Synthesis, characterization and reactions of novel ferrocenylimidazoles as donor ligands
- Authors: Onyancha, Douglas Okerio
- Date: 2010
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10390 , http://hdl.handle.net/10948/1150 , Ferrocene
- Description: In this project a series of ferrocenylimidazole derivatives were successfully prepared and characterized using an array of analytical techniques. Reactions of ferrocenylcarbinols with N,N′-thiocarbonyldiimidazole under both solvent-free conditions and in dichloromethane are described. The reaction of ferrocenylmethanol afforded S,S-bis(ferrocenylmethyl)dithiocarbonate, the reaction of α-substituted ferrocenylcarbinols provided ferrocenylalkylimidazolides, while ω-ferrocenylcarbinols yielded ferrocenylimidazolecarbothioates. The reactions were carried out under solvent-free conditions, consistent with the principles of Green Chemistry. Ferrocenyl benzyl ethers were successfully prepared by reacting 4-ferrocenylbenzyl-1Hcarboxylate with a series of primary alcohols under catalytic condition and under a catalyst– free environment. Refluxing a mixture of alcohol-water and 4-ferrocenylbenzyl-1Hcarboxylate provided the corresponding ethers in modest yields. The same ethers were obtained at room temperature by employing potassium tetrachloroplatinate or hydrochloric acid as catalyst. Ferrocenyl-1H-imidazole, 4-ferrocenylphenyl-1H-imidazole and their corresponding ferrocenyl-3-subsitituted imidazolium salts have been successfully synthesized. The compounds were characterized and the electrochemical properties of selected imidazolium salts were examined by cyclic voltammetry. Additionally, X-ray structures of two of the imidazolium salts were determined. The imidazolium salts were found to be good catalysts for the Heck and Suzuki cross-coupling reactions.
- Full Text:
- Date Issued: 2010
- Authors: Onyancha, Douglas Okerio
- Date: 2010
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10390 , http://hdl.handle.net/10948/1150 , Ferrocene
- Description: In this project a series of ferrocenylimidazole derivatives were successfully prepared and characterized using an array of analytical techniques. Reactions of ferrocenylcarbinols with N,N′-thiocarbonyldiimidazole under both solvent-free conditions and in dichloromethane are described. The reaction of ferrocenylmethanol afforded S,S-bis(ferrocenylmethyl)dithiocarbonate, the reaction of α-substituted ferrocenylcarbinols provided ferrocenylalkylimidazolides, while ω-ferrocenylcarbinols yielded ferrocenylimidazolecarbothioates. The reactions were carried out under solvent-free conditions, consistent with the principles of Green Chemistry. Ferrocenyl benzyl ethers were successfully prepared by reacting 4-ferrocenylbenzyl-1Hcarboxylate with a series of primary alcohols under catalytic condition and under a catalyst– free environment. Refluxing a mixture of alcohol-water and 4-ferrocenylbenzyl-1Hcarboxylate provided the corresponding ethers in modest yields. The same ethers were obtained at room temperature by employing potassium tetrachloroplatinate or hydrochloric acid as catalyst. Ferrocenyl-1H-imidazole, 4-ferrocenylphenyl-1H-imidazole and their corresponding ferrocenyl-3-subsitituted imidazolium salts have been successfully synthesized. The compounds were characterized and the electrochemical properties of selected imidazolium salts were examined by cyclic voltammetry. Additionally, X-ray structures of two of the imidazolium salts were determined. The imidazolium salts were found to be good catalysts for the Heck and Suzuki cross-coupling reactions.
- Full Text:
- Date Issued: 2010
Synthetic pathways to water-soluble phthalocyanines and close analogs
- Dumoulin, Fabienne, Durmus, Mahmut, Ahsen, Vefa, Nyokong, Tebello
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
Systemic influence on Black South African adolescents' career development : adolescent and parental perspectives
- Authors: Collett, Gary Reece
- Date: 2010
- Subjects: Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9863 , http://hdl.handle.net/10948/1513 , Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Description: Currently, no career theories exist that sufficiently explain the career development of South Africa’s diverse population groups. Consequently, South African researchers have been entirely dependent on international, western-informed career theories. While such theories have taken on a more ethnocentric complexion in recent times, they remain essentially decontextualised for South Africa. Furthermore, although the influence of family and the significant roles of parents have been theoretically acknowledged as critical influences in adolescent career development, there is still a considerable lack of research in South Africa on this topic. The present study therefore explored the perceptions of systemic influences on adolescent career development from the perspectives of both Black middle-class South African Grade 11 learners and their parents. The research was conceptualised within the Systems Theory Framework (STF) of career development and used its derivative instrument, the My Systems of Career Influences (MSCI, Adolescent). The present study utilised a qualitative research method, using answers derived from the MSCI (Adolescent) booklets to inform semi-structured interviews. The data analysis procedure involved the use of Interpretive Phenomenological Analysis to qualitatively analyse data obtained from the semistructured interviews. Findings revealed a number of influences within the individual system (personality, values, abilities), social system (adolescents’ parents and teachers) and societal-environmental system (financial support, the opportunity to work overseas, geographical location, job availability, and the location of universities) that were acknowledged as having an influence on the career development of South African Black middle class adolescents. Each of these findings were explored and unpacked under the four xii identified Interpretive Phenomenological Analysis (IPA) superordinate themes of Family Dynamics, Great Expectations, The Ghost of Apartheid and Coconuts Fall Far From the Tree. Lastly, the limitations of the present study, as well as recommendations for future research are discussed.
- Full Text:
- Date Issued: 2010
- Authors: Collett, Gary Reece
- Date: 2010
- Subjects: Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9863 , http://hdl.handle.net/10948/1513 , Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Description: Currently, no career theories exist that sufficiently explain the career development of South Africa’s diverse population groups. Consequently, South African researchers have been entirely dependent on international, western-informed career theories. While such theories have taken on a more ethnocentric complexion in recent times, they remain essentially decontextualised for South Africa. Furthermore, although the influence of family and the significant roles of parents have been theoretically acknowledged as critical influences in adolescent career development, there is still a considerable lack of research in South Africa on this topic. The present study therefore explored the perceptions of systemic influences on adolescent career development from the perspectives of both Black middle-class South African Grade 11 learners and their parents. The research was conceptualised within the Systems Theory Framework (STF) of career development and used its derivative instrument, the My Systems of Career Influences (MSCI, Adolescent). The present study utilised a qualitative research method, using answers derived from the MSCI (Adolescent) booklets to inform semi-structured interviews. The data analysis procedure involved the use of Interpretive Phenomenological Analysis to qualitatively analyse data obtained from the semistructured interviews. Findings revealed a number of influences within the individual system (personality, values, abilities), social system (adolescents’ parents and teachers) and societal-environmental system (financial support, the opportunity to work overseas, geographical location, job availability, and the location of universities) that were acknowledged as having an influence on the career development of South African Black middle class adolescents. Each of these findings were explored and unpacked under the four xii identified Interpretive Phenomenological Analysis (IPA) superordinate themes of Family Dynamics, Great Expectations, The Ghost of Apartheid and Coconuts Fall Far From the Tree. Lastly, the limitations of the present study, as well as recommendations for future research are discussed.
- Full Text:
- Date Issued: 2010
Take my word for it: a new approach to the problem of sincerity in the epistemology of testimony
- Authors: Dewhurst, Therese
- Date: 2010
- Subjects: Sincerity Philosophy Terminology Knowledge, Theory of Honesty
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2707 , http://hdl.handle.net/10962/d1002837
- Description: The epistemological problem of sincerity in testimony is often approached in the following way: We, as a matter of fact, accept utterances as sincere. We do so in the face of knowledge that people lie and deceive,and yet we still count these beliefs as good beliefs. Therefore there must be some reason or argument that we can cite in order to justify our acceptance of the sincerity of the speaker. In this thesis I will argue, contra this, that there is no reason, per se, that justifies our of a speakers sincerity: this is because recognition of the obligation to accept the sincerity is a necessary condition on the possibility of communication and interpretation. In the first three of the thesis I will argue against three of the main approaches to the problem by focusing on what I believe to be the strongest accounts of each: Elizabeth Fricker's reductionism, Tyler Burge's non-reductionism, and Paul Faulkner's trust account of testimony. In the final chapter I will put forward my positive account. I will argue that it is a constitutive rule of language that a speaker be sincere, and then make the further claim, that it is a constitutive rule of interpretation that the hearer take an utterance as sincere. On my account, successful communication does not just depend on a speaker making sincere utterances,but just as importantly,, on the hearer recognising an obligation to take those utterances as being sincere.
