The effects of selected reference toxicants on embryonic development of the freshwater shrimp caridina nilotica (Decapoda: Atyidae)
- Authors: Ketse, Noziphiwo
- Date: 2007
- Subjects: Toxicity testing -- South Africa , Shrimp fisheries -- South Africa , Decapoda , Caridina , Water quality management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6025 , http://hdl.handle.net/10962/d1005367 , Toxicity testing -- South Africa , Shrimp fisheries -- South Africa , Decapoda , Caridina , Water quality management -- South Africa
- Description: Aquatic toxicity tests are increasingly being used in water resource management worldwide, and currently in South Africa, policy and legislation are being drafted to reflect this international trend. While standard toxicity test methods and test organisms are being considered to develop and set water quality guidelines and effluent discharge limits, it is not clear whether guidelines and discharge limits set using these standard test organisms will be sufficient to protect South Africa’s scarce water resources. As part of ongoing research to investigate the use of indigenous riverine organisms as toxicity test organisms a number of potential species have been identified, including the freshwater shrimp Caridina nilotica. For much of the history of aquatic toxicological data the bulk of the data has been generated by acute toxicity testing, based on short exposures and using mortality as the response end point. There are relatively few chronic, longterm tests with sub-lethal endpoints. However, it was recognized that information about longer exposure durations and non lethal response endpoints was needed, instead of mortality. Chronic tests can provide a more environmentally realistic measure of chemical toxicity than acute toxicity tests. Caridina nilotica has been identified as a potential standard toxicity test organism, as it is widely distributed, easy to find and it occurs in flowing waters. It is an indigenous species which can be easily cultured and maintained in the laboratory and is also ecologically important. Both adults and juveniles have been used successfully in acute toxicity tests at the Institute for Water Research (Rhodes University) and the ability to rear the organisms under laboratory conditions has allowed the development of chronic toxicity tests using C. nilotica. Chronic early life stage tests include continuous exposure of the early life stages, which are presumed to be the most sensitive for aquatic organisms. This study reports on the embryonic development of C. nilotica at the culture temperature of 24⁰C. Morphological developmental stages were monitored and measured and 7 developmental stages were identified. Based on the measurements of the features that were identified, toxicity tests using the reference chemicals sodium chloride (NaCl), sodium sulphate (Na₂SO₄) and cadmium chloride (CdCl₂) were undertaken to test the suitability of C. nilotica embryonic development for chronic toxicity tests for use in water resource management. The length, width, length:width ratios and area of the features decreased in size when exposed to the chemicals. The Lowest Observed Effect Concentration (LOEC) values were 2000mg/L for Na₂SO₄, 3000mg/L for NaCl and 0.31mg/L for CdCl₂. The No Observed Effect Concentration (NOEC) values were 1000mg/L for Na₂SO₄, 2000mg/L for NaCl and <0.31mg/L for CdCl₂. Further research on the teratogenic effects of single chemicals and industrial effluent on developing C. nilotica embryos needs to be undertaken in order to evaluate the described test protocol for use in water resource management.
- Full Text:
- Date Issued: 2007
- Authors: Ketse, Noziphiwo
- Date: 2007
- Subjects: Toxicity testing -- South Africa , Shrimp fisheries -- South Africa , Decapoda , Caridina , Water quality management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6025 , http://hdl.handle.net/10962/d1005367 , Toxicity testing -- South Africa , Shrimp fisheries -- South Africa , Decapoda , Caridina , Water quality management -- South Africa
- Description: Aquatic toxicity tests are increasingly being used in water resource management worldwide, and currently in South Africa, policy and legislation are being drafted to reflect this international trend. While standard toxicity test methods and test organisms are being considered to develop and set water quality guidelines and effluent discharge limits, it is not clear whether guidelines and discharge limits set using these standard test organisms will be sufficient to protect South Africa’s scarce water resources. As part of ongoing research to investigate the use of indigenous riverine organisms as toxicity test organisms a number of potential species have been identified, including the freshwater shrimp Caridina nilotica. For much of the history of aquatic toxicological data the bulk of the data has been generated by acute toxicity testing, based on short exposures and using mortality as the response end point. There are relatively few chronic, longterm tests with sub-lethal endpoints. However, it was recognized that information about longer exposure durations and non lethal response endpoints was needed, instead of mortality. Chronic tests can provide a more environmentally realistic measure of chemical toxicity than acute toxicity tests. Caridina nilotica has been identified as a potential standard toxicity test organism, as it is widely distributed, easy to find and it occurs in flowing waters. It is an indigenous species which can be easily cultured and maintained in the laboratory and is also ecologically important. Both adults and juveniles have been used successfully in acute toxicity tests at the Institute for Water Research (Rhodes University) and the ability to rear the organisms under laboratory conditions has allowed the development of chronic toxicity tests using C. nilotica. Chronic early life stage tests include continuous exposure of the early life stages, which are presumed to be the most sensitive for aquatic organisms. This study reports on the embryonic development of C. nilotica at the culture temperature of 24⁰C. Morphological developmental stages were monitored and measured and 7 developmental stages were identified. Based on the measurements of the features that were identified, toxicity tests using the reference chemicals sodium chloride (NaCl), sodium sulphate (Na₂SO₄) and cadmium chloride (CdCl₂) were undertaken to test the suitability of C. nilotica embryonic development for chronic toxicity tests for use in water resource management. The length, width, length:width ratios and area of the features decreased in size when exposed to the chemicals. The Lowest Observed Effect Concentration (LOEC) values were 2000mg/L for Na₂SO₄, 3000mg/L for NaCl and 0.31mg/L for CdCl₂. The No Observed Effect Concentration (NOEC) values were 1000mg/L for Na₂SO₄, 2000mg/L for NaCl and <0.31mg/L for CdCl₂. Further research on the teratogenic effects of single chemicals and industrial effluent on developing C. nilotica embryos needs to be undertaken in order to evaluate the described test protocol for use in water resource management.
- Full Text:
- Date Issued: 2007
A study of the conflict between maintenance and production functions in a manufacturing organisation in Port Elizabeth
- Authors: Petronio, Riccardo Vinicio
- Date: 2007
- Subjects: Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8737 , http://hdl.handle.net/10948/794 , Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Description: If manufacturing organisations are to improve their competitive positions in the global arena and increase profitability, their operations strategies need to be focused on: reducing cost, improving quality, increasing efficiency, improving the speed of delivery, developing and improving process flexibility, and ensuring that higher service levels are achieved and maintained. One of the critical success factors in implementing these strategies, within manufacturing organisations, is the relationship that exists between the maintenance and production functions. There is sufficient evidence to suggest that in many manufacturing organisations, the relationship that exists between these two functions is usually one of conflict, which if left unmanaged or unresolved has the potential to severely hamper effectiveness, productivity, creativity, and profitability of the organisation. The overall purpose of this research was to identify the interventions that manufacturing organisations can pursue, to effectively manage and resolve the conflict between the production and maintenance functions, in order to improve their competitive position in the global economy. The study was conducted in one particular manufacturing organisation in Port Elizabeth in the Eastern Cape. A research questionnaire was used as a means for collecting empirical data. The research questionnaire included various instruments used by previous conflict researchers, to identify and analyse the following dimensions of conflict within the organisation: conflict management styles used, the types of conflict perceived, and the amount of conflict perceived. The questionnaire was also designed to identify the sources of conflict, collect demographic information, identify issues relating to diversity, and indicate the respondents’ preferences to various organisational reporting structures. The results of the survey revealed key findings, which enabled the researcher to draw meaningful conclusions, and make recommendations as to how organisations can effectively manage and resolve the conflict that exists between maintenance and production functions.
