Social workers perceptions on unionisation and collective bargaining : an exploratory study of the central region of the Eastern Cape
- Authors: Dyakala, Tumeka
- Date: 2000
- Subjects: Social workers -- South Africa -- Eastern Cape -- Attitudes , Labor unions -- South Africa , Collective bargaining -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:695 , http://hdl.handle.net/10962/d1006405 , Social workers -- South Africa -- Eastern Cape -- Attitudes , Labor unions -- South Africa , Collective bargaining -- South Africa
- Description: This study explores primarily the views of social workers in the Central region of the Eastern Cape on unionisation and collective bargaining, and at a secondary level the views of their employers and of the trade unions organising social workers, regarding social workers' involvement and non-involvement in these processes. It examines the paradox of compatibility of professionalism and unionism. There are two schools of thought regarding compatibility of professionalism and unionisation one views these concepts as antagonistic whilst the other views these concepts as complementary. Some social workers have been reluctant to participate in trade unions in the past until recently. Reasons advanced for their recent accelerated involvement in trade unions are explored in this study. Social workers views on the Labour Relations Act 66 of 1995 as the source of the legal framework, within which trade unions and employers interact, through the process of collective bargaining are explored. Proposed alternative mechanisms to these processes as perceived by social workers are closely examined. Semi-structured, self administered questionnaires were distributed to social workers whilst semi-structured interviews were conducted with employer representatives and trade union officials. This helped the researcher to have a broader view of the situation. Findings point to a scenario of disunity of both employers and employees in the social work profession. The study is a pioneering effort in the Central region and sets a way forward for further exploration of this subject. It is hoped that this study will make a worthwhile contribution to the social work profession's industrial relations field
- Full Text:
- Date Issued: 2000
- Authors: Dyakala, Tumeka
- Date: 2000
- Subjects: Social workers -- South Africa -- Eastern Cape -- Attitudes , Labor unions -- South Africa , Collective bargaining -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:695 , http://hdl.handle.net/10962/d1006405 , Social workers -- South Africa -- Eastern Cape -- Attitudes , Labor unions -- South Africa , Collective bargaining -- South Africa
- Description: This study explores primarily the views of social workers in the Central region of the Eastern Cape on unionisation and collective bargaining, and at a secondary level the views of their employers and of the trade unions organising social workers, regarding social workers' involvement and non-involvement in these processes. It examines the paradox of compatibility of professionalism and unionism. There are two schools of thought regarding compatibility of professionalism and unionisation one views these concepts as antagonistic whilst the other views these concepts as complementary. Some social workers have been reluctant to participate in trade unions in the past until recently. Reasons advanced for their recent accelerated involvement in trade unions are explored in this study. Social workers views on the Labour Relations Act 66 of 1995 as the source of the legal framework, within which trade unions and employers interact, through the process of collective bargaining are explored. Proposed alternative mechanisms to these processes as perceived by social workers are closely examined. Semi-structured, self administered questionnaires were distributed to social workers whilst semi-structured interviews were conducted with employer representatives and trade union officials. This helped the researcher to have a broader view of the situation. Findings point to a scenario of disunity of both employers and employees in the social work profession. The study is a pioneering effort in the Central region and sets a way forward for further exploration of this subject. It is hoped that this study will make a worthwhile contribution to the social work profession's industrial relations field
- Full Text:
- Date Issued: 2000
Souleymaan
- Fatou Laobe (performer, composer), Mareme Ndiaye, Kouna Sow, Aissata Sow, Law Kouyate (chorus), Mbeya Samb (bass guitar), Assana Aldara (guitar), Azizi Diallo (piano), Beydi Thior (pianos), Law Kouyate (kora), Amadou Athiel (xalam), Moussa Gningue (drums), Elle Mbaye, Mbaye Thiam (sabar), Jololi
- Authors: Fatou Laobe (performer, composer) , Mareme Ndiaye, Kouna Sow, Aissata Sow, Law Kouyate (chorus) , Mbeya Samb (bass guitar) , Assana Aldara (guitar) , Azizi Diallo (piano) , Beydi Thior (pianos) , Law Kouyate (kora) , Amadou Athiel (xalam) , Moussa Gningue (drums) , Elle Mbaye, Mbaye Thiam (sabar) , Jololi
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/127688 , vital:36035 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDCO6-04
- Description: Senegalese band featuring solo and chorus singers accampanied by kora, xalam, sabar, guitar and piano
- Full Text: false
- Date Issued: 2000
- Authors: Fatou Laobe (performer, composer) , Mareme Ndiaye, Kouna Sow, Aissata Sow, Law Kouyate (chorus) , Mbeya Samb (bass guitar) , Assana Aldara (guitar) , Azizi Diallo (piano) , Beydi Thior (pianos) , Law Kouyate (kora) , Amadou Athiel (xalam) , Moussa Gningue (drums) , Elle Mbaye, Mbaye Thiam (sabar) , Jololi
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/127688 , vital:36035 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDCO6-04
- Description: Senegalese band featuring solo and chorus singers accampanied by kora, xalam, sabar, guitar and piano
- Full Text: false
- Date Issued: 2000
South Africa's growth, employment and redistribution strategy in the context of structural adjustment programmes in the South
- Authors: Lehloesa, Thembinkosi L
- Date: 2000
- Subjects: Growth, Employment And Redistribution Programme (South Africa) , South Africa -- Economic policy , South Africa -- Politics and government -- 1989-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2794 , http://hdl.handle.net/10962/d1003004 , Growth, Employment And Redistribution Programme (South Africa) , South Africa -- Economic policy , South Africa -- Politics and government -- 1989-1994
- Description: This study is a contribution to the ongoing debate concerning the future of South Africa’s macro-economic policy known as the Growth, Employment and Redistribution (GEAR) strategy. The study attempts to draw parallels between the GEAR macro-economic policy framework and structural adjustment programmes in the South. By making use of this comparison, the study argues that the outcome of the GEAR will be no different from structural adjustment programmes in that it will fail to reduce poverty and cause government to meet the basic needs of the people. These conclusions are drawn from the fact that the GEAR policy is premised on the faith that the market is capable of redistributing income and wealth, and providing people with their basic needs.
- Full Text:
- Date Issued: 2000
- Authors: Lehloesa, Thembinkosi L
- Date: 2000
- Subjects: Growth, Employment And Redistribution Programme (South Africa) , South Africa -- Economic policy , South Africa -- Politics and government -- 1989-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2794 , http://hdl.handle.net/10962/d1003004 , Growth, Employment And Redistribution Programme (South Africa) , South Africa -- Economic policy , South Africa -- Politics and government -- 1989-1994
- Description: This study is a contribution to the ongoing debate concerning the future of South Africa’s macro-economic policy known as the Growth, Employment and Redistribution (GEAR) strategy. The study attempts to draw parallels between the GEAR macro-economic policy framework and structural adjustment programmes in the South. By making use of this comparison, the study argues that the outcome of the GEAR will be no different from structural adjustment programmes in that it will fail to reduce poverty and cause government to meet the basic needs of the people. These conclusions are drawn from the fact that the GEAR policy is premised on the faith that the market is capable of redistributing income and wealth, and providing people with their basic needs.
- Full Text:
- Date Issued: 2000
Southern African Development Community foreign policy behaviour: the case of trade with external actors
- Authors: Tebu, Perminus Waithaka
- Date: 2000
- Subjects: Southern African Development Community , International trade , Africa, Southern -- Foreign relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2834 , http://hdl.handle.net/10962/d1003044 , Southern African Development Community , International trade , Africa, Southern -- Foreign relations
- Description: This thesis is structured around two main and interwoven assumptions operating at two levels. On the one level the external dimension of security threat in Southern Africa is assumed to be the most critical factor for regional renewal and stability. It hinges on pertinent regional issues such as negative trade balances, economic dependence, poverty, unemployment, poor economic growth rates and so forth. The corollary of this assumption is that within the operative framework of SADC, Southern African states are assumed capable of effectively integrating their economies through trade and related arrangements with dominant external actors in the highly competitive global economy. The European Union (EU) and the United States (US) are used as the focal points for illumination. A structured interaction between SADC and the EU within a revised North-South framework of interaction is hypothesized and critically examined. On the other hand, SADC-US interactions are assessed within the context of the new US Africa policy. At another level, the assumption is also made that the post-apartheid democratic state possesses both the political will and the wherewithal to provide regiol].al Leadership. This latter assumption is put to test within the framework of South Africa's regional foreign policy. Adopting an explicit regional unit of analysis, the study utilizes international regime theory as the theoretical and conceptual point of departure. The realist conception of the international system and the underlying assumptions usually considered as obstacles to international cooperation are critically examined in the context of the post-Cold War expanded security agenda. Regime theory is used to provide insight on the motivations that lead states to cooperate in situations of mutual dilemma by institutionalizing patterns of interaction at the regional and international systemic levels. Interstate economic relations at these levels are explained as state actions that are influenced by certain norms and that such norm-governed behaviour is wholly consistent with the pursuit of national interest. Application of the theory explains why such foreign policy behaviour of states is particularly relevant in the post-Cold War era. The thesis has argued that SADC states are capable of conducting a coordinated trade foreign policy in which regional positions are elaborated and adopted. It is argued further that a regional capacity to institute trade and economic policies that reflect local circumstances (necessary for effective integration with the world economy) calls for strong regional developmental democracies in the tradition of social market economy. Regional leadership by South Africa is considered indispensable where Sbuth Africa must find a sustainable balance between its national and regional interests.
