An investigation into the extent and nature of the understanding first year college of education students have of aspects of arithematic and elementary number theory
- Authors: Oliphant, Vincent George
- Date: 1996
- Subjects: Mathematics teachers -- Training of Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1606 , http://hdl.handle.net/10962/d1003488
- Description: First Year College of Education students who have done and/or passed mathematics at matric level, often lack adequate understanding of basic mathematical concepts and principles. This is due to the fact that formal tests and examinations often fail to assess understanding at anything but a basic level. It is against this background that this study uses alternative and more direct means of assessing the level and nature of the understanding such students have of aspects of basic arithmetic and number theory. More specifically, the goals of the study are: 1. To determine the students' levels of understanding of the following number concepts: Rational numbers; Irrational numbers Real numbers and Imaginary numbers. 2. To determine whether the students understand the rules governing operations with negative numbers and with zero as principles rather than conventions. 3. To determine whether the students understand the rule governing the order of operations as a matter of convention rather than as a matter of principle. A survey of the literature concerning the nature of understanding as well as the nature of assessment is given. The students' understanding in the above areas was assessed by means of a written test followid by interviews. A sample of 50 students participated in the study while a sub-sample of 6 were interviewed. Some of the significant findings of the study were : 1. The students largely failed to draw clear distinctions between Real and Rational numbers as well as between Irrational and Imaginary numbers. 2. Very few of the students could explain the rationale behind the rules governing the. operations with negative numbers and zero. 3. Only half of the students had any knowledge of the rule governing the order of operations. Only one student demonstrated an understanding of the rule as a convention.
- Full Text:
- Date Issued: 1996
- Authors: Oliphant, Vincent George
- Date: 1996
- Subjects: Mathematics teachers -- Training of Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1606 , http://hdl.handle.net/10962/d1003488
- Description: First Year College of Education students who have done and/or passed mathematics at matric level, often lack adequate understanding of basic mathematical concepts and principles. This is due to the fact that formal tests and examinations often fail to assess understanding at anything but a basic level. It is against this background that this study uses alternative and more direct means of assessing the level and nature of the understanding such students have of aspects of basic arithmetic and number theory. More specifically, the goals of the study are: 1. To determine the students' levels of understanding of the following number concepts: Rational numbers; Irrational numbers Real numbers and Imaginary numbers. 2. To determine whether the students understand the rules governing operations with negative numbers and with zero as principles rather than conventions. 3. To determine whether the students understand the rule governing the order of operations as a matter of convention rather than as a matter of principle. A survey of the literature concerning the nature of understanding as well as the nature of assessment is given. The students' understanding in the above areas was assessed by means of a written test followid by interviews. A sample of 50 students participated in the study while a sub-sample of 6 were interviewed. Some of the significant findings of the study were : 1. The students largely failed to draw clear distinctions between Real and Rational numbers as well as between Irrational and Imaginary numbers. 2. Very few of the students could explain the rationale behind the rules governing the. operations with negative numbers and zero. 3. Only half of the students had any knowledge of the rule governing the order of operations. Only one student demonstrated an understanding of the rule as a convention.
- Full Text:
- Date Issued: 1996
An investigation into the relationship between adolescent parasuicide, depressive illness and associated risk factors
- Authors: Read, Gary Frank Hoyland
- Date: 1996
- Subjects: Youth -- Suicidal behavior , Depression in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3116 , http://hdl.handle.net/10962/d1004615 , Youth -- Suicidal behavior , Depression in adolescence
- Description: This study aimed at investigating the relationship between adolescent parasuicide, depressive illness and associated risk factors. Reports worldwide indicate that suicidal behaviour in this age group has risen 150% over the past 20 years, whilst the rate for suicide in adults and the elderly has remained the same (Deykin et al, 1985; Neiger & Hopkins, 1988; Sudak, Ford & Rushforth, 1984a). In South Africa statistics confirm similar trends with regard to attempted and completed suicide. Statistics reveal that a high local incidence of adolescent suicide attempters are seen at psychiatric units. One pilot study recorded 187 adolescent suicide attempters during a three month period. This study was based on the hypothesis that the incidence of depressive illness in adolescent suicide attempters is higher than is generally accepted and that this condition often goes unrecognised and is misdiagnosed because it manifests differently with acting out behaviour and "masked" symptomatology. A random sample of suicide attempters between the ages of 13 - 25 who presented at C23 (psychiatric emergencies) Groote Schuur Hospital following a suicide attempt were assessed. 100 subjects were seen over a period of three months. The research procedure comprised a comprehensive assessment incorporating a semi-structured interview, self-report and objective rating scales for depression as well as instruments designed to assess the general health of each subject and their level of suicide intent. The depressive inventories used have been validated for use in this age group and were designed to elicit the associated features of adolescent depression. If warranted, a clinical diagnoses was given based on DSM 1V criteria. This diagnosis was substantiated by information from the research instruments which formed part of the assessment process. A high incidence of clinical disorders was diagnosed in the sample (86%). Depressive illness was found to be a significant risk factor for suicidal behaviour with 68% of the subjects suffering from an affective disorder and 21% reporting depressive symptoms. This study shows that the correlation between parasuicide and depressive illness is high enough to suggest that all suicidal behaviour in this age group should be taken seriously as parasuicide in itself is often a reliable indicator of an underlying depressive condition. Additional risk factors for adolescent parasuicide identified in this study correlated well with the findings of similar research studies. Psychiatric co-morbidity, especially substance use (42%) and cluster B personality factors (54%), were high and served to increase an individual's vulnerability to suicide risk. Psychosocial factors such as sexual abuse (28%) and physical abuse (37%) were also identified as high risk factors for adolescent suicidal behaviour. Individuals at risk for depression and suicidal behaviour typically came from broken homes which were disrupted and unsupportive. Family members were frequently abusing alcohol and 67% of the subjects reported the presence of psychiatric illness in the family. The preferred method of suicide attempt was an overdose (90%). These attempts were generally unplanned and impulsive with no disclosure prior to the event. Intent was usually high at the time of the act. It is only through identifying the risk factors specific to the developmental concerns of this age group and acknowledging the role of depressive illness in adolescent suicidal behaviour that effective preventative measures can be devised.
- Full Text:
- Date Issued: 1996
- Authors: Read, Gary Frank Hoyland
- Date: 1996
- Subjects: Youth -- Suicidal behavior , Depression in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3116 , http://hdl.handle.net/10962/d1004615 , Youth -- Suicidal behavior , Depression in adolescence
- Description: This study aimed at investigating the relationship between adolescent parasuicide, depressive illness and associated risk factors. Reports worldwide indicate that suicidal behaviour in this age group has risen 150% over the past 20 years, whilst the rate for suicide in adults and the elderly has remained the same (Deykin et al, 1985; Neiger & Hopkins, 1988; Sudak, Ford & Rushforth, 1984a). In South Africa statistics confirm similar trends with regard to attempted and completed suicide. Statistics reveal that a high local incidence of adolescent suicide attempters are seen at psychiatric units. One pilot study recorded 187 adolescent suicide attempters during a three month period. This study was based on the hypothesis that the incidence of depressive illness in adolescent suicide attempters is higher than is generally accepted and that this condition often goes unrecognised and is misdiagnosed because it manifests differently with acting out behaviour and "masked" symptomatology. A random sample of suicide attempters between the ages of 13 - 25 who presented at C23 (psychiatric emergencies) Groote Schuur Hospital following a suicide attempt were assessed. 100 subjects were seen over a period of three months. The research procedure comprised a comprehensive assessment incorporating a semi-structured interview, self-report and objective rating scales for depression as well as instruments designed to assess the general health of each subject and their level of suicide intent. The depressive inventories used have been validated for use in this age group and were designed to elicit the associated features of adolescent depression. If warranted, a clinical diagnoses was given based on DSM 1V criteria. This diagnosis was substantiated by information from the research instruments which formed part of the assessment process. A high incidence of clinical disorders was diagnosed in the sample (86%). Depressive illness was found to be a significant risk factor for suicidal behaviour with 68% of the subjects suffering from an affective disorder and 21% reporting depressive symptoms. This study shows that the correlation between parasuicide and depressive illness is high enough to suggest that all suicidal behaviour in this age group should be taken seriously as parasuicide in itself is often a reliable indicator of an underlying depressive condition. Additional risk factors for adolescent parasuicide identified in this study correlated well with the findings of similar research studies. Psychiatric co-morbidity, especially substance use (42%) and cluster B personality factors (54%), were high and served to increase an individual's vulnerability to suicide risk. Psychosocial factors such as sexual abuse (28%) and physical abuse (37%) were also identified as high risk factors for adolescent suicidal behaviour. Individuals at risk for depression and suicidal behaviour typically came from broken homes which were disrupted and unsupportive. Family members were frequently abusing alcohol and 67% of the subjects reported the presence of psychiatric illness in the family. The preferred method of suicide attempt was an overdose (90%). These attempts were generally unplanned and impulsive with no disclosure prior to the event. Intent was usually high at the time of the act. It is only through identifying the risk factors specific to the developmental concerns of this age group and acknowledging the role of depressive illness in adolescent suicidal behaviour that effective preventative measures can be devised.
- Full Text:
- Date Issued: 1996
An investigation into the use of a nature reserve as a cross-curricular teaching resource
- Authors: Luckhoff, Augusta Henrietta
- Date: 1996
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1616 , http://hdl.handle.net/10962/d1003498
- Description: This study documents the development of the Queenstown nature reserve as a cross-curricular tea~hing resource. Participants in the project included the researcher, the municipality nature conservation officer and the senior Geography and Biology teachers from five high schools in the town. A modified action research approach was adopted. Data was collected from workshops and interviews and then analyzed. The conclusion of the research was that the participants perceived that the project had been worthwhile and was to be continued. The nature reserve is now more widely and usefully used
- Full Text:
- Date Issued: 1996
- Authors: Luckhoff, Augusta Henrietta
- Date: 1996
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1616 , http://hdl.handle.net/10962/d1003498
- Description: This study documents the development of the Queenstown nature reserve as a cross-curricular tea~hing resource. Participants in the project included the researcher, the municipality nature conservation officer and the senior Geography and Biology teachers from five high schools in the town. A modified action research approach was adopted. Data was collected from workshops and interviews and then analyzed. The conclusion of the research was that the participants perceived that the project had been worthwhile and was to be continued. The nature reserve is now more widely and usefully used
- Full Text:
- Date Issued: 1996
Anaesthesia in abalone, Haliotis midae
- Authors: White, Hermien Ilse
- Date: 1996
- Subjects: Abalones , Animal anesthesia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5216 , http://hdl.handle.net/10962/d1005059 , Abalones , Animal anesthesia
- Description: The principle aim of this study was to isolate a chemical for the "safe anaesthesia" of abalone under commercial farming conditions. "Safe anaesthesia" implied that the anaesthetic had no immediate detrimental or long term sublethal effect on the abalone, that it was safe for the farmer, the consumer and the environment. Four chemicals, magnesium sulphate (MgS0₄), ethylenediamine tetra-acetic acid (EDTA), 2-phenoxyethanol and procaine hydrochloride were shown to effectively inhibit the in vitro contraction of isolated tarsal muscle of Haliotis midae. This identified them as potential anaesthetics for abalone. Since abalone, like any other aquaculture species, would be subject to frequent size-sorting during the grow-out period, size related dosage tables were developed for the four chemicals at a temperature of 18⁰C. Dosage tables were also developed for benzocaine and carbon dioxide (C0₂), Three size classes (5-15, 20-50 and 60-90 mm shell length (SL)) of abalone were considered. Only three of the six chemicals, viz. MgS0₄, 2-phenoxyethanol and CO₂, met the criteria of an effective abalone anaesthetic in that they effected rapid and mortality-free anaesthesia. The other three chemicals caused mortalities and were considered to be unsuitable for commercial scale anaesthesia. Temperature related dosage tables were then developed for MgS0₄ and CO₂, MgS0₄ concentrations and CO₂ flow rates for effective anaesthesia in abalone were found to be inversely related to temperature. The three size classes of H. midae were intermittently exposed to MgS0₄ and 2-phenoxyethanol anaesthesia for an eight month period to determine the effect of the anaesthetics on growth rate. Because of an increased resistance to the efficacy of 2-phenoxyethanol and high monthly mortalities it was concluded that this chemical was unsafe and unsuitable for commercial use. MgS0₄, on the other hand, had no effect on growth of abalone and no significant effect on the rate of mortality. MgS0₄ also had no measurable effect on H. midae muscle ultrastructure and, by implication had no effect on flesh texture. The use of MgS0₄ as an anaesthetic would, therefore, not affect marketability. Moreover, no magnesium residues were found in H. midae muscle tissue after short term or intermittent long term exposure to MgS0₄ anaesthesia. It was found that the three size classes of H. midae used in this study could be safely exposed to the recommended MgS0₄ concentrations for up to 40 minutes without any mortalities. This is more than adequate for routine farming procedures. Medium size abalone (20-50 mm SL) were also safely exposed to 14 g.100 ml⁻¹ MgS0₄ for up to 6 hours without any mortalities. The results have shown that MgS0₄ was undoubtedly the best chemical that was evaluated for anaesthesia of H. midae in this study. It fulfils the requirements set forth by the U.S.A. Food and Drug Administration (FDA) in that it is safe for the abalone, the farmer, the consumer and the environment.
