Population dynamics of the raggedtooth shark (carcharias taurus) along the east coast of South Africa
- Authors: Dicken, Matthew Laurence
- Date: 2006
- Subjects: Sharks -- South Africa Shark fisheries -- South Africa Fish populations -- South Africa Sand tiger shark Fish tagging -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5310 , http://hdl.handle.net/10962/d1005155
- Description: This thesis develops the first open population model for any shark species worldwide using the Cormack-Jolly-Seber (CJS) model. In conjunction with a tagging study, five auxiliary studies were conducted to investigate stock structure, post-release mortality, tag shedding, and tag-reporting rates. The results from each of the studies were used to correct for any violations of the models assumptions to provide the first unbiased estimates of survival and abundance for the raggedtooth shark (Carcharias taurus) in South Africa. The C. taurus population exhibited complex stock structuring, by size and sex. Competitive shore anglers fished an estimated 37, 820 fishing days.year⁻¹ (95% C.I. = 28, 281 - 47, 359 days.year⁻¹) for sharks, and caught 1764 (95% C.I. = 321 – 3207) C. taurus. Although released alive, post-release mortality ranged from 3.85% for young-of-the-year sharks to 18.46% for adult sharks. Between 1984 and 2004, a total of 3471 C. taurus were tagged. In all, 302-tagged sharks (8.7%) were recaptured. Both juvenile (< 1.8 m TL) and adult sharks (> 1.8 m TL) displayed philopatric behaviour for specific parts of their ranges, including gestating and parturition areas. Significant differences were observed in the percentage of recaptures between the different tag types, tagging programs, individual taggers and capture methods used to tag sharks. The annual tag retention rate for juvenile sharks, 94.19% (95% C.I. = 80.68% - 100.00%) was significantly higher than for adult sharks, estimated at 29.00% (95% C.I. = 6.76% - 64.39%). Tag reporting rates, from fishermen varied both spatially and temporally from 0.28 (95% C.I. = 0.00 – 0.63) to 0.77 (95% C.I. = 0.56 – 0.97). Associated tag wound damage and biofouling growth indicated that B-type tags were a suitable tag type for use on C. taurus, whereas C-type tags were not. The CJS bias-adjusted estimate for juvenile survival was 0.456 (95% C.I. = 0.367 – 0.516) and for adult sharks, 0.865 (95% C.I. = 0.795 – 0.915). From 1984 to 2004 the mean bias-adjusted population size for juvenile sharks was estimated at 3506 (95% C.I. = 2433 – 4350) and for adult sharks, 5899 (95% C.I. = 7216 – 11904). Trends in abundance over the 20-year study period indicated a stable, healthy population.
- Full Text:
- Date Issued: 2006
- Authors: Dicken, Matthew Laurence
- Date: 2006
- Subjects: Sharks -- South Africa Shark fisheries -- South Africa Fish populations -- South Africa Sand tiger shark Fish tagging -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5310 , http://hdl.handle.net/10962/d1005155
- Description: This thesis develops the first open population model for any shark species worldwide using the Cormack-Jolly-Seber (CJS) model. In conjunction with a tagging study, five auxiliary studies were conducted to investigate stock structure, post-release mortality, tag shedding, and tag-reporting rates. The results from each of the studies were used to correct for any violations of the models assumptions to provide the first unbiased estimates of survival and abundance for the raggedtooth shark (Carcharias taurus) in South Africa. The C. taurus population exhibited complex stock structuring, by size and sex. Competitive shore anglers fished an estimated 37, 820 fishing days.year⁻¹ (95% C.I. = 28, 281 - 47, 359 days.year⁻¹) for sharks, and caught 1764 (95% C.I. = 321 – 3207) C. taurus. Although released alive, post-release mortality ranged from 3.85% for young-of-the-year sharks to 18.46% for adult sharks. Between 1984 and 2004, a total of 3471 C. taurus were tagged. In all, 302-tagged sharks (8.7%) were recaptured. Both juvenile (< 1.8 m TL) and adult sharks (> 1.8 m TL) displayed philopatric behaviour for specific parts of their ranges, including gestating and parturition areas. Significant differences were observed in the percentage of recaptures between the different tag types, tagging programs, individual taggers and capture methods used to tag sharks. The annual tag retention rate for juvenile sharks, 94.19% (95% C.I. = 80.68% - 100.00%) was significantly higher than for adult sharks, estimated at 29.00% (95% C.I. = 6.76% - 64.39%). Tag reporting rates, from fishermen varied both spatially and temporally from 0.28 (95% C.I. = 0.00 – 0.63) to 0.77 (95% C.I. = 0.56 – 0.97). Associated tag wound damage and biofouling growth indicated that B-type tags were a suitable tag type for use on C. taurus, whereas C-type tags were not. The CJS bias-adjusted estimate for juvenile survival was 0.456 (95% C.I. = 0.367 – 0.516) and for adult sharks, 0.865 (95% C.I. = 0.795 – 0.915). From 1984 to 2004 the mean bias-adjusted population size for juvenile sharks was estimated at 3506 (95% C.I. = 2433 – 4350) and for adult sharks, 5899 (95% C.I. = 7216 – 11904). Trends in abundance over the 20-year study period indicated a stable, healthy population.
- Full Text:
- Date Issued: 2006
Effects of an agribusiness collapse on contract growers and their communities : a case study of Makeni Cooperative Society, Lusaka, Zambia
- Authors: Mfune, Elizabeth
- Date: 2006
- Subjects: Agriculture -- Economic aspects -- Zambia , Agricultural industries -- Zambia , Farmers -- Zambia -- Economic conditions , Cooperative societies -- Zambia , Contracts, Agricultural -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3357 , http://hdl.handle.net/10962/d1007627 , Agriculture -- Economic aspects -- Zambia , Agricultural industries -- Zambia , Farmers -- Zambia -- Economic conditions , Cooperative societies -- Zambia , Contracts, Agricultural -- Zambia
- Description: This study assesses the effects of an agribusiness collapse, on the contracted growers and their surrounding communities in Lusaka Province, Zambia. In 2004, Agriflora Limited, a Trans-Zambezi Industries Limited (TZI) agribusiness in Lusaka Zambia was sold off. Agriflora Limited was one ofthe largest fresh vegetable exporters in Africa. It had contracted almost 500 small-scale farmers with 1-4 hectares of land within 50 km radius of Lusaka to grow vegetables for export. Makeni Cooperative Society was one of the targeted groups of growers. It grew baby corn, mangetout peas, and sugar snap and fine beans for export. The case study relied on both primary and secondary data. I undertook two months of ethnographic fieldwork utilising observations, in-depth interviews and informal discussions with some community members in Makeni. I also reviewed the literature on contract farming schemes (documenting both the negative and positive effects for growers) in developing countries. The case study showed that the impact of the collapse of Agriflora on the growers has been severe indeed; there has been a significant reduction in production with only a few farmers producing for export. Those that are producing are limited to one crop, baby corn. The effect on the local labour market (farm workers) has been quite drastic with a drop in employment. A new agribusiness company, York Farm, was sourced by the government for the contract growers of Makeni. York Farm has signed a procurement contract under which only sale and purchase conditions are specified. This means that, services such as extension services are no longer provided. It was also found that despite the price for baby corn at York Farm being better than what Agriflora used to offer the farmers, farmers are not producing peas which have a higher turnover than baby corn because York farm does not buy peas from the farmers. However, the farmers are hopeful that they will soon start producing peas after they pass the Eurep gap requirements. Furthermore, the farmers are still interested in contract farming as they are convinced that it can lead to higher farm incomes. While the neoliberal critique of the pre- Structural Adjustment agricultural policies was based on the need to improve rural farming income and productivity, my study shows that the contract farmers are not the "traditional" peasant farmers but retired civil servants or former public sector employees who lost their jobs during the contraction of the sector. In conclusion, my field work revealed that the collapse of Agriflora has had negative effects on the growers of MCS in terms a significant decrease in crop production, decline in farmer income, lack of technical assistance such as extension services, transportation problems (to take produce to the new market-York Farm) and reduced contraction in employment opportunities for farm workers.
- Full Text:
- Date Issued: 2006
- Authors: Mfune, Elizabeth
- Date: 2006
- Subjects: Agriculture -- Economic aspects -- Zambia , Agricultural industries -- Zambia , Farmers -- Zambia -- Economic conditions , Cooperative societies -- Zambia , Contracts, Agricultural -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3357 , http://hdl.handle.net/10962/d1007627 , Agriculture -- Economic aspects -- Zambia , Agricultural industries -- Zambia , Farmers -- Zambia -- Economic conditions , Cooperative societies -- Zambia , Contracts, Agricultural -- Zambia
- Description: This study assesses the effects of an agribusiness collapse, on the contracted growers and their surrounding communities in Lusaka Province, Zambia. In 2004, Agriflora Limited, a Trans-Zambezi Industries Limited (TZI) agribusiness in Lusaka Zambia was sold off. Agriflora Limited was one ofthe largest fresh vegetable exporters in Africa. It had contracted almost 500 small-scale farmers with 1-4 hectares of land within 50 km radius of Lusaka to grow vegetables for export. Makeni Cooperative Society was one of the targeted groups of growers. It grew baby corn, mangetout peas, and sugar snap and fine beans for export. The case study relied on both primary and secondary data. I undertook two months of ethnographic fieldwork utilising observations, in-depth interviews and informal discussions with some community members in Makeni. I also reviewed the literature on contract farming schemes (documenting both the negative and positive effects for growers) in developing countries. The case study showed that the impact of the collapse of Agriflora on the growers has been severe indeed; there has been a significant reduction in production with only a few farmers producing for export. Those that are producing are limited to one crop, baby corn. The effect on the local labour market (farm workers) has been quite drastic with a drop in employment. A new agribusiness company, York Farm, was sourced by the government for the contract growers of Makeni. York Farm has signed a procurement contract under which only sale and purchase conditions are specified. This means that, services such as extension services are no longer provided. It was also found that despite the price for baby corn at York Farm being better than what Agriflora used to offer the farmers, farmers are not producing peas which have a higher turnover than baby corn because York farm does not buy peas from the farmers. However, the farmers are hopeful that they will soon start producing peas after they pass the Eurep gap requirements. Furthermore, the farmers are still interested in contract farming as they are convinced that it can lead to higher farm incomes. While the neoliberal critique of the pre- Structural Adjustment agricultural policies was based on the need to improve rural farming income and productivity, my study shows that the contract farmers are not the "traditional" peasant farmers but retired civil servants or former public sector employees who lost their jobs during the contraction of the sector. In conclusion, my field work revealed that the collapse of Agriflora has had negative effects on the growers of MCS in terms a significant decrease in crop production, decline in farmer income, lack of technical assistance such as extension services, transportation problems (to take produce to the new market-York Farm) and reduced contraction in employment opportunities for farm workers.