- Full Text:
- Date Issued: 2007
- Authors: Petronio, Riccardo Vinicio
- Date: 2007
- Subjects: Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8737 , http://hdl.handle.net/10948/794 , Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Description: If manufacturing organisations are to improve their competitive positions in the global arena and increase profitability, their operations strategies need to be focused on: reducing cost, improving quality, increasing efficiency, improving the speed of delivery, developing and improving process flexibility, and ensuring that higher service levels are achieved and maintained. One of the critical success factors in implementing these strategies, within manufacturing organisations, is the relationship that exists between the maintenance and production functions. There is sufficient evidence to suggest that in many manufacturing organisations, the relationship that exists between these two functions is usually one of conflict, which if left unmanaged or unresolved has the potential to severely hamper effectiveness, productivity, creativity, and profitability of the organisation. The overall purpose of this research was to identify the interventions that manufacturing organisations can pursue, to effectively manage and resolve the conflict between the production and maintenance functions, in order to improve their competitive position in the global economy. The study was conducted in one particular manufacturing organisation in Port Elizabeth in the Eastern Cape. A research questionnaire was used as a means for collecting empirical data. The research questionnaire included various instruments used by previous conflict researchers, to identify and analyse the following dimensions of conflict within the organisation: conflict management styles used, the types of conflict perceived, and the amount of conflict perceived. The questionnaire was also designed to identify the sources of conflict, collect demographic information, identify issues relating to diversity, and indicate the respondents’ preferences to various organisational reporting structures. The results of the survey revealed key findings, which enabled the researcher to draw meaningful conclusions, and make recommendations as to how organisations can effectively manage and resolve the conflict that exists between maintenance and production functions.
- Full Text:
- Date Issued: 2007
More media for Southern Africa?: the place of politics, economics and convergence in developing media density
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147825 , vital:38676 , https://0-doi.org.wam.seals.ac.za/10.1080/02560240485310041
- Description: In line with global trends, media in Southern Africa in the past decade has been moving slowly towards mergers, partnerships and multi-platform publishing. Driven by politics and facilitated by technology, the process has had to confront the difficulty of establishing viable economic models, the lack of regional integration within Southern African countries, and what is sometimes a difficult political environment. Markets remain largely national or local and economically weak. Print media faces huge hurdles. Broadcast media density is improving, partly through noncommercial mechanisms. News websites are understaffed, lacking in viable survival strategies and skills, and are incompletely integrated with parent media platforms. Economic pressures, however, are likely to force Southern African media operations into greater synergies in search of survival. The various convergences entailed may increase media density.
- Full Text:
- Date Issued: 2007
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147825 , vital:38676 , https://0-doi.org.wam.seals.ac.za/10.1080/02560240485310041
- Description: In line with global trends, media in Southern Africa in the past decade has been moving slowly towards mergers, partnerships and multi-platform publishing. Driven by politics and facilitated by technology, the process has had to confront the difficulty of establishing viable economic models, the lack of regional integration within Southern African countries, and what is sometimes a difficult political environment. Markets remain largely national or local and economically weak. Print media faces huge hurdles. Broadcast media density is improving, partly through noncommercial mechanisms. News websites are understaffed, lacking in viable survival strategies and skills, and are incompletely integrated with parent media platforms. Economic pressures, however, are likely to force Southern African media operations into greater synergies in search of survival. The various convergences entailed may increase media density.
- Full Text:
- Date Issued: 2007
Excited state dynamics of zinc and aluminum phthalocyanine carboxylates
- Idowu, Mopelola, Ogunsipe, Abimbola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271228 , vital:54523 , xlink:href="https://doi.org/10.1016/j.saa.2007.01.025"
- Description: Photophysical parameters for zinc and aluminium tetracarboxylphthalocyanines (ZnTCPc and AlTCPc, respectively) and their octacarboxy substituted counterparts (ZnOCPc and AlOCPc) were studied. Data for the fluorescence quenching of the complexes by benzoquinone (BQ) were treated using the Stern–Volmer analysis, and the quenching was found to follow a diffusion-controlled (dynamic) bimolecular mechanism. Theoretical values of bimolecular rate constant for complex-BQ interactions were determined using the Stokes–Einstein–Smoluchowski model; and the values, together with the Stern–Volmer quenching constants were used in calculating the fluorescence lifetimes of the complexes. The thermodynamics of the MPc-BQ interaction, in terms of solvent reorientation energy is also discussed.
- Full Text:
- Date Issued: 2007
- Authors: Idowu, Mopelola , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271228 , vital:54523 , xlink:href="https://doi.org/10.1016/j.saa.2007.01.025"
- Description: Photophysical parameters for zinc and aluminium tetracarboxylphthalocyanines (ZnTCPc and AlTCPc, respectively) and their octacarboxy substituted counterparts (ZnOCPc and AlOCPc) were studied. Data for the fluorescence quenching of the complexes by benzoquinone (BQ) were treated using the Stern–Volmer analysis, and the quenching was found to follow a diffusion-controlled (dynamic) bimolecular mechanism. Theoretical values of bimolecular rate constant for complex-BQ interactions were determined using the Stokes–Einstein–Smoluchowski model; and the values, together with the Stern–Volmer quenching constants were used in calculating the fluorescence lifetimes of the complexes. The thermodynamics of the MPc-BQ interaction, in terms of solvent reorientation energy is also discussed.
- Full Text:
- Date Issued: 2007
Passing the spear : a grounded theory study of the influence of family business value sets on succession planning in black family-owned businesses
- Authors: Musengi, Sandra
- Date: 2007
- Subjects: Grounded theory Family-owned business enterprises Family-owned business enterprises -- Succession Family-owned business enterprises -- Management Business enterprises, Black Business planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1192 , http://hdl.handle.net/10962/d1007056
- Description: Literature suggests that a small number of family businesses are able to make the transition from the founder to other family members with a common reason cited being the lack of planning. This study aims to build understanding of leadership succession in family businesses by focusing on the influence of a founder's family business value set on the succession planning process in Black family-owned businesses. Using the Strauss and Corbin (1990) grounded theory method, this study develops a theory of succession planning of Black familyowned businesses labelled Passing the Spear which is comprised of three stages based on an analysis of 21 qualitative interviews. The Spear was an analogy used to represent both the values of the founder and the family business, thus in Passing the Spear, founders where essentially performing a dual transfer of their values and leadership to the successor. The implementation of the process Passing the Spear was influenced by the family business value set of the founder, which in this study, were labelled as Traditional, Progressive, and Transitional. These value sets were distinguished by their behaviour regarding their choice of successor where founders with a traditional value set exhibited gatekeeping behaviour, while the behaviour of founders with a progressive value set was labelled navigating, and finally, founders with a transitional value set demonstrated behaviour labelled exploring. Furthermore, it was found that after the successor had been chosen, founders appeared to follow a generic succession planning process, however, the ease and timing of implementation was influenced by the family business context, evidence of being proactive and the degree of family business resilience. The process of Passing the Spear comprised of three stages of (a) Showing the spear where the founder's focus is on the induction and socialization of the successor using the strategies of bringing the successor into the family business and managing the family-business interface using relationships; (b) Explaining the spear entailed founders using the strategies of sharing knowledge and teaching the successors about the family business; and ( c) Sharing the spear was where founders focused on empowering the successors by implementing strategies of sharing responsibilities and learning from the successor.The process provides insights into the influence of family business values on the succession planning process and can be useful for founders of Black family-owned businesses in planning for succession in their businesses. In addition, the study provides another perspective of succession planning and offers a contribution to the literature for understanding succession in Black family-owned businesses.
