The effects of level and quality of education on a South African sample of English and African first language speakers, for WAIS-III digit symbol-incidental learning
- Donnelly, Martin Joseph Rhodes
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text:
- Date Issued: 2001
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text:
- Date Issued: 2001
The effects of melatonin on the testis, epididymis and sperm physiology of the Wistar rat
- Authors: Gwayi, Noluzuko
- Date: 2001
- Subjects: Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5681 , http://hdl.handle.net/10962/d1005366 , Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Description: Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.
- Full Text:
- Date Issued: 2001
- Authors: Gwayi, Noluzuko
- Date: 2001
- Subjects: Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5681 , http://hdl.handle.net/10962/d1005366 , Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Description: Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.
- Full Text:
- Date Issued: 2001
The garden as a metaphor for paradise
- Authors: Adlard, Michelle Catherine
- Date: 2001
- Subjects: Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2391 , http://hdl.handle.net/10962/d1002187 , Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Description: In this half thesis the use of the garden as a metaphor for paradise has been explored. The English word “ paradise“ was derived from the Greek word “ paradeisos” which in turn was derived from the Old Avestana “ pairi-daeza,” meaning an enclosure. In Ancient Persia the concept applied to an enclosed garden in the modern sense of the word. For this reason the thesis begins with an examination of the development of the garden in this desert region. A more-or-less continuous chain of development in both the physical and allegorical nature of the garden is traced through history from these Ancient Persian beginnings to the height of Mughal architecture (epitomised by the Taj Mahal), by way of the Muslim expansion through Central Asia and Europe. While the core elements of garden design were set in Ancient Persian times, and recur throughout the period studied, the impact of Islam on the local Persian culture brought about a new development of allegorical meaning associated with the garden. This allegorical development reached its apex, too, in the Taj Mahal in which, it is argued, the metaphorical representation of paradise in the garden tomb was made astonishingly explicit. The research for this mini thesis was gathered from secondary sources, including many published books and academic papers, photographic and diagrammatic evidence of extant ancient gardens, and reproductions of carpet designs.
- Full Text:
- Date Issued: 2001
- Authors: Adlard, Michelle Catherine
- Date: 2001
- Subjects: Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2391 , http://hdl.handle.net/10962/d1002187 , Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Description: In this half thesis the use of the garden as a metaphor for paradise has been explored. The English word “ paradise“ was derived from the Greek word “ paradeisos” which in turn was derived from the Old Avestana “ pairi-daeza,” meaning an enclosure. In Ancient Persia the concept applied to an enclosed garden in the modern sense of the word. For this reason the thesis begins with an examination of the development of the garden in this desert region. A more-or-less continuous chain of development in both the physical and allegorical nature of the garden is traced through history from these Ancient Persian beginnings to the height of Mughal architecture (epitomised by the Taj Mahal), by way of the Muslim expansion through Central Asia and Europe. While the core elements of garden design were set in Ancient Persian times, and recur throughout the period studied, the impact of Islam on the local Persian culture brought about a new development of allegorical meaning associated with the garden. This allegorical development reached its apex, too, in the Taj Mahal in which, it is argued, the metaphorical representation of paradise in the garden tomb was made astonishingly explicit. The research for this mini thesis was gathered from secondary sources, including many published books and academic papers, photographic and diagrammatic evidence of extant ancient gardens, and reproductions of carpet designs.
- Full Text:
- Date Issued: 2001
The influence of a methylated-β-Cyclodextrin on the solubility and photostability of midazolam in aqueous solution
- Authors: Lebete, Mosimotsana Leah
- Date: 2001 , 2013-04-26
- Subjects: Midazolam -- Solubility
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3823 , http://hdl.handle.net/10962/d1005923 , Midazolam -- Solubility
- Description: Midazolam, used clinically as an anticonvulsant, anxiolytic, muscle relaxant and sedative is a photolabile imidazo-benzodiazepine which is marketed under the trade names Dormicum® and Hypnovel® as tablets and injectables. Because of an aqueous solubility of < 0.1 mg/ml above pH 4, the preparation of aqueous dosage formulations near physiological pH, requires a solubilizer. The aim of this study was thus to prepare a 10 mg/ml midazolam aqueous solution for topical application using randomly-methylated-pcyclodextrin (RAMEB), considered to be a suitable candidate as a solubilizer because of its absorption enhancing properties, and to investigate its effect on both the solubility and the photostability of midazolam. Solubility studies of midazolam (excess of 15 mg/ml) in the presence of 0, 5,10,20, 30% m/v of RAMEB at pH 5.0 and pH 5.8 (phosphate buffer) were undertaken and the results analyzed using a UV method validated for linearity, accuracy, precision and specificity. A stability-indicating HPLC method was developed and validated (precision and accuracy, linearity, range, limit of quantitation, specificity, robustness and ruggedness) for application to kinetic photostability studies and the identification of photodegradants by LC-MS. Forced degradation studies were carried out at concentrations of 0.5 mg/ml of midazolam instead of the target concentration of 10 mg/ml because of the acceleratory effect of the decreased concentration on the rate of photodegradation. The solutions of midazolam with and without RAMEB were irradiated at 550 W/m² for 12 hrs in order to degrade the drug to ± 10% of the original concentration. The UV method proved to be valid in terms of linearity with a correlation coefficient of 0.9998, precise and accurate, and specific for the determination of midazolam in the presence of RAMEB. The results of the phase solubility studies indicated that desired solubility of 10 mg/ml was achieved with 30% m/v RAMEB at pH 5.0. RAMEB slightly decreased the photostability of midazolam, the rate constants being 0.137 and 0.154 hr⁻¹ in the absence and presence of RAMEB, respectively. LC-MS analysis revealed that one of the major photoproducts in the presence and absence of RAMEB was N-desalkylflurazepam, a starting material in the synthesis of midazolam. RAMEB inhibited formation of some photoproducts and introduced two new photoproducts, a dimer and an addition product. The difference in the nature of these photoproducts formed may be attributed to the ability of RAMEB to provide conformational control and to stabilize free radicals. Although RAMEB improved the solubility of midazolam to the target concentration, photostability is decreased with the presence of different photoproducts. These studies have however provided information on the overall photostability of midazolam, the identity of its photodegradants and the photodegradation pathway in the presence and absence of RAMEB, and may be used for further method development and validation for the analysis of aqueous dosage forms containing RAMEB as a solubilizer. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
- Authors: Lebete, Mosimotsana Leah
- Date: 2001 , 2013-04-26
- Subjects: Midazolam -- Solubility
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3823 , http://hdl.handle.net/10962/d1005923 , Midazolam -- Solubility
- Description: Midazolam, used clinically as an anticonvulsant, anxiolytic, muscle relaxant and sedative is a photolabile imidazo-benzodiazepine which is marketed under the trade names Dormicum® and Hypnovel® as tablets and injectables. Because of an aqueous solubility of < 0.1 mg/ml above pH 4, the preparation of aqueous dosage formulations near physiological pH, requires a solubilizer. The aim of this study was thus to prepare a 10 mg/ml midazolam aqueous solution for topical application using randomly-methylated-pcyclodextrin (RAMEB), considered to be a suitable candidate as a solubilizer because of its absorption enhancing properties, and to investigate its effect on both the solubility and the photostability of midazolam. Solubility studies of midazolam (excess of 15 mg/ml) in the presence of 0, 5,10,20, 30% m/v of RAMEB at pH 5.0 and pH 5.8 (phosphate buffer) were undertaken and the results analyzed using a UV method validated for linearity, accuracy, precision and specificity. A stability-indicating HPLC method was developed and validated (precision and accuracy, linearity, range, limit of quantitation, specificity, robustness and ruggedness) for application to kinetic photostability studies and the identification of photodegradants by LC-MS. Forced degradation studies were carried out at concentrations of 0.5 mg/ml of midazolam instead of the target concentration of 10 mg/ml because of the acceleratory effect of the decreased concentration on the rate of photodegradation. The solutions of midazolam with and without RAMEB were irradiated at 550 W/m² for 12 hrs in order to degrade the drug to ± 10% of the original concentration. The UV method proved to be valid in terms of linearity with a correlation coefficient of 0.9998, precise and accurate, and specific for the determination of midazolam in the presence of RAMEB. The results of the phase solubility studies indicated that desired solubility of 10 mg/ml was achieved with 30% m/v RAMEB at pH 5.0. RAMEB slightly decreased the photostability of midazolam, the rate constants being 0.137 and 0.154 hr⁻¹ in the absence and presence of RAMEB, respectively. LC-MS analysis revealed that one of the major photoproducts in the presence and absence of RAMEB was N-desalkylflurazepam, a starting material in the synthesis of midazolam. RAMEB inhibited formation of some photoproducts and introduced two new photoproducts, a dimer and an addition product. The difference in the nature of these photoproducts formed may be attributed to the ability of RAMEB to provide conformational control and to stabilize free radicals. Although RAMEB improved the solubility of midazolam to the target concentration, photostability is decreased with the presence of different photoproducts. These studies have however provided information on the overall photostability of midazolam, the identity of its photodegradants and the photodegradation pathway in the presence and absence of RAMEB, and may be used for further method development and validation for the analysis of aqueous dosage forms containing RAMEB as a solubilizer. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
The legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts
- Authors: Ndou, Fulufhelo Clyde
- Date: 2001
- Subjects: Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3688 , http://hdl.handle.net/10962/d1003203 , Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Description: The thesis covers the field of the contract law known as the consumer credit law. It deals with the legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts. The thesis focuses on those credit contracts in which the legal relationship between the consumer and the dominant party is contained in the standard-form contracts, specifically credit agreements relating to money lending transactions in which the credit grantor’s rights are secured either by means of mortgage agreement, a suretyship contract, or a deed of cession. In South Africa the right to equality and human dignity, as opposed to the classical theories of contract: pacta sunt servanda and the principle of freedom of contract, are supported by the Constitution of the Republic of South Africa Act 108 of 1996 which entrenched democratic values permeating all areas of the law including contract law. In this thesis the harmonisation of these classical theories of contract law and the constitutional values of human dignity and equality have been considered. As has been shown in a number of cases, notably those relating to the contracts of suretyship, cession in securitatem debiti, and mortgage, the current law regulating the relationship between the credit grantors and the credit receivers is in need of law reform to fall in line with the constitutional values of equality and human dignity. The greatest difficulty inherent in this area of the law is the reluctance of the courts to intervene at the instance of consumers. The courts would only intervene in the clearest of the cases, and would only do so in the public interest. In this thesis the current South African Law is considered in the light of the developments elsewhere. The tendency of credit providers to alter the terms of the contracts unilaterally and the growing number of conflicting decisions of the Provincial Divisions of High Court has also been considered. The writer also considers the role of the newly created Consumer Affairs Court.
