An investigation into the executive mayoral system, with reference to the Nelson Mandela Metropolitan Municipality
- Authors: Nkayitshana, Zweledinga
- Date: 2003
- Subjects: Mayors -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech (Public Management)
- Identifier: vital:10775 , http://hdl.handle.net/10948/246 , Mayors -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth
- Description: In this mini-dissertation, a study is undertaken for an investigation into the Executive Mayoral System with reference to the Nelson Mandela Metropolitan Municipality. The mini-dissertation comprises of five chapters. The study is based on the assumption that the introduction of an executive mayoral system will enhance the decision-making and policy-making processes at the Nelson Mandela Metropolitan Municipality. This is also based on the assumption that all local authorities and the Nelson Mandela Metropolitan Municipality in particular are faced with challenges of developmental local government. The Executive Mayoral System, therefore, is expected to provide possible solutions and avenues to promote and improve socio-economic development and service delivery to strengthen the local tax base. Another challenging aspect is the capacity building for the staff members of the Nelson Mandela Metropolitan Municipality especially the Executive Mayor who has all the powers vested in him. The main objectives of the research include, inter alia, to provide a brief theoretical background explanation regarding the reasons for the existence of local authorities and restructuring of local government in South Africa. To investigate and report on the implementation of the new mandate for local government with reference to the Executive Mayoral System at the Nelson Mandela Metropolitan Municipality. To investigate whether the Executive Mayoral System at the NMMM will contribute towards efficient and effective service delivery. This will be followed by the impact of the Metropole to promote and encourage community involvement on all the programmes of the municipality. This investigation will ensure that the Nelson Mandela Metropolitan Municipality provides conducive environment for socio-economic development and achieve the national economic strategy under Growth, Employment and Redistribution (GEAR) policy. To bring about experiences from other countries and learn from those experiences based on their approach to the Executive Mayoral System. An overview of the legislative framework and an explanation of selected policies for the Executive Mayoral System are made. Finally, a number of conclusions that were arrived during the study, followed by various recommendations are made. These are based on the qualitative research analysis in order to come up with solutions of ensuring sustainable service delivery with the Executive Mayoral System.
- Full Text:
- Date Issued: 2003
- Authors: Nkayitshana, Zweledinga
- Date: 2003
- Subjects: Mayors -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech (Public Management)
- Identifier: vital:10775 , http://hdl.handle.net/10948/246 , Mayors -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth
- Description: In this mini-dissertation, a study is undertaken for an investigation into the Executive Mayoral System with reference to the Nelson Mandela Metropolitan Municipality. The mini-dissertation comprises of five chapters. The study is based on the assumption that the introduction of an executive mayoral system will enhance the decision-making and policy-making processes at the Nelson Mandela Metropolitan Municipality. This is also based on the assumption that all local authorities and the Nelson Mandela Metropolitan Municipality in particular are faced with challenges of developmental local government. The Executive Mayoral System, therefore, is expected to provide possible solutions and avenues to promote and improve socio-economic development and service delivery to strengthen the local tax base. Another challenging aspect is the capacity building for the staff members of the Nelson Mandela Metropolitan Municipality especially the Executive Mayor who has all the powers vested in him. The main objectives of the research include, inter alia, to provide a brief theoretical background explanation regarding the reasons for the existence of local authorities and restructuring of local government in South Africa. To investigate and report on the implementation of the new mandate for local government with reference to the Executive Mayoral System at the Nelson Mandela Metropolitan Municipality. To investigate whether the Executive Mayoral System at the NMMM will contribute towards efficient and effective service delivery. This will be followed by the impact of the Metropole to promote and encourage community involvement on all the programmes of the municipality. This investigation will ensure that the Nelson Mandela Metropolitan Municipality provides conducive environment for socio-economic development and achieve the national economic strategy under Growth, Employment and Redistribution (GEAR) policy. To bring about experiences from other countries and learn from those experiences based on their approach to the Executive Mayoral System. An overview of the legislative framework and an explanation of selected policies for the Executive Mayoral System are made. Finally, a number of conclusions that were arrived during the study, followed by various recommendations are made. These are based on the qualitative research analysis in order to come up with solutions of ensuring sustainable service delivery with the Executive Mayoral System.
- Full Text:
- Date Issued: 2003
An investigation into the feeding biology and factors influencing the population dynamics of Terebrasabella heterouncinata (Polychaeta: Sabellidae), a problematic tube-dwelling polychaete in farmed abalone in South Africa
- Authors: Chalmers, Russell
- Date: 2003
- Subjects: Polychaeta -- South Africa , Sabellidae -- South Africa , Abalones -- Feeding and feeds -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5291 , http://hdl.handle.net/10962/d1005136 , Polychaeta -- South Africa , Sabellidae -- South Africa , Abalones -- Feeding and feeds -- South Africa
- Description: Since the discovery of a new species of sabellid worm in 1993, the Californian and South African abalone industries have experienced increasing shell breakage and reduced growth rates of abalone, resulting in reduced market value of product. This polychaete worm can reach very high infestation levels. It was described as Terebrasabella heterouncinata in 1999, having originated from the South African coastline where it had been observed on several wild mollusc species. Although not a shell borer, it occupies tubes on the growing edge which are formed by deposition of nacreous shell over sabellid larvae by the host abalone. Heavy sabellid infestation levels have placed the economic viability of several South African farms under threat. Past research methods have not been successful in establishing effective means of eradication or control, partly due to the lack of knowledge of basic biological information on this species. This study forms the first part of an ongoing research project into the biology of terebrasabella heterouncinata. Abalone farms in South African utilise two main diets in abalone culture. An artificial formulated feed, Abfeed, is produced in South Africa and is used by the majority of farms as it increases abalone growth rate. Kelp, a natural diet of abalone, is harvested and also used as a feed. Farmers have observed higher sabellid infestation levels on Abfeed-fed abalone and suspect that diet may be an important factor influencing sabellid infestation. Abalone stocking density has also been identified as a potential factor influencing sabellid population growth on commercial farms. In order to better understand sabellid nutrition, the feeding behaviour of the sabellid in response to suspended solids of various particle size classes from both abalone diets were investigated. Both the effect of abalone diet and stocking density and their effects on sabellid morphometrics were quantified. The proximate composition and particle size distribution of suspended-solids present within kelp and Abfeed abalone raceways were also quantified. Results indicate that sabellid feeding follows no structured behavioural pattern for both abalone diets. The quantity of suspended solids in kelp raceways was greater than in Abfeed raceways (p<0.02) while there was no difference in particulate level between three abalone stocking densities (p>0.05). Protein (p<0.0001) and energy (p<0.0.1) levels of suspended solids were significantly greater in raceways dedicated to feeding Abfeed. The infestation level (number of tubes/centimetre on the grwoing edge) was significantly higher (p<0.001) in Abfeed-fed abalone. The morphometrics of the sabellids indicated that sabellids from Abfeed-fed abalone were larger in various body measurements: length (p<0.00001); neck width (p<0.001); base width (p<0.001); and surface area (p<0.001). This study suggests that abalone diet has an important influence on the infestation level and size of sabellids and that this is likely to be due to the fragmentation and leaching of nutrients from the artificially enriched commercial abalone diet.
- Full Text:
- Date Issued: 2003
- Authors: Chalmers, Russell
- Date: 2003
- Subjects: Polychaeta -- South Africa , Sabellidae -- South Africa , Abalones -- Feeding and feeds -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5291 , http://hdl.handle.net/10962/d1005136 , Polychaeta -- South Africa , Sabellidae -- South Africa , Abalones -- Feeding and feeds -- South Africa
- Description: Since the discovery of a new species of sabellid worm in 1993, the Californian and South African abalone industries have experienced increasing shell breakage and reduced growth rates of abalone, resulting in reduced market value of product. This polychaete worm can reach very high infestation levels. It was described as Terebrasabella heterouncinata in 1999, having originated from the South African coastline where it had been observed on several wild mollusc species. Although not a shell borer, it occupies tubes on the growing edge which are formed by deposition of nacreous shell over sabellid larvae by the host abalone. Heavy sabellid infestation levels have placed the economic viability of several South African farms under threat. Past research methods have not been successful in establishing effective means of eradication or control, partly due to the lack of knowledge of basic biological information on this species. This study forms the first part of an ongoing research project into the biology of terebrasabella heterouncinata. Abalone farms in South African utilise two main diets in abalone culture. An artificial formulated feed, Abfeed, is produced in South Africa and is used by the majority of farms as it increases abalone growth rate. Kelp, a natural diet of abalone, is harvested and also used as a feed. Farmers have observed higher sabellid infestation levels on Abfeed-fed abalone and suspect that diet may be an important factor influencing sabellid infestation. Abalone stocking density has also been identified as a potential factor influencing sabellid population growth on commercial farms. In order to better understand sabellid nutrition, the feeding behaviour of the sabellid in response to suspended solids of various particle size classes from both abalone diets were investigated. Both the effect of abalone diet and stocking density and their effects on sabellid morphometrics were quantified. The proximate composition and particle size distribution of suspended-solids present within kelp and Abfeed abalone raceways were also quantified. Results indicate that sabellid feeding follows no structured behavioural pattern for both abalone diets. The quantity of suspended solids in kelp raceways was greater than in Abfeed raceways (p<0.02) while there was no difference in particulate level between three abalone stocking densities (p>0.05). Protein (p<0.0001) and energy (p<0.0.1) levels of suspended solids were significantly greater in raceways dedicated to feeding Abfeed. The infestation level (number of tubes/centimetre on the grwoing edge) was significantly higher (p<0.001) in Abfeed-fed abalone. The morphometrics of the sabellids indicated that sabellids from Abfeed-fed abalone were larger in various body measurements: length (p<0.00001); neck width (p<0.001); base width (p<0.001); and surface area (p<0.001). This study suggests that abalone diet has an important influence on the infestation level and size of sabellids and that this is likely to be due to the fragmentation and leaching of nutrients from the artificially enriched commercial abalone diet.
