The effects of a 160 km run on selected anthropometric, physiological and psychological parameters
- Authors: Oltmann, Carmen
- Date: 1992
- Subjects: Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5148 , http://hdl.handle.net/10962/d1009706 , Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Description: Twenty-one male subjects volunteered to participate in this study of the effects of an ultramarathon run under competitive conditions. Selected anthropometric measurements were made before and after the race. Blood samples were taken before, and within 10 min. of completing the race. Haematocrit and cortisol concentrations were analysed from each sample. Three ratings of perceived exertion (RPE) - local, central and overall, were obtained at two-hourly intervals throughout the race. The shortened form of the Eysenck Personality Inventory (EPI) was administered before the race. The Profile of Mood States (POMS) test was completed both before and immediately after the race. The average running intensity was estimated to be about 32% VO₂max which would not have caused major lactate accumulation. Repetitive compressive forces as a result of heel-strike resulted in intervertebral disc fluid loss. This resulted in a significant (p<0.05) decrease in stature after the race. Mobilization of glycogen, trig1ycerides and protein for metabolism as well as fluid loss via sweat resulted in significantly decreased body mass after the race. Plasma volume and serum cortisol concentrations were significantly increased after the race compared to pre-race baseline levels. Local RPE responses were dominant throughout the entire race, followed by overall RPE. Running 160 km had an effect on mood state. "Depression", "fatigue" and "confusion" (profile of Mood states) were all significantly increased compared to pre-race scores. Sleep deprivation as a result of running through the night was probably an important contributing factor. The anthropometric profile of the ultramarathon runners in this sample was more like that of the general population than elite marathon runners from the literature. The ultramarathon runners were more extroverted than elite marathon runners, but exhibited a similar Profile of Mood state before the race. The stressor - running 160 km - resulted in a 'strain response'. This was evident in the decreased stature and mass, and increased serum cortisol, "depression", "confusion" and above all "fatigue".
- Full Text:
- Date Issued: 1992
- Authors: Oltmann, Carmen
- Date: 1992
- Subjects: Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5148 , http://hdl.handle.net/10962/d1009706 , Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Description: Twenty-one male subjects volunteered to participate in this study of the effects of an ultramarathon run under competitive conditions. Selected anthropometric measurements were made before and after the race. Blood samples were taken before, and within 10 min. of completing the race. Haematocrit and cortisol concentrations were analysed from each sample. Three ratings of perceived exertion (RPE) - local, central and overall, were obtained at two-hourly intervals throughout the race. The shortened form of the Eysenck Personality Inventory (EPI) was administered before the race. The Profile of Mood States (POMS) test was completed both before and immediately after the race. The average running intensity was estimated to be about 32% VO₂max which would not have caused major lactate accumulation. Repetitive compressive forces as a result of heel-strike resulted in intervertebral disc fluid loss. This resulted in a significant (p<0.05) decrease in stature after the race. Mobilization of glycogen, trig1ycerides and protein for metabolism as well as fluid loss via sweat resulted in significantly decreased body mass after the race. Plasma volume and serum cortisol concentrations were significantly increased after the race compared to pre-race baseline levels. Local RPE responses were dominant throughout the entire race, followed by overall RPE. Running 160 km had an effect on mood state. "Depression", "fatigue" and "confusion" (profile of Mood states) were all significantly increased compared to pre-race scores. Sleep deprivation as a result of running through the night was probably an important contributing factor. The anthropometric profile of the ultramarathon runners in this sample was more like that of the general population than elite marathon runners from the literature. The ultramarathon runners were more extroverted than elite marathon runners, but exhibited a similar Profile of Mood state before the race. The stressor - running 160 km - resulted in a 'strain response'. This was evident in the decreased stature and mass, and increased serum cortisol, "depression", "confusion" and above all "fatigue".
- Full Text:
- Date Issued: 1992
The evaluation of an individualised language programme in two multicultural Standard 9 classes : a pilot study
- Authors: Hartman, Lorraine Mary
- Date: 1992
- Subjects: English language -- Study and teaching (Secondary) -- South Africa English language -- Study and teaching (Secondary) -- South Africa -- Foreign speakers Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1523 , http://hdl.handle.net/10962/d1003405
- Description: Two multicultural, mixed-ability Standard Nine classes (17 year olds) were selected for this pilot study. As they were half way through the Senior Secondary phase they had completed most of their English Language syllabus. There was a wide range of achievement in English in addition to which, fifteen of the thirty-nine pupils were English second language speakers. The teacher had to decide how to cope adequately with these differences in the subject English in general and in particular, in the Language component. A Language programme was devised, based on the prescribed textbooks. The pupils could work through the programme at their own pace and order and could consult the researcher during or after class time. The programme only covered the prescribed Language Study component and only a quarter of the total English time during an eight-week period (one term) was given to its completion. A Pre-test was set, the Senior Certificate Language examination paper of 1986, and the results analysed. The two classes were combined into one group and then randomly placed in the experimental and control groups apart from eight boys whose timetable requirements restricted them to being in the same group. The experimental and control groups were not matched. Aspects of Action Research were included in the design; pupils kept individual records; diaries were written by three pupils from each group and an independent observation was made of each group. A Post-test was administered (the 1989 Human Sciences Research Council examination) and this was followed by a questionnaire. The hypothesis, stated in null form, was: Pupils taught by individualised methods will not achieve better results than those taught by traditional methods. This hypothesis proved to be true. The experimental group, who achieved a better result in the pre-test maintained their lead over the control group but did not increase it. Neither group fared well on the post-test but the experimental group achieved a result slightly higher than the provincial average. The affective results were more positive, most pupils enjoying their autonomy and experiencing a sense of achievement despite their results in the post-test. A few preferred whole and small-group teaching, showing that the teacher needs to present the subject in more than one style. This small-scale experiment dealt only with one aspect of English teaching, but there is potential for development particularly with regard to the use of individualised programmes both for remedial and enrichment purposes. The innovative teacher in the multicultural classroom could use individualised programmes profitably as part of his teaching repertoire.
- Full Text:
- Date Issued: 1992
- Authors: Hartman, Lorraine Mary
- Date: 1992
- Subjects: English language -- Study and teaching (Secondary) -- South Africa English language -- Study and teaching (Secondary) -- South Africa -- Foreign speakers Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1523 , http://hdl.handle.net/10962/d1003405
- Description: Two multicultural, mixed-ability Standard Nine classes (17 year olds) were selected for this pilot study. As they were half way through the Senior Secondary phase they had completed most of their English Language syllabus. There was a wide range of achievement in English in addition to which, fifteen of the thirty-nine pupils were English second language speakers. The teacher had to decide how to cope adequately with these differences in the subject English in general and in particular, in the Language component. A Language programme was devised, based on the prescribed textbooks. The pupils could work through the programme at their own pace and order and could consult the researcher during or after class time. The programme only covered the prescribed Language Study component and only a quarter of the total English time during an eight-week period (one term) was given to its completion. A Pre-test was set, the Senior Certificate Language examination paper of 1986, and the results analysed. The two classes were combined into one group and then randomly placed in the experimental and control groups apart from eight boys whose timetable requirements restricted them to being in the same group. The experimental and control groups were not matched. Aspects of Action Research were included in the design; pupils kept individual records; diaries were written by three pupils from each group and an independent observation was made of each group. A Post-test was administered (the 1989 Human Sciences Research Council examination) and this was followed by a questionnaire. The hypothesis, stated in null form, was: Pupils taught by individualised methods will not achieve better results than those taught by traditional methods. This hypothesis proved to be true. The experimental group, who achieved a better result in the pre-test maintained their lead over the control group but did not increase it. Neither group fared well on the post-test but the experimental group achieved a result slightly higher than the provincial average. The affective results were more positive, most pupils enjoying their autonomy and experiencing a sense of achievement despite their results in the post-test. A few preferred whole and small-group teaching, showing that the teacher needs to present the subject in more than one style. This small-scale experiment dealt only with one aspect of English teaching, but there is potential for development particularly with regard to the use of individualised programmes both for remedial and enrichment purposes. The innovative teacher in the multicultural classroom could use individualised programmes profitably as part of his teaching repertoire.
- Full Text:
- Date Issued: 1992
The evaluation of indomethacin and theophylline oral controlled/modified-release dosage forms in vitro-in vivo correlations
- Tandt, Ludo Alfons Germaan Luc
- Authors: Tandt, Ludo Alfons Germaan Luc
- Date: 1992
- Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
- Full Text:
- Date Issued: 1992
- Authors: Tandt, Ludo Alfons Germaan Luc
- Date: 1992
- Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
- Full Text:
- Date Issued: 1992
The exploitation of methane from landfill
- Authors: Schütte, Renate
- Date: 1992
- Subjects: Methane , Waste products as fuel , Refuse as fuel , Sanitary landfills -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4530 , http://hdl.handle.net/10962/d1015949
- Description: A review of literature on the subject of methane exploitation from landfill is presented in conjunction with the results of experiments concerning landfill gas extraction at the Grahamstown Landfill Site. A description of the LFG extraction system and the utilisation of LFG at the Grahamstown Landfill Site is included. Data concerning LFG enhancement parameters, LFG compositions and flow rates, refuse composition, LFG modelling, LFG pumping trials and the economics of LFG extraction and utilisation are presented. The indication is that LFG can be economically extracted and utilised as a heating fuel in South Africa.
