The dynamics of space use in some Lake Malawi fishes
- Authors: Robinson, Rosanna Lesley
- Date: 1996
- Subjects: Cichlids -- Nyasa, Lake Fishes -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5264 , http://hdl.handle.net/10962/d1005108
- Description: Behaviour and space utilisation of rock-dwelling cichlids were observed at Thumbi East Island, Lake Malawi. 1. Males of five species of the mbuna complex held long-term territories. Pseudotropheus elongatus "aggressive" vigorously defended a feeding area and sometimes a spawning site interspecifically, but did not feed in the peripheral part of their territory. Spawning sites of Pseudotropheus zebra, Pseudotropheus tropheops "orange chest", Labeotropheus fuelleborni, and Petrotilapia nigra were interspecifically-defended, while larger mating territories were defended against conspecific neighbours. Feeding areas were shared with many fish and often extended beyond the defended area. There was considerable variation in behaviour and space use within and between species and between times of day. 2. Non-territorial P. zebra used larger ranges than territorial conspecifics, and fed more on plankton, but individuals had preferred benthic feeding areas, often in conspecific territories. These 'floaters' were often aggressive. Both size and relative brightness independently predicted the outcome of aggressive interactions between floaters, and a site-specific dominance hierarchy was suggested, with some individuals appearing to be semi-territorial. 3. Males and females of 21 and 13 species respectively were found to establish temporary breeding territories. Overall breeding seasonality was bimodal, but reproductive timing and territory characteristics differed among species. Temporary territories had a considerable impact on the behaviour and habitat use of all resident mbuna species, even causing abandonment of territories. 4. Non-breeding Protomelas taeniolatus had limited home ranges, and showed little aggression. During the highly-synchronised reproductive season, males defended spawning sites and females fry-guarding territories. Most chases were directed towards the commonest fish, but predators were chased further and faster. Female behaviour changed over the guarding period. Females generally continued territorial defence after the brood had disappeared. Most broods contained fry of different sizes and species. Significant benefits were found for guarding females with clustered territories, but females did not appear to choose sites adjacent to conspecific parental females. 5. Territoriality in fish is taxonomically widespread and may serve several functions according to species, sex and developmental stage. It also varies according to genotype- and phenotype-limited strategies and short term costs and benefits. Territories may be simultaneously multifunctional.
- Full Text:
- Date Issued: 1996
- Authors: Robinson, Rosanna Lesley
- Date: 1996
- Subjects: Cichlids -- Nyasa, Lake Fishes -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5264 , http://hdl.handle.net/10962/d1005108
- Description: Behaviour and space utilisation of rock-dwelling cichlids were observed at Thumbi East Island, Lake Malawi. 1. Males of five species of the mbuna complex held long-term territories. Pseudotropheus elongatus "aggressive" vigorously defended a feeding area and sometimes a spawning site interspecifically, but did not feed in the peripheral part of their territory. Spawning sites of Pseudotropheus zebra, Pseudotropheus tropheops "orange chest", Labeotropheus fuelleborni, and Petrotilapia nigra were interspecifically-defended, while larger mating territories were defended against conspecific neighbours. Feeding areas were shared with many fish and often extended beyond the defended area. There was considerable variation in behaviour and space use within and between species and between times of day. 2. Non-territorial P. zebra used larger ranges than territorial conspecifics, and fed more on plankton, but individuals had preferred benthic feeding areas, often in conspecific territories. These 'floaters' were often aggressive. Both size and relative brightness independently predicted the outcome of aggressive interactions between floaters, and a site-specific dominance hierarchy was suggested, with some individuals appearing to be semi-territorial. 3. Males and females of 21 and 13 species respectively were found to establish temporary breeding territories. Overall breeding seasonality was bimodal, but reproductive timing and territory characteristics differed among species. Temporary territories had a considerable impact on the behaviour and habitat use of all resident mbuna species, even causing abandonment of territories. 4. Non-breeding Protomelas taeniolatus had limited home ranges, and showed little aggression. During the highly-synchronised reproductive season, males defended spawning sites and females fry-guarding territories. Most chases were directed towards the commonest fish, but predators were chased further and faster. Female behaviour changed over the guarding period. Females generally continued territorial defence after the brood had disappeared. Most broods contained fry of different sizes and species. Significant benefits were found for guarding females with clustered territories, but females did not appear to choose sites adjacent to conspecific parental females. 5. Territoriality in fish is taxonomically widespread and may serve several functions according to species, sex and developmental stage. It also varies according to genotype- and phenotype-limited strategies and short term costs and benefits. Territories may be simultaneously multifunctional.
- Full Text:
- Date Issued: 1996
The future role of TGWU in relation to Bus Transport in a changing environment
- TGWU
- Authors: TGWU
- Date: 1996
- Subjects: TGWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/111258 , vital:33425
- Description: One will assume that the topic chosen for me to present a paper on,is no the one which looks on organisational and analytic development of TGWU. I will therefore focus on TGWU 's perspective on the current bus crisis future perspective and TGWU organisational role in the bus industry I felt it important to outline a brief background and our perspective cm the industry and how that dictates our attitude towards the industry. This paper is divided along the following sections;- Use of transport in internal economic and labour control. Contradictions and conflicts over transport policy. The future and its implications for Transport policy after apartheid. TGWU's organisational role and influence in the industry.
- Full Text:
- Date Issued: 1996
- Authors: TGWU
- Date: 1996
- Subjects: TGWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/111258 , vital:33425
- Description: One will assume that the topic chosen for me to present a paper on,is no the one which looks on organisational and analytic development of TGWU. I will therefore focus on TGWU 's perspective on the current bus crisis future perspective and TGWU organisational role in the bus industry I felt it important to outline a brief background and our perspective cm the industry and how that dictates our attitude towards the industry. This paper is divided along the following sections;- Use of transport in internal economic and labour control. Contradictions and conflicts over transport policy. The future and its implications for Transport policy after apartheid. TGWU's organisational role and influence in the industry.
- Full Text:
- Date Issued: 1996
The geology of the Unki platinum-base metal deposit, Selukwe subchamber, great dyke, Zimbabwe
- Authors: Murahwi, Charley Zvinaiye
- Date: 1996
- Subjects: Platinum ores -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4962 , http://hdl.handle.net/10962/d1005574 , Platinum ores -- Zimbabwe
- Description: This thesis focuses on platinu'm group element (PGE) mineralization in the Unki Section of the Selukwe Subchamber of the Great Dyke (Zimbabwe), and is based on drill hole intersections and underground and surface exposures of the Main Sulphide Zone (MSZ) which hosts significant concentrations of PGE. The petrological and geochemical data presented are part of a broader study currently underway and the present are restricted to the 2m section of the PGE-rich MSZ encountered in drill hole MR126. The PGE-rich MSZ at Unki is unique in having a shear, locally referred to as the Footwall Shear, developed at or close to its base . It is however, similar to the other PGE occurrences on the Great Dyke (MSZ) in having its hanging-wall restricted to within 1m of the websterite/bronzitite contact. Slight axial tilting to t he west is indicated by steeper dips on the eastern flank. The sulphide concentration wit hin the MSZ can be used as a rough guide to the PGE-rich zone, but is not sufficiently precise to be used in stope control. The visual identification of the potentially mineable zone remains a problem that is unlikely to be solved. Based on petrological evidence, the bulk of the sulphides with which the PGE are associated, are cumulus in status. This provides unequivocal evidence for an orthomagmatic origin of the MSZ. The dominant platinum group mineral (PGM) phase is the Arsenide/Sperrylite group which is most commonly found at the contact zones between base metal sulphides (BMS) and gangue. The PGM range up to 90 ~m in length. Geochemical evidence from the analyses of cumulate orthopyroxenes through the 2m PGE-rich MSZ interval at Unki reveals a trend of arked Fe enrichment upwards which corresponds to an enrichment in sulphide. This indicates that precipitation of sulphide was caused by fractionation with lowering of temperature in the magma. The Fe enrichment is followed by a reversal in Mg# of orthopyroxene which corresponds to the decrease in sulphide content, suggest i ng that the termination of the PGE-rich MSZ was due to an increase in temperature associated with an influx of new magma. Coupled with these magmatic events are a complex interplay of chemical and physical processes occurring at a critical stage in the overall fractionation of the Great Dyke magma chamber. The overall persistence and continuity of t he PGE zone as observed in the Unki area is consistent with the inferred orthomagmatic origin of the mineralization
- Full Text:
- Date Issued: 1996
- Authors: Murahwi, Charley Zvinaiye
- Date: 1996
- Subjects: Platinum ores -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4962 , http://hdl.handle.net/10962/d1005574 , Platinum ores -- Zimbabwe
- Description: This thesis focuses on platinu'm group element (PGE) mineralization in the Unki Section of the Selukwe Subchamber of the Great Dyke (Zimbabwe), and is based on drill hole intersections and underground and surface exposures of the Main Sulphide Zone (MSZ) which hosts significant concentrations of PGE. The petrological and geochemical data presented are part of a broader study currently underway and the present are restricted to the 2m section of the PGE-rich MSZ encountered in drill hole MR126. The PGE-rich MSZ at Unki is unique in having a shear, locally referred to as the Footwall Shear, developed at or close to its base . It is however, similar to the other PGE occurrences on the Great Dyke (MSZ) in having its hanging-wall restricted to within 1m of the websterite/bronzitite contact. Slight axial tilting to t he west is indicated by steeper dips on the eastern flank. The sulphide concentration wit hin the MSZ can be used as a rough guide to the PGE-rich zone, but is not sufficiently precise to be used in stope control. The visual identification of the potentially mineable zone remains a problem that is unlikely to be solved. Based on petrological evidence, the bulk of the sulphides with which the PGE are associated, are cumulus in status. This provides unequivocal evidence for an orthomagmatic origin of the MSZ. The dominant platinum group mineral (PGM) phase is the Arsenide/Sperrylite group which is most commonly found at the contact zones between base metal sulphides (BMS) and gangue. The PGM range up to 90 ~m in length. Geochemical evidence from the analyses of cumulate orthopyroxenes through the 2m PGE-rich MSZ interval at Unki reveals a trend of arked Fe enrichment upwards which corresponds to an enrichment in sulphide. This indicates that precipitation of sulphide was caused by fractionation with lowering of temperature in the magma. The Fe enrichment is followed by a reversal in Mg# of orthopyroxene which corresponds to the decrease in sulphide content, suggest i ng that the termination of the PGE-rich MSZ was due to an increase in temperature associated with an influx of new magma. Coupled with these magmatic events are a complex interplay of chemical and physical processes occurring at a critical stage in the overall fractionation of the Great Dyke magma chamber. The overall persistence and continuity of t he PGE zone as observed in the Unki area is consistent with the inferred orthomagmatic origin of the mineralization
