The effects of age and education on selected cognitive tests: the trail making test, the digit symbol sub-test, and the finger tapping test
- Authors: Stewart, Maureen
- Date: 2003
- Subjects: Aging -- Psychological testing , Brain -- Aging , Neuropsychology , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3114 , http://hdl.handle.net/10962/d1004601 , Aging -- Psychological testing , Brain -- Aging , Neuropsychology , Neuropsychological tests
- Description: Numerous studies have suggested that neuropsychological test performance is affected by demographic variables such as age and education. This study examined the effects of age and education on the Trail Making Test, the Digit Symbol Sub-Test, and the Finger Tapping Test in a non-clinical sample of community dwellers with a relatively low level of education (8 to 12 years) in South Africa. The sample consisted of 161 participants across six age groups: 20-39, 40-59, 69-69, 70-79, 80-89 and 90-95 years. Results were examined for mean age effects and variability trends. Highly significant age effects were present across the age groups for all tests, however, there was no uniform pattern of variability across the tests. The Digit Symbol Substitution Test and the Finger Tapping Tests showed a pattern of increasing variability with increasing age, followed by a decrease in very old age while no trend was evident for the Digit Symbol extensions (the Immediate and Delayed Recall tests). The Trail Making Test, Parts A and B, showed a consistent trend of increasing variability across the age groups. Data from the present study was compared with existing data from two relatively high education samples, with equivalent age groupings, to examine education effects. Results showed an education effect for all tests with the high education groups outperforming the low education groups. Although the effects of education became less potent with advancing age, the mean performance of the oldest (80-89 years) high education age group was superior to that of the equivalent low education age group. Comparison of variability trends across both samples showed that the highest variability (the shuttle bulge) was present at the same point along the age axis, or at a later point, for the low education group, as that for the high education group. This finding is inconsistent with Jordan's (1997) 'shuttle model of variability' which predicts an earlier occurrence of the shuttle bulge (left shuttle shift effect) for a low education sample. This study demonstrated that performance on neuropsychological tests is influenced by age and education and highlighted the dangers inherent in unquestionably applying norms, which have not been corrected for age and education, when assessing the older adult.
- Full Text:
- Date Issued: 2003
- Authors: Stewart, Maureen
- Date: 2003
- Subjects: Aging -- Psychological testing , Brain -- Aging , Neuropsychology , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3114 , http://hdl.handle.net/10962/d1004601 , Aging -- Psychological testing , Brain -- Aging , Neuropsychology , Neuropsychological tests
- Description: Numerous studies have suggested that neuropsychological test performance is affected by demographic variables such as age and education. This study examined the effects of age and education on the Trail Making Test, the Digit Symbol Sub-Test, and the Finger Tapping Test in a non-clinical sample of community dwellers with a relatively low level of education (8 to 12 years) in South Africa. The sample consisted of 161 participants across six age groups: 20-39, 40-59, 69-69, 70-79, 80-89 and 90-95 years. Results were examined for mean age effects and variability trends. Highly significant age effects were present across the age groups for all tests, however, there was no uniform pattern of variability across the tests. The Digit Symbol Substitution Test and the Finger Tapping Tests showed a pattern of increasing variability with increasing age, followed by a decrease in very old age while no trend was evident for the Digit Symbol extensions (the Immediate and Delayed Recall tests). The Trail Making Test, Parts A and B, showed a consistent trend of increasing variability across the age groups. Data from the present study was compared with existing data from two relatively high education samples, with equivalent age groupings, to examine education effects. Results showed an education effect for all tests with the high education groups outperforming the low education groups. Although the effects of education became less potent with advancing age, the mean performance of the oldest (80-89 years) high education age group was superior to that of the equivalent low education age group. Comparison of variability trends across both samples showed that the highest variability (the shuttle bulge) was present at the same point along the age axis, or at a later point, for the low education group, as that for the high education group. This finding is inconsistent with Jordan's (1997) 'shuttle model of variability' which predicts an earlier occurrence of the shuttle bulge (left shuttle shift effect) for a low education sample. This study demonstrated that performance on neuropsychological tests is influenced by age and education and highlighted the dangers inherent in unquestionably applying norms, which have not been corrected for age and education, when assessing the older adult.
- Full Text:
- Date Issued: 2003
Email security policy implementation in multinational organisations with special reference to privacy laws
- Authors: Dixon, Henry George
- Date: 2003
- Subjects: Electronic mail systems -- Security measures , Privacy, Right of , Electronic mail systems -- Management , Electronic mail systems -- Law and legislation
- Language: English
- Type: Thesis , Masters , MTech (Business Information Systems)
- Identifier: vital:10790 , http://hdl.handle.net/10948/229 , Electronic mail systems -- Security measures , Privacy, Right of , Electronic mail systems -- Management , Electronic mail systems -- Law and legislation
- Description: In 1971, scientist Ray Tomlinson sent what is now considered the first email message. It was considered as “nothing short of revolutionary … deserv[ing] a spot in the list of great communication inventions such as the printing press, telegraph and telephone” (Festa, 2001). Whereas email was first used exclusively in the military (Arpanet) and in academic circles, it has now become almost ubiquitous, used widely for private, as well as for business correspondence. According to a Berkeley study (Berkeley, 2000), there were approximately 440 million corporate and personal [e-] mailboxes worldwide in 2001, of which more than a third was corporate mailboxes. As a result of the extensive use of email in the corporate environment, Information Officers have to ensure that the use of email adds business value. In an “always on” market place, the efficiency, immediacy and cost effectiveness of email communication are immediately evident. A study by Ferris Research, quoted by Nchor (2001), shows that there is “an overall productivity gain of US$9000 per employee as they send and receive emails to get projects done.” However, the use of email in the corporate envi-ronment also poses business risks that need to be uniquely addressed. Among these “key business risks” (Surfcontrol, 2001) are security risks, viruses, legal liability, pro-ductivity loss and bandwidth abuse. To address the risks mentioned above and to protect the business value of email, spe-cific policies have to be implemented that address email usage. Information Security Policies are defined in most corporate environments. In a study done by Elron Soft-ware (2001), 83% of respondents who have abused email have company policies regu-lating email usage. There appears to be a gap between policy conception and policy implementation. Various factors inhibit effective policy implementation – ethical, legal and cultural. The implementation of corporate policy becomes especially complex in multinational environments where differing information law Email usage is ubiquitous in the modern business environment, but few companies adequately manage the risks associated with email.
- Full Text:
- Date Issued: 2003
- Authors: Dixon, Henry George
- Date: 2003
- Subjects: Electronic mail systems -- Security measures , Privacy, Right of , Electronic mail systems -- Management , Electronic mail systems -- Law and legislation
- Language: English
- Type: Thesis , Masters , MTech (Business Information Systems)
- Identifier: vital:10790 , http://hdl.handle.net/10948/229 , Electronic mail systems -- Security measures , Privacy, Right of , Electronic mail systems -- Management , Electronic mail systems -- Law and legislation
- Description: In 1971, scientist Ray Tomlinson sent what is now considered the first email message. It was considered as “nothing short of revolutionary … deserv[ing] a spot in the list of great communication inventions such as the printing press, telegraph and telephone” (Festa, 2001). Whereas email was first used exclusively in the military (Arpanet) and in academic circles, it has now become almost ubiquitous, used widely for private, as well as for business correspondence. According to a Berkeley study (Berkeley, 2000), there were approximately 440 million corporate and personal [e-] mailboxes worldwide in 2001, of which more than a third was corporate mailboxes. As a result of the extensive use of email in the corporate environment, Information Officers have to ensure that the use of email adds business value. In an “always on” market place, the efficiency, immediacy and cost effectiveness of email communication are immediately evident. A study by Ferris Research, quoted by Nchor (2001), shows that there is “an overall productivity gain of US$9000 per employee as they send and receive emails to get projects done.” However, the use of email in the corporate envi-ronment also poses business risks that need to be uniquely addressed. Among these “key business risks” (Surfcontrol, 2001) are security risks, viruses, legal liability, pro-ductivity loss and bandwidth abuse. To address the risks mentioned above and to protect the business value of email, spe-cific policies have to be implemented that address email usage. Information Security Policies are defined in most corporate environments. In a study done by Elron Soft-ware (2001), 83% of respondents who have abused email have company policies regu-lating email usage. There appears to be a gap between policy conception and policy implementation. Various factors inhibit effective policy implementation – ethical, legal and cultural. The implementation of corporate policy becomes especially complex in multinational environments where differing information law Email usage is ubiquitous in the modern business environment, but few companies adequately manage the risks associated with email.
