The effects of night work and task diversification on efficiency of performance
- Authors: Munton, Lynne Kerry
- Date: 1998
- Subjects: Night work -- Evaluation , Shift systems , Performance
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:5175 , http://hdl.handle.net/10962/d1018253
- Description: This study investigated the effects of night work on performance efficiency. Night work is generally acknowledged to impair performance, yet much research has contradicted this assertion. The feasibility of including brief periods of physical activity to stimulate arousal within mentally demanding work shifts was also evaluated. Thirty six postgraduate volunteers were assigned to either the cognitive tasks (CT) or cognitive and motor tasks (CMT) group. All subjects performed three psycho-motor tests, using the Vienna Test System, at midday and midnight. The CMT group performed a short cycling activity before each test. Heart rate responses served as physiological measures, the Perceived Strain Scale was used to quantify individual perceptions of strain and performance efficiency was assessed in terms of speed and accuracy. Although several trends were apparent, no significant differences (p < 0.05) were revealed with respect to the three performance variables between the midday and midnight test sessions, or between the CT and CMT subjects, other than the higher heart rates recorded in the CMT group. In summary, neither time of day nor physical activity were found to affect performance within the controlled environment of this study.
- Full Text:
- Date Issued: 1998
- Authors: Munton, Lynne Kerry
- Date: 1998
- Subjects: Night work -- Evaluation , Shift systems , Performance
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:5175 , http://hdl.handle.net/10962/d1018253
- Description: This study investigated the effects of night work on performance efficiency. Night work is generally acknowledged to impair performance, yet much research has contradicted this assertion. The feasibility of including brief periods of physical activity to stimulate arousal within mentally demanding work shifts was also evaluated. Thirty six postgraduate volunteers were assigned to either the cognitive tasks (CT) or cognitive and motor tasks (CMT) group. All subjects performed three psycho-motor tests, using the Vienna Test System, at midday and midnight. The CMT group performed a short cycling activity before each test. Heart rate responses served as physiological measures, the Perceived Strain Scale was used to quantify individual perceptions of strain and performance efficiency was assessed in terms of speed and accuracy. Although several trends were apparent, no significant differences (p < 0.05) were revealed with respect to the three performance variables between the midday and midnight test sessions, or between the CT and CMT subjects, other than the higher heart rates recorded in the CMT group. In summary, neither time of day nor physical activity were found to affect performance within the controlled environment of this study.
- Full Text:
- Date Issued: 1998
The child witness in the accusatorial system
- Authors: Müller, Karen, 1964-
- Date: 1998
- Subjects: Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3715 , http://hdl.handle.net/10962/d1007708 , Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Description: For the purpose of this study tbe child witness in the accusatorial system will be viewed as a source of information. When a witness gives evidence in court, the function of the witness is to provide the court with certain information. A number of crucial questions arise when the witness is a child. Do children bave the ability to remember and relate an event accurately? Are children prone to suggestion and fantasy? What effect, if any, does the court environment have on a child 's ability to convey information? What perceptions do children have about the legal process, and how do these perceptions affect their ability to testify? Do adults influence the information which children impart by the techniques they employ to obtain such information? Accepting the hypothesis that child witnesses are sources of information, the purpose of this study is to evaluate all aspects of the criminal justice system relating to child witnesses as well as available research on children to determine whether it is possible to obtain reliable and accurate information from children. Proposals will be formulated regarding the most successful methods of obtaining reliable and accurate information from children, and how these can be adapted for use by the legal system. The purpose of the study is to develop an approach to children in the legal system that will be fair to children while at the same time protecting the rights of the accused, and which will lead to a successful method of obtaining accurate information.
- Full Text:
- Date Issued: 1998
- Authors: Müller, Karen, 1964-
- Date: 1998
- Subjects: Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3715 , http://hdl.handle.net/10962/d1007708 , Child witnesses , Children -- Legal status, laws, etc. , Child witnesses -- South Africa , Evidence (Law)
- Description: For the purpose of this study tbe child witness in the accusatorial system will be viewed as a source of information. When a witness gives evidence in court, the function of the witness is to provide the court with certain information. A number of crucial questions arise when the witness is a child. Do children bave the ability to remember and relate an event accurately? Are children prone to suggestion and fantasy? What effect, if any, does the court environment have on a child 's ability to convey information? What perceptions do children have about the legal process, and how do these perceptions affect their ability to testify? Do adults influence the information which children impart by the techniques they employ to obtain such information? Accepting the hypothesis that child witnesses are sources of information, the purpose of this study is to evaluate all aspects of the criminal justice system relating to child witnesses as well as available research on children to determine whether it is possible to obtain reliable and accurate information from children. Proposals will be formulated regarding the most successful methods of obtaining reliable and accurate information from children, and how these can be adapted for use by the legal system. The purpose of the study is to develop an approach to children in the legal system that will be fair to children while at the same time protecting the rights of the accused, and which will lead to a successful method of obtaining accurate information.
- Full Text:
- Date Issued: 1998
New rules for security and survival: Southern Africa's adaptation to a changing world environment
- Authors: Naidoo, Sagaren Krishna
- Date: 1998
- Subjects: Internal security -- South Africa , National security -- South Africa , South Africa -- Politics and government -- 1994- , South Africa -- Economic conditions -- 1991-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2814 , http://hdl.handle.net/10962/d1003024 , Internal security -- South Africa , National security -- South Africa , South Africa -- Politics and government -- 1994- , South Africa -- Economic conditions -- 1991-
- Description: In the wake of the post-Cold War era, students of international relations were forced to review their theoretical frameworks to explain new rules for international peace and security. States are now confronted with new constraints for their security and survival as current trends in international politics depict a 'regionalisation' of peace and security. For southern Africa, likewise, the end of the Cold War and, moreover, apartheid, compels its member states to redefine their security strategies and mechanisms for survival. This thesis undertakes to examine southern Africa's adaptation to new rules of a changing world environment, to ensure a stable and secure region, into the next millennium. At the outset of this thesis lies a conceptual contextualisation of security within the major contemporary theoretical approaches of international relations. By examining the essential differences between the redefinitions and new conceptualisations of security, this thesis, firstly argues that the state in southern Africa must be retained as a primary referent of security. This argument is premised on the need to create stronger states for a 'regionalisation' of security in southern Africa. The second issue examined is the changing world environment and its impact on the state and development in Africa, as the new constraints to which the continent must adapt, for security and survival. Arguing that the new international economic order and 'globalisation' dictate the new rules, this chapter asserts that the 'weak' states in Africa need to be strengthened to have the necessary capacity to be the means for its people's security. Finally this thesis examines the new rules for southern Africa's adaptation to a changing world environment. The new rules for the African sub-continent involve the formation of a security regime and economic community with, the power-house, South Africa. Using the Southern African Development Community(SADC) as the umbrella body, the formation of the Organ for Politics, Defence and Security, and signing of trade protocols for a movement towards a free trade area, are evidence of southern Africa's attempts to adapt to new rules for its security. Such adaptation cannot, however, be accomplished with 'weak' states. Southern African states will have to, therefore, be strengthened to attain a more secure adaptation to the new international (economic) order.
- Full Text:
- Date Issued: 1998
- Authors: Naidoo, Sagaren Krishna
- Date: 1998
- Subjects: Internal security -- South Africa , National security -- South Africa , South Africa -- Politics and government -- 1994- , South Africa -- Economic conditions -- 1991-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2814 , http://hdl.handle.net/10962/d1003024 , Internal security -- South Africa , National security -- South Africa , South Africa -- Politics and government -- 1994- , South Africa -- Economic conditions -- 1991-
- Description: In the wake of the post-Cold War era, students of international relations were forced to review their theoretical frameworks to explain new rules for international peace and security. States are now confronted with new constraints for their security and survival as current trends in international politics depict a 'regionalisation' of peace and security. For southern Africa, likewise, the end of the Cold War and, moreover, apartheid, compels its member states to redefine their security strategies and mechanisms for survival. This thesis undertakes to examine southern Africa's adaptation to new rules of a changing world environment, to ensure a stable and secure region, into the next millennium. At the outset of this thesis lies a conceptual contextualisation of security within the major contemporary theoretical approaches of international relations. By examining the essential differences between the redefinitions and new conceptualisations of security, this thesis, firstly argues that the state in southern Africa must be retained as a primary referent of security. This argument is premised on the need to create stronger states for a 'regionalisation' of security in southern Africa. The second issue examined is the changing world environment and its impact on the state and development in Africa, as the new constraints to which the continent must adapt, for security and survival. Arguing that the new international economic order and 'globalisation' dictate the new rules, this chapter asserts that the 'weak' states in Africa need to be strengthened to have the necessary capacity to be the means for its people's security. Finally this thesis examines the new rules for southern Africa's adaptation to a changing world environment. The new rules for the African sub-continent involve the formation of a security regime and economic community with, the power-house, South Africa. Using the Southern African Development Community(SADC) as the umbrella body, the formation of the Organ for Politics, Defence and Security, and signing of trade protocols for a movement towards a free trade area, are evidence of southern Africa's attempts to adapt to new rules for its security. Such adaptation cannot, however, be accomplished with 'weak' states. Southern African states will have to, therefore, be strengthened to attain a more secure adaptation to the new international (economic) order.
- Full Text:
- Date Issued: 1998
Natural resources and local management in the Hewu District of the Eastern Cape : limitations to achieving sustainability
- Authors: Nkansa-Dwamena, Yaw
- Date: 1998
- Subjects: Natural resources -- South Africa -- Management , Natural resources -- South Africa -- Eastern Cape -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4218 , http://hdl.handle.net/10962/d1003787 , Natural resources -- South Africa -- Management , Natural resources -- South Africa -- Eastern Cape -- Management
- Description: The Mceula Commonage Land in the Hewu district lies due northwest of Whittle sea and west of Queenstown in the Eastern Cape. This thesis has two main objectives. Firstly, to survey and analyse the condition of the natural resource. base in the Hewu district with particular reference to water, soil, vegetation and land use. Secondly, to investigate the relationship between scientific approaches to assessing land use degradation and to compare these to the results obtained using a participatory approach of the rural environment of the Hewu district of the Eastern Cape. Random quadrats (4m2) were sampled and corresponding line transects were done with increasing distances from the villages. The Braun-Blanquet method was used to find the cover and abundance of the various species of plants. Data obtained from point sampling along 100 metre line transects was used to assess the condition of the veld using Trollope's technique. Six communities were defined using TWINSP AN, and grazing capacities and veld condition scores of the respective sites were calculated. It was concluded that the six communities were distributed along a gradient of palatable to non palatable grass and grasslike species. Rangelands close to the villages had low veld condition scores and percentage plant cover as opposed to those farther away from the villages. The null hypothesis of no significant difference between the percentage plant cover and condition of the veld close to the villages and farther away from the villages was rejected. Whilst it is urgent to resolve political disputes around land through land distribution, a key issue for the future is sustainability of the natural resource base of South Africa. To attain this, the old traditional methods of research must be supplemented with the participatory method, where the local community becomes fully involved. The central theme of the participatory approach was to investigate the possibility of promoting local management of the natural resources. Workshops were conducted to involve the local community in the project. The community formed six discussion groups that met regularly to discuss environmental issues. The six groups that were formed were: Firewood or woodlot collectors, shepherds / livestock raisers, crop fanners / agriculturists, water collectors, building material / soil collectors and medicinal plant users. The results obtained from the meeting of the discussion groups were used to compare the scientific results obtained from Braun-Blanquet method. Perceptions about their environment, which came out of the results of the discussion groups showed that the local knowledge of the rural community of Mceula was sufficient to train them to manage their environment sustainably.
