Teaching the principles of ecology in the urban environment: an investigation into the development of resource materials
- Authors: Wagiet, Mogamat Fadli
- Date: 1996
- Subjects: Environmental education -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1799 , http://hdl.handle.net/10962/d1003684
- Description: The combined potential of two crucial factors in 1993, which afforded the promotion of socially just and ecologically sustainable ways of living, led to the instigation of this research project. The first was the imminence og our first democratic election; the second was the possible introduction of environmental education into formal education. In the light of these momentous shifts, it became apparent to me that teachers would have to radically transform their practices in order to play their part in transforming society from the dark days of apartheid into one of equity and harmony. The implications of these factors precipitated the falling into place of the rationale for my research: teachers had to look for professional development experiences which could facilitate the creation of alternative ways of thinking and doing. As a result, I approached a group of biology and geography teachers on the Cape Flats and, after protracted discussions, we decided to examine the potential of the urban environment for the teaching of ecology from the perspective of socially just and environmentally sustainable living. Out of this decision was born this study, which aimed at examining whether this process could, as a means to professional development, be a 'moment' in our journey to becoming transformative intellectuals. From this aim, the central research question emerged: Can emancipatory action research play a role in empowering teachers to become transformative intellectuals? The study consisted of five stages: - exploring the problem by reviewing the literature on the research problem; - the semi-structured interviews; - five workshops; - the 'sensing the urban environment' fieldtrip; and, - the various evaluation sessions. What we achieved during this research project, firstly, was a better understanding of our practices, which led us to seeing our roles as teachers differently and altered our pedagogical approaches. Secondly, this process developed the belief within ourselves that we, as teachers, can and should make a difference to the educational world in which we live. Lastly, this process laid the foundation for continued collaborative action by the participants. This process taught us that educational transformation is difficult and painful, and that present educational structures are not conducive to change. Nonetheless, in the historical context of this research, emancipatory action research was successful in giving us a consciousness-raising experience and closed the rhetoric-reality gap as we engaged in praxis (the practitioners developing and implementing their own curriculum). If we, as transformative intellectuals, are to engage in intellectual labour in the future, we are not only going to need to change our way of thinking and doing but will have to create an enabling infrastructure to realise this as well. We will, in addition, have to change the structures of the institutions in which we work in order to practise as transformative intellectuals.
- Full Text:
- Date Issued: 1996
- Authors: Wagiet, Mogamat Fadli
- Date: 1996
- Subjects: Environmental education -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1799 , http://hdl.handle.net/10962/d1003684
- Description: The combined potential of two crucial factors in 1993, which afforded the promotion of socially just and ecologically sustainable ways of living, led to the instigation of this research project. The first was the imminence og our first democratic election; the second was the possible introduction of environmental education into formal education. In the light of these momentous shifts, it became apparent to me that teachers would have to radically transform their practices in order to play their part in transforming society from the dark days of apartheid into one of equity and harmony. The implications of these factors precipitated the falling into place of the rationale for my research: teachers had to look for professional development experiences which could facilitate the creation of alternative ways of thinking and doing. As a result, I approached a group of biology and geography teachers on the Cape Flats and, after protracted discussions, we decided to examine the potential of the urban environment for the teaching of ecology from the perspective of socially just and environmentally sustainable living. Out of this decision was born this study, which aimed at examining whether this process could, as a means to professional development, be a 'moment' in our journey to becoming transformative intellectuals. From this aim, the central research question emerged: Can emancipatory action research play a role in empowering teachers to become transformative intellectuals? The study consisted of five stages: - exploring the problem by reviewing the literature on the research problem; - the semi-structured interviews; - five workshops; - the 'sensing the urban environment' fieldtrip; and, - the various evaluation sessions. What we achieved during this research project, firstly, was a better understanding of our practices, which led us to seeing our roles as teachers differently and altered our pedagogical approaches. Secondly, this process developed the belief within ourselves that we, as teachers, can and should make a difference to the educational world in which we live. Lastly, this process laid the foundation for continued collaborative action by the participants. This process taught us that educational transformation is difficult and painful, and that present educational structures are not conducive to change. Nonetheless, in the historical context of this research, emancipatory action research was successful in giving us a consciousness-raising experience and closed the rhetoric-reality gap as we engaged in praxis (the practitioners developing and implementing their own curriculum). If we, as transformative intellectuals, are to engage in intellectual labour in the future, we are not only going to need to change our way of thinking and doing but will have to create an enabling infrastructure to realise this as well. We will, in addition, have to change the structures of the institutions in which we work in order to practise as transformative intellectuals.
- Full Text:
- Date Issued: 1996
Technologies of the self in the writings of William S Burroughs
- Authors: Williams, Michael John
- Date: 1996
- Subjects: Burroughs, William S., 1914- -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2225 , http://hdl.handle.net/10962/d1002268 , Burroughs, William S., 1914- -- Criticism and interpretation
- Description: William Burroughs's profane life has been an affront to conventional morality, and his transgressive works have strained against the thematic and formal boundaries of literature. Although he has remained a problematic figure, he is gradually gaining recognition as a literary innovator. This thesis argues that his writings may be understood as technologies of the self, that is, the texts are tools that the writer Oses to transform himself. The Introduction outlines the problems that his writings pose for criticism; provides an overview of critical responses to his work; and demonstrates the appropriateness of Michel Foucault's theory of the technologies of the self as an approach to his texts. Furthermore, it makes a comparison between Burroughs's concerns and similar concerns evident in Foucault. The most prominent of these is a fear of control, and a desire to escape from control. It is argued that this similarity arises from the writers' shared experience of homosexuality in the twentieth century. This experience provokes them to undertake a·work of homographesis, in which they attempt to undermine the construction of identity in text, whilst simultaneously reinscribing identity in problematized autobiographical writing. Chapter One provides a corrective to the critical neglect of Burroughs's homosexuality and focuses on his sexual problematic as a key factor in the development of his literary style. It argues that the writer has an abject imagination that was precipitated by three principal traumatic experiences: his homosexuality, his addiction to opiates, and the accidental shooting of his wife. The chapter examines the way that the writer develops his unique literary style, the routine, in an attempt to express his psychic disintegration. The routine becomes the basic building block of Naked Lunch, serving both as a cathartic release of psychic anguish and as an attempt to subvert repressive social and linguistic structures. The metaphor of the anal aesthetic is introduced to describe the intersection of linguistic, psychic and political strategies in the texts. Chapter Two addresses the period,subsequent to Naked Lunch, in which Burroughs experimented extensively with the cut-up technique to develop a form of aleatory collage. The chapter argues that the writer hoped that the technique would enable him to transform himself and to~discover a new way of thinking, but suggests that its extreme nature both isolated him from his audience and intensified his psychic abjection. Chapter Three follows on from this to argue that the writer responds to the limitations of the cut-up in The Wild Boys by returning to a more intelligible form of writing. This return corresponds with an attempt to inscribe homosexual themes into his work directly. However, the combination of a homosexual agenda and the writer's defence against the identity loss of abjection leads him to assert a radical masculine identity that causes him to perceive women as the chief perpetrators of control. As a result, he rejects women from his mythological system. Chapter Four suggests that in Cities of the Red Night and The Place of Dead Roads the writer moves away from the radical queer agenda of The Wild Boys in the hope of discovering a form of ethics that avoids the traps of universalized humanism and the harsh "othering" of the queer agenda. The chapter draws a parallel between Burroughs's individualized ethics and Foucault's idea of an ethics grounded in aesthetic self-fashioning. Chapter Five examines The Western Lands, in which the writer confronts death in order to discover the nature of individual value in a normalized culture. Like Foucault, Burroughs believes that the most important task in a limited existence is the dandyistic creation of the self.
- Full Text:
- Date Issued: 1996
- Authors: Williams, Michael John
- Date: 1996
- Subjects: Burroughs, William S., 1914- -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2225 , http://hdl.handle.net/10962/d1002268 , Burroughs, William S., 1914- -- Criticism and interpretation
- Description: William Burroughs's profane life has been an affront to conventional morality, and his transgressive works have strained against the thematic and formal boundaries of literature. Although he has remained a problematic figure, he is gradually gaining recognition as a literary innovator. This thesis argues that his writings may be understood as technologies of the self, that is, the texts are tools that the writer Oses to transform himself. The Introduction outlines the problems that his writings pose for criticism; provides an overview of critical responses to his work; and demonstrates the appropriateness of Michel Foucault's theory of the technologies of the self as an approach to his texts. Furthermore, it makes a comparison between Burroughs's concerns and similar concerns evident in Foucault. The most prominent of these is a fear of control, and a desire to escape from control. It is argued that this similarity arises from the writers' shared experience of homosexuality in the twentieth century. This experience provokes them to undertake a·work of homographesis, in which they attempt to undermine the construction of identity in text, whilst simultaneously reinscribing identity in problematized autobiographical writing. Chapter One provides a corrective to the critical neglect of Burroughs's homosexuality and focuses on his sexual problematic as a key factor in the development of his literary style. It argues that the writer has an abject imagination that was precipitated by three principal traumatic experiences: his homosexuality, his addiction to opiates, and the accidental shooting of his wife. The chapter examines the way that the writer develops his unique literary style, the routine, in an attempt to express his psychic disintegration. The routine becomes the basic building block of Naked Lunch, serving both as a cathartic release of psychic anguish and as an attempt to subvert repressive social and linguistic structures. The metaphor of the anal aesthetic is introduced to describe the intersection of linguistic, psychic and political strategies in the texts. Chapter Two addresses the period,subsequent to Naked Lunch, in which Burroughs experimented extensively with the cut-up technique to develop a form of aleatory collage. The chapter argues that the writer hoped that the technique would enable him to transform himself and to~discover a new way of thinking, but suggests that its extreme nature both isolated him from his audience and intensified his psychic abjection. Chapter Three follows on from this to argue that the writer responds to the limitations of the cut-up in The Wild Boys by returning to a more intelligible form of writing. This return corresponds with an attempt to inscribe homosexual themes into his work directly. However, the combination of a homosexual agenda and the writer's defence against the identity loss of abjection leads him to assert a radical masculine identity that causes him to perceive women as the chief perpetrators of control. As a result, he rejects women from his mythological system. Chapter Four suggests that in Cities of the Red Night and The Place of Dead Roads the writer moves away from the radical queer agenda of The Wild Boys in the hope of discovering a form of ethics that avoids the traps of universalized humanism and the harsh "othering" of the queer agenda. The chapter draws a parallel between Burroughs's individualized ethics and Foucault's idea of an ethics grounded in aesthetic self-fashioning. Chapter Five examines The Western Lands, in which the writer confronts death in order to discover the nature of individual value in a normalized culture. Like Foucault, Burroughs believes that the most important task in a limited existence is the dandyistic creation of the self.