- Full Text:
- Date Issued: 2003
Photochemical studies of binuclear phenoxysubstituted phthalocyanines containing catecholate bridges
- Seotsanyana-Mokhosi, Itumeleng, Maree, Suzanne, Maree, M David, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Maree, Suzanne , Maree, M David , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304808 , vital:58492 , xlink:href="https://doi.org/10.1142/S1088424603000239"
- Description: Binuclear ZnPc complexes covalently bridged by catechol units have been synthesized and their absorption and photochemical properties examined. The complexes studied are 1,2-bis-2',9',16',23'-triphenoxyphthalocyaninatozinc benzene (6a), 1,2-bis-2'-9',16',23'-tri-4-carboxyphe-noxyphthalocyaninatozinc benzene (6b), 1,2-bis-2',9',16',23'-tri-4-nitrophenoxyphthalocyaninato- zinc benzene (6c) and 1,2-bis-2'-9',16',23'-tri-4-tert-butylphenoxyphthalocyaninatozinc benzene (6d). Larger intramolecular coupling was observed for 6b and 6c, containing the carboxyphenoxy and nitrophenoxy substituents, respectively, than for 6a and 6d. A single Q band peak was observed for the fluorescence spectra of 6b and 6c, whereas, 6a and 6d showed a split Q band. The absence of the high energy fluorescence peaks corresponding to absorbance peaks in the 640 nm region, suggests that the intramolecular coupling is broken by excitation for complexes 6b and 6c.
- Full Text:
- Date Issued: 2003
Photochemical studies of binuclear phenoxysubstituted phthalocyanines containing catecholate bridges
- Authors: Seotsanyana-Mokhosi, Itumeleng , Maree, Suzanne , Maree, M David , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304808 , vital:58492 , xlink:href="https://doi.org/10.1142/S1088424603000239"
- Description: Binuclear ZnPc complexes covalently bridged by catechol units have been synthesized and their absorption and photochemical properties examined. The complexes studied are 1,2-bis-2',9',16',23'-triphenoxyphthalocyaninatozinc benzene (6a), 1,2-bis-2'-9',16',23'-tri-4-carboxyphe-noxyphthalocyaninatozinc benzene (6b), 1,2-bis-2',9',16',23'-tri-4-nitrophenoxyphthalocyaninato- zinc benzene (6c) and 1,2-bis-2'-9',16',23'-tri-4-tert-butylphenoxyphthalocyaninatozinc benzene (6d). Larger intramolecular coupling was observed for 6b and 6c, containing the carboxyphenoxy and nitrophenoxy substituents, respectively, than for 6a and 6d. A single Q band peak was observed for the fluorescence spectra of 6b and 6c, whereas, 6a and 6d showed a split Q band. The absence of the high energy fluorescence peaks corresponding to absorbance peaks in the 640 nm region, suggests that the intramolecular coupling is broken by excitation for complexes 6b and 6c.
- Full Text:
- Date Issued: 2003
Pipes, poles and people:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159153 , vital:40273 , https://hdl.handle.net/10520/EJC146268
- Description: Tina James, a South African ICT consultant, tells the story of Minnie Barendse Kruger who had been struggling to get a Khoisan Cultural Village going in the Eastern Cape. Kruger set up a restaurant where traditional food is prepared, and the Barendse Griquas Trust stepped in and helped set up a multi-purpose Community Centre.
- Full Text:
- Date Issued: 2003
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159153 , vital:40273 , https://hdl.handle.net/10520/EJC146268
- Description: Tina James, a South African ICT consultant, tells the story of Minnie Barendse Kruger who had been struggling to get a Khoisan Cultural Village going in the Eastern Cape. Kruger set up a restaurant where traditional food is prepared, and the Barendse Griquas Trust stepped in and helped set up a multi-purpose Community Centre.
- Full Text:
- Date Issued: 2003
Development of a language policy in a rural school
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
- Date Issued: 2003
- Authors: Fumba, Zamumzi Norman
- Date: 2003
- Subjects: Language policy -- South Africa Language and education -- South Africa Education, Rural -- South Africa -- Peddie Black people -- Education -- South Africa Native language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1940 , http://hdl.handle.net/10962/d1007798
- Description: The study was undertaken to observe and participate in the process and development of a language policy for a rural secondary school in Peddie in the Eastern Cape. This was done in collaboration with parents, learners, and teachers. The researcher acted as a researcher, facilitator and learner in the process that Iead to the final product. Twenty four learners were selected from Grade 8 to Grade 10. These learners formed three focus groups. A questionnaire and lesson observation were used to establish what was taking place in the school with regard to language practices and preferences by learners, teachers and parents. Lesson observations were recorded by a tape recorder. Outcomes are that Xhosa is the dominant language to which the learners are exposed. They only have the exposure to 'chunks' of English in class and when they read magazines, newspapers and listening to radio and TV. Teachers code switch. This is supported by both learners and their parents. Parents want their children to improve performance by being taught in the medium of a language they understand well enough. The study shows different perceptions about the language that should be used as LOLT. Parents in the study favour English as LOLT, while parents in general favour Xhosa. This view is also held by both teachers and learners. At a conscious level when teachers and learners talk about the language to be used as LOLT, they favour English, but when they are faced with the reality of the class they are ambivalent, hence they code switch. The study finally reports on the divergent views of the parents, on one hand, and those of the teachers and the learners on the other hand. The divergence will be resolved in a workshop, part of the broader process of school language policy research, which is beyond the scope of the research reported in the thesis. The final product, in the form of the school language policy, will then be drafted for presentation to the School Governing Body (SGB) for ratification and writing up process.
- Full Text:
- Date Issued: 2003
The evaluation of potential improvements of barton pot oxides for lead acid batteries
- Authors: Geyer, Laurence Thomas
- Date: 2003
- Subjects: Lead oxides -- South Africa , Lead acid batteries -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10982 , http://hdl.handle.net/10948/233 , Lead oxides -- South Africa , Lead acid batteries -- South Africa
- Description: Lead Oxide (PbO) is the main material used for the preparation of the active material for the positive and negative electrodes in the lead acid battery where the electrochemical reaction that provides the electrical energy of the battery takes place. The particle size distribution and surface area characteristics of the lead oxide play a major role in the electrical performance of the completed battery. The two most commonly used processes to manufacture PbO in the lead acid battery industry are the Barton pot and the Ball mill processes. These two processes produce oxides that differ in particle size distribution, particle shape and surface area. It is generally accepted that the Ball mill process produces an oxide with a smaller mean particle size with a higher surface area and better initial electrical performance than the Barton pot process to the detriment of an initial higher capital and running cost. The study showed that it is possible to improve the surface area and particle size distribution characteristics of Barton pot oxide, by subsequently hammer milling the oxide particles before the paste manufacturing process. The results showed that there was an initial reduction in the particle size with an increase in the surface area. This increased the electrochemical performance in terms of the high rate discharge. However, further hammering of the oxide reduced the average particle size only slightly with little change in the surface area and a reduction in the electrochemical performance. The study showed that an improvement in Barton pot oxide can be achieved with a hammering of the oxide in order to obtain a uniform particle size with improved surface area and an improved high rate performance of the electrochemical cells made with such an oxide. As a comparison, the particle size and surface area characteristics of Ball mill lead oxide subjected to the hammer milling process was also studied. The results showed a similar effect to the Barton pot oxide on the particle size distribution. However, there was no appreciable change in the surface area due to the hammer milling process.
- Full Text:
- Date Issued: 2003
- Authors: Geyer, Laurence Thomas
- Date: 2003
- Subjects: Lead oxides -- South Africa , Lead acid batteries -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10982 , http://hdl.handle.net/10948/233 , Lead oxides -- South Africa , Lead acid batteries -- South Africa
- Description: Lead Oxide (PbO) is the main material used for the preparation of the active material for the positive and negative electrodes in the lead acid battery where the electrochemical reaction that provides the electrical energy of the battery takes place. The particle size distribution and surface area characteristics of the lead oxide play a major role in the electrical performance of the completed battery. The two most commonly used processes to manufacture PbO in the lead acid battery industry are the Barton pot and the Ball mill processes. These two processes produce oxides that differ in particle size distribution, particle shape and surface area. It is generally accepted that the Ball mill process produces an oxide with a smaller mean particle size with a higher surface area and better initial electrical performance than the Barton pot process to the detriment of an initial higher capital and running cost. The study showed that it is possible to improve the surface area and particle size distribution characteristics of Barton pot oxide, by subsequently hammer milling the oxide particles before the paste manufacturing process. The results showed that there was an initial reduction in the particle size with an increase in the surface area. This increased the electrochemical performance in terms of the high rate discharge. However, further hammering of the oxide reduced the average particle size only slightly with little change in the surface area and a reduction in the electrochemical performance. The study showed that an improvement in Barton pot oxide can be achieved with a hammering of the oxide in order to obtain a uniform particle size with improved surface area and an improved high rate performance of the electrochemical cells made with such an oxide. As a comparison, the particle size and surface area characteristics of Ball mill lead oxide subjected to the hammer milling process was also studied. The results showed a similar effect to the Barton pot oxide on the particle size distribution. However, there was no appreciable change in the surface area due to the hammer milling process.