- Full Text:
- Date Issued: 2007
- Authors: Musengi, Sandra
- Date: 2007
- Subjects: Grounded theory Family-owned business enterprises Family-owned business enterprises -- Succession Family-owned business enterprises -- Management Business enterprises, Black Business planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1192 , http://hdl.handle.net/10962/d1007056
- Description: Literature suggests that a small number of family businesses are able to make the transition from the founder to other family members with a common reason cited being the lack of planning. This study aims to build understanding of leadership succession in family businesses by focusing on the influence of a founder's family business value set on the succession planning process in Black family-owned businesses. Using the Strauss and Corbin (1990) grounded theory method, this study develops a theory of succession planning of Black familyowned businesses labelled Passing the Spear which is comprised of three stages based on an analysis of 21 qualitative interviews. The Spear was an analogy used to represent both the values of the founder and the family business, thus in Passing the Spear, founders where essentially performing a dual transfer of their values and leadership to the successor. The implementation of the process Passing the Spear was influenced by the family business value set of the founder, which in this study, were labelled as Traditional, Progressive, and Transitional. These value sets were distinguished by their behaviour regarding their choice of successor where founders with a traditional value set exhibited gatekeeping behaviour, while the behaviour of founders with a progressive value set was labelled navigating, and finally, founders with a transitional value set demonstrated behaviour labelled exploring. Furthermore, it was found that after the successor had been chosen, founders appeared to follow a generic succession planning process, however, the ease and timing of implementation was influenced by the family business context, evidence of being proactive and the degree of family business resilience. The process of Passing the Spear comprised of three stages of (a) Showing the spear where the founder's focus is on the induction and socialization of the successor using the strategies of bringing the successor into the family business and managing the family-business interface using relationships; (b) Explaining the spear entailed founders using the strategies of sharing knowledge and teaching the successors about the family business; and ( c) Sharing the spear was where founders focused on empowering the successors by implementing strategies of sharing responsibilities and learning from the successor.The process provides insights into the influence of family business values on the succession planning process and can be useful for founders of Black family-owned businesses in planning for succession in their businesses. In addition, the study provides another perspective of succession planning and offers a contribution to the literature for understanding succession in Black family-owned businesses.
- Full Text:
- Date Issued: 2007
The role of aardvarks (Orycteropus afer) as ecosystem engineers in arid and semi-arid landscapes of South Africa
- Whittington-Jones, Gareth Morgan
- Authors: Whittington-Jones, Gareth Morgan
- Date: 2007
- Subjects: Aardvark , Aardvark -- South Africa , Aardvark -- South Africa -- Habitations , Animal burrowing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5757 , http://hdl.handle.net/10962/d1005445 , Aardvark , Aardvark -- South Africa , Aardvark -- South Africa -- Habitations , Animal burrowing
- Description: Arid and semi arid environments are characterised by extreme fluctuations in temperature and low rainfall which present significant challenges to the animals inhabiting these areas. Mammals, such as aardvarks (Orycteropus afer, Pallas 1766), excavate burrows in order to avoid predators and climatic extremes and are termed “ecosystem engineers” as they physically modify their environment and in doing so create new habitats and alter the availability of resources to other species. In this study I assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark burrows in relation to paired control sites. In addition, I evaluated the use of aardvark burrows by other vertebrate and invertebrate species and investigated the impact of aardvark burrow mounds on landscape scale floristic diversity. Maximum temperatures were significantly lower (p < 0.05) and minimum temperatures and midday humidity were significantly higher (p < 0.05) inside the burrows at the three study sites, Kwandwe Private Game Reserve (Kwandwe), Mountain Zebra National Park (MZNP) and Tswalu Kalahari Reserve (Tswalu). There were no significant differences between the concentration of seeds, the average numbers of unique individual small mammals, trap success or small mammal species richness recorded inside the burrows compared to outside (p > 0.05). At all three sites, small mammal species diversity was higher in the burrows but this result was also not significant (p > 0.05 for all). Trap success and the number of individuals captured was higher at Tswalu than the other two sites (p < 0.05 for both). The different methods used in this study revealed a total of 25 mammal, seven bird, one amphibian and six reptile species utilising aardvark burrows. There were significant differences in insect community assemblages between the burrows and open control areas at Kwandwe and Tswalu (p < 0.05 for both) but not at MZNP (p > 0.05). The parasitic guild was more prominent inside the burrows than outside but their abundance was not as high as anticipated, possibly due to the placement of traps closer to the burrow entrances than the sleeping chambers. The complex structure of the burrows prevented the placement of traps in close proximity to the sleeping chambers. As expected, the amount of bare earth was significantly higher on active and recently abandoned burrow mounds compared to the old burrow mounds and reference plots at all three sites (p < 0.05 for all), with the exception of the active burrows at Tswalu. Overall, the different plot types were characterised by significantly different plant communities during all the seasons at MZNP, during three of the seasons at Kwandwe and only during winter at Tswalu. The total species richness recorded on the reference plots was higher than on the burrow mounds at all three sites. However, species diversity on the reference plots was not significantly higher than the burrows at any of the sites (p > 0.05 for all sites). Although the results were not significant, the overall species diversity at a site level was greater than the reference patches at Kwandwe and Tswalu (p > 0.05 for both). Aardvarks fulfil the criteria of a significant ecosystem engineer and their presence in arid and semi-arid environments is likely to be critical to the survival of other individual organisms and species, particularly when alternative burrowing animals are either absent or restricted in their activities. Thus, aardvark populations should be considered a conservation priority in arid and semi-arid ecosystems.
