'Rhodesians' in South Africa : a study of immigrants from Zimbabwe
- Authors: Simon, Alan
- Date: 1984
- Subjects: Zimbabweans South Africa -- Foreign population Zimbabwe -- Emigration and immigration South Africa -- Emigration and immigration
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3345 , http://hdl.handle.net/10962/d1005630
- Description: Although most whites have remained in Zimbabwe after independence and not all who have emigrated came to South Africa, large numbers established themselves as an immigrant community in this country. The aim of this study is to "sociologically capture" this community's views about their past experiences in Rhodesia/Zimbabwe and their present experiences in South Africa. This is done by employing a generative methodological procedure whereby members of the target population themselves generated issues considered to be of importance to their previous and new situational contexts. As it was not possible to obtain a random sample of all Zimbabwean immigrants in South Africa, questionnaire data were collected from four separate categories of respondents. In addition, depth interviews were conducted and thus responses have been analysed both qualitatively and quantitatively. The findings demonstrate that for the most part, few "Zimbabweans" - whites who are reasonably accepting of the new socio-political order in independent Zimbabwe - have come to South Africa. Rather, most of the immigrants, whose views were canvassed in this research investigation, seem to be bitter "Rhodesians" who have been unable to accept change and integration and the consequent loss of white privilege in the new Zimbabwe. These recent immigrants have not found all things to their satisfaction in South Africa moreover, despite the similar socio-political structures in former Rhodesia and contemporary South Africa.
- Full Text:
- Date Issued: 1984
- Authors: Simon, Alan
- Date: 1984
- Subjects: Zimbabweans South Africa -- Foreign population Zimbabwe -- Emigration and immigration South Africa -- Emigration and immigration
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3345 , http://hdl.handle.net/10962/d1005630
- Description: Although most whites have remained in Zimbabwe after independence and not all who have emigrated came to South Africa, large numbers established themselves as an immigrant community in this country. The aim of this study is to "sociologically capture" this community's views about their past experiences in Rhodesia/Zimbabwe and their present experiences in South Africa. This is done by employing a generative methodological procedure whereby members of the target population themselves generated issues considered to be of importance to their previous and new situational contexts. As it was not possible to obtain a random sample of all Zimbabwean immigrants in South Africa, questionnaire data were collected from four separate categories of respondents. In addition, depth interviews were conducted and thus responses have been analysed both qualitatively and quantitatively. The findings demonstrate that for the most part, few "Zimbabweans" - whites who are reasonably accepting of the new socio-political order in independent Zimbabwe - have come to South Africa. Rather, most of the immigrants, whose views were canvassed in this research investigation, seem to be bitter "Rhodesians" who have been unable to accept change and integration and the consequent loss of white privilege in the new Zimbabwe. These recent immigrants have not found all things to their satisfaction in South Africa moreover, despite the similar socio-political structures in former Rhodesia and contemporary South Africa.
- 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
A phenomenological explication of dream interpretation among rural and urban Nguni people
- Authors: Schweitzer, Robert David
- Date: 1984
- Subjects: Nguni (African people) -- Religion Nguni (African people) -- Psychology Dreams Dreams -- Psychological aspects Healing -- South Africa -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3125 , http://hdl.handle.net/10962/d1006189
- Description: Psychologists investigating dreams in non-Western cultures have generally not considered the meanings of dreams within the unique meaning-structure of the person in his or her societal context. The majority of dream studies in African societies are no exception. Researchers approaching dreams within rural Xhosa and Zulu speaking societies have either adopted an anthropological or a psychodynamic orientation. The latter approach particularly imposes a Western perspective in the interpretation of dream material. There have been no comparable studies of dream interpretation among urban blacks participating in the African Independent Church Movement. The present study focuses on the rural Xhosa speaking people and the urban black population who speak one of the Nguni languages and identify with the African Independent Church Movement. The study is concerned with understanding the meanings of dreams within the cultural context in which they occur. The specific aims of the study are: 1. To explicate the indigenous system of dream interpretation as revealed by acknowledged dream experts. 2. To examine the commonalities and the differences between the interpretation of dreams in two groups, drawn from a rural and urban setting respectively. 3. To elaborate upon the life-world of the participants by the interpretations gained from the above investigation. One hundred dreams and interpretations are collected from two categories of participants referred to as the Rural Group and the Urban Group. The Rural Group is made up of amagqira [traditional healers] and their clients, while the Urban Group consists of prophets and members of the African Independent Churches. Each group includes acknowledged dream experts. A phenomenological methodology is adopted in explicating the data. The methodological precedure involves a number of rigorous stages of explication whereby the original data is reduced to Constituent Profiles leading to the construction of a Thematic Index File. By searching and reflecting upon the data, interpretative themes are identified. These themes are explicated to provide a rigorous description of the interpretative-reality of each group. Themes explicated within the Rural Group are: the physiognomy of the dreamer's life- world as revealed by ithongo, the interpretation of ithongo as revealed through action, the dream relationship as an anticipatory mode-of-existence, iphupha as disclosing a vulnerable mode-of-being, human bodiliness as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. Themes explicated within the Urban Group are : the physiognomy of the dreamer's life-world revealed in their dream-existence, the interpretative-reality revealed through the enaction of dreams, tension between the newer Christian-based cosomology and the traditional cultural-based cosmology, a moral imperative, prophetic perception and human bodiliness, as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. The essence of the interpretative-reality of both groups is very similar and is expressed in the notion of relatedness to a cosmic mode-of-being. The cosmic mode-of-being includes a numinous dimension which is expressed through divine presence in the form of ancestors, Holy Spirit or God. These notions cannot be apprehended by theoretical constructs alone but may be grasped and given form in meaning-disclosing intuitions which are expressed in the lifeworld in terms of bodiliness, revelatory knowledge, action and healing. Some differences between the two groups are evident and reveal some conflict between the monotheistic Christian cosmology and the traditional cosmology. Unique aspects of the interpetative-reality of the Urban Group are expressed in terms of difficulties in the urban social environment and the notion of a moral imperative. It is observed that cultural self-expression based upon traditional ideas continues to play a significant role in the urban environment. The apparent conflict revealed between the respective cosmologies underlies an integration of traditional meanings with Christian concepts. This finding is consistent with the literature suggesting that the African Independent Church is a syncretic movement. The life-world is based upon the immediate and vivid experience of the numinous as revealed in the dream phenomenon. The participants' approach to dreams is not based upon an explicit theory, but upon an immediate and pathic understanding of the dream phenomenon. The understanding is based upon the interpreter's concrete understanding of the life-world, which includes the possibility of cosmic integration and continuity between the personal and transpersonal realms of being. The approach is characterized as an expression of man's primordial attunement with the cosmos. The approach of the participants to dreams may not be consistent with a Western rational orientation, but nevertheless, it is a valid approach. The validity is based upon the immediate life-world of experience which is intelligible, coherent, and above all, it is meaning-giving in revealing life-possibility within the context of human existence.