- Full Text:
- Date Issued: 2003
Biogeography and community structure of fishes in South African estuaries
- Authors: Harrison, Trevor D
- Date: 2003
- Subjects: Estuarine ecology -- South Africa Estuarine fishes -- South Africa Fish communities -- South Africa Biogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5235 , http://hdl.handle.net/10962/d1005078
- Description: The biogeography and community structure of the fishes of South African estuaries was investigated. In all, 109 systems were examined representing two broad types: temporarily closed and permanently open estuaries. Multivariate analyses of the fish communities identified three biogeographic regions. A cool-temperate region extended along the west and southwest coasts; a warmtemperate zone stretched along the south, southeast and east coasts and a subtropical region occurred along the east coast. The boundaries of these biogeographic regions were also delineated. The general physico-chemical characteristics of the estuaries within the three biogeographic regions also reflected regional differences in climate, rainfall and ocean conditions. Estuarine temperatures followed the trend for marine coastal waters, decreasing from subtropical estuaries toward cool-temperate systems. The low rainfall and runoff in the warm-temperate region together with high evaporation rates and strong seawater input resulted in higher salinities in these estuaries. These factors also accounted for the predominantly clearer waters in warm-temperate estuaries. The estuaries in the three biogeographic regions were also shown to contain somewhat distinctive fish assemblages. Temperature and salinity appeared to be the two main factors affecting the distribution and abundance of fishes in South African estuaries. Subtropical systems were characterised by fishes mostly of tropical origin as well as certain south coast endemic species. Warm-temperate estuaries were dominated by endemic taxa with some tropical species also present. The fish fauna of cooltemperate estuaries mostly comprised south coast endemic species with cosmopolitan and temperate taxa also present. Certain functional components of the ichthyofauna also exhibited slight differences between regions. Freshwater fishes were a major component of closed subtropical estuaries while estuarine resident species were more abundant in warm-temperate estuaries. Overall, estuarine-dependent marine species dominated the fish fauna of the estuaries in all biogeographic regions, signifying that South African estuaries perform a vital nursery function for this group of fishes. Slight differences were also apparent in the trophic structure of the fishes; these were related to environmental differences between regions. Zooplanktivores and fishes that feed on aquatic macrophytes/invertebrates assumed a relatively higher importance in warm-temperate systems. Overall, detritivores dominated the estuarine fish fauna in all regions, indicating that detritus forms the main energy source in South African estuaries.
- Full Text:
- Date Issued: 2003
- Authors: Harrison, Trevor D
- Date: 2003
- Subjects: Estuarine ecology -- South Africa Estuarine fishes -- South Africa Fish communities -- South Africa Biogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5235 , http://hdl.handle.net/10962/d1005078
- Description: The biogeography and community structure of the fishes of South African estuaries was investigated. In all, 109 systems were examined representing two broad types: temporarily closed and permanently open estuaries. Multivariate analyses of the fish communities identified three biogeographic regions. A cool-temperate region extended along the west and southwest coasts; a warmtemperate zone stretched along the south, southeast and east coasts and a subtropical region occurred along the east coast. The boundaries of these biogeographic regions were also delineated. The general physico-chemical characteristics of the estuaries within the three biogeographic regions also reflected regional differences in climate, rainfall and ocean conditions. Estuarine temperatures followed the trend for marine coastal waters, decreasing from subtropical estuaries toward cool-temperate systems. The low rainfall and runoff in the warm-temperate region together with high evaporation rates and strong seawater input resulted in higher salinities in these estuaries. These factors also accounted for the predominantly clearer waters in warm-temperate estuaries. The estuaries in the three biogeographic regions were also shown to contain somewhat distinctive fish assemblages. Temperature and salinity appeared to be the two main factors affecting the distribution and abundance of fishes in South African estuaries. Subtropical systems were characterised by fishes mostly of tropical origin as well as certain south coast endemic species. Warm-temperate estuaries were dominated by endemic taxa with some tropical species also present. The fish fauna of cooltemperate estuaries mostly comprised south coast endemic species with cosmopolitan and temperate taxa also present. Certain functional components of the ichthyofauna also exhibited slight differences between regions. Freshwater fishes were a major component of closed subtropical estuaries while estuarine resident species were more abundant in warm-temperate estuaries. Overall, estuarine-dependent marine species dominated the fish fauna of the estuaries in all biogeographic regions, signifying that South African estuaries perform a vital nursery function for this group of fishes. Slight differences were also apparent in the trophic structure of the fishes; these were related to environmental differences between regions. Zooplanktivores and fishes that feed on aquatic macrophytes/invertebrates assumed a relatively higher importance in warm-temperate systems. Overall, detritivores dominated the estuarine fish fauna in all regions, indicating that detritus forms the main energy source in South African estuaries.
- Full Text:
- Date Issued: 2003
Predictive modelling of species' potential geographical distributions
- Authors: Robertson, Mark Peter
- Date: 2003
- Subjects: Alien plants -- South Africa -- Geographical distribution Species -- Geographical distribution -- Mathematical models Cicadas -- South Africa -- Geographical distribution Scaevola plumieri -- South Africa -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5816 , http://hdl.handle.net/10962/d1007189
- Description: Models that are used for predicting species' potential distributions are important tools that have found applications in a number of areas of applied ecology. The majority of these models can be classified as correlative, as they rely on strong, often indirect, links between species distribution records and environmental predictor variables to make predictions. Correlative models are an alternative to more complex mechanistic models that attempt to simulate the mechanisms considered to underlie the observed correlations with environmental attributes. This study explores the influence of the type and quality of the data used to calibrate correlative models. In terms of data type, the most popular techniques in use are group discrimination techniques, those that use both presence and absence locality data to make predictions. However, for many organisms absence data are either not available or are considered to be unreliable. As the available range of profile techniques (those using presence only data) appeared to be limited, new profile techniques were investigated and evaluated. A new profile modelling technique based on fuzzy classification (the Fuzzy Envelope Model) was developed and implemented. A second profile technique based on Principal Components Analysis was implemented and evaluated. Based on quantitative model evaluation tests, both of these techniques performed well and show considerable promise. In terms of data quality, the effects on model performance of false absence records, the number of locality records (sample size) and the proportion of localities representing species presence (prevalence) in samples were investigated for logistic regression distribution models. Sample size and prevalence both had a significant effect on model performance. False absence records had a significant influence on model performance, which was affected by sample size. A quantitative comparison of the performance of selected profile models and group discrimination modelling techniques suggests that different techniques may be more successful for predicting distributions for particular species or types of organism than others. The results also suggest that several different model design! sample size combinations are capable of making predictions that will on average not differ significantly in performance for a particular species. A further quantitative comparison among modelling techniques suggests that correlative techniques can perform as well as simple mechanistic techniques for predicting potential distributions.
- Full Text:
- Date Issued: 2003
- Authors: Robertson, Mark Peter
- Date: 2003
- Subjects: Alien plants -- South Africa -- Geographical distribution Species -- Geographical distribution -- Mathematical models Cicadas -- South Africa -- Geographical distribution Scaevola plumieri -- South Africa -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5816 , http://hdl.handle.net/10962/d1007189
- Description: Models that are used for predicting species' potential distributions are important tools that have found applications in a number of areas of applied ecology. The majority of these models can be classified as correlative, as they rely on strong, often indirect, links between species distribution records and environmental predictor variables to make predictions. Correlative models are an alternative to more complex mechanistic models that attempt to simulate the mechanisms considered to underlie the observed correlations with environmental attributes. This study explores the influence of the type and quality of the data used to calibrate correlative models. In terms of data type, the most popular techniques in use are group discrimination techniques, those that use both presence and absence locality data to make predictions. However, for many organisms absence data are either not available or are considered to be unreliable. As the available range of profile techniques (those using presence only data) appeared to be limited, new profile techniques were investigated and evaluated. A new profile modelling technique based on fuzzy classification (the Fuzzy Envelope Model) was developed and implemented. A second profile technique based on Principal Components Analysis was implemented and evaluated. Based on quantitative model evaluation tests, both of these techniques performed well and show considerable promise. In terms of data quality, the effects on model performance of false absence records, the number of locality records (sample size) and the proportion of localities representing species presence (prevalence) in samples were investigated for logistic regression distribution models. Sample size and prevalence both had a significant effect on model performance. False absence records had a significant influence on model performance, which was affected by sample size. A quantitative comparison of the performance of selected profile models and group discrimination modelling techniques suggests that different techniques may be more successful for predicting distributions for particular species or types of organism than others. The results also suggest that several different model design! sample size combinations are capable of making predictions that will on average not differ significantly in performance for a particular species. A further quantitative comparison among modelling techniques suggests that correlative techniques can perform as well as simple mechanistic techniques for predicting potential distributions.
