of the final product. Part of this component, however, is degraded during the ponding process. It was shown that an extracellular polysaccharide (EPS) produced by Dunaliella. spp., which proliferates in the evaporation ponds, contributes in a major way to the accumulation of TOC in the system. This was demonstrated by relating the sugar profile of carbohydrates isolated from the pond brine and final product, being arabinose, xylose, 2-o-methyl hexose, mannose, glucose and galactose. Studies reported show that EPS production was enhanced when algal cultures were exposed to stress conditions of high illumination, increasing salinity and temperature, and nitrogen limitation. Studies undertaken for the development of a remediation process for this system have shown that nutrient stripping and bacterial systems could be applied to deal with the dissolved TOC fraction, whereas adsorption systems could deal with the particulate fractions. Algal systems showed most potential for the removal of nutrients in the influent well-brine compared to chemical processes.Complete removal of ammonium and phosphorus removal efficiencies of pproximately 50% were achieved in an unoptimised pilot-scale Dunaliella-based HRAP. While similar effects were demonstrated for chemical processes, some economic constraints were noted. The potential of halophilic bacterial systems for the degradation of organic compounds in brine was also demonstrated. The limitations on the performance of such systems, associated with the low metabolic diversity, and poor immobilisation of physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product.halobacteria, however, were noted. Although physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product. Apart from a description of the microbial ecology of the ponds and the identification of major contributions to the TOC of the final product, a number of remediation strategies were evaluated and are described. These include chemical and biological stripping of nutrients sustaining microbial TOC production in the ponds, and also biological and physico-chemical processes for their removal once formed. Future studies to undertake the further development of these proposals has been described
- Full Text:
- Date Issued: 2000
The new initiative of the East African Cooperation : opportunities, challenges and prospects
- Authors: Kimemia, Peter Njau
- Date: 2000 , 2013-04-25
- Subjects: International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1041 , http://hdl.handle.net/10962/d1004743 , International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Description: The landmark inauguration of the East African Cooperation (EAC) on 14 March 1996 brought to the fore some key issues regarding regional economic integration in East Africa, particularly since it signalled the second attempt by Kenya, Uganda and Tanzania to form a regional economic bloc. The EAC's predecessor, the East African Community, had collapsed in 1977 in acrimonious circumstances. Prominent among the issues that led to the collapse of the East African Community was the perception of unequal gains from the integration scheme, with Uganda and Tanzania considering that disproportionate benefits were accruing to Kenya at their expense. With the new initiative, the question emerges as to whether the problems that caused the collapse of the Community will not beset the EAC and subject it to a similar fate. In an attempt to address this question, this study considers some of the theoretical issues relating to regional economic integration among countries at different levels of development, and attempts to provide an analysis of the new initiative of the EAC in the light of this theory and the history of the East African Community. The study also critically examines the objectives of the EAC and the integration strategy adopted by the three countries, and offers suggestions on the way forward. Among the arguments made in this thesis are that, contrary to the suggestions of orthodox static analysis, if the dynamic effects of integration are considered, then there may be important gains which may accrue to integrating states in the developing country context. It is also argued that different levels of development among integrating states need not necessarily be an impediment to economic integration. The study finds that, in spite of the enormous challenges facing the EAC, member states may be better off within the integration scheme than if they acted as individual units in a rapidly globalizing international system.