- Full Text:
- Date Issued: 1984
- Authors: Schweitzer, Robert David
- Date: 1984
- Subjects: Nguni (African people) -- Religion Nguni (African people) -- Psychology Dreams Dreams -- Psychological aspects Healing -- South Africa -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3125 , http://hdl.handle.net/10962/d1006189
- Description: Psychologists investigating dreams in non-Western cultures have generally not considered the meanings of dreams within the unique meaning-structure of the person in his or her societal context. The majority of dream studies in African societies are no exception. Researchers approaching dreams within rural Xhosa and Zulu speaking societies have either adopted an anthropological or a psychodynamic orientation. The latter approach particularly imposes a Western perspective in the interpretation of dream material. There have been no comparable studies of dream interpretation among urban blacks participating in the African Independent Church Movement. The present study focuses on the rural Xhosa speaking people and the urban black population who speak one of the Nguni languages and identify with the African Independent Church Movement. The study is concerned with understanding the meanings of dreams within the cultural context in which they occur. The specific aims of the study are: 1. To explicate the indigenous system of dream interpretation as revealed by acknowledged dream experts. 2. To examine the commonalities and the differences between the interpretation of dreams in two groups, drawn from a rural and urban setting respectively. 3. To elaborate upon the life-world of the participants by the interpretations gained from the above investigation. One hundred dreams and interpretations are collected from two categories of participants referred to as the Rural Group and the Urban Group. The Rural Group is made up of amagqira [traditional healers] and their clients, while the Urban Group consists of prophets and members of the African Independent Churches. Each group includes acknowledged dream experts. A phenomenological methodology is adopted in explicating the data. The methodological precedure involves a number of rigorous stages of explication whereby the original data is reduced to Constituent Profiles leading to the construction of a Thematic Index File. By searching and reflecting upon the data, interpretative themes are identified. These themes are explicated to provide a rigorous description of the interpretative-reality of each group. Themes explicated within the Rural Group are: the physiognomy of the dreamer's life- world as revealed by ithongo, the interpretation of ithongo as revealed through action, the dream relationship as an anticipatory mode-of-existence, iphupha as disclosing a vulnerable mode-of-being, human bodiliness as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. Themes explicated within the Urban Group are : the physiognomy of the dreamer's life-world revealed in their dream-existence, the interpretative-reality revealed through the enaction of dreams, tension between the newer Christian-based cosomology and the traditional cultural-based cosmology, a moral imperative, prophetic perception and human bodiliness, as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. The essence of the interpretative-reality of both groups is very similar and is expressed in the notion of relatedness to a cosmic mode-of-being. The cosmic mode-of-being includes a numinous dimension which is expressed through divine presence in the form of ancestors, Holy Spirit or God. These notions cannot be apprehended by theoretical constructs alone but may be grasped and given form in meaning-disclosing intuitions which are expressed in the lifeworld in terms of bodiliness, revelatory knowledge, action and healing. Some differences between the two groups are evident and reveal some conflict between the monotheistic Christian cosmology and the traditional cosmology. Unique aspects of the interpetative-reality of the Urban Group are expressed in terms of difficulties in the urban social environment and the notion of a moral imperative. It is observed that cultural self-expression based upon traditional ideas continues to play a significant role in the urban environment. The apparent conflict revealed between the respective cosmologies underlies an integration of traditional meanings with Christian concepts. This finding is consistent with the literature suggesting that the African Independent Church is a syncretic movement. The life-world is based upon the immediate and vivid experience of the numinous as revealed in the dream phenomenon. The participants' approach to dreams is not based upon an explicit theory, but upon an immediate and pathic understanding of the dream phenomenon. The understanding is based upon the interpreter's concrete understanding of the life-world, which includes the possibility of cosmic integration and continuity between the personal and transpersonal realms of being. The approach is characterized as an expression of man's primordial attunement with the cosmos. The approach of the participants to dreams may not be consistent with a Western rational orientation, but nevertheless, it is a valid approach. The validity is based upon the immediate life-world of experience which is intelligible, coherent, and above all, it is meaning-giving in revealing life-possibility within the context of human existence.
- 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
An analysis of the basic needs approach in its application to regional economic development with specific reference to Ciske
- Authors: Keeton, Gavin Rodney
- Date: 1984
- Subjects: Basic needs -- South Africa -- Ciskei Ciskei (South Africa) -- Economic conditions Ciskei (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1037 , http://hdl.handle.net/10962/d1004566
- Description: In Chapter 7, it was argued that improved satisfaction of basic needs could in principle lead to increased labour productivity and, via a comulative process, to increased output and income levels. Higher incomes could in turn mean further improved satisfaction of basic needs, greater labour productivity and even greater output and income levels. Thus the satisfaction of basic needs could be seen as a means towards the end of improved living standards and the reduction of poverty, and hence an instrument of development policy. From the analysis of basic needs in Ciskei, it is apparent that government expenditure has been such that the "core" basic needs have evidently been catered for, at least to some extent, for some time. Yet, there has been nothing like a concerted strategy, and expenditure on basic needs was the result of ad hoc measures, rather than a conscious strategy or development policy as such. Basic needs were therefore seen simply as ends in themselves, rather than as means to the end of self-sustained economic development. In the case of Ciskei, more information about the satisfaction of basic needs, especially health, and water supply and sanitation, is required at the present stage. Such information should not only be seen in quantitative terms (as "inputs"), but also be evaluated qualitatively (as "outputs"). In other words, basic needs should be viewed functionally as thresholds to the goal of self-sustained economic development. This applies particularly to educatfon, where the total supply may be misleading, more significant measures being quality, access and actual consumption. Data for health, and water supply and sanitation, are not readily available, and again should reflect access and usage as well as availability. Nutritional data should not only reveal the extent and nature of poor nutrition (malnutrition) but also its causes, such as, inadequate expenditure on food on account of low income levels, or inappropriate nutritional patterns of consumption. Data on shelter should take into account the appropriateness of standards and types of shelter, rather than simply the number of houses as such. At the same time, the extent to which basic needs are complementary should be investigated; e.g. the effect the improved satisfaction of education would have on shelter, shelter on health, etc. The stronger such complementarities, the lower total government expenditure on basic needs would have to be. Similarly, if expenditure on basic needs is inappropriate or ill-directed, a revision of standards and redirection of resources may be necessary. In the case of Ciskei, it may well be that total expenditure on basic needs may not be inadequate as such at the present stage, but rather that co-ordination of existing expenditure is required to yield a purposive development policy. A powerful case for the suitability of a Basic Needs strategy for Ciskei may be suggested by the intermediate nature of economic development within its borders. To the extent that some basic needs are already satisfied, at least to some degree and some more than others, certain preconditions for economic development can be said to already exist. Yet it cannot be claimed that Ciskei has reached the "take-off" stage into self-sustained economic growth in the Rostovian sense. Nevertheless, a deliberately co-ordinated Basic Needs strategy may well move Ciskei away from the danger of slipping back into the so-called "Low-Level Equilibrium Trap." In other words, a more scientifically designed, co-ordinated and deliberately applied strategy, whereby basic needs become the means towards self-sustained economic growth, should at least be able to establish the "preconditions for take-off" necessary for sustained economic development.