- Full Text:
- Date Issued: 1996
- Authors: White, Hermien Ilse
- Date: 1996
- Subjects: Abalones , Animal anesthesia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5216 , http://hdl.handle.net/10962/d1005059 , Abalones , Animal anesthesia
- Description: The principle aim of this study was to isolate a chemical for the "safe anaesthesia" of abalone under commercial farming conditions. "Safe anaesthesia" implied that the anaesthetic had no immediate detrimental or long term sublethal effect on the abalone, that it was safe for the farmer, the consumer and the environment. Four chemicals, magnesium sulphate (MgS0₄), ethylenediamine tetra-acetic acid (EDTA), 2-phenoxyethanol and procaine hydrochloride were shown to effectively inhibit the in vitro contraction of isolated tarsal muscle of Haliotis midae. This identified them as potential anaesthetics for abalone. Since abalone, like any other aquaculture species, would be subject to frequent size-sorting during the grow-out period, size related dosage tables were developed for the four chemicals at a temperature of 18⁰C. Dosage tables were also developed for benzocaine and carbon dioxide (C0₂), Three size classes (5-15, 20-50 and 60-90 mm shell length (SL)) of abalone were considered. Only three of the six chemicals, viz. MgS0₄, 2-phenoxyethanol and CO₂, met the criteria of an effective abalone anaesthetic in that they effected rapid and mortality-free anaesthesia. The other three chemicals caused mortalities and were considered to be unsuitable for commercial scale anaesthesia. Temperature related dosage tables were then developed for MgS0₄ and CO₂, MgS0₄ concentrations and CO₂ flow rates for effective anaesthesia in abalone were found to be inversely related to temperature. The three size classes of H. midae were intermittently exposed to MgS0₄ and 2-phenoxyethanol anaesthesia for an eight month period to determine the effect of the anaesthetics on growth rate. Because of an increased resistance to the efficacy of 2-phenoxyethanol and high monthly mortalities it was concluded that this chemical was unsafe and unsuitable for commercial use. MgS0₄, on the other hand, had no effect on growth of abalone and no significant effect on the rate of mortality. MgS0₄ also had no measurable effect on H. midae muscle ultrastructure and, by implication had no effect on flesh texture. The use of MgS0₄ as an anaesthetic would, therefore, not affect marketability. Moreover, no magnesium residues were found in H. midae muscle tissue after short term or intermittent long term exposure to MgS0₄ anaesthesia. It was found that the three size classes of H. midae used in this study could be safely exposed to the recommended MgS0₄ concentrations for up to 40 minutes without any mortalities. This is more than adequate for routine farming procedures. Medium size abalone (20-50 mm SL) were also safely exposed to 14 g.100 ml⁻¹ MgS0₄ for up to 6 hours without any mortalities. The results have shown that MgS0₄ was undoubtedly the best chemical that was evaluated for anaesthesia of H. midae in this study. It fulfils the requirements set forth by the U.S.A. Food and Drug Administration (FDA) in that it is safe for the abalone, the farmer, the consumer and the environment.
- Full Text:
- Date Issued: 1996
Architecture and landscape design : an investigation into the harmonising of these two aspects of design as exemplified by the collaboration of Gertrude Jekyll and Sir Edwin Landseer Lutyens
- Authors: Judge, Stephen Michael
- Date: 1996
- Subjects: Lutyens, Edwin Landseer, Sir, 1869-1944 Jekyll, Gertrude, 1843-1932 Gardens -- Design Architecture, British
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2405 , http://hdl.handle.net/10962/d1002201
- Description: Sir Edwin Lutyens and Miss Gertrude Jekyll were part of the 'Art's and Crafts' movement, which advocated the use of local techniques and materials. They grew up separately, both in the Surrey country-side and both among creative people. Jekyll later worked with Edward Hudson (the author of 'Country Life') who persuaded her to be a garden designer . Lutyens was inspired first by the architecture of Surrey (mostly that of Norman Shaw), then by his friend, Herbert Baker, at architectural school, and lastly, by his long - time partner Jekyll. Munstead Wood, Surrey, England, was the partners' first project and it embodies nearly all of their ideals; the natural and indigenous use of flowers and plants, with an ordered colour scheme ; graded colour schemes without discord; the use of entirely local materials ; the sole use of local craftsmen and local techniques; a garden of 'rooms'; the intergration of architecture and garden design. A revival of interest in the partners work has helped to recreate some of the lost gardens of Jekyll. This interest has in turn put a spotlight on the ideals employed by the partners. Their wide influence has also produced many great buildings and gardens, most notably through the work of Sir Herbert Baker in South Africa. The Union Buildings are a perfect example of Baker's work, and much of it has the stamp of Lutyens' style and ideals. Through my own interest in Lutyens and Jekyll I have created my own Jekyll-style border in Grahamstown, Eastern Cape, to try and prove that her ideals can be translated into climates other than that of England. In this experiment, I succeeded in using indigenous South African plants and flowers with a colour scheme in the style of Jekyll, proving that the ideals to which she aspired could be applied in other countries.
- Full Text:
- Date Issued: 1996
- Authors: Judge, Stephen Michael
- Date: 1996
- Subjects: Lutyens, Edwin Landseer, Sir, 1869-1944 Jekyll, Gertrude, 1843-1932 Gardens -- Design Architecture, British
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2405 , http://hdl.handle.net/10962/d1002201
- Description: Sir Edwin Lutyens and Miss Gertrude Jekyll were part of the 'Art's and Crafts' movement, which advocated the use of local techniques and materials. They grew up separately, both in the Surrey country-side and both among creative people. Jekyll later worked with Edward Hudson (the author of 'Country Life') who persuaded her to be a garden designer . Lutyens was inspired first by the architecture of Surrey (mostly that of Norman Shaw), then by his friend, Herbert Baker, at architectural school, and lastly, by his long - time partner Jekyll. Munstead Wood, Surrey, England, was the partners' first project and it embodies nearly all of their ideals; the natural and indigenous use of flowers and plants, with an ordered colour scheme ; graded colour schemes without discord; the use of entirely local materials ; the sole use of local craftsmen and local techniques; a garden of 'rooms'; the intergration of architecture and garden design. A revival of interest in the partners work has helped to recreate some of the lost gardens of Jekyll. This interest has in turn put a spotlight on the ideals employed by the partners. Their wide influence has also produced many great buildings and gardens, most notably through the work of Sir Herbert Baker in South Africa. The Union Buildings are a perfect example of Baker's work, and much of it has the stamp of Lutyens' style and ideals. Through my own interest in Lutyens and Jekyll I have created my own Jekyll-style border in Grahamstown, Eastern Cape, to try and prove that her ideals can be translated into climates other than that of England. In this experiment, I succeeded in using indigenous South African plants and flowers with a colour scheme in the style of Jekyll, proving that the ideals to which she aspired could be applied in other countries.
- Full Text:
- Date Issued: 1996
Asleep in a glass coffin: fairy tales as illuminating attitudes to women in the novels of Charles Dickens
- Authors: Daly, Robyn Anne
- Date: 1996
- Subjects: Dickens, Charles, 1812-1870 -- Criticism and interpretation Dickens, Charles, 1812-1870 -- Folklore Dickens, Charles, 1812-1870 -- Characters Women Dickens, Charles, 1812-1870 -- Symbolism Fairy tales -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2227 , http://hdl.handle.net/10962/d1002270
- Description: The field of research of this thesis covers three main areas: the novels of Charles Dickens; fairy tales and storytelling; and notions of women as reflected in feminist literary theory. A reading of selected novels by Dickens provides the primary source. That he copiously drew on fairy tales has been explored in such notable works as Harry Stone's, but the thesis concentrates on Dickens 's propensity in his creation of female protagonists to give them a voice which is vivified through fairy tale. The analysis of fairy story through narrative theory and feminist literary theory functions as the basis of an exploration of the role female narrative voices play in a reading of the novels which reveals a more sympathetic vision of the feminine than has been observed hitherto. The context of this study is Victorian attitudes to women and that modem criticism has not sufficiently acknowledged Dickens's insight into of the condition of women; much of this is discovered through an examination of his use of fairy tale wherein the woman is bearer of imaginative and emotional capacities magically bestowed. The research aims to counter the view of Dickens's novels as being sexist, through the iIluminatory characteristics of fairy tale. Dickens activates his women characters by means of their often being tellers of tales replete with fairy tale imagery, and their tales are almost always seminal to the novelist's moral purpose.
- Full Text:
- Date Issued: 1996
- Authors: Daly, Robyn Anne
- Date: 1996
- Subjects: Dickens, Charles, 1812-1870 -- Criticism and interpretation Dickens, Charles, 1812-1870 -- Folklore Dickens, Charles, 1812-1870 -- Characters Women Dickens, Charles, 1812-1870 -- Symbolism Fairy tales -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2227 , http://hdl.handle.net/10962/d1002270
- Description: The field of research of this thesis covers three main areas: the novels of Charles Dickens; fairy tales and storytelling; and notions of women as reflected in feminist literary theory. A reading of selected novels by Dickens provides the primary source. That he copiously drew on fairy tales has been explored in such notable works as Harry Stone's, but the thesis concentrates on Dickens 's propensity in his creation of female protagonists to give them a voice which is vivified through fairy tale. The analysis of fairy story through narrative theory and feminist literary theory functions as the basis of an exploration of the role female narrative voices play in a reading of the novels which reveals a more sympathetic vision of the feminine than has been observed hitherto. The context of this study is Victorian attitudes to women and that modem criticism has not sufficiently acknowledged Dickens's insight into of the condition of women; much of this is discovered through an examination of his use of fairy tale wherein the woman is bearer of imaginative and emotional capacities magically bestowed. The research aims to counter the view of Dickens's novels as being sexist, through the iIluminatory characteristics of fairy tale. Dickens activates his women characters by means of their often being tellers of tales replete with fairy tale imagery, and their tales are almost always seminal to the novelist's moral purpose.
