Biopharmaceutics of phenylpropanolamine
- Authors: Dowse, Roslind
- Date: 1984
- Subjects: Biopharmaceutics Pharmacokinetics Phenylpropanolamine Pharmacology High performance liquid chromatography
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3818 , http://hdl.handle.net/10962/d1004915
- Description: Phenylpropanolamine (PPA), a sympathomimetic amine, has been widely used over the past 40 years as a decongestant and, in much larger dosages, as an appetite suppressant. Considerable interest has recently been shown in this drug due to its increasing popularity as an over-the-counter anorectic agent. Much controversy exists concerning the unfavourable side-effects of PPA resulting from the higher doses required for appetite suppression and the potential of this drug for abuse. A literature search revealed a paucity of information concerning the determination of PPA in biological fluids and, most noticeably, on the pharmacokinetics of this drug. An original method for determining PPA in serum and urine using high performance liquid chromatography (HPLC) which has increased sensitivity over other published HPLC methods is presented here. The simplicity of the extraction from biological fluids and subsequent determination by HPLC, enables concentrations of PPA to be monitored after a single dose of the drug. This method is therefore readily applicable to bioavailability and pharmacokinetic studies. The dissolution profiles of 4 sustained-release formulations of PPA were determined in a modified USP rotating paddle apparatus and the samples analysed using HPLC. A mathematical equation was applied to these data which are expressed in terms of dissolution parameters. Oral test dosage forms and solutions of PPA were investigated in bioavailability trials using the developed HPLC method to analyse the urine and serum samples. Linear one body compartment kinetics were assumed and the WagnerNelson method used to transform in vivo serum data to absorption plots which were then fitted to the well known Weibull equation. In order to more appropriately characterize the kinetic processes of absorption, distribution and elimination, a more complex model was utilized which involved numerical integration of a series of differential equations. The data were fitted to these models using nonlinear regression techniques. The pharmacokinetics of PPA are shown to exhibit some evidence of nonlinearity. The absorption of the drug appears to be di scontinuous and PPA seems to favour a two body compartment model.
- Full Text:
- Date Issued: 1984
- Authors: Dowse, Roslind
- Date: 1984
- Subjects: Biopharmaceutics Pharmacokinetics Phenylpropanolamine Pharmacology High performance liquid chromatography
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3818 , http://hdl.handle.net/10962/d1004915
- Description: Phenylpropanolamine (PPA), a sympathomimetic amine, has been widely used over the past 40 years as a decongestant and, in much larger dosages, as an appetite suppressant. Considerable interest has recently been shown in this drug due to its increasing popularity as an over-the-counter anorectic agent. Much controversy exists concerning the unfavourable side-effects of PPA resulting from the higher doses required for appetite suppression and the potential of this drug for abuse. A literature search revealed a paucity of information concerning the determination of PPA in biological fluids and, most noticeably, on the pharmacokinetics of this drug. An original method for determining PPA in serum and urine using high performance liquid chromatography (HPLC) which has increased sensitivity over other published HPLC methods is presented here. The simplicity of the extraction from biological fluids and subsequent determination by HPLC, enables concentrations of PPA to be monitored after a single dose of the drug. This method is therefore readily applicable to bioavailability and pharmacokinetic studies. The dissolution profiles of 4 sustained-release formulations of PPA were determined in a modified USP rotating paddle apparatus and the samples analysed using HPLC. A mathematical equation was applied to these data which are expressed in terms of dissolution parameters. Oral test dosage forms and solutions of PPA were investigated in bioavailability trials using the developed HPLC method to analyse the urine and serum samples. Linear one body compartment kinetics were assumed and the WagnerNelson method used to transform in vivo serum data to absorption plots which were then fitted to the well known Weibull equation. In order to more appropriately characterize the kinetic processes of absorption, distribution and elimination, a more complex model was utilized which involved numerical integration of a series of differential equations. The data were fitted to these models using nonlinear regression techniques. The pharmacokinetics of PPA are shown to exhibit some evidence of nonlinearity. The absorption of the drug appears to be di scontinuous and PPA seems to favour a two body compartment model.
- Full Text:
- Date Issued: 1984
A critical investigation of the semantic and morphological aspects of terminological incompetence (with special reference to the English-speaking student of Physical Science and History in the Cape Education Department high school)
- Authors: Venter, Malcolm Gordon
- Date: 1984
- Subjects: English language -- Semantics English language -- Morphology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2369 , http://hdl.handle.net/10962/d1003810
- Description: From Background to the thesis: It has been said that 'educational failure is language failure'. It can be argued here that there are many other factors which could cause educational failure and that language failure does not necessarily result in lack of academic success. However, it is no doubt true that the schoolchild who does not attain a certain type of language competence will be handicapped as regards academic performance. The underlying reason for this is the fact that our educational system is heavily reliant on language - and espacially the written language - as a medium of learning as opposed to the 'direct learning' experiences advocated by certain educationists today such as Ivan Illich in America and John Holt in Britain. Language is the basis both of learning and of communicating what has been learnt. From the moment the child steps into his first period class in the morning till he leaves the last five hours later the child is involved in what is primarily a verbal experience.
- Full Text:
- Date Issued: 1984
- Authors: Venter, Malcolm Gordon
- Date: 1984
- Subjects: English language -- Semantics English language -- Morphology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2369 , http://hdl.handle.net/10962/d1003810
- Description: From Background to the thesis: It has been said that 'educational failure is language failure'. It can be argued here that there are many other factors which could cause educational failure and that language failure does not necessarily result in lack of academic success. However, it is no doubt true that the schoolchild who does not attain a certain type of language competence will be handicapped as regards academic performance. The underlying reason for this is the fact that our educational system is heavily reliant on language - and espacially the written language - as a medium of learning as opposed to the 'direct learning' experiences advocated by certain educationists today such as Ivan Illich in America and John Holt in Britain. Language is the basis both of learning and of communicating what has been learnt. From the moment the child steps into his first period class in the morning till he leaves the last five hours later the child is involved in what is primarily a verbal experience.
- Full Text:
- Date Issued: 1984
The effects of relative market share and the rate of market growth on the strategic attributes and financial performance of selected South African companies from 1977 to 1981
- Authors: Viljoen, John
- Date: 1984
- Subjects: Johannesburg Stock Exchange Boston Consulting Group Business enterprises -- Valuation -- South Africa Business enterprises -- South Africa -- Finance Business enterprises -- Economic aspects -- South Africa Stock exchanges -- South Africa Success in business Marketing research Strategic planning Business planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:722 , http://hdl.handle.net/10962/d1003816
- Description: This thesis analyses the effects of relative market share and the rate of market growth on the strategic characteristics and financial performance of selected companies quoted on the Johannesburg Stock Exchange over the period 1977 to 198. It is well established that business performance is partially contingent upon relative market share position and the rate of market growth. Together these variables comprise the basis of the Boston Consulting Group approach to portfolio analysis in the form of the Boston Consulting Group Growth/Share Matrix. A methodology was designed to test the validity of this matrix in measuring and predicting corporate behaviour at the business level in South Africa. Selected companies were placed into the matrix and analysed in terms of their strategic attributes (represented by selected financial ratios) and their level of performance (represented by a wide range of financial performance measures). The research findings show that relative market share and the rate of market growth have a significant impact on the strategic attributes and financial performance of South African businesses. Also, certain attributes are closely associated with particular types of performance. Therefore, given a specific performance target, management should ultimately be able to isolate and monitor the relevant strategic attributes in ensuring that the target is achieved. The analysis of contingent models of strategy is still in its infancy, but this study indicates that the field is possessed of great potential.