- Full Text:
- Date Issued: 2003
An investigation into the induction of oxidative stress and apoptosis by microcystin-LR in the CaCo2 cell line and intestinal tract of Balb/c mice
- Authors: Botha, Nicolette
- Date: 2003
- Subjects: Microcystis aeruginosa -- Toxicology , Apoptosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11066 , http://hdl.handle.net/10948/349 , Microcystis aeruginosa -- Toxicology , Apoptosis
- Description: This study reports the findings on the effect of Microcystin-LR (MCLR) on the gastrointestinal tract cells of mice and on two different cell lines, Caco2 and MCF-7. The cyanobacterium Microcystis aeruginosa produces the potent toxin, MCLR. This toxin has been implicated in a number of cases of ill-health. It was decided to investigate whether microcystin-LR induced apoptosis in the gastrointestinal tract of mice and also which possible mechanisms were involved in the induction in vitro. Balb/c mice were given a 75% LD50 intraperitoneal dose of pure microcystin -LR and sacrificed at 8, 16, 24 and 32 hours post-exposure. The small intestinal sections were stained with haematoxylin and eosin and examined for apoptotic cells. There was a time-dependent increase in the number of apoptotic cells with most in the duodenum and the jejunum. No change in glycogen content was evident at 24 hours post exposure when PAS-stained sections were examined. To determine that microcystin was the agent responsible for the changes, fluoroscein isothiocyanate (FITC) immunostaining for the toxin was done on the sections. Apoptosis in vitro was investigated in Caco2, a cell line that behaves like normal enterocytes when the cells are differentiated at confluency, and MCF-7, a breast cancer cell line deficient in pro-caspase-3, cells by 3-[dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays and by staining with DAPI and Rhodamine 123. MCLR exposure induced apoptosis, as seen in decreased cell viability and increased leakage of LDH, as well as mitochondrial damage shown by Rhodamine staining. The MCF-7 cells, deficient in pro-caspase-3, and Caco2 cells did not show cleavage of poly(ADP)ribose polymerase (PARP) after exposure to 50μM MCLR after 72 hours exposure. Both micro- and milli-calpain activity was however significantly increased in both cell lines exposed to the toxin. There was a significant increase in H2O2, one of the key reactive oxygen species, production during the first 30 minutes that the cells were exposed to 50 mM MCLR.
- Full Text:
- Date Issued: 2003
- Authors: Botha, Nicolette
- Date: 2003
- Subjects: Microcystis aeruginosa -- Toxicology , Apoptosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11066 , http://hdl.handle.net/10948/349 , Microcystis aeruginosa -- Toxicology , Apoptosis
- Description: This study reports the findings on the effect of Microcystin-LR (MCLR) on the gastrointestinal tract cells of mice and on two different cell lines, Caco2 and MCF-7. The cyanobacterium Microcystis aeruginosa produces the potent toxin, MCLR. This toxin has been implicated in a number of cases of ill-health. It was decided to investigate whether microcystin-LR induced apoptosis in the gastrointestinal tract of mice and also which possible mechanisms were involved in the induction in vitro. Balb/c mice were given a 75% LD50 intraperitoneal dose of pure microcystin -LR and sacrificed at 8, 16, 24 and 32 hours post-exposure. The small intestinal sections were stained with haematoxylin and eosin and examined for apoptotic cells. There was a time-dependent increase in the number of apoptotic cells with most in the duodenum and the jejunum. No change in glycogen content was evident at 24 hours post exposure when PAS-stained sections were examined. To determine that microcystin was the agent responsible for the changes, fluoroscein isothiocyanate (FITC) immunostaining for the toxin was done on the sections. Apoptosis in vitro was investigated in Caco2, a cell line that behaves like normal enterocytes when the cells are differentiated at confluency, and MCF-7, a breast cancer cell line deficient in pro-caspase-3, cells by 3-[dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays and by staining with DAPI and Rhodamine 123. MCLR exposure induced apoptosis, as seen in decreased cell viability and increased leakage of LDH, as well as mitochondrial damage shown by Rhodamine staining. The MCF-7 cells, deficient in pro-caspase-3, and Caco2 cells did not show cleavage of poly(ADP)ribose polymerase (PARP) after exposure to 50μM MCLR after 72 hours exposure. Both micro- and milli-calpain activity was however significantly increased in both cell lines exposed to the toxin. There was a significant increase in H2O2, one of the key reactive oxygen species, production during the first 30 minutes that the cells were exposed to 50 mM MCLR.
- Full Text:
- Date Issued: 2003
An investigation into the neuroprotective properties of curcumin
- Authors: Daniel, Sheril
- Date: 2003
- Subjects: Turmeric -- Therapeutic use , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3753 , http://hdl.handle.net/10962/d1003231 , Turmeric -- Therapeutic use , Nervous system -- Degeneration -- Prevention
- Description: An increasing number of studies show that nutritional antioxidants such as vitamin E and polyphenols are capable of blocking neuronal death in vitro and may have therapeutic properties in animal models of neurodegenerative diseases including Alzheimer’s and Parkinson’s diseases. In the present study, the neuroprotective ability of one such polyphenolic antioxidant, curcumin, was investigated. Curcumin is the yellow curry spice derived from turmeric, and is widely used as a dietary component and herbal medicine in India. Most neurological disorders are postulated to have an oxidative or excitototoxic basis. Thus the effects of curcumin on oxidative stress in the rat brain were investigated. Curcumin, administered to the rat in vivo and in vitro, was able to exert protective effects on oxidative damage in the brain, induced by cyanide, a mitochondrial inhibitor. Curcumin also offered protection against quinolinic acid induced lipid peroxidation, and this protection was extended to lipid peroxidation induced by metals such as lead and cadmium in the rat brain. Experiments conducted on the pineal gland revealed an increased production of the neuroprotective hormone melatonin in presence of curcumin in vivo. The hippocampus is functionally related to vital behaviour and intellectual activities and is known to be a primary target for neuronal degeneration in the brains of patients with Alzheimer’s disease. Histological studies were undertaken to assess the effects of curcumin on lead induced toxicity on the rat hippocampus, the results of which show that curcumin affords significant protection to the hippocampus of the lead treated rats. This study also sought to elucidate possible mechanisms by which curcumin exerts its neuroprotective capabilities. Curcumin was found to inhibit the action of cyanide on the mitochondrial electron transport chain, one of the most common sources of free radicals. Electrochemical, UV/VIS and Infrared spectroscopy were used to characterise interactions between curcumin and the metals lead, cadmium, iron (II) and iron (III). Curcumin was shown to directly chelate these metals with the formation and isolation of two new curcumin complexes with lead, and one complex each with cadmium and iron (III). These results suggest chelation of toxic metals as a mechanism of neuroprotection afforded by curcumin. The need for neuroprotective agents is urgent considering the rapid rise in the elderly population and the proportionate increase in neurological disorders. The findings of this study indicate that curcumin, a well-established dietary antioxidant, is capable of playing a bigger role in neuroprotection, which needs to be further explored and exploited.
- Full Text:
- Date Issued: 2003
- Authors: Daniel, Sheril
- Date: 2003
- Subjects: Turmeric -- Therapeutic use , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3753 , http://hdl.handle.net/10962/d1003231 , Turmeric -- Therapeutic use , Nervous system -- Degeneration -- Prevention
- Description: An increasing number of studies show that nutritional antioxidants such as vitamin E and polyphenols are capable of blocking neuronal death in vitro and may have therapeutic properties in animal models of neurodegenerative diseases including Alzheimer’s and Parkinson’s diseases. In the present study, the neuroprotective ability of one such polyphenolic antioxidant, curcumin, was investigated. Curcumin is the yellow curry spice derived from turmeric, and is widely used as a dietary component and herbal medicine in India. Most neurological disorders are postulated to have an oxidative or excitototoxic basis. Thus the effects of curcumin on oxidative stress in the rat brain were investigated. Curcumin, administered to the rat in vivo and in vitro, was able to exert protective effects on oxidative damage in the brain, induced by cyanide, a mitochondrial inhibitor. Curcumin also offered protection against quinolinic acid induced lipid peroxidation, and this protection was extended to lipid peroxidation induced by metals such as lead and cadmium in the rat brain. Experiments conducted on the pineal gland revealed an increased production of the neuroprotective hormone melatonin in presence of curcumin in vivo. The hippocampus is functionally related to vital behaviour and intellectual activities and is known to be a primary target for neuronal degeneration in the brains of patients with Alzheimer’s disease. Histological studies were undertaken to assess the effects of curcumin on lead induced toxicity on the rat hippocampus, the results of which show that curcumin affords significant protection to the hippocampus of the lead treated rats. This study also sought to elucidate possible mechanisms by which curcumin exerts its neuroprotective capabilities. Curcumin was found to inhibit the action of cyanide on the mitochondrial electron transport chain, one of the most common sources of free radicals. Electrochemical, UV/VIS and Infrared spectroscopy were used to characterise interactions between curcumin and the metals lead, cadmium, iron (II) and iron (III). Curcumin was shown to directly chelate these metals with the formation and isolation of two new curcumin complexes with lead, and one complex each with cadmium and iron (III). These results suggest chelation of toxic metals as a mechanism of neuroprotection afforded by curcumin. The need for neuroprotective agents is urgent considering the rapid rise in the elderly population and the proportionate increase in neurological disorders. The findings of this study indicate that curcumin, a well-established dietary antioxidant, is capable of playing a bigger role in neuroprotection, which needs to be further explored and exploited.