- Full Text:
- Date Issued: 1996
The geology, geochemistry and stratigraphic correlations of the farm Rietfontein 70 JS on the south -eastern flank of the Dennilton Dome, Transvaal, South Africa
- Authors: Crous, Stephanus Philippus
- Date: 1996
- Subjects: Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4960 , http://hdl.handle.net/10962/d1005572 , Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Description: The study area is located between Loskop Dam and the town of Groblersdal, on the southeastern flank of the Dennilton dome, and is underlain by lithologies of the Pretoria Group, Bushveld Complex mafics and ultramafics and acid lavas that resort under the Rooiberg felsites. Field work comprised of geological mapping, soil-, hard-rock- and stream sediment geochemistry, various geophysical techniques and diamond drilling. The rocktypes that resembles the Rustenburg Layered Suite on the farm Rietfontein 70JS is subdivided into a Mixed Zone, Critical Zone and Main Zone, on grounds of geochemical and certain geophysical attributes. The Mixed Zone that overlies the Bushveld Complex floor-rocks, is furthermore separated into an i) Lower-, ii) Middle- and, iii) Upper Unit. The Lower Unit of the Mixed Zone consists primarily of magnetite-gabbros, iron-rich pegmatites, harzburgites and feldspathic pyroxenites. The Fe-rich constituents of this stratigraphic horizon generates a pronounced magnetic anomaly within the study area. On the basis of; amongst other parameters, Zr/Rb and Sr/Al₂0₃ ratios, the magnetite-gabbros are postulated to conform to lithotypes in the vicinity of magnetite layers 8 to 14 of Upper Zone Subzone B in a normal Bushveld Complex stratigraphical scenario. Similarly, it is argued that the feldspathic pyroxenites and norites that display elevated chromium values are analogues to normal Critical Zone rocktypes of the Rustenburg Layered Snite. A more elaborate and precise stratigraphic correlation for the Critical zone was, however, not possible. It is advocated that a volume imbalance was created by the hot, ascending mafic magmas of the intruding Bushveld Complex, resulting in the updoming of certain prevailing basement features such as the Dennilton Dome. In addition to this ideology, it is proposed that the Mineral Range Fragment is in fact a large xenolith underlain by mafics, after being detached from the Dennilton Dome during the intrusion event. Evidence generated by this study unequivocally indicate that the potential for viable PGE's, Ni, Cu and Au within a Merensky Reef- type configuration or a Plat Reef-type scenario under a relatively thin veneer of acid Bushveld Complex roof-rocks on the eastern flank of the Dennilton Dome, appears feasible.
- Full Text:
- Date Issued: 1996
- Authors: Crous, Stephanus Philippus
- Date: 1996
- Subjects: Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4960 , http://hdl.handle.net/10962/d1005572 , Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Description: The study area is located between Loskop Dam and the town of Groblersdal, on the southeastern flank of the Dennilton dome, and is underlain by lithologies of the Pretoria Group, Bushveld Complex mafics and ultramafics and acid lavas that resort under the Rooiberg felsites. Field work comprised of geological mapping, soil-, hard-rock- and stream sediment geochemistry, various geophysical techniques and diamond drilling. The rocktypes that resembles the Rustenburg Layered Suite on the farm Rietfontein 70JS is subdivided into a Mixed Zone, Critical Zone and Main Zone, on grounds of geochemical and certain geophysical attributes. The Mixed Zone that overlies the Bushveld Complex floor-rocks, is furthermore separated into an i) Lower-, ii) Middle- and, iii) Upper Unit. The Lower Unit of the Mixed Zone consists primarily of magnetite-gabbros, iron-rich pegmatites, harzburgites and feldspathic pyroxenites. The Fe-rich constituents of this stratigraphic horizon generates a pronounced magnetic anomaly within the study area. On the basis of; amongst other parameters, Zr/Rb and Sr/Al₂0₃ ratios, the magnetite-gabbros are postulated to conform to lithotypes in the vicinity of magnetite layers 8 to 14 of Upper Zone Subzone B in a normal Bushveld Complex stratigraphical scenario. Similarly, it is argued that the feldspathic pyroxenites and norites that display elevated chromium values are analogues to normal Critical Zone rocktypes of the Rustenburg Layered Snite. A more elaborate and precise stratigraphic correlation for the Critical zone was, however, not possible. It is advocated that a volume imbalance was created by the hot, ascending mafic magmas of the intruding Bushveld Complex, resulting in the updoming of certain prevailing basement features such as the Dennilton Dome. In addition to this ideology, it is proposed that the Mineral Range Fragment is in fact a large xenolith underlain by mafics, after being detached from the Dennilton Dome during the intrusion event. Evidence generated by this study unequivocally indicate that the potential for viable PGE's, Ni, Cu and Au within a Merensky Reef- type configuration or a Plat Reef-type scenario under a relatively thin veneer of acid Bushveld Complex roof-rocks on the eastern flank of the Dennilton Dome, appears feasible.
- Full Text:
- Date Issued: 1996
The implications of the IMF programme in Zambia: lessons for South Africa in the Reconstruction and Development Programme (RDP)
- Authors: Motsilili, Phoka
- Date: 1996
- Subjects: International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2811 , http://hdl.handle.net/10962/d1003021 , International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Description: This study attempts to present a comparative analysis of the implication of the IMF in Zambia and South Africa in its Reconstruction and Development Programme (RDP). In examining the IMF programme, the study focuses on the Fund's understanding of such economies and its prescriptions for development. It is argued that IMF's familiar orthodoxy will have disastrous consequences for South Africa's poor, disadvantaged and rural communities. Finally, the IMF's market-oriented policy prescriptions are likely to erode democracy and have devastating effects to people-centred development programmes such as the RDP.
- Full Text:
- Date Issued: 1996
- Authors: Motsilili, Phoka
- Date: 1996
- Subjects: International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2811 , http://hdl.handle.net/10962/d1003021 , International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Description: This study attempts to present a comparative analysis of the implication of the IMF in Zambia and South Africa in its Reconstruction and Development Programme (RDP). In examining the IMF programme, the study focuses on the Fund's understanding of such economies and its prescriptions for development. It is argued that IMF's familiar orthodoxy will have disastrous consequences for South Africa's poor, disadvantaged and rural communities. Finally, the IMF's market-oriented policy prescriptions are likely to erode democracy and have devastating effects to people-centred development programmes such as the RDP.
- Full Text:
- Date Issued: 1996
The influence of oceanographic conditions and culture methods on the dynamics of mussel farming in Saldanha Bay, South Africa
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
The inner image: an examination of the life of Helen Elizabeth Martins leading to her creation The Owl House and A Camel Yard as outsider art
- Authors: Ross, Susan Imrie
- Date: 1996
- Subjects: Sculptors -- South Africa -- Biography Martins, Helen Elizabeth, 1897-1976 Owl House (Nieu Bethesda, South Africa) Art brut Women artists -- South Africa Nieu bethesda (South africa) -- Description and travel Primitivism in art Creation (Literary, artistic, etc.) Artists -- Psychology Symbolism in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2430 , http://hdl.handle.net/10962/d1002227
- Description: The Owl House is situated in the Karoo village of Nieu Bethesda, and the person responsible for its creation, Helen Elizabeth Martins (1897-1976), is South Africa's best known Outsider artist. A number of newspaper and magazine articles, television programmes, radio interviews, play, films, short stories, theses and art works have resulted directly from her work. Interest in The Owl House continues to grow, with visitors coming from all over South Africa, and various parts of the world,to visit it. The Owl House was Helen Martins' home for most of her 78 years. During the last 30 or so years of her life she devoted all her time and energy to transforming the interior of her house into a glistening fantasy world of colour and light, using crushed glass stuck to almost every surface, coloured glass pane inserts in the walls, mirrors of many sizes and shapes, and countless paraffin lamps and candles. She called her garden' A Camel Yard', and filled it with over 500 cement statues, structures and bas reliefs. All the labour involved, apart from crushing and sorting the coloured glass, was provided by at least four different men, who assisted her over the years, Johannes Hattingh, Jonas Adams, Piet van der Merwe and Koos Malgas, though Helen Martins was the inspiration and director behind it all. Through a study of Helen Martins' background and life, and their effects upon her psyche, a rigorous attempt has been made to reach some understanding of why she became a recluse, and what caused her to create this unique body of work comprising her entire domestic environment. She became increasingly asocial as her life progressed, and ultimately ended it by committing suicide in 1976. Through the universality of symbolism, the meanings of the subjects, themes and concerns which she chose to depict are studied. Then, together with some knowledge of her life and personal influences, an attempt has been made to deduce what it was that Helen Martins was trying to express and work through in her creations. This study also led to an awareness of the fact that, although each one is unique, there are many examples of Outsider Art throughout the world. Fundamentally, creators of Outsider Art remain asocial in relation to their cultural milieu and cultural context. Some other examples of Outsider Art, both in South Africa as well as in Europe and India, were visited, and are described and compared with The Owl House as well as with one another. The way in which society reacts or responds to Outsider Art and its creators is studied through the comprehensive records of one specific case which caused great controversy in Johannesburg during the 1970s. Ultimately, working alone or with assistance, it is the Outsider artist who is the driving force behind these unique works, and whose indefinable inner fire of passion alone makes it possible to bring them into being. It would seem that the fascination with Outsider Art is that through their work, creators allow others a glimpse into a different sense of reality which is both mysterious and inexplicable.
