The study of the interactions of cobalt (II) tetrasulfophthalocyanine with cysteine and histidine
- Sekota, Mantoa, Nyokong, Tebello
- Authors: Sekota, Mantoa , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293458 , vital:57087 , xlink:href="https://doi.org/10.1016/S0277-5387(97)00096-X"
- Description: Kinetics for the interaction of cobalt(II) tetrasulfophthalocyanine ([CoIITSPc]4−, Pc(−2) = phthalocyanine dianion) with the amino acids, histidine and cysteine, in pH 7.2 phosphate buffer were studied. The rates were found to be first order in both the [CoIITSPc]4− and the amino acid. The formation of the [CoIIITSPc]3− species in the presence of histidine occurred with a rate constant of 0.16 dm3 mol−s−1, whereas the formation of the [CoITSPc]5− species in the presence of cysteine gave a rate constant of 2.2 dm3 mol−1.
- Full Text:
- Date Issued: 1997
- Authors: Sekota, Mantoa , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293458 , vital:57087 , xlink:href="https://doi.org/10.1016/S0277-5387(97)00096-X"
- Description: Kinetics for the interaction of cobalt(II) tetrasulfophthalocyanine ([CoIITSPc]4−, Pc(−2) = phthalocyanine dianion) with the amino acids, histidine and cysteine, in pH 7.2 phosphate buffer were studied. The rates were found to be first order in both the [CoIITSPc]4− and the amino acid. The formation of the [CoIIITSPc]3− species in the presence of histidine occurred with a rate constant of 0.16 dm3 mol−s−1, whereas the formation of the [CoITSPc]5− species in the presence of cysteine gave a rate constant of 2.2 dm3 mol−1.
- Full Text:
- Date Issued: 1997
The timing and duration of the Karoo igneous event, southern Gondwana
- Duncan, R A, Hooper, P R, Rehacek, J, Marsh, Julian S, Duncan, Andrew R
- Authors: Duncan, R A , Hooper, P R , Rehacek, J , Marsh, Julian S , Duncan, Andrew R
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149485 , vital:38857 , https://doi.org/10.1029/97JB00972
- Description: A volcanic event of immense scale occurred within a relatively short period in early Jurassic time over large regions of the contiguous Gondwana supercontinent. In southern Africa, associated remnants of thick volcanic successions of lava flows and extensive dike and sill complexes of similar composition have been grouped together as the Karoo Igneous Province. Correlative volcanic and plutonic rocks occur in Antarctica and Australia as the Ferrar Province.
- Full Text:
- Date Issued: 1997
- Authors: Duncan, R A , Hooper, P R , Rehacek, J , Marsh, Julian S , Duncan, Andrew R
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149485 , vital:38857 , https://doi.org/10.1029/97JB00972
- Description: A volcanic event of immense scale occurred within a relatively short period in early Jurassic time over large regions of the contiguous Gondwana supercontinent. In southern Africa, associated remnants of thick volcanic successions of lava flows and extensive dike and sill complexes of similar composition have been grouped together as the Karoo Igneous Province. Correlative volcanic and plutonic rocks occur in Antarctica and Australia as the Ferrar Province.
- Full Text:
- Date Issued: 1997
The use of remote sensing and Geographic Information System (GIS) techniques, to interpret savanna ecosystem patterns in the Sabi Sand Game Reserve, Mpumalanga province
- Fortescue, Alexander Kenneth John
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
The use of the female voice in three novels by J.M. Coetzee
- Authors: Graham, Lucy Valerie
- Date: 1997
- Subjects: Coetzee, J. M., 1940- -- Criticism and interpretation , Coetzee, J. M., 1940- Foe , Coetzee, J. M., 1940- In the heart of the country , Coetzee, J. M., 1940- Age Of Iron , Women in literature , Voice in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2224 , http://hdl.handle.net/10962/d1002267 , Coetzee, J. M., 1940- -- Criticism and interpretation , Coetzee, J. M., 1940- Foe , Coetzee, J. M., 1940- In the heart of the country , Coetzee, J. M., 1940- Age Of Iron , Women in literature , Voice in literature
- Description: This study investigates J.M. Coetzee's use of the female voice in In the Heart of the Country, Foe and Age of Iron, and is based on the premise that Coetzee's position as a male author using a female voice is important for readings of these novels. Although the implications of Coetzee's strategy are examined against the theoretical background of feminist or gender-related discourses, this study does not attempt to claim Coetzee for feminism, nor to prove him a misogynist. Instead, it focuses on the specific positional and narrative possibilities afforded by Coetzee's use of a female voice. Chapter One comments on the fact that Coetzee's strategy of "textual cross-dressing" has not been given much critical attention in the past, observing that research on South African literature has largely been limited to studies of racial and colonial problematics. This introductory chapter mentions that the different female narrators in Coetzee's novels articulate aspects of a discourse in crisis, resulting in profound ambivalence in their representation. Chapter Two observes that the female voices in Coetzee's novels invoke the textual illusion of a speaking/writing female body, and explains that this is useful in expressing aspects of what Coetzee refers to as the suffering body. Although Coetzee appropriates a female narrative position and employs certain subversive textual elements associated with "the feminine", attempts made by certain critics to label Coetzee's writing as ecriture feminine are rejected as highly problematic. Instead, the study contends that the femaleness of the narrators relative to "masculine" discursive power enables Coetzee to perform a critique of power "from a position of weakness". Furthermore, the presence of certain "feminine" elements within these narrators suggests Coetzee's affiliation with characteristics derided within phallocratic discourses, and becomes a strategic means of fictive self-positioning, of figuring his own position as a dissident. Chapter Three is a study of In the Heart of the Country, and proposes that Magda is represented as a typical nineteenth century hysteric. Her hystericized narrative is linked to certain avant-garde narratives, such as the nouveau roman and "New Wave" cinematography, both cited by Coetzee as influences on the novel. Furthermore, the novel provides insight into the ambiguous role of the hysteric and dramatises the position of the dissident: on a discursive level Magda's narrative is subversive, and yet in terms of social "reality" her revolt is ineffectual. Chapter Four addresses the issue of author-ity in Foe, and draws on Coetzee's affiliation with Susan Barton, the struggling authoress, whose narrative reveals the levels of power and authority operating within, novelistic discourse when she asks "Who ,is speaking me?". The study observes that Foe also performs a critique of the power-seeking project of liberal feminism, as the novel sets Susan's quest for authorship against the background of a more radical "otherness", that of Friday. Chapter Five asserts that Age of Iron exploits the ethical possibilities of a maternal discourse. Tracing parallels between images of motherhood in psychoanalytic feminism and in Age of Iron, this chapter argues that Kristeva's theory of abjection is relevant for a reading of Elizabeth Curren's position as a mother who has cancer. The childbirth metaphor as it appears in Age- of Iron becomes an alternative and profoundly ethical way of figuring the process of novel writing.