- Full Text:
- Date Issued: 2003
An investigation into the occurrence of major abscess causing bacteria at the law meat exporting abattoir in the Northern Cape province of South Africa
- Authors: Delport, Riëtte
- Date: 2003
- Subjects: Abscess , Meat -- Microbiology , Slaughtering and slaughter-houses -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10971 , http://hdl.handle.net/10948/249 , Abscess , Meat -- Microbiology , Slaughtering and slaughter-houses -- South Africa -- Northern Cape
- Description: The main objectives of this study can be divided into four categories: a) The determination of the presence of abscesses in carcasses. b) The determination whether the abscesses are area bound. c) The determination of the causative bacteria which is responsible for abscess formation. d) The determination of the economic impact due to carcass rejections and trimmings. The research area consists of the biggest part of the Northern Cape province, which can further be divided into three main production areas, namely Groblershoop, Gordonia and Hantam. The Groblershoop area includes Groblershoop and the surrounding districts. The Gordonia area includes Upington and the Kalahari. The Hantam area includes Calvinia, Springbok and the other districts bordering the areas. All the carcasses were slaughtered at an export abattoir, namely LAW, which is situated in Groblershoop. The Upington veterinary laboratory bacteriologically cultured the abscess material and the results were processed and noted. The following results were prominent: a) It was determined that abscesses did occur in carcasses. b) It was determined that in the Hantam main production area the prevalence of abscesses is the highest, although the slaughter numbers are the lowest. c) It was determined that the bacterium that was responsible for most of the abscesses was Escherichia coli. d) It was determined that the total occurrence of bacteria did not have a significant economic impact, because there were not many carcass rejections due to abscesses. The economic impact, however, of the value of the total rejections, might become a problem.
- Full Text:
- Date Issued: 2003
- Authors: Delport, Riëtte
- Date: 2003
- Subjects: Abscess , Meat -- Microbiology , Slaughtering and slaughter-houses -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10971 , http://hdl.handle.net/10948/249 , Abscess , Meat -- Microbiology , Slaughtering and slaughter-houses -- South Africa -- Northern Cape
- Description: The main objectives of this study can be divided into four categories: a) The determination of the presence of abscesses in carcasses. b) The determination whether the abscesses are area bound. c) The determination of the causative bacteria which is responsible for abscess formation. d) The determination of the economic impact due to carcass rejections and trimmings. The research area consists of the biggest part of the Northern Cape province, which can further be divided into three main production areas, namely Groblershoop, Gordonia and Hantam. The Groblershoop area includes Groblershoop and the surrounding districts. The Gordonia area includes Upington and the Kalahari. The Hantam area includes Calvinia, Springbok and the other districts bordering the areas. All the carcasses were slaughtered at an export abattoir, namely LAW, which is situated in Groblershoop. The Upington veterinary laboratory bacteriologically cultured the abscess material and the results were processed and noted. The following results were prominent: a) It was determined that abscesses did occur in carcasses. b) It was determined that in the Hantam main production area the prevalence of abscesses is the highest, although the slaughter numbers are the lowest. c) It was determined that the bacterium that was responsible for most of the abscesses was Escherichia coli. d) It was determined that the total occurrence of bacteria did not have a significant economic impact, because there were not many carcass rejections due to abscesses. The economic impact, however, of the value of the total rejections, might become a problem.
- Full Text:
- Date Issued: 2003
An investigation into the relationship marketing strategies applied by Eastern Cape based travel agents
- Authors: Fisher, Gary
- Date: 2003
- Subjects: Relationship marketing -- South Africa -- Eastern Cape , Travel agents -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10766 , http://hdl.handle.net/10948/251 , Relationship marketing -- South Africa -- Eastern Cape , Travel agents -- South Africa -- Eastern Cape
- Description: Relationship marketing has grown in importance. This growth affects all industries, including the tourism, hospitality and travel industry. Of particular importance is the bond of relationship marketing between suppliers (principals) and retailers (travel agents) in the distribution channel. The research was undertaken to: determine whether Eastern Cape travel agents perceive relationship marketing as important; establish, what the key elements of relationship marketing strategies are,according to literature; determine what marketing strategies are currently applied by Eastern Cape travel agents; provide guidelines to Eastern Cape travel agents to implement or improve their relationship marketing strategies. Fifty self-administered questionnaires were distributed to the entire population of travel agents in the Eastern Cape. A total of 30 travel agents responded. The empirical findings showed that: Most Eastern Cape travel agents perceived relationship marketing as important; Travel agents realized the importance of the management of such relationship marketing strategies; Most travel agents were aware of or used retention strategies to enhance relationship marketing strategies; Travel agents realized that to survive relationship marketing should be part of their future planning; All respondents believed that to successfully implement relationship marketing, all staff, from front-line to top-management, need to be committed to the programme. In conclusion, relationship marketing is growing in importance and all role players need to acknowledge and manage this trend. However, this research has shown that there is a paradigm shift as more travel agents are moving away from the traditional marketing to relationship marketing.
- Full Text:
- Date Issued: 2003
- Authors: Fisher, Gary
- Date: 2003
- Subjects: Relationship marketing -- South Africa -- Eastern Cape , Travel agents -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10766 , http://hdl.handle.net/10948/251 , Relationship marketing -- South Africa -- Eastern Cape , Travel agents -- South Africa -- Eastern Cape
- Description: Relationship marketing has grown in importance. This growth affects all industries, including the tourism, hospitality and travel industry. Of particular importance is the bond of relationship marketing between suppliers (principals) and retailers (travel agents) in the distribution channel. The research was undertaken to: determine whether Eastern Cape travel agents perceive relationship marketing as important; establish, what the key elements of relationship marketing strategies are,according to literature; determine what marketing strategies are currently applied by Eastern Cape travel agents; provide guidelines to Eastern Cape travel agents to implement or improve their relationship marketing strategies. Fifty self-administered questionnaires were distributed to the entire population of travel agents in the Eastern Cape. A total of 30 travel agents responded. The empirical findings showed that: Most Eastern Cape travel agents perceived relationship marketing as important; Travel agents realized the importance of the management of such relationship marketing strategies; Most travel agents were aware of or used retention strategies to enhance relationship marketing strategies; Travel agents realized that to survive relationship marketing should be part of their future planning; All respondents believed that to successfully implement relationship marketing, all staff, from front-line to top-management, need to be committed to the programme. In conclusion, relationship marketing is growing in importance and all role players need to acknowledge and manage this trend. However, this research has shown that there is a paradigm shift as more travel agents are moving away from the traditional marketing to relationship marketing.
- Full Text:
- Date Issued: 2003
An investigation into whether a leadership and management development project changed the perceptions of the educators in a black, disadvantaged school
- Authors: Jaftha, A P
- Date: 2003
- Subjects: University of Port Elizabeth -- Institute for Development Planning and Research Delta Foundation -- Centres of Learning School management and organization -- South Africa Educational leadership -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1620 , http://hdl.handle.net/10962/d1003502
- Description: This study investigates whether a leadership and management development programme changed the management perceptions of the teachers of one of the schools that participated in the programme. The programme seeks to change the organisational culture of schools and develop effective management. The development philosophy of the programme is informed by literature on school effectiveness, organisation development, whole school development and systemic change. My research is conducted in the interpretive paradigm. Interpretive researchers view reality a construct of the human mind, and therefore the way people perceive the world is not necessarily the same since there can be different understandings of what is real. I employ convenience sampling to select the school and purposive sampling to identify my research participants. Whilst overall impression that the data conveys is that much of the programme does not seem to have had a lasting effect on the culture of the school, it nonetheless made an impression on the teachers’ perceptions of management. There clearly seems to be a greater appreciation of participative management processes. The reintroduction of proper prior planning played a decisive role in re-establishing sound work ethics at the school and contributes to a more structured approach to events at the school. Some sort of organisational learning has also been introduced at the school. The realisation on the part of the staff that they now have their destiny in their own hands is an especially critical development. And whilst the vision is not a compelling force in the organisation, it has nevertheless produced some strategic focus at the school. The insights and skills they acquired concerning resource management will also stand them in good stead.
- Full Text:
- Date Issued: 2003
- Authors: Jaftha, A P
- Date: 2003
- Subjects: University of Port Elizabeth -- Institute for Development Planning and Research Delta Foundation -- Centres of Learning School management and organization -- South Africa Educational leadership -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1620 , http://hdl.handle.net/10962/d1003502
- Description: This study investigates whether a leadership and management development programme changed the management perceptions of the teachers of one of the schools that participated in the programme. The programme seeks to change the organisational culture of schools and develop effective management. The development philosophy of the programme is informed by literature on school effectiveness, organisation development, whole school development and systemic change. My research is conducted in the interpretive paradigm. Interpretive researchers view reality a construct of the human mind, and therefore the way people perceive the world is not necessarily the same since there can be different understandings of what is real. I employ convenience sampling to select the school and purposive sampling to identify my research participants. Whilst overall impression that the data conveys is that much of the programme does not seem to have had a lasting effect on the culture of the school, it nonetheless made an impression on the teachers’ perceptions of management. There clearly seems to be a greater appreciation of participative management processes. The reintroduction of proper prior planning played a decisive role in re-establishing sound work ethics at the school and contributes to a more structured approach to events at the school. Some sort of organisational learning has also been introduced at the school. The realisation on the part of the staff that they now have their destiny in their own hands is an especially critical development. And whilst the vision is not a compelling force in the organisation, it has nevertheless produced some strategic focus at the school. The insights and skills they acquired concerning resource management will also stand them in good stead.
- Full Text:
- Date Issued: 2003
An investigation of code switching in different learning areas in a grade seven class
- Authors: Ndabeni, Bulelwa
- Date: 2003
- Subjects: Code switching (Linguistics) -- South Africa Language and education -- South Africa Education, Bilingual -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1621 , http://hdl.handle.net/10962/d1003503
- Description: The research described in this thesis is a case study of the communicative repertoires of teachers and learners of a grade seven class in a small rural primary school. The aim of the investigation was to find out if code switching is different in content-subject classes than in an English language class. The study accomplishes this by looking at code switching in different learning areas. Different research techniques such as observations, video. recording, taking of field notes and interviews are used as the means of data collection. The study does not attempt a full linguistic description of the switches made by the research subjects. For example, it does not deal with linguistic constraints on code switching, but instead it focuses on the functional aspects of code switching. The study reveals that there are various functions of code switching in the classroom. The following are the major findings noted in this study: • Code switching is a communicative resource, which enables the teachers and learners to accomplish a considerable number and range of social and educational objectives. • Code switching is used to negotiate and renegotiate meaning. • How teachers code switch in class depends on how difficult the lesson is for the learners. • The study reveals no major differences between code switching In content subjects than in English as a subject. • Although tbe subjects engage in code switching, they seem to feel guilty about their behaviour.