- Full Text:
- Date Issued: 1996
Aspects of nutrition of the swordtail fish, Xiphophorus Helleri, (Family : Poeciliidae) under intensive culture conditions
- Authors: Kruger, David Philip
- Date: 1996
- Subjects: Xiphophorus helleri -- Nutrition , Fish culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5219 , http://hdl.handle.net/10962/d1005062 , Xiphophorus helleri -- Nutrition , Fish culture
- Description: The aim of this work was to investigate the nutrition of a popular ornamental fish, the swordtail (Xiphophorus helleri), under intensive aquaculture conditions. The study focused on the formulation and manufacture of artificial dry diets, as well as the influence of livefeed supplementation on growth and nutritional indices of both juvenile and broodstock fish. A combination of 65% fishmeal and 35% soya oil cake meal was found to closely approximate the essential amino acid profile of X helleri (r² = 94,3%) and lysine was identified as the first limiting amino acid. The influence of dietary protein and energy on the growth of X helleri was investigated by means of a growth trial comparing a range of nine test diets combining 3 crude protein (45,38 and 30%) and 3 digestible energy (16,5, 14,5 and 12,5 kJ/gram) levels. A high crude protein content (45% dry matter) and a protein to energy ratio of ≥ 27 mg protein per kJ digestible energy was shown to promote optimal growth rate and feed conversion ratio in juvenile X helleri. The final body protein and lipid content of the fish were significantly correlated with the dietary protein to energy ratio. The nutritional value of identical dietary formulations prepared by drum-drying or cold extrusion techniques and presented either as flake or crumble particles was evaluated in a growth trial and through analysis of vitamin C levels in the diets. Up to 27% of vitamin C activity was destroyed during the drum-drying of flake diets, while 80% of the remaining vitamin C was lost through leaching within 10 minutes of immersion in water. A crumble-type diet was shown to be acceptable to X helleri, and yielded significantly better growth rate and feed conversion than the equivalent flake feed. Almost 19% of fish fed the flake diets developed vitamin C deficiency symptoms including scoliosis and lordosis, while this was completely prevented by feeding crumbles, indicating a significant restriction of leaching losses from this type of particle. The use of livefeed (Daphnia spp.) as a daily supplement to dry feeds was shown to result in a significant improvement in growth rate and survival of juvenile swordtail fish. Furthermore, the synergistic action of nutrients contained in the livefeed resulted in an improvement in the feed conversion efficiency of the artificial formulation. While mortalities of 13,4% and 15% were recorded in fish fed exclusively on flake feed or Daphnia, no mortality occurred in the group fed the supplemented diet. Furthermore, the incidence of vitamin C deficiency symptoms was prevented by daily supplementation with Daphnia. Fish fed exclusively on Daphnia exhibited significantly more intense pigmentation due to carotenoids contained in the livefeed. In broodstock fish maintained primarily on flake diets, growth rate, feed conversion ratio as well as reproductive performance, as measured by fecundity, were significantly improved by daily livefeed supplementation. Weekly supplementation showed no measurable advantage over flake feed only. A direct correlation was demonstrated between fecundity and size of female fish with a mean fecundity of 190 embryos per female in those fed a daily Daphnia supplement. This was significantly higher than the yield from the non-supplemented or weekly supplemented treatments (133 and 140 embryos per female respectively). Despite these differences, the number of young harvested during the experiment did not differ between treatments and this discrepancy was ascribed to parental cannibalism of newborn juveniles. This phenomenon constitutes a major potential bottleneck in production with estimates of up to seventy percent of young lost in some exp experimental tanks. In conclusion, the present study demonstrated that established aquaculture nutrition principles and techniques are applicable to the tropical ornamental fish species, X helleri. It was demonstrated that by using balanced crumble feed formulations, and regular livefeed supplementation, production yields under intensive conditions may be significantly improved. Suggestions for future work on poeciliid production in South Africa include investigation of the economic implications of the recommendations stemming from this project, and further research into effective restriction of parental cannibalism of newborn fish.
- Full Text:
- Date Issued: 1996
- Authors: Kruger, David Philip
- Date: 1996
- Subjects: Xiphophorus helleri -- Nutrition , Fish culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5219 , http://hdl.handle.net/10962/d1005062 , Xiphophorus helleri -- Nutrition , Fish culture
- Description: The aim of this work was to investigate the nutrition of a popular ornamental fish, the swordtail (Xiphophorus helleri), under intensive aquaculture conditions. The study focused on the formulation and manufacture of artificial dry diets, as well as the influence of livefeed supplementation on growth and nutritional indices of both juvenile and broodstock fish. A combination of 65% fishmeal and 35% soya oil cake meal was found to closely approximate the essential amino acid profile of X helleri (r² = 94,3%) and lysine was identified as the first limiting amino acid. The influence of dietary protein and energy on the growth of X helleri was investigated by means of a growth trial comparing a range of nine test diets combining 3 crude protein (45,38 and 30%) and 3 digestible energy (16,5, 14,5 and 12,5 kJ/gram) levels. A high crude protein content (45% dry matter) and a protein to energy ratio of ≥ 27 mg protein per kJ digestible energy was shown to promote optimal growth rate and feed conversion ratio in juvenile X helleri. The final body protein and lipid content of the fish were significantly correlated with the dietary protein to energy ratio. The nutritional value of identical dietary formulations prepared by drum-drying or cold extrusion techniques and presented either as flake or crumble particles was evaluated in a growth trial and through analysis of vitamin C levels in the diets. Up to 27% of vitamin C activity was destroyed during the drum-drying of flake diets, while 80% of the remaining vitamin C was lost through leaching within 10 minutes of immersion in water. A crumble-type diet was shown to be acceptable to X helleri, and yielded significantly better growth rate and feed conversion than the equivalent flake feed. Almost 19% of fish fed the flake diets developed vitamin C deficiency symptoms including scoliosis and lordosis, while this was completely prevented by feeding crumbles, indicating a significant restriction of leaching losses from this type of particle. The use of livefeed (Daphnia spp.) as a daily supplement to dry feeds was shown to result in a significant improvement in growth rate and survival of juvenile swordtail fish. Furthermore, the synergistic action of nutrients contained in the livefeed resulted in an improvement in the feed conversion efficiency of the artificial formulation. While mortalities of 13,4% and 15% were recorded in fish fed exclusively on flake feed or Daphnia, no mortality occurred in the group fed the supplemented diet. Furthermore, the incidence of vitamin C deficiency symptoms was prevented by daily supplementation with Daphnia. Fish fed exclusively on Daphnia exhibited significantly more intense pigmentation due to carotenoids contained in the livefeed. In broodstock fish maintained primarily on flake diets, growth rate, feed conversion ratio as well as reproductive performance, as measured by fecundity, were significantly improved by daily livefeed supplementation. Weekly supplementation showed no measurable advantage over flake feed only. A direct correlation was demonstrated between fecundity and size of female fish with a mean fecundity of 190 embryos per female in those fed a daily Daphnia supplement. This was significantly higher than the yield from the non-supplemented or weekly supplemented treatments (133 and 140 embryos per female respectively). Despite these differences, the number of young harvested during the experiment did not differ between treatments and this discrepancy was ascribed to parental cannibalism of newborn juveniles. This phenomenon constitutes a major potential bottleneck in production with estimates of up to seventy percent of young lost in some exp experimental tanks. In conclusion, the present study demonstrated that established aquaculture nutrition principles and techniques are applicable to the tropical ornamental fish species, X helleri. It was demonstrated that by using balanced crumble feed formulations, and regular livefeed supplementation, production yields under intensive conditions may be significantly improved. Suggestions for future work on poeciliid production in South Africa include investigation of the economic implications of the recommendations stemming from this project, and further research into effective restriction of parental cannibalism of newborn fish.
- Full Text:
- Date Issued: 1996
Aspects of the physiology of the South African abalone, Haliotis Midae L., and implications for intensive abalone culture
- Authors: Lyon, Robert Gary
- Date: 1996
- Subjects: Abalones -- Physiology , Abalone culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5226 , http://hdl.handle.net/10962/d1005069 , Abalones -- Physiology , Abalone culture
- Description: A physiological study was carried out to determine the effects of temperature, quantity of food fed, feeding activity and size class on the oxygen consumption and ammonia production of the South African abalone Haliotis midae L.. A set of intermittent flow respirometer chambers were used in a recirculating system to measure the oxygen consumption rates of fed (postprandial) and unfed (postabsorptive) abalone for three different size classes (15, 30, and 50mm) at three different temperatures (16°, 20° and 23°C) over a 24 hour period. Ammonia production rates and food consumption rates were simultaneously determined. Oxygen consumption and Ammonia production rates per gram abalone were linear functions of abalone size, temperature, and mass of food consumed. Oxygen consumption and ammonia production rates were found to increase proportionally to temperature and in inverse proportion to abalone size. These rates were significantly higher for fed as opposed to unfed abalone. Equations were derived to predict oxygen consumption and ammonia production for fed and unfed animals for a range of temperatures and size classes of abalone. A 96h LC50 lethal toxicity test for exposure to ammonia established 1.08mg.1⁻¹ of unionised ammonia as the lethal limit. A test on the long term effects on growth of acute exposure (12h) to various sublethal concentrations of ammonia showed no significant effects on growth for concentrations below 0.88 mg.1⁻¹. A safe chronic exposure level of 0.02 mg.1¹ NH₃-N was used to predict optimal flow rates required per kilogram of abalone in a rearing tank over a range of size classes and temperatures. The physiological and biological requirements of H. midae and the implications of this knowledge for rearing tank management and optimal design are discussed.
- Full Text:
- Date Issued: 1996
- Authors: Lyon, Robert Gary
- Date: 1996
- Subjects: Abalones -- Physiology , Abalone culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5226 , http://hdl.handle.net/10962/d1005069 , Abalones -- Physiology , Abalone culture
- Description: A physiological study was carried out to determine the effects of temperature, quantity of food fed, feeding activity and size class on the oxygen consumption and ammonia production of the South African abalone Haliotis midae L.. A set of intermittent flow respirometer chambers were used in a recirculating system to measure the oxygen consumption rates of fed (postprandial) and unfed (postabsorptive) abalone for three different size classes (15, 30, and 50mm) at three different temperatures (16°, 20° and 23°C) over a 24 hour period. Ammonia production rates and food consumption rates were simultaneously determined. Oxygen consumption and Ammonia production rates per gram abalone were linear functions of abalone size, temperature, and mass of food consumed. Oxygen consumption and ammonia production rates were found to increase proportionally to temperature and in inverse proportion to abalone size. These rates were significantly higher for fed as opposed to unfed abalone. Equations were derived to predict oxygen consumption and ammonia production for fed and unfed animals for a range of temperatures and size classes of abalone. A 96h LC50 lethal toxicity test for exposure to ammonia established 1.08mg.1⁻¹ of unionised ammonia as the lethal limit. A test on the long term effects on growth of acute exposure (12h) to various sublethal concentrations of ammonia showed no significant effects on growth for concentrations below 0.88 mg.1⁻¹. A safe chronic exposure level of 0.02 mg.1¹ NH₃-N was used to predict optimal flow rates required per kilogram of abalone in a rearing tank over a range of size classes and temperatures. The physiological and biological requirements of H. midae and the implications of this knowledge for rearing tank management and optimal design are discussed.