- Full Text:
- Date Issued: 2010
- Authors: Dewhurst, Therese
- Date: 2010
- Subjects: Sincerity Philosophy Terminology Knowledge, Theory of Honesty
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2707 , http://hdl.handle.net/10962/d1002837
- Description: The epistemological problem of sincerity in testimony is often approached in the following way: We, as a matter of fact, accept utterances as sincere. We do so in the face of knowledge that people lie and deceive,and yet we still count these beliefs as good beliefs. Therefore there must be some reason or argument that we can cite in order to justify our acceptance of the sincerity of the speaker. In this thesis I will argue, contra this, that there is no reason, per se, that justifies our of a speakers sincerity: this is because recognition of the obligation to accept the sincerity is a necessary condition on the possibility of communication and interpretation. In the first three of the thesis I will argue against three of the main approaches to the problem by focusing on what I believe to be the strongest accounts of each: Elizabeth Fricker's reductionism, Tyler Burge's non-reductionism, and Paul Faulkner's trust account of testimony. In the final chapter I will put forward my positive account. I will argue that it is a constitutive rule of language that a speaker be sincere, and then make the further claim, that it is a constitutive rule of interpretation that the hearer take an utterance as sincere. On my account, successful communication does not just depend on a speaker making sincere utterances,but just as importantly,, on the hearer recognising an obligation to take those utterances as being sincere.
- Full Text:
- Date Issued: 2010
Target costing as a strategic cost management tool in the South African motor industry
- Authors: Slater, Michael, M A
- Date: 2010
- Subjects: Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8974 , http://hdl.handle.net/10948/1094 , Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Description: Traditional cost-accounting approaches have served manufacturers well over a long period, but due to the changing nature of the modern manufacturing environment shortcomings have resulted and are no longer regarded as suitable (Gagne & Discenza 1993: 68). Similarly, Monden and Lee (1993: 22) state that many practitioners and academicians have questioned the effectiveness of standard cost systems, which have been used as the primary cost control measure for the last several decades. Cooper and Slagmulder (1997: 2) point out that in contrast to the conventional cost management techniques, target costing adopts a feed-forward approach. The objective of target costing is to design costs out of products, and not to find ways of eliminating costs after the products enter production. Few firms can afford to ignore such a powerful mechanism to increase profits in today’s highly competitive environment.
- Full Text:
- Date Issued: 2010
- Authors: Slater, Michael, M A
- Date: 2010
- Subjects: Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8974 , http://hdl.handle.net/10948/1094 , Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Description: Traditional cost-accounting approaches have served manufacturers well over a long period, but due to the changing nature of the modern manufacturing environment shortcomings have resulted and are no longer regarded as suitable (Gagne & Discenza 1993: 68). Similarly, Monden and Lee (1993: 22) state that many practitioners and academicians have questioned the effectiveness of standard cost systems, which have been used as the primary cost control measure for the last several decades. Cooper and Slagmulder (1997: 2) point out that in contrast to the conventional cost management techniques, target costing adopts a feed-forward approach. The objective of target costing is to design costs out of products, and not to find ways of eliminating costs after the products enter production. Few firms can afford to ignore such a powerful mechanism to increase profits in today’s highly competitive environment.
- Full Text:
- Date Issued: 2010
TB treatment initiation and adherence in a South African community influenced more by perceptions than by knowledge of tuberculosis
- Cramm, Jane M, Finkenflügel, Harry J M, Moller, Valerie, Nieboer, Anna P
- Authors: Cramm, Jane M , Finkenflügel, Harry J M , Moller, Valerie , Nieboer, Anna P
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:7101 , http://hdl.handle.net/10962/d1010657
- Description: Background Tuberculosis (TB) is a global health concern. Inadequate case finding and case holding has been cited as major barrier to the control of TB. The TB literature is written almost entirely from a biomedical perspective, while recent studies show that it is imperative to understand lay perception to determine why people seek treatment and may stop taking treatment. The Eastern Cape is known as a province with high TB incidence, prevalence and with one of the worst cure rates of South Africa. Its inhabitants can be considered lay experts when it comes to TB. Therefore, we investigated knowledge, perceptions of (access to) TB treatment and adherence to treatment among an Eastern Cape population. Methods An area-stratified sampling design was applied. A total of 1020 households were selected randomly in proportion to the total number of households in each neighbourhood. Results TB knowledge can be considered fairly good among this community. Respondents' perceptions suggest that stigma may influence TB patients' decision in health seeking behavior and adherence to TB treatment. A full 95 percent of those interviewed believe people with TB tend to hide their TB status out of fear of what others may say. Regression analyses revealed that in this population young and old, men and women and the lower and higher educated share the same attitudes and perceptions. Our findings are therefore likely to reflect the actual situation of TB patients in this population. Conclusions The lay experts' perceptions suggests that stigma appears to effect case holding and case finding. Future interventions should be directed at improving attitudes and perceptions to potentially reduce stigma. This requires a patient-centered approach to empower TB patients and active involvement in the development and implementation of stigma reduction programs.
- Full Text:
- Date Issued: 2010
- Authors: Cramm, Jane M , Finkenflügel, Harry J M , Moller, Valerie , Nieboer, Anna P
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:7101 , http://hdl.handle.net/10962/d1010657
- Description: Background Tuberculosis (TB) is a global health concern. Inadequate case finding and case holding has been cited as major barrier to the control of TB. The TB literature is written almost entirely from a biomedical perspective, while recent studies show that it is imperative to understand lay perception to determine why people seek treatment and may stop taking treatment. The Eastern Cape is known as a province with high TB incidence, prevalence and with one of the worst cure rates of South Africa. Its inhabitants can be considered lay experts when it comes to TB. Therefore, we investigated knowledge, perceptions of (access to) TB treatment and adherence to treatment among an Eastern Cape population. Methods An area-stratified sampling design was applied. A total of 1020 households were selected randomly in proportion to the total number of households in each neighbourhood. Results TB knowledge can be considered fairly good among this community. Respondents' perceptions suggest that stigma may influence TB patients' decision in health seeking behavior and adherence to TB treatment. A full 95 percent of those interviewed believe people with TB tend to hide their TB status out of fear of what others may say. Regression analyses revealed that in this population young and old, men and women and the lower and higher educated share the same attitudes and perceptions. Our findings are therefore likely to reflect the actual situation of TB patients in this population. Conclusions The lay experts' perceptions suggests that stigma appears to effect case holding and case finding. Future interventions should be directed at improving attitudes and perceptions to potentially reduce stigma. This requires a patient-centered approach to empower TB patients and active involvement in the development and implementation of stigma reduction programs.
- Full Text:
- Date Issued: 2010
Teaching conflict-sensitive journalism:
- Authors: du Toit, Peter
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159449 , vital:40298 , https://hdl.handle.net/10520/EJC139358
- Description: We expect court reporters to know something about the law, financial journalists to have a grounding in economics, and parliamentary correspondents to understand politics, but many journalists are ill-equipped handle social phenomenon that is ubiquitous to most beats - conflict.
- Full Text:
- Date Issued: 2010
- Authors: du Toit, Peter
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159449 , vital:40298 , https://hdl.handle.net/10520/EJC139358
- Description: We expect court reporters to know something about the law, financial journalists to have a grounding in economics, and parliamentary correspondents to understand politics, but many journalists are ill-equipped handle social phenomenon that is ubiquitous to most beats - conflict.
- Full Text:
- Date Issued: 2010
Teaching journalism to produce “interpretive communities" rather than just “professionals”:
- Authors: Garman, Anthea
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159846 , vital:40349 , DOI: 10.1080/02560054.2005.9653330
- Description: Debates about whether journalism is a “trade” and can only be learnt “on the job”, or whether journalism should even be taught at universities, are no longer fruitful or even interesting for teachers in tertiary environments. The far more important discussion around the teaching of journalism should be on the approach which focuses too exclusively on its nature as a “profession” and so ignores the critical function of journalists in the world as “interpretive communities”.
