A pastoral theological examination of inner healing
- Authors: Velthuysen, Daniel Nicholas
- Date: 1990
- Subjects: Pastoral theology , Healing -- Religious aspects -- Christianity , Mental healing -- Religious aspects -- Christianity , Inner child -- Religious aspects -- Christianity , Primal therapy -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1300 , http://hdl.handle.net/10962/d1016248
- Description: Doing a survey of the ministry of inner healing, one is arrested by three salient features: its pragmatic and correlative development, its lay orientation, and the inconsistent and naïve theoretical explanation of the phenomenon. Inner healing, or as it was first known, the healing of the memories, appears to have its roots with Agnes Sanford during the 1940's (Sandford 1982: 3-4). Over a period of time and through a series of events, Sanford experienced what she termed a healing of memories. After some reflection on her experiences she began to teach her views at the School of Pastoral Care started by her husband in 1958, at Camps Farthest Out (CFO), and at numerous churches and conferences.
- Full Text:
- Date Issued: 1990
- Authors: Velthuysen, Daniel Nicholas
- Date: 1990
- Subjects: Pastoral theology , Healing -- Religious aspects -- Christianity , Mental healing -- Religious aspects -- Christianity , Inner child -- Religious aspects -- Christianity , Primal therapy -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1300 , http://hdl.handle.net/10962/d1016248
- Description: Doing a survey of the ministry of inner healing, one is arrested by three salient features: its pragmatic and correlative development, its lay orientation, and the inconsistent and naïve theoretical explanation of the phenomenon. Inner healing, or as it was first known, the healing of the memories, appears to have its roots with Agnes Sanford during the 1940's (Sandford 1982: 3-4). Over a period of time and through a series of events, Sanford experienced what she termed a healing of memories. After some reflection on her experiences she began to teach her views at the School of Pastoral Care started by her husband in 1958, at Camps Farthest Out (CFO), and at numerous churches and conferences.
- Full Text:
- Date Issued: 1990
A study of the reading interests and reading habits of English (first language) secondary-school pupils in South Africa: with particular reference to the Province of Natal
- Authors: Gardner, John Murray
- Date: 1990
- Subjects: Reading interests English language -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal Books and reading -- South Africa -- KwaZulu-Natal Readership surveys -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1781 , http://hdl.handle.net/10962/d1003666
- Description: The study derives from a belief, based on many researchers' writings, that wide and frequent book-reading aids the development of knowledge, emotional maturity and human sympathy, which are all essential attributes in a fragmented culture such as South Africa's. It is not accepted that conventional secondary-school literature-teaching in this country promotes a lifelong reading habit among the majority of pupils and a plea is made for the recognition of Reading as a curricular entity in its own right. The study suggests that, owing to a paucity of local research in this field, South African teachers and educational authorities are severely disadvantaged. If they are unable to offer advice based on a proper study of their pupils as readers, they run the risk of guiding many pupils' reading along paths that cannot promise satisfaction and fulfilment. Such stultifying of reading habits would contradict the aims of the present National Core Syllabuses for English (First Language). The thesis sets little store by the investigation of specific bookchoices, pointing out that the validity of such incidental findings, if gleaned from a latitudinal survey, is questionable. Instead, using the findings of questionnaires administered to nearly 2 800 pupils and their teachers, the thesis investigates the relationships between voluntary leisure-time reading and such factors as age, gender, intelligence, academic achievement and standard of living. It also looks at the influences of parents, teachers, peers, contemporary literature-teaching practices, school and public libraries, and leisure- time pursuits other than reading. Many suggestions are offered for further research into finer aspects of those considerations. Many of the findings serve merely to corroborate research from abroad, particularly in respect of age, gender and intelligence. That is none the less alarming when a striking decline in reading is found to occur in the early years of the secondary school. A number of other interesting findings emerge. Standard of living is shown to be inversely correlated with amount of reading, and television-viewing is not found to displace reading. Nor are other leisure-time pursuits found to affect amount of reading: avid readers are by and large extremely active and committed pupils. Reading emerges from the study as providing its own peculiar satisfaction, as does each of the other leisure activities investigated. The challenge is to ensure that infrequent readers become aware of what reading has to offer, and strategies for attempting to achieve that are posited, particularly with regard to the roles of public and school libraries. The roles of teachers and parents are found to be crucial to the development of an appetite for books, and it is suggested that schools and parents liaise formally and closely in this matter. The study groups pupils by a number of personal variables, and investigates their reactions to common forms and genres as well as to certain specifics of style, thereby discussing the relationship between reading, social maturity and academic achievement It argues strongly for recognition of the fact that educating secondary-school pupils in the development of keen and sensitive lifelong reading habits is a process which cannot be systematically taught as a set of skills.
- Full Text:
- Date Issued: 1990
- Authors: Gardner, John Murray
- Date: 1990
- Subjects: Reading interests English language -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal Books and reading -- South Africa -- KwaZulu-Natal Readership surveys -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1781 , http://hdl.handle.net/10962/d1003666
- Description: The study derives from a belief, based on many researchers' writings, that wide and frequent book-reading aids the development of knowledge, emotional maturity and human sympathy, which are all essential attributes in a fragmented culture such as South Africa's. It is not accepted that conventional secondary-school literature-teaching in this country promotes a lifelong reading habit among the majority of pupils and a plea is made for the recognition of Reading as a curricular entity in its own right. The study suggests that, owing to a paucity of local research in this field, South African teachers and educational authorities are severely disadvantaged. If they are unable to offer advice based on a proper study of their pupils as readers, they run the risk of guiding many pupils' reading along paths that cannot promise satisfaction and fulfilment. Such stultifying of reading habits would contradict the aims of the present National Core Syllabuses for English (First Language). The thesis sets little store by the investigation of specific bookchoices, pointing out that the validity of such incidental findings, if gleaned from a latitudinal survey, is questionable. Instead, using the findings of questionnaires administered to nearly 2 800 pupils and their teachers, the thesis investigates the relationships between voluntary leisure-time reading and such factors as age, gender, intelligence, academic achievement and standard of living. It also looks at the influences of parents, teachers, peers, contemporary literature-teaching practices, school and public libraries, and leisure- time pursuits other than reading. Many suggestions are offered for further research into finer aspects of those considerations. Many of the findings serve merely to corroborate research from abroad, particularly in respect of age, gender and intelligence. That is none the less alarming when a striking decline in reading is found to occur in the early years of the secondary school. A number of other interesting findings emerge. Standard of living is shown to be inversely correlated with amount of reading, and television-viewing is not found to displace reading. Nor are other leisure-time pursuits found to affect amount of reading: avid readers are by and large extremely active and committed pupils. Reading emerges from the study as providing its own peculiar satisfaction, as does each of the other leisure activities investigated. The challenge is to ensure that infrequent readers become aware of what reading has to offer, and strategies for attempting to achieve that are posited, particularly with regard to the roles of public and school libraries. The roles of teachers and parents are found to be crucial to the development of an appetite for books, and it is suggested that schools and parents liaise formally and closely in this matter. The study groups pupils by a number of personal variables, and investigates their reactions to common forms and genres as well as to certain specifics of style, thereby discussing the relationship between reading, social maturity and academic achievement It argues strongly for recognition of the fact that educating secondary-school pupils in the development of keen and sensitive lifelong reading habits is a process which cannot be systematically taught as a set of skills.