- Full Text:
- Date Issued: 1996
Basin analysis and sequence stratigraphy a review, with a short account of its applicability and utility for the exploration of auriferous placers in the Witwatersrand Basin
- Authors: Van Eeden, Johan
- Date: 1996
- Subjects: Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4934 , http://hdl.handle.net/10962/d1005546 , Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
- Description: The Witwatersrand basin is unique in terms of its mineral wealth. The gold in the Witwatersrand basin is mainly concentrated in the placers and two types of unconformities are associated with the placer formation. This paper attempts to quantitatively describe the origin and depositional process of placers within the context of basin analysis, geohistory and sequences stratigraphic framework. Several tectonic models have been proposed for the evolution of the Witwater~rand basin and it seems as if a cratonic foreland basin accounts for many of the observed features observed the Central Rand Group basin. The tectonic subsidence curve generated for the Witwatersrand Basin clearly implies foreland basin response which was superimposed an older, deep seated extensional basin. These compressive tectonics can be superimposed on extensional basins, where the shift from extensional to compressional tectonics lead to inversion processes. The critical issues about the Witwatersrand basin which were addresed in this review, is the validity of basin wide correlation of placer unconformuties and whether sequence stratigraphy is applicable to fluvial systems of the Witwatersrand sequence. It is believed that the Central Rand Group was deposited as alluvial - fan deltas by fluvially dominated, braidplain systems with minor marine interaction which had a considerable impact on the preservation of economically viable placers. Most important to the exploration geologist is the recognition of stacking patterns of the fluvial strata to determine change in the rate at which accommodation was created. Identifying sequence boundaries and other relevant surfaces important for identifying these stacking patterns of the sequences, depends entirely on the recognition of a hierarchy of stratal units including beds, bedsets, parasequences, parasequence sets and the surfaces bounding sequences. Placers are closely associated with the development of disconformities and therefore become important to recognise in fluvial strata. If these placers are to become economic, the duration of subaerial exposure of the unconformities that allowed the placers to become reworked and concentrated must be determined. In order to preserve the placer, a sudden marine transgression is necessary to allow for minimal shoreline reworking and to cap the placer to prevent it from being dispersed. The placers in the Witwatersrand basin occur in four major gold-bearing placer zones in the Central Rand Group. Accordingly they can be assigned to four supercycles, which are cyclical and therefore predictive. It is the predictive nature of these rocks and the ability of sequence stratigraphy to enhance this aspect, which is a pre-requisite for an effective exploration tool in the search for new ore bodies or their extension in the Witwatersrand basin.
- Full Text:
- Date Issued: 1996
- Authors: Van Eeden, Johan
- Date: 1996
- Subjects: Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4934 , http://hdl.handle.net/10962/d1005546 , Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
- Description: The Witwatersrand basin is unique in terms of its mineral wealth. The gold in the Witwatersrand basin is mainly concentrated in the placers and two types of unconformities are associated with the placer formation. This paper attempts to quantitatively describe the origin and depositional process of placers within the context of basin analysis, geohistory and sequences stratigraphic framework. Several tectonic models have been proposed for the evolution of the Witwater~rand basin and it seems as if a cratonic foreland basin accounts for many of the observed features observed the Central Rand Group basin. The tectonic subsidence curve generated for the Witwatersrand Basin clearly implies foreland basin response which was superimposed an older, deep seated extensional basin. These compressive tectonics can be superimposed on extensional basins, where the shift from extensional to compressional tectonics lead to inversion processes. The critical issues about the Witwatersrand basin which were addresed in this review, is the validity of basin wide correlation of placer unconformuties and whether sequence stratigraphy is applicable to fluvial systems of the Witwatersrand sequence. It is believed that the Central Rand Group was deposited as alluvial - fan deltas by fluvially dominated, braidplain systems with minor marine interaction which had a considerable impact on the preservation of economically viable placers. Most important to the exploration geologist is the recognition of stacking patterns of the fluvial strata to determine change in the rate at which accommodation was created. Identifying sequence boundaries and other relevant surfaces important for identifying these stacking patterns of the sequences, depends entirely on the recognition of a hierarchy of stratal units including beds, bedsets, parasequences, parasequence sets and the surfaces bounding sequences. Placers are closely associated with the development of disconformities and therefore become important to recognise in fluvial strata. If these placers are to become economic, the duration of subaerial exposure of the unconformities that allowed the placers to become reworked and concentrated must be determined. In order to preserve the placer, a sudden marine transgression is necessary to allow for minimal shoreline reworking and to cap the placer to prevent it from being dispersed. The placers in the Witwatersrand basin occur in four major gold-bearing placer zones in the Central Rand Group. Accordingly they can be assigned to four supercycles, which are cyclical and therefore predictive. It is the predictive nature of these rocks and the ability of sequence stratigraphy to enhance this aspect, which is a pre-requisite for an effective exploration tool in the search for new ore bodies or their extension in the Witwatersrand basin.
- Full Text:
- Date Issued: 1996
Boyzie Cekwana the South African dancing body in transition
- Authors: Pienaar, Samantha
- Date: 1996
- Subjects: Cekwana, Ntsikelelo , Dance -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2144 , http://hdl.handle.net/10962/d1002376 , Cekwana, Ntsikelelo , Dance -- South Africa
- Description: Boyzie Cekwana is one of many black male dancers and choreographers that is currently receiving widespread support and recognition for his contribution to the field of contemporary dance in South Africa. Why certain images of the dancing body - as presented by this individual dance practitioner - are currently being promoted as artistically more viable than others by dance critics and the media is the central concern of this thesis. An analysis of the dancing body in contemporary South Africa must take into account the current post-apartheid condition, a condition of transformation and reconstruction that allows people greater freedom to select the country's leaders, popularize its heroes and heroines, market and capitalize on images and icons of a New South Africa. By opting to look specifically at a black male dancer, social appreciations of the body in terms of ethnicity and gender can be challenged. This latter area of research - the role of gender in the production, presentation and appreciation of the dancing body - is largely unchallenged in South Africa. Yet, if South African's want to truly rid themselves of the shackles of hegemonic rule, gender-construction is an area of social experience that needs intensive confrontation. Chapter one will suggest some of the obstacles that might limit the South African dance researcher seeking an indepth analysis of the black dancing body, taking into consideration the country's history of elitist and autonomous rule. Attention will be drawn to multidisciplinary sites of information that might assist the researcher in such an excavation. The context of the research, however, is less interested in historical descriptions of the dancing body than with current motivating factors behind the preferential promotion of certain images over others in contemporary dance. Personal interviews and observations will therefore also provide crucial resource material. In chapter two, a case study of Boyzie Cekwana will be made looking at his personal background and the way in which it may have informed his contemporary experiences as a black male dancer and choreographer. The underlying belief of such a case-study approach is that "it carries implications about the extents to which the resulting analysis is applicable to other similar cases" ¹. This individual analysis includes information gathered from persona1 interviews with Cekwana; the author's own observations and experiences of Cekwana' s work at the Vita FNB Dance Umbrella, the Grahamstown National Arts Festival, and the Durban Playhouse Theatre; and analyses of articles on Cekwana by journalists, and performance reviews by dance and theatre critics such as Adrienne Sichel (The Star Tonight!), Tommy Ballantyne (The Natal Sunday Tribune) and David Coleman (The Mercury). Further examinations in chapter three and four will assess to what degree Cekwana re-presents culture-specific images of gender-modelling in his own performing body and the bodies of his multi-racial and multi-gendered dancers in selected dances. To prevent placing sole responsibility at Cekwana' s feet for the representation of the dancing body to a society in transformation, the role of dance critics and mass mediators in this process of artistic communication will also be dealt with. It is hoped that the ensuing discussion will suggest the possible effects that present frameworks of aesthetic appreciation may hold for choreographers and dancers in the country's future cultural development; this involves confronting a still controversial issue in South Africa the relationship between dance and politics, choreographer and social responsibility. The thesis will round-off very briefly with suggestions to dance practitioners and educators in South Africa of alternative ways of perceiving and appreciating the dancing body based on gender, and· not just racial, constructions; this is especially invaluable in the light of current efforts to include dance as a core-curriculum subject in all schools.
- Full Text:
- Date Issued: 1996
- Authors: Pienaar, Samantha
- Date: 1996
- Subjects: Cekwana, Ntsikelelo , Dance -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2144 , http://hdl.handle.net/10962/d1002376 , Cekwana, Ntsikelelo , Dance -- South Africa
- Description: Boyzie Cekwana is one of many black male dancers and choreographers that is currently receiving widespread support and recognition for his contribution to the field of contemporary dance in South Africa. Why certain images of the dancing body - as presented by this individual dance practitioner - are currently being promoted as artistically more viable than others by dance critics and the media is the central concern of this thesis. An analysis of the dancing body in contemporary South Africa must take into account the current post-apartheid condition, a condition of transformation and reconstruction that allows people greater freedom to select the country's leaders, popularize its heroes and heroines, market and capitalize on images and icons of a New South Africa. By opting to look specifically at a black male dancer, social appreciations of the body in terms of ethnicity and gender can be challenged. This latter area of research - the role of gender in the production, presentation and appreciation of the dancing body - is largely unchallenged in South Africa. Yet, if South African's want to truly rid themselves of the shackles of hegemonic rule, gender-construction is an area of social experience that needs intensive confrontation. Chapter one will suggest some of the obstacles that might limit the South African dance researcher seeking an indepth analysis of the black dancing body, taking into consideration the country's history of elitist and autonomous rule. Attention will be drawn to multidisciplinary sites of information that might assist the researcher in such an excavation. The context of the research, however, is less interested in historical descriptions of the dancing body than with current motivating factors behind the preferential promotion of certain images over others in contemporary dance. Personal interviews and observations will therefore also provide crucial resource material. In chapter two, a case study of Boyzie Cekwana will be made looking at his personal background and the way in which it may have informed his contemporary experiences as a black male dancer and choreographer. The underlying belief of such a case-study approach is that "it carries implications about the extents to which the resulting analysis is applicable to other similar cases" ¹. This individual analysis includes information gathered from persona1 interviews with Cekwana; the author's own observations and experiences of Cekwana' s work at the Vita FNB Dance Umbrella, the Grahamstown National Arts Festival, and the Durban Playhouse Theatre; and analyses of articles on Cekwana by journalists, and performance reviews by dance and theatre critics such as Adrienne Sichel (The Star Tonight!), Tommy Ballantyne (The Natal Sunday Tribune) and David Coleman (The Mercury). Further examinations in chapter three and four will assess to what degree Cekwana re-presents culture-specific images of gender-modelling in his own performing body and the bodies of his multi-racial and multi-gendered dancers in selected dances. To prevent placing sole responsibility at Cekwana' s feet for the representation of the dancing body to a society in transformation, the role of dance critics and mass mediators in this process of artistic communication will also be dealt with. It is hoped that the ensuing discussion will suggest the possible effects that present frameworks of aesthetic appreciation may hold for choreographers and dancers in the country's future cultural development; this involves confronting a still controversial issue in South Africa the relationship between dance and politics, choreographer and social responsibility. The thesis will round-off very briefly with suggestions to dance practitioners and educators in South Africa of alternative ways of perceiving and appreciating the dancing body based on gender, and· not just racial, constructions; this is especially invaluable in the light of current efforts to include dance as a core-curriculum subject in all schools.