- Full Text:
- Date Issued: 1996
The alternative press in Namibia, 1960-1990
- Authors: Heuva, William Edward
- Date: 1996
- Subjects: Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3434 , http://hdl.handle.net/10962/d1002888 , Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Description: The study seeks to document the development of the alternative press in Namibia from 1960 to 1990. It traces the reasons for its emergence and outlines the stated aims and objectives in order to illustrate its attempts to nurture a culture - of colonial resistance. It is argued that structural factors such as funding, distribution, advertisements and ownership enabled the alternative press to operate outside the South African apartheid hegemony. The study explains how the intellectuals used the alternative press in their attempts to mobilise and organise colonised Namibians for social change. They did this by formulating and disseminating ideologically constructed discourses (messages) which challenged the colonial discourse. These messages were produced and directed towards a specific audience, the masses to whom the intellectuals were organically linked. Their primary news definers were also drawn from the ranks of these masses. It is further argued that the alternative press came to represent the colonised masses by voicing their needs and aspirations which were marginalised by the mainstream colonial media. Finally, a relatively detailed analysis of the content, the language used and the'messages carried by the alternative press has been made to demonstrate its political agenda, which was to empower the masses to achieve their objective - the attainment of political independence. These issues are analyzed against a background of theoretical frameworks which seek to explain how subordinated groups and classes in a state of domination sought to establish alternative channels of communication in the creation of a counter hegemonic order.
- Full Text:
- Date Issued: 1996
- Authors: Heuva, William Edward
- Date: 1996
- Subjects: Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3434 , http://hdl.handle.net/10962/d1002888 , Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Description: The study seeks to document the development of the alternative press in Namibia from 1960 to 1990. It traces the reasons for its emergence and outlines the stated aims and objectives in order to illustrate its attempts to nurture a culture - of colonial resistance. It is argued that structural factors such as funding, distribution, advertisements and ownership enabled the alternative press to operate outside the South African apartheid hegemony. The study explains how the intellectuals used the alternative press in their attempts to mobilise and organise colonised Namibians for social change. They did this by formulating and disseminating ideologically constructed discourses (messages) which challenged the colonial discourse. These messages were produced and directed towards a specific audience, the masses to whom the intellectuals were organically linked. Their primary news definers were also drawn from the ranks of these masses. It is further argued that the alternative press came to represent the colonised masses by voicing their needs and aspirations which were marginalised by the mainstream colonial media. Finally, a relatively detailed analysis of the content, the language used and the'messages carried by the alternative press has been made to demonstrate its political agenda, which was to empower the masses to achieve their objective - the attainment of political independence. These issues are analyzed against a background of theoretical frameworks which seek to explain how subordinated groups and classes in a state of domination sought to establish alternative channels of communication in the creation of a counter hegemonic order.
- Full Text:
- Date Issued: 1996
The annual cycle of wing‐moult and breeding in the Wattled Starling Creatophora cinerea
- Authors: Craig, Adrian J F K
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/465496 , vital:76614 , https://doi.org/10.1111/j.1474-919X.1996.tb08063.x
- Description: Moult, breeding and seasonal occurrence of the Wattled Starling Creatophora cinerea throughout its range in Africa are reviewed based on data from museum specimens and the published literature. Neither moult nor breeding follows a rigid seasonal pattern, although there are some regional differences, and overlap between moult and breeding is unlikely. The regular occurrence of interrupted wing‐moult may be associated with nomadic movements rather than opportunistic breeding.
- Full Text:
- Date Issued: 1996
- Authors: Craig, Adrian J F K
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/465496 , vital:76614 , https://doi.org/10.1111/j.1474-919X.1996.tb08063.x
- Description: Moult, breeding and seasonal occurrence of the Wattled Starling Creatophora cinerea throughout its range in Africa are reviewed based on data from museum specimens and the published literature. Neither moult nor breeding follows a rigid seasonal pattern, although there are some regional differences, and overlap between moult and breeding is unlikely. The regular occurrence of interrupted wing‐moult may be associated with nomadic movements rather than opportunistic breeding.
- Full Text:
- Date Issued: 1996
The Bender Gestalt Test: an investigation into problems concerning administration and scoring and its application to low-educated adults
- Authors: Dyall, Kate
- Date: 1996
- Subjects: Bender-Gestalt Test , Psychological tests , Brain-damaged children -- Psychological testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2968 , http://hdl.handle.net/10962/d1002477 , Bender-Gestalt Test , Psychological tests , Brain-damaged children -- Psychological testing
- Description: The study investigates .the use of the Bender Gestalt Test (BGT) amongst low-educated adults. Three versions of the BGT are used in this study; the original 'copy' version as well as the 'immediate' and 'delayed'recall versions. This is done so as to expand the ability of the BGT to identify neurological impairment and to differentiate between this and functional impairment. A literature review explores the problems of standardization in the administration, scoring and application of all three versions of the test Suggestions are made to correct the problems identified and a novel system of scoring the recall versions are proposed, which allows for the comparison of results of the three versions of the test and which is based on Lacks's (1984) and Weiss's (1970) systems. Administration procedures were also developed to suit the context of the study. The copy, immediate and delayed versions of the BGT were administered to a group of 184 low-educated adults. Statistical analyses revealed significant education effects for the sample tested with regards to both test scores and performance time. The finding of an education effect for performance time is discussed at length, as some literature regards excessive time as a neurological indicator. An anomaly for the group with no education was found to exist, with the scores of these subjects not Significantly different from those with 4-6 years of education. Possible reasons for this were explored. In addition, the findings of this research revealed a plateau effect with those having less than 6 years of education scoring substantially lower than those with 7 years and more. The scores of adults with 7 and more years of education level out with no significant differences between educational levels. This appears to suggest that education effects rather than the developmental maturity level proposed by Koppitz, are involved. In addition, the scores of low-educated adults on the expanded Bender Gestalt Test were significantly lower than those of children with similar educational levels, in other studies. These findings and possible explanations are discussed. The study concludes by suggesting new research areas and emphasizing the urgent need for separate normative data on the expanded BGT for low-educated adults, and the establishment of appropriate 'cut-off' points.
- Full Text:
- Date Issued: 1996
- Authors: Dyall, Kate
- Date: 1996
- Subjects: Bender-Gestalt Test , Psychological tests , Brain-damaged children -- Psychological testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2968 , http://hdl.handle.net/10962/d1002477 , Bender-Gestalt Test , Psychological tests , Brain-damaged children -- Psychological testing
- Description: The study investigates .the use of the Bender Gestalt Test (BGT) amongst low-educated adults. Three versions of the BGT are used in this study; the original 'copy' version as well as the 'immediate' and 'delayed'recall versions. This is done so as to expand the ability of the BGT to identify neurological impairment and to differentiate between this and functional impairment. A literature review explores the problems of standardization in the administration, scoring and application of all three versions of the test Suggestions are made to correct the problems identified and a novel system of scoring the recall versions are proposed, which allows for the comparison of results of the three versions of the test and which is based on Lacks's (1984) and Weiss's (1970) systems. Administration procedures were also developed to suit the context of the study. The copy, immediate and delayed versions of the BGT were administered to a group of 184 low-educated adults. Statistical analyses revealed significant education effects for the sample tested with regards to both test scores and performance time. The finding of an education effect for performance time is discussed at length, as some literature regards excessive time as a neurological indicator. An anomaly for the group with no education was found to exist, with the scores of these subjects not Significantly different from those with 4-6 years of education. Possible reasons for this were explored. In addition, the findings of this research revealed a plateau effect with those having less than 6 years of education scoring substantially lower than those with 7 years and more. The scores of adults with 7 and more years of education level out with no significant differences between educational levels. This appears to suggest that education effects rather than the developmental maturity level proposed by Koppitz, are involved. In addition, the scores of low-educated adults on the expanded Bender Gestalt Test were significantly lower than those of children with similar educational levels, in other studies. These findings and possible explanations are discussed. The study concludes by suggesting new research areas and emphasizing the urgent need for separate normative data on the expanded BGT for low-educated adults, and the establishment of appropriate 'cut-off' points.