- Full Text:
- Date Issued: 2010
- Authors: Garman, Anthea
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159846 , vital:40349 , DOI: 10.1080/02560054.2005.9653330
- Description: Debates about whether journalism is a “trade” and can only be learnt “on the job”, or whether journalism should even be taught at universities, are no longer fruitful or even interesting for teachers in tertiary environments. The far more important discussion around the teaching of journalism should be on the approach which focuses too exclusively on its nature as a “profession” and so ignores the critical function of journalists in the world as “interpretive communities”.
- Full Text:
- Date Issued: 2010
Technology solutions to strengthen the integration of marginalized communities into the global knowledge society
- Hlungulu, Bulumko, Kunjuzwa, Dumani, Ndlovu, Nyankiso, Samalenge, Jimmy, Sikhumbuzo, Ngwenya, Thinyane, Mamello, Terzoli, Alfredo
- Authors: Hlungulu, Bulumko , Kunjuzwa, Dumani , Ndlovu, Nyankiso , Samalenge, Jimmy , Sikhumbuzo, Ngwenya , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430769 , vital:72714 , https://ieeexplore.ieee.org/abstract/document/5753005
- Description: Information and Communication Technology (ICT) has made it possible to explore novel and innovative mechanisms to leap-frog socio-economic development in rural and marginalized communities. An ICT for development intervention called Siyakhula Living Lab (SLL) has been underway in Dwesa, a rural community in the Eastern Cape Prov-ince, for the past four years. The living lab methodology, which enables user-driven innovation within a multi-stakeholder relationship of aca-demia, user communities, government and private industry, has facili-tated greater integration of the Dwesa community into the digital ecolo-gy and subsequently the knowledge society. This paper introduces the SLL intervention, discusses the SLL's supporting technical infrastruc-ture and the interventions that are undertaken towards long-term sus-tainability of the project. The developed eServices are also discussed, with a view to highlighting the key characteristics that contribute to in-creased context-sensitivity, ownership, and buy-in from the community.
- Full Text:
- Date Issued: 2010
- Authors: Hlungulu, Bulumko , Kunjuzwa, Dumani , Ndlovu, Nyankiso , Samalenge, Jimmy , Sikhumbuzo, Ngwenya , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430769 , vital:72714 , https://ieeexplore.ieee.org/abstract/document/5753005
- Description: Information and Communication Technology (ICT) has made it possible to explore novel and innovative mechanisms to leap-frog socio-economic development in rural and marginalized communities. An ICT for development intervention called Siyakhula Living Lab (SLL) has been underway in Dwesa, a rural community in the Eastern Cape Prov-ince, for the past four years. The living lab methodology, which enables user-driven innovation within a multi-stakeholder relationship of aca-demia, user communities, government and private industry, has facili-tated greater integration of the Dwesa community into the digital ecolo-gy and subsequently the knowledge society. This paper introduces the SLL intervention, discusses the SLL's supporting technical infrastruc-ture and the interventions that are undertaken towards long-term sus-tainability of the project. The developed eServices are also discussed, with a view to highlighting the key characteristics that contribute to in-creased context-sensitivity, ownership, and buy-in from the community.
- Full Text:
- Date Issued: 2010
The adoption of quality assurance in e-Health acquisition for rural hospitals in the Eastern Cape Province
- Authors: Ruxwana, Nkqubela
- Date: 2010
- Subjects: Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9731 , http://hdl.handle.net/10948/1514 , Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Description: The evolution of e-health has the potential to assist in the management of scarce resources and the shortage of skills, enhance efficiencies, improve quality and increase work productivity within the healthcare sector. As a result, an increase is seen in e-health solutions developments with the aim to improve healthcare services, hospital information systems, health decision support, telemedicine and other technical systems that have the potential to reduce cost, improve quality, and enhance the accessibility and delivery of healthcare. However, unfortunately their implementation contiues to fail. Although there are several reasons for this, in this study a lack of project quality management is viewed as a key contributor to the failure of e-health solutions implementation projects in rural hospitals. This results in neglected aspects of quality assurance (QA), which forms an integral part of project quality management. The purpose of this study is to develop a Genertic Quality Assurance Model (GQAM) for the successful acquisition (i.e. development and implementation) of e-health solutions in rural hospitals in the Eastern Cape Province to enable improved quality of care and service delivery. In order to develop and test this model it was necessary to identify the QA methodologies that are currently used in rural hospitals and to evaluate their strengths and weaknesses, as well as their impact on project success. The study is divided into four phases; in each phase different study designs were followed. The study used triangulation of qualitative and some elements of quantitative research approaches, in terms of which a case study approach was adpoted to answer the research questions. This study did indeed develop a GQAM that can be used to ensure e-health solution success in rural hospitals. Furthermore, to aid in the implementation of this model, a set of QA value chain implementation guidelines were developed, as a framework, to inject the nodel into typical (SDLC) phases.
- Full Text:
- Date Issued: 2010
- Authors: Ruxwana, Nkqubela
- Date: 2010
- Subjects: Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9731 , http://hdl.handle.net/10948/1514 , Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Description: The evolution of e-health has the potential to assist in the management of scarce resources and the shortage of skills, enhance efficiencies, improve quality and increase work productivity within the healthcare sector. As a result, an increase is seen in e-health solutions developments with the aim to improve healthcare services, hospital information systems, health decision support, telemedicine and other technical systems that have the potential to reduce cost, improve quality, and enhance the accessibility and delivery of healthcare. However, unfortunately their implementation contiues to fail. Although there are several reasons for this, in this study a lack of project quality management is viewed as a key contributor to the failure of e-health solutions implementation projects in rural hospitals. This results in neglected aspects of quality assurance (QA), which forms an integral part of project quality management. The purpose of this study is to develop a Genertic Quality Assurance Model (GQAM) for the successful acquisition (i.e. development and implementation) of e-health solutions in rural hospitals in the Eastern Cape Province to enable improved quality of care and service delivery. In order to develop and test this model it was necessary to identify the QA methodologies that are currently used in rural hospitals and to evaluate their strengths and weaknesses, as well as their impact on project success. The study is divided into four phases; in each phase different study designs were followed. The study used triangulation of qualitative and some elements of quantitative research approaches, in terms of which a case study approach was adpoted to answer the research questions. This study did indeed develop a GQAM that can be used to ensure e-health solution success in rural hospitals. Furthermore, to aid in the implementation of this model, a set of QA value chain implementation guidelines were developed, as a framework, to inject the nodel into typical (SDLC) phases.
- Full Text:
- Date Issued: 2010
The advent of the 'Festivore' an exploration of South African audience attendance in the performing arts at the National Arts Festival
- Authors: Antrobus, Richard Roy
- Date: 2010
- Subjects: Standard Bank National Arts Festival -- Economic aspects , Arts -- Economic aspects , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown , Arts -- South Africa -- Economic aspects , Arts -- South Africa -- Finance , Arts -- South Africa -- Political aspects , Arts audiences -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2130 , http://hdl.handle.net/10962/d1002362
- Description: In South Africa, the performing arts have contributed to enhancing national identity and distinctiveness despite coming up against weak legislation, policy and infrastructure to support their growth and proliferation (Fredericks, 2005: 9). Coupled with a decline in both government and consumer support and the contradictory disparity between valuing the arts and the funding of the arts, theatre companies can no longer rely on the comfort of external subsidies and financial support. In order to be economically viable and sustainable to ensure their survival, there is an increasing demand for theatre companies to look to novel ways of increasing audience demand for theatre and improving audience attendance. However, instead of risking artistic integrity and the performance product to satisfy the market, this research suggests that promotion and development of theatre at arts festivals provides a platform to access a wider theatre-going public, which therefore facilitates a change in the market focus toward appreciation of the product (production). It explores leading arguments pertaining to the attendance of arts and cultural events, namely, Peterson and Simkus (1992), later updated by Peterson‟s (2005)„omnivore-univore‟ argument. The argument purports cultural consumption as binary in nature: either significant and diverse or limited, if not absent altogether. Supported by a number of case-studies, including Chan and Goldthorpe (2005) and Montgomery and Robinson (2008) and Snowball et al. (2009), the investigation challenges Bourdieu‟s (1984) theory on cultural distinction as well as the homology and individualisation argument. In determining the factors that influence cultural taste and consumer behaviour, including motivators and inhibitors of attendance and a predominant emphasis on audience risk and information asymmetry, the research was placed in a local context, providing an overview of the socio-economic theatre environment in South Africa. It investigated the nature, structure and impact of local festivals (as events) in changing audience demand and theatre attendance. With specific reference to the South African National Arts Festival (NAF) the research notes the effects of Hauptfleisch‟s „eventification‟ phenomenon on univore attenders and therefore expands the omnivore-univore theory to include a new breed of attender: the “Festivore”. A case study explored the “Festivore” hypothesis through empirical research, surveys and face-to-face qualitative interviews and on-seat questionnaire responses by festival attenders. Personal interviews and communication was also carried out with leading experts in the field. The data was then analysed using SPSS 13 electronic statistical analysis programme to determine the socio-demographics and the factors that affect theatre attendance of existing, as well as potential target, theatre audiences at the National Arts Festival The study concluded that South African theatre attenders are generally omnivorous consumers and that, more importantly, there seems to be a shift towards „festivorous‟ consumption. Furthermore, evidence supports the development and proliferation of festivals as a means not only to support and promote the arts in South Africa but, more importantly, to generate new theatre audiences and entrench theatre attendance into South African culture.
