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:
- 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:
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:
- 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.
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The evaluation of pharmaceutical pictograms in a low-literate South African population
- Dowse, Roslind, Ehlers, Martina S
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
- Full Text:
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
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The experiences of couples in relationships characterized by alcohol dependency
- Authors: Mgilane, Nomgcobo Eunice
- Date: 2001
- Subjects: Alcoholism -- South Africa Alcoholics -- Family relationships Alcoholics' spouses -- South Africa Alcoholics -- South Africa -- Conduct of life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:702 , http://hdl.handle.net/10962/d1006461
- Description: The study focused on the expenences of Xhosa-speaking couples in relationships characterized by alcohol dependency. The goal was to generate greater understanding of the descriptions of relationship issues faced by alcohol dependent respondents and their partners. Specifically, the study focused on exploring how the alcohol dependent respondents relate to their partners, their behaviour at home when drinking prior to their admission for rehabilitation, the experiences of their partners in living with alcohol dependent partners and how they coped with the situation. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the alcohol dependent individual's behaviour, his emotions, relapse, the family's coping strategies, alcohol and marital problems and the role of the social worker as part of the rehabilitation team. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Fifteen alcohol dependent clients who were admitted for treatment and rehabilitation at Thembelitsha Rehabilitation Centre (TRC) were selected. These clients were admitted to TRC during the period starting from January 1997 to June 1999 and were discharged to their homes during the research study. To collect data, interviews were conducted separately to a total of thirty respondents. Two interview schedules were used, one for the alcohol dependent respondents (Appendix A) and the other for their partners (Appendix B). This study revealed a remarkable consistency in the descriptions of relationship issues faced by alcohol dependent respondents and their partners. These are abusive behaviours by alcohol dependent respondents. The partners were reluctant and feared challenging the behaviour. The way in which partners responded to drinking and the reactions of alcohol dependent respondents are indicative of the difficult issues faced by the couples. The study also revealed that couples experience communication, financial and sexual relationship problems. The study concludes with recommendations based on the research findings
- Full Text:
- Authors: Mgilane, Nomgcobo Eunice
- Date: 2001
- Subjects: Alcoholism -- South Africa Alcoholics -- Family relationships Alcoholics' spouses -- South Africa Alcoholics -- South Africa -- Conduct of life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:702 , http://hdl.handle.net/10962/d1006461
- Description: The study focused on the expenences of Xhosa-speaking couples in relationships characterized by alcohol dependency. The goal was to generate greater understanding of the descriptions of relationship issues faced by alcohol dependent respondents and their partners. Specifically, the study focused on exploring how the alcohol dependent respondents relate to their partners, their behaviour at home when drinking prior to their admission for rehabilitation, the experiences of their partners in living with alcohol dependent partners and how they coped with the situation. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the alcohol dependent individual's behaviour, his emotions, relapse, the family's coping strategies, alcohol and marital problems and the role of the social worker as part of the rehabilitation team. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Fifteen alcohol dependent clients who were admitted for treatment and rehabilitation at Thembelitsha Rehabilitation Centre (TRC) were selected. These clients were admitted to TRC during the period starting from January 1997 to June 1999 and were discharged to their homes during the research study. To collect data, interviews were conducted separately to a total of thirty respondents. Two interview schedules were used, one for the alcohol dependent respondents (Appendix A) and the other for their partners (Appendix B). This study revealed a remarkable consistency in the descriptions of relationship issues faced by alcohol dependent respondents and their partners. These are abusive behaviours by alcohol dependent respondents. The partners were reluctant and feared challenging the behaviour. The way in which partners responded to drinking and the reactions of alcohol dependent respondents are indicative of the difficult issues faced by the couples. The study also revealed that couples experience communication, financial and sexual relationship problems. The study concludes with recommendations based on the research findings
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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:
- 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.
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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:
- 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
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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:
- 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.
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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:
- 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.
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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:
- 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:
The many faces of racism:
- Garman, Anthea, Baumann, Melissa
- Authors: Garman, Anthea , Baumann, Melissa
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158729 , vital:40223 , https://hdl.handle.net/10520/EJC144727
- Description: Last year South African journalists reluctantly agreed to examine themselves under the public spotlight when the Human Rights Commission decided to hold hearings into racism in the media.