- Full Text:
- Date Issued: 2001
- Authors: Ndou, Fulufhelo Clyde
- Date: 2001
- Subjects: Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3688 , http://hdl.handle.net/10962/d1003203 , Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Description: The thesis covers the field of the contract law known as the consumer credit law. It deals with the legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts. The thesis focuses on those credit contracts in which the legal relationship between the consumer and the dominant party is contained in the standard-form contracts, specifically credit agreements relating to money lending transactions in which the credit grantor’s rights are secured either by means of mortgage agreement, a suretyship contract, or a deed of cession. In South Africa the right to equality and human dignity, as opposed to the classical theories of contract: pacta sunt servanda and the principle of freedom of contract, are supported by the Constitution of the Republic of South Africa Act 108 of 1996 which entrenched democratic values permeating all areas of the law including contract law. In this thesis the harmonisation of these classical theories of contract law and the constitutional values of human dignity and equality have been considered. As has been shown in a number of cases, notably those relating to the contracts of suretyship, cession in securitatem debiti, and mortgage, the current law regulating the relationship between the credit grantors and the credit receivers is in need of law reform to fall in line with the constitutional values of equality and human dignity. The greatest difficulty inherent in this area of the law is the reluctance of the courts to intervene at the instance of consumers. The courts would only intervene in the clearest of the cases, and would only do so in the public interest. In this thesis the current South African Law is considered in the light of the developments elsewhere. The tendency of credit providers to alter the terms of the contracts unilaterally and the growing number of conflicting decisions of the Provincial Divisions of High Court has also been considered. The writer also considers the role of the newly created Consumer Affairs Court.
- Full Text:
- Date Issued: 2001
The mandibular gland secretions and ovarial development of worker honeybees (Apis Mellifera) in the Eastern Cape Province of South Africa
- Authors: Reece, Sacha Louise
- Date: 2001
- Subjects: Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5729 , http://hdl.handle.net/10962/d1005415 , Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Description: The Eastern Cape is an area in which Apis mellifera capensis, A. m. scutellata and their hybrid are known to naturally occur. I investigated the mandibular gland profiles and ovarial development of queenright workers from 4 localities. Their queens were then removed to determine how these aspects changed upon queen loss. In addition, drifted bees were analysed in the same way to determine how these factors changed once they had gained entry to a foreign hive. The queenright bees, form all 4 localities were found to have 9HDA as the most abundant of the 5 fatty acids measured and all localities had small percentages of 9ODA in their mandibular gland secretions. This resulted in relatively high queenright 9ODA:10HDA and 9HDA:10HDAA ratios. Despite this the percentage of bees with undeveloped ovaries was consistent with their queenright status. The mean values of these 2 ratios were significantly higher in the bees from East London and Cradock than those from Port Elizabeth. Steynsburg's bees were intermediate in this regard. Upon queen loss, the bees from all 4 localities had an increase in the percentage of 9ODA but the other compound changes in varying ways. East London's bees were the only ones not to become significantly more queen-like after queen loss. After 14 days without a queen, the mean values of these 2 ratios were much higher in the bees from Port Elizabeth than those from the other localities. Certain individuals from Port Elizabeth had values of these ratios that exceeded those found in A. m. capensis queens. Port Elizabeth was the only locality to display any surrogate queens and exhibited the highest increase in the number of bees with partially or fully developed ovaries. While certain individuals from the other localities had values of these ratios that exceeded these values reported in A. m. scutellata queens, Steynsburg's bees were the only ones that did increase in in terms of the number of bees with developed ovaries subsequent. The bees from Steynsburg were shown to suppress the mandibular gland and ovarial development of drifters from Port Elizabeth while bees from East London did not.
- Full Text:
- Date Issued: 2001
- Authors: Reece, Sacha Louise
- Date: 2001
- Subjects: Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5729 , http://hdl.handle.net/10962/d1005415 , Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Description: The Eastern Cape is an area in which Apis mellifera capensis, A. m. scutellata and their hybrid are known to naturally occur. I investigated the mandibular gland profiles and ovarial development of queenright workers from 4 localities. Their queens were then removed to determine how these aspects changed upon queen loss. In addition, drifted bees were analysed in the same way to determine how these factors changed once they had gained entry to a foreign hive. The queenright bees, form all 4 localities were found to have 9HDA as the most abundant of the 5 fatty acids measured and all localities had small percentages of 9ODA in their mandibular gland secretions. This resulted in relatively high queenright 9ODA:10HDA and 9HDA:10HDAA ratios. Despite this the percentage of bees with undeveloped ovaries was consistent with their queenright status. The mean values of these 2 ratios were significantly higher in the bees from East London and Cradock than those from Port Elizabeth. Steynsburg's bees were intermediate in this regard. Upon queen loss, the bees from all 4 localities had an increase in the percentage of 9ODA but the other compound changes in varying ways. East London's bees were the only ones not to become significantly more queen-like after queen loss. After 14 days without a queen, the mean values of these 2 ratios were much higher in the bees from Port Elizabeth than those from the other localities. Certain individuals from Port Elizabeth had values of these ratios that exceeded those found in A. m. capensis queens. Port Elizabeth was the only locality to display any surrogate queens and exhibited the highest increase in the number of bees with partially or fully developed ovaries. While certain individuals from the other localities had values of these ratios that exceeded these values reported in A. m. scutellata queens, Steynsburg's bees were the only ones that did increase in in terms of the number of bees with developed ovaries subsequent. The bees from Steynsburg were shown to suppress the mandibular gland and ovarial development of drifters from Port Elizabeth while bees from East London did not.
- Full Text:
- Date Issued: 2001
The mandibular gland secretions of the Cape honeybee (Apis mellifera capensis ESCH.) : factors affecting the production of the chemical signal and implications for further development of beekeeping in South Africa
- Authors: Jones, Georgina Elizabeth
- Date: 2001
- Subjects: Honeybee Honeybee -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5730 , http://hdl.handle.net/10962/d1005416
- Description: The chemical composition of the mandibular gland extracts of Apis mellifera capensis virgin queens was analysed by gas chromatography-mass spectroscopy. Thirty-seven compounds from various chemical groups including aliphatic and aromatic acids and diacids, phenols, alkanes, amino acids and sugars were identified. Among the identified compounds were the queen mandibular pheromone components 9ODA, 9HDA, HVA and HOB and the other aliphatic acids and phenols considered to be the major components of A.m. capensis mandibular glands. Ontogenetic changes in the concentration of the mandibular gland secretions of virgin queens were largely quantitative in nature with the total volume and that of most of the compounds increasing with queen age. The final level of 9ODA is reached at the premating stage, approximately three days after emergence, when it comprises approximately 87% of the major constituents of the mandibular gland signal. Hostile reactions by workers towards introduced virgin queens can be correlated to the relative proportion of 9ODA present in the mandibular gland secretions. This seems to indicate that it is the complete spectrum of the signal and not individual compounds that determine worker reaction towards introduced queens. Keeping queens singly, with or without workers, in an incubator and in small mating nucleus hives proved to be the most successful methods of queen rearing in respect to survival rate in A.m. capensis. The presence of workers during the ageing of virgin queens was found to significantly affect the chemical composition of the mandibular gland secretions of queens. The reaction of workers towards introduced virgin queens reared under different holding conditions varied, with queens reared with workers eliciting significantly less hostile reactions from workers than those reared without workers. Mated queens from five localities in the Eastern Cape were characterised on the basis of the chemical composition of their mandibular gland secretions and the ratio of 9ODA:10HDA. No significant differences were detected and none of the queens sampled could be considered to be A.m. capensis based on their mandibular gland signal. The findings of this study provide baseline data for the development of a queen-rearing program tailored to the specific requirements of A.m. capensis.
- Full Text:
- Date Issued: 2001
- Authors: Jones, Georgina Elizabeth
- Date: 2001
- Subjects: Honeybee Honeybee -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5730 , http://hdl.handle.net/10962/d1005416
- Description: The chemical composition of the mandibular gland extracts of Apis mellifera capensis virgin queens was analysed by gas chromatography-mass spectroscopy. Thirty-seven compounds from various chemical groups including aliphatic and aromatic acids and diacids, phenols, alkanes, amino acids and sugars were identified. Among the identified compounds were the queen mandibular pheromone components 9ODA, 9HDA, HVA and HOB and the other aliphatic acids and phenols considered to be the major components of A.m. capensis mandibular glands. Ontogenetic changes in the concentration of the mandibular gland secretions of virgin queens were largely quantitative in nature with the total volume and that of most of the compounds increasing with queen age. The final level of 9ODA is reached at the premating stage, approximately three days after emergence, when it comprises approximately 87% of the major constituents of the mandibular gland signal. Hostile reactions by workers towards introduced virgin queens can be correlated to the relative proportion of 9ODA present in the mandibular gland secretions. This seems to indicate that it is the complete spectrum of the signal and not individual compounds that determine worker reaction towards introduced queens. Keeping queens singly, with or without workers, in an incubator and in small mating nucleus hives proved to be the most successful methods of queen rearing in respect to survival rate in A.m. capensis. The presence of workers during the ageing of virgin queens was found to significantly affect the chemical composition of the mandibular gland secretions of queens. The reaction of workers towards introduced virgin queens reared under different holding conditions varied, with queens reared with workers eliciting significantly less hostile reactions from workers than those reared without workers. Mated queens from five localities in the Eastern Cape were characterised on the basis of the chemical composition of their mandibular gland secretions and the ratio of 9ODA:10HDA. No significant differences were detected and none of the queens sampled could be considered to be A.m. capensis based on their mandibular gland signal. The findings of this study provide baseline data for the development of a queen-rearing program tailored to the specific requirements of A.m. capensis.