- Full Text:
- Date Issued: 2010
- Authors: Antrobus, Richard Roy
- Date: 2010
- Subjects: Standard Bank National Arts Festival -- Economic aspects , Arts -- Economic aspects , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown , Arts -- South Africa -- Economic aspects , Arts -- South Africa -- Finance , Arts -- South Africa -- Political aspects , Arts audiences -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2130 , http://hdl.handle.net/10962/d1002362
- Description: In South Africa, the performing arts have contributed to enhancing national identity and distinctiveness despite coming up against weak legislation, policy and infrastructure to support their growth and proliferation (Fredericks, 2005: 9). Coupled with a decline in both government and consumer support and the contradictory disparity between valuing the arts and the funding of the arts, theatre companies can no longer rely on the comfort of external subsidies and financial support. In order to be economically viable and sustainable to ensure their survival, there is an increasing demand for theatre companies to look to novel ways of increasing audience demand for theatre and improving audience attendance. However, instead of risking artistic integrity and the performance product to satisfy the market, this research suggests that promotion and development of theatre at arts festivals provides a platform to access a wider theatre-going public, which therefore facilitates a change in the market focus toward appreciation of the product (production). It explores leading arguments pertaining to the attendance of arts and cultural events, namely, Peterson and Simkus (1992), later updated by Peterson‟s (2005)„omnivore-univore‟ argument. The argument purports cultural consumption as binary in nature: either significant and diverse or limited, if not absent altogether. Supported by a number of case-studies, including Chan and Goldthorpe (2005) and Montgomery and Robinson (2008) and Snowball et al. (2009), the investigation challenges Bourdieu‟s (1984) theory on cultural distinction as well as the homology and individualisation argument. In determining the factors that influence cultural taste and consumer behaviour, including motivators and inhibitors of attendance and a predominant emphasis on audience risk and information asymmetry, the research was placed in a local context, providing an overview of the socio-economic theatre environment in South Africa. It investigated the nature, structure and impact of local festivals (as events) in changing audience demand and theatre attendance. With specific reference to the South African National Arts Festival (NAF) the research notes the effects of Hauptfleisch‟s „eventification‟ phenomenon on univore attenders and therefore expands the omnivore-univore theory to include a new breed of attender: the “Festivore”. A case study explored the “Festivore” hypothesis through empirical research, surveys and face-to-face qualitative interviews and on-seat questionnaire responses by festival attenders. Personal interviews and communication was also carried out with leading experts in the field. The data was then analysed using SPSS 13 electronic statistical analysis programme to determine the socio-demographics and the factors that affect theatre attendance of existing, as well as potential target, theatre audiences at the National Arts Festival The study concluded that South African theatre attenders are generally omnivorous consumers and that, more importantly, there seems to be a shift towards „festivorous‟ consumption. Furthermore, evidence supports the development and proliferation of festivals as a means not only to support and promote the arts in South Africa but, more importantly, to generate new theatre audiences and entrench theatre attendance into South African culture.
- Full Text:
- Date Issued: 2010
The ambivalence of African elitehood:
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
The anticancer activity of Cyathula prostrata on two malignant cell lines
- Authors: Schnablegger, Gerald
- Date: 2010
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10309 , http://hdl.handle.net/10948/1563 , Medicinal plants
- Description: Plants have always been a source of medicine and are still being used by traditional healers in the rural part of Africa, Asia and India to treat a range of illnesses including cancer. The in vitro anticancer activity of an 80 percent ethanol extract of Cyathula prostrata, an annual branching shrub used by traditional healers in Nigeria to treat cancer was investigated. No previous studies have outlined the possible pathways and mechanisms used by cancer cells when treated with C. prostrata. Dose response analysis was performed to determine the effective cytotoxic concentrations of C. prostrata on HeLa (cervical cancer cell line) and U937 (myelo-monocytic cell line). The IC50 values were 100.8 μg/ml and 64.4 μg/ml for HeLa and U937 cells, respectively. All further experiments were performed using 125 μg/ml C. prostrata extract and 50 μM cisplatin as positive control. With the use of the fluorescent DNA binding dye propidium iodide, the induction of tumour cell death by C. prostrata extract has been linked to cell cycle arrest in the G1 phase at 24 and 48 h. In both cell lines, more than 80 percent of the C. prostrata treated cells were found in the G1 phase after 48 hours of treatment. The annexin V-FITC/PI assay revealed an increase in the percentage apoptotic cells from 4.9 percent to 53.1 percent at 24 h and 8.3 percent to 50.3 percent at 48 h. Since apoptosis induction can occur via a number of different pathways, distinct features were used as markers to investigate the mode of action of this C. prostrata extract. Markers such as activated caspase-8, p21 and cyt-c, were investigated with the aid of fluorescently labelled (FITC) antibodies with analysis using flow cytometry. No change in p21 levels was observed in response to treatment with the extract for up to 48 h. Cell cycle arrest in G1 was therefore not induced by this cyclin-CDK inhibitor. Increase in caspase-8 activation was observed in response to treatment with the extract with no cyt-c release from the mitochondria. The lack of cyt-c release was due to no change in mitochondrial membrane potential, which was investigated with the aid of fluorescent mitochondrial dyes and flow cytometric techniques. Caspase-8 activation is unique to the extrinsic apoptotic pathway. The results from this study therefore show that C. prostrata extract induces apoptosis via the extrinsic pathway and that this activation in independent of the mitochondria. The levels of hTERT, the catalytic subunit of telomerase, were investigated as an additional molecular target for C. prostrata. This was also investigated using FITC labelled antibodies and flow cytometry. A decrease in hTERT levels was observed following C. prostrata treatment. The findings from this study suggest that the extract acts through multiple targets, by inducing: cell cycle arrest in the G1 phase through an unknown mechanism; apoptosis through an extrinsic death receptor pathway and replicative senescence through inhibition of telomerase.