- Full Text:
- Date Issued: 1996
- Authors: Ross, Susan Imrie
- Date: 1996
- Subjects: Sculptors -- South Africa -- Biography Martins, Helen Elizabeth, 1897-1976 Owl House (Nieu Bethesda, South Africa) Art brut Women artists -- South Africa Nieu bethesda (South africa) -- Description and travel Primitivism in art Creation (Literary, artistic, etc.) Artists -- Psychology Symbolism in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2430 , http://hdl.handle.net/10962/d1002227
- Description: The Owl House is situated in the Karoo village of Nieu Bethesda, and the person responsible for its creation, Helen Elizabeth Martins (1897-1976), is South Africa's best known Outsider artist. A number of newspaper and magazine articles, television programmes, radio interviews, play, films, short stories, theses and art works have resulted directly from her work. Interest in The Owl House continues to grow, with visitors coming from all over South Africa, and various parts of the world,to visit it. The Owl House was Helen Martins' home for most of her 78 years. During the last 30 or so years of her life she devoted all her time and energy to transforming the interior of her house into a glistening fantasy world of colour and light, using crushed glass stuck to almost every surface, coloured glass pane inserts in the walls, mirrors of many sizes and shapes, and countless paraffin lamps and candles. She called her garden' A Camel Yard', and filled it with over 500 cement statues, structures and bas reliefs. All the labour involved, apart from crushing and sorting the coloured glass, was provided by at least four different men, who assisted her over the years, Johannes Hattingh, Jonas Adams, Piet van der Merwe and Koos Malgas, though Helen Martins was the inspiration and director behind it all. Through a study of Helen Martins' background and life, and their effects upon her psyche, a rigorous attempt has been made to reach some understanding of why she became a recluse, and what caused her to create this unique body of work comprising her entire domestic environment. She became increasingly asocial as her life progressed, and ultimately ended it by committing suicide in 1976. Through the universality of symbolism, the meanings of the subjects, themes and concerns which she chose to depict are studied. Then, together with some knowledge of her life and personal influences, an attempt has been made to deduce what it was that Helen Martins was trying to express and work through in her creations. This study also led to an awareness of the fact that, although each one is unique, there are many examples of Outsider Art throughout the world. Fundamentally, creators of Outsider Art remain asocial in relation to their cultural milieu and cultural context. Some other examples of Outsider Art, both in South Africa as well as in Europe and India, were visited, and are described and compared with The Owl House as well as with one another. The way in which society reacts or responds to Outsider Art and its creators is studied through the comprehensive records of one specific case which caused great controversy in Johannesburg during the 1970s. Ultimately, working alone or with assistance, it is the Outsider artist who is the driving force behind these unique works, and whose indefinable inner fire of passion alone makes it possible to bring them into being. It would seem that the fascination with Outsider Art is that through their work, creators allow others a glimpse into a different sense of reality which is both mysterious and inexplicable.
- Full Text:
- Date Issued: 1996
The interface between Western mental health care and indigenous healing in South Africa: Xhosa psychiatric nurses' views on traditional healers
- Authors: Kahn, Marc Simon
- Date: 1996
- Subjects: Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2999 , http://hdl.handle.net/10962/d1002508 , Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Description: Xhosa psychiatric nurses stand unique at the interface between Western mental health care and indigenous healing in South Africa. They stem from a cultural history that is embedded within traditional health care discourses and yet are trained and work within a Western psychiatric model. In embodying the intersection between these two paradigms, they are faced with the challenge of making sense of such an amalgamation. These nurses' views are thus valuable in reflecting this intersection and illustrating many of the central concerns that surround it. This study explicates the views of these nurses toward traditional healers and their potential role in mental health care in South Africa. In addition, it illuminates some of the cultural dynamics at work amongst these subjects as they struggle to make sense of their unique cultural position. Using a questionnaire-based methodology, the views of Xhosa psychiatric nurses in a psychiatric hospital in the Eastern Cape, toward traditional healers and their role in mental-health care, were examined. The findings reveal that the vast majority of these nurses believe in traditional cosmology, involve themselves in traditional ritual practices and regularly visit traditional healers as patients. In suggesting ways in which indigenous healing and Western mental health care can work together, 75% of the nurses were in favour of a general referral system between the hospital and traditional healers, most (77%) agreed that certain patients would be better off being treated by both the hospital and traditional healers than they would if they were only being treated by the hospital alone, and 85% of the subjects agreed that patients who are already seeing traditional healers should check if psychiatric medication might help them. These findings indicate that these nurses operate across two healing systems which are at this point not conceptually compatible. This results in deep cultural tension for the nurses. In being entangled in the dialectical tension created in this context, the nurses manage the incongruencies in three general ways: a) Most, in one form or another, incorporate beliefs from both systems into an integrative model, b) some assimilate their cultural belief system into the Western mental health paradigm, throwing off their beliefs in traditional healing, and c) others remain ambivalent in the dialectic between traditional and Western health care discourses. Although this may suggest that these nurses reside within a cultural milieu that is somewhat unhealthy, at another level, in managing and containing the incompatibility between the two systems, these nurses ensure a space for on-going and healthy critique of the underlying assumptions involved in this health care malaise.
- Full Text:
- Date Issued: 1996
- Authors: Kahn, Marc Simon
- Date: 1996
- Subjects: Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2999 , http://hdl.handle.net/10962/d1002508 , Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Description: Xhosa psychiatric nurses stand unique at the interface between Western mental health care and indigenous healing in South Africa. They stem from a cultural history that is embedded within traditional health care discourses and yet are trained and work within a Western psychiatric model. In embodying the intersection between these two paradigms, they are faced with the challenge of making sense of such an amalgamation. These nurses' views are thus valuable in reflecting this intersection and illustrating many of the central concerns that surround it. This study explicates the views of these nurses toward traditional healers and their potential role in mental health care in South Africa. In addition, it illuminates some of the cultural dynamics at work amongst these subjects as they struggle to make sense of their unique cultural position. Using a questionnaire-based methodology, the views of Xhosa psychiatric nurses in a psychiatric hospital in the Eastern Cape, toward traditional healers and their role in mental-health care, were examined. The findings reveal that the vast majority of these nurses believe in traditional cosmology, involve themselves in traditional ritual practices and regularly visit traditional healers as patients. In suggesting ways in which indigenous healing and Western mental health care can work together, 75% of the nurses were in favour of a general referral system between the hospital and traditional healers, most (77%) agreed that certain patients would be better off being treated by both the hospital and traditional healers than they would if they were only being treated by the hospital alone, and 85% of the subjects agreed that patients who are already seeing traditional healers should check if psychiatric medication might help them. These findings indicate that these nurses operate across two healing systems which are at this point not conceptually compatible. This results in deep cultural tension for the nurses. In being entangled in the dialectical tension created in this context, the nurses manage the incongruencies in three general ways: a) Most, in one form or another, incorporate beliefs from both systems into an integrative model, b) some assimilate their cultural belief system into the Western mental health paradigm, throwing off their beliefs in traditional healing, and c) others remain ambivalent in the dialectic between traditional and Western health care discourses. Although this may suggest that these nurses reside within a cultural milieu that is somewhat unhealthy, at another level, in managing and containing the incompatibility between the two systems, these nurses ensure a space for on-going and healthy critique of the underlying assumptions involved in this health care malaise.