- Full Text:
- Date Issued: 1992
- Authors: Schütte, Renate
- Date: 1992
- Subjects: Methane , Waste products as fuel , Refuse as fuel , Sanitary landfills -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4530 , http://hdl.handle.net/10962/d1015949
- Description: A review of literature on the subject of methane exploitation from landfill is presented in conjunction with the results of experiments concerning landfill gas extraction at the Grahamstown Landfill Site. A description of the LFG extraction system and the utilisation of LFG at the Grahamstown Landfill Site is included. Data concerning LFG enhancement parameters, LFG compositions and flow rates, refuse composition, LFG modelling, LFG pumping trials and the economics of LFG extraction and utilisation are presented. The indication is that LFG can be economically extracted and utilised as a heating fuel in South Africa.
- Full Text:
- Date Issued: 1992
The exploration for and possible genesis of, some Archaean granite/gneiss-hosted gold deposits in the Pietersburg granite-greenstone terrane
- Linklater, Michael Anthony Leonard Flanders
- Authors: Linklater, Michael Anthony Leonard Flanders
- Date: 1992
- Subjects: Gold ores -- Geology -- South Africa , Gneiss , Granite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4945 , http://hdl.handle.net/10962/d1005557 , Gold ores -- Geology -- South Africa , Gneiss , Granite
- Description: Abstract The gold mineralization event within Archaean granite-greenstone terranes occurred during the late Archaean, and followed the intrusion of syn- to late-tectonic granitic plutons into previously deformed greenstone belts. An Archaean granite/gneiss-hosted gold deposit, in terms of this project, is classified as having a gold-assay cutoff of 1g/metric ton over widths of at least several metres, or higher grades over narrower widths and/or verbal descriptions that indicate such values. Fluid inclusion studies and isotopic data identify two possible origins for the auriferous fluids; namely magmatic and metamorphic. The exploration target according to the magmatic model, is a late-Archaean, hydrothermally altered, mineralized and fractured granitic intrusion preferably with a granodioritic or quartz-dioritic composition. The exploration target according to the metamorphic replacement model is a granitic stock that has intruded a zone of crustal weakness such as a shear zone, active during the late Archaean. Alternatively, the granitic intrusion should be affected by regionally extensive late-Archaean shearing. It should be hydrothermally altered, deformed and mineralized. Five areas within the Pietersburg granite-greenstone terrane were selected for the 'Regional Area Selection' phase of exploration for Archaean granite/gneiss-hosted gold deposits; namely Roodepoort, Waterval, Ramagoep, Moletsie and Matlala. Roodepoort contains a known granodiorite-hosted gold deposit; the Knight's Pluton, and served as an orientation survey for this project. The use and interpretation of LANDSAT images formed an integral part of exploration techniques; to assess their usefulness in the exploration of Archaean granite/gneiss-hosted gold deposits. Area selection criteria for granite/gneiss-hosted gold mineralization at Roodepoort are the major ENE-trending shear zone, the NNW-trending lineament and hydrothermal alteration, shearing, quartz-stockworks and sulphide mineralization within the Knight's Pluton. The origin of the gold within the Knight's Pluton is uncertain; both magmatic and metamorphic models are possibilities. Ongoing exploration is in progress at Roodepoort. The only area selection criterion for granite/gneiss-hosted gold mineralization at Waterval is the sericitized, subcropping granites located within trenches. Gold mineralization is insignificant. No area selection criteria for Archaean granite/gneiss-hosted gold mineralization were located at Ramagoep, Matlala and Moletsie. No further exploration is recommended for all these areas. The MES image interpretations were successful in identifying lineaments, granitic outcrops, greenstones, vegetation and soil cover. The Clay-iron images adequately differentiated betweeen iron-rich and clay-bearing areas. However, not all clay-bearing areas were associated with hydrothermal alteratian; field checks were necessary to discriminate between weathered granites and hydrothermally altered granites. The Wallis images served to locally enhance the contrasts of the MES and Clay-iron images.
- Full Text:
- Date Issued: 1992
- Authors: Linklater, Michael Anthony Leonard Flanders
- Date: 1992
- Subjects: Gold ores -- Geology -- South Africa , Gneiss , Granite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4945 , http://hdl.handle.net/10962/d1005557 , Gold ores -- Geology -- South Africa , Gneiss , Granite
- Description: Abstract The gold mineralization event within Archaean granite-greenstone terranes occurred during the late Archaean, and followed the intrusion of syn- to late-tectonic granitic plutons into previously deformed greenstone belts. An Archaean granite/gneiss-hosted gold deposit, in terms of this project, is classified as having a gold-assay cutoff of 1g/metric ton over widths of at least several metres, or higher grades over narrower widths and/or verbal descriptions that indicate such values. Fluid inclusion studies and isotopic data identify two possible origins for the auriferous fluids; namely magmatic and metamorphic. The exploration target according to the magmatic model, is a late-Archaean, hydrothermally altered, mineralized and fractured granitic intrusion preferably with a granodioritic or quartz-dioritic composition. The exploration target according to the metamorphic replacement model is a granitic stock that has intruded a zone of crustal weakness such as a shear zone, active during the late Archaean. Alternatively, the granitic intrusion should be affected by regionally extensive late-Archaean shearing. It should be hydrothermally altered, deformed and mineralized. Five areas within the Pietersburg granite-greenstone terrane were selected for the 'Regional Area Selection' phase of exploration for Archaean granite/gneiss-hosted gold deposits; namely Roodepoort, Waterval, Ramagoep, Moletsie and Matlala. Roodepoort contains a known granodiorite-hosted gold deposit; the Knight's Pluton, and served as an orientation survey for this project. The use and interpretation of LANDSAT images formed an integral part of exploration techniques; to assess their usefulness in the exploration of Archaean granite/gneiss-hosted gold deposits. Area selection criteria for granite/gneiss-hosted gold mineralization at Roodepoort are the major ENE-trending shear zone, the NNW-trending lineament and hydrothermal alteration, shearing, quartz-stockworks and sulphide mineralization within the Knight's Pluton. The origin of the gold within the Knight's Pluton is uncertain; both magmatic and metamorphic models are possibilities. Ongoing exploration is in progress at Roodepoort. The only area selection criterion for granite/gneiss-hosted gold mineralization at Waterval is the sericitized, subcropping granites located within trenches. Gold mineralization is insignificant. No area selection criteria for Archaean granite/gneiss-hosted gold mineralization were located at Ramagoep, Matlala and Moletsie. No further exploration is recommended for all these areas. The MES image interpretations were successful in identifying lineaments, granitic outcrops, greenstones, vegetation and soil cover. The Clay-iron images adequately differentiated betweeen iron-rich and clay-bearing areas. However, not all clay-bearing areas were associated with hydrothermal alteratian; field checks were necessary to discriminate between weathered granites and hydrothermally altered granites. The Wallis images served to locally enhance the contrasts of the MES and Clay-iron images.
- Full Text:
- Date Issued: 1992
The failure of the Coloured Persons' Representative Council and its constitutional repercussions, 1956-1985
- Authors: Saks, David
- Date: 1992
- Subjects: South African Labour Party , Federal Coloured People's Party -- South Africa , South Africa. Parliament , South Africa -- Politics and government -- 20th century , South Africa -- Race relations , Coloured Persons Representative Council of South Africa , Colored people (South Africa) -- Politics and government , Political parties -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2624 , http://hdl.handle.net/10962/d1015907
- Description: The thesis starts by providing a brief overview of South African ''Coloured" politics from the passing of Ordinance 50 in 1828 to the removal of the Cape Coloured people from the common voter's roll in 1956. It then goes on to discuss in detail the structures instituted by successive Nationalist Governments to serve as an alternative to parliamentary representation for the coloured people, the role of the various coloured political parties within such structures and the latter's gradual adaptation and development, culminating in the inauguration of the Tricameral Parliament in early 1985. The thesis is, on the one hand, a detailed record of coloured political activity following the loss of common roll voting rights in the Cape, focusing on specifically coloured political parties rather than on broader, non-ethnic resistance movements in which many coloured people took part during the same period. This covers the rise and rapid decline of a conservative grouping within the coloured community which sought to foster an exclusively coloured nationalism operating within the Government's policy of parallel development, and attempted to use the Coloured Persons' Representative Council as a means towards achieving the economic, social and political upliftment of the coloured people. It also deals with the important role of the Labour Party after 1966, showing how a moderate resistance movement carne to use the Council as a platform from which to confront the Government's apartheid policies and to render the institutions of parallel development unworkable through noncooperation and boycotting. The second important preoccupation of the thesis concerns the ambiguous and often contradictory attitudes towards the "coloured question" within the National Party itself. This ambivalence, it is argued, not only had much to do with the eventual failure of the Coloured Persons' Representative Council to become a viable substitute for Parliamentary representation acceptable to the majority of coloured people, but was also a primary cause of the National Party split in 1982. It shows too how the collapse of Grand Apartheid had its origins in the failure to incorporate the coloured population within its framework. The thesis is concerned primarily with coloured political developments. When relevant, however, the establishment and development of representative institutions for the Indian people is also dealt with, in so far as this overlaps with issues and events concerning the coloured Council. Finally, the five year period following the dissolution of the Coloured Persons' Representative Council in 1980 and the inauguration of the Tricameral Parliament in 1985 is briefly dealt with in a concluding chapter. This mainly concerns the gradual accommodation reached between the Government and the Labour Party when the latter eventually agreed, conditionally, to take part in the new constitution.