- Full Text:
- Date Issued: 2003
On the use of metabolic rate measurements to assess the stress response in juvenile spotted grunter, Pomadasys commersonnii (Haemulidae, Pisces)
- Authors: Radull, John
- Date: 2003
- Subjects: Fishes -- Metabolism Fishes -- Physiology Pomadasys -- Physiology Grunts (Fishes) -- Physiology Stress (Psychology) Stress (Physiology)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5350 , http://hdl.handle.net/10962/d1007564
- Description: Quantitication of stress requires the use of a stress indicator that is easy to measure, and which can be readily interpreted in terms of the potential long-term effects to an organism. This study evaluates the suitability of metabolic rate as an indicator of the stress response in fish. By comparing the metabolic with the cortisol stress response, the most commonly used indicator of stress in fish, it was possible to assess the suitability of metabolic rate as a stress indicator. Changes in metabolic rate were used to predict the long-term effects of transport-related stressors. This study also detennined the baseline metabolic rates of the tish. The standard and the active metabolic rates of juvenile P. cummersonnii were 0.16 ± 0.02 (mean ± S.D, n = 6) mg O₂g⁻¹h⁻¹, and 0.56 ± 0.04 mg O₂g⁻¹h⁻¹, respectively, whereas the routine metabolic rate for the fish was 0.25 ± 0.03 mg O₂g⁻¹h¹. The relationship between metabolic rate and body weight was described by the equation ϺO₂ = 0.64 W⁻°·³⁸. 24-h oxygen consumption measurements showed that juvenile P. commersonnii exhibited diel rhythmicity in oxygen consumption rate, the higher rates occurring at night and the lower rates during the daytime. The higher nocturnal metabolic activity may have been due to increased activity induced by an endogenous rhythm related to feeding. Diel rhythmicity has direct implications for the measurement of baseline metabolic rates since it could result in overestimation or underestimation of these rates. 24-h continuous oxygen consumption measurements enabled the detection of the rhythmicity in oxygen consumption rate, and thereby ensured a greater degree of accuracy in the estimation of these parameters. The metabolic stress response in juvenile P. commersonnii was best described by the equation, y = -0.0013 x² + 0.0364 x ÷ 0.3052, where x = time after application of stressor, and y = oxygen consumption rate. Using the derivative of this equation, the metabolic stress response was estimated to peak approximately 14 min after application of a simulated capture and handling stressor. Oxygen consumption increased by about 300 % as a result of the stress. Approximately 15 min after application of a similar stressor, plasma cortisol levels in stressed fish was 200 % higher than baseline levels. However, cortisol levels in fish sampled 30 min after the disturbance was similar to the baseline cortisol levels, indicating that full recovery had occurred. Although the patterns in the metabolic and cortisol stress responses were similar, metabolic rate could be measured continuously, thereby ensuring accurate interpretation of the data. Furthermore, increases in metabolic rate during the stress response are a culmination of physiological events from the primary to the tertiary levels of biological organization and are, therefore, easier to interpret in terms of long-term effects on the fish. Different transportation procedures elicited variable degrees of stress in juvenile P. commersonnii. The cost of metabolism attributed to the effects of capture and handling was twice as much as that attributed to acute temperature elevation. Acute temperature decrease resulted in a signiticant reduction in the oxygen consumption rate (ANOVA, P < 0.05). Oxygen consumption by the fish was not affected by fish density (ANOVA: F = 2.002, P = 0.5), or by oxygen depletion at dissolved oxygen concentrations above the critical level. Below this level, however, oxygen consumption decreased linearly with further decrease in dissolved oxygen concentration. These results showed that the highest energetic cost to juvenile P. commersonnii was incurred as a result of capture and handling. The results also showed that by subjecting fish to different stressors, it was possible to categorize them according to their relative metabolic costs to the fish. At 25º C, the effective concentration of 2-phenoxyethanol to fully anaesthetize (Stage IV, McFarland 1960) juvenile P. commersonnii was 0.4 ml l⁻¹ and the most appropriate concentration for deep sedation (Stage II, McFarland 1960) of the fish for at least 24 h was 0.2 ml l⁻¹. A maximum of 3 minutes was required by the fish to recover from the effects of the anaesthetic. There was no correlation between fish weight and the rate of induction of anaesthesia (r² = 0.001, p = 0.3). At the peak of the metabolic stress response, oxygen consumption was twice as high in the un-anaesthetized fish compared to the fish anaesthetized after the application of the simulated capture and handling stressor, suggesting that anaesthetization with 2-phenoxyethanol may have reduced the effect of the disturbance on the fish. Similar oxygen consumption rates for the fish anaesthetized prior to capture and the non-stressed fish suggested that the increases in metabolic rate could be linked to the struggling associated with attempts by fish to escape from the perceived stressor. Anaesthetization of juvenile P. commersonnii with 0.3 ml l⁻¹ 2-phenoxyethanol resulted in a more than 200 % increase in plasma cortisol concentration. The elevated levels of plasma cortisol in the anaesthetized fish suggested a manifestation of 2-phenoxyethanol as a stressor. At the time of capture, cortisol levels in fish that were anaesthetized prior to capture were the same as those measured in the disturbed fish at the peak of the stress response (ANOVA, p = 0.95), suggesting that the anaesthetized fish were already experiencing considerable stress at the time they were captured. Undisturbed juvenile P. commersonnii that were anaesthetized for 1 h also had cortisol levels that were five times higher than those measured in undisturbed-unanaesthetized fish, indicating that the duration of exposure to the anaesthetic had a significant effect on plasma cortisol levels. The results presented in this study demonstrate the usefulness of metabolic rate as an indicator of acute stress in fish. This was achieved by comparing the metabolic and the cortisol stress responses. The ease and accuracy with which oxygen consumption of fish could be measured made it possible to measure the stress response more accurately than by plasma cortisol concentration. It was also possible to monitor metabolic rate continuously over a long duration using polarographic oxygen sensors, thus enabling a better evaluation of the stress response. These results, thus, suggest that metabolic rate measurements could be a more practical way to quantify the effects of acute stressors on juvenile fishes. By detailing the profile of the metabolic stress response in P. commersonnii, this study makes a contribution towards understanding the physiological effects of stress in fishes. The study also contributes towards the quantification of baseline metabolic rates of this species under captivity. This study also contributes towards understanding the effects of 2-phenoxyethanol on the stress physiology of fish. By anaesthetizing fish under different conditions of stress, it was possible to evaluate the effect of 2-phenoxyethanol on the metabolic stress response. The ability of 2-phenoxyethanol to reduce physical activity of the fish, and thereby reduce the impact of acute stress on the metabolic stress response, makes it a good agent for the mitigation of stress during the capture and handling of fish. However, the increase in plasma cortisol concentration during prolonged anaesthetization using this drug suggests that the anaesthetic might be a stressor to fish and may, therefore, not be suitable for long-term sedation.
- Full Text:
- Date Issued: 2003
- Authors: Radull, John
- Date: 2003
- Subjects: Fishes -- Metabolism Fishes -- Physiology Pomadasys -- Physiology Grunts (Fishes) -- Physiology Stress (Psychology) Stress (Physiology)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5350 , http://hdl.handle.net/10962/d1007564
- Description: Quantitication of stress requires the use of a stress indicator that is easy to measure, and which can be readily interpreted in terms of the potential long-term effects to an organism. This study evaluates the suitability of metabolic rate as an indicator of the stress response in fish. By comparing the metabolic with the cortisol stress response, the most commonly used indicator of stress in fish, it was possible to assess the suitability of metabolic rate as a stress indicator. Changes in metabolic rate were used to predict the long-term effects of transport-related stressors. This study also detennined the baseline metabolic rates of the tish. The standard and the active metabolic rates of juvenile P. cummersonnii were 0.16 ± 0.02 (mean ± S.D, n = 6) mg O₂g⁻¹h⁻¹, and 0.56 ± 0.04 mg O₂g⁻¹h⁻¹, respectively, whereas the routine metabolic rate for the fish was 0.25 ± 0.03 mg O₂g⁻¹h¹. The relationship between metabolic rate and body weight was described by the equation ϺO₂ = 0.64 W⁻°·³⁸. 24-h oxygen consumption measurements showed that juvenile P. commersonnii exhibited diel rhythmicity in oxygen consumption rate, the higher rates occurring at night and the lower rates during the daytime. The higher nocturnal metabolic activity may have been due to increased activity induced by an endogenous rhythm related to feeding. Diel rhythmicity has direct implications for the measurement of baseline metabolic rates since it could result in overestimation or underestimation of these rates. 24-h continuous oxygen consumption measurements enabled the detection of the rhythmicity in oxygen consumption rate, and thereby ensured a greater degree of accuracy in the estimation of these parameters. The metabolic stress response in juvenile P. commersonnii was best described by the equation, y = -0.0013 x² + 0.0364 x ÷ 0.3052, where x = time after application of stressor, and y = oxygen consumption rate. Using the derivative of this equation, the metabolic stress response was estimated to peak approximately 14 min after application of a simulated capture and handling stressor. Oxygen consumption increased by about 300 % as a result of the stress. Approximately 15 min after application of a similar stressor, plasma cortisol levels in stressed fish was 200 % higher than baseline levels. However, cortisol levels in fish sampled 30 min after the disturbance was similar to the baseline cortisol levels, indicating that full recovery had occurred. Although the patterns in the metabolic and cortisol stress responses were similar, metabolic rate could be measured continuously, thereby ensuring accurate interpretation of the data. Furthermore, increases in metabolic rate during the stress response are a culmination of physiological events from the primary to the tertiary levels of biological organization and are, therefore, easier to interpret in terms of long-term effects on the fish. Different transportation procedures elicited variable degrees of stress in juvenile P. commersonnii. The cost of metabolism attributed to the effects of capture and handling was twice as much as that attributed to acute temperature elevation. Acute temperature decrease resulted in a signiticant reduction in the oxygen consumption rate (ANOVA, P < 0.05). Oxygen consumption by the fish was not affected by fish density (ANOVA: F = 2.002, P = 0.5), or by oxygen depletion at dissolved oxygen concentrations above the critical level. Below this level, however, oxygen consumption decreased linearly with further decrease in dissolved oxygen concentration. These results showed that the highest energetic cost to juvenile P. commersonnii was incurred as a result of capture and handling. The results also showed that by subjecting fish to different stressors, it was possible to categorize them according to their relative metabolic costs to the fish. At 25º C, the effective concentration of 2-phenoxyethanol to fully anaesthetize (Stage IV, McFarland 1960) juvenile P. commersonnii was 0.4 ml l⁻¹ and the most appropriate concentration for deep sedation (Stage II, McFarland 1960) of the fish for at least 24 h was 0.2 ml l⁻¹. A maximum of 3 minutes was required by the fish to recover from the effects of the anaesthetic. There was no correlation between fish weight and the rate of induction of anaesthesia (r² = 0.001, p = 0.3). At the peak of the metabolic stress response, oxygen consumption was twice as high in the un-anaesthetized fish compared to the fish anaesthetized after the application of the simulated capture and handling