- Full Text:
- Date Issued: 2006
Relationship between employee performance, leadership and emotional intelligence in a South African parastatal organisation
- Authors: Hayward, Brett Anthony
- Date: 2006
- Subjects: Employees -- Rating of , Leadership , Leadership -- Psychological aspects , Emotional intelligence , Government business enterprises -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1206 , http://hdl.handle.net/10962/d1019740
- Description: This research investigates the relationship between employee performance, leadership and emotional intelligence in a South African parastatal. The literature provided discusses the three variables of performance, leadership and emotional intelligence. Information was gathered, using three instruments, from a sample of 160 leaders and 800 raters. The Multifactor Leadership Questionnaire was used to determine leadership style within the parastatal, while the Emotional Competency Profiler was used to determine the emotional intelligence of the leaders within the parastatal. Employee performance was captured and recorded using the parastatal’s performance appraisal process. Leadership and emotional intelligence were identified as the independent variables and employee performance as the dependent variable. Data obtained from each of the research instruments was then statistically analysed. Through linear regression analysis it was concluded that there is a significant relationship between employee performance and an emotionally intelligent, transactional leader. However, no significant linear relationship was found between employee performance and an emotionally intelligent, transformational leader. Simple correlation analysis showed that there is a relatively weak significant linear relationship between emotional intelligence and transactional leadership. Moreover, it was found that there is a very strong significant linear relationship between emotional intelligence and transformational leadership. This research therefore adds a new dimension to employee performance, leadership and emotional intelligence, since no similar study has been conducted. As this research takes place in the South African context, it contributes to the bank of findings relating to the concepts.
- Full Text:
- Date Issued: 2006
- Authors: Hayward, Brett Anthony
- Date: 2006
- Subjects: Employees -- Rating of , Leadership , Leadership -- Psychological aspects , Emotional intelligence , Government business enterprises -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1206 , http://hdl.handle.net/10962/d1019740
- Description: This research investigates the relationship between employee performance, leadership and emotional intelligence in a South African parastatal. The literature provided discusses the three variables of performance, leadership and emotional intelligence. Information was gathered, using three instruments, from a sample of 160 leaders and 800 raters. The Multifactor Leadership Questionnaire was used to determine leadership style within the parastatal, while the Emotional Competency Profiler was used to determine the emotional intelligence of the leaders within the parastatal. Employee performance was captured and recorded using the parastatal’s performance appraisal process. Leadership and emotional intelligence were identified as the independent variables and employee performance as the dependent variable. Data obtained from each of the research instruments was then statistically analysed. Through linear regression analysis it was concluded that there is a significant relationship between employee performance and an emotionally intelligent, transactional leader. However, no significant linear relationship was found between employee performance and an emotionally intelligent, transformational leader. Simple correlation analysis showed that there is a relatively weak significant linear relationship between emotional intelligence and transactional leadership. Moreover, it was found that there is a very strong significant linear relationship between emotional intelligence and transformational leadership. This research therefore adds a new dimension to employee performance, leadership and emotional intelligence, since no similar study has been conducted. As this research takes place in the South African context, it contributes to the bank of findings relating to the concepts.
- Full Text:
- Date Issued: 2006
Security community building? : an assessment of Southern African regional integration in the post-apartheid era
- Authors: Lekhooa, Tumo
- Date: 2006
- Subjects: South Africa -- Politics and government -- 1994- , Africa, Southern -- Economic integration , National security -- Africa, Southern , Political stability -- Africa, Southern , Southern African Development Community
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2844 , http://hdl.handle.net/10962/d1005958 , South Africa -- Politics and government -- 1994- , Africa, Southern -- Economic integration , National security -- Africa, Southern , Political stability -- Africa, Southern , Southern African Development Community
- Description: The thesis traces Southern African security dimensions from the Cold War and the period of apartheid in South Africa to the post-apartheid era. It makes an attempt to investigate the prospects of Southern Africa becoming a security community and the processes and practices underlying these efforts. Using the constructivist theory approach to international relations, the thesis argues that the preoccupation with principles of sovereignty and non-interference, a lack of political will and the absence of common values that could help SADC institute binding rules and decision-making are the main blocks that prevent the region from asserting itself as a security community. All these militate against the idea of mutual accountability among SADC member states and have a negative impact on the institutional and functional capacity of SADC. This also prevents SADC from dealing with the emerging non-military human security threats in the region. In consideration of this, the thesis argues that the idea of security community building in Southern Africa remains not only a regional issue, but also requires the involvement of extra-regional actors.
- Full Text:
- Date Issued: 2006
- Authors: Lekhooa, Tumo
- Date: 2006
- Subjects: South Africa -- Politics and government -- 1994- , Africa, Southern -- Economic integration , National security -- Africa, Southern , Political stability -- Africa, Southern , Southern African Development Community
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2844 , http://hdl.handle.net/10962/d1005958 , South Africa -- Politics and government -- 1994- , Africa, Southern -- Economic integration , National security -- Africa, Southern , Political stability -- Africa, Southern , Southern African Development Community
- Description: The thesis traces Southern African security dimensions from the Cold War and the period of apartheid in South Africa to the post-apartheid era. It makes an attempt to investigate the prospects of Southern Africa becoming a security community and the processes and practices underlying these efforts. Using the constructivist theory approach to international relations, the thesis argues that the preoccupation with principles of sovereignty and non-interference, a lack of political will and the absence of common values that could help SADC institute binding rules and decision-making are the main blocks that prevent the region from asserting itself as a security community. All these militate against the idea of mutual accountability among SADC member states and have a negative impact on the institutional and functional capacity of SADC. This also prevents SADC from dealing with the emerging non-military human security threats in the region. In consideration of this, the thesis argues that the idea of security community building in Southern Africa remains not only a regional issue, but also requires the involvement of extra-regional actors.
- Full Text:
- Date Issued: 2006
The evaluation of Phenrica sp.2 (Coleoptera: Chrysomelidae: Alticinae), as a possible biological control agent for Madeira vine, Anredera cordifolia (Ten.) Steenis in South Africa
- Authors: Van der Westhuizen, Liamé
- Date: 2006
- Subjects: Weeds -- Biological control -- South Africa , Biological pest control agents -- South Africa , Invasive plants -- Biological control -- South Africa , Chrysomelidae , Beetles , Flea beetles , Anredera cordifolia -- Biological control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5689 , http://hdl.handle.net/10962/d1005375 , Weeds -- Biological control -- South Africa , Biological pest control agents -- South Africa , Invasive plants -- Biological control -- South Africa , Chrysomelidae , Beetles , Flea beetles , Anredera cordifolia -- Biological control
- Description: Anredera cordifolia (Basellaceae), Madeira vine, is a perennial, semi- succulent climber native from Paraguay to southern Brazil and northern Argentina. It has a history of weediness and difficulty of control once established. In South Africa Madeira vine has a wide range and distribution with altitudes ranging from 10-1800m above sea level. Described as a transformer species, its sheer weight is capable of breaking branches off trees, causing the potential collapse of forest canopies. Chemical and mechanical control methods are expensive, labour intensive and may provide only temporary relief. A biological control programme was therefore initiated in 2003. Cf Phenrica sp. 2 (Coleoptera: Chrysomelidae: Alticinae), was field collected from A. cordifolia in Brazil, SSW of Cascavel in the Paraná Province during a survey in November 2003. Eggs are laid in groups of 16 with the average fertility rate being 89%. After going though three larval instars, the larvae pupate in the soil with the adults eclosing after a period of 17 days. The total developmental time for a generation from egg to egg ranges between 7-8 weeks. Biological traits that favour the flea beetle as a possible biological control agent include long-lived adults (up to 5 months) and multiple generations during the summer period. Both adults and larvae feed extensively on leaves and stems and although developmental rates will slow down during the winter period, no indication of a definite diapause was found under the prevailing laboratory conditions. After completing the larval no-choice trials with twenty-six plant species from 14 plant families Phenrica sp. 2 proved to be adequately host specific, as larval development was only supported by 3 Basellaceae species (including the control A. cordifolia) and one Portulacaceae species. All of these are introduced species in South Africa. The only indigenous Basella species could not be tested as it has a very marginal distribution, and because it’s inconspicuous nature, it is seldom seen or collected. Adult multi-choice trials were restricted to species that could sustain larval development to give some indication of the acceptability of these species for adult feeding and oviposition. Although adult feeding was initially concentrated on B. alba, the oviposition preference was clear-cut as females only oviposited on A. cordifolia. In order to quantify the impact of Phenrica sp. 2 on plant biomass and to assess the incidence and intensity of foliar damage, a pair of adults was confined to the host plant, for 2 generations, with different levels of larval densities. The results indicated that the host plant, due to both larval and adult feeding, suffered leaf losses of up to 55%. Anredera cordifolia was however still capable of enlarging the root mass despite suffering huge leaf losses. This would imply that A. cordifolia has an effective re-growth capacity and it will only be vulnerable to attack of the storage organs that enable re-growth, or to repeated attack of other plant parts through which reserves are exhausted. Unfortunately the period of exposure (24 days) was too short to prove that Phenrica sp. 2 impacts on the below ground dry mass, but should the plant be completely defoliated, as was observed in the field, the host plant would be forced to deplete stored resources. Phenrica sp.2 has shown to be very host specific and although A.cordifoia loses its leaves during the winter period in most provinces in South Africa, the adults are long-lived and should be able to survive the leafless periods. Further more the relatively short life cycle, high fecundity and 3 generations per year should theoretically insure a strong population build-up that would improve the chances of establishment in the field. All indications are that Phenrica sp. 2 is an agent well worth considering for the biological control of A. cordifolia.