- Full Text:
- Date Issued: 1996
The manufacture of chaos and compromise: an analysis of the path to reform in South Africa
- Authors: Ryklief, Cheryl Cecelia
- Date: 1996
- Subjects: South Africa -- Politics and government -- 1994- , Apartheid -- South Africa -- History , South Africa -- Race relations , Black people -- South Africa -- Politics and government , South Africa -- Social conditions
- Language: English
- Type: text , thesis
- Identifier: http://hdl.handle.net/10962/76218 , vital:30521
- Description: This dissertation examines the factors leading to the opening of negotiations to majority rule in South Africa. It argues that changes to the socio-economic environment led to the growth of the strategic relevance of the black working class, and also created certain points of collision between the black working class and the policies of the state. These sectoral collisions engendered both the partial reforms of the Botha era as well as the rejection of these reforms by the black majority. The developments that emerged from the ensuing process of reform, resistance and repression in the 1980s weakened both the state and the black opposition sufficiently to allow for the emergence of a consensual solution to the political stalemate. , Dissertation submitted in accordance with the requirements of the University of Liverpool for the degree of Master of Arts
- Full Text:
- Date Issued: 1996
- Authors: Ryklief, Cheryl Cecelia
- Date: 1996
- Subjects: South Africa -- Politics and government -- 1994- , Apartheid -- South Africa -- History , South Africa -- Race relations , Black people -- South Africa -- Politics and government , South Africa -- Social conditions
- Language: English
- Type: text , thesis
- Identifier: http://hdl.handle.net/10962/76218 , vital:30521
- Description: This dissertation examines the factors leading to the opening of negotiations to majority rule in South Africa. It argues that changes to the socio-economic environment led to the growth of the strategic relevance of the black working class, and also created certain points of collision between the black working class and the policies of the state. These sectoral collisions engendered both the partial reforms of the Botha era as well as the rejection of these reforms by the black majority. The developments that emerged from the ensuing process of reform, resistance and repression in the 1980s weakened both the state and the black opposition sufficiently to allow for the emergence of a consensual solution to the political stalemate. , Dissertation submitted in accordance with the requirements of the University of Liverpool for the degree of Master of Arts
- Full Text:
- Date Issued: 1996
The nutritional requirements of Haliotis midae and development of a practical diet for abalone aquaculture
- Authors: Britz, Peter Jacobus
- Date: 1996
- Subjects: Abalones -- Nutrition Abalone culture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5307 , http://hdl.handle.net/10962/d1005152
- Description: The available literature on abalone nutrition was synthesised and the prospects for developing a complete pelleted dry feed for Haliotis midae evaluated. The similar body compositions, digestive structures, enzyme activity, acceptance of a wide variety of feed ingredients and comparable growth performance on formulated diets of various abalone species suggests that they have similar nutritional requirements. Abalone also appear to be similar to other farmed monogastric animals in that digestion is primarily extracelluar and they possess a large, muscular crop and stomach. Abalone energy metabolism is carbohydrate based. They are capable of digesting high levels of dietary protein but their ability to utilise fat is limited. Abalone have been shown to consume predictable amounts of dry feed which is efficiently converted into body weight. Efficiency indices of utilisation of formulated feeds, such as feed conversion ratio, protein efficiency ratio, net protein utilisation and apparent digestibility have been successfully applied to abalone. It was concluded that the prospects for developing complete diets for H. midae using a conventional animal feed science model were good. The ability of H. midae to utilise a range of proteins which had potential for inclusion in practical diets was investigated. Five protein rich ingredients, namely, casein, fishmeal, soya oil cake, Spirulina, and torula yeast, were fed to H. midae in semi-purified diets. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina based diets displayed significantly higher growth rates than diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed with P. corallorhiza were significantly lower than all other diets. All artificial diets yield lower feed conversion ratios (0.7-1.8) and higher protein efficiency ratios (3.3-6.5) ratios than the seaweed control diets (FCR = 2.8-3.4; PER = 2.2-3.0). The results indicated that fishmeal and Spirulina were the most suitable proteins for inclusion in practical diets for H. midae. The effect of protein level on growth rate and nutritional indices was evaluated by feeding starch bound, fishmeal based diets containing 27, 32, 37, 42 and 47% protein to juvenile H. midae. Weight gain was positively related to the level of dietary protein, increasing by 18% between 27% and 47% protein. Protein efficiency ratio declining from 3.2 to 2.3 with an increasing dietary protein content. Feed consumption rate was approximately 1% of body weight per day for all diets. Post-weaning abalone (ca. lOmm shell length, 0.2g) differed from larger juveniles (ca. 35mm, 8g) in their response to varying proportions of dietary protein and energy. The smaller animals appeared to have a lower protein requirement and poorer ability to utilise lipid than the larger juveniles. Proximate analyses revealed that the levels of protein, lipid and carbohydrate in abalone soft tissue increased with increasing dietary levels of these nutrients. Larger juveniles contained significantly higher levels of protein and carbohydrate, but lower levels of lipid, ash and moisture, than the smaller post-weaning abalone. The assimilation efficiency of [U-¹⁴C]-arginine by H. midae fed diets enriched with [U-¹⁴C]-arginine was only 0.45%. Furthennore, supplementation of diets with graded levels of crystalline arginine did not have any effect on growth rates. It was concluded that the prospects for defining the quantitative amino acid requirements of H. midae using crystalline amino acids are not promising. Rates of gastric evacuation and enzyme secretion were monitored in juvenile H. midae fed an extruded, fishmeal based dry feed. Gut fullness peaked 6h after feed was offered and the bulk of feed consumed was digested within 24 h. Enzyme secretion appeared to begin with the onset of feeding and continued for at least 6h after peak gut fullness was attained. Protease activity increased significantly following ingestion but amylase activity was maintained at a more or less constant level. A low level of lipase activity was observed suggesting that the ability of H. midae to digest fat is limited. The growth rate of H. midae fed an extruded, fishmeal based feed increased with increasing temperature between 12°C and 20°C. Between 20°C and 24°C a marked decline in growth rate accompanied by a deterioration in feed conversion and increased mortality was observed. Consumption of a dry pelleted feed was shown to be a function of body size and temperature. Based on these data a model which predicts a daily ration for H. midae was developed. The present study showed that H. midae efficiently utilises extruded dry feeds containing conventional feed ingredients. Although technical difficulties were encountered in measuring apparent digestibility, it was concluded that the prospects for developing practical diets according to established nutritional principles are promising.
- Full Text:
- Date Issued: 1996
- Authors: Britz, Peter Jacobus
- Date: 1996
- Subjects: Abalones -- Nutrition Abalone culture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5307 , http://hdl.handle.net/10962/d1005152
- Description: The available literature on abalone nutrition was synthesised and the prospects for developing a complete pelleted dry feed for Haliotis midae evaluated. The similar body compositions, digestive structures, enzyme activity, acceptance of a wide variety of feed ingredients and comparable growth performance on formulated diets of various abalone species suggests that they have similar nutritional requirements. Abalone also appear to be similar to other farmed monogastric animals in that digestion is primarily extracelluar and they possess a large, muscular crop and stomach. Abalone energy metabolism is carbohydrate based. They are capable of digesting high levels of dietary protein but their ability to utilise fat is limited. Abalone have been shown to consume predictable amounts of dry feed which is efficiently converted into body weight. Efficiency indices of utilisation of formulated feeds, such as feed conversion ratio, protein efficiency ratio, net protein utilisation and apparent digestibility have been successfully applied to abalone. It was concluded that the prospects for developing complete diets for H. midae using a conventional animal feed science model were good. The ability of H. midae to utilise a range of proteins which had potential for inclusion in practical diets was investigated. Five protein rich ingredients, namely, casein, fishmeal, soya oil cake, Spirulina, and torula yeast, were fed to H. midae in semi-purified diets. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina based diets displayed significantly higher growth rates than diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed with P. corallorhiza were significantly lower than all other diets. All artificial diets yield lower feed conversion ratios (0.7-1.8) and higher protein efficiency ratios (3.3-6.5) ratios than the seaweed control diets (FCR = 2.8-3.4; PER = 2.2-3.0). The results indicated that fishmeal and Spirulina were the most suitable proteins for inclusion in practical diets for H. midae. The effect of protein level on growth rate and nutritional indices was evaluated by feeding starch bound, fishmeal based diets containing 27, 32, 37, 42 and 47% protein to juvenile H. midae. Weight gain was positively related to the level of dietary protein, increasing by 18% between 27% and 47% protein. Protein efficiency ratio declining from 3.2 to 2.3 with an increasing dietary protein content. Feed consumption rate was approximately 1% of body weight per day for all diets. Post-weaning abalone (ca. lOmm shell length, 0.2g) differed from larger juveniles (ca. 35mm, 8g) in their response to varying proportions of dietary protein and energy. The smaller animals appeared to have a lower protein requirement and poorer ability to utilise lipid than the larger juveniles. Proximate analyses revealed that the levels of protein, lipid and carbohydrate in abalone soft tissue increased with increasing dietary levels of these nutrients. Larger juveniles contained significantly higher levels of protein and carbohydrate, but lower levels of lipid, ash and moisture, than the smaller post-weaning abalone. The assimilation efficiency of [U-¹⁴C]-arginine by H. midae fed diets enriched with [U-¹⁴C]-arginine was only 0.45%. Furthennore, supplementation of diets with graded levels of crystalline arginine did not have any effect on growth rates. It was concluded that the prospects for defining the quantitative amino acid requirements of H. midae using crystalline amino acids are not promising. Rates of gastric evacuation and enzyme secretion were monitored in juvenile H. midae fed an extruded, fishmeal based dry feed. Gut fullness peaked 6h after feed was offered and the bulk of feed consumed was digested within 24 h. Enzyme secretion appeared to begin with the onset of feeding and continued for at least 6h after peak gut fullness was attained. Protease activity increased significantly following ingestion but amylase activity was maintained at a more or less constant level. A low level of lipase activity was observed suggesting that the ability of H. midae to digest fat is limited. The growth rate of H. midae fed an extruded, fishmeal based feed increased with increasing temperature between 12°C and 20°C. Between 20°C and 24°C a marked decline in growth rate accompanied by a deterioration in feed conversion and increased mortality was observed. Consumption of a dry pelleted feed was shown to be a function of body size and temperature. Based on these data a model which predicts a daily ration for H. midae was developed. The present study showed that H. midae efficiently utilises extruded dry feeds containing conventional feed ingredients. Although technical difficulties were encountered in measuring apparent digestibility, it was concluded that the prospects for developing practical diets according to established nutritional principles are promising.
- Full Text:
- Date Issued: 1996
The political significance of the liberal media coverage of District Six from 1949 to 1970
- Authors: Marquard, Andrew Keith
- Date: 1996
- Subjects: Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2802 , http://hdl.handle.net/10962/d1003012 , Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Description: The political significance of the media coverage of District Six is approached in the following way: the issue is approached theoretically by posing the question of the general political significance of news as a communicative form. This question is resolved by an examination of the complicated relationship between the tradition of political thought and the development of modem political forms, specifically the issue of the importance of communication in modern political forms. This is explored by considering the problem of the political outlined by Heller. Arendt reconceptua1izes the problem in terms of political judgement, which is discussed in relation to postmodernism and Wittgenstein's philosophy of language, to establish a new conceptualization of political judgement based on Arendt's view of narrative and Benjamin's writing on history. This conceptualization is used to formulated a notion of the general political significance of news, which is a form of political judgement related to a specific political culture. On this basis the media material is analysed in terms of two processes: the representation of District Six in the liberal media, and the representation of the political process surrounding its racial zoning and demolition. It is concluded that the media coverage of Distract Six during this period is characterized by a political culture termed the politics of the ordinary based on a reification of 'Europe' as part of a ' colonial attitude', and the idealization of specific urban forms, with a special relationship to urban planning. Thus the political significance of the media coverage resides in the perpetuation of this political culture, representative of the politics of the white English-speaking middle class, in terms of which an authentic urban politics is not conceivable. Additional conclusions are also drawn concerning the relationship between this political culture and the politics of Apartheid.