- Full Text:
- Date Issued: 1996
The development of an ecological model to determine flood release options for the management of the Phongolo floodplain in Kwazulu/Natal (South Africa)
- Authors: Weldrick, Sarah Katharine
- Date: 1996
- Subjects: Flood control -- Environmental aspects -- South Africa -- KwaZulu-Natal -- Pongolo floodplain , Fishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5258 , http://hdl.handle.net/10962/d1005102 , Flood control -- Environmental aspects -- South Africa -- KwaZulu-Natal -- Pongolo floodplain , Fishes -- Behavior
- Description: The Phongolo River floodplain in KwaZulu/Natal is a river-associated wetland which was subject to regular cycles of flooding in the past. The floods were associated with seasonal summer rainfall. Through the wet and dry cycles on the floodplain there was an alternation between the aquatic and terrestrial biomes. Many of the fishes on the floodplain are dependent on this cycle for their survival. The construction of the Pongolapoort Dam in 1969 has resulted in alterations to the timing, magnitudes and duration of the natural flooding events of the Phongolo River. This alteration has affected the fisheries. It is now necessary to simulate natural floods by artificial water releases from the dam. There are several demands on the water supply, so it has not always been possible to adhere to the natural flood regime. This necessitated the need for an integrated management programme to ensure the sustainability of the natural resources. A practical ecological model of the fishery was developed to determine an optimum flood release scenario for the floodplain. The relative abundances, distribution and species richness of the fishes were determined at various lakes and rivers on the floodplain. A community classification of the fishes was determined using TWINSPAN ordination. The potential yield of the fish at each site was calculated. Flood releases of varying magnitudes were simulated using Geographic Information Systems (GIS). This information was combined in a model which can be used by resource managers to estimate the percentage species compositions of fishes at each of the lakes, and to compare the actual harvest to the potential calculated sustainable yields of fishes for various flood release regimes. Subsistence agriculture and other beneficial ecological information can be incorporated into the model to determine the effect of different flood release options for the Phongolo floodplain.
- Full Text:
- Date Issued: 1996
- Authors: Weldrick, Sarah Katharine
- Date: 1996
- Subjects: Flood control -- Environmental aspects -- South Africa -- KwaZulu-Natal -- Pongolo floodplain , Fishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5258 , http://hdl.handle.net/10962/d1005102 , Flood control -- Environmental aspects -- South Africa -- KwaZulu-Natal -- Pongolo floodplain , Fishes -- Behavior
- Description: The Phongolo River floodplain in KwaZulu/Natal is a river-associated wetland which was subject to regular cycles of flooding in the past. The floods were associated with seasonal summer rainfall. Through the wet and dry cycles on the floodplain there was an alternation between the aquatic and terrestrial biomes. Many of the fishes on the floodplain are dependent on this cycle for their survival. The construction of the Pongolapoort Dam in 1969 has resulted in alterations to the timing, magnitudes and duration of the natural flooding events of the Phongolo River. This alteration has affected the fisheries. It is now necessary to simulate natural floods by artificial water releases from the dam. There are several demands on the water supply, so it has not always been possible to adhere to the natural flood regime. This necessitated the need for an integrated management programme to ensure the sustainability of the natural resources. A practical ecological model of the fishery was developed to determine an optimum flood release scenario for the floodplain. The relative abundances, distribution and species richness of the fishes were determined at various lakes and rivers on the floodplain. A community classification of the fishes was determined using TWINSPAN ordination. The potential yield of the fish at each site was calculated. Flood releases of varying magnitudes were simulated using Geographic Information Systems (GIS). This information was combined in a model which can be used by resource managers to estimate the percentage species compositions of fishes at each of the lakes, and to compare the actual harvest to the potential calculated sustainable yields of fishes for various flood release regimes. Subsistence agriculture and other beneficial ecological information can be incorporated into the model to determine the effect of different flood release options for the Phongolo floodplain.
- Full Text:
- Date Issued: 1996
The development of the hydraulic biotope concept within a catchment based hierarchical geomorphological model
- Authors: Wadeson, R A (Roy A)
- Date: 1996
- Subjects: Stream ecology -- South Africa Stream measurements -- South Africa Hydrology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4826 , http://hdl.handle.net/10962/d1005501
- Description: This thesis develops a technique for the identification, classification and quantification of instream flow environments. These features have been traditionally referred to as 'habitats' by lotic ecologists, in this research they are termed 'hydraulic biotopes'. The hydraulic biotope is the lowest of six nested levels of a hierarchical geomorphological model. This model has been developed as a tool to assist river managers, researchers and conservationists to categorise or classify rivers with respect to their geomorphic characteristics. Each level of the model provides data at a different level of resolution. This ranges from the broad scale catchment data to the site specific 'habitat' or hydraulic biotope data. Although this thesis is primarily concerned with the development of the hydraulic biotope, the interaction of all catchment variables needs to be recognised. Detailed analysis of hydraulic biotope data in the Buffalo River are presented within the broader hierarchical model. Consultation with lotic ecologists, together with a review of ecological literature, emphasised the need for a standardised terminology for the classification of ecologically significant instream flow environments. At present a fairly haphazard 'habitat' classification tends to be carried out by most researchers, this often leads to confusion in the identification and naming of different hydraulic biotopes ('habitats'). This confusion is exaggerated by the sharing of terminology between lotic ecology and fluvial geomorphology, usually for the categorisation of different types of features. A review of the ecological literature emphasises the importance of flow hydraulics within a river to describe the distribution of biota. The hydraulic variables considered to be most significant include velocity and depth. As river morphology directly determines the prevailing distribution of depth, velocity and substratum, it is obvious that there are important links to be made between fluvial geomorphology and lotic ecology. This thesis explores the potential of the hydraulic biotope as a tool to help develop those links. This thesis presents a standardised classification matrix for the identification of hydraulic biotopes. The matrix is simply based on water surface characteristics together with channel bed substratum. The validity of this matrix is tested by statistical analysis of hydraulic variables quantifying flow conditions within the various hydraulic biotope classes. Data is presented from four different river systems, each representing a different sedimentological environment. Where possible the influence of discharge has been considered. Results from more than 3000 data points show that hydraulic biotopes have distinct hydraulic characteristics in terms of velocity-depth ratio, Froude number, Reynolds number, 'roughness' Reynolds number and shear velocity. These hydraulic indices represent flow conditions both as an average within the water column, and near the bed. Statistical analysis shows that the hydraulic characteristics of the various hydraulic biotope classes are relatively consistent both within different fluvial environments and at different stages of flow. Unlike the morphological unit in which the hydraulic biotope is nested, in stream flow environments are shown to be temporally dynamic. Using the classification matrix as a tool for identification, hydraulic biotopes identified at one discharge are shown to be transformed from one class to another as a response to change in stage. The pattern of transformation is shown to be consistent within different sedimentological environments. An examination of the associations between hydraulic biotopes and morphological units demonstrates that, although some hydraulic biotopes are common to all morphological units (backwater pools, pools and runs), some features have specific associations. In this study rapids were found to be prevalent in bedrock pavement, bedrock pool and plane bed morphology, while cascades, chutes and riffles were common to plane bed, step and riffle morphology. Results from this research indicate that the hydraulic biotope, within the hierarchical geomorphological model, has the potential to aid the prediction of channel adjustment and associated 'habitat' (hydraulic biotope) transformation in response to changes in flow and sediment yield. These are likely to become increasingly important issues as South Africa strives to maintain a balance between the development of water resources to meet the needs of the rapidly expanding population, whilst at the same time maintaining the fluvial environment for sustainable use.