- Full Text:
- Date Issued: 1997
- Authors: Graham, Lucy Valerie
- Date: 1997
- Subjects: Coetzee, J. M., 1940- -- Criticism and interpretation , Coetzee, J. M., 1940- Foe , Coetzee, J. M., 1940- In the heart of the country , Coetzee, J. M., 1940- Age Of Iron , Women in literature , Voice in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2224 , http://hdl.handle.net/10962/d1002267 , Coetzee, J. M., 1940- -- Criticism and interpretation , Coetzee, J. M., 1940- Foe , Coetzee, J. M., 1940- In the heart of the country , Coetzee, J. M., 1940- Age Of Iron , Women in literature , Voice in literature
- Description: This study investigates J.M. Coetzee's use of the female voice in In the Heart of the Country, Foe and Age of Iron, and is based on the premise that Coetzee's position as a male author using a female voice is important for readings of these novels. Although the implications of Coetzee's strategy are examined against the theoretical background of feminist or gender-related discourses, this study does not attempt to claim Coetzee for feminism, nor to prove him a misogynist. Instead, it focuses on the specific positional and narrative possibilities afforded by Coetzee's use of a female voice. Chapter One comments on the fact that Coetzee's strategy of "textual cross-dressing" has not been given much critical attention in the past, observing that research on South African literature has largely been limited to studies of racial and colonial problematics. This introductory chapter mentions that the different female narrators in Coetzee's novels articulate aspects of a discourse in crisis, resulting in profound ambivalence in their representation. Chapter Two observes that the female voices in Coetzee's novels invoke the textual illusion of a speaking/writing female body, and explains that this is useful in expressing aspects of what Coetzee refers to as the suffering body. Although Coetzee appropriates a female narrative position and employs certain subversive textual elements associated with "the feminine", attempts made by certain critics to label Coetzee's writing as ecriture feminine are rejected as highly problematic. Instead, the study contends that the femaleness of the narrators relative to "masculine" discursive power enables Coetzee to perform a critique of power "from a position of weakness". Furthermore, the presence of certain "feminine" elements within these narrators suggests Coetzee's affiliation with characteristics derided within phallocratic discourses, and becomes a strategic means of fictive self-positioning, of figuring his own position as a dissident. Chapter Three is a study of In the Heart of the Country, and proposes that Magda is represented as a typical nineteenth century hysteric. Her hystericized narrative is linked to certain avant-garde narratives, such as the nouveau roman and "New Wave" cinematography, both cited by Coetzee as influences on the novel. Furthermore, the novel provides insight into the ambiguous role of the hysteric and dramatises the position of the dissident: on a discursive level Magda's narrative is subversive, and yet in terms of social "reality" her revolt is ineffectual. Chapter Four addresses the issue of author-ity in Foe, and draws on Coetzee's affiliation with Susan Barton, the struggling authoress, whose narrative reveals the levels of power and authority operating within, novelistic discourse when she asks "Who ,is speaking me?". The study observes that Foe also performs a critique of the power-seeking project of liberal feminism, as the novel sets Susan's quest for authorship against the background of a more radical "otherness", that of Friday. Chapter Five asserts that Age of Iron exploits the ethical possibilities of a maternal discourse. Tracing parallels between images of motherhood in psychoanalytic feminism and in Age of Iron, this chapter argues that Kristeva's theory of abjection is relevant for a reading of Elizabeth Curren's position as a mother who has cancer. The childbirth metaphor as it appears in Age- of Iron becomes an alternative and profoundly ethical way of figuring the process of novel writing.
- Full Text:
- Date Issued: 1997
Theories of exchange rates and the methodology of economics
- Authors: Hodge, Duncan
- Date: 1997
- Subjects: Foreign exchange rates Economics -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1012 , http://hdl.handle.net/10962/d1002747
- Description: This thesis is an exercise in applied methodology. Ideas in the history and philosophy of science which have proved to be influential in the methodology of economics, and in shaping economists' self-image in this regard, are selected for closer analysis and criticism. The main ideas that are addressed are those of empiricism, with emphasis on the methodological falsificationism of Karl Popper and Imre Lakatos, and Laudan's problem solving model of scientific progress . The thesis examines the relationship between empirical evidence, in the form of both econometric test results and stylized facts, and the development of theories about exchange rates and the open economy. This analysis begins with Cassel's formulation of purchasing power parity theory in 1916, through the elasticities, absorption, and Mundell-Fleming models of exchange rates and the balance of payments, up to the present day monetary and asset market models. This is done with regard to the broad methodological issues examined earlier in the thesis. Some of the main empirical and methodological difficulties in testing such theories are addressed, with particular reference to the role played by the Duhem-Quine thesis and the ceteris paribus assumption. Although some of these difficulties may be regarded as a matter of degree compared to similar problems in the natural sciences, it is argued that this difference is significant for the workability of falsification in economics . Moreover, the presence of hypotheses about expectations in many economic theories appears to be a substantive difference such that the difficulties posed by the Duhem-Quine thesis apply with much greater force in a social science like economics. The main conclusions are that neither the Popperian nor Lakatosian versions of falsification are seriously practiced in the area of exchange rate economics and that, unlike the position taken by advocates of falsification such as Mark Blaug, it would be inappropriate and misguided to do so. A tentative case is made, with some reference to the theories surveyed in this thesis, for the possibly greater relevance of Laudan' s more pragmatic problem solving model for the methodology of economics, particularly as regards his analysis and emphasis on conceptual problem solving in the progress of knowledge.
- Full Text:
- Date Issued: 1997
- Authors: Hodge, Duncan
- Date: 1997
- Subjects: Foreign exchange rates Economics -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1012 , http://hdl.handle.net/10962/d1002747
- Description: This thesis is an exercise in applied methodology. Ideas in the history and philosophy of science which have proved to be influential in the methodology of economics, and in shaping economists' self-image in this regard, are selected for closer analysis and criticism. The main ideas that are addressed are those of empiricism, with emphasis on the methodological falsificationism of Karl Popper and Imre Lakatos, and Laudan's problem solving model of scientific progress . The thesis examines the relationship between empirical evidence, in the form of both econometric test results and stylized facts, and the development of theories about exchange rates and the open economy. This analysis begins with Cassel's formulation of purchasing power parity theory in 1916, through the elasticities, absorption, and Mundell-Fleming models of exchange rates and the balance of payments, up to the present day monetary and asset market models. This is done with regard to the broad methodological issues examined earlier in the thesis. Some of the main empirical and methodological difficulties in testing such theories are addressed, with particular reference to the role played by the Duhem-Quine thesis and the ceteris paribus assumption. Although some of these difficulties may be regarded as a matter of degree compared to similar problems in the natural sciences, it is argued that this difference is significant for the workability of falsification in economics . Moreover, the presence of hypotheses about expectations in many economic theories appears to be a substantive difference such that the difficulties posed by the Duhem-Quine thesis apply with much greater force in a social science like economics. The main conclusions are that neither the Popperian nor Lakatosian versions of falsification are seriously practiced in the area of exchange rate economics and that, unlike the position taken by advocates of falsification such as Mark Blaug, it would be inappropriate and misguided to do so. A tentative case is made, with some reference to the theories surveyed in this thesis, for the possibly greater relevance of Laudan' s more pragmatic problem solving model for the methodology of economics, particularly as regards his analysis and emphasis on conceptual problem solving in the progress of knowledge.