- Full Text:
- Date Issued: 1984
- Authors: Viljoen, John
- Date: 1984
- Subjects: Johannesburg Stock Exchange Boston Consulting Group Business enterprises -- Valuation -- South Africa Business enterprises -- South Africa -- Finance Business enterprises -- Economic aspects -- South Africa Stock exchanges -- South Africa Success in business Marketing research Strategic planning Business planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:722 , http://hdl.handle.net/10962/d1003816
- Description: This thesis analyses the effects of relative market share and the rate of market growth on the strategic characteristics and financial performance of selected companies quoted on the Johannesburg Stock Exchange over the period 1977 to 198. It is well established that business performance is partially contingent upon relative market share position and the rate of market growth. Together these variables comprise the basis of the Boston Consulting Group approach to portfolio analysis in the form of the Boston Consulting Group Growth/Share Matrix. A methodology was designed to test the validity of this matrix in measuring and predicting corporate behaviour at the business level in South Africa. Selected companies were placed into the matrix and analysed in terms of their strategic attributes (represented by selected financial ratios) and their level of performance (represented by a wide range of financial performance measures). The research findings show that relative market share and the rate of market growth have a significant impact on the strategic attributes and financial performance of South African businesses. Also, certain attributes are closely associated with particular types of performance. Therefore, given a specific performance target, management should ultimately be able to isolate and monitor the relevant strategic attributes in ensuring that the target is achieved. The analysis of contingent models of strategy is still in its infancy, but this study indicates that the field is possessed of great potential.
- Full Text:
- Date Issued: 1984
A geohydrological evaluation of the coastal area between Bushmans River Mouth and Cape Mouth and Cape Padrone, Eastern Cape, South Africa
- Authors: Jolly, J L
- Date: 1984 , 2013-03-15
- Subjects: Hydrogeology -- South Africa -- Eastern Cape , Coastal zone management -- South Africa -- Eastern Cape , Coastal ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4859 , http://hdl.handle.net/10962/d1005635 , Hydrogeology -- South Africa -- Eastern Cape , Coastal zone management -- South Africa -- Eastern Cape , Coastal ecology -- South Africa -- Eastern Cape
- Full Text:
- Date Issued: 1984
- Authors: Jolly, J L
- Date: 1984 , 2013-03-15
- Subjects: Hydrogeology -- South Africa -- Eastern Cape , Coastal zone management -- South Africa -- Eastern Cape , Coastal ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4859 , http://hdl.handle.net/10962/d1005635 , Hydrogeology -- South Africa -- Eastern Cape , Coastal zone management -- South Africa -- Eastern Cape , Coastal ecology -- South Africa -- Eastern Cape
- Full Text:
- Date Issued: 1984
The synthesis and properties of some polymer hydrogels
- Authors: Hird, Bryn
- Date: 1984 , 2013-04-05
- Subjects: Colloids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4428 , http://hdl.handle.net/10962/d1006975 , Colloids
- Description: The interactions between water molecules and polyelectrolyte species in aqueous solutions are reviewed and are used to infer interactions occuring in swollen crosslinked polyelectrolyte hydrogels. Linear poly(acrylic acid ) and derivatives neutralised to varying degrees with alkali-metal hydroxides are prepared and characterised. Samples of these compounds are crosslinked by 'Y - irradiation to form hydrogels. Hydration studies on linear polymers, crosslinked material and a commercial polyacrylate hydrogel indicate a possible hydration structure and provide some insight into the nature of water-polymer interactions within a sHollen polyacrylate gel. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984
- Authors: Hird, Bryn
- Date: 1984 , 2013-04-05
- Subjects: Colloids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4428 , http://hdl.handle.net/10962/d1006975 , Colloids
- Description: The interactions between water molecules and polyelectrolyte species in aqueous solutions are reviewed and are used to infer interactions occuring in swollen crosslinked polyelectrolyte hydrogels. Linear poly(acrylic acid ) and derivatives neutralised to varying degrees with alkali-metal hydroxides are prepared and characterised. Samples of these compounds are crosslinked by 'Y - irradiation to form hydrogels. Hydration studies on linear polymers, crosslinked material and a commercial polyacrylate hydrogel indicate a possible hydration structure and provide some insight into the nature of water-polymer interactions within a sHollen polyacrylate gel. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984
The historical collection, King George VI Art Gallery, Port Elizabeth
- Authors: Forster-Towne, Rosemary
- Date: 1984
- Subjects: Art collections and art museums Fine arts and History of art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2463 , http://hdl.handle.net/10962/d1008567
- Description: From Conclusion: For the sake of posterity and historical research, our need for secure origins and our appreciation of and pleasure in fine craftsmanship and art, it is important that any Art Collection, particularly an Historical one, be fully documented. All data pertaining to the pictures should be recorded from an artistic, historical and even scientific point of view and photographs should be taken of the pictures. An organized classification system, the correct registering and labeling of each picture and its accessioning and cataloguing as part of the contents of the Gallery and for visitors information, should be constantly 53 maintained and where necessary and in as many ways as possible, cross-references made so that the stored information be usable. To this end and with the growth and increasing importance being placed on Art Museums and Galleries in the community it would probably be of value to cross-reference with other similar institutions and in the respect and day and age, it is not unrealistic to propose that the King George VI Art Gallery consider a computer cataloguing system to facilitate research and complement a more simplified version for the use and guide of the general viewing public . The significance of a picture is not only its value as such, but also the information relating to it. The importance of the Historical Collection as Africana and works of art, expressive of the places, events, people and even attitudes, and as cultural and historic items, goes without saying. Without the Historical Collection of the King George VI Art Gallery, Port Elizabeth, the Eastern Cape community and South Africa too, would be the poorer. The pictures have their role to play .
- Full Text:
- Date Issued: 1984
- Authors: Forster-Towne, Rosemary
- Date: 1984
- Subjects: Art collections and art museums Fine arts and History of art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2463 , http://hdl.handle.net/10962/d1008567
- Description: From Conclusion: For the sake of posterity and historical research, our need for secure origins and our appreciation of and pleasure in fine craftsmanship and art, it is important that any Art Collection, particularly an Historical one, be fully documented. All data pertaining to the pictures should be recorded from an artistic, historical and even scientific point of view and photographs should be taken of the pictures. An organized classification system, the correct registering and labeling of each picture and its accessioning and cataloguing as part of the contents of the Gallery and for visitors information, should be constantly 53 maintained and where necessary and in as many ways as possible, cross-references made so that the stored information be usable. To this end and with the growth and increasing importance being placed on Art Museums and Galleries in the community it would probably be of value to cross-reference with other similar institutions and in the respect and day and age, it is not unrealistic to propose that the King George VI Art Gallery consider a computer cataloguing system to facilitate research and complement a more simplified version for the use and guide of the general viewing public . The significance of a picture is not only its value as such, but also the information relating to it. The importance of the Historical Collection as Africana and works of art, expressive of the places, events, people and even attitudes, and as cultural and historic items, goes without saying. Without the Historical Collection of the King George VI Art Gallery, Port Elizabeth, the Eastern Cape community and South Africa too, would be the poorer. The pictures have their role to play .
- Full Text:
- Date Issued: 1984
Image and symbol : some aspects of the creative impulse in the visual arts
- Authors: Stonestreet, Lyn
- Date: 1984
- Subjects: Art Symbolism in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2445 , http://hdl.handle.net/10962/d1006138
- Description: From Introduction: The making of images has been a human activity since Prehistory, undergoing many and drastic changes over the centuries, but the symbols integral to images have proved enduring and recurrent. This is because the artist draws on that stratum of the psyche which C.G. Jung calls the collective unconscious: a universal archaic memory within the human mind, containing the archetypes of all human experience.In this essay I have dealt with aspects of two of these archetypes; the anima and, to a lesser extent, the mother. I have limited my study to the work of male artists. Long sanctioned by tradition, images of women as seen by men, have provided an acceptable vehicle for men to express their own female principle. As long as a man operates in the world with total apparant masculinity, the anima or female principle is repressed and denied at a conscious level.