- Full Text:
- Date Issued: 2000
- Authors: Tebu, Perminus Waithaka
- Date: 2000
- Subjects: Southern African Development Community , International trade , Africa, Southern -- Foreign relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2834 , http://hdl.handle.net/10962/d1003044 , Southern African Development Community , International trade , Africa, Southern -- Foreign relations
- Description: This thesis is structured around two main and interwoven assumptions operating at two levels. On the one level the external dimension of security threat in Southern Africa is assumed to be the most critical factor for regional renewal and stability. It hinges on pertinent regional issues such as negative trade balances, economic dependence, poverty, unemployment, poor economic growth rates and so forth. The corollary of this assumption is that within the operative framework of SADC, Southern African states are assumed capable of effectively integrating their economies through trade and related arrangements with dominant external actors in the highly competitive global economy. The European Union (EU) and the United States (US) are used as the focal points for illumination. A structured interaction between SADC and the EU within a revised North-South framework of interaction is hypothesized and critically examined. On the other hand, SADC-US interactions are assessed within the context of the new US Africa policy. At another level, the assumption is also made that the post-apartheid democratic state possesses both the political will and the wherewithal to provide regiol].al Leadership. This latter assumption is put to test within the framework of South Africa's regional foreign policy. Adopting an explicit regional unit of analysis, the study utilizes international regime theory as the theoretical and conceptual point of departure. The realist conception of the international system and the underlying assumptions usually considered as obstacles to international cooperation are critically examined in the context of the post-Cold War expanded security agenda. Regime theory is used to provide insight on the motivations that lead states to cooperate in situations of mutual dilemma by institutionalizing patterns of interaction at the regional and international systemic levels. Interstate economic relations at these levels are explained as state actions that are influenced by certain norms and that such norm-governed behaviour is wholly consistent with the pursuit of national interest. Application of the theory explains why such foreign policy behaviour of states is particularly relevant in the post-Cold War era. The thesis has argued that SADC states are capable of conducting a coordinated trade foreign policy in which regional positions are elaborated and adopted. It is argued further that a regional capacity to institute trade and economic policies that reflect local circumstances (necessary for effective integration with the world economy) calls for strong regional developmental democracies in the tradition of social market economy. Regional leadership by South Africa is considered indispensable where Sbuth Africa must find a sustainable balance between its national and regional interests.
- Full Text:
- Date Issued: 2000
Southern African Journal of Gerontology 1992-2000: Content pages
- Authors: Ferreira, Monica (editor)
- Date: 2000
- Subjects: Gerontology
- Language: English
- Type: Text
- Identifier: vital:8064 , http://hdl.handle.net/10962/d1012657
- Description: Southern African Journal of Gerontology 1992-2000: Content pages compiled by Monica Ferreira
- Full Text:
- Date Issued: 2000
- Authors: Ferreira, Monica (editor)
- Date: 2000
- Subjects: Gerontology
- Language: English
- Type: Text
- Identifier: vital:8064 , http://hdl.handle.net/10962/d1012657
- Description: Southern African Journal of Gerontology 1992-2000: Content pages compiled by Monica Ferreira
- Full Text:
- Date Issued: 2000
Southern African Journal of Gerontology, volume 9, number 1, April 2000
- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 2000
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8080 , http://hdl.handle.net/10962/d1012914
- Description: [From Editorial] Four of the five articles in this issue either deal explicitly with or refer to the effects of the AIDS epidemics in the authors' countries. The fifth paper deals with late-life chronic diseases of life-style. In the first paper, Akinsola examines effects of the epidemic on older Batswana and evaluates the effectiveness of his country's Community Home-Based Care programme against the programme's objectives, with special reference to the situation of older persons as primary caregivers to PWAs and AIDS orphans. He concludes that the situation of older carers calls for strong and urgent policy action to assist this highly vulnerable and marginalized group in its critical and valuable role and function as carers. In her paper on the provision of housing and care for older persons in Zambia, Sichingabula considers implications of the anticipated increases in AIDS morbidity and mortality, in the form of an increased demand for formal housing and care by older Zambians in the face of diminished traditional support. Given effects of the country's Structural Adjustment Programme and the Zambian government's inability to expand provision of formal support for the older population, the author makes recommendations for initiatives which NGOs can undertake towards meeting the needs and improving the quality of life of older persons. Next, Shaibu examines the experiences of caregivers to older persons in Botswana within a context of pervasive, abject poverty and multiple, unmet basic needs. The author notes how the HIV I AIDS epidemic, in addition to other social forces, impacts family structures and the capacity of Batswana to care for older relatives. In their paper, authors Patel, Steyn, Charlton, Bourne, Laubscher, Fourie and Jooste describe the risk-factor profile for chronic diseases of life-style, such as hypertension, hypercholesterolaemia and obesity, in the older black population of Cape Town and compare it with risk profiles in other South African ethnic groups. The authors note that although the study population is still at low risk of cardiovascular disease - for example, demographic changes, including urbanisation and the adoption of urban life-styles, are likely to lead to an increase in chronic morbidity in future older cohorts in this population. In a second paper, Sichingabula assesses the physical and social environment of Divine Providence Home, a residential care facility for destitute older persons in Lusaka, Zambia. She draws practitioners' attention to the prudence of incorporating design features in facilities built for older persons which enhance the users' mobility, independence and quality of life. She also highlights a lack of social stimulation and the inactivity of the residents at the home. The author makes the point that given an anticipated increased demand for admission to residential care facilities as a result of AIDS-related deaths and loss of traditional support for older persons, living environments in these facilities must be optimized. In sum, the AIDS-related research papers in this number highlight a need to identify and to strengthen social and care systems which can assist older persons in Africa, as traditional systems are increasingly affected by demographic forces, particularly the effects of the HIV/AIDS epidemics. Finally, Moller reviews a recent, landmark Help Age International report (1999), which is a compilation of 15 papers on ageing in developing countries and challenges facing research, policy and practice.
- Full Text:
- Date Issued: 2000
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 2000
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8080 , http://hdl.handle.net/10962/d1012914
- Description: [From Editorial] Four of the five articles in this issue either deal explicitly with or refer to the effects of the AIDS epidemics in the authors' countries. The fifth paper deals with late-life chronic diseases of life-style. In the first paper, Akinsola examines effects of the epidemic on older Batswana and evaluates the effectiveness of his country's Community Home-Based Care programme against the programme's objectives, with special reference to the situation of older persons as primary caregivers to PWAs and AIDS orphans. He concludes that the situation of older carers calls for strong and urgent policy action to assist this highly vulnerable and marginalized group in its critical and valuable role and function as carers. In her paper on the provision of housing and care for older persons in Zambia, Sichingabula considers implications of the anticipated increases in AIDS morbidity and mortality, in the form of an increased demand for formal housing and care by older Zambians in the face of diminished traditional support. Given effects of the country's Structural Adjustment Programme and the Zambian government's inability to expand provision of formal support for the older population, the author makes recommendations for initiatives which NGOs can undertake towards meeting the needs and improving the quality of life of older persons. Next, Shaibu examines the experiences of caregivers to older persons in Botswana within a context of pervasive, abject poverty and multiple, unmet basic needs. The author notes how the HIV I AIDS epidemic, in addition to other social forces, impacts family structures and the capacity of Batswana to care for older relatives. In their paper, authors Patel, Steyn, Charlton, Bourne, Laubscher, Fourie and Jooste describe the risk-factor profile for chronic diseases of life-style, such as hypertension, hypercholesterolaemia and obesity, in the older black population of Cape Town and compare it with risk profiles in other South African ethnic groups. The authors note that although the study population is still at low risk of cardiovascular disease - for example, demographic changes, including urbanisation and the adoption of urban life-styles, are likely to lead to an increase in chronic morbidity in future older cohorts in this population. In a second paper, Sichingabula assesses the physical and social environment of Divine Providence Home, a residential care facility for destitute older persons in Lusaka, Zambia. She draws practitioners' attention to the prudence of incorporating design features in facilities built for older persons which enhance the users' mobility, independence and quality of life. She also highlights a lack of social stimulation and the inactivity of the residents at the home. The author makes the point that given an anticipated increased demand for admission to residential care facilities as a result of AIDS-related deaths and loss of traditional support for older persons, living environments in these facilities must be optimized. In sum, the AIDS-related research papers in this number highlight a need to identify and to strengthen social and care systems which can assist older persons in Africa, as traditional systems are increasingly affected by demographic forces, particularly the effects of the HIV/AIDS epidemics. Finally, Moller reviews a recent, landmark Help Age International report (1999), which is a compilation of 15 papers on ageing in developing countries and challenges facing research, policy and practice.