- Full Text:
- Date Issued: 1990
Alternative mythical structures in the fiction of Patrick White
- Authors: Bosman, Brenda Evadne
- Date: 1990
- Subjects: White, Patrick, 1912-1990 , White, Patrick, 1912-1990 -- Criticism and interpretation , Myth in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2170 , http://hdl.handle.net/10962/d1001821
- Description: The texts in this study interrogate the dominant myths which have affected the constructs of identity and history in the white Australian socio-historical context. These myths are exposed by White as ideologically determined and as operating by processes of exclusion, repression and marginalisation. White challenges the autonomy of both European and Australian cultures, reveals the ideological complicity between them and adopts a critical approach to all Western cultural assumptions. As a post-colonial writer, White shares the need of both post-colonising and post-colonised groups for an identity established not in terms of the colonial power but in terms of themselves. As a dissident white male, he is a privileged member of the post- colonising group but one who rejects the dominant discourses as illegitimate and unlegitimating. He offers a re-writing of the myths underpinning colonial and post-colonising discourses which privileges their suppressed and repressed elements. His re-writings affect aboriginal men and women, white women and the 'privileged' white male whose subjection to social control is masked as unproblematic freedom. White's re-writing of myth enbraces the post-modern as well as the post- colonial. He not only deconstructs and demystifies the phallogocentric/ethnocentric order of things; he also attempts to avoid totalization by privileging indeterminacy, fragmentation, hybridization and those liminary states which defy articulation: the ecstatic, the abject, the unspeakable. He himself is denied authority in that his re-writings are presented as mere acts in the always provisional process of making interpretations. White acknowledges the problematics of both presentation and re-presentation - an unresolved tension between the post-colonial desire for self-definition and the post-modern decentring of all meaning and interpretation permeates his discourse. The close readings of the texts attempt, accordingly, to reflect varying oppositional strategies: those which seek to overturn hierarchies and expose power-relations and those which seek an idiom in which contemporary Australia may find its least distorted reflexion. Within this ideological context, the Lacanian thematics of the subject, and their re-writing by Kristeva, are linked with dialectical criticism in an attempt to reflect a strictly provisional process of (re) construction
- Full Text:
- Date Issued: 1990
- Authors: Bosman, Brenda Evadne
- Date: 1990
- Subjects: White, Patrick, 1912-1990 , White, Patrick, 1912-1990 -- Criticism and interpretation , Myth in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2170 , http://hdl.handle.net/10962/d1001821
- Description: The texts in this study interrogate the dominant myths which have affected the constructs of identity and history in the white Australian socio-historical context. These myths are exposed by White as ideologically determined and as operating by processes of exclusion, repression and marginalisation. White challenges the autonomy of both European and Australian cultures, reveals the ideological complicity between them and adopts a critical approach to all Western cultural assumptions. As a post-colonial writer, White shares the need of both post-colonising and post-colonised groups for an identity established not in terms of the colonial power but in terms of themselves. As a dissident white male, he is a privileged member of the post- colonising group but one who rejects the dominant discourses as illegitimate and unlegitimating. He offers a re-writing of the myths underpinning colonial and post-colonising discourses which privileges their suppressed and repressed elements. His re-writings affect aboriginal men and women, white women and the 'privileged' white male whose subjection to social control is masked as unproblematic freedom. White's re-writing of myth enbraces the post-modern as well as the post- colonial. He not only deconstructs and demystifies the phallogocentric/ethnocentric order of things; he also attempts to avoid totalization by privileging indeterminacy, fragmentation, hybridization and those liminary states which defy articulation: the ecstatic, the abject, the unspeakable. He himself is denied authority in that his re-writings are presented as mere acts in the always provisional process of making interpretations. White acknowledges the problematics of both presentation and re-presentation - an unresolved tension between the post-colonial desire for self-definition and the post-modern decentring of all meaning and interpretation permeates his discourse. The close readings of the texts attempt, accordingly, to reflect varying oppositional strategies: those which seek to overturn hierarchies and expose power-relations and those which seek an idiom in which contemporary Australia may find its least distorted reflexion. Within this ideological context, the Lacanian thematics of the subject, and their re-writing by Kristeva, are linked with dialectical criticism in an attempt to reflect a strictly provisional process of (re) construction
- Full Text:
- Date Issued: 1990
Aspects of the biology of the infaunal bivalve Mollusc Solen cylindraceus (Hanley) in the Kariega estuary
- De Villiers, Casper Johannes
- Authors: De Villiers, Casper Johannes
- Date: 1990
- Subjects: Mollusks -- South Africa -- Eastern Cape Bivalves -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5639 , http://hdl.handle.net/10962/d1005321
- Description: Solen cylindraceus is an infaunal filter-feeding bivalve inhabiting the intertidal mud banks of many southern African estuaries. It is particularly abundant in the Kariega estuary (33°41'S; 26°42'E) where it reaches densities of 400m⁻² (192g shell-free dry wt. m⁻²). The Kariega is a permanently open, marine dominated estuary about 18km in length, and S. cylindraceus is most abundant in its middle and upper reaches. Some physical characteristics of the estuary (temperature, salinity, sediment and water turbidity) are described, and the possible role of these factors in determining the density and distribution of S. cylindraceus within the Kariega estuary, is discussed. The structure of the alimentary system, gills and labial palps of S. cylintfraceus is described, all of which showed no major variation from the "typical" eulamellibranchiate form. Solen cylintfraceus was found to be a euryhaline osmoconformer with a salinity tolerance range of 15-65%. When animals were removed from their burrows, osmotic equilibration of the haemolymph was rapid (1-2 hours). By contrast, in animals left undisturbed in their burrows, osmotic equilibration was retarded (72-204 hours). It is suggested that the observed decrease in the rate of change of haemolymph osmolarity for animals in their burrows is linked to the stability of the interstitial salinity. A temperature tolerance range of 5-44°C was determined for S. cylintfraceus (in situ), in which prolonged exposure to 5°C and 40-45°C (12-36 hours respectively) resulted in a decreased burrowing ability, coma and death. Animal burrowing responses were not affected by temperatures in the range 15-35°C. Field experiments were carried out over several tidal cycles, in which the measurement of crystalline style volume was used as a means of assessing extracellular digestive activity. No major variation in style volume was recorded and it appeared that S. cylindraceus did not exhibit any cyclical pattern of style dissolution and regeneration. It is suggested that S. cylindraceus feeds continuously from the water column during high tide and possibly within its burrow, at or below the water table, during low tide. At a suspensoid concentration of 5Omg l⁻¹, S. cylindraceus was found to filter water almost continuously (90-95% of the time). Time spent filtering dropped to 68% at 100mg l⁻¹ and 32% at 500mg l⁻¹. Filtration rates for summer collected animals (25°C) were 22.86 ± 4.36ml min.⁻¹, some 3ml min.⁻¹ greater than that recorded for winter (16°C) collected animals. Filtration rate may be expressed as a function of shell length by the equations: y=0.247x¹̇⁰⁶⁶ (winter) and y=0.758x⁰̇⁸²⁶ (summer). Solen cylindraceus was capable of acclimating its filtration rate to both high and low temperatures under laboratory conditions. Filtration rate exhibited a thermal optimum in the range 15-35°C, declining at higher and lower temperatures. Q₁₀ values of filtration decreased rapidly from greater than 4 to less than 2, when the thermal optimum was reached. Maximum rates generally occurred at approximately 5°C above the temperature to which the animal had been acclimated. Optimal filtration rates (19-23ml min.⁻¹) were recorded in the salinity range 15-45%. When subjected to abrupt changes in salinity, filtration rates were immediately depressed. The extent and duration of these decreased filtration rates were dependent upon the magnitude and direction of salinity change, and were always less in animals exposed to hyper- than hyposaline conditions. Animals exposed to increased temperature and simultaneous elevated or unchanged salinity, showed a slight increase in filtration rate followed by rapid acclimation. A decrease in both temperature and salinity resulted in an initial decrease in filtration rate and a longer acclimation period. The ability of S. cylindraceus to acclimate fully within a wide temperature and salinity range, and to filter maximally in hypersaline conditions may, in part, explain its unusually high abundance in the Kariega estuary, despite it being close to the southernmost limit of the animal's geographical distribution. No significant difference in flItration rate was recorded at suspensoid concentrations of 5-100mg 1⁻¹. However, at 250 and 500mg l⁻¹ filtration rates decreased significantly, and coincided with increased levels of pseudofaecal production. Solen cylindraceus retained particles down to 2.5-3.0µm with great efficiency (ca. 60-90% efficiency). Below this particle size, retention efficiency decreased rapidly and a net production of particles was recorded below 1.51µm. Particle retention was independent of temperature (15 and 25°C) and salinity (15 and 35%). Use was made of stable carbon isotope analyses (¹³C/¹²C ratios) in an attempt to determine the important food sources of S. cylindraceus within the Kariega estuary. The results obtained demonstrated an enrichment in δ¹³ values for S. cylindraceus from the upper (-27.9%) to the middle (-25%c) and lower (-21.6%o ) reaches of the estuary, with no seasonal variation apparent. The bivalve was substantially more depleted in ¹³C relative to the dominant aquatic macrophytes Zostera capensis (-9.1 to -15.6%o) and Spartina maritima (-12.5%o). The use of δ¹³ alone, however, to unequivocally "pin point" specific food sources of a filter feeder in a predominantly detritus based food web, is limited. It is suggested that in the Kariega estuary, riparian litter and other terrestrially derived vegetation contribute to the carbon pool. A possible contribution of ¹³C depleted food sources via chemoautotrophic and/or anaerobic pathways, to the diet of S. cylindraceus, is suggested.
- Full Text:
- Date Issued: 1990
- Authors: De Villiers, Casper Johannes
- Date: 1990
- Subjects: Mollusks -- South Africa -- Eastern Cape Bivalves -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5639 , http://hdl.handle.net/10962/d1005321
- Description: Solen cylindraceus is an infaunal filter-feeding bivalve inhabiting the intertidal mud banks of many southern African estuaries. It is particularly abundant in the Kariega estuary (33°41'S; 26°42'E) where it reaches densities of 400m⁻² (192g shell-free dry wt. m⁻²). The Kariega is a permanently open, marine dominated estuary about 18km in length, and S. cylindraceus is most abundant in its middle and upper reaches. Some physical characteristics of the estuary (temperature, salinity, sediment and water turbidity) are described, and the possible role of these factors in determining the density and distribution of S. cylindraceus within the Kariega estuary, is discussed. The structure of the alimentary system, gills and labial palps of S. cylintfraceus is described, all of which showed no major variation from the "typical" eulamellibranchiate form. Solen cylintfraceus was found to be a euryhaline osmoconformer with a salinity tolerance range of 15-65%. When animals were removed from their burrows, osmotic equilibration of the haemolymph was rapid (1-2 hours). By contrast, in animals left undisturbed in their burrows, osmotic equilibration was retarded (72-204 hours). It is suggested that the observed decrease in the rate of change of haemolymph osmolarity for animals in their burrows is linked to the stability of the interstitial salinity. A temperature tolerance range of 5-44°C was determined for S. cylintfraceus (in situ), in which prolonged exposure to 5°C and 40-45°C (12-36 hours respectively) resulted in a decreased burrowing ability, coma and death. Animal burrowing responses were not affected by temperatures in the range 15-35°C. Field experiments were carried out over several tidal cycles, in which the measurement of crystalline style volume was used as a means of assessing extracellular digestive activity. No major variation in style volume was recorded and it appeared that S. cylindraceus did not exhibit any cyclical pattern of style dissolution and regeneration. It is suggested that S. cylindraceus feeds continuously from the water column during high tide and possibly within its burrow, at or below the water table, during low tide. At a suspensoid concentration of 5Omg l⁻¹, S. cylindraceus was found to filter water almost continuously (90-95% of the time). Time spent filtering dropped to 68% at 100mg l⁻¹ and 32% at 500mg l⁻¹. Filtration rates for summer collected animals (25°C) were 22.86 ± 4.36ml min.⁻¹, some 3ml min.⁻¹ greater than that recorded for winter (16°C) collected animals. Filtration rate may be expressed as a function of shell length by the equations: y=0.247x¹̇⁰⁶⁶ (winter) and y=0.758x⁰̇⁸²⁶ (summer). Solen cylindraceus was capable of acclimating its filtration rate to both high and low temperatures under laboratory conditions. Filtration rate exhibited a thermal optimum in the range 15-35°C, declining at higher and lower temperatures. Q₁₀ values of filtration decreased rapidly from greater than 4 to less than 2, when the thermal optimum was reached. Maximum rates generally occurred at approximately 5°C above the temperature to which the animal had been acclimated. Optimal filtration rates (19-23ml min.⁻¹) were recorded in the salinity range 15-45%. When subjected to abrupt changes in salinity, filtration rates were immediately depressed. The extent and duration of these decreased filtration rates were dependent upon the magnitude and direction of salinity change, and were always less in animals exposed to hyper- than hyposaline conditions. Animals exposed to increased temperature and simultaneous elevated or unchanged salinity, showed a slight increase in filtration rate followed by rapid acclimation. A decrease in both temperature and salinity resulted in an initial decrease in filtration rate and a longer acclimation period. The ability of S. cylindraceus to acclimate fully within a wide temperature and salinity range, and to filter maximally in hypersaline conditions may, in part, explain its unusually high abundance in the Kariega estuary, despite it being close to the southernmost limit of the animal's geographical distribution. No significant difference in flItration rate was recorded at suspensoid concentrations of 5-100mg 1⁻¹. However, at 250 and 500mg l⁻¹ filtration rates decreased significantly, and coincided with increased levels of pseudofaecal production. Solen cylindraceus retained particles down to 2.5-3.0µm with great efficiency (ca. 60-90% efficiency). Below this particle size, retention efficiency decreased rapidly and a net production of particles was recorded below 1.51µm. Particle retention was independent of temperature (15 and 25°C) and salinity (15 and 35%). Use was made of stable carbon isotope analyses (¹³C/¹²C ratios) in an attempt to determine the important food sources of S. cylindraceus within the Kariega estuary. The results obtained demonstrated an enrichment in δ¹³ values for S. cylindraceus from the upper (-27.9%) to the middle (-25%c) and lower (-21.6%o ) reaches of the estuary, with no seasonal variation apparent. The bivalve was substantially more depleted in ¹³C relative to the dominant aquatic macrophytes Zostera capensis (-9.1 to -15.6%o) and Spartina maritima (-12.5%o). The use of δ¹³ alone, however, to unequivocally "pin point" specific food sources of a filter feeder in a predominantly detritus based food web, is limited. It is suggested that in the Kariega estuary, riparian litter and other terrestrially derived vegetation contribute to the carbon pool. A possible contribution of ¹³C depleted food sources via chemoautotrophic and/or anaerobic pathways, to the diet of S. cylindraceus, is suggested.