- Full Text:
- Date Issued: 1996
- Authors: Wadeson, R A (Roy A)
- Date: 1996
- Subjects: Stream ecology -- South Africa Stream measurements -- South Africa Hydrology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4826 , http://hdl.handle.net/10962/d1005501
- Description: This thesis develops a technique for the identification, classification and quantification of instream flow environments. These features have been traditionally referred to as 'habitats' by lotic ecologists, in this research they are termed 'hydraulic biotopes'. The hydraulic biotope is the lowest of six nested levels of a hierarchical geomorphological model. This model has been developed as a tool to assist river managers, researchers and conservationists to categorise or classify rivers with respect to their geomorphic characteristics. Each level of the model provides data at a different level of resolution. This ranges from the broad scale catchment data to the site specific 'habitat' or hydraulic biotope data. Although this thesis is primarily concerned with the development of the hydraulic biotope, the interaction of all catchment variables needs to be recognised. Detailed analysis of hydraulic biotope data in the Buffalo River are presented within the broader hierarchical model. Consultation with lotic ecologists, together with a review of ecological literature, emphasised the need for a standardised terminology for the classification of ecologically significant instream flow environments. At present a fairly haphazard 'habitat' classification tends to be carried out by most researchers, this often leads to confusion in the identification and naming of different hydraulic biotopes ('habitats'). This confusion is exaggerated by the sharing of terminology between lotic ecology and fluvial geomorphology, usually for the categorisation of different types of features. A review of the ecological literature emphasises the importance of flow hydraulics within a river to describe the distribution of biota. The hydraulic variables considered to be most significant include velocity and depth. As river morphology directly determines the prevailing distribution of depth, velocity and substratum, it is obvious that there are important links to be made between fluvial geomorphology and lotic ecology. This thesis explores the potential of the hydraulic biotope as a tool to help develop those links. This thesis presents a standardised classification matrix for the identification of hydraulic biotopes. The matrix is simply based on water surface characteristics together with channel bed substratum. The validity of this matrix is tested by statistical analysis of hydraulic variables quantifying flow conditions within the various hydraulic biotope classes. Data is presented from four different river systems, each representing a different sedimentological environment. Where possible the influence of discharge has been considered. Results from more than 3000 data points show that hydraulic biotopes have distinct hydraulic characteristics in terms of velocity-depth ratio, Froude number, Reynolds number, 'roughness' Reynolds number and shear velocity. These hydraulic indices represent flow conditions both as an average within the water column, and near the bed. Statistical analysis shows that the hydraulic characteristics of the various hydraulic biotope classes are relatively consistent both within different fluvial environments and at different stages of flow. Unlike the morphological unit in which the hydraulic biotope is nested, in stream flow environments are shown to be temporally dynamic. Using the classification matrix as a tool for identification, hydraulic biotopes identified at one discharge are shown to be transformed from one class to another as a response to change in stage. The pattern of transformation is shown to be consistent within different sedimentological environments. An examination of the associations between hydraulic biotopes and morphological units demonstrates that, although some hydraulic biotopes are common to all morphological units (backwater pools, pools and runs), some features have specific associations. In this study rapids were found to be prevalent in bedrock pavement, bedrock pool and plane bed morphology, while cascades, chutes and riffles were common to plane bed, step and riffle morphology. Results from this research indicate that the hydraulic biotope, within the hierarchical geomorphological model, has the potential to aid the prediction of channel adjustment and associated 'habitat' (hydraulic biotope) transformation in response to changes in flow and sediment yield. These are likely to become increasingly important issues as South Africa strives to maintain a balance between the development of water resources to meet the needs of the rapidly expanding population, whilst at the same time maintaining the fluvial environment for sustainable use.
- Full Text:
- Date Issued: 1996
The dynamics of space use in some Lake Malawi fishes
- Authors: Robinson, Rosanna Lesley
- Date: 1996
- Subjects: Cichlids -- Nyasa, Lake Fishes -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5264 , http://hdl.handle.net/10962/d1005108
- Description: Behaviour and space utilisation of rock-dwelling cichlids were observed at Thumbi East Island, Lake Malawi. 1. Males of five species of the mbuna complex held long-term territories. Pseudotropheus elongatus "aggressive" vigorously defended a feeding area and sometimes a spawning site interspecifically, but did not feed in the peripheral part of their territory. Spawning sites of Pseudotropheus zebra, Pseudotropheus tropheops "orange chest", Labeotropheus fuelleborni, and Petrotilapia nigra were interspecifically-defended, while larger mating territories were defended against conspecific neighbours. Feeding areas were shared with many fish and often extended beyond the defended area. There was considerable variation in behaviour and space use within and between species and between times of day. 2. Non-territorial P. zebra used larger ranges than territorial conspecifics, and fed more on plankton, but individuals had preferred benthic feeding areas, often in conspecific territories. These 'floaters' were often aggressive. Both size and relative brightness independently predicted the outcome of aggressive interactions between floaters, and a site-specific dominance hierarchy was suggested, with some individuals appearing to be semi-territorial. 3. Males and females of 21 and 13 species respectively were found to establish temporary breeding territories. Overall breeding seasonality was bimodal, but reproductive timing and territory characteristics differed among species. Temporary territories had a considerable impact on the behaviour and habitat use of all resident mbuna species, even causing abandonment of territories. 4. Non-breeding Protomelas taeniolatus had limited home ranges, and showed little aggression. During the highly-synchronised reproductive season, males defended spawning sites and females fry-guarding territories. Most chases were directed towards the commonest fish, but predators were chased further and faster. Female behaviour changed over the guarding period. Females generally continued territorial defence after the brood had disappeared. Most broods contained fry of different sizes and species. Significant benefits were found for guarding females with clustered territories, but females did not appear to choose sites adjacent to conspecific parental females. 5. Territoriality in fish is taxonomically widespread and may serve several functions according to species, sex and developmental stage. It also varies according to genotype- and phenotype-limited strategies and short term costs and benefits. Territories may be simultaneously multifunctional.
- Full Text:
- Date Issued: 1996
- Authors: Robinson, Rosanna Lesley
- Date: 1996
- Subjects: Cichlids -- Nyasa, Lake Fishes -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5264 , http://hdl.handle.net/10962/d1005108
- Description: Behaviour and space utilisation of rock-dwelling cichlids were observed at Thumbi East Island, Lake Malawi. 1. Males of five species of the mbuna complex held long-term territories. Pseudotropheus elongatus "aggressive" vigorously defended a feeding area and sometimes a spawning site interspecifically, but did not feed in the peripheral part of their territory. Spawning sites of Pseudotropheus zebra, Pseudotropheus tropheops "orange chest", Labeotropheus fuelleborni, and Petrotilapia nigra were interspecifically-defended, while larger mating territories were defended against conspecific neighbours. Feeding areas were shared with many fish and often extended beyond the defended area. There was considerable variation in behaviour and space use within and between species and between times of day. 2. Non-territorial P. zebra used larger ranges than territorial conspecifics, and fed more on plankton, but individuals had preferred benthic feeding areas, often in conspecific territories. These 'floaters' were often aggressive. Both size and relative brightness independently predicted the outcome of aggressive interactions between floaters, and a site-specific dominance hierarchy was suggested, with some individuals appearing to be semi-territorial. 3. Males and females of 21 and 13 species respectively were found to establish temporary breeding territories. Overall breeding seasonality was bimodal, but reproductive timing and territory characteristics differed among species. Temporary territories had a considerable impact on the behaviour and habitat use of all resident mbuna species, even causing abandonment of territories. 4. Non-breeding Protomelas taeniolatus had limited home ranges, and showed little aggression. During the highly-synchronised reproductive season, males defended spawning sites and females fry-guarding territories. Most chases were directed towards the commonest fish, but predators were chased further and faster. Female behaviour changed over the guarding period. Females generally continued territorial defence after the brood had disappeared. Most broods contained fry of different sizes and species. Significant benefits were found for guarding females with clustered territories, but females did not appear to choose sites adjacent to conspecific parental females. 5. Territoriality in fish is taxonomically widespread and may serve several functions according to species, sex and developmental stage. It also varies according to genotype- and phenotype-limited strategies and short term costs and benefits. Territories may be simultaneously multifunctional.
- Full Text:
- Date Issued: 1996
The Faire Queene who liked blacks
- Authors: Butler, Guy F
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457753 , vital:75676 , https://hdl.handle.net/10520/AJA1011582X_91
- Description: Anne of Denmark (1574-1619), wife ofJames VI of Scotland and I of England, needs to be rescued from undeserved neglect. The literature about her husband, the Scottish Solomon, is extensive, I as is that about her younger son, King Charles 1; 2 her eldest son, the heroic Henry, who died young,(and with it, it seems, the English Renaissance) has been recently studied and psychoanalysed; 3 and her daughter Elizabeth, who married the Elector Palatine, has attracted much sympa-thetic biography as the Winter Queen or the Queen of Hearts 4 The on-ly recent biography of Anne, Ethel Carlton Williams's Anne of Denmark (1970), does little to modify the almost unanimous verdict that she was" a dumb blonde,"(Ashley 116) whose" innate frivolity"(Stephen 431) was in some respects proof against the influences of the fair education which her parents provided for their children. According to the Diction-ary of National Biography," in the midst of her mostly frivolous existence she would seem to have cherished a desire if not to have possessed a capacity for higher things"(Stephen 441). I find it difficult to reconcile this vacuous figure with the woman who endured an appalling marriage with her homosexual husband; who, though a Lutheran by upbringing, rebelled against the rigours of the Scots Kirk, and became a Catholic; who had the personal confidence, within three months of arriving in England, to star as Juno in a court masque 6 with her ladies in waiting; who on Twelfth Night, 1605, appeared with them, all blackface, in The Masque of Blackness 7-a revolutionary work which critics agree marks a new beginning in the history of the English theatre.
- Full Text:
- Date Issued: 1996
- Authors: Butler, Guy F
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457753 , vital:75676 , https://hdl.handle.net/10520/AJA1011582X_91
- Description: Anne of Denmark (1574-1619), wife ofJames VI of Scotland and I of England, needs to be rescued from undeserved neglect. The literature about her husband, the Scottish Solomon, is extensive, I as is that about her younger son, King Charles 1; 2 her eldest son, the heroic Henry, who died young,(and with it, it seems, the English Renaissance) has been recently studied and psychoanalysed; 3 and her daughter Elizabeth, who married the Elector Palatine, has attracted much sympa-thetic biography as the Winter Queen or the Queen of Hearts 4 The on-ly recent biography of Anne, Ethel Carlton Williams's Anne of Denmark (1970), does little to modify the almost unanimous verdict that she was" a dumb blonde,"(Ashley 116) whose" innate frivolity"(Stephen 431) was in some respects proof against the influences of the fair education which her parents provided for their children. According to the Diction-ary of National Biography," in the midst of her mostly frivolous existence she would seem to have cherished a desire if not to have possessed a capacity for higher things"(Stephen 441). I find it difficult to reconcile this vacuous figure with the woman who endured an appalling marriage with her homosexual husband; who, though a Lutheran by upbringing, rebelled against the rigours of the Scots Kirk, and became a Catholic; who had the personal confidence, within three months of arriving in England, to star as Juno in a court masque 6 with her ladies in waiting; who on Twelfth Night, 1605, appeared with them, all blackface, in The Masque of Blackness 7-a revolutionary work which critics agree marks a new beginning in the history of the English theatre.