- Full Text:
- Date Issued: 2010
- Authors: Schnablegger, Gerald
- Date: 2010
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10309 , http://hdl.handle.net/10948/1563 , Medicinal plants
- Description: Plants have always been a source of medicine and are still being used by traditional healers in the rural part of Africa, Asia and India to treat a range of illnesses including cancer. The in vitro anticancer activity of an 80 percent ethanol extract of Cyathula prostrata, an annual branching shrub used by traditional healers in Nigeria to treat cancer was investigated. No previous studies have outlined the possible pathways and mechanisms used by cancer cells when treated with C. prostrata. Dose response analysis was performed to determine the effective cytotoxic concentrations of C. prostrata on HeLa (cervical cancer cell line) and U937 (myelo-monocytic cell line). The IC50 values were 100.8 μg/ml and 64.4 μg/ml for HeLa and U937 cells, respectively. All further experiments were performed using 125 μg/ml C. prostrata extract and 50 μM cisplatin as positive control. With the use of the fluorescent DNA binding dye propidium iodide, the induction of tumour cell death by C. prostrata extract has been linked to cell cycle arrest in the G1 phase at 24 and 48 h. In both cell lines, more than 80 percent of the C. prostrata treated cells were found in the G1 phase after 48 hours of treatment. The annexin V-FITC/PI assay revealed an increase in the percentage apoptotic cells from 4.9 percent to 53.1 percent at 24 h and 8.3 percent to 50.3 percent at 48 h. Since apoptosis induction can occur via a number of different pathways, distinct features were used as markers to investigate the mode of action of this C. prostrata extract. Markers such as activated caspase-8, p21 and cyt-c, were investigated with the aid of fluorescently labelled (FITC) antibodies with analysis using flow cytometry. No change in p21 levels was observed in response to treatment with the extract for up to 48 h. Cell cycle arrest in G1 was therefore not induced by this cyclin-CDK inhibitor. Increase in caspase-8 activation was observed in response to treatment with the extract with no cyt-c release from the mitochondria. The lack of cyt-c release was due to no change in mitochondrial membrane potential, which was investigated with the aid of fluorescent mitochondrial dyes and flow cytometric techniques. Caspase-8 activation is unique to the extrinsic apoptotic pathway. The results from this study therefore show that C. prostrata extract induces apoptosis via the extrinsic pathway and that this activation in independent of the mitochondria. The levels of hTERT, the catalytic subunit of telomerase, were investigated as an additional molecular target for C. prostrata. This was also investigated using FITC labelled antibodies and flow cytometry. A decrease in hTERT levels was observed following C. prostrata treatment. The findings from this study suggest that the extract acts through multiple targets, by inducing: cell cycle arrest in the G1 phase through an unknown mechanism; apoptosis through an extrinsic death receptor pathway and replicative senescence through inhibition of telomerase.
- Full Text:
- Date Issued: 2010
The applicability of the promotion of Administrative Justice Act in review of CCMA arbitration awards
- Phanyane, Namadzavho California
- Authors: Phanyane, Namadzavho California
- Date: 2010
- Subjects: Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10219 , http://hdl.handle.net/10948/1282 , Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Description: South Africa’s employment law has undergone more frequent and dynamic changes than any area of the law, in recent years. The ability of employers and employees to regulate their respective rights and duties vis-à-vis each other by independent agreement has been progressively whittled down by statutory intervention. In so limiting the capacity of parties to the employment relationship to regulate the nature of their relationship, South Africa has followed development in Western industrialised nations. Against this background, the drafters of the Labour Relations Act1 (LRA), as amended, proposed a comprehensive framework of law governing the collective relations between employers and trade unions in all sectors of the economy. The LRA2 created a specialised set of forums and tribunals to deal with labour and employment related matters. It established Bargaining Councils, the Commission for Conciliation Mediation and Arbitration (CCMA), the Labour Court (LC) and the Labour Appeal Court (LAC). It also created procedures designed to accomplish the objective of simple, inexpensive and accessible resolution of labour disputes. In redesigning labour law, the legislature decided that some disputes between employers and employees should be dealt with by arbitrators and others by judges. It is this distinction that resulted in the creation of the CCMA and the Labour Court to perform arbitration and adjudication respectively. The result of adjudication is generally subject to appeal to a higher court. The result of arbitration is generally subject to review. Arbitration was given statutory recognition in South Africa by the Arbitration Act3. That Act provides a framework within which parties in dispute may if they wish appoint their own “judge” and supply him or her with their terms of reference tailored to their needs. With the foregoing in mind, the purpose of this work is the provision of a selection of landmark cases that dealt with the review function of CCMA awards. This selection 1 Act 66 of 1995 as amended comprises of landmark judgments of the different courts of the land. The study uses, as it departure point, legislative framework to elicit the extent to which review is extended to the litigants. Apart from looking at the legislative provisions towards review grounds, reference is made to specific landmark judgments that have an effect on this subject in order to provide a comprehensive and explicit picture of how CCMA arbitration awards may be taken on review. This study focuses on substantive law developed by the Labour Court, High Court, Supreme Court of Appeal and finally the Constitutional Court. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of review could lead to failure to achieve the objectives of the study. It looks at specific South African case law, judgments of the courts and the jurisprudence in the field of employment law so that the reader is presented with a clearer picture of recent developments in addressing review of arbitration awards. The concluding remarks are drawn from a variety of approaches used by the authorities in the field of employment law in dealing with review of CCMA arbitration awards and issues for further research are highlighted.
- Full Text:
- Date Issued: 2010
- Authors: Phanyane, Namadzavho California
- Date: 2010
- Subjects: Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10219 , http://hdl.handle.net/10948/1282 , Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Description: South Africa’s employment law has undergone more frequent and dynamic changes than any area of the law, in recent years. The ability of employers and employees to regulate their respective rights and duties vis-à-vis each other by independent agreement has been progressively whittled down by statutory intervention. In so limiting the capacity of parties to the employment relationship to regulate the nature of their relationship, South Africa has followed development in Western industrialised nations. Against this background, the drafters of the Labour Relations Act1 (LRA), as amended, proposed a comprehensive framework of law governing the collective relations between employers and trade unions in all sectors of the economy. The LRA2 created a specialised set of forums and tribunals to deal with labour and employment related matters. It established Bargaining Councils, the Commission for Conciliation Mediation and Arbitration (CCMA), the Labour Court (LC) and the Labour Appeal Court (LAC). It also created procedures designed to accomplish the objective of simple, inexpensive and accessible resolution of labour disputes. In redesigning labour law, the legislature decided that some disputes between employers and employees should be dealt with by arbitrators and others by judges. It is this distinction that resulted in the creation of the CCMA and the Labour Court to perform arbitration and adjudication respectively. The result of adjudication is generally subject to appeal to a higher court. The result of arbitration is generally subject to review. Arbitration was given statutory recognition in South Africa by the Arbitration Act3. That Act provides a framework within which parties in dispute may if they wish appoint their own “judge” and supply him or her with their terms of reference tailored to their needs. With the foregoing in mind, the purpose of this work is the provision of a selection of landmark cases that dealt with the review function of CCMA awards. This selection 1 Act 66 of 1995 as amended comprises of landmark judgments of the different courts of the land. The study uses, as it departure point, legislative framework to elicit the extent to which review is extended to the litigants. Apart from looking at the legislative provisions towards review grounds, reference is made to specific landmark judgments that have an effect on this subject in order to provide a comprehensive and explicit picture of how CCMA arbitration awards may be taken on review. This study focuses on substantive law developed by the Labour Court, High Court, Supreme Court of Appeal and finally the Constitutional Court. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of review could lead to failure to achieve the objectives of the study. It looks at specific South African case law, judgments of the courts and the jurisprudence in the field of employment law so that the reader is presented with a clearer picture of recent developments in addressing review of arbitration awards. The concluding remarks are drawn from a variety of approaches used by the authorities in the field of employment law in dealing with review of CCMA arbitration awards and issues for further research are highlighted.
- Full Text:
- Date Issued: 2010
The attitudes of isiXhosa-speaking students toward language of learning and teaching issues at Rhodes University, South Africa: General trends1
- Aziakpono, Philomena, Bekker, Ian
- Authors: Aziakpono, Philomena , Bekker, Ian
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469212 , vital:77220 , https://doi.org/10.2989/16073614.2010.488442
- Description: This paper, selectively based on the results of Aziakpono (2007), examines the beliefs of isiXhosa-speaking students and in the process reveals their attitudes toward various languages of learning and teaching (LOLT) issues at Rhodes University, South Africa. The relevant data were gathered using a survey questionnaire and interviews (individual and focus group).
- Full Text:
- Date Issued: 2010
- Authors: Aziakpono, Philomena , Bekker, Ian
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469212 , vital:77220 , https://doi.org/10.2989/16073614.2010.488442
- Description: This paper, selectively based on the results of Aziakpono (2007), examines the beliefs of isiXhosa-speaking students and in the process reveals their attitudes toward various languages of learning and teaching (LOLT) issues at Rhodes University, South Africa. The relevant data were gathered using a survey questionnaire and interviews (individual and focus group).