- Full Text:
- Date Issued: 1992
- Authors: Saks, David
- Date: 1992
- Subjects: South African Labour Party , Federal Coloured People's Party -- South Africa , South Africa. Parliament , South Africa -- Politics and government -- 20th century , South Africa -- Race relations , Coloured Persons Representative Council of South Africa , Colored people (South Africa) -- Politics and government , Political parties -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2624 , http://hdl.handle.net/10962/d1015907
- Description: The thesis starts by providing a brief overview of South African ''Coloured" politics from the passing of Ordinance 50 in 1828 to the removal of the Cape Coloured people from the common voter's roll in 1956. It then goes on to discuss in detail the structures instituted by successive Nationalist Governments to serve as an alternative to parliamentary representation for the coloured people, the role of the various coloured political parties within such structures and the latter's gradual adaptation and development, culminating in the inauguration of the Tricameral Parliament in early 1985. The thesis is, on the one hand, a detailed record of coloured political activity following the loss of common roll voting rights in the Cape, focusing on specifically coloured political parties rather than on broader, non-ethnic resistance movements in which many coloured people took part during the same period. This covers the rise and rapid decline of a conservative grouping within the coloured community which sought to foster an exclusively coloured nationalism operating within the Government's policy of parallel development, and attempted to use the Coloured Persons' Representative Council as a means towards achieving the economic, social and political upliftment of the coloured people. It also deals with the important role of the Labour Party after 1966, showing how a moderate resistance movement carne to use the Council as a platform from which to confront the Government's apartheid policies and to render the institutions of parallel development unworkable through noncooperation and boycotting. The second important preoccupation of the thesis concerns the ambiguous and often contradictory attitudes towards the "coloured question" within the National Party itself. This ambivalence, it is argued, not only had much to do with the eventual failure of the Coloured Persons' Representative Council to become a viable substitute for Parliamentary representation acceptable to the majority of coloured people, but was also a primary cause of the National Party split in 1982. It shows too how the collapse of Grand Apartheid had its origins in the failure to incorporate the coloured population within its framework. The thesis is concerned primarily with coloured political developments. When relevant, however, the establishment and development of representative institutions for the Indian people is also dealt with, in so far as this overlaps with issues and events concerning the coloured Council. Finally, the five year period following the dissolution of the Coloured Persons' Representative Council in 1980 and the inauguration of the Tricameral Parliament in 1985 is briefly dealt with in a concluding chapter. This mainly concerns the gradual accommodation reached between the Government and the Labour Party when the latter eventually agreed, conditionally, to take part in the new constitution.
- Full Text:
- Date Issued: 1992
The FITE for reading teaching : an examination of the initial training of senior primary teachers at a sample of institutions in England and South Africa
- Authors: McKellar, David William
- Date: 1992
- Subjects: Reading (Elementary) -- South Africa Reading (Elementary) -- Great Britain Teachers -- Training of -- South Africa Teachers -- Training of -- Great Britain
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1545 , http://hdl.handle.net/10962/d1003427
- Description: Primary school teachers are expected to teach reading. Whether they are adequately prepared to fulfil this role, particularly for those preparing to teach in the senior primary phase, is the concern of this thesis. Reading teaching models are useful to reading teaching course developers for devising initial training syllabuses. Such models are described, followed by an example of such a syllabus developed at Rhodes University. The Rhodes University model, described early in the thesis, is used as a background for the further consideration of aspects of reading teaching at other institutions. This model is also used as an instrument for assessing the pre-service teaching experience of student teachers. The study focuses on English speaking teacher training institutions where the majority of the student teachers are preparing to teach in English speaking primary schools. Because of the considerable influence of developments in England on South African English speaking teacher training institutions, reading teaching developments in England from 1972 to 1990 are described. The pioneering work of Cook and Moyle provides a background against which subsequent developments in reading teaching are traced. Reports produced by the Department of Education and Science provide many insights into the state of reading teaching in schools in England as well as developments in teacher training. The reading teaching courses at six teacher training institutions are examined - three in England and three in South Africa. The differences are considerable, particularly the amount of time allocated to reading teaching during the four years of initial teacher education and training common to the six institutions. Two cohorts of student teachers review and assess the Rhodes University reading teaching course in terms of the extent of its interest and value for them as prospective teachers, and the amount of time allocated to the course. The most disturbing finding of this study is the nature of reading teaching observed in schools by student teachers. It is suggested that if reading teaching in senior primary schools is to be improved, the deadlocked cycle needs to be broken by education authorities, teachers and teacher trainers resolving the problem jointly.
- Full Text:
- Date Issued: 1992
- Authors: McKellar, David William
- Date: 1992
- Subjects: Reading (Elementary) -- South Africa Reading (Elementary) -- Great Britain Teachers -- Training of -- South Africa Teachers -- Training of -- Great Britain
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1545 , http://hdl.handle.net/10962/d1003427
- Description: Primary school teachers are expected to teach reading. Whether they are adequately prepared to fulfil this role, particularly for those preparing to teach in the senior primary phase, is the concern of this thesis. Reading teaching models are useful to reading teaching course developers for devising initial training syllabuses. Such models are described, followed by an example of such a syllabus developed at Rhodes University. The Rhodes University model, described early in the thesis, is used as a background for the further consideration of aspects of reading teaching at other institutions. This model is also used as an instrument for assessing the pre-service teaching experience of student teachers. The study focuses on English speaking teacher training institutions where the majority of the student teachers are preparing to teach in English speaking primary schools. Because of the considerable influence of developments in England on South African English speaking teacher training institutions, reading teaching developments in England from 1972 to 1990 are described. The pioneering work of Cook and Moyle provides a background against which subsequent developments in reading teaching are traced. Reports produced by the Department of Education and Science provide many insights into the state of reading teaching in schools in England as well as developments in teacher training. The reading teaching courses at six teacher training institutions are examined - three in England and three in South Africa. The differences are considerable, particularly the amount of time allocated to reading teaching during the four years of initial teacher education and training common to the six institutions. Two cohorts of student teachers review and assess the Rhodes University reading teaching course in terms of the extent of its interest and value for them as prospective teachers, and the amount of time allocated to the course. The most disturbing finding of this study is the nature of reading teaching observed in schools by student teachers. It is suggested that if reading teaching in senior primary schools is to be improved, the deadlocked cycle needs to be broken by education authorities, teachers and teacher trainers resolving the problem jointly.
- Full Text:
- Date Issued: 1992
The geochemical evolution of three alkaline complexes in the Kuboos-Bremen igneous province, southern Namibia
- Authors: Smithies, Robert Hugh
- Date: 1992
- Subjects: Alkalic igneous rocks -- Namibia Geochemistry -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4952 , http://hdl.handle.net/10962/d1005564
- Description: The Kuboos-Bremen Igneous Province comprises a linear zone of alkaline complexes that intrude Proterozoic and Pan-African rocks and trends in a northeast direction from the northwest of the Cape Province in South Africa into southern Namibia. Of the three most southerly complexes in Namibia. two comprise silicate rocks ranging from nepheline syenite to alkali-granite and are called the Grootpenseiland and Marinkas Kwela Complexes (GPC and MKC). The Marinkas Kwela Carbonatite Complex is the third and most northerly of the complexes. Isotopic age determinations on a number of rock types from both the silicate complexes yield ages around 520Ma and are consistent with published Pan-African ages for the Province. Each silicate complex shows a migrating locus of intrusion from Siundersaturated rocks in the southwest to Si-oversaturated rocks in the northeast. The complexes overlap in outcrop. The rocks are moderately to highly felsiC and none reflects primary magma compositions. The Si-undersaturated rocks from both complexes include side-wall cumulates formed from magmas that fractionated alkali-feldspar, clinopyroxene and amphibole. Foyaites also occur in the MKC and have a compositional range reflecting alkali-feldspar fractionation and, probably, some interaction with dolomite country rocks. Major and trace element data suggest that critically saturated alkali syenites occurring in both complexes evolved via protracted feldspar fractionation, and that critically saturated alkali-feldspar syenite occurring only in the GPC is a cumulate. The two rock types cannot be related genetically. Of the SI-oversaturated rocks in both complexes, those in the compositional range monzonite to granite were intruded before alkali-granites. Compositional diversity amongst the former reflects fractionation of feldspar and of mafic phases, but that process cannot genetically link the rocks to the alkali-granites. Isotopic compositions of Sr and Nd indicate that the silicate magmas were derived from an upper mantle source region characterised by low time-integrated Rb/Sr ratios and high time-Integrated Sm/Nd ratios, However, the evidence of Sr and 0 isotopic data is that the Si-oversaturated melts possibly interacted with a crustal component. presumably the Proterowlc rocks of the Namaqua Metamorphic Province. This interaction may explain the occurrence of apparently co-genetic rock series that evolved on opposite sides of the feldspar join in Petrogeny's Residua System. The Marinkas Kwela Carbonatite Complex was emplaced before the final intrusive phases of the MKC and exhibits unusually pronounced late-stage enrichment in manganese. The earliest intrusive rocks in the complex were nepheline syenites which were fenitised by later intrusions of sôvites. Although the commonly occurring magmatic sequence of sôvite-beforsite-ferrocarbonatite is observed at Marinkas Kwela, sôvites do not appear to have been parental to beforsites. Removal of apatite and early crystallisation of magnetite distinguish magnetite-rich beforsite from co-genetic apatite-rich beforsite. Two further magmatic sequences. the first from apatite-rich beforsite through ferrocarbonatite to Mn-rich ferrocarbonatite (high Fe/Mn) and the second from magnetite-rich beforsite to Mn-rich ferrocarbonatite (low Fe/Mn). reflect fractionation of dolomite and of dolomite+magnetite respectively.