- Full Text:
- Date Issued: 1996
Cell-free biosynthesis of abscisic acid (ABA) in extracts of flavedo from Citrus sinensis (L.) osbeck
- Richardson, Gaynor Rose-Marie
- Authors: Richardson, Gaynor Rose-Marie
- Date: 1996
- Subjects: Biosynthesis Abscisic acid Citrus fruits
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4221 , http://hdl.handle.net/10962/d1003790
- Description: The biosynthetic origin of the plant growth regulator abscisic acid remains equivocal and almost nothing is known about the enzymes involved in this process. The present research programme describes the development of a cell-free system, capable of synthesizing abscisic acid and attempts to provide further information about the biochemistry and enzymology of this important biosynthetic pathway. Cell-free extracts were prepared either directly from the flavedo (crude) or from an acetone powder derived from flavedo, of mature coloured fruits of Citrus sinensis L. cv. Midknight and incubated with mevalonic acid, isopentenyl pyrophosphate, famesylpyrophosphate, geranylgeranyl pyrophosphate, ß-carotene and 1',4'-trans-abscisic acid diol. The neutral and acidic products formed were purified by thin-layer chromatography and high performance liquid chromatography, and quantified by high performance liquid chromatography, gas chromatography-electron capture and unequivocally identified by combined gas chromatography-mass spectrometry. Abscisic acid, 1',4'-trans-abscisic acid diol and phaseic acid were unequivocally identified as the major acidic products formed in this cell-free system. The acid fraction also contained xanthoxin acid. Labelled and unlabelled ß-carotene was converted into the neutral compounds xanthoxin and xanthoxin alcohol. In addition. high performance liquid chromatography-photodiode array analYSis of the oxy-carotenoid fraction revealed the complete spectrum of ß, ß-carotenoids induding zeaxanthin, antheraxanthin and violaxanthin with accumulation of an oxygenated carotenoid tentatively identified as 9- cis-violaxanthin. Identification of putative C₁₅ intermediates was achieved by either UV spectrophotometry and combined capillary gas chromatography-mass spectrometry or microchemical analYSis and co-chromatography. Refeeding studies using (±)-[2-¹⁴C]_ abscisic acid diol as substrate revealed that abscisic acid was not metabolized to abscisic acid diol, suggesting that it was/is produced as an intermediate rather than as a catabolite of ABA in this system. Stigmasterol, and to a lesser extent cholesterol reduced conversion of ß-carotene to abscisic acid but did not influence transformation of 1',4'-trans-abscisic acid diol to abscisic acid. AM01618 stimulated fonnation of abscisic acid and appeared to exert its effect at the level of conversion of 1' ,4'-trans-abscisic acid diol. Zeatin and the cytokinin analogue, ancymidol inhibited the biosynthesis of abscisic acid whereas dithiothreitol increased incorporation of label from ß-carotene into abscisic acid suggesting involvement of a cytochrome P450-type mixed function oxidase in this reaction sequence. Sodium dodecylsulphate polyacrylamide gel electrophoresis of the enzyme extract derived from Citrus flavedo revealed the presence of a 53 kD protein with peroxidase activity characteristic of a cytochrome P-450. Abscisic acid biosynthesizing activity was always greater in extracts from acetone powder and abscisic acid biosynthesis was enhanced in the presence of AMO 1618, NAD+, NADH, NADPH, MgCI₂ and Molybdate but was inhibited by FAD. Activity was further enhanced by the addition of (R,S)-abscisic acid as a cold-pool trap and by induding 0.1% w/v of either Tween 20 or Triton X 100 in the extraction buffer. When cis-ß-carotene was used as substrate, no abscisic acid was produced. Conversely when either all-trans-ß-carotene or a mixture of the two isomers was used, incorporation into abscisic acid occurred. Upoxygenase activity in cell-free extracts of Citrus flavedo increased with increasing protein concentration. As the ability of lipoxygenase to make xanthoxin from violaxanthin, had been reported, increased activity in the cell-free system implied that carotenoid deavage was being brought about by a non-haem oxygenase with lipoxygenase-like properties. Reports had implicated phoshorylation in the activation of many catalytic enzymes (Hanks et aI., 1985). Phosphorylation of the enzymes in this cell-free system proved unsuccessful. Further, it had been reported that in vitro phosphorylation of several membrane polypeptides and soluble polypeptides from com, had been promoted by the addition of Ca²₊ In this cell-free system Ca + did not have a stimulatory effect on protein phosphorylation. Dioxygenases generally occur as soluble enzymes, where they catalyse many oxygenation reactions in metabolic pathways. The addition of 2-oxo-glutarate, a requirement of most soluble oxidases, did not affect the activity of the cell-free system.
- Full Text:
- Date Issued: 1996
- Authors: Richardson, Gaynor Rose-Marie
- Date: 1996
- Subjects: Biosynthesis Abscisic acid Citrus fruits
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4221 , http://hdl.handle.net/10962/d1003790
- Description: The biosynthetic origin of the plant growth regulator abscisic acid remains equivocal and almost nothing is known about the enzymes involved in this process. The present research programme describes the development of a cell-free system, capable of synthesizing abscisic acid and attempts to provide further information about the biochemistry and enzymology of this important biosynthetic pathway. Cell-free extracts were prepared either directly from the flavedo (crude) or from an acetone powder derived from flavedo, of mature coloured fruits of Citrus sinensis L. cv. Midknight and incubated with mevalonic acid, isopentenyl pyrophosphate, famesylpyrophosphate, geranylgeranyl pyrophosphate, ß-carotene and 1',4'-trans-abscisic acid diol. The neutral and acidic products formed were purified by thin-layer chromatography and high performance liquid chromatography, and quantified by high performance liquid chromatography, gas chromatography-electron capture and unequivocally identified by combined gas chromatography-mass spectrometry. Abscisic acid, 1',4'-trans-abscisic acid diol and phaseic acid were unequivocally identified as the major acidic products formed in this cell-free system. The acid fraction also contained xanthoxin acid. Labelled and unlabelled ß-carotene was converted into the neutral compounds xanthoxin and xanthoxin alcohol. In addition. high performance liquid chromatography-photodiode array analYSis of the oxy-carotenoid fraction revealed the complete spectrum of ß, ß-carotenoids induding zeaxanthin, antheraxanthin and violaxanthin with accumulation of an oxygenated carotenoid tentatively identified as 9- cis-violaxanthin. Identification of putative C₁₅ intermediates was achieved by either UV spectrophotometry and combined capillary gas chromatography-mass spectrometry or microchemical analYSis and co-chromatography. Refeeding studies using (±)-[2-¹⁴C]_ abscisic acid diol as substrate revealed that abscisic acid was not metabolized to abscisic acid diol, suggesting that it was/is produced as an intermediate rather than as a catabolite of ABA in this system. Stigmasterol, and to a lesser extent cholesterol reduced conversion of ß-carotene to abscisic acid but did not influence transformation of 1',4'-trans-abscisic acid diol to abscisic acid. AM01618 stimulated fonnation of abscisic acid and appeared to exert its effect at the level of conversion of 1' ,4'-trans-abscisic acid diol. Zeatin and the cytokinin analogue, ancymidol inhibited the biosynthesis of abscisic acid whereas dithiothreitol increased incorporation of label from ß-carotene into abscisic acid suggesting involvement of a cytochrome P450-type mixed function oxidase in this reaction sequence. Sodium dodecylsulphate polyacrylamide gel electrophoresis of the enzyme extract derived from Citrus flavedo revealed the presence of a 53 kD protein with peroxidase activity characteristic of a cytochrome P-450. Abscisic acid biosynthesizing activity was always greater in extracts from acetone powder and abscisic acid biosynthesis was enhanced in the presence of AMO 1618, NAD+, NADH, NADPH, MgCI₂ and Molybdate but was inhibited by FAD. Activity was further enhanced by the addition of (R,S)-abscisic acid as a cold-pool trap and by induding 0.1% w/v of either Tween 20 or Triton X 100 in the extraction buffer. When cis-ß-carotene was used as substrate, no abscisic acid was produced. Conversely when either all-trans-ß-carotene or a mixture of the two isomers was used, incorporation into abscisic acid occurred. Upoxygenase activity in cell-free extracts of Citrus flavedo increased with increasing protein concentration. As the ability of lipoxygenase to make xanthoxin from violaxanthin, had been reported, increased activity in the cell-free system implied that carotenoid deavage was being brought about by a non-haem oxygenase with lipoxygenase-like properties. Reports had implicated phoshorylation in the activation of many catalytic enzymes (Hanks et aI., 1985). Phosphorylation of the enzymes in this cell-free system proved unsuccessful. Further, it had been reported that in vitro phosphorylation of several membrane polypeptides and soluble polypeptides from com, had been promoted by the addition of Ca²₊ In this cell-free system Ca + did not have a stimulatory effect on protein phosphorylation. Dioxygenases generally occur as soluble enzymes, where they catalyse many oxygenation reactions in metabolic pathways. The addition of 2-oxo-glutarate, a requirement of most soluble oxidases, did not affect the activity of the cell-free system.
- Full Text:
- Date Issued: 1996
Cognition and multiple sclerosis: a neuropsychological and MRI study
- Authors: Thornton, Helena Barbara
- Date: 1996
- Subjects: Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3144 , http://hdl.handle.net/10962/d1007290 , Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
- Description: Ten people with multiple sclerosis (MS) who felt they had cognitive difficulties because of their MS were investigated. This study had multiple aims. Firstly, to explore the subjective experience of cognitive deficits. Secondly, to assess whether or not there was objective evidence of cognitive difficulties on neuropsychological testing, and whether this was commensurate with a pattern of subcortical dementia. Thirdly, to determine whether their magnetic resonance imaging (MRI) scans replicated the patterns of atrophy frequently reported in MS patients with cognitive difficulties. And finally, to investigate the psychological well-being of the subjects. In depth neuropsychiatric interviews, psychiatric and psychological inventories, a comprehensive neuropsychological battery, and MRI investigations were done. The mean Full Scale Intelligence Quotient (FSIQ) fell within the superior range, at the 89th percentile. On tests of general intelligence, mental state examinations, there was little or no indication of cognitive deterioration. However, on sophisticated neuropsychological testing, there was convincing evidence of cognitive problems. Magnetic resonance imaging lesions were atypical of the reported research on cognitively compromised MS patients.
- Full Text:
- Date Issued: 1996
- Authors: Thornton, Helena Barbara
- Date: 1996
- Subjects: Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3144 , http://hdl.handle.net/10962/d1007290 , Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
- Description: Ten people with multiple sclerosis (MS) who felt they had cognitive difficulties because of their MS were investigated. This study had multiple aims. Firstly, to explore the subjective experience of cognitive deficits. Secondly, to assess whether or not there was objective evidence of cognitive difficulties on neuropsychological testing, and whether this was commensurate with a pattern of subcortical dementia. Thirdly, to determine whether their magnetic resonance imaging (MRI) scans replicated the patterns of atrophy frequently reported in MS patients with cognitive difficulties. And finally, to investigate the psychological well-being of the subjects. In depth neuropsychiatric interviews, psychiatric and psychological inventories, a comprehensive neuropsychological battery, and MRI investigations were done. The mean Full Scale Intelligence Quotient (FSIQ) fell within the superior range, at the 89th percentile. On tests of general intelligence, mental state examinations, there was little or no indication of cognitive deterioration. However, on sophisticated neuropsychological testing, there was convincing evidence of cognitive problems. Magnetic resonance imaging lesions were atypical of the reported research on cognitively compromised MS patients.