- Full Text:
- Date Issued: 2000
- Authors: Kimemia, Peter Njau
- Date: 2000 , 2013-04-25
- Subjects: International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1041 , http://hdl.handle.net/10962/d1004743 , International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Description: The landmark inauguration of the East African Cooperation (EAC) on 14 March 1996 brought to the fore some key issues regarding regional economic integration in East Africa, particularly since it signalled the second attempt by Kenya, Uganda and Tanzania to form a regional economic bloc. The EAC's predecessor, the East African Community, had collapsed in 1977 in acrimonious circumstances. Prominent among the issues that led to the collapse of the East African Community was the perception of unequal gains from the integration scheme, with Uganda and Tanzania considering that disproportionate benefits were accruing to Kenya at their expense. With the new initiative, the question emerges as to whether the problems that caused the collapse of the Community will not beset the EAC and subject it to a similar fate. In an attempt to address this question, this study considers some of the theoretical issues relating to regional economic integration among countries at different levels of development, and attempts to provide an analysis of the new initiative of the EAC in the light of this theory and the history of the East African Community. The study also critically examines the objectives of the EAC and the integration strategy adopted by the three countries, and offers suggestions on the way forward. Among the arguments made in this thesis are that, contrary to the suggestions of orthodox static analysis, if the dynamic effects of integration are considered, then there may be important gains which may accrue to integrating states in the developing country context. It is also argued that different levels of development among integrating states need not necessarily be an impediment to economic integration. The study finds that, in spite of the enormous challenges facing the EAC, member states may be better off within the integration scheme than if they acted as individual units in a rapidly globalizing international system.
- Full Text:
- Date Issued: 2000
The political significance of Winnie-Madikazela Mandela's position in the African National Congress
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- Date Issued: 2000
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- Date Issued: 2000
The presence and role of arbuscular mycorrhizal fungi in coastal sand dune systems
- Authors: Haller, Anjanette H. A
- Date: 2000
- Subjects: Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4196 , http://hdl.handle.net/10962/d1003765 , Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Description: Arbuscular mycorrhizas (AM) are mutually beneficial symbiotic associations between the roots of plants and certain Zygomycetous fungi. The role of AM fungi in coastal sand dunes has been explored in many parts of the world, though little work has been conducted in South African dune systems. This study aimed to investigate the presence and extent of mycorrhizal colonisation of a coastal sand dune in South Africa. The roots of five plant species (Scaevola plumieri, Arctotheca populifolia, Ipomoea pes-caprae, Ehrharta villosa and Chrysanthemoides monilifera) were sampled along a foredune profile at Old Woman's River in the Eastern Cape. These roots were assessed for the percentage mycorrhizal colonisation they supported. Spores extracted from the rhizosphere sand of each plant species were counted and identified to genus level. Results were related to seasonality and the position of the plants along the profile. All plant species were found to be mycorrhizal. Percentage colonisation ranged from 0-92%, depending on plant species and season. Mycorrhizal colonisation was generally highest in the winter months, and especially so in I pes-caprae and E. villosa. The extent of various mycorrhizal structures in root tissue varied between plant species. Spore numbers ranged from 0-48 spores 100g-1 sand with highest numbers occurring in winter. S. plumieri and A. populifolia were associated with greatest spore abundance. Four fungal genera (Glomus, Acaulospora, Scutellospora and Gigaspora) were identified. Distribution of these genera showed seasonal variations between plant species. A bioassay, using Sorghum, was conducted to test the inoculum potentials of sand from the Scaevola hummock and the IpomoealEhrharta dune. Highest percentage colonisation occurred in plants grown in the Scaevola sand, which also had the lowest root and shoot measurements. The bioassay confirmed that AM propagules are present and viable, even in the mobile sand of the foredune. This study showed that mycorrhizal colonisation and spore numbers varied seasonally, but that the extent of this was dependent on plant species. The position of plants along the foredune profile tended to be less important than plant species. It is thought that the growth cycle and rooting system of each plant species determines seasonal cycles and abundance of AM fungi. Variation within fungal populations probably also impacts on this. Knowledge of the presence and distribution of AM fungi in this system paves the way for more detailed studies which need to examine the role of these endophytes in South African sand dunes.