- Full Text:
- Date Issued: 1984
- Authors: Stonestreet, Lyn
- Date: 1984
- Subjects: Art Symbolism in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2445 , http://hdl.handle.net/10962/d1006138
- Description: From Introduction: The making of images has been a human activity since Prehistory, undergoing many and drastic changes over the centuries, but the symbols integral to images have proved enduring and recurrent. This is because the artist draws on that stratum of the psyche which C.G. Jung calls the collective unconscious: a universal archaic memory within the human mind, containing the archetypes of all human experience.In this essay I have dealt with aspects of two of these archetypes; the anima and, to a lesser extent, the mother. I have limited my study to the work of male artists. Long sanctioned by tradition, images of women as seen by men, have provided an acceptable vehicle for men to express their own female principle. As long as a man operates in the world with total apparant masculinity, the anima or female principle is repressed and denied at a conscious level.
- Full Text:
- Date Issued: 1984
The population dynamics of the rock hyrax procavia capensis (Pallas, 1766) in the Mountain Zebra National Park
- Authors: Fourie, Leon Johan
- Date: 1984
- Subjects: Rock hyrax Mountain Zebra National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5743 , http://hdl.handle.net/10962/d1005429
- Description: The chief objective of the study was to investigate the population dynamics of the hyrax in the Mountain Zebra National Park (MZNP). To realise this objective information on growth, age determination, reproduction, habitat utilization, behaviour, parasites and mortality had to be gathered. The growth of hyrax in relation to age is described by means of Stevens asymptotic regression equations. Near asymptotic measurements are attained first in hind foot length (at 30-33 months of age), head/body length (at 37-39 months of age), girth (at 41-48 months of age) and body mass (at 68-70 months of age). Allometric growth of the various body measurements was investigated and useful predictive relationships for mass are presented. Age determination of hyrax was studied in detail. Cementum annuli counts provided reliable estimates of age. One primary cementum line is formed annually. The dried eye lens mass was an accurate means of age determination up to c. 72 months of age. A summary of findings which will facilitate age determination of dead animals or skulls, and live animals, is provided. Reproduction in the hyrax was studied with emphasis on breeding season, age-specific litter sizes, prenatal mortality and lactation. Male hyrax attained puberty at 15-17 months of age or one year later. Females generally attained puberty at 15-17 months of age. One female (1,4% of total shot sample for the specific age group) attained puberty at 4-5 months of age. Middle-aged hyrax had significantly larger litter sizes than younger animals. Hyrax in the MZNP feed on at least 80 different plant species belonging to 33 plant families. Crude protein of stomach contents and faecal samples showed little seasonal fluctuation implying that hyrax in the MZNP were on a stable quality diet. Female hyrax enjoyed a significantly better quality diet than males for the four month period prior to parturition and during the first two months of lactation. The crude protein values of faecal and stomach samples had a significant correlation. Body fat of male and female hyrax showed seasonal variation related to physiologically stressful periods. Seasonal differences in activity patterns were demonstrated. The basic structure of hyrax social organization is the multi-female kinship group that is matrilocal. Territorial dominant males maintain harems and exclude all other adult males. Peripheral males occupy areas on the periphery of the activity areas of other members of the hyrax colony. Peripheral males do not form bachelor groups and are normally younger than territorial males. It is suggested that territorial males are able to monopolize between 3-17 females in a successful and energetic manner. Both natal and breeding dispersal occurred, the former being considerably more extensive than the latter. The ecto- and endoparasites of hyrax were identified and their burdens quantified over a 13 month period. Juveniles had significantly larger burdens of ectoparasites than did adults. Information on age-specific mortality was obtained from skulls collected in the field and at black eagles' nests. Losses that occurred in the study population due to caracal and black eagle predation were quantified. Evidence is supplied which indicates that juvenile mortality may fluctuate markedly. The population dynamics of the hyrax population in the MZNP was studied by the use of time specific life-tables, models on population growth rates, population simulation models and sensitivity analysis. Sensitivity coefficients were used as a predictor of population regulation. Female juvenile mortality was considered to be the main regulating factor. Changes in fecundity schedule are important compensatory mechanisms and also play an important role in the regulation of a hyrax population. Predation, particularly by caracal, is thought to dampen population fluctuations.
- Full Text:
- Date Issued: 1984
- Authors: Fourie, Leon Johan
- Date: 1984
- Subjects: Rock hyrax Mountain Zebra National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5743 , http://hdl.handle.net/10962/d1005429
- Description: The chief objective of the study was to investigate the population dynamics of the hyrax in the Mountain Zebra National Park (MZNP). To realise this objective information on growth, age determination, reproduction, habitat utilization, behaviour, parasites and mortality had to be gathered. The growth of hyrax in relation to age is described by means of Stevens asymptotic regression equations. Near asymptotic measurements are attained first in hind foot length (at 30-33 months of age), head/body length (at 37-39 months of age), girth (at 41-48 months of age) and body mass (at 68-70 months of age). Allometric growth of the various body measurements was investigated and useful predictive relationships for mass are presented. Age determination of hyrax was studied in detail. Cementum annuli counts provided reliable estimates of age. One primary cementum line is formed annually. The dried eye lens mass was an accurate means of age determination up to c. 72 months of age. A summary of findings which will facilitate age determination of dead animals or skulls, and live animals, is provided. Reproduction in the hyrax was studied with emphasis on breeding season, age-specific litter sizes, prenatal mortality and lactation. Male hyrax attained puberty at 15-17 months of age or one year later. Females generally attained puberty at 15-17 months of age. One female (1,4% of total shot sample for the specific age group) attained puberty at 4-5 months of age. Middle-aged hyrax had significantly larger litter sizes than younger animals. Hyrax in the MZNP feed on at least 80 different plant species belonging to 33 plant families. Crude protein of stomach contents and faecal samples showed little seasonal fluctuation implying that hyrax in the MZNP were on a stable quality diet. Female hyrax enjoyed a significantly better quality diet than males for the four month period prior to parturition and during the first two months of lactation. The crude protein values of faecal and stomach samples had a significant correlation. Body fat of male and female hyrax showed seasonal variation related to physiologically stressful periods. Seasonal differences in activity patterns were demonstrated. The basic structure of hyrax social organization is the multi-female kinship group that is matrilocal. Territorial dominant males maintain harems and exclude all other adult males. Peripheral males occupy areas on the periphery of the activity areas of other members of the hyrax colony. Peripheral males do not form bachelor groups and are normally younger than territorial males. It is suggested that territorial males are able to monopolize between 3-17 females in a successful and energetic manner. Both natal and breeding dispersal occurred, the former being considerably more extensive than the latter. The ecto- and endoparasites of hyrax were identified and their burdens quantified over a 13 month period. Juveniles had significantly larger burdens of ectoparasites than did adults. Information on age-specific mortality was obtained from skulls collected in the field and at black eagles' nests. Losses that occurred in the study population due to caracal and black eagle predation were quantified. Evidence is supplied which indicates that juvenile mortality may fluctuate markedly. The population dynamics of the hyrax population in the MZNP was studied by the use of time specific life-tables, models on population growth rates, population simulation models and sensitivity analysis. Sensitivity coefficients were used as a predictor of population regulation. Female juvenile mortality was considered to be the main regulating factor. Changes in fecundity schedule are important compensatory mechanisms and also play an important role in the regulation of a hyrax population. Predation, particularly by caracal, is thought to dampen population fluctuations.