- Full Text:
- Date Issued: 1992
- Authors: Smithies, Robert Hugh
- Date: 1992
- Subjects: Alkalic igneous rocks -- Namibia Geochemistry -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4952 , http://hdl.handle.net/10962/d1005564
- Description: The Kuboos-Bremen Igneous Province comprises a linear zone of alkaline complexes that intrude Proterozoic and Pan-African rocks and trends in a northeast direction from the northwest of the Cape Province in South Africa into southern Namibia. Of the three most southerly complexes in Namibia. two comprise silicate rocks ranging from nepheline syenite to alkali-granite and are called the Grootpenseiland and Marinkas Kwela Complexes (GPC and MKC). The Marinkas Kwela Carbonatite Complex is the third and most northerly of the complexes. Isotopic age determinations on a number of rock types from both the silicate complexes yield ages around 520Ma and are consistent with published Pan-African ages for the Province. Each silicate complex shows a migrating locus of intrusion from Siundersaturated rocks in the southwest to Si-oversaturated rocks in the northeast. The complexes overlap in outcrop. The rocks are moderately to highly felsiC and none reflects primary magma compositions. The Si-undersaturated rocks from both complexes include side-wall cumulates formed from magmas that fractionated alkali-feldspar, clinopyroxene and amphibole. Foyaites also occur in the MKC and have a compositional range reflecting alkali-feldspar fractionation and, probably, some interaction with dolomite country rocks. Major and trace element data suggest that critically saturated alkali syenites occurring in both complexes evolved via protracted feldspar fractionation, and that critically saturated alkali-feldspar syenite occurring only in the GPC is a cumulate. The two rock types cannot be related genetically. Of the SI-oversaturated rocks in both complexes, those in the compositional range monzonite to granite were intruded before alkali-granites. Compositional diversity amongst the former reflects fractionation of feldspar and of mafic phases, but that process cannot genetically link the rocks to the alkali-granites. Isotopic compositions of Sr and Nd indicate that the silicate magmas were derived from an upper mantle source region characterised by low time-integrated Rb/Sr ratios and high time-Integrated Sm/Nd ratios, However, the evidence of Sr and 0 isotopic data is that the Si-oversaturated melts possibly interacted with a crustal component. presumably the Proterowlc rocks of the Namaqua Metamorphic Province. This interaction may explain the occurrence of apparently co-genetic rock series that evolved on opposite sides of the feldspar join in Petrogeny's Residua System. The Marinkas Kwela Carbonatite Complex was emplaced before the final intrusive phases of the MKC and exhibits unusually pronounced late-stage enrichment in manganese. The earliest intrusive rocks in the complex were nepheline syenites which were fenitised by later intrusions of sôvites. Although the commonly occurring magmatic sequence of sôvite-beforsite-ferrocarbonatite is observed at Marinkas Kwela, sôvites do not appear to have been parental to beforsites. Removal of apatite and early crystallisation of magnetite distinguish magnetite-rich beforsite from co-genetic apatite-rich beforsite. Two further magmatic sequences. the first from apatite-rich beforsite through ferrocarbonatite to Mn-rich ferrocarbonatite (high Fe/Mn) and the second from magnetite-rich beforsite to Mn-rich ferrocarbonatite (low Fe/Mn). reflect fractionation of dolomite and of dolomite+magnetite respectively.
- Full Text:
- Date Issued: 1992
The geology and evaluation of the "A"-reef at No.3 shaft, Western Holdings Mine, Welkom goldfield
- Blamey, Nigel John Frederick
- Authors: Blamey, Nigel John Frederick
- Date: 1992
- Subjects: Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4957 , http://hdl.handle.net/10962/d1005569 , Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
- Description: The "A" -Reef occurs within the Aandenk Formation of the Central Rand Group, Witwatersrand Supergroup, in the Welkom Goldfield. It comprises the Witpan and Uitsig Reefs which are both oligomictic conglomerates, and are exploited for their gold content by Anglo American Corporation. The main Witpan channel complex is orientated in a NW-SE direction and occurs close to No.3 Shaft of Western Holdings Mine where it is currently being mined. The Witpan Reef varies in thickness from 7-220cm, with lateral facies changes controlling the thickness. Within the reef, gold is associated with degradation surfaces, carbonaceous material, increase in pebble sphericity, and channel edges. Two channel edges have yielded the best gold values on No.3 Shaft although the potential for further payable gold lies in the recognition of sieve conditions. The potential also exists for extensions of the "carbon"-bearing Uitsig channel currently being mined on President Steyn Mine. The palaeo-environment proposed for formation of the Witpan Reef is a braidplain that was partly reworked by a brief transgression. Ore evaluation using geostatistics was considered a valid technique as the dataset is sufficiently well structured. Semi-variograms in the channel and across-channel directions differ markedly. It was found that variograms of gold in cmg/t lacked sufficient structure for modelling, however, log semi-variogram modelling followed by simple log-kriging and back-transformation, proved to be the most successful method. Owing to the morphology and distribution of gold within the reef, a geologically based geostatistical valuation method is proposed. The potential for further exploration of "A" -Reef depends on a substantially higher gold price. In this event, exploration of Uitsig Reef to the southwest of the current mining area is recommended as well as a new exploration strategy for Witpan Reef.
- Full Text:
- Date Issued: 1992
- Authors: Blamey, Nigel John Frederick
- Date: 1992
- Subjects: Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4957 , http://hdl.handle.net/10962/d1005569 , Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
- Description: The "A" -Reef occurs within the Aandenk Formation of the Central Rand Group, Witwatersrand Supergroup, in the Welkom Goldfield. It comprises the Witpan and Uitsig Reefs which are both oligomictic conglomerates, and are exploited for their gold content by Anglo American Corporation. The main Witpan channel complex is orientated in a NW-SE direction and occurs close to No.3 Shaft of Western Holdings Mine where it is currently being mined. The Witpan Reef varies in thickness from 7-220cm, with lateral facies changes controlling the thickness. Within the reef, gold is associated with degradation surfaces, carbonaceous material, increase in pebble sphericity, and channel edges. Two channel edges have yielded the best gold values on No.3 Shaft although the potential for further payable gold lies in the recognition of sieve conditions. The potential also exists for extensions of the "carbon"-bearing Uitsig channel currently being mined on President Steyn Mine. The palaeo-environment proposed for formation of the Witpan Reef is a braidplain that was partly reworked by a brief transgression. Ore evaluation using geostatistics was considered a valid technique as the dataset is sufficiently well structured. Semi-variograms in the channel and across-channel directions differ markedly. It was found that variograms of gold in cmg/t lacked sufficient structure for modelling, however, log semi-variogram modelling followed by simple log-kriging and back-transformation, proved to be the most successful method. Owing to the morphology and distribution of gold within the reef, a geologically based geostatistical valuation method is proposed. The potential for further exploration of "A" -Reef depends on a substantially higher gold price. In this event, exploration of Uitsig Reef to the southwest of the current mining area is recommended as well as a new exploration strategy for Witpan Reef.
- Full Text:
- Date Issued: 1992
The geology and geochemistry of the north-western portion of the Usushwana Complex, South-Eastern Transvaal
- Authors: Riganti, Angela
- Date: 1992
- Subjects: Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4958 , http://hdl.handle.net/10962/d1005570 , Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Description: The 2.9 Ga old Usushwana Complex in the Piet Retief-Amsterdam area (south-eastern Transvaal) represents an exposed segment of a layered intrusion. It has the form of a dyke-like body elongated in a northwesterly direction, and extends to an estimated depth of 3000 -5500 m. Lithologically, the Complex consists of a cumulate succession of mafic rocks capped by granitoids and has intruded along the contact between the basement and the supracrustal sequences of the Kaapvaal Craton. Differentiation of an already contaminated gabbroic magma resulted in an ordered stratigraphic sequence comprising progressively more evolved lithotypes, with at least two imperfect cyclic units developed over a stratigraphic thickness of about 700 metres (Hlelo River Section). Meso- to orthocumulate textured gabbros and quartz gabbros grade upwards into magnetite- and apatite-bearing quartz gabbros, interlayered with discontinuous magnetitite horizons. The gabbros in turn grade into hornblende-rich, granophyric granodiorites. The differentiation process is regarded as having been considerably enhanced by the assimilation of acidic material, derived by partial melting of the felsic country rocks at the roof of the magma chamber. Recrystallisation of these rocks gave rise to the microgranites that locally overlie the granodiorites. Mineralogical, textural and geochemical features indicate a relatively advanced fractionation stage, suggesting that the exposed sequence of the Usushwana Complex in the study area represents the upper portion of the intrusion. No significant mineralised occurrences were identified. However, on the basis of similarities between the Usushwana Complex and other mafic layered intrusions which host significant ore deposits, it is suggested that economic concentrations of base metal(Cu-Ni) sulphides, PGE and chromitites are likely to be developed at lower stratigraphic levels.
- Full Text:
- Date Issued: 1992
- Authors: Riganti, Angela
- Date: 1992
- Subjects: Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4958 , http://hdl.handle.net/10962/d1005570 , Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Description: The 2.9 Ga old Usushwana Complex in the Piet Retief-Amsterdam area (south-eastern Transvaal) represents an exposed segment of a layered intrusion. It has the form of a dyke-like body elongated in a northwesterly direction, and extends to an estimated depth of 3000 -5500 m. Lithologically, the Complex consists of a cumulate succession of mafic rocks capped by granitoids and has intruded along the contact between the basement and the supracrustal sequences of the Kaapvaal Craton. Differentiation of an already contaminated gabbroic magma resulted in an ordered stratigraphic sequence comprising progressively more evolved lithotypes, with at least two imperfect cyclic units developed over a stratigraphic thickness of about 700 metres (Hlelo River Section). Meso- to orthocumulate textured gabbros and quartz gabbros grade upwards into magnetite- and apatite-bearing quartz gabbros, interlayered with discontinuous magnetitite horizons. The gabbros in turn grade into hornblende-rich, granophyric granodiorites. The differentiation process is regarded as having been considerably enhanced by the assimilation of acidic material, derived by partial melting of the felsic country rocks at the roof of the magma chamber. Recrystallisation of these rocks gave rise to the microgranites that locally overlie the granodiorites. Mineralogical, textural and geochemical features indicate a relatively advanced fractionation stage, suggesting that the exposed sequence of the Usushwana Complex in the study area represents the upper portion of the intrusion. No significant mineralised occurrences were identified. However, on the basis of similarities between the Usushwana Complex and other mafic layered intrusions which host significant ore deposits, it is suggested that economic concentrations of base metal(Cu-Ni) sulphides, PGE and chromitites are likely to be developed at lower stratigraphic levels.