- Full Text:
- Date Issued: 2000
Southern African Journal of Gerontology, volume 9, number 2, October 2000
- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 2000
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8081 , http://hdl.handle.net/10962/d1012915
- Description: [From Editorial] In this special issue of SAJG, an attempt is made to demonstrate how a selection of studies were conducted and how the research outcomes have been translated into action. Heslop, Agyarko, Adjetey-Sorsey and Mapetla give us a paper in which they have evaluated the methodology used in studies in Ghana and South Africa to determine the contributions of older people. After long periods of implementation and learning, this participatory-research methodology has become synonymous with HAl's research work. The authors take us through the methodology, describe the studies carried out in the two countries, and provide us with a vivid picture of not only the problems which older people in the countries face, but also the immense contribution which they make to the well-being of other people. The impact which this work has had in both countries is notable. Older participants in the studies have taken it upon themselves to advocate their rights, and the governments in the two countries have started to put measures in place to address some of the problems identified in the studies. The paper by Van Vuuren and Groenewald examines the pattern of expenditure of pension income by black pension beneficiaries in the Free State Province of South Africa, against a backdrop of these persons' living circumstances. It goes into detail about issues regarding the payment of pensions, pension sharing within households and expenditure of pension money on specific items, and challenges allegations that pensioners are frequently robbed of their pension money and that they lose this income to loan sharks. Some of the findings of this paper contrast with the findings of the HAl studies conducted with partners in the Northem, Gauteng and Kwazulu-Natal provinces of South Africa (see the first paper in this issue by Heslop and colleagues). In their paper, Kowal, Wolfson and Dowd point out that there is a dearth of empirical and credible data on older people in Africa. Although some research has been conducted on this population, the authors note that by and large the available data derive from small samples, are scattered, and have neither been widely disseminated nor shared. The authors further note a lack of common approaches to data collection. Realising these gaps, the World Health Organisation arranged a workshop in Harare, Zimbabwe in January 2000, to begin a process to develop a minimum data set (MDS) for use by researchers in Africa. An overall aim of the MDS project is to provide data to influence policy and decision makers in various areas which affect older persons. , Needs-driven research on nutrition and ageing, carried out by HAl in collaboration with the London School of Hygiene and Tropical Medicine, is reported by Busolo, Ismail and Peachey in their paper. Nutrition and ageing in developing countries is an area which bas received scant attention. The nutritional requirements of older persons in these countries have not only been inadequately investigated but as a result, nutrition practitioners in various settings simply shoot in the dark. The authors take us down the path which the research took, from bow the needs were identified, to how the research was conducted, to how an intervention programme was set up. They give us some key findings of the research, describe the dissemination process and the application of the findings, and suggest a way forward. An Africa-wide programme currently being implemented as a direct result of this work is aimed at providing knowledge and information on the nutritional requirements of older people to key nutrition institutes, older people's organisations, N GOs (particularly those working in emergency situations), donors and governments. HelpAge International earlier conducted research in the Magu district of Tanzania on the plight of older women who are victimised on suspicion of their being witches (cf. Forrester Kibuga, 1999). Forrester Kibuga and Dianga now draw on this work in their paper. The authors take us through facts pertaining to the witchcraft-related killings, some of the problems which older people in the district face, the changing roles of older people in that area, beliefs and customs of the communities, and the stance of the government and the church on witchcraft. The dynamics of gender issues are also discussed. Following on this research, HAl designed and is now implementing a programme aimed at addressing some of the factors which lead up to these killings and developing sustainable structures to protect older people from violence. In his paper, Gorman draws on the work of HAl in various parts of the world, particularly in Africa - including Tanzania, Ghana, South Africa and Kenya. He argues that violence against older women and men in Africa cannot be attributed to a single, straight-forward problem but must be understood within a complex web that touches on history, family structures, and social and economic factors. He makes practical suggestions on what needs to be done to deal with the problem of violence. HelpAge International will soon be implementing an Africa-wide programme as a response to some of the issues which have been raised in its research on violence. While there is a clear need for more research on ageing in Africa, the research should not be done in a vacuum. There is a simultaneous need for greater collaboration and sharing of research results, and perhaps most importantly, for more action based on research outcomes. At the end of the day researchers should never forget that they have an ethical commitment to their subjects, to society and to their colleagues. , Thanks are due to Karen Peachey and Alex Dianga in the HAl Africa Regional Development Centre for the co-ordination of this special issue. Special thanks are due to Monica Ferreira for dedicating the issue to the experience and work of HAl, and for her commitment to addressing issues pertaining to ageing in Africa. She has worked tirelessly to ensure the success of not only this issue of SAJG but of previous issues as well. I have found her a pillar of support and a pleasure to work with. Tavengwa M. Nhongo.
- Full Text:
- Date Issued: 2000
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 2000
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8081 , http://hdl.handle.net/10962/d1012915
- Description: [From Editorial] In this special issue of SAJG, an attempt is made to demonstrate how a selection of studies were conducted and how the research outcomes have been translated into action. Heslop, Agyarko, Adjetey-Sorsey and Mapetla give us a paper in which they have evaluated the methodology used in studies in Ghana and South Africa to determine the contributions of older people. After long periods of implementation and learning, this participatory-research methodology has become synonymous with HAl's research work. The authors take us through the methodology, describe the studies carried out in the two countries, and provide us with a vivid picture of not only the problems which older people in the countries face, but also the immense contribution which they make to the well-being of other people. The impact which this work has had in both countries is notable. Older participants in the studies have taken it upon themselves to advocate their rights, and the governments in the two countries have started to put measures in place to address some of the problems identified in the studies. The paper by Van Vuuren and Groenewald examines the pattern of expenditure of pension income by black pension beneficiaries in the Free State Province of South Africa, against a backdrop of these persons' living circumstances. It goes into detail about issues regarding the payment of pensions, pension sharing within households and expenditure of pension money on specific items, and challenges allegations that pensioners are frequently robbed of their pension money and that they lose this income to loan sharks. Some of the findings of this paper contrast with the findings of the HAl studies conducted with partners in the Northem, Gauteng and Kwazulu-Natal provinces of South Africa (see the first paper in this issue by Heslop and colleagues). In their paper, Kowal, Wolfson and Dowd point out that there is a dearth of empirical and credible data on older people in Africa. Although some research has been conducted on this population, the authors note that by and large the available data derive from small samples, are scattered, and have neither been widely disseminated nor shared. The authors further note a lack of common approaches to data collection. Realising these gaps, the World Health Organisation arranged a workshop in Harare, Zimbabwe in January 2000, to begin a process to develop a minimum data set (MDS) for use by researchers in Africa. An overall aim of the MDS project is to provide data to influence policy and decision makers in various areas which affect older persons. , Needs-driven research on nutrition and ageing, carried out by HAl in collaboration with the London School of Hygiene and Tropical Medicine, is reported by Busolo, Ismail and Peachey in their paper. Nutrition and ageing in developing countries is an area which bas received scant attention. The nutritional requirements of older persons in these countries have not only been inadequately investigated but as a result, nutrition practitioners in various settings simply shoot in the dark. The authors take us down the path which the research took, from bow the needs were identified, to how the research was conducted, to how an intervention programme was set up. They give us some key findings of the research, describe the dissemination process and the application of the findings, and suggest a way forward. An Africa-wide programme currently being implemented as a direct result of this work is aimed at providing knowledge and information on the nutritional requirements of older people to key nutrition institutes, older people's organisations, N GOs (particularly those working in emergency situations), donors and governments. HelpAge International earlier conducted research in the Magu district of Tanzania on the plight of older women who are victimised on suspicion of their being witches (cf. Forrester Kibuga, 1999). Forrester Kibuga and Dianga now draw on this work in their paper. The authors take us through facts pertaining to the witchcraft-related killings, some of the problems which older people in the district face, the changing roles of older people in that area, beliefs and customs of the communities, and the stance of the government and the church on witchcraft. The dynamics of gender issues are also discussed. Following on this research, HAl designed and is now implementing a programme aimed at addressing some of the factors which lead up to these killings and developing sustainable structures to protect older people from violence. In his paper, Gorman draws on the work of HAl in various parts of the world, particularly in Africa - including Tanzania, Ghana, South Africa and Kenya. He argues that violence against older women and men in Africa cannot be attributed to a single, straight-forward problem but must be understood within a complex web that touches on history, family structures, and social and economic factors. He makes practical suggestions on what needs to be done to deal with the problem of violence. HelpAge International will soon be implementing an Africa-wide programme as a response to some of the issues which have been raised in its research on violence. While there is a clear need for more research on ageing in Africa, the research should not be done in a vacuum. There is a simultaneous need for greater collaboration and sharing of research results, and perhaps most importantly, for more action based on research outcomes. At the end of the day researchers should never forget that they have an ethical commitment to their subjects, to society and to their colleagues. , Thanks are due to Karen Peachey and Alex Dianga in the HAl Africa Regional Development Centre for the co-ordination of this special issue. Special thanks are due to Monica Ferreira for dedicating the issue to the experience and work of HAl, and for her commitment to addressing issues pertaining to ageing in Africa. She has worked tirelessly to ensure the success of not only this issue of SAJG but of previous issues as well. I have found her a pillar of support and a pleasure to work with. Tavengwa M. Nhongo.