- Full Text:
- Date Issued: 1984
South African farm wages and working conditions: with special reference to the Albany district, 1957 to 1977
- Authors: Antrobus, Geoffrey Gordon
- Date: 1984
- Subjects: Agricultural wages -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1028 , http://hdl.handle.net/10962/d1003722
- Description: The focus of the study is the wages and working conditions of farm labourers in commercial agriculture. After an outline examination of the broad trends in employment and wages in the agricultural industry as a whole, the emphasis falls on a micro-study of employment practices in the Eastern Cape magisterial district of Albany. The results of a survey of farmers was used to determine the level of wages, including payments in kind, the value of housing, cropping and grazing rights. It was found that cash wages made up only 25% of the total remuneration of R684 per annum, while purchased and farm produced rations made up a further 40% of the total. A survey conducted in the Albany district two decades previously was used to compare the real earnings in 1957 and 1977. Although real cash wages and rations increased over the twenty year period the restriction of cropping and grazing rights had the effect of keeping real earnings static. In the light of the improvement of other working conditions, such as the reduction in working hours, however, it is concluded that some increase in real wages did occur . It is evident that there are no clear-cut recipes for successful farm labour management and no unequivocal statements should be made about the most visible element, namely cash wages.
- Full Text:
- Date Issued: 1984
- Authors: Antrobus, Geoffrey Gordon
- Date: 1984
- Subjects: Agricultural wages -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1028 , http://hdl.handle.net/10962/d1003722
- Description: The focus of the study is the wages and working conditions of farm labourers in commercial agriculture. After an outline examination of the broad trends in employment and wages in the agricultural industry as a whole, the emphasis falls on a micro-study of employment practices in the Eastern Cape magisterial district of Albany. The results of a survey of farmers was used to determine the level of wages, including payments in kind, the value of housing, cropping and grazing rights. It was found that cash wages made up only 25% of the total remuneration of R684 per annum, while purchased and farm produced rations made up a further 40% of the total. A survey conducted in the Albany district two decades previously was used to compare the real earnings in 1957 and 1977. Although real cash wages and rations increased over the twenty year period the restriction of cropping and grazing rights had the effect of keeping real earnings static. In the light of the improvement of other working conditions, such as the reduction in working hours, however, it is concluded that some increase in real wages did occur . It is evident that there are no clear-cut recipes for successful farm labour management and no unequivocal statements should be made about the most visible element, namely cash wages.
- Full Text:
- Date Issued: 1984
Aspects of the ecology of the shrimp Palaemon pacificus (Stimpson) (Decapoda,Palaemonidae) in the Bushmans river estuary
- Authors: Robertson, Wendy Daryl
- Date: 1984
- Subjects: Shrimps -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5815 , http://hdl.handle.net/10962/d1007184 , Shrimps -- South Africa
- Description: The recruitment of Palaemon pacificus to the Bushmans River estuary was studied over a 12 month period. The dynamics of a population of shrimps in a small, tidal channel in the lower reaches of the estuary was investigated over a similar time span. Temperature and salinity tolerances of various stages and sizes of shrimps were compared in controlled experiments and are discussed in the light of the distribution and general ecology of the shrimp. Stage 6 zoeae and post-larvae entered the estuary on nocturnal flood tides throughout the year with peak recruitment occurring in March/April. The population of shrimps in the study site was predominantly juvenile for most of the year, with peak sub-adult numbers occurring in midsummer. The sex ratio was female-biased throughout the year except for short bursts of male predominance in February and April. Average growth rate was 0,043 mm carapace length per day. Maximum residence time in the study site was estimated to be four months and in the estuary at least six months. Flooding of the estuary resulted in a considerable reduction in juvenile numbers in the study site and some loss of sub-adults. Shrimps tolerated a temperature range of 4,3 to 30,9⁰C for 144 hours. Their long term tolerance range is probably narrower (10 to 28⁰C) because of the effects of temperature related factors such as starvation and disease. Their distribution in South Africa (Olifants River to Kosi Bay ) is consistent with this tolerance range. Sub-adults tolerated salinities of 1 to 79 ‰ and post-larvae 2 to 60 ‰ at 15⁰C for 144 hours. Low moulting success (low and high salinities ) and starvation (high salinities) would probably reduce these tolerance ranges to 2 to 56 ‰ (sub-adults) and 4 to 56 ‰ (post-larvae). Higher and lower temperatures (10 and 20⁰C) reduced the tolerance of post-larvae to low salinities, but sub-adults were only affected at 30⁰C. Stages 4 and 5 and stage 6 zoeae were intolerant of salinities below 14 ‰. The development of salinity tolerance with age is consistent with the retention of a marine breeding phase. It also explains the high loss of juveniles from the study site following the flood. It is postulated that recovery of the population after a flood would be fairly rapid except in extreme cases when estuarine vegetation is severely affected.
- Full Text:
- Date Issued: 1984
- Authors: Robertson, Wendy Daryl
- Date: 1984
- Subjects: Shrimps -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5815 , http://hdl.handle.net/10962/d1007184 , Shrimps -- South Africa
- Description: The recruitment of Palaemon pacificus to the Bushmans River estuary was studied over a 12 month period. The dynamics of a population of shrimps in a small, tidal channel in the lower reaches of the estuary was investigated over a similar time span. Temperature and salinity tolerances of various stages and sizes of shrimps were compared in controlled experiments and are discussed in the light of the distribution and general ecology of the shrimp. Stage 6 zoeae and post-larvae entered the estuary on nocturnal flood tides throughout the year with peak recruitment occurring in March/April. The population of shrimps in the study site was predominantly juvenile for most of the year, with peak sub-adult numbers occurring in midsummer. The sex ratio was female-biased throughout the year except for short bursts of male predominance in February and April. Average growth rate was 0,043 mm carapace length per day. Maximum residence time in the study site was estimated to be four months and in the estuary at least six months. Flooding of the estuary resulted in a considerable reduction in juvenile numbers in the study site and some loss of sub-adults. Shrimps tolerated a temperature range of 4,3 to 30,9⁰C for 144 hours. Their long term tolerance range is probably narrower (10 to 28⁰C) because of the effects of temperature related factors such as starvation and disease. Their distribution in South Africa (Olifants River to Kosi Bay ) is consistent with this tolerance range. Sub-adults tolerated salinities of 1 to 79 ‰ and post-larvae 2 to 60 ‰ at 15⁰C for 144 hours. Low moulting success (low and high salinities ) and starvation (high salinities) would probably reduce these tolerance ranges to 2 to 56 ‰ (sub-adults) and 4 to 56 ‰ (post-larvae). Higher and lower temperatures (10 and 20⁰C) reduced the tolerance of post-larvae to low salinities, but sub-adults were only affected at 30⁰C. Stages 4 and 5 and stage 6 zoeae were intolerant of salinities below 14 ‰. The development of salinity tolerance with age is consistent with the retention of a marine breeding phase. It also explains the high loss of juveniles from the study site following the flood. It is postulated that recovery of the population after a flood would be fairly rapid except in extreme cases when estuarine vegetation is severely affected.