- Full Text:
- Authors: Garman, Anthea , Baumann, Melissa
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158729 , vital:40223 , https://hdl.handle.net/10520/EJC144727
- Description: Last year South African journalists reluctantly agreed to examine themselves under the public spotlight when the Human Rights Commission decided to hold hearings into racism in the media.
- Full Text:
The myth of authenticity : folktales and nationalism in the 'new South Africa'
- Authors: Naidu, Samantha
- Date: 2001
- Language: English
- Type: Article , text
- Identifier: vital:26378 , http://hdl.handle.net/10962/54047 , https://orcid.org/0000-0001-9456-8657
- Description: Folktales texts are published in glorious, polychromatic, innovative forms that promote the texts as both culturally educational and entertaining.
- Full Text: false
- Authors: Naidu, Samantha
- Date: 2001
- Language: English
- Type: Article , text
- Identifier: vital:26378 , http://hdl.handle.net/10962/54047 , https://orcid.org/0000-0001-9456-8657
- Description: Folktales texts are published in glorious, polychromatic, innovative forms that promote the texts as both culturally educational and entertaining.
- Full Text: false
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:
- 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:
The need for formal training in social work supervision
- Authors: Moss, Antoinette Rosemary
- Date: 2001
- Subjects: Social workers -- Supervision of , Social workers -- Training of
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:703 , http://hdl.handle.net/10962/d1006466 , Social workers -- Supervision of , Social workers -- Training of
- Description: The research is based on the need for formal training in social work supervision with the emphasis on the experiences and feelings associated with the role change from supervisee to supervisor. Practice has shown that the transition from supervisee to supervisor takes place with very little, if any, formal training. It is assumed that any experienced social worker could give supervision as if this is merely an extension of your field work activities – which include casework, group work and community work. Whilst doing supervision cognisance was taken of the fact that the task of the supervisor was to help the supervisee gain access to a more advantageous position from which to consider or view their work. A supervisor had a crucial role in professional development. The opinion is upheld that there has to be a working alliance to attain this development. This working alliance can be taken further when viewed by the fact that the supervisor also has to establish communication networks that enable the supervisor to work both at a managerial level while maintaining positive relationships with his or her supervisees – a process which is fraught with complications. Semi-structured interviews were conducted with fourteen social work supervisors and a focus group was conducted with five social work supervisors from the Department of Welfare and Private Welfare Organizations. These interviews were conducted to obtain their perspectives on the need for training in social work supervision and how training could help them in their supervision role which ultimately could result in a more efficient service that is rendered to the client. The data analysis was conducted at the same time as the data collection. The researcher had a clear plan for the data management. The researcher utilized reasoning strategies, identified themes, categories and subcategories. It was borne in mind that there was no one way of performing data analysis. The researcher was open and flexible. Final conclusions of the data analysis was grounded in the data obtained. The key issue in ensuring the trustworthiness was the verification of the results of the data analysis. The research study suggests that there is a genuine need for formal training in social work supervision. With training the supervisors can develop competencies, knowledge and professional attitudes, they can be helpful to neophytes and to each other. With training they can avoid some of the pitfalls in supervision and become more efficient and competent
- Full Text:
- Authors: Moss, Antoinette Rosemary
- Date: 2001
- Subjects: Social workers -- Supervision of , Social workers -- Training of
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:703 , http://hdl.handle.net/10962/d1006466 , Social workers -- Supervision of , Social workers -- Training of
- Description: The research is based on the need for formal training in social work supervision with the emphasis on the experiences and feelings associated with the role change from supervisee to supervisor. Practice has shown that the transition from supervisee to supervisor takes place with very little, if any, formal training. It is assumed that any experienced social worker could give supervision as if this is merely an extension of your field work activities – which include casework, group work and community work. Whilst doing supervision cognisance was taken of the fact that the task of the supervisor was to help the supervisee gain access to a more advantageous position from which to consider or view their work. A supervisor had a crucial role in professional development. The opinion is upheld that there has to be a working alliance to attain this development. This working alliance can be taken further when viewed by the fact that the supervisor also has to establish communication networks that enable the supervisor to work both at a managerial level while maintaining positive relationships with his or her supervisees – a process which is fraught with complications. Semi-structured interviews were conducted with fourteen social work supervisors and a focus group was conducted with five social work supervisors from the Department of Welfare and Private Welfare Organizations. These interviews were conducted to obtain their perspectives on the need for training in social work supervision and how training could help them in their supervision role which ultimately could result in a more efficient service that is rendered to the client. The data analysis was conducted at the same time as the data collection. The researcher had a clear plan for the data management. The researcher utilized reasoning strategies, identified themes, categories and subcategories. It was borne in mind that there was no one way of performing data analysis. The researcher was open and flexible. Final conclusions of the data analysis was grounded in the data obtained. The key issue in ensuring the trustworthiness was the verification of the results of the data analysis. The research study suggests that there is a genuine need for formal training in social work supervision. With training the supervisors can develop competencies, knowledge and professional attitudes, they can be helpful to neophytes and to each other. With training they can avoid some of the pitfalls in supervision and become more efficient and competent
- Full Text:
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:
- 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:
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:
- 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:
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.
