An investigation of an undergraduate course module on the ethical aspects of information systems
- Authors: Charlesworth, Matthew
- Date: 2005
- Subjects: Information technology , Information technology -- Moral and ethical aspects , Computers -- Moral and ethical aspects , Computer science -- Study and teaching (Higher) -- Curricula , Computer engineering -- Study and teaching (Higher) -- Curricula , Software engineering -- Study and teaching (Higher) -- Curricula , Information technology -- study and teaching (Higher) -- Curricula
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1139 , http://hdl.handle.net/10962/d1002768 , Information technology , Information technology -- Moral and ethical aspects , Computers -- Moral and ethical aspects , Computer science -- Study and teaching (Higher) -- Curricula , Computer engineering -- Study and teaching (Higher) -- Curricula , Software engineering -- Study and teaching (Higher) -- Curricula , Information technology -- study and teaching (Higher) -- Curricula
- Description: An increased emphasis is being placed on ethics in Information Systems. An investigation of: the relevant literature which highlighted the growth of, and importance in understanding the moral philosophies which underlie Computer Ethics; and the official curricula recommendations that have increasingly and consistently recommended inclusion of courses describing the Social, Professional and Ethical responsibilities of Information Systems Professionals; and informed by the observations from two empirical Studies that showed the extent of unethical behaviour, and how this behaviour is diminished in those who have received formal tertiary level education resulted in a proposed new course module on Ethics in Information Systems. The module follows a sandwich-approach whereby two stand-alone modules are conducted on either side of integrated Computer Ethics content within the rest of the curriculum.
- Full Text:
- Authors: Charlesworth, Matthew
- Date: 2005
- Subjects: Information technology , Information technology -- Moral and ethical aspects , Computers -- Moral and ethical aspects , Computer science -- Study and teaching (Higher) -- Curricula , Computer engineering -- Study and teaching (Higher) -- Curricula , Software engineering -- Study and teaching (Higher) -- Curricula , Information technology -- study and teaching (Higher) -- Curricula
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1139 , http://hdl.handle.net/10962/d1002768 , Information technology , Information technology -- Moral and ethical aspects , Computers -- Moral and ethical aspects , Computer science -- Study and teaching (Higher) -- Curricula , Computer engineering -- Study and teaching (Higher) -- Curricula , Software engineering -- Study and teaching (Higher) -- Curricula , Information technology -- study and teaching (Higher) -- Curricula
- Description: An increased emphasis is being placed on ethics in Information Systems. An investigation of: the relevant literature which highlighted the growth of, and importance in understanding the moral philosophies which underlie Computer Ethics; and the official curricula recommendations that have increasingly and consistently recommended inclusion of courses describing the Social, Professional and Ethical responsibilities of Information Systems Professionals; and informed by the observations from two empirical Studies that showed the extent of unethical behaviour, and how this behaviour is diminished in those who have received formal tertiary level education resulted in a proposed new course module on Ethics in Information Systems. The module follows a sandwich-approach whereby two stand-alone modules are conducted on either side of integrated Computer Ethics content within the rest of the curriculum.
- Full Text:
An investigation of female leaders' perceptions of organisational culture and leadership in a Catholic High School
- Jean-Louis, Lily-Claire Virginie
- Authors: Jean-Louis, Lily-Claire Virginie
- Date: 2005
- Subjects: Catholic schools -- South Africa -- Administration School management and organization -- South Africa Educational leadership -- South Africa Corporate culture -- South Africa Women school administrators -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1625 , http://hdl.handle.net/10962/d1003507
- Description: For the past thirty years, leadership theories have focused on the importance of the individual within the school organisation. The shared assumptions and beliefs of the individuals working in the same organisation shape the school’s organisational culture, and organisational culture is a salient factor which should be considered when understanding educational leadership. The focus of my study is to explore the relationship between organisational culture and leadership. In the same context, new approaches to the study of leadership have explored the issue of gender in leadership. Female leadership studies - the second focus of this study - seek not only to restore the place of the individual but also argue a place for women in educational leadership. Based in the interpretive paradigm, this is a case study of a Catholic all-girl secondary school called the Loreto Convent School of Pretoria. Historically, the Loreto schools have aimed at promoting and empowering girls’ education and female leadership. It was therefore an appropriate site in which to explore organisational culture and its relationship with leadership, particularly female leadership. I purposefully chose three of the school’s female leaders - the school’s principal, the High school Head of Department and the High school head girl - focusing on their perceptions and experiences of their leadership and the school’s culture. My research findings show that an understanding of the relationship between organisational culture and leadership cannot be complete without acknowledging the importance of the leader as an individual, with his/her personal background and values, taking into account gender as well as the multiple roles that the individual has in society. Furthermore, the ‘humane’ characteristic of educational leadership leads to an understanding that the leader is often confronted with conflicting situations where he/she is caught between personal/organisational values and the need to achieve the task. Finally, my findings show that contemporary leaders are now called upon to work and participate in the promotion of social justice in order to fight against society’s socio-economic inequality and improve the quality of education and life.
- Full Text:
- Authors: Jean-Louis, Lily-Claire Virginie
- Date: 2005
- Subjects: Catholic schools -- South Africa -- Administration School management and organization -- South Africa Educational leadership -- South Africa Corporate culture -- South Africa Women school administrators -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1625 , http://hdl.handle.net/10962/d1003507
- Description: For the past thirty years, leadership theories have focused on the importance of the individual within the school organisation. The shared assumptions and beliefs of the individuals working in the same organisation shape the school’s organisational culture, and organisational culture is a salient factor which should be considered when understanding educational leadership. The focus of my study is to explore the relationship between organisational culture and leadership. In the same context, new approaches to the study of leadership have explored the issue of gender in leadership. Female leadership studies - the second focus of this study - seek not only to restore the place of the individual but also argue a place for women in educational leadership. Based in the interpretive paradigm, this is a case study of a Catholic all-girl secondary school called the Loreto Convent School of Pretoria. Historically, the Loreto schools have aimed at promoting and empowering girls’ education and female leadership. It was therefore an appropriate site in which to explore organisational culture and its relationship with leadership, particularly female leadership. I purposefully chose three of the school’s female leaders - the school’s principal, the High school Head of Department and the High school head girl - focusing on their perceptions and experiences of their leadership and the school’s culture. My research findings show that an understanding of the relationship between organisational culture and leadership cannot be complete without acknowledging the importance of the leader as an individual, with his/her personal background and values, taking into account gender as well as the multiple roles that the individual has in society. Furthermore, the ‘humane’ characteristic of educational leadership leads to an understanding that the leader is often confronted with conflicting situations where he/she is caught between personal/organisational values and the need to achieve the task. Finally, my findings show that contemporary leaders are now called upon to work and participate in the promotion of social justice in order to fight against society’s socio-economic inequality and improve the quality of education and life.