- Full Text:
- Date Issued: 1997
Theories of international cooperation and the GATT/WTO regime: beyond the dichotomy of rational and cognitive approaches
- Authors: Nischalke, Tobias Ingo
- Date: 1997
- Subjects: General Agreement on Tariffs and Trade (Organization) , World Trade Organization , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2817 , http://hdl.handle.net/10962/d1003027 , General Agreement on Tariffs and Trade (Organization) , World Trade Organization , International trade
- Description: This thesis aspires to assess the explanatory value of different theories of international cooperation for the case of the world trade regime of GATT/WTO and subsequently strives to reach a satisfactory interpretation of the instance of cooperation. The world trade regime embarked on a process of transformation with the signing of the Marrakech Agreements of 15th April 1994. The event marked the conclusion of the Uruguay Round and, with the establishment of the WTO, the beginning of a new era for the world trade regime. The thesis endeavours to establish the substance of the regime change from GATT to the WTO. It outlines the most significant provisions of the agreement of the Uruguay Round and, subsequently, analyses the change on the level of regime norms underlying the world trade regime. The analysis of regime norms yields insights about the essence of the regime transformation and as to what factors proved to be conducive to cooperation in the sphere of the world trade. The GATT/WTO regime with its extended scope and more sophisticated institutional structures can be regarded as a prime example of successful cooperation. However, the prospects for cooperation between states in an anarchic environment without central authority for enforcement are the subject of a remarkably intense scholarly debate. Therefore it is worthwhile to examine which theoretical framework proves to be most adept at elucidating the circumstances of this instance of cooperation. This thesis applies different theories of international cooperation to the case of the GATT/WTO regime. While a large array of rational theories attempts to explain cooperation from a perspective which focuses on interests and capabilities, a different strand of theories, that of cognitive approaches, emphasizes the paramountcy of ideas and beliefs as variables which explain cooperation. They endogenize the process of interest formation. This thesis seeks to synthesise the strong points of rational and cognitive approaches and thus to reconcile the divergent schools of thought. Its further purpose is to set out factors which are conducive to cooperation.
- Full Text:
- Date Issued: 1997
- Authors: Nischalke, Tobias Ingo
- Date: 1997
- Subjects: General Agreement on Tariffs and Trade (Organization) , World Trade Organization , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2817 , http://hdl.handle.net/10962/d1003027 , General Agreement on Tariffs and Trade (Organization) , World Trade Organization , International trade
- Description: This thesis aspires to assess the explanatory value of different theories of international cooperation for the case of the world trade regime of GATT/WTO and subsequently strives to reach a satisfactory interpretation of the instance of cooperation. The world trade regime embarked on a process of transformation with the signing of the Marrakech Agreements of 15th April 1994. The event marked the conclusion of the Uruguay Round and, with the establishment of the WTO, the beginning of a new era for the world trade regime. The thesis endeavours to establish the substance of the regime change from GATT to the WTO. It outlines the most significant provisions of the agreement of the Uruguay Round and, subsequently, analyses the change on the level of regime norms underlying the world trade regime. The analysis of regime norms yields insights about the essence of the regime transformation and as to what factors proved to be conducive to cooperation in the sphere of the world trade. The GATT/WTO regime with its extended scope and more sophisticated institutional structures can be regarded as a prime example of successful cooperation. However, the prospects for cooperation between states in an anarchic environment without central authority for enforcement are the subject of a remarkably intense scholarly debate. Therefore it is worthwhile to examine which theoretical framework proves to be most adept at elucidating the circumstances of this instance of cooperation. This thesis applies different theories of international cooperation to the case of the GATT/WTO regime. While a large array of rational theories attempts to explain cooperation from a perspective which focuses on interests and capabilities, a different strand of theories, that of cognitive approaches, emphasizes the paramountcy of ideas and beliefs as variables which explain cooperation. They endogenize the process of interest formation. This thesis seeks to synthesise the strong points of rational and cognitive approaches and thus to reconcile the divergent schools of thought. Its further purpose is to set out factors which are conducive to cooperation.
- Full Text:
- Date Issued: 1997
Towards a developed regional order: which way forward southern Africa?
- Authors: Blaauw, Abraham Lesley
- Date: 1997
- Subjects: Common Market for Eastern and Southern Africa , Regional planning -- Africa, Southern , Regional planning -- South Africa , Southern African Customs Union , Southern African Development Community , Africa, Southern -- Economic conditions , Africa, Southern -- Politics and government -- 1975-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2760 , http://hdl.handle.net/10962/d1002970 , Common Market for Eastern and Southern Africa , Regional planning -- Africa, Southern , Regional planning -- South Africa , Southern African Customs Union , Southern African Development Community , Africa, Southern -- Economic conditions , Africa, Southern -- Politics and government -- 1975-1994
- Description: The regionalisation of politics on a global scale, Call be seen as one of the defining features of contemporary international relations. Given this phenomenon, the tasks which confronted this thesis, was to consider the conditions and requirements necessary within the Southern African region to build an all-embracing developed regional order. The urgency with which the latter task should be undertaken, is premised on an increased realisation that the region, and indeed the continent as a whole, are becoming of lesser significance in international affairs. However, a number of impediments will have to be overcome, before the goal of a developed regional order can be achieved, which will contribute to lasting security in the region. Foremost amongst many issues, is how to employ the approaches to integration, in attempting to explain how the goal of a developed order should be achieved. A second problem which this thesis was confronted with, relates to which organisation shoulO be' considered the best vehicle, to drive the integration process forward- COMESA, SACU or SADC. The decision take SADC as the organisation to drive the integration process forward, is premised on a number of factors. Amongst many, it qualifies in geographical terms as a region, the historical linkages of the countries of the region (based on their fight against apartheid, division of labour, etc.), serves as a basis for building a sense of community. Thirdly its institutions can be developed to achieve the goal of an all-embracing regional order. Lastly and most importantly, SADC realises that regional integration will remain unattainable without the involvement of the peoples of Southern Africa. The identification of the organisation to drive the integration process forward, serves to bolster moves towards a maximalist order. However, significant changes in the structure and institutions of SADC is necessary, before it can be considered an all-embracing and developed regional order. Not suprisingly, therefore, we have witness a number of institutional changes to the SADC structures. Amongst many, the establishment of the Organ on Politics, Defence and Security , the signing of the SADC Trade Facilitation Protocol, and the commitment to democracy and a human rights culture, are most significant and will, it is hoped, provide the building-blocks for deeper integration in Southern Africa. Apart from the above, which occur between and among the states of the region, steps are underway between and among the agents of civil society to work closely with each other, to establish a regional civil society. Most notably, the establishment of a media society for Southern Africa, the calls by COSATU for a Social Charter with a regional flavour, the establishment of environmental and human rights networks, and the support for the Gay and Lesbian Movement of Zimbabwe (GALZ), represent landmarks, in the search for a developed regional order. However, the reluctance of the governments of the Southern African countries, to consult with the NGOs, before the adoption of the Organ Politics, clearly bears testimony to their present inability to take the necessary steps needed to move from a minimalist to a maximalist conception of regional organisation. The suggestion of this thesis is that the move-away from minimalism to maximalism can be facilitated by the development of a political centre-around which both governments and NGO activities can be articulated, since both are primarily concerned with the security and welfare of the Southern African region.