- Full Text:
- Date Issued: 2006
- Authors: Van der Westhuizen, Liamé
- Date: 2006
- Subjects: Weeds -- Biological control -- South Africa , Biological pest control agents -- South Africa , Invasive plants -- Biological control -- South Africa , Chrysomelidae , Beetles , Flea beetles , Anredera cordifolia -- Biological control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5689 , http://hdl.handle.net/10962/d1005375 , Weeds -- Biological control -- South Africa , Biological pest control agents -- South Africa , Invasive plants -- Biological control -- South Africa , Chrysomelidae , Beetles , Flea beetles , Anredera cordifolia -- Biological control
- Description: Anredera cordifolia (Basellaceae), Madeira vine, is a perennial, semi- succulent climber native from Paraguay to southern Brazil and northern Argentina. It has a history of weediness and difficulty of control once established. In South Africa Madeira vine has a wide range and distribution with altitudes ranging from 10-1800m above sea level. Described as a transformer species, its sheer weight is capable of breaking branches off trees, causing the potential collapse of forest canopies. Chemical and mechanical control methods are expensive, labour intensive and may provide only temporary relief. A biological control programme was therefore initiated in 2003. Cf Phenrica sp. 2 (Coleoptera: Chrysomelidae: Alticinae), was field collected from A. cordifolia in Brazil, SSW of Cascavel in the Paraná Province during a survey in November 2003. Eggs are laid in groups of 16 with the average fertility rate being 89%. After going though three larval instars, the larvae pupate in the soil with the adults eclosing after a period of 17 days. The total developmental time for a generation from egg to egg ranges between 7-8 weeks. Biological traits that favour the flea beetle as a possible biological control agent include long-lived adults (up to 5 months) and multiple generations during the summer period. Both adults and larvae feed extensively on leaves and stems and although developmental rates will slow down during the winter period, no indication of a definite diapause was found under the prevailing laboratory conditions. After completing the larval no-choice trials with twenty-six plant species from 14 plant families Phenrica sp. 2 proved to be adequately host specific, as larval development was only supported by 3 Basellaceae species (including the control A. cordifolia) and one Portulacaceae species. All of these are introduced species in South Africa. The only indigenous Basella species could not be tested as it has a very marginal distribution, and because it’s inconspicuous nature, it is seldom seen or collected. Adult multi-choice trials were restricted to species that could sustain larval development to give some indication of the acceptability of these species for adult feeding and oviposition. Although adult feeding was initially concentrated on B. alba, the oviposition preference was clear-cut as females only oviposited on A. cordifolia. In order to quantify the impact of Phenrica sp. 2 on plant biomass and to assess the incidence and intensity of foliar damage, a pair of adults was confined to the host plant, for 2 generations, with different levels of larval densities. The results indicated that the host plant, due to both larval and adult feeding, suffered leaf losses of up to 55%. Anredera cordifolia was however still capable of enlarging the root mass despite suffering huge leaf losses. This would imply that A. cordifolia has an effective re-growth capacity and it will only be vulnerable to attack of the storage organs that enable re-growth, or to repeated attack of other plant parts through which reserves are exhausted. Unfortunately the period of exposure (24 days) was too short to prove that Phenrica sp. 2 impacts on the below ground dry mass, but should the plant be completely defoliated, as was observed in the field, the host plant would be forced to deplete stored resources. Phenrica sp.2 has shown to be very host specific and although A.cordifoia loses its leaves during the winter period in most provinces in South Africa, the adults are long-lived and should be able to survive the leafless periods. Further more the relatively short life cycle, high fecundity and 3 generations per year should theoretically insure a strong population build-up that would improve the chances of establishment in the field. All indications are that Phenrica sp. 2 is an agent well worth considering for the biological control of A. cordifolia.
- Full Text:
- Date Issued: 2006
A review of the actuaries' capitalisation rate from an economic perspective
- Authors: Turner, Jason
- Date: 2006
- Subjects: Macroeconomics , Keynesian economics , Insurance -- Mathematics , South Africa -- Economic conditions -- 1961-1991 , South Africa -- Economic policy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:992 , http://hdl.handle.net/10962/d1002727 , Macroeconomics , Keynesian economics , Insurance -- Mathematics , South Africa -- Economic conditions -- 1961-1991 , South Africa -- Economic policy
- Description: The purpose of this paper was to evaluate if the macroeconomic change that has occurred in the South African economy since the 1980s has been significant enough to justify a re-examination of the actuaries’ capitalisation rate, due to its formulation processes dependence on the macroeconomic situation. The need for the reexamination arises from the use of the capitalisation in the calculation of lump sum awards where even a small change in the rate can have a significant impact on the value of the final award. In order to address the issue an examination of how Keynesian expectations are formulated and an examination of the Government’s macroeconomic policy was conducted to provide the foundation. On this foundation, a trend analysis of the major groups of financial instruments, as well as the current outlooks for the South African economy, was conducted to determine if there was any indication of a significant change in the macroeconomic conditions. The results of the analysis provided a compelling case for the urgent need for the actuaries’ capitalisation rate to be recalculated to account for the changed economic situation.
- Full Text:
- Date Issued: 2006
- Authors: Turner, Jason
- Date: 2006
- Subjects: Macroeconomics , Keynesian economics , Insurance -- Mathematics , South Africa -- Economic conditions -- 1961-1991 , South Africa -- Economic policy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:992 , http://hdl.handle.net/10962/d1002727 , Macroeconomics , Keynesian economics , Insurance -- Mathematics , South Africa -- Economic conditions -- 1961-1991 , South Africa -- Economic policy
- Description: The purpose of this paper was to evaluate if the macroeconomic change that has occurred in the South African economy since the 1980s has been significant enough to justify a re-examination of the actuaries’ capitalisation rate, due to its formulation processes dependence on the macroeconomic situation. The need for the reexamination arises from the use of the capitalisation in the calculation of lump sum awards where even a small change in the rate can have a significant impact on the value of the final award. In order to address the issue an examination of how Keynesian expectations are formulated and an examination of the Government’s macroeconomic policy was conducted to provide the foundation. On this foundation, a trend analysis of the major groups of financial instruments, as well as the current outlooks for the South African economy, was conducted to determine if there was any indication of a significant change in the macroeconomic conditions. The results of the analysis provided a compelling case for the urgent need for the actuaries’ capitalisation rate to be recalculated to account for the changed economic situation.
- Full Text:
- Date Issued: 2006
Against supererogationism
- Authors: Van Niekerk, Jason Bradley
- Date: 2006
- Subjects: Supererogation , Supererogation -- History , Values , Ethics -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2731 , http://hdl.handle.net/10962/d1004268 , Supererogation , Supererogation -- History , Values , Ethics -- History
- Description: In this thesis, I argue that we have no reason to accept the existence of a category of supererogatory moral goods: that is, good acts that carry no pressure to bring them about. Despite the counterintuitive nature and suspicious provenance of the concept, Supererogationism is the orthodoxy in Ethics, and I examine promising but unsuccessful responses to it by Peter Singer and Kwame Gyekye. Responding in particular to David Heyd's Supererogationism - but also to J. O. Urmson, Susan Wolf, and Jonathan Dancy - I develop an account of the principle "Good implies Ought" that does not entail absurd over-obligation. I argue that this Anti-Supererogationist model stands up to the four strongest arguments against such a position, and that it embraces a more accurate account of the relation between values and oughts than Supererogationists are capable of supplying. Finally, I sketch a detailed eudaimonist account of the principle umuntu ngumuntu ngabantu - that our commitment to the good of others stems from our flourishing being caught up with theirs.
- Full Text:
- Date Issued: 2006
- Authors: Van Niekerk, Jason Bradley
- Date: 2006
- Subjects: Supererogation , Supererogation -- History , Values , Ethics -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2731 , http://hdl.handle.net/10962/d1004268 , Supererogation , Supererogation -- History , Values , Ethics -- History
- Description: In this thesis, I argue that we have no reason to accept the existence of a category of supererogatory moral goods: that is, good acts that carry no pressure to bring them about. Despite the counterintuitive nature and suspicious provenance of the concept, Supererogationism is the orthodoxy in Ethics, and I examine promising but unsuccessful responses to it by Peter Singer and Kwame Gyekye. Responding in particular to David Heyd's Supererogationism - but also to J. O. Urmson, Susan Wolf, and Jonathan Dancy - I develop an account of the principle "Good implies Ought" that does not entail absurd over-obligation. I argue that this Anti-Supererogationist model stands up to the four strongest arguments against such a position, and that it embraces a more accurate account of the relation between values and oughts than Supererogationists are capable of supplying. Finally, I sketch a detailed eudaimonist account of the principle umuntu ngumuntu ngabantu - that our commitment to the good of others stems from our flourishing being caught up with theirs.
- Full Text:
- Date Issued: 2006
Making sense of Men's Health: an investigation into the meanings men and women make of Men's Health
- Authors: McCance-Price, Maris
- Date: 2006
- Subjects: Men's Health (South Africa) , Men's magazines -- South Africa , Men in mass media , Women in mass media , Sex role in mass media , Men in popular culture , Women in popular culture , Mass media -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3464 , http://hdl.handle.net/10962/d1002919 , Men's Health (South Africa) , Men's magazines -- South Africa , Men in mass media , Women in mass media , Sex role in mass media , Men in popular culture , Women in popular culture , Mass media -- Social aspects
- Description: This study investigates the popular pleasures produced by readers of men's magazines, focusing primarily on the publication, Men's Health, which represents a new type of magazine catering for men. Using qualitative research methods such as textual analysis and reception analysis, the study explores the pleasures produced by both men and women from the consumption of such texts. The theoretical perspective of cultural studies informs this project, an approach that focuses on the generation and circulation of meanings in society. Focusing on the notion of the active audience and Hall's encoding/decoding model, this study examines readers' interpretations of the Men's Health text, focusing on the moment of consumption in the circuit of culture. Reception theory proposes the existence of "clustered readings" produced by interpretive communities that are socially rather than individually constructed. As a critical ethnography, the study interrogates these meanings with particular reference to questions of gender relations and power in society. Access to different discourses is structured by the social position of readers within relations of power and this study takes gender as a structuring principle. Therefore, this study also explores the particular discursive practices through which masculine and feminine imagery is produced by the Men's Health text and by its readers. The research findings support the more limited notion of the active audience espoused by theorists such as Hall (1980) offering further evidence to suggest that readers produce readings other than those preferred by the text and that therein lies the pleasure of the text for male and female readers. The research concludes that the popularity of Men's Health derives from the capacity of its readers to make multiple meanings of the text.