- Full Text:
- Date Issued: 2007
- Authors: Whittington-Jones, Gareth Morgan
- Date: 2007
- Subjects: Aardvark , Aardvark -- South Africa , Aardvark -- South Africa -- Habitations , Animal burrowing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5757 , http://hdl.handle.net/10962/d1005445 , Aardvark , Aardvark -- South Africa , Aardvark -- South Africa -- Habitations , Animal burrowing
- Description: Arid and semi arid environments are characterised by extreme fluctuations in temperature and low rainfall which present significant challenges to the animals inhabiting these areas. Mammals, such as aardvarks (Orycteropus afer, Pallas 1766), excavate burrows in order to avoid predators and climatic extremes and are termed “ecosystem engineers” as they physically modify their environment and in doing so create new habitats and alter the availability of resources to other species. In this study I assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark burrows in relation to paired control sites. In addition, I evaluated the use of aardvark burrows by other vertebrate and invertebrate species and investigated the impact of aardvark burrow mounds on landscape scale floristic diversity. Maximum temperatures were significantly lower (p < 0.05) and minimum temperatures and midday humidity were significantly higher (p < 0.05) inside the burrows at the three study sites, Kwandwe Private Game Reserve (Kwandwe), Mountain Zebra National Park (MZNP) and Tswalu Kalahari Reserve (Tswalu). There were no significant differences between the concentration of seeds, the average numbers of unique individual small mammals, trap success or small mammal species richness recorded inside the burrows compared to outside (p > 0.05). At all three sites, small mammal species diversity was higher in the burrows but this result was also not significant (p > 0.05 for all). Trap success and the number of individuals captured was higher at Tswalu than the other two sites (p < 0.05 for both). The different methods used in this study revealed a total of 25 mammal, seven bird, one amphibian and six reptile species utilising aardvark burrows. There were significant differences in insect community assemblages between the burrows and open control areas at Kwandwe and Tswalu (p < 0.05 for both) but not at MZNP (p > 0.05). The parasitic guild was more prominent inside the burrows than outside but their abundance was not as high as anticipated, possibly due to the placement of traps closer to the burrow entrances than the sleeping chambers. The complex structure of the burrows prevented the placement of traps in close proximity to the sleeping chambers. As expected, the amount of bare earth was significantly higher on active and recently abandoned burrow mounds compared to the old burrow mounds and reference plots at all three sites (p < 0.05 for all), with the exception of the active burrows at Tswalu. Overall, the different plot types were characterised by significantly different plant communities during all the seasons at MZNP, during three of the seasons at Kwandwe and only during winter at Tswalu. The total species richness recorded on the reference plots was higher than on the burrow mounds at all three sites. However, species diversity on the reference plots was not significantly higher than the burrows at any of the sites (p > 0.05 for all sites). Although the results were not significant, the overall species diversity at a site level was greater than the reference patches at Kwandwe and Tswalu (p > 0.05 for both). Aardvarks fulfil the criteria of a significant ecosystem engineer and their presence in arid and semi-arid environments is likely to be critical to the survival of other individual organisms and species, particularly when alternative burrowing animals are either absent or restricted in their activities. Thus, aardvark populations should be considered a conservation priority in arid and semi-arid ecosystems.
- Full Text:
- Date Issued: 2007
Photophysical and photochemical properties of zinc and aluminum phthalocyanines in the presence of magnetic fluid
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281298 , vital:55710 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.12.013"
- Description: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching.
- Full Text:
- Date Issued: 2007
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281298 , vital:55710 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.12.013"
- Description: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching.
- Full Text:
- Date Issued: 2007
Comparative photocatalytic efficiency of oxotitanium (IV) phthalocyanines for the oxidation of 1-hexene
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271193 , vital:54520 , xlink:href="https://doi.org/10.1016/j.molcata.2007.04.005"
- Description: The comparative photocatalytic activities of aryloxy and arylthio tetrasubstituted oxotitanium(IV) phthalocyanine complexes for the oxidation of 1-hexene in DCM are reported for the first time. The singlet oxygen quantum yield, photostability and photocatalytic properties are investigated. The catalysts effectively catalyse 1-hexene to 1,2-epoxyhexane and 1-hexen-3-ol as major and minor products respectively. The photooxidation products are formed via two reaction mechanisms, namely via singlet oxygen (Type II) and radical (Type I) reaction pathways. These are also dependent on the singlet oxygen quantum yields and photostabilities of the phthalocyanines. Complex 1a that is peripherally substituted with phenoxy groups exhibited the best activity in terms of overall performance.
- Full Text:
- Date Issued: 2007
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271193 , vital:54520 , xlink:href="https://doi.org/10.1016/j.molcata.2007.04.005"
- Description: The comparative photocatalytic activities of aryloxy and arylthio tetrasubstituted oxotitanium(IV) phthalocyanine complexes for the oxidation of 1-hexene in DCM are reported for the first time. The singlet oxygen quantum yield, photostability and photocatalytic properties are investigated. The catalysts effectively catalyse 1-hexene to 1,2-epoxyhexane and 1-hexen-3-ol as major and minor products respectively. The photooxidation products are formed via two reaction mechanisms, namely via singlet oxygen (Type II) and radical (Type I) reaction pathways. These are also dependent on the singlet oxygen quantum yields and photostabilities of the phthalocyanines. Complex 1a that is peripherally substituted with phenoxy groups exhibited the best activity in terms of overall performance.
- Full Text:
- Date Issued: 2007
Limiting vulnerability exposure through effective patch management: threat mitigation through vulnerability remediation
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
An examination of internet usage patterns by mature travellers
- Authors: Correia, Sérgio Barradas
- Date: 2007
- Subjects: Tourism -- Marketing , Internet marketing , Internet users , Older people -- Travel , Older consumers -- Travel
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1194 , http://hdl.handle.net/10962/d1008182 , Tourism -- Marketing , Internet marketing , Internet users , Older people -- Travel , Older consumers -- Travel
- Description: The tourism industry has been identified as the industry with the most potential to create jobs and contribute largely to economic growth. In order to live up to this potential, tourism businesses need to create tourism products for potential tourists which need to be promoted successfully through a number of mediums. The use of the Internet as a medium for promoting and selling tourism products is increasing, however, in order for tourism businesses to successfully promote the tourism product through the Internet, they have to understand the needs and wants of their current and potential target markets. One segment of the tourism market that has come under increasing attention is the mature traveller market. This market is defined as travellers who are 50 years of age and older. Generally, the mature traveller market is viewed as a small homogenous group of old consumers with little or no spending power. However, evidence suggests that this market is comprised of an increasing number of diverse people, who use the Internet and like to spend on tourism products. Therefore, this research will examine differences between Internet users and Internet non-users in the mature traveller market. Specific attention will be paid to investigate differences in demographic, socioeconomic, Internet use and travel-related characteristics. The identification of these characteristics will enable a profile to be d~veloped for each group, which can be used by tourism businesses to effectively promote tourism products over the Internet to the mature market In order to collect data from potential respondents, a questionnaire which was used in a similar study conducted in the US was used. Data was collected using a convenience sample of Internet users and Internet non-users from the Eastern Cape and Gauteng provinces of South Africa. Cronbach alpha and factor analysis were used to assess the reliability and validity of the research instrument and measurement scales. In order to test whether differences did exist between the two groups the Chi-square and t-test statistics were used. Finally in order to examine which factors where influential in differentiating between Internet users and Internet non-users discriminant analysis was employed. The findings in the present study suggest that there are significant differences in demographics, socioeconomic, Internet use and travel-related characteristics between Internet users and Internet non-users in the mature market. By understanding the differences between Internet users and Internet non-users, tourism businesses can identify marketing strategies that appeal to mature travellers who use the Internet and to those do not, by utilising information gathered from Internet users and Internet non-users demographic, socio-economic and travel-related characteristics.