- Full Text:
- Date Issued: 1984
- Authors: Keeton, Gavin Rodney
- Date: 1984
- Subjects: Basic needs -- South Africa -- Ciskei Ciskei (South Africa) -- Economic conditions Ciskei (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1037 , http://hdl.handle.net/10962/d1004566
- Description: In Chapter 7, it was argued that improved satisfaction of basic needs could in principle lead to increased labour productivity and, via a comulative process, to increased output and income levels. Higher incomes could in turn mean further improved satisfaction of basic needs, greater labour productivity and even greater output and income levels. Thus the satisfaction of basic needs could be seen as a means towards the end of improved living standards and the reduction of poverty, and hence an instrument of development policy. From the analysis of basic needs in Ciskei, it is apparent that government expenditure has been such that the "core" basic needs have evidently been catered for, at least to some extent, for some time. Yet, there has been nothing like a concerted strategy, and expenditure on basic needs was the result of ad hoc measures, rather than a conscious strategy or development policy as such. Basic needs were therefore seen simply as ends in themselves, rather than as means to the end of self-sustained economic development. In the case of Ciskei, more information about the satisfaction of basic needs, especially health, and water supply and sanitation, is required at the present stage. Such information should not only be seen in quantitative terms (as "inputs"), but also be evaluated qualitatively (as "outputs"). In other words, basic needs should be viewed functionally as thresholds to the goal of self-sustained economic development. This applies particularly to educatfon, where the total supply may be misleading, more significant measures being quality, access and actual consumption. Data for health, and water supply and sanitation, are not readily available, and again should reflect access and usage as well as availability. Nutritional data should not only reveal the extent and nature of poor nutrition (malnutrition) but also its causes, such as, inadequate expenditure on food on account of low income levels, or inappropriate nutritional patterns of consumption. Data on shelter should take into account the appropriateness of standards and types of shelter, rather than simply the number of houses as such. At the same time, the extent to which basic needs are complementary should be investigated; e.g. the effect the improved satisfaction of education would have on shelter, shelter on health, etc. The stronger such complementarities, the lower total government expenditure on basic needs would have to be. Similarly, if expenditure on basic needs is inappropriate or ill-directed, a revision of standards and redirection of resources may be necessary. In the case of Ciskei, it may well be that total expenditure on basic needs may not be inadequate as such at the present stage, but rather that co-ordination of existing expenditure is required to yield a purposive development policy. A powerful case for the suitability of a Basic Needs strategy for Ciskei may be suggested by the intermediate nature of economic development within its borders. To the extent that some basic needs are already satisfied, at least to some degree and some more than others, certain preconditions for economic development can be said to already exist. Yet it cannot be claimed that Ciskei has reached the "take-off" stage into self-sustained economic growth in the Rostovian sense. Nevertheless, a deliberately co-ordinated Basic Needs strategy may well move Ciskei away from the danger of slipping back into the so-called "Low-Level Equilibrium Trap." In other words, a more scientifically designed, co-ordinated and deliberately applied strategy, whereby basic needs become the means towards self-sustained economic growth, should at least be able to establish the "preconditions for take-off" necessary for sustained economic development.
- Full Text:
- Date Issued: 1984
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
Equilibrium, expectations and information : a study of the general theory, the neo-classical synthesis and modern classical macroeconomics
- Authors: Torr, Christopher
- Date: 1984
- Subjects: Macroeconomics Equilibrium (Economics) Economics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1035 , http://hdl.handle.net/10962/d1004515
- Description: From Introduction: It is now nearly 50 years since the appearance of Keynes's General Theory of Employment, Interest and Money and the stream of articles and books on what Keynes really meant or didn't mean shows no sign of abating. In part, this dissertation is a contribution to this voluminous literature, but what follows is hardly an attempt to provide an exhaustive interpretation. Instead the General Theory is examined from a certain angle, with the title "Equilibrium, Expectations and Information" providing the framework for the investigation. That the title has been borrowed from G.B. Richdrdson's 1959 Economic Journal article is no accident. Richardson's work has been unduly neglected and his trichotomy serves as a convenient platform from which to analyse Keynes's method and those of his interpreters, in particular the approaches stemming from the work of Clower and Leijonhufvud. The information structure of the Walrasian type of general equilibrium model is also examined as the latter forms the basis of both the neo-classical interpretation of Keynes's contribution and the rational expectations approach that will be discussed. Finally Richardson's framework is applied in an analysis of two modern classical schools of thought, namely the rational expectations approach headed by Lucas, and the neoRicardian school amongst which Garegnani, Eatwell and Milgate, for example, are prominent. In a sentence, therefore, what follows is an examination of the General Theory and certain interpretations thereof as well as an analysis of modern classical macroeconomics, with the equilibrium-expectations-information framework providing the unifying theme. As will become apparent, the framework does not consist of three watertight compartments. For example, whether a system is in equilibrium or not will depend on whether the expectations of those who have the ablility to effect change are realised. The specification of which agents have this power will depend on the information with which the model builder endows the agents in the model. In discussing this, attention is drawn to Keynes's important distinction between an entrepreneur economy and a cooperative economy. The distinction between the information available to the model builder and that with which he endows the agents in the model is also emphasized.