- Full Text:
- Date Issued: 1997
- Authors: Blaauw, Abraham Lesley
- Date: 1997
- Subjects: Common Market for Eastern and Southern Africa , Regional planning -- Africa, Southern , Regional planning -- South Africa , Southern African Customs Union , Southern African Development Community , Africa, Southern -- Economic conditions , Africa, Southern -- Politics and government -- 1975-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2760 , http://hdl.handle.net/10962/d1002970 , Common Market for Eastern and Southern Africa , Regional planning -- Africa, Southern , Regional planning -- South Africa , Southern African Customs Union , Southern African Development Community , Africa, Southern -- Economic conditions , Africa, Southern -- Politics and government -- 1975-1994
- Description: The regionalisation of politics on a global scale, Call be seen as one of the defining features of contemporary international relations. Given this phenomenon, the tasks which confronted this thesis, was to consider the conditions and requirements necessary within the Southern African region to build an all-embracing developed regional order. The urgency with which the latter task should be undertaken, is premised on an increased realisation that the region, and indeed the continent as a whole, are becoming of lesser significance in international affairs. However, a number of impediments will have to be overcome, before the goal of a developed regional order can be achieved, which will contribute to lasting security in the region. Foremost amongst many issues, is how to employ the approaches to integration, in attempting to explain how the goal of a developed order should be achieved. A second problem which this thesis was confronted with, relates to which organisation shoulO be' considered the best vehicle, to drive the integration process forward- COMESA, SACU or SADC. The decision take SADC as the organisation to drive the integration process forward, is premised on a number of factors. Amongst many, it qualifies in geographical terms as a region, the historical linkages of the countries of the region (based on their fight against apartheid, division of labour, etc.), serves as a basis for building a sense of community. Thirdly its institutions can be developed to achieve the goal of an all-embracing regional order. Lastly and most importantly, SADC realises that regional integration will remain unattainable without the involvement of the peoples of Southern Africa. The identification of the organisation to drive the integration process forward, serves to bolster moves towards a maximalist order. However, significant changes in the structure and institutions of SADC is necessary, before it can be considered an all-embracing and developed regional order. Not suprisingly, therefore, we have witness a number of institutional changes to the SADC structures. Amongst many, the establishment of the Organ on Politics, Defence and Security , the signing of the SADC Trade Facilitation Protocol, and the commitment to democracy and a human rights culture, are most significant and will, it is hoped, provide the building-blocks for deeper integration in Southern Africa. Apart from the above, which occur between and among the states of the region, steps are underway between and among the agents of civil society to work closely with each other, to establish a regional civil society. Most notably, the establishment of a media society for Southern Africa, the calls by COSATU for a Social Charter with a regional flavour, the establishment of environmental and human rights networks, and the support for the Gay and Lesbian Movement of Zimbabwe (GALZ), represent landmarks, in the search for a developed regional order. However, the reluctance of the governments of the Southern African countries, to consult with the NGOs, before the adoption of the Organ Politics, clearly bears testimony to their present inability to take the necessary steps needed to move from a minimalist to a maximalist conception of regional organisation. The suggestion of this thesis is that the move-away from minimalism to maximalism can be facilitated by the development of a political centre-around which both governments and NGO activities can be articulated, since both are primarily concerned with the security and welfare of the Southern African region.
- Full Text:
- Date Issued: 1997
Towards an understanding of Amayeza esiXhosa stores (African chemists): how they operate, and the services they offer in the Eastern Cape
- Authors: Cocks, Michelle L
- Date: 1997
- Subjects: Medical anthropology -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2096 , http://hdl.handle.net/10962/d1002659 , Medical anthropology -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Description: In medical anthropology there has been a tendency to dichotomize western biomedical . healtb services, on the one hand, and traditional health care practices on the other. Much attention has been focused on the comparison between these two approaches in the hope that they might be reconciled. The problem with this approach is twofold. In the first place, it has not always acknowledged the local, historic~1, political and economic contexts in which different approaches to health care have evolved and in the second place, health care services which belong to neither the western nor traditional healing spheres and which are driven by commercial interests have been almost completely neglected because they fall outside of the basic dichotomy. Amayeza stores have been a feature of South African towns and cities for many years. They mayor may not be run by Africans, but their clientele is almost exclusively African in this region. They deal in a bewildering variety of products and remedies, from untreated herbal and animal products to pharmaceuticals specially prepared for the African market, to Dutch and Indian Remedies. These stores both reflect transfonnations in indigenous perceptions of health care and, by virtue of the choices they offer, generate change. In this empirical study three stores in the Eastern Cape are selected for detailed study - two in King William's Town, the regional capital, and one in the small town of Peddie. The approach is holistic, emphasizing the social, political and economic context, the business histories and running of each shop, and, in particular, the perceptions and choices of a sample of the customers in each case. The success of the amayeza phenomenon derives from its eclecticism and syncretism. These stores impose neither a western nor a traditional model of health care on their clients, but offer them a range of choices that reflects the complex multicultural history of their own South African society.
- Full Text:
- Date Issued: 1997
- Authors: Cocks, Michelle L
- Date: 1997
- Subjects: Medical anthropology -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2096 , http://hdl.handle.net/10962/d1002659 , Medical anthropology -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape
- Description: In medical anthropology there has been a tendency to dichotomize western biomedical . healtb services, on the one hand, and traditional health care practices on the other. Much attention has been focused on the comparison between these two approaches in the hope that they might be reconciled. The problem with this approach is twofold. In the first place, it has not always acknowledged the local, historic~1, political and economic contexts in which different approaches to health care have evolved and in the second place, health care services which belong to neither the western nor traditional healing spheres and which are driven by commercial interests have been almost completely neglected because they fall outside of the basic dichotomy. Amayeza stores have been a feature of South African towns and cities for many years. They mayor may not be run by Africans, but their clientele is almost exclusively African in this region. They deal in a bewildering variety of products and remedies, from untreated herbal and animal products to pharmaceuticals specially prepared for the African market, to Dutch and Indian Remedies. These stores both reflect transfonnations in indigenous perceptions of health care and, by virtue of the choices they offer, generate change. In this empirical study three stores in the Eastern Cape are selected for detailed study - two in King William's Town, the regional capital, and one in the small town of Peddie. The approach is holistic, emphasizing the social, political and economic context, the business histories and running of each shop, and, in particular, the perceptions and choices of a sample of the customers in each case. The success of the amayeza phenomenon derives from its eclecticism and syncretism. These stores impose neither a western nor a traditional model of health care on their clients, but offer them a range of choices that reflects the complex multicultural history of their own South African society.