stressor, suggesting that anaesthetization with 2-phenoxyethanol may have reduced the effect of the disturbance on the fish. Similar oxygen consumption rates for the fish anaesthetized prior to capture and the non-stressed fish suggested that the increases in metabolic rate could be linked to the struggling associated with attempts by fish to escape from the perceived stressor. Anaesthetization of juvenile P. commersonnii with 0.3 ml l⁻¹ 2-phenoxyethanol resulted in a more than 200 % increase in plasma cortisol concentration. The elevated levels of plasma cortisol in the anaesthetized fish suggested a manifestation of 2-phenoxyethanol as a stressor. At the time of capture, cortisol levels in fish that were anaesthetized prior to capture were the same as those measured in the disturbed fish at the peak of the stress response (ANOVA, p = 0.95), suggesting that the anaesthetized fish were already experiencing considerable stress at the time they were captured. Undisturbed juvenile P. commersonnii that were anaesthetized for 1 h also had cortisol levels that were five times higher than those measured in undisturbed-unanaesthetized fish, indicating that the duration of exposure to the anaesthetic had a significant effect on plasma cortisol levels. The results presented in this study demonstrate the usefulness of metabolic rate as an indicator of acute stress in fish. This was achieved by comparing the metabolic and the cortisol stress responses. The ease and accuracy with which oxygen consumption of fish could be measured made it possible to measure the stress response more accurately than by plasma cortisol concentration. It was also possible to monitor metabolic rate continuously over a long duration using polarographic oxygen sensors, thus enabling a better evaluation of the stress response. These results, thus, suggest that metabolic rate measurements could be a more practical way to quantify the effects of acute stressors on juvenile fishes. By detailing the profile of the metabolic stress response in P. commersonnii, this study makes a contribution towards understanding the physiological effects of stress in fishes. The study also contributes towards the quantification of baseline metabolic rates of this species under captivity. This study also contributes towards understanding the effects of 2-phenoxyethanol on the stress physiology of fish. By anaesthetizing fish under different conditions of stress, it was possible to evaluate the effect of 2-phenoxyethanol on the metabolic stress response. The ability of 2-phenoxyethanol to reduce physical activity of the fish, and thereby reduce the impact of acute stress on the metabolic stress response, makes it a good agent for the mitigation of stress during the capture and handling of fish. However, the increase in plasma cortisol concentration during prolonged anaesthetization using this drug suggests that the anaesthetic might be a stressor to fish and may, therefore, not be suitable for long-term sedation.
- Full Text:
- Date Issued: 2003
An exploration into the reasons for the resignation of ex-employees from the University of Port Elizabeth against international indicators in employee retention
- Authors: Anderson, Amber Cristal
- Date: 2003
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11000 , http://hdl.handle.net/10948/289
- Description: South African organisations have not been left untouched by the impact of globalisation on their business practices. In a bid to maintain and improve on their competitive advantage, they have had to embark on initiatives to secure a place in the global economy. Entwined herein is the challenge to embrace a whole new definition of equality and develop their human capital as described in various legislative interventions of the South African Government. This study reflects the outcomes of an exploratory study into the reasons for the resignation of ex-employees from the University of Port Elizabeth, against international indicators in employee retention. The research was based on the premise that an effective and efficient transformation strategy should originate from a tangible understanding of all the socio-behavioural and influencing aspects of employee retention. The results suggest the development of an employee-retention strategy which could facilitate the realisation of the Employment Equity Plan. The objectives of the study were: to provide critical insight into why employees are resigning from the University of Port Elizabeth (UPE), to determine the social and developmental expectations of ex-UPE employees while in a transforming organisation, to identify and analyse ex-employees’ perceptions of the implementation of UPE’s Employment Equity Plan, to analyse ex-employees’ perceptions of existing retention practices at UPE, to provide recommendations towards an employee-retention strategy for UPE. The study is exploratory and descriptive in nature, and is quantitatively analysed with limited qualitative inferences. The population consisted of ex-UPE employees who had left the service of the university, from 01 January 2000 to 31 October 2002, by resignation. The period coincided with the implementation phase of the UPE Employment Equity Plan. For the purpose of this study, N=69. Twenty-eight ex-employees were untraceable, therefore n=41. Thirty ex-employees took part in the survey, thus making the sample return 73%. Eight of the respondents were dispersed across three continents other than Africa. The survey instrument, administered as an e-mailed and mailed questionnaire, was selected as the most suitable quantitative research method, because respondents were globally dispersed. Content analysis was selected as the most appropriate technique to produce findings in the qualitative aspect of the research. Where appropriate, descriptive statistics (univariate and bivariate analyses) were applied to describe the variables, the results of which were exhibited as tabular or graphical displays. Inferential statistical analyses (Pearson Chi-square and M-L Chisquare tests) were also conducted.
- Full Text:
- Date Issued: 2003
- Authors: Anderson, Amber Cristal
- Date: 2003
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11000 , http://hdl.handle.net/10948/289
- Description: South African organisations have not been left untouched by the impact of globalisation on their business practices. In a bid to maintain and improve on their competitive advantage, they have had to embark on initiatives to secure a place in the global economy. Entwined herein is the challenge to embrace a whole new definition of equality and develop their human capital as described in various legislative interventions of the South African Government. This study reflects the outcomes of an exploratory study into the reasons for the resignation of ex-employees from the University of Port Elizabeth, against international indicators in employee retention. The research was based on the premise that an effective and efficient transformation strategy should originate from a tangible understanding of all the socio-behavioural and influencing aspects of employee retention. The results suggest the development of an employee-retention strategy which could facilitate the realisation of the Employment Equity Plan. The objectives of the study were: to provide critical insight into why employees are resigning from the University of Port Elizabeth (UPE), to determine the social and developmental expectations of ex-UPE employees while in a transforming organisation, to identify and analyse ex-employees’ perceptions of the implementation of UPE’s Employment Equity Plan, to analyse ex-employees’ perceptions of existing retention practices at UPE, to provide recommendations towards an employee-retention strategy for UPE. The study is exploratory and descriptive in nature, and is quantitatively analysed with limited qualitative inferences. The population consisted of ex-UPE employees who had left the service of the university, from 01 January 2000 to 31 October 2002, by resignation. The period coincided with the implementation phase of the UPE Employment Equity Plan. For the purpose of this study, N=69. Twenty-eight ex-employees were untraceable, therefore n=41. Thirty ex-employees took part in the survey, thus making the sample return 73%. Eight of the respondents were dispersed across three continents other than Africa. The survey instrument, administered as an e-mailed and mailed questionnaire, was selected as the most suitable quantitative research method, because respondents were globally dispersed. Content analysis was selected as the most appropriate technique to produce findings in the qualitative aspect of the research. Where appropriate, descriptive statistics (univariate and bivariate analyses) were applied to describe the variables, the results of which were exhibited as tabular or graphical displays. Inferential statistical analyses (Pearson Chi-square and M-L Chisquare tests) were also conducted.
- Full Text:
- Date Issued: 2003
In defence of moral objectivity
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
From labour reserve to investment opportunity: economic development planning in the Mbashe Local Municipal area in the Eastern Cape
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
Putting participatory communication into practice through community radio: a case study of how policies on programming and production are formulated and implemented at Radio Graaff-Reinet
- Kanyegirire, Andrew Steve Tumuhirwe
- Authors: Kanyegirire, Andrew Steve Tumuhirwe
- Date: 2003
- Subjects: Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3442 , http://hdl.handle.net/10962/d1002896 , Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Description: In the South African (SA) model of community radio, listeners are expected to be in charge of the management and programming operations of stations. This study tests the SA model against the actual conditions at an existing station. For this purpose, the study focuses on Radio Graaff-Reinet, a community radio station in the Eastern Cape. Emphasis is on examining the extent to which members of the station’s target community are involved in its operations. The study first assesses the nature of this involvement, keeping in mind the principles of, ‘community ownership’ and ‘participatory programming’ on which the SA model of community radio is based. It is argued that the station does provide a valuable ‘public sphere’ for its listeners. The potential of this sphere remains limited, however, due to the impact of ongoing power struggles around the ownership of the station. The lack of proper systems for managing these struggles has contributed to the fact that the station continues to be in a constant state of flux, with a high turnover of staff and regular changes in its policies and strategies. The study argues that, until such systems are put in place, the principles of community ownership will not be fully realizable. Areas in which the struggle over ownership plays itself out can be identified in the relationship between the station’s Board of Directors and its managing staff, between one particular station manager and her staff and between the station and its target community. These struggles often take place in context of a debate about the financial sustainability of the station versus its developmental aims. It is argued that this opposition needs to be questioned since, until the station is financially stable, it will remain vulnerable to interference by powerful individuals and groups in its attempts to establish such developmental aims. The study then goes on to identify key weaknesses in the station’s approach to community ownership and participation. In particular, it is pointed out that various stakeholders in the station have contradictory understandings of what is meant by ‘community’, using the term to include or exclude sections of the Graaff-Reinet society in very different ways. There are also very different understandings at play about the concept of community radio itself. These contradictions have an impact on the station’s ability to implement participatory programming. This situation is exacerbated by the fact that the station does not have a consistent forum in which shared decision-making can take place. Consequently, the station also remains unable to draw effectively on its own volunteer staff and on its community as resources for programming content. Finally, the study explores the broader significance of the weaknesses that exist in the case of Graaff-Reinet, arguing that these are problems that repeat themselves throughout the South African community radio sector. Possible strategies for addressing these problems are suggested, including approaches to monitoring and research, training, organizational development and advocacy.