- Full Text:
- Date Issued: 1984
- Authors: Torr, Christopher
- Date: 1984
- Subjects: Macroeconomics Equilibrium (Economics) Economics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1035 , http://hdl.handle.net/10962/d1004515
- Description: From Introduction: It is now nearly 50 years since the appearance of Keynes's General Theory of Employment, Interest and Money and the stream of articles and books on what Keynes really meant or didn't mean shows no sign of abating. In part, this dissertation is a contribution to this voluminous literature, but what follows is hardly an attempt to provide an exhaustive interpretation. Instead the General Theory is examined from a certain angle, with the title "Equilibrium, Expectations and Information" providing the framework for the investigation. That the title has been borrowed from G.B. Richdrdson's 1959 Economic Journal article is no accident. Richardson's work has been unduly neglected and his trichotomy serves as a convenient platform from which to analyse Keynes's method and those of his interpreters, in particular the approaches stemming from the work of Clower and Leijonhufvud. The information structure of the Walrasian type of general equilibrium model is also examined as the latter forms the basis of both the neo-classical interpretation of Keynes's contribution and the rational expectations approach that will be discussed. Finally Richardson's framework is applied in an analysis of two modern classical schools of thought, namely the rational expectations approach headed by Lucas, and the neoRicardian school amongst which Garegnani, Eatwell and Milgate, for example, are prominent. In a sentence, therefore, what follows is an examination of the General Theory and certain interpretations thereof as well as an analysis of modern classical macroeconomics, with the equilibrium-expectations-information framework providing the unifying theme. As will become apparent, the framework does not consist of three watertight compartments. For example, whether a system is in equilibrium or not will depend on whether the expectations of those who have the ablility to effect change are realised. The specification of which agents have this power will depend on the information with which the model builder endows the agents in the model. In discussing this, attention is drawn to Keynes's important distinction between an entrepreneur economy and a cooperative economy. The distinction between the information available to the model builder and that with which he endows the agents in the model is also emphasized.
- Full Text:
- Date Issued: 1984
Public utility pricing and industrial decentralization in South Africa
- Authors: Wallis, Joseph Lyall
- Date: 1984
- Subjects: Industrial management -- South Africa Public utilities -- South Africa Pricing -- South Africa Decentralization in management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1030 , http://hdl.handle.net/10962/d1003747
- Description: From Introduction: 1. Background to the thesis: During the 1950' sand 1960' s it would appear that the explicit objectives of economic policy in South Africa were full employment and economic growth with some occasional emphasis on the pursuit of relative price stability. Other goals such as efficiency in resource allocation and the pursuit of an "acceptable" income distribution were at best implicit and subordinate to these objectives. This is exemplified by the fact that a number of key prices which were controlled by the authorities such as the exchange rate, interest rates and public utility tariffs were generally set at levels which were either over- or under-priced relative to factor scarcities throughout this period.
- Full Text:
- Date Issued: 1984
- Authors: Wallis, Joseph Lyall
- Date: 1984
- Subjects: Industrial management -- South Africa Public utilities -- South Africa Pricing -- South Africa Decentralization in management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1030 , http://hdl.handle.net/10962/d1003747
- Description: From Introduction: 1. Background to the thesis: During the 1950' sand 1960' s it would appear that the explicit objectives of economic policy in South Africa were full employment and economic growth with some occasional emphasis on the pursuit of relative price stability. Other goals such as efficiency in resource allocation and the pursuit of an "acceptable" income distribution were at best implicit and subordinate to these objectives. This is exemplified by the fact that a number of key prices which were controlled by the authorities such as the exchange rate, interest rates and public utility tariffs were generally set at levels which were either over- or under-priced relative to factor scarcities throughout this period.
- 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
Some aspects of the African mission policy of the Presbytery of Adelaide/Port Elizabeth with special reference to the origin and development of the New Brighton Presbyterian Mission Church, 1898-1962
- Authors: Hunter, Celene Frances Dill
- Date: 1984
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1228 , http://hdl.handle.net/10962/d1007225
- Full Text:
- Date Issued: 1984
- Authors: Hunter, Celene Frances Dill
- Date: 1984
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1228 , http://hdl.handle.net/10962/d1007225
- 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
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
The "Civilised Labour Policy" and the private sector : the operation of the South African Wage Act, 1925-1937
- Authors: Phillips, Ian Munro
- Date: 1984
- Subjects: Wages -- Government policy -- South Africa. Labour policy -- South Africa Discrimination in employment -- South Africa Wages -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2594 , http://hdl.handle.net/10962/d1007354
- Description: The early history of South African industrial development has been approached from essentially two angles. One body of thought has concentrated on the adverse effect colour bars have had on the development of South Africa. It is argued that racial discrimination in industry originated from the racial prejudice of white workers and from state intervention in the economy. Opposed to that view is the interpretation that the colour bar originated out of the specific character and subsequent development of South African capitalism. This study approaches the debates and arguments through an analysis of the Wage Act of 1925. The industrial relations system which operates in South Africa has its origins in the legislation of the 1920s. It is based on the Industrial Conciliation Act of 1924 and the Wage Act of 1925. Very few systematic analyses of the Wage Act have been produced hitherto. Most commentators have focussed on single aspects of the Act, but very few have attempted an examination of the operation of the Wage Board which was established by the Act. The Wage Board was instituted as an element to promote the civilised labour policy in the private sector. Whereas the Industrial Conciliation Act operated to protect organised labour, the Wage Act concentrated on unorganised trades and sections of trades. Although empowered to investigate conditions in the mining industry, the Wage Board was never used to regulate wages in that industry under the Wage Act due to opposition from the industry. It was concerned solely with secondary industrial and manufacturing establishments because agriculture and domestic service were excluded from the Wage Act. The Wage Act was based on the principal of compulsory regulation. Determinations in terms of the Board's recommendations were binding on employees and employers alike. Complex procedures hampered the activity of the Board until 1930 when the Act was amended and simplified. The Board faced a great deal of opposition from manufacturers in its early years. But a cautious approach and the gradual implementation of determinations ensured that employers opposition soon changed to support when it became clear the Board was not an arbitrary one. The Board had to take a number of strict considerations into account. It could not recommend wages if its recommendation would affect the particular trade concerned adversely. It concerned itself with the promotion of efficiency in business, production costs, consumerism , the wasteful employment of labour, the length of the working day and the productivity of employees. As such it was used as a means to assist the necessary rationalisation and reorganisation of South African industry. It could not recommend wages without the Minister's express instructions if all the employees covered by a reference could not receive a civilised wage . Civilised wages were classified as wages at which employees could enjoy white standards of living. This clause effectively introduced a colour bar into wage determinations. It operated before 1930 to buttress Industrial Council Agreements to prevent the displacement of whites by Africans at lower rates. The Wage Board also considered investigations from unskilled, African workers. The Board was not permitted by law to discriminate against people of colour. Apart from the potential colour bar of wage regulation in general in South Africa, the Board was instructed in 1930 to refrain from issuing recommendations for African workers. Regulations were also altered to exclude Africans. The Wage Act declined in importance after the Great Depression as white workers were drawn closer to the wider-reaching Industrial Conciliation Act. The need to regulate African wages and to control African labour became more evident during the period of economic expansion in the 1930s. The Act was replaced in 1937 and the restrictions formerly placed on Africans were removed. The workforce had finally been separated with the provision of different industrial relations appartuses." "...Every industrial and commercial centre in England now possesses a working class divided into two hostile camps, English proletarians and Irish proletarians. The ordinary English worker hates the Irish worker as a competitor who lowers his standard of life. In relation to the Irish worker he feels himself a member of the ruling nation and so turns himself into a tool of the aristocrats and capitalists of his country against Ireland, thus strengthening their domination over himself. He cherishes religious, social, and national prejudices against the Irish worker. His attitude towards him is much the same as that of the 'poor whites' to the 'niggers' in the former slave states of the USA. The Irishman pays him back with interest in his own money. He sees in the English worker at once the accomplice and the stupid tool of the English rule in Ireland. This antagonism is artificially kept alive and intensified by the press, the pulpit, the comic papers, in short, by all the means at the disposal of the ruling classes. This antagonism is the secret of the impotence of the English working class, despite its organisation. It is the secret by which the capitalist class maintains its power. And that class is fully aware of it." Marx to Siegfried Meyer and August Vogt April 9 1870 Marx and Engels Ireland and the Irish Question.