- Full Text:
- Date Issued: 1992
The growth characteristics of sparid otoliths
- Authors: Lang, Judy Brenda
- Date: 1992
- Subjects: Fishes -- Age determination , Otoliths , Sparidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5285 , http://hdl.handle.net/10962/d1005129 , Fishes -- Age determination , Otoliths , Sparidae
- Description: The periodicity of formation of growth increments in the otoliths of South African sparids was validated by the oxytetracycline labelling technique. Intramuscular injections of oxytetracycline at a dosage of 250mg/kg marked the otoliths of laboratory held juvenile sparids, while a dosage range of 50 - 100mg/kg oxytetracycline, injected intramuscularly, marked adult sparids in the field. Laboratory held, larval sparid otoliths were marked by immersion for 24hrs a solution of 100-150mg/l alizarin complexone. Both daily (microstructural) and annual (macrostructural) growth increments were identified in the otoliths. The micro incremental pattern of deposition in the sparid otoliths conformed to the general pattern of otolith structure. Sparid otoliths consisted of a central opaque nucleus composed of multiple primordia. surrounding this nucleus were daily increments which decreased in width as the distance from the nucleus increased. Both check rings and subdaily increments were visible throughout the otolith. Minor environmental changes did not affect micro incremental deposition. Narrow opaque and wide hyaline annual growth zones were identified in sectioned sparid otoliths. Scanning electron microscope analysis of the annual growth zones revealed that microincrements within the opaque zone were narrowly spaced with prominent discontinuous phases. This resulted in the greater optical density and higher protein content of the zone. The hyaline zone was composed of widely spaced daily increments with prominent incremental phases accounting for the translucent nature of this zone. Opaque zone formation in the otoliths of many South African sparids was found to occur primarily during periods of reproductive activity and was shown to be indicative of slow otolith growth. The hyaline zone was formed after the spawning season, representative of fast otolith growth. The results of this study have resolved much of the controversy surrounding the rate of growth and time of formation of the opaque and hyaline growth zones in South African sparid otoliths.
- Full Text:
- Date Issued: 1992
- Authors: Lang, Judy Brenda
- Date: 1992
- Subjects: Fishes -- Age determination , Otoliths , Sparidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5285 , http://hdl.handle.net/10962/d1005129 , Fishes -- Age determination , Otoliths , Sparidae
- Description: The periodicity of formation of growth increments in the otoliths of South African sparids was validated by the oxytetracycline labelling technique. Intramuscular injections of oxytetracycline at a dosage of 250mg/kg marked the otoliths of laboratory held juvenile sparids, while a dosage range of 50 - 100mg/kg oxytetracycline, injected intramuscularly, marked adult sparids in the field. Laboratory held, larval sparid otoliths were marked by immersion for 24hrs a solution of 100-150mg/l alizarin complexone. Both daily (microstructural) and annual (macrostructural) growth increments were identified in the otoliths. The micro incremental pattern of deposition in the sparid otoliths conformed to the general pattern of otolith structure. Sparid otoliths consisted of a central opaque nucleus composed of multiple primordia. surrounding this nucleus were daily increments which decreased in width as the distance from the nucleus increased. Both check rings and subdaily increments were visible throughout the otolith. Minor environmental changes did not affect micro incremental deposition. Narrow opaque and wide hyaline annual growth zones were identified in sectioned sparid otoliths. Scanning electron microscope analysis of the annual growth zones revealed that microincrements within the opaque zone were narrowly spaced with prominent discontinuous phases. This resulted in the greater optical density and higher protein content of the zone. The hyaline zone was composed of widely spaced daily increments with prominent incremental phases accounting for the translucent nature of this zone. Opaque zone formation in the otoliths of many South African sparids was found to occur primarily during periods of reproductive activity and was shown to be indicative of slow otolith growth. The hyaline zone was formed after the spawning season, representative of fast otolith growth. The results of this study have resolved much of the controversy surrounding the rate of growth and time of formation of the opaque and hyaline growth zones in South African sparid otoliths.
- Full Text:
- Date Issued: 1992
The in-service development of primary school teachers in the use of computers in education with special reference to computer assisted learning: a case study
- Authors: Murray, John Charles
- Date: 1992
- Subjects: Education, Elementary -- South Africa -- Data processing Computer-assisted instruction Teachers -- In-service training -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1572 , http://hdl.handle.net/10962/d1003454
- Description: Many white primary schools in South Africa have acquired computers which are being used in various ways. In my experience few members of staff are confident enough to use the computers in the school for educational purposes. Those who have been using them, generally have been doing computer literacy. The teachers in our school expressed the view that they would like to be able to use the computer, but that they lack the necessary skills and therefore would welcome some form of training. In my opinion computers should form an integral part of a child's learning environment. It has, for some time formed a part of his social environment, either in the home or in the workplace. For computers to be used effectively in the classroom, it follows that the teachers need to be trained to use them. In an attempt to overcome this problem, I designed and presented an in-service course, which used selected computer assisted learning (CAL) programs with teachers. These teachers then used these programs with the pupils in their class and evaluated the pupils' reactions to the innovation. As a result of the observations and the feedback provided by the sample of teachers, it is suggested that this might be a possible approach to in-service training for other schools. With adaptation it should be possible to follow this approach in any school which has a computer and someone on the staff who is willing to take the initiative to implement such an innovation.
- Full Text:
- Date Issued: 1992
- Authors: Murray, John Charles
- Date: 1992
- Subjects: Education, Elementary -- South Africa -- Data processing Computer-assisted instruction Teachers -- In-service training -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1572 , http://hdl.handle.net/10962/d1003454
- Description: Many white primary schools in South Africa have acquired computers which are being used in various ways. In my experience few members of staff are confident enough to use the computers in the school for educational purposes. Those who have been using them, generally have been doing computer literacy. The teachers in our school expressed the view that they would like to be able to use the computer, but that they lack the necessary skills and therefore would welcome some form of training. In my opinion computers should form an integral part of a child's learning environment. It has, for some time formed a part of his social environment, either in the home or in the workplace. For computers to be used effectively in the classroom, it follows that the teachers need to be trained to use them. In an attempt to overcome this problem, I designed and presented an in-service course, which used selected computer assisted learning (CAL) programs with teachers. These teachers then used these programs with the pupils in their class and evaluated the pupils' reactions to the innovation. As a result of the observations and the feedback provided by the sample of teachers, it is suggested that this might be a possible approach to in-service training for other schools. With adaptation it should be possible to follow this approach in any school which has a computer and someone on the staff who is willing to take the initiative to implement such an innovation.
- Full Text:
- Date Issued: 1992
The influence of children on decision-makers in their homes : a case study in environmental education
- Authors: Kruger, Jacqueline
- Date: 1992
- Subjects: Environmental education -- South Africa , Parent and child -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1574 , http://hdl.handle.net/10962/d1003456
- Description: This study explores the possible influence of twenty children on their 'parents', with a view to better understanding the potential 'multiplier effect' of children regarding environmental responsibility. The criteria employed to study the potential influence included certain of the environmental activities learnt by the children during an Environmental Education programme. The programme was undertaken by the researcher with a Std 4 class from Ryneveld Primêreskool in Graaff-Reinet. An action research approach was adopted and results were analysed qualitatively. Due to the short duration and exploratory nature of the project, these results should be viewed as tentative. Proposals are made for increasing the impact of Environmental Education programmes in peri-urban township communities, and recommendations are put forward to help facilitate related studies in the future.
- Full Text:
- Date Issued: 1992
- Authors: Kruger, Jacqueline
- Date: 1992
- Subjects: Environmental education -- South Africa , Parent and child -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1574 , http://hdl.handle.net/10962/d1003456
- Description: This study explores the possible influence of twenty children on their 'parents', with a view to better understanding the potential 'multiplier effect' of children regarding environmental responsibility. The criteria employed to study the potential influence included certain of the environmental activities learnt by the children during an Environmental Education programme. The programme was undertaken by the researcher with a Std 4 class from Ryneveld Primêreskool in Graaff-Reinet. An action research approach was adopted and results were analysed qualitatively. Due to the short duration and exploratory nature of the project, these results should be viewed as tentative. Proposals are made for increasing the impact of Environmental Education programmes in peri-urban township communities, and recommendations are put forward to help facilitate related studies in the future.