- Full Text:
- Date Issued: 2006
- Authors: McCance-Price, Maris
- Date: 2006
- Subjects: Men's Health (South Africa) , Men's magazines -- South Africa , Men in mass media , Women in mass media , Sex role in mass media , Men in popular culture , Women in popular culture , Mass media -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3464 , http://hdl.handle.net/10962/d1002919 , Men's Health (South Africa) , Men's magazines -- South Africa , Men in mass media , Women in mass media , Sex role in mass media , Men in popular culture , Women in popular culture , Mass media -- Social aspects
- Description: This study investigates the popular pleasures produced by readers of men's magazines, focusing primarily on the publication, Men's Health, which represents a new type of magazine catering for men. Using qualitative research methods such as textual analysis and reception analysis, the study explores the pleasures produced by both men and women from the consumption of such texts. The theoretical perspective of cultural studies informs this project, an approach that focuses on the generation and circulation of meanings in society. Focusing on the notion of the active audience and Hall's encoding/decoding model, this study examines readers' interpretations of the Men's Health text, focusing on the moment of consumption in the circuit of culture. Reception theory proposes the existence of "clustered readings" produced by interpretive communities that are socially rather than individually constructed. As a critical ethnography, the study interrogates these meanings with particular reference to questions of gender relations and power in society. Access to different discourses is structured by the social position of readers within relations of power and this study takes gender as a structuring principle. Therefore, this study also explores the particular discursive practices through which masculine and feminine imagery is produced by the Men's Health text and by its readers. The research findings support the more limited notion of the active audience espoused by theorists such as Hall (1980) offering further evidence to suggest that readers produce readings other than those preferred by the text and that therein lies the pleasure of the text for male and female readers. The research concludes that the popularity of Men's Health derives from the capacity of its readers to make multiple meanings of the text.
- Full Text:
- Date Issued: 2006
The 'global' and the 'local' : a comparative study of development practices in three South African municipalities
- Authors: Gibb, Matthew William
- Date: 2013-08-15
- Subjects: Ndlambe Municipality Emalahleni Municipality Cape Town Municipality Local government -- South Africa Poor -- South Africa Globalization Economic development -- South Africa Community development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4871 , http://hdl.handle.net/10962/d1008413
- Description: On first impression, it would seem that globalisation is producing an increasingly homogenous trans-border world, whereby, as a result of key changes including the impact of technological improvements, foreign travel, the spread of westernised cultural identities, market capitalism, and liberal democracy, the point has been reached where it is now becoming difficult to tell different localities apart. In this process, it is often forgotten what role individual places assume in the creation of this globalised world and that not all will benefit from globalisation. In many respects, locally specific activities, including urban renewal, place promotion, and infrastructural developments pursued within a selection of the planet's most strategically connected cities are now the primary catalysts of, and the influence behind, globalisation. Likewise, community-businesses, rural micro-industries, and alternative livelihoods are some of the key mechanisms that under-privileged localities in developing countries are employing to either respond to the marginalization imposed by globalisation, or to simply ensure survival. The emergence of localisation theory has therefore acknowledged and exemplified the importance of the locality in the context of the global economy as either a key node within it or a point within which people must engage in coping strategies, often as a result of the negative impacts of globalisation. In recent years, varying styles of locality-based development have become central to enhancing both the pro-growth global competitiveness of a number of South African localities, as well as for initiating pro-poor interventions in several of the country's smaller towns and rural areas. In the City of Cape Town, millions of Rands have been invested by the municipality and the private sector in urban regeneration strategies,which have led to an economic rebirth in the city centre and have generated numerous jobs in the tertiary and construction sectors that have helped to enhance the city's global stature. In Ndlambe Municipality, two community-businesses, which have received national funding and have strong municipal support, employ fifty people between them and have demonstrated the advantages of participatory action in propoor local development, within the context of the open market. In Emalahleni Municipality, attempts at locality-based development have been instigated directly by the local poor themselves and have been organised by members of the community in the face of non-existent local government support, which have resulted in the creation of several hundred income-earning opportunities for area residents. In summary, these three cases illustrate a range of approaches to locality-based development cunently undertaken in South Africa by different localities possessing widely differing resources, skills, and degrees of global connectivity in order to initiate growth and enhance standards of living. From a theoretical perspective this study provides a South African slant on global theories and processes and further indicates the role that a series of localities in the South are playing in a changing global system. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Gibb, Matthew William
- Date: 2013-08-15
- Subjects: Ndlambe Municipality Emalahleni Municipality Cape Town Municipality Local government -- South Africa Poor -- South Africa Globalization Economic development -- South Africa Community development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4871 , http://hdl.handle.net/10962/d1008413
- Description: On first impression, it would seem that globalisation is producing an increasingly homogenous trans-border world, whereby, as a result of key changes including the impact of technological improvements, foreign travel, the spread of westernised cultural identities, market capitalism, and liberal democracy, the point has been reached where it is now becoming difficult to tell different localities apart. In this process, it is often forgotten what role individual places assume in the creation of this globalised world and that not all will benefit from globalisation. In many respects, locally specific activities, including urban renewal, place promotion, and infrastructural developments pursued within a selection of the planet's most strategically connected cities are now the primary catalysts of, and the influence behind, globalisation. Likewise, community-businesses, rural micro-industries, and alternative livelihoods are some of the key mechanisms that under-privileged localities in developing countries are employing to either respond to the marginalization imposed by globalisation, or to simply ensure survival. The emergence of localisation theory has therefore acknowledged and exemplified the importance of the locality in the context of the global economy as either a key node within it or a point within which people must engage in coping strategies, often as a result of the negative impacts of globalisation. In recent years, varying styles of locality-based development have become central to enhancing both the pro-growth global competitiveness of a number of South African localities, as well as for initiating pro-poor interventions in several of the country's smaller towns and rural areas. In the City of Cape Town, millions of Rands have been invested by the municipality and the private sector in urban regeneration strategies,which have led to an economic rebirth in the city centre and have generated numerous jobs in the tertiary and construction sectors that have helped to enhance the city's global stature. In Ndlambe Municipality, two community-businesses, which have received national funding and have strong municipal support, employ fifty people between them and have demonstrated the advantages of participatory action in propoor local development, within the context of the open market. In Emalahleni Municipality, attempts at locality-based development have been instigated directly by the local poor themselves and have been organised by members of the community in the face of non-existent local government support, which have resulted in the creation of several hundred income-earning opportunities for area residents. In summary, these three cases illustrate a range of approaches to locality-based development cunently undertaken in South Africa by different localities possessing widely differing resources, skills, and degrees of global connectivity in order to initiate growth and enhance standards of living. From a theoretical perspective this study provides a South African slant on global theories and processes and further indicates the role that a series of localities in the South are playing in a changing global system. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
The power of hegemonic theory in Southern Africa: why Lesotho cannot develop an independent foreign policy
- Authors: Mahao, Lehloenya
- Date: 2006
- Subjects: Hegemony -- South Africa , Lesotho -- Politics and government , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2799 , http://hdl.handle.net/10962/d1003009 , Hegemony -- South Africa , Lesotho -- Politics and government , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho
- Description: This thesis critiques hegemonic theory – especially the impact of a hegemonic state on the ability of small states to develop an independent foreign policy. The research uses Lesotho as a case study of a subordinate state in relation to the Republic of South Africa (RSA) as a hegemonic state. It draws on the history of Lesotho’s quest for sovereignty and argues that this sovereignty is constantly eroded to the advantage of its hegemonic neighbour. This constrains Lesotho’s ability to develop an independent foreign policy.
- Full Text:
- Date Issued: 2006
- Authors: Mahao, Lehloenya
- Date: 2006
- Subjects: Hegemony -- South Africa , Lesotho -- Politics and government , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2799 , http://hdl.handle.net/10962/d1003009 , Hegemony -- South Africa , Lesotho -- Politics and government , Lesotho -- Foreign relations -- South Africa , South Africa -- Foreign relations -- Lesotho
- Description: This thesis critiques hegemonic theory – especially the impact of a hegemonic state on the ability of small states to develop an independent foreign policy. The research uses Lesotho as a case study of a subordinate state in relation to the Republic of South Africa (RSA) as a hegemonic state. It draws on the history of Lesotho’s quest for sovereignty and argues that this sovereignty is constantly eroded to the advantage of its hegemonic neighbour. This constrains Lesotho’s ability to develop an independent foreign policy.