- Full Text:
- Date Issued: 2010
The biology of austroglanis gilli and austroglanis barnardi (siluriformes : austroglanididae) in the Olifants River system, South Africa
- Authors: Mthombeni, Vusi Gedla
- Date: 2010
- Subjects: Catfishes -- South Africa -- Olifants River , Fishes -- South Africa -- Olifants River -- Growth , Freshwater fishes -- Effect of pesticides on -- South Africa -- Olifants River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5370 , http://hdl.handle.net/10962/d1015222
- Description: Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.
- Full Text:
- Date Issued: 2010
- Authors: Mthombeni, Vusi Gedla
- Date: 2010
- Subjects: Catfishes -- South Africa -- Olifants River , Fishes -- South Africa -- Olifants River -- Growth , Freshwater fishes -- Effect of pesticides on -- South Africa -- Olifants River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5370 , http://hdl.handle.net/10962/d1015222
- Description: Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.
- Full Text:
- Date Issued: 2010
The biotechnology of hard coal utilization as a bioprocess substrate
- Mutambanengwe, Cecil Clifford Zvandada
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2010
- Subjects: Coal -- Biotechnology Acid mine drainage Coal mines and mining -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3934 , http://hdl.handle.net/10962/d1003993
- Description: The development of coal biotechnology, using hard coal as a substrate, has been impeded by its low reactivity in biological processes. As a result, the more successful application studies have focused on lignitic soft coals. However, new studies have reported using biologically or geologically oxidized hard coal as a functional substrate option for bioprocess applications on a large scale. This study undertook a preliminary investigation into the feasibility of environmental applications of coal biotechnology using oxidized hard coal substrates in both anaerobic and aerobic processes with carbon dioxide, sulfate and oxygen as terminal electron acceptors. A preliminary characterization of the oxidized hard coal substrates was undertaken to determine and predict their viability and behavior as electron donors and carbon sources for environmental bioprocess applications of direct interest to the coal mining industry. Both biologically and geologically oxidized coal substrates showed loss of up to 17% and 52% carbon respectively and incorporation of oxygen ranging from 0.9 – 24%. The latter substrate showed greater loss of carbon and increased oxygenation. The biologically and geologically oxidized hard coal substrates were shown to partition readily into 23% and 32% organic humic acid, a 0.1% fulvic acid fraction and 65% and 59% inorganic and humin fractions respectively. These organic components were shown to be potentially available for biological consumption. In the unmodified hard coal substrate, partitioning was not observed and it did not perform as a functional substrate for any of the bioprocesses investigated. Where carbon dioxide was used as a terminal electron acceptor, methane production ranging from 9 – 26 mg CH4.g substrate-1 was demonstrated from both oxidized coal substrates. Geologically oxidized coal produced 30% more methane than biologically oxidized coal. Methane yields from the geologically oxidized coal in the presence and absence of a co-substrate were 5 – 13-fold higher than previous studies that used hard coal for methanogenesis. Based on these results, and that the development and optimization of the biological oxidation process is currently ongoing, further applications investigated in this study were undertaken using geologically oxidized coal. It was shown using pyrolysis gas chromatography mass spectrometry that the methanogenic system was dependent on the presence of an effective co-substrate supporting the breakdown of the complex organic structures within the oxidized hard coal substrate. Also that the accumulation of aromatic intermediate breakdown compounds predominantly including toluene, furfural, styrene and 2-methoxy vinyl phenol appeared to become inhibitory to both methanogenic and sulfidogenic reactions. This was shown to be a more likely cause of reactor failure rather than substrate exhaustion over time. Evidence of a reductive degradation pathway of the complex organic structures within the oxidized hard coal substrates was shown through the production, accumulation and utilization of volatile fatty acids including acetic, formic, propionic, butyric and valeric acids. Comparative analysis of the volatile fatty acids produced in this system showed that geologically oxidized coal produced 20% more of the volatile fatty acids profiled and double the total concentration compared to the biologically oxidized coal. The use of geologically oxidized hard coal as a functional substrate for biological sulfate reduction was demonstrated in the neutralization of a simulated acid mine drainage wastewater in both batch and continuous process operations. Results showed an increase in pH from pH 4.0 to ~ pH 8.0 with sulfide production rates of ~ 86 mgL-1.day-1 in the batch reactions, while the pH increased to pH 9.0 and sulfide production rates of up to 450 mgL-1.day-1 were measured in the continuous process studies using sand and coal up-flow packed bed reactors. Again, the requirement for an effective co-substrate was demonstrated with lactate shown to function as a true co-substrate in this system. However, a low cost alternative to lactate would need to emerge if the process was to function in large-scale commercial environmental treatment applications. In this regard, the aerobic growth and production of Neosartorya fischeri biomass (0.64 g.biomass.g SOC-1) was demonstrated using oxidized hard coal and glutamate as a co-substrate. Both can be produced from wastes generated on coal mines, with the fungal biomass generated in potentially large volumes. Preliminary demonstration of the use of the fungal biomass as a carbon and electron donor source for biological sulfate reduction was shown and thus that this could serve as an effective substrate for anaerobic environmental treatment processes. Based on these findings, an Integrated Coal Bioprocess model was proposed using oxidized hard coal as a substrate for environmental remediation applications on coal mines. In this approach, potential applications included methane recovery from waste coal, use of waste coal in the treatment of acid mine drainage waste waters and the recovery and use of humic acids in the rehabilitation of open cast mining soils. This study provided a first report demonstrating the use of biologically and geologically oxidized hard coals as bioprocess substrates in environmental bioremediation applications. It also provided an indication that follow-up bioengineering studies to investigate scaled-up applications of these findings would be warranted.
- Full Text:
- Date Issued: 2010
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2010
- Subjects: Coal -- Biotechnology Acid mine drainage Coal mines and mining -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3934 , http://hdl.handle.net/10962/d1003993
- Description: The development of coal biotechnology, using hard coal as a substrate, has been impeded by its low reactivity in biological processes. As a result, the more successful application studies have focused on lignitic soft coals. However, new studies have reported using biologically or geologically oxidized hard coal as a functional substrate option for bioprocess applications on a large scale. This study undertook a preliminary investigation into the feasibility of environmental applications of coal biotechnology using oxidized hard coal substrates in both anaerobic and aerobic processes with carbon dioxide, sulfate and oxygen as terminal electron acceptors. A preliminary characterization of the oxidized hard coal substrates was undertaken to determine and predict their viability and behavior as electron donors and carbon sources for environmental bioprocess applications of direct interest to the coal mining industry. Both biologically and geologically oxidized coal substrates showed loss of up to 17% and 52% carbon respectively and incorporation of oxygen ranging from 0.9 – 24%. The latter substrate showed greater loss of carbon and increased oxygenation. The biologically and geologically oxidized hard coal substrates were shown to partition readily into 23% and 32% organic humic acid, a 0.1% fulvic acid fraction and 65% and 59% inorganic and humin fractions respectively. These organic components were shown to be potentially available for biological consumption. In the unmodified hard coal substrate, partitioning was not observed and it did not perform as a functional substrate for any of the bioprocesses investigated. Where carbon dioxide was used as a terminal electron acceptor, methane production ranging from 9 – 26 mg CH4.g substrate-1 was demonstrated from both oxidized coal substrates. Geologically oxidized coal produced 30% more methane than biologically oxidized coal. Methane yields from the geologically oxidized coal in the presence and absence of a co-substrate were 5 – 13-fold higher than previous studies that used hard coal for methanogenesis. Based on these results, and that the development and optimization of the biological oxidation process is currently ongoing, further applications investigated in this study were undertaken using geologically oxidized coal. It was shown using pyrolysis gas chromatography mass spectrometry that the methanogenic system was dependent on the presence of an effective co-substrate supporting the breakdown of the complex organic structures within the oxidized hard coal substrate. Also that the accumulation of aromatic intermediate breakdown compounds predominantly including toluene, furfural, styrene and 2-methoxy vinyl phenol appeared to become inhibitory to both methanogenic and sulfidogenic reactions. This was shown to be a more likely cause of reactor failure rather than substrate exhaustion over time. Evidence of a reductive degradation pathway of the complex organic structures within the oxidized hard coal substrates was shown through the production, accumulation and utilization of volatile fatty acids including acetic, formic, propionic, butyric and valeric acids. Comparative analysis of the volatile fatty acids produced in this system showed that geologically oxidized coal produced 20% more of the volatile fatty acids profiled and double the total concentration compared to the biologically oxidized coal. The use of geologically oxidized hard coal as a functional substrate for biological sulfate reduction was demonstrated in the neutralization of a simulated acid mine drainage wastewater in both batch and continuous process operations. Results showed an increase in pH from pH 4.0 to ~ pH 8.0 with sulfide production rates of ~ 86 mgL-1.day-1 in the batch reactions, while the pH increased to pH 9.0 and sulfide production rates of up to 450 mgL-1.day-1 were measured in the continuous process studies using sand and coal up-flow packed bed reactors. Again, the requirement for an effective co-substrate was demonstrated with lactate shown to function as a true co-substrate in this system. However, a low cost alternative to lactate would need to emerge if the process was to function in large-scale commercial environmental treatment applications. In this regard, the aerobic growth and production of Neosartorya fischeri biomass (0.64 g.biomass.g SOC-1) was demonstrated using oxidized hard coal and glutamate as a co-substrate. Both can be produced from wastes generated on coal mines, with the fungal biomass generated in potentially large volumes. Preliminary demonstration of the use of the fungal biomass as a carbon and electron donor source for biological sulfate reduction was shown and thus that this could serve as an effective substrate for anaerobic environmental treatment processes. Based on these findings, an Integrated Coal Bioprocess model was proposed using oxidized hard coal as a substrate for environmental remediation applications on coal mines. In this approach, potential applications included methane recovery from waste coal, use of waste coal in the treatment of acid mine drainage waste waters and the recovery and use of humic acids in the rehabilitation of open cast mining soils. This study provided a first report demonstrating the use of biologically and geologically oxidized hard coals as bioprocess substrates in environmental bioremediation applications. It also provided an indication that follow-up bioengineering studies to investigate scaled-up applications of these findings would be warranted.