- Full Text:
- Date Issued: 2000
- Authors: Haller, Anjanette H. A
- Date: 2000
- Subjects: Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4196 , http://hdl.handle.net/10962/d1003765 , Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Description: Arbuscular mycorrhizas (AM) are mutually beneficial symbiotic associations between the roots of plants and certain Zygomycetous fungi. The role of AM fungi in coastal sand dunes has been explored in many parts of the world, though little work has been conducted in South African dune systems. This study aimed to investigate the presence and extent of mycorrhizal colonisation of a coastal sand dune in South Africa. The roots of five plant species (Scaevola plumieri, Arctotheca populifolia, Ipomoea pes-caprae, Ehrharta villosa and Chrysanthemoides monilifera) were sampled along a foredune profile at Old Woman's River in the Eastern Cape. These roots were assessed for the percentage mycorrhizal colonisation they supported. Spores extracted from the rhizosphere sand of each plant species were counted and identified to genus level. Results were related to seasonality and the position of the plants along the profile. All plant species were found to be mycorrhizal. Percentage colonisation ranged from 0-92%, depending on plant species and season. Mycorrhizal colonisation was generally highest in the winter months, and especially so in I pes-caprae and E. villosa. The extent of various mycorrhizal structures in root tissue varied between plant species. Spore numbers ranged from 0-48 spores 100g-1 sand with highest numbers occurring in winter. S. plumieri and A. populifolia were associated with greatest spore abundance. Four fungal genera (Glomus, Acaulospora, Scutellospora and Gigaspora) were identified. Distribution of these genera showed seasonal variations between plant species. A bioassay, using Sorghum, was conducted to test the inoculum potentials of sand from the Scaevola hummock and the IpomoealEhrharta dune. Highest percentage colonisation occurred in plants grown in the Scaevola sand, which also had the lowest root and shoot measurements. The bioassay confirmed that AM propagules are present and viable, even in the mobile sand of the foredune. This study showed that mycorrhizal colonisation and spore numbers varied seasonally, but that the extent of this was dependent on plant species. The position of plants along the foredune profile tended to be less important than plant species. It is thought that the growth cycle and rooting system of each plant species determines seasonal cycles and abundance of AM fungi. Variation within fungal populations probably also impacts on this. Knowledge of the presence and distribution of AM fungi in this system paves the way for more detailed studies which need to examine the role of these endophytes in South African sand dunes.
- Full Text:
- Date Issued: 2000
The Raven's Coloured Progressive Matrices Test: a pilot study for the establishment of normative data for Xhosa-speaking primary school pupils in the Grahamstown region
- Authors: Bass, Natalie Tanyia
- Date: 2000
- Subjects: Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2930 , http://hdl.handle.net/10962/d1002439 , Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Description: The Raven’s Coloured Progressive Matrices (CPM) test is used extensively across a wide variety of settings in South Africa, however more appropriate local normative data has yet to be established. The CPM is internationally recognised as a culture-fair test of nonverbal intelligence, designed for use with children between the ages of 5½ and 11½. This pilot study thus sought to establish normative data for this instrument for a population of Xhosa-speaking Primary School children in the peri-urban township area in the Grahamstown region. The booklet version of the test was used and it was administered in group format and according to an alternate method of test administration (using Xhosa instructions) developed by Vass in 1992. The final normative sample consisted of 197 male and 182 female Xhosa-speaking children in Grades Two to Seven (N=379). The results showed (1) a significant effect of age on test scores, where scores increased with age as expected; (2) a consistent tendency for males to outperform females was also noted, however small sample sizes precluded any categorical claims to this effect; (3) no significant effect of education on test scores was observed and finally; (4) and finally, it appeared that the norms generated for this study revealed a tendency to be lower than those obtained by Raven, Court and Raven (1990) during the standardisation of this instrument in the United Kingdom and America. The study concluded that (1) there is an urgent need for more appropriate South African normative data for this test; and (2) that when assessing African children from disadvantaged backgrounds, further research into the effects of cultural and socio-economic factors and gender on non-verbal intelligence (and on performance on this test in particular) is required.