- Full Text:
- Date Issued: 2003
- Authors: Ndabeni, Bulelwa
- Date: 2003
- Subjects: Code switching (Linguistics) -- South Africa Language and education -- South Africa Education, Bilingual -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1621 , http://hdl.handle.net/10962/d1003503
- Description: The research described in this thesis is a case study of the communicative repertoires of teachers and learners of a grade seven class in a small rural primary school. The aim of the investigation was to find out if code switching is different in content-subject classes than in an English language class. The study accomplishes this by looking at code switching in different learning areas. Different research techniques such as observations, video. recording, taking of field notes and interviews are used as the means of data collection. The study does not attempt a full linguistic description of the switches made by the research subjects. For example, it does not deal with linguistic constraints on code switching, but instead it focuses on the functional aspects of code switching. The study reveals that there are various functions of code switching in the classroom. The following are the major findings noted in this study: • Code switching is a communicative resource, which enables the teachers and learners to accomplish a considerable number and range of social and educational objectives. • Code switching is used to negotiate and renegotiate meaning. • How teachers code switch in class depends on how difficult the lesson is for the learners. • The study reveals no major differences between code switching In content subjects than in English as a subject. • Although tbe subjects engage in code switching, they seem to feel guilty about their behaviour.
- Full Text:
- Date Issued: 2003
An investigation of female leaders' perceptions of themselves and their roles as leaders in a Catholic School
- Authors: Kauaria, Vejanda
- Date: 2003
- Subjects: Catholic schools -- Namibia -- Administration Women school administrators -- Namibia School management and organization -- Namibia Educational leadership -- Namibia Women in public life -- Namibia Sex discrimination against women -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1626 , http://hdl.handle.net/10962/d1003508
- Description: The question of gender in leadership continues to be a contentious and poorly understood phenomenon. There seems general agreement that women do lead differently from men, and this study begins from that premise, focusing on a case in which leadership has traditionally been the domain of females. The case was chosen for its uniqueness, the assumption being that in these circumstances leadership may have developed particular characteristics. Following a qualitative approach (drawing on phenomenology), the study seeks to investigate how women leaders experience their roles as leaders. In-depth interviews made it possible for me to capture the perceptions and experiences of the three women leaders I interviewed. The study reveals that women are more inclined to use interactive styles of leadership. Women use leadership that is more participative, negotiative, cooperative, shared and collaborative. These characteristics are in line with the features of transformational leadership which differs from the more traditional transactional leadership that is more controlled and directive. The study has also shown that leadership develops from within the person of the leader as the leader is the one who spearheads the organization through vision, ideas, beliefs andassumptions. The findings of this study suggest thus that unless women are given chances to prove how they can lead, this new approach of leadership within them and that is required by modern organizations would be lost and leadership would remain relatively unchanged and undesirable. In the context of Namibia, this study should be of potential significance because of the rapid change that is taking place in the inclusion of women in leadership and management positions in education.
- Full Text:
- Date Issued: 2003
- Authors: Kauaria, Vejanda
- Date: 2003
- Subjects: Catholic schools -- Namibia -- Administration Women school administrators -- Namibia School management and organization -- Namibia Educational leadership -- Namibia Women in public life -- Namibia Sex discrimination against women -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1626 , http://hdl.handle.net/10962/d1003508
- Description: The question of gender in leadership continues to be a contentious and poorly understood phenomenon. There seems general agreement that women do lead differently from men, and this study begins from that premise, focusing on a case in which leadership has traditionally been the domain of females. The case was chosen for its uniqueness, the assumption being that in these circumstances leadership may have developed particular characteristics. Following a qualitative approach (drawing on phenomenology), the study seeks to investigate how women leaders experience their roles as leaders. In-depth interviews made it possible for me to capture the perceptions and experiences of the three women leaders I interviewed. The study reveals that women are more inclined to use interactive styles of leadership. Women use leadership that is more participative, negotiative, cooperative, shared and collaborative. These characteristics are in line with the features of transformational leadership which differs from the more traditional transactional leadership that is more controlled and directive. The study has also shown that leadership develops from within the person of the leader as the leader is the one who spearheads the organization through vision, ideas, beliefs andassumptions. The findings of this study suggest thus that unless women are given chances to prove how they can lead, this new approach of leadership within them and that is required by modern organizations would be lost and leadership would remain relatively unchanged and undesirable. In the context of Namibia, this study should be of potential significance because of the rapid change that is taking place in the inclusion of women in leadership and management positions in education.
- Full Text:
- Date Issued: 2003
An investigation of knowledge management implementation strategies
- Authors: Sunassee, Nakkiran N
- Date: 2003
- Subjects: Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1141 , http://hdl.handle.net/10962/d1002770 , Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Description: The world is experiencing an era which has been termed the “knowledge age” or the “knowledge economy”. In this new context, knowledge is the primary commodity, and knowledge flows are regarded as the most important factors in the economy. The management of knowledge flows within organisations has become a crucial activity because many of the activities of organisations and the broader economic and social life today are knowledge-driven. In recent years, this managerial activity has become known as Knowledge Management. Equally important are the associated Knowledge Management implementation strategies. Driven by a need expressed by the South African Motor Vehicle Industry for a knowledge management implementation strategy tailored to their needs, this research aimed to develop a knowledge management implementation strategy suited to the needs of this industry. Following an extensive literature survey and a study of the target industry using Duffy’s Knowledge Benchmarking Questionnaire, a model of knowledge management implementation is proposed that is suited to the needs of the South African Motor Vehicle Industry. The model consists of three main interlinked components: Knowledge Management of the Organisation, People, and Infrastructure and Processes. Furthermore, the model recommends a holistic approach to managing knowledge. The critical success factors of the model were tested by means of a survey of industry opinions that validated certain aspects of the model and motivated for changes in others. Additionally, despite the focus of the model on the target industry, it is considered sufficiently appropriate for use by other organisations.
- Full Text:
- Date Issued: 2003
- Authors: Sunassee, Nakkiran N
- Date: 2003
- Subjects: Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1141 , http://hdl.handle.net/10962/d1002770 , Knowledge management , Strategic planning , Automobile industry and trade -- South Africa -- Management
- Description: The world is experiencing an era which has been termed the “knowledge age” or the “knowledge economy”. In this new context, knowledge is the primary commodity, and knowledge flows are regarded as the most important factors in the economy. The management of knowledge flows within organisations has become a crucial activity because many of the activities of organisations and the broader economic and social life today are knowledge-driven. In recent years, this managerial activity has become known as Knowledge Management. Equally important are the associated Knowledge Management implementation strategies. Driven by a need expressed by the South African Motor Vehicle Industry for a knowledge management implementation strategy tailored to their needs, this research aimed to develop a knowledge management implementation strategy suited to the needs of this industry. Following an extensive literature survey and a study of the target industry using Duffy’s Knowledge Benchmarking Questionnaire, a model of knowledge management implementation is proposed that is suited to the needs of the South African Motor Vehicle Industry. The model consists of three main interlinked components: Knowledge Management of the Organisation, People, and Infrastructure and Processes. Furthermore, the model recommends a holistic approach to managing knowledge. The critical success factors of the model were tested by means of a survey of industry opinions that validated certain aspects of the model and motivated for changes in others. Additionally, despite the focus of the model on the target industry, it is considered sufficiently appropriate for use by other organisations.
- Full Text:
- Date Issued: 2003
An investigation of knowledge management practices in the Old Mutual, Buffalo City Metropole branch
- Authors: Siqoko, Kolisa
- Date: 2003
- Subjects: Knowledge management , Insurance companies -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10879 , http://hdl.handle.net/10948/252 , Knowledge management , Insurance companies -- South Africa -- East London
- Description: The study has sought to examine knowledge management practice in the Old Mutual, Buffalo City Metropole. The study has been conducted against the backdrop of measuring how far South African companies are in applying Knowledge Management (KM) tools and techniques to improve their competitive advantage. The study was conducted based on the assumption that insurance companies in South Africa are at the forefront in the use and application of technology. Various concepts are defined throughout the study. In reviewing literature for example, the study introduces the reader to various theories, views and approaches to KM. The most significant of these are the cultural and social systems approach on one hand and the product or process approach on the other. The study relied on the use of a variety of data collection methods such as questionnaires, interviews and participant observation for the purposes of collecting primary data. From the primary data collected, it was discovered that the largest number of responses came from marketing, sales and customer services departments. The employees have limited flexibility in terms of decision making and team work, due to the rigidity of tasks. The findings revealed that the company has a loosely structured infrastructure, where each strategic business unit (SBU) manages its own IT tools and documents. All these underlying aspects are not conducive to the promotion of and growth of KM in any company. The final chapter concludes with a model for KM implementation and the procedures to be followed to ensure that the practice adds value to the company.
- Full Text:
- Date Issued: 2003
- Authors: Siqoko, Kolisa
- Date: 2003
- Subjects: Knowledge management , Insurance companies -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10879 , http://hdl.handle.net/10948/252 , Knowledge management , Insurance companies -- South Africa -- East London
- Description: The study has sought to examine knowledge management practice in the Old Mutual, Buffalo City Metropole. The study has been conducted against the backdrop of measuring how far South African companies are in applying Knowledge Management (KM) tools and techniques to improve their competitive advantage. The study was conducted based on the assumption that insurance companies in South Africa are at the forefront in the use and application of technology. Various concepts are defined throughout the study. In reviewing literature for example, the study introduces the reader to various theories, views and approaches to KM. The most significant of these are the cultural and social systems approach on one hand and the product or process approach on the other. The study relied on the use of a variety of data collection methods such as questionnaires, interviews and participant observation for the purposes of collecting primary data. From the primary data collected, it was discovered that the largest number of responses came from marketing, sales and customer services departments. The employees have limited flexibility in terms of decision making and team work, due to the rigidity of tasks. The findings revealed that the company has a loosely structured infrastructure, where each strategic business unit (SBU) manages its own IT tools and documents. All these underlying aspects are not conducive to the promotion of and growth of KM in any company. The final chapter concludes with a model for KM implementation and the procedures to be followed to ensure that the practice adds value to the company.