- Full Text:
- Date Issued: 2001
The nature of economic integration and co-operation within the South African region and a survey of economic benefits to member states
- Authors: Mutambara, Tsitsi Effie
- Date: 2001
- Subjects: Africa, Southern -- Economic integration , Southern African Development Community
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:938 , http://hdl.handle.net/10962/d1002671 , Africa, Southern -- Economic integration , Southern African Development Community
- Description: The transformation of SADCC into the Southern African Development Community (SADC) has paved the way towards closer regional economic integration in southern Africa. The regional grouping no longer only focuses on sectoral cooperation, but is steadily moving towards increased cooperation in trade development and promotion, industrial development and the diversification of national economies, with the aim of increasing regional economic integration. A free trade area ranks second lowest in the steps towards the highest levels of economic integration. Thus, the signing of the SADC Trade Protocol, which serves to pave way for a SADC Free Trade Area, has initiated steps to facilitate and promote the formal economic integration of all countries in the southern African region. It has been noted that at various periods, the region has adopted a variety of approaches to integration. As such, the present study reviews the different approaches to integration, namely the market integration model, the neo-functional integration model, the development integration model and the theory of common markets. Since the essential question with which this thesis is concerned is whether, and to what extent, the benefits expected from SADC and SACU in terms of their aims and objectives have accrued to member states, an insight into the expected benefits arising from the application of each theoretical framework can help to facilitate an evaluation of the benefits which the countries have enjoyed from these two regional groupings. The thesis highlights that throughout the ten years during which the original SADCC was in place, it based its approach to regional integration on the neo-functional and development integration models, although the former tended to be more dominant. With the regional grouping transforming into SADC, the market integration model was adopted, even though the grouping still had features of the aforementioned approaches. The relevance of the three approaches can be seen in: (i) the continued importance of SADC's sectoral projects, particularly in the field of transport and communication: (ii) continued attempts to put in place a suitable regional) industrial development strategy and implement policies to attract foreign investment; and (iii) the signing of the SADCC Trade Protocol to facilitate the implementation of a free trade area. The thesis argues that member states have enjoyed considerable economic benefits from the SADC sectoral projects. However, in some cases, members have lost out on potential benefits as a result of projects failing to be implemented or completed, mainly due to inadequate funding. Further, delays and inefficiencies at some border posts constitute significant non-tariff barriers which could be a hindrance to intra-regional trade. Progress towards diversification of exports has been limited as the region still relies mostly on the export of the traditional agricultural and mineral raw materials. While all countries have made efforts to diversify their industrial bases, attempts at implementing a meaningful regional industrial development strategy have met with limited success. Intra-regional trade has been increasing over the years. Since the SADC Trade Protocol only came into effect in September 2000, the increased levels of trade integration in the region appear to have been a result of the bilateral trade agreements between countries, and the customs union between South Africa and Botswana, Lesotho, Namibia and Swaziland (BLNS), as well as the structural adjustment programmes and the significant growth experienced in some countries. Outstanding intra-regional trade volumes have been experienced within SACU. In trade terms, benefits have varied between member states, with the more powerful countries like South Africa, Zimbabwe and Mauritius experiencing substantial trade surpluses vis-a.-vis their trade, partners. Countries with bilateral preferential trade agreements have also benefited more due to increased access into each other's markets compared to those without or with bilateral trade agreements of an MFN nature. However, it is important to note that, despite the increase in trade integration in the region, southern Africa is still heavily dependent on the rest of the world for its export markets and as its source of imports. The study finds that intra-industry trade (IIT) exists within the region and, in a number of sectors, high IIT indices are recorded;--although some such sectors do not display significant trade - voIumes. The opening of the region through the implementation of the SADC FTA could promote the expansion of IIT .as-the free trade area )'Till create an enlarged regional market. As such, SADC could benefit from dynamic effects such as scale economies in production and marketing, with member states working on having complementary production structures so as to facilitate specialisation. The thesis argues that the potential for intra-regional trade expansion in the SADC FT A also exists bearing in mind trade complementarity between countries as well as revealed comparative advantages in different sectors. One of the benefits which have accrued to the region as a result of facilitating and promoting greater cooperation and deepening the integration process has been an expansion in cross border investment. The study finds that the 1990s witnessed a gradual increase in cross border investment to take advantage of investment opportunities in member states. South Africa has become the primary source of foreign direct investment flows to a number of SADC countries, with mergers and acquisitions being the dominant mode of its foreign direct investment. Cross border investment helps in supplementing low domestic savings, thus providing substantial parts of the shortfall in capital needed to finance economic growth and development. It can thus promote development in the industrial sector, transfer of capital, skills and technology, and development of infrastructure. Many SADC countries are unable to compete effectively due to lack of export supply capacity. The thesis suggests that capitalising on investment by South African firms could enhance local supply capabilities and raise export competitiveness. The study concludes that for market integration to succeed in the SADC region, the neofunctional and development integration approaches need to be actively pursued simultaneously, particularly with respect to infrastructural and industrial development.
- Full Text:
- Date Issued: 2001
- Authors: Mutambara, Tsitsi Effie
- Date: 2001
- Subjects: Africa, Southern -- Economic integration , Southern African Development Community
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:938 , http://hdl.handle.net/10962/d1002671 , Africa, Southern -- Economic integration , Southern African Development Community
- Description: The transformation of SADCC into the Southern African Development Community (SADC) has paved the way towards closer regional economic integration in southern Africa. The regional grouping no longer only focuses on sectoral cooperation, but is steadily moving towards increased cooperation in trade development and promotion, industrial development and the diversification of national economies, with the aim of increasing regional economic integration. A free trade area ranks second lowest in the steps towards the highest levels of economic integration. Thus, the signing of the SADC Trade Protocol, which serves to pave way for a SADC Free Trade Area, has initiated steps to facilitate and promote the formal economic integration of all countries in the southern African region. It has been noted that at various periods, the region has adopted a variety of approaches to integration. As such, the present study reviews the different approaches to integration, namely the market integration model, the neo-functional integration model, the development integration model and the theory of common markets. Since the essential question with which this thesis is concerned is whether, and to what extent, the benefits expected from SADC and SACU in terms of their aims and objectives have accrued to member states, an insight into the expected benefits arising from the application of each theoretical framework can help to facilitate an evaluation of the benefits which the countries have enjoyed from these two regional groupings. The thesis highlights that throughout the ten years during which the original SADCC was in place, it based its approach to regional integration on the neo-functional and development integration models, although the former tended to be more dominant. With the regional grouping transforming into SADC, the market integration model was adopted, even though the grouping still had features of the aforementioned approaches. The relevance of the three approaches can be seen in: (i) the continued importance of SADC's sectoral projects, particularly in the field of transport and communication: (ii) continued attempts to put in place a suitable regional) industrial development strategy and implement policies to attract foreign investment; and (iii) the signing of the SADCC Trade Protocol to facilitate the implementation of a free trade area. The thesis argues that member states have enjoyed considerable economic benefits from the SADC sectoral projects. However, in some cases, members have lost out on potential benefits as a result of projects failing to be implemented or completed, mainly due to inadequate funding. Further, delays and inefficiencies at some border posts constitute significant non-tariff barriers which could be a hindrance to intra-regional trade. Progress towards diversification of exports has been limited as the region still relies mostly on the export of the traditional agricultural and mineral raw materials. While all countries have made efforts to diversify their industrial bases, attempts at implementing a meaningful regional industrial development strategy have met with limited success. Intra-regional trade has been increasing over the years. Since the SADC Trade Protocol only came into effect in September 2000, the increased levels of trade integration in the region appear to have been a result of the bilateral trade agreements between countries, and the customs union between South Africa and Botswana, Lesotho, Namibia and Swaziland (BLNS), as well as the structural adjustment programmes and the significant growth experienced in some countries. Outstanding intra-regional trade volumes have been experienced within SACU. In trade terms, benefits have varied between member states, with the more powerful countries like South Africa, Zimbabwe and Mauritius experiencing substantial trade surpluses vis-a.-vis their trade, partners. Countries with bilateral preferential trade agreements have also benefited more due to increased access into each other's markets compared to those without or with bilateral trade agreements of an MFN nature. However, it is important to note that, despite the increase in trade integration in the region, southern Africa is still heavily dependent on the rest of the world for its export markets and as its source of imports. The study finds that intra-industry trade (IIT) exists within the region and, in a number of sectors, high IIT indices are recorded;--although some such sectors do not display significant trade - voIumes. The opening of the region through the implementation of the SADC FTA could promote the expansion of IIT .as-the free trade area )'Till create an enlarged regional market. As such, SADC could benefit from dynamic effects such as scale economies in production and marketing, with member states working on having complementary production structures so as to facilitate specialisation. The thesis argues that the potential for intra-regional trade expansion in the SADC FT A also exists bearing in mind trade complementarity between countries as well as revealed comparative advantages in different sectors. One of the benefits which have accrued to the region as a result of facilitating and promoting greater cooperation and deepening the integration process has been an expansion in cross border investment. The study finds that the 1990s witnessed a gradual increase in cross border investment to take advantage of investment opportunities in member states. South Africa has become the primary source of foreign direct investment flows to a number of SADC countries, with mergers and acquisitions being the dominant mode of its foreign direct investment. Cross border investment helps in supplementing low domestic savings, thus providing substantial parts of the shortfall in capital needed to finance economic growth and development. It can thus promote development in the industrial sector, transfer of capital, skills and technology, and development of infrastructure. Many SADC countries are unable to compete effectively due to lack of export supply capacity. The thesis suggests that capitalising on investment by South African firms could enhance local supply capabilities and raise export competitiveness. The study concludes that for market integration to succeed in the SADC region, the neofunctional and development integration approaches need to be actively pursued simultaneously, particularly with respect to infrastructural and industrial development.
- Full Text:
- Date Issued: 2001
The operation of letters of credit with particular reference to the doctrine of strict compliance, the principle of independence, the fraud exception and conflict of laws
- Makobe, Melanchton Phillip Malepe
- Authors: Makobe, Melanchton Phillip Malepe
- Date: 2001
- Subjects: Letters of credit Conflict of laws Fraud
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3710 , http://hdl.handle.net/10962/d1007281
- Description: The thesis covers aspects of the law relating to letters of credit. It deals with the operation of letters of credit with particular reference to the doctrine of strict compliance, the principle of independence, the fraud exception and conflict of laws. According to the principle of independence, banks must make payment in terms of the letter of credit irrespective of any dispute that may exist between the buyer and the seller in an underlying contract or other contracts. Although the principle of independence is clearly established, it is not absolute. An exception occurs in the case of fraud. Thus, if the seller has committed fraud, such as tendering forged documents, the buyer can instruct the bank not to make payment in terms of the credit. If the bank refuses to dishonour the letter of credit, the buyer can apply to a court to interdict the bank from making payment. In South African law the buyer must establish that the seller was party to fraud in relation to the documents presented to the bank for payment before the court can grant an interdict. This thesis also examines the standard of proof of fraud required in letters of credit transactions and proposes a standard of proof which will not unduly favour the seller whose good faith is in dispute. The fast growing technology of computers and telecommunications is rapidly changing the methods of transacting business by paper documentation and letter of credit transactions are no exception. At present the buyer can apply to the bank to issue a letter of credit through the computer and banks also communicate letter of credit transactions through computer networks. However, the beneficiary still has to present documents to the bank for payment in paper form. It is proposed that the Uniform Custom and Practice For Documentary Credits (UCP) be amended to provide for fully computerised letters of credit transactions. Another objective of the thesis is to examine the doctrine of strict compliance. In terms of the doctrine of strict compliance documents presented under the credit must comply strictly with the requirements set out in the credit. If banks are satisfied that the documents presented by the seller strictly conform with the requirements of the credit they are obliged to make payment as required by the credit. It is proposed that the doctrine of strict compliance should not be applied strictly. In other words, the banks should make payment in terms of the credit if the discrepancy in the documents is trivial. The thesis also covers conflict of laws issues. As the UCP does not have rules dealing with conflict of laws, most jurisdictions have developed their own rules to be applied by the courts in cases of conflict of laws. The thesis examines the different rules of conflict of laws as developed and practiced by different jurisdictions.
- Full Text:
- Date Issued: 2001
- Authors: Makobe, Melanchton Phillip Malepe
- Date: 2001
- Subjects: Letters of credit Conflict of laws Fraud
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3710 , http://hdl.handle.net/10962/d1007281
- Description: The thesis covers aspects of the law relating to letters of credit. It deals with the operation of letters of credit with particular reference to the doctrine of strict compliance, the principle of independence, the fraud exception and conflict of laws. According to the principle of independence, banks must make payment in terms of the letter of credit irrespective of any dispute that may exist between the buyer and the seller in an underlying contract or other contracts. Although the principle of independence is clearly established, it is not absolute. An exception occurs in the case of fraud. Thus, if the seller has committed fraud, such as tendering forged documents, the buyer can instruct the bank not to make payment in terms of the credit. If the bank refuses to dishonour the letter of credit, the buyer can apply to a court to interdict the bank from making payment. In South African law the buyer must establish that the seller was party to fraud in relation to the documents presented to the bank for payment before the court can grant an interdict. This thesis also examines the standard of proof of fraud required in letters of credit transactions and proposes a standard of proof which will not unduly favour the seller whose good faith is in dispute. The fast growing technology of computers and telecommunications is rapidly changing the methods of transacting business by paper documentation and letter of credit transactions are no exception. At present the buyer can apply to the bank to issue a letter of credit through the computer and banks also communicate letter of credit transactions through computer networks. However, the beneficiary still has to present documents to the bank for payment in paper form. It is proposed that the Uniform Custom and Practice For Documentary Credits (UCP) be amended to provide for fully computerised letters of credit transactions. Another objective of the thesis is to examine the doctrine of strict compliance. In terms of the doctrine of strict compliance documents presented under the credit must comply strictly with the requirements set out in the credit. If banks are satisfied that the documents presented by the seller strictly conform with the requirements of the credit they are obliged to make payment as required by the credit. It is proposed that the doctrine of strict compliance should not be applied strictly. In other words, the banks should make payment in terms of the credit if the discrepancy in the documents is trivial. The thesis also covers conflict of laws issues. As the UCP does not have rules dealing with conflict of laws, most jurisdictions have developed their own rules to be applied by the courts in cases of conflict of laws. The thesis examines the different rules of conflict of laws as developed and practiced by different jurisdictions.