- Full Text:
- Date Issued: 2007
- Authors: Correia, Sérgio Barradas
- Date: 2007
- Subjects: Tourism -- Marketing , Internet marketing , Internet users , Older people -- Travel , Older consumers -- Travel
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1194 , http://hdl.handle.net/10962/d1008182 , Tourism -- Marketing , Internet marketing , Internet users , Older people -- Travel , Older consumers -- Travel
- Description: The tourism industry has been identified as the industry with the most potential to create jobs and contribute largely to economic growth. In order to live up to this potential, tourism businesses need to create tourism products for potential tourists which need to be promoted successfully through a number of mediums. The use of the Internet as a medium for promoting and selling tourism products is increasing, however, in order for tourism businesses to successfully promote the tourism product through the Internet, they have to understand the needs and wants of their current and potential target markets. One segment of the tourism market that has come under increasing attention is the mature traveller market. This market is defined as travellers who are 50 years of age and older. Generally, the mature traveller market is viewed as a small homogenous group of old consumers with little or no spending power. However, evidence suggests that this market is comprised of an increasing number of diverse people, who use the Internet and like to spend on tourism products. Therefore, this research will examine differences between Internet users and Internet non-users in the mature traveller market. Specific attention will be paid to investigate differences in demographic, socioeconomic, Internet use and travel-related characteristics. The identification of these characteristics will enable a profile to be d~veloped for each group, which can be used by tourism businesses to effectively promote tourism products over the Internet to the mature market In order to collect data from potential respondents, a questionnaire which was used in a similar study conducted in the US was used. Data was collected using a convenience sample of Internet users and Internet non-users from the Eastern Cape and Gauteng provinces of South Africa. Cronbach alpha and factor analysis were used to assess the reliability and validity of the research instrument and measurement scales. In order to test whether differences did exist between the two groups the Chi-square and t-test statistics were used. Finally in order to examine which factors where influential in differentiating between Internet users and Internet non-users discriminant analysis was employed. The findings in the present study suggest that there are significant differences in demographics, socioeconomic, Internet use and travel-related characteristics between Internet users and Internet non-users in the mature market. By understanding the differences between Internet users and Internet non-users, tourism businesses can identify marketing strategies that appeal to mature travellers who use the Internet and to those do not, by utilising information gathered from Internet users and Internet non-users demographic, socio-economic and travel-related characteristics.
- Full Text:
- Date Issued: 2007
Estimating the willingness-to-pay for restoring indigenous vegetation at selected sites in South Africa
- Authors: Tessendorf, Sharon Erica
- Date: 2007
- Subjects: Water resources development -- South Africa , Water-supply -- South Africa , Alien plants -- South Africa , Restoration ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8999 , http://hdl.handle.net/10948/617 , Water resources development -- South Africa , Water-supply -- South Africa , Alien plants -- South Africa , Restoration ecology -- South Africa
- Description: The Working for Water (WfW) Programme is a public works programme designed to clear South Africa of invasive alien vegetation and to restore lowwater consuming indigenous vegetation in the areas that have been cleared. Funds to clear alien invasives were initially secured on the basis that such a programme would increase water runoff, facilitate biodiversity and ecosystem functioning, and provide social benefits through job creation. The economic merits of the Programme, in terms of increased water yields, has been established in the Western Cape and KwaZulu-Natal, but questioned in the Eastern and Southern Cape. However, there are economic aspects of the studies carried out in the Eastern and Southern Cape that merit more attention than was given them; one of these being the issue of non-water benefits. Preliminary figures emanating from contingent valuation pilot studies conducted at six WfW projects sites indicated that one of these non-water benefits, namely the biodiversity and ecosystem resilience benefit, could be substantial. As such, the primary objective of the present study was to apply the contingent valuation method (CVM) to value people’s preference for indigenous vegetation. This value was intended to serve as a proxy for increased biodiversity and ecosystem resilience at three WfW sites. Despite the controversy surrounding the CVM, it has been found that it is a credible valuation tool. The CVM’s merits lie in its versatility and in the fact that it is the only method available which is capable of obtaining estimates of both nonuse and use values, thus making it applicable for valuing biodiversity. The primary aim of a CVM study is to determine an estimate of the total willingness-to-pay (WTP). In this study, the total WTP figure was calculated by multiplying the median WTP for the local WfW Programme by the total number of user households. The respective total WTP amounts are shown in Table 1. It was anticipated that respondents would be willing to pay more for the national WfW Programme, than for the less inclusive good (i.e. the local WfW Programme). The results correspond with this expectation at the Port Elizabeth and Underberg sites. However, due to strategic factors Worcester respondents were willing to pay more for the local WfW Programme than for the national Programme.
- Full Text:
- Date Issued: 2007
- Authors: Tessendorf, Sharon Erica
- Date: 2007
- Subjects: Water resources development -- South Africa , Water-supply -- South Africa , Alien plants -- South Africa , Restoration ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8999 , http://hdl.handle.net/10948/617 , Water resources development -- South Africa , Water-supply -- South Africa , Alien plants -- South Africa , Restoration ecology -- South Africa
- Description: The Working for Water (WfW) Programme is a public works programme designed to clear South Africa of invasive alien vegetation and to restore lowwater consuming indigenous vegetation in the areas that have been cleared. Funds to clear alien invasives were initially secured on the basis that such a programme would increase water runoff, facilitate biodiversity and ecosystem functioning, and provide social benefits through job creation. The economic merits of the Programme, in terms of increased water yields, has been established in the Western Cape and KwaZulu-Natal, but questioned in the Eastern and Southern Cape. However, there are economic aspects of the studies carried out in the Eastern and Southern Cape that merit more attention than was given them; one of these being the issue of non-water benefits. Preliminary figures emanating from contingent valuation pilot studies conducted at six WfW projects sites indicated that one of these non-water benefits, namely the biodiversity and ecosystem resilience benefit, could be substantial. As such, the primary objective of the present study was to apply the contingent valuation method (CVM) to value people’s preference for indigenous vegetation. This value was intended to serve as a proxy for increased biodiversity and ecosystem resilience at three WfW sites. Despite the controversy surrounding the CVM, it has been found that it is a credible valuation tool. The CVM’s merits lie in its versatility and in the fact that it is the only method available which is capable of obtaining estimates of both nonuse and use values, thus making it applicable for valuing biodiversity. The primary aim of a CVM study is to determine an estimate of the total willingness-to-pay (WTP). In this study, the total WTP figure was calculated by multiplying the median WTP for the local WfW Programme by the total number of user households. The respective total WTP amounts are shown in Table 1. It was anticipated that respondents would be willing to pay more for the national WfW Programme, than for the less inclusive good (i.e. the local WfW Programme). The results correspond with this expectation at the Port Elizabeth and Underberg sites. However, due to strategic factors Worcester respondents were willing to pay more for the local WfW Programme than for the national Programme.
- Full Text:
- Date Issued: 2007
Photophysical and photochemical studies of long chain-substituted zinc phthalocyanines
- Durmus, Mahmut, Ahsen, Vefa, Nyokong, Tebello
- Authors: Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281310 , vital:55711 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.025"
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetra(13,17-dioxanonacosane-15-hydroxy)-substituted zinc phthalocyanines (1, 2). General trends are described for quantum yields of photodegradation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet quantum yields of these compounds in dimethylformamide (DMF) and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2) are reported.