- Full Text:
- Date Issued: 2003
An investigation of the relative importance of the media in influencing the voting behaviour of Evelyn Hone College students in Lusaka during the December, 2001 presidential elections in Zambia
- Authors: Jere, Caesar
- Date: 2003
- Subjects: Voting -- Zambia Mass media -- Political aspects -- Zambia Presidents -- Zambia -- Election -- 2001
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3516 , http://hdl.handle.net/10962/d1007803
- Description: This study explores the relative importance of the media in influencing the electoral choices of a small group of Zambians, namely Evelyn Hone College students in Lusaka who participated in the December 2001 elections in Zambia. The study investigates the interplay of mediation between the lived cultural experiences of the sample of students and the impact of media messages. Students at Evelyn Hone College come from different ethnic groupings, social classes, religions and regions. They are exposed to both the state and the privately owned media, which represent a range of political viewpoints. The outcome of the December 2001 elections in Zambia gave the impression that people in urban areas in Zambia were less likely to vote on ethnic lines because they had easy access to different media, ranging from print to electronic, which provided them with diverse information about the political scene, and probably shaped their electoral choices. Conversely, their counterparts in the rural areas appeared to vote along ethnic lines, seemingly because of lack of exposure to the media. It was also assumed that most people in rural areas were not as modernized as their urban counterparts who were more exposed to enlightened sources of information such as professional groups and other elite social institutions which helped them to shape their political opinions than most rural people. The study attempts to establish to what extent the media impacted on the selected sample of urban students in the choice of their presidential candidates in the December 2001 elections in Zambia. The study further investigates to what extent other factors such as ethnic inclinations and other social predispositions influenced them in their choice of the candidates. The interviewees for this study were randomly drawn from a population of Evelyn Hone College students that voted in the December 2001 presidential elections in Zambia. The sample consisted of 30 randomly selected students who were purposely stratified in three focus groups of ten each. Each stratum represented the approximate ethnic equivalence of one of the presidential candidates who contested the December 2001 elections.
- Full Text:
- Date Issued: 2003
- Authors: Jere, Caesar
- Date: 2003
- Subjects: Voting -- Zambia Mass media -- Political aspects -- Zambia Presidents -- Zambia -- Election -- 2001
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3516 , http://hdl.handle.net/10962/d1007803
- Description: This study explores the relative importance of the media in influencing the electoral choices of a small group of Zambians, namely Evelyn Hone College students in Lusaka who participated in the December 2001 elections in Zambia. The study investigates the interplay of mediation between the lived cultural experiences of the sample of students and the impact of media messages. Students at Evelyn Hone College come from different ethnic groupings, social classes, religions and regions. They are exposed to both the state and the privately owned media, which represent a range of political viewpoints. The outcome of the December 2001 elections in Zambia gave the impression that people in urban areas in Zambia were less likely to vote on ethnic lines because they had easy access to different media, ranging from print to electronic, which provided them with diverse information about the political scene, and probably shaped their electoral choices. Conversely, their counterparts in the rural areas appeared to vote along ethnic lines, seemingly because of lack of exposure to the media. It was also assumed that most people in rural areas were not as modernized as their urban counterparts who were more exposed to enlightened sources of information such as professional groups and other elite social institutions which helped them to shape their political opinions than most rural people. The study attempts to establish to what extent the media impacted on the selected sample of urban students in the choice of their presidential candidates in the December 2001 elections in Zambia. The study further investigates to what extent other factors such as ethnic inclinations and other social predispositions influenced them in their choice of the candidates. The interviewees for this study were randomly drawn from a population of Evelyn Hone College students that voted in the December 2001 presidential elections in Zambia. The sample consisted of 30 randomly selected students who were purposely stratified in three focus groups of ten each. Each stratum represented the approximate ethnic equivalence of one of the presidential candidates who contested the December 2001 elections.
- Full Text:
- Date Issued: 2003
An object relational psychoanalysis of selected Tennessee Williams play texts
- Authors: Tosio, Paul
- Date: 2003
- Subjects: Williams, Tennessee, 1911-1983 Williams, Tennessee, 1911-1983 -- Knowledge -- Psychology Object relations (Psychoanalysis) Psychoanalysis Drama -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2150 , http://hdl.handle.net/10962/d1002382
- Description: Tennessee Williams is a playwright of great psychological depth. This thesis probes some of the complexities of his work through the use of Object Relational Psychoanalysis, specifically employing the theories of Melanie Klein, W.R.D. Fairbairn and Donald Winnicott. The Glass Menagerie, A Streetcar Named Desire, Cat On A Hot Tin Roof and The Night of The Iguana are analysed from this theoretical stance. All of these plays display great perceptiveness into the human condition, accurately portraying many psychological relational themes. Certain Object Relational themes become very apparent in these analyses. These themes include, Dependency (especially in The Glass Menagerie), Reparation (particularly in A Streetcar Named Desire), Falsehood (notably in Cat on a Hot Tin Roof), Idealisation (evident in The Night of The Iguana), Honest Empathetic Relations (apparent in Cat on a Hot Tin Roof and The Night of The Iguana) as well as Guilt, Object Loss, Sexual Guilt, and Obligation (recurring throughout these plays). It is advanced that Williams’ plays posses an honest and insightful understanding of human relations and, as such, are of contemporary value. This Thesis is not only an academic study, but also has practical applications for dramatists. With an increased understanding of the intrinsic tensions and motivations within such plays, offered by such psychoanalytic strategy, performance and staging of such work may be enhanced valuably.
- Full Text:
- Date Issued: 2003
- Authors: Tosio, Paul
- Date: 2003
- Subjects: Williams, Tennessee, 1911-1983 Williams, Tennessee, 1911-1983 -- Knowledge -- Psychology Object relations (Psychoanalysis) Psychoanalysis Drama -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2150 , http://hdl.handle.net/10962/d1002382
- Description: Tennessee Williams is a playwright of great psychological depth. This thesis probes some of the complexities of his work through the use of Object Relational Psychoanalysis, specifically employing the theories of Melanie Klein, W.R.D. Fairbairn and Donald Winnicott. The Glass Menagerie, A Streetcar Named Desire, Cat On A Hot Tin Roof and The Night of The Iguana are analysed from this theoretical stance. All of these plays display great perceptiveness into the human condition, accurately portraying many psychological relational themes. Certain Object Relational themes become very apparent in these analyses. These themes include, Dependency (especially in The Glass Menagerie), Reparation (particularly in A Streetcar Named Desire), Falsehood (notably in Cat on a Hot Tin Roof), Idealisation (evident in The Night of The Iguana), Honest Empathetic Relations (apparent in Cat on a Hot Tin Roof and The Night of The Iguana) as well as Guilt, Object Loss, Sexual Guilt, and Obligation (recurring throughout these plays). It is advanced that Williams’ plays posses an honest and insightful understanding of human relations and, as such, are of contemporary value. This Thesis is not only an academic study, but also has practical applications for dramatists. With an increased understanding of the intrinsic tensions and motivations within such plays, offered by such psychoanalytic strategy, performance and staging of such work may be enhanced valuably.
- Full Text:
- Date Issued: 2003
Analysis of material flow around a retractable pin in a friction stir weld
- Authors: Georgeou, Zacharias
- Date: 2003
- Subjects: Friction welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:10812 , http://hdl.handle.net/10948/196 , Friction welding , Aluminum alloys -- Welding
- Description: Friction StirWelding (FSW) has been researched for a number of years since its inception in 1991. The work thus far has been based on understanding the material and thermal flow using the standard fixed pin tool. The keyhole resulting during tool extraction in a FSW weld, is a disadvantage and a current limiting factor. Eliminating this effect from a weld using a movable pin tools would make FSW more commercially viable. This dissertation focuses on the design of a novel retractable pin tool, and highlights the problems encountered during the welding of Aluminum plates, Al2024 and Al5083. Previously studied techniques of material and thermal flow were used, to investigate the effect of the tool during extraction in a FSW weld. A prototype retractable tool was designed using parametric and axiomatic design theory, and implementing a pneumatic muscle actuation system. The resulting problems in the calibration of the retractable pin tool and the resulting welds are presented, these results confirming previous studies. The movable pin produced discrepancies the heat generation around the shoulder during a FSW weld. The failure of this tool to produce a reasonable weld showed that previous ideas into the workings of a retractable pin tool requires further investigation, furthermore a fresh approach to the interpretation and understanding of the FSW weld process needs consideration.
- Full Text:
- Date Issued: 2003
- Authors: Georgeou, Zacharias
- Date: 2003
- Subjects: Friction welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:10812 , http://hdl.handle.net/10948/196 , Friction welding , Aluminum alloys -- Welding
- Description: Friction StirWelding (FSW) has been researched for a number of years since its inception in 1991. The work thus far has been based on understanding the material and thermal flow using the standard fixed pin tool. The keyhole resulting during tool extraction in a FSW weld, is a disadvantage and a current limiting factor. Eliminating this effect from a weld using a movable pin tools would make FSW more commercially viable. This dissertation focuses on the design of a novel retractable pin tool, and highlights the problems encountered during the welding of Aluminum plates, Al2024 and Al5083. Previously studied techniques of material and thermal flow were used, to investigate the effect of the tool during extraction in a FSW weld. A prototype retractable tool was designed using parametric and axiomatic design theory, and implementing a pneumatic muscle actuation system. The resulting problems in the calibration of the retractable pin tool and the resulting welds are presented, these results confirming previous studies. The movable pin produced discrepancies the heat generation around the shoulder during a FSW weld. The failure of this tool to produce a reasonable weld showed that previous ideas into the workings of a retractable pin tool requires further investigation, furthermore a fresh approach to the interpretation and understanding of the FSW weld process needs consideration.