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- 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.
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The relationship between subjective well-being and domain satisfactions in South Africa
- Authors: Moller, Valerie , Saris, W E
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:7116 , http://hdl.handle.net/10962/d1010749 , http://dx.doi.org/10.1023/A:1010851412273
- Description: This paper examines the relationship between subjective well-being and domain satisfactions. In the past different models have been specified. The most commonly applied model is the bottom-up model in which domain satisfactions affect subjective well-being. The more recent top-down model suggests a reversed relationship. Finally there is the supposition that the correlations between these variables can be spurious due to the effect of personality characteristics. Empirical research has shown that different models are found for different domains and in different countries. Focussing on the effects of the domain satisfactions of finances, housing and social contacts it has been found that subjective well-being is mainly affected by satisfaction with social contacts in Western developed countries and by satisfaction with finances in East European countries. The question we should like to answer in this study is whether a similar pattern obtains for the factors which influence subjective well-being among the different race groups in South Africa. Interestingly, coloured people and Asians did indeed show the expected effects but the groups with the most extreme living conditions did not. Evaluation of life circumstances by black and white South Africans was determined by expectations for the future rather than by current living conditions. This surprising result is discussed in the light of the political situation in South Africa.
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- Authors: Moller, Valerie , Saris, W E
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:7116 , http://hdl.handle.net/10962/d1010749 , http://dx.doi.org/10.1023/A:1010851412273
- Description: This paper examines the relationship between subjective well-being and domain satisfactions. In the past different models have been specified. The most commonly applied model is the bottom-up model in which domain satisfactions affect subjective well-being. The more recent top-down model suggests a reversed relationship. Finally there is the supposition that the correlations between these variables can be spurious due to the effect of personality characteristics. Empirical research has shown that different models are found for different domains and in different countries. Focussing on the effects of the domain satisfactions of finances, housing and social contacts it has been found that subjective well-being is mainly affected by satisfaction with social contacts in Western developed countries and by satisfaction with finances in East European countries. The question we should like to answer in this study is whether a similar pattern obtains for the factors which influence subjective well-being among the different race groups in South Africa. Interestingly, coloured people and Asians did indeed show the expected effects but the groups with the most extreme living conditions did not. Evaluation of life circumstances by black and white South Africans was determined by expectations for the future rather than by current living conditions. This surprising result is discussed in the light of the political situation in South Africa.
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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:
- 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
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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:
- 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).
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The role of land-based strategies in rural livelihoods: The contribution of arable production, animal husbandry and natural resource harvesting in communal areas in South Africa
- Shackleton, Charlie M, Shackleton, Sheona E, Cousins, Ben
- Authors: Shackleton, Charlie M , Shackleton, Sheona E , Cousins, Ben
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181651 , vital:43755 , xlink:href="https://doi.org/10.1080/03768350120097441"
- Description: Shackleton, C.M., Shackleton, S.E. and Cousins, B., 2001. The role of land-based strategies in rural livelihoods: the contribution of arable production, animal husbandry and natural resource harvesting in communal areas in South Africa. Development Southern Africa, 18(5), pp.581-604.
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- Authors: Shackleton, Charlie M , Shackleton, Sheona E , Cousins, Ben
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181651 , vital:43755 , xlink:href="https://doi.org/10.1080/03768350120097441"
- Description: Shackleton, C.M., Shackleton, S.E. and Cousins, B., 2001. The role of land-based strategies in rural livelihoods: the contribution of arable production, animal husbandry and natural resource harvesting in communal areas in South Africa. Development Southern Africa, 18(5), pp.581-604.
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