- Full Text:
- Date Issued: 2000
- Authors: Bass, Natalie Tanyia
- Date: 2000
- Subjects: Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2930 , http://hdl.handle.net/10962/d1002439 , Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Description: The Raven’s Coloured Progressive Matrices (CPM) test is used extensively across a wide variety of settings in South Africa, however more appropriate local normative data has yet to be established. The CPM is internationally recognised as a culture-fair test of nonverbal intelligence, designed for use with children between the ages of 5½ and 11½. This pilot study thus sought to establish normative data for this instrument for a population of Xhosa-speaking Primary School children in the peri-urban township area in the Grahamstown region. The booklet version of the test was used and it was administered in group format and according to an alternate method of test administration (using Xhosa instructions) developed by Vass in 1992. The final normative sample consisted of 197 male and 182 female Xhosa-speaking children in Grades Two to Seven (N=379). The results showed (1) a significant effect of age on test scores, where scores increased with age as expected; (2) a consistent tendency for males to outperform females was also noted, however small sample sizes precluded any categorical claims to this effect; (3) no significant effect of education on test scores was observed and finally; (4) and finally, it appeared that the norms generated for this study revealed a tendency to be lower than those obtained by Raven, Court and Raven (1990) during the standardisation of this instrument in the United Kingdom and America. The study concluded that (1) there is an urgent need for more appropriate South African normative data for this test; and (2) that when assessing African children from disadvantaged backgrounds, further research into the effects of cultural and socio-economic factors and gender on non-verbal intelligence (and on performance on this test in particular) is required.
- Full Text:
- Date Issued: 2000
The representation of "South Africanness" in the locally produced television production, Generations
- Authors: Dentlinger, Lindsay
- Date: 2000
- Subjects: Television soap operas -- South Africa , National characteristics, South African, In Literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3425 , http://hdl.handle.net/10962/d1002878 , Television soap operas -- South Africa , National characteristics, South African, In Literature
- Description: The aim of this study is to analyse selected episodes of the locally produced television programme Generations, in order to identify specific ways in which the programme seeks to forge a South African identity, and in so doing, 'flag' our nationhood as South Africans. These elements of 'South Africanness' are broadly defined as connections to a South African way of life, context, values and experiences. Generations is a programme produced under South African broadcasting local content provisions. These provisions arise out of the need, inter alia, to reflect the identity and multi-cultural nature of South Africa in order to foster 'national identity' and 'national culture'. These elements of 'South Africanness' are extracted through a genre and ideological analysis of selected sample episodes, taking into consideration the theoretical frameworks of the politics of representation and identity. The production context of, and representations made, in Generations, are found to be situated largely within the context of the South African discourses of the ‘rainbow nation', 'African renaissance' and 'black economic empowerment'. The analysis concludes that through the various categories of representations of 'South Africanness' in the selected episodes of Generations, specific instances of identity, that of national culture and national identity are formed.
- Full Text:
- Date Issued: 2000
The representation of "South Africanness" in the locally produced television production, Generations
- Authors: Dentlinger, Lindsay
- Date: 2000
- Subjects: Television soap operas -- South Africa , National characteristics, South African, In Literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3425 , http://hdl.handle.net/10962/d1002878 , Television soap operas -- South Africa , National characteristics, South African, In Literature
- Description: The aim of this study is to analyse selected episodes of the locally produced television programme Generations, in order to identify specific ways in which the programme seeks to forge a South African identity, and in so doing, 'flag' our nationhood as South Africans. These elements of 'South Africanness' are broadly defined as connections to a South African way of life, context, values and experiences. Generations is a programme produced under South African broadcasting local content provisions. These provisions arise out of the need, inter alia, to reflect the identity and multi-cultural nature of South Africa in order to foster 'national identity' and 'national culture'. These elements of 'South Africanness' are extracted through a genre and ideological analysis of selected sample episodes, taking into consideration the theoretical frameworks of the politics of representation and identity. The production context of, and representations made, in Generations, are found to be situated largely within the context of the South African discourses of the ‘rainbow nation', 'African renaissance' and 'black economic empowerment'. The analysis concludes that through the various categories of representations of 'South Africanness' in the selected episodes of Generations, specific instances of identity, that of national culture and national identity are formed.