- Full Text:
- Date Issued: 2001
The phloem unloading and sucrose-sequestration pathway in the internodal stem tissue of the Saccharum hybrid var. NCo376
- Authors: Gerber, Jacqués
- Date: 2001
- Subjects: Saccharum , Sugarcane , Sugar -- Synthesis , Sugar growing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4194 , http://hdl.handle.net/10962/d1003763
- Description: Internodes 5-8, 10, 13 and 15 of Saccharum sp. var. NCo376 were examined for evidence of symplasmic phloem unloading of sucrose from the phloem, via the bundle sheath to the storage parenchyma. The vascular bundle possesses wellisolated phloem comprised of large diameter sieve elements and small diameter companion cells. A layer of phloem parenchyma surrounds the phloem, except where the phloem abuts the crushed protophloem. Outside this is a sclerenchymatous sheath, directly endarch to a parenchymatous bundle sheath, which is surrounded by storage parenchyma. The bundle sheath is interrupted at the centrifugal pole of the vascular bundle by a phloem fibre cap. Scanning Electron Microscopy revealed plasmodesmal fields throughout the bundle sheath and pith tissue. Transmission Electron Microscopy studies provided evidence of plasmodesmal occlusion, but not in all tissues. Aniline blue reactions under UV light indicate the presence of occluded plasmodesmal fields at the phloem parenchyma / sclerenchymatous sheath interface, and in localised regions of cells which are smaller than the surrounding storage parenchyma cells. This suggests a symplasmic transport pathway at these locations, and, based on these positive aniline blue reactions, with regulation via callose-mediated transplasmodesmal transport. Osmotic stress experiments, which included the addition of Ca2+, did not reveal further callose occlusion in the parenchyma, suggesting that the plasmodesmata in these regions may be closed via a noncallosic mechanism. Dye-coupling studies, using Lucifer Yellow (LYCH), which was iontophoretically injected following turgor-pressure equalisation, showed only rare, limited symplastic transport, usually only between the injected cell and one adjacent cell. Most injections did not result in transport of LYCH, suggesting either a lack of plasmodesmal connectivity, occlusion, or gating of any plasmodesmata present. This limited symplasmic transport, combined with the presence of occluded plasmodesmata at the phloem parenchyma / sclerenchymatous sheath interface suggests the presence of a two-domain phloem-unloading pathway. While symplastic transport may occur from the phloem to the sclerenchymatous sheath, further sucrose transport to the storage parenchyma appears to proceed apoplasmically from the sclerenchymatous sheath / bundle sheath interface, and into storage parenchyma cells across the cell wall and cell membrane via specialised sucrose transporters.
- Full Text:
- Date Issued: 2001
- Authors: Gerber, Jacqués
- Date: 2001
- Subjects: Saccharum , Sugarcane , Sugar -- Synthesis , Sugar growing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4194 , http://hdl.handle.net/10962/d1003763
- Description: Internodes 5-8, 10, 13 and 15 of Saccharum sp. var. NCo376 were examined for evidence of symplasmic phloem unloading of sucrose from the phloem, via the bundle sheath to the storage parenchyma. The vascular bundle possesses wellisolated phloem comprised of large diameter sieve elements and small diameter companion cells. A layer of phloem parenchyma surrounds the phloem, except where the phloem abuts the crushed protophloem. Outside this is a sclerenchymatous sheath, directly endarch to a parenchymatous bundle sheath, which is surrounded by storage parenchyma. The bundle sheath is interrupted at the centrifugal pole of the vascular bundle by a phloem fibre cap. Scanning Electron Microscopy revealed plasmodesmal fields throughout the bundle sheath and pith tissue. Transmission Electron Microscopy studies provided evidence of plasmodesmal occlusion, but not in all tissues. Aniline blue reactions under UV light indicate the presence of occluded plasmodesmal fields at the phloem parenchyma / sclerenchymatous sheath interface, and in localised regions of cells which are smaller than the surrounding storage parenchyma cells. This suggests a symplasmic transport pathway at these locations, and, based on these positive aniline blue reactions, with regulation via callose-mediated transplasmodesmal transport. Osmotic stress experiments, which included the addition of Ca2+, did not reveal further callose occlusion in the parenchyma, suggesting that the plasmodesmata in these regions may be closed via a noncallosic mechanism. Dye-coupling studies, using Lucifer Yellow (LYCH), which was iontophoretically injected following turgor-pressure equalisation, showed only rare, limited symplastic transport, usually only between the injected cell and one adjacent cell. Most injections did not result in transport of LYCH, suggesting either a lack of plasmodesmal connectivity, occlusion, or gating of any plasmodesmata present. This limited symplasmic transport, combined with the presence of occluded plasmodesmata at the phloem parenchyma / sclerenchymatous sheath interface suggests the presence of a two-domain phloem-unloading pathway. While symplastic transport may occur from the phloem to the sclerenchymatous sheath, further sucrose transport to the storage parenchyma appears to proceed apoplasmically from the sclerenchymatous sheath / bundle sheath interface, and into storage parenchyma cells across the cell wall and cell membrane via specialised sucrose transporters.
- Full Text:
- Date Issued: 2001
The refining of calcium using a sulfate reducing bacterial system
- Authors: Horne, Kerry Allison
- Date: 2001
- Subjects: Calcium carbonate -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3915 , http://hdl.handle.net/10962/d1003974 , Calcium carbonate -- Synthesis
- Description: White lime is used in many industries in South Africa but is not produced locally and must be imported. Many technologies have been suggested for the large-scale manufacture of calcium carbonate but these are not necessarily suitable for application in South Africa. This study investigated a chemical preparation of calcium carbonate combined with biological purification Calcium containing materials from the Pretoria Portland Cement, Lime Division factory at Lime Acres in the Northern Cape were studied as the starting materials for the manufacture. Investigation showed that they contained various impurities, including iron and manganese compounds which were largely responsible for the brown-grey colour of the lime products. Complete dissolution of calcium hydroxide, the purest of the potential starting materials, and subsequent hydroxide precipitation was not successful in removing all iron and manganese. Precipitation with sulfide ions was successfill, decreasing levels of metals to below the detection limit of atomic absorption spectrophotometry. Studies of all potential starting materials revealed that the levels of impurities in the starting material did not have a large effect on levels of impurities in the calcium carbonate produced. It was therefore possible to convert the residual calcium oxide or hydroxide in waste lime dusts to white calcium carbonate, a marketable prciduct Recycling of the water and starting material used in the process served to increase, rather than decrease, the purity of the calcium carbonate product. This allows for water conservation as water is not consumed in the process but merely utilised. When waste lime dust was used as the starting material, sulfate was found in the product. While still a white lime, the calcium carbonate was not chemically pure. Sulfate removal was therefore investigated and the use of sulfate-reducing bacteria was studied as a novel application. A mixed sulfate-reducing bacterial population was isolated and found to be hIghly active at sulfate concentrations between 0.2 and 2 ~~~. They were capable of autotrophic growth and could reduce sulfate in solutions with elevated pH and in calcium carbonate suspensions, although they did not grow readily in these media. A process was designed for the production of bulk quantities of calcium carbonate making use of the facilities and materials available at Lime Acres. This was tested using a small scale bench-top reactor series, with favourable results. The process would allow automatic, continuous production of large quantities of white lime using waste lime dust. Provision was also made for manufacture of smaller quantities of pure calcium carbonate using sulfate-reducing bacteria to remove the sulfate impurity.
- Full Text:
- Date Issued: 2001
- Authors: Horne, Kerry Allison
- Date: 2001
- Subjects: Calcium carbonate -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3915 , http://hdl.handle.net/10962/d1003974 , Calcium carbonate -- Synthesis
- Description: White lime is used in many industries in South Africa but is not produced locally and must be imported. Many technologies have been suggested for the large-scale manufacture of calcium carbonate but these are not necessarily suitable for application in South Africa. This study investigated a chemical preparation of calcium carbonate combined with biological purification Calcium containing materials from the Pretoria Portland Cement, Lime Division factory at Lime Acres in the Northern Cape were studied as the starting materials for the manufacture. Investigation showed that they contained various impurities, including iron and manganese compounds which were largely responsible for the brown-grey colour of the lime products. Complete dissolution of calcium hydroxide, the purest of the potential starting materials, and subsequent hydroxide precipitation was not successful in removing all iron and manganese. Precipitation with sulfide ions was successfill, decreasing levels of metals to below the detection limit of atomic absorption spectrophotometry. Studies of all potential starting materials revealed that the levels of impurities in the starting material did not have a large effect on levels of impurities in the calcium carbonate produced. It was therefore possible to convert the residual calcium oxide or hydroxide in waste lime dusts to white calcium carbonate, a marketable prciduct Recycling of the water and starting material used in the process served to increase, rather than decrease, the purity of the calcium carbonate product. This allows for water conservation as water is not consumed in the process but merely utilised. When waste lime dust was used as the starting material, sulfate was found in the product. While still a white lime, the calcium carbonate was not chemically pure. Sulfate removal was therefore investigated and the use of sulfate-reducing bacteria was studied as a novel application. A mixed sulfate-reducing bacterial population was isolated and found to be hIghly active at sulfate concentrations between 0.2 and 2 ~~~. They were capable of autotrophic growth and could reduce sulfate in solutions with elevated pH and in calcium carbonate suspensions, although they did not grow readily in these media. A process was designed for the production of bulk quantities of calcium carbonate making use of the facilities and materials available at Lime Acres. This was tested using a small scale bench-top reactor series, with favourable results. The process would allow automatic, continuous production of large quantities of white lime using waste lime dust. Provision was also made for manufacture of smaller quantities of pure calcium carbonate using sulfate-reducing bacteria to remove the sulfate impurity.