- Full Text:
- Date Issued: 2010
The botanical importance and health of the Bushmans estuary, Eastern Cape, South Africa
- Authors: Jafta, Nolusindiso
- Date: 2010
- Subjects: Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10614 , http://hdl.handle.net/10948/1255 , Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Description: The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators for the East London Department of Water Affairs, River Health Programme. Changes in the estuary over time were determined from available historical data which were compared with present data. This analysis showed that under normal average conditions freshwater inflow to the estuary is very low, less that 0.02 m3 s-1 most of the time. Under these conditions the estuary is in a homogenous marine state. Vertical and horizontal salinity gradients only form when high rainfall and run-off occurs (> 5 m3.s-1). Salinity gradients from 30.1 PSU at the mouth to 2.2 PSU in the upper reaches were measured in 2006 after a high flow event. However the estuary quickly reverted back to its homogenous condition within weeks after this flood. This study showed that freshwater inflow increased nutrient input to the estuary. Total oxidised nitrogen (TOxN) and soluble reactive phosphorus (SRP) concentrations were higher in August 2006, after the flood, than during the other low flow sampling sessions. TOxN decreased from a mean concentration of 21.6 μM in 2006 to 1.93 μM in February 2009. SRP decreased from 55.3 μM to 0.2 μM respectively. With the increased nutrient availability, the response in the estuary was an increase in phytoplankton biomass. After the 2006 floods the average water column chlorophyll-a was 9.0 μg l-1, while in the low freshwater inflow years it ranged from 2.1 to 4.8 μg l-1. The composition of the phytoplankton community was always dominated by flagellates and then diatoms, with higher cell numbers in the nutrient-enriched 2006 period. Although the water column nutrient data indicated that the estuary was oligotrophic, benthic microalgal biomass (11.9-16.1 μg.g-1) in the intertidal zone was comparable with nutrient rich estuaries. Benthic species indicative of polluted conditions were found (Nitzschia frustulum, Navicula gregaria, Navicula cryptotenelloides). These benthic species were found at the sites where wastewater / sewage seepage had occurred. Benthic diatom species also indicated freshwater inflow. During the high flow period in 2006 the dominant diatoms were fresh to brackish species that were strongly associated with the high concentrations of TOxN and SRP (Tryblionella constricta, Diploneis smithii, Hippodonta cf. gremainii, and Navicula species). During the freshwater limited period of 2008 and 2009 the benthic diatom species shifted to a group responding to the high salinity, ammonium and silicate concentrations. The species in this group were Nitzschia flexa, Navicula tenneloides, Diploneis elliptica, Amphora subacutiuscula and Nitzschia coarctata. Ordination results showed that the epiphytic diatom species responded to different environmental variables in the different years. Most of the species in 2008/2009 were associated with high salinity, temperature, dissolved oxygen, ammonium and silicate concentrations while the response was towards TOxN and SRP in 2006. The dominant species were Cocconeis placentula v euglyphyta in 2006; Nitzschia frustulum in 2008; and Synedra spp in 2009. The average biomass of the epiphytes was significantly lower in May 2008 than in both August 2006 and February 2009; 88.0 + 17.7 mg.m-2, 1.7 + 0.8 mg.m-2, and 61.8 + 14.4 mg.m-2 respectively. GIS mapping of past and present aerial photographs showed that submerged macrophyte (Zostera capensis) cover in 1966 and 1973 was less than that mapped for 2004. Salt marsh also increased its cover over time, from 86.9 ha in 1966 to 126 ha in 2004, colonizing what were bare sandy areas. Long-term monitoring of the health of the Bushmans Estuary should focus on salinity (as an indicator of inflow or deprivation of freshwater), benthic diatom identification and macrophyte distribution and composition (for the detection of pollution input), and bathymetric surveys (for shallowing of the estuary due to sedimentation).
- Full Text:
- Date Issued: 2010
- Authors: Jafta, Nolusindiso
- Date: 2010
- Subjects: Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10614 , http://hdl.handle.net/10948/1255 , Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Description: The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators for the East London Department of Water Affairs, River Health Programme. Changes in the estuary over time were determined from available historical data which were compared with present data. This analysis showed that under normal average conditions freshwater inflow to the estuary is very low, less that 0.02 m3 s-1 most of the time. Under these conditions the estuary is in a homogenous marine state. Vertical and horizontal salinity gradients only form when high rainfall and run-off occurs (> 5 m3.s-1). Salinity gradients from 30.1 PSU at the mouth to 2.2 PSU in the upper reaches were measured in 2006 after a high flow event. However the estuary quickly reverted back to its homogenous condition within weeks after this flood. This study showed that freshwater inflow increased nutrient input to the estuary. Total oxidised nitrogen (TOxN) and soluble reactive phosphorus (SRP) concentrations were higher in August 2006, after the flood, than during the other low flow sampling sessions. TOxN decreased from a mean concentration of 21.6 μM in 2006 to 1.93 μM in February 2009. SRP decreased from 55.3 μM to 0.2 μM respectively. With the increased nutrient availability, the response in the estuary was an increase in phytoplankton biomass. After the 2006 floods the average water column chlorophyll-a was 9.0 μg l-1, while in the low freshwater inflow years it ranged from 2.1 to 4.8 μg l-1. The composition of the phytoplankton community was always dominated by flagellates and then diatoms, with higher cell numbers in the nutrient-enriched 2006 period. Although the water column nutrient data indicated that the estuary was oligotrophic, benthic microalgal biomass (11.9-16.1 μg.g-1) in the intertidal zone was comparable with nutrient rich estuaries. Benthic species indicative of polluted conditions were found (Nitzschia frustulum, Navicula gregaria, Navicula cryptotenelloides). These benthic species were found at the sites where wastewater / sewage seepage had occurred. Benthic diatom species also indicated freshwater inflow. During the high flow period in 2006 the dominant diatoms were fresh to brackish species that were strongly associated with the high concentrations of TOxN and SRP (Tryblionella constricta, Diploneis smithii, Hippodonta cf. gremainii, and Navicula species). During the freshwater limited period of 2008 and 2009 the benthic diatom species shifted to a group responding to the high salinity, ammonium and silicate concentrations. The species in this group were Nitzschia flexa, Navicula tenneloides, Diploneis elliptica, Amphora subacutiuscula and Nitzschia coarctata. Ordination results showed that the epiphytic diatom species responded to different environmental variables in the different years. Most of the species in 2008/2009 were associated with high salinity, temperature, dissolved oxygen, ammonium and silicate concentrations while the response was towards TOxN and SRP in 2006. The dominant species were Cocconeis placentula v euglyphyta in 2006; Nitzschia frustulum in 2008; and Synedra spp in 2009. The average biomass of the epiphytes was significantly lower in May 2008 than in both August 2006 and February 2009; 88.0 + 17.7 mg.m-2, 1.7 + 0.8 mg.m-2, and 61.8 + 14.4 mg.m-2 respectively. GIS mapping of past and present aerial photographs showed that submerged macrophyte (Zostera capensis) cover in 1966 and 1973 was less than that mapped for 2004. Salt marsh also increased its cover over time, from 86.9 ha in 1966 to 126 ha in 2004, colonizing what were bare sandy areas. Long-term monitoring of the health of the Bushmans Estuary should focus on salinity (as an indicator of inflow or deprivation of freshwater), benthic diatom identification and macrophyte distribution and composition (for the detection of pollution input), and bathymetric surveys (for shallowing of the estuary due to sedimentation).