- Full Text:
- Date Issued: 2000
Spirulina as a bioremediation agent : interaction with metals and involvement of carbonic anhydrase
- Authors: Payne, Rosemary Anne
- Date: 2000
- Subjects: Spirulina , Bioremediation , Carbonic anhydrase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3909 , http://hdl.handle.net/10962/d1003968 , Spirulina , Bioremediation , Carbonic anhydrase
- Description: Heavy metal contamination from mining and other industrial operations is becoming an increasing problem with regards to the depleting water resources in South Africa. This study involved the investigation of the use of an algal biomass as a possible alternative to the traditional chemical means of removing these metals. When the toxic effects of metals were investigated, Spirulina was found to have a threshold level of about 30 μM for copper, zinc and lead. Copper and zinc appeared to have a direct effect on the photosynthetic pathway, thereby causing a rapid decline in cell growth. Lead on the other hand seemed to affect surface properties and hence took longer to cause deterioration in growth. Although relatively low concentrations of metal may have a toxic effect on the cyanobacterium, Spirulina may have potential as a precipitation agent. The role of Spirulina in the precipitation of heavy metals appears to be through its ability to maintain a high pH in the surrounding medium, possibly through the enzyme carbonic anhydrase. Subsequent studies therefore focused on the assay and isolation of this enzyme. Two different radiotracer assays, in which carbonic anhydrase converts radiolabelled bicarbonate to carbon dioxide, were investigated, but were found to have several problems. Results were insensitive and could not be reproduced. The standard Wilbur-Anderson method subsequently investigated also proved to be insensitive with a tremendous degree of variability. Although not quantitative, SDS-PAGE proved to be the most reliable method of detection, and was therefore used in subsequent procedures. Chlamydomonas reinhardtii was the subject of initial enzyme isolation studies as these procedures are well documented. Although the published protocols proved unsuccessful, affinity chromatography of a membrane stock solution from Chlamydomonas reinhardtii yielded two relatively pure protein bands. These bands were presumed to represent two subunits of carbonic anhydrase, although Western blot analysis would be required to confirm their identity. Purification of carbonic anhydrase from Spirulina, however, proved unsuccessful and results obtained were very inconclusive. Hence, further analysis of Spirulina is required. The possibility of cloning CA from a genomic library was also considered, but suitable primers could not be designed from the aligned sequences.
- Full Text:
- Date Issued: 2000
- Authors: Payne, Rosemary Anne
- Date: 2000
- Subjects: Spirulina , Bioremediation , Carbonic anhydrase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3909 , http://hdl.handle.net/10962/d1003968 , Spirulina , Bioremediation , Carbonic anhydrase
- Description: Heavy metal contamination from mining and other industrial operations is becoming an increasing problem with regards to the depleting water resources in South Africa. This study involved the investigation of the use of an algal biomass as a possible alternative to the traditional chemical means of removing these metals. When the toxic effects of metals were investigated, Spirulina was found to have a threshold level of about 30 μM for copper, zinc and lead. Copper and zinc appeared to have a direct effect on the photosynthetic pathway, thereby causing a rapid decline in cell growth. Lead on the other hand seemed to affect surface properties and hence took longer to cause deterioration in growth. Although relatively low concentrations of metal may have a toxic effect on the cyanobacterium, Spirulina may have potential as a precipitation agent. The role of Spirulina in the precipitation of heavy metals appears to be through its ability to maintain a high pH in the surrounding medium, possibly through the enzyme carbonic anhydrase. Subsequent studies therefore focused on the assay and isolation of this enzyme. Two different radiotracer assays, in which carbonic anhydrase converts radiolabelled bicarbonate to carbon dioxide, were investigated, but were found to have several problems. Results were insensitive and could not be reproduced. The standard Wilbur-Anderson method subsequently investigated also proved to be insensitive with a tremendous degree of variability. Although not quantitative, SDS-PAGE proved to be the most reliable method of detection, and was therefore used in subsequent procedures. Chlamydomonas reinhardtii was the subject of initial enzyme isolation studies as these procedures are well documented. Although the published protocols proved unsuccessful, affinity chromatography of a membrane stock solution from Chlamydomonas reinhardtii yielded two relatively pure protein bands. These bands were presumed to represent two subunits of carbonic anhydrase, although Western blot analysis would be required to confirm their identity. Purification of carbonic anhydrase from Spirulina, however, proved unsuccessful and results obtained were very inconclusive. Hence, further analysis of Spirulina is required. The possibility of cloning CA from a genomic library was also considered, but suitable primers could not be designed from the aligned sequences.
- Full Text:
- Date Issued: 2000
Stability of prochlorperazine in solution and in the solid-state
- Authors: Antunes, Edith Martins
- Date: 2000
- Subjects: Phenothiazine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4536 , http://hdl.handle.net/10962/d1016399
- Description: Prochlorperazine, a member of the piperazine subclass of phenothiazines, widely used as an anti-emetic, is susceptible to oxidation to sulfoxides. These are main metabolites and degradants of all phenothiazines which are found to be inactive at the dopamine receptors. Prochlorperazine causes photosensitivity effects in patients attributed to dechlorination at C2 with the release of HCI (Huang and Sands, 1967; Nejmeh and Pilpel, 1978; Moore and Tamat, 1980). The aim of this study is to investigate the thermal and photostability of prochlorperazine edisylate and mesylate salts in the solid state and in solution. Prochlorperazine is available as a fine chemical and in a variety of dosage forms, including injectables and tablets. According to ICH guidelines, any degradants greater than 0.1 % are required to be isolated and identified. In order to assess the photostability of the two salts, an HPLC method was developed and validated for linearity, accuracy and precision, selectivity, limit of detection, quantitation and ruggedness. Sulfoxides were synthesised for use as standards in the rate studies according to the well-known hydrogen peroxide method (Owens et al., 1989). The rate of prochlorperazine degradation in solution under various light sources (254 nm UV light, diffuse light and sunlight) was studied. The light sources used abovF were quantified using potassium ferrioxalate as a chemical actinometer). The photodegradation rate was found to be greater in ampoules sealed under nitrogen than air, but the thermal degradation was faster in ampoules sealed with air than those purged with nitrogen. Amber ampoules retarded the rate of degradation under all photolytic conditions. This is a vital consideration for the packaging and storage of prochlorperazine in injectables. Degradation was found to occur mainly by first-order kinetics and the degradation rate decreased in the following order: sunlight » UV light 254 nm > fluorescent I diffuse light. Solid state samples, however, were found to be relatively stable to the various light / heat conditions over a 6 month period when compared to prochlorperazine solutions, but still considerably unstable. Thus both storage and packaging is a vital consideration for prochlorperazine injectables. The thermal behaviour of mixtures of prochlorperazine with standard excipients, was assessed for potential interactions, using differential scanning calorimetry. For most of the excipients (magnesium stearate, stearic acid, Explotab®, AC-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500®) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab®, however, was the only 'inert' excipient tested. Liquid chromatography - mass spectrometry (LC-MS) was used to determine the nature of the degradation products. The major degradation pathways included dechlorination and demethylation of the parent drug, as well as sulfoxidation and Noxidation. Prochlorperazine underwent dechlorination and sulfoxidation with subsequent photosubstitution to yield the 2-hydroxy derivative. The solid state photostudies showed the formation of dealkylated, oxidised and hydroxylated products, sulfoxides and dimers. Since N-demethylation, N-oxidation, sulfoxidation and aromatic hydroxylation are reported to occur in the in vitro metabolism of perazine derivatives, it does appear that there is some relationship between metabolites and photoproducts (Breyer, 1974). This study has been successful in providing understanding of the photolytic and thermal degradation pathways of prochlorperazine.
- Full Text:
- Date Issued: 2000
- Authors: Antunes, Edith Martins
- Date: 2000
- Subjects: Phenothiazine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4536 , http://hdl.handle.net/10962/d1016399
- Description: Prochlorperazine, a member of the piperazine subclass of phenothiazines, widely used as an anti-emetic, is susceptible to oxidation to sulfoxides. These are main metabolites and degradants of all phenothiazines which are found to be inactive at the dopamine receptors. Prochlorperazine causes photosensitivity effects in patients attributed to dechlorination at C2 with the release of HCI (Huang and Sands, 1967; Nejmeh and Pilpel, 1978; Moore and Tamat, 1980). The aim of this study is to investigate the thermal and photostability of prochlorperazine edisylate and mesylate salts in the solid state and in solution. Prochlorperazine is available as a fine chemical and in a variety of dosage forms, including injectables and tablets. According to ICH guidelines, any degradants greater than 0.1 % are required to be isolated and identified. In order to assess the photostability of the two salts, an HPLC method was developed and validated for linearity, accuracy and precision, selectivity, limit of detection, quantitation and ruggedness. Sulfoxides were synthesised for use as standards in the rate studies according to the well-known hydrogen peroxide method (Owens et al., 1989). The rate of prochlorperazine degradation in solution under various light sources (254 nm UV light, diffuse light and sunlight) was studied. The light sources used abovF were quantified using potassium ferrioxalate as a chemical actinometer). The photodegradation rate was found to be greater in ampoules sealed under nitrogen than air, but the thermal degradation was faster in ampoules sealed with air than those purged with nitrogen. Amber ampoules retarded the rate of degradation under all photolytic conditions. This is a vital consideration for the packaging and storage of prochlorperazine in injectables. Degradation was found to occur mainly by first-order kinetics and the degradation rate decreased in the following order: sunlight » UV light 254 nm > fluorescent I diffuse light. Solid state samples, however, were found to be relatively stable to the various light / heat conditions over a 6 month period when compared to prochlorperazine solutions, but still considerably unstable. Thus both storage and packaging is a vital consideration for prochlorperazine injectables. The thermal behaviour of mixtures of prochlorperazine with standard excipients, was assessed for potential interactions, using differential scanning calorimetry. For most of the excipients (magnesium stearate, stearic acid, Explotab®, AC-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500®) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab®, however, was the only 'inert' excipient tested. Liquid chromatography - mass spectrometry (LC-MS) was used to determine the nature of the degradation products. The major degradation pathways included dechlorination and demethylation of the parent drug, as well as sulfoxidation and Noxidation. Prochlorperazine underwent dechlorination and sulfoxidation with subsequent photosubstitution to yield the 2-hydroxy derivative. The solid state photostudies showed the formation of dealkylated, oxidised and hydroxylated products, sulfoxides and dimers. Since N-demethylation, N-oxidation, sulfoxidation and aromatic hydroxylation are reported to occur in the in vitro metabolism of perazine derivatives, it does appear that there is some relationship between metabolites and photoproducts (Breyer, 1974). This study has been successful in providing understanding of the photolytic and thermal degradation pathways of prochlorperazine.