- Full Text:
- Date Issued: 1996
The future role of TGWU in relation to Bus Transport in a changing environment
- TGWU
- Authors: TGWU
- Date: 1996
- Subjects: TGWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/111258 , vital:33425
- Description: One will assume that the topic chosen for me to present a paper on,is no the one which looks on organisational and analytic development of TGWU. I will therefore focus on TGWU 's perspective on the current bus crisis future perspective and TGWU organisational role in the bus industry I felt it important to outline a brief background and our perspective cm the industry and how that dictates our attitude towards the industry. This paper is divided along the following sections;- Use of transport in internal economic and labour control. Contradictions and conflicts over transport policy. The future and its implications for Transport policy after apartheid. TGWU's organisational role and influence in the industry.
- Full Text:
- Date Issued: 1996
- Authors: TGWU
- Date: 1996
- Subjects: TGWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/111258 , vital:33425
- Description: One will assume that the topic chosen for me to present a paper on,is no the one which looks on organisational and analytic development of TGWU. I will therefore focus on TGWU 's perspective on the current bus crisis future perspective and TGWU organisational role in the bus industry I felt it important to outline a brief background and our perspective cm the industry and how that dictates our attitude towards the industry. This paper is divided along the following sections;- Use of transport in internal economic and labour control. Contradictions and conflicts over transport policy. The future and its implications for Transport policy after apartheid. TGWU's organisational role and influence in the industry.
- Full Text:
- Date Issued: 1996
The geology of the Unki platinum-base metal deposit, Selukwe subchamber, great dyke, Zimbabwe
- Authors: Murahwi, Charley Zvinaiye
- Date: 1996
- Subjects: Platinum ores -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4962 , http://hdl.handle.net/10962/d1005574 , Platinum ores -- Zimbabwe
- Description: This thesis focuses on platinu'm group element (PGE) mineralization in the Unki Section of the Selukwe Subchamber of the Great Dyke (Zimbabwe), and is based on drill hole intersections and underground and surface exposures of the Main Sulphide Zone (MSZ) which hosts significant concentrations of PGE. The petrological and geochemical data presented are part of a broader study currently underway and the present are restricted to the 2m section of the PGE-rich MSZ encountered in drill hole MR126. The PGE-rich MSZ at Unki is unique in having a shear, locally referred to as the Footwall Shear, developed at or close to its base . It is however, similar to the other PGE occurrences on the Great Dyke (MSZ) in having its hanging-wall restricted to within 1m of the websterite/bronzitite contact. Slight axial tilting to t he west is indicated by steeper dips on the eastern flank. The sulphide concentration wit hin the MSZ can be used as a rough guide to the PGE-rich zone, but is not sufficiently precise to be used in stope control. The visual identification of the potentially mineable zone remains a problem that is unlikely to be solved. Based on petrological evidence, the bulk of the sulphides with which the PGE are associated, are cumulus in status. This provides unequivocal evidence for an orthomagmatic origin of the MSZ. The dominant platinum group mineral (PGM) phase is the Arsenide/Sperrylite group which is most commonly found at the contact zones between base metal sulphides (BMS) and gangue. The PGM range up to 90 ~m in length. Geochemical evidence from the analyses of cumulate orthopyroxenes through the 2m PGE-rich MSZ interval at Unki reveals a trend of arked Fe enrichment upwards which corresponds to an enrichment in sulphide. This indicates that precipitation of sulphide was caused by fractionation with lowering of temperature in the magma. The Fe enrichment is followed by a reversal in Mg# of orthopyroxene which corresponds to the decrease in sulphide content, suggest i ng that the termination of the PGE-rich MSZ was due to an increase in temperature associated with an influx of new magma. Coupled with these magmatic events are a complex interplay of chemical and physical processes occurring at a critical stage in the overall fractionation of the Great Dyke magma chamber. The overall persistence and continuity of t he PGE zone as observed in the Unki area is consistent with the inferred orthomagmatic origin of the mineralization
- Full Text:
- Date Issued: 1996
- Authors: Murahwi, Charley Zvinaiye
- Date: 1996
- Subjects: Platinum ores -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4962 , http://hdl.handle.net/10962/d1005574 , Platinum ores -- Zimbabwe
- Description: This thesis focuses on platinu'm group element (PGE) mineralization in the Unki Section of the Selukwe Subchamber of the Great Dyke (Zimbabwe), and is based on drill hole intersections and underground and surface exposures of the Main Sulphide Zone (MSZ) which hosts significant concentrations of PGE. The petrological and geochemical data presented are part of a broader study currently underway and the present are restricted to the 2m section of the PGE-rich MSZ encountered in drill hole MR126. The PGE-rich MSZ at Unki is unique in having a shear, locally referred to as the Footwall Shear, developed at or close to its base . It is however, similar to the other PGE occurrences on the Great Dyke (MSZ) in having its hanging-wall restricted to within 1m of the websterite/bronzitite contact. Slight axial tilting to t he west is indicated by steeper dips on the eastern flank. The sulphide concentration wit hin the MSZ can be used as a rough guide to the PGE-rich zone, but is not sufficiently precise to be used in stope control. The visual identification of the potentially mineable zone remains a problem that is unlikely to be solved. Based on petrological evidence, the bulk of the sulphides with which the PGE are associated, are cumulus in status. This provides unequivocal evidence for an orthomagmatic origin of the MSZ. The dominant platinum group mineral (PGM) phase is the Arsenide/Sperrylite group which is most commonly found at the contact zones between base metal sulphides (BMS) and gangue. The PGM range up to 90 ~m in length. Geochemical evidence from the analyses of cumulate orthopyroxenes through the 2m PGE-rich MSZ interval at Unki reveals a trend of arked Fe enrichment upwards which corresponds to an enrichment in sulphide. This indicates that precipitation of sulphide was caused by fractionation with lowering of temperature in the magma. The Fe enrichment is followed by a reversal in Mg# of orthopyroxene which corresponds to the decrease in sulphide content, suggest i ng that the termination of the PGE-rich MSZ was due to an increase in temperature associated with an influx of new magma. Coupled with these magmatic events are a complex interplay of chemical and physical processes occurring at a critical stage in the overall fractionation of the Great Dyke magma chamber. The overall persistence and continuity of t he PGE zone as observed in the Unki area is consistent with the inferred orthomagmatic origin of the mineralization
- Full Text:
- Date Issued: 1996
The geology, geochemistry and stratigraphic correlations of the farm Rietfontein 70 JS on the south -eastern flank of the Dennilton Dome, Transvaal, South Africa
- Authors: Crous, Stephanus Philippus
- Date: 1996
- Subjects: Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4960 , http://hdl.handle.net/10962/d1005572 , Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Description: The study area is located between Loskop Dam and the town of Groblersdal, on the southeastern flank of the Dennilton dome, and is underlain by lithologies of the Pretoria Group, Bushveld Complex mafics and ultramafics and acid lavas that resort under the Rooiberg felsites. Field work comprised of geological mapping, soil-, hard-rock- and stream sediment geochemistry, various geophysical techniques and diamond drilling. The rocktypes that resembles the Rustenburg Layered Suite on the farm Rietfontein 70JS is subdivided into a Mixed Zone, Critical Zone and Main Zone, on grounds of geochemical and certain geophysical attributes. The Mixed Zone that overlies the Bushveld Complex floor-rocks, is furthermore separated into an i) Lower-, ii) Middle- and, iii) Upper Unit. The Lower Unit of the Mixed Zone consists primarily of magnetite-gabbros, iron-rich pegmatites, harzburgites and feldspathic pyroxenites. The Fe-rich constituents of this stratigraphic horizon generates a pronounced magnetic anomaly within the study area. On the basis of; amongst other parameters, Zr/Rb and Sr/Al₂0₃ ratios, the magnetite-gabbros are postulated to conform to lithotypes in the vicinity of magnetite layers 8 to 14 of Upper Zone Subzone B in a normal Bushveld Complex stratigraphical scenario. Similarly, it is argued that the feldspathic pyroxenites and norites that display elevated chromium values are analogues to normal Critical Zone rocktypes of the Rustenburg Layered Snite. A more elaborate and precise stratigraphic correlation for the Critical zone was, however, not possible. It is advocated that a volume imbalance was created by the hot, ascending mafic magmas of the intruding Bushveld Complex, resulting in the updoming of certain prevailing basement features such as the Dennilton Dome. In addition to this ideology, it is proposed that the Mineral Range Fragment is in fact a large xenolith underlain by mafics, after being detached from the Dennilton Dome during the intrusion event. Evidence generated by this study unequivocally indicate that the potential for viable PGE's, Ni, Cu and Au within a Merensky Reef- type configuration or a Plat Reef-type scenario under a relatively thin veneer of acid Bushveld Complex roof-rocks on the eastern flank of the Dennilton Dome, appears feasible.