- Full Text:
- Date Issued: 1998
- Authors: Nkansa-Dwamena, Yaw
- Date: 1998
- Subjects: Natural resources -- South Africa -- Management , Natural resources -- South Africa -- Eastern Cape -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4218 , http://hdl.handle.net/10962/d1003787 , Natural resources -- South Africa -- Management , Natural resources -- South Africa -- Eastern Cape -- Management
- Description: The Mceula Commonage Land in the Hewu district lies due northwest of Whittle sea and west of Queenstown in the Eastern Cape. This thesis has two main objectives. Firstly, to survey and analyse the condition of the natural resource. base in the Hewu district with particular reference to water, soil, vegetation and land use. Secondly, to investigate the relationship between scientific approaches to assessing land use degradation and to compare these to the results obtained using a participatory approach of the rural environment of the Hewu district of the Eastern Cape. Random quadrats (4m2) were sampled and corresponding line transects were done with increasing distances from the villages. The Braun-Blanquet method was used to find the cover and abundance of the various species of plants. Data obtained from point sampling along 100 metre line transects was used to assess the condition of the veld using Trollope's technique. Six communities were defined using TWINSP AN, and grazing capacities and veld condition scores of the respective sites were calculated. It was concluded that the six communities were distributed along a gradient of palatable to non palatable grass and grasslike species. Rangelands close to the villages had low veld condition scores and percentage plant cover as opposed to those farther away from the villages. The null hypothesis of no significant difference between the percentage plant cover and condition of the veld close to the villages and farther away from the villages was rejected. Whilst it is urgent to resolve political disputes around land through land distribution, a key issue for the future is sustainability of the natural resource base of South Africa. To attain this, the old traditional methods of research must be supplemented with the participatory method, where the local community becomes fully involved. The central theme of the participatory approach was to investigate the possibility of promoting local management of the natural resources. Workshops were conducted to involve the local community in the project. The community formed six discussion groups that met regularly to discuss environmental issues. The six groups that were formed were: Firewood or woodlot collectors, shepherds / livestock raisers, crop fanners / agriculturists, water collectors, building material / soil collectors and medicinal plant users. The results obtained from the meeting of the discussion groups were used to compare the scientific results obtained from Braun-Blanquet method. Perceptions about their environment, which came out of the results of the discussion groups showed that the local knowledge of the rural community of Mceula was sufficient to train them to manage their environment sustainably.
- Full Text:
- Date Issued: 1998
A synthetic and spectrometric study of the initial phases in urea-formaldehyde resin formation
- Authors: Nocanda, Xolani Wittleton
- Date: 1998
- Subjects: Phenolic resins , Gums and resins, Synthetic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4383 , http://hdl.handle.net/10962/d1005048 , Phenolic resins , Gums and resins, Synthetic
- Description: In a series ofpreIiminary studies of urea-formaldehyde reactions, the influence of the U:F molar ratio, the temperature and the catalyst were investigated. Subsequently, in a more rigorous evaluation of the influence of four variables on urea-formaldehyde resin formation, viz., U:F molar ratio, pH, temperature and reaction time, a set of twenty reactions were performed using a statistical approach. The results indicate that high resin viscosity is best achieved by using a high U:F molar ratio (1:2) and conducting the reaction at 90°C. Several basic components produced in urea-formaldehyde reactions have been synthesised, characterised by NMR spectroscopy, silylated using bis(trimethylsilyl)trifluoroacetamide and analysed by low resolution mass spectrometry. The use oftriazones as cross-linking agents has been investigated, and a series of 5-substituted triazones have been prepared and their mass fragmentation patterns explored using a combination of low and high resolution mass spectrometry. In order to facilitate interpretation of ¹³C NMR data obtained for U-F resins, internal rotation in various urea derivatives was investigated using variable temperature ¹H and ¹³C NMR spectroscopic study. Signal splittings observed below 247 K have been rationalised in terms of various rotameric structures.
- Full Text:
- Date Issued: 1998
- Authors: Nocanda, Xolani Wittleton
- Date: 1998
- Subjects: Phenolic resins , Gums and resins, Synthetic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4383 , http://hdl.handle.net/10962/d1005048 , Phenolic resins , Gums and resins, Synthetic
- Description: In a series ofpreIiminary studies of urea-formaldehyde reactions, the influence of the U:F molar ratio, the temperature and the catalyst were investigated. Subsequently, in a more rigorous evaluation of the influence of four variables on urea-formaldehyde resin formation, viz., U:F molar ratio, pH, temperature and reaction time, a set of twenty reactions were performed using a statistical approach. The results indicate that high resin viscosity is best achieved by using a high U:F molar ratio (1:2) and conducting the reaction at 90°C. Several basic components produced in urea-formaldehyde reactions have been synthesised, characterised by NMR spectroscopy, silylated using bis(trimethylsilyl)trifluoroacetamide and analysed by low resolution mass spectrometry. The use oftriazones as cross-linking agents has been investigated, and a series of 5-substituted triazones have been prepared and their mass fragmentation patterns explored using a combination of low and high resolution mass spectrometry. In order to facilitate interpretation of ¹³C NMR data obtained for U-F resins, internal rotation in various urea derivatives was investigated using variable temperature ¹H and ¹³C NMR spectroscopic study. Signal splittings observed below 247 K have been rationalised in terms of various rotameric structures.
- Full Text:
- Date Issued: 1998
A study of the transdermal drug diffusion properties of rooperol tetra-acetate
- Authors: Pefile, Sibongile C.
- Date: 1998 , 2013-08-29
- Subjects: Transdermal medication , Skin absorption , Dermatologic agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3838 , http://hdl.handle.net/10962/d1007649 , Transdermal medication , Skin absorption , Dermatologic agents
- Description: The rapidly growing interest in the potential use of topical drug delivery formulations has resulted in increased use of the skin as a vital port for drug delivery. Extensive research has been conducted in designing vehicles capable of delivering a desired amount of drug to a specific site, to produce the desired pharmacological response. Rooperol tetra-acetate is a lipophilic, cytotoxic drug with the potential for use in the treatment of solar keratosis. For effective pharmacological action, delivery of the drug to the epidermal/dermal junction of the skin is required. A study of the topical penetration properties of rooperol tetra-acetate from different topical bases, each possessing different physico-chemical properties, was performed. The assessment involved a comparison of the diffusion properties under occlusive and non occlusive conditions when the drug was formulated into a gel, Cetomacrogol Cream B.P. (oil-inwater), Simple Ointment B.P. and an extemporaneously prepared water-in-oil topical cream. The in vitro experiments were conducted using polydimethylsiloxane and rat membrane mounted in a Franz diffusion cell. The topical permeation kinetics of rooperol tetra-acetate were determined by exploring the release characteristics of the active ingredient from the vehicles formulated and the permeability properties of the drug through the membranes employed. Further studies involved investigating the utilization of supersaturated systems intended to increase the thermodynamic activity of the drug when formulated into a propylene glycol/water vehicle (with and without polymer). To measure the release of rooperol tetra-acetate into the skin from a topical base it was necessary to, firstly, develop a suitable quantitative method for the analysis of the active drug in the aqueous receptor phase of in vitro diffusion cells. The second stage of product development was the design of an effective delivery system to facilitate the release of the diffusant from its base. A high performance liquid chromatographic method was utilized for the identification and quantification of the active drug. As validation is an important aspect in the development and subsequent utilization of an analytical procedure, the developed HPLC technique was validated by determining the precision, accuracy, range, limit of quantitation and sensitivity of the system. Lastly, the stability of rooperol tetra-acetate at elevated temperatures was assessed and a stability profile of the drug was generated for the three-month period of analysis. The results obtained following chromatographic analysis of the receptor phase sampled during the diffusion experiments indicate that the gel and oil-in-water formulations most effectively promoted the diffusion of rooperol tetra-acetate across polydimethylsiloxane membrane. The water-in-oil system exhibited lower flux rates and the ointment showed the least drug release. Occlusion of the topical vehicle increased the diffusitivity of the permeant from all formulations analysed. The permeation assessment results of the supersaturated systems showed enhanced diffusion of rooperol tetra-acetate across polydimethylsiloxane and rat membrane. The high thermodynamic activity existing in supersaturated systems most effectively increased the driving force for drug diffusion resulting in enhanced percutaneous penetration of rooperol tetra-acetate beyond the release and transport limitations of saturated solutions. These results provide the basis on which an effective topical drug delivery vehicle may be designed for this new drug entity.
- Full Text:
- Date Issued: 1998
- Authors: Pefile, Sibongile C.