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An investigation of hair modelling and rendering techniques with emphasis on African hairstyles
- Authors: Patrick, Deborah Michelle
- Date: 2005 , 2013-10-17
- Subjects: RenderMan , Hairstyles -- Africa , Hairstyles -- Computer simulation -- Africa , Hairdressing of Black people , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4639 , http://hdl.handle.net/10962/d1006561 , RenderMan , Hairstyles -- Africa , Hairstyles -- Computer simulation -- Africa , Hairdressing of Black people , Computer graphics
- Description: Many computer graphics applications make use of virtual humans. Methods for modelling and rendering hair are needed so that hairstyles can be added to the virtual humans. Modelling and rendering hair is challenging due to the large number of hair strands and their geometric properties, the complex lighting effects that occur among the strands of hair, and the complexity and large variation of human hairstyles. While methods have been developed for generating hair, no methods exist for generating African hair, which differs from hair of other ethnic groups. This thesis presents methods for modelling and rendering African hair. Existing hair modelling and rendering techniques are investigated, and the knowledge gained from the investigation is used to develop or enhance hair modelling and rendering techniques to produce three different forms of hair commonly found in African hairstyles. The different forms of hair identified are natural curly hair, straightened hair, and braids or twists of hair. The hair modelling techniques developed are implemented as plug-ins for the graphics program LightWave 3D. The plug-ins developed not only model the three identified forms of hair, but also add the modelled hair to a model of a head, and can be used to create a variety of African hairstyles. The plug-ins significantly reduce the time spent on hair modelling. Tests performed show that increasing the number of polygons used to model hair increases the quality of the hair produced, but also increases the rendering time. However, there is usually an upper bound to the number of polygons needed to produce a reasonable hairstyle, making it feasible to add African hairstyles to virtual humans. The rendering aspects investigated include hair illumination, texturing, shadowing and antialiasing. An anisotropic illumination model is developed that considers the properties of African hair, including the colouring, opacity and narrow width of the hair strands. Texturing is used in several instances to create the effect of individual strands of hair. Results show that texturing is useful for representing many hair strands because the density of the hair in a texture map does not have an effect on the rendering time. The importance of including a shadowing technique and applying an anti-aliasing method when rendering hair is demonstrated. The rendering techniques are implemented using the RenderMan Interface and Shading Language. A number of complete African hairstyles are shown, demonstrating that the techniques can be used to model and render African hair successfully. , GNU Ghostscript 7.07
- Full Text:
- Authors: Patrick, Deborah Michelle
- Date: 2005 , 2013-10-17
- Subjects: RenderMan , Hairstyles -- Africa , Hairstyles -- Computer simulation -- Africa , Hairdressing of Black people , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4639 , http://hdl.handle.net/10962/d1006561 , RenderMan , Hairstyles -- Africa , Hairstyles -- Computer simulation -- Africa , Hairdressing of Black people , Computer graphics
- Description: Many computer graphics applications make use of virtual humans. Methods for modelling and rendering hair are needed so that hairstyles can be added to the virtual humans. Modelling and rendering hair is challenging due to the large number of hair strands and their geometric properties, the complex lighting effects that occur among the strands of hair, and the complexity and large variation of human hairstyles. While methods have been developed for generating hair, no methods exist for generating African hair, which differs from hair of other ethnic groups. This thesis presents methods for modelling and rendering African hair. Existing hair modelling and rendering techniques are investigated, and the knowledge gained from the investigation is used to develop or enhance hair modelling and rendering techniques to produce three different forms of hair commonly found in African hairstyles. The different forms of hair identified are natural curly hair, straightened hair, and braids or twists of hair. The hair modelling techniques developed are implemented as plug-ins for the graphics program LightWave 3D. The plug-ins developed not only model the three identified forms of hair, but also add the modelled hair to a model of a head, and can be used to create a variety of African hairstyles. The plug-ins significantly reduce the time spent on hair modelling. Tests performed show that increasing the number of polygons used to model hair increases the quality of the hair produced, but also increases the rendering time. However, there is usually an upper bound to the number of polygons needed to produce a reasonable hairstyle, making it feasible to add African hairstyles to virtual humans. The rendering aspects investigated include hair illumination, texturing, shadowing and antialiasing. An anisotropic illumination model is developed that considers the properties of African hair, including the colouring, opacity and narrow width of the hair strands. Texturing is used in several instances to create the effect of individual strands of hair. Results show that texturing is useful for representing many hair strands because the density of the hair in a texture map does not have an effect on the rendering time. The importance of including a shadowing technique and applying an anti-aliasing method when rendering hair is demonstrated. The rendering techniques are implemented using the RenderMan Interface and Shading Language. A number of complete African hairstyles are shown, demonstrating that the techniques can be used to model and render African hair successfully. , GNU Ghostscript 7.07
- Full Text:
An investigation of how Kampala teenagers who read Straight talk negotiate HIV/AIDS messages
- Kaija, Barbara Night Mbabazi
- Authors: Kaija, Barbara Night Mbabazi
- Date: 2005
- Subjects: AIDS (Disease) -- Uganda -- Kampala Straight talk AIDS (Disease) -- Social aspects -- Uganda -- Kampala AIDS (Disease) in adolescence -- Uganda -- Kampala Teenagers -- Diseases -- Uganda -- Kampala AIDS (Disease) -- Study and teaching AIDS (Disease) in mass media Teenagers -- Sexual behavior -- Uganda -- Kampala AIDS (Disease) -- Prevention -- Uganda -- Kampala
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3440 , http://hdl.handle.net/10962/d1002894
- Description: This study is a qualitative ethnographic investigation of how teenagers in Kampala, Uganda, who read the HIV/AIDS publication aimed at adolescents, Straight Talk, negotiate HIV/AIDS messages. It seeks to establish to what extent these secondary school teenagers accept the key messages (known as ABC; Abstain, Be faithful or use a Condom) and understand the factual aspects of the messages about HIV/AIDS, its process of transmission and prevention. It also seeks to probe how the lived realities of the teenagers affect their particular negotiations of the HIV/AIDS messages. It includes a focus on how proximity to HIV/AIDS, gender and family economic disposition might affect teenagers, negotiation of the HIV/AIDS meanings. To investigate the respondents’ reception of HIV/AIDS messages, the study employed focus groups that consisted of two stages, namely the ‘news game’ and group discussions. In the ‘news game’ stage (Philo, 1990; Kitzinger, 1993) the teenage participants were required to produce a version of a one-page copy of an HIV/AIDS newspaper targeting teenagers. In the second stage of the focus group a structured discussion probed the teenagers’ negotiation of the HIV/AIDS media messages. In the news game, the teenagers on the whole reproduced the key Straight Talk HIV/AIDS messages ‘Abstain, Be faithful or use a Condom’ and also images showing the effects of HIV/AIDS but featured fewer images depicting the factual aspects of HIV/AIDS process of transmission and risky behaviour. In the structured discussion that followed the news game, it was evident that not all the teenagers necessarily believed the messages they produced. In spite of producing the ABC Straight Talk messages, some of them were uncertain and confused about the absolute safety of the condom because of fears that they were either porous, expired or would interfere with sexual pleasure. Secondly, though many of the teenagers in the study reproduced images that showed that they consider marriage as desirable and talked about their desire to abstain from sex till marriage, a considerable number think abstinence is not achievable due to competing values. Thirdly, the participant teenagers could differentiate between HIV and AIDS but many did not realise that with the advent of anti-retroviral drugs even people who have AIDS can look normal. In spite of repeating the Straight Talk message that “no one was safe” and being aware of the risky behaviour that their fellow teenagers get involved in, the teenagers seemed to think that their age cohort is safe from HIV and it is the adults who are likely to infect them. The study findings further indicate that the teenagers’ lived experience at times influence their negotiation of HIV/AIDS media messages. This was probed in terms of economic standing, gender and proximity to HIV/AIDS. In relation to gender one surprising discovery was that certain girls in the study feared getting pregnant more than getting HIV/AIDS. The study finally suggests that these findings are of significance for designing future media initiatives in relation to HIV/AIDS.
- Full Text:
- Authors: Kaija, Barbara Night Mbabazi
- Date: 2005
- Subjects: AIDS (Disease) -- Uganda -- Kampala Straight talk AIDS (Disease) -- Social aspects -- Uganda -- Kampala AIDS (Disease) in adolescence -- Uganda -- Kampala Teenagers -- Diseases -- Uganda -- Kampala AIDS (Disease) -- Study and teaching AIDS (Disease) in mass media Teenagers -- Sexual behavior -- Uganda -- Kampala AIDS (Disease) -- Prevention -- Uganda -- Kampala
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3440 , http://hdl.handle.net/10962/d1002894
- Description: This study is a qualitative ethnographic investigation of how teenagers in Kampala, Uganda, who read the HIV/AIDS publication aimed at adolescents, Straight Talk, negotiate HIV/AIDS messages. It seeks to establish to what extent these secondary school teenagers accept the key messages (known as ABC; Abstain, Be faithful or use a Condom) and understand the factual aspects of the messages about HIV/AIDS, its process of transmission and prevention. It also seeks to probe how the lived realities of the teenagers affect their particular negotiations of the HIV/AIDS messages. It includes a focus on how proximity to HIV/AIDS, gender and family economic disposition might affect teenagers, negotiation of the HIV/AIDS meanings. To investigate the respondents’ reception of HIV/AIDS messages, the study employed focus groups that consisted of two stages, namely the ‘news game’ and group discussions. In the ‘news game’ stage (Philo, 1990; Kitzinger, 1993) the teenage participants were required to produce a version of a one-page copy of an HIV/AIDS newspaper targeting teenagers. In the second stage of the focus group a structured discussion probed the teenagers’ negotiation of the HIV/AIDS media messages. In the news game, the teenagers on the whole reproduced the key Straight Talk HIV/AIDS messages ‘Abstain, Be faithful or use a Condom’ and also images showing the effects of HIV/AIDS but featured fewer images depicting the factual aspects of HIV/AIDS process of transmission and risky behaviour. In the structured discussion that followed the news game, it was evident that not all the teenagers necessarily believed the messages they produced. In spite of producing the ABC Straight Talk messages, some of them were uncertain and confused about the absolute safety of the condom because of fears that they were either porous, expired or would interfere with sexual pleasure. Secondly, though many of the teenagers in the study reproduced images that showed that they consider marriage as desirable and talked about their desire to abstain from sex till marriage, a considerable number think abstinence is not achievable due to competing values. Thirdly, the participant teenagers could differentiate between HIV and AIDS but many did not realise that with the advent of anti-retroviral drugs even people who have AIDS can look normal. In spite of repeating the Straight Talk message that “no one was safe” and being aware of the risky behaviour that their fellow teenagers get involved in, the teenagers seemed to think that their age cohort is safe from HIV and it is the adults who are likely to infect them. The study findings further indicate that the teenagers’ lived experience at times influence their negotiation of HIV/AIDS media messages. This was probed in terms of economic standing, gender and proximity to HIV/AIDS. In relation to gender one surprising discovery was that certain girls in the study feared getting pregnant more than getting HIV/AIDS. The study finally suggests that these findings are of significance for designing future media initiatives in relation to HIV/AIDS.