- Full Text:
- Date Issued: 2000
The response of the two interrelated river components, geomorphology and riparian vegetation, to interbasin water transfers in the Orange-Fish-Sundays River Interbasin Transfer Scheme
- Authors: du Plessis, A J E
- Date: 2000
- Subjects: Skoenmakers River (South Africa) , Riparian ecology -- South Africa -- Eastern Cape , Geomorphology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4850 , http://hdl.handle.net/10962/d1005526
- Description: The Skoenmakers River (located in the semi-arid Karoo region of the Eastern Cape) is being used as a transfer route for water transferred by the Orange-Fish-Sundays River Interbasin Transfer Scheme. The change in the hydrological regime of this once ephemeral stream to a much bigger perennial river led to dramatic changes to both the physical structure and riparian vegetation structure of the river system. These changes differ for each of the three river sections, the upper,middle and lower reaches. Qualitative, descriptive geomorphological data was gathered by means of field observations and this was then compared to the quantitative data collected by means of surveyed cross-sectional profiles at selected sites along the length of both the regulated Skoenmakers River and a nonregulated tributary of equivalent size, the Volkers River. Riparian vegetation data was gathered by means of plot sampling along belt transects at each site. A qualitative assessment of the vegetation conditions was also made at each site and then added to the quantitative data from the plot sampling. At each site the different morphological units were identified along the cross-section and changes in the vegetation and sediment composition were recorded. Aerial photographs were used as additional sources of data and observations made from these were compared to data gathered in the field. The pre-IBT channel in this river section was formed by low frequency flood flows but the hydrological regime has now been converted to base flows much higher than normal flood flows. Severe incision, erosion and degradation of both the channel bed and banks occurred. In the lower reaches, post-IBT base flows are lower than pre-IBT flood flows and, due to the increased catchment area, the impact of the IBT was better ‘absorbed’ by the river system. Aggradation and deposition increased for the regulated river in comparison to the non-regulated river due to more sediment introduced The IBT had the greatest impact in the upper reaches of the regulated river due to more sediment introduced at the top of the system.
- Full Text:
- Date Issued: 2000
- Authors: du Plessis, A J E
- Date: 2000
- Subjects: Skoenmakers River (South Africa) , Riparian ecology -- South Africa -- Eastern Cape , Geomorphology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4850 , http://hdl.handle.net/10962/d1005526
- Description: The Skoenmakers River (located in the semi-arid Karoo region of the Eastern Cape) is being used as a transfer route for water transferred by the Orange-Fish-Sundays River Interbasin Transfer Scheme. The change in the hydrological regime of this once ephemeral stream to a much bigger perennial river led to dramatic changes to both the physical structure and riparian vegetation structure of the river system. These changes differ for each of the three river sections, the upper,middle and lower reaches. Qualitative, descriptive geomorphological data was gathered by means of field observations and this was then compared to the quantitative data collected by means of surveyed cross-sectional profiles at selected sites along the length of both the regulated Skoenmakers River and a nonregulated tributary of equivalent size, the Volkers River. Riparian vegetation data was gathered by means of plot sampling along belt transects at each site. A qualitative assessment of the vegetation conditions was also made at each site and then added to the quantitative data from the plot sampling. At each site the different morphological units were identified along the cross-section and changes in the vegetation and sediment composition were recorded. Aerial photographs were used as additional sources of data and observations made from these were compared to data gathered in the field. The pre-IBT channel in this river section was formed by low frequency flood flows but the hydrological regime has now been converted to base flows much higher than normal flood flows. Severe incision, erosion and degradation of both the channel bed and banks occurred. In the lower reaches, post-IBT base flows are lower than pre-IBT flood flows and, due to the increased catchment area, the impact of the IBT was better ‘absorbed’ by the river system. Aggradation and deposition increased for the regulated river in comparison to the non-regulated river due to more sediment introduced The IBT had the greatest impact in the upper reaches of the regulated river due to more sediment introduced at the top of the system.