- Date: 1998 , 2013-08-29
- Subjects: Transdermal medication , Skin absorption , Dermatologic agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3838 , http://hdl.handle.net/10962/d1007649 , Transdermal medication , Skin absorption , Dermatologic agents
- Description: The rapidly growing interest in the potential use of topical drug delivery formulations has resulted in increased use of the skin as a vital port for drug delivery. Extensive research has been conducted in designing vehicles capable of delivering a desired amount of drug to a specific site, to produce the desired pharmacological response. Rooperol tetra-acetate is a lipophilic, cytotoxic drug with the potential for use in the treatment of solar keratosis. For effective pharmacological action, delivery of the drug to the epidermal/dermal junction of the skin is required. A study of the topical penetration properties of rooperol tetra-acetate from different topical bases, each possessing different physico-chemical properties, was performed. The assessment involved a comparison of the diffusion properties under occlusive and non occlusive conditions when the drug was formulated into a gel, Cetomacrogol Cream B.P. (oil-inwater), Simple Ointment B.P. and an extemporaneously prepared water-in-oil topical cream. The in vitro experiments were conducted using polydimethylsiloxane and rat membrane mounted in a Franz diffusion cell. The topical permeation kinetics of rooperol tetra-acetate were determined by exploring the release characteristics of the active ingredient from the vehicles formulated and the permeability properties of the drug through the membranes employed. Further studies involved investigating the utilization of supersaturated systems intended to increase the thermodynamic activity of the drug when formulated into a propylene glycol/water vehicle (with and without polymer). To measure the release of rooperol tetra-acetate into the skin from a topical base it was necessary to, firstly, develop a suitable quantitative method for the analysis of the active drug in the aqueous receptor phase of in vitro diffusion cells. The second stage of product development was the design of an effective delivery system to facilitate the release of the diffusant from its base. A high performance liquid chromatographic method was utilized for the identification and quantification of the active drug. As validation is an important aspect in the development and subsequent utilization of an analytical procedure, the developed HPLC technique was validated by determining the precision, accuracy, range, limit of quantitation and sensitivity of the system. Lastly, the stability of rooperol tetra-acetate at elevated temperatures was assessed and a stability profile of the drug was generated for the three-month period of analysis. The results obtained following chromatographic analysis of the receptor phase sampled during the diffusion experiments indicate that the gel and oil-in-water formulations most effectively promoted the diffusion of rooperol tetra-acetate across polydimethylsiloxane membrane. The water-in-oil system exhibited lower flux rates and the ointment showed the least drug release. Occlusion of the topical vehicle increased the diffusitivity of the permeant from all formulations analysed. The permeation assessment results of the supersaturated systems showed enhanced diffusion of rooperol tetra-acetate across polydimethylsiloxane and rat membrane. The high thermodynamic activity existing in supersaturated systems most effectively increased the driving force for drug diffusion resulting in enhanced percutaneous penetration of rooperol tetra-acetate beyond the release and transport limitations of saturated solutions. These results provide the basis on which an effective topical drug delivery vehicle may be designed for this new drug entity.
- Full Text:
- Date Issued: 1998
A nutritional evaluation of effluent grown algae and zooplakton as feed ingredients for Xiphohorous helleri, Poecilia reticulata and Poecilia velifera (Pisces : Poeciliidae)
- Authors: Potts, Warren M
- Date: 1998
- Subjects: Poeciliidae , Poeciliidae -- Nutrition , Zooplankton , Algae , Poeciliidae -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5306 , http://hdl.handle.net/10962/d1005151 , Poeciliidae , Poeciliidae -- Nutrition , Zooplankton , Algae , Poeciliidae -- Feeding and feeds
- Description: The aim of this study was to evaluate the nutritional value of algae and zooplankton grown in an algal integrated ponding system for poeciliids. The available information on the nutritional requirements of poeciliids was compared with a proximate analysis of the algae and zooplankton. The effluent grown algae and zooplankton had a crude protein value of 41.47 ± 0.2% and 36.84 ± 0.3%, a lipid content of 4.8 ±. 0.4% and 11.1 ± 0.8% and a carbohydrate content of 35.13 ± 0.8% and 31.06 ± 0.6% respectively. These values compared favourably with those of the known nutritional requirements of poeciliids. To test if the nutritional value of the algae and zooplankton in the AlPS was constant, the species composition of the algae and the crude protein content of the algae and zooplankton in the high rate oxidation ponds were measured monthly and bi-weekly for a year respectively. The species composition remained fairly stable for the duration of the experiment and the average protein composition of the algae and zooplankton was 43.4 ± 4.4% and 38.6 ±2.8% respectively. This indicated that the algae and zooplankton in the AlPS provided high protein biomass through the year. The quality of the effluent grown algal and zooplankton biomass was evaluated by analysing their amino acid composition and comparing it with the amino acid composition of the body tissue of X. helleri. With respect to the amino acid composition of the body tissue of X. helleri, the amino acid profile of the algae had a 69% and the zooplankton a 63% similarity. The quality of the pure algal and zooplankton protein was also tested biologically, by feeding them directly to poeciliids during a ten week growth trial. The algae and zooplankton diets did not result in adequate growth compared to poeciliids which were fed a formulated control diet. The initial growth trial also evaluated the effect of processing on the chemical composition of the algae and its biological effect on fish fed with it. There were no significant differences in the chemical composition of fresh and sun dried algae and this was reflected in the growth rates of the fish which did not differ significantly. Freeze dried algae had a lower crude protein content than fresh and sun dried algae and a poorer amino acid composition. Fish fed freeze dried algae exhibited poorer growth and survival in comparison to the other treatments. The gut transit times of X. helleri and the gastric evacuation times of poeciliids were determined using colour dyes incorporated in the diet and by sacrificing fish at predetermined intervals after feeding respectively. The gut transit time of X. helleri fed a sun dried algal diet and a formulated diet was 225 ± 8.55 minutes and 261.93 ± 10.86 minutes respectively. The gastric evacuation times of X. helleri, P. reticu/ata and P. velifera were 7, 9 and 8 hours respectively. Since the maximum amount of food in the hindgut after feeding was detemined to be 3, 5 and 3 hours in X. helleri, P. reticulata and P. velifera respectively, fish were sacrificed at these times in the digestibility study. The digestibility of sun dried algae was determined using 1 % chromic oxide as an internal marker in the algae. The apparent crude protein digestibility of sun dried effluent grown algae ranged from 65%-75% in the three poeciliid species. Based on the results of the chemical and biological analysis of the algae and zooplankton, conventional diets incorporating algae at 5% and 20% protein inclusion levels were formulated. These diets and a treatment in which zooplankton, reared in the AlPS were fed as a dietary supplement to a formulated diet were fed to poeciliids for twelve weeks. No significant differences in the growth of poeciliids fed any of the test diets were observed. It was concluded that the algae could be incorporated into poeciliid formulated diets up to level of 20% protein inclusion without any negative effect on the growth of the fish. The chemical and biological evaluation of the algae suggested that it had a similar nutritional quality to soyabean meal. Poeciliid growth was not enhanced with a zooplankton supplement, however a possible low feeding rate by poeciliids on the zooplankton as a result of their small size may have affected the result. The colour enhancement potential of effluent grown algae and zooplankton was evaluated biologically in ten and twelve week growth trials using visual observation (31 people) and by using a chromameter. While pure, sun dried algae significantly enhanced the colour of P. reticulata, no significant differences in the colour of poeciliids were observed or recorded when fish were fed diets incorporating sun dried algae up to levels of 20% protein inclusion. The effect of effluent grown algae and zooplankton on poeciliid health was also tested biologically in the ten and twelve week growth trials. The high mortalities (75%-84%) recorded for X. hel/eri when fed the pure algal and zooplankton diets were considered to be as a result of the nutritional inadequacy of the diets since there were significantly less mortalities in fish fed the formulated control diet and 63% of the fish that died during the course of the trial were emaciated. In addition, fewer mortalities (10%-40%) were recorded in X. hel/eri fed the nutritionally adequate formulated diets in the twelve week growth trial. No symptoms of disease were recorded in the twelve week growth trial and the algae was considered to have no toxicological or pathological effects on poeciliids. Centrifugation, sand filtration, sedimentation, microstraining and biological harvest were evaluated as methods of small scale algal harvest from the high rate oxidation ponds. Algae could be harvested most efficiently with little associated labour by sedimentation (without flocculating agents) and by microstraining with 60IJm mesh. Effluent grown algae can replace conventional feed ingredients up to a level of 20% protein inclusion without negatively effecting the growth, colour, health or survival of poeciliids.
- Full Text:
- Date Issued: 1998
- Authors: Potts, Warren M
- Date: 1998
- Subjects: Poeciliidae , Poeciliidae -- Nutrition , Zooplankton , Algae , Poeciliidae -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5306 , http://hdl.handle.net/10962/d1005151 , Poeciliidae , Poeciliidae -- Nutrition , Zooplankton , Algae , Poeciliidae -- Feeding and feeds
- Description: The aim of this study was to evaluate the nutritional value of algae and zooplankton grown in an algal integrated ponding system for poeciliids. The available information on the nutritional requirements of poeciliids was compared with a proximate analysis of the algae and zooplankton. The effluent grown algae and zooplankton had a crude protein value of 41.47 ± 0.2% and 36.84 ± 0.3%, a lipid content of 4.8 ±. 0.4% and 11.1 ± 0.8% and a carbohydrate content of 35.13 ± 0.8% and 31.06 ± 0.6% respectively. These values compared favourably with those of the known nutritional requirements of poeciliids. To test if the nutritional value of the algae and zooplankton in the AlPS was constant, the species composition of the algae and the crude protein content of the algae and zooplankton in the high rate oxidation ponds were measured monthly and bi-weekly for a year respectively. The species composition remained fairly stable for the duration of the experiment and the average protein composition of the algae and zooplankton was 43.4 ± 4.4% and 38.6 ±2.8% respectively. This indicated that the algae and zooplankton in the AlPS provided high protein biomass through the year. The quality of the effluent grown algal and zooplankton biomass was evaluated by analysing their amino acid composition and comparing it with the amino acid composition of the body tissue of X. helleri. With respect to the amino acid composition of the body tissue of X. helleri, the amino acid profile of the algae had a 69% and the zooplankton a 63% similarity. The quality of the pure algal and zooplankton protein was also tested biologically, by feeding them directly to poeciliids during a ten week growth trial. The algae and zooplankton diets did not result in adequate growth compared to poeciliids which were fed a formulated control diet. The initial growth trial also evaluated the effect of processing on the chemical composition of the algae and its biological effect on fish fed with it. There were no significant differences in the chemical composition of fresh and sun dried algae and this was reflected in the growth rates of the fish which did not differ significantly. Freeze dried algae had a lower crude protein content than fresh and sun dried algae and a poorer amino acid composition. Fish fed freeze dried algae exhibited poorer growth and survival in comparison to the other treatments. The gut transit times of X. helleri and the gastric evacuation times of poeciliids were determined using colour dyes incorporated in the diet and by sacrificing fish at predetermined intervals after feeding respectively. The gut transit time of X. helleri fed a sun dried algal diet and a formulated diet was 225 ± 8.55 minutes and 261.93 ± 10.86 minutes respectively. The gastric evacuation times of X. helleri, P. reticu/ata and P. velifera were 7, 9 and 8 hours respectively. Since the maximum amount of food in the hindgut after feeding was detemined to be 3, 5 and 3 hours in X. helleri, P. reticulata and P. velifera respectively, fish were sacrificed at these times in the digestibility study. The digestibility of sun dried algae was determined using 1 % chromic oxide as an internal marker in the algae. The apparent crude protein digestibility of sun dried effluent grown algae ranged from 65%-75% in the three poeciliid species. Based on the results of the chemical and biological analysis of the algae and zooplankton, conventional diets incorporating algae at 5% and 20% protein inclusion levels were formulated. These diets and a treatment in which zooplankton, reared in the AlPS were fed as a dietary supplement to a formulated diet were fed to poeciliids for twelve weeks. No significant differences in the growth of poeciliids fed any of the test diets were observed. It was concluded that the algae could be incorporated into poeciliid formulated diets up to level of 20% protein inclusion without any negative effect on the growth of the fish. The chemical and biological evaluation of the algae suggested that it had a similar nutritional quality to soyabean meal. Poeciliid growth was not enhanced with a zooplankton supplement, however a possible low feeding rate by poeciliids on the zooplankton as a result of their small size may have affected the result. The colour enhancement potential of effluent grown algae and zooplankton was evaluated biologically in ten and twelve week growth trials using visual observation (31 people) and by using a chromameter. While pure, sun dried algae significantly enhanced the colour of P. reticulata, no significant differences in the colour of poeciliids were observed or recorded when fish were fed diets incorporating sun dried algae up to levels of 20% protein inclusion. The effect of effluent grown algae and zooplankton on poeciliid health was also tested biologically in the ten and twelve week growth trials. The high mortalities (75%-84%) recorded for X. hel/eri when fed the pure algal and zooplankton diets were considered to be as a result of the nutritional inadequacy of the diets since there were significantly less mortalities in fish fed the formulated control diet and 63% of the fish that died during the course of the trial were emaciated. In addition, fewer mortalities (10%-40%) were recorded in X. hel/eri fed the nutritionally adequate formulated diets in the twelve week growth trial. No symptoms of disease were recorded in the twelve week growth trial and the algae was considered to have no toxicological or pathological effects on poeciliids. Centrifugation, sand filtration, sedimentation, microstraining and biological harvest were evaluated as methods of small scale algal harvest from the high rate oxidation ponds. Algae could be harvested most efficiently with little associated labour by sedimentation (without flocculating agents) and by microstraining with 60IJm mesh. Effluent grown algae can replace conventional feed ingredients up to a level of 20% protein inclusion without negatively effecting the growth, colour, health or survival of poeciliids.