- Full Text:
- Date Issued: 2001
The Rhodes BioSure process in the treatment of acid mine drainage wastewaters
- Authors: Corbett, Christopher John
- Date: 2001 , 2013-05-03
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4077 , http://hdl.handle.net/10962/d1007405
- Description: While sulphate-enriched wastewaters are generated in a number of industrial processes, such as tanning, paper manufacture and metals processing, the principal contributors to large-scale pollution from this source in South Africa are the gold and coal mining industries. Both biological and physico-chemical processes, set in train by mining operations, give rise to the oxidation of sulphur species, and the resultant generation of AMD. The Vaal River system is most affected and receives large tonnages of mining related salinity as both direct discharges, and in diffuse runoff flows. The long-term burden of this problem, and sustaining ongoing treatment over the time-frames involved will almost certainly resort to the community inhabiting the area, notwithstanding progressive mine closure legislation and comprehensive regulation governing the polluterpays principle. The volume and time-frame of the AMD problem, and the need for a long-term and sustainable response has focused interest in biological treatment approaches. These have concentrated on active and passive treatment systems, both of which rely on microbial activity related to the biological sulphur cycle. Notwithstanding the reactor type, and the particular treatment approach used, widespread application of active AMD treatment has not yet been seen on any large scale. Singular factors constraining process development are bioreactor design, cost of bioreactor construction, and the cost of the carbon source and electron donor for the biological sulphate reduction process. The SRB are able to utilise only a limited range of small organic molecules. The studies reported here were motivated by the need to evaluate low-cost options and the treatment of high volume AMD flows. This has focussed research activity on bioprocess developments using complex organic compounds derived from waste streams as electron donor sources, and the integration of AMD treatment with other waste treatment objectives. The co-disposal of organic wastes with AMD treatment would enable the development of an 'integrated resource management' approach to the problem, including sustainability of treatment operations over the long time-frames involved. Apart from the cost advantages accrued to waste treatment, the recovery of the treated water as a resource to the wider community provides a potentially important value-added function to the combined operation. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
- Authors: Corbett, Christopher John
- Date: 2001 , 2013-05-03
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4077 , http://hdl.handle.net/10962/d1007405
- Description: While sulphate-enriched wastewaters are generated in a number of industrial processes, such as tanning, paper manufacture and metals processing, the principal contributors to large-scale pollution from this source in South Africa are the gold and coal mining industries. Both biological and physico-chemical processes, set in train by mining operations, give rise to the oxidation of sulphur species, and the resultant generation of AMD. The Vaal River system is most affected and receives large tonnages of mining related salinity as both direct discharges, and in diffuse runoff flows. The long-term burden of this problem, and sustaining ongoing treatment over the time-frames involved will almost certainly resort to the community inhabiting the area, notwithstanding progressive mine closure legislation and comprehensive regulation governing the polluterpays principle. The volume and time-frame of the AMD problem, and the need for a long-term and sustainable response has focused interest in biological treatment approaches. These have concentrated on active and passive treatment systems, both of which rely on microbial activity related to the biological sulphur cycle. Notwithstanding the reactor type, and the particular treatment approach used, widespread application of active AMD treatment has not yet been seen on any large scale. Singular factors constraining process development are bioreactor design, cost of bioreactor construction, and the cost of the carbon source and electron donor for the biological sulphate reduction process. The SRB are able to utilise only a limited range of small organic molecules. The studies reported here were motivated by the need to evaluate low-cost options and the treatment of high volume AMD flows. This has focussed research activity on bioprocess developments using complex organic compounds derived from waste streams as electron donor sources, and the integration of AMD treatment with other waste treatment objectives. The co-disposal of organic wastes with AMD treatment would enable the development of an 'integrated resource management' approach to the problem, including sustainability of treatment operations over the long time-frames involved. Apart from the cost advantages accrued to waste treatment, the recovery of the treated water as a resource to the wider community provides a potentially important value-added function to the combined operation. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
The role of a symbiotic bryozoan in the chemical ecology of a marine benthic predator-prey interaction
- Authors: Gray, Christopher Anthony
- Date: 2001
- Subjects: Marine animals , Marine ecology , Benthic animals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5756 , http://hdl.handle.net/10962/d1005444 , Marine animals , Marine ecology , Benthic animals
- Description: The subtidal whelk Burnupena papyracea (Brugière) co-occurs with a voracious predator, the rock lobster Jasus lalandii (Milne Edwards), in situations where other potential prey are largely eliminated. This has been ascribed to a symbiotic bryozoan, Alcyonidium nodosum (O’Donoghue and de Watteville), which characteristically encrusts the shells of B. papyracea and deters feeding by Jasus. In this study it is shown that this is not due to physical effects of either induced physical defences in the bryozoan or increased shell strength due to the presence of the bryozoan. Neither spectroscopic screening of chemical extracts of the bryozoan nor analysis for volatile constituents revealed any apparent chemical components that are likely to deter feeding. Chemical extracts also failed to show larvicidal effects in a standard toxicity assay using the brine shrimp Artemia salina (Leach). Despite this, bioassays using individual Jasus indicated a chemical basis for feeding deterrence. The assays were run separately on three sets of Jasus and some repeats of assays gave contradictory results. However, assays showing no significant effect of treatment occurred with moulting Jasus, involved very low overall feeding rates and so gave a less convincing result. In other assays Jasus always avoided Burnupena papyracea with live Alcyonidium encrusting the shell, and food pellets containing Alcyonidium or an Alcyonidium extract. Significant preferences were shown for an unencrusted whelk, B. cincta (Röding), over B. papyracea; for B. papyracea with the bryozoan scraped off over natural B. papyracea; for B. papyracea on which the bryozoans had been killed with liquid nitrogen over untreated B. papyracea; and for food pellets prepared from ground, dried mussel over pellets prepared with dried mussel mixed with A. nodosum or its crude organic extract. It is concluded that the protection which Alcyonidium confers on Burnupena papyracea does have a chemical basis, but that the chemical responsible is either present in only trace quantities, or that it is a structurally unremarkable compound which is distasteful to Jasus. This work highlights both the advantages of using ecologically relevant bioassays (positive results when standard techniques give a negative result) and also the disadvantages (logistic constraints on sample sizes when using large test animals and individual variability in a relatively sophisticated test animal).
- Full Text:
- Date Issued: 2001
- Authors: Gray, Christopher Anthony
- Date: 2001
- Subjects: Marine animals , Marine ecology , Benthic animals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5756 , http://hdl.handle.net/10962/d1005444 , Marine animals , Marine ecology , Benthic animals
- Description: The subtidal whelk Burnupena papyracea (Brugière) co-occurs with a voracious predator, the rock lobster Jasus lalandii (Milne Edwards), in situations where other potential prey are largely eliminated. This has been ascribed to a symbiotic bryozoan, Alcyonidium nodosum (O’Donoghue and de Watteville), which characteristically encrusts the shells of B. papyracea and deters feeding by Jasus. In this study it is shown that this is not due to physical effects of either induced physical defences in the bryozoan or increased shell strength due to the presence of the bryozoan. Neither spectroscopic screening of chemical extracts of the bryozoan nor analysis for volatile constituents revealed any apparent chemical components that are likely to deter feeding. Chemical extracts also failed to show larvicidal effects in a standard toxicity assay using the brine shrimp Artemia salina (Leach). Despite this, bioassays using individual Jasus indicated a chemical basis for feeding deterrence. The assays were run separately on three sets of Jasus and some repeats of assays gave contradictory results. However, assays showing no significant effect of treatment occurred with moulting Jasus, involved very low overall feeding rates and so gave a less convincing result. In other assays Jasus always avoided Burnupena papyracea with live Alcyonidium encrusting the shell, and food pellets containing Alcyonidium or an Alcyonidium extract. Significant preferences were shown for an unencrusted whelk, B. cincta (Röding), over B. papyracea; for B. papyracea with the bryozoan scraped off over natural B. papyracea; for B. papyracea on which the bryozoans had been killed with liquid nitrogen over untreated B. papyracea; and for food pellets prepared from ground, dried mussel over pellets prepared with dried mussel mixed with A. nodosum or its crude organic extract. It is concluded that the protection which Alcyonidium confers on Burnupena papyracea does have a chemical basis, but that the chemical responsible is either present in only trace quantities, or that it is a structurally unremarkable compound which is distasteful to Jasus. This work highlights both the advantages of using ecologically relevant bioassays (positive results when standard techniques give a negative result) and also the disadvantages (logistic constraints on sample sizes when using large test animals and individual variability in a relatively sophisticated test animal).
- Full Text:
- Date Issued: 2001
The use of interactive computer simulations to engender conceptual changes about wave motion
- Authors: Jacob, Sunny
- Date: 2001
- Subjects: Computer simulation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1921 , http://hdl.handle.net/10962/d1007409
- Description: Computers are expensive equipment which most schools in South Africa cannot afford to use as an instructional tool in the same way as they are being used in affluent schools in the countly and in the western world. In this study a computer was used as a demonstration tool to help learners to visualise the different aspects of wave motion with the aid of interactive computer simulations. The study investigated how learners alter their intuitive notions of wave motion after experiencing the common teaching techniques in township schools, and then by observing interactive computer simulations. Data was collected by means of field notes, observation, questionnaires and in-depth semi-structured interviews with the participation of twelve Grade 9 learners in a secondary school over a three-week period. A combination of qualitative and quantitative methods was used in the study and the data was analysed within an interpretive framework. A detailed analysis revealed that interactive computer simulations could bring about positive conceptual changes in learners, especially in the micro level aspects of wave motion. The inexperience of the learners in a discovery method of learning and a learner centred approach of teaching seemed to interfere with the teaching techniques. To a considerable extent, language problems also hindered the revelation of conceptualisation.In writing this report of the research study J agree wilh Squires and McDougall (1994: 12) that it is difficult to use a non-interactive medium (paper-based text) to report on the interactive medium of computer simulations, as written words cannot bring out all the essential aspects of interactive computer simulations.
- Full Text:
- Date Issued: 2001
- Authors: Jacob, Sunny
- Date: 2001
- Subjects: Computer simulation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1921 , http://hdl.handle.net/10962/d1007409
- Description: Computers are expensive equipment which most schools in South Africa cannot afford to use as an instructional tool in the same way as they are being used in affluent schools in the countly and in the western world. In this study a computer was used as a demonstration tool to help learners to visualise the different aspects of wave motion with the aid of interactive computer simulations. The study investigated how learners alter their intuitive notions of wave motion after experiencing the common teaching techniques in township schools, and then by observing interactive computer simulations. Data was collected by means of field notes, observation, questionnaires and in-depth semi-structured interviews with the participation of twelve Grade 9 learners in a secondary school over a three-week period. A combination of qualitative and quantitative methods was used in the study and the data was analysed within an interpretive framework. A detailed analysis revealed that interactive computer simulations could bring about positive conceptual changes in learners, especially in the micro level aspects of wave motion. The inexperience of the learners in a discovery method of learning and a learner centred approach of teaching seemed to interfere with the teaching techniques. To a considerable extent, language problems also hindered the revelation of conceptualisation.In writing this report of the research study J agree wilh Squires and McDougall (1994: 12) that it is difficult to use a non-interactive medium (paper-based text) to report on the interactive medium of computer simulations, as written words cannot bring out all the essential aspects of interactive computer simulations.