- Full Text:
- Date Issued: 1996
Computer modelling of pyrotechnic combustion
- Authors: Taylor, Steven John
- Date: 1996
- Subjects: Combustion -- Computer simulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4426 , http://hdl.handle.net/10962/d1006913
- Description: One of the most important industrial uses of pyrotechnic compositions is as delay fuses in electric detonators. Many factors influence the rate of burning of such fuses. These include (a) the primary choice of chemical components, followed by (b) the physical properties of these components, particularly the particle-size and distribution of the fuel, (c) the composition of the system chosen and (d) the presence of additives and/or impurities. A full experimental study of the influences of even a few of these factors, while attempting to hold other potential variables constant, would be extremely time consuming and hence attention has been focused on the possibilities of modelling pyrotechnic combustion. Various approaches to the modelling of pyrotechnic combustion are discussed. These include:- (i) one-dimensional finite-difference models; (ii) two-dimensional finite-element models; (iii) particle-packing considerations; (iv) Monte Carlo models. Predicted behaviour is compared with extensive experimental information for the widely-used antimony/potassium permanganate pyrotechnic system, and the tungsten /potassium dichromate pyrotechnic system. The one-dimensional finite-difference model was investigated to give a simple means of investigating the effects of some parameters on the combustion of a pyrotechnic. The two-dimensional finite-difference model used similar inputs, but at the expense of considerably more computer power, gave more extensive information such as the shape of the burning front and the temperature gradients throughout the column and within the casing material. Both these models gave improved results when allowance was made for autocatalytic kinetics in place of the usual assumption of an "order-of-reaction", n ≤ 1. The particle-packing model investigated the qualitative relationship between the maximum burning rate of a pyrotechnic system and the maximum number of contact points (per 1.00 g composition) calculated for that system. Qualitative agreement was found for those systems which are presumed to burn mainly via solid-solid reactions. The Monte Carlo model investigated the effect of the random packing of fuel and oxidant particles on the variability of the burning rate of a pyrotechnic composition.
- Full Text:
- Date Issued: 1996
- Authors: Taylor, Steven John
- Date: 1996
- Subjects: Combustion -- Computer simulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4426 , http://hdl.handle.net/10962/d1006913
- Description: One of the most important industrial uses of pyrotechnic compositions is as delay fuses in electric detonators. Many factors influence the rate of burning of such fuses. These include (a) the primary choice of chemical components, followed by (b) the physical properties of these components, particularly the particle-size and distribution of the fuel, (c) the composition of the system chosen and (d) the presence of additives and/or impurities. A full experimental study of the influences of even a few of these factors, while attempting to hold other potential variables constant, would be extremely time consuming and hence attention has been focused on the possibilities of modelling pyrotechnic combustion. Various approaches to the modelling of pyrotechnic combustion are discussed. These include:- (i) one-dimensional finite-difference models; (ii) two-dimensional finite-element models; (iii) particle-packing considerations; (iv) Monte Carlo models. Predicted behaviour is compared with extensive experimental information for the widely-used antimony/potassium permanganate pyrotechnic system, and the tungsten /potassium dichromate pyrotechnic system. The one-dimensional finite-difference model was investigated to give a simple means of investigating the effects of some parameters on the combustion of a pyrotechnic. The two-dimensional finite-difference model used similar inputs, but at the expense of considerably more computer power, gave more extensive information such as the shape of the burning front and the temperature gradients throughout the column and within the casing material. Both these models gave improved results when allowance was made for autocatalytic kinetics in place of the usual assumption of an "order-of-reaction", n ≤ 1. The particle-packing model investigated the qualitative relationship between the maximum burning rate of a pyrotechnic system and the maximum number of contact points (per 1.00 g composition) calculated for that system. Qualitative agreement was found for those systems which are presumed to burn mainly via solid-solid reactions. The Monte Carlo model investigated the effect of the random packing of fuel and oxidant particles on the variability of the burning rate of a pyrotechnic composition.
- Full Text:
- Date Issued: 1996
Computer modelling of the thermal decomposition of solids
- Authors: De la Croix, Annemarie
- Date: 1996
- Subjects: Solids -- Thermal properties -- Computer simulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4302 , http://hdl.handle.net/10962/d1004960 , Solids -- Thermal properties -- Computer simulation
- Description: Decompositions of solids are typically of the form: A(s) ----> B(s) + gases. Symmetry-controlled routes (based on known and hypothetical crystal structures) for transforming the solid reactant into the solid product were devised as possible decomposition pathways. Lattice energies of the reactants, of the postulated transient intermediate structures and of the final solid products were then estimated by crystal modelling procedures. Profiles of lattice energy changes during the proposed decomposition routes were constructed and any energy barriers were compared with experimental activation energies reported for the thermal decompositions. The crystal modelling was performed with the computer program WMIN. Calculation of the lattice energies involved the development of a model potential for the perfect lattice and the evaluation of the interatomic parameters. The potential was based on the Born model of ionic solids using the Buckingham potential (Ø(r)= Ae⁻r/p - C/r⁶) to describe the short-range energy contribution. Empirical fitting was used to establish reliable interatomic energy parameters. The reliability of the interatomic potentials was assessed by calculating crystal structures and lattice energies (which were not included in the fitting). The particular reactions selected for modelling were the decompositions of the alkaline-earth metal (Ca, Sr, Ba) peroxides and carbonates: M0₂(s) ---> MO(s) + ¹/₂0₂(g) MC0₃(s) ---> MO(s) + CO₂(g)The lattice energies calculated for the known structures were in good agreement with reported values, (except for Ba0₂ and BaC0₃) which provided support for the adequacy of the potential model used. Activation energies calculated for the decomposition of the carbonates were in the correct order but hlgher than experimental values, i. e., 422, 422, 465 and 499 kJ mol̄̄⁻¹ compared to the experimental values of 205, 87(?), 222 and 283 kJ mol̄̄⁻¹ for CaC0₃ (calcite), CaC0₃(aragonite), SrC0₃ and BaC0₃. The values calculated for the peroxides (91 and 100 kJ mol⁻¹ compared to the experimental values of 119 and 185 kJ mol⁻¹ for Sr0₂ and Ba0₂ respectively) were less satisfactory but could be a reflection of the poor structural data used for the peroxides. The significance of this approach to the modelling of solid decompositions is discussed.
- Full Text:
- Date Issued: 1996
- Authors: De la Croix, Annemarie
- Date: 1996
- Subjects: Solids -- Thermal properties -- Computer simulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4302 , http://hdl.handle.net/10962/d1004960 , Solids -- Thermal properties -- Computer simulation
- Description: Decompositions of solids are typically of the form: A(s) ----> B(s) + gases. Symmetry-controlled routes (based on known and hypothetical crystal structures) for transforming the solid reactant into the solid product were devised as possible decomposition pathways. Lattice energies of the reactants, of the postulated transient intermediate structures and of the final solid products were then estimated by crystal modelling procedures. Profiles of lattice energy changes during the proposed decomposition routes were constructed and any energy barriers were compared with experimental activation energies reported for the thermal decompositions. The crystal modelling was performed with the computer program WMIN. Calculation of the lattice energies involved the development of a model potential for the perfect lattice and the evaluation of the interatomic parameters. The potential was based on the Born model of ionic solids using the Buckingham potential (Ø(r)= Ae⁻r/p - C/r⁶) to describe the short-range energy contribution. Empirical fitting was used to establish reliable interatomic energy parameters. The reliability of the interatomic potentials was assessed by calculating crystal structures and lattice energies (which were not included in the fitting). The particular reactions selected for modelling were the decompositions of the alkaline-earth metal (Ca, Sr, Ba) peroxides and carbonates: M0₂(s) ---> MO(s) + ¹/₂0₂(g) MC0₃(s) ---> MO(s) + CO₂(g)The lattice energies calculated for the known structures were in good agreement with reported values, (except for Ba0₂ and BaC0₃) which provided support for the adequacy of the potential model used. Activation energies calculated for the decomposition of the carbonates were in the correct order but hlgher than experimental values, i. e., 422, 422, 465 and 499 kJ mol̄̄⁻¹ compared to the experimental values of 205, 87(?), 222 and 283 kJ mol̄̄⁻¹ for CaC0₃ (calcite), CaC0₃(aragonite), SrC0₃ and BaC0₃. The values calculated for the peroxides (91 and 100 kJ mol⁻¹ compared to the experimental values of 119 and 185 kJ mol⁻¹ for Sr0₂ and Ba0₂ respectively) were less satisfactory but could be a reflection of the poor structural data used for the peroxides. The significance of this approach to the modelling of solid decompositions is discussed.
- Full Text:
- Date Issued: 1996
Conrad's impressionism : the treatment of space and atmosphere in selected works
- Authors: De Lange, Adriaan Michiel
- Date: 1996
- Subjects: Conrad, Joseph, 1857-1924 -- Criticism and interpretation Conrad, Joseph, 1857-1924 -- Heart of darkness Conrad, Joseph, 1857-1924 -- Nigger of the Narcissus Conrad, Joseph, 1857-1924 -- Nostromo Conrad, Joseph, 1857-1924 -- Lord Jim
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2229 , http://hdl.handle.net/10962/d1002272
- Description: This thesis focuses on Conrad's representation of space and atmosphere in the "impressionistic" works published between 1897 and 1904, notably The Nigger of the "Narcissus" (1897), "Heart of Darkness" (1899), Lord Jim (1900), and Nostromo (1904). The many conflicting statements regarding the nature of Conrad's impressionism lead one to ask two fundamental questions: What constitutes this strange and elusive phenomenon, and how does it bear upon interpretation? This thesis works towards defining the elusive quality of Conrad's writing by investigating and assessing the contribution of impressionist techniques in the creation of a pervasive space and atmosphere; secondly, it considers how the various constituent elements interact with, and complement one another to form a dominant mode of fictional space in each work; and, thirdly, it indicates the possible impact that these particular Conradian configurations of space and atmosphere might have upon the interpretation of his impressionist works. The thesis argues that the existential condition of isolatio~experienced by Conrad's heroes and narrators is a consequence of epistemological frustration and fragmentation, which, in turn, is a function of impressionist ontology. There is a definite and complementary relationship between each of these notions in Conrad's fiction. The mysterious atmosphere in his works results from the interplay between various configurations of theme, narration and description, and these novelistic elements correspond roughly with the notions of existential isolation (the dominant theme), epistemology (narrating, telling and (re)telling as a method of knowing and understanding the space in which the characters find themselves) and, lastly, the ontological dimensions of the various modes of fictional space (as realized in description). The evocation and invocation of cosmic space in The Nigger of the "Narcissus," the mapping of a dorriinant symbolic space in "Heart of Darkness," the (re)constructions of Jim's psychological space in Lord Jim, and, finally, the "transcription" and "inscription" of a mythical space in Nostromo, indicate a definite development from epistemological to ontological issues. Phrased in more theoretical terms, this development is a movement from asking predominantly epistemological questions like "How can I interpret this world of which I am a part?" "What is there to be known?" "Who knows it ... and with what degree of certainty?", to asking predominantly ontological questions, such as "Which world is this?" "What kinds of worlds are there ... and how are they constituted?". Such questions, categorized by McHale as the dominant characteristics of Modernist and Postmodernist fiction respectively, are already present in Conrad's texts, thus undermining any clear-cut division between these broad categories. Indeed, this thesis suggests that these categories are at best tenuous, and that they should perhaps be used heuristically, rather than definitively
- Full Text:
- Date Issued: 1996
- Authors: De Lange, Adriaan Michiel
- Date: 1996
- Subjects: Conrad, Joseph, 1857-1924 -- Criticism and interpretation Conrad, Joseph, 1857-1924 -- Heart of darkness Conrad, Joseph, 1857-1924 -- Nigger of the Narcissus Conrad, Joseph, 1857-1924 -- Nostromo Conrad, Joseph, 1857-1924 -- Lord Jim
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2229 , http://hdl.handle.net/10962/d1002272