- Full Text:
- Date Issued: 2003
Apollo, Dionysus, dialectical reason and critical cinema
- Authors: Konik, Adrian
- Date: 2003
- Subjects: Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10990 , http://hdl.handle.net/10948/295 , Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Description: The contemporary era is dominated by an Apollonian visual language, i.e. the visual language of mainstream cinema and the mass media, and this study concerns the role that critical cinema, as Dionysian subverter, plays under such conditions. I argue that critical cinema should not be viewed as something completely ‘new’ but rather as a new, or at least the latest, manifestation of an older subversive ‘Dionysian’ voice that has made its presence felt since the dawn of the hegemony of an Apollonian disposition in Homeric epic. (I maintain that the history of western culture can be understood in terms of the persistent tension between Apollonian and Dionysian dispositions, and I use the distinction Derrida makes in Différance, between restricted and general economies, to distinguish between them, respectively.) I begin by considering the Dionysian echoes within Homer’s Iliad and then consider the way in which they became a ‘roar’ in the tragedies of Aeschylus. After Aeschylus a predominantly Apollonian voice asserted itself once again (to various degrees) through the work of Sophocles and Euripides. This was in keeping with the trend towards a more (Apollonian) restricted economy that is reflected in the writings of Homer’s literary successors, and which reached a crucial stage in Plato’s valorisation of ‘dialectics’, or what I term ‘dialecticis m’, which saw the birth of ‘dialectical language’. Through Plato dialecticism, or dialectical language, became instantiated as the ‘language’ of western philosophy and this predisposed western culture to develop along predominantly Apollonian lines. This continued from Plato, through the Middle Ages, until in the 17th century this Apollonian trend became manifest in the concept of the stable, integral, autonomous and self -transparent Cartesian ego, which is inextricably linked to dialectical language that promises certainty of ‘truth’ and maintains the possibility of representing the world in its entirety (as a system). In the contemporary ‘age of a world picture’, the hegemonic (Apollonian) visual language of mainstream cinema and the mass media propagates and perpetuates the belief in the possibility of representing the world in its entirety through the image, and insofar as it caters to audiences’ needs for stability and certainty (of ‘truth’) through providing such ‘complete’ representations, shapes their subjectivity along the lines of the Cartesian ego. According to Baudrillard, in contemporary society and culture the hyperreal realm of visual language has become far more significant for individuals than their immediate, empirical experiences, and that, as a result, they are far less predisposed to discussion and reflection and far more prone to passive ‘watching’. Also, Adorno maintains that it is impossible to have a form of critical cinema because of the way in which features inherent to cinema predispose it towards being an ideological apparatus. However, if both Baudrillard and Adorno are correct then the future appears increasingly bleak as it involves nothing other than the continuation and propagation of the hegemony of the visual language of mainstream cinema and the mass media, with no possibility for critical resistance. I argue instead that critical cinema is possible because the move towards a more restricted economy, motivated by an Apollonian disposition, did not develop from Homer to the contemporary era without meeting Dionysian resistance. I trace the presence of a subversive Dionysian voice through Homer’s Iliad, through Aeschylus’ Prometheus Bound, and through Plato’s Dialogues, where it echoes in the sentiments of some of Plato’s interlocutors, such as Callicles. In addition, I maintain that a ‘Dionysian’ voice resonates through both Nietzsche’s and Heidegger’s respective criticisms of ‘dialectical language’ and the ‘validity’ of the Cartesian ego. I argue that critical cinema, particularly Aronofsky’s postmodern critical cinema, parallels their similar epistemological and ontological perspectives in the way in which it engages with the (Apollonian) visual language of mainstream cinema and the mass media, and thereby, potentially, facilitates a more porous and protean subjectivity.
- Full Text:
- Date Issued: 2003
- Authors: Konik, Adrian
- Date: 2003
- Subjects: Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10990 , http://hdl.handle.net/10948/295 , Motion pictures and language , Philosophy in motion pictures , Dionysus (Greek deity) in literature , Apollo (Greek deity) in literature
- Description: The contemporary era is dominated by an Apollonian visual language, i.e. the visual language of mainstream cinema and the mass media, and this study concerns the role that critical cinema, as Dionysian subverter, plays under such conditions. I argue that critical cinema should not be viewed as something completely ‘new’ but rather as a new, or at least the latest, manifestation of an older subversive ‘Dionysian’ voice that has made its presence felt since the dawn of the hegemony of an Apollonian disposition in Homeric epic. (I maintain that the history of western culture can be understood in terms of the persistent tension between Apollonian and Dionysian dispositions, and I use the distinction Derrida makes in Différance, between restricted and general economies, to distinguish between them, respectively.) I begin by considering the Dionysian echoes within Homer’s Iliad and then consider the way in which they became a ‘roar’ in the tragedies of Aeschylus. After Aeschylus a predominantly Apollonian voice asserted itself once again (to various degrees) through the work of Sophocles and Euripides. This was in keeping with the trend towards a more (Apollonian) restricted economy that is reflected in the writings of Homer’s literary successors, and which reached a crucial stage in Plato’s valorisation of ‘dialectics’, or what I term ‘dialecticis m’, which saw the birth of ‘dialectical language’. Through Plato dialecticism, or dialectical language, became instantiated as the ‘language’ of western philosophy and this predisposed western culture to develop along predominantly Apollonian lines. This continued from Plato, through the Middle Ages, until in the 17th century this Apollonian trend became manifest in the concept of the stable, integral, autonomous and self -transparent Cartesian ego, which is inextricably linked to dialectical language that promises certainty of ‘truth’ and maintains the possibility of representing the world in its entirety (as a system). In the contemporary ‘age of a world picture’, the hegemonic (Apollonian) visual language of mainstream cinema and the mass media propagates and perpetuates the belief in the possibility of representing the world in its entirety through the image, and insofar as it caters to audiences’ needs for stability and certainty (of ‘truth’) through providing such ‘complete’ representations, shapes their subjectivity along the lines of the Cartesian ego. According to Baudrillard, in contemporary society and culture the hyperreal realm of visual language has become far more significant for individuals than their immediate, empirical experiences, and that, as a result, they are far less predisposed to discussion and reflection and far more prone to passive ‘watching’. Also, Adorno maintains that it is impossible to have a form of critical cinema because of the way in which features inherent to cinema predispose it towards being an ideological apparatus. However, if both Baudrillard and Adorno are correct then the future appears increasingly bleak as it involves nothing other than the continuation and propagation of the hegemony of the visual language of mainstream cinema and the mass media, with no possibility for critical resistance. I argue instead that critical cinema is possible because the move towards a more restricted economy, motivated by an Apollonian disposition, did not develop from Homer to the contemporary era without meeting Dionysian resistance. I trace the presence of a subversive Dionysian voice through Homer’s Iliad, through Aeschylus’ Prometheus Bound, and through Plato’s Dialogues, where it echoes in the sentiments of some of Plato’s interlocutors, such as Callicles. In addition, I maintain that a ‘Dionysian’ voice resonates through both Nietzsche’s and Heidegger’s respective criticisms of ‘dialectical language’ and the ‘validity’ of the Cartesian ego. I argue that critical cinema, particularly Aronofsky’s postmodern critical cinema, parallels their similar epistemological and ontological perspectives in the way in which it engages with the (Apollonian) visual language of mainstream cinema and the mass media, and thereby, potentially, facilitates a more porous and protean subjectivity.
- Full Text:
- Date Issued: 2003
Applied studies of some Southern African blowflies (Diptera: Calliphoridae) of forensic importance
- Authors: Lunt, Nicola
- Date: 2003
- Subjects: Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5803 , http://hdl.handle.net/10962/d1006202 , Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Description: Three major aspects of blowfly (Diptera: Calliphoridae) research were the focus of this study. Firstly, the phylogenetic relationships of 40 oestroid species from a variety of geographical localities were investigated using Cytochrome Oxidase b subunit I (COl) gene sequences. Maximum parsimony (MP) and Jukes-Cantor neighbor-joining (NJ) analyses both extracted a paraphyletic Calliphoridae, with the Calliphorinae-Luciliinae clade being sister to the Sarcophagidae. Short branch lengths within Chrysomya indicate a recent rapid radiation of this genus. Phormia and Protophormia either formed a sister clade to Chrysomya, or were embedded in this genus. Tree topologies were comparable between MP and NJ trees, but the positions of some genera were ambiguous. Secondly, developmental parameters and behaviour were investigated for four southern African species of forensically important blowflies viz. Chrysomya chloropyga, C. putoria, C. megacephala and Lucilia sericata, and ad hoc observations were made for Calliphora croceipalpis, Chrysomya marginalis and the predatory C. albiceps. Choice of oviposition substrate differed between species, mirroring substrate preferences in the field. Sexual dimorphism and dwarfism within a cohort complicated ageing maggots using size, but the use of developmental events (e.g. ecdysis) allowed ages to be determined unambiguously. Separate species status was supported for the previously synonymised C. chloropyga and C. putoria, by differences in maggot behaviour, larval growth rates and temperature optima. The proportion of total development time assigned to each larval instar and pupariation was variable among temperatures, but similar between congeneric species. Thirdly, since a negative linear relationship was found to occur between the developmental constant (K) and developmental zero (D₀) for both Calliphoridae and Sarcophagidae, the potential for predicting physiological parameters of unstudied taxa was investigated. Species and genera of Palaearctic origin generally had high K's and low D₀'s, and the reverse was true for the tropical taxa. It was found that both K and D₀ can be estimated for "unknown" taxa using the Felsenstein's Independent Contrasts (FIC) method of PDTree (Garland et al. 200 I), provided that branch lengths are relatively short and the phylogenetic position of the estimated taxon is unambiguous.