- Full Text:
- Date Issued: 1990
Aspects of the nutritional physiology and dietary requirements of juvenile and adult sharptooth catfish, Clarias Gariepinus (Pisces : clariidae)
- Authors: Uys, Wynand
- Date: 1990
- Subjects: Clariidae Catfishes Catfishes -- Nutrition-requirements Clarias
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5225 , http://hdl.handle.net/10962/d1005068
- Description: Past and current research on the biology and culture of the sharptooth catfish (Clarias gariepinus) has stimulated the development of its commercial production. At the inception of this project in 1985, it was decided that the development of an optimal dry feed was the most important step in developing a more complete culture technology for the species. The objectives of the project were, therefore, to investigate aspects of the nutritional physiology and dietary requirements of the species to provide the necessary information for the formulation of optimum economical feeds. A review of the natural feeding biology of the species provided valuable information with regard to its food preferences. From this information, and by estimating the nutritional composition of its preferred natural diet, it could be concluded that the animal requires a relatively high dietary protein content. This conclusion was substantiated by studies of the functional morphology of the digestive system (gross and fine structure). The characteristics of the digestive system and external anatomy were found to be typical of an opportunistic, omnivorous predator. The ontogenetic development of the digestive system is relatively fast, and enables the utilization of a variety of diets efficiently from an early stage. Since the ability of an animal to digest a given substance is predominantly dependent on the presence of appropriate enzymes the quantification and characterization of C. gariepinus digestive enzyme activities were investigated on an experimental basis. This work revealed that the animal has relatively high levels of digestive enzyme activities, and that its proteolytic enzyme activities correspond with those of other carnivorous fishes, while its starch digesting abilities correspond with those of specialized herbivores. Also, the high levels of lysozyme and alkaline phosphatase indicate an adaptation to detritivory, making this fish a truly opportunistic omnivore. Evidence was found to suggest that sharptooth catfish are able to re-absorb secreted digestive enzymes in the posterior section of its intestinal tract. It was shown that digestive enzyme activities were induced by food intake, and that no inherent rhythmicity in digestive activities seemed to occur. The development of digestive enzyme systems in the early life history of this animal was found to be also extremely rapid (complete within 10-16 days after hatching). It was also shown that artificial dry feed stimulates higher levels of digestive enzyme activities in larvae and juveniles than natural food. Although increased cellulase activity was found in larvae and juveniles that were fed on live zooplankton, the relative contribution of exogenous prey enzymes to protein digestion could not be ascertained. Specific nutritional requirements were investigated by means of feeding trials. The results of these trials confirmed the above indications regarding the dietary requirements of sharptooth catfish. It was concluded that for optimal growth and production performance, this animal requires a dietary protein content of 40-42%, a dietary lipid content of 10-12% and that diets should contain 14-16 kJ/g digestible energy. The optimum protein-to-energy ratio was found to be 26-29mg protein per kJ of digestible energy. Dietary requirements are evidently the same for juveniles and adults, except that younger fish require higher relative feeding levels. Finally, practical feed formulations were evaluated in terms of their economic feasibility. The results of these trials are presented along with recommendations on the formulation of commercial feeds for C. gariepinus. A computer program with which to implement least cost feed formulation by means of linear programming is provided.
- Full Text:
- Date Issued: 1990
- Authors: Uys, Wynand
- Date: 1990
- Subjects: Clariidae Catfishes Catfishes -- Nutrition-requirements Clarias
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5225 , http://hdl.handle.net/10962/d1005068
- Description: Past and current research on the biology and culture of the sharptooth catfish (Clarias gariepinus) has stimulated the development of its commercial production. At the inception of this project in 1985, it was decided that the development of an optimal dry feed was the most important step in developing a more complete culture technology for the species. The objectives of the project were, therefore, to investigate aspects of the nutritional physiology and dietary requirements of the species to provide the necessary information for the formulation of optimum economical feeds. A review of the natural feeding biology of the species provided valuable information with regard to its food preferences. From this information, and by estimating the nutritional composition of its preferred natural diet, it could be concluded that the animal requires a relatively high dietary protein content. This conclusion was substantiated by studies of the functional morphology of the digestive system (gross and fine structure). The characteristics of the digestive system and external anatomy were found to be typical of an opportunistic, omnivorous predator. The ontogenetic development of the digestive system is relatively fast, and enables the utilization of a variety of diets efficiently from an early stage. Since the ability of an animal to digest a given substance is predominantly dependent on the presence of appropriate enzymes the quantification and characterization of C. gariepinus digestive enzyme activities were investigated on an experimental basis. This work revealed that the animal has relatively high levels of digestive enzyme activities, and that its proteolytic enzyme activities correspond with those of other carnivorous fishes, while its starch digesting abilities correspond with those of specialized herbivores. Also, the high levels of lysozyme and alkaline phosphatase indicate an adaptation to detritivory, making this fish a truly opportunistic omnivore. Evidence was found to suggest that sharptooth catfish are able to re-absorb secreted digestive enzymes in the posterior section of its intestinal tract. It was shown that digestive enzyme activities were induced by food intake, and that no inherent rhythmicity in digestive activities seemed to occur. The development of digestive enzyme systems in the early life history of this animal was found to be also extremely rapid (complete within 10-16 days after hatching). It was also shown that artificial dry feed stimulates higher levels of digestive enzyme activities in larvae and juveniles than natural food. Although increased cellulase activity was found in larvae and juveniles that were fed on live zooplankton, the relative contribution of exogenous prey enzymes to protein digestion could not be ascertained. Specific nutritional requirements were investigated by means of feeding trials. The results of these trials confirmed the above indications regarding the dietary requirements of sharptooth catfish. It was concluded that for optimal growth and production performance, this animal requires a dietary protein content of 40-42%, a dietary lipid content of 10-12% and that diets should contain 14-16 kJ/g digestible energy. The optimum protein-to-energy ratio was found to be 26-29mg protein per kJ of digestible energy. Dietary requirements are evidently the same for juveniles and adults, except that younger fish require higher relative feeding levels. Finally, practical feed formulations were evaluated in terms of their economic feasibility. The results of these trials are presented along with recommendations on the formulation of commercial feeds for C. gariepinus. A computer program with which to implement least cost feed formulation by means of linear programming is provided.