- Full Text:
- Date Issued: 2003
- Authors: Kanyegirire, Andrew Steve Tumuhirwe
- Date: 2003
- Subjects: Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3442 , http://hdl.handle.net/10962/d1002896 , Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Description: In the South African (SA) model of community radio, listeners are expected to be in charge of the management and programming operations of stations. This study tests the SA model against the actual conditions at an existing station. For this purpose, the study focuses on Radio Graaff-Reinet, a community radio station in the Eastern Cape. Emphasis is on examining the extent to which members of the station’s target community are involved in its operations. The study first assesses the nature of this involvement, keeping in mind the principles of, ‘community ownership’ and ‘participatory programming’ on which the SA model of community radio is based. It is argued that the station does provide a valuable ‘public sphere’ for its listeners. The potential of this sphere remains limited, however, due to the impact of ongoing power struggles around the ownership of the station. The lack of proper systems for managing these struggles has contributed to the fact that the station continues to be in a constant state of flux, with a high turnover of staff and regular changes in its policies and strategies. The study argues that, until such systems are put in place, the principles of community ownership will not be fully realizable. Areas in which the struggle over ownership plays itself out can be identified in the relationship between the station’s Board of Directors and its managing staff, between one particular station manager and her staff and between the station and its target community. These struggles often take place in context of a debate about the financial sustainability of the station versus its developmental aims. It is argued that this opposition needs to be questioned since, until the station is financially stable, it will remain vulnerable to interference by powerful individuals and groups in its attempts to establish such developmental aims. The study then goes on to identify key weaknesses in the station’s approach to community ownership and participation. In particular, it is pointed out that various stakeholders in the station have contradictory understandings of what is meant by ‘community’, using the term to include or exclude sections of the Graaff-Reinet society in very different ways. There are also very different understandings at play about the concept of community radio itself. These contradictions have an impact on the station’s ability to implement participatory programming. This situation is exacerbated by the fact that the station does not have a consistent forum in which shared decision-making can take place. Consequently, the station also remains unable to draw effectively on its own volunteer staff and on its community as resources for programming content. Finally, the study explores the broader significance of the weaknesses that exist in the case of Graaff-Reinet, arguing that these are problems that repeat themselves throughout the South African community radio sector. Possible strategies for addressing these problems are suggested, including approaches to monitoring and research, training, organizational development and advocacy.
- Full Text:
- Date Issued: 2003
Building blocks of marketing strategy for targeting local biltong hunters: an evaluation
- Authors: Van Eyk, Marlé
- Date: 2003
- Subjects: Marketing , Big game hunting -- South Africa -- Eastern Cape -- Marketing , Dried meat -- South Africa -- Eastern Cape , Hunters -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10770 , http://hdl.handle.net/10948/207 , Marketing , Big game hunting -- South Africa -- Eastern Cape -- Marketing , Dried meat -- South Africa -- Eastern Cape , Hunters -- South Africa -- Eastern Cape
- Description: Game ranch owners are spoilt by the high prices overseas hunters are prepared to pay, and tend to forget that in the long term it is the local market that may ensure the survival of the game industry. More effort should therefore be put into marketing hunting opportunities for the local hunter. This research focused on analysing the typical building blocks of marketing strategy applicable to service organizations. This was done to determine and evaluate the building blocks of marketing strategy applicable to game ranches in the Eastern Cape Province who are targeting local biltong hunters. A literature review was conducted to determine the ideal building blocks of marketing strategy for service organizations such as game ranches. Thereafter, a survey was conducted by means of a questionnaire to determine the ranchers' perceptions of marketing and evaluate their marketing strategies. Most of the respondents: had a fair idea of what marketing entails; were unaware of the thread that links customer expectations, satisfaction and loyalty; realized the importance of relationship marketing with external markets, but not with internal markets; perceived direct competition as their biggest threat, while other travel opportunities were seen as the most important substitute for hunting; mainly positioned themselves based on the features the ranch offered, and believed that the standard of service delivery and physical features of the ranch (the nature of the offering) were their important competitive advantages. The study proposes that the framework of building blocks of marketing strategy, designed by the researcher be used as a tool with which marketing strategies for game ranches in the Eastern Cape Province targeting local biltong hunters could be developed. Additional research on topics such as advertising and the various market opportunity strategies of diversification and product development, could lead to improvement and modification of this framework, making it an even more powerful tool in developing marketing strategies.
- Full Text:
- Date Issued: 2003
- Authors: Van Eyk, Marlé
- Date: 2003
- Subjects: Marketing , Big game hunting -- South Africa -- Eastern Cape -- Marketing , Dried meat -- South Africa -- Eastern Cape , Hunters -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10770 , http://hdl.handle.net/10948/207 , Marketing , Big game hunting -- South Africa -- Eastern Cape -- Marketing , Dried meat -- South Africa -- Eastern Cape , Hunters -- South Africa -- Eastern Cape
- Description: Game ranch owners are spoilt by the high prices overseas hunters are prepared to pay, and tend to forget that in the long term it is the local market that may ensure the survival of the game industry. More effort should therefore be put into marketing hunting opportunities for the local hunter. This research focused on analysing the typical building blocks of marketing strategy applicable to service organizations. This was done to determine and evaluate the building blocks of marketing strategy applicable to game ranches in the Eastern Cape Province who are targeting local biltong hunters. A literature review was conducted to determine the ideal building blocks of marketing strategy for service organizations such as game ranches. Thereafter, a survey was conducted by means of a questionnaire to determine the ranchers' perceptions of marketing and evaluate their marketing strategies. Most of the respondents: had a fair idea of what marketing entails; were unaware of the thread that links customer expectations, satisfaction and loyalty; realized the importance of relationship marketing with external markets, but not with internal markets; perceived direct competition as their biggest threat, while other travel opportunities were seen as the most important substitute for hunting; mainly positioned themselves based on the features the ranch offered, and believed that the standard of service delivery and physical features of the ranch (the nature of the offering) were their important competitive advantages. The study proposes that the framework of building blocks of marketing strategy, designed by the researcher be used as a tool with which marketing strategies for game ranches in the Eastern Cape Province targeting local biltong hunters could be developed. Additional research on topics such as advertising and the various market opportunity strategies of diversification and product development, could lead to improvement and modification of this framework, making it an even more powerful tool in developing marketing strategies.
- Full Text:
- Date Issued: 2003
The natural product chemistry of South African Plocamium species
- Authors: Knott, Michael George
- Date: 2003
- Subjects: Marine algae -- South Africa Red algae -- South Africa Green algae -- South Africa Halimeda -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3820 , http://hdl.handle.net/10962/d1004920
- Description: The brine shrimp lethality assay was used as a preliminary tool to screen eighteen seaweeds collected from the South African coast. Of the seaweeds tested, the red algae Plocamium corallorhiza and Hypnea rosea, and the green alga Halimeda sp., showed the most potent activity. The chemical investigation of P. corallorhiza resulted in the isolation and structural elucidation of five previously undescribed secondary metabolites, along with three known compounds and four possible artifacts of the extraction process. Standard spectroscopic methods and comparison with known compounds were used to determine the structures of the new metabolites. The new compounds included the linear halogenated monoterpenes 4,8-dibromo-1, 1-dichloro-3,7-dimethyl-2,6-octadiene (99), 4,6-dibromo-l, 1-dichloro-3,7-dimethyl-2,7-octadiene (100), 4,8-dibromo-l, 1,7-trichloro-3,7-dimethyl-2,5-octadiene (101) and 3,4,6,7-tetrachloro-3,7-dimethyl-l-octene (102) and the cyclic monoterpene 5-bromo-5-bromomethyl-I-chlorovinyl-2,4-dichloro-methylcyclohexane (103) while the known compounds were identified as 4-bromo-5-bromomethyl-1chlorovinyl-2,5-dichloro-methylcyclohexane (35), 1,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1,5-octadiene (94) and 8-bromo-1,3,4,7-tetrachloro-3,7-dimethyl-1,5-octadiene (96). The four methoxylated compounds (104-107) were presumably formed via a standard substitution reaction between the halogenated monoterpenes 96 and 101 and MeOH, which was used as a component in the extraction solvent. With over 100 000 natural products having been reported, it has become necessary to employ an efficient dereplication strategy to quickly identify known compounds. A simple Gas Chromatography-Mass Spectrometry (GC-MS) method for the efficient physicochemical screening, identification and dereplication of Plocamium metabolites was developed. In this study the crude extracts of P. corallorhiza, P. cornutum and P. maxillosum were screened by GC-MS and the retention times and mass spectral fragmentation patterns of compounds 94, 96, 99 - 107 were used to quickly identify known and new compounds in the crude extracts of P. cornutum and P. maxillosum. This data indicated that compounds 99, 100, 103 were present in both P. corallorhiza and P.cornutum, while compound 102 was found to be present in P. corallorhiza, P. cornutum and P. maxillosum. These studies also indicated that ecotypes and chemotypes are not a significant feature of P. corallorhiza and P. cornutum. Different species of Plocamium (namely: P. corallorhiza, P. cornutum, and P. maxillosum) have very different chemical profiles, and GC may therefore have appreciable taxonomic application in the identification of the different Plocamium spp. which are endemic to South Africa.