- Full Text:
- Date Issued: 2000
The role of black consciousness in the experience of being black in South Africa: the shaping of the identity of two members of AZAPO
- Authors: Mnguni, Mphikeleli Matthew
- Date: 2000
- Subjects: Black consciousness , Azanian People's Organization , Identity (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3022 , http://hdl.handle.net/10962/d1002531 , Black consciousness , Azanian People's Organization , Identity (Psychology)
- Description: The research attempts to understand the role Black Consciousness (BC) plays in the identity of blacks in South Africa by exploring and describing the experience of self-identity in the life-history context of two members of AZAPO, a BC organisation. The literature review explores the work of Biko, Manganyi, and Fanon with a view to understanding whether and how it might be claimed that BC galvanises the black person to discard the crippling fear of colonialism which inflicts feelings of inferiority, and to rise up to claim his/her rightful place in community life. To explore the philosophical assumptions made in the literature review, a qualitative study was conducted. Interviews were conducted with two black adults who have adopted BC philosophy. Three separate in-depth phenomenological interviews were conducted which yielded a description of the experiences of each respondent. A tape recorder was used to record the interviews and they were transcribed for analysis. A thematic analysis was conducted using the reading guide method. The material was thematised using the following questions: What biographical factors are seen as being important prior to the respondent becoming black conscious? How did the participant come to realise his/her self-identity as problematic? How did the process of adopting BC change the participant’s selfidentity? The results indicate that participants became aware very early in their lives and prior to adopting BC, that their own supportive and cohesive family cultures were at odds with the surrounding social context. Early experiences of this were initially unintelligible but impressionable. BC in this sense provided a framework for understanding and engaging with these experiences. The study shows that the adoption of BC helped to make sense of experiences of community isolation, discrimination, oppression and provided them with a mode of engaging practically with these issues. It was not adopted from a perspective of poor self-esteem or other such purely personal characteristics which may have been expected on the basis of literature in the area. BC was adopted as a way of understanding the relationship between their communities or backgrounds and the broader social environment and if there was a ‘healing’ project it was at this level.However, the study did show the close relationship between individual and social well-being that emerged as intrinsic both to the philosophy of BC and the lives of these individuals. This was shown to play out in the commitment of these individuals to the development of black communities and in their tying of their own destinies to the destiny of the oppressed black people in general. These and other issues which emerged in the two case studies are discussed in relation to the literature in the area.
- Full Text:
- Date Issued: 2000
- Authors: Mnguni, Mphikeleli Matthew
- Date: 2000
- Subjects: Black consciousness , Azanian People's Organization , Identity (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3022 , http://hdl.handle.net/10962/d1002531 , Black consciousness , Azanian People's Organization , Identity (Psychology)
- Description: The research attempts to understand the role Black Consciousness (BC) plays in the identity of blacks in South Africa by exploring and describing the experience of self-identity in the life-history context of two members of AZAPO, a BC organisation. The literature review explores the work of Biko, Manganyi, and Fanon with a view to understanding whether and how it might be claimed that BC galvanises the black person to discard the crippling fear of colonialism which inflicts feelings of inferiority, and to rise up to claim his/her rightful place in community life. To explore the philosophical assumptions made in the literature review, a qualitative study was conducted. Interviews were conducted with two black adults who have adopted BC philosophy. Three separate in-depth phenomenological interviews were conducted which yielded a description of the experiences of each respondent. A tape recorder was used to record the interviews and they were transcribed for analysis. A thematic analysis was conducted using the reading guide method. The material was thematised using the following questions: What biographical factors are seen as being important prior to the respondent becoming black conscious? How did the participant come to realise his/her self-identity as problematic? How did the process of adopting BC change the participant’s selfidentity? The results indicate that participants became aware very early in their lives and prior to adopting BC, that their own supportive and cohesive family cultures were at odds with the surrounding social context. Early experiences of this were initially unintelligible but impressionable. BC in this sense provided a framework for understanding and engaging with these experiences. The study shows that the adoption of BC helped to make sense of experiences of community isolation, discrimination, oppression and provided them with a mode of engaging practically with these issues. It was not adopted from a perspective of poor self-esteem or other such purely personal characteristics which may have been expected on the basis of literature in the area. BC was adopted as a way of understanding the relationship between their communities or backgrounds and the broader social environment and if there was a ‘healing’ project it was at this level.However, the study did show the close relationship between individual and social well-being that emerged as intrinsic both to the philosophy of BC and the lives of these individuals. This was shown to play out in the commitment of these individuals to the development of black communities and in their tying of their own destinies to the destiny of the oppressed black people in general. These and other issues which emerged in the two case studies are discussed in relation to the literature in the area.