- Full Text:
- Date Issued: 1984
Advanced ionospheric chirpsounding
- Authors: Poole, Allon William Victor
- Date: 1984
- Subjects: Ionospheric sounds Ionosphere -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5446 , http://hdl.handle.net/10962/d1001999
- Description: This dissertation reports research into the theory and practical application of linear frequency modulated ionospheric sounding, as an alternative to the more usual technique of pulse modulation. A comparison of this technique with that of conventional pulse sounders is given, based on the concepts of matched filters and ambiguity functions for both modulations. A theory is developed to relate the group range and phase velocity of the ionospheric target to the phase and frequency of the difference signal at the receiver output. A method is then described whereby the group range and phase velocity of the reflection point as well as the amplitude, arrival angle and polarisation mode of the reflected energy can be measured. A description of the implementation of the technique is given together with some initial results. Finally, some suggestions for improvements are given
- Full Text:
- Date Issued: 1984
- Authors: Poole, Allon William Victor
- Date: 1984
- Subjects: Ionospheric sounds Ionosphere -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5446 , http://hdl.handle.net/10962/d1001999
- Description: This dissertation reports research into the theory and practical application of linear frequency modulated ionospheric sounding, as an alternative to the more usual technique of pulse modulation. A comparison of this technique with that of conventional pulse sounders is given, based on the concepts of matched filters and ambiguity functions for both modulations. A theory is developed to relate the group range and phase velocity of the ionospheric target to the phase and frequency of the difference signal at the receiver output. A method is then described whereby the group range and phase velocity of the reflection point as well as the amplitude, arrival angle and polarisation mode of the reflected energy can be measured. A description of the implementation of the technique is given together with some initial results. Finally, some suggestions for improvements are given
- Full Text:
- Date Issued: 1984
Art and technology: an analysis of this relationship in the field of graphic art since 1960, with specific emphasis on the development of printmaking
- Authors: Thorburn, Dominic
- Date: 1984
- Subjects: Graphic arts -- History -- 20th century Prints -- Technique Art and technology
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2444 , http://hdl.handle.net/10962/d1006136
- Description: From Introduction: The reIationship between technology and art today is a logical extension of a collaborative tradition with ancient roots. The artist has always been a principal perpetrator of technological innovation. He, through the natural progression of technical means, has virtually evolved each new art form. There are many examples such as the 'lost wax' casting process, Jan Van Eycks oil paint innovations, Senefelders 'chemical printing' and Niecephore Niepce's first eight hour photographic exposures. Even woodblocks were in their time an innovation. All art uses technology of a kind and artists who prefer to remain aloof from it are in fact merely using technologies absorbed in older traditional media further back in the history of art. It is the flexibility of art to adapt to changing conditions of the world today which has spurred change and brought about a new dynamism in the graphic arts. The present intensity of interest in the print can be directly attributed to the advancement of technology and communication in this century. A whole new field of materials, methods and techniques are now available to the venturesome graphic artist and printmaker. Along with the contemporary technology dedication to expression leads naturally to innovation in aesthetics.
- Full Text:
- Date Issued: 1984
- Authors: Thorburn, Dominic
- Date: 1984
- Subjects: Graphic arts -- History -- 20th century Prints -- Technique Art and technology
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2444 , http://hdl.handle.net/10962/d1006136
- Description: From Introduction: The reIationship between technology and art today is a logical extension of a collaborative tradition with ancient roots. The artist has always been a principal perpetrator of technological innovation. He, through the natural progression of technical means, has virtually evolved each new art form. There are many examples such as the 'lost wax' casting process, Jan Van Eycks oil paint innovations, Senefelders 'chemical printing' and Niecephore Niepce's first eight hour photographic exposures. Even woodblocks were in their time an innovation. All art uses technology of a kind and artists who prefer to remain aloof from it are in fact merely using technologies absorbed in older traditional media further back in the history of art. It is the flexibility of art to adapt to changing conditions of the world today which has spurred change and brought about a new dynamism in the graphic arts. The present intensity of interest in the print can be directly attributed to the advancement of technology and communication in this century. A whole new field of materials, methods and techniques are now available to the venturesome graphic artist and printmaker. Along with the contemporary technology dedication to expression leads naturally to innovation in aesthetics.
- Full Text:
- Date Issued: 1984
An investigation of the groundwater seepage and irrigation return flow of the Middleton area of the Great Fish River
- Authors: Reynders, Anthony Gerard
- Date: 1984 , 2013-04-11
- Subjects: Irrigation -- South Africa -- Great Fish River , Seepage , Groundwater flow -- South Africa -- Great Fish River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5035 , http://hdl.handle.net/10962/d1007380 , Irrigation -- South Africa -- Great Fish River , Seepage , Groundwater flow -- South Africa -- Great Fish River
- Description: From introduction: This study is concerned with the factors responsible for mineralisation of water in the Great Fish River, in particular the irrigation return flow and groundwater seepage components. A small irrigated area in the lower Fish River Basin was chosen for a detailed study of irrigation water input, groundwater and seepage water fluctuati ons, and the affect of soils and rocks on river water mineralisation. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984
- Authors: Reynders, Anthony Gerard
- Date: 1984 , 2013-04-11
- Subjects: Irrigation -- South Africa -- Great Fish River , Seepage , Groundwater flow -- South Africa -- Great Fish River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5035 , http://hdl.handle.net/10962/d1007380 , Irrigation -- South Africa -- Great Fish River , Seepage , Groundwater flow -- South Africa -- Great Fish River
- Description: From introduction: This study is concerned with the factors responsible for mineralisation of water in the Great Fish River, in particular the irrigation return flow and groundwater seepage components. A small irrigated area in the lower Fish River Basin was chosen for a detailed study of irrigation water input, groundwater and seepage water fluctuati ons, and the affect of soils and rocks on river water mineralisation. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984
The geology, mineralogy and chemistry of the Grahamstown clay deposits
- Authors: Smuts, Johann, 1951-
- Date: 1984
- Subjects: Clay minerals -- South Africa -- Grahamstown , Mineralogy -- South Africa -- Grahamstown , Geochemistry -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5080 , http://hdl.handle.net/10962/d1015969
- Description: The Grahamstown clay deposits extend in a broad belt from 26°23 to 26°50 East longitude and from 33°15 to 33°22 South latitude along two distinct geomorphological features, the Grahamstown Peneplane (650 m) and the Coastal Plain (520m). The clay deposits traverse four different lithologies including the Bokkeveld Shale, Witteberg Shale, Dwyka Tillite and Ecca Shale. The two planes invariably have a covering of silcrete which is also present over most of the clay deposits except where erosion has taken place. X-ray fluorescence analysis shows that chemically there is a fairly wide variation between and witnin the deposits. The greatest variation is in the Si0₂/Al₂0₃ ratio which appears to be controlled by the parent lithology and to some extent by the amount of leaching. K²0 shows an increase in concentration with depth and therefore indicates the limits of hydrolysis and leaching and of the clay. X-ray diffraction study shows the Peneplane and Coastal Plain deposits to be quite distinct. The Peneplane deposits consist of kaolinite, illite and quartz and the Coastal Plain deposits of kaolinite, illite, quartz and pyrophyllite. The presence of pyrophyllite is not fully understood as there is no indication of major faulting, metamorphism or pyrophyllite in the parent rock. The pyrophyllite most probably represents a transformation product of kaolinite. The kaolinite from the various deposits shows a considerable variation in crystallinity in both the X-ray diffraction traces and electron photomicrographs. The most poorly crystalline kaolinites are from the Coastal Plain deposits and the difference in crystallinity is most probably due to differences in the degree of hydrolysis and the parent rock material in the case of the tillite. Genetically all of the deposits are residual types generated by hydrolysis and subsequent leaching of micas and feldspars. The principal elements leached are silicon, iron and potassium. The hydrolysis and leaching took place over a long period of time in the flat lying areas of the Peneplane and Coastal Plain. The deposits are exploited economically and the clay is used principally in the tile, pottery and whiteware industries with some usage in the paper, refractory and brickmaking industries. The price commanded by raw kaolin is not very high and as a result the clay industry in Grahamstown is not as viable economically as it could be.