- Full Text:
- Date Issued: 1998
The Anglican Church's mission to the Muslims in Cape Town during the nineteenth and twentieth centuries : a study in the changes of missiological methods and attitudes
- Authors: Pratt, Derek Alfred
- Date: 1998
- Subjects: Missions to Muslims -- South Africa -- Cape Town Mission of the church Anglican Communion -- South Africa -- Cape Town Christianity and other religions -- Islam
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1236 , http://hdl.handle.net/10962/d1007592
- Description: When Bishop Robert Gray arrived at the Cape in 1848, he was concerned at the large percentage of the former slave population who had been attracted to the Muslim faith. He appointed Michael Angelo Camilleri (1848-1854) as a missionary to the Muslims of Cape Town. Camilleri's tenure was short and he was frequently used to fill other ecclesiastical posts. From 1854 until 1911 the responsibility of mission to the Muslims was given to priests whose parishes had large Muslims populations. In 1911 a fulltime missionary was once again appointed. Thomas Fothergill Lightfoot, arrived at the Cape in 1858 and served at St Paul's, Bree Street until his death in 1904. His was a ministry of love and caring. He was greatly respected for his work by all sections of the population. John Mühleissen Arnold worked in the parish of St Mary's, Woodstock. His aggressive missiological technique broke down much of the religious tolerance which had existed. His publication of a pamphlet supposedly written by a Muslim, raises doubts about his integrity as a missionary and his ethical stance as a Christian. In 1907 the Diocesan Mission Board took control of the Muslim mission and in 1911 appointed Stephen Garabedian as director. Under Garabedian the policy of the mission was aimed primarily at preventing Christian women 'lapsing' from Christianity and becoming Muslims through marriage. After his resignation in 1922, the work continued under numerous women workers who concentrated on Muslim women and children through sewing guilds and childrens' clubs. In 1960, George Swartz was appointed as director. Swartz was the first Coloured and South African-born priest to hold the post of director. Swartz served as director until he was appointed to Bonteheuwel as parish priest. He subsequently chaired the board until it ceased to meet in 1976. Throughout its one hundred twenty eight years of active existence, the Anglican mission to the Muslims failed to attract a large number of converts. Initially this could be attributed to the attraction the Muslims had to those seeking a strong community life. Later, outside influences from the Islamic world strengthened the faith of the Muslim community against any Christian conversion attempts. During the latter part of the twentieth century the mission viewed its tasks as preventing the conversion of Christians who wished to marry Muslims and informing and educating Christians on the Islamic faith. In the late 1960s, the Board encouraged dialogue rather than confrontation. It changed its name to the Board of Muslim Relationship. Apartheid was seen as the common enemy of both Christians and Muslims and they worked together against its evils. The need for a Mission Board was seen as redundant and from 1976 it ceased to be active.
- Full Text:
- Date Issued: 1998
- Authors: Pratt, Derek Alfred
- Date: 1998
- Subjects: Missions to Muslims -- South Africa -- Cape Town Mission of the church Anglican Communion -- South Africa -- Cape Town Christianity and other religions -- Islam
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1236 , http://hdl.handle.net/10962/d1007592
- Description: When Bishop Robert Gray arrived at the Cape in 1848, he was concerned at the large percentage of the former slave population who had been attracted to the Muslim faith. He appointed Michael Angelo Camilleri (1848-1854) as a missionary to the Muslims of Cape Town. Camilleri's tenure was short and he was frequently used to fill other ecclesiastical posts. From 1854 until 1911 the responsibility of mission to the Muslims was given to priests whose parishes had large Muslims populations. In 1911 a fulltime missionary was once again appointed. Thomas Fothergill Lightfoot, arrived at the Cape in 1858 and served at St Paul's, Bree Street until his death in 1904. His was a ministry of love and caring. He was greatly respected for his work by all sections of the population. John Mühleissen Arnold worked in the parish of St Mary's, Woodstock. His aggressive missiological technique broke down much of the religious tolerance which had existed. His publication of a pamphlet supposedly written by a Muslim, raises doubts about his integrity as a missionary and his ethical stance as a Christian. In 1907 the Diocesan Mission Board took control of the Muslim mission and in 1911 appointed Stephen Garabedian as director. Under Garabedian the policy of the mission was aimed primarily at preventing Christian women 'lapsing' from Christianity and becoming Muslims through marriage. After his resignation in 1922, the work continued under numerous women workers who concentrated on Muslim women and children through sewing guilds and childrens' clubs. In 1960, George Swartz was appointed as director. Swartz was the first Coloured and South African-born priest to hold the post of director. Swartz served as director until he was appointed to Bonteheuwel as parish priest. He subsequently chaired the board until it ceased to meet in 1976. Throughout its one hundred twenty eight years of active existence, the Anglican mission to the Muslims failed to attract a large number of converts. Initially this could be attributed to the attraction the Muslims had to those seeking a strong community life. Later, outside influences from the Islamic world strengthened the faith of the Muslim community against any Christian conversion attempts. During the latter part of the twentieth century the mission viewed its tasks as preventing the conversion of Christians who wished to marry Muslims and informing and educating Christians on the Islamic faith. In the late 1960s, the Board encouraged dialogue rather than confrontation. It changed its name to the Board of Muslim Relationship. Apartheid was seen as the common enemy of both Christians and Muslims and they worked together against its evils. The need for a Mission Board was seen as redundant and from 1976 it ceased to be active.
- Full Text:
- Date Issued: 1998
An examination of patients' responses to framework breaks in psychotherapy in an institutional context
- Authors: Rees, Christopher Lewis
- Date: 1998
- Subjects: Psychotherapy patients Psychotherapy -- Research Psychotherapy Case studies Psychiatric hospital care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3042 , http://hdl.handle.net/10962/d1002551
- Description: This study examines the workings of the ground rules which make up the framework of psychotherapy, in an institutional context, by analysing transcripts of twelve audio taped sessions of therapy conducted in a psychiatric hospital. The breaks in the ground rules of the sessions are noted and the patients' responses to these breaks are analysed using Langs's (1982, 1988) method for decoding patients' material, suitably modified for use as a hermeneutic research method. Although all of the ground rules are broken in the institutional context, only one of the ten ground rules appears to be essentially affected by this particular institutional context. Other ground rules are broken out of choice of technique or through error. The institutional context has a structural impact only on the ground rule requiring a one to one relationship with privacy and confidentiality and this ground rule is transgressed in a number of ways in all twelve sessions examined in this study. However the patients' responses to this breach only occur in ways predicted by communicative theory when the break in the ground rule involves actual entry into the therapy space by another person. Other contraventions to this ground rule that do not involve such an entry do not elicit the predicted patient responses. The many other ground rule breaks occurring in the institutional context evoke the predicted responses in the patients' material. In the study, no therapist interventions are found to comply with the communicative therapy requirements for sound interventions; concomitantly it was found that no therapist interventions receive the required derivative validation. The results indicate that it is possible to conduct therapy of a substantially secure frame variety in this institutional context with minimum effort on the part of therapists and given proper training and supervision of therapists in the techniques of communicative psychotherapy. Furthermore the results lend weight to the importance of the communicative methodology for listening to patients' material in psychotherapy in an institutional context. However, further rigorous study of competently performed therapy, executed within the context of a secure frame within an institutional context, is needed in order to demonstrate the benefits of the communicative psychotherapy interventions and interpretations in this context.
- Full Text:
- Date Issued: 1998
- Authors: Rees, Christopher Lewis
- Date: 1998
- Subjects: Psychotherapy patients Psychotherapy -- Research Psychotherapy Case studies Psychiatric hospital care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3042 , http://hdl.handle.net/10962/d1002551
- Description: This study examines the workings of the ground rules which make up the framework of psychotherapy, in an institutional context, by analysing transcripts of twelve audio taped sessions of therapy conducted in a psychiatric hospital. The breaks in the ground rules of the sessions are noted and the patients' responses to these breaks are analysed using Langs's (1982, 1988) method for decoding patients' material, suitably modified for use as a hermeneutic research method. Although all of the ground rules are broken in the institutional context, only one of the ten ground rules appears to be essentially affected by this particular institutional context. Other ground rules are broken out of choice of technique or through error. The institutional context has a structural impact only on the ground rule requiring a one to one relationship with privacy and confidentiality and this ground rule is transgressed in a number of ways in all twelve sessions examined in this study. However the patients' responses to this breach only occur in ways predicted by communicative theory when the break in the ground rule involves actual entry into the therapy space by another person. Other contraventions to this ground rule that do not involve such an entry do not elicit the predicted patient responses. The many other ground rule breaks occurring in the institutional context evoke the predicted responses in the patients' material. In the study, no therapist interventions are found to comply with the communicative therapy requirements for sound interventions; concomitantly it was found that no therapist interventions receive the required derivative validation. The results indicate that it is possible to conduct therapy of a substantially secure frame variety in this institutional context with minimum effort on the part of therapists and given proper training and supervision of therapists in the techniques of communicative psychotherapy. Furthermore the results lend weight to the importance of the communicative methodology for listening to patients' material in psychotherapy in an institutional context. However, further rigorous study of competently performed therapy, executed within the context of a secure frame within an institutional context, is needed in order to demonstrate the benefits of the communicative psychotherapy interventions and interpretations in this context.