- Full Text:
- Date Issued: 2007
- Authors: Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281310 , vital:55711 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.025"
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetra(13,17-dioxanonacosane-15-hydroxy)-substituted zinc phthalocyanines (1, 2). General trends are described for quantum yields of photodegradation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet quantum yields of these compounds in dimethylformamide (DMF) and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2) are reported.
- Full Text:
- Date Issued: 2007
Towards a theory of choral conducting gestures
- Oosthuizen, Benjamin William
- Authors: Oosthuizen, Benjamin William
- Date: 2007
- Subjects: Choral conducting
- Language: English
- Type: Thesis , Doctoral , DMus
- Identifier: vital:8505 , http://hdl.handle.net/10948/589 , Choral conducting
- Description: It is an oversimplification to look only at the manner in which a two-dimensional drawing suggests a three-dimensional movement in order to study choral conducting gestures. It must be recognised that there is a myriad of tacit aspects of knowledge surrounding conducting gestures. These aspects of tacit knowledge might be the reason why the teaching of conducting is done mostly in a continuous practicum, where the apprentice learns from the master, because in the practical situation the novice learns not only explicit knowledge, but also tacit knowledge. On the other hand, it is vital that the process of categorising and theorising about gestures continues in order to at least gain a better explicit knowledge of the process. In doing so, a theoretical knowledge base will strengthen the body of knowledge. This explicit knowledge should contain information with regard to the anatomy of the conductor, a basic understanding of a balanced posture, bilateral symmetry and vertical alignment, and a basic knowledge which will help to understand which main muscle groups are responsible for which basic movements involving gestures. The study of gestures from a theoretical point of view is barely more than five decades old. The demands which 20th and 21st century composers make on conductors question the traditional approaches of the functions of the hands. It has become essential for a conductor to develop greater skill of ambidexterity in order to cope with these demands. Despite the notion by some authors that choral conducting gestures employ standard gestures, it has been shown in this study that this is simply not the case. An overview of the work of authors in the field of conducting gestures was presented through a literature study. Concepts and their definitions have been selected and explained through the answering of research questions. Definitions of parameters and functionality of gestures were clarified to decide which gestures were the most appropriate in certain circumstances. This theory aims to be both descriptive and normative. It is descriptive in the sense that the concepts and issues and relationships around the characteristic aspects of gestures are indicated. It is normative in terms of the suggestions offered with regard to issues pertaining to gestures. This thesis sets out to contribute to the formulation of theoretical aspects of choral conducting gestures in an effort to codify and structure knowledge which is often stored in composers minds and experience, in an effort to pass down this knowledge to other apprentices in the field.
- Full Text:
- Date Issued: 2007
- Authors: Oosthuizen, Benjamin William
- Date: 2007
- Subjects: Choral conducting
- Language: English
- Type: Thesis , Doctoral , DMus
- Identifier: vital:8505 , http://hdl.handle.net/10948/589 , Choral conducting
- Description: It is an oversimplification to look only at the manner in which a two-dimensional drawing suggests a three-dimensional movement in order to study choral conducting gestures. It must be recognised that there is a myriad of tacit aspects of knowledge surrounding conducting gestures. These aspects of tacit knowledge might be the reason why the teaching of conducting is done mostly in a continuous practicum, where the apprentice learns from the master, because in the practical situation the novice learns not only explicit knowledge, but also tacit knowledge. On the other hand, it is vital that the process of categorising and theorising about gestures continues in order to at least gain a better explicit knowledge of the process. In doing so, a theoretical knowledge base will strengthen the body of knowledge. This explicit knowledge should contain information with regard to the anatomy of the conductor, a basic understanding of a balanced posture, bilateral symmetry and vertical alignment, and a basic knowledge which will help to understand which main muscle groups are responsible for which basic movements involving gestures. The study of gestures from a theoretical point of view is barely more than five decades old. The demands which 20th and 21st century composers make on conductors question the traditional approaches of the functions of the hands. It has become essential for a conductor to develop greater skill of ambidexterity in order to cope with these demands. Despite the notion by some authors that choral conducting gestures employ standard gestures, it has been shown in this study that this is simply not the case. An overview of the work of authors in the field of conducting gestures was presented through a literature study. Concepts and their definitions have been selected and explained through the answering of research questions. Definitions of parameters and functionality of gestures were clarified to decide which gestures were the most appropriate in certain circumstances. This theory aims to be both descriptive and normative. It is descriptive in the sense that the concepts and issues and relationships around the characteristic aspects of gestures are indicated. It is normative in terms of the suggestions offered with regard to issues pertaining to gestures. This thesis sets out to contribute to the formulation of theoretical aspects of choral conducting gestures in an effort to codify and structure knowledge which is often stored in composers minds and experience, in an effort to pass down this knowledge to other apprentices in the field.
- Full Text:
- Date Issued: 2007
Lazarus in the Constitutional Court: an exhumation of the exceptio doli generalis
- Authors: Glover, Graham B
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70678 , vital:29688 , https://hdl.handle.net/10520/EJC53775
- Description: A landmark moment in the history of South African contract law was the emphatic interment of the exceptio doli generalis by Joubert JA in Bank of Lisbon and South Africa v De Ornelas 1988 (3) SA580 (A). Throughout most of the twentieth century, the exceptio doli generalis had been viewed as an equitable defence that allowed a defendant to resist a claim for performance under a contract when there was something unconscionable about the plaintiff's seeking to enforce the contract (or a clause thereof) in the specific circumstances of that case (see A J Kerr Principles of the Law of Contract 6 ed (2002) 637ff; P J Aronstam 'Unconscionable contracts: The South African solution?' (1979) 42 THRHR 21; P van Warmelo 'Exceptio doli' 1981 De Jure 202).
- Full Text: false
- Date Issued: 2007
- Authors: Glover, Graham B
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70678 , vital:29688 , https://hdl.handle.net/10520/EJC53775
- Description: A landmark moment in the history of South African contract law was the emphatic interment of the exceptio doli generalis by Joubert JA in Bank of Lisbon and South Africa v De Ornelas 1988 (3) SA580 (A). Throughout most of the twentieth century, the exceptio doli generalis had been viewed as an equitable defence that allowed a defendant to resist a claim for performance under a contract when there was something unconscionable about the plaintiff's seeking to enforce the contract (or a clause thereof) in the specific circumstances of that case (see A J Kerr Principles of the Law of Contract 6 ed (2002) 637ff; P J Aronstam 'Unconscionable contracts: The South African solution?' (1979) 42 THRHR 21; P van Warmelo 'Exceptio doli' 1981 De Jure 202).