- Full Text:
- Date Issued: 1996
- Authors: Crous, Stephanus Philippus
- Date: 1996
- Subjects: Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4960 , http://hdl.handle.net/10962/d1005572 , Stratigraphic correlation -- South Africa -- Transvaal , Geology, Stratigraphic , Geochemistry -- South Africa -- Transvaal , Geology -- South Africa -- Transvaal
- Description: The study area is located between Loskop Dam and the town of Groblersdal, on the southeastern flank of the Dennilton dome, and is underlain by lithologies of the Pretoria Group, Bushveld Complex mafics and ultramafics and acid lavas that resort under the Rooiberg felsites. Field work comprised of geological mapping, soil-, hard-rock- and stream sediment geochemistry, various geophysical techniques and diamond drilling. The rocktypes that resembles the Rustenburg Layered Suite on the farm Rietfontein 70JS is subdivided into a Mixed Zone, Critical Zone and Main Zone, on grounds of geochemical and certain geophysical attributes. The Mixed Zone that overlies the Bushveld Complex floor-rocks, is furthermore separated into an i) Lower-, ii) Middle- and, iii) Upper Unit. The Lower Unit of the Mixed Zone consists primarily of magnetite-gabbros, iron-rich pegmatites, harzburgites and feldspathic pyroxenites. The Fe-rich constituents of this stratigraphic horizon generates a pronounced magnetic anomaly within the study area. On the basis of; amongst other parameters, Zr/Rb and Sr/Al₂0₃ ratios, the magnetite-gabbros are postulated to conform to lithotypes in the vicinity of magnetite layers 8 to 14 of Upper Zone Subzone B in a normal Bushveld Complex stratigraphical scenario. Similarly, it is argued that the feldspathic pyroxenites and norites that display elevated chromium values are analogues to normal Critical Zone rocktypes of the Rustenburg Layered Snite. A more elaborate and precise stratigraphic correlation for the Critical zone was, however, not possible. It is advocated that a volume imbalance was created by the hot, ascending mafic magmas of the intruding Bushveld Complex, resulting in the updoming of certain prevailing basement features such as the Dennilton Dome. In addition to this ideology, it is proposed that the Mineral Range Fragment is in fact a large xenolith underlain by mafics, after being detached from the Dennilton Dome during the intrusion event. Evidence generated by this study unequivocally indicate that the potential for viable PGE's, Ni, Cu and Au within a Merensky Reef- type configuration or a Plat Reef-type scenario under a relatively thin veneer of acid Bushveld Complex roof-rocks on the eastern flank of the Dennilton Dome, appears feasible.
- Full Text:
- Date Issued: 1996
The implications of the IMF programme in Zambia: lessons for South Africa in the Reconstruction and Development Programme (RDP)
- Authors: Motsilili, Phoka
- Date: 1996
- Subjects: International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2811 , http://hdl.handle.net/10962/d1003021 , International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Description: This study attempts to present a comparative analysis of the implication of the IMF in Zambia and South Africa in its Reconstruction and Development Programme (RDP). In examining the IMF programme, the study focuses on the Fund's understanding of such economies and its prescriptions for development. It is argued that IMF's familiar orthodoxy will have disastrous consequences for South Africa's poor, disadvantaged and rural communities. Finally, the IMF's market-oriented policy prescriptions are likely to erode democracy and have devastating effects to people-centred development programmes such as the RDP.
- Full Text:
- Date Issued: 1996
- Authors: Motsilili, Phoka
- Date: 1996
- Subjects: International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2811 , http://hdl.handle.net/10962/d1003021 , International Monetary Fund , Reconstruction and Development Programme (South Africa) , Social service -- South Africa , Economic assistance -- South Africa , Zambia -- Economic conditions -- 1964-
- Description: This study attempts to present a comparative analysis of the implication of the IMF in Zambia and South Africa in its Reconstruction and Development Programme (RDP). In examining the IMF programme, the study focuses on the Fund's understanding of such economies and its prescriptions for development. It is argued that IMF's familiar orthodoxy will have disastrous consequences for South Africa's poor, disadvantaged and rural communities. Finally, the IMF's market-oriented policy prescriptions are likely to erode democracy and have devastating effects to people-centred development programmes such as the RDP.
- Full Text:
- Date Issued: 1996
The influence of oceanographic conditions and culture methods on the dynamics of mussel farming in Saldanha Bay, South Africa
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
The inner image: an examination of the life of Helen Elizabeth Martins leading to her creation The Owl House and A Camel Yard as outsider art
- Authors: Ross, Susan Imrie
- Date: 1996
- Subjects: Sculptors -- South Africa -- Biography Martins, Helen Elizabeth, 1897-1976 Owl House (Nieu Bethesda, South Africa) Art brut Women artists -- South Africa Nieu bethesda (South africa) -- Description and travel Primitivism in art Creation (Literary, artistic, etc.) Artists -- Psychology Symbolism in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2430 , http://hdl.handle.net/10962/d1002227
- Description: The Owl House is situated in the Karoo village of Nieu Bethesda, and the person responsible for its creation, Helen Elizabeth Martins (1897-1976), is South Africa's best known Outsider artist. A number of newspaper and magazine articles, television programmes, radio interviews, play, films, short stories, theses and art works have resulted directly from her work. Interest in The Owl House continues to grow, with visitors coming from all over South Africa, and various parts of the world,to visit it. The Owl House was Helen Martins' home for most of her 78 years. During the last 30 or so years of her life she devoted all her time and energy to transforming the interior of her house into a glistening fantasy world of colour and light, using crushed glass stuck to almost every surface, coloured glass pane inserts in the walls, mirrors of many sizes and shapes, and countless paraffin lamps and candles. She called her garden' A Camel Yard', and filled it with over 500 cement statues, structures and bas reliefs. All the labour involved, apart from crushing and sorting the coloured glass, was provided by at least four different men, who assisted her over the years, Johannes Hattingh, Jonas Adams, Piet van der Merwe and Koos Malgas, though Helen Martins was the inspiration and director behind it all. Through a study of Helen Martins' background and life, and their effects upon her psyche, a rigorous attempt has been made to reach some understanding of why she became a recluse, and what caused her to create this unique body of work comprising her entire domestic environment. She became increasingly asocial as her life progressed, and ultimately ended it by committing suicide in 1976. Through the universality of symbolism, the meanings of the subjects, themes and concerns which she chose to depict are studied. Then, together with some knowledge of her life and personal influences, an attempt has been made to deduce what it was that Helen Martins was trying to express and work through in her creations. This study also led to an awareness of the fact that, although each one is unique, there are many examples of Outsider Art throughout the world. Fundamentally, creators of Outsider Art remain asocial in relation to their cultural milieu and cultural context. Some other examples of Outsider Art, both in South Africa as well as in Europe and India, were visited, and are described and compared with The Owl House as well as with one another. The way in which society reacts or responds to Outsider Art and its creators is studied through the comprehensive records of one specific case which caused great controversy in Johannesburg during the 1970s. Ultimately, working alone or with assistance, it is the Outsider artist who is the driving force behind these unique works, and whose indefinable inner fire of passion alone makes it possible to bring them into being. It would seem that the fascination with Outsider Art is that through their work, creators allow others a glimpse into a different sense of reality which is both mysterious and inexplicable.
- Full Text:
- Date Issued: 1996
- Authors: Ross, Susan Imrie
- Date: 1996
- Subjects: Sculptors -- South Africa -- Biography Martins, Helen Elizabeth, 1897-1976 Owl House (Nieu Bethesda, South Africa) Art brut Women artists -- South Africa Nieu bethesda (South africa) -- Description and travel Primitivism in art Creation (Literary, artistic, etc.) Artists -- Psychology Symbolism in art
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2430 , http://hdl.handle.net/10962/d1002227
- Description: The Owl House is situated in the Karoo village of Nieu Bethesda, and the person responsible for its creation, Helen Elizabeth Martins (1897-1976), is South Africa's best known Outsider artist. A number of newspaper and magazine articles, television programmes, radio interviews, play, films, short stories, theses and art works have resulted directly from her work. Interest in The Owl House continues to grow, with visitors coming from all over South Africa, and various parts of the world,to visit it. The Owl House was Helen Martins' home for most of her 78 years. During the last 30 or so years of her life she devoted all her time and energy to transforming the interior of her house into a glistening fantasy world of colour and light, using crushed glass stuck to almost every surface, coloured glass pane inserts in the walls, mirrors of many sizes and shapes, and countless paraffin lamps and candles. She called her garden' A Camel Yard', and filled it with over 500 cement statues, structures and bas reliefs. All the labour involved, apart from crushing and sorting the coloured glass, was provided by at least four different men, who assisted her over the years, Johannes Hattingh, Jonas Adams, Piet van der Merwe and Koos Malgas, though Helen Martins was the inspiration and director behind it all. Through a study of Helen Martins' background and life, and their effects upon her psyche, a rigorous attempt has been made to reach some understanding of why she became a recluse, and what caused her to create this unique body of work comprising her entire domestic environment. She became increasingly asocial as her life progressed, and ultimately ended it by committing suicide in 1976. Through the universality of symbolism, the meanings of the subjects, themes and concerns which she chose to depict are studied. Then, together with some knowledge of her life and personal influences, an attempt has been made to deduce what it was that Helen Martins was trying to express and work through in her creations. This study also led to an awareness of the fact that, although each one is unique, there are many examples of Outsider Art throughout the world. Fundamentally, creators of Outsider Art remain asocial in relation to their cultural milieu and cultural context. Some other examples of Outsider Art, both in South Africa as well as in Europe and India, were visited, and are described and compared with The Owl House as well as with one another. The way in which society reacts or responds to Outsider Art and its creators is studied through the comprehensive records of one specific case which caused great controversy in Johannesburg during the 1970s. Ultimately, working alone or with assistance, it is the Outsider artist who is the driving force behind these unique works, and whose indefinable inner fire of passion alone makes it possible to bring them into being. It would seem that the fascination with Outsider Art is that through their work, creators allow others a glimpse into a different sense of reality which is both mysterious and inexplicable.