- Full Text:
- Date Issued: 1997
Towards sustainable conversation: Developing environmental education processes
- Authors: Le Roux, Kim
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389884 , vital:68492 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137446"
- Description: This paper highlights the importance of seeing environmental education as a process and considers the value of conversation and storytelling in environmental education processes. These processes are explored from a post-structural perspective within the context of the writer's own involvement in supporting environmental education processes.
- Full Text:
- Date Issued: 1997
- Authors: Le Roux, Kim
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389884 , vital:68492 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137446"
- Description: This paper highlights the importance of seeing environmental education as a process and considers the value of conversation and storytelling in environmental education processes. These processes are explored from a post-structural perspective within the context of the writer's own involvement in supporting environmental education processes.
- Full Text:
- Date Issued: 1997
Troubled waters in south-western New Georgia, Solomon Islands: Is codification of the commons a viable avenue for resource use regularisation
- Authors: Shankar, Aswani
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440061 , vital:73732
- Description: In recent decades there has been a growing interest in indigenous sea tenure institutions and their possible role in establishing a framework for sustainable resource use and conservation. Yet the feasibility of these institutions to cope with social and economic changes have been seldom explored. In this paper a case study is presented where internal deregularisation of the ‘commons’ is the result of existing socio-cultural principles combined with outside influences. Two territorial models are compared to elucidate emerging internal instabilities of sea tenure institutions and possible ways to correct existing problems. The codification of the commons is suggested here as a possible measure to strengthen indigenous common property regimes.
- Full Text:
- Date Issued: 1997
- Authors: Shankar, Aswani
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440061 , vital:73732
- Description: In recent decades there has been a growing interest in indigenous sea tenure institutions and their possible role in establishing a framework for sustainable resource use and conservation. Yet the feasibility of these institutions to cope with social and economic changes have been seldom explored. In this paper a case study is presented where internal deregularisation of the ‘commons’ is the result of existing socio-cultural principles combined with outside influences. Two territorial models are compared to elucidate emerging internal instabilities of sea tenure institutions and possible ways to correct existing problems. The codification of the commons is suggested here as a possible measure to strengthen indigenous common property regimes.
- Full Text:
- Date Issued: 1997
Urban agriculture: advocacy and practice: a discursive study with particular reference to three Eastern Cape centres
- Authors: Webb, Nigel Leigh
- Date: 1997
- Subjects: Urban agriculture -- South Africa -- Eastern Cape Land use, Urban -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2095 , http://hdl.handle.net/10962/d1002658
- Description: The purpose of this thesis is to explain the continued advocacy of 'urban agriculture' (UA) in the literature in the face of the seemingly modest role played by cultivation in practice. The analytical framework adopted isrthat of discourse, the theoretical underpinnings of which are derived from the early works of Foucault, and applications such as those of Escobar (1989; 1991) and Ferguson (1990). Using a discursive orientation involves two main tasks - an explanation of how 'UA' has gained some prominence and the man~er in which its currency is able to be maintained. The investigation included an in-depth analysis of the literature and empirical research in th!"e~Eastern Cape centres. The function of the empirical findings is to expose the discourse, as well as to extend the empirical base relating to 'urban agricultural' research in general. The thesis suggests that the growth in interest in 'UA' is a result of a Foucaultian "gap" opening in the discourse. Changes in the conceptualisation of development, the rise-in prominence of the urban poor and emerging ecodevelopment views, among others, have given proponents of "UA' greater room for manoeuvre. However, most case studies promote 'UA' despite providing little evidence of its role in household welfare. The way the discourse maintains its' currency is in the manner in which the objects of 'UA' are constituted. Firstly, the people are characterised as poor, largely divorced from their rural origins, and mainly female. Each of these assertions is questioned on the basis of the literature itself and the empirical findings. Secondly, in the practice of cultivation, emphasis is placed on the inputs used, and the crops that are produced. The treatment of both the inputs and the crops by the literature is cursory. Investigations show that land availability, garden size and irrigation water are e~pecially problematic and vegetable consumption remains low. Four types of alleged benefit associated with 'UA' are analysed - environmental and ecological, psychological and social, financial, and nutritional. In each case commonly held assumptions are undermined by closer investigation. Thus, the thesis contends that the role played by cultivation is a modest one. Most of the claims made on behalf of 'UA' are more congruent with development discourse than actual cultivation practice.
- Full Text:
- Date Issued: 1997
- Authors: Webb, Nigel Leigh
- Date: 1997
- Subjects: Urban agriculture -- South Africa -- Eastern Cape Land use, Urban -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2095 , http://hdl.handle.net/10962/d1002658
- Description: The purpose of this thesis is to explain the continued advocacy of 'urban agriculture' (UA) in the literature in the face of the seemingly modest role played by cultivation in practice. The analytical framework adopted isrthat of discourse, the theoretical underpinnings of which are derived from the early works of Foucault, and applications such as those of Escobar (1989; 1991) and Ferguson (1990). Using a discursive orientation involves two main tasks - an explanation of how 'UA' has gained some prominence and the man~er in which its currency is able to be maintained. The investigation included an in-depth analysis of the literature and empirical research in th!"e~Eastern Cape centres. The function of the empirical findings is to expose the discourse, as well as to extend the empirical base relating to 'urban agricultural' research in general. The thesis suggests that the growth in interest in 'UA' is a result of a Foucaultian "gap" opening in the discourse. Changes in the conceptualisation of development, the rise-in prominence of the urban poor and emerging ecodevelopment views, among others, have given proponents of "UA' greater room for manoeuvre. However, most case studies promote 'UA' despite providing little evidence of its role in household welfare. The way the discourse maintains its' currency is in the manner in which the objects of 'UA' are constituted. Firstly, the people are characterised as poor, largely divorced from their rural origins, and mainly female. Each of these assertions is questioned on the basis of the literature itself and the empirical findings. Secondly, in the practice of cultivation, emphasis is placed on the inputs used, and the crops that are produced. The treatment of both the inputs and the crops by the literature is cursory. Investigations show that land availability, garden size and irrigation water are e~pecially problematic and vegetable consumption remains low. Four types of alleged benefit associated with 'UA' are analysed - environmental and ecological, psychological and social, financial, and nutritional. In each case commonly held assumptions are undermined by closer investigation. Thus, the thesis contends that the role played by cultivation is a modest one. Most of the claims made on behalf of 'UA' are more congruent with development discourse than actual cultivation practice.