- Full Text:
- Date Issued: 2006
Nutrient dynamics in and offshore of two permanently open South African estuaries with contrasting fresh water inflow
- Authors: Jennings, Michael Evan
- Date: 2006
- Subjects: Estuaries -- South Africa -- Great Fish River , Estuaries -- South Africa -- Kariega River , Marine ecology -- South Africa , Freshwater ecology -- South Africa , Rivers -- Environmental aspects , Water quality management -- South Africa , Water -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5735 , http://hdl.handle.net/10962/d1005421 , Estuaries -- South Africa -- Great Fish River , Estuaries -- South Africa -- Kariega River , Marine ecology -- South Africa , Freshwater ecology -- South Africa , Rivers -- Environmental aspects , Water quality management -- South Africa , Water -- Analysis
- Description: The nutrient dynamics in two contrasting estuaries and in the adjacent nearshore environment along the south-east coast of South Africa was investigated seasonally. Due to an inter-basin transfer of water from the Gariep Dam to the Great Fish River, the Great Fish estuary is a fresh water dominated, terrestrially driven system with an annual fresh water inflow of 250 – 650 x 10⁶ m³ per year. In contrast, the Kariega estuary is a fresh water deprived, marine dominated system with a fresh water inflow estimated at 2.5 – 35 x 10⁶ m³per year. The reduced fresh water inflow into the estuary is attributed to regular impoundments along the Kariega River. Water samples were collected from surface and subsurface layers along the length of the estuaries as well as from a series of transects occupied in the nearshore environment. Samples were analysed for nitrate, nitrite, ammonium, phosphate and silicate. Temperature and salinity were recorded at each station. A Land-Ocean Interactions in the Coastal Zone (LOICZ) budget was constructed for each estuary to describe the role of ecosystem-level metabolism as either a sink or a source of phosphorus, nitrogen and carbon. Seasonal variation in physico-chemical properties and nutrient concentrations in the Kariega estuary was minimal due to constant low inflow, while in the Great Fish estuary, concentrations varied in response to changes in flow rate. Nutrient concentrations were consistently higher in the Great Fish estuary than in the Kariega estuary, largely reflecting differences in fresh water inflow. During periods of high flow (32.92 m³.s⁻¹in the Great Fish River) dissolved inorganic nitrogen (DIN) concentrations in the Great Fish estuary were an order of magnitude higher than those recorded in the Kariega estuary. Results of the LOICZ budgeting procedures revealed that in spite of the contrasting hydrodynamic features, the estuaries behave in largely the same manner – both predominantly sources of nutrients with heterotrophic processes dominating over autotrophic actions and both were net denitrifyers during all surveys. This was, however, due to different sets of processes operating in the two estuaries, namely low nutrient concentrations resulting in microbial activity in the Kariega estuary, and riverine influx of nutrients and phytoplankton combined with a short residence time of the water in the Great Fish estuary. In the marine nearshore environment, higher nutrient concentrations were recorded adjacent to the Great Fish estuary than offshore of the Kariega estuary. This was due to a surface plume of less saline water leaving the Great Fish estuary, which acted as an ‘outweller’ of nutrients. Offshore of the Kariega estuary, on the other hand, the nutrient concentrations were characteristic of marine waters due to a lack of fresh water outflow from the estuary. Nutrient concentrations in the marine environment adjacent to the Kariega estuary were, at times, higher than those recorded within the estuary. This observation supports previous statements which suggest that the Kariega estuary is not an ‘outweller’ of dissolved nutrients and particulate material, but rather an extension of the marine environment.
- Full Text:
- Date Issued: 2006
- Authors: Jennings, Michael Evan
- Date: 2006
- Subjects: Estuaries -- South Africa -- Great Fish River , Estuaries -- South Africa -- Kariega River , Marine ecology -- South Africa , Freshwater ecology -- South Africa , Rivers -- Environmental aspects , Water quality management -- South Africa , Water -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5735 , http://hdl.handle.net/10962/d1005421 , Estuaries -- South Africa -- Great Fish River , Estuaries -- South Africa -- Kariega River , Marine ecology -- South Africa , Freshwater ecology -- South Africa , Rivers -- Environmental aspects , Water quality management -- South Africa , Water -- Analysis
- Description: The nutrient dynamics in two contrasting estuaries and in the adjacent nearshore environment along the south-east coast of South Africa was investigated seasonally. Due to an inter-basin transfer of water from the Gariep Dam to the Great Fish River, the Great Fish estuary is a fresh water dominated, terrestrially driven system with an annual fresh water inflow of 250 – 650 x 10⁶ m³ per year. In contrast, the Kariega estuary is a fresh water deprived, marine dominated system with a fresh water inflow estimated at 2.5 – 35 x 10⁶ m³per year. The reduced fresh water inflow into the estuary is attributed to regular impoundments along the Kariega River. Water samples were collected from surface and subsurface layers along the length of the estuaries as well as from a series of transects occupied in the nearshore environment. Samples were analysed for nitrate, nitrite, ammonium, phosphate and silicate. Temperature and salinity were recorded at each station. A Land-Ocean Interactions in the Coastal Zone (LOICZ) budget was constructed for each estuary to describe the role of ecosystem-level metabolism as either a sink or a source of phosphorus, nitrogen and carbon. Seasonal variation in physico-chemical properties and nutrient concentrations in the Kariega estuary was minimal due to constant low inflow, while in the Great Fish estuary, concentrations varied in response to changes in flow rate. Nutrient concentrations were consistently higher in the Great Fish estuary than in the Kariega estuary, largely reflecting differences in fresh water inflow. During periods of high flow (32.92 m³.s⁻¹in the Great Fish River) dissolved inorganic nitrogen (DIN) concentrations in the Great Fish estuary were an order of magnitude higher than those recorded in the Kariega estuary. Results of the LOICZ budgeting procedures revealed that in spite of the contrasting hydrodynamic features, the estuaries behave in largely the same manner – both predominantly sources of nutrients with heterotrophic processes dominating over autotrophic actions and both were net denitrifyers during all surveys. This was, however, due to different sets of processes operating in the two estuaries, namely low nutrient concentrations resulting in microbial activity in the Kariega estuary, and riverine influx of nutrients and phytoplankton combined with a short residence time of the water in the Great Fish estuary. In the marine nearshore environment, higher nutrient concentrations were recorded adjacent to the Great Fish estuary than offshore of the Kariega estuary. This was due to a surface plume of less saline water leaving the Great Fish estuary, which acted as an ‘outweller’ of nutrients. Offshore of the Kariega estuary, on the other hand, the nutrient concentrations were characteristic of marine waters due to a lack of fresh water outflow from the estuary. Nutrient concentrations in the marine environment adjacent to the Kariega estuary were, at times, higher than those recorded within the estuary. This observation supports previous statements which suggest that the Kariega estuary is not an ‘outweller’ of dissolved nutrients and particulate material, but rather an extension of the marine environment.
- Full Text:
- Date Issued: 2006
Ionospheric total electron content variability and its influence in radio astronomy
- Authors: Botai, Ondego Joel
- Date: 2006
- Subjects: Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5473 , http://hdl.handle.net/10962/d1005258 , Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Description: Ionospheric phase delays of radio signals from Global Positioning System (GPS) satellites have been used to compute ionospheric Total Electron Content (TEC). An extended Chapman profle model is used to estimate the electron density profles and TEC. The Chapman profle that can be used to predict TEC over the mid-latitudes only applies during day time. To model night time TEC variability, a polynomial function is fitted to the night time peak electron density profles derived from the online International Reference Ionosphere (IRI) 2001. The observed and predicted TEC and its variability have been used to study ionospheric in°uence on Radio Astronomy in South Africa region. Di®erential phase delays of the radio signals from Radio Astronomy sources have been simulated using TEC. Using the simulated phase delays, the azimuth and declination o®sets of the radio sources have been estimated. Results indicate that, pointing errors of the order of miliarcseconds (mas) are likely if the ionospheric phase delays are not corrected for. These delays are not uniform and vary over a broad spectrum of timescales. This implies that fast frequency (referencing) switching, closure phases and fringe ¯tting schemes for ionospheric correction in astrometry are not the best option as they do not capture the real state of the ionosphere especially if the switching time is greater than the ionospheric TEC variability. However, advantage can be taken of the GPS satellite data available at intervals of a second from the GPS receiver network in South Africa to derive parameters which could be used to correct for the ionospheric delays. Furthermore GPS data can also be used to monitor the occurrence of scintillations, (which might corrupt radio signals) especially for the proposed, Square Kilometer Array (SKA) stations closer to the equatorial belt during magnetic storms and sub-storms. A 10 minute snapshot of GPS data recorded with the Hermanus [34:420 S, 19:220 E ] dual frequency receiver on 2003-04-11 did not show the occurrence of scintillations. This time scale is however too short and cannot be representative. Longer time scales; hours, days, seasons are needed to monitor the occurrence of scintillations.
- Full Text:
- Date Issued: 2006
- Authors: Botai, Ondego Joel
- Date: 2006
- Subjects: Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5473 , http://hdl.handle.net/10962/d1005258 , Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Description: Ionospheric phase delays of radio signals from Global Positioning System (GPS) satellites have been used to compute ionospheric Total Electron Content (TEC). An extended Chapman profle model is used to estimate the electron density profles and TEC. The Chapman profle that can be used to predict TEC over the mid-latitudes only applies during day time. To model night time TEC variability, a polynomial function is fitted to the night time peak electron density profles derived from the online International Reference Ionosphere (IRI) 2001. The observed and predicted TEC and its variability have been used to study ionospheric in°uence on Radio Astronomy in South Africa region. Di®erential phase delays of the radio signals from Radio Astronomy sources have been simulated using TEC. Using the simulated phase delays, the azimuth and declination o®sets of the radio sources have been estimated. Results indicate that, pointing errors of the order of miliarcseconds (mas) are likely if the ionospheric phase delays are not corrected for. These delays are not uniform and vary over a broad spectrum of timescales. This implies that fast frequency (referencing) switching, closure phases and fringe ¯tting schemes for ionospheric correction in astrometry are not the best option as they do not capture the real state of the ionosphere especially if the switching time is greater than the ionospheric TEC variability. However, advantage can be taken of the GPS satellite data available at intervals of a second from the GPS receiver network in South Africa to derive parameters which could be used to correct for the ionospheric delays. Furthermore GPS data can also be used to monitor the occurrence of scintillations, (which might corrupt radio signals) especially for the proposed, Square Kilometer Array (SKA) stations closer to the equatorial belt during magnetic storms and sub-storms. A 10 minute snapshot of GPS data recorded with the Hermanus [34:420 S, 19:220 E ] dual frequency receiver on 2003-04-11 did not show the occurrence of scintillations. This time scale is however too short and cannot be representative. Longer time scales; hours, days, seasons are needed to monitor the occurrence of scintillations.
- Full Text:
- Date Issued: 2006
Ameliorating poverty in South Africa through natural resource commercialisation : how can the private sector make a difference?