- Description: This thesis focuses on Conrad's representation of space and atmosphere in the "impressionistic" works published between 1897 and 1904, notably The Nigger of the "Narcissus" (1897), "Heart of Darkness" (1899), Lord Jim (1900), and Nostromo (1904). The many conflicting statements regarding the nature of Conrad's impressionism lead one to ask two fundamental questions: What constitutes this strange and elusive phenomenon, and how does it bear upon interpretation? This thesis works towards defining the elusive quality of Conrad's writing by investigating and assessing the contribution of impressionist techniques in the creation of a pervasive space and atmosphere; secondly, it considers how the various constituent elements interact with, and complement one another to form a dominant mode of fictional space in each work; and, thirdly, it indicates the possible impact that these particular Conradian configurations of space and atmosphere might have upon the interpretation of his impressionist works. The thesis argues that the existential condition of isolatio~experienced by Conrad's heroes and narrators is a consequence of epistemological frustration and fragmentation, which, in turn, is a function of impressionist ontology. There is a definite and complementary relationship between each of these notions in Conrad's fiction. The mysterious atmosphere in his works results from the interplay between various configurations of theme, narration and description, and these novelistic elements correspond roughly with the notions of existential isolation (the dominant theme), epistemology (narrating, telling and (re)telling as a method of knowing and understanding the space in which the characters find themselves) and, lastly, the ontological dimensions of the various modes of fictional space (as realized in description). The evocation and invocation of cosmic space in The Nigger of the "Narcissus," the mapping of a dorriinant symbolic space in "Heart of Darkness," the (re)constructions of Jim's psychological space in Lord Jim, and, finally, the "transcription" and "inscription" of a mythical space in Nostromo, indicate a definite development from epistemological to ontological issues. Phrased in more theoretical terms, this development is a movement from asking predominantly epistemological questions like "How can I interpret this world of which I am a part?" "What is there to be known?" "Who knows it ... and with what degree of certainty?", to asking predominantly ontological questions, such as "Which world is this?" "What kinds of worlds are there ... and how are they constituted?". Such questions, categorized by McHale as the dominant characteristics of Modernist and Postmodernist fiction respectively, are already present in Conrad's texts, thus undermining any clear-cut division between these broad categories. Indeed, this thesis suggests that these categories are at best tenuous, and that they should perhaps be used heuristically, rather than definitively
- Full Text:
- Date Issued: 1996
Death and gnosis: archetypal dream imagery in terminal illness
- Authors: Welman, Mark
- Date: 1996
- Subjects: Jung, C G (Carl Gustav), 1875-1961 Thanatology Death -- Psychological aspects Dreams Dreams Case studies Death in dreams
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3084 , http://hdl.handle.net/10962/d1002593
- Description: The central aim of this study was to explore the meaning of death as both a literal and an imaginative reality, and to elucidate the fundamental tensions between these meanings of death in modern existence. Recognition was given to the need for a poetic rather than a scientific approach to thanatology, and an epistemological foundation for a poetics of death was sought in the tradition of gnosis. Theoretically, the study was grounded in the analytical psychology of C.G. Jung. It was argued that despite Jung's erratic allegiance to a Cartesian ontology and epistemology, his approach to death was nevertheless fundamentally poetic. The poetic parameters of death and dying were explored in the context of Jung's understanding of the dialectical tension between the ego and the self, and it was concluded that while death represents an opening to the imaginative possibilities of existence, these potentialities can come to the fore only when there is a corresponding willingness to die. In these terms, it was concluded that the tension between life and death forms a pivotal dynamic of human existence. These considerations led to the Question of whether the poetic parameters of death and dying are applicable to the encounter with death as a concrete actuality. It was hypothesised that the approach of death would be met at two levels of reality, that of the ego and that of the self. The expectation was that while death would be seen as a literal ending from the perspective of the former, it may represent the fulfilment of Being from the viewpoint of the self. It was also assumed that the tension between these images of death would be mediated by way of archetypal symbols, which represent the bearers of gnosis in modern culture. To address these issues at an empirical level, a hermeneutically grounded thematic analysis of 108 dreams reported by dying persons was undertaken. Twenty initial themes emerged from the data. Each of these themes was in turn elucidated by way of Jung's method of amplification. This exercise yielded five concise themes, these being (a) death, (b) transformation, (c) the self (d) the Feminine, and (e) the Masculine. It was concluded that dreams manifesting during the dying process reveal a fundamental tension between literal and metaphoric possibilities of death. Dream symbols were also found to mediate between this tension, and to orchestrate the individuation process. It was concluded that in the context of dying, dreams may reflect and facilitate the emergence of a meaningful gnosis of death. The clinical implications of these findings were onsidered, and indications for further research were provided.
- Full Text:
- Date Issued: 1996
- Authors: Welman, Mark
- Date: 1996
- Subjects: Jung, C G (Carl Gustav), 1875-1961 Thanatology Death -- Psychological aspects Dreams Dreams Case studies Death in dreams
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3084 , http://hdl.handle.net/10962/d1002593
- Description: The central aim of this study was to explore the meaning of death as both a literal and an imaginative reality, and to elucidate the fundamental tensions between these meanings of death in modern existence. Recognition was given to the need for a poetic rather than a scientific approach to thanatology, and an epistemological foundation for a poetics of death was sought in the tradition of gnosis. Theoretically, the study was grounded in the analytical psychology of C.G. Jung. It was argued that despite Jung's erratic allegiance to a Cartesian ontology and epistemology, his approach to death was nevertheless fundamentally poetic. The poetic parameters of death and dying were explored in the context of Jung's understanding of the dialectical tension between the ego and the self, and it was concluded that while death represents an opening to the imaginative possibilities of existence, these potentialities can come to the fore only when there is a corresponding willingness to die. In these terms, it was concluded that the tension between life and death forms a pivotal dynamic of human existence. These considerations led to the Question of whether the poetic parameters of death and dying are applicable to the encounter with death as a concrete actuality. It was hypothesised that the approach of death would be met at two levels of reality, that of the ego and that of the self. The expectation was that while death would be seen as a literal ending from the perspective of the former, it may represent the fulfilment of Being from the viewpoint of the self. It was also assumed that the tension between these images of death would be mediated by way of archetypal symbols, which represent the bearers of gnosis in modern culture. To address these issues at an empirical level, a hermeneutically grounded thematic analysis of 108 dreams reported by dying persons was undertaken. Twenty initial themes emerged from the data. Each of these themes was in turn elucidated by way of Jung's method of amplification. This exercise yielded five concise themes, these being (a) death, (b) transformation, (c) the self (d) the Feminine, and (e) the Masculine. It was concluded that dreams manifesting during the dying process reveal a fundamental tension between literal and metaphoric possibilities of death. Dream symbols were also found to mediate between this tension, and to orchestrate the individuation process. It was concluded that in the context of dying, dreams may reflect and facilitate the emergence of a meaningful gnosis of death. The clinical implications of these findings were onsidered, and indications for further research were provided.
- Full Text:
- Date Issued: 1996
Defining governance in Uganda in a changing world order, 1962-94
- Authors: Kintu-Nyago, Crispin
- Date: 1996
- Subjects: Uganda -- Politics and government , Uganda -- Economic conditions , World politics , International relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2788 , http://hdl.handle.net/10962/d1002998 , Uganda -- Politics and government , Uganda -- Economic conditions , World politics , International relations
- Description: This study argues that much of early post colonial Uganda's political developments, had its roots in the colonial patterns of governance. It was, however, the imperative of Uganda's early post colonial rulers to have formulated and maintained conditions for legitimate and orderly governance. Largely, this required a coherent political class with a mass based and mobilising political movement, that moreover had a political programme that catered for the interests of its support base. Indeed, their opting to negate these very prerequisite conditions, contributed greatly to Uganda's subsequent political disorder, and it's further marginalisation in the International Political Economy. This study suggests that since the impact of colonialism in Uganda, its governance policies have closely been linked to the broader dictates of the International Political Economy. A reality that the policy makers in post colonial Uganda should have realised, and in the process attempted to advantageously adapt to the Ugandan situation. Their was a qualitative improvement in Uganda's governance from 1986. This study illustrates that this was a result of the emerging into power of a political class, whose policies deliberately and strenuously attempted to fulfil the above mentioned criteria. Their is need to link Uganda's foreign and governance policies. Consequently a conscious and deliberate effort has to made by its policy makers, to ensure that the two are amicably adapted to each other, so as to derive the best possible benefits. For instance what Uganda needs in the existing New World Order are development, domestic and foreign investments and export markets for its produce. All of which can only be obtained if political order through a legitimate political system and government exists. With a leadership, that moreover, deliberately attracts foreign investments and creates the enabling conditions for competitive economic production. The onus is upon Ugandans to ensure that they institutionalise conditions for their appropriate governance and foreign policies. For this thesis argues that the International Political Economy is dynamic, and Uganda was never predestined to be at its margins.
- Full Text:
- Date Issued: 1996
- Authors: Kintu-Nyago, Crispin
- Date: 1996
- Subjects: Uganda -- Politics and government , Uganda -- Economic conditions , World politics , International relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2788 , http://hdl.handle.net/10962/d1002998 , Uganda -- Politics and government , Uganda -- Economic conditions , World politics , International relations
- Description: This study argues that much of early post colonial Uganda's political developments, had its roots in the colonial patterns of governance. It was, however, the imperative of Uganda's early post colonial rulers to have formulated and maintained conditions for legitimate and orderly governance. Largely, this required a coherent political class with a mass based and mobilising political movement, that moreover had a political programme that catered for the interests of its support base. Indeed, their opting to negate these very prerequisite conditions, contributed greatly to Uganda's subsequent political disorder, and it's further marginalisation in the International Political Economy. This study suggests that since the impact of colonialism in Uganda, its governance policies have closely been linked to the broader dictates of the International Political Economy. A reality that the policy makers in post colonial Uganda should have realised, and in the process attempted to advantageously adapt to the Ugandan situation. Their was a qualitative improvement in Uganda's governance from 1986. This study illustrates that this was a result of the emerging into power of a political class, whose policies deliberately and strenuously attempted to fulfil the above mentioned criteria. Their is need to link Uganda's foreign and governance policies. Consequently a conscious and deliberate effort has to made by its policy makers, to ensure that the two are amicably adapted to each other, so as to derive the best possible benefits. For instance what Uganda needs in the existing New World Order are development, domestic and foreign investments and export markets for its produce. All of which can only be obtained if political order through a legitimate political system and government exists. With a leadership, that moreover, deliberately attracts foreign investments and creates the enabling conditions for competitive economic production. The onus is upon Ugandans to ensure that they institutionalise conditions for their appropriate governance and foreign policies. For this thesis argues that the International Political Economy is dynamic, and Uganda was never predestined to be at its margins.
- Full Text:
- Date Issued: 1996
Distribution patterns of fishes in the head region of a turbid Eastern Cape estuary
- Ter Morshuizen, Leslie David
- Authors: Ter Morshuizen, Leslie David
- Date: 1996
- Subjects: Fishes -- South Africa -- Eastern Cape -- great fish river -- Geographical distribution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5261 , http://hdl.handle.net/10962/d1005105 , Fishes -- South Africa -- Eastern Cape -- great fish river -- Geographical distribution
- Description: Two and a half years of data were collected from the Great Fish River and estuary using seine nets and gill nets to determine the fish species composition within these regions. The head region of the Great Fish River estuary was found to have a rich fish fauna, with the euryhaline marine fish component totally dominating the catch in all three regions. Gilchristella aesiuaria was the single most common species and several euryhaline marine species were captured in freshwater for the first time. Physical parameters were also measured in an effort to ascertain the possible factors which may affect the distribution and length frequency of the most common species within this area. Salinity was found to be the single most important factor affecting the species composition, and the sampling area was consequently divided into three regions, viz. river (< I ‰), head (1-4 ‰) and estuary (> 4 ‰). In addition, it was determined that river flow rate during the month prior to sampling also had a profound effect on species composition in all three regions. Based on the available evidence it is suggested that for most species this is related to conductivity levels rather than flow per se.