- Full Text:
- Date Issued: 1998
A description of the language experiences of English Second-Language students entering the academic discourse communities of Rhodes University
- Authors: Reynolds, Judith Marsha
- Date: 1998
- Subjects: English language -- Study and teaching -- Foreign speakers , English language -- Ability testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2361 , http://hdl.handle.net/10962/d1002644 , English language -- Study and teaching -- Foreign speakers , English language -- Ability testing
- Description: This study is a description of the language experiences of English Second Language students in their first year at Rhodes University. It took place in the context of the changes that are currently occurring in higher education in South Africa in terms of student populations. More and more students are entering tertiary education institutions, including HWESUs, such as Rhodes University, who are considered non-traditional. These students typically have English as their second, or additional, language, and have not been adequately prepared for university study by their secondary education. This study describes the experiences of three such students in their first year at Rhodes University. Entry into a university is seen not just as acquiring knowledge, but as entering, or attempting to enter, a new culture. It is recognised that all students enter universities with other cultures or literacies already in place. In the case of non-traditional students tbese other literacies are usually at some distance from those of the university. The work of James Gee (1990) is particularly useful in understanding this process of adjusting to the demands of university study and the effect that previous experiences have on this process. This study is an attempt to discover and describe the literacies that these three students brought with them to university and the effect these literacies had on their attempts to enter academic discourse communities of the university. An ethnographic research method was adopted in order to do this. The study is also an attempt to evaluate, from the perspective of the three students, the appropriacy of the various changes that Rhodes University has made since the numbers of non-traditional students has started to increase.
- Full Text:
- Date Issued: 1998
- Authors: Reynolds, Judith Marsha
- Date: 1998
- Subjects: English language -- Study and teaching -- Foreign speakers , English language -- Ability testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2361 , http://hdl.handle.net/10962/d1002644 , English language -- Study and teaching -- Foreign speakers , English language -- Ability testing
- Description: This study is a description of the language experiences of English Second Language students in their first year at Rhodes University. It took place in the context of the changes that are currently occurring in higher education in South Africa in terms of student populations. More and more students are entering tertiary education institutions, including HWESUs, such as Rhodes University, who are considered non-traditional. These students typically have English as their second, or additional, language, and have not been adequately prepared for university study by their secondary education. This study describes the experiences of three such students in their first year at Rhodes University. Entry into a university is seen not just as acquiring knowledge, but as entering, or attempting to enter, a new culture. It is recognised that all students enter universities with other cultures or literacies already in place. In the case of non-traditional students tbese other literacies are usually at some distance from those of the university. The work of James Gee (1990) is particularly useful in understanding this process of adjusting to the demands of university study and the effect that previous experiences have on this process. This study is an attempt to discover and describe the literacies that these three students brought with them to university and the effect these literacies had on their attempts to enter academic discourse communities of the university. An ethnographic research method was adopted in order to do this. The study is also an attempt to evaluate, from the perspective of the three students, the appropriacy of the various changes that Rhodes University has made since the numbers of non-traditional students has started to increase.
- Full Text:
- Date Issued: 1998
Transformational leadership and organisational effectiveness in the administration of cricket in South Africa
- Authors: Ristow, Adrian
- Date: 1998
- Subjects: Cricket--South Africa , Cricket -- South Africa -- Management , Sports administration -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1182 , http://hdl.handle.net/10962/d1002799 , Cricket--South Africa , Cricket -- South Africa -- Management , Sports administration -- South Africa
- Description: After years of isolation from the international sporting arena, South African sports teams have recently achieved much success. This study is concerned specifically with managing for organisational effectiveness in South African cricket. According to the theory of transformational leadership, there should be a positive relationship between this style of leadership and organisational effectiveness. The Multifactor Leadership Questionnaire was used to collect information about leadership while data for organisational effectiveness, the dependent variable, was collected using the Effectiveness Survey for Cricket Administration. Most of the results regarding the relationship of the transformational leadership factors and organisational effectiveness were significant. On the other hand, most of the results regarding the relationship of the transactional leadership factors and organisational effectiveness were not significant. The overall results provide general support of the relevance of the transformational leadership theory in the context of cricket administration in South Africa. The results also support Bass's (1990b) argument of the universal application of the transformational leadership theory.
- Full Text:
- Date Issued: 1998
- Authors: Ristow, Adrian
- Date: 1998
- Subjects: Cricket--South Africa , Cricket -- South Africa -- Management , Sports administration -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1182 , http://hdl.handle.net/10962/d1002799 , Cricket--South Africa , Cricket -- South Africa -- Management , Sports administration -- South Africa
- Description: After years of isolation from the international sporting arena, South African sports teams have recently achieved much success. This study is concerned specifically with managing for organisational effectiveness in South African cricket. According to the theory of transformational leadership, there should be a positive relationship between this style of leadership and organisational effectiveness. The Multifactor Leadership Questionnaire was used to collect information about leadership while data for organisational effectiveness, the dependent variable, was collected using the Effectiveness Survey for Cricket Administration. Most of the results regarding the relationship of the transformational leadership factors and organisational effectiveness were significant. On the other hand, most of the results regarding the relationship of the transactional leadership factors and organisational effectiveness were not significant. The overall results provide general support of the relevance of the transformational leadership theory in the context of cricket administration in South Africa. The results also support Bass's (1990b) argument of the universal application of the transformational leadership theory.
- Full Text:
- Date Issued: 1998
Baylis-Hillman derived benzopyrans and related systems : a synthetic and mechanistic study
- Authors: Robinson, Ross Stuart
- Date: 1998
- Subjects: Benzopyrans Coumarins Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4429 , http://hdl.handle.net/10962/d1007193
- Description: The Baylis-Hillman reaction between substituted salicylaldehydes and various acrylate species has been shown to afford complex reaction mixtures, careful chromatography of which has led to the isolation of an extensive range of novel compounds. One- and two-dimensional NMR spectroscopic, mass spectrometric and X-ray crystallographic analysis of these compounds have permitted identification of no less than eight general classes of chromene and coumarin derivatives. The formation of the various product types is attributed to cascades of successive reactions stemming, in each case, from a Baylis-Hillman product as the common intermediate. The mechanistic sequence involved in the formation of the various chromene and coumarin derivatives have been elucidated by examining isolated or specifically prepared compounds as putative reaction intermediates. Conjugate addition and acyl or allylic substitution by various nucleophiles appear to be common processes in the formation of the chromene and coumarin derivatives, and studies focussing on these processes have been undertaken. Reactions of Baylis-Hillman adducts have been carried out, using oxygen, sulfur and nitrogen nucleophiles, in order to explore stereoselectivity and regioselectivity trends. The results show that the reactions proceed with a very high degree of regioselectivity, affording conjugate addition rather than acyl substitution products. The diastereoselectivity observed for the addition products, however was typically low. A kinetic study to explore the regioselectivity of the reaction between various Baylis-Hillman derived halogeno esters and the nucleophile, methyl 3-oxobutanolate enloate, in two different base-solvent systems at high dilution was also undertaken. The reactions were monitored by ¹H NMR spectroscopy, and the results revealed that the reaction kinetics are more complex than originally anticipated. A mechanistic rationalisation is offered which is consistent with both the kinetic data and the observed regioselectivity trends.
- Full Text:
- Date Issued: 1998
- Authors: Robinson, Ross Stuart
- Date: 1998
- Subjects: Benzopyrans Coumarins Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4429 , http://hdl.handle.net/10962/d1007193
- Description: The Baylis-Hillman reaction between substituted salicylaldehydes and various acrylate species has been shown to afford complex reaction mixtures, careful chromatography of which has led to the isolation of an extensive range of novel compounds. One- and two-dimensional NMR spectroscopic, mass spectrometric and X-ray crystallographic analysis of these compounds have permitted identification of no less than eight general classes of chromene and coumarin derivatives. The formation of the various product types is attributed to cascades of successive reactions stemming, in each case, from a Baylis-Hillman product as the common intermediate. The mechanistic sequence involved in the formation of the various chromene and coumarin derivatives have been elucidated by examining isolated or specifically prepared compounds as putative reaction intermediates. Conjugate addition and acyl or allylic substitution by various nucleophiles appear to be common processes in the formation of the chromene and coumarin derivatives, and studies focussing on these processes have been undertaken. Reactions of Baylis-Hillman adducts have been carried out, using oxygen, sulfur and nitrogen nucleophiles, in order to explore stereoselectivity and regioselectivity trends. The results show that the reactions proceed with a very high degree of regioselectivity, affording conjugate addition rather than acyl substitution products. The diastereoselectivity observed for the addition products, however was typically low. A kinetic study to explore the regioselectivity of the reaction between various Baylis-Hillman derived halogeno esters and the nucleophile, methyl 3-oxobutanolate enloate, in two different base-solvent systems at high dilution was also undertaken. The reactions were monitored by ¹H NMR spectroscopy, and the results revealed that the reaction kinetics are more complex than originally anticipated. A mechanistic rationalisation is offered which is consistent with both the kinetic data and the observed regioselectivity trends.
- Full Text:
- Date Issued: 1998
Aspects of renormalisation in some quantum field theories
- Authors: Roy, Alan A
- Date: 1998
- Subjects: Quantum field theory , Renormalization group
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5400 , http://hdl.handle.net/10962/d1005214 , Quantum field theory , Renormalization group
- Description: Renormalisation is an important aspect of Quantum Field Theory. It is used to create physically meaningful theories and some major developments took place in the 1970's and onwards. We consider Renormalisation in its application to the theories of ψ⁴ , Quantum Electrodynamics, Quantum Chromodynamics and the Background Field Method. Feynman diagrams are used to illustrate many of the concepts.
- Full Text:
- Date Issued: 1998
- Authors: Roy, Alan A
- Date: 1998
- Subjects: Quantum field theory , Renormalization group
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5400 , http://hdl.handle.net/10962/d1005214 , Quantum field theory , Renormalization group
- Description: Renormalisation is an important aspect of Quantum Field Theory. It is used to create physically meaningful theories and some major developments took place in the 1970's and onwards. We consider Renormalisation in its application to the theories of ψ⁴ , Quantum Electrodynamics, Quantum Chromodynamics and the Background Field Method. Feynman diagrams are used to illustrate many of the concepts.