- Full Text:
- Date Issued: 1997
Use of cobalt (II) phthalocyanine to improve the sensitivity and stability of glassy carbon electrodes for the detection of cresols, chlorophenols and phenol
- Mafatle, Tsukutlane J, Nyokong, Tebello
- Authors: Mafatle, Tsukutlane J , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293335 , vital:57076 , xlink:href="https://doi.org/10.1016/S0003-2670(97)00464-9"
- Description: A cobalt(II) phthalocyanine-modified glassy carbon electrode (CoPc-GCE) was used for the detection of o-, m- and p-cresols, and of 2-chlorophenol, 4-chlorophenol and phenol. Modification of the glassy carbon electrode with CoPc increases the oxidation currents of these species and increases the stability of the electrode. CoPc-GCE showed less fouling by the oxidation products of these compounds than the unmodified GCE. Comparison of some first row transition metal phthalocyanines showed the following trend for the enhancement of the currents for the oxidation of cresols and phenols: Co(II)Pc > Mn(II)Pc > Fe(II)Pc > Ni(II)Pc > Cu(II)Pc > H2Pc > Zn(II)Pc > GCE. When [Co(II)TSPc]4− (TSPc=tetrasulfo Pc) was added to aqueous solutions containing the cresols and phenols, an enhancement of the oxidation currents was also observed.
- Full Text:
- Date Issued: 1997
- Authors: Mafatle, Tsukutlane J , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293335 , vital:57076 , xlink:href="https://doi.org/10.1016/S0003-2670(97)00464-9"
- Description: A cobalt(II) phthalocyanine-modified glassy carbon electrode (CoPc-GCE) was used for the detection of o-, m- and p-cresols, and of 2-chlorophenol, 4-chlorophenol and phenol. Modification of the glassy carbon electrode with CoPc increases the oxidation currents of these species and increases the stability of the electrode. CoPc-GCE showed less fouling by the oxidation products of these compounds than the unmodified GCE. Comparison of some first row transition metal phthalocyanines showed the following trend for the enhancement of the currents for the oxidation of cresols and phenols: Co(II)Pc > Mn(II)Pc > Fe(II)Pc > Ni(II)Pc > Cu(II)Pc > H2Pc > Zn(II)Pc > GCE. When [Co(II)TSPc]4− (TSPc=tetrasulfo Pc) was added to aqueous solutions containing the cresols and phenols, an enhancement of the oxidation currents was also observed.
- Full Text:
- Date Issued: 1997
Variation in foraging activity of Acanthochitona garnoti (Mollusca: Polyplacophora) from different habitats
- Cretchley, Robyn, Hodgson, Alan N, Gray David R, Reddy, Kasturi
- Authors: Cretchley, Robyn , Hodgson, Alan N , Gray David R , Reddy, Kasturi
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447642 , vital:74663 , https://www.ajol.info/index.php/az/article/view/154647
- Description: Activity of Acanthochitona garno {i was studied on an exposed horizon-tal platform of aeolian sandstone (I (enton-on-Sea-33'41'S; 26'40'E) and a quartzitic sandstone boulder shore (Cannon Rocks-33 44'S; 26'35'E), during 1994. In addition, the activity rhythms of chitons which were permanent inhabitants of high sbore rock pools at Kenton-on Sea were observed. All sites experienced semi-diurnal tides, the tidal range being about 1.9 m on mean spring tides. and 0.9 m on mean neap tides, with highest spring tides phased around.
- Full Text:
- Date Issued: 1997
- Authors: Cretchley, Robyn , Hodgson, Alan N , Gray David R , Reddy, Kasturi
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447642 , vital:74663 , https://www.ajol.info/index.php/az/article/view/154647
- Description: Activity of Acanthochitona garno {i was studied on an exposed horizon-tal platform of aeolian sandstone (I (enton-on-Sea-33'41'S; 26'40'E) and a quartzitic sandstone boulder shore (Cannon Rocks-33 44'S; 26'35'E), during 1994. In addition, the activity rhythms of chitons which were permanent inhabitants of high sbore rock pools at Kenton-on Sea were observed. All sites experienced semi-diurnal tides, the tidal range being about 1.9 m on mean spring tides. and 0.9 m on mean neap tides, with highest spring tides phased around.
- Full Text:
- Date Issued: 1997
Vitamin E supplementation and secondary metabolites interactions and effects on melanoma growth
- Authors: Ottino, Paulo
- Date: 1997
- Subjects: Vitamin E Melanoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4016 , http://hdl.handle.net/10962/d1004076
- Description: The present study was undertaken to determine the effects and possible mechanism of action of vitamin E succinate on malignant murine melanoma (BL6) and non-malignant monkey kidney (LLCMK) cell growth in vitro. Studies revealed that supplementation of 5, 7 and lOJLg/ml vitamin E succinate significantly inhibited BL6 cell growth, while in LLCMK cells no significant increase or decrease in growth was observed. The actual mechanism by which vitamin E succinate inhibits BL6 cell growth is at present unclear. Studies have suggested a radical or oxidant involvement in a number of degenerative diseases such as cancer, and that supplementation of antioxidant vitamins such as vitamin E may function to reduce cancer cell growth by quenching free radical species and preventing lipid peroxidation. In addition to its antioxidant role in a cell, vitamin E is believed to modulate the activities of various enzymes and metabolites in the eicosanoid pathway. Hence, this study investigated the effects of vitamin E succinate supplementation on free radical and lipid peroxidation levels, as well as the activities of various enzymes and metabolites ill the eicosanoid pathway. Throughout this study, emphasis was placed on BL6 melanoma cells since the magnitude of the relationship between LLCMK growth and the levels of various enzymes and metabolites in the eicosanoid pathway varied considerably from one experiment to another and did not show the consistent trend found with the BL6 cells. A decrease in cell growth was found to be accompanied by a concomitant increase rather than a decrease in the levels of free radicals and lipid peroxidation, suggesting that the growth inhibitory effects of vitamin E succinate on BL6 cells in vitro was not due to its antioxidant properties associated with the vitamin E component, but rather due to one or more of its other potential roles within the cell. This proposal was further strengthened by findings that vitamin E succinate, a non-physiological antioxidant in its esterified form, did not undergo significant cleavage to free vitamin E in the BL6 cells. Vitamin E succinate is believed to modulate membrane bound enzyme activities through physicochemical interactions with membrane lipids and changes in membrane fluidity. Hence, this study investigated the role of vitamin E succinate in modulating the activity of various enzymes and secondary messengers in the eicosanoid pathway. Supplementation of l-lOjLg/ml vitamin E succinate resulted in an overall increase in phospholipase A2 activity while cyclooxygenase and adenyl ate cyclase activities were found to be significantly increased at vitamin E succinate concentrations of 7 and WjLg/ml respectively. A significant increase in" 5-LOX activity was observed a! 10jLg/mi supplementation. The suggestion that vitamin E succinate modulates membrane bound enzyme activities was further strengthened by uptake and cellular distribution studies, which showed significantly higher levels of vitamin E succinate in membrane fractions of BL6 cells when compared with stroma fractions. Another factor which could account for elevated PLA2,-5-LOX and COX activities in BL6 cells as a result of vitamin E succinate supplementation, was that of intracellular calcium levels. Supplementation of BL6 cells with 1-7 jLg/ml vitamin E succinate resulted in an overall increase in intracellular calcium levels. These changes in calcium levels however were positively correlated with changes in PLA2 activity only. Since the rate of prostaglandin synthesis is controlled by phospholipase A2 activity, and net prostagiandin production is dependant on cyclooxygenase activity, the effects of vitamin E succinate supplementation on prostaglandin levels in BL6 cells was determined. Vitamin E succinate supplementation resulted in a significant decrease in prostaglandin D2 levels at vitamin E succinate concentrations of 3, 5, 7 and lOjLg/ml respectively, while prostaglandin F2a levels were significantly decreased at 1-10jLg/ml vitamin E succinate. The increases in prostaglandin E2 and 12 levels were inversely related to BL6 cell growth suggesting that both prostaglandins may act as negative regulators of BL6 cell growth. When comparing prostaglandin E2 levels to prostaglandin 12 levels in BL6 cells, significantly higher levels of prostaglandin E2 were found, suggesting that vitamin E succinate effects were mediated primarily through an increase in prostaglandin E2 levels. Furthermore, prostaglandin E2 levels are believed to modulate adenylate cyclase activity. It is therefore reasonable to conclude that the increased adenyl