- Full Text:
- Date Issued: 1990
Between freedom and givenness: (a study of the hermeneutical consequences of the concept of canon for the authority of scripture)
- Authors: Latham, Jonathan Cyril
- Date: 1990
- Subjects: Bible -- Evidences, authority, etc. , Authority -- Religious aspects , Canon (Literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1216 , http://hdl.handle.net/10962/d1001546
- Description: The aim of this thesis is to arrive at an understanding of the authority of scripture that is able to accommodate both a faith perspective and the fruits of the historical-critical approach to the New Testament. Put differently, the aim of this thesis is the pursuit of a specifically christian, faith-promoting, reading of the New Testament whilst still enjoying the benefit, in an as uncompromised a form as possible, of the historical- critical approach. In a sense it may be said that this task, given that the roots of both the historical-critical approach and modern Western culture are deeply imbedded in Rationalism, is equivalent to the basic hermeneutical question of whether it is possible to interpret scripture relevantly from within a cultural web of meaning that does not readily accommodate that embodied in the New Testament. In section one of this dissertation we present a characteristic depiction, based on the historical-critical theory of literature, of the authority of the New Testament. This is followed by a brief assessment that makes explicit why the historical- critical approach is not conducive to the adoption of a faith perspective on these writings. In section two, still and inevitably based on critical foundations, we adopt a perspective that is more sympathetic to faith and that seeks to discover in the concerns evidenced in the canonical process, when traditions about Jesus gradually took on more complex and stable forms, culminating in the canon of the New Testament, guidelines in helping us to deal with the problem with which this study is concerned . In the specific example of the rather ordinary concerns underlying the unusual history of the pericope de adultera (John 7:53-8:11), examined against the background of the interests underlying the canonical process, it becomes clear that christians from the very beginning faced a dilemma not unlike that with which the historical-critical approach confronts us. They had to interpret afresh, and faithfully, the traditions in order to meet the demands of situations that had never been foreseen by earlier tradents. In this respect, therefore, the history of the pericope de adultera presents us with an ongoing struggle to hold in tension the demands of new contexts with the imperative of strict continuity with Jesus. In section three, on the basis of the foundation of the authority of scripture in strict continuity with Jesus combined with the contextual reinterpretation of the tradition, the social sciences are employed. Using the social sciences, it is discovered that the two contradictory approaches that we wish to reconcile form part of two different models for interpreting reality. It is on this basis, and made possible by the common culture underlying these opposing models and by the common contact with an unspecified common core of concrete reality, that a solution is proposed in terms of a complex 'fusion of horizons', promoted by a 'precipitative environment'. In the conclusion our solution is decisively aligned with the concerns evidenced in the canonical process
- Full Text:
- Date Issued: 1990
- Authors: Latham, Jonathan Cyril
- Date: 1990
- Subjects: Bible -- Evidences, authority, etc. , Authority -- Religious aspects , Canon (Literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1216 , http://hdl.handle.net/10962/d1001546
- Description: The aim of this thesis is to arrive at an understanding of the authority of scripture that is able to accommodate both a faith perspective and the fruits of the historical-critical approach to the New Testament. Put differently, the aim of this thesis is the pursuit of a specifically christian, faith-promoting, reading of the New Testament whilst still enjoying the benefit, in an as uncompromised a form as possible, of the historical- critical approach. In a sense it may be said that this task, given that the roots of both the historical-critical approach and modern Western culture are deeply imbedded in Rationalism, is equivalent to the basic hermeneutical question of whether it is possible to interpret scripture relevantly from within a cultural web of meaning that does not readily accommodate that embodied in the New Testament. In section one of this dissertation we present a characteristic depiction, based on the historical-critical theory of literature, of the authority of the New Testament. This is followed by a brief assessment that makes explicit why the historical- critical approach is not conducive to the adoption of a faith perspective on these writings. In section two, still and inevitably based on critical foundations, we adopt a perspective that is more sympathetic to faith and that seeks to discover in the concerns evidenced in the canonical process, when traditions about Jesus gradually took on more complex and stable forms, culminating in the canon of the New Testament, guidelines in helping us to deal with the problem with which this study is concerned . In the specific example of the rather ordinary concerns underlying the unusual history of the pericope de adultera (John 7:53-8:11), examined against the background of the interests underlying the canonical process, it becomes clear that christians from the very beginning faced a dilemma not unlike that with which the historical-critical approach confronts us. They had to interpret afresh, and faithfully, the traditions in order to meet the demands of situations that had never been foreseen by earlier tradents. In this respect, therefore, the history of the pericope de adultera presents us with an ongoing struggle to hold in tension the demands of new contexts with the imperative of strict continuity with Jesus. In section three, on the basis of the foundation of the authority of scripture in strict continuity with Jesus combined with the contextual reinterpretation of the tradition, the social sciences are employed. Using the social sciences, it is discovered that the two contradictory approaches that we wish to reconcile form part of two different models for interpreting reality. It is on this basis, and made possible by the common culture underlying these opposing models and by the common contact with an unspecified common core of concrete reality, that a solution is proposed in terms of a complex 'fusion of horizons', promoted by a 'precipitative environment'. In the conclusion our solution is decisively aligned with the concerns evidenced in the canonical process
- Full Text:
- Date Issued: 1990
Chemical and spectroscopic studies of the capsular polysaccharides of some klebsiella and escherichia coli serotypes
- Authors: Stanley, Shawn Mark Ross
- Date: 1990
- Subjects: Polysaccharides , Klebsiella , Escherichia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3736 , http://hdl.handle.net/10962/d1001525
- Description: The work described in this thesis forms part of an international programme concerned with the structure elucidation of the capsular antigens of some Enterobacteriaceae. Many of the Klebsiella and some of the Escherichia coli are pathogenic to man and, hence, they are of interest. The virulence of bacteria is a multifactorial phenomenon, in which characteristic traits of bacteria and their hosts play comparable and complementary roles. It is accepted that pathogens are more virulent when encapsulated, because, nearly all disease causing bacteria have a capsule when freshly isolated from the host. This increase in pathogenicity is related, in part, to the capsular polysaccharides' ability to avoid or attenuate the host defence mechanisms. In the majority of cases the protective aspects of the capsule are overcome in the latter stages of infection when the formation of specific antibodies by the host has occurred. However there are situations in which an immune state of the infected host is virtually never reached, and susceptiblity to the infecting bacteria is maintained even in the advanced stage of an infection. Explanation of this phenomenon becomes possible by analysing the structure of the polysaccharides. The inability of the host to raise an immune response to the capsule may be because the structure of the polysaccharide is similar or identical to the host's carbohydrates. The serological and pathogenic relatedness of encapsulated E. coli and Klebsiella, to the encapsulated strains of other genera, is based on structural identity or similarity of the respective capsules. Capsular polysaccharides are analysed by both chemical and instrumental methods, and, at present, nuclear magnetic resonance spectroscopy is the most important analytical technique
- Full Text:
- Date Issued: 1990
- Authors: Stanley, Shawn Mark Ross
- Date: 1990
- Subjects: Polysaccharides , Klebsiella , Escherichia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3736 , http://hdl.handle.net/10962/d1001525
- Description: The work described in this thesis forms part of an international programme concerned with the structure elucidation of the capsular antigens of some Enterobacteriaceae. Many of the Klebsiella and some of the Escherichia coli are pathogenic to man and, hence, they are of interest. The virulence of bacteria is a multifactorial phenomenon, in which characteristic traits of bacteria and their hosts play comparable and complementary roles. It is accepted that pathogens are more virulent when encapsulated, because, nearly all disease causing bacteria have a capsule when freshly isolated from the host. This increase in pathogenicity is related, in part, to the capsular polysaccharides' ability to avoid or attenuate the host defence mechanisms. In the majority of cases the protective aspects of the capsule are overcome in the latter stages of infection when the formation of specific antibodies by the host has occurred. However there are situations in which an immune state of the infected host is virtually never reached, and susceptiblity to the infecting bacteria is maintained even in the advanced stage of an infection. Explanation of this phenomenon becomes possible by analysing the structure of the polysaccharides. The inability of the host to raise an immune response to the capsule may be because the structure of the polysaccharide is similar or identical to the host's carbohydrates. The serological and pathogenic relatedness of encapsulated E. coli and Klebsiella, to the encapsulated strains of other genera, is based on structural identity or similarity of the respective capsules. Capsular polysaccharides are analysed by both chemical and instrumental methods, and, at present, nuclear magnetic resonance spectroscopy is the most important analytical technique
- Full Text:
- Date Issued: 1990
Essential fatty acids and ascorbic acid- interactions and effects on melanoma growth
- Authors: Gardiner, Neil Stockenstrom
- Date: 1990
- Subjects: Fatty acids , Melanoma , Mice -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4549 , http://hdl.handle.net/10962/d1018230
- Description: The present study was carried out to determine the effects and possible mechanisms of action of the essential fatty acids (EFAs) (linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (AA)) and ascorbic acid (Asc) on BL6 murine melanoma growth in cell culture and in mice. Interactions between the nutrients in influencing melanoma growth as well as possible mechanisms of the interactions were also examined in the above systems. Cell culture studies revealed that all three EFAs (0-SOμg/ml) and Asc (0-200μg/ml) significantly inhibited melanoma growth at the concentrations used. The EF As were also found to significantly inhibit growth, although to a lesser extent than BL6 cells, of monkey kidney (LLCMK) cells which were used as a non-malignant control cell line. Asc in contrast was found not to inhibit growth of these cells. Supplementation of Asc (lOO)μg/ml) to EFA containing (0-50μg/ml) medium was found to significantly increase inhibition of cell growth in both cell lines, and in the BL6 cells in particular, after taking into account the growth inhibitory effects of Asc in the absence of EFAs. The mechanism of cell growth inhibition by the EF As appeared to involve lipid peroxidation but not enhanced prostaglandin (PG) or leukotriene (LT) synthesis. While Asc was found to increase both lipid peroxidation and PG synthesis in the cells, these mechanisms and enhanced LT synthesis did not appear to have played a role in the inhibition of cell growth by Asc or in the growth inhibitory interaction between Asc and the EF As. In vivo studies revealed that diets containing essential or polyunsaturated fatty acids (EFAs/PUFAs) in the form of vegetable oils, and in particular GLA in the form of evening primrose oil, significantly promoted melanoma growth in mice when compared with an EFA/PUFA free diet containing predominantly saturated fats (SF). Supplementary dietary Asc in contrast was found to significantly inhibit melanoma growth in mice fed EFA/PUFA, and in particular GLA, containing diets but not in mice fed SF cont~g diets. This result appears to indicate the occurrence of an interaction between the two nutrients. Ul The mechanism of tumour promotion by the EP As/PUP As did not appear to have involved enhanced PG or LT synthesis or lipid peroxidation. Since dietary EPA/PUPA manipulation was found to significantly alter the EPA content of tissues, including the melanomas, the mechanism of tumour promotion may have involved changes in the EPA composition of the tumour cells. While supplementary Asc was found to significantly increase the Asc content of certain tissues, including the melanomas, which may have played a role in tumour growth inhibition by Asc, it was found not to affect the EPA content of tissues. Enhanced PG or LT synthesis and lipid perox:idation did not appear to have been involved in the tumour growth inhibitory interaction between Asc and the EP As/PUP As. THe activity of the enzyme delta-6-desaturase, a key enzyme in EF A metabolism which catalyses the desaturation of LA to GLA, and the influence of Asc on activity of the enzyme were also examined. The cultured cells, and BL6 cells in particular, were found to contain significant activity of the enzyme. Whereas murine liver microsomal fractions were found to contain delta-6-desaturase activity, microsomes from melanomas grown in mice were found to lack activity of the enzyme. The significant tumour promoting effects of the GLA containing EPO diet may have been the result of the lack of delta-6-desaturase activity in tumour cells grown in mice. Asc was found to stimulate activity of the enzyme in cultured BL6 cells but not in LLCM.K cells, while dietary Asc and EF A/PUP A manipulation did not influence activity of the enzyme in microsomal fractions. This study has confirmed previous reports of the in vivo tumour promoting effects of dietary EP As/PUP As and the tumour growth inhibitory effects of Asc. The in vitro cell growth inhibitory effects of Asc and the EP As also confirm the results of previous reports. Previous studies investigating possible interactions between Asc and EP As/PUP As in influencing tumour cell growth could not be located in the relevant literature. This study may therefore be one of the first investigations of any such interaction between these nutrients in tumour cells. While this study was not able to identify the mechanisms involved in the different tumour promoting or tumour growth inhibitory effects of the two nutrients in the two systems, it did eliminate a number of potential mechanisms. The results of this study also emphasise the difficulty of attempting to compare the results of in vitro and in vivo studies.