- Full Text:
- Date Issued: 1984
- Authors: Smuts, Johann, 1951-
- Date: 1984
- Subjects: Clay minerals -- South Africa -- Grahamstown , Mineralogy -- South Africa -- Grahamstown , Geochemistry -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5080 , http://hdl.handle.net/10962/d1015969
- Description: The Grahamstown clay deposits extend in a broad belt from 26°23 to 26°50 East longitude and from 33°15 to 33°22 South latitude along two distinct geomorphological features, the Grahamstown Peneplane (650 m) and the Coastal Plain (520m). The clay deposits traverse four different lithologies including the Bokkeveld Shale, Witteberg Shale, Dwyka Tillite and Ecca Shale. The two planes invariably have a covering of silcrete which is also present over most of the clay deposits except where erosion has taken place. X-ray fluorescence analysis shows that chemically there is a fairly wide variation between and witnin the deposits. The greatest variation is in the Si0₂/Al₂0₃ ratio which appears to be controlled by the parent lithology and to some extent by the amount of leaching. K²0 shows an increase in concentration with depth and therefore indicates the limits of hydrolysis and leaching and of the clay. X-ray diffraction study shows the Peneplane and Coastal Plain deposits to be quite distinct. The Peneplane deposits consist of kaolinite, illite and quartz and the Coastal Plain deposits of kaolinite, illite, quartz and pyrophyllite. The presence of pyrophyllite is not fully understood as there is no indication of major faulting, metamorphism or pyrophyllite in the parent rock. The pyrophyllite most probably represents a transformation product of kaolinite. The kaolinite from the various deposits shows a considerable variation in crystallinity in both the X-ray diffraction traces and electron photomicrographs. The most poorly crystalline kaolinites are from the Coastal Plain deposits and the difference in crystallinity is most probably due to differences in the degree of hydrolysis and the parent rock material in the case of the tillite. Genetically all of the deposits are residual types generated by hydrolysis and subsequent leaching of micas and feldspars. The principal elements leached are silicon, iron and potassium. The hydrolysis and leaching took place over a long period of time in the flat lying areas of the Peneplane and Coastal Plain. The deposits are exploited economically and the clay is used principally in the tile, pottery and whiteware industries with some usage in the paper, refractory and brickmaking industries. The price commanded by raw kaolin is not very high and as a result the clay industry in Grahamstown is not as viable economically as it could be.
- Full Text:
- Date Issued: 1984
Investigations into the dietary requirements of Clarias gariepinus larvae (Pisces : Clariidae) and the formulation and manufacture of an artificial dry feed for use in intensive larval rearing
- Authors: Uys, Wynand
- Date: 1984
- Subjects: Clarias gariepinus Catfishes -- Africa Clariidae Catfishes -- Africa -- Nutrition -- Requirements Clarias
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5205 , http://hdl.handle.net/10962/d1004446
- Description: The need for developing an artificial dry feed for Clarias gariepinus larvae was identified. Dry larval fishfeed requires certain physical properties. Techniques for manufacturing feeds which comply with these requirements were evolved and are recomended for practical use. The techniques that were used for artificial reproduction of C. gariepinus larvae are briefly discussed. The larvae were fed on various dietary formulations and their growth responses were monitored in order to determine their nutritional requirements. A feed was developed which gave superior results to those obtained with natural food organisms. This feed consisted of Torula yeast(69,8%), fishmeal(23,3%), vitamin supplements(O,9%), methionine supplement (150mg/kg), bactericide and preservatives. The feed particles were coated with a lipid supplement which was added at a ratio of 6% to the weight of the feed. The optimum particle size (diameter) for C. gariepinus larvae is 2,2% of their mean total length. The larvae should be given a feed ration of 25% of body weight per day at a frequency of once every four hours. A favourable feed conversion ratio of 1.1g of feed consumed per gram of larval weight gain was experienced. The established dry feed is suitable for use in commercial hatcheries and can be used as a standard and proven food source for further research on the intensive rearing of C. gariepinus larvae.
- Full Text:
- Date Issued: 1984
- Authors: Uys, Wynand
- Date: 1984
- Subjects: Clarias gariepinus Catfishes -- Africa Clariidae Catfishes -- Africa -- Nutrition -- Requirements Clarias
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5205 , http://hdl.handle.net/10962/d1004446
- Description: The need for developing an artificial dry feed for Clarias gariepinus larvae was identified. Dry larval fishfeed requires certain physical properties. Techniques for manufacturing feeds which comply with these requirements were evolved and are recomended for practical use. The techniques that were used for artificial reproduction of C. gariepinus larvae are briefly discussed. The larvae were fed on various dietary formulations and their growth responses were monitored in order to determine their nutritional requirements. A feed was developed which gave superior results to those obtained with natural food organisms. This feed consisted of Torula yeast(69,8%), fishmeal(23,3%), vitamin supplements(O,9%), methionine supplement (150mg/kg), bactericide and preservatives. The feed particles were coated with a lipid supplement which was added at a ratio of 6% to the weight of the feed. The optimum particle size (diameter) for C. gariepinus larvae is 2,2% of their mean total length. The larvae should be given a feed ration of 25% of body weight per day at a frequency of once every four hours. A favourable feed conversion ratio of 1.1g of feed consumed per gram of larval weight gain was experienced. The established dry feed is suitable for use in commercial hatcheries and can be used as a standard and proven food source for further research on the intensive rearing of C. gariepinus larvae.
- Full Text:
- Date Issued: 1984
Somewhat strange : a study of the relationships between text and music in English song, 1588-1789
- Hutchings, Geoffrey Justin Mackay
- Authors: Hutchings, Geoffrey Justin Mackay
- Date: 1984
- Subjects: Songs, English -- 16th century -- HIstory and criticism Songs, English -- 17th century -- HIstory and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2670 , http://hdl.handle.net/10962/d1006978
- Description: This study is concerned with the ways in which linguistic texts combine with music to form song, essentially an art of relationship. It argues that the relationship has never been a very stable one outside folk song, and traces the development of the relationship in English song from the appearance of the first English madrigals in 1588 to the death of G F Handel in 1759. The different sorts of relationship during this period are discussed in detail, with particular attention being paid to the sort of lyric poetry that is most suitable for musical setting. The conclusion is reached that, in the art of setting a poem to music, the late Elizabethan masters, Thomas Campion and John Dowlland, were supreme in the period under discussion. After them, the aevelopment of a new system of tonality and of denser textures of accompaniment resulted in music's assumption of a more and more Dominant role in the relationship to the neglect and detriment of poetic text.
- Full Text:
- Date Issued: 1984
- Authors: Hutchings, Geoffrey Justin Mackay
- Date: 1984
- Subjects: Songs, English -- 16th century -- HIstory and criticism Songs, English -- 17th century -- HIstory and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2670 , http://hdl.handle.net/10962/d1006978
- Description: This study is concerned with the ways in which linguistic texts combine with music to form song, essentially an art of relationship. It argues that the relationship has never been a very stable one outside folk song, and traces the development of the relationship in English song from the appearance of the first English madrigals in 1588 to the death of G F Handel in 1759. The different sorts of relationship during this period are discussed in detail, with particular attention being paid to the sort of lyric poetry that is most suitable for musical setting. The conclusion is reached that, in the art of setting a poem to music, the late Elizabethan masters, Thomas Campion and John Dowlland, were supreme in the period under discussion. After them, the aevelopment of a new system of tonality and of denser textures of accompaniment resulted in music's assumption of a more and more Dominant role in the relationship to the neglect and detriment of poetic text.