- Authors: Shackleton, Sheona E
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6616 , http://hdl.handle.net/10962/d1016223
- Description: [From Introduction] Some of the poorest rural people in South Africa are using traditional skills to convert a variety of wild resources into commodities that are sold in the market place. Wood and woven craft, medicines, fresh and processed wild foods, alcoholic beverages, building materials, fuelwood, dried mopane worms, cultural artefacts and brooms are just some examples of the array of natural resource products increasingly seen for sale in local and external markets. The majority of participants in this trade have minimal education, few assets to draw on, and little access to alternative sources of income or jobs. A significant proportion are women, with more than half heading their own households. Many come from households devastated by HIV/AIDS. The cash earned from selling natural resource products, however modest, is of critical importance, preventing producers and their households from slipping deeper into poverty. “Since I have been making brooms my children no longer go to bed crying of hunger,” observed one broom producer. Research across the country has revealed that the private sector can play an important role in making some of the poorest people in our society a little less poor by assisting producers overcome some of the obstacles they face. Two main areas for private sector involvement were identified: securing raw material access and product marketing. , This policy brief is based on the original brief made available for a workshop in August 2006. It draws on, amongst other sources, the results of several case studies of natural resource commercialisation undertaken across South Africa. The project was funded by the South Africa-Netherlands Programme on Alternatives in Development (SANPAD), BP South Africa and the National Research Foundation (NRF). The Center for International Forestry Research, with support from SIDA, provided the funding to share these findings with key stakeholders including government policy and decision makers.
- Full Text:
- Date Issued: 2009
- Authors: Shackleton, Sheona E
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6616 , http://hdl.handle.net/10962/d1016223
- Description: [From Introduction] Some of the poorest rural people in South Africa are using traditional skills to convert a variety of wild resources into commodities that are sold in the market place. Wood and woven craft, medicines, fresh and processed wild foods, alcoholic beverages, building materials, fuelwood, dried mopane worms, cultural artefacts and brooms are just some examples of the array of natural resource products increasingly seen for sale in local and external markets. The majority of participants in this trade have minimal education, few assets to draw on, and little access to alternative sources of income or jobs. A significant proportion are women, with more than half heading their own households. Many come from households devastated by HIV/AIDS. The cash earned from selling natural resource products, however modest, is of critical importance, preventing producers and their households from slipping deeper into poverty. “Since I have been making brooms my children no longer go to bed crying of hunger,” observed one broom producer. Research across the country has revealed that the private sector can play an important role in making some of the poorest people in our society a little less poor by assisting producers overcome some of the obstacles they face. Two main areas for private sector involvement were identified: securing raw material access and product marketing. , This policy brief is based on the original brief made available for a workshop in August 2006. It draws on, amongst other sources, the results of several case studies of natural resource commercialisation undertaken across South Africa. The project was funded by the South Africa-Netherlands Programme on Alternatives in Development (SANPAD), BP South Africa and the National Research Foundation (NRF). The Center for International Forestry Research, with support from SIDA, provided the funding to share these findings with key stakeholders including government policy and decision makers.
- Full Text:
- Date Issued: 2009
Discursive space in the discourse of a woman school leader
- Authors: Thawley, Sarah
- Date: 2006
- Subjects: Educational leadership -- Namibia Women school administrators -- Namibia School management and organization -- Namibia Discourse analysis
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1498 , http://hdl.handle.net/10962/d1003380
- Description: Women in leadership has become an increasingly popular area of research within the field of Educational Leadership and Management. As women hold more leadership roles and responsibilities in education it is increasingly important this subject is researched to enrich our understanding and knowledge of an area in which there have been silences. This research is a case study of a woman school leader in Namibia. The purpose was to explore the language she used and the impact of the discourses emerging from the text. The discourses are explained, described and interpreted through a critical discourse analysis to examine the discursive space and its relationship to the organisation. A feminist post-structural framework provided the basis for the critical orientation of this research. The findings of this study indicate that the leader occupied a discursive space of multiple positions that perpetuated and reproduced the school’s organizational structure and culture. The significance of this study lies in the possibilities for future research. The use of a poststructural framework to critically analyze discourses, combined with the use of leadership and management theory provided a means by which to explore and understand the multiple positions a woman leader takes up. By analyzing the discursive space in a discourse researchers are able to explore new ways of examining women and leadership in education.
- Full Text:
- Date Issued: 2006
- Authors: Thawley, Sarah
- Date: 2006
- Subjects: Educational leadership -- Namibia Women school administrators -- Namibia School management and organization -- Namibia Discourse analysis
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1498 , http://hdl.handle.net/10962/d1003380
- Description: Women in leadership has become an increasingly popular area of research within the field of Educational Leadership and Management. As women hold more leadership roles and responsibilities in education it is increasingly important this subject is researched to enrich our understanding and knowledge of an area in which there have been silences. This research is a case study of a woman school leader in Namibia. The purpose was to explore the language she used and the impact of the discourses emerging from the text. The discourses are explained, described and interpreted through a critical discourse analysis to examine the discursive space and its relationship to the organisation. A feminist post-structural framework provided the basis for the critical orientation of this research. The findings of this study indicate that the leader occupied a discursive space of multiple positions that perpetuated and reproduced the school’s organizational structure and culture. The significance of this study lies in the possibilities for future research. The use of a poststructural framework to critically analyze discourses, combined with the use of leadership and management theory provided a means by which to explore and understand the multiple positions a woman leader takes up. By analyzing the discursive space in a discourse researchers are able to explore new ways of examining women and leadership in education.
- Full Text:
- Date Issued: 2006
Voltammetric analysis of pesticides and their degradation: A case study of Amitraz and its degradants
- Authors: Brimecombe, Rory Dennis
- Date: 2006
- Subjects: Hydrolysis , Biodegradation , Voltammetry , Pesticides -- Biodegradation , Pesticides -- Environmental aspects , Acaricides , Acaricides -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4131 , http://hdl.handle.net/10962/d1015724
- Description: Amitraz is a formamide acaricide used predominantly in the control of ectoparasites in livestock and honeybees. Amitraz hydrolysis is rapid and occurs under acidic conditions, exposure to sunlight and biodegradation by microorganisms. The main hydrolysis product of amitraz, 2,4-dimethylaniline, is recalcitrant in the environment and toxic to humans. An electrochemical method for the determination of total amitraz residues and its final breakdown product, 2,4-dimethylaniline, in spent cattle dip, is presented. Cyclic voltammetry at a glassy carbon electrode showed the irreversible oxidation of amitraz and 2,4-dimethylaniline. A limit of detection in the range of 8.5 x 10⁻⁸ M for amitraz and 2 x 10⁻⁸ M for 2,4-dimethylaniline was determined using differential pulse voltammetry. Feasibility studies in which the effect of supporting electrolyte type and pH had on electroanalysis of amitraz and its degradants, showed that pH affects current response as well as the potential at which amitraz and its degradants are oxidised. Britton-Robinson buffer was found to be the most suitable supporting electrolyte for detection of amitraz and its degradants in terms of sensitivity and reproducibility. Studies performed using environmental samples showed that the sensitivity and reproducibility of amitraz and 2,4-dimethylaniline analyses in spent cattle dip were comparable to analyses of amitraz and 2,4-dimethylaniline performed in Britton-Robinson buffer. In addition, the feasibility qf measuring amitraz and 2,4-dimethylaniline in environmental samples was assessed and compared to amitraz and 2,4-dimethylaniline analyses in Britton-Robinson buffer. Amitraz and 2,4-dimethylaniline were readily detectable in milk and honey. Furthermore, it was elucidated that 2,4-dimethylaniline can be metabolised to 3-methylcatechol by Pseudomonas species and the proposed breakdown pathway is presented. The biological degradation of amitraz and subsequent formation of 2,4-dimethylaniline was readily monitored in spent cattle dip. The breakdown of amitraz to 2,4-dimethylaniline and then to 3-MC was monitored using cyclic voltammetry.
- Full Text:
- Date Issued: 2006
- Authors: Brimecombe, Rory Dennis
- Date: 2006
- Subjects: Hydrolysis , Biodegradation , Voltammetry , Pesticides -- Biodegradation , Pesticides -- Environmental aspects , Acaricides , Acaricides -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4131 , http://hdl.handle.net/10962/d1015724
- Description: Amitraz is a formamide acaricide used predominantly in the control of ectoparasites in livestock and honeybees. Amitraz hydrolysis is rapid and occurs under acidic conditions, exposure to sunlight and biodegradation by microorganisms. The main hydrolysis product of amitraz, 2,4-dimethylaniline, is recalcitrant in the environment and toxic to humans. An electrochemical method for the determination of total amitraz residues and its final breakdown product, 2,4-dimethylaniline, in spent cattle dip, is presented. Cyclic voltammetry at a glassy carbon electrode showed the irreversible oxidation of amitraz and 2,4-dimethylaniline. A limit of detection in the range of 8.5 x 10⁻⁸ M for amitraz and 2 x 10⁻⁸ M for 2,4-dimethylaniline was determined using differential pulse voltammetry. Feasibility studies in which the effect of supporting electrolyte type and pH had on electroanalysis of amitraz and its degradants, showed that pH affects current response as well as the potential at which amitraz and its degradants are oxidised. Britton-Robinson buffer was found to be the most suitable supporting electrolyte for detection of amitraz and its degradants in terms of sensitivity and reproducibility. Studies performed using environmental samples showed that the sensitivity and reproducibility of amitraz and 2,4-dimethylaniline analyses in spent cattle dip were comparable to analyses of amitraz and 2,4-dimethylaniline performed in Britton-Robinson buffer. In addition, the feasibility qf measuring amitraz and 2,4-dimethylaniline in environmental samples was assessed and compared to amitraz and 2,4-dimethylaniline analyses in Britton-Robinson buffer. Amitraz and 2,4-dimethylaniline were readily detectable in milk and honey. Furthermore, it was elucidated that 2,4-dimethylaniline can be metabolised to 3-methylcatechol by Pseudomonas species and the proposed breakdown pathway is presented. The biological degradation of amitraz and subsequent formation of 2,4-dimethylaniline was readily monitored in spent cattle dip. The breakdown of amitraz to 2,4-dimethylaniline and then to 3-MC was monitored using cyclic voltammetry.