- Full Text:
- Date Issued: 1990
- Authors: Gardiner, Neil Stockenstrom
- Date: 1990
- Subjects: Fatty acids , Melanoma , Mice -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4549 , http://hdl.handle.net/10962/d1018230
- Description: The present study was carried out to determine the effects and possible mechanisms of action of the essential fatty acids (EFAs) (linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (AA)) and ascorbic acid (Asc) on BL6 murine melanoma growth in cell culture and in mice. Interactions between the nutrients in influencing melanoma growth as well as possible mechanisms of the interactions were also examined in the above systems. Cell culture studies revealed that all three EFAs (0-SOμg/ml) and Asc (0-200μg/ml) significantly inhibited melanoma growth at the concentrations used. The EF As were also found to significantly inhibit growth, although to a lesser extent than BL6 cells, of monkey kidney (LLCMK) cells which were used as a non-malignant control cell line. Asc in contrast was found not to inhibit growth of these cells. Supplementation of Asc (lOO)μg/ml) to EFA containing (0-50μg/ml) medium was found to significantly increase inhibition of cell growth in both cell lines, and in the BL6 cells in particular, after taking into account the growth inhibitory effects of Asc in the absence of EFAs. The mechanism of cell growth inhibition by the EF As appeared to involve lipid peroxidation but not enhanced prostaglandin (PG) or leukotriene (LT) synthesis. While Asc was found to increase both lipid peroxidation and PG synthesis in the cells, these mechanisms and enhanced LT synthesis did not appear to have played a role in the inhibition of cell growth by Asc or in the growth inhibitory interaction between Asc and the EF As. In vivo studies revealed that diets containing essential or polyunsaturated fatty acids (EFAs/PUFAs) in the form of vegetable oils, and in particular GLA in the form of evening primrose oil, significantly promoted melanoma growth in mice when compared with an EFA/PUFA free diet containing predominantly saturated fats (SF). Supplementary dietary Asc in contrast was found to significantly inhibit melanoma growth in mice fed EFA/PUFA, and in particular GLA, containing diets but not in mice fed SF cont~g diets. This result appears to indicate the occurrence of an interaction between the two nutrients. Ul The mechanism of tumour promotion by the EP As/PUP As did not appear to have involved enhanced PG or LT synthesis or lipid peroxidation. Since dietary EPA/PUPA manipulation was found to significantly alter the EPA content of tissues, including the melanomas, the mechanism of tumour promotion may have involved changes in the EPA composition of the tumour cells. While supplementary Asc was found to significantly increase the Asc content of certain tissues, including the melanomas, which may have played a role in tumour growth inhibition by Asc, it was found not to affect the EPA content of tissues. Enhanced PG or LT synthesis and lipid perox:idation did not appear to have been involved in the tumour growth inhibitory interaction between Asc and the EP As/PUP As. THe activity of the enzyme delta-6-desaturase, a key enzyme in EF A metabolism which catalyses the desaturation of LA to GLA, and the influence of Asc on activity of the enzyme were also examined. The cultured cells, and BL6 cells in particular, were found to contain significant activity of the enzyme. Whereas murine liver microsomal fractions were found to contain delta-6-desaturase activity, microsomes from melanomas grown in mice were found to lack activity of the enzyme. The significant tumour promoting effects of the GLA containing EPO diet may have been the result of the lack of delta-6-desaturase activity in tumour cells grown in mice. Asc was found to stimulate activity of the enzyme in cultured BL6 cells but not in LLCM.K cells, while dietary Asc and EF A/PUP A manipulation did not influence activity of the enzyme in microsomal fractions. This study has confirmed previous reports of the in vivo tumour promoting effects of dietary EP As/PUP As and the tumour growth inhibitory effects of Asc. The in vitro cell growth inhibitory effects of Asc and the EP As also confirm the results of previous reports. Previous studies investigating possible interactions between Asc and EP As/PUP As in influencing tumour cell growth could not be located in the relevant literature. This study may therefore be one of the first investigations of any such interaction between these nutrients in tumour cells. While this study was not able to identify the mechanisms involved in the different tumour promoting or tumour growth inhibitory effects of the two nutrients in the two systems, it did eliminate a number of potential mechanisms. The results of this study also emphasise the difficulty of attempting to compare the results of in vitro and in vivo studies.
- Full Text:
- Date Issued: 1990
Interrupt-generating active data objects
- Authors: Clayton, Peter Graham
- Date: 1990
- Subjects: Parallel programming (Computer science) Electronic data processing -- Distributed processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4677 , http://hdl.handle.net/10962/d1006700
- Description: An investigation is presented into an interrupt-generating object model which is designed to reduce the effort of programming distributed memory multicomputer networks. The object model is aimed at the natural modelling of problem domains in which a number of concurrent entities interrupt one another as they lay claim to shared resources. The proposed computational model provides for the safe encapsulation of shared data, and incorporates inherent arbitration for simultaneous access to the data. It supplies a predicate triggering mechanism for use in conditional synchronization and as an alternative mechanism to polling. Linguistic support for the proposal requires a novel form of control structure which is able to interface sensibly with interrupt-generating active data objects. The thesis presents the proposal as an elemental language structure, with axiomatic guarantees which enforce safety properties and aid in program proving. The established theory of CSP is used to reason about the object model and its interface. An overview is presented of a programming language called HUL, whose semantics reflect the proposed computational model. Using the syntax of HUL, the application of the interrupt-generating active data object is illustrated. A range of standard concurrent problems is presented to demonstrate the properties of the interrupt-generating computational model. Furthermore, the thesis discusses implementation considerations which enable the model to be mapped precisely onto multicomputer networks, and which sustain the abstract programming level provided by the interrupt-generating active data object in the wider programming structures of HUL.
- Full Text:
- Date Issued: 1990
- Authors: Clayton, Peter Graham
- Date: 1990
- Subjects: Parallel programming (Computer science) Electronic data processing -- Distributed processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4677 , http://hdl.handle.net/10962/d1006700
- Description: An investigation is presented into an interrupt-generating object model which is designed to reduce the effort of programming distributed memory multicomputer networks. The object model is aimed at the natural modelling of problem domains in which a number of concurrent entities interrupt one another as they lay claim to shared resources. The proposed computational model provides for the safe encapsulation of shared data, and incorporates inherent arbitration for simultaneous access to the data. It supplies a predicate triggering mechanism for use in conditional synchronization and as an alternative mechanism to polling. Linguistic support for the proposal requires a novel form of control structure which is able to interface sensibly with interrupt-generating active data objects. The thesis presents the proposal as an elemental language structure, with axiomatic guarantees which enforce safety properties and aid in program proving. The established theory of CSP is used to reason about the object model and its interface. An overview is presented of a programming language called HUL, whose semantics reflect the proposed computational model. Using the syntax of HUL, the application of the interrupt-generating active data object is illustrated. A range of standard concurrent problems is presented to demonstrate the properties of the interrupt-generating computational model. Furthermore, the thesis discusses implementation considerations which enable the model to be mapped precisely onto multicomputer networks, and which sustain the abstract programming level provided by the interrupt-generating active data object in the wider programming structures of HUL.
- Full Text:
- Date Issued: 1990
Isolation of and interaction of nutrients with the linoleoyl-coa desaturase complex
- Authors: Perkins, Denise Mary
- Date: 1990
- Subjects: Cell proliferation , Cancer cells -- Growth -- Regulation , Enzymes -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4558 , http://hdl.handle.net/10962/d1018264
- Description: The termina1 enzyme in the linoleoyl-CoA desaturase enzyme complex, delta-6-desaturase was implied in the control of cell proliferation in cancer cells. One of the aims of this study was to isolate the terminal enzyme. It was decided that in order to isolate this enzyme it was first necessary to isolate the entire complex and then to enzymatically solubilise the first two components of the complex i e cytochrome b5 reductase and cytochrome b5 from the complex resulting in a pure delta-6-desaturase . The first two components were isolated and purified using simplified and easily reproducible methodologies which could be utilised in the final purification of delta-6- desaturase. The entire enzyme complex, linoleoyl-CoA desaturase was also isolated in a pure form and this pure complex was used to attempt to isolate delta-6-desaturase. The terminal enzyme was isolated with some cytochrome b5 still bound to it. The methods used had proven to be successful and with some modifications should yield a pure enzyme. Zinc and GLA were known to play a role in the inhibition of cancer cell proliferation and zinc was hypothesised to inhibit cell growth by stimulating the activity of the linoleoyl-CoA desaturase enzyme complex which is involved in the regulation of cell proliferation. GLA is the product of the reaction that this enzyme complex catalyses and GLA has been shown to inhibit cancer ce ll growth. The effect of GLA on cell growth and linoleoyl-CoA desaturase activity was thus investigated. Results showed that both zinc and GLA inhibited cell growth and that the combined addition of zinc and GLA generally resulted in the inhibition of cell growth and the activation of linoleoyl-CoA desaturase activity in the BL-6 cells while having a less pronounced effect on the LLCMK cells. The results of this study support the hypothesis that zinc may be a cofactor of linoleoyl-CoA desaturase.