- Full Text:
- Date Issued: 1996
- Authors: Ter Morshuizen, Leslie David
- Date: 1996
- Subjects: Fishes -- South Africa -- Eastern Cape -- great fish river -- Geographical distribution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5261 , http://hdl.handle.net/10962/d1005105 , Fishes -- South Africa -- Eastern Cape -- great fish river -- Geographical distribution
- Description: Two and a half years of data were collected from the Great Fish River and estuary using seine nets and gill nets to determine the fish species composition within these regions. The head region of the Great Fish River estuary was found to have a rich fish fauna, with the euryhaline marine fish component totally dominating the catch in all three regions. Gilchristella aesiuaria was the single most common species and several euryhaline marine species were captured in freshwater for the first time. Physical parameters were also measured in an effort to ascertain the possible factors which may affect the distribution and length frequency of the most common species within this area. Salinity was found to be the single most important factor affecting the species composition, and the sampling area was consequently divided into three regions, viz. river (< I ‰), head (1-4 ‰) and estuary (> 4 ‰). In addition, it was determined that river flow rate during the month prior to sampling also had a profound effect on species composition in all three regions. Based on the available evidence it is suggested that for most species this is related to conductivity levels rather than flow per se.
- Full Text:
- Date Issued: 1996
Does drafting beat "bleeding"? : an action research investigation into the introduction of a cognitivist process approach to the teaching of writing at senior secondary level
- McKellar, Elizabeth Jennifer Kelk
- Authors: McKellar, Elizabeth Jennifer Kelk
- Date: 1996
- Subjects: Action research in education English language -- Writing -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1499 , http://hdl.handle.net/10962/d1003381
- Description: In this study an attempt is made to describe and illuminate the attitude of both pupils and teachers to the introduction of a cognitivist process approach to the teaching of written literacy in one standard in a multi-cuI tural Eastern Cape Model C secondary school. Because the cognitivist process approach to the teaching of written literacy was to complement already existing strategies for the teaching of written literacy, the research took the form of collaborative action research in three standard nine English classrooms. Teacher- and pupil diaries were the main means of data collection. Two spirals of action research were conducted in an attempt to identify difficulties and improve practice. Diaries and discussion revealed a positive response to the drafting, revision and editing processes which researchers had already identified as the processes which skilled writers use in creating text. Acknowledgement of the benefits to be derived from peer response as audience was also established. Anomalies relating to the grouping of pupils for peer-editing were found to be a key issue in determining the relative success of the project. Difficulties were also found to exist in the ability of some of the pupils to engage effectively in peer-peer and teacher-peer negotiation of text. Possible reasons for these difficulties have been identified , and further research into the nature of the inherent power relationships which exist implicitly in a multi-cultural educational setting and impede negotiation would be necessary to appreciate fully the difficulties experienced.
- Full Text:
- Date Issued: 1996
- Authors: McKellar, Elizabeth Jennifer Kelk
- Date: 1996
- Subjects: Action research in education English language -- Writing -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1499 , http://hdl.handle.net/10962/d1003381
- Description: In this study an attempt is made to describe and illuminate the attitude of both pupils and teachers to the introduction of a cognitivist process approach to the teaching of written literacy in one standard in a multi-cuI tural Eastern Cape Model C secondary school. Because the cognitivist process approach to the teaching of written literacy was to complement already existing strategies for the teaching of written literacy, the research took the form of collaborative action research in three standard nine English classrooms. Teacher- and pupil diaries were the main means of data collection. Two spirals of action research were conducted in an attempt to identify difficulties and improve practice. Diaries and discussion revealed a positive response to the drafting, revision and editing processes which researchers had already identified as the processes which skilled writers use in creating text. Acknowledgement of the benefits to be derived from peer response as audience was also established. Anomalies relating to the grouping of pupils for peer-editing were found to be a key issue in determining the relative success of the project. Difficulties were also found to exist in the ability of some of the pupils to engage effectively in peer-peer and teacher-peer negotiation of text. Possible reasons for these difficulties have been identified , and further research into the nature of the inherent power relationships which exist implicitly in a multi-cultural educational setting and impede negotiation would be necessary to appreciate fully the difficulties experienced.
- Full Text:
- Date Issued: 1996
Domino Servite School: an evaluative case study of a private Christian secondary school in rural Natal
- Authors: Davidson, Michael R
- Date: 1996
- Subjects: Christian education -- South Africa Church schools -- South Africa Education -- South Africa -- Kwazulu Private schools -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1500 , http://hdl.handle.net/10962/d1003382
- Description: Domino Servite School (DSS) is a private school, founded in 1986, and situated on KwaSizabantu (KSB) mission station in the Natal midlands. This research into DSS is a case study which aims to present an illuminative evaluation in the Whole School genre, within that branch of educational research concerned with effective schools. The project aimed to make use of a compatibility paradigm accommodating nomothetic and anthropological data. In attempting triangulation of methodological approaches, it tried to establish the extent to which DSS may be considered an efficient and effective 'New Private' school. It also aimed to understand the school's raison d'ětre. In order to illuminate the relevance and social processes of DSS, evaluation made use of internal and external referents. The internal investigation sought to make judgements in reference to the efficiency of the school as an organisation. On the macro-level, whole school evaluation required extensive curriculum evaluation. On the micro-level, appraisal of teaching and assessment of pupil performance was undertaken. This internal investigation required a critical analysis of the school's formal, informal and hidden curriculum. The external evaluation sought to make judgement in reference to the effectiveness of DSS. On the macro-level, this required evaluation of the findings of the internal investigation in terms of a broader South African context. Implications, for example of the school's 'private' status, and its 'Christian' curriculum in respect of multi-culturalism, education for nationhood , and ethnicity were examined. The analysis of these dimensions paid attention to the school's spatial context in terms of both its 'rural' and missionary setting. Here the focus was on the school's formal curriculum. Analysis of the inter-relational context paid attention to its informal curriculum or the way in which the school deals with the commonality and diversity of its clientele and staff. The inter-relational context of the school examined the hidden curriculum, or the relationship between the school and the broader South African Community. A critical ethnographic account of this institution was therefore possible because of the dual focus on the internal and external evaluation reference points. Internal evaluation made extensive use of direct (non-participant) observation, structured and nonstructured interviews, questionnaires, and documentary analysis. Indirect (participant) observation, in particular Clinical Supervision (CS), was also used. Indirect (non-participant) observation made extensive use of Flanders' Interaction Analysis Categories (FIAC). Teacher self-evaluation was also included, while analysis of pupil performance made use of 'standardised' achievement testing and a tracer study. External evaluation required detailed study of local and international literature on issues relating to private schooling, rural and multi-cultural education, education for nationhood and ethnicity. The research found that much of the school's curriculum path is incongruous with its rural context largely because of its association with the former Department of Education and Training (DET), and because of its missionary heritage. As such the school is presently (1) located within a questionable (formal) curriculum tradition which has little relevance to, nor potential for, the transformational needs of either rural Natal or South Africa in general. However, this does not preclude the possibility of the school making a contribution to education for development in South Africa. (2) The school advocates a mono-cultural Christian value system and modified cultural pluralism which attempts to assimilate pupils from diverse socio-economic and ideologically homogeneous backgrounds. Multi-cultural education, plural values, religious and values democracy are therefore not part of the school's raison d'ětre. (3) The school, through its associated organisation Christians for Truth (CFT), represents a social view espousing either a modified cultural pluralism or multi-nationalism which allows for allegiance to a transcendent value system without compromising group. values and associations. This means that the school aims at assimilating or amalgamating diversity into a mono-cultural unity that transcends group identity. This transcendent culture is defined in Christian terms. The study recommends inter alia, further investigation into the educational implications of_values neutrality and the particularism of secular humanism; a comparative analysis of a random sample of private missionary schools and ordinary state controlled rural schools so that more generalisable results might be obtained; and a more thorough investigation into the parental and pupil contributions to the school, their attitudes and perspectives on missionary education and their feelings about the management styles evident in the organisation.
- Full Text:
- Date Issued: 1996
- Authors: Davidson, Michael R
- Date: 1996
- Subjects: Christian education -- South Africa Church schools -- South Africa Education -- South Africa -- Kwazulu Private schools -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1500 , http://hdl.handle.net/10962/d1003382
- Description: Domino Servite School (DSS) is a private school, founded in 1986, and situated on KwaSizabantu (KSB) mission station in the Natal midlands. This research into DSS is a case study which aims to present an illuminative evaluation in the Whole School genre, within that branch of educational research concerned with effective schools. The project aimed to make use of a compatibility paradigm accommodating nomothetic and anthropological data. In attempting triangulation of methodological approaches, it tried to establish the extent to which DSS may be considered an efficient and effective 'New Private' school. It also aimed to understand the school's raison d'ětre. In order to illuminate the relevance and social processes of DSS, evaluation made use of internal and external referents. The internal investigation sought to make judgements in reference to the efficiency of the school as an organisation. On the macro-level, whole school evaluation required extensive curriculum evaluation. On the micro-level, appraisal of teaching and assessment of pupil performance was undertaken. This internal investigation required a critical analysis of the school's formal, informal and hidden curriculum. The external evaluation sought to make judgement in reference to the effectiveness of DSS. On the macro-level, this required evaluation of the findings of the internal investigation in terms of a broader South African context. Implications, for example of the school's 'private' status, and its 'Christian' curriculum in respect of multi-culturalism, education for nationhood , and ethnicity were examined. The analysis of these dimensions paid attention to the school's spatial context in terms of both its 'rural' and missionary setting. Here the focus was on the school's formal curriculum. Analysis of the inter-relational context paid attention to its informal curriculum or the way in which the school deals with the commonality and diversity of its clientele and staff. The inter-relational context of the school examined the hidden curriculum, or the relationship between the school and the broader South African Community. A critical ethnographic account of this institution was therefore possible because of the dual focus on the internal and external evaluation reference points. Internal evaluation made extensive use of direct (non-participant) observation, structured and nonstructured interviews, questionnaires, and documentary analysis. Indirect (participant) observation, in particular Clinical Supervision (CS), was also used. Indirect (non-participant) observation made extensive use of Flanders' Interaction Analysis Categories (FIAC). Teacher self-evaluation was also included, while analysis of pupil performance made use of 'standardised' achievement testing and a tracer study. External evaluation required detailed study of local and international literature on issues relating to private schooling, rural and multi-cultural education, education for nationhood and ethnicity. The research found that much of the school's curriculum path is incongruous with its rural context largely because of its association with the former Department of Education and Training (DET), and because of its missionary heritage. As such the school is presently (1) located within a questionable (formal) curriculum tradition which has little relevance to, nor potential for, the transformational needs of either rural Natal or South Africa in general. However, this does not preclude the possibility of the school making a contribution to education for development in South Africa. (2) The school advocates a mono-cultural Christian value system and modified cultural pluralism which attempts to assimilate pupils from diverse socio-economic and ideologically homogeneous backgrounds. Multi-cultural education, plural values, religious and values democracy are therefore not part of the school's raison d'ětre. (3) The school, through its associated organisation Christians for Truth (CFT), represents a social view espousing either a modified cultural pluralism or multi-nationalism which allows for allegiance to a transcendent value system without compromising group. values and associations. This means that the school aims at assimilating or amalgamating diversity into a mono-cultural unity that transcends group identity. This transcendent culture is defined in Christian terms. The study recommends inter alia, further investigation into the educational implications of_values neutrality and the particularism of secular humanism; a comparative analysis of a random sample of private missionary schools and ordinary state controlled rural schools so that more generalisable results might be obtained; and a more thorough investigation into the parental and pupil contributions to the school, their attitudes and perspectives on missionary education and their feelings about the management styles evident in the organisation.
- Full Text:
- Date Issued: 1996