- Full Text:
- Date Issued: 2006
The establishment of normative data on Xhosa-speaking high school learners using the ImPACT 3.0 programme
- Salman-Godlo, Noluthando Cikizwa
- Authors: Salman-Godlo, Noluthando Cikizwa
- Date: 2006
- Subjects: Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3048 , http://hdl.handle.net/10962/d1002557 , Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Description: Concussion is a common form of brain injury, especially amongst sports players of all age groups. ImPACT is a valid and reliable measure of a variety of cognitive functions commonly affected by such injuries, which allows for objective return-to-play decision making (Iverson, Lovell, & Collins, 2003). However, studies show that the transfer of such tests from one ethnic group to another without appropriate standardization is highly problematic (Ardila, 1995). Thus, the relative absence of South African normative data for the ImPACT 3.0 programme is an issue for concern. Consequently, this study aimed to establish norms for semi-rural Xhosa-speaking schoolboys with an advantaged education (ages 14, 16 and 18) for the ImPACT 3.0 programme as administered in English. Administrative and linguistic difficulties that were experienced by individuals during completion of the battery were also identified. Finally, the study included a comparison of the percentile scores of this sample to the USA norms for boys of a similar age group. Subtests scores were generated for 70 schoolboys and the data were then subjected to statistical analysis. A significant difference between English proficiency of the Grade 8 and Grade 12 boys was found. This indicates the importance of including an English proficiency test with the ImPACT battery when assessing such populations. No other significant differences were found between these age group samples. Although this requires further investigation, the comparison of the USA and SA percentiles suggests the use of local norms for this population. South African boys in this study consistently scored lower than the USA sample. Finally, it is recommended that symptom selfreports should be verbally investigated with each boy after testing, given indications of comprehension problems. In closing, limitations and future possible studies are discussed.
- Full Text:
- Date Issued: 2006
- Authors: Salman-Godlo, Noluthando Cikizwa
- Date: 2006
- Subjects: Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3048 , http://hdl.handle.net/10962/d1002557 , Brain -- Concussion -- South Africa , Sports -- Psychological aspects -- South Africa , Sports injuries -- Psychological spects , Neuropsychological tests , ImPACT 3.0
- Description: Concussion is a common form of brain injury, especially amongst sports players of all age groups. ImPACT is a valid and reliable measure of a variety of cognitive functions commonly affected by such injuries, which allows for objective return-to-play decision making (Iverson, Lovell, & Collins, 2003). However, studies show that the transfer of such tests from one ethnic group to another without appropriate standardization is highly problematic (Ardila, 1995). Thus, the relative absence of South African normative data for the ImPACT 3.0 programme is an issue for concern. Consequently, this study aimed to establish norms for semi-rural Xhosa-speaking schoolboys with an advantaged education (ages 14, 16 and 18) for the ImPACT 3.0 programme as administered in English. Administrative and linguistic difficulties that were experienced by individuals during completion of the battery were also identified. Finally, the study included a comparison of the percentile scores of this sample to the USA norms for boys of a similar age group. Subtests scores were generated for 70 schoolboys and the data were then subjected to statistical analysis. A significant difference between English proficiency of the Grade 8 and Grade 12 boys was found. This indicates the importance of including an English proficiency test with the ImPACT battery when assessing such populations. No other significant differences were found between these age group samples. Although this requires further investigation, the comparison of the USA and SA percentiles suggests the use of local norms for this population. South African boys in this study consistently scored lower than the USA sample. Finally, it is recommended that symptom selfreports should be verbally investigated with each boy after testing, given indications of comprehension problems. In closing, limitations and future possible studies are discussed.
- Full Text:
- Date Issued: 2006
Teachers as recontextualisers: a case study analysis of outcomes-based assessment policy implementation in two South African schools
- Authors: Wilmot, Pamela Dianne
- Date: 2006
- Subjects: Competency-based education -- South Africa Competency-based education -- South Africa -- Case studies Educational change -- South Africa Teacher participation in curriculum planning -- South Africa Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1792 , http://hdl.handle.net/10962/d1003677
- Description: The research presented in this thesis is a case study analysis of outcomes-based assessment in Grade 9 Human and Social Sciences of Curriculum 2005 in two South African schools. The research consists of two parts: Phase One, 2002 to 2003, was a qualitative case study, interpretive in orientation and using ethnographic techniques, aimed at understanding teachers’ responses to curriculum policy and the role of a school-based intervention, located within critically reflexive practice, in supporting change. During this phase, I was a co-participant operating from an insider position. During Phase Two, 2004-2005, I withdrew from the schools and took up an outsider position in order to analyse and theorise the case study. The findings of the interpretive review revealed a fascinating process of change, with some unexpected results that I lacked the theoretical and methodological tools to process. With support from critical friends, I realised that a dynamic and social process of knowledge recontextualisation had taken place, and that the research had moved beyond its initial goals. Not wishing to compromise my integrity as a qualitative researcher, I changed direction and made use of Basil Bernstein’s theorising (1990, 1996) to arrive at a suitable vantage point for the analysis. The main contention of this thesis is that the new OBE curriculum framework offers exciting opportunities for teacher participation in curriculum processes. However, if teachers are to maximise these and become agents of change, they need to acquire the rules of recontextualisation and reposition themselves in the recontextualising field. This implies epistemological empowerment, which takes time and mediation but which can be achieved through an approach to teacher professional development located in critically reflexive practice.
- Full Text:
- Date Issued: 2006
- Authors: Wilmot, Pamela Dianne
- Date: 2006
- Subjects: Competency-based education -- South Africa Competency-based education -- South Africa -- Case studies Educational change -- South Africa Teacher participation in curriculum planning -- South Africa Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1792 , http://hdl.handle.net/10962/d1003677
- Description: The research presented in this thesis is a case study analysis of outcomes-based assessment in Grade 9 Human and Social Sciences of Curriculum 2005 in two South African schools. The research consists of two parts: Phase One, 2002 to 2003, was a qualitative case study, interpretive in orientation and using ethnographic techniques, aimed at understanding teachers’ responses to curriculum policy and the role of a school-based intervention, located within critically reflexive practice, in supporting change. During this phase, I was a co-participant operating from an insider position. During Phase Two, 2004-2005, I withdrew from the schools and took up an outsider position in order to analyse and theorise the case study. The findings of the interpretive review revealed a fascinating process of change, with some unexpected results that I lacked the theoretical and methodological tools to process. With support from critical friends, I realised that a dynamic and social process of knowledge recontextualisation had taken place, and that the research had moved beyond its initial goals. Not wishing to compromise my integrity as a qualitative researcher, I changed direction and made use of Basil Bernstein’s theorising (1990, 1996) to arrive at a suitable vantage point for the analysis. The main contention of this thesis is that the new OBE curriculum framework offers exciting opportunities for teacher participation in curriculum processes. However, if teachers are to maximise these and become agents of change, they need to acquire the rules of recontextualisation and reposition themselves in the recontextualising field. This implies epistemological empowerment, which takes time and mediation but which can be achieved through an approach to teacher professional development located in critically reflexive practice.
- Full Text:
- Date Issued: 2006
An investigation of the relationship between journalists and their news sources: a case study of The Post newspaper in Zambia
- Authors: Kabeta, Jacqueline Milambo
- Date: 2006
- Subjects: The Post (Zambia) , Newspapers -- Zambia , Journalism -- Zambia , Journalists -- Zambia , Reporters and reporting -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3438 , http://hdl.handle.net/10962/d1002892 , The Post (Zambia) , Newspapers -- Zambia , Journalism -- Zambia , Journalists -- Zambia , Reporters and reporting -- Zambia
- Description: Normative professional journalism and the need to re-evaluate the structural social context of journalism practice and its role in emerging democracies has led to the increased scrutiny of journalists and their relationship to news sources. This study conceptualises the relationship between journalists and news sources as a dual process of consensus and conflict of interests in the newsgathering practice in Zambia, an emerging democracy. The study suggests that journalists actively pursue powerful individuals in society such as those in government, pressure groups and business as news sources who have been available and suitable in the past. Journalists’ view of society as bureaucratically organised and the short turn-around time of news production are among the organisational factors attributed to this tendency. This study adopts a sociological approach to investigate the journalist-news source relationship at The Post, in Zambia, by factoring in the perspectives of social organisation of newswork and political economy. Whereas the social organisation perspective focuses on the organisational and occupational demands of journalists, political economy reinforces the larger context of journalist-news source interaction in a society. Additionally, the social constructivist theory, which is premised around the idea that the agenda and content of journalism production, is in part a product of non-journalistic social factors is useful in understanding the various influences on the relationship. The study investigates the nature of the journalist-news source relationship using two diametrically opposed views – the dominant (exchange) and competitive (adversarial) paradigms. This is aimed at establishing whether the relationship is an exchange or adversarial. While the latter relationship is common in liberal democracies where the media are seen as part of elite structures with considerable power on their own, the thinking is that inequalities in resource distribution and political power generate social tensions in developing countries that require media to be carefully managed. Using qualitative semi-structured interviews and observation methods, this study establishes that while the adversarial role has an attraction for the journalists investigated, the exchange model comes closest to describing the nature of relationship they share with their news sources.
- Full Text:
- Date Issued: 2006
- Authors: Kabeta, Jacqueline Milambo
- Date: 2006
- Subjects: The Post (Zambia) , Newspapers -- Zambia , Journalism -- Zambia , Journalists -- Zambia , Reporters and reporting -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3438 , http://hdl.handle.net/10962/d1002892 , The Post (Zambia) , Newspapers -- Zambia , Journalism -- Zambia , Journalists -- Zambia , Reporters and reporting -- Zambia
- Description: Normative professional journalism and the need to re-evaluate the structural social context of journalism practice and its role in emerging democracies has led to the increased scrutiny of journalists and their relationship to news sources. This study conceptualises the relationship between journalists and news sources as a dual process of consensus and conflict of interests in the newsgathering practice in Zambia, an emerging democracy. The study suggests that journalists actively pursue powerful individuals in society such as those in government, pressure groups and business as news sources who have been available and suitable in the past. Journalists’ view of society as bureaucratically organised and the short turn-around time of news production are among the organisational factors attributed to this tendency. This study adopts a sociological approach to investigate the journalist-news source relationship at The Post, in Zambia, by factoring in the perspectives of social organisation of newswork and political economy. Whereas the social organisation perspective focuses on the organisational and occupational demands of journalists, political economy reinforces the larger context of journalist-news source interaction in a society. Additionally, the social constructivist theory, which is premised around the idea that the agenda and content of journalism production, is in part a product of non-journalistic social factors is useful in understanding the various influences on the relationship. The study investigates the nature of the journalist-news source relationship using two diametrically opposed views – the dominant (exchange) and competitive (adversarial) paradigms. This is aimed at establishing whether the relationship is an exchange or adversarial. While the latter relationship is common in liberal democracies where the media are seen as part of elite structures with considerable power on their own, the thinking is that inequalities in resource distribution and political power generate social tensions in developing countries that require media to be carefully managed. Using qualitative semi-structured interviews and observation methods, this study establishes that while the adversarial role has an attraction for the journalists investigated, the exchange model comes closest to describing the nature of relationship they share with their news sources.