- Full Text:
- Date Issued: 1990
- Authors: Perkins, Denise Mary
- Date: 1990
- Subjects: Cell proliferation , Cancer cells -- Growth -- Regulation , Enzymes -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4558 , http://hdl.handle.net/10962/d1018264
- Description: The termina1 enzyme in the linoleoyl-CoA desaturase enzyme complex, delta-6-desaturase was implied in the control of cell proliferation in cancer cells. One of the aims of this study was to isolate the terminal enzyme. It was decided that in order to isolate this enzyme it was first necessary to isolate the entire complex and then to enzymatically solubilise the first two components of the complex i e cytochrome b5 reductase and cytochrome b5 from the complex resulting in a pure delta-6-desaturase . The first two components were isolated and purified using simplified and easily reproducible methodologies which could be utilised in the final purification of delta-6- desaturase. The entire enzyme complex, linoleoyl-CoA desaturase was also isolated in a pure form and this pure complex was used to attempt to isolate delta-6-desaturase. The terminal enzyme was isolated with some cytochrome b5 still bound to it. The methods used had proven to be successful and with some modifications should yield a pure enzyme. Zinc and GLA were known to play a role in the inhibition of cancer cell proliferation and zinc was hypothesised to inhibit cell growth by stimulating the activity of the linoleoyl-CoA desaturase enzyme complex which is involved in the regulation of cell proliferation. GLA is the product of the reaction that this enzyme complex catalyses and GLA has been shown to inhibit cancer ce ll growth. The effect of GLA on cell growth and linoleoyl-CoA desaturase activity was thus investigated. Results showed that both zinc and GLA inhibited cell growth and that the combined addition of zinc and GLA generally resulted in the inhibition of cell growth and the activation of linoleoyl-CoA desaturase activity in the BL-6 cells while having a less pronounced effect on the LLCMK cells. The results of this study support the hypothesis that zinc may be a cofactor of linoleoyl-CoA desaturase.
- Full Text:
- Date Issued: 1990
Radio studies of ionized hydrogen in the southern Milky Way
- Authors: Gaylard, Michael John
- Date: 1990
- Subjects: Interstellar hydrogen Milky Way Astrophysics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5440 , http://hdl.handle.net/10962/d1001993
- Description: This thesis describes the results of a survey of the HI42ɑ recombination line emission at 2.3 GHz from HII regions in the Southern Milky Way, carried out with the 26 m diameter Hartebeesthoek radio telescope. The Galactic Longitude range covered was 290° to 40°. Single recombination lines were detected from 375 positions. Multiple lines were observed towards 90 positions in the inner Galaxy. No line emission could be detected in 28 positions. Continuum antenna temperatures were estimated from drift scans or radio maps observed for the purpose. LTE electron temperatures and turbulent velocities of the HII regions were calculated where possible. The properties of the sample were compared to those observed in HI09ɑ surveys. The lines observed from over 50 positions were first detections, of which half were associated with optically-identified HII regions. In about 150 cases the lines were only the second to be detected from those HII regions. The processes of the radio emission, detection, and analysis were simulated numerically. The detectability of the emission and the magnitude of non-LTE effects and pressure-broadening in multi-component HII regions was predicted and compared to observations. The radio luminosity function of the HII regions was determined over a range of three orders of magnitude in intrinsic brightness for the first time, using techniques which corrected for different types of incompleteness in the samples. The luminosity function was compared to those in five selected spiral galaxies, and shown to lie between those of M33 and M81. An alternate form of the luminosity function was developed for use with a numerical model of the spiral arm structure of the Milky Way. The physical parameters defining the major spiral arms were established by comparing synthesized diagrams of radial velocity versus Galactic Longitude with those actually observed. The faint, extended HII regions S9 and RCW129 in Scorpius, the Barnard Loop in Orion, and S296 in Canis Major were analyzed, using all available data. All the recombination lines from these HII regions were first detections
- Full Text:
- Date Issued: 1990
- Authors: Gaylard, Michael John
- Date: 1990
- Subjects: Interstellar hydrogen Milky Way Astrophysics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5440 , http://hdl.handle.net/10962/d1001993
- Description: This thesis describes the results of a survey of the HI42ɑ recombination line emission at 2.3 GHz from HII regions in the Southern Milky Way, carried out with the 26 m diameter Hartebeesthoek radio telescope. The Galactic Longitude range covered was 290° to 40°. Single recombination lines were detected from 375 positions. Multiple lines were observed towards 90 positions in the inner Galaxy. No line emission could be detected in 28 positions. Continuum antenna temperatures were estimated from drift scans or radio maps observed for the purpose. LTE electron temperatures and turbulent velocities of the HII regions were calculated where possible. The properties of the sample were compared to those observed in HI09ɑ surveys. The lines observed from over 50 positions were first detections, of which half were associated with optically-identified HII regions. In about 150 cases the lines were only the second to be detected from those HII regions. The processes of the radio emission, detection, and analysis were simulated numerically. The detectability of the emission and the magnitude of non-LTE effects and pressure-broadening in multi-component HII regions was predicted and compared to observations. The radio luminosity function of the HII regions was determined over a range of three orders of magnitude in intrinsic brightness for the first time, using techniques which corrected for different types of incompleteness in the samples. The luminosity function was compared to those in five selected spiral galaxies, and shown to lie between those of M33 and M81. An alternate form of the luminosity function was developed for use with a numerical model of the spiral arm structure of the Milky Way. The physical parameters defining the major spiral arms were established by comparing synthesized diagrams of radial velocity versus Galactic Longitude with those actually observed. The faint, extended HII regions S9 and RCW129 in Scorpius, the Barnard Loop in Orion, and S296 in Canis Major were analyzed, using all available data. All the recombination lines from these HII regions were first detections
- Full Text:
- Date Issued: 1990
Students' conceptions of simple D.C. electricity circuits: a study of primary, inappropriate conceptions, learning difficulties of physics students, and implications for instruction
- Authors: Jiya, Zindlovu
- Date: 1990
- Subjects: Physical sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5441 , http://hdl.handle.net/10962/d1001994
- Description: The work attempts to identify the general conceptual problems of the generations of Black students who pass through flrst year physics courses at the University of Fort Hare. In particular the alternative conceptions of students in the area of direct current electricity are investigated, using various techniques including written diagnostic tests. The main method used in the investigation of the student frameworks is the personal interview. A varied number of inappropriate conceptions are identifled in the students in significantly large proportions, and these are found to be dependent on many factors; for example the socio-cultural background like language and its metaphors, and media images. It is established that some of these are exacerbated by student perceptions about the nature of physics and of the scientific enterprise in general. Certain proposals are made about how to remedy the situation; relying mainly on the recently established innovative instructional strategies like conceptual change and cognitive conflict, and on making proposals about restructuring certain forms of presentation of the subject matter, paying attention to how language is used to address the speciflc problems of the students. The importance of providing practical experiences for the students is also emphasised
- Full Text:
- Date Issued: 1990
- Authors: Jiya, Zindlovu
- Date: 1990
- Subjects: Physical sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5441 , http://hdl.handle.net/10962/d1001994
- Description: The work attempts to identify the general conceptual problems of the generations of Black students who pass through flrst year physics courses at the University of Fort Hare. In particular the alternative conceptions of students in the area of direct current electricity are investigated, using various techniques including written diagnostic tests. The main method used in the investigation of the student frameworks is the personal interview. A varied number of inappropriate conceptions are identifled in the students in significantly large proportions, and these are found to be dependent on many factors; for example the socio-cultural background like language and its metaphors, and media images. It is established that some of these are exacerbated by student perceptions about the nature of physics and of the scientific enterprise in general. Certain proposals are made about how to remedy the situation; relying mainly on the recently established innovative instructional strategies like conceptual change and cognitive conflict, and on making proposals about restructuring certain forms of presentation of the subject matter, paying attention to how language is used to address the speciflc problems of the students. The importance of providing practical experiences for the students is also emphasised
- Full Text:
- Date Issued: 1990
The development of theology at Stellenbosch from 1859-1919
- Authors: Thom, Gideon
- Date: 1990
- Subjects: Nederduitse Gereformeerde Kerk , Stellenbosch Theological Seminary
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1215 , http://hdl.handle.net/10962/d1001544
- Description: This study seeks to give an exposition of the development of theology at the Stellenbosch Kweekskool from 1859 until 1919, a period that coincided with the formative years of Afrikaner nationalism. John Murray (1826-1882) was nurtured in evangelical Calvinism but received his theological training in 'moderate' Utrecht. As Calvinist he emphasized salvation by grace and Christian obedience, as evangelical, union with Christ, and as kenoticist he emphasized the relevance of the humanity of Christ. N.J. Hofmeyr (1827-1909) was converted under an evangelical Lutheran and received his training in Utrecht, in the heyday of Dutch ethical and German mediating theology. He was fascinated by the historical Jesus. In his view, the 'religion of Jesus' was not the moralistic one imagined by the modernists, but an experience of sonship, continually challenged by severe temptations. The central theme of his theology was the huiothesia, the sonship of Jesus being the prototype of our sonship. As he was the spiritual father of many generations of Stellenbosch students, his Christocentric emphasis and his doctrine of huiothesia played an important role in the development of NGK spirituality. Other themes in Hofmeyr's theology bore the marks of mediating theology: The idea that the conscience is the voice of God, the 'natural' compatibility between the human and the divine, the importance of experience in the theological enterprise and the idea that grace must accommodate itself to nature. J.I. Marais (1848-1919) and P.J.G. de Vos (1842-1931), who received part of their training in Scotland, were more conservative in theology than Hofmeyr. By the turn of the century De Vos has fully accepted scholastic Calvinism and premillenniaIism; Marais accepted premillennialism around 1914. The experiences of the Anglo-Boer War precipitated the close relationship between the Afrikaner and the NGK, and the lack of a strong doctrine of the church in Stellenbosch theology added to the blurring of distinctions between church and people. The national church of the Scots and Dutch traditions became the volkskerk of the Afrikaner. Important biblical dimensions of Murray and Hofmeyr's theology were neglected after Hofmeyr's death. The conviction that God revealed himself completely in the human Christ was weakened by fundamentalism and the tendency to see God's will in the history of the volk. Their eschatology - which expected great success for the gospel - was replaced by premillennialism, which expected only limited success for missions before the parousia. Hofmeyr's social gospel, which was applied to the problem of the 'poor whites', was gradually replaced by a negative view of the social relevance of the gospel, especially in racial matters. This gradual change of theological direction involved a growing sympathy with fundamentalism and Kuyperianism, but did not consist in a full revival of reformation theology