- Full Text:
- Date Issued: 2000
The scrum-down on brain damage effects of cumulative mild head injury in rugby: a comparison of group mean scores between national rugby players and non-contact sport controls
- Authors: Finkelstein, Melissa
- Date: 2000
- Subjects: Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2976 , http://hdl.handle.net/10962/d1002485 , Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Description: The present study comprises the second phase of a larger and ongoing research study investigating the brain damage effects of cumulative mild head injury in rugby. The purpose of this study was to determine whether cumulative mild head injury sustained in the game of rugby would cause brain injury as evidenced by impaired performance on sensitive neuropsychological tests. Participants were Springbok professional rugby players (n = 26), Under 21 rugby players (n = 19), and a non-contact sport control of national hockey players (n = 21). Comparisons of performance were carried out across a spectrum of neuropsychological tests for the three rugby groups (Total Rugby, Springbok Rugby, and Under 21 Rugby) versus the performance of the non-contact sport control group (Hockey Control), as well as comparisons of performance f9r the subgroups of Rugby Forwards versus Rugby Backs. Comparisons revealed a consistent pattern of poorer performance across all rugby groups relative to the performance of the controls on tests highly sensitive to the effects of diffuse brain damage. Within rugby group comparisons (Forwards versus Backs) showed significantly poorer performance for Total Rugby Forwards and Springbok Rugby Forwards relative to the performance of the respective Total Rugby Backs and Springbok Rugby Backs on sensitive, as well as on somewhat less sensitive, neuropsychological tests. The performance of Under 21 Rugby Forwards relative to Under 21 Rugby Backs demonstrated similar trends. Brain reserve capacity theory was used as a conceptual basis for discussing the implications of these findings.
- Full Text:
- Date Issued: 2000
- Authors: Finkelstein, Melissa
- Date: 2000
- Subjects: Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2976 , http://hdl.handle.net/10962/d1002485 , Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Description: The present study comprises the second phase of a larger and ongoing research study investigating the brain damage effects of cumulative mild head injury in rugby. The purpose of this study was to determine whether cumulative mild head injury sustained in the game of rugby would cause brain injury as evidenced by impaired performance on sensitive neuropsychological tests. Participants were Springbok professional rugby players (n = 26), Under 21 rugby players (n = 19), and a non-contact sport control of national hockey players (n = 21). Comparisons of performance were carried out across a spectrum of neuropsychological tests for the three rugby groups (Total Rugby, Springbok Rugby, and Under 21 Rugby) versus the performance of the non-contact sport control group (Hockey Control), as well as comparisons of performance f9r the subgroups of Rugby Forwards versus Rugby Backs. Comparisons revealed a consistent pattern of poorer performance across all rugby groups relative to the performance of the controls on tests highly sensitive to the effects of diffuse brain damage. Within rugby group comparisons (Forwards versus Backs) showed significantly poorer performance for Total Rugby Forwards and Springbok Rugby Forwards relative to the performance of the respective Total Rugby Backs and Springbok Rugby Backs on sensitive, as well as on somewhat less sensitive, neuropsychological tests. The performance of Under 21 Rugby Forwards relative to Under 21 Rugby Backs demonstrated similar trends. Brain reserve capacity theory was used as a conceptual basis for discussing the implications of these findings.
- Full Text:
- Date Issued: 2000