- Full Text:
An investigation of information security in small and medium enterprises (SME's) in the Eastern Cape
- Authors: Upfold, Christopher Tennant
- Date: 2005
- Subjects: Small business -- South Africa -- Eastern Cape Computer security -- South Africa Information technology -- South Africa -- Eastern Cape Management information systems -- South Africa -- Eastern Cape Computer security -- Standards -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:727 , http://hdl.handle.net/10962/d1003847
- Description: Small and Medium Enterprises (SME’s) embrace a wide range of information systems and technology that range from basic bookkeeping and general purpose office packages, through to advanced E-Business Web portals and Electronic Data Interchange (EDI). A survey, based on SABS ISO/IEC 17799 was administered to a select number of SME’s in the services sector, in the Eastern Cape. The results of the survey revealed that the level of information security awareness amongst SME leadership is as diverse as the state of practice of their information systems and technology. Although a minority of SME’s do embrace security frameworks such as SABS ISO/IEC 17799 or the International equivalent, BS7799, most SME leaders have not heard of security standards, and see information security as a technical intervention designed to address virus threats and data backups. Furthermore, there are several “stripped-down” standards and guidelines for SME’s, based mostly on SABS ISO/IEC 17799, but designed as streamlined, more easily implemented options. Again, these “lighter” frameworks are scarcely used and largely unknown by SME’s. Far from blaming SME leadership for not understanding the critical issues surrounding information security, the research concludes that SME leadership need to engage, understand and implement formal information security processes, failing which their organisations may be severely impacted by inadvertent threats / deliberate attacks on their information systems which could ultimately lead to business failure.
- Full Text:
An investigation of information security in small and medium enterprises (SME's) in the Eastern Cape
- Authors: Upfold, Christopher Tennant
- Date: 2005
- Subjects: Small business -- South Africa -- Eastern Cape Computer security -- South Africa Information technology -- South Africa -- Eastern Cape Management information systems -- South Africa -- Eastern Cape Computer security -- Standards -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:727 , http://hdl.handle.net/10962/d1003847
- Description: Small and Medium Enterprises (SME’s) embrace a wide range of information systems and technology that range from basic bookkeeping and general purpose office packages, through to advanced E-Business Web portals and Electronic Data Interchange (EDI). A survey, based on SABS ISO/IEC 17799 was administered to a select number of SME’s in the services sector, in the Eastern Cape. The results of the survey revealed that the level of information security awareness amongst SME leadership is as diverse as the state of practice of their information systems and technology. Although a minority of SME’s do embrace security frameworks such as SABS ISO/IEC 17799 or the International equivalent, BS7799, most SME leaders have not heard of security standards, and see information security as a technical intervention designed to address virus threats and data backups. Furthermore, there are several “stripped-down” standards and guidelines for SME’s, based mostly on SABS ISO/IEC 17799, but designed as streamlined, more easily implemented options. Again, these “lighter” frameworks are scarcely used and largely unknown by SME’s. Far from blaming SME leadership for not understanding the critical issues surrounding information security, the research concludes that SME leadership need to engage, understand and implement formal information security processes, failing which their organisations may be severely impacted by inadvertent threats / deliberate attacks on their information systems which could ultimately lead to business failure.
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An investigation of instructional leadership in a Namibian teacher training college
- Alexander, Christa Henriette
- Authors: Alexander, Christa Henriette
- Date: 2005
- Subjects: Windhoek College of Education Educational leadership -- Namibia Education -- Namibia Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1634 , http://hdl.handle.net/10962/d1003516
- Description: This thesis investigates how instructional leaders at the Windhoek College of Education (in Namibia) make sense of their roles. The Windhoek College of Education (WCE) was selected for this study because that is where I work, therefore it would be easy to observe some of the responses provided by the interviewees. It was also observed that instructional leadership is little researched in Namibia and hence study would contribute towards understanding the various perceptions that instructional leaders have of their roles. There is a need for information about the skills and tasks required to support practices of instructional leadership so that the best possible instruction can be provided. The thesis examines and presents such skills. A qualitative research framework, in particular an interpretative approach was used for the study. As my research is concerned with people’s perceptions, it is located in the interpretative paradigm. Semi-structured, open-ended interview questions were asked in order to gather information on how the participants make meaning of their roles as instructional leaders. The sample for the study consisted of eleven instructional leaders over different levels, i.e., executive leaders, leaders on middle-management level and leaders on classroom-instructional level. The findings indicated a narrow view of instructional leadership at the college. Factors contributing to this narrowness are addressed, e.g., the way concepts such as delegation, guidance and monitoring/supervision are perceived. The findings also addressed certain expectations that are needed from instructional leaders in order to ensure efficiency in their practice. The study concludes by recommending alternative, expansive ways of thinking about instructional leadership.
- Full Text:
- Authors: Alexander, Christa Henriette
- Date: 2005
- Subjects: Windhoek College of Education Educational leadership -- Namibia Education -- Namibia Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1634 , http://hdl.handle.net/10962/d1003516
- Description: This thesis investigates how instructional leaders at the Windhoek College of Education (in Namibia) make sense of their roles. The Windhoek College of Education (WCE) was selected for this study because that is where I work, therefore it would be easy to observe some of the responses provided by the interviewees. It was also observed that instructional leadership is little researched in Namibia and hence study would contribute towards understanding the various perceptions that instructional leaders have of their roles. There is a need for information about the skills and tasks required to support practices of instructional leadership so that the best possible instruction can be provided. The thesis examines and presents such skills. A qualitative research framework, in particular an interpretative approach was used for the study. As my research is concerned with people’s perceptions, it is located in the interpretative paradigm. Semi-structured, open-ended interview questions were asked in order to gather information on how the participants make meaning of their roles as instructional leaders. The sample for the study consisted of eleven instructional leaders over different levels, i.e., executive leaders, leaders on middle-management level and leaders on classroom-instructional level. The findings indicated a narrow view of instructional leadership at the college. Factors contributing to this narrowness are addressed, e.g., the way concepts such as delegation, guidance and monitoring/supervision are perceived. The findings also addressed certain expectations that are needed from instructional leaders in order to ensure efficiency in their practice. The study concludes by recommending alternative, expansive ways of thinking about instructional leadership.
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An investigation of local community contributions to the Malawi College of Fisheries curriculum: a case study focussing on the Chambo fishery
- Kachilonda, Dick Daffu Kachanga
- Authors: Kachilonda, Dick Daffu Kachanga
- Date: 2005
- Subjects: Malawi College of Fisheries -- Curricula Fishery management -- Study and teaching Fishery management -- Malawi Fisheries -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1857 , http://hdl.handle.net/10962/d1004537
- Description: The aim of the study was to investigate local community contributions to the existing Malawi College of Fisheries curriculum with a focus on Chambo fishery. Chambo fish (Oreochromis species) is the most favoured fish in Lake Malawi. Chambo catches have declined over the years. Responding to the declining catches, the Fisheries Department is engaged in a number of management options to address the issues. Most of these management options are governed by scientific recommendations and do not consider the socio-economic situation of the people who are dependent on fishery. This approach to fishery has influenced the Malawi College of Fisheries curriculum. The existing curriculum is product-centred, developed by a consultant. During the development of the curriculum, there was little consultation with the lecturers and no consultation with the local communities who are using the resource. The fishing communities have been fishing for a long time and have acquired knowledge, skills and experience worth investigating for its potential role in improving the existing curriculum. Through the use of interviews, focus group discussions and workshops with local communities local knowledge was identified for inclusion into the curriculum. A review of the existing curriculum revealed that it has primarily technical focus, grounded in the protection, control and management of the fish stocks, while the local knowledge has a practical focus based on existing practices and requiring an understanding of the sources of the issues. There is also more emphasis on a historical perspective and the context in which fishing practices take place at the moment. It was evident from the study that local communities have much of knowledge, skills and experience gained over the years of fishing , and if properly utilised, it can improve the MCF curriculum. I therefore recommend in this study that the curriculum be reviewed in order to integrate and draw on the local knowledge through a deliberative and participatory process between the local communities and the government so that it addresses the needs of the local communities and improves the training of the extension workers.
- Full Text:
- Authors: Kachilonda, Dick Daffu Kachanga
- Date: 2005
- Subjects: Malawi College of Fisheries -- Curricula Fishery management -- Study and teaching Fishery management -- Malawi Fisheries -- Malawi Fishes -- Nyasa, Lake
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1857 , http://hdl.handle.net/10962/d1004537
- Description: The aim of the study was to investigate local community contributions to the existing Malawi College of Fisheries curriculum with a focus on Chambo fishery. Chambo fish (Oreochromis species) is the most favoured fish in Lake Malawi. Chambo catches have declined over the years. Responding to the declining catches, the Fisheries Department is engaged in a number of management options to address the issues. Most of these management options are governed by scientific recommendations and do not consider the socio-economic situation of the people who are dependent on fishery. This approach to fishery has influenced the Malawi College of Fisheries curriculum. The existing curriculum is product-centred, developed by a consultant. During the development of the curriculum, there was little consultation with the lecturers and no consultation with the local communities who are using the resource. The fishing communities have been fishing for a long time and have acquired knowledge, skills and experience worth investigating for its potential role in improving the existing curriculum. Through the use of interviews, focus group discussions and workshops with local communities local knowledge was identified for inclusion into the curriculum. A review of the existing curriculum revealed that it has primarily technical focus, grounded in the protection, control and management of the fish stocks, while the local knowledge has a practical focus based on existing practices and requiring an understanding of the sources of the issues. There is also more emphasis on a historical perspective and the context in which fishing practices take place at the moment. It was evident from the study that local communities have much of knowledge, skills and experience gained over the years of fishing , and if properly utilised, it can improve the MCF curriculum. I therefore recommend in this study that the curriculum be reviewed in order to integrate and draw on the local knowledge through a deliberative and participatory process between the local communities and the government so that it addresses the needs of the local communities and improves the training of the extension workers.