- Full Text:
- Date Issued: 2003
- Authors: Knott, Michael George
- Date: 2003
- Subjects: Marine algae -- South Africa Red algae -- South Africa Green algae -- South Africa Halimeda -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3820 , http://hdl.handle.net/10962/d1004920
- Description: The brine shrimp lethality assay was used as a preliminary tool to screen eighteen seaweeds collected from the South African coast. Of the seaweeds tested, the red algae Plocamium corallorhiza and Hypnea rosea, and the green alga Halimeda sp., showed the most potent activity. The chemical investigation of P. corallorhiza resulted in the isolation and structural elucidation of five previously undescribed secondary metabolites, along with three known compounds and four possible artifacts of the extraction process. Standard spectroscopic methods and comparison with known compounds were used to determine the structures of the new metabolites. The new compounds included the linear halogenated monoterpenes 4,8-dibromo-1, 1-dichloro-3,7-dimethyl-2,6-octadiene (99), 4,6-dibromo-l, 1-dichloro-3,7-dimethyl-2,7-octadiene (100), 4,8-dibromo-l, 1,7-trichloro-3,7-dimethyl-2,5-octadiene (101) and 3,4,6,7-tetrachloro-3,7-dimethyl-l-octene (102) and the cyclic monoterpene 5-bromo-5-bromomethyl-I-chlorovinyl-2,4-dichloro-methylcyclohexane (103) while the known compounds were identified as 4-bromo-5-bromomethyl-1chlorovinyl-2,5-dichloro-methylcyclohexane (35), 1,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1,5-octadiene (94) and 8-bromo-1,3,4,7-tetrachloro-3,7-dimethyl-1,5-octadiene (96). The four methoxylated compounds (104-107) were presumably formed via a standard substitution reaction between the halogenated monoterpenes 96 and 101 and MeOH, which was used as a component in the extraction solvent. With over 100 000 natural products having been reported, it has become necessary to employ an efficient dereplication strategy to quickly identify known compounds. A simple Gas Chromatography-Mass Spectrometry (GC-MS) method for the efficient physicochemical screening, identification and dereplication of Plocamium metabolites was developed. In this study the crude extracts of P. corallorhiza, P. cornutum and P. maxillosum were screened by GC-MS and the retention times and mass spectral fragmentation patterns of compounds 94, 96, 99 - 107 were used to quickly identify known and new compounds in the crude extracts of P. cornutum and P. maxillosum. This data indicated that compounds 99, 100, 103 were present in both P. corallorhiza and P.cornutum, while compound 102 was found to be present in P. corallorhiza, P. cornutum and P. maxillosum. These studies also indicated that ecotypes and chemotypes are not a significant feature of P. corallorhiza and P. cornutum. Different species of Plocamium (namely: P. corallorhiza, P. cornutum, and P. maxillosum) have very different chemical profiles, and GC may therefore have appreciable taxonomic application in the identification of the different Plocamium spp. which are endemic to South Africa.
- Full Text:
- Date Issued: 2003
Cyclodepsipeptides from a Kenyan marine cyanobacterium
- Authors: Dzeha, Thomas Mwambire
- Date: 2003
- Subjects: Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4303 , http://hdl.handle.net/10962/d1004961 , Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Description: An examination of an organic extract of the cyanobacterium Lyngbya majuscula collected from Wasini Island off the southern Kenyan coast led to the isolation of the known cyclodepsipeptide antanapeptin A (7), recently isolated from a Madagascan collection of L. majuscula, and a new bioactive cyclodepsipeptide, homodolastatin 16 (42). Although L. majuscula is a common, pantropical cyanobacterium this study represents the first investigation of the natural product chemistry of a Kenyan population of L. majuscula. The structures of the two cyclodepsipeptides were determined from 2D NMR and mass spectrometry data. The L- stereochemistry of the proline, valine, and N-methylphenylalanine amino acids in 7 and the L – proline configuration in 42, was confirmed by Marfey’s HPLC method. Chiral GC was used to determine the absolute stereochemistry of the hydroxyisovaleric acid moiety in 7 and 42, the lactate residue in 42 and tentatively propose an L-stereochemistry for the Nmethylisoleucine amino acid in 42. Homodolastatin 16, a higher homologue of the potential anti-cancer agent, dolastatin 16, exhibited moderate activity against two oesophageal cancer cell lines.
- Full Text:
- Date Issued: 2003
- Authors: Dzeha, Thomas Mwambire
- Date: 2003
- Subjects: Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4303 , http://hdl.handle.net/10962/d1004961 , Cyanobacteria , Stereochemistry , Natural products -- Kenya
- Description: An examination of an organic extract of the cyanobacterium Lyngbya majuscula collected from Wasini Island off the southern Kenyan coast led to the isolation of the known cyclodepsipeptide antanapeptin A (7), recently isolated from a Madagascan collection of L. majuscula, and a new bioactive cyclodepsipeptide, homodolastatin 16 (42). Although L. majuscula is a common, pantropical cyanobacterium this study represents the first investigation of the natural product chemistry of a Kenyan population of L. majuscula. The structures of the two cyclodepsipeptides were determined from 2D NMR and mass spectrometry data. The L- stereochemistry of the proline, valine, and N-methylphenylalanine amino acids in 7 and the L – proline configuration in 42, was confirmed by Marfey’s HPLC method. Chiral GC was used to determine the absolute stereochemistry of the hydroxyisovaleric acid moiety in 7 and 42, the lactate residue in 42 and tentatively propose an L-stereochemistry for the Nmethylisoleucine amino acid in 42. Homodolastatin 16, a higher homologue of the potential anti-cancer agent, dolastatin 16, exhibited moderate activity against two oesophageal cancer cell lines.