- Full Text:
- Date Issued: 1984
- Authors: Phillips, Ian Munro
- Date: 1984
- Subjects: Wages -- Government policy -- South Africa. Labour policy -- South Africa Discrimination in employment -- South Africa Wages -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2594 , http://hdl.handle.net/10962/d1007354
- Description: The early history of South African industrial development has been approached from essentially two angles. One body of thought has concentrated on the adverse effect colour bars have had on the development of South Africa. It is argued that racial discrimination in industry originated from the racial prejudice of white workers and from state intervention in the economy. Opposed to that view is the interpretation that the colour bar originated out of the specific character and subsequent development of South African capitalism. This study approaches the debates and arguments through an analysis of the Wage Act of 1925. The industrial relations system which operates in South Africa has its origins in the legislation of the 1920s. It is based on the Industrial Conciliation Act of 1924 and the Wage Act of 1925. Very few systematic analyses of the Wage Act have been produced hitherto. Most commentators have focussed on single aspects of the Act, but very few have attempted an examination of the operation of the Wage Board which was established by the Act. The Wage Board was instituted as an element to promote the civilised labour policy in the private sector. Whereas the Industrial Conciliation Act operated to protect organised labour, the Wage Act concentrated on unorganised trades and sections of trades. Although empowered to investigate conditions in the mining industry, the Wage Board was never used to regulate wages in that industry under the Wage Act due to opposition from the industry. It was concerned solely with secondary industrial and manufacturing establishments because agriculture and domestic service were excluded from the Wage Act. The Wage Act was based on the principal of compulsory regulation. Determinations in terms of the Board's recommendations were binding on employees and employers alike. Complex procedures hampered the activity of the Board until 1930 when the Act was amended and simplified. The Board faced a great deal of opposition from manufacturers in its early years. But a cautious approach and the gradual implementation of determinations ensured that employers opposition soon changed to support when it became clear the Board was not an arbitrary one. The Board had to take a number of strict considerations into account. It could not recommend wages if its recommendation would affect the particular trade concerned adversely. It concerned itself with the promotion of efficiency in business, production costs, consumerism , the wasteful employment of labour, the length of the working day and the productivity of employees. As such it was used as a means to assist the necessary rationalisation and reorganisation of South African industry. It could not recommend wages without the Minister's express instructions if all the employees covered by a reference could not receive a civilised wage . Civilised wages were classified as wages at which employees could enjoy white standards of living. This clause effectively introduced a colour bar into wage determinations. It operated before 1930 to buttress Industrial Council Agreements to prevent the displacement of whites by Africans at lower rates. The Wage Board also considered investigations from unskilled, African workers. The Board was not permitted by law to discriminate against people of colour. Apart from the potential colour bar of wage regulation in general in South Africa, the Board was instructed in 1930 to refrain from issuing recommendations for African workers. Regulations were also altered to exclude Africans. The Wage Act declined in importance after the Great Depression as white workers were drawn closer to the wider-reaching Industrial Conciliation Act. The need to regulate African wages and to control African labour became more evident during the period of economic expansion in the 1930s. The Act was replaced in 1937 and the restrictions formerly placed on Africans were removed. The workforce had finally been separated with the provision of different industrial relations appartuses." "...Every industrial and commercial centre in England now possesses a working class divided into two hostile camps, English proletarians and Irish proletarians. The ordinary English worker hates the Irish worker as a competitor who lowers his standard of life. In relation to the Irish worker he feels himself a member of the ruling nation and so turns himself into a tool of the aristocrats and capitalists of his country against Ireland, thus strengthening their domination over himself. He cherishes religious, social, and national prejudices against the Irish worker. His attitude towards him is much the same as that of the 'poor whites' to the 'niggers' in the former slave states of the USA. The Irishman pays him back with interest in his own money. He sees in the English worker at once the accomplice and the stupid tool of the English rule in Ireland. This antagonism is artificially kept alive and intensified by the press, the pulpit, the comic papers, in short, by all the means at the disposal of the ruling classes. This antagonism is the secret of the impotence of the English working class, despite its organisation. It is the secret by which the capitalist class maintains its power. And that class is fully aware of it." Marx to Siegfried Meyer and August Vogt April 9 1870 Marx and Engels Ireland and the Irish Question.