- Full Text:
- Date Issued: 2010
The characterisation of trypanosomal type 1 DnaJ-like proteins
- Authors: Ludewig, Michael Hans
- Date: 2010
- Subjects: Molecular genetics , Molecular chaperones , Protozoa , Heat shock proteins , Trypanosoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4126 , http://hdl.handle.net/10962/d1015205
- Description: Trypanosomes are protozoans, of which many are parasitic, and possess complex lifecycles which alternate between mammalian and arthropod hosts. As is the case with most organisms, molecular chaperones and heat shock proteins are encoded within the genomes of these protozoans. These proteins are an integral part of maintaining the structural integrity of proteins during normal and stress conditions. Heat shock protein 40 (Hsp40) is a co-chaperone of heat shock protein 70 (Hsp70) and in some cases can act as a chaperone. These proteins work together to bind non-native polypeptide structures to prevent unfolded protein aggregrate formation in times of stress, translocate proteins across organelle membranes, and transport unsalvageable proteins to proteolytic degradation by the cellular proteasome. Hsp40s are divided into four types based on their domain structure. Analysis of the nuclear genomes of eight trypanosomatid species revealed that less than 10 of the approximate 70 Hsp40 sequences per genome were Type 1 Hsp40s, many of which contained putative orthologues in the other seven trypanosomatid genomes. One of these Type 1 Hsp40s from T b. brucei, Trypanosoma brucei DnaJ 2 (Tbj2), was functionally characterised in T brucei brucei. RNA interference knockdown of expression in T brucei brucei showed that cells deficient in Tbj2 displayed a severe inhibition of the growth of the cell population. The levels of the Tbj2 protein population in T brucei brucei cells increases after exposure to 42°c and the protein was found to have a generalized cytoplasmic subcellular localization at 37°c. These findings provide evidence that Tbj2 is an orthologue of Yeast DnaJ 1 (Y dj l), an essential S. cerevisiae protein. Hsp40s interact with their partner Hsp70s through their J-domain. The amino acids of the J-domain important for a functional interaction with Hsp70 were examined in Trypanosoma cruzi DnaJ 2 (Tcj2) (the orthologue of Tbj2) and T cruzi DnaJ protein 3 (Tcj3) by testing their ability to substitute for Y dj l in Saccharomyces cerevisae and for DnaJ in Escherichia coli. In both systems, the positively charged amino acids of Helix II and III of the J-domain disrupted the functional interaction of these Hsp40s with their partner Hsp70s. Substitutions in Helix I and IV of the J-domains of Tcj2 and Tcj3 produced varied results in the two different systems, possibly suggesting that these helices serve to define with which Hsp70s a given Hsp40 can interact. The inability of an Hsp40 and an Hsp70 to interact functionally does not necessarily mean a total absence of physical interaction between these proteins. The amino acid substitution of the histidine in the HPD motif (H34Q) of the J-domain of Tcj2 and Tcj3 removed the ability of these proteins to interact functionally with S. cerevisiae Hsp70 (Ssal) in vivo. However, preliminary binding studies using the quartz crystal microbalance with dissipation monitoring (QCM-D) show that Tcj2 and Tcj2(H34Q) both physically interact with M sativa Hsp70 in vitro. This study is the first report to provide evidence that certain trypanosoma! Type 1 Hsp40s are essential proteins. Futhermore, the interaction of these Hsp40s with Hsp70 identified important features of the functional interface of this chaperone machinery.
- Full Text:
- Date Issued: 2010
- Authors: Ludewig, Michael Hans
- Date: 2010
- Subjects: Molecular genetics , Molecular chaperones , Protozoa , Heat shock proteins , Trypanosoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4126 , http://hdl.handle.net/10962/d1015205
- Description: Trypanosomes are protozoans, of which many are parasitic, and possess complex lifecycles which alternate between mammalian and arthropod hosts. As is the case with most organisms, molecular chaperones and heat shock proteins are encoded within the genomes of these protozoans. These proteins are an integral part of maintaining the structural integrity of proteins during normal and stress conditions. Heat shock protein 40 (Hsp40) is a co-chaperone of heat shock protein 70 (Hsp70) and in some cases can act as a chaperone. These proteins work together to bind non-native polypeptide structures to prevent unfolded protein aggregrate formation in times of stress, translocate proteins across organelle membranes, and transport unsalvageable proteins to proteolytic degradation by the cellular proteasome. Hsp40s are divided into four types based on their domain structure. Analysis of the nuclear genomes of eight trypanosomatid species revealed that less than 10 of the approximate 70 Hsp40 sequences per genome were Type 1 Hsp40s, many of which contained putative orthologues in the other seven trypanosomatid genomes. One of these Type 1 Hsp40s from T b. brucei, Trypanosoma brucei DnaJ 2 (Tbj2), was functionally characterised in T brucei brucei. RNA interference knockdown of expression in T brucei brucei showed that cells deficient in Tbj2 displayed a severe inhibition of the growth of the cell population. The levels of the Tbj2 protein population in T brucei brucei cells increases after exposure to 42°c and the protein was found to have a generalized cytoplasmic subcellular localization at 37°c. These findings provide evidence that Tbj2 is an orthologue of Yeast DnaJ 1 (Y dj l), an essential S. cerevisiae protein. Hsp40s interact with their partner Hsp70s through their J-domain. The amino acids of the J-domain important for a functional interaction with Hsp70 were examined in Trypanosoma cruzi DnaJ 2 (Tcj2) (the orthologue of Tbj2) and T cruzi DnaJ protein 3 (Tcj3) by testing their ability to substitute for Y dj l in Saccharomyces cerevisae and for DnaJ in Escherichia coli. In both systems, the positively charged amino acids of Helix II and III of the J-domain disrupted the functional interaction of these Hsp40s with their partner Hsp70s. Substitutions in Helix I and IV of the J-domains of Tcj2 and Tcj3 produced varied results in the two different systems, possibly suggesting that these helices serve to define with which Hsp70s a given Hsp40 can interact. The inability of an Hsp40 and an Hsp70 to interact functionally does not necessarily mean a total absence of physical interaction between these proteins. The amino acid substitution of the histidine in the HPD motif (H34Q) of the J-domain of Tcj2 and Tcj3 removed the ability of these proteins to interact functionally with S. cerevisiae Hsp70 (Ssal) in vivo. However, preliminary binding studies using the quartz crystal microbalance with dissipation monitoring (QCM-D) show that Tcj2 and Tcj2(H34Q) both physically interact with M sativa Hsp70 in vitro. This study is the first report to provide evidence that certain trypanosoma! Type 1 Hsp40s are essential proteins. Futhermore, the interaction of these Hsp40s with Hsp70 identified important features of the functional interface of this chaperone machinery.
- Full Text:
- Date Issued: 2010
The characteristics and role of informal leaders in work groups : a South African perspective
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010