- Full Text:
- Date Issued: 2003
- Authors: Lunt, Nicola
- Date: 2003
- Subjects: Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5803 , http://hdl.handle.net/10962/d1006202 , Diptera -- South Africa , Blowflies -- South Africa , Forensic entomology
- Description: Three major aspects of blowfly (Diptera: Calliphoridae) research were the focus of this study. Firstly, the phylogenetic relationships of 40 oestroid species from a variety of geographical localities were investigated using Cytochrome Oxidase b subunit I (COl) gene sequences. Maximum parsimony (MP) and Jukes-Cantor neighbor-joining (NJ) analyses both extracted a paraphyletic Calliphoridae, with the Calliphorinae-Luciliinae clade being sister to the Sarcophagidae. Short branch lengths within Chrysomya indicate a recent rapid radiation of this genus. Phormia and Protophormia either formed a sister clade to Chrysomya, or were embedded in this genus. Tree topologies were comparable between MP and NJ trees, but the positions of some genera were ambiguous. Secondly, developmental parameters and behaviour were investigated for four southern African species of forensically important blowflies viz. Chrysomya chloropyga, C. putoria, C. megacephala and Lucilia sericata, and ad hoc observations were made for Calliphora croceipalpis, Chrysomya marginalis and the predatory C. albiceps. Choice of oviposition substrate differed between species, mirroring substrate preferences in the field. Sexual dimorphism and dwarfism within a cohort complicated ageing maggots using size, but the use of developmental events (e.g. ecdysis) allowed ages to be determined unambiguously. Separate species status was supported for the previously synonymised C. chloropyga and C. putoria, by differences in maggot behaviour, larval growth rates and temperature optima. The proportion of total development time assigned to each larval instar and pupariation was variable among temperatures, but similar between congeneric species. Thirdly, since a negative linear relationship was found to occur between the developmental constant (K) and developmental zero (D₀) for both Calliphoridae and Sarcophagidae, the potential for predicting physiological parameters of unstudied taxa was investigated. Species and genera of Palaearctic origin generally had high K's and low D₀'s, and the reverse was true for the tropical taxa. It was found that both K and D₀ can be estimated for "unknown" taxa using the Felsenstein's Independent Contrasts (FIC) method of PDTree (Garland et al. 200 I), provided that branch lengths are relatively short and the phylogenetic position of the estimated taxon is unambiguous.
- Full Text:
- Date Issued: 2003
Aspekte van die prosa van André P Brink met spesifieke verwysing na Sandkastele (1995)
- Authors: Vermeulen, Liezel
- Date: 2003
- Subjects: Brink, André P (André Philippus), 1935-2015 -- Sandkastele Brink, André P (André Philippus), 1935-2015
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3605 , http://hdl.handle.net/10962/d1003809
- Description: Hierdie studie ondersoek aspekte van die prosa-oeuvre van die Suid-Afrikaanse outeur André P. Brink, met spesifieke verwysing na sy eerste post-apartheid roman Sandkastele (1995). Hierdie teks se feministiese hersiening van en alternatief tot die manlikgedomineerde en -gedokumenteerde amptelike geskiedenis van Suider-Afrika staan sentraal in die postmodernistiese, postkoloniale fase waarin die Brink prosa-oeuvre die verlede heroorweeg. Die pre-koloniale en koloniale verlede van die landstreek word herkaart deur die vertelling van stories van vroue van die verlede in 'n unieke vertelsituasie wat 'n her-verbeelde, tekstuele vrouegeskiedenis registreer. Die konsep "reimagination" wat ontwikkel in Brink se kritiese en literêr-teoretiese werke vanaf die publikasie van die essay "Imagining the real" in Mapmakers (1983) en Elleke Boehmer se konseptualisering van die tekstuele gevolge van dekolonisasie (1995) word ontgin. Spore van die magiese realisme, die postkolonialisme, die poststrukturalistiese postmodernisme en leeswyses en denkrigtings wat in die feminisme en genderstudies aandag geniet, word in Sandkastele se vertelling, narratiewe figure en ruimte ondersoek. Hierdie leesstrategie akkommodeer die Brink-oeuvre se voortdurende heroorweging en ontdekking van nuwe tekstuele moontlikhede, 'n proses wat gekenmerk word deur 'n reeks tematiese of konseptuele ontwikkelinge en die uit-en deurwerk van belangstellings van vorige Brinktekste. ABSTRACT: This study investigates aspects of the prose oeuvre of the South African author André P. Brink, with specific reference to his first post-apartheid novel Imaginings of Sand (1995). The feminist revisioning of the text as an alternative to the male-dominated and -documented official history of Southern Africa is central to the postmodernist, postcolonial phase of the Brink oeuvre in which the past is reconsidered. The pre-colonial and colonial past of the country is remapped through the stories of women of the past in a narrative construction which registers a re-imagined textual women's history. The concept "reimagination" which develops in Brink's critical and literary theoretical works from the publication of the essay "Imagining the real" in Mapmakers (1983) and Elleke Boehmer's conceptualisation of the textual effects of decolonisation (1995) is utilised. Traces of the magical realism, postcolonialism, poststructuralist postmodernism and approaches which are explored in feminism and gender studies are explored in Sandkastele's narrative construction, characters and space. This reading strategy accommodates the Brink oeuvre's continual re-evaluation and uncovering of new textual possibilities, a process that is characterised by a series of thematic or conceptual developments and the deployment of themes from previous Brink prose texts.
- Full Text:
- Date Issued: 2003
- Authors: Vermeulen, Liezel
- Date: 2003
- Subjects: Brink, André P (André Philippus), 1935-2015 -- Sandkastele Brink, André P (André Philippus), 1935-2015
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3605 , http://hdl.handle.net/10962/d1003809
- Description: Hierdie studie ondersoek aspekte van die prosa-oeuvre van die Suid-Afrikaanse outeur André P. Brink, met spesifieke verwysing na sy eerste post-apartheid roman Sandkastele (1995). Hierdie teks se feministiese hersiening van en alternatief tot die manlikgedomineerde en -gedokumenteerde amptelike geskiedenis van Suider-Afrika staan sentraal in die postmodernistiese, postkoloniale fase waarin die Brink prosa-oeuvre die verlede heroorweeg. Die pre-koloniale en koloniale verlede van die landstreek word herkaart deur die vertelling van stories van vroue van die verlede in 'n unieke vertelsituasie wat 'n her-verbeelde, tekstuele vrouegeskiedenis registreer. Die konsep "reimagination" wat ontwikkel in Brink se kritiese en literêr-teoretiese werke vanaf die publikasie van die essay "Imagining the real" in Mapmakers (1983) en Elleke Boehmer se konseptualisering van die tekstuele gevolge van dekolonisasie (1995) word ontgin. Spore van die magiese realisme, die postkolonialisme, die poststrukturalistiese postmodernisme en leeswyses en denkrigtings wat in die feminisme en genderstudies aandag geniet, word in Sandkastele se vertelling, narratiewe figure en ruimte ondersoek. Hierdie leesstrategie akkommodeer die Brink-oeuvre se voortdurende heroorweging en ontdekking van nuwe tekstuele moontlikhede, 'n proses wat gekenmerk word deur 'n reeks tematiese of konseptuele ontwikkelinge en die uit-en deurwerk van belangstellings van vorige Brinktekste. ABSTRACT: This study investigates aspects of the prose oeuvre of the South African author André P. Brink, with specific reference to his first post-apartheid novel Imaginings of Sand (1995). The feminist revisioning of the text as an alternative to the male-dominated and -documented official history of Southern Africa is central to the postmodernist, postcolonial phase of the Brink oeuvre in which the past is reconsidered. The pre-colonial and colonial past of the country is remapped through the stories of women of the past in a narrative construction which registers a re-imagined textual women's history. The concept "reimagination" which develops in Brink's critical and literary theoretical works from the publication of the essay "Imagining the real" in Mapmakers (1983) and Elleke Boehmer's conceptualisation of the textual effects of decolonisation (1995) is utilised. Traces of the magical realism, postcolonialism, poststructuralist postmodernism and approaches which are explored in feminism and gender studies are explored in Sandkastele's narrative construction, characters and space. This reading strategy accommodates the Brink oeuvre's continual re-evaluation and uncovering of new textual possibilities, a process that is characterised by a series of thematic or conceptual developments and the deployment of themes from previous Brink prose texts.
- Full Text:
- Date Issued: 2003
Bioaccumulation and histopathology of copper in Oreochromis mossambicus
- Authors: Naigaga, Irene
- Date: 2003
- Subjects: Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5234 , http://hdl.handle.net/10962/d1005077 , Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Description: Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes.
- Full Text:
- Date Issued: 2003
- Authors: Naigaga, Irene
- Date: 2003
- Subjects: Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5234 , http://hdl.handle.net/10962/d1005077 , Mozambique tilapia , Copper , Marine toxins , Fishes -- Effect of water pollution on , Water -- Pollution -- Environmental aspects
- Description: Cu is one of the most toxic elements that affect fish populations when the fish are exposed to concentrations exceeding their tolerance. To investigate the effects of elementary Cu on aspects of bioconcentration, histology and behaviour, O. mossambicus were exposed to 0 and 0.75 ± 0.20 mg/l of Cu for 96 hours (short-term study), and 0, 0.11 ± 0.02, 0.29 ± 0.02, and 0.47 ± 0.04 mg/l of Cu for 64 days (longterm study) under controlled conditions in the laboratory. For the long-term study fish were sampled for gills, liver, and kidney Cu accumulation analysis after 1, 32 and 64 days of exposure and after 1, 2, 4, 16, 32, and 64 days for gills, liver and spleen histology analysis. Cu accumulation was concentration-duration dependent with the highest accumulation capacity in the liver. A multifactor linear model was developed for the relationship between exposure dose, exposure duration and Cu accumulation in the organs with the liver model: Log L = 3.35 + 0.85W + 0.31T (r² = 0.892) giving a better fit than the gills: G = −35.09 + 10.58W + 17.58T (r² = 0.632). Where L = Cu accumulation values in the liver, G = Cu accumulation values in the gills (both in μg/g dry mass); W = exposure dose in water (mg/l); and T = exposure time (days). Using this model Cu accumulation in organs can be estimated when exposure concentration and duration is known. This model should be tested under different conditions to determine the potential of the model in monitoring Cu toxicity in the environment. Lesions were observed in the liver, gills and spleen in all Cu treatments at all exposure concentration and exposure durations. However, the incidence and the degree of alteration was related to the concentration of Cu and duration of exposure. The sequential appearance of lesions in the order of, hepatic vacuolar degeneration, fatty degeneration and necrosis indicated a gradual increase in liver damage with larger duration of exposure time and increasing Cu concentration. The initial lesions in the gills were manifested as hypertrophy and hyperplasia of the gill epithelium causing increase in the thickness of the secondary lamellae, mucous cell hypertrophy and proliferation, mucous hypersecretion, proliferation of eosinophilic granule cells and hyperplasia of interlamellar cells. With increase in exposure time, necrosis of the eosinophilic granule cells, lamellar oedema, epithelial desquamation and increase in severity of lamellar hyperplasia were observed. These lesions indicated an initial defence mechanism of the fish against Cu toxicity followed by advanced histological changes that were related to Cu concentration and duration of exposure. Changes in the spleen were haemosiderosis, increase in the white pulp and macrophage centres, reduction in the red pulp, and necrosis suggesting that fish exposed to environmentally relevant levels of Cu may be histopathologically altered leading to anaemia and immunosuppression. Regression analysis was used to quantify the relationship between the total activity of the fish, and duration of exposure. There was a gradual decline in fish activity related to Cu concentration and duration of exposure before introducing food into the tanks. There was a constant activity after introducing food in the tanks at the control and 0.11 ± 0.02 mg/l Cu exposure levels irrespective of exposure time. Analysis of covariance (ANCOVA) was used to test for the difference in slopes between treatments. There was no significant difference (p > 0.05) between slopes of the control and 0.11 ± 0.02 mg/l Cu, and between 0.29 ± 0.02 and 47 ± 0.04 mg/l Cu before and after introducing food in the tanks. The slopes of both the control and 0.11 ± 0.02 mg/l Cu were significantly different from those of 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu (p < 0.05). There were significant differences in the mean opercular movements per minute between treatments (p < 0.05). There was hyperventilation at 0.11 ± 0.02 mg/l Cu i.e. 87 ± 18 opercular movements per minute (mean ± standard deviation) and hypoventilation at 0.29 ± 0.02 and 0.47 ± 0.04 mg/l Cu i.e. 37 ± 34 and 13 ± 6 opercular movements per minute compared to the control. Hypo- and hyperventilation were related to the lesser and greater gill damage, respectively. In conclusion Cu accumulation and effects on histology of the liver, gills and were related to the concentration of Cu in the water and duration of exposure showing a gradual increase in incidence and intensity with larger duration of exposure time and increasing Cu concentration. The fish were initially able to homeostatically regulate and detoxify Cu. However, as the exposure continued, the homeostatic mechanism appears to have failed to cope with the increasing metal burden causing advanced histological changes.