- Full Text:
- Date Issued: 1984
The demography, breeding biology and management of two mullet species (Pisces : Mugilidae) in the Eastern Cape, South Africa
- Authors: Bok, Anton
- Date: 1984
- Subjects: Fishes -- South Africa -- Eastern Cape Mullidae -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5213 , http://hdl.handle.net/10962/d1004931
- Description: Aspects of the life history of Myxus capensis which were likely to be most affected by man-induced habitat changes, were studied in the eastern Cape. Myxus capensis was found to be specialized for a catadromous life history. The fry migrate into freshwater reaches of rivers within a few months of being spawned at sea and return to an estuarine or marine environment when maximum size has been attained and large energy reserves necessary for spawning have been accumulated. Myxus capensis penetrates considerable distances up eastern Cape rivers and although present in the upper reaches of some estuaries, is only common in freshwater-dominated systems. Myxus capensis has adapted its life history style in a number of ways to overcome the constraints associated with the spatial separation of the freshwater feeding areas and the marine spawning grounds in a region prone to droughts and erratic river flow. Research on the more estuarine-dependent Mugil cephalus, which is also found in the freshwater reaches of eastern Cape rivers, enabled useful comparisons to be drawn. As the latter species is not dependent on a freshwater phase in its life cycle, it is subject to different selection pressures. This comparative approach gave insights into the adaptive significance of the life history tactics of Myxus capensis. Myxus capensis displays a number of life history tactics characteristic of migratory fish species which are thought to increase population fecundity by increasing the number of large females and hence maximizing egg production. These include a sex ratio in favour of females, faster female growth, females remaining longer in the freshwater feeding areas and reaching a larger ultimate size. Possible adaptations to the periodic isolation of the feeding and spawning areas include: (i) the development of ripe gonads only in estuarine or marine areas when access to the spawning grounds is ensured; (ii) year-round spawning and hence recruitment which enables the erratic floods to be used at any time for downriver spawning migrations and reduces the chances of total recruitment failure due to short-term adverse environmental conditions and (iii) a relatively wide range of size and age at first (and final) sexual maturity (2+ to 5+ years); this tends to ensure successful reproduction and recruitment in spite of a series of poor years, as well as dampen population fluctuations after long periods of isolation in fresh water. The dependence of Myxus capensis on the freshwater reaches of eastern Cape rivers makes this species vulnerable to man-induced habitat changes. The erection of barriers to migration has cut off large stretches of suitable habitat and almost completely eliminated Myxus capensis from certain rivers. This detrimental effect has been largely responsible for the recent inclusion of this species on the Red Data list of endangered fish species in South Africa. This study demonstrated the considerable fisheries potential of both mullet species and this should ensure that their conservation and wise utilization be given high priority. Management proposals include: (i) the netting and lifting of Myxus capensis over barriers to migration; (ii) the construction of fish ladders when feasible and (iii) the artificial propagation of this species to enable large-scale stockings of existing man-made impoundments as well as natural habitats to be carried out. It is predicted that the life history characteristics of Myxus capensis, which evolved in response to an erratic freshwater environment, should ensure that when man-induced habitat changes are rectified, this species will again flourish in eastern Cape rivers.
- Full Text:
- Date Issued: 1984
- Authors: Bok, Anton
- Date: 1984
- Subjects: Fishes -- South Africa -- Eastern Cape Mullidae -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5213 , http://hdl.handle.net/10962/d1004931
- Description: Aspects of the life history of Myxus capensis which were likely to be most affected by man-induced habitat changes, were studied in the eastern Cape. Myxus capensis was found to be specialized for a catadromous life history. The fry migrate into freshwater reaches of rivers within a few months of being spawned at sea and return to an estuarine or marine environment when maximum size has been attained and large energy reserves necessary for spawning have been accumulated. Myxus capensis penetrates considerable distances up eastern Cape rivers and although present in the upper reaches of some estuaries, is only common in freshwater-dominated systems. Myxus capensis has adapted its life history style in a number of ways to overcome the constraints associated with the spatial separation of the freshwater feeding areas and the marine spawning grounds in a region prone to droughts and erratic river flow. Research on the more estuarine-dependent Mugil cephalus, which is also found in the freshwater reaches of eastern Cape rivers, enabled useful comparisons to be drawn. As the latter species is not dependent on a freshwater phase in its life cycle, it is subject to different selection pressures. This comparative approach gave insights into the adaptive significance of the life history tactics of Myxus capensis. Myxus capensis displays a number of life history tactics characteristic of migratory fish species which are thought to increase population fecundity by increasing the number of large females and hence maximizing egg production. These include a sex ratio in favour of females, faster female growth, females remaining longer in the freshwater feeding areas and reaching a larger ultimate size. Possible adaptations to the periodic isolation of the feeding and spawning areas include: (i) the development of ripe gonads only in estuarine or marine areas when access to the spawning grounds is ensured; (ii) year-round spawning and hence recruitment which enables the erratic floods to be used at any time for downriver spawning migrations and reduces the chances of total recruitment failure due to short-term adverse environmental conditions and (iii) a relatively wide range of size and age at first (and final) sexual maturity (2+ to 5+ years); this tends to ensure successful reproduction and recruitment in spite of a series of poor years, as well as dampen population fluctuations after long periods of isolation in fresh water. The dependence of Myxus capensis on the freshwater reaches of eastern Cape rivers makes this species vulnerable to man-induced habitat changes. The erection of barriers to migration has cut off large stretches of suitable habitat and almost completely eliminated Myxus capensis from certain rivers. This detrimental effect has been largely responsible for the recent inclusion of this species on the Red Data list of endangered fish species in South Africa. This study demonstrated the considerable fisheries potential of both mullet species and this should ensure that their conservation and wise utilization be given high priority. Management proposals include: (i) the netting and lifting of Myxus capensis over barriers to migration; (ii) the construction of fish ladders when feasible and (iii) the artificial propagation of this species to enable large-scale stockings of existing man-made impoundments as well as natural habitats to be carried out. It is predicted that the life history characteristics of Myxus capensis, which evolved in response to an erratic freshwater environment, should ensure that when man-induced habitat changes are rectified, this species will again flourish in eastern Cape rivers.
- 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
The evolution of heteronomous host relationships in Aphelinidaa (Hymenoptera Chalcidoidea) with special reference to the biology of Coccophagus Bartletti Annecke and Insley
- Authors: Walter, Grenville Hugh
- Date: 1984
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5620 , http://hdl.handle.net/10962/d1003746
- Description: Résumé: Heteronomous host relationships are unique to parasitoids in about 8 aphelinid genera. Males have host relationships quite distinct from those of their females. Females of ALL species are primary endoparasitoids of homopterous hosts. Males, on the other hand, may be either primary ectoparasitoids of the same host species as their conspecific females, or they may be hyperparasitic upon parasitoids within Homoptera, and some are primary endoparasitoids of moth eggs. Species in these groups are termed DIPHAGOUS PARASITOIDS, HETERONOMOUS HYPERPARASITOIDS and HETEROTROPHIC PARASITOIDS, respectively. The selective advantages proposed to explain the evolution of these unusual host relationships are examined in this thesis. The biology of a diphagous parasitoid was examined in detail because diphagous parasitism is considered the most primitive of heteronomous host relationships. Diphagous parasitism is thought to have evolved during a period when ovipositing females continuously encountered large proportions of parasitised hosts. Larval competition may have generated the selection pressures that favoured male ectoparasitism. Ectoparasitoids are known to be superior in competition against other larvae, even older ones. A series of observations was carried out on the diphagous parasitoid, Coccophagus bartletti. Information was gathered on oviposition and host-feeding behaviour, daily activity patterns, and sex ratios in the laboratory and field. This enabled the design and interpretation of a series of observations on the responses of mated C. bartletti females to already-parasitised hosts. The results indicate that competition from other parasitoids probably played no role in the evolution of diphagous host relationships. Heteronomous hyperparasitoids, thought to have evolved from diphagous parasitoids, appear to be strong competitors because their males kill other parasitoids. However, an alternative hypothesis to the competition one, and based on the present study, is presented. Implications for the generally-held view, that competition is important in moulding species' characters, are discussed.