- Full Text: false
- Date Issued: 2007
Stakeholders' perceptions of parents' involvement in the governance of a Namibian rural school
- Authors: Niitembu, Martha M
- Date: 2007
- Subjects: School management and organization -- Namibia Education -- Parent participation -- Namibia Education and state -- Namibia Rural schools -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1770 , http://hdl.handle.net/10962/d1003655
- Description: The issue of decentralisation has been one of the top priorities of the Namibian education system since independence in 1990. One of the decentralisation aims was to enhance parental involvement in education by establishing School Boards. However, School Boards and the role of parents in school management have been considered ineffective for several years which led to the promulgation of Education Act 16 of 2001 in which the roles of School Boards are strengthened and clarified. This study sought to investigate School Board members’ perceptions, understanding and experiences of parents’ involvement in school governance more specifically after the implementation of the Education Act of 2001 in 2003. This study is an interpretive case study of one combined rural school in the Ohangwena educational region of Namibia. This research employed three data collection techniques, namely semi-structured interviews, observation and document analysis. The main findings of this study reveal that there is a lack of joint understanding and shared vision between educators and parents in the School Board. This problem underpins other more symptomatic problems, such as lack of accountability in the matter of school finances, differences in understanding the roles of School Board members and lack of parents’ motivation from the school management. The study further reveals the ineffectiveness and insufficiency of the training provided in the past. It highlights some of the challenges that hinder the effective involvement of parents in rural school governance, such as poor educational background among parents, poor knowledge of the English language and poor understanding of educational issues. However the findings also acknowledge parents’ participation and their full involvement in decision-making. The findings show that the new School Board elected in terms of the Education Act of 2001 has been more effective than previous School Boards and has reached a number of achievements such as being instrumental in solving disciplinary problems, purchasing school assets and renovating classrooms. Recommendations for practice and for further research are made.
- Full Text:
- Date Issued: 2007
- Authors: Niitembu, Martha M
- Date: 2007
- Subjects: School management and organization -- Namibia Education -- Parent participation -- Namibia Education and state -- Namibia Rural schools -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1770 , http://hdl.handle.net/10962/d1003655
- Description: The issue of decentralisation has been one of the top priorities of the Namibian education system since independence in 1990. One of the decentralisation aims was to enhance parental involvement in education by establishing School Boards. However, School Boards and the role of parents in school management have been considered ineffective for several years which led to the promulgation of Education Act 16 of 2001 in which the roles of School Boards are strengthened and clarified. This study sought to investigate School Board members’ perceptions, understanding and experiences of parents’ involvement in school governance more specifically after the implementation of the Education Act of 2001 in 2003. This study is an interpretive case study of one combined rural school in the Ohangwena educational region of Namibia. This research employed three data collection techniques, namely semi-structured interviews, observation and document analysis. The main findings of this study reveal that there is a lack of joint understanding and shared vision between educators and parents in the School Board. This problem underpins other more symptomatic problems, such as lack of accountability in the matter of school finances, differences in understanding the roles of School Board members and lack of parents’ motivation from the school management. The study further reveals the ineffectiveness and insufficiency of the training provided in the past. It highlights some of the challenges that hinder the effective involvement of parents in rural school governance, such as poor educational background among parents, poor knowledge of the English language and poor understanding of educational issues. However the findings also acknowledge parents’ participation and their full involvement in decision-making. The findings show that the new School Board elected in terms of the Education Act of 2001 has been more effective than previous School Boards and has reached a number of achievements such as being instrumental in solving disciplinary problems, purchasing school assets and renovating classrooms. Recommendations for practice and for further research are made.
- Full Text:
- Date Issued: 2007
The idea of regionalism in West and Southern Africa : a critical social enquiry
- Authors: Lindsay, Albert Domson
- Date: 2007
- Subjects: Regionalism -- Africa, West Regionalism -- Africa, Southern Africa, West -- Politics and government Africa, Southern -- Politics and government Africa -- Foreign relations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2848 , http://hdl.handle.net/10962/d1006118
- Description: Traditional views on International Relations dominate regional analyses. These invariably emphasize the dominance of state and market forces in inter-state relations. Experiences and expectations of people are less prominent in these discourses, and the practices they foster. This thesis critically analyses the regional processes in West and southern Africa within the framework of Critical Theory. It argues that these processes are constrained by instability and the increasing legitimacy crises of the State. The thesis demonstrates that the State, through exclusive nationalist practices, hinder the growth of a cosmopolitan order, and it argues that neo-liberal regionalism is a contested phenomenon because of its exclusive nature. Finally, the thesis suggests steps needed to resolve the legitimacy crises and to build an inclusive regional order, based on cosmopolitan values.
- Full Text:
- Date Issued: 2007
- Authors: Lindsay, Albert Domson
- Date: 2007
- Subjects: Regionalism -- Africa, West Regionalism -- Africa, Southern Africa, West -- Politics and government Africa, Southern -- Politics and government Africa -- Foreign relations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2848 , http://hdl.handle.net/10962/d1006118
- Description: Traditional views on International Relations dominate regional analyses. These invariably emphasize the dominance of state and market forces in inter-state relations. Experiences and expectations of people are less prominent in these discourses, and the practices they foster. This thesis critically analyses the regional processes in West and southern Africa within the framework of Critical Theory. It argues that these processes are constrained by instability and the increasing legitimacy crises of the State. The thesis demonstrates that the State, through exclusive nationalist practices, hinder the growth of a cosmopolitan order, and it argues that neo-liberal regionalism is a contested phenomenon because of its exclusive nature. Finally, the thesis suggests steps needed to resolve the legitimacy crises and to build an inclusive regional order, based on cosmopolitan values.
- Full Text:
- Date Issued: 2007
The relationship between individual needs and the choice of incentive schemes in the South African Breweries
- Authors: Long, Allan
- Date: 2007
- Subjects: South African Breweries Ltd. Incentives in industry -- South Africa Workers' compensation -- South Africa Performance -- Management Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:800 , http://hdl.handle.net/10962/d1006119
- Description: After careful review of all the relevant literature pertaining to motivation, performance management and compensation in the form of incentives, this thesis focuses primarily on determining whether a statistically significant relationship exists between individual needs and the choice of an incentive scheme option. The secondary aims of the research are to determine whether: A relationship exists between the job grade of an individual and the choice of an incentive scheme. A particular incentive scheme option is preferred by the employees in The South African Breweries (SAB). A particular preference exists, and if so, to make recommendations to SAB for consideration as alternatives to their existing incentive scheme options. After collation of the survey data from the respondents in the sample, the analysis and discussion of the results determined that no significant relationship exists between individual needs and the choice of an incentive scheme option. It was, however, determined that a significant relationship exists between the grade of the employees in SAB and their choice of an incentive scheme. 81% of all respondents indicated a desire for shares as an option in their Short Term Incentives (STI) which indicates a desire for shares in some form or another and may well indicate a level of confidence and commitment by the employees to the organisation. Although the research hypothesis was not proven, significant insights into remuneration within SAB was obtained, which has resulted in recommendations being made for further research into the option of shares in some form or another in the organisation. A further recommendation for SAB is to consider some form of share options for all employees in the organisation. As many other organisations that are performing at remarkable levels attest this performance to share ownership and the behaviour that emanates from it, it would be in the interests of SAB to further investigate the issue as it may improve performance, ownership and retention within the company.