ate cyclase activity found in BL6 cells was dependant on prostaglandin E2 levels, since increases in prostaglandin E2 levels at 7 and lOjLg/ml vitamin E succinate correlated with an increase in adenylate cyclase activity and cyclic adenosine monophosphate levels. Thus it appeared that the observed inhibitory effects of vitamin E succinate supplementation on BL6 cell growth was not due to the antioxidant properties associated with the vitamin E component of the vitamin E succinate molecule, but was rather mediated in part through a cascade effect initiated by phospholipase A2 activation and archidonic acid release. This initial effect then appeared to result in an increase in cyclooxygenase activity and activation of a prostaglandin E2-adenylate cyclase-cyclic adenosine monophosphate linked system, ultimately altering cyclic adenosine monophosphate levels and inhibiting BL6 cell growth. This was confirmed when BL6 cells were supplemented with indomethacin, a cyclooxygenase inhibitor. Supplementation with the inhibitor resulted in vitamin E succinate having no inhibitory effects on BL6 cell growth. Furthermore, when comparing the levels of prostaglandin ~, adenylate cyclase activity and cyclIC adenosine monophosphate in the indomethacin treated cultures to non-indomethacin treated cultures, markedly lower levels of these metabolites were found in the indomethacin treated cultures. The cause of the increase in free radical and lipid peroxidation levels in BL6 cells following vitamin E succinate supplementation was further investigated. Cyclooxygenase enzymes are believed to generate free radical species and contribute to lipid peroxidation levels during catalytic activity. Markedly lower levels of free radicals and lipid peroxidation in indomethacin treated cultures were found when compared with vitamin E succinate treated cultures alone, suggesting that the increases in free radical and lipid peroxidation levels in BL6 cells supplemented with vitamin E succinate were indirectly due to an increase in cyclooxygenase activity in these cells.
- Full Text:
- Date Issued: 1997
- Authors: Ottino, Paulo
- Date: 1997
- Subjects: Vitamin E Melanoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4016 , http://hdl.handle.net/10962/d1004076
- Description: The present study was undertaken to determine the effects and possible mechanism of action of vitamin E succinate on malignant murine melanoma (BL6) and non-malignant monkey kidney (LLCMK) cell growth in vitro. Studies revealed that supplementation of 5, 7 and lOJLg/ml vitamin E succinate significantly inhibited BL6 cell growth, while in LLCMK cells no significant increase or decrease in growth was observed. The actual mechanism by which vitamin E succinate inhibits BL6 cell growth is at present unclear. Studies have suggested a radical or oxidant involvement in a number of degenerative diseases such as cancer, and that supplementation of antioxidant vitamins such as vitamin E may function to reduce cancer cell growth by quenching free radical species and preventing lipid peroxidation. In addition to its antioxidant role in a cell, vitamin E is believed to modulate the activities of various enzymes and metabolites in the eicosanoid pathway. Hence, this study investigated the effects of vitamin E succinate supplementation on free radical and lipid peroxidation levels, as well as the activities of various enzymes and metabolites ill the eicosanoid pathway. Throughout this study, emphasis was placed on BL6 melanoma cells since the magnitude of the relationship between LLCMK growth and the levels of various enzymes and metabolites in the eicosanoid pathway varied considerably from one experiment to another and did not show the consistent trend found with the BL6 cells. A decrease in cell growth was found to be accompanied by a concomitant increase rather than a decrease in the levels of free radicals and lipid peroxidation, suggesting that the growth inhibitory effects of vitamin E succinate on BL6 cells in vitro was not due to its antioxidant properties associated with the vitamin E component, but rather due to one or more of its other potential roles within the cell. This proposal was further strengthened by findings that vitamin E succinate, a non-physiological antioxidant in its esterified form, did not undergo significant cleavage to free vitamin E in the BL6 cells. Vitamin E succinate is believed to modulate membrane bound enzyme activities through physicochemical interactions with membrane lipids and changes in membrane fluidity. Hence, this study investigated the role of vitamin E succinate in modulating the activity of various enzymes and secondary messengers in the eicosanoid pathway. Supplementation of l-lOjLg/ml vitamin E succinate resulted in an overall increase in phospholipase A2 activity while cyclooxygenase and adenyl ate cyclase activities were found to be significantly increased at vitamin E succinate concentrations of 7 and WjLg/ml respectively. A significant increase in" 5-LOX activity was observed a! 10jLg/mi supplementation. The suggestion that vitamin E succinate modulates membrane bound enzyme activities was further strengthened by uptake and cellular distribution studies, which showed significantly higher levels of vitamin E succinate in membrane fractions of BL6 cells when compared with stroma fractions. Another factor which could account for elevated PLA2,-5-LOX and COX activities in BL6 cells as a result of vitamin E succinate supplementation, was that of intracellular calcium levels. Supplementation of BL6 cells with 1-7 jLg/ml vitamin E succinate resulted in an overall increase in intracellular calcium levels. These changes in calcium levels however were positively correlated with changes in PLA2 activity only. Since the rate of prostaglandin synthesis is controlled by phospholipase A2 activity, and net prostagiandin production is dependant on cyclooxygenase activity, the effects of vitamin E succinate supplementation on prostaglandin levels in BL6 cells was determined. Vitamin E succinate supplementation resulted in a significant decrease in prostaglandin D2 levels at vitamin E succinate concentrations of 3, 5, 7 and lOjLg/ml respectively, while prostaglandin F2a levels were significantly decreased at 1-10jLg/ml vitamin E succinate. The increases in prostaglandin E2 and 12 levels were inversely related to BL6 cell growth suggesting that both prostaglandins may act as negative regulators of BL6 cell growth. When comparing prostaglandin E2 levels to prostaglandin 12 levels in BL6 cells, significantly higher levels of prostaglandin E2 were found, suggesting that vitamin E succinate effects were mediated primarily through an increase in prostaglandin E2 levels. Furthermore, prostaglandin E2 levels are believed to modulate adenylate cyclase activity. It is therefore reasonable to conclude that the increased adenyl ate cyclase activity found in BL6 cells was dependant on prostaglandin E2 levels, since increases in prostaglandin E2 levels at 7 and lOjLg/ml vitamin E succinate correlated with an increase in adenylate cyclase activity and cyclic adenosine monophosphate levels. Thus it appeared that the observed inhibitory effects of vitamin E succinate supplementation on BL6 cell growth was not due to the antioxidant properties associated with the vitamin E component of the vitamin E succinate molecule, but was rather mediated in part through a cascade effect initiated by phospholipase A2 activation and archidonic acid release. This initial effect then appeared to result in an increase in cyclooxygenase activity and activation of a prostaglandin E2-adenylate cyclase-cyclic adenosine monophosphate linked system, ultimately altering cyclic adenosine monophosphate levels and inhibiting BL6 cell growth. This was confirmed when BL6 cells were supplemented with indomethacin, a cyclooxygenase inhibitor. Supplementation with the inhibitor resulted in vitamin E succinate having no inhibitory effects on BL6 cell growth. Furthermore, when comparing the levels of prostaglandin ~, adenylate cyclase activity and cyclIC adenosine monophosphate in the indomethacin treated cultures to non-indomethacin treated cultures, markedly lower levels of these metabolites were found in the indomethacin treated cultures. The cause of the increase in free radical and lipid peroxidation levels in BL6 cells following vitamin E succinate supplementation was further investigated. Cyclooxygenase enzymes are believed to generate free radical species and contribute to lipid peroxidation levels during catalytic activity. Markedly lower levels of free radicals and lipid peroxidation in indomethacin treated cultures were found when compared with vitamin E succinate treated cultures alone, suggesting that the increases in free radical and lipid peroxidation levels in BL6 cells supplemented with vitamin E succinate were indirectly due to an increase in cyclooxygenase activity in these cells.