- Full Text:
- Date Issued: 1984
- Authors: Walter, Grenville Hugh
- Date: 1984
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5620 , http://hdl.handle.net/10962/d1003746
- Description: Résumé: Heteronomous host relationships are unique to parasitoids in about 8 aphelinid genera. Males have host relationships quite distinct from those of their females. Females of ALL species are primary endoparasitoids of homopterous hosts. Males, on the other hand, may be either primary ectoparasitoids of the same host species as their conspecific females, or they may be hyperparasitic upon parasitoids within Homoptera, and some are primary endoparasitoids of moth eggs. Species in these groups are termed DIPHAGOUS PARASITOIDS, HETERONOMOUS HYPERPARASITOIDS and HETEROTROPHIC PARASITOIDS, respectively. The selective advantages proposed to explain the evolution of these unusual host relationships are examined in this thesis. The biology of a diphagous parasitoid was examined in detail because diphagous parasitism is considered the most primitive of heteronomous host relationships. Diphagous parasitism is thought to have evolved during a period when ovipositing females continuously encountered large proportions of parasitised hosts. Larval competition may have generated the selection pressures that favoured male ectoparasitism. Ectoparasitoids are known to be superior in competition against other larvae, even older ones. A series of observations was carried out on the diphagous parasitoid, Coccophagus bartletti. Information was gathered on oviposition and host-feeding behaviour, daily activity patterns, and sex ratios in the laboratory and field. This enabled the design and interpretation of a series of observations on the responses of mated C. bartletti females to already-parasitised hosts. The results indicate that competition from other parasitoids probably played no role in the evolution of diphagous host relationships. Heteronomous hyperparasitoids, thought to have evolved from diphagous parasitoids, appear to be strong competitors because their males kill other parasitoids. However, an alternative hypothesis to the competition one, and based on the present study, is presented. Implications for the generally-held view, that competition is important in moulding species' characters, are discussed.
- Full Text:
- Date Issued: 1984
The Hakea fruit weevil, Erytenna consputa Pascoe (Coleoptera: Curculionidae), and the biological control of Hakea sericea Schrader in South Africa
- Authors: Kluge, Robert Louis
- Date: 1984
- Subjects: Insects as biological pest control agents -- South Africa Biological pest control agents -- South Africa Beetles -- South Africa Curculionidae -- South Africa Weeds -- Biological control -- South Africa Pests -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5629 , http://hdl.handle.net/10962/d1004911
- Description: Hakea sericea is a shrub, introduced into South Africa from southern Australia, that is now invading the indigenous "fynbos" vegetation in the Cape mountains. Presently an area of 480 000 hectares is affected. One of the main factors contributing to the success of H. sericea as a weed is its copious seed production. The seeds are accumulated on the plant throughout its life-time. When the plant eventually dies, usually after a fire, the fruits dehisce and all the seeds are released within the space of a few days, resulting in seed densities of up to 7 500 seeds per m². Dense, impenetrable stands of H. sericea develop which suppress the indigenous vegetation. Apart from the labour intensive mechanical clearing of H. sericea, biological control appears to be the only other means of control. This study deals with the post-release evaluation of the effectiveness of the first successfully-established, biological control agent, the hakea fruit weevil, Erytenna consputa. Most of the damage is done by the larval stage of the weevil which attacks the young developing fruits, thereby reducing seed production.
- Full Text:
- Date Issued: 1984
- Authors: Kluge, Robert Louis
- Date: 1984
- Subjects: Insects as biological pest control agents -- South Africa Biological pest control agents -- South Africa Beetles -- South Africa Curculionidae -- South Africa Weeds -- Biological control -- South Africa Pests -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5629 , http://hdl.handle.net/10962/d1004911
- Description: Hakea sericea is a shrub, introduced into South Africa from southern Australia, that is now invading the indigenous "fynbos" vegetation in the Cape mountains. Presently an area of 480 000 hectares is affected. One of the main factors contributing to the success of H. sericea as a weed is its copious seed production. The seeds are accumulated on the plant throughout its life-time. When the plant eventually dies, usually after a fire, the fruits dehisce and all the seeds are released within the space of a few days, resulting in seed densities of up to 7 500 seeds per m². Dense, impenetrable stands of H. sericea develop which suppress the indigenous vegetation. Apart from the labour intensive mechanical clearing of H. sericea, biological control appears to be the only other means of control. This study deals with the post-release evaluation of the effectiveness of the first successfully-established, biological control agent, the hakea fruit weevil, Erytenna consputa. Most of the damage is done by the larval stage of the weevil which attacks the young developing fruits, thereby reducing seed production.