- Full Text:
- Date Issued: 1992
The interactive effects of light, temperature and CO₂/O₂ ratios in photosynthesis of Coix lachryma-jobi L
- Authors: Mjwara, Jabulani Michael
- Date: 1992
- Subjects: Coix , Plants -- Effect of light on , Plants -- Effect of oxygen on , Plants -- Effect of carbon dioxide on , Photosynthesis , Plants -- Effect of temperature on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4216 , http://hdl.handle.net/10962/d1003785
- Description: A portable infra red gas analyzer was used to investigate the interactive effects of light, temperature, and CO,jO, ratios under controlled environmental conditions in an attempt to model gas exchange characteristics of Coix Iachryma-jobi L. Plotting light response curves as a function of temperature (20, 25 30 and 35°C) revealed no sign of light saturation even at a photosynthetic photon flux density (PPFD) close to 2000 !Lmol m-' sol. High net assimilation rates (A) of approximately 24 !Lmol CO, m"s'! were realized at 30-35°C. Assimilation (A) versus internal CO, partial pressure (C,) curves showed a steep rise with increase in C, but saturated at approximately 150 (JLII-!) and all the results, either in the absence or presence of 0" showed a similar response under all temperature regimes. C. Iachryma-jobi exhibited low CO, compensation points cr ) between 0 and 10 JLlI-! under similar experimental temperatures and either at 0 or 21%0,. The slopes of double reciprocal plots of llA versus llCi, were nearly identical and crossed the yintercept at almost identical points under all 0, concentrations. These data indicate first; that there was no apparent 0, inhibition and second; indicated that the apparent inhIbitor constant (K,) for 0, at the site of carboxylation did not change with increase in [OJ from 0 to 21% oxygen. These observations were further confirmed by results obtained from the analysis of apparent carboxylation efficiency (CE, as defined as the slope of response of A to increasing CO,), as no inhibition of A with increase of [OJ occurred. These characteristics were consistent with typical features of C,photosynthesis. The absence of 0, inhibition and low r values indicated that an efficient CO, concentrating mechanism which eliminates photorespiration exists in C. Iachryma-jobi. At the light microscope level, leaf anatomy exhibited typical C, structure viz. bundle sheath with large chloroplasts and this sheath is further surrounded by a radiate Kranz mesophyU cells. Furthermore the anatomical features suggested that C. wchryma-jobi was an NADP-ME species. Stomatal conductance (g,) to assimilation (g,/A) indicated an increase in A with decrease in g" an essential feature of improving water use efficiency (WUE), but one which drastically reduces CO, diffusion rate. The physical lintitation (stomatal lintitation, t) to CO, diffusion under various [0,] and temperatures, but constant PPFD, did not exhibit statistically significant change in t values at either 0 or 21% a, within each temperature regime, however there was a marked decrease in t as the plant approached its optimum photosynthetic temperature.
- Full Text:
- Date Issued: 1992
- Authors: Mjwara, Jabulani Michael
- Date: 1992
- Subjects: Coix , Plants -- Effect of light on , Plants -- Effect of oxygen on , Plants -- Effect of carbon dioxide on , Photosynthesis , Plants -- Effect of temperature on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4216 , http://hdl.handle.net/10962/d1003785
- Description: A portable infra red gas analyzer was used to investigate the interactive effects of light, temperature, and CO,jO, ratios under controlled environmental conditions in an attempt to model gas exchange characteristics of Coix Iachryma-jobi L. Plotting light response curves as a function of temperature (20, 25 30 and 35°C) revealed no sign of light saturation even at a photosynthetic photon flux density (PPFD) close to 2000 !Lmol m-' sol. High net assimilation rates (A) of approximately 24 !Lmol CO, m"s'! were realized at 30-35°C. Assimilation (A) versus internal CO, partial pressure (C,) curves showed a steep rise with increase in C, but saturated at approximately 150 (JLII-!) and all the results, either in the absence or presence of 0" showed a similar response under all temperature regimes. C. Iachryma-jobi exhibited low CO, compensation points cr ) between 0 and 10 JLlI-! under similar experimental temperatures and either at 0 or 21%0,. The slopes of double reciprocal plots of llA versus llCi, were nearly identical and crossed the yintercept at almost identical points under all 0, concentrations. These data indicate first; that there was no apparent 0, inhibition and second; indicated that the apparent inhIbitor constant (K,) for 0, at the site of carboxylation did not change with increase in [OJ from 0 to 21% oxygen. These observations were further confirmed by results obtained from the analysis of apparent carboxylation efficiency (CE, as defined as the slope of response of A to increasing CO,), as no inhibition of A with increase of [OJ occurred. These characteristics were consistent with typical features of C,photosynthesis. The absence of 0, inhibition and low r values indicated that an efficient CO, concentrating mechanism which eliminates photorespiration exists in C. Iachryma-jobi. At the light microscope level, leaf anatomy exhibited typical C, structure viz. bundle sheath with large chloroplasts and this sheath is further surrounded by a radiate Kranz mesophyU cells. Furthermore the anatomical features suggested that C. wchryma-jobi was an NADP-ME species. Stomatal conductance (g,) to assimilation (g,/A) indicated an increase in A with decrease in g" an essential feature of improving water use efficiency (WUE), but one which drastically reduces CO, diffusion rate. The physical lintitation (stomatal lintitation, t) to CO, diffusion under various [0,] and temperatures, but constant PPFD, did not exhibit statistically significant change in t values at either 0 or 21% a, within each temperature regime, however there was a marked decrease in t as the plant approached its optimum photosynthetic temperature.
- Full Text:
- Date Issued: 1992
The microbial production of polyphenol oxidase enzyme systems and their application in the treatment of phenolic wastewaters
- Scherman, Patricia Ann (neé Goetch)
- Authors: Scherman, Patricia Ann (neé Goetch)
- Date: 1992
- Subjects: Phenol oxidase Water -- Purification -- Biological treatment Enzymes -- Regulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4047 , http://hdl.handle.net/10962/d1004108
- Description: Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organic solvents. The enzyme system is widely distributed in nature, with Agaricus bisporus (the common mushroom) being the best known producer. Biochemical investigations of the enzyme system were therefore carried out using this extract. A screening programme was initiated to identify microbial polyphenol oxidase producers which could be cultured in liquid media, thereby enabling the production of large quantities of enzyme in fermentation systems. Extensive growth optimization and enzyme induction and optimization studies were carried out on selected cultures. A number of good producers were isolated, namely a bacterial culture designated AECI culture no. 26, Streptomyces antibioticus, Streptomyces glaucescens and a manipulated strain, Streptomyces lividans (pIJ702). Enzyme production by Agaricus bisporus mycelia was optimized in deep-liquid culture; enzyme extracts showed high phenol removal efficiencies. Streptomyces antibioticus, Streptomyces glaucescens, Streptomyces lividans (pIJ702) and AECI culture no. 26 whole cells were also investigated for phenol-removing ability in simulated phenolic effluents. The use of whole cells reduces enzyme inactivation and instability due to the protection of the enzyme system within the cell. All cultures showed improved removal efficiencies in phenolic growth media. These results strongly suggest their use for phenol removal in continuous systems.
- Full Text:
- Date Issued: 1992
- Authors: Scherman, Patricia Ann (neé Goetch)
- Date: 1992
- Subjects: Phenol oxidase Water -- Purification -- Biological treatment Enzymes -- Regulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4047 , http://hdl.handle.net/10962/d1004108
- Description: Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organic solvents. The enzyme system is widely distributed in nature, with Agaricus bisporus (the common mushroom) being the best known producer. Biochemical investigations of the enzyme system were therefore carried out using this extract. A screening programme was initiated to identify microbial polyphenol oxidase producers which could be cultured in liquid media, thereby enabling the production of large quantities of enzyme in fermentation systems. Extensive growth optimization and enzyme induction and optimization studies were carried out on selected cultures. A number of good producers were isolated, namely a bacterial culture designated AECI culture no. 26, Streptomyces antibioticus, Streptomyces glaucescens and a manipulated strain, Streptomyces lividans (pIJ702). Enzyme production by Agaricus bisporus mycelia was optimized in deep-liquid culture; enzyme extracts showed high phenol removal efficiencies. Streptomyces antibioticus, Streptomyces glaucescens, Streptomyces lividans (pIJ702) and AECI culture no. 26 whole cells were also investigated for phenol-removing ability in simulated phenolic effluents. The use of whole cells reduces enzyme inactivation and instability due to the protection of the enzyme system within the cell. All cultures showed improved removal efficiencies in phenolic growth media. These results strongly suggest their use for phenol removal in continuous systems.
- Full Text:
- Date Issued: 1992
The psychological sequelae of involvement in combat: a preliminary investigation
- Authors: Hodgson, Shane Ralph Colin
- Date: 1992
- Subjects: War -- Psychological aspects , War victims -- Mental health , Post-traumatic stress disorder
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2993 , http://hdl.handle.net/10962/d1002502 , War -- Psychological aspects , War victims -- Mental health , Post-traumatic stress disorder
- Description: The psychological sequelae of being involved in combat are only recently coming to be understood. Most of the available data are from research conducted on help-seeking Vietnam veterans in the United States, and very little work has been done in South Africa. There does not as yet appear to be any instrument designed specifically to detect combat-related psychopathologies amongst soldiers who are still in active service, either in the USA or in South Africa. Combat involvement has been shown to lead to a high incidence of combat stress reaction. This in turn has shown that it can predispose sufferers to the development of a Post-traumatic Stress Disorder. It is thus expected that there would be significantly higher incidences of reported symptoms of stress disorders amongst soldiers exposed to high levels of combat as compared with a similar group of soldiers who had no combat involvement. This study used a self-reporting questionnaire, developed in the USA but adapted for use in South Africa, to allow the soldiers in the study to rate the severity of various symptoms derived from the DSM-III criteria for Post-traumatic Stress Disorder. A Beck Depression Inventory was also administered to eliminate any persons who nay have been exhibiting symptoms of depression, as this would have confounded the results. Both questionnaires were administered to serving members of the Permanent Force of the South African Defence Force, with one group being members of various high-combat units based in what was then South West Africa, and the other group being non-combat or Headquarters elements. As a precondition of the study, absolute confidentiality of the respondents and their units was maintained. The study found the expected higher scores in the high-combat group, and also showed that the Keane questionnaire has a good coefficient alpha in South Africa. The study closes with several recommendations for further research, especially in the light of the new PTSD criteria in the DSM-IIIR.