- Full Text:
- Date Issued: 2000
Strategic analysis of the South African motor manufacturing industry's changing business environment
- Authors: Stockwell, Cecil
- Date: 2000
- Subjects: Automobile industry and trade -- South Africa , Automobile industry and trade -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10840 , http://hdl.handle.net/10948/36 , Automobile industry and trade -- South Africa , Automobile industry and trade -- Management
- Description: Introduction: The South African economy has shown very little economic growth and car sales declined steadily from 1988 till they increased slightly in 1999. 2000 saw the economy recovering from a recession, and motor vehicle sales increasing. In order for the South African motor manufacturing industry to remain viable, the manufacturers, who must operate within the framework of the Motor Industry Development Plan, face increasing international competition as the large motor firms from around the world strive to gain a foothold in Africa in anticipation of an “African Renaissance.” South African manufacturers have to develop appropriate strategies to ensure profitability and survival in the new millennium. This entails a thorough analysis of the changing business environment the industry finds itself trading in.
- Full Text:
- Date Issued: 2000
Strategic analysis of the South African motor manufacturing industry's changing business environment
- Authors: Stockwell, Cecil
- Date: 2000
- Subjects: Automobile industry and trade -- South Africa , Automobile industry and trade -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10840 , http://hdl.handle.net/10948/36 , Automobile industry and trade -- South Africa , Automobile industry and trade -- Management
- Description: Introduction: The South African economy has shown very little economic growth and car sales declined steadily from 1988 till they increased slightly in 1999. 2000 saw the economy recovering from a recession, and motor vehicle sales increasing. In order for the South African motor manufacturing industry to remain viable, the manufacturers, who must operate within the framework of the Motor Industry Development Plan, face increasing international competition as the large motor firms from around the world strive to gain a foothold in Africa in anticipation of an “African Renaissance.” South African manufacturers have to develop appropriate strategies to ensure profitability and survival in the new millennium. This entails a thorough analysis of the changing business environment the industry finds itself trading in.
- Full Text:
- Date Issued: 2000
Strike comparison of the compositional variations of the lower group and middle group chromitite seams of the critical zone, Western Bushveld complex
- Authors: Doig, Heather Leslie
- Date: 2000
- Subjects: Chromite -- South Africa , Geology -- South Africa , Mineralogy -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5005 , http://hdl.handle.net/10962/d1005618
- Description: The variations in the composition, specifically the Cr20 S content and the Cr:Fe ratio, and the morphology of the Lower Group (LG) and Middle Group (MG) chromitite seams of the Critical Zone (CZ) across the western Bushveld Complex, including the Ruighoek and Brits sections, is investigated by means of whole-rock chemical data, both major and trace elements analysis, XRD and electron microprobe data. As a result ofthe paucity of exposed or developed LG1 - LG5 chromitite seams in the western Bushveld Complex, this study is confined to the investigation of the compositional variations of the LG6 to MG4 chromitite seams. In only one section, the Ruighoek section, was the entire succession of chromitite seams, from the LG1 - MG4, exposed. The silicate host rocks from the LG6 pyroxenite footwall to the collar of the CC2 drillcore (lower uCZ) in the Rustenburg section were sampled. This study reviews the compositional trends of the silicate host rocks, as the compositional variations of the chromitite seams reflect the chemical evolution of the host cumulate environment and, to a lesser degree, the composition onhe interstitial mineral phases in the chromitite seams. The compositional variations of the LG and MG chromitite seams are attributed to the compositional contrast between the replenishing magma and the resident magma. The chemical trends of the LG and MG chromitite layers and the host cumUlate rOCKS do not support the existence of two compositionalfy dissimilar magmas in the CZ, rather the cyclic layering of the CZ and the chemical variations of the chromitite seams are attributed to the mixing of primitive magma with the resident magma, both of which have essentially similar compositions. The compositional variations of the LG and MG chromitite seams along strike away from the supposed feeder site (Union section) to the distal facies (Brits section) are attributed to the advanced compositional contrast between the resident magma and the replenishing primitive magma pulses. The CZ is characterized by reversals in fractionation trends and this is attributed to the compositional evolution of the parental magma and not to the replenishment of the resident magma by influxes of grossly dissimilar magma compositions. The Cr20 S content and the Cr:Fe ratio of the MG chromitite layers increase from the Ruighoek (near proximal) section to the Brits section (distal facies). This is attributed to the advanced compositional contrasts between the resident magma and the replenishing primitive magma. In contrast, the Cr20 3 content and Cr:Fe ratios ofthe LG6 and LG8a chromitite seams decreases eastwards from the Ruighoek section. The average Cr:Fe ratio for the western Bushveld Complex is between 1.5 and\2.0, nonetheless, a progressively lower Cr:Fe ratio is noted from the LG1 chromitite up through to the MG4 chromitite seam in the Ruighoek section. tn the LG2 - LG4 chromitite interval a deviation to higher.lratios is encountered. A progressive substitution of Cr by AT and Fe in the Cr-spinel crystal lattice characterizes the chromitite succession from the LG1 seam up through the chromitite succession to MG4. The petrogeneSiS of the chromitite seams of the CZ is attributed to magma mixing and fractional crystallization of a single magma type.
- Full Text:
- Date Issued: 2000
- Authors: Doig, Heather Leslie
- Date: 2000
- Subjects: Chromite -- South Africa , Geology -- South Africa , Mineralogy -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5005 , http://hdl.handle.net/10962/d1005618
- Description: The variations in the composition, specifically the Cr20 S content and the Cr:Fe ratio, and the morphology of the Lower Group (LG) and Middle Group (MG) chromitite seams of the Critical Zone (CZ) across the western Bushveld Complex, including the Ruighoek and Brits sections, is investigated by means of whole-rock chemical data, both major and trace elements analysis, XRD and electron microprobe data. As a result ofthe paucity of exposed or developed LG1 - LG5 chromitite seams in the western Bushveld Complex, this study is confined to the investigation of the compositional variations of the LG6 to MG4 chromitite seams. In only one section, the Ruighoek section, was the entire succession of chromitite seams, from the LG1 - MG4, exposed. The silicate host rocks from the LG6 pyroxenite footwall to the collar of the CC2 drillcore (lower uCZ) in the Rustenburg section were sampled. This study reviews the compositional trends of the silicate host rocks, as the compositional variations of the chromitite seams reflect the chemical evolution of the host cumulate environment and, to a lesser degree, the composition onhe interstitial mineral phases in the chromitite seams. The compositional variations of the LG and MG chromitite seams are attributed to the compositional contrast between the replenishing magma and the resident magma. The chemical trends of the LG and MG chromitite layers and the host cumUlate rOCKS do not support the existence of two compositionalfy dissimilar magmas in the CZ, rather the cyclic layering of the CZ and the chemical variations of the chromitite seams are attributed to the mixing of primitive magma with the resident magma, both of which have essentially similar compositions. The compositional variations of the LG and MG chromitite seams along strike away from the supposed feeder site (Union section) to the distal facies (Brits section) are attributed to the advanced compositional contrast between the resident magma and the replenishing primitive magma pulses. The CZ is characterized by reversals in fractionation trends and this is attributed to the compositional evolution of the parental magma and not to the replenishment of the resident magma by influxes of grossly dissimilar magma compositions. The Cr20 S content and the Cr:Fe ratio of the MG chromitite layers increase from the Ruighoek (near proximal) section to the Brits section (distal facies). This is attributed to the advanced compositional contrasts between the resident magma and the replenishing primitive magma. In contrast, the Cr20 3 content and Cr:Fe ratios ofthe LG6 and LG8a chromitite seams decreases eastwards from the Ruighoek section. The average Cr:Fe ratio for the western Bushveld Complex is between 1.5 and\2.0, nonetheless, a progressively lower Cr:Fe ratio is noted from the LG1 chromitite up through to the MG4 chromitite seam in the Ruighoek section. tn the LG2 - LG4 chromitite interval a deviation to higher.lratios is encountered. A progressive substitution of Cr by AT and Fe in the Cr-spinel crystal lattice characterizes the chromitite succession from the LG1 seam up through the chromitite succession to MG4. The petrogeneSiS of the chromitite seams of the CZ is attributed to magma mixing and fractional crystallization of a single magma type.