- Full Text:
- Date Issued: 2003
Introduction [to the book "Scatter the Shrilling Bones" by Sithembele Isaac Xhegwana]
- Authors: Wright, Laurence
- Date: 2003
- Language: English
- Type: text , article
- Identifier: vital:7056 , http://hdl.handle.net/10962/d1007417
- Description: preprint , Scatter the Shrilling Bones by Sithembele Xhegwana comprises an ordered sequence of poems that conveys a journey both literal and spiritual. Revisitation is the organizing principle of the collection – the return to rural sources and origins by a consciousness estranged and illumined by modernity (cf. ‘The Return’). Underlying the collection is the theme of the night journey, whose archetype in western culture is Odysseus’ descent to the underworld – a pattern identified as such in the concluding essay ‘Starting from my Place: Notes on an Aesthetic’. The underworld here is literally the return to the home territory – a journey from Cape Town to the rural Eastern Cape – but also a revisiting of the mental world of traditional Africa: ‘Here at home, here all guilt begins’ (‘Homecoming’). The return journey is haunted by nightmare memories of mental illness, the schizophrenic episodes accompanying (or occasioned by?) the poet’s initial encounters with modernity. This illness is represented as both pathological and cultural – a price paid for challenging and rejecting the old certainties while grappling with new assumptions: “He undermines the ancestors, That’s why he suffers. Let him.” (‘To Himself’)
- Full Text:
- Date Issued: 2003
- Authors: Wright, Laurence
- Date: 2003
- Language: English
- Type: text , article
- Identifier: vital:7056 , http://hdl.handle.net/10962/d1007417
- Description: preprint , Scatter the Shrilling Bones by Sithembele Xhegwana comprises an ordered sequence of poems that conveys a journey both literal and spiritual. Revisitation is the organizing principle of the collection – the return to rural sources and origins by a consciousness estranged and illumined by modernity (cf. ‘The Return’). Underlying the collection is the theme of the night journey, whose archetype in western culture is Odysseus’ descent to the underworld – a pattern identified as such in the concluding essay ‘Starting from my Place: Notes on an Aesthetic’. The underworld here is literally the return to the home territory – a journey from Cape Town to the rural Eastern Cape – but also a revisiting of the mental world of traditional Africa: ‘Here at home, here all guilt begins’ (‘Homecoming’). The return journey is haunted by nightmare memories of mental illness, the schizophrenic episodes accompanying (or occasioned by?) the poet’s initial encounters with modernity. This illness is represented as both pathological and cultural – a price paid for challenging and rejecting the old certainties while grappling with new assumptions: “He undermines the ancestors, That’s why he suffers. Let him.” (‘To Himself’)
- Full Text:
- Date Issued: 2003
The development of a science competency test for technikon students
- Authors: Davids, Samiega
- Date: 2003
- Subjects: Science -- Study and teaching (Higher) -- South Africa , Universities and colleges -- South Africa -- Entrance requirements , Port Elizabeth Technikon Entrance requirements
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10782 , http://hdl.handle.net/10948/87 , Science -- Study and teaching (Higher) -- South Africa , Universities and colleges -- South Africa -- Entrance requirements , Port Elizabeth Technikon Entrance requirements
- Description: In the mid-1980’s institutions of higher learning were coerced by the South African government to admit students from all races. As a result, these institutions were confronted with the need to identify preparedness for higher learning, especially amongst the ex-Department of Education and Training (DET) learners. Grade 12 results were not a sufficient predictor for ex-DET learners, and a review of current admission criteria became a necessity. This study aims to develop a suitable science entry-level test to be used as a component of an existing test battery. The test battery is used as an admission tool by the Port Elizabeth Technikon to further assess first year applicants who do not meet the normal entrance requirements for a science course. The only requirement for further assessment being Grade 12 physical science. The science entry-level test consists of a list of validated science skills and knowledge to be used to assess the skills and knowledge mastered at the time of test taking. On the basis of test scores, an assessment is made regarding the applicant’s preparedness for higher learning. This study holds the view that preparedness in students for higher learning in science can be measured by means of valid science competencies. In addition, knowledge of the level of preparedness of the applicant enables further educational support and guidance to be provided where necessary. Research which measures manifest academic ability rather than potential to learn is favoured since it is believed that the former generates psychometric evidence of that which was already mastered academically whilst the latter determines whether the student will be able to achieve under ideal conditions. The content covered by the proposed Science Competency Test was sanctioned by technikon lecturers of first year physics and chemistry courses. The content was taken from the examinable section of the Grade 11 and 12 physical science syllabi. This content is the most acceptable and fair knowledge-base a prospective science student can be expected to have mastered at school. The content was limited to those skills and knowledge believed by the lecturers to contribute to academic success in the first year. Items that tested this content were compiled and pilot tests were administered to Grade 12 physical science learners at various disadvantaged schools. The Science Competency Test was compiled from the pool of trial items after the performance of the items was statistically determined. This final Science Competency Test was completed by a sample of 179 first-time first year science students. The findings of the study were inconclusive as the Science Competency Test showed a moderate predictive ability for only one section of the sample. It further showed that the weighted matric score, WMS was not a significant predictor of future academic performance of the sample either. A discrepancy in performance amongst learners of different home languages and educational backgrounds was also noted.
- Full Text:
- Date Issued: 2003
- Authors: Davids, Samiega
- Date: 2003
- Subjects: Science -- Study and teaching (Higher) -- South Africa , Universities and colleges -- South Africa -- Entrance requirements , Port Elizabeth Technikon Entrance requirements
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10782 , http://hdl.handle.net/10948/87 , Science -- Study and teaching (Higher) -- South Africa , Universities and colleges -- South Africa -- Entrance requirements , Port Elizabeth Technikon Entrance requirements
- Description: In the mid-1980’s institutions of higher learning were coerced by the South African government to admit students from all races. As a result, these institutions were confronted with the need to identify preparedness for higher learning, especially amongst the ex-Department of Education and Training (DET) learners. Grade 12 results were not a sufficient predictor for ex-DET learners, and a review of current admission criteria became a necessity. This study aims to develop a suitable science entry-level test to be used as a component of an existing test battery. The test battery is used as an admission tool by the Port Elizabeth Technikon to further assess first year applicants who do not meet the normal entrance requirements for a science course. The only requirement for further assessment being Grade 12 physical science. The science entry-level test consists of a list of validated science skills and knowledge to be used to assess the skills and knowledge mastered at the time of test taking. On the basis of test scores, an assessment is made regarding the applicant’s preparedness for higher learning. This study holds the view that preparedness in students for higher learning in science can be measured by means of valid science competencies. In addition, knowledge of the level of preparedness of the applicant enables further educational support and guidance to be provided where necessary. Research which measures manifest academic ability rather than potential to learn is favoured since it is believed that the former generates psychometric evidence of that which was already mastered academically whilst the latter determines whether the student will be able to achieve under ideal conditions. The content covered by the proposed Science Competency Test was sanctioned by technikon lecturers of first year physics and chemistry courses. The content was taken from the examinable section of the Grade 11 and 12 physical science syllabi. This content is the most acceptable and fair knowledge-base a prospective science student can be expected to have mastered at school. The content was limited to those skills and knowledge believed by the lecturers to contribute to academic success in the first year. Items that tested this content were compiled and pilot tests were administered to Grade 12 physical science learners at various disadvantaged schools. The Science Competency Test was compiled from the pool of trial items after the performance of the items was statistically determined. This final Science Competency Test was completed by a sample of 179 first-time first year science students. The findings of the study were inconclusive as the Science Competency Test showed a moderate predictive ability for only one section of the sample. It further showed that the weighted matric score, WMS was not a significant predictor of future academic performance of the sample either. A discrepancy in performance amongst learners of different home languages and educational backgrounds was also noted.
- Full Text:
- Date Issued: 2003
The writing is on the wall: ways that work
- Authors: Amner, Roderick J
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159102 , vital:40267 , https://hdl.handle.net/10520/EJC146296
- Description: When I proposed to 26 third-year journalism students that our writing class take inspiration from an idea pioneered in places as unfashionable and inhospitable as the former Soviet Union and Nepal, I should have expected the icy stares. But happily, within five weeks, this winter of classroom discontent, had begun to thaw into a tentative spring of journalistic and pedagogical innovation.
- Full Text:
- Date Issued: 2003
- Authors: Amner, Roderick J
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159102 , vital:40267 , https://hdl.handle.net/10520/EJC146296
- Description: When I proposed to 26 third-year journalism students that our writing class take inspiration from an idea pioneered in places as unfashionable and inhospitable as the former Soviet Union and Nepal, I should have expected the icy stares. But happily, within five weeks, this winter of classroom discontent, had begun to thaw into a tentative spring of journalistic and pedagogical innovation.
- Full Text:
- Date Issued: 2003
Botanical inventory and phenology in relation to foraging behaviour of the Cape honeybees (Apis Mellifera Capensis) at a site in the Eastern Cape, South Africa
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
- Full Text:
- Date Issued: 2003
- Authors: Merti, Admassu Addi
- Date: 2003
- Subjects: Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4214 , http://hdl.handle.net/10962/d1003783 , Fynbos -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape , Honey plants -- South Africa -- Eastern Cape , Honeybee -- South Africa -- Eastern Cape -- Food , Plant ecology -- South Africa -- Eastern Cape
- Description: From an apicultural point of view the Cape fynbos is under-utilised and our knowledge of its utilization by the Cape honeybees is incomplete. The key aim of this study was to test the hypothesis that the Cape honeybees utilize the fynbos species as the preferred source of nectar and pollen. Subsidiary aims included distinguishing vegetation communities in the area, identifying pollen and nectar sources, the relationship between brood population and seasonal pollen collection patterns, examining the effect of meteorological factors on pollen collection. The study site was on Rivendell Farm within the Eastern Cape Albany district: an area of high species richness. A checklist of vascular plant species was produced revealing 97 families, 271 genera and 448 species. A classification by two-way indicator species (TWINSPAN) recognized seven vegetation communities: Forest, Bush clumps, Acacia savanna, Grassland, Grassy fynbos, Fynbos and Shrubland. Direct field observations of the foraging of Cape honeybees identified 54 nectar and pollen source plant species. Honeybee pollen loads trapped from four colonies of hives identified 37 pollen source plants of which Metalasia muricata, Eucalyptus grandis, Eucalyptus camaldulensis, Erica chamissonis, Helichrysum odoratissimum, Helichrysum anomalum, Crassula cultrata and Acacia longifolia were the predominant pollen source plants. It was also found that 60% of pollen yield derived from fynbos vegetation. The pollen source plants came from both Cape endemic and from nonendemic species. Thus we reject the hypothesis that Cape honeybees selectively forage fynbos species as a preferred source of pollen and nectar. The examination of the effect of temperature, wind-speed and temperature on pollen collection activity of honeybees revealed that: a temperature range of between 14°C to 26°C was optimal for pollen collection; wind speeds of up to 4m/s were conducive for pollen collection; relative humidity was found to have no significant influence on pollen collection. Pollen collection and brood rearing patterns are positively correlated with flowering intensities, but we found in our Eastern Cape study site that brood rearing was not limited to the spring flowering season but did extend to the end of summer. In order to determine the available nectar yield of common plant species hourly secretion of nectar volumes was measured for 24 hours to determine the variation of available nectar during different times of the day. In all nectar producing species the nectar volume was high in the early morning and declined as the day progressed. We found that the volume of available nectar was affected by prevailing temperature and humidity around the flowers.
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- Date Issued: 2003