- Full Text:
- Date Issued: 1992
- Authors: Hodgson, Shane Ralph Colin
- Date: 1992
- Subjects: War -- Psychological aspects , War victims -- Mental health , Post-traumatic stress disorder
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2993 , http://hdl.handle.net/10962/d1002502 , War -- Psychological aspects , War victims -- Mental health , Post-traumatic stress disorder
- Description: The psychological sequelae of being involved in combat are only recently coming to be understood. Most of the available data are from research conducted on help-seeking Vietnam veterans in the United States, and very little work has been done in South Africa. There does not as yet appear to be any instrument designed specifically to detect combat-related psychopathologies amongst soldiers who are still in active service, either in the USA or in South Africa. Combat involvement has been shown to lead to a high incidence of combat stress reaction. This in turn has shown that it can predispose sufferers to the development of a Post-traumatic Stress Disorder. It is thus expected that there would be significantly higher incidences of reported symptoms of stress disorders amongst soldiers exposed to high levels of combat as compared with a similar group of soldiers who had no combat involvement. This study used a self-reporting questionnaire, developed in the USA but adapted for use in South Africa, to allow the soldiers in the study to rate the severity of various symptoms derived from the DSM-III criteria for Post-traumatic Stress Disorder. A Beck Depression Inventory was also administered to eliminate any persons who nay have been exhibiting symptoms of depression, as this would have confounded the results. Both questionnaires were administered to serving members of the Permanent Force of the South African Defence Force, with one group being members of various high-combat units based in what was then South West Africa, and the other group being non-combat or Headquarters elements. As a precondition of the study, absolute confidentiality of the respondents and their units was maintained. The study found the expected higher scores in the high-combat group, and also showed that the Keane questionnaire has a good coefficient alpha in South Africa. The study closes with several recommendations for further research, especially in the light of the new PTSD criteria in the DSM-IIIR.
- Full Text:
- Date Issued: 1992
The relationship of general retention ability to new South African group test non-verbal/verbal IQ discrepancies and their academic correlates
- Authors: Watson, Peter James
- Date: 1992
- Subjects: Intellect Intelligence tests -- South Africa Academic achievement -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1725 , http://hdl.handle.net/10962/d1003608
- Description: Both experimental research (Robbertse,1952)and clinical observation (Kruger, 1972; van der Merwe,1978) have indicated that pupils with a Verbal IQ score 10 or more points lower than their non-Verbal IQ (termed a 'Type 1' discrepancy in the present research) on the New South African Group Test (NSAGT) show poorer academic achievement than their peers of similar ability. The present research investigates the relationship of general retention ability, as defined by Hakstian and Cattell (1978), to Type 1 discrepancies as well as to their academic correlates. One hundred and thirty-nine standard seven English-speaking boys were tested on the NSAGT and the Junior Aptitude Test (JAT) (of which tests 8 and 9 give an indication of general retention ability) and divided into a group with Type 1 discrepancies and two control groups. All three groups were matched on full-scale IQ. Comparison of these three groups, using the analysis of variance technique, showed that there was no significant difference between them in level of general retention ability or in academic performance (measured by average percentage in the final standard seven examination). While no significant difference was found between the three groups regarding the relationship of general retention ability to academic performance, in the Type 1 discrepancy group the relationship of rote memory (JAT test 8) to academic performance differed markedly from that of associative memory (JAT test 9) to academic performance. In the Type 1 discrepancy group rote memory was highly associated with academic performance, possibly indicating a compensatory strategy for the lower Verbal ability in this group, enabling it to achieve academically on par with the control groups, contrary to what would be expected on the basis of Robbertse's (1962) findings. In terms of Jensen's (1982) Level 1/Level 11 theory of intelligence, it appears from the present research that rote memory ability (JAT test 8) varies between being a Level 11 ability (in the Type 1 discrepancy group) to acting as a Level 1 ability in the two control groups. The present research questions Verwey and Wolmarans's (1980) description of both JAT tests 8 and 9 as simple measures of retention Test 9, in particular, appears to function consistently as a Level 11 ability.
- Full Text:
- Date Issued: 1992
- Authors: Watson, Peter James
- Date: 1992
- Subjects: Intellect Intelligence tests -- South Africa Academic achievement -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1725 , http://hdl.handle.net/10962/d1003608
- Description: Both experimental research (Robbertse,1952)and clinical observation (Kruger, 1972; van der Merwe,1978) have indicated that pupils with a Verbal IQ score 10 or more points lower than their non-Verbal IQ (termed a 'Type 1' discrepancy in the present research) on the New South African Group Test (NSAGT) show poorer academic achievement than their peers of similar ability. The present research investigates the relationship of general retention ability, as defined by Hakstian and Cattell (1978), to Type 1 discrepancies as well as to their academic correlates. One hundred and thirty-nine standard seven English-speaking boys were tested on the NSAGT and the Junior Aptitude Test (JAT) (of which tests 8 and 9 give an indication of general retention ability) and divided into a group with Type 1 discrepancies and two control groups. All three groups were matched on full-scale IQ. Comparison of these three groups, using the analysis of variance technique, showed that there was no significant difference between them in level of general retention ability or in academic performance (measured by average percentage in the final standard seven examination). While no significant difference was found between the three groups regarding the relationship of general retention ability to academic performance, in the Type 1 discrepancy group the relationship of rote memory (JAT test 8) to academic performance differed markedly from that of associative memory (JAT test 9) to academic performance. In the Type 1 discrepancy group rote memory was highly associated with academic performance, possibly indicating a compensatory strategy for the lower Verbal ability in this group, enabling it to achieve academically on par with the control groups, contrary to what would be expected on the basis of Robbertse's (1962) findings. In terms of Jensen's (1982) Level 1/Level 11 theory of intelligence, it appears from the present research that rote memory ability (JAT test 8) varies between being a Level 11 ability (in the Type 1 discrepancy group) to acting as a Level 1 ability in the two control groups. The present research questions Verwey and Wolmarans's (1980) description of both JAT tests 8 and 9 as simple measures of retention Test 9, in particular, appears to function consistently as a Level 11 ability.
- Full Text:
- Date Issued: 1992
The role of the queen in wax secretion and comb building in the Cape honeybee, Aps mellifera capensis (Escholtz)
- Authors: Whiffler, Lynne Anne
- Date: 1992
- Subjects: Honeybee Honey, Comb Beeswax Bee culture -- Queen rearing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5763 , http://hdl.handle.net/10962/d1005451
- Description: The role of the queen in wax secretion and comb building was studied in the the Cape honeybee, Apis mellifera capensis (Escholtz). The percentage of bees bearing wax and the amount of wax borne by these bees did not differ between the experiments. This meant that the queenless and queenright colonies had the potential to construct equal amounts of comb as the amounts of wax available for comb building was the same. Contrary to this prediction, queenright colonies constructed 8 times more comb than their queenless counterparts. Queenright Apis mellifera scutellata colonies constructed 4 times more comb than their queenless counterparts. The increased amount of 9-oxo-2-decanoic acid (90DA) in the A.m.capensis mandibular gland secretions could not alone account for this difference. In fact, A.m.capensis and A.m.scutellata colonies constructed similar amounts of comb when they were given their own queens or queens from the other race. Worker bees need to have direct contact with their queen for comb building to be enhanced. Even when the queen had her mandibular glands extirpated and tergite glands occluded large amounts of comb were constructed than when access to the queen was limited. Direct access to the head of a mated queen proved to be the stimulus enhancing comb building. No comb was constructed when the workers had access to the abdomen of the queen. Virgin queens did not stimulate comb building. The relatively large amounts of 90DA and 9HDA from the mandibular glands of Cape virgin queens had not influenced comb building. Worker sized cells were generally constructed. These cells were slightly smaller than those constructed by European honeybees, but were indicative of African bees. A few queen less colonies constructed cells that were of an intermediate drone and worker size. Four mandibular gland pneromones were measured by gas chromatography. No correlations between these pheromones and the comb construction measurements were found. It is unlikely that the mandibular gland pheromones are the only pheromones that stimulate comb building. Pheromones from other glands on the head may contribute towards the enhancement of comb building, and they are not present in virgin queens
- Full Text:
- Date Issued: 1992
- Authors: Whiffler, Lynne Anne
- Date: 1992
- Subjects: Honeybee Honey, Comb Beeswax Bee culture -- Queen rearing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5763 , http://hdl.handle.net/10962/d1005451
- Description: The role of the queen in wax secretion and comb building was studied in the the Cape honeybee, Apis mellifera capensis (Escholtz). The percentage of bees bearing wax and the amount of wax borne by these bees did not differ between the experiments. This meant that the queenless and queenright colonies had the potential to construct equal amounts of comb as the amounts of wax available for comb building was the same. Contrary to this prediction, queenright colonies constructed 8 times more comb than their queenless counterparts. Queenright Apis mellifera scutellata colonies constructed 4 times more comb than their queenless counterparts. The increased amount of 9-oxo-2-decanoic acid (90DA) in the A.m.capensis mandibular gland secretions could not alone account for this difference. In fact, A.m.capensis and A.m.scutellata colonies constructed similar amounts of comb when they were given their own queens or queens from the other race. Worker bees need to have direct contact with their queen for comb building to be enhanced. Even when the queen had her mandibular glands extirpated and tergite glands occluded large amounts of comb were constructed than when access to the queen was limited. Direct access to the head of a mated queen proved to be the stimulus enhancing comb building. No comb was constructed when the workers had access to the abdomen of the queen. Virgin queens did not stimulate comb building. The relatively large amounts of 90DA and 9HDA from the mandibular glands of Cape virgin queens had not influenced comb building. Worker sized cells were generally constructed. These cells were slightly smaller than those constructed by European honeybees, but were indicative of African bees. A few queen less colonies constructed cells that were of an intermediate drone and worker size. Four mandibular gland pneromones were measured by gas chromatography. No correlations between these pheromones and the comb construction measurements were found. It is unlikely that the mandibular gland pheromones are the only pheromones that stimulate comb building. Pheromones from other glands on the head may contribute towards the enhancement of comb building, and they are not present in virgin queens
- Full Text:
- Date Issued: 1992
The role of the teachers' centre in the professional development and in-service training of teachers with specific reference to the East London Teachers' Centre
- Authors: Badenhorst, John Henry
- Date: 1992
- Subjects: Teachers -- In-service training -- South Africa , Education -- South Africa -- East London , Professional education -- South Africa , Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1755 , http://hdl.handle.net/10962/d1003639 , Teachers -- In-service training -- South Africa , Education -- South Africa -- East London , Professional education -- South Africa , Educational change -- South Africa
- Description: Teachers' Centres are one of the means whereby teachers needs for in-service education and training (Inset) can be met. The professional basis of Teachers' Centres as providers of in-service education and training derives from the need of teachers to develop professionally throughout their careers. Aspects which need to be considered are the need for professional growth and the professional nature of teaching. The effective provision of in-service training requires a knowledge of effective in-service training practise and the barriers that could be encountered in presenting it. Central to any Inset for teachers would be the teachers' needs for such activity. Following on a general statement of teachers needs for Inset the role of the Teachers' Centre in meeting these needs will be examined. Teachers' Centres have specific advantages in meeting certain areas of need for Inset by teachers. A knowledge of the professional activities of teachers activity and methods of establishing the needs for Inset of teachers should promote the effective provision of these programmes. The teacher as an adult learner is important to effective Teachers' Centre operation and the nature of adult learning and variables which affect it will determine the Teachers' Centre reaction in providing Inset. Subject study group activity is very important in Teachers' Centres in the Cape Province and the principles involved in their operation together with practical considerations regarding their operation are important in the provision of Inset. The practical application of theory is illustrated by examples from the East London Teachers' Centre with an emphasis on organisation and the creation of a climate within the Centre for the existence of study groups. The presentation methods used in these study group activities are important and will vary according to the needs of the study group. The selection of methods together with the organisation of presentations and practical methods used in presentation will have an important effect on how they operate. Teachers' Centres have a role to play in promoting change and innovation in schools. The theories of promoting innovation and the roles of the change agent are important. Practical examples from the East London Teachers' Centre are provided. This research, thus, provides a theoretical study of the role of Teachers' Centres in meeting some of the inset needs of teachers as well as practical examples of such activities.