- Full Text:
- Date Issued: 2001
The vegetation potential of natural rangelands in the mid-Fish River Valley, Eastern Cape, South Africa: towards a sustainable and acceptable management system
- Birch, Natalie Vivienne Evans
- Authors: Birch, Natalie Vivienne Evans
- Date: 2001
- Subjects: Vegetation and climate -- South Africa -- Eastern Cape Vegetation dynamics -- South Africa -- Eastern Cape Vegetation surveys -- South Africa -- Eastern Cape Land -- South Africa -- Eastern Cape Rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4186 , http://hdl.handle.net/10962/d1003754
- Description: Desertification is the diminution or destruction of the biological potential of land, and can lead ultimately to desert-like conditions. The vegetation of southern Africa is claimed to have altered over the past 100 years and much of the change is attributed to pastoral practice. In recent years however there has been much debate around the issue of the deterioration and loss of productivity of the natural rangelands, specifically those under communal management. It is one thing to claim that the vegetation has changed but quite another to produce data and analyses to show this unequivocally. Furthermore it is generally difficult to determine the nature and extent of change in natural ecosystems, as one does not know what the optimal base-line conditions should be. For this reason emphasis has been placed on developing models of potential or expected vegetation. By comparing a model of potential or expected vegetation with that of the contemporary vegetation, areas that deviate from expectation can be identified, in so doing providing evidence of the direction of change in the rangelands under various management treatments. The objective of this study was to determine shifts in the vegetation under different land-use treatments, by developing a technique to predict the potential vegetation of an area. In order to explore the nature and extent of degradation at the landscape scale a study site was selected where a range of land-use and rangeland management practices could be studied in parallel. The mid-Fish River valley consists of three markedly different units of land management, namely commercial rangelands, communal rangelands and nature conservation areas. The vegetation within the mid-Fish River valley falls within the Thicket biome and consists of three main vegetation types namely, Short Succulent Thicket, Medium Succulent Thicket and Mesic Bushclump Savanna. The creation of this potential vegetation model was dependent on the direct gradient analysis approach of relating the community patterns with environmental variables. To achieve this, floristic information was collected at sites along a topographical-moisture gradient. A Canonical Correspondence Analysis (CCA) between the environmental variables and the plant communities produced a classification from which the conditions normally associated with the major plant communities were predicted. When projected as a digital map, the qualifying sites provided a testable hypothesis of the potential vegetation. The results of this study showed a definite grazing gradient, which reflects a change from a more mesic environment towards a more arid environment with an increase in utilisation pressure. The predictive vegetation model proved to be useful for predicting the occurrence of the valley thicket communities within the Eastern Cape.
- Full Text:
- Date Issued: 2001
- Authors: Birch, Natalie Vivienne Evans
- Date: 2001
- Subjects: Vegetation and climate -- South Africa -- Eastern Cape Vegetation dynamics -- South Africa -- Eastern Cape Vegetation surveys -- South Africa -- Eastern Cape Land -- South Africa -- Eastern Cape Rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4186 , http://hdl.handle.net/10962/d1003754
- Description: Desertification is the diminution or destruction of the biological potential of land, and can lead ultimately to desert-like conditions. The vegetation of southern Africa is claimed to have altered over the past 100 years and much of the change is attributed to pastoral practice. In recent years however there has been much debate around the issue of the deterioration and loss of productivity of the natural rangelands, specifically those under communal management. It is one thing to claim that the vegetation has changed but quite another to produce data and analyses to show this unequivocally. Furthermore it is generally difficult to determine the nature and extent of change in natural ecosystems, as one does not know what the optimal base-line conditions should be. For this reason emphasis has been placed on developing models of potential or expected vegetation. By comparing a model of potential or expected vegetation with that of the contemporary vegetation, areas that deviate from expectation can be identified, in so doing providing evidence of the direction of change in the rangelands under various management treatments. The objective of this study was to determine shifts in the vegetation under different land-use treatments, by developing a technique to predict the potential vegetation of an area. In order to explore the nature and extent of degradation at the landscape scale a study site was selected where a range of land-use and rangeland management practices could be studied in parallel. The mid-Fish River valley consists of three markedly different units of land management, namely commercial rangelands, communal rangelands and nature conservation areas. The vegetation within the mid-Fish River valley falls within the Thicket biome and consists of three main vegetation types namely, Short Succulent Thicket, Medium Succulent Thicket and Mesic Bushclump Savanna. The creation of this potential vegetation model was dependent on the direct gradient analysis approach of relating the community patterns with environmental variables. To achieve this, floristic information was collected at sites along a topographical-moisture gradient. A Canonical Correspondence Analysis (CCA) between the environmental variables and the plant communities produced a classification from which the conditions normally associated with the major plant communities were predicted. When projected as a digital map, the qualifying sites provided a testable hypothesis of the potential vegetation. The results of this study showed a definite grazing gradient, which reflects a change from a more mesic environment towards a more arid environment with an increase in utilisation pressure. The predictive vegetation model proved to be useful for predicting the occurrence of the valley thicket communities within the Eastern Cape.
- Full Text:
- Date Issued: 2001
Tolerance of selected riverine indigenous macroinvertebrates from the Sabie River (Mpumalanga), and Buffalo River (Eastern Cape) to complex saline kraft and textile effluents
- Authors: Zokufa, T S
- Date: 2001
- Subjects: Water quality management -- South Africa -- Sabie River , Water -- South Africa -- Analysis , Water -- Toxicology -- South Africa , Mayflies -- South Africa , Freshwater invertebrates -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5787 , http://hdl.handle.net/10962/d1005475
- Description: Whole Effluent Toxicity (WET) testing has been identified as one of the tools in the management of complex effluents in aquatic ecosystems. In South Africa, toxicity testing has not been required for regulatory purposes. Recently, the Department of Water Affairs and Forestry has adopted WET testing as a tool to evaluate the suitability of hazardous effluent for discharge into receiving environments. This has necessitated suitable procedures to be established for use in the South African situation. With the implementation of the new National Water Act (No 36 of 1998), industries have to comply with set standards to protect the aquatic environment. However, the South African Water Quality Guidelines for Aquatic Ecosystems have been set using international toxicity data, and it is not known if they are comparable with South African conditions. The aim of this study was to investigate the tolerances of selected indigenous riverine invertebrates to complex saline effluents. The study investigated the effects of kraft mill effluent to Tricorythus tinctus, a tricorythid mayfly from the Sabie River, Mpumalanga, and the effects of a textile effluent to baetid mayflies of the Buffalo River, Eastern Cape. Indigenous riverine invertebrates were chosen as test organisms, as there is no toxicity data in South Africa which could be used to evaluate the level of protection afforded by the South African Water Quality Guidelines for Aquatic Ecosystems. The use of indigenous riverine invertebrates added the challenge of variability of a wild population, and the use of a complex effluent as toxicant added the variability of effluent composition. In this study, WET testing was used to determine the dilution of whole effluents required for discharge. Hazard-based guidelines were developed for the disposal of kraft and textile effluents. The level of environmental hazard posed by different effluent concentrations was ranked, and was related to the River Health Class. This indicated effluent concentrations that may be allowed to enter the aquatic environment, e.g. 3% effluent concentration guideline for both general kraft effluent and general textile effluent for the protection of a Class A river. This approach could contribute to the use of an Environmental Risk Assessment, approach for the management of complex effluents. A number of acute 96 hour toxicity tests were conducted following an unreplicated regression design, using kraft and textile effluents as toxicants, mayfly nymphs as test organisms, and river water as diluent and control. Test organisms were sampled from unimpacted, flowing-water riffle areas, and were exposed in recirculating artificial streams (or channels) to a range of effluent concentrations. Mortality was selected as end-point and observed twice daily. The experimental results showed the variability and acute toxicity of both kraft and textile mill effluents. Baetids were more sensitive (mean LC50=16% effluent concentration) to General Textile Effluent (GTE), but less sensitive to Post Irrigation Textile Effluent (PITE). Textile effluent (PITE) held in a holding dam were therefore less variable and less toxic; suggesting that stabilization of the effluent could have contributed to reduced toxicity. Effluent composition, e.g. higher calcium levels, may also have contributed to lowering toxicity. T. tinctus was sensitive to kraft effluents, but showed less variable responses to Irrigation Kraft Effluent than General Kraft Effluent. Toxicity test data indicated that GKE, IKE and GTE should not enter the aquatic environment without treatment, as they can cause adverse effects to aquatic biota. Both kraft and textile effluents must therefore be treated before discharge. Different responses to different effluent batches were probably due to effluent variability. The use of indigenous organisms, and not a standard laboratory organism, could also have contributed to variability. A hazard-based approach could be useful, as it will provide a consistent basis for deciding on the acceptability of impacts, while allowing natural site-specific differences to be taken into account.
- Full Text:
- Date Issued: 2001
- Authors: Zokufa, T S
- Date: 2001
- Subjects: Water quality management -- South Africa -- Sabie River , Water -- South Africa -- Analysis , Water -- Toxicology -- South Africa , Mayflies -- South Africa , Freshwater invertebrates -- South Africa -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5787 , http://hdl.handle.net/10962/d1005475
- Description: Whole Effluent Toxicity (WET) testing has been identified as one of the tools in the management of complex effluents in aquatic ecosystems. In South Africa, toxicity testing has not been required for regulatory purposes. Recently, the Department of Water Affairs and Forestry has adopted WET testing as a tool to evaluate the suitability of hazardous effluent for discharge into receiving environments. This has necessitated suitable procedures to be established for use in the South African situation. With the implementation of the new National Water Act (No 36 of 1998), industries have to comply with set standards to protect the aquatic environment. However, the South African Water Quality Guidelines for Aquatic Ecosystems have been set using international toxicity data, and it is not known if they are comparable with South African conditions. The aim of this study was to investigate the tolerances of selected indigenous riverine invertebrates to complex saline effluents. The study investigated the effects of kraft mill effluent to Tricorythus tinctus, a tricorythid mayfly from the Sabie River, Mpumalanga, and the effects of a textile effluent to baetid mayflies of the Buffalo River, Eastern Cape. Indigenous riverine invertebrates were chosen as test organisms, as there is no toxicity data in South Africa which could be used to evaluate the level of protection afforded by the South African Water Quality Guidelines for Aquatic Ecosystems. The use of indigenous riverine invertebrates added the challenge of variability of a wild population, and the use of a complex effluent as toxicant added the variability of effluent composition. In this study, WET testing was used to determine the dilution of whole effluents required for discharge. Hazard-based guidelines were developed for the disposal of kraft and textile effluents. The level of environmental hazard posed by different effluent concentrations was ranked, and was related to the River Health Class. This indicated effluent concentrations that may be allowed to enter the aquatic environment, e.g. 3% effluent concentration guideline for both general kraft effluent and general textile effluent for the protection of a Class A river. This approach could contribute to the use of an Environmental Risk Assessment, approach for the management of complex effluents. A number of acute 96 hour toxicity tests were conducted following an unreplicated regression design, using kraft and textile effluents as toxicants, mayfly nymphs as test organisms, and river water as diluent and control. Test organisms were sampled from unimpacted, flowing-water riffle areas, and were exposed in recirculating artificial streams (or channels) to a range of effluent concentrations. Mortality was selected as end-point and observed twice daily. The experimental results showed the variability and acute toxicity of both kraft and textile mill effluents. Baetids were more sensitive (mean LC50=16% effluent concentration) to General Textile Effluent (GTE), but less sensitive to Post Irrigation Textile Effluent (PITE). Textile effluent (PITE) held in a holding dam were therefore less variable and less toxic; suggesting that stabilization of the effluent could have contributed to reduced toxicity. Effluent composition, e.g. higher calcium levels, may also have contributed to lowering toxicity. T. tinctus was sensitive to kraft effluents, but showed less variable responses to Irrigation Kraft Effluent than General Kraft Effluent. Toxicity test data indicated that GKE, IKE and GTE should not enter the aquatic environment without treatment, as they can cause adverse effects to aquatic biota. Both kraft and textile effluents must therefore be treated before discharge. Different responses to different effluent batches were probably due to effluent variability. The use of indigenous organisms, and not a standard laboratory organism, could also have contributed to variability. A hazard-based approach could be useful, as it will provide a consistent basis for deciding on the acceptability of impacts, while allowing natural site-specific differences to be taken into account.