- Full Text:
- Date Issued: 2000
Structural and synthetic investigations of South African marine natural products
- Authors: Beukes, Denzil Ronwynne
- Date: 2000
- Subjects: Natural products -- South Africa Marine invertebrates -- South Africa Marine metabolites -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4350 , http://hdl.handle.net/10962/d1005015
- Description: A chemical investigation of six different marine invertebrates, collected along the South African coastline, resulted in the isolation and structural elucidation of fifteen previously undescribed secondary metabolites along with seven known compounds. The structures of the new metabolites were determined by a combination of spectroscopic and chemical methods. The endemic false limpet Siphonaria capensis was shown to contain two unusual polypropionate metabolites capensinone (162) and capensifuranone (163) as well as 2,4,6,8-tetramethyl-2-undecenoic acid (164) and the known polypropionates (E)- and (Z)siphonarienfuranone (149 and 161). Capensinone is the first example of a marine polypropionate containing a cyc1opentenone moiety. An investigation of the endemic South African soft coral Pieterfaurea unilobata yielded six new, highly oxygenated, pregnadiene sterols (180-185) and the known metabolite (169). Compounds 180-185 are the first pregnadienes obtained from the marine environment containing a C-7 substituent. An alternative procedure for the quick assignment of the absolute configuration at C-3 in this series of compounds was proposed. A companson of the pyrroloiminoquinone alkaloids of three undescribed l'}trunculid sponges resulted in the isolation of 3-dih¥drodiscorhabdin C (243), 3-dihydrodiscorhabdin B (244), discorhabdin H (197) and the previously reported alkaloids discorhabdin A (189) and discorhabdin D (192). While all three sponges were found to be morphologically different they all contained discorhabdin A as the major metabolite and discorhabdin H as one of their minor metabolites. It was found that a feature common to most of the South African latrunculid sponges is the reduction of the C-3 carbonyl gr,o up in some of the minor metabolites. The indole alkaloids, dilemmaones A-C (261-263), containing an unusual cyc1opentanone-indole skeleton, were isolated in trace amounts by bioassay guided fractionation of an extract obtained from a mixed collection of sponges collected near Cape Town. In an attempt to acquire more of these novel compounds for further investigation of their biological activity, several synthetic strategies towards their total synthesis were explored. A key feature of these approaches was the exploitation of the regioselective Gassman's artha-alkylation procedure for the introduction of an aromatic methyl substituent.
- Full Text:
- Date Issued: 2000
- Authors: Beukes, Denzil Ronwynne
- Date: 2000
- Subjects: Natural products -- South Africa Marine invertebrates -- South Africa Marine metabolites -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4350 , http://hdl.handle.net/10962/d1005015
- Description: A chemical investigation of six different marine invertebrates, collected along the South African coastline, resulted in the isolation and structural elucidation of fifteen previously undescribed secondary metabolites along with seven known compounds. The structures of the new metabolites were determined by a combination of spectroscopic and chemical methods. The endemic false limpet Siphonaria capensis was shown to contain two unusual polypropionate metabolites capensinone (162) and capensifuranone (163) as well as 2,4,6,8-tetramethyl-2-undecenoic acid (164) and the known polypropionates (E)- and (Z)siphonarienfuranone (149 and 161). Capensinone is the first example of a marine polypropionate containing a cyc1opentenone moiety. An investigation of the endemic South African soft coral Pieterfaurea unilobata yielded six new, highly oxygenated, pregnadiene sterols (180-185) and the known metabolite (169). Compounds 180-185 are the first pregnadienes obtained from the marine environment containing a C-7 substituent. An alternative procedure for the quick assignment of the absolute configuration at C-3 in this series of compounds was proposed. A companson of the pyrroloiminoquinone alkaloids of three undescribed l'}trunculid sponges resulted in the isolation of 3-dih¥drodiscorhabdin C (243), 3-dihydrodiscorhabdin B (244), discorhabdin H (197) and the previously reported alkaloids discorhabdin A (189) and discorhabdin D (192). While all three sponges were found to be morphologically different they all contained discorhabdin A as the major metabolite and discorhabdin H as one of their minor metabolites. It was found that a feature common to most of the South African latrunculid sponges is the reduction of the C-3 carbonyl gr,o up in some of the minor metabolites. The indole alkaloids, dilemmaones A-C (261-263), containing an unusual cyc1opentanone-indole skeleton, were isolated in trace amounts by bioassay guided fractionation of an extract obtained from a mixed collection of sponges collected near Cape Town. In an attempt to acquire more of these novel compounds for further investigation of their biological activity, several synthetic strategies towards their total synthesis were explored. A key feature of these approaches was the exploitation of the regioselective Gassman's artha-alkylation procedure for the introduction of an aromatic methyl substituent.
- Full Text:
- Date Issued: 2000
Studies of the population structure and generic diversity of domesticated and "wild" ostriches (Struthio camelus)
- Bezuidenhout, Cornelius Carlos
- Authors: Bezuidenhout, Cornelius Carlos
- Date: 2000
- Subjects: Ostriches Ostriches -- Genetics Ostriches -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3907 , http://hdl.handle.net/10962/d1003966
- Description: DNA sequencing and restriction fragment length polymorphism analysis (RFLP) of polymerase chain reaction (PCR) amplified mitochondrial DNA fragments, and random amplified polymorphic DNA sequence (RAPD) analysis were techniques evaluated in this study for applicability in the investigation various aspects of genetic diversity within the ostrich (Struthio camelus). The genetic aspects that were investigated were (i) relationships between ostrich subspecies, (ii) genetic variability between and within domesticated populations of southern African ostriches (Struthio camelus australis), (iii) linking egg production in domesticated ostriches to RAPD profiles, and (iv) determining the zygosity of twin ostriches. In the first part of this study DNA sequencing and the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) methods were evaluated for resolving genetic differences in the small mtDNA fragments ofthe ostrich. DNA sequencing ofPCR amplified 450 bp 12S rRNA gene fragments of representatives from the southern African population ostrich (S.c. australis) did not reveal any differences between the populatiohs from different geographical areas, representing ostrich lineages with different breeding histories. The PCRRFLP analysis ofmtDNA fragments (450 bp 12S rRNA gene fragment and 550 bp D-loop region) also did not reveal any genetic variability between the domesticated s.,c. australis populations included in this study. PCR-RFLP analysis of a 450 bp 12S rRNA gene fragment, however, showed differences between the subspecies s.c. australis and s.c. molybdophanes. The proportion of shared fragments (F) between these two subspecies was 0.286 and nucleotide sequence divergence estimated at 8.9 %. Divergence time between these two subspecies was estimated at 4.5 million years ago. The data presented from this study are comparable to the data from a previous study in which the entire mitochondrial genome and a larger number of restriction enzymes were used. The PCR-RFLP method thus demonstrated its usefulness for genetic studies of ostriches at thesubspecies level. The sequences used in this study could not reveal any markers that were useful for genetic studies of ostriches at the population level. In the second part of the study the RAPD method was evaluated for application in the genetic studies of ostriches. RAPD profiles, based on three RAPD primers, revealed differences between three subspecies of ostriches and indicated relationships between these subspecies that are consistent with observations from other studies. The numerical analysis of pooled and individual primer data demonstrated that the subspecies s.c. australis is more closely related to s.c. massaicus than to s.c. molybdophanes. RAPD marker differences between s.c. molybdophanes on the one hand, and s.c. massaicus and s.c. australis on the other is also consistent with observations from studies that proposed separate specie~ status for s.c. molybdophanes. RAPD analysis by five primers revealed geographic variation between s.c. australis populations. The clustering patterns observed in the dendrograms and Neighbour Joining Trees generated by computer programs showed trends of separating ostric1;t populations into geographical groups, possibly reflecting their different breeding histories. In the RAPD profiles of the inbred population, band-sharing was generally greater than in the outbreeding group. RAPD analysis thus showed that it may be a useful method in the population studies of domesticated S. c. australis. RAPDs also generated data that grouped ostriches according to trends in egg production capabilities. Analysis ofRAPD profiles by computer software showed a Neighbour Joining Tree and a dendrogram that predominantly grouped ostriches into clusters associated with either good or poor egg production. Evidence supporting the suitability of RAPDs as a tool in breeding programmes of ostriches was thus provided by this study. RAPDs also provided data, demonstrating that two sets of ostrich twins were non-identical twins. It was demonstrated by this study that RAPDs analysis may be a useful technique for applying to (1) systematic (2) population (3) breeding and (4) twin studies of ostriches (Struthio camelus).