- Full Text:
- Date Issued: 1996
- Authors: Marquard, Andrew Keith
- Date: 1996
- Subjects: Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2802 , http://hdl.handle.net/10962/d1003012 , Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Description: The political significance of the media coverage of District Six is approached in the following way: the issue is approached theoretically by posing the question of the general political significance of news as a communicative form. This question is resolved by an examination of the complicated relationship between the tradition of political thought and the development of modem political forms, specifically the issue of the importance of communication in modern political forms. This is explored by considering the problem of the political outlined by Heller. Arendt reconceptua1izes the problem in terms of political judgement, which is discussed in relation to postmodernism and Wittgenstein's philosophy of language, to establish a new conceptualization of political judgement based on Arendt's view of narrative and Benjamin's writing on history. This conceptualization is used to formulated a notion of the general political significance of news, which is a form of political judgement related to a specific political culture. On this basis the media material is analysed in terms of two processes: the representation of District Six in the liberal media, and the representation of the political process surrounding its racial zoning and demolition. It is concluded that the media coverage of Distract Six during this period is characterized by a political culture termed the politics of the ordinary based on a reification of 'Europe' as part of a ' colonial attitude', and the idealization of specific urban forms, with a special relationship to urban planning. Thus the political significance of the media coverage resides in the perpetuation of this political culture, representative of the politics of the white English-speaking middle class, in terms of which an authentic urban politics is not conceivable. Additional conclusions are also drawn concerning the relationship between this political culture and the politics of Apartheid.
- Full Text:
- Date Issued: 1996
The pyrrolizidine alkaloids of Senecio chrysocoma and Senecio paniculatus
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996
The reintegration of Walvis Bay and its Penguin/Off-shore Island into Namibia
- Authors: Kodisang, J M
- Date: 1996
- Subjects: Penguin Islands , Walvis Bay (Namibia) -- International status , Namibia -- Politics and government , South Africa -- Foreign relations -- Namibia , Namibia -- Foreign relations -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2790 , http://hdl.handle.net/10962/d1003000 , Penguin Islands , Walvis Bay (Namibia) -- International status , Namibia -- Politics and government , South Africa -- Foreign relations -- Namibia , Namibia -- Foreign relations -- South Africa
- Description: The thesis focuses upon the final reintegration of Walvis Bay and its twelve Penguin/Off-Shore Islands into Namibia. As Namibia's only deep water port, it escaped reintegration in 1989 when the United Nations Security Council Resolution (UNSCR) 435 (1978) was implemented. Hence the study argues that the exclusion of Walvis Bay from the Settlement Plan falls outside the parameters of various UNSC and UN General Assembly Resolutions, viz 385 and 432 of 1976 respectively. Such an arrangement has to be looked at as Pretoria's non-compliance with the above resolutions. South Africa got away with such an arrangement with the blessing of the Western Contact Group of Nations, i.e the United States; Britain; (former West) Germany; France and Canada. The argument advances further to capture the sudden emergence of Walvis Bay as a dispute between the National Party regime and the African National Congress (ANC) in particular. The dispute came about when the National Party submitted a controversial constitutional proposal during South Africa's transition to democracy at Kempton Park. They were proposing Walvis Bay to constitute part of the new Western Cape province in the postapartheid South Africa. Namibia's diplomacy paid off when the return of Walvis Bay was agreed upon as it became entangled in the constitutional talks for South Africa's transition to democracy at Kempton Park in 1993-1994.
- Full Text:
- Date Issued: 1996
- Authors: Kodisang, J M
- Date: 1996
- Subjects: Penguin Islands , Walvis Bay (Namibia) -- International status , Namibia -- Politics and government , South Africa -- Foreign relations -- Namibia , Namibia -- Foreign relations -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2790 , http://hdl.handle.net/10962/d1003000 , Penguin Islands , Walvis Bay (Namibia) -- International status , Namibia -- Politics and government , South Africa -- Foreign relations -- Namibia , Namibia -- Foreign relations -- South Africa
- Description: The thesis focuses upon the final reintegration of Walvis Bay and its twelve Penguin/Off-Shore Islands into Namibia. As Namibia's only deep water port, it escaped reintegration in 1989 when the United Nations Security Council Resolution (UNSCR) 435 (1978) was implemented. Hence the study argues that the exclusion of Walvis Bay from the Settlement Plan falls outside the parameters of various UNSC and UN General Assembly Resolutions, viz 385 and 432 of 1976 respectively. Such an arrangement has to be looked at as Pretoria's non-compliance with the above resolutions. South Africa got away with such an arrangement with the blessing of the Western Contact Group of Nations, i.e the United States; Britain; (former West) Germany; France and Canada. The argument advances further to capture the sudden emergence of Walvis Bay as a dispute between the National Party regime and the African National Congress (ANC) in particular. The dispute came about when the National Party submitted a controversial constitutional proposal during South Africa's transition to democracy at Kempton Park. They were proposing Walvis Bay to constitute part of the new Western Cape province in the postapartheid South Africa. Namibia's diplomacy paid off when the return of Walvis Bay was agreed upon as it became entangled in the constitutional talks for South Africa's transition to democracy at Kempton Park in 1993-1994.
- Full Text:
- Date Issued: 1996
The reproduction biology of four species of South African dolphins
- Authors: Reddy, Kasturi
- Date: 1996
- Subjects: Dolphins -- South Africa -- Reproduction , Bottlenose dolphin -- Reproduction , Striped dolphin -- Reproduction , Chinese white dolphin -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5753 , http://hdl.handle.net/10962/d1005441 , Dolphins -- South Africa -- Reproduction , Bottlenose dolphin -- Reproduction , Striped dolphin -- Reproduction , Chinese white dolphin -- Reproduction
- Description: Seasonality of reproduction in common dolphins (Delphinus delphis), bottlenosed dolphins (Tursiops aduncus), striped dolphins (Stenella coeruleoalba) and humpbacked dolphins (Sousa chinensis) was examined using standard light microscope techniques. In the males four stages of testicular development could be identified. Individuals less than 2.26m in length and 105kg in mass had testes that contained small seminiferous tubules (0.048mm ± O.Olmm in diameter) and were classified either as juveniles (gonocytes present) or inactive (no gonocytes). Adults whose testes contained spermatozoa were said to be in late spermatogenesis while those whose testes contained no spermatids or spermatozoa were referred to as being in early spermatogenesis. In the males of D. delphis, T. aduncus and S. chinensis, late spermatogenesis occurred throughout the year and there was no significant difference in the monthly mean seminiferous tubule diameters (p > 0.05) within species. I conclude therefore that in these three species spermatogenesis is aseasonal. No conclusions about seasonality of spermatogenesis could be made for S. coeruleoalba owing to the small sample size. Large Graafian follicles occurred in the ovaries of all four species in most months of the year. However, the presence of Graafian follicles can not be taken as an indication of timing of reproduction since they may be remnants of follicles that have not yet degenerated. In D. delphis, T. aduncus and S. coeruleoalba luteal bodies (corpora albicans or corpora lutea) occurred in most months of the year. Active corpora lutea will be present in all months, in some members of the population, since gestation is approximately 12 months. The sperm structure of D. delphis was examined by scanning electron microscopy. The sperm of D. delphis is essentially similar to that described for two other species of Cetacea (Physeter catodon and Tursiops aduncus), having an ellipsoidally shaped head and a short mid-piece with nine mitochondria. The sperm dimensions for D. delphis were head length, 4.4pm; head width, 2.0pm and mid-piece length, 2.4pm. An analysis of foetal age in D. delphis showed that the majority of the foetuses were conceived in January with birth occurring the following summer (December), suggesting that reproduction is seasonal. Neonates of T. aduncus were found throughout the year suggesting aseasonal reproduction. Foetal material was not available for S. coeruleoalba and S. chinensis. Seasonality of reproduction in the four species of dolphins studied has been discussed in relation to feeding, migration and worldwide distribution of the species.