- Full Text:
- Date Issued: 2001
Towards a broader application of decision-making paradigms: a case study of the establishment of ECOWAS Cease-fire Monitoring Group (ECOMOG)
- Authors: Domson-Lindsay, Albert
- Date: 2001
- Subjects: Liberia -- History -- Civil War, 1989-1996 , Liberia -- politics and government -- 1980- , Ecomog , Economic community of west african states
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2771 , http://hdl.handle.net/10962/d1002981 , Liberia -- History -- Civil War, 1989-1996 , Liberia -- politics and government -- 1980- , Ecomog , Economic community of west african states
- Description: The thesis in the main, looks at the decision-making process which underlined the Economic Community of West African States' attempt to end the Liberian crisis. It examines the establishment of ECOMOG to intervene in the Liberian civil crisis and the various pacific attempts to resolve the Liberian question. It does so through the medium of decision - making theory and some of the conceptual models that have flowed out of it. The thesis' focus on the decisional process of a regional body marks an attempt to broaden the scope of application of decision - making paradigms, which are usually employed to analyse decisions of national governments. The imperative for analysing the decisional process of ECOWAS in its quest to find solution to the Liberian problem has in part been dictated by the novelty of the ECOMOG concept. It marks the first major attempt of a sub - regional economic organization to successfully find solution to a civil conflict, as a result, there are numerous lessons to be gleaned from its failures and successes. Its relevance in the African context, with its intractable conflicts cannot be overemphasized. It has also been motivated by the fact that more works need to be produced on the decision-making processes of governments and regional bodies within the continent. The thesis argues that, both rational and "irrational" elements infused the decisional process of ECOW AS in its bid to solve the Liberian Crisis. Among other things, Policy-makers were influenced in their choice of decision by rational calculations based on national interest. It examines the clash of interests which characterized the establishment ofECOMOG as an tntervention force, the impasse this fostered and how it was eventually resolved. It postulates that exteljIlal actors influenced the decision process and that policy :Qiakers were aided to make the decisions they made by other organs in the decisional chain. The "irrational" component of the process, among other things, could be seen from the fact that the Liberian question was solved in " bits and pieces". Besides, blunders were committed through defective decision - making mechanism. The thesis concludes by offering suggestions to improve the quality of ECOW AS decision-making process with regard to conflict resolution and how to achieve regional consensus.
- Full Text:
- Date Issued: 2001
- Authors: Domson-Lindsay, Albert
- Date: 2001
- Subjects: Liberia -- History -- Civil War, 1989-1996 , Liberia -- politics and government -- 1980- , Ecomog , Economic community of west african states
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2771 , http://hdl.handle.net/10962/d1002981 , Liberia -- History -- Civil War, 1989-1996 , Liberia -- politics and government -- 1980- , Ecomog , Economic community of west african states
- Description: The thesis in the main, looks at the decision-making process which underlined the Economic Community of West African States' attempt to end the Liberian crisis. It examines the establishment of ECOMOG to intervene in the Liberian civil crisis and the various pacific attempts to resolve the Liberian question. It does so through the medium of decision - making theory and some of the conceptual models that have flowed out of it. The thesis' focus on the decisional process of a regional body marks an attempt to broaden the scope of application of decision - making paradigms, which are usually employed to analyse decisions of national governments. The imperative for analysing the decisional process of ECOWAS in its quest to find solution to the Liberian problem has in part been dictated by the novelty of the ECOMOG concept. It marks the first major attempt of a sub - regional economic organization to successfully find solution to a civil conflict, as a result, there are numerous lessons to be gleaned from its failures and successes. Its relevance in the African context, with its intractable conflicts cannot be overemphasized. It has also been motivated by the fact that more works need to be produced on the decision-making processes of governments and regional bodies within the continent. The thesis argues that, both rational and "irrational" elements infused the decisional process of ECOW AS in its bid to solve the Liberian Crisis. Among other things, Policy-makers were influenced in their choice of decision by rational calculations based on national interest. It examines the clash of interests which characterized the establishment ofECOMOG as an tntervention force, the impasse this fostered and how it was eventually resolved. It postulates that exteljIlal actors influenced the decision process and that policy :Qiakers were aided to make the decisions they made by other organs in the decisional chain. The "irrational" component of the process, among other things, could be seen from the fact that the Liberian question was solved in " bits and pieces". Besides, blunders were committed through defective decision - making mechanism. The thesis concludes by offering suggestions to improve the quality of ECOW AS decision-making process with regard to conflict resolution and how to achieve regional consensus.
- Full Text:
- Date Issued: 2001
Towards a collaborative approach to teacher professional development : a journey of negotiation
- Authors: Southwood, Sue
- Date: 2001
- Subjects: Teachers -- Training of -- South Africa Teachers -- In-service training -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1866 , http://hdl.handle.net/10962/d1004649
- Description: The research presented in this thesis is a case study, based on ethnographic principles, located in the interpretive paradigm of qualitative research. The focus is specifically on the development of a collaborative approach ro teacher professional development: an approach that recognises and celebrates teachers themselves as resources for their own and other teachers' professional development. The study was carried out over a period of four years with a group of twelve teachers who had recognised the need and expressed the desire to develop their teaching. The research evolved in two main phases. The initial phase was based on the implementation and evaluation of a project designed to encourage a collaborative approach to teacher development based on mutual peer support. This led to a second phase, the main focus of the research, aimed at gaining a greater understanding of the teachers' situation and situating their practice in the wider context generated by this understanding. Conversations with the teachers led to the identification of dimensions and tensions characterising their experience. The research presented here, represents an attempt to understand, interpret and make recommendations relating to the professional development of teachers. The understanding is linked to the teachers' educational biographies and experience of the culture in which they are situated. The interpretation is based on what may be viewed as a dynamic ongoing construction of meaning - a journey of negotiation. The text, described as a narrative collage, a tapestry of voices interwoven by threads of negotiation, represents a collaborative accomplishment. The teachers' words have been interpretively framed and these constructions validated in an interpersonal construction of social reality. The reader is invited to engage in an act of complicity, to collude with the text in the construction and negotiation of shared meaning, possibly finding resonance with their own situations. Reflections on the teachers' experience reveal journeys which resonate with that of the society in which the school is located - 'a case in transition' - situated between an environment characterised by constrained cooperation and an environment characterised by freer collaboration. The overall tension may be viewed metaphorically as a 'Tug o' War'. On one end of the rope is a cultural legacy of authority, isolation, social division and conservatism, while on the other end there is a pull towards greater autonomy and interaction, to adapt rather than conserve and to work together in mutual collegial support: a struggle between cooperating with what is and collaborating towards what could be. The main contention of this thesis is that we ought strongly to support and encourage collaborative approaches to professional development based on mutual peer support. We need to look towards a future of open professionalism where the teachers are regarded as key persons in the process. The attainment of such an ideal needs to be seen as part of systemic changes in management, policies and structure geared towards greater inclusivity and democratic practice; it necessitates a coherent approach that is based on relationships of mutual respect and appreciation.
- Full Text:
- Date Issued: 2001
- Authors: Southwood, Sue
- Date: 2001
- Subjects: Teachers -- Training of -- South Africa Teachers -- In-service training -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1866 , http://hdl.handle.net/10962/d1004649
- Description: The research presented in this thesis is a case study, based on ethnographic principles, located in the interpretive paradigm of qualitative research. The focus is specifically on the development of a collaborative approach ro teacher professional development: an approach that recognises and celebrates teachers themselves as resources for their own and other teachers' professional development. The study was carried out over a period of four years with a group of twelve teachers who had recognised the need and expressed the desire to develop their teaching. The research evolved in two main phases. The initial phase was based on the implementation and evaluation of a project designed to encourage a collaborative approach to teacher development based on mutual peer support. This led to a second phase, the main focus of the research, aimed at gaining a greater understanding of the teachers' situation and situating their practice in the wider context generated by this understanding. Conversations with the teachers led to the identification of dimensions and tensions characterising their experience. The research presented here, represents an attempt to understand, interpret and make recommendations relating to the professional development of teachers. The understanding is linked to the teachers' educational biographies and experience of the culture in which they are situated. The interpretation is based on what may be viewed as a dynamic ongoing construction of meaning - a journey of negotiation. The text, described as a narrative collage, a tapestry of voices interwoven by threads of negotiation, represents a collaborative accomplishment. The teachers' words have been interpretively framed and these constructions validated in an interpersonal construction of social reality. The reader is invited to engage in an act of complicity, to collude with the text in the construction and negotiation of shared meaning, possibly finding resonance with their own situations. Reflections on the teachers' experience reveal journeys which resonate with that of the society in which the school is located - 'a case in transition' - situated between an environment characterised by constrained cooperation and an environment characterised by freer collaboration. The overall tension may be viewed metaphorically as a 'Tug o' War'. On one end of the rope is a cultural legacy of authority, isolation, social division and conservatism, while on the other end there is a pull towards greater autonomy and interaction, to adapt rather than conserve and to work together in mutual collegial support: a struggle between cooperating with what is and collaborating towards what could be. The main contention of this thesis is that we ought strongly to support and encourage collaborative approaches to professional development based on mutual peer support. We need to look towards a future of open professionalism where the teachers are regarded as key persons in the process. The attainment of such an ideal needs to be seen as part of systemic changes in management, policies and structure geared towards greater inclusivity and democratic practice; it necessitates a coherent approach that is based on relationships of mutual respect and appreciation.
- Full Text:
- Date Issued: 2001
Towards more accurate measurement of the value of the arts to society: economic impact and willingness to pay studies at the Standard Bank National Arts Festival
- Authors: Snowball, Jeanette Dalziel
- Date: 2001
- Subjects: Standard Bank National Arts Festival , Standard Bank National Arts Festival -- Economic aspects , Art -- Economic aspects , Money in art , Art -- Marketing , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:939 , http://hdl.handle.net/10962/d1002672
- Description: The accurate measurement of the value of the arts to society is becoming increasingly important in developing countries, like South Africa, where the arts must compete with housing, health, education and the like for public funds. Motivation for the public funding of arts events, like the Standard Bank National Arts Festival in Grahamstown, is usually based on the economic impact, that is, the financial benefits to the region, of such events. The argument is problematic, however, because the primary recipients of such economic benefits are often middle to upper income groups who also attend more arts performances. Furthermore, the studies have not taken into account the positive externalities which, it is argued, are generated by the arts and are enjoyed by attenders and non attenders alike. This thesis argues that it is the social benefits which the arts provide, those external to the market, which should be the basis of public funding. In order to quantify these positive externalities, a willingness to pay (WTP) study was conducted in the Grahamstown region. It is generally, but erroneously, believed that the Festival does not benefit the poorer, largely black, Grahamstown East residents. The study found that, in addition to the economic value (R23 - 25 million a year), the non-market benefits which the festival provides are worth between R2.3 and R3 million a year and form a very important part of its value, particularly to low income groups. The study also found that there are methodological adjustments which can be made to WTP studies to successfully control for the many forms of bias it is prone to. By using a combination of closed and open ended and liable and non-liable questions, the motivation of respondents' answers to WTP questions was determined, making it possible to adjust for bias caused by, for example, "free rider" and "warm glow" responses. It is argued that by identifying and excluding such responses from WTP surveys, it is possible to reduce bias to an acceptable level.