- Full Text:
- Date Issued: 1992
- Authors: Badenhorst, John Henry
- Date: 1992
- Subjects: Teachers -- In-service training -- South Africa , Education -- South Africa -- East London , Professional education -- South Africa , Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1755 , http://hdl.handle.net/10962/d1003639 , Teachers -- In-service training -- South Africa , Education -- South Africa -- East London , Professional education -- South Africa , Educational change -- South Africa
- Description: Teachers' Centres are one of the means whereby teachers needs for in-service education and training (Inset) can be met. The professional basis of Teachers' Centres as providers of in-service education and training derives from the need of teachers to develop professionally throughout their careers. Aspects which need to be considered are the need for professional growth and the professional nature of teaching. The effective provision of in-service training requires a knowledge of effective in-service training practise and the barriers that could be encountered in presenting it. Central to any Inset for teachers would be the teachers' needs for such activity. Following on a general statement of teachers needs for Inset the role of the Teachers' Centre in meeting these needs will be examined. Teachers' Centres have specific advantages in meeting certain areas of need for Inset by teachers. A knowledge of the professional activities of teachers activity and methods of establishing the needs for Inset of teachers should promote the effective provision of these programmes. The teacher as an adult learner is important to effective Teachers' Centre operation and the nature of adult learning and variables which affect it will determine the Teachers' Centre reaction in providing Inset. Subject study group activity is very important in Teachers' Centres in the Cape Province and the principles involved in their operation together with practical considerations regarding their operation are important in the provision of Inset. The practical application of theory is illustrated by examples from the East London Teachers' Centre with an emphasis on organisation and the creation of a climate within the Centre for the existence of study groups. The presentation methods used in these study group activities are important and will vary according to the needs of the study group. The selection of methods together with the organisation of presentations and practical methods used in presentation will have an important effect on how they operate. Teachers' Centres have a role to play in promoting change and innovation in schools. The theories of promoting innovation and the roles of the change agent are important. Practical examples from the East London Teachers' Centre are provided. This research, thus, provides a theoretical study of the role of Teachers' Centres in meeting some of the inset needs of teachers as well as practical examples of such activities.
- Full Text:
- Date Issued: 1992
The status of the American bollworm, Heliothis armigera (Hubner) (Lepidoptera : Noctuidae), on sunflower in the central Transvaal
- Authors: Von Maltitz, Emil Friedrich
- Date: 1992
- Subjects: Helicoverpa armigera , Noctuidae -- South Africa -- Transvaal , Noctuidae , Sunflowers -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5773 , http://hdl.handle.net/10962/d1005461 , Helicoverpa armigera , Noctuidae -- South Africa -- Transvaal , Noctuidae , Sunflowers -- Diseases and pests
- Description: Sunflower production in South Africa has increased four fold since the 1970's. This study was done to elucidate the pest status of Heliothis armigera (Hiibner) on sunflower. Field studies were undertaken at Warmbaths, Brits and Delmas during the summer seasons of 1988/89 to 1990/91. The infestations at the latter two areas were negligible throughout the study period and their statistics have not been included in this thesis. Plant development and oviposition by natural H. armigera populations were found to be correlated as, regardless of planting date, oviposition started at six to seven weeks after planting; when the flowering stage began. A peak in egg numbers was reached by the tenth week with an average for the three seasons at two eggs per plant. The eggs were laid singly on the bracts and bases of the flower buds. A peak in larval numbers was reached at the thirteenth week after planting with the average for the three seasons of 0,4 larvae per plant. The preferred feeding sites were on, between and under the bracts from where the larvae burrow into the pithy tissue of the receptacle. Only six percent of the larvae were found feeding directly on the achenes. Eggs and larvae collected were reared to determine the degree of parasitism. Overall, 19% of the eggs were parasitised; 18% by Telenomus ullyetti Nixon (Scelionidae) and one percent by Trichogrammatoidea lutea (Trichogrammatidae). Larval parasitism at Warmbaths was 23% in 1988/89, 27% in 1989/90 and 34% in 1990/91. Of the parasitised larvae, 44% succumbed to Palexorista prob. laxa (Tachinidae). The remainder were unidentified Braconidae and Ichneumonidae. Predators, such as chrysopids, were observed during the study but their effect on egg and larvae numbers was not studied in detail. A polyhedral virus occurred late in the seasons and caused mortality of the larvae. The low numbers of H. armigera on sunflower, the slight damage to the crop and the reasonably high rate of parasitism, all seem to indicate that H. armigera is not an economica1ly important pest of sunflower and that additional control methods are not justified.
- Full Text:
- Date Issued: 1992
- Authors: Von Maltitz, Emil Friedrich
- Date: 1992
- Subjects: Helicoverpa armigera , Noctuidae -- South Africa -- Transvaal , Noctuidae , Sunflowers -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5773 , http://hdl.handle.net/10962/d1005461 , Helicoverpa armigera , Noctuidae -- South Africa -- Transvaal , Noctuidae , Sunflowers -- Diseases and pests
- Description: Sunflower production in South Africa has increased four fold since the 1970's. This study was done to elucidate the pest status of Heliothis armigera (Hiibner) on sunflower. Field studies were undertaken at Warmbaths, Brits and Delmas during the summer seasons of 1988/89 to 1990/91. The infestations at the latter two areas were negligible throughout the study period and their statistics have not been included in this thesis. Plant development and oviposition by natural H. armigera populations were found to be correlated as, regardless of planting date, oviposition started at six to seven weeks after planting; when the flowering stage began. A peak in egg numbers was reached by the tenth week with an average for the three seasons at two eggs per plant. The eggs were laid singly on the bracts and bases of the flower buds. A peak in larval numbers was reached at the thirteenth week after planting with the average for the three seasons of 0,4 larvae per plant. The preferred feeding sites were on, between and under the bracts from where the larvae burrow into the pithy tissue of the receptacle. Only six percent of the larvae were found feeding directly on the achenes. Eggs and larvae collected were reared to determine the degree of parasitism. Overall, 19% of the eggs were parasitised; 18% by Telenomus ullyetti Nixon (Scelionidae) and one percent by Trichogrammatoidea lutea (Trichogrammatidae). Larval parasitism at Warmbaths was 23% in 1988/89, 27% in 1989/90 and 34% in 1990/91. Of the parasitised larvae, 44% succumbed to Palexorista prob. laxa (Tachinidae). The remainder were unidentified Braconidae and Ichneumonidae. Predators, such as chrysopids, were observed during the study but their effect on egg and larvae numbers was not studied in detail. A polyhedral virus occurred late in the seasons and caused mortality of the larvae. The low numbers of H. armigera on sunflower, the slight damage to the crop and the reasonably high rate of parasitism, all seem to indicate that H. armigera is not an economica1ly important pest of sunflower and that additional control methods are not justified.
- Full Text:
- Date Issued: 1992