- Full Text:
- Date Issued: 1996
- Authors: Reddy, Kasturi
- Date: 1996
- Subjects: Dolphins -- South Africa -- Reproduction , Bottlenose dolphin -- Reproduction , Striped dolphin -- Reproduction , Chinese white dolphin -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5753 , http://hdl.handle.net/10962/d1005441 , Dolphins -- South Africa -- Reproduction , Bottlenose dolphin -- Reproduction , Striped dolphin -- Reproduction , Chinese white dolphin -- Reproduction
- Description: Seasonality of reproduction in common dolphins (Delphinus delphis), bottlenosed dolphins (Tursiops aduncus), striped dolphins (Stenella coeruleoalba) and humpbacked dolphins (Sousa chinensis) was examined using standard light microscope techniques. In the males four stages of testicular development could be identified. Individuals less than 2.26m in length and 105kg in mass had testes that contained small seminiferous tubules (0.048mm ± O.Olmm in diameter) and were classified either as juveniles (gonocytes present) or inactive (no gonocytes). Adults whose testes contained spermatozoa were said to be in late spermatogenesis while those whose testes contained no spermatids or spermatozoa were referred to as being in early spermatogenesis. In the males of D. delphis, T. aduncus and S. chinensis, late spermatogenesis occurred throughout the year and there was no significant difference in the monthly mean seminiferous tubule diameters (p > 0.05) within species. I conclude therefore that in these three species spermatogenesis is aseasonal. No conclusions about seasonality of spermatogenesis could be made for S. coeruleoalba owing to the small sample size. Large Graafian follicles occurred in the ovaries of all four species in most months of the year. However, the presence of Graafian follicles can not be taken as an indication of timing of reproduction since they may be remnants of follicles that have not yet degenerated. In D. delphis, T. aduncus and S. coeruleoalba luteal bodies (corpora albicans or corpora lutea) occurred in most months of the year. Active corpora lutea will be present in all months, in some members of the population, since gestation is approximately 12 months. The sperm structure of D. delphis was examined by scanning electron microscopy. The sperm of D. delphis is essentially similar to that described for two other species of Cetacea (Physeter catodon and Tursiops aduncus), having an ellipsoidally shaped head and a short mid-piece with nine mitochondria. The sperm dimensions for D. delphis were head length, 4.4pm; head width, 2.0pm and mid-piece length, 2.4pm. An analysis of foetal age in D. delphis showed that the majority of the foetuses were conceived in January with birth occurring the following summer (December), suggesting that reproduction is seasonal. Neonates of T. aduncus were found throughout the year suggesting aseasonal reproduction. Foetal material was not available for S. coeruleoalba and S. chinensis. Seasonality of reproduction in the four species of dolphins studied has been discussed in relation to feeding, migration and worldwide distribution of the species.
- Full Text:
- Date Issued: 1996
The role of microzooplankton in carbon cycling in the Southern Ocean
- Authors: Froneman, Pierre William
- Date: 1996
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21066 , http://hdl.handle.net/10962/6234
- Description: A 3-year study was carried out on the role of microzooplankton in carbon cycling in the south Atlantic and the Atlantic sector of the Southern Ocean. Microzooplankton grazing impact on phytoplankton was estimated during austral summer and winter employing the dilution technique. Carnivory by larger zooplankton on microzooplankton during summer was estimated using in vitro incubations. Microzooplankton assemblages were always dominated by protozoans comprising ciliates and dinoflagellates. In the ( 20 um chlorophyll fraction, microzooplankton grazing was sufficient to control the growth of the nano- and picophytoplankton suggesting that, where larger microphytoplankton cells dominate, micro zooplankton maintain the background concentrations of the nano- and picophytoplankton. During winter, when small nano- and picophytoplankton cells dominate total chlorophyll concentrations, the microzooplankton grazing impact on phytoplankton is dramatically increased. Microzooplankton removed on average 37% of the initial phytoplankton stock or 70% of the daily phytoplankton production. These results suggest that in winter, micro zooplankton are the main sink for phytoplankton production. Carnivory experiments conducted with selected meso- (copepods) and macro zooplankton (euphausiids and tunicates) showed that all species examined consumed micro zooplankton in the presence of substantial chlorophyll concentrations. Microzooplankton can, therefore, be regarded as trophic intermediates between bacterioplankton, small phytoplankton cells and larger zooplankton species in the Southern Ocean. The results of this investigation suggest a spatiotemporal shift in efficiency of the biological pump mediated by changes in the size composition of the phytoplankton assemblages. South of the Antarctic Polar Front (APF) large IV microphytoplankton cells dominate the summer chlorophyll biomass, suggesting that larger zooplankton grazers represent the main sink for phytoplankton production. Under these conditions, carbon flux to the interior of the ocean will be high due to diel vertical migrations by grazers and the production of large, fast sinking faecal pellets. The sedimentation of large phytoplankton cells also contributes to flux. In the permanently open waters south of the APF and throughout the Southern Ocean during winter, small phytoplankton cells dominate total chlorophyll, resulting in the microbial loop being the main sink for phytoplankton production. The close coupling between the micro zooplankton and the microbial loop dramatically reduces the transfer of organic carbon from the surface layers to depth. Carnivory by metazoans on microzooplankton may reduce the high grazing impact of micro zooplankton and, may also represent an important source of carbon flux originating from the microbial loop.
- Full Text:
- Date Issued: 1996
- Authors: Froneman, Pierre William
- Date: 1996
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21066 , http://hdl.handle.net/10962/6234
- Description: A 3-year study was carried out on the role of microzooplankton in carbon cycling in the south Atlantic and the Atlantic sector of the Southern Ocean. Microzooplankton grazing impact on phytoplankton was estimated during austral summer and winter employing the dilution technique. Carnivory by larger zooplankton on microzooplankton during summer was estimated using in vitro incubations. Microzooplankton assemblages were always dominated by protozoans comprising ciliates and dinoflagellates. In the ( 20 um chlorophyll fraction, microzooplankton grazing was sufficient to control the growth of the nano- and picophytoplankton suggesting that, where larger microphytoplankton cells dominate, micro zooplankton maintain the background concentrations of the nano- and picophytoplankton. During winter, when small nano- and picophytoplankton cells dominate total chlorophyll concentrations, the microzooplankton grazing impact on phytoplankton is dramatically increased. Microzooplankton removed on average 37% of the initial phytoplankton stock or 70% of the daily phytoplankton production. These results suggest that in winter, micro zooplankton are the main sink for phytoplankton production. Carnivory experiments conducted with selected meso- (copepods) and macro zooplankton (euphausiids and tunicates) showed that all species examined consumed micro zooplankton in the presence of substantial chlorophyll concentrations. Microzooplankton can, therefore, be regarded as trophic intermediates between bacterioplankton, small phytoplankton cells and larger zooplankton species in the Southern Ocean. The results of this investigation suggest a spatiotemporal shift in efficiency of the biological pump mediated by changes in the size composition of the phytoplankton assemblages. South of the Antarctic Polar Front (APF) large IV microphytoplankton cells dominate the summer chlorophyll biomass, suggesting that larger zooplankton grazers represent the main sink for phytoplankton production. Under these conditions, carbon flux to the interior of the ocean will be high due to diel vertical migrations by grazers and the production of large, fast sinking faecal pellets. The sedimentation of large phytoplankton cells also contributes to flux. In the permanently open waters south of the APF and throughout the Southern Ocean during winter, small phytoplankton cells dominate total chlorophyll, resulting in the microbial loop being the main sink for phytoplankton production. The close coupling between the micro zooplankton and the microbial loop dramatically reduces the transfer of organic carbon from the surface layers to depth. Carnivory by metazoans on microzooplankton may reduce the high grazing impact of micro zooplankton and, may also represent an important source of carbon flux originating from the microbial loop.
- Full Text:
- Date Issued: 1996
The role of student writing in learning in zoology
- Authors: Moore, Robin Stanley
- Date: 1996
- Subjects: Zoology -- Study and teaching Communication in science -- Study and teaching Science -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1752 , http://hdl.handle.net/10962/d1003636
- Description: In this study I attempt to develop a rationale for the role of student writing in advancing learning in Zoology. To this end, I use the informed and insightful voices of five academics from the University of Cape Town's Department of Zoology to present a picture of the goals of the discipline, how they view the role that student writing plays in advan~ing these goals, a sense of the tensions they face in dealing with student diversity, and the promise and challenges of innovative approaches. My interest in how staff view student writing stems from a belief that staff make use of student writing in different ways, depending on their assumptions about writing. I explore these assumptions by means of interviews with members of staff, in which I ask about how they understand the pursuit of science, the qualities a scientist needs to develop, the best ways to develop these qualities in students, and the part that student writing plays in this development. What emerges in this study is the understanding that the kinds of writing we ask students to do reflect the forms of educational practice that we sustain. On the one hand, certain forms of writing may support forms of transmission pedagogy that are viewed as being at odds with progressive science education. On the other hand, if we are to develop alternative teaching approaches which are in keeping with contemporary views of science and learning, then we need to develop new genres of student writing that give expression to these goals and methods. The study concludes with suggested avenues into curriculum review that would operationalise the insights developed by this study.
- Full Text:
- Date Issued: 1996
- Authors: Moore, Robin Stanley
- Date: 1996
- Subjects: Zoology -- Study and teaching Communication in science -- Study and teaching Science -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1752 , http://hdl.handle.net/10962/d1003636
- Description: In this study I attempt to develop a rationale for the role of student writing in advancing learning in Zoology. To this end, I use the informed and insightful voices of five academics from the University of Cape Town's Department of Zoology to present a picture of the goals of the discipline, how they view the role that student writing plays in advan~ing these goals, a sense of the tensions they face in dealing with student diversity, and the promise and challenges of innovative approaches. My interest in how staff view student writing stems from a belief that staff make use of student writing in different ways, depending on their assumptions about writing. I explore these assumptions by means of interviews with members of staff, in which I ask about how they understand the pursuit of science, the qualities a scientist needs to develop, the best ways to develop these qualities in students, and the part that student writing plays in this development. What emerges in this study is the understanding that the kinds of writing we ask students to do reflect the forms of educational practice that we sustain. On the one hand, certain forms of writing may support forms of transmission pedagogy that are viewed as being at odds with progressive science education. On the other hand, if we are to develop alternative teaching approaches which are in keeping with contemporary views of science and learning, then we need to develop new genres of student writing that give expression to these goals and methods. The study concludes with suggested avenues into curriculum review that would operationalise the insights developed by this study.