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An investigation of the development and adoption of educational metadata standards for the widespread use of learning objects
- Authors: Krull, Greig Emil
- Date: 2005
- Subjects: Metadata , Internet in education , Web databases , Education -- Standards , Educational technology , Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1142 , http://hdl.handle.net/10962/d1002771 , Metadata , Internet in education , Web databases , Education -- Standards , Educational technology , Computer-assisted instruction
- Description: This research investigates the development and adoption of educational metadata standards for the widespread use of learning objects. Learning objects, metadata, the related IEEE standard and the various application profiles derived from the standard are discussed. A number of standards and specifications for educational metadata used to describe learning objects are explored, namely the Dublin Core, IMS, SCORM, ARIADNE, CanCore and the UK LOM Core. Three metadata editors and the experience with using one of them, RELOAD, is described. These educational metadata specifications are used in a practical metadata implementation scenario and the experiences are extrapolated to derive a localised instance of the generic IEEE standard. A new application profile is proposed, “RU LOM Core”, for the South African higher education context. Some existing results are confirmed about the complexity of using the IEEE standard and it is demonstrated that it is possible to instantiate the standard for South African conditions. The results are largely qualitative and based on practical experience. However, the results concur with results from related research. Although the development of an application profile is certainly not new, the development of RU LOM Core illustrates that the IEEE standard, developed largely within the northern hemisphere, can be adapted to work in the South African scenario. RU LOM Core has been developed for the South African higher education environment and takes linguistic and cultural diversity and the low rate of technological literacy into consideration. The lessons learned and the proposed LOM core can be built upon in further research and collaboration to use and support the use of such standards within South Africa.
- Full Text:
- Authors: Krull, Greig Emil
- Date: 2005
- Subjects: Metadata , Internet in education , Web databases , Education -- Standards , Educational technology , Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1142 , http://hdl.handle.net/10962/d1002771 , Metadata , Internet in education , Web databases , Education -- Standards , Educational technology , Computer-assisted instruction
- Description: This research investigates the development and adoption of educational metadata standards for the widespread use of learning objects. Learning objects, metadata, the related IEEE standard and the various application profiles derived from the standard are discussed. A number of standards and specifications for educational metadata used to describe learning objects are explored, namely the Dublin Core, IMS, SCORM, ARIADNE, CanCore and the UK LOM Core. Three metadata editors and the experience with using one of them, RELOAD, is described. These educational metadata specifications are used in a practical metadata implementation scenario and the experiences are extrapolated to derive a localised instance of the generic IEEE standard. A new application profile is proposed, “RU LOM Core”, for the South African higher education context. Some existing results are confirmed about the complexity of using the IEEE standard and it is demonstrated that it is possible to instantiate the standard for South African conditions. The results are largely qualitative and based on practical experience. However, the results concur with results from related research. Although the development of an application profile is certainly not new, the development of RU LOM Core illustrates that the IEEE standard, developed largely within the northern hemisphere, can be adapted to work in the South African scenario. RU LOM Core has been developed for the South African higher education environment and takes linguistic and cultural diversity and the low rate of technological literacy into consideration. The lessons learned and the proposed LOM core can be built upon in further research and collaboration to use and support the use of such standards within South Africa.
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An investigation of the experiences and perceptions of teachers with regards to staff development in a Namibian secondary school
- Authors: Nasima, Gideon Emmanuel
- Date: 2005
- Subjects: Education -- Namibia Teachers -- In-service training -- Namibia School management and organization -- Namibia School principals -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1649 , http://hdl.handle.net/10962/d1003532
- Description: Staff development (SD) is regarded as an important process, both for the professional growth of teachers and the organizational development of schools. The literature on SD uses the concepts of ‘SD’, ‘professional development’ and ‘in-service training of teachers’ interchangeably. The purpose of this study is to investigate the teachers’ experiences and perceptions of SD practices in a Namibian secondary school. This qualitative case study was carried out at the school where I am teaching. Two methods were used to collect the data, namely a blend of semi-structured and unstructured interviews with three teachers and one focus group interview with five teachers. The analysis of the data collected was carried using the method suggested by Taylor and Bogdan (1998) which includes discovery, coding and discounting. These concepts are discussed in Chapter Three. The main finding of this research regards SD at the school as mainly in line with the traditional view. The study also made three other unusual findings that differ from the traditional view of SD held at the school. First, the principal’s role as a human resource manager of SD; second the pastoral role of a principal in SD and third the role of teachers’ unions in SD. All these findings are important for SD practices in schools and for further research because little is known in the current literature on SD. Finally, this study proposes further research to develop an organizational development (OD) cycle of problem solving to help create an internal policy on SD, which is currently nonexistent at the school.
- Full Text:
- Authors: Nasima, Gideon Emmanuel
- Date: 2005
- Subjects: Education -- Namibia Teachers -- In-service training -- Namibia School management and organization -- Namibia School principals -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1649 , http://hdl.handle.net/10962/d1003532
- Description: Staff development (SD) is regarded as an important process, both for the professional growth of teachers and the organizational development of schools. The literature on SD uses the concepts of ‘SD’, ‘professional development’ and ‘in-service training of teachers’ interchangeably. The purpose of this study is to investigate the teachers’ experiences and perceptions of SD practices in a Namibian secondary school. This qualitative case study was carried out at the school where I am teaching. Two methods were used to collect the data, namely a blend of semi-structured and unstructured interviews with three teachers and one focus group interview with five teachers. The analysis of the data collected was carried using the method suggested by Taylor and Bogdan (1998) which includes discovery, coding and discounting. These concepts are discussed in Chapter Three. The main finding of this research regards SD at the school as mainly in line with the traditional view. The study also made three other unusual findings that differ from the traditional view of SD held at the school. First, the principal’s role as a human resource manager of SD; second the pastoral role of a principal in SD and third the role of teachers’ unions in SD. All these findings are important for SD practices in schools and for further research because little is known in the current literature on SD. Finally, this study proposes further research to develop an organizational development (OD) cycle of problem solving to help create an internal policy on SD, which is currently nonexistent at the school.
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An investigation of the factors that influence Grahamstown East grade 12 learners to aspire to higher education : a case study
- Burns-Ncamashe, Zimasa Nomsawezulu Ancilla
- Authors: Burns-Ncamashe, Zimasa Nomsawezulu Ancilla
- Date: 2005
- Subjects: Education -- South Africa -- Grahamstown -- Case studies , Education, Secondary -- South Africa -- Grahamstown -- Case studies , Education, Higher -- South Africa -- Grahamstown -- Case studies , Student aspirations -- South Africa -- Grahamstown -- Case studies , High school graduates -- South Africa -- Attitudes -- Case studies , Vocational interests -- South Africa -- Grahamstown -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1650 , http://hdl.handle.net/10962/d1003533 , Education -- South Africa -- Grahamstown -- Case studies , Education, Secondary -- South Africa -- Grahamstown -- Case studies , Education, Higher -- South Africa -- Grahamstown -- Case studies , Student aspirations -- South Africa -- Grahamstown -- Case studies , High school graduates -- South Africa -- Attitudes -- Case studies , Vocational interests -- South Africa -- Grahamstown -- Case studies
- Description: This research is an investigation into the factors that influence the decisions of grade 12 learners from Grahamstown East disadvantaged communities to pursue higher education. Research on learner aspirations has largely focused on access to higher education and little or no attention has been has been paid to the enabling or limiting factors and what can be done to increase the numbers of learners from disadvantaged communities who enrol at higher education institutions. This study aims to fill that gap. The research was a qualitative case study located in the interpretive paradigm. The data was gathered using questionnaires and focus group interviews for grade 12 learners. Individual interviews were conducted with the parents of the grade 12 research participants, educators and the school management team. Observation and documentary evidence from school documents were also used for data collection. The data were analysed using systematic patterning, were interpreted, and given meaning linking it to the literature surveyed. The main findings indicate that a number of enabling factors that influence grade 12 learners to pursue higher education co-exist with limiting factors. Recommendations arising from the main findings are presented and the limitations of the research are identified. Areas for possible further research in strengthening learner support so as to increase the numbers of learners who qualify for higher education and to enable the learners from disadvantaged communities to realise their aspirations, are suggested.