- Full Text:
- Date Issued: 2003
Biology and demography of the spotted grunter Pomadasys commersonnii (Haemulidae) in South African waters
- Authors: Webb, Garth Anthony
- Date: 2003
- Subjects: Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5201 , http://hdl.handle.net/10962/d1003727 , Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Description: The spotted grunter, Pomadasys commersonnii (Haemulidae), is an Indian Ocean coastal species, extending from India to False Bay but is absent from the central Indian Ocean islands. Its taste and texture has made it one of the most important line fish species and is caught by recreational and subsistence fisherman along the entire east coast of South Africa. Because of its inshore distribution, reduced catch rates and estuarine dependence the species was de-commercialised in 1992. Since then it has been investigated as a candidate species for mariculture. All previous work on the biology of the species was undertaken on fish collected in KwaZulu-Natal in the mid 1970's. All other information has been incidental and formed part of other ecological studies. All management plans for this species have been based on these data. To develop a more comprehensive management plan that incorporates the entire population of spotted grunter, it was deemed necessary to reassess the biology (including feeding biology, age and growth and reproductive biology) as well as the demography of the population throughout its distributional range in South African waters. Analysis of the diet of spotted grunter, collected in estuaries, indicates that crustaceans form the bulk of the prey selected. Amphipods, mysids and estuarine brachyura predominate the diet of fish < 300 mm TL. At 200 mm TL fish start to prey on anomurans, which are extracted from their burrows using the 'blowing' feeding mechanism. Anomurans, in particular Upogebia africana and Callianassa krausii, become the preferred prey of fish larger than 300 mm TL. The high degree of diet flexibility that spotted grunter exhibit means that the composition and abundance of the macrobenthos of a particular environment will dictate the diet of the species. Otolith growth zones were found to be deposited annually with the opaque zones being deposited during the austral summer (November - February). The optical definition of annual otolith growth rings differed significantly between geographic regions (namely: Western Cape, South Eastern Cape and KwaZulu-Natal). Growth (sex combined) offish in the Western Cape were best described by the specialised 3 parameter Von Bertalanffy with a relative error structure in the form : Lt = 753(1- e⁻°·¹⁵⁴ ⁽t +¹·⁶¹⁵⁾) while growth in the South Eastern Cape was best described by using the Schnute model with an absolute error structure in the form: Lt=177°·⁴¹⁶ + (676.2⁻¹·²⁶⁶ - 169.2⁻¹²⁶⁶)[1-e°·⁴¹⁶⁽t-t₁⁾ / 1-e°·⁴¹⁶⁽t₂-t₁⁾]¹/¹·²⁶⁶ whereas growth was best described in KwaZulu-Natal using the specialised 3 parameter Von Bertalanffy with a relative error structure in the form: Lt = 839(1-e°·¹⁷⁽t⁺°·⁴⁹⁾) In the South Eastern Cape, length at 50% maturity was found to be 305 mm TL for males. Since females with ripe & running or spent gonads were not found in the South Eastern Cape and since histological evidence suggests that females in the South Eastern Cape have spawned, it appears that spawning does not occur in the South Eastern Cape. These results suggest that adults are resident in the estuaries of the Western and South Eastern Cape and undertake the spring/summer, northward spawning migration to KwaZulu-Natal. After joining the resident spawner stock in KwaZulu-Natal and spawning in the offshore environment of KwaZulu-Natal, adults soon return to the southern regions of their distributional range. Juveniles recruit into KwaZulu-Natal estuaries at a length of 25 - 35 mm TL. A proportion of the eggs and larvae are transported southwards along the periphery of the western boundary Agulhas Current where juveniles (25 - 30 mm TL) recruit into the estuaries as far south as the Swartvlei estuary in the Western Cape. There is evidence to suggest that the fish, which occur in the Western Cape estuaries, have migrated there once they have attained sexual maturity further east.
- Full Text:
- Date Issued: 2003
- Authors: Webb, Garth Anthony
- Date: 2003
- Subjects: Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5201 , http://hdl.handle.net/10962/d1003727 , Grunts (Fishes) -- South Africa , Grunts (Fishes) -- South Africa -- Ecology
- Description: The spotted grunter, Pomadasys commersonnii (Haemulidae), is an Indian Ocean coastal species, extending from India to False Bay but is absent from the central Indian Ocean islands. Its taste and texture has made it one of the most important line fish species and is caught by recreational and subsistence fisherman along the entire east coast of South Africa. Because of its inshore distribution, reduced catch rates and estuarine dependence the species was de-commercialised in 1992. Since then it has been investigated as a candidate species for mariculture. All previous work on the biology of the species was undertaken on fish collected in KwaZulu-Natal in the mid 1970's. All other information has been incidental and formed part of other ecological studies. All management plans for this species have been based on these data. To develop a more comprehensive management plan that incorporates the entire population of spotted grunter, it was deemed necessary to reassess the biology (including feeding biology, age and growth and reproductive biology) as well as the demography of the population throughout its distributional range in South African waters. Analysis of the diet of spotted grunter, collected in estuaries, indicates that crustaceans form the bulk of the prey selected. Amphipods, mysids and estuarine brachyura predominate the diet of fish < 300 mm TL. At 200 mm TL fish start to prey on anomurans, which are extracted from their burrows using the 'blowing' feeding mechanism. Anomurans, in particular Upogebia africana and Callianassa krausii, become the preferred prey of fish larger than 300 mm TL. The high degree of diet flexibility that spotted grunter exhibit means that the composition and abundance of the macrobenthos of a particular environment will dictate the diet of the species. Otolith growth zones were found to be deposited annually with the opaque zones being deposited during the austral summer (November - February). The optical definition of annual otolith growth rings differed significantly between geographic regions (namely: Western Cape, South Eastern Cape and KwaZulu-Natal). Growth (sex combined) offish in the Western Cape were best described by the specialised 3 parameter Von Bertalanffy with a relative error structure in the form : Lt = 753(1- e⁻°·¹⁵⁴ ⁽t +¹·⁶¹⁵⁾) while growth in the South Eastern Cape was best described by using the Schnute model with an absolute error structure in the form: Lt=177°·⁴¹⁶ + (676.2⁻¹·²⁶⁶ - 169.2⁻¹²⁶⁶)[1-e°·⁴¹⁶⁽t-t₁⁾ / 1-e°·⁴¹⁶⁽t₂-t₁⁾]¹/¹·²⁶⁶ whereas growth was best described in KwaZulu-Natal using the specialised 3 parameter Von Bertalanffy with a relative error structure in the form: Lt = 839(1-e°·¹⁷⁽t⁺°·⁴⁹⁾) In the South Eastern Cape, length at 50% maturity was found to be 305 mm TL for males. Since females with ripe & running or spent gonads were not found in the South Eastern Cape and since histological evidence suggests that females in the South Eastern Cape have spawned, it appears that spawning does not occur in the South Eastern Cape. These results suggest that adults are resident in the estuaries of the Western and South Eastern Cape and undertake the spring/summer, northward spawning migration to KwaZulu-Natal. After joining the resident spawner stock in KwaZulu-Natal and spawning in the offshore environment of KwaZulu-Natal, adults soon return to the southern regions of their distributional range. Juveniles recruit into KwaZulu-Natal estuaries at a length of 25 - 35 mm TL. A proportion of the eggs and larvae are transported southwards along the periphery of the western boundary Agulhas Current where juveniles (25 - 30 mm TL) recruit into the estuaries as far south as the Swartvlei estuary in the Western Cape. There is evidence to suggest that the fish, which occur in the Western Cape estuaries, have migrated there once they have attained sexual maturity further east.
- Full Text:
- Date Issued: 2003
Botanical inventory and phenology in relation to foraging behaviour of the Cape honeybees (Apis Mellifera Capensis) at a site in the Eastern Cape, South Africa
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
- Full Text:
- Date Issued: 2003
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
- Full Text:
- Date Issued: 2003