- Full Text:
- Date Issued: 2006
Development and assessment of azithromycin paediatric suppository formulations
- Authors: Mollel, Happiness
- Date: 2006
- Subjects: Azithromycin , Pediatrics , Clinical pharmacology , Pharmacokinetics , Suppositories , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3774 , http://hdl.handle.net/10962/d1003252 , Azithromycin , Pediatrics , Clinical pharmacology , Pharmacokinetics , Suppositories , Drugs -- Dosage forms
- Description: The use of the oral route of administration for the treatment of young children with antibiotics can at times be problematic since, factors such as nausea, vomiting, taste and/or smell, in addition to the challenges associated with the administration of suspensions, may contribute to poor patient compliance. In such cases, the use of the rectal route of administration may be appropriate. Therefore, suppositories containing 250 mg azithromycin (AZI) were manufactured and assessed for potential as an antibiotic suppository dosage form. Suppositories, containing AZI dihydrate were manufactured by the fusion method, using different grades of PEG, Witepsol® and Suppocire® bases. The rate and extent of AZI release was evaluated using USP apparatus I, and samples were analyzed using a validated HPLC method. Differences in the rate and extent of AZI release were observed with the greatest amount of AZI being released from PEG formulations. The rate and extent of AZI release from formulations manufactured using fatty bases were influenced by physicochemical properties, such as melting rate and hydroxyl value, of the bases. In addition drug partitioning appeared to favor the lipid phase and had a negative impact on AZI release characteristics. Two different formulation approaches were used in an attempt to increase the rate and extent of AZI release from fatty base formulations. The use of surfactants significantly increased AZI release from formulations manufactured with fatty bases with high hydroxyl values. The use of urea or Povidone K25 in combination with AZI as a physical mixture or solid dispersion did not increase the rate and extent of AZI release from the fatty suppositories, to any significant extent. The mechanism of drug release was evaluated using several mathematical models, including the Higuchi, Korsmeyer- eppas, Zero and, First order models. In addition, in vitro dissolution profiles were characterized by the difference and similarity factors, f1 and f2 and by use of the Gohel similarity factor, Sd. AZI release kinetics were best described by the Higuchi and Korsmeyer-Peppas models and the values of the release exponent, n, revealed that drug release was a consequence of the combined effects of AZI diffusion, rate of melting of the base and partitioning of the drug which can be considered to be anomalous release.
- Full Text:
- Date Issued: 2006
- Authors: Mollel, Happiness
- Date: 2006
- Subjects: Azithromycin , Pediatrics , Clinical pharmacology , Pharmacokinetics , Suppositories , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3774 , http://hdl.handle.net/10962/d1003252 , Azithromycin , Pediatrics , Clinical pharmacology , Pharmacokinetics , Suppositories , Drugs -- Dosage forms
- Description: The use of the oral route of administration for the treatment of young children with antibiotics can at times be problematic since, factors such as nausea, vomiting, taste and/or smell, in addition to the challenges associated with the administration of suspensions, may contribute to poor patient compliance. In such cases, the use of the rectal route of administration may be appropriate. Therefore, suppositories containing 250 mg azithromycin (AZI) were manufactured and assessed for potential as an antibiotic suppository dosage form. Suppositories, containing AZI dihydrate were manufactured by the fusion method, using different grades of PEG, Witepsol® and Suppocire® bases. The rate and extent of AZI release was evaluated using USP apparatus I, and samples were analyzed using a validated HPLC method. Differences in the rate and extent of AZI release were observed with the greatest amount of AZI being released from PEG formulations. The rate and extent of AZI release from formulations manufactured using fatty bases were influenced by physicochemical properties, such as melting rate and hydroxyl value, of the bases. In addition drug partitioning appeared to favor the lipid phase and had a negative impact on AZI release characteristics. Two different formulation approaches were used in an attempt to increase the rate and extent of AZI release from fatty base formulations. The use of surfactants significantly increased AZI release from formulations manufactured with fatty bases with high hydroxyl values. The use of urea or Povidone K25 in combination with AZI as a physical mixture or solid dispersion did not increase the rate and extent of AZI release from the fatty suppositories, to any significant extent. The mechanism of drug release was evaluated using several mathematical models, including the Higuchi, Korsmeyer- eppas, Zero and, First order models. In addition, in vitro dissolution profiles were characterized by the difference and similarity factors, f1 and f2 and by use of the Gohel similarity factor, Sd. AZI release kinetics were best described by the Higuchi and Korsmeyer-Peppas models and the values of the release exponent, n, revealed that drug release was a consequence of the combined effects of AZI diffusion, rate of melting of the base and partitioning of the drug which can be considered to be anomalous release.
- Full Text:
- Date Issued: 2006
A global ionospheric F2 region peak electron density model using neural networks and extended geophysically relevant inputs
- Authors: Oyeyemi, Elijah Oyedola
- Date: 2006
- Subjects: Neural networks (Computer science) Ionospheric electron density Ionosphere Ionosphere -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5470 , http://hdl.handle.net/10962/d1005255
- Description: This thesis presents my research on the development of a neural network (NN) based global empirical model of the ionospheric F2 region peak electron density using extended geophysically relevant inputs. The main principle behind this approach has been to utilize parameters other than simple geographic co-ordinates, on which the F2 peak electron density is known to depend, and to exploit the technique of NNs, thereby establishing and modeling the non-linear dynamic processes (both in space and time)associated with the F2 region electron density on a global scale. Four different models have been developed in this work. These are the foF2 NN model, M(3000)F2 NN model, short-term forecasting foF2 NN, and a near-real time foF2 NN model. Data used in the training of the NNs were obtained from the worldwide ionosonde stations spanning the period 1964 to 1986 based on availability, which included all periods of calm and disturbed magnetic activity. Common input parameters used in the training of all 4 models are day number (day of the year, DN), Universal Time (UT), a 2 month running mean of the sunspot number (R2), a 2 day running mean of the 3-hour planetary magnetic index ap (A16), solar zenith angle (CHI), geographic latitude (q), magnetic dip angle (I), angle of magnetic declination (D), angle of meridian relative to subsolar point (M). For the short-term and near-real time foF2 models, additional input parameters related to recent past observations of foF2 itself were included in the training of the NNs. The results of the foF2 NN model and M(3000)F2 NN model presented in this work, which compare favourably with the IRI (International Reference Ionosphere) model successfully demonstrate the potential of NNs for spatial and temporal modeling of the ionospheric parameters foF2 and M(3000)F2 globally. The results obtained from the short-term foF2 NN model and nearreal time foF2 NN model reveal that, in addition to the temporal and spatial input variables, short-term forecasting of foF2 is much improved by including past observations of foF2 itself. Results obtained from the near-real time foF2 NN model also reveal that there exists a correlation between measured foF2 values at different locations across the globe. Again, comparisons of the foF2 NN model and M(3000)F2 NN model predictions with that of the IRI model predictions and observed values at some selected high latitude stations, suggest that the NN technique can successfully be employed to model the complex irregularities associated with the high latitude regions. Based on the results obtained in this research and the comparison made with the IRI model (URSI and CCIR coefficients), these results justify consideration of the NN technique for the prediction of global ionospheric parameters. I believe that, after consideration by the IRI community, these models will prove to be valuable to both the high frequency (HF) communication and worldwide ionospheric communities.
- Full Text:
- Date Issued: 2006
- Authors: Oyeyemi, Elijah Oyedola
- Date: 2006
- Subjects: Neural networks (Computer science) Ionospheric electron density Ionosphere Ionosphere -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5470 , http://hdl.handle.net/10962/d1005255
- Description: This thesis presents my research on the development of a neural network (NN) based global empirical model of the ionospheric F2 region peak electron density using extended geophysically relevant inputs. The main principle behind this approach has been to utilize parameters other than simple geographic co-ordinates, on which the F2 peak electron density is known to depend, and to exploit the technique of NNs, thereby establishing and modeling the non-linear dynamic processes (both in space and time)associated with the F2 region electron density on a global scale. Four different models have been developed in this work. These are the foF2 NN model, M(3000)F2 NN model, short-term forecasting foF2 NN, and a near-real time foF2 NN model. Data used in the training of the NNs were obtained from the worldwide ionosonde stations spanning the period 1964 to 1986 based on availability, which included all periods of calm and disturbed magnetic activity. Common input parameters used in the training of all 4 models are day number (day of the year, DN), Universal Time (UT), a 2 month running mean of the sunspot number (R2), a 2 day running mean of the 3-hour planetary magnetic index ap (A16), solar zenith angle (CHI), geographic latitude (q), magnetic dip angle (I), angle of magnetic declination (D), angle of meridian relative to subsolar point (M). For the short-term and near-real time foF2 models, additional input parameters related to recent past observations of foF2 itself were included in the training of the NNs. The results of the foF2 NN model and M(3000)F2 NN model presented in this work, which compare favourably with the IRI (International Reference Ionosphere) model successfully demonstrate the potential of NNs for spatial and temporal modeling of the ionospheric parameters foF2 and M(3000)F2 globally. The results obtained from the short-term foF2 NN model and nearreal time foF2 NN model reveal that, in addition to the temporal and spatial input variables, short-term forecasting of foF2 is much improved by including past observations of foF2 itself. Results obtained from the near-real time foF2 NN model also reveal that there exists a correlation between measured foF2 values at different locations across the globe. Again, comparisons of the foF2 NN model and M(3000)F2 NN model predictions with that of the IRI model predictions and observed values at some selected high latitude stations, suggest that the NN technique can successfully be employed to model the complex irregularities associated with the high latitude regions. Based on the results obtained in this research and the comparison made with the IRI model (URSI and CCIR coefficients), these results justify consideration of the NN technique for the prediction of global ionospheric parameters. I believe that, after consideration by the IRI community, these models will prove to be valuable to both the high frequency (HF) communication and worldwide ionospheric communities.
- Full Text:
- Date Issued: 2006