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- Authors: Burns-Ncamashe, Zimasa Nomsawezulu Ancilla
- Date: 2005
- Subjects: Education -- South Africa -- Grahamstown -- Case studies , Education, Secondary -- South Africa -- Grahamstown -- Case studies , Education, Higher -- South Africa -- Grahamstown -- Case studies , Student aspirations -- South Africa -- Grahamstown -- Case studies , High school graduates -- South Africa -- Attitudes -- Case studies , Vocational interests -- South Africa -- Grahamstown -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1650 , http://hdl.handle.net/10962/d1003533 , Education -- South Africa -- Grahamstown -- Case studies , Education, Secondary -- South Africa -- Grahamstown -- Case studies , Education, Higher -- South Africa -- Grahamstown -- Case studies , Student aspirations -- South Africa -- Grahamstown -- Case studies , High school graduates -- South Africa -- Attitudes -- Case studies , Vocational interests -- South Africa -- Grahamstown -- Case studies
- Description: This research is an investigation into the factors that influence the decisions of grade 12 learners from Grahamstown East disadvantaged communities to pursue higher education. Research on learner aspirations has largely focused on access to higher education and little or no attention has been has been paid to the enabling or limiting factors and what can be done to increase the numbers of learners from disadvantaged communities who enrol at higher education institutions. This study aims to fill that gap. The research was a qualitative case study located in the interpretive paradigm. The data was gathered using questionnaires and focus group interviews for grade 12 learners. Individual interviews were conducted with the parents of the grade 12 research participants, educators and the school management team. Observation and documentary evidence from school documents were also used for data collection. The data were analysed using systematic patterning, were interpreted, and given meaning linking it to the literature surveyed. The main findings indicate that a number of enabling factors that influence grade 12 learners to pursue higher education co-exist with limiting factors. Recommendations arising from the main findings are presented and the limitations of the research are identified. Areas for possible further research in strengthening learner support so as to increase the numbers of learners who qualify for higher education and to enable the learners from disadvantaged communities to realise their aspirations, are suggested.
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An investigation of the role of news values in the selection of news sources in a contemporary third world newspaper: a case study of the Daily Nation newspaper
- Authors: Kisuke, Connie Syomiti
- Date: 2005
- Subjects: Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3446 , http://hdl.handle.net/10962/d1002900 , Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Description: News in our contemporary newspapers has come to be associated more and more with what the elites do and say. Both their deeds and misdeeds are treated as newsworthy events and in the process they become newsmakers, both actors and sources of news. Even when they are not directly involved in news events they are sought out by journalists to validate those events and to interpret the social reality to the readers as news sources. This study is about the selection of news sources in the Daily Nation, a contemporary, independent newspaper based in Nairobi, Kenya. In this study, I set out to unravel the complex processes that underlie newsmaking and source selection. This study is informed by the theory of news values and the paradigm of the role of media in democracy. Based on qualitative interviews, observations and content analysis of the front-page stories, it investigates the process of news and source selection in front-page stories. Through these approaches, I established that news values are significant criteria that inform journalists in both the selection of front-page news stories and the sources of these stories. I also established that social values of the society in which this newspaper operates are heavily embedded in the news. For example, the journalists preferred male politicians as sources of news in the front-page stories to women, and the elites to ordinary people, and this reflected on the social structures and cultural norms that are prevalent in this society. This study, further, established that the news values of this newspaper share commonly with the Western news media in terms of journalistic conventions and ways of interpreting the social reality in the news. Ideally, the newspaper embraces the principles of democracy in news reporting, but in practice it does not satisfactorily adhere to the full requirements of its democratic role in terms of source selection. The democratic principles in news reporting require, among other things, that the newspaper should allow a diversity of views in the news, representing various groups that are found in real society including the elites, non-elites, women, ordinary people and minorities. In the case of the Daily Nation, a tiny group of elite male professional politicians made up the largest majority of its front-page news sources.
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- Authors: Kisuke, Connie Syomiti
- Date: 2005
- Subjects: Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3446 , http://hdl.handle.net/10962/d1002900 , Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Description: News in our contemporary newspapers has come to be associated more and more with what the elites do and say. Both their deeds and misdeeds are treated as newsworthy events and in the process they become newsmakers, both actors and sources of news. Even when they are not directly involved in news events they are sought out by journalists to validate those events and to interpret the social reality to the readers as news sources. This study is about the selection of news sources in the Daily Nation, a contemporary, independent newspaper based in Nairobi, Kenya. In this study, I set out to unravel the complex processes that underlie newsmaking and source selection. This study is informed by the theory of news values and the paradigm of the role of media in democracy. Based on qualitative interviews, observations and content analysis of the front-page stories, it investigates the process of news and source selection in front-page stories. Through these approaches, I established that news values are significant criteria that inform journalists in both the selection of front-page news stories and the sources of these stories. I also established that social values of the society in which this newspaper operates are heavily embedded in the news. For example, the journalists preferred male politicians as sources of news in the front-page stories to women, and the elites to ordinary people, and this reflected on the social structures and cultural norms that are prevalent in this society. This study, further, established that the news values of this newspaper share commonly with the Western news media in terms of journalistic conventions and ways of interpreting the social reality in the news. Ideally, the newspaper embraces the principles of democracy in news reporting, but in practice it does not satisfactorily adhere to the full requirements of its democratic role in terms of source selection. The democratic principles in news reporting require, among other things, that the newspaper should allow a diversity of views in the news, representing various groups that are found in real society including the elites, non-elites, women, ordinary people and minorities. In the case of the Daily Nation, a tiny group of elite male professional politicians made up the largest majority of its front-page news sources.
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An organisation development intervention in a previously disadvantaged school in the Eastern Cape
- Authors: Mitchell, Pauline
- Date: 2005
- Subjects: Educational change -- South Africa -- Eastern Cape Education and state -- South Africa -- Eastern Cape Education -- Social aspects -- South Africa -- Eastern Cape Education -- South Africa -- Eastern Cape School improvement programs -- South Africa -- Eastern Cape -- Case studies Education -- Aims and objectives -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1682 , http://hdl.handle.net/10962/d1003565
- Description: “We often spend too much time coping with problems along our path that we forget why we are on that path” Peter Senge This study describes and analyses the implementation of Organisation Development (OD) to a previously disadvantaged school. OD is a relatively new method of planned change in South Africa. Unlike more traditional change initiatives, OD promotes collaboration; it tries to involve all members of an organisation in problem solving and decision-making. It is an applied behavioural science discipline dedicated to improving organisations and the people in them. Previously disadvantaged schools in South Africa continue to be disadvantaged. Ten years after the introduction of democracy there have been few changes in some of these schools and some seem to be getting worse. This study was an attempt to introduce a process of planned change to one such school. Since 1994 many changes have been imposed on our schools with new curricula, increased class sizes, changes in systems of assessment and teaching methods and the abolishment of past procedures such as corporal punishment. Teachers have had little say in any of these changes and this has resulted in resistance, resignation, frustration and in many cases a lack of ability to cope. OD was introduced to Acacia High School in the form of a Survey Data Feedback (SDF). An action research process followed and a diagnosis was made followed by action planning and then the execution of a plan. My study follows this process and the implementation of the plan describing its successes. Sadly change was not sustained and I highlight some of the challenges that face the school in order to bring about real long-term improvement in the culture of learning and teaching.
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- Authors: Mitchell, Pauline
- Date: 2005
- Subjects: Educational change -- South Africa -- Eastern Cape Education and state -- South Africa -- Eastern Cape Education -- Social aspects -- South Africa -- Eastern Cape Education -- South Africa -- Eastern Cape School improvement programs -- South Africa -- Eastern Cape -- Case studies Education -- Aims and objectives -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1682 , http://hdl.handle.net/10962/d1003565
- Description: “We often spend too much time coping with problems along our path that we forget why we are on that path” Peter Senge This study describes and analyses the implementation of Organisation Development (OD) to a previously disadvantaged school. OD is a relatively new method of planned change in South Africa. Unlike more traditional change initiatives, OD promotes collaboration; it tries to involve all members of an organisation in problem solving and decision-making. It is an applied behavioural science discipline dedicated to improving organisations and the people in them. Previously disadvantaged schools in South Africa continue to be disadvantaged. Ten years after the introduction of democracy there have been few changes in some of these schools and some seem to be getting worse. This study was an attempt to introduce a process of planned change to one such school. Since 1994 many changes have been imposed on our schools with new curricula, increased class sizes, changes in systems of assessment and teaching methods and the abolishment of past procedures such as corporal punishment. Teachers have had little say in any of these changes and this has resulted in resistance, resignation, frustration and in many cases a lack of ability to cope. OD was introduced to Acacia High School in the form of a Survey Data Feedback (SDF). An action research process followed and a diagnosis was made followed by action planning and then the execution of a plan. My study follows this process and the implementation of the plan describing its successes. Sadly change was not sustained and I highlight some of the challenges that face the school in order to bring about real long-term improvement in the culture of learning and teaching.
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Animal suffering in factory farming and the best way to prevent it
- Authors: Watkins, Gareth
- Date: 2005
- Subjects: Vegetarianism -- Moral and ethical aspects Food animals -- Moral and ethical aspects Animal rights Animal welfare Animal welfare -- Moral and ethical aspects Vegetarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2728 , http://hdl.handle.net/10962/d1003736
- Description: This thesis moves beyond the traditional approaches of how we ought to treat animals, and instead concentrates on the best strategy for preventing animal suffering in the farming industry. Chapter 1 considers the question of how we can know that animals feel pain, and concludes not only that it is rational to believe that they can, but also that this is a significant fact. Chapter 2 then analyses one possible strategy for helping to prevent animal suffering, namely demi-vegetarianism. For a number of reasons, however, this strategy is found to be flawed, therefore Chapter 3 analyses a second possible strategy, namely vegetarianism, and concludes that this is, in fact, the best strategy for helping to prevent animal suffering in the farming industry.