- Full Text:
- Date Issued: 1984
An inquiry into relationships between certain personality factors and attitudes to mathematics in some selected schools in the range standards three to five
- Authors: Light, David Leon
- Date: 1984
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1880 , http://hdl.handle.net/10962/d1005866
- Description: Mathematics--Study and teaching (Elementary)--Psychological aspects
- Full Text:
- Date Issued: 1984
- Authors: Light, David Leon
- Date: 1984
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1880 , http://hdl.handle.net/10962/d1005866
- Description: Mathematics--Study and teaching (Elementary)--Psychological aspects
- Full Text:
- Date Issued: 1984
Resource partitioning by top predatory teleosts in eastern Cape coastal waters (South Africa)
- Authors: Smale, Malcolm J
- Date: 1984
- Subjects: Osteichthyes -- Nutrition Osteichthyes -- Behavior
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5210 , http://hdl.handle.net/10962/d1004775
- Description: A detailed feeding study of eleven inshore top predatory teleosts in the eastern Cape is presented. Material collected largely from line-caught fish was augmented by spearfishing. The predators were grouped according to habitat: pelagic, soft-sediment demersal and reef species. Pelagic fish examined were Lichia amia, Pomatomus saltatrix, Seriola lalandi, Atractoscion aequidens, Katsuwonus pelamis and Thunnus albacares. Stomach content analyses revealed that their prey varied according to size and between species. In coastal areas important prey species were Sardinops ocellata, Etrumeus teres, Engraulis capensis and Loligo reynaudi. The use of fish otoliths and squid beaks allowed accurate identification of the prey and their measurement provided details of their size composition. This has provided greater insight into the distribution of prey species and their importance in food webs. The principal large predator of shallow coastal soft substrates is Argyrosomus hololepidotus, which takes pelagic and demersal prey. Important prey of small specimens are mysids, whereas fish and squid become more important in the diet of larger specimens (>300 mm). Fish prey include Sardinops ocellata, Engraulis capensis, Pomadasys olivaceum and A. hololepidotus. Loligo reynaudi is the dominant cephalopod prey. Selectivity of A. hololepidotus was investigated. Prey were compared to catches made during a small-mesh trawl survey. The absence of certain species from the diet suggests that they avoid predation, possibly by outswimming A. hololepidotus (e.g. P. saltatrix) while large Galeichthys feliceps are rare in the diet, probably because of their formidable spines. Flatfishes, P. olivaceum, juvenile G. feliceps and small A. hololepidotus appear to be preferred food items. The depth distribution of predators and prey is described, and it appears that the distribution of predators may be influenced by their prey. Top predatory teleosts inhabiting coastal reefs are Cheimerius nufar, Petrus rupestris, Polysteganus praeorbitalis and Epinephelus guaza. Diet changes with size and locality but comprises small reef fishes for most of the sparids. C. nufar takes pelagic fish and squid more than the other predators while P. rupestris and P. praeorbitalis prey on cheilodactylids, clinids and other reef associated prey predominantly. E. guaza takes principally crabs and octopods. Classification and ordination analyses of the prey taken illustrated the inter-relationships of predators, which change with increasing size. The pelagic predators are most similar to each other and A. hololepidotus is closer to this group than to reef predators. The reef predators are less similar to each other, although this group as a whole is segregated from pelagic predators. Exceptions to this are large C. nufar and large P. praeorbitalis, which fall into the pelagic predator group, as they took pelagic prey to a large extent. These results are discussed and the patterns shown are compared to other studies and current resource partitioning theory. Two food webs are provided for the coastal waters of the eastern Cape. The pelagic food web has clupeids, engraulids and L. reynaudi as principal components. The reef system is more complex and the Clinidae, Cheilodactylidae and Octopus spp. are important. The use of food webs in management and in providing a framework for testing theoretical models is shown to be important. Research needs are identified and include more detailed work on the basic biology and ecology of the top predators and their prey.
- Full Text:
- Date Issued: 1984
- Authors: Smale, Malcolm J
- Date: 1984
- Subjects: Osteichthyes -- Nutrition Osteichthyes -- Behavior
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5210 , http://hdl.handle.net/10962/d1004775
- Description: A detailed feeding study of eleven inshore top predatory teleosts in the eastern Cape is presented. Material collected largely from line-caught fish was augmented by spearfishing. The predators were grouped according to habitat: pelagic, soft-sediment demersal and reef species. Pelagic fish examined were Lichia amia, Pomatomus saltatrix, Seriola lalandi, Atractoscion aequidens, Katsuwonus pelamis and Thunnus albacares. Stomach content analyses revealed that their prey varied according to size and between species. In coastal areas important prey species were Sardinops ocellata, Etrumeus teres, Engraulis capensis and Loligo reynaudi. The use of fish otoliths and squid beaks allowed accurate identification of the prey and their measurement provided details of their size composition. This has provided greater insight into the distribution of prey species and their importance in food webs. The principal large predator of shallow coastal soft substrates is Argyrosomus hololepidotus, which takes pelagic and demersal prey. Important prey of small specimens are mysids, whereas fish and squid become more important in the diet of larger specimens (>300 mm). Fish prey include Sardinops ocellata, Engraulis capensis, Pomadasys olivaceum and A. hololepidotus. Loligo reynaudi is the dominant cephalopod prey. Selectivity of A. hololepidotus was investigated. Prey were compared to catches made during a small-mesh trawl survey. The absence of certain species from the diet suggests that they avoid predation, possibly by outswimming A. hololepidotus (e.g. P. saltatrix) while large Galeichthys feliceps are rare in the diet, probably because of their formidable spines. Flatfishes, P. olivaceum, juvenile G. feliceps and small A. hololepidotus appear to be preferred food items. The depth distribution of predators and prey is described, and it appears that the distribution of predators may be influenced by their prey. Top predatory teleosts inhabiting coastal reefs are Cheimerius nufar, Petrus rupestris, Polysteganus praeorbitalis and Epinephelus guaza. Diet changes with size and locality but comprises small reef fishes for most of the sparids. C. nufar takes pelagic fish and squid more than the other predators while P. rupestris and P. praeorbitalis prey on cheilodactylids, clinids and other reef associated prey predominantly. E. guaza takes principally crabs and octopods. Classification and ordination analyses of the prey taken illustrated the inter-relationships of predators, which change with increasing size. The pelagic predators are most similar to each other and A. hololepidotus is closer to this group than to reef predators. The reef predators are less similar to each other, although this group as a whole is segregated from pelagic predators. Exceptions to this are large C. nufar and large P. praeorbitalis, which fall into the pelagic predator group, as they took pelagic prey to a large extent. These results are discussed and the patterns shown are compared to other studies and current resource partitioning theory. Two food webs are provided for the coastal waters of the eastern Cape. The pelagic food web has clupeids, engraulids and L. reynaudi as principal components. The reef system is more complex and the Clinidae, Cheilodactylidae and Octopus spp. are important. The use of food webs in management and in providing a framework for testing theoretical models is shown to be important. Research needs are identified and include more detailed work on the basic biology and ecology of the top predators and their prey.