- Full Text:
- Date Issued: 1998
At play in the master's workshop: the experience of reading in the novels of Henry James
- Authors: Seddon, Deborah Ann
- Date: 1998
- Subjects: James, Henry, 1843-1916 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2278 , http://hdl.handle.net/10962/d1007451 , James, Henry, 1843-1916 -- Criticism and interpretation
- Description: James's belief that "it is art that makes life" is essential to his own literary technique and to the reading experience within and in relation to his novels. The thesis seeks to posit the notion of reading as a fundamental concern in Henry James's fiction. Drawing largely on the phenomenological and anthropological approaches to the reading process of Wolfgang Iser, this thesis examines the Jamesian text as a performative event involving author, reader and character in creative and interpretative narrational struggles. Iser uses "play" as an integral term to describe the dynamic between author-reader-text which produces a literary work of art. In James's fiction the doubling of the author/reader and reader/character role within the text crucially structures a narrative form which is itself an inquiry into the human use of fiction. The Iserian conception of the act of reading as an engagement with the "gaps" within the play-space of the literary text can elucidate James's structural and thematic use of such sites of indeterminacy to foreground the enlivening necessity of an indeterminate "felt life" within human narrative structures. What Maisie Knew highlights the most important rule in the game -- the necessity for the reader to create meaning from the indeterminate aspects of the text. The shared exercise for author-reader-character is the attempt to access the child's unformulated inner reality to ascertain what Maisie knows. In the section on The Portrait of a Lady Iser's notion of reading as an ideational activity aids an inquiry into the human use of mental fictive picturing to compose reality. The Ambassadors demonstrates the "anthropological" need for the particular mode of consciousness brought about by the literary text when we engage in a world as real as but different to our own. Strether is the reader's ambassador in this world and his interpretative activity mirrors the reader's quest. In The Golden Bowl the bewildering multiplicity of readings made possible by the indeterminate aspects of the literary text instigates a contest for narrative forms in which the chosen fictions of the readers/characters must be actively willed into existence.
- Full Text:
- Date Issued: 1998
- Authors: Seddon, Deborah Ann
- Date: 1998
- Subjects: James, Henry, 1843-1916 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2278 , http://hdl.handle.net/10962/d1007451 , James, Henry, 1843-1916 -- Criticism and interpretation
- Description: James's belief that "it is art that makes life" is essential to his own literary technique and to the reading experience within and in relation to his novels. The thesis seeks to posit the notion of reading as a fundamental concern in Henry James's fiction. Drawing largely on the phenomenological and anthropological approaches to the reading process of Wolfgang Iser, this thesis examines the Jamesian text as a performative event involving author, reader and character in creative and interpretative narrational struggles. Iser uses "play" as an integral term to describe the dynamic between author-reader-text which produces a literary work of art. In James's fiction the doubling of the author/reader and reader/character role within the text crucially structures a narrative form which is itself an inquiry into the human use of fiction. The Iserian conception of the act of reading as an engagement with the "gaps" within the play-space of the literary text can elucidate James's structural and thematic use of such sites of indeterminacy to foreground the enlivening necessity of an indeterminate "felt life" within human narrative structures. What Maisie Knew highlights the most important rule in the game -- the necessity for the reader to create meaning from the indeterminate aspects of the text. The shared exercise for author-reader-character is the attempt to access the child's unformulated inner reality to ascertain what Maisie knows. In the section on The Portrait of a Lady Iser's notion of reading as an ideational activity aids an inquiry into the human use of mental fictive picturing to compose reality. The Ambassadors demonstrates the "anthropological" need for the particular mode of consciousness brought about by the literary text when we engage in a world as real as but different to our own. Strether is the reader's ambassador in this world and his interpretative activity mirrors the reader's quest. In The Golden Bowl the bewildering multiplicity of readings made possible by the indeterminate aspects of the literary text instigates a contest for narrative forms in which the chosen fictions of the readers/characters must be actively willed into existence.
- Full Text:
- Date Issued: 1998
The growth, development and impact of the Grahamstown Festival of the Arts with special reference to music
- Authors: Silva, Jane Susan
- Date: 1998
- Subjects: Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2656 , http://hdl.handle.net/10962/d1002322 , Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Description: The Grahamstown Festival has become a huge and complex annual celebration of the arts, transforming the small Eastern Cape city for ten days every year. However this event had very modest beginnings, as did music and festivals in the city of Grahamstown. From its early days Grahamstown showed strong signs of becoming an important cultural centre, presenting numerous musical concerts from 1812, the festival tradition in the city beginning in 1887. The modern arts festival, initiated in 1971, had a chequered history during the early and mid 1970's, weathering economic recession, petrol restrictions and a repressive and restrictive political atmosphere. However by 1979 the event had become established and popular enough to ensure continued success during the 1980's. The period 1980-89 was one of great growth and development for the festival regarding attendance, and the number and nature of productions presented. Music had always been an integral part of the festival, and for the first time its role in this artistic celebration is being examined. The impact of such an event is varied and far-reaching, and thus difficult to assess, but the thesis ends with an attempt to gauge the Festival's impact.
- Full Text:
- Date Issued: 1998
- Authors: Silva, Jane Susan
- Date: 1998
- Subjects: Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2656 , http://hdl.handle.net/10962/d1002322 , Standard Bank National Arts Festival -- Grahamstown , Standard Bank National Arts Festival -- Influence , Grahamstown (South Africa) -- Art and music , Music -- South Africa -- Eastern Cape -- Grahamstown
- Description: The Grahamstown Festival has become a huge and complex annual celebration of the arts, transforming the small Eastern Cape city for ten days every year. However this event had very modest beginnings, as did music and festivals in the city of Grahamstown. From its early days Grahamstown showed strong signs of becoming an important cultural centre, presenting numerous musical concerts from 1812, the festival tradition in the city beginning in 1887. The modern arts festival, initiated in 1971, had a chequered history during the early and mid 1970's, weathering economic recession, petrol restrictions and a repressive and restrictive political atmosphere. However by 1979 the event had become established and popular enough to ensure continued success during the 1980's. The period 1980-89 was one of great growth and development for the festival regarding attendance, and the number and nature of productions presented. Music had always been an integral part of the festival, and for the first time its role in this artistic celebration is being examined. The impact of such an event is varied and far-reaching, and thus difficult to assess, but the thesis ends with an attempt to gauge the Festival's impact.
- Full Text:
- Date Issued: 1998
A molecular genetic assessment of the population structure and variation in two inshore dolphin genera on the east coast of South Africa
- Smith-Goodwin, Jacqueline Anne
- Authors: Smith-Goodwin, Jacqueline Anne
- Date: 1998
- Subjects: Dolphins -- South Africa Variation (Biology) Dolphins -- Genetics Population genetics Bottlenose dolphin -- South Africa Sousa -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4007 , http://hdl.handle.net/10962/d1004067
- Description: Coastal dolphins on the South African east coast are threatened by degradation and loss of habitat as a result of increasing coastal development, industrial effluent and agricultural runoff. In addition, dolphins off the coast of KwaZulu-Natal have, for more than four decades, been heavily exploited through unchecked incidental capture in shark nets set at 45 beaches. In light of the high rate of mortality and apparent depletion of both species, the persistence of bottlenose (Tursiops truncatus) and humpback (Sousa chinensis) dolphins in that region has been questioned. Genetic variation in south east African dolphin populations was determined as a means of assessing the fitness of the populations and their resilience to demographic disturbances. Furthermore, in order to determine the effects of continued mortality on the KwaZulu-Natal subpopulations, it was necessary to determine whether they are open or closed to immigration from the adjacent East Cape region, which represents a relatively unstressed region, characterised by a lack of shark nets and less intensive coastal activities. Genetic variation and differentiation in the maternal genome was assessed by determining the sequence of the first 400 bases of the mtDNA control region in bottlenose and humpback dolphins from KwaZulu-Natal and the East Cape. Nuclear variation and differentiation was estimated at six microsatellite loci and compared with earlier estimates determined from allozyme electrophoresis. Random amplified polymorphic DNA (RAPD) was assessed as a means of identifying population subdivisions and diagnostic population markers. Both bottlenose and humpback dolphins on the South African east coast are characterised by low nuclear and organellar genetic variation, consistent with a possible genetic bottleneck, the inferred date of which coincides with the onset of the last glacial period. Genetic variation in South African bottlenose dolphins was lower than that reported elsewhere for the species, while an intraspecific comparison supported lower genetic variation in South African humpback dolphins than in humpback dolphins sampled off Hong Kong. An analysis of molecular variance (AMOVA), performed on mtDNA haplotype frequency data indicated, for both species, significant genetic subdivision, concordant with geographic location. The data suggested female bottlenose dolphins demonstrate regional philopatry, displaying limited movement between KwaZulu-Natal and the East Cape. Female humpback dolphins tend towards strict local philopatry, with significant maternal differentiation evident both within and between regional subdivisions. Differentiation in microsatellite allele frequencies was also demonstrated between KwaZulu-Natal and the East Cape for both species, suggesting that the movement of male bottlenose and humpback dolphins may also be restricted. Nonetheless, considerably higher nuclear gene flow estimates suggested that males of both species represent the principal vectors of gene dispersal. The implications of historically low genetic variability and population subdivision in South African dolphins are important in view of the current rate of mortality in KwaZulu-Natal. The persistence of coastal dolphin populations relies on their ability to recover following a bottleneck event. Continued removal of demographically important age-sex classes such as occurs in shark nets, may not only further reduce the genetic variation, but would ultimately deplete dolphin populations in KwaZulu-Natal beyond a sustainable number, resulting in eventual local extinction. The differentiation of the two regions implies that, in the event of local extinction occurring, dolphins, particularly females, from adjacent regions will not readily re-colonise the area. This would result in fragmentation of the south east African populations and ensure reproductive isolation from neighbouring populations on the east African coast.