- Full Text:
- Date Issued: 1990
- Authors: Thom, Gideon
- Date: 1990
- Subjects: Nederduitse Gereformeerde Kerk , Stellenbosch Theological Seminary
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1215 , http://hdl.handle.net/10962/d1001544
- Description: This study seeks to give an exposition of the development of theology at the Stellenbosch Kweekskool from 1859 until 1919, a period that coincided with the formative years of Afrikaner nationalism. John Murray (1826-1882) was nurtured in evangelical Calvinism but received his theological training in 'moderate' Utrecht. As Calvinist he emphasized salvation by grace and Christian obedience, as evangelical, union with Christ, and as kenoticist he emphasized the relevance of the humanity of Christ. N.J. Hofmeyr (1827-1909) was converted under an evangelical Lutheran and received his training in Utrecht, in the heyday of Dutch ethical and German mediating theology. He was fascinated by the historical Jesus. In his view, the 'religion of Jesus' was not the moralistic one imagined by the modernists, but an experience of sonship, continually challenged by severe temptations. The central theme of his theology was the huiothesia, the sonship of Jesus being the prototype of our sonship. As he was the spiritual father of many generations of Stellenbosch students, his Christocentric emphasis and his doctrine of huiothesia played an important role in the development of NGK spirituality. Other themes in Hofmeyr's theology bore the marks of mediating theology: The idea that the conscience is the voice of God, the 'natural' compatibility between the human and the divine, the importance of experience in the theological enterprise and the idea that grace must accommodate itself to nature. J.I. Marais (1848-1919) and P.J.G. de Vos (1842-1931), who received part of their training in Scotland, were more conservative in theology than Hofmeyr. By the turn of the century De Vos has fully accepted scholastic Calvinism and premillenniaIism; Marais accepted premillennialism around 1914. The experiences of the Anglo-Boer War precipitated the close relationship between the Afrikaner and the NGK, and the lack of a strong doctrine of the church in Stellenbosch theology added to the blurring of distinctions between church and people. The national church of the Scots and Dutch traditions became the volkskerk of the Afrikaner. Important biblical dimensions of Murray and Hofmeyr's theology were neglected after Hofmeyr's death. The conviction that God revealed himself completely in the human Christ was weakened by fundamentalism and the tendency to see God's will in the history of the volk. Their eschatology - which expected great success for the gospel - was replaced by premillennialism, which expected only limited success for missions before the parousia. Hofmeyr's social gospel, which was applied to the problem of the 'poor whites', was gradually replaced by a negative view of the social relevance of the gospel, especially in racial matters. This gradual change of theological direction involved a growing sympathy with fundamentalism and Kuyperianism, but did not consist in a full revival of reformation theology
- Full Text:
- Date Issued: 1990
The Eucharist and history
- Paterson, Torquil John Macleod
- Authors: Paterson, Torquil John Macleod
- Date: 1990
- Subjects: Lord's Supper , History -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1311 , http://hdl.handle.net/10962/d1018262
- Description: The thesis delineates an existential view of history, in which the eternal is defined as the ground of authentic human life which underlies true historical action. The historical is the manifestation of the eternal in the unique moment, and redefines the ahistorical conditions of human life. The ahistorical is the social and ideological conditioning of all human knowledge, usually presented in terms of various kinds of myth and ritual . The ahistorical contains both good and bad elements, but always has the tendency to become oppressive and is therefore constantly in conflict with the historical. The life of Jesus is described as the perfect expression of the eternal in true historical action, by which he came into conflict with the ahistorical of his society, as expressed in his death. By his resurrection, his life breaks the limitations of time and becomes transformative enabling all subsequent historical action. The eucharist is described as engaging with each of these dimensions of our existence. By being itself a ritual action containing a myth, the eucharist has an ahistorical form and therefore easily engages with the ahistorical dimensions of society. However, without a constant dialogue with the historical, the eucharist, as an ahistorical medium, can become allied to the dominant forces of society and become a means of oppression. The eucharist has at its centre the remembrance of the historical action of Jesus. True historical action in the present will result from a proper hermeneutic of the gospels. The eucharistic anamnesis must be regarded as part of the wider search for a relevant contemporary christology. The eucharist remembers the Last Supper, which is a parable of the whole life of Jesus and a prelude to his death and is a sacrifice in that it has a sacrificial form, and leads to our historical action, which will usually take the form of a conflict with the ahistorical and have sacrificial dimensions. The eternal only becomes present in our historical action, but the eucharist, by uniting us with the transforming power of the death and resurrection of Jesus, is a powerful aid to such action. The eucharist also provides the opportunity for resonances between Jesus and the ground of our being, thus enabling deep shifts of attitude and consciousness. Three fundamental prerequisites for human life are isolated and related to the eucharist: belonging, nurturing and giving. In order for the eucharist to ennable historical action is must hold these dimensions in tension. In its actual form it does this through the balance between the Words of Institution and the Epiclesis, which, in turn, provide the christological ground of the eucharist and relate this to the present through a particular pneumatology. The real presence is described by the thesis in a way which connects the eucharistic presence with the historical Jesus and leads to our historical action. Finally, some consequences of the thesis for Eucharistic practice are suggested. The relationship between the ahistorical form of the eucharist and the anamnesis is important. In this way the eucharist objectifies the ahistorical, reflects on this in terms of the historical action of Jesus, and reforms the ahistorical by modelling a response. This should lead to a more authentic expression of the eternal in the contemporary world
- Full Text:
- Date Issued: 1990
- Authors: Paterson, Torquil John Macleod
- Date: 1990
- Subjects: Lord's Supper , History -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1311 , http://hdl.handle.net/10962/d1018262
- Description: The thesis delineates an existential view of history, in which the eternal is defined as the ground of authentic human life which underlies true historical action. The historical is the manifestation of the eternal in the unique moment, and redefines the ahistorical conditions of human life. The ahistorical is the social and ideological conditioning of all human knowledge, usually presented in terms of various kinds of myth and ritual . The ahistorical contains both good and bad elements, but always has the tendency to become oppressive and is therefore constantly in conflict with the historical. The life of Jesus is described as the perfect expression of the eternal in true historical action, by which he came into conflict with the ahistorical of his society, as expressed in his death. By his resurrection, his life breaks the limitations of time and becomes transformative enabling all subsequent historical action. The eucharist is described as engaging with each of these dimensions of our existence. By being itself a ritual action containing a myth, the eucharist has an ahistorical form and therefore easily engages with the ahistorical dimensions of society. However, without a constant dialogue with the historical, the eucharist, as an ahistorical medium, can become allied to the dominant forces of society and become a means of oppression. The eucharist has at its centre the remembrance of the historical action of Jesus. True historical action in the present will result from a proper hermeneutic of the gospels. The eucharistic anamnesis must be regarded as part of the wider search for a relevant contemporary christology. The eucharist remembers the Last Supper, which is a parable of the whole life of Jesus and a prelude to his death and is a sacrifice in that it has a sacrificial form, and leads to our historical action, which will usually take the form of a conflict with the ahistorical and have sacrificial dimensions. The eternal only becomes present in our historical action, but the eucharist, by uniting us with the transforming power of the death and resurrection of Jesus, is a powerful aid to such action. The eucharist also provides the opportunity for resonances between Jesus and the ground of our being, thus enabling deep shifts of attitude and consciousness. Three fundamental prerequisites for human life are isolated and related to the eucharist: belonging, nurturing and giving. In order for the eucharist to ennable historical action is must hold these dimensions in tension. In its actual form it does this through the balance between the Words of Institution and the Epiclesis, which, in turn, provide the christological ground of the eucharist and relate this to the present through a particular pneumatology. The real presence is described by the thesis in a way which connects the eucharistic presence with the historical Jesus and leads to our historical action. Finally, some consequences of the thesis for Eucharistic practice are suggested. The relationship between the ahistorical form of the eucharist and the anamnesis is important. In this way the eucharist objectifies the ahistorical, reflects on this in terms of the historical action of Jesus, and reforms the ahistorical by modelling a response. This should lead to a more authentic expression of the eternal in the contemporary world
- Full Text:
- Date Issued: 1990
The observation of extended sources with the Hartebeesthoek radio telescope
- Authors: Mountfort, Peter Ian
- Date: 1990
- Subjects: Radio telescopes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5479 , http://hdl.handle.net/10962/d1005265
- Description: The Hartebeesthoek Radio Telescope is well suited to mapping large areas of sky at 2.3 GHz because of the stability and sensitivity of the noise-adding radiometer (Nicolson, 1970) and cryogenic amplifier used at this frequency, the relatively large 20' beam of the 26 m dish antenna, and its high-speed drive capability. Telescope control programs were written for the Observatory's online computer for automated mapping. Effort centred on removing the curved baseline or 'background' from each Declination (Dec) scan, due to atmospheric and ground radiation contributions varying as the antenna is scanned. Initially these backgrounds were measured over a wide range of Hour Angle (HA) for the Dec range of a map, and an interpolated curve subtracted from each on-source scan for its HA. A common base level was established by comparison with drift scans (observed with the antenna stationary). These different observations (on- and off-source Dec scans and drift scans) were combined into one in the Skymap system by performing Dec scans at a fixed starting HA for a period long enough to permit 'cold sky' and the source to drift through. A background formed by fitting a smooth curve through the lowest sample at each Dec provides a consistent relative base level for all the scans in an observation. A high scanning speed is used so that observations may fruitfully be repeated three times and interleaved to build a reliable, fully sampled map. As each observation has its own background removed, it may be made at any HA. For comparison, maps of Upper Scorpio produced by the earlier method (Baart et al., 1980) and the Magellanic Cloud region produced by Skymap (Mountfort et al., 1987) are shown. Skymap provides a simple and flexible mapping method which relies on the stability of the noise-adding radiometer and high-speed repeated scans to produce good maps of large or small extent with little computation. Correction for drift is more difficult than with systems which use intersecting scans, such as the 'nodding' scans used by Haslam et al. (1981) or the Azimuth scans of Reich (1982).