- Full Text:
- Date Issued: 2001
- Authors: Snowball, Jeanette Dalziel
- Date: 2001
- Subjects: Standard Bank National Arts Festival , Standard Bank National Arts Festival -- Economic aspects , Art -- Economic aspects , Money in art , Art -- Marketing , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:939 , http://hdl.handle.net/10962/d1002672
- Description: The accurate measurement of the value of the arts to society is becoming increasingly important in developing countries, like South Africa, where the arts must compete with housing, health, education and the like for public funds. Motivation for the public funding of arts events, like the Standard Bank National Arts Festival in Grahamstown, is usually based on the economic impact, that is, the financial benefits to the region, of such events. The argument is problematic, however, because the primary recipients of such economic benefits are often middle to upper income groups who also attend more arts performances. Furthermore, the studies have not taken into account the positive externalities which, it is argued, are generated by the arts and are enjoyed by attenders and non attenders alike. This thesis argues that it is the social benefits which the arts provide, those external to the market, which should be the basis of public funding. In order to quantify these positive externalities, a willingness to pay (WTP) study was conducted in the Grahamstown region. It is generally, but erroneously, believed that the Festival does not benefit the poorer, largely black, Grahamstown East residents. The study found that, in addition to the economic value (R23 - 25 million a year), the non-market benefits which the festival provides are worth between R2.3 and R3 million a year and form a very important part of its value, particularly to low income groups. The study also found that there are methodological adjustments which can be made to WTP studies to successfully control for the many forms of bias it is prone to. By using a combination of closed and open ended and liable and non-liable questions, the motivation of respondents' answers to WTP questions was determined, making it possible to adjust for bias caused by, for example, "free rider" and "warm glow" responses. It is argued that by identifying and excluding such responses from WTP surveys, it is possible to reduce bias to an acceptable level.
- Full Text:
- Date Issued: 2001
Trends in mobilisation and unionisation in South Africa and Germany: a comparative analysis
- Authors: Whiteley, Julianne Beverley
- Date: 2001
- Subjects: Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3332 , http://hdl.handle.net/10962/d1003125 , Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Description: The purpose of this study is to investigate long-term trends in the union membership of South Africa and Germany, and to highlight trends in unionisation in both of these countries over a period of time. The long-term aspect of this study differentiates it from more detailed specific studies concerned with the individual fortunes of confederations or unions. The changing fortunes of trade unions have been associated with changes in work organisation, the influence of institutional pressures, or long term changes in the economic cycle. All these factors may, of course, shape and be shaped by each other. From a comparative perspective this dissertation determines whether the fortunes of unions are ultimately a product of the long waves of an economic cycle, or if other factors, such as variations in union/state relations, changes in the forms of work organisation and shifts in the employment market, impact upon union membership and mobilisation. It is hoped that the comparison of a transitional and an advanced economy may shed new light on the causes of union growth and decline, and the impact of specific social, legal and cultural variables thereon. The theoretical frame of reference for this study emerged from literature pertaining to union growth and decline. This literature discusses the historical, economic and sectoral challenges that confront the identity of unions and their ability to mobilise membership within contemporary labour markets. The entire study relies heavily on primary data collected from a wide range of sources in both countries. This method facilitates the comparison and cross-checking of information, which ensures a full and balanced study. A synthesis of the facts obtained led to certain suggestions relating to the areas in which both South African and German labour organisations could adapt their agenda and interests to the changing nature of the employment market in order to avert membership decline. The methodology of this research draws from Skopol’s work which argues that social studies ought to be grounded in historical experience in order to make sense out of specific social events that occur today. The research design utilises an initial comparative historical-political analysis of the emergence of unionism in South Africa and Germany, so as to establish those factors which have, in the past, affected union growth and decline in both countries. Thereafter, the impact of contemporary economic and sectoral trends that reoccur in the South African and German labour markets are examined and compared, in order to establish their influence on the growth or decline of union membership in both countries in the future. This study consists of four sections. The first section comprises a historical dimension that uses Valenzuela’s work relating to the political nature of labour movements to establish those factors which, in the past, have affected union growth and decline. This is done to determine whether the type of insertion of labour movements into historical national political processes, and the links formed between trade unions and political parties influences membership growth or decline. The following three sections deal with the present challenges that may affect the unions in the future. Section Two deals with factors of economic recession (namely, poverty and unemployment) which confront trade unions in the 1990s. Hyman’s Theory of Disaggregation is applied to determine if recessive socio-economic factors can account for the strength of decline of unions, as opposed to union mobilisation being purely linked to transitions between long waves of the economy as Kelly suggests. The relevance of these theories to the rise and decline of unionism in South Africa and Germany is compared and contrasted. The third section determines whether changes to more flexible forms of work organisation and shifts in the employment market can account for the contrasting strength of the South African labour movement and the decline of the German labour movement today. The way in which these issues impact negatively upon union strength in South Africa and Germany in the 1990s is compared and contrasted, again using Hyman’s Theory of Disaggregation. The final section establishes whether or not the roles adopted by the South African and German labour movements during their confrontation with labour repressive regimes impacts upon their ability to attract union membership today, despite the constraints imposed upon unions by prevailing economic and structural uncertainties. Therefore the historicity of the South African and German labour movements, (based upon the findings of the first part of this study), is referred back to. At the same time, the reactions of the South African and German labour movements to prevailing economic and structural realities, (as examined in the second part of this research) are re-examined. Three conclusions are reached. Firstly, regardless of their strengths or weaknesses, all labour organisations are capable of adjusting to the adverse changes taking place in contemporary employment markets if they prove willing to advance and defend the interests of all who work, including those in the informal sector. If unions continue to neglect the informal labour market, they run the risk of being transposed by social movements that are antagonistic to trade unions or new expressions of the workforce’s latent collectivism. Secondly, in successfully playing a social movement role that led to the downfall of Apartheid in 1994, the South African labour movement has evolved as an energetic body with a dimension of recumbent militancy that attempts to adapt its identity to the changing nature of the employment market. This enables the South African labour movement to continue to attract membership despite the prevailing economic uncertainties. In contrast, forced co-operation and consensus within the German industrial relations arena since World War Two has resulted in a less dynamic union movement that lacks initiative in adapting to the changing nature of the employment market. The result is a decline in unionism. Finally, the fortunes of unions are not, as Kelly suggests, purely a product of economic cycles. Political climates can also influence mobilisation, as has occurred in both South Africa and Germany. This implies that mobilisation is not only activated by the economic dissatisfaction of a union movement.
- Full Text:
- Date Issued: 2001
- Authors: Whiteley, Julianne Beverley
- Date: 2001
- Subjects: Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3332 , http://hdl.handle.net/10962/d1003125 , Industrial mobilization -- South Africa , Labor unions -- South Africa , Industrial mobilization -- Germany , Labor unions -- Germany , South Africa -- Economic conditions , Germany -- Economic conditions
- Description: The purpose of this study is to investigate long-term trends in the union membership of South Africa and Germany, and to highlight trends in unionisation in both of these countries over a period of time. The long-term aspect of this study differentiates it from more detailed specific studies concerned with the individual fortunes of confederations or unions. The changing fortunes of trade unions have been associated with changes in work organisation, the influence of institutional pressures, or long term changes in the economic cycle. All these factors may, of course, shape and be shaped by each other. From a comparative perspective this dissertation determines whether the fortunes of unions are ultimately a product of the long waves of an economic cycle, or if other factors, such as variations in union/state relations, changes in the forms of work organisation and shifts in the employment market, impact upon union membership and mobilisation. It is hoped that the comparison of a transitional and an advanced economy may shed new light on the causes of union growth and decline, and the impact of specific social, legal and cultural variables thereon. The theoretical frame of reference for this study emerged from literature pertaining to union growth and decline. This literature discusses the historical, economic and sectoral challenges that confront the identity of unions and their ability to mobilise membership within contemporary labour markets. The entire study relies heavily on primary data collected from a wide range of sources in both countries. This method facilitates the comparison and cross-checking of information, which ensures a full and balanced study. A synthesis of the facts obtained led to certain suggestions relating to the areas in which both South African and German labour organisations could adapt their agenda and interests to the changing nature of the employment market in order to avert membership decline. The methodology of this research draws from Skopol’s work which argues that social studies ought to be grounded in historical experience in order to make sense out of specific social events that occur today. The research design utilises an initial comparative historical-political analysis of the emergence of unionism in South Africa and Germany, so as to establish those factors which have, in the past, affected union growth and decline in both countries. Thereafter, the impact of contemporary economic and sectoral trends that reoccur in the South African and German labour markets are examined and compared, in order to establish their influence on the growth or decline of union membership in both countries in the future. This study consists of four sections. The first section comprises a historical dimension that uses Valenzuela’s work relating to the political nature of labour movements to establish those factors which, in the past, have affected union growth and decline. This is done to determine whether the type of insertion of labour movements into historical national political processes, and the links formed between trade unions and political parties influences membership growth or decline. The following three sections deal with the present challenges that may affect the unions in the future. Section Two deals with factors of economic recession (namely, poverty and unemployment) which confront trade unions in the 1990s. Hyman’s Theory of Disaggregation is applied to determine if recessive socio-economic factors can account for the strength of decline of unions, as opposed to union mobilisation being purely linked to transitions between long waves of the economy as Kelly suggests. The relevance of these theories to the rise and decline of unionism in South Africa and Germany is compared and contrasted. The third section determines whether changes to more flexible forms of work organisation and shifts in the employment market can account for the contrasting strength of the South African labour movement and the decline of the German labour movement today. The way in which these issues impact negatively upon union strength in South Africa and Germany in the 1990s is compared and contrasted, again using Hyman’s Theory of Disaggregation. The final section establishes whether or not the roles adopted by the South African and German labour movements during their confrontation with labour repressive regimes impacts upon their ability to attract union membership today, despite the constraints imposed upon unions by prevailing economic and structural uncertainties. Therefore the historicity of the South African and German labour movements, (based upon the findings of the first part of this study), is referred back to. At the same time, the reactions of the South African and German labour movements to prevailing economic and structural realities, (as examined in the second part of this research) are re-examined. Three conclusions are reached. Firstly, regardless of their strengths or weaknesses, all labour organisations are capable of adjusting to the adverse changes taking place in contemporary employment markets if they prove willing to advance and defend the interests of all who work, including those in the informal sector. If unions continue to neglect the informal labour market, they run the risk of being transposed by social movements that are antagonistic to trade unions or new expressions of the workforce’s latent collectivism. Secondly, in successfully playing a social movement role that led to the downfall of Apartheid in 1994, the South African labour movement has evolved as an energetic body with a dimension of recumbent militancy that attempts to adapt its identity to the changing nature of the employment market. This enables the South African labour movement to continue to attract membership despite the prevailing economic uncertainties. In contrast, forced co-operation and consensus within the German industrial relations arena since World War Two has resulted in a less dynamic union movement that lacks initiative in adapting to the changing nature of the employment market. The result is a decline in unionism. Finally, the fortunes of unions are not, as Kelly suggests, purely a product of economic cycles. Political climates can also influence mobilisation, as has occurred in both South Africa and Germany. This implies that mobilisation is not only activated by the economic dissatisfaction of a union movement.
- Full Text:
- Date Issued: 2001