- Full Text:
- Date Issued: 1996
The interface between Western mental health care and indigenous healing in South Africa: Xhosa psychiatric nurses' views on traditional healers
- Authors: Kahn, Marc Simon
- Date: 1996
- Subjects: Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2999 , http://hdl.handle.net/10962/d1002508 , Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Description: Xhosa psychiatric nurses stand unique at the interface between Western mental health care and indigenous healing in South Africa. They stem from a cultural history that is embedded within traditional health care discourses and yet are trained and work within a Western psychiatric model. In embodying the intersection between these two paradigms, they are faced with the challenge of making sense of such an amalgamation. These nurses' views are thus valuable in reflecting this intersection and illustrating many of the central concerns that surround it. This study explicates the views of these nurses toward traditional healers and their potential role in mental health care in South Africa. In addition, it illuminates some of the cultural dynamics at work amongst these subjects as they struggle to make sense of their unique cultural position. Using a questionnaire-based methodology, the views of Xhosa psychiatric nurses in a psychiatric hospital in the Eastern Cape, toward traditional healers and their role in mental-health care, were examined. The findings reveal that the vast majority of these nurses believe in traditional cosmology, involve themselves in traditional ritual practices and regularly visit traditional healers as patients. In suggesting ways in which indigenous healing and Western mental health care can work together, 75% of the nurses were in favour of a general referral system between the hospital and traditional healers, most (77%) agreed that certain patients would be better off being treated by both the hospital and traditional healers than they would if they were only being treated by the hospital alone, and 85% of the subjects agreed that patients who are already seeing traditional healers should check if psychiatric medication might help them. These findings indicate that these nurses operate across two healing systems which are at this point not conceptually compatible. This results in deep cultural tension for the nurses. In being entangled in the dialectical tension created in this context, the nurses manage the incongruencies in three general ways: a) Most, in one form or another, incorporate beliefs from both systems into an integrative model, b) some assimilate their cultural belief system into the Western mental health paradigm, throwing off their beliefs in traditional healing, and c) others remain ambivalent in the dialectic between traditional and Western health care discourses. Although this may suggest that these nurses reside within a cultural milieu that is somewhat unhealthy, at another level, in managing and containing the incompatibility between the two systems, these nurses ensure a space for on-going and healthy critique of the underlying assumptions involved in this health care malaise.
- Full Text:
- Date Issued: 1996
- Authors: Kahn, Marc Simon
- Date: 1996
- Subjects: Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2999 , http://hdl.handle.net/10962/d1002508 , Mental health services -- Research -- South Africa , Traditional medicine -- South Africa , Black people -- Mental health -- South Africa , Mental health -- South Africa
- Description: Xhosa psychiatric nurses stand unique at the interface between Western mental health care and indigenous healing in South Africa. They stem from a cultural history that is embedded within traditional health care discourses and yet are trained and work within a Western psychiatric model. In embodying the intersection between these two paradigms, they are faced with the challenge of making sense of such an amalgamation. These nurses' views are thus valuable in reflecting this intersection and illustrating many of the central concerns that surround it. This study explicates the views of these nurses toward traditional healers and their potential role in mental health care in South Africa. In addition, it illuminates some of the cultural dynamics at work amongst these subjects as they struggle to make sense of their unique cultural position. Using a questionnaire-based methodology, the views of Xhosa psychiatric nurses in a psychiatric hospital in the Eastern Cape, toward traditional healers and their role in mental-health care, were examined. The findings reveal that the vast majority of these nurses believe in traditional cosmology, involve themselves in traditional ritual practices and regularly visit traditional healers as patients. In suggesting ways in which indigenous healing and Western mental health care can work together, 75% of the nurses were in favour of a general referral system between the hospital and traditional healers, most (77%) agreed that certain patients would be better off being treated by both the hospital and traditional healers than they would if they were only being treated by the hospital alone, and 85% of the subjects agreed that patients who are already seeing traditional healers should check if psychiatric medication might help them. These findings indicate that these nurses operate across two healing systems which are at this point not conceptually compatible. This results in deep cultural tension for the nurses. In being entangled in the dialectical tension created in this context, the nurses manage the incongruencies in three general ways: a) Most, in one form or another, incorporate beliefs from both systems into an integrative model, b) some assimilate their cultural belief system into the Western mental health paradigm, throwing off their beliefs in traditional healing, and c) others remain ambivalent in the dialectic between traditional and Western health care discourses. Although this may suggest that these nurses reside within a cultural milieu that is somewhat unhealthy, at another level, in managing and containing the incompatibility between the two systems, these nurses ensure a space for on-going and healthy critique of the underlying assumptions involved in this health care malaise.
- Full Text:
- Date Issued: 1996
The manufacture of chaos and compromise: an analysis of the path to reform in South Africa
- Authors: Ryklief, Cheryl Cecelia
- Date: 1996
- Subjects: South Africa -- Politics and government -- 1994- , Apartheid -- South Africa -- History , South Africa -- Race relations , Black people -- South Africa -- Politics and government , South Africa -- Social conditions
- Language: English
- Type: text , thesis
- Identifier: http://hdl.handle.net/10962/76218 , vital:30521
- Description: This dissertation examines the factors leading to the opening of negotiations to majority rule in South Africa. It argues that changes to the socio-economic environment led to the growth of the strategic relevance of the black working class, and also created certain points of collision between the black working class and the policies of the state. These sectoral collisions engendered both the partial reforms of the Botha era as well as the rejection of these reforms by the black majority. The developments that emerged from the ensuing process of reform, resistance and repression in the 1980s weakened both the state and the black opposition sufficiently to allow for the emergence of a consensual solution to the political stalemate. , Dissertation submitted in accordance with the requirements of the University of Liverpool for the degree of Master of Arts
- Full Text:
- Date Issued: 1996
- Authors: Ryklief, Cheryl Cecelia
- Date: 1996
- Subjects: South Africa -- Politics and government -- 1994- , Apartheid -- South Africa -- History , South Africa -- Race relations , Black people -- South Africa -- Politics and government , South Africa -- Social conditions
- Language: English
- Type: text , thesis
- Identifier: http://hdl.handle.net/10962/76218 , vital:30521
- Description: This dissertation examines the factors leading to the opening of negotiations to majority rule in South Africa. It argues that changes to the socio-economic environment led to the growth of the strategic relevance of the black working class, and also created certain points of collision between the black working class and the policies of the state. These sectoral collisions engendered both the partial reforms of the Botha era as well as the rejection of these reforms by the black majority. The developments that emerged from the ensuing process of reform, resistance and repression in the 1980s weakened both the state and the black opposition sufficiently to allow for the emergence of a consensual solution to the political stalemate. , Dissertation submitted in accordance with the requirements of the University of Liverpool for the degree of Master of Arts
- Full Text:
- Date Issued: 1996
The nutritional requirements of Haliotis midae and development of a practical diet for abalone aquaculture
- Authors: Britz, Peter Jacobus
- Date: 1996
- Subjects: Abalones -- Nutrition Abalone culture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5307 , http://hdl.handle.net/10962/d1005152
- Description: The available literature on abalone nutrition was synthesised and the prospects for developing a complete pelleted dry feed for Haliotis midae evaluated. The similar body compositions, digestive structures, enzyme activity, acceptance of a wide variety of feed ingredients and comparable growth performance on formulated diets of various abalone species suggests that they have similar nutritional requirements. Abalone also appear to be similar to other farmed monogastric animals in that digestion is primarily extracelluar and they possess a large, muscular crop and stomach. Abalone energy metabolism is carbohydrate based. They are capable of digesting high levels of dietary protein but their ability to utilise fat is limited. Abalone have been shown to consume predictable amounts of dry feed which is efficiently converted into body weight. Efficiency indices of utilisation of formulated feeds, such as feed conversion ratio, protein efficiency ratio, net protein utilisation and apparent digestibility have been successfully applied to abalone. It was concluded that the prospects for developing complete diets for H. midae using a conventional animal feed science model were good. The ability of H. midae to utilise a range of proteins which had potential for inclusion in practical diets was investigated. Five protein rich ingredients, namely, casein, fishmeal, soya oil cake, Spirulina, and torula yeast, were fed to H. midae in semi-purified diets. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina based diets displayed significantly higher growth rates than diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed with P. corallorhiza were significantly lower than all other diets. All artificial diets yield lower feed conversion ratios (0.7-1.8) and higher protein efficiency ratios (3.3-6.5) ratios than the seaweed control diets (FCR = 2.8-3.4; PER = 2.2-3.0). The results indicated that fishmeal and Spirulina were the most suitable proteins for inclusion in practical diets for H. midae. The effect of protein level on growth rate and nutritional indices was evaluated by feeding starch bound, fishmeal based diets containing 27, 32, 37, 42 and 47% protein to juvenile H. midae. Weight gain was positively related to the level of dietary protein, increasing by 18% between 27% and 47% protein. Protein efficiency ratio declining from 3.2 to 2.3 with an increasing dietary protein content. Feed consumption rate was approximately 1% of body weight per day for all diets. Post-weaning abalone (ca. lOmm shell length, 0.2g) differed from larger juveniles (ca. 35mm, 8g) in their response to varying proportions of dietary protein and energy. The smaller animals appeared to have a lower protein requirement and poorer ability to utilise lipid than the larger juveniles. Proximate analyses revealed that the levels of protein, lipid and carbohydrate in abalone soft tissue increased with increasing dietary levels of these nutrients. Larger juveniles contained significantly higher levels of protein and carbohydrate, but lower levels of lipid, ash and moisture, than the smaller post-weaning abalone. The assimilation efficiency of [U-¹⁴C]-arginine by H. midae fed diets enriched with [U-¹⁴C]-arginine was only 0.45%. Furthennore, supplementation of diets with graded levels of crystalline arginine did not have any effect on growth rates. It was concluded that the prospects for defining the quantitative amino acid requirements of H. midae using crystalline amino acids are not promising. Rates of gastric evacuation and enzyme secretion were monitored in juvenile H. midae fed an extruded, fishmeal based dry feed. Gut fullness peaked 6h after feed was offered and the bulk of feed consumed was digested within 24 h. Enzyme secretion appeared to begin with the onset of feeding and continued for at least 6h after peak gut fullness was attained. Protease activity increased significantly following ingestion but amylase activity was maintained at a more or less constant level. A low level of lipase activity was observed suggesting that the ability of H. midae to digest fat is limited. The growth rate of H. midae fed an extruded, fishmeal based feed increased with increasing temperature between 12°C and 20°C. Between 20°C and 24°C a marked decline in growth rate accompanied by a deterioration in feed conversion and increased mortality was observed. Consumption of a dry pelleted feed was shown to be a function of body size and temperature. Based on these data a model which predicts a daily ration for H. midae was developed. The present study showed that H. midae efficiently utilises extruded dry feeds containing conventional feed ingredients. Although technical difficulties were encountered in measuring apparent digestibility, it was concluded that the prospects for developing practical diets according to established nutritional principles are promising.