- Full Text:
- Date Issued: 2000
- Authors: Bezuidenhout, Cornelius Carlos
- Date: 2000
- Subjects: Ostriches Ostriches -- Genetics Ostriches -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3907 , http://hdl.handle.net/10962/d1003966
- Description: DNA sequencing and restriction fragment length polymorphism analysis (RFLP) of polymerase chain reaction (PCR) amplified mitochondrial DNA fragments, and random amplified polymorphic DNA sequence (RAPD) analysis were techniques evaluated in this study for applicability in the investigation various aspects of genetic diversity within the ostrich (Struthio camelus). The genetic aspects that were investigated were (i) relationships between ostrich subspecies, (ii) genetic variability between and within domesticated populations of southern African ostriches (Struthio camelus australis), (iii) linking egg production in domesticated ostriches to RAPD profiles, and (iv) determining the zygosity of twin ostriches. In the first part of this study DNA sequencing and the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) methods were evaluated for resolving genetic differences in the small mtDNA fragments ofthe ostrich. DNA sequencing ofPCR amplified 450 bp 12S rRNA gene fragments of representatives from the southern African population ostrich (S.c. australis) did not reveal any differences between the populatiohs from different geographical areas, representing ostrich lineages with different breeding histories. The PCRRFLP analysis ofmtDNA fragments (450 bp 12S rRNA gene fragment and 550 bp D-loop region) also did not reveal any genetic variability between the domesticated s.,c. australis populations included in this study. PCR-RFLP analysis of a 450 bp 12S rRNA gene fragment, however, showed differences between the subspecies s.c. australis and s.c. molybdophanes. The proportion of shared fragments (F) between these two subspecies was 0.286 and nucleotide sequence divergence estimated at 8.9 %. Divergence time between these two subspecies was estimated at 4.5 million years ago. The data presented from this study are comparable to the data from a previous study in which the entire mitochondrial genome and a larger number of restriction enzymes were used. The PCR-RFLP method thus demonstrated its usefulness for genetic studies of ostriches at thesubspecies level. The sequences used in this study could not reveal any markers that were useful for genetic studies of ostriches at the population level. In the second part of the study the RAPD method was evaluated for application in the genetic studies of ostriches. RAPD profiles, based on three RAPD primers, revealed differences between three subspecies of ostriches and indicated relationships between these subspecies that are consistent with observations from other studies. The numerical analysis of pooled and individual primer data demonstrated that the subspecies s.c. australis is more closely related to s.c. massaicus than to s.c. molybdophanes. RAPD marker differences between s.c. molybdophanes on the one hand, and s.c. massaicus and s.c. australis on the other is also consistent with observations from studies that proposed separate specie~ status for s.c. molybdophanes. RAPD analysis by five primers revealed geographic variation between s.c. australis populations. The clustering patterns observed in the dendrograms and Neighbour Joining Trees generated by computer programs showed trends of separating ostric1;t populations into geographical groups, possibly reflecting their different breeding histories. In the RAPD profiles of the inbred population, band-sharing was generally greater than in the outbreeding group. RAPD analysis thus showed that it may be a useful method in the population studies of domesticated S. c. australis. RAPDs also generated data that grouped ostriches according to trends in egg production capabilities. Analysis ofRAPD profiles by computer software showed a Neighbour Joining Tree and a dendrogram that predominantly grouped ostriches into clusters associated with either good or poor egg production. Evidence supporting the suitability of RAPDs as a tool in breeding programmes of ostriches was thus provided by this study. RAPDs also provided data, demonstrating that two sets of ostrich twins were non-identical twins. It was demonstrated by this study that RAPDs analysis may be a useful technique for applying to (1) systematic (2) population (3) breeding and (4) twin studies of ostriches (Struthio camelus).
- Full Text:
- Date Issued: 2000
Stuffed birds on trees: an historical review of avian systematics in southern Africa
- Authors: Craig, Adrian J F K
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6931 , http://hdl.handle.net/10962/d1011949
- Description: Avian systematics in southern Africa has been heavily dependent on a small number of museum-based specialists. They produced bird checklists which prescribed the names to be used by other scientists. After an initial phase of cataloguing the avifauna, a major preoccupation was the description of geographical variation, which was documented in an extensive subspecific nomenclature. Until recent years, few African ornithologists have been involved in systematics as a biological discipline. This historical overview considers the contribution of particular individuals from Andrew Smith to Phillip Clancey.
- Full Text: false
- Date Issued: 2000
- Authors: Craig, Adrian J F K
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6931 , http://hdl.handle.net/10962/d1011949
- Description: Avian systematics in southern Africa has been heavily dependent on a small number of museum-based specialists. They produced bird checklists which prescribed the names to be used by other scientists. After an initial phase of cataloguing the avifauna, a major preoccupation was the description of geographical variation, which was documented in an extensive subspecific nomenclature. Until recent years, few African ornithologists have been involved in systematics as a biological discipline. This historical overview considers the contribution of particular individuals from Andrew Smith to Phillip Clancey.
- Full Text: false
- Date Issued: 2000
Stump size and the number of coppice shoots for selected savanna tree species
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181896 , vital:43778 , xlink:href="https://doi.org/10.1016/S0254-6299(15)31074-7"
- Description: Management of coppice dynamics of indigenous savanna trees could assist in increasing the regrowth rates or number of coppice shoots produced. This would be useful in natural resource management programmes to promote sustainable resource management. This study examined the influence of cutting height, stem size and surface area on the number of coppice shoots produced for twelve savanna species from a communal land in the Bushbuckndge lowveld. All species exhibited a strong coppicing ability following cutting. The number of shoots per stump was most frequently related to cutting height, although this was not always the most significant predictor. There were clear differences between species with respect to the number of shoots per unit surface area, the highest being for Albizia harveyii and the least Piliostlgma thonningii. The taller the potential height of a species, the fewer were the coppice shoots per stump surface area.
- Full Text:
- Date Issued: 2000
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181896 , vital:43778 , xlink:href="https://doi.org/10.1016/S0254-6299(15)31074-7"
- Description: Management of coppice dynamics of indigenous savanna trees could assist in increasing the regrowth rates or number of coppice shoots produced. This would be useful in natural resource management programmes to promote sustainable resource management. This study examined the influence of cutting height, stem size and surface area on the number of coppice shoots produced for twelve savanna species from a communal land in the Bushbuckndge lowveld. All species exhibited a strong coppicing ability following cutting. The number of shoots per stump was most frequently related to cutting height, although this was not always the most significant predictor. There were clear differences between species with respect to the number of shoots per unit surface area, the highest being for Albizia harveyii and the least Piliostlgma thonningii. The taller the potential height of a species, the fewer were the coppice shoots per stump surface area.
- Full Text:
- Date Issued: 2000
Suba
- Rokia Traore (author, composer, arranger, interpreter, lead singer, guitar), Coco Mbassi, Rokia Traore (chorus), Andra Kouyate (N'Goni Ba), Label Bleu
- Authors: Rokia Traore (author, composer, arranger, interpreter, lead singer, guitar) , Coco Mbassi, Rokia Traore (chorus) , Andra Kouyate (N'Goni Ba) , Label Bleu
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cameroon Yaounde f-cm
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/131028 , vital:36516 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC49-03
- Description: Non-Malian vocal style and multilayered singing accompanied by traditional Malian instuments played with a modern edge
- Full Text: false
- Date Issued: 2000
- Authors: Rokia Traore (author, composer, arranger, interpreter, lead singer, guitar) , Coco Mbassi, Rokia Traore (chorus) , Andra Kouyate (N'Goni Ba) , Label Bleu
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cameroon Yaounde f-cm
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/131028 , vital:36516 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC49-03
- Description: Non-Malian vocal style and multilayered singing accompanied by traditional Malian instuments played with a modern edge
- Full Text: false
- Date Issued: 2000
Sulphide-enhanced hydrolysis of primary sewage sludge : implications for the bioremediation of sulphate-enriched wastewaters
- Whittington-Jones, Kevin John
- Authors: Whittington-Jones, Kevin John
- Date: 2000
- Subjects: Bioremediation Sewage sludge Hydrolysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3910 , http://hdl.handle.net/10962/d1003969
- Description: The potential application of sulphate reducing bacteria for the bioremediation of acid mine drainage has already been recognised, and offers significant financial advantages over conventional chemical treatment approaches. Although the technology has been demonstrated successfully on both small- and large-scale, it’s extensive implementation has been constrained by the provision of suitable and cost effective electron donor and carbon sources. Primary sewage sludge is readily available in large quantities, but the slow rate of solubilization and low yield of soluble products do not apparently favour its use for this application. A number of pre-treatment steps have been introduced in an attempt to improve the yield and rates under methanogenic conditions. However, although early work suggested that degradation of lignocellulose and proteins may be more rapid under sulphate reducing conditions, the fate of primary sewage sludge under these conditions has been ignored. It was proposed that by combining the hydrolysis of primary sewage sludge and biological sulphate reduction, in a settling sludge bed, both processes would be enhanced. The aim of this study was to test this hypothesis on laboratory- and pilot-scale, and attempt to elucidate the underlying mechanism involved. The solubilization of primary sewage sludge was enhanced in the presence of sulphate reduction in continuous laboratory-scale reactors. Particulate matter accumulated in the bed of non-sulphidogenic systems, but not in sulphidogenic ones. This was attributed to increased solubilization and the smaller average floc size in the latter. Solubilization occurred within the settling sludge bed of the reactors, and offered a possible explanation for the better performance of the multiple- over single-stage reactor. A pilot-scale Falling Sludge Bed Reactor was constructed at Grootvlei Gold Mine, Springs, South Africa, and resulted in the solubilization of more than 70% of the influent primary sewage sludge. The system was also found to be highly resilient to severe perturbations, and returned rapidly to steady-state. Flask studies revealed that the hydrolysis of both proteins and complex carbohydrates was accelerated in the presence of biological sulphate reduction or sulphide. A study of the enzymology of sludge digestion revealed that sulphate reduction had little direct effect on the activity of the hydrolytic enzymes, but that reactor design was critical in the prevention of washout of these enzymes. Finally, a descriptive model was developed to explain the enhanced hydrolysis of primary sewage sludge. The model incorporated the effect of sulphidogenesis on floc fracture and reflocculation, and likely implications for mass transfer limitations.