- Full Text:
- Date Issued: 1998
- Authors: Smith-Goodwin, Jacqueline Anne
- Date: 1998
- Subjects: Dolphins -- South Africa Variation (Biology) Dolphins -- Genetics Population genetics Bottlenose dolphin -- South Africa Sousa -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4007 , http://hdl.handle.net/10962/d1004067
- Description: Coastal dolphins on the South African east coast are threatened by degradation and loss of habitat as a result of increasing coastal development, industrial effluent and agricultural runoff. In addition, dolphins off the coast of KwaZulu-Natal have, for more than four decades, been heavily exploited through unchecked incidental capture in shark nets set at 45 beaches. In light of the high rate of mortality and apparent depletion of both species, the persistence of bottlenose (Tursiops truncatus) and humpback (Sousa chinensis) dolphins in that region has been questioned. Genetic variation in south east African dolphin populations was determined as a means of assessing the fitness of the populations and their resilience to demographic disturbances. Furthermore, in order to determine the effects of continued mortality on the KwaZulu-Natal subpopulations, it was necessary to determine whether they are open or closed to immigration from the adjacent East Cape region, which represents a relatively unstressed region, characterised by a lack of shark nets and less intensive coastal activities. Genetic variation and differentiation in the maternal genome was assessed by determining the sequence of the first 400 bases of the mtDNA control region in bottlenose and humpback dolphins from KwaZulu-Natal and the East Cape. Nuclear variation and differentiation was estimated at six microsatellite loci and compared with earlier estimates determined from allozyme electrophoresis. Random amplified polymorphic DNA (RAPD) was assessed as a means of identifying population subdivisions and diagnostic population markers. Both bottlenose and humpback dolphins on the South African east coast are characterised by low nuclear and organellar genetic variation, consistent with a possible genetic bottleneck, the inferred date of which coincides with the onset of the last glacial period. Genetic variation in South African bottlenose dolphins was lower than that reported elsewhere for the species, while an intraspecific comparison supported lower genetic variation in South African humpback dolphins than in humpback dolphins sampled off Hong Kong. An analysis of molecular variance (AMOVA), performed on mtDNA haplotype frequency data indicated, for both species, significant genetic subdivision, concordant with geographic location. The data suggested female bottlenose dolphins demonstrate regional philopatry, displaying limited movement between KwaZulu-Natal and the East Cape. Female humpback dolphins tend towards strict local philopatry, with significant maternal differentiation evident both within and between regional subdivisions. Differentiation in microsatellite allele frequencies was also demonstrated between KwaZulu-Natal and the East Cape for both species, suggesting that the movement of male bottlenose and humpback dolphins may also be restricted. Nonetheless, considerably higher nuclear gene flow estimates suggested that males of both species represent the principal vectors of gene dispersal. The implications of historically low genetic variability and population subdivision in South African dolphins are important in view of the current rate of mortality in KwaZulu-Natal. The persistence of coastal dolphin populations relies on their ability to recover following a bottleneck event. Continued removal of demographically important age-sex classes such as occurs in shark nets, may not only further reduce the genetic variation, but would ultimately deplete dolphin populations in KwaZulu-Natal beyond a sustainable number, resulting in eventual local extinction. The differentiation of the two regions implies that, in the event of local extinction occurring, dolphins, particularly females, from adjacent regions will not readily re-colonise the area. This would result in fragmentation of the south east African populations and ensure reproductive isolation from neighbouring populations on the east African coast.
- Full Text:
- Date Issued: 1998
A case study of the implementation of the communicative approach to English second language progress testing in one secondary school in the Alexandria Circuit of the Eastern Cape Department of Education
- Authors: Ssemakalu, John
- Date: 1998
- Subjects: Communicative competence , Communicative competence in children , English language -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Language and languages -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Second language acquisition -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2362 , http://hdl.handle.net/10962/d1002645 , Communicative competence , Communicative competence in children , English language -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Language and languages -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Second language acquisition -- South Africa -- Eastern Cape
- Description: This study explores the implementation of the communicative approach (CA) to English second language progress testing in an African secondary school which falls under the Eastern Cape Department of Education. The goal of the research is to establish how teachers access, conceptualise, and apply the CA to language testing in their specific working conditions. The report of the findings of the research reveals that teachers' understanding of the CA to testing differs from that of the linguists, curriculum designers, innovators, and syllabus writers. This is caused by a combination of factors including teachers' poor working conditions, the lack of focused pre-service training and effective in-service structures for their empowennent as the agents of innovation, coupled with the poor circulation and a lack of clarity in official documents on the CA to language testing. These constraints made it impossible for teachers to implement the CA to language testing. In order to carry on with their work, however, teachers developed coping strategies by drawing, probably unconsciously, on a mixture of structuralist, sociolinguistic-psycholinguistic, communicative and any other testing practices they may have acquired during their years of service. Although based only on one school, the findings of this study indicate that for fundamental innovations such as the CA to take root, there is a need for the adoption of more dedicated, reflective implementation strategies involving proper planning and monitoring, as well as evaluation and re-evaluation of the entire process. This necessarily slow process must go hand-in-hand with a dedicated pre-service and in-service empowerment program based on consultative communication between innovator and agent; and a persuasive education/re-education approach which will encourage teachers to change their entrenched practices.
- Full Text:
- Date Issued: 1998
- Authors: Ssemakalu, John
- Date: 1998
- Subjects: Communicative competence , Communicative competence in children , English language -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Language and languages -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Second language acquisition -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2362 , http://hdl.handle.net/10962/d1002645 , Communicative competence , Communicative competence in children , English language -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Language and languages -- Study and teaching (Secondary) -- Foreign speakers -- South Africa -- Eastern Cape , Second language acquisition -- South Africa -- Eastern Cape
- Description: This study explores the implementation of the communicative approach (CA) to English second language progress testing in an African secondary school which falls under the Eastern Cape Department of Education. The goal of the research is to establish how teachers access, conceptualise, and apply the CA to language testing in their specific working conditions. The report of the findings of the research reveals that teachers' understanding of the CA to testing differs from that of the linguists, curriculum designers, innovators, and syllabus writers. This is caused by a combination of factors including teachers' poor working conditions, the lack of focused pre-service training and effective in-service structures for their empowennent as the agents of innovation, coupled with the poor circulation and a lack of clarity in official documents on the CA to language testing. These constraints made it impossible for teachers to implement the CA to language testing. In order to carry on with their work, however, teachers developed coping strategies by drawing, probably unconsciously, on a mixture of structuralist, sociolinguistic-psycholinguistic, communicative and any other testing practices they may have acquired during their years of service. Although based only on one school, the findings of this study indicate that for fundamental innovations such as the CA to take root, there is a need for the adoption of more dedicated, reflective implementation strategies involving proper planning and monitoring, as well as evaluation and re-evaluation of the entire process. This necessarily slow process must go hand-in-hand with a dedicated pre-service and in-service empowerment program based on consultative communication between innovator and agent; and a persuasive education/re-education approach which will encourage teachers to change their entrenched practices.
- Full Text:
- Date Issued: 1998
Women's experience of abortion : a qualitative study
- Authors: Taylor, Gaye Lesley
- Date: 1998
- Subjects: Abortion , Abortion -- South Africa , Women -- Counseling of
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:708 , http://hdl.handle.net/10962/d1006522 , Abortion , Abortion -- South Africa , Women -- Counseling of
- Description: Abortion is an emotive topic that always raises strong feelings. The purpose of this study, however, is not to focus on the religious, political or moral questions surrounding abortion. Abortion is a reality and in South Africa, where it has only recently become legal, there is a need to have an understanding of the effects on women in order to provide counselling services. There is also a need to provide services for the many women who have had illegal terminations in the past. This study reviewed the most recent literature on the subject and the researcher takes the view that although the scientific literature states there is little long term psychological effect of abortion, the non-positivist literature which records women's experiences tells another story. Some of the problems with the scientific literature is that psychological effects are not defined and there may be political motivation for the study, ie. an attempt is made to prove that the health costs are not high for abortion because there is little long term effect. The researcher, however, feels this does a disservice to women who have had abortions because there is a failure to provide counselling services. Some members of the feminist movement also deserve criticism because in their haste to give women their rights they fail to allow a woman to thoroughly explore her options beforehand and to provide support services afterwards. The researcher, however, also identified a new theme in the literature which has been called a maturing of the feminist viewpoint that along with the right to abortion, women also have a right to the mixed feelings that go with making, what is for many, a very painful decision. There is a recognition that abortion is about loss and thus there is a corresponding need to acknowledge women's need to mourn and to provide services. The study does not include the experience of women who seek abortions for reasons of poverty. It also excludes the experience of women who have abortions as a result of rape, incest or harm to the foetus. It is a qualitative study and a non-probability sampling technique which comprised snowball and purposive methods was used to identify respondents. In-depth semi-structured interviews using a broad theme of questions were conducted with five respondents. The women were asked to tell the stories of their abortions: their and their partner's feelings before and after, how they decided and the actual experience. They were also asked to identify counselling requirements, what they found helpful and what would have helped. The literature and the findings support the researcher's view that women who find themselves with an unexpected pregnancy need an opportunity to objectively consider all their options, namely keeping the baby, adoption or abortion, and to have an objective counsellor assist them in vigorously considering these. If they decide on a termination they need to be given as much information as possible about the procedure and about how they are likely to feel. Afterwards counselling should be made available and women should be encouraged to use the service. They need to be assisted to explore all ways of coming to terms with it such as through dream work, dialogueing with the unborn child through a letter and for those with religious beliefs seeking absolution from the church. There is a great need for a Christian and other religious ministry in this regard. Self-help therapies such as support groups can also be helpful
- Full Text:
- Date Issued: 1998
- Authors: Taylor, Gaye Lesley
- Date: 1998
- Subjects: Abortion , Abortion -- South Africa , Women -- Counseling of
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:708 , http://hdl.handle.net/10962/d1006522 , Abortion , Abortion -- South Africa , Women -- Counseling of
- Description: Abortion is an emotive topic that always raises strong feelings. The purpose of this study, however, is not to focus on the religious, political or moral questions surrounding abortion. Abortion is a reality and in South Africa, where it has only recently become legal, there is a need to have an understanding of the effects on women in order to provide counselling services. There is also a need to provide services for the many women who have had illegal terminations in the past. This study reviewed the most recent literature on the subject and the researcher takes the view that although the scientific literature states there is little long term psychological effect of abortion, the non-positivist literature which records women's experiences tells another story. Some of the problems with the scientific literature is that psychological effects are not defined and there may be political motivation for the study, ie. an attempt is made to prove that the health costs are not high for abortion because there is little long term effect. The researcher, however, feels this does a disservice to women who have had abortions because there is a failure to provide counselling services. Some members of the feminist movement also deserve criticism because in their haste to give women their rights they fail to allow a woman to thoroughly explore her options beforehand and to provide support services afterwards. The researcher, however, also identified a new theme in the literature which has been called a maturing of the feminist viewpoint that along with the right to abortion, women also have a right to the mixed feelings that go with making, what is for many, a very painful decision. There is a recognition that abortion is about loss and thus there is a corresponding need to acknowledge women's need to mourn and to provide services. The study does not include the experience of women who seek abortions for reasons of poverty. It also excludes the experience of women who have abortions as a result of rape, incest or harm to the foetus. It is a qualitative study and a non-probability sampling technique which comprised snowball and purposive methods was used to identify respondents. In-depth semi-structured interviews using a broad theme of questions were conducted with five respondents. The women were asked to tell the stories of their abortions: their and their partner's feelings before and after, how they decided and the actual experience. They were also asked to identify counselling requirements, what they found helpful and what would have helped. The literature and the findings support the researcher's view that women who find themselves with an unexpected pregnancy need an opportunity to objectively consider all their options, namely keeping the baby, adoption or abortion, and to have an objective counsellor assist them in vigorously considering these. If they decide on a termination they need to be given as much information as possible about the procedure and about how they are likely to feel. Afterwards counselling should be made available and women should be encouraged to use the service. They need to be assisted to explore all ways of coming to terms with it such as through dream work, dialogueing with the unborn child through a letter and for those with religious beliefs seeking absolution from the church. There is a great need for a Christian and other religious ministry in this regard. Self-help therapies such as support groups can also be helpful
- Full Text:
- Date Issued: 1998
The invertebrates of temporary rivers in the Eastern Cape, South Africa
- Authors: Uys, Amanda Cloete
- Date: 1998
- Subjects: Rivers -- South Africa -- Eastern Cape Stream ecology -- South Africa -- Eastern Cape Freshwater invertebrates -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5628 , http://hdl.handle.net/10962/d1004908
- Description: Temporary rivers in dryland regions are subject to highly variable and unpredictable rainfall and flow, and are considered unstable systems relative to perennial rivers of temperate zones. Little is known of the ecology of South Africa's temporary rivers, despite their abundance. The research presented focusses on the aquatic invertebrates inhabiting intermittently-flowing rivers in the 'arid corridor' of the Eastern Cape, South Africa. The major aims of the work were: to investigate which invertebrates inhabit these rivers, how the fauna is affected by environmental variability at various spatial and temporal scales, whether or not a characteristic fauna can be associated with these rivers or the hydrological phases which characterise them, and to establish to what extent faunal overlap occurs between different temporary rivers and between natural and modified temporary and perennial rivers. Research results indicate that the fauna of the Eastern Cape temporary rivers shows little structure at the scales of investigation, and that communities are generally non-equilibrial in character. The major forces shaping the biota are considered to be physical rather than biological, and the most important of these are: present and antecedent hydrological conditions and their duration; time of year; and biotope character, extent and heterogeneity. Three groups of fauna were identified as inhabitants of the temporary rivers: 'residents', 'facultative taxa' and 'opportunist colonists'. Taxa were tentatively allocated to these groups. Faunal resemblance was fairly high in Eastern Cape temporary rivers at the level of family, but not at more detailed taxonomic levels. A comparison between faunas of temporary and perennial rivers in different regions of South Africa illustrated the influence of geographical location on diversity. Within regions, however, there was no indication that perennial rivers were more diverse than intermittent rivers. The relatively high diversities in temporary rivers in this study are attributed at least in part to the heterogeneity in surface water conditions over time. A conceptual framework envisioning a continuum between perennial and temporary rivers is proposed as a basis for ongoing research into these rivers. A supporting terminology for the range of river flow types in South Africa is presented.