- Full Text:
- Date Issued: 1990
- Authors: Mountfort, Peter Ian
- Date: 1990
- Subjects: Radio telescopes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5479 , http://hdl.handle.net/10962/d1005265
- Description: The Hartebeesthoek Radio Telescope is well suited to mapping large areas of sky at 2.3 GHz because of the stability and sensitivity of the noise-adding radiometer (Nicolson, 1970) and cryogenic amplifier used at this frequency, the relatively large 20' beam of the 26 m dish antenna, and its high-speed drive capability. Telescope control programs were written for the Observatory's online computer for automated mapping. Effort centred on removing the curved baseline or 'background' from each Declination (Dec) scan, due to atmospheric and ground radiation contributions varying as the antenna is scanned. Initially these backgrounds were measured over a wide range of Hour Angle (HA) for the Dec range of a map, and an interpolated curve subtracted from each on-source scan for its HA. A common base level was established by comparison with drift scans (observed with the antenna stationary). These different observations (on- and off-source Dec scans and drift scans) were combined into one in the Skymap system by performing Dec scans at a fixed starting HA for a period long enough to permit 'cold sky' and the source to drift through. A background formed by fitting a smooth curve through the lowest sample at each Dec provides a consistent relative base level for all the scans in an observation. A high scanning speed is used so that observations may fruitfully be repeated three times and interleaved to build a reliable, fully sampled map. As each observation has its own background removed, it may be made at any HA. For comparison, maps of Upper Scorpio produced by the earlier method (Baart et al., 1980) and the Magellanic Cloud region produced by Skymap (Mountfort et al., 1987) are shown. Skymap provides a simple and flexible mapping method which relies on the stability of the noise-adding radiometer and high-speed repeated scans to produce good maps of large or small extent with little computation. Correction for drift is more difficult than with systems which use intersecting scans, such as the 'nodding' scans used by Haslam et al. (1981) or the Azimuth scans of Reich (1982).
- Full Text:
- Date Issued: 1990
The rise of the French organ symphony with special reference to the works of Alexandre Guilmant and Charles-Marie Widor
- Authors: Johnson, Bruce Richard
- Date: 1990
- Subjects: Guilmant, Alexandre, 1837-1911 Widor, Charles-Marie, 1844-1937 Organ music -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2643 , http://hdl.handle.net/10962/d1002308
- Description: This thesis on the Rise of the French Organ Symphony refers especially to the relevant works of Alexandre Guilmant and Charles-Marie Widor. It commences with a survey of the historical background, dealing with the development of French organ music from the 16th to 19th Century and the development of organ building in France from the 17th to 19th Century. It then proceeds to descriptions of the organs of St Clotilde, La Trinité and St Sulpice Churches in Paris, which are followed by biographical profiles of Cesar Franck, Alexandre Guilmant and Charles-Marie Widor, respectively. The major part of the thesis is devoted to a detailed analysis of the organ sonatas of Guilmant and the organ symphonies of Widor, which are discussed from the point of their cyclic outline and aspects of form and of style. The final chapter summarises the major findings of the analytical research and evaluates by comparative method, the merits and achievements of the two composers. In addition, Appendices are attached, providing specifications of various French organs and pictorial material relevant to the thesis. A separate cassette tape features characteristic sounds of Cavailie-Coll organs.
- Full Text:
- Date Issued: 1990
- Authors: Johnson, Bruce Richard
- Date: 1990
- Subjects: Guilmant, Alexandre, 1837-1911 Widor, Charles-Marie, 1844-1937 Organ music -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2643 , http://hdl.handle.net/10962/d1002308
- Description: This thesis on the Rise of the French Organ Symphony refers especially to the relevant works of Alexandre Guilmant and Charles-Marie Widor. It commences with a survey of the historical background, dealing with the development of French organ music from the 16th to 19th Century and the development of organ building in France from the 17th to 19th Century. It then proceeds to descriptions of the organs of St Clotilde, La Trinité and St Sulpice Churches in Paris, which are followed by biographical profiles of Cesar Franck, Alexandre Guilmant and Charles-Marie Widor, respectively. The major part of the thesis is devoted to a detailed analysis of the organ sonatas of Guilmant and the organ symphonies of Widor, which are discussed from the point of their cyclic outline and aspects of form and of style. The final chapter summarises the major findings of the analytical research and evaluates by comparative method, the merits and achievements of the two composers. In addition, Appendices are attached, providing specifications of various French organs and pictorial material relevant to the thesis. A separate cassette tape features characteristic sounds of Cavailie-Coll organs.
- Full Text:
- Date Issued: 1990
The taxonomy, biogeography and biology of cow and frilled sharks (Chondrichthyes : Hexanchiformes)
- Authors: Ebert, David A
- Date: 1990
- Subjects: Chondrichthyes Hexanchiformes Sharks
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5186 , http://hdl.handle.net/10962/d1001962
- Description: This study was undertaken to investigate the taxonomy, biogeography and biology of cow and frilled sharks (Chondrichthyes: Hexanchiformes). This taxon comprises two families, four genera and six extant species. The hexanchoids are a distinctive group of sharks characterized by six or seven paired gill openings, a single dorsal fin and an anal fin. Adult males of this group lack a siphon sac, but have in its place a clasper sac. This structure, which develops along the claspers, is unique to the Hexanchiformes. Hexanchoid sharks are widely distributed in area and depth. This group ranges from coastal bays and harbors along the open coast out across the continental shelf and down along the slopes to considerable depths. They occur from the equatorial zone to sub-polar regions. However, little is known about the ecology and life history of these sharks. Intraspecific variation of meristic counts were generally low for the Hexanchidae, but high for the Chlamydoselachidae, indicating that subpopulations, subspecies or even additional, new species exist within this family. Based on the indicators used in this study, maturity in male frilled sharks was attained at 916 mm TL, perlon sharks between 700 and 800 mm TL, sixgill sharks approximately 3140 mm TL, bigeyed sixgill sharks at about 1250 mm TL and sevengill sharks at approximately 1550 mm TL. Male reproductive success did not appear to be seasonal since males were found to contain viable sperm all year round. Female perlon sharks begin maturing between 950 mm and 1100 mm TL. Gravid females and newborns were absent from the other size classes and it is suspected that they aggregate in different locations to those of adult males and non-breeding females. Adult females are known at 4210 mm TL and immature at 3500 mm TL, However, a more accurate estimate of the size at maturity is wanting. Newborn sixgills were caught off southern Namibia during mid to late summer over three successive seasons. The occurrence of gravid females carrying term embryos during spring months and newborns during the summer months suggests a late spring or summer pupping period. Sixgill and sevengill sharks give birth in areas of high primary productivity. Energetically, this is advantageous for the newborns to be placed in an area with an abundant food source. The rapid growth rates of sixgill and sevengill sharks over the first year would enhance their survivorship since neither species has many predators. The number of female sevengills entering the breeding population is regulated to ensure that some portion of the population is reproductively active at any one time. The "staggering" of females which enter into the breeding population in any given year indicates a two year reproductive cycle. Fecundity estimates for 19 specimens with a largest egg diameter of at least 40 mm indicates a litter size of 67 to 104. The recapture of an adult female sevengill in approximately the same location in which it was tagged suggests that the same individual sharks may return to the same breeding grounds. As with any predators, sharks tend to exploit advantages over their prey. The hexanchoids, especially the sevengill, have evolved complex foraging strategies including social facilitation whereby they actively hunt in packs for large prey species. Sharks of the order Hexanchiformes, although lacking the diversity of the major shark orders, nonetheless play an integral role in the marine environment. The group's success can be attributed to their apical trophic position. In most habitats in which they occur, hexanchoids have no comparable competitors since equivalent sized sympatric squaloids and carcharhinoids feed at a lower trophic level.
- Full Text:
- Date Issued: 1990
- Authors: Ebert, David A
- Date: 1990
- Subjects: Chondrichthyes Hexanchiformes Sharks
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5186 , http://hdl.handle.net/10962/d1001962
- Description: This study was undertaken to investigate the taxonomy, biogeography and biology of cow and frilled sharks (Chondrichthyes: Hexanchiformes). This taxon comprises two families, four genera and six extant species. The hexanchoids are a distinctive group of sharks characterized by six or seven paired gill openings, a single dorsal fin and an anal fin. Adult males of this group lack a siphon sac, but have in its place a clasper sac. This structure, which develops along the claspers, is unique to the Hexanchiformes. Hexanchoid sharks are widely distributed in area and depth. This group ranges from coastal bays and harbors along the open coast out across the continental shelf and down along the slopes to considerable depths. They occur from the equatorial zone to sub-polar regions. However, little is known about the ecology and life history of these sharks. Intraspecific variation of meristic counts were generally low for the Hexanchidae, but high for the Chlamydoselachidae, indicating that subpopulations, subspecies or even additional, new species exist within this family. Based on the indicators used in this study, maturity in male frilled sharks was attained at 916 mm TL, perlon sharks between 700 and 800 mm TL, sixgill sharks approximately 3140 mm TL, bigeyed sixgill sharks at about 1250 mm TL and sevengill sharks at approximately 1550 mm TL. Male reproductive success did not appear to be seasonal since males were found to contain viable sperm all year round. Female perlon sharks begin maturing between 950 mm and 1100 mm TL. Gravid females and newborns were absent from the other size classes and it is suspected that they aggregate in different locations to those of adult males and non-breeding females. Adult females are known at 4210 mm TL and immature at 3500 mm TL, However, a more accurate estimate of the size at maturity is wanting. Newborn sixgills were caught off southern Namibia during mid to late summer over three successive seasons. The occurrence of gravid females carrying term embryos during spring months and newborns during the summer months suggests a late spring or summer pupping period. Sixgill and sevengill sharks give birth in areas of high primary productivity. Energetically, this is advantageous for the newborns to be placed in an area with an abundant food source. The rapid growth rates of sixgill and sevengill sharks over the first year would enhance their survivorship since neither species has many predators. The number of female sevengills entering the breeding population is regulated to ensure that some portion of the population is reproductively active at any one time. The "staggering" of females which enter into the breeding population in any given year indicates a two year reproductive cycle. Fecundity estimates for 19 specimens with a largest egg diameter of at least 40 mm indicates a litter size of 67 to 104. The recapture of an adult female sevengill in approximately the same location in which it was tagged suggests that the same individual sharks may return to the same breeding grounds. As with any predators, sharks tend to exploit advantages over their prey. The hexanchoids, especially the sevengill, have evolved complex foraging strategies including social facilitation whereby they actively hunt in packs for large prey species. Sharks of the order Hexanchiformes, although lacking the diversity of the major shark orders, nonetheless play an integral role in the marine environment. The group's success can be attributed to their apical trophic position. In most habitats in which they occur, hexanchoids have no comparable competitors since equivalent sized sympatric squaloids and carcharhinoids feed at a lower trophic level.
- Full Text:
- Date Issued: 1990
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