- Full Text:
- Date Issued: 1984
The career maturity of the gifted and talented pupil
- Authors: Rainier, Markseller Garrett
- Date: 1984
- Subjects: Gifted children--Psychology Counseling in vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1371 , http://hdl.handle.net/10962/d1001437
- Description: In 1980 the cape Education Department launched a Gifted and Talented programme in some schools which was intended to enrich the educational experience of the more able pupils. Numerous studies have shown these pupils to have a higher level of career maturity than non-gifted pupils, but the studies have also shown that these pupils face unique career- development problems. Gifted and Talented pupils constitute an important source of manpower and their potential contribution to the total society is great. Consequently they are in need of effective career guidance to help them overcome their unique problems and realize their potential. This study set out to discover if the career maturity of a group of Standard 9 Gifted and Talented pupils, identified according to the original Cape Education Department criteria, is indeed higher than that of their peers and to make recommendations for facilitating career education among these pupils. Contrary to expectations the Gifted and Talented pupils did not show significantly higher levels of career maturity than their peers, as measured on the Attitude Scale of Crites ' Career Maturity Inventory. Compared with the American norms , the scores obtained by the research population were unfavourable. The validity of the I .Q. scores used and the criteria for identification of Gifted and Talented pupils are seen as questionable which could have led to an inaccurate grouping of the pupils as Gifted and Talented or non- gifted. Recommendations are made for a basic career education programme for all pupils which would include periods of active work experience. Recommendations for additional career education for those currently classified as Gifted and Talented pupils are also made, so as to allow these pupils additional time for self- development, decisionmaking and dealing with their unique life situation
- Full Text:
- Date Issued: 1984
- Authors: Rainier, Markseller Garrett
- Date: 1984
- Subjects: Gifted children--Psychology Counseling in vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1371 , http://hdl.handle.net/10962/d1001437
- Description: In 1980 the cape Education Department launched a Gifted and Talented programme in some schools which was intended to enrich the educational experience of the more able pupils. Numerous studies have shown these pupils to have a higher level of career maturity than non-gifted pupils, but the studies have also shown that these pupils face unique career- development problems. Gifted and Talented pupils constitute an important source of manpower and their potential contribution to the total society is great. Consequently they are in need of effective career guidance to help them overcome their unique problems and realize their potential. This study set out to discover if the career maturity of a group of Standard 9 Gifted and Talented pupils, identified according to the original Cape Education Department criteria, is indeed higher than that of their peers and to make recommendations for facilitating career education among these pupils. Contrary to expectations the Gifted and Talented pupils did not show significantly higher levels of career maturity than their peers, as measured on the Attitude Scale of Crites ' Career Maturity Inventory. Compared with the American norms , the scores obtained by the research population were unfavourable. The validity of the I .Q. scores used and the criteria for identification of Gifted and Talented pupils are seen as questionable which could have led to an inaccurate grouping of the pupils as Gifted and Talented or non- gifted. Recommendations are made for a basic career education programme for all pupils which would include periods of active work experience. Recommendations for additional career education for those currently classified as Gifted and Talented pupils are also made, so as to allow these pupils additional time for self- development, decisionmaking and dealing with their unique life situation
- Full Text:
- Date Issued: 1984
Design automation of a machine-independent code generator
- Authors: Clayton, Peter Graham
- Date: 1984 , 2013-01-22
- Subjects: Compilers (Computer programs) , Programming languages (Electronic computers)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4676 , http://hdl.handle.net/10962/d1006699 , Compilers (Computer programs) , Programming languages (Electronic computers)
- Description: As both computer languages and architectures continue to proliferate, there is a continuing need for new compilers. Researchers have attempted to ease the work of producing compilers by developing methods to automate compiler writing. While much work has been done (and considerable success achieved) in writing parsers which can handle a variety of source languages (using mainly table-driven analysis methods), less progress has been made in formalizing the code generation end of the compiler. Nevertheless, some of the more recent publications in code generation stress portability or retargetability of the resulting compiler. A number of code generator synthesisers have been developed, some of which produce code that can be compared in quality with that produced by a conventional code generator. However, because of the complexity of generalizing the mapping from source language to target machine, and the need for efficiency of various kinds, code generator synthesisers are large, complicated programs. Consequently, the person who develops a code generator using one of these tools invariably needs to be a code generation specialist himself. Many compilers follow a pattern of having a front end which generates intermediate code, and a back end which converts intermediate code to machine code. The intermediate code is effectively machine independent, or can be designed that way. With these points in mind, we have set out to write a system of programs which -- 1. will allow the generation of such a back end in a reasonably short time, for a general intermediate code, and for a general machine code, and -- 2. can be used by anyone who has a sound knowledge of the target machine's architecture and associated assembler language, but is not necessarily a specialist compiler writer. The system consists of a series of friendly, interactive programs by means of which the user sets up tables defining the architecture and assembly level instructions for the target machine, and the code templates onto which intermediate codes produced by a parser have been mapped. A general notation has been developed to represent machine instructions using the same format as the target assembler. Thus the code generator writer is able to write code sequences to perform the effects of the intermediate codes, using assembly mnemonics familiar to him. The resultant table-driven code generator simply replaces a sequence of intermediate codes by their respective code templates, relocating them in memory and filling in addresses known only at code-generation time. This thesis describes the use and implementation details of this generalized code generation system. As an example, the implementation of a code generator for a CLANG [23] parser on an 8080 processor is described. The discussion also includes guide-lines on how to implement a loader and associated run-time routines for use in executing the object code. The results of a number of bench-marks have shown, as expected, that code produced by a code generator developed in this manner is larger and slower than that from a special purpose optimizing code generator, but is still several times faster than interpreting the intermediate code. The major benefit to be gained from using this system lies in the shorter development time by a less skilled person. , KMBT_223 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984
- Authors: Clayton, Peter Graham
- Date: 1984 , 2013-01-22
- Subjects: Compilers (Computer programs) , Programming languages (Electronic computers)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4676 , http://hdl.handle.net/10962/d1006699 , Compilers (Computer programs) , Programming languages (Electronic computers)
- Description: As both computer languages and architectures continue to proliferate, there is a continuing need for new compilers. Researchers have attempted to ease the work of producing compilers by developing methods to automate compiler writing. While much work has been done (and considerable success achieved) in writing parsers which can handle a variety of source languages (using mainly table-driven analysis methods), less progress has been made in formalizing the code generation end of the compiler. Nevertheless, some of the more recent publications in code generation stress portability or retargetability of the resulting compiler. A number of code generator synthesisers have been developed, some of which produce code that can be compared in quality with that produced by a conventional code generator. However, because of the complexity of generalizing the mapping from source language to target machine, and the need for efficiency of various kinds, code generator synthesisers are large, complicated programs. Consequently, the person who develops a code generator using one of these tools invariably needs to be a code generation specialist himself. Many compilers follow a pattern of having a front end which generates intermediate code, and a back end which converts intermediate code to machine code. The intermediate code is effectively machine independent, or can be designed that way. With these points in mind, we have set out to write a system of programs which -- 1. will allow the generation of such a back end in a reasonably short time, for a general intermediate code, and for a general machine code, and -- 2. can be used by anyone who has a sound knowledge of the target machine's architecture and associated assembler language, but is not necessarily a specialist compiler writer. The system consists of a series of friendly, interactive programs by means of which the user sets up tables defining the architecture and assembly level instructions for the target machine, and the code templates onto which intermediate codes produced by a parser have been mapped. A general notation has been developed to represent machine instructions using the same format as the target assembler. Thus the code generator writer is able to write code sequences to perform the effects of the intermediate codes, using assembly mnemonics familiar to him. The resultant table-driven code generator simply replaces a sequence of intermediate codes by their respective code templates, relocating them in memory and filling in addresses known only at code-generation time. This thesis describes the use and implementation details of this generalized code generation system. As an example, the implementation of a code generator for a CLANG [23] parser on an 8080 processor is described. The discussion also includes guide-lines on how to implement a loader and associated run-time routines for use in executing the object code. The results of a number of bench-marks have shown, as expected, that code produced by a code generator developed in this manner is larger and slower than that from a special purpose optimizing code generator, but is still several times faster than interpreting the intermediate code. The major benefit to be gained from using this system lies in the shorter development time by a less skilled person. , KMBT_223 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1984