- Full Text:
- Date Issued: 2000
- Authors: Whittington-Jones, Kevin John
- Date: 2000
- Subjects: Bioremediation Sewage sludge Hydrolysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3910 , http://hdl.handle.net/10962/d1003969
- Description: The potential application of sulphate reducing bacteria for the bioremediation of acid mine drainage has already been recognised, and offers significant financial advantages over conventional chemical treatment approaches. Although the technology has been demonstrated successfully on both small- and large-scale, it’s extensive implementation has been constrained by the provision of suitable and cost effective electron donor and carbon sources. Primary sewage sludge is readily available in large quantities, but the slow rate of solubilization and low yield of soluble products do not apparently favour its use for this application. A number of pre-treatment steps have been introduced in an attempt to improve the yield and rates under methanogenic conditions. However, although early work suggested that degradation of lignocellulose and proteins may be more rapid under sulphate reducing conditions, the fate of primary sewage sludge under these conditions has been ignored. It was proposed that by combining the hydrolysis of primary sewage sludge and biological sulphate reduction, in a settling sludge bed, both processes would be enhanced. The aim of this study was to test this hypothesis on laboratory- and pilot-scale, and attempt to elucidate the underlying mechanism involved. The solubilization of primary sewage sludge was enhanced in the presence of sulphate reduction in continuous laboratory-scale reactors. Particulate matter accumulated in the bed of non-sulphidogenic systems, but not in sulphidogenic ones. This was attributed to increased solubilization and the smaller average floc size in the latter. Solubilization occurred within the settling sludge bed of the reactors, and offered a possible explanation for the better performance of the multiple- over single-stage reactor. A pilot-scale Falling Sludge Bed Reactor was constructed at Grootvlei Gold Mine, Springs, South Africa, and resulted in the solubilization of more than 70% of the influent primary sewage sludge. The system was also found to be highly resilient to severe perturbations, and returned rapidly to steady-state. Flask studies revealed that the hydrolysis of both proteins and complex carbohydrates was accelerated in the presence of biological sulphate reduction or sulphide. A study of the enzymology of sludge digestion revealed that sulphate reduction had little direct effect on the activity of the hydrolytic enzymes, but that reactor design was critical in the prevention of washout of these enzymes. Finally, a descriptive model was developed to explain the enhanced hydrolysis of primary sewage sludge. The model incorporated the effect of sulphidogenesis on floc fracture and reflocculation, and likely implications for mass transfer limitations.
- Full Text:
- Date Issued: 2000
Sumbera
- Ma Sane, Do Sagna, Yade (vocals), Toto (guitar), Race, Magx Thiam (keyboards), Galass, Mbaye Joola (percussion), Beuz (drums), Studio 2000
- Authors: Ma Sane, Do Sagna, Yade (vocals) , Toto (guitar) , Race, Magx Thiam (keyboards) , Galass, Mbaye Joola (percussion) , Beuz (drums) , Studio 2000
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Thies f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128108 , vital:36076 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC10-01
- Description: Senegalese band featuring singing accompanied by keyboard, guitar and percussion
- Full Text: false
- Date Issued: 2000
- Authors: Ma Sane, Do Sagna, Yade (vocals) , Toto (guitar) , Race, Magx Thiam (keyboards) , Galass, Mbaye Joola (percussion) , Beuz (drums) , Studio 2000
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Thies f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128108 , vital:36076 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC10-01
- Description: Senegalese band featuring singing accompanied by keyboard, guitar and percussion
- Full Text: false
- Date Issued: 2000
Sutura
- Ajah Sy ( lead vocals, author, composer, chorus), Biram Ndeck Ndiaye, El Hadji Niang (arrangement), Lamine Faye (guitar), El Hadji Niang (bass), Bakane Seck (percussion), Marie Codou Pouye, Ajah Sy, Abdourahmane Diallo,Missala man, Aly Hachem, Mame Gor Mboup (chorus), El Hadji Niang, Aly Hachem, Ousmane Wade (keyboards), Studio 2000
- Authors: Ajah Sy ( lead vocals, author, composer, chorus) , Biram Ndeck Ndiaye , El Hadji Niang (arrangement) , Lamine Faye (guitar) , El Hadji Niang (bass) , Bakane Seck (percussion) , Marie Codou Pouye, Ajah Sy, Abdourahmane Diallo,Missala man, Aly Hachem, Mame Gor Mboup (chorus) , El Hadji Niang, Aly Hachem, Ousmane Wade (keyboards) , Studio 2000
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129350 , vital:36264 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC27-02
- Description: A homage to women in general and rural women in particular, for courageously and stoically facing their arduous socetal burden
- Full Text: false
- Date Issued: 2000
- Authors: Ajah Sy ( lead vocals, author, composer, chorus) , Biram Ndeck Ndiaye , El Hadji Niang (arrangement) , Lamine Faye (guitar) , El Hadji Niang (bass) , Bakane Seck (percussion) , Marie Codou Pouye, Ajah Sy, Abdourahmane Diallo,Missala man, Aly Hachem, Mame Gor Mboup (chorus) , El Hadji Niang, Aly Hachem, Ousmane Wade (keyboards) , Studio 2000
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129350 , vital:36264 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC27-02
- Description: A homage to women in general and rural women in particular, for courageously and stoically facing their arduous socetal burden
- Full Text: false
- Date Issued: 2000
Synthetic and analytical studies of biomimetic metal complexes
- Authors: Wellington, Kevin Wayne
- Date: 2000
- Subjects: Biomimetics Metal complexes Metalloenzymes Metal ions Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4377 , http://hdl.handle.net/10962/d1005042
- Description: Several series of novel diamido, diamino and diimino ligands containing different spacers and heterocyclic donors have been synthesised. The spacers include the flexible biphenyl, the rigid 1,1 O-phenanthroline and various acyclic moieties, while the heterocyclic donors comprise pyridine, imidazole or benzimidazole groups. These ligands have been designed to complex copper and act as biomimetic models of the active site of the enzyme, tyrosinase, and their complexes with copper, cobalt, nickel and platinum have been analysed using microanalytical, IR, UV-Visible and cyclic voltammetric techniques. Attempted reduction of the biphenyl-based diimino ligands resulted in an unexpected intramolecular cyclisation affording azepine derivatives, the structures of which were elucidated with the aid of single crystal X-ray analysis of cobalt and nickel complexes. Computer modelling methods have been used to explore the conformational options of the copper complexes, and to assess the accessibility of the dinuclear copper site to substrate molecules. Computer modelling has also been used, in conjunction with the available analytical data, to visualise the possible structures of selected ligands and complexes. The copper complexes, although predominantly polymeric, were evaluated as biomimetic catalysts using 3,5-di-t-butylphenol and 3,5-di-t-butylcatechol as substrates. Some of the complexes clearly displayed biomimetic potential, exhibiting both phenolase and catecholase activity.
- Full Text:
- Date Issued: 2000
- Authors: Wellington, Kevin Wayne
- Date: 2000
- Subjects: Biomimetics Metal complexes Metalloenzymes Metal ions Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4377 , http://hdl.handle.net/10962/d1005042
- Description: Several series of novel diamido, diamino and diimino ligands containing different spacers and heterocyclic donors have been synthesised. The spacers include the flexible biphenyl, the rigid 1,1 O-phenanthroline and various acyclic moieties, while the heterocyclic donors comprise pyridine, imidazole or benzimidazole groups. These ligands have been designed to complex copper and act as biomimetic models of the active site of the enzyme, tyrosinase, and their complexes with copper, cobalt, nickel and platinum have been analysed using microanalytical, IR, UV-Visible and cyclic voltammetric techniques. Attempted reduction of the biphenyl-based diimino ligands resulted in an unexpected intramolecular cyclisation affording azepine derivatives, the structures of which were elucidated with the aid of single crystal X-ray analysis of cobalt and nickel complexes. Computer modelling methods have been used to explore the conformational options of the copper complexes, and to assess the accessibility of the dinuclear copper site to substrate molecules. Computer modelling has also been used, in conjunction with the available analytical data, to visualise the possible structures of selected ligands and complexes. The copper complexes, although predominantly polymeric, were evaluated as biomimetic catalysts using 3,5-di-t-butylphenol and 3,5-di-t-butylcatechol as substrates. Some of the complexes clearly displayed biomimetic potential, exhibiting both phenolase and catecholase activity.
- Full Text:
- Date Issued: 2000