- Full Text:
- Date Issued: 1984
The petrology of the Merensky cyclic unit and associated rocks and their significance in the evolution of the Western Bushveld Complex
- Authors: Kruger, Floris Johan
- Date: 1984
- Subjects: Petrology -- Africa, Southern Petrofabric analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5006 , http://hdl.handle.net/10962/d1005636
- Description: A brief review of the various models proposed to account for the Bushveld Complex shows that there are two main hypotheses. These are the Multiple Intrusion hypothesis and the In Situ Crystallization hypothesis. The latter also allows for multiple additions to the crystallizing magma, and several variants involving the number of these inputs , their composition, volume and timing have been proposed. To facilitate description and investigation of the study section, the stratigraphic nomenclature of this part of the Rustenberg Layered Suite is revised and clarified. It is proposed that the boundary between the Critical Zone and Main Zone be placed at the base of the Merensky cyclic unit, and thus the whole of the Merensky and Bastard cyclic units are included in the Main Zone. Furthermore, the extremely confused terminology for smaller units within the Merensky and Bastard cyclic units is resolved by discarding the term Reef as a formal term and substituting lithological terms such as Merensky pegmatoid, Merensky pyroxenite, Bastard pyroxenite and Merensky mottled anorthosite etc. It is recommended that the term Reef be retained as an informal term to designate the mineralized horizon which may be mined, regardless of lithology. The term "pegmatoid" is restricted to stratiform or lensoid masses of coarse grained feldspathic pyroxenite or harzburgite which are part of the layered sequence. The transgressive vertical pipe-like, coarse-grained ultramafic "iron-rich bodies are termed "ultramafic pegmatites ". The main features of the Merensky and Bastard cyclic units are the regular chemical and mineralogical changes that occur with respect to stratigraphic height in these units. In the Merensky cyclic unit there is a smooth iron enrichment in the orthopyroxenes upward in the succession and a transition from pyroxenite at the base to mottled anorthosite at the top of the unit. The Bastard cyclic unit is broadly similar to the Merensky cyclic unit. A variety of textures and chemical features are in disequilibrium in some samples but not in others, and great complexity is evident wh en individual samples are studied in detail. The initial ⁸⁷Sr/⁸⁶Sr ratios of plagioclase separates and whole rocks from the study section show a distinct step-like increase in the Merensky cyclic unit to .70806 at the base of the, Merensky cyclic unit to .70806 at the base of the Bastard cyclic unit. In contrast , samples from below the Merensky cyclic unit have a constant initial Sr-isotopic ratio, as do the samples from the Bastard cyclic unit. These isotopic and chemical data, and available published geologic relationships suggest that a major new influx of basic magma occurred after the Footwall unit was deposited and that this mixed with the residual magma in the chamber and then precipitated the Merensky and Bastard cyclic units. The crystal settling theory as outlined by Wager and Brown (1968) fails to account for the chemical and stratigraphic variations observed in the study section. The theory of bottom crystallization, initially proposed by Jackson (1961), more adequately explains the features observed. Applying a model outlined by Irvine (1980a & b), it has been established from chemical data, that the Merensky cyclic unit crystallized from a magma layer with a thickness roughly equivalent to the average thickness of the cyclic unit itself (±10m). A similar exercise on the Bastard unit was not possible. The formation of the Footwall unit is still enigmatic. Infiltration metasomatism and sintering can modify the petrographic and chemical characteristics of rocks and minerals after deposition at the liquidus stage. During the solidification of the crystal mush a separate vapour phase may form in the crystal mush, which could move up through the crystal pile. This process may ultimately be responsible for the generation of potholes and pegmatoidal horizons, such as the Merensky pegmatoid. The upward increase in the initial ⁸⁷Sr/⁸⁶Sr ratio within the Merensky cyclic unit is strong evidence that infiltration metasomatism has played an important part in the generation of the Merensky cyclic unit. This process, coupled with fluid enrichment, may also result in the formation of pegmatoid layers. Sintering appears to have been a common process in the mottled anorthosites of the study section and may have severely reduced the amount of trapped interstitial liquid in these rocks.
- Full Text:
- Date Issued: 1984
- Authors: Kruger, Floris Johan
- Date: 1984
- Subjects: Petrology -- Africa, Southern Petrofabric analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5006 , http://hdl.handle.net/10962/d1005636
- Description: A brief review of the various models proposed to account for the Bushveld Complex shows that there are two main hypotheses. These are the Multiple Intrusion hypothesis and the In Situ Crystallization hypothesis. The latter also allows for multiple additions to the crystallizing magma, and several variants involving the number of these inputs , their composition, volume and timing have been proposed. To facilitate description and investigation of the study section, the stratigraphic nomenclature of this part of the Rustenberg Layered Suite is revised and clarified. It is proposed that the boundary between the Critical Zone and Main Zone be placed at the base of the Merensky cyclic unit, and thus the whole of the Merensky and Bastard cyclic units are included in the Main Zone. Furthermore, the extremely confused terminology for smaller units within the Merensky and Bastard cyclic units is resolved by discarding the term Reef as a formal term and substituting lithological terms such as Merensky pegmatoid, Merensky pyroxenite, Bastard pyroxenite and Merensky mottled anorthosite etc. It is recommended that the term Reef be retained as an informal term to designate the mineralized horizon which may be mined, regardless of lithology. The term "pegmatoid" is restricted to stratiform or lensoid masses of coarse grained feldspathic pyroxenite or harzburgite which are part of the layered sequence. The transgressive vertical pipe-like, coarse-grained ultramafic "iron-rich bodies are termed "ultramafic pegmatites ". The main features of the Merensky and Bastard cyclic units are the regular chemical and mineralogical changes that occur with respect to stratigraphic height in these units. In the Merensky cyclic unit there is a smooth iron enrichment in the orthopyroxenes upward in the succession and a transition from pyroxenite at the base to mottled anorthosite at the top of the unit. The Bastard cyclic unit is broadly similar to the Merensky cyclic unit. A variety of textures and chemical features are in disequilibrium in some samples but not in others, and great complexity is evident wh en individual samples are studied in detail. The initial ⁸⁷Sr/⁸⁶Sr ratios of plagioclase separates and whole rocks from the study section show a distinct step-like increase in the Merensky cyclic unit to .70806 at the base of the, Merensky cyclic unit to .70806 at the base of the Bastard cyclic unit. In contrast , samples from below the Merensky cyclic unit have a constant initial Sr-isotopic ratio, as do the samples from the Bastard cyclic unit. These isotopic and chemical data, and available published geologic relationships suggest that a major new influx of basic magma occurred after the Footwall unit was deposited and that this mixed with the residual magma in the chamber and then precipitated the Merensky and Bastard cyclic units. The crystal settling theory as outlined by Wager and Brown (1968) fails to account for the chemical and stratigraphic variations observed in the study section. The theory of bottom crystallization, initially proposed by Jackson (1961), more adequately explains the features observed. Applying a model outlined by Irvine (1980a & b), it has been established from chemical data, that the Merensky cyclic unit crystallized from a magma layer with a thickness roughly equivalent to the average thickness of the cyclic unit itself (±10m). A similar exercise on the Bastard unit was not possible. The formation of the Footwall unit is still enigmatic. Infiltration metasomatism and sintering can modify the petrographic and chemical characteristics of rocks and minerals after deposition at the liquidus stage. During the solidification of the crystal mush a separate vapour phase may form in the crystal mush, which could move up through the crystal pile. This process may ultimately be responsible for the generation of potholes and pegmatoidal horizons, such as the Merensky pegmatoid. The upward increase in the initial ⁸⁷Sr/⁸⁶Sr ratio within the Merensky cyclic unit is strong evidence that infiltration metasomatism has played an important part in the generation of the Merensky cyclic unit. This process, coupled with fluid enrichment, may also result in the formation of pegmatoid layers. Sintering appears to have been a common process in the mottled anorthosites of the study section and may have severely reduced the amount of trapped interstitial liquid in these rocks.
- 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
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