- Full Text:
- Date Issued: 1996
- Authors: Britz, Peter Jacobus
- Date: 1996
- Subjects: Abalones -- Nutrition Abalone culture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5307 , http://hdl.handle.net/10962/d1005152
- Description: The available literature on abalone nutrition was synthesised and the prospects for developing a complete pelleted dry feed for Haliotis midae evaluated. The similar body compositions, digestive structures, enzyme activity, acceptance of a wide variety of feed ingredients and comparable growth performance on formulated diets of various abalone species suggests that they have similar nutritional requirements. Abalone also appear to be similar to other farmed monogastric animals in that digestion is primarily extracelluar and they possess a large, muscular crop and stomach. Abalone energy metabolism is carbohydrate based. They are capable of digesting high levels of dietary protein but their ability to utilise fat is limited. Abalone have been shown to consume predictable amounts of dry feed which is efficiently converted into body weight. Efficiency indices of utilisation of formulated feeds, such as feed conversion ratio, protein efficiency ratio, net protein utilisation and apparent digestibility have been successfully applied to abalone. It was concluded that the prospects for developing complete diets for H. midae using a conventional animal feed science model were good. The ability of H. midae to utilise a range of proteins which had potential for inclusion in practical diets was investigated. Five protein rich ingredients, namely, casein, fishmeal, soya oil cake, Spirulina, and torula yeast, were fed to H. midae in semi-purified diets. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina based diets displayed significantly higher growth rates than diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed with P. corallorhiza were significantly lower than all other diets. All artificial diets yield lower feed conversion ratios (0.7-1.8) and higher protein efficiency ratios (3.3-6.5) ratios than the seaweed control diets (FCR = 2.8-3.4; PER = 2.2-3.0). The results indicated that fishmeal and Spirulina were the most suitable proteins for inclusion in practical diets for H. midae. The effect of protein level on growth rate and nutritional indices was evaluated by feeding starch bound, fishmeal based diets containing 27, 32, 37, 42 and 47% protein to juvenile H. midae. Weight gain was positively related to the level of dietary protein, increasing by 18% between 27% and 47% protein. Protein efficiency ratio declining from 3.2 to 2.3 with an increasing dietary protein content. Feed consumption rate was approximately 1% of body weight per day for all diets. Post-weaning abalone (ca. lOmm shell length, 0.2g) differed from larger juveniles (ca. 35mm, 8g) in their response to varying proportions of dietary protein and energy. The smaller animals appeared to have a lower protein requirement and poorer ability to utilise lipid than the larger juveniles. Proximate analyses revealed that the levels of protein, lipid and carbohydrate in abalone soft tissue increased with increasing dietary levels of these nutrients. Larger juveniles contained significantly higher levels of protein and carbohydrate, but lower levels of lipid, ash and moisture, than the smaller post-weaning abalone. The assimilation efficiency of [U-¹⁴C]-arginine by H. midae fed diets enriched with [U-¹⁴C]-arginine was only 0.45%. Furthennore, supplementation of diets with graded levels of crystalline arginine did not have any effect on growth rates. It was concluded that the prospects for defining the quantitative amino acid requirements of H. midae using crystalline amino acids are not promising. Rates of gastric evacuation and enzyme secretion were monitored in juvenile H. midae fed an extruded, fishmeal based dry feed. Gut fullness peaked 6h after feed was offered and the bulk of feed consumed was digested within 24 h. Enzyme secretion appeared to begin with the onset of feeding and continued for at least 6h after peak gut fullness was attained. Protease activity increased significantly following ingestion but amylase activity was maintained at a more or less constant level. A low level of lipase activity was observed suggesting that the ability of H. midae to digest fat is limited. The growth rate of H. midae fed an extruded, fishmeal based feed increased with increasing temperature between 12°C and 20°C. Between 20°C and 24°C a marked decline in growth rate accompanied by a deterioration in feed conversion and increased mortality was observed. Consumption of a dry pelleted feed was shown to be a function of body size and temperature. Based on these data a model which predicts a daily ration for H. midae was developed. The present study showed that H. midae efficiently utilises extruded dry feeds containing conventional feed ingredients. Although technical difficulties were encountered in measuring apparent digestibility, it was concluded that the prospects for developing practical diets according to established nutritional principles are promising.
- Full Text:
- Date Issued: 1996
The political significance of the liberal media coverage of District Six from 1949 to 1970
- Authors: Marquard, Andrew Keith
- Date: 1996
- Subjects: Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2802 , http://hdl.handle.net/10962/d1003012 , Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Description: The political significance of the media coverage of District Six is approached in the following way: the issue is approached theoretically by posing the question of the general political significance of news as a communicative form. This question is resolved by an examination of the complicated relationship between the tradition of political thought and the development of modem political forms, specifically the issue of the importance of communication in modern political forms. This is explored by considering the problem of the political outlined by Heller. Arendt reconceptua1izes the problem in terms of political judgement, which is discussed in relation to postmodernism and Wittgenstein's philosophy of language, to establish a new conceptualization of political judgement based on Arendt's view of narrative and Benjamin's writing on history. This conceptualization is used to formulated a notion of the general political significance of news, which is a form of political judgement related to a specific political culture. On this basis the media material is analysed in terms of two processes: the representation of District Six in the liberal media, and the representation of the political process surrounding its racial zoning and demolition. It is concluded that the media coverage of Distract Six during this period is characterized by a political culture termed the politics of the ordinary based on a reification of 'Europe' as part of a ' colonial attitude', and the idealization of specific urban forms, with a special relationship to urban planning. Thus the political significance of the media coverage resides in the perpetuation of this political culture, representative of the politics of the white English-speaking middle class, in terms of which an authentic urban politics is not conceivable. Additional conclusions are also drawn concerning the relationship between this political culture and the politics of Apartheid.
- Full Text:
- Date Issued: 1996
- Authors: Marquard, Andrew Keith
- Date: 1996
- Subjects: Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2802 , http://hdl.handle.net/10962/d1003012 , Mass media -- Political aspects , District Six (Cape Town, South Africa) , District Six (Cape Town, South Africa), In The Press
- Description: The political significance of the media coverage of District Six is approached in the following way: the issue is approached theoretically by posing the question of the general political significance of news as a communicative form. This question is resolved by an examination of the complicated relationship between the tradition of political thought and the development of modem political forms, specifically the issue of the importance of communication in modern political forms. This is explored by considering the problem of the political outlined by Heller. Arendt reconceptua1izes the problem in terms of political judgement, which is discussed in relation to postmodernism and Wittgenstein's philosophy of language, to establish a new conceptualization of political judgement based on Arendt's view of narrative and Benjamin's writing on history. This conceptualization is used to formulated a notion of the general political significance of news, which is a form of political judgement related to a specific political culture. On this basis the media material is analysed in terms of two processes: the representation of District Six in the liberal media, and the representation of the political process surrounding its racial zoning and demolition. It is concluded that the media coverage of Distract Six during this period is characterized by a political culture termed the politics of the ordinary based on a reification of 'Europe' as part of a ' colonial attitude', and the idealization of specific urban forms, with a special relationship to urban planning. Thus the political significance of the media coverage resides in the perpetuation of this political culture, representative of the politics of the white English-speaking middle class, in terms of which an authentic urban politics is not conceivable. Additional conclusions are also drawn concerning the relationship between this political culture and the politics of Apartheid.
- Full Text:
- Date Issued: 1996
The pyrrolizidine alkaloids of Senecio chrysocoma and Senecio paniculatus
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996