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- Authors: Watkins, Gareth
- Date: 2005
- Subjects: Vegetarianism -- Moral and ethical aspects Food animals -- Moral and ethical aspects Animal rights Animal welfare Animal welfare -- Moral and ethical aspects Vegetarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2728 , http://hdl.handle.net/10962/d1003736
- Description: This thesis moves beyond the traditional approaches of how we ought to treat animals, and instead concentrates on the best strategy for preventing animal suffering in the farming industry. Chapter 1 considers the question of how we can know that animals feel pain, and concludes not only that it is rational to believe that they can, but also that this is a significant fact. Chapter 2 then analyses one possible strategy for helping to prevent animal suffering, namely demi-vegetarianism. For a number of reasons, however, this strategy is found to be flawed, therefore Chapter 3 analyses a second possible strategy, namely vegetarianism, and concludes that this is, in fact, the best strategy for helping to prevent animal suffering in the farming industry.
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Aspects of the ecology and management of the Soupfin shark (Galeorhinus galeus) in South Africa
- Authors: McCord, Meaghen Erica
- Date: 2005
- Subjects: Soupfin shark -- South Africa , Soupfin shark -- Ecology -- South Africa , Fishery management -- South Africa , Shark fisheries -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5223 , http://hdl.handle.net/10962/d1005066 , Soupfin shark -- South Africa , Soupfin shark -- Ecology -- South Africa , Fishery management -- South Africa , Shark fisheries -- Management -- South Africa
- Description: Global trends in teleost fisheries indicate significant population declines. Thus, alternative fisheries are being developed to meet the growing economic and nutritional demands of the expanding human population. Recently, it has been established that elasmobranch fisheries may fulfill these demands. As many elasmobranchs possess life-history characteristics that make them particularly vulnerable to overfishing, it is imperative to develop management strategies prior to the inception of these fisheries to ensure sustainable resource utilisation. In South Africa, elasmobranchs have been commercially exploited since the 1930s. Although generally considered an under-exploited resource, the potential for growth within these fisheries has been recognized. In 2005, the commercial shark fishery will undergo a transition from medium to long-term rights allocations. This represents an ideal opportunity for scientists and managers to develop precautionary species-specific management plans for commercially exploitable elasmobranch species. The soupfin shark (Galeorhinus galeus) is one of the principal target species in South Africa’s shark fisheries. Given its inherent susceptibility to overexploitation, G. galeus was selected as a management priority by South Africa’s regional fisheries organisation. The purpose of this study was to examine and describe the stock status of G. galeus in South Africa, and to develop a precautionary fishery management plan to ensure the sustainability of this resource. Age, growth, and mortality calculations for G. galeus were made from research survey data collected between 1996 and 1999. A small sample size precluded independent analyses of females. The maximum recorded age for G. galeus was 33 years. Estimated von Bertalanffy growth parameters from observed length-at-age for males and combined sexes were: L∞ 1542.8 mm TL, K 0.21 year⁻¹ , t₀ -2.79 year⁻¹ and L∞ 1560.3 mm TL, K 0.19 year¹, t₀ -3.03 year⁻¹, respectively. The age-at-50% maturity was determined to be 6 years, corresponding to 1011 mm TL for males and 1100 mm TL for combined sexes. Natural mortality was calculated as 0.126 yr⁻¹. The rate of instantaneous total mortality was calculated as 0.27 yr⁻¹. Catch trend analysis showed that catches and CPUE of G. galeus are increasing in the demersal longline fishery, and decreasing in the handline fishery. Decreasing catches and CPUE were observed in fishery-independent research survey data. The status of the soupfin shark stock was modelled using per-recruit analysis. The SB/R model indicated the soupfin shark is being optimally exploited and spawner biomass is at 43% of preexploitation levels. Current fishing levels ( F = 0.14 yr⁻¹) approximate the Fsb₄₀ level (F = 0.17 yr¹); thus, an increase in fishing pressure may lead to stock collapse. It was determined that the current age-at-capture (7.9 years) should be increased to 10 years, or 1420 mm TL, to maximize yield and minimize the possibility of recruitment failure. The results of this study indicate a need for immediate scientific and management intervention in South Africa’s soupfin shark fishery. An assessment report and fishery management plan for G. galeus was compiled, and several management options were proposed. These include the implementation of licence and size restrictions, as well as seasonal/area closures. The potential for an experimental gillnet fishery should be investigated.
- Full Text:
- Authors: McCord, Meaghen Erica
- Date: 2005
- Subjects: Soupfin shark -- South Africa , Soupfin shark -- Ecology -- South Africa , Fishery management -- South Africa , Shark fisheries -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5223 , http://hdl.handle.net/10962/d1005066 , Soupfin shark -- South Africa , Soupfin shark -- Ecology -- South Africa , Fishery management -- South Africa , Shark fisheries -- Management -- South Africa
- Description: Global trends in teleost fisheries indicate significant population declines. Thus, alternative fisheries are being developed to meet the growing economic and nutritional demands of the expanding human population. Recently, it has been established that elasmobranch fisheries may fulfill these demands. As many elasmobranchs possess life-history characteristics that make them particularly vulnerable to overfishing, it is imperative to develop management strategies prior to the inception of these fisheries to ensure sustainable resource utilisation. In South Africa, elasmobranchs have been commercially exploited since the 1930s. Although generally considered an under-exploited resource, the potential for growth within these fisheries has been recognized. In 2005, the commercial shark fishery will undergo a transition from medium to long-term rights allocations. This represents an ideal opportunity for scientists and managers to develop precautionary species-specific management plans for commercially exploitable elasmobranch species. The soupfin shark (Galeorhinus galeus) is one of the principal target species in South Africa’s shark fisheries. Given its inherent susceptibility to overexploitation, G. galeus was selected as a management priority by South Africa’s regional fisheries organisation. The purpose of this study was to examine and describe the stock status of G. galeus in South Africa, and to develop a precautionary fishery management plan to ensure the sustainability of this resource. Age, growth, and mortality calculations for G. galeus were made from research survey data collected between 1996 and 1999. A small sample size precluded independent analyses of females. The maximum recorded age for G. galeus was 33 years. Estimated von Bertalanffy growth parameters from observed length-at-age for males and combined sexes were: L∞ 1542.8 mm TL, K 0.21 year⁻¹ , t₀ -2.79 year⁻¹ and L∞ 1560.3 mm TL, K 0.19 year¹, t₀ -3.03 year⁻¹, respectively. The age-at-50% maturity was determined to be 6 years, corresponding to 1011 mm TL for males and 1100 mm TL for combined sexes. Natural mortality was calculated as 0.126 yr⁻¹. The rate of instantaneous total mortality was calculated as 0.27 yr⁻¹. Catch trend analysis showed that catches and CPUE of G. galeus are increasing in the demersal longline fishery, and decreasing in the handline fishery. Decreasing catches and CPUE were observed in fishery-independent research survey data. The status of the soupfin shark stock was modelled using per-recruit analysis. The SB/R model indicated the soupfin shark is being optimally exploited and spawner biomass is at 43% of preexploitation levels. Current fishing levels ( F = 0.14 yr⁻¹) approximate the Fsb₄₀ level (F = 0.17 yr¹); thus, an increase in fishing pressure may lead to stock collapse. It was determined that the current age-at-capture (7.9 years) should be increased to 10 years, or 1420 mm TL, to maximize yield and minimize the possibility of recruitment failure. The results of this study indicate a need for immediate scientific and management intervention in South Africa’s soupfin shark fishery. An assessment report and fishery management plan for G. galeus was compiled, and several management options were proposed. These include the implementation of licence and size restrictions, as well as seasonal/area closures. The potential for an experimental gillnet fishery should be investigated.
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Asset prices and inflation-targeting : implications for South Africa
- Authors: Cosser, Leigh Emma
- Date: 2005
- Subjects: South African Reserve Bank , Monetary policy -- South Africa , Inflation (Finance) -- South Africa , South Africa -- Economic policy , Banks and banking, Central -- South Africa , Anti-inflationary policies , Monetary policy -- Japan , Monetary policy -- United States
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1127 , http://hdl.handle.net/10962/d1020849
- Description: An analysis of the current monetary policy framework in South Africa, which followed the exampie of a number of developed countries by implementing an inflation-targeting regime in 2000, is presented. The primary goal of the framework is to establish price stability, with financial stability a secondary objective. However, as has been evident in other countries, price stability does not guarantee financial stability. Movements in asset prices and the development of asset price bubbles have resulted in a number of episodes of financial instability, which negatively impacted on the growth and development of the countries involved. In addition, the majority of these episodes have occurred in periods of low and stable inflation. The dissertation analyses whether monetary policy would be more efficient if asset price movements were incorporated within the inflation-targeting regime. International experience indicates that early intervention of monetary policy can dampen the negative effects that result when an asset price bubble "bursts". However, if the monetary authorities act too early the effects on the economy can be just as disruptive. The literature is scrutinized to establish what the most effective form of monetary policy should be. The results are then transposed within the South African context to establish how the South African Reserve Bank can best ensure both price and financial stability.