- Full Text:
- Date Issued: 2007
- Authors: Long, Allan
- Date: 2007
- Subjects: South African Breweries Ltd. Incentives in industry -- South Africa Workers' compensation -- South Africa Performance -- Management Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:800 , http://hdl.handle.net/10962/d1006119
- Description: After careful review of all the relevant literature pertaining to motivation, performance management and compensation in the form of incentives, this thesis focuses primarily on determining whether a statistically significant relationship exists between individual needs and the choice of an incentive scheme option. The secondary aims of the research are to determine whether: A relationship exists between the job grade of an individual and the choice of an incentive scheme. A particular incentive scheme option is preferred by the employees in The South African Breweries (SAB). A particular preference exists, and if so, to make recommendations to SAB for consideration as alternatives to their existing incentive scheme options. After collation of the survey data from the respondents in the sample, the analysis and discussion of the results determined that no significant relationship exists between individual needs and the choice of an incentive scheme option. It was, however, determined that a significant relationship exists between the grade of the employees in SAB and their choice of an incentive scheme. 81% of all respondents indicated a desire for shares as an option in their Short Term Incentives (STI) which indicates a desire for shares in some form or another and may well indicate a level of confidence and commitment by the employees to the organisation. Although the research hypothesis was not proven, significant insights into remuneration within SAB was obtained, which has resulted in recommendations being made for further research into the option of shares in some form or another in the organisation. A further recommendation for SAB is to consider some form of share options for all employees in the organisation. As many other organisations that are performing at remarkable levels attest this performance to share ownership and the behaviour that emanates from it, it would be in the interests of SAB to further investigate the issue as it may improve performance, ownership and retention within the company.
- Full Text:
- Date Issued: 2007
Local food choices and nutrition : a case study of amarewu in the FET consumer studies curriculum
- Authors: Kota, Lutho Siyabulela
- Date: 2007
- Subjects: Continuing education -- South Africa -- Eastern Cape -- Curricula Education -- South Africa -- Eastern Cape -- Curricula Ethnoscience -- South Africa -- Eastern Cape Indigenous peoples -- Study and teaching -- South Africa -- Eastern Cape Nutrition -- Study and teaching -- South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1666 , http://hdl.handle.net/10962/d1003549
- Description: This case study examines the introduction of Indigenous Knowledge (IK) in the Consumer Studies curriculum of Further Education and Training (FET). The research is centred on the use of enquiry methodologies involving learners observing parent demonstrations of the making of ‘amarewu’ and other activities centred on the propositional knowledge dealing with fermentation in the Consumer Studies curriculum. The research involved a review of curriculum documents, participant observation of a demonstration of local food practices related to ‘amarewu’ and learner research activities and interviews to review the developing learning interactions. The learning activities were focused on the learners’ researching the cultural and nutritional value of ‘amarewu’ and included an audit of food consumed in the community. What transpired from this study was that working with IK in the curriculum is possible. The inclusion of IK is not only possible but desirable and has exciting possibilities for relevance in contemporary education. The active involvement in parent demonstration engaged the learners in IK in their mother tongue, therefore indigenous knowledge has relevance. The curriculum concepts also enhanced the engagement by giving rise to more relevant knowledge and a respect for cultural matters. Intergenerational capital and subject concepts also enabled learners to engage with local nutritional problems and to come up with practical solutions. This study demonstrates how IK intergenerational capital in combination in combination with curriculum concepts (subject knowledge capital) can enhance relevance and the learners’ real engagement with local health and nutritional problems. Not only did the learners have culturally valued knowledge, but also knowledge that has a practical grasp of the problem and that they could use to engage relevant issues. These two views of knowledge join in learning and can be used to address health issues. I therefore recommend connection of cultural knowledge and conceptual knowledge to strengthen the revitalisation of cultural heritage, thus equalising it to the modern patterns of life and enhancing meaningful curriculum orientation.
- Full Text:
- Date Issued: 2007
- Authors: Kota, Lutho Siyabulela
- Date: 2007
- Subjects: Continuing education -- South Africa -- Eastern Cape -- Curricula Education -- South Africa -- Eastern Cape -- Curricula Ethnoscience -- South Africa -- Eastern Cape Indigenous peoples -- Study and teaching -- South Africa -- Eastern Cape Nutrition -- Study and teaching -- South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1666 , http://hdl.handle.net/10962/d1003549
- Description: This case study examines the introduction of Indigenous Knowledge (IK) in the Consumer Studies curriculum of Further Education and Training (FET). The research is centred on the use of enquiry methodologies involving learners observing parent demonstrations of the making of ‘amarewu’ and other activities centred on the propositional knowledge dealing with fermentation in the Consumer Studies curriculum. The research involved a review of curriculum documents, participant observation of a demonstration of local food practices related to ‘amarewu’ and learner research activities and interviews to review the developing learning interactions. The learning activities were focused on the learners’ researching the cultural and nutritional value of ‘amarewu’ and included an audit of food consumed in the community. What transpired from this study was that working with IK in the curriculum is possible. The inclusion of IK is not only possible but desirable and has exciting possibilities for relevance in contemporary education. The active involvement in parent demonstration engaged the learners in IK in their mother tongue, therefore indigenous knowledge has relevance. The curriculum concepts also enhanced the engagement by giving rise to more relevant knowledge and a respect for cultural matters. Intergenerational capital and subject concepts also enabled learners to engage with local nutritional problems and to come up with practical solutions. This study demonstrates how IK intergenerational capital in combination in combination with curriculum concepts (subject knowledge capital) can enhance relevance and the learners’ real engagement with local health and nutritional problems. Not only did the learners have culturally valued knowledge, but also knowledge that has a practical grasp of the problem and that they could use to engage relevant issues. These two views of knowledge join in learning and can be used to address health issues. I therefore recommend connection of cultural knowledge and conceptual knowledge to strengthen the revitalisation of cultural heritage, thus equalising it to the modern patterns of life and enhancing meaningful curriculum orientation.
- Full Text:
- Date Issued: 2007
Cobalt Phthalocyanine Molecular Electrode for the Electrochemical Investigation of the Release of Glutathione upon Copper-Catalyzed Decomposition of S-Nitrosoglutathione
- Sehlotho, Nthapo, Griveau, Sophie, Nyokong, Tebello, Bedioui, Fethi
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281201 , vital:55701 , xlink:href="https://doi.org/10.1002/elan.200603656"
- Description: Decomposition of S-nitrosoglutathione (GSNO) in phosphate buffer solution at physiological pH 7.4 in the presence of cuprous ion as a catalyst and sodium borohydride as a reducing agent is analyzed by observing the transient apparition of reduced glutathione GSH through its electrooxidation. Transient formation of GSH, upon decomposition of 1 mM GSNO in presence of 0.025 mM Cu(NO3)2 and 1 mM NaBH4 was detected by using an ordinary pyrolytic graphite electrode modified with an adsorbed monolayer of cobalt phthalocyanine at 0 V vs. SCE.
- Full Text:
- Date Issued: 2007
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281201 , vital:55701 , xlink:href="https://doi.org/10.1002/elan.200603656"
- Description: Decomposition of S-nitrosoglutathione (GSNO) in phosphate buffer solution at physiological pH 7.4 in the presence of cuprous ion as a catalyst and sodium borohydride as a reducing agent is analyzed by observing the transient apparition of reduced glutathione GSH through its electrooxidation. Transient formation of GSH, upon decomposition of 1 mM GSNO in presence of 0.025 mM Cu(NO3)2 and 1 mM NaBH4 was detected by using an ordinary pyrolytic graphite electrode modified with an adsorbed monolayer of cobalt phthalocyanine at 0 V vs. SCE.
- Full Text:
- Date Issued: 2007
Contributions to the use of microalgae in estuarine freshwater reserve determinations
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007