- Full Text:
- Date Issued: 1996
The role of the cadence as determining factor of phrasing of the organ toccatas, preludes and fantasias of Johann Sebastian Bach
- Authors: Du Plooy, Jacobus Stephanus
- Date: 1996
- Subjects: Bach, Johann Sebastian, 1685-1750 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2636 , http://hdl.handle.net/10962/d1002301
- Description: This study examines the phrasing of J.S. Bach's preludes, toccatas and fantasias for organ. Consequent upon Bach's silence on the subject and the inadequacy of available sources, the cadence has been used as a means to determine the phrasing of these works. The goal of this thesis is to identify those characteristics of the cadence that can assist the performer in two ways: On the one hand, to select the appropriate type of break between phrases, and, the other hand, selecting the appropriate changes in tempo and articulation essential to the shaping of phrases. The term, 'cadence', therefore, applies not merely to an isolated entity of two chords, but rather to a broader formula including the progressions towards and away from it. This investigation follows an eclectic approach. Accordingly, the exploration of various sources is combined with diverse methods of analyses. The first method is a detailed structural analysis of Bach's cadential progressions, and more specifically, the way in which he integrated the basic musical elements into them. This shows the points of tension and relaxation, two musico-psychological effects fundamental to any decision regarding phrasing. The second method puts Bach's cadences within the context of the larger musical structure, including the 'extra-musical' (i.e. grammatical, rhetorical and 'affective') forms. This method organises cadences according to their various punctuation functions, hence main and secondary cadences. The cadences of twenty-eight works - those works of which the authenticity is more or less secure - are analysed. Descriptions cover a selection from these works considered to be the most representative. A significant number of examples, induding performing suggestions, accompany and elaborate in detail on all descriptions of cadences. An application of the findings is presented by an analysis and di scussion that elaborates in detail on the suggested performance of two works, BWV 542 and 541. These two works epitomize, and simultaneously form the culmination of the two principal styles (i.e. the improvisatory and motorically-orientated) prevalent in Bach's free organ works. Examination of the findings of this study and implications for further research conclude this thesis.
- Full Text:
- Date Issued: 1996
- Authors: Du Plooy, Jacobus Stephanus
- Date: 1996
- Subjects: Bach, Johann Sebastian, 1685-1750 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2636 , http://hdl.handle.net/10962/d1002301
- Description: This study examines the phrasing of J.S. Bach's preludes, toccatas and fantasias for organ. Consequent upon Bach's silence on the subject and the inadequacy of available sources, the cadence has been used as a means to determine the phrasing of these works. The goal of this thesis is to identify those characteristics of the cadence that can assist the performer in two ways: On the one hand, to select the appropriate type of break between phrases, and, the other hand, selecting the appropriate changes in tempo and articulation essential to the shaping of phrases. The term, 'cadence', therefore, applies not merely to an isolated entity of two chords, but rather to a broader formula including the progressions towards and away from it. This investigation follows an eclectic approach. Accordingly, the exploration of various sources is combined with diverse methods of analyses. The first method is a detailed structural analysis of Bach's cadential progressions, and more specifically, the way in which he integrated the basic musical elements into them. This shows the points of tension and relaxation, two musico-psychological effects fundamental to any decision regarding phrasing. The second method puts Bach's cadences within the context of the larger musical structure, including the 'extra-musical' (i.e. grammatical, rhetorical and 'affective') forms. This method organises cadences according to their various punctuation functions, hence main and secondary cadences. The cadences of twenty-eight works - those works of which the authenticity is more or less secure - are analysed. Descriptions cover a selection from these works considered to be the most representative. A significant number of examples, induding performing suggestions, accompany and elaborate in detail on all descriptions of cadences. An application of the findings is presented by an analysis and di scussion that elaborates in detail on the suggested performance of two works, BWV 542 and 541. These two works epitomize, and simultaneously form the culmination of the two principal styles (i.e. the improvisatory and motorically-orientated) prevalent in Bach's free organ works. Examination of the findings of this study and implications for further research conclude this thesis.
- Full Text:
- Date Issued: 1996
The significance of trade policy in promoting the international competitiveness of South African industry
- Authors: Hofmeyr, Lynne Mary
- Date: 1996
- Subjects: South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2781 , http://hdl.handle.net/10962/d1002991 , South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Description: This study proposes to examme the significance of trade policy in promoting the international competitiveness of South African industry during the period from the early 1970s up until the present day. By providing a background of South Africa's past trade policies, it is argued that the origins of South Africa's low levels of competitiveness essentially lie in the apartheid years where trade policies were not linked to the attainment of international competitiveness and improved productivity. The study then reviews the development of South Africa's trade policies in the 1990s. In so doing, it reveals weaknesses in the areas of implementation which are critiqued in greater detail by using the clothing and textile industries as a case study, and other selected examples. The study finally concludes that trade policy is crucial to global competitiveness and that it is the responsibility of all parties concerned to ensure that trade policies enhance and not inhibit competitiveness.
- Full Text:
- Date Issued: 1996
- Authors: Hofmeyr, Lynne Mary
- Date: 1996
- Subjects: South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2781 , http://hdl.handle.net/10962/d1002991 , South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Description: This study proposes to examme the significance of trade policy in promoting the international competitiveness of South African industry during the period from the early 1970s up until the present day. By providing a background of South Africa's past trade policies, it is argued that the origins of South Africa's low levels of competitiveness essentially lie in the apartheid years where trade policies were not linked to the attainment of international competitiveness and improved productivity. The study then reviews the development of South Africa's trade policies in the 1990s. In so doing, it reveals weaknesses in the areas of implementation which are critiqued in greater detail by using the clothing and textile industries as a case study, and other selected examples. The study finally concludes that trade policy is crucial to global competitiveness and that it is the responsibility of all parties concerned to ensure that trade policies enhance and not inhibit competitiveness.
- Full Text:
- Date Issued: 1996
The social identity and inter-group attitudes of white English- and Afrikaans-speaking adolescents
- Authors: Smith, Timothy Byron
- Date: 1996
- Subjects: Afrikaners -- Ethnic identity , Whites -- South Africa -- Attitudes , Teenagers -- South Africa -- Attitudes , Youth -- South Africa -- Attitudes , Identity (Psychology) in adolescence , Prejudices -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3059 , http://hdl.handle.net/10962/d1002568 , Afrikaners -- Ethnic identity , Whites -- South Africa -- Attitudes , Teenagers -- South Africa -- Attitudes , Youth -- South Africa -- Attitudes , Identity (Psychology) in adolescence , Prejudices -- South Africa
- Description: Issues of group identity and prejudice have played a large role in the history of South Africa. To examine differences between White English- and Afrikaans-speaking adolescents within the context of the "new" South Africa, data was collected from 553 high school students using a questionnaire which assessed aspects of these groups' perceptions of themselves (their identities), attitudes toward other racial groups (their prejudices), and beliefs about their rapidly changing socio-political environment. A discriminant function analysis conducted with these variables correctly identified group membership at a rate much higher than chance (p < .00001). Post hoc univariate analyses indicated that compared with Afrikaans-speakers, English-speakers demonstrated significantly less identification with their own culture, less racial prejudice but also less willingness to make retribution to those who were oppressed by Apartheid, and less concern/confusion over the recent changes which have taken place in the country. Descriptive and correlational analyses also provided additional, valuable information regarding the variables assessed in the study. Overall, the results seemed to indicate that the adolescent subjects of this study find themselves in a state of transition.
- Full Text:
- Date Issued: 1996
- Authors: Smith, Timothy Byron
- Date: 1996
- Subjects: Afrikaners -- Ethnic identity , Whites -- South Africa -- Attitudes , Teenagers -- South Africa -- Attitudes , Youth -- South Africa -- Attitudes , Identity (Psychology) in adolescence , Prejudices -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3059 , http://hdl.handle.net/10962/d1002568 , Afrikaners -- Ethnic identity , Whites -- South Africa -- Attitudes , Teenagers -- South Africa -- Attitudes , Youth -- South Africa -- Attitudes , Identity (Psychology) in adolescence , Prejudices -- South Africa
- Description: Issues of group identity and prejudice have played a large role in the history of South Africa. To examine differences between White English- and Afrikaans-speaking adolescents within the context of the "new" South Africa, data was collected from 553 high school students using a questionnaire which assessed aspects of these groups' perceptions of themselves (their identities), attitudes toward other racial groups (their prejudices), and beliefs about their rapidly changing socio-political environment. A discriminant function analysis conducted with these variables correctly identified group membership at a rate much higher than chance (p < .00001). Post hoc univariate analyses indicated that compared with Afrikaans-speakers, English-speakers demonstrated significantly less identification with their own culture, less racial prejudice but also less willingness to make retribution to those who were oppressed by Apartheid, and less concern/confusion over the recent changes which have taken place in the country. Descriptive and correlational analyses also provided additional, valuable information regarding the variables assessed in the study. Overall, the results seemed to indicate that the adolescent subjects of this study find themselves in a state of transition.