- Full Text:
- Authors: Cosser, Leigh Emma
- Date: 2005
- Subjects: South African Reserve Bank , Monetary policy -- South Africa , Inflation (Finance) -- South Africa , South Africa -- Economic policy , Banks and banking, Central -- South Africa , Anti-inflationary policies , Monetary policy -- Japan , Monetary policy -- United States
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1127 , http://hdl.handle.net/10962/d1020849
- Description: An analysis of the current monetary policy framework in South Africa, which followed the exampie of a number of developed countries by implementing an inflation-targeting regime in 2000, is presented. The primary goal of the framework is to establish price stability, with financial stability a secondary objective. However, as has been evident in other countries, price stability does not guarantee financial stability. Movements in asset prices and the development of asset price bubbles have resulted in a number of episodes of financial instability, which negatively impacted on the growth and development of the countries involved. In addition, the majority of these episodes have occurred in periods of low and stable inflation. The dissertation analyses whether monetary policy would be more efficient if asset price movements were incorporated within the inflation-targeting regime. International experience indicates that early intervention of monetary policy can dampen the negative effects that result when an asset price bubble "bursts". However, if the monetary authorities act too early the effects on the economy can be just as disruptive. The literature is scrutinized to establish what the most effective form of monetary policy should be. The results are then transposed within the South African context to establish how the South African Reserve Bank can best ensure both price and financial stability.
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Betwixt and between: exploring the passage of liminal space
- Authors: Key, Michelle
- Date: 2005
- Subjects: Bourgeois, Louis, 1911- Spider , Art and anthropology , Art criticism , Liminality
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2406 , http://hdl.handle.net/10962/d1002202 , Bourgeois, Louis, 1911- Spider , Art and anthropology , Art criticism , Liminality
- Description: The focus of this thesis is on the liminal space, limen being Latin for threshold. The liminal space is used as a means of figuring and reading artworks that appear to be in a process of becoming and disappearing. A dialectical and reciprocal reading is made of Bourgeois’ “neo-Baroque” artwork Spider (1997) and Michelle Key’s Betwixt-in-Between (2004). Liminality here is discussed within the theoretical framework of several key conceptual concerns, including abjection (as examined principally by Julia Kristeva), Baroque thought (as discussed by Mieke Bal, Gilles Deleuze, Jacques Lacan and Slavoj Žižek) and allegory (as figured primarily by Walter Benjamin and commentators on Benjamin’s writings). What links these concerns are their focus on indeterminacy, instability, and process as opposed to certitude and finitude. The exploration of the inscription of time in space; that is the temporal process, which gives rise to, which produces, the spatial dimension, is attempted in order to make meaning, however provisionally, of what may be argued to destabilise meaning and to consider possibilities for both art-making and interpretation that would engage critically with this instability.
- Full Text:
- Authors: Key, Michelle
- Date: 2005
- Subjects: Bourgeois, Louis, 1911- Spider , Art and anthropology , Art criticism , Liminality
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2406 , http://hdl.handle.net/10962/d1002202 , Bourgeois, Louis, 1911- Spider , Art and anthropology , Art criticism , Liminality
- Description: The focus of this thesis is on the liminal space, limen being Latin for threshold. The liminal space is used as a means of figuring and reading artworks that appear to be in a process of becoming and disappearing. A dialectical and reciprocal reading is made of Bourgeois’ “neo-Baroque” artwork Spider (1997) and Michelle Key’s Betwixt-in-Between (2004). Liminality here is discussed within the theoretical framework of several key conceptual concerns, including abjection (as examined principally by Julia Kristeva), Baroque thought (as discussed by Mieke Bal, Gilles Deleuze, Jacques Lacan and Slavoj Žižek) and allegory (as figured primarily by Walter Benjamin and commentators on Benjamin’s writings). What links these concerns are their focus on indeterminacy, instability, and process as opposed to certitude and finitude. The exploration of the inscription of time in space; that is the temporal process, which gives rise to, which produces, the spatial dimension, is attempted in order to make meaning, however provisionally, of what may be argued to destabilise meaning and to consider possibilities for both art-making and interpretation that would engage critically with this instability.
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Bioactive 4-methoxypyrrolic natural products from two South African marine invertebrates
- Authors: Rapson, Trevor Douglas
- Date: 2005
- Subjects: Natural products -- South Africa , Marine invertebrates -- South Africa , Bryozoa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4412 , http://hdl.handle.net/10962/d1006766 , Natural products -- South Africa , Marine invertebrates -- South Africa , Bryozoa
- Description: This thesis presents an investigation of the 4-methoxypyrrolic constituents of two South African marine invertebrates, the nudibranch Tambja capensis and the bryozoan Bugula dentata. Three known compounds tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15) were isolated during this investigation. All three compounds were shown to be active against oesophageal cancer in accordance with the general anticancer and immunosuppressive properties observed for 4-methoxypyrrolic natural products. Tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15), together with tambjamine K (21) and L (22) (previously isolated in our laboratory) were used as standards to quantitatively assess the presence of these tambjamines in T. capensis and B. dentata collected from three different sites along the South African coast. This study confirmed that B. dentata is the source of the 4-methoxypyrrolic natural products sequestered by T. capensis and eliminated the closely related bryozoan B. neritina as a source of these metabolites. The paucity of tambjamine L (21) and K (22) obtained in previous investigations of the sequestered chemistry of T. capensis prompted an attempt at the development of synthetic methodology that could be used to synthesize tambjamines in sufficient yield for in depth bioactivity studies. In order to by pass the extensively reported problems associated with the synthesis of this group of compound 3-methoxy-2-formylpyrrole (47), readily accessible from 3-methoxypyridine N-oxide (48), was used as the starting material in a singlet oxygen induced 2,2’ bipyrrole coupling reaction. Although 47 proved unreactive in this coupling reaction, when the N-Boc protected analogue of 47 was used, and the reaction worked up in the dark, the novel methyl 4-aza-5-oxo-6,6-di-(2-pyrrolyl)-2(Z)-hexenoate (57) was obtained in low yield. The physical properties of tambjamine (E) (13) and the tetrapyrrole (15) were investigated to further the understanding of the proposed oxidative DNA cleavage mechanism and to determine the potential of the 4-methoxypyrrolic natural products as photodynamic therapy agents.
- Full Text:
- Authors: Rapson, Trevor Douglas
- Date: 2005
- Subjects: Natural products -- South Africa , Marine invertebrates -- South Africa , Bryozoa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4412 , http://hdl.handle.net/10962/d1006766 , Natural products -- South Africa , Marine invertebrates -- South Africa , Bryozoa
- Description: This thesis presents an investigation of the 4-methoxypyrrolic constituents of two South African marine invertebrates, the nudibranch Tambja capensis and the bryozoan Bugula dentata. Three known compounds tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15) were isolated during this investigation. All three compounds were shown to be active against oesophageal cancer in accordance with the general anticancer and immunosuppressive properties observed for 4-methoxypyrrolic natural products. Tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15), together with tambjamine K (21) and L (22) (previously isolated in our laboratory) were used as standards to quantitatively assess the presence of these tambjamines in T. capensis and B. dentata collected from three different sites along the South African coast. This study confirmed that B. dentata is the source of the 4-methoxypyrrolic natural products sequestered by T. capensis and eliminated the closely related bryozoan B. neritina as a source of these metabolites. The paucity of tambjamine L (21) and K (22) obtained in previous investigations of the sequestered chemistry of T. capensis prompted an attempt at the development of synthetic methodology that could be used to synthesize tambjamines in sufficient yield for in depth bioactivity studies. In order to by pass the extensively reported problems associated with the synthesis of this group of compound 3-methoxy-2-formylpyrrole (47), readily accessible from 3-methoxypyridine N-oxide (48), was used as the starting material in a singlet oxygen induced 2,2’ bipyrrole coupling reaction. Although 47 proved unreactive in this coupling reaction, when the N-Boc protected analogue of 47 was used, and the reaction worked up in the dark, the novel methyl 4-aza-5-oxo-6,6-di-(2-pyrrolyl)-2(Z)-hexenoate (57) was obtained in low yield. The physical properties of tambjamine (E) (13) and the tetrapyrrole (15) were investigated to further the understanding of the proposed oxidative DNA cleavage mechanism and to determine the potential of the 4-methoxypyrrolic natural products as photodynamic therapy agents.