- Full Text:
- Date Issued: 1998
- Authors: Uys, Amanda Cloete
- Date: 1998
- Subjects: Rivers -- South Africa -- Eastern Cape Stream ecology -- South Africa -- Eastern Cape Freshwater invertebrates -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5628 , http://hdl.handle.net/10962/d1004908
- Description: Temporary rivers in dryland regions are subject to highly variable and unpredictable rainfall and flow, and are considered unstable systems relative to perennial rivers of temperate zones. Little is known of the ecology of South Africa's temporary rivers, despite their abundance. The research presented focusses on the aquatic invertebrates inhabiting intermittently-flowing rivers in the 'arid corridor' of the Eastern Cape, South Africa. The major aims of the work were: to investigate which invertebrates inhabit these rivers, how the fauna is affected by environmental variability at various spatial and temporal scales, whether or not a characteristic fauna can be associated with these rivers or the hydrological phases which characterise them, and to establish to what extent faunal overlap occurs between different temporary rivers and between natural and modified temporary and perennial rivers. Research results indicate that the fauna of the Eastern Cape temporary rivers shows little structure at the scales of investigation, and that communities are generally non-equilibrial in character. The major forces shaping the biota are considered to be physical rather than biological, and the most important of these are: present and antecedent hydrological conditions and their duration; time of year; and biotope character, extent and heterogeneity. Three groups of fauna were identified as inhabitants of the temporary rivers: 'residents', 'facultative taxa' and 'opportunist colonists'. Taxa were tentatively allocated to these groups. Faunal resemblance was fairly high in Eastern Cape temporary rivers at the level of family, but not at more detailed taxonomic levels. A comparison between faunas of temporary and perennial rivers in different regions of South Africa illustrated the influence of geographical location on diversity. Within regions, however, there was no indication that perennial rivers were more diverse than intermittent rivers. The relatively high diversities in temporary rivers in this study are attributed at least in part to the heterogeneity in surface water conditions over time. A conceptual framework envisioning a continuum between perennial and temporary rivers is proposed as a basis for ongoing research into these rivers. A supporting terminology for the range of river flow types in South Africa is presented.
- Full Text:
- Date Issued: 1998
Improvement of fertility and hatchability of artificially incubated ostrich eggs in the little Karoo
- Van Schalkwyk, Salmon Jacobus
- Authors: Van Schalkwyk, Salmon Jacobus
- Date: 1998
- Subjects: Ostrich farming -- South Africa , Eggs -- Hatchability , Eggs -- Incubation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5713 , http://hdl.handle.net/10962/d1005399
- Description: Ostriches are an important commercial species in South Africa and are becoming increasingly so in other parts of the world. Fertility and hatchability of artificially incubated ostrich eggs, however, is generally regarded as low compared to other poultry species and to ostriches in the wild. Investigation into specific farming practices at present indicated scope for an overall improvement in productivity through a sound breeding strategy. This thesis investigated factors that affect egg production, fertility, and hatchability of artificially incubated eggs in the Little Karoo region of South Africa. Specific breeding pair combinations accounted for the major variations in egg weight, hatchability, chick production and offspring weight at slaughter age. An appreciable proportion of variation in reproductive traits was attributable to the repeatable nature of breeding pair performance from year to year, even from first breeding attempts, suggesting that selection of good breeding stock can be made from an early age. Artificially incubated eggs showed improved hatchability when eggs were collected two to three hours after lay rather than the following morning. Storing position of eggs did not significantly effect hatchability when eggs were stored for a maximum of one week. The critical zero temperature for ostrich eggs, below which no embryonical development takes place, was found to be ± 25°C and cooling eggs to temperatures below 20°C for complete cessation of embryonic development during storage resulted in better hatchabilities compared to eggs stored at 25°C room temperature. Hatchability decreased when incubator temperatures were raised from 36 to 37.3°C. Large temperature fluctuations and gradients, which encompass detrimental temperatures, persist within forced draught wooden incubators of the type most commonly in use in the Little Karoo region. The highest temperatures occurred at the top of these incubators and will consequently have a negative impact on hatchability. The ontogeny of ostrich egg metabolism showed an exponential increase during the first 70% of incubation followed by a decline to 75% of the peak value between days 31 and 38 of incubation. From peak levels of embryonic development it was calculated that single stage incubators needs an airflow of 54.4 1/egg.hour to maintain oxygen levels just below 21% and carbon dioxide levels below 0.5%. Lower embryonic mortalities were observed when eggs were turned twenty-four times/day in an electronic incubator compared to hand turning twice a day. Eggs rotated through increasing angles between 60 and 90° resulted in a linear improvement in hatchability. In incubators where turning angles were fixed at 60°, lower hatchabilities were overcome by incubating eggs for 2 - 3 weeks in a horizontal position before placing them vertically. No specific farming practice could be singled out as the main cause of low fertility or hatchability but rather a combination of certain practices applied wrongly.
- Full Text:
- Date Issued: 1998
Improvement of fertility and hatchability of artificially incubated ostrich eggs in the little Karoo
- Authors: Van Schalkwyk, Salmon Jacobus
- Date: 1998
- Subjects: Ostrich farming -- South Africa , Eggs -- Hatchability , Eggs -- Incubation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5713 , http://hdl.handle.net/10962/d1005399
- Description: Ostriches are an important commercial species in South Africa and are becoming increasingly so in other parts of the world. Fertility and hatchability of artificially incubated ostrich eggs, however, is generally regarded as low compared to other poultry species and to ostriches in the wild. Investigation into specific farming practices at present indicated scope for an overall improvement in productivity through a sound breeding strategy. This thesis investigated factors that affect egg production, fertility, and hatchability of artificially incubated eggs in the Little Karoo region of South Africa. Specific breeding pair combinations accounted for the major variations in egg weight, hatchability, chick production and offspring weight at slaughter age. An appreciable proportion of variation in reproductive traits was attributable to the repeatable nature of breeding pair performance from year to year, even from first breeding attempts, suggesting that selection of good breeding stock can be made from an early age. Artificially incubated eggs showed improved hatchability when eggs were collected two to three hours after lay rather than the following morning. Storing position of eggs did not significantly effect hatchability when eggs were stored for a maximum of one week. The critical zero temperature for ostrich eggs, below which no embryonical development takes place, was found to be ± 25°C and cooling eggs to temperatures below 20°C for complete cessation of embryonic development during storage resulted in better hatchabilities compared to eggs stored at 25°C room temperature. Hatchability decreased when incubator temperatures were raised from 36 to 37.3°C. Large temperature fluctuations and gradients, which encompass detrimental temperatures, persist within forced draught wooden incubators of the type most commonly in use in the Little Karoo region. The highest temperatures occurred at the top of these incubators and will consequently have a negative impact on hatchability. The ontogeny of ostrich egg metabolism showed an exponential increase during the first 70% of incubation followed by a decline to 75% of the peak value between days 31 and 38 of incubation. From peak levels of embryonic development it was calculated that single stage incubators needs an airflow of 54.4 1/egg.hour to maintain oxygen levels just below 21% and carbon dioxide levels below 0.5%. Lower embryonic mortalities were observed when eggs were turned twenty-four times/day in an electronic incubator compared to hand turning twice a day. Eggs rotated through increasing angles between 60 and 90° resulted in a linear improvement in hatchability. In incubators where turning angles were fixed at 60°, lower hatchabilities were overcome by incubating eggs for 2 - 3 weeks in a horizontal position before placing them vertically. No specific farming practice could be singled out as the main cause of low fertility or hatchability but rather a combination of certain practices applied wrongly.
- Full Text:
- Date Issued: 1998