- Full Text:
- Date Issued: 1996
The taxonomy and life-history of Argyrosomus japonicus and A. inodorus, two important sciaenids off the South African coast
- Authors: Griffiths, Marc H
- Date: 1996
- Subjects: Argyrosomus Sciaenidae -- South Africa Sciaenidae -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5323 , http://hdl.handle.net/10962/d1005169
- Description: A study of the biology, anatomy and taxonomy of the sciaenid fishes of the genus Argyrosomus from South Africa and Namibia revealed that three species were confused under the name "Argyrosomus Izololepidotus (Lacepède 1801)". Comparison of morphometric and meristic data, otoliths, swim-bladders, drumming muscles, and other morphological features of specimens from southern Africa, Madagascar, the Mediterranean, the eastern Atlantic Ocean, Japan and Australia, revealed that "A. hololepidotus" is a complex of four species: A. japonicus (Temminck & Schlegel 1843), which occurs off southern Africa, Japan and Australia; A. inodorus sp. nov., which is known from Namibia to the Kei River (32°40'S) on the east coast of South Africa; A. coronus sp. nov., which is known from central and northern Namibia and Angola, and A. hololepidotus, which appears to be endemic to Madagascar. Both A. japonicus and A. inodorus are important recreational and commercial linefish species in South Africa. Although A. inodorus occurs on the east and west coasts of South Africa, and A. japonicus is found between Cape Point and Mozambique, the former species is abundant only between Cape Point and the Kei River, and the latter species from Cape Agulhas to northern KwaZulu/Natal. The life-histories of Argyrosomus japonicus and A. inodorus, within these respective ranges, were elucidated using length-at-age, reproductive, catch and effort, size composition, otolith dimension/fish length and tagging data. Median sizes at maturity (L₅₀) for A. japonicus were 920 mm TL (5 years) for males and 1070 mm TL (6 years) for females. All males >1100 mm TL (7 years) and all females >1200 mm TL (8 years) were mature. Females grew faster than males, but in both sexes growth slowed dramatically after maturity. Maximum age recorded was 42 years, but fish older than 27 years were rare. Adult A. japonicus were predominantly found in the nearshore marine environment, but also occurred in estuaries and in the surf zone. Spawning takes place in the nearshore environment, from August to November in Natal, and from October to January in the Southern and South-Eastern Cape regions. A large proportion of the adult population migrate to Natal to spawn, although spawning may continue once they return to the Cape. Early juveniles of 20-30 mm TL recruit into turbid estuaries along the entire east coast, possibly aided by olfactory cues. They appear to remain in the upper reaches of the estuaries where they find suitable food and refuge from predators until they grow to about 150 mm TL. Juveniles larger than this size were found in the middle and lower reaches of estuaries and also in the surf zone. Juvenile A. japonicus (<1000 mm TL) generally did not migrate long distances, but remained as separate sub-stocks until they reached maturity. A. inodorus grows more slowly than A. japonicus, and attains a lower maximum age (25 years) and a smaller maximum size (34 vs 75 kg). There was no significant difference between the growth rates of male and female A. inodorus. Those in the South-Westem Cape initially grew faster than those on the east coast, but growth slowed sooner in the former region with the result that these fish attained a smaller maximum size. Although ripe A. inodorus were sampled throughout the year, there was a distinct spawning season from August to December, with a peak in spring (Sept-Nov). Spawning occurred throughout the study area for this species, in <50 m depth. Size at sexual maturity for A. inodorus was smaller in the South-Eastern Cape than in the Southern Cape. Median size at maturity for females was attained at 310 mm TL (1.3 years) in the former and at 375 mm TL (2.4 years) in the latter region, and the length at which all females were mature was 400 mm (3.5 years) and 550 mm (4.7 years) respectively. For males the estimates of Lso and total maturity were 200 mm (1 year) and 400 mm (2.8 years) for the SouthEastern Cape and 250 mm (1.5 years) and 450 mm (3.4 years) in the Southern Cape. East of Cape Agulhas, A. inodorus was found from just beyond the surf zone to depths of 120 m. Adults occurred predominantly on reef (>20 m) while juveniles were found mainly over soft substrata of sand/mud (5-120 m depth). Early juveniles do not enter estuaries, but apparently recruit to nursery areas immediately beyond the backline of breakers (5-10 m depth), and then move seawards with growth. No juveniles were obtained from the area west of Cape Agulhas as substrates <200 m depth were unsuitable for trawling. Due to lower water temperatures, the adults in this area were found from within the surf zone to depths of only 20 m. East and west of Cape Agulhas there was evidence of offshore dispersal in winter, in response to oceanographic changes. Based upon otolith morphology, juvenile and adult distribution patterns, sizes at sexual maturity and on tagging data, A. inodorus between Cape Point and the Kei River apparently exist as three separate stocks, one in the South-Eastern Cape, one in the Southern Cape and one in the South-Western Cape, with limited exchange. The life-histories of A. japonicus and A. inodorus are discussed in terms of their management. The large size at maturity of A. japonicus together with evidence for considerable human impact on the early juvenile, juvenile, and the adult phases of the life-cycle indicate that estuarine nursery habitats need to be conserved, that the minimum size limit should be increased, and that current bag limits for this species should be reviewed. Although the current minimum size limit provides protection for A. illodorus until maturity, evidence is presented which indicates that at least one and possibly all of the stocks of this species are currently over-exploited. Stock assessment of the South African A. japonicus and A. inodorus resources, and the implementation of effective management strategies, are therefore a matter of urgency.
- Full Text:
- Date Issued: 1996
- Authors: Griffiths, Marc H
- Date: 1996
- Subjects: Argyrosomus Sciaenidae -- South Africa Sciaenidae -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5323 , http://hdl.handle.net/10962/d1005169
- Description: A study of the biology, anatomy and taxonomy of the sciaenid fishes of the genus Argyrosomus from South Africa and Namibia revealed that three species were confused under the name "Argyrosomus Izololepidotus (Lacepède 1801)". Comparison of morphometric and meristic data, otoliths, swim-bladders, drumming muscles, and other morphological features of specimens from southern Africa, Madagascar, the Mediterranean, the eastern Atlantic Ocean, Japan and Australia, revealed that "A. hololepidotus" is a complex of four species: A. japonicus (Temminck & Schlegel 1843), which occurs off southern Africa, Japan and Australia; A. inodorus sp. nov., which is known from Namibia to the Kei River (32°40'S) on the east coast of South Africa; A. coronus sp. nov., which is known from central and northern Namibia and Angola, and A. hololepidotus, which appears to be endemic to Madagascar. Both A. japonicus and A. inodorus are important recreational and commercial linefish species in South Africa. Although A. inodorus occurs on the east and west coasts of South Africa, and A. japonicus is found between Cape Point and Mozambique, the former species is abundant only between Cape Point and the Kei River, and the latter species from Cape Agulhas to northern KwaZulu/Natal. The life-histories of Argyrosomus japonicus and A. inodorus, within these respective ranges, were elucidated using length-at-age, reproductive, catch and effort, size composition, otolith dimension/fish length and tagging data. Median sizes at maturity (L₅₀) for A. japonicus were 920 mm TL (5 years) for males and 1070 mm TL (6 years) for females. All males >1100 mm TL (7 years) and all females >1200 mm TL (8 years) were mature. Females grew faster than males, but in both sexes growth slowed dramatically after maturity. Maximum age recorded was 42 years, but fish older than 27 years were rare. Adult A. japonicus were predominantly found in the nearshore marine environment, but also occurred in estuaries and in the surf zone. Spawning takes place in the nearshore environment, from August to November in Natal, and from October to January in the Southern and South-Eastern Cape regions. A large proportion of the adult population migrate to Natal to spawn, although spawning may continue once they return to the Cape. Early juveniles of 20-30 mm TL recruit into turbid estuaries along the entire east coast, possibly aided by olfactory cues. They appear to remain in the upper reaches of the estuaries where they find suitable food and refuge from predators until they grow to about 150 mm TL. Juveniles larger than this size were found in the middle and lower reaches of estuaries and also in the surf zone. Juvenile A. japonicus (<1000 mm TL) generally did not migrate long distances, but remained as separate sub-stocks until they reached maturity. A. inodorus grows more slowly than A. japonicus, and attains a lower maximum age (25 years) and a smaller maximum size (34 vs 75 kg). There was no significant difference between the growth rates of male and female A. inodorus. Those in the South-Westem Cape initially grew faster than those on the east coast, but growth slowed sooner in the former region with the result that these fish attained a smaller maximum size. Although ripe A. inodorus were sampled throughout the year, there was a distinct spawning season from August to December, with a peak in spring (Sept-Nov). Spawning occurred throughout the study area for this species, in <50 m depth. Size at sexual maturity for A. inodorus was smaller in the South-Eastern Cape than in the Southern Cape. Median size at maturity for females was attained at 310 mm TL (1.3 years) in the former and at 375 mm TL (2.4 years) in the latter region, and the length at which all females were mature was 400 mm (3.5 years) and 550 mm (4.7 years) respectively. For males the estimates of Lso and total maturity were 200 mm (1 year) and 400 mm (2.8 years) for the SouthEastern Cape and 250 mm (1.5 years) and 450 mm (3.4 years) in the Southern Cape. East of Cape Agulhas, A. inodorus was found from just beyond the surf zone to depths of 120 m. Adults occurred predominantly on reef (>20 m) while juveniles were found mainly over soft substrata of sand/mud (5-120 m depth). Early juveniles do not enter estuaries, but apparently recruit to nursery areas immediately beyond the backline of breakers (5-10 m depth), and then move seawards with growth. No juveniles were obtained from the area west of Cape Agulhas as substrates <200 m depth were unsuitable for trawling. Due to lower water temperatures, the adults in this area were found from within the surf zone to depths of only 20 m. East and west of Cape Agulhas there was evidence of offshore dispersal in winter, in response to oceanographic changes. Based upon otolith morphology, juvenile and adult distribution patterns, sizes at sexual maturity and on tagging data, A. inodorus between Cape Point and the Kei River apparently exist as three separate stocks, one in the South-Eastern Cape, one in the Southern Cape and one in the South-Western Cape, with limited exchange. The life-histories of A. japonicus and A. inodorus are discussed in terms of their management. The large size at maturity of A. japonicus together with evidence for considerable human impact on the early juvenile, juvenile, and the adult phases of the life-cycle indicate that estuarine nursery habitats need to be conserved, that the minimum size limit should be increased, and that current bag limits for this species should be reviewed. Although the current minimum size limit provides protection for A. illodorus until maturity, evidence is presented which indicates that at least one and possibly all of the stocks of this species are currently over-exploited. Stock assessment of the South African A. japonicus and A. inodorus resources, and the implementation of effective management strategies, are therefore a matter of urgency.
- Full Text:
- Date Issued: 1996