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Biology, population dynamics and management of carpenter (Argyrozona argyrozona) an endemic South African reef fish
- Authors: Brouwer, Stephen Leonard
- Date: 2005
- Subjects: Reef fishes -- South Africa Sparidae -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5241 , http://hdl.handle.net/10962/d1005084
- Description: Carpenter, Argyrozona argyrozona (Valenciennes, 1830), is an endemic South African sparid fish. They form an important component of the commercial linefishery on the South African east coast, where they are the third most important species landed. Recent investigations revealed that the catch per unit effort (cpue) of this species has declined markedly since the early 1900’s. Despite these declines and the importance of this resource, remarkably little biological information on this species exists for providing management advice. This thesis investigates the life history of carpenter, particularly those aspects that are used for management. This includes an investigation into the stock distribution and identification of nursery areas, and an assessment of age, growth, reproduction and movement patterns. Age and growth was assessed using methods based on both otoliths and mark-recapture. Transverse sagittal sections from the Tsitsikamma National Park showed clear opaque and translucent growth increments. Marginal growth zone analysis and mark-recapture of chemically tagged fish (Oxytetracycline) revealed that these were deposited on an annual basis: opaque in summer and translucent in winter. A. argyrozona were found to be long lived (up to 27 years) and slow growing. Within reader (between counts) and between readers average percent error (APE) was 5.3 and 1.8, respectively, showing that readability of carpenter otoliths is high. Comparison between whole and sectioned otoliths showed that the former significantly under-estimated the age of fish older than 10 years (p<0.01). A large proportion (68%) of the individual growth rates derived from mark-recapture data were below those predicted by the otolith based von Bertalanffy growth model (p<0.01). This was attributed to the negative influence of external tags, as hydroids, frequently occurring on the tags of recaptured fish, were observed to cause severe lesions and in some cases, extensive fin damage. This brings into question the use of mark-recapture studies to calculate growth of some species. The effects of sampling design and sample size on age and growth estimation were assessed. The minimum sample size required to accurately estimate growth and mortality, and the effects of using either random or stratified sampling procedures were tested. Decimal and integer ageing both produced similar estimates of von Bertalanffy growth parameters, growth curves, spawner biomass-per-recruit (SB/R) and fishing mortality (F) estimates. Sampling monthly throughout the year and collecting data in a single large sample provided similar growth curves, von Bertalanffy, F and SB/R estimates. The data showed that estimates based on less than 300 random samples were unreliable. However, accurate growth parameter estimates were achievable with less than 200 samples if the sample was stratified with 10 or more samples per 2 cm size class. An investigation into the reproductive biology of A. argyrozona within the Tsitsikamma National Park revealed that they were serial spawning late gonochorists. The size at 50% maturity (L₅₀) was estimated at 292 and 297 mm FL for females and males, respectively. Both monthly gonadosomatic indices and macroscopically determined ovarian stages strongly suggest that A. argyrozona within the Tsitsikamma National Park spawn in the austral summer between November and April. The presence of post-ovulatory follicles (POF's) confirmed the six month spawning season, while monthly proportions of early (0-6 hour old) POF's showed that spawning frequency was highest (once every 1-2 days) from December to March. Although spawning season was more highly correlated to photoperiod (r = 0.859) than temperature (r = -0.161), the daily proportion of spawning fish was strongly correlated (r = 0.93) to ambient temperature over the range 9-22⁰C. Both spawning frequency and season increased with fish length. As a result of the allometric relationship between annual fecundity and fish mass a 3 kg fish was calculated to produce 5 fold more eggs per kilogram of body weight than a fish of 1 kg. In addition to producing more eggs per unit weight each year, larger fish also produce significantly larger eggs. Adult emigration and larval dispersal of A. argyrozona from the Tsitsikamma National Park (TNP), South Africa, were investigated using mark-recapture data and Acoustic Doppler Current Profiler measurements of currents. Tagging data showed that adult carpenter were mainly resident, with a small proportion (7%) leaving the TNP in both easterly and westerly directions. No relationship was found between fish movement patterns and fish size or time-at-liberty. Current patterns suggest that eggs and larvae spawned within the TNP are mainly transported eastwards towards established nursery grounds; the median estimated distance moved was 299 km (range 42-561 km) in 30 days (time to flexion). Given this pattern of ichthyoplankton dispersal together with the fact that adult carpenter within the TNP display a high degree of residency and that they are much more abundant than in adjacent fishing grounds (cpue = 23 times greater), it appears that the TNP protects a viable carpenter spawner population capable of seeding adjacent fishing grounds. Fishery independent biomass surveys and commercial linefish catch returns were used to elucidate the spatial patterns of A. argyrozona distributed along the South African continental shelf. Two distinct areas of abundance were determined, one on the central and the other on the eastern Agulhas Bank. Tagging studies revealed little exchange between them. Two distinct nursery areas were identified. These data suggest that in each area juvenile A. argyrozona settle and move inshore, and then move offshore as they grow. Otolith readability and growth rates varied between regions, with fish from the Eastern Cape having the lowest average percentage error and the slowest growth rates, readability decreased westward. L₅₀ varied between the central and eastern Agulhas Bank as did mass at length. Based on the distribution of carpenter, variability in otolith readability, mass at length, variation in growth and size at maturity, it is concluded that carpenter exist as two separate stocks, one on the central Agulhas Bank and the other on the eastern Agulhas Bank. SB/R, fecundity-per-recruit (Egg/R) and yield-per-recruit (Y/R) models were used to model both South African carpenter stocks. Owing to the allometric relationship between annual fecundity and individual size, Egg/R ratios were between 40 and 74% of SB/R at equivalent F. Egg/R ratios account for allometric increases in fecundity with size/age, and are therefore regarded as more accurate estimates of reproductive potential, and biological reference points for per-recruit analysis should wherever possible be based on this quantum. It is shown that the current length at first capture (lc) (250 mm TL) and F (at M = 0.1) will reduce Egg/R to 6.41% of the pristine value in the Eastern Cape and between 6.06 and 14.15% on the central Agulhas Bank, indicating that both stocks are heavily over exploited. An increase in lc from 250 to 350 mm TL and a 70% reduction in commercial fishing effort is recommended to attain a target reference point of 40% Egg/RF=0. Bag frequency analysis indicates that a reduction in daily bag limit from 10 to 4 fish.person¹.day⁻¹ would effect an equivalent reduction in recreational F. The trawl bycatch of carpenter is only 3% of the reported line catch, consequently restrictions to this fishery are not recommended.
- Full Text:
- Authors: Brouwer, Stephen Leonard
- Date: 2005
- Subjects: Reef fishes -- South Africa Sparidae -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5241 , http://hdl.handle.net/10962/d1005084
- Description: Carpenter, Argyrozona argyrozona (Valenciennes, 1830), is an endemic South African sparid fish. They form an important component of the commercial linefishery on the South African east coast, where they are the third most important species landed. Recent investigations revealed that the catch per unit effort (cpue) of this species has declined markedly since the early 1900’s. Despite these declines and the importance of this resource, remarkably little biological information on this species exists for providing management advice. This thesis investigates the life history of carpenter, particularly those aspects that are used for management. This includes an investigation into the stock distribution and identification of nursery areas, and an assessment of age, growth, reproduction and movement patterns. Age and growth was assessed using methods based on both otoliths and mark-recapture. Transverse sagittal sections from the Tsitsikamma National Park showed clear opaque and translucent growth increments. Marginal growth zone analysis and mark-recapture of chemically tagged fish (Oxytetracycline) revealed that these were deposited on an annual basis: opaque in summer and translucent in winter. A. argyrozona were found to be long lived (up to 27 years) and slow growing. Within reader (between counts) and between readers average percent error (APE) was 5.3 and 1.8, respectively, showing that readability of carpenter otoliths is high. Comparison between whole and sectioned otoliths showed that the former significantly under-estimated the age of fish older than 10 years (p<0.01). A large proportion (68%) of the individual growth rates derived from mark-recapture data were below those predicted by the otolith based von Bertalanffy growth model (p<0.01). This was attributed to the negative influence of external tags, as hydroids, frequently occurring on the tags of recaptured fish, were observed to cause severe lesions and in some cases, extensive fin damage. This brings into question the use of mark-recapture studies to calculate growth of some species. The effects of sampling design and sample size on age and growth estimation were assessed. The minimum sample size required to accurately estimate growth and mortality, and the effects of using either random or stratified sampling procedures were tested. Decimal and integer ageing both produced similar estimates of von Bertalanffy growth parameters, growth curves, spawner biomass-per-recruit (SB/R) and fishing mortality (F) estimates. Sampling monthly throughout the year and collecting data in a single large sample provided similar growth curves, von Bertalanffy, F and SB/R estimates. The data showed that estimates based on less than 300 random samples were unreliable. However, accurate growth parameter estimates were achievable with less than 200 samples if the sample was stratified with 10 or more samples per 2 cm size class. An investigation into the reproductive biology of A. argyrozona within the Tsitsikamma National Park revealed that they were serial spawning late gonochorists. The size at 50% maturity (L₅₀) was estimated at 292 and 297 mm FL for females and males, respectively. Both monthly gonadosomatic indices and macroscopically determined ovarian stages strongly suggest that A. argyrozona within the Tsitsikamma National Park spawn in the austral summer between November and April. The presence of post-ovulatory follicles (POF's) confirmed the six month spawning season, while monthly proportions of early (0-6 hour old) POF's showed that spawning frequency was highest (once every 1-2 days) from December to March. Although spawning season was more highly correlated to photoperiod (r = 0.859) than temperature (r = -0.161), the daily proportion of spawning fish was strongly correlated (r = 0.93) to ambient temperature over the range 9-22⁰C. Both spawning frequency and season increased with fish length. As a result of the allometric relationship between annual fecundity and