- Full Text:
- Date Issued: 1997
Voltammetric behavior of cysteine and metallothionein on cobalt (II) tetrasulfonated phthalocyanine modified glassy carbon electrodes
- Limson, Janice L, Nyokong, Tebello
- Authors: Limson, Janice L , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293346 , vital:57077 , xlink:href="https://doi.org/10.1002/elan.1140090314"
- Description: Cysteine, and rat Cd, Zn-metallothionein (Cd, Zn-MT) have been studied electrochemically at glassy carbon electrodes modified with cobalt(II) tetrasulfonated phthalocyanine, [CoIITSPc]4−, where Pc(2-) = phthalocyanine dianion. The electrode was modified by electrodeposition of [CoIITSPc]4−. The anodic currents for the oxidation of cysteine on these electrodes are observed at 0.82 V (vs. Ag/AgCl) in acidic media. The anodic currents for the oxidation of Cd, Zn-MT are observed at 0.90 V at pH 8.4 (Tris buffer).
- Full Text:
- Date Issued: 1997
- Authors: Limson, Janice L , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293346 , vital:57077 , xlink:href="https://doi.org/10.1002/elan.1140090314"
- Description: Cysteine, and rat Cd, Zn-metallothionein (Cd, Zn-MT) have been studied electrochemically at glassy carbon electrodes modified with cobalt(II) tetrasulfonated phthalocyanine, [CoIITSPc]4−, where Pc(2-) = phthalocyanine dianion. The electrode was modified by electrodeposition of [CoIITSPc]4−. The anodic currents for the oxidation of cysteine on these electrodes are observed at 0.82 V (vs. Ag/AgCl) in acidic media. The anodic currents for the oxidation of Cd, Zn-MT are observed at 0.90 V at pH 8.4 (Tris buffer).
- Full Text:
- Date Issued: 1997
WCED causes crisis in education
- SADTU
- Authors: SADTU
- Date: 1997
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162052 , vital:40752
- Description: On 15 December 1997 the WCED tabled a proposal in the ELRC. This would effectively terminate the contracts of 3333 temporary educators who were filling vacant substantive posts that were created after 1 July 1996 as a result of the rationalisation process. Not only will temporary educators be dismissed, but the posts that they occupy will be frozen. This means that the teachers who remain behind at schools will have increased workloads and will have to manage bigger class sizes
- Full Text:
- Date Issued: 1997
- Authors: SADTU
- Date: 1997
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162052 , vital:40752
- Description: On 15 December 1997 the WCED tabled a proposal in the ELRC. This would effectively terminate the contracts of 3333 temporary educators who were filling vacant substantive posts that were created after 1 July 1996 as a result of the rationalisation process. Not only will temporary educators be dismissed, but the posts that they occupy will be frozen. This means that the teachers who remain behind at schools will have increased workloads and will have to manage bigger class sizes
- Full Text:
- Date Issued: 1997
Chris McGregor and the South African Exiles
- Authors: Loupien, Serge
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Shepp, Archie
- Language: French
- Type: Text
- Identifier: vital:13592 , http://hdl.handle.net/10962/d1012247 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Shepp, Archie
- Description: Photocopied article in French about the reissue of the recording of Chris McGregor's "Thunderbolt" with his exiled friends from Blue Notes and British improvisers. There is also a picture of the CD's front cover with this article.
- Full Text:
- Authors: Loupien, Serge
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Shepp, Archie
- Language: French
- Type: Text
- Identifier: vital:13592 , http://hdl.handle.net/10962/d1012247 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Shepp, Archie
- Description: Photocopied article in French about the reissue of the recording of Chris McGregor's "Thunderbolt" with his exiled friends from Blue Notes and British improvisers. There is also a picture of the CD's front cover with this article.
- Full Text:
Chris McGregor's music is still resonating!
- Authors: Rabez, Marie-Paule
- Language: French
- Type: Article
- Identifier: vital:13642 , http://hdl.handle.net/10962/d1012546
- Description: Photocopied article from the French newspaper La Dépêche in memory of Chris McGregor. There is also a picture of Chris McGregor in the center of this article.
- Full Text:
- Authors: Rabez, Marie-Paule
- Language: French
- Type: Article
- Identifier: vital:13642 , http://hdl.handle.net/10962/d1012546
- Description: Photocopied article from the French newspaper La Dépêche in memory of Chris McGregor. There is also a picture of Chris McGregor in the center of this article.
- Full Text:
Music Universe
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz
- Language: English
- Type: Article
- Identifier: vital:13734 , http://hdl.handle.net/10962/d1012748
- Description: Photocopied article from the New Zealand Jazziz Magazine about Maxine McGregor's book "Chris McGregor and The Brotherhood of Breath" (Bamberger Books).
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz
- Language: English
- Type: Article
- Identifier: vital:13734 , http://hdl.handle.net/10962/d1012748
- Description: Photocopied article from the New Zealand Jazziz Magazine about Maxine McGregor's book "Chris McGregor and The Brotherhood of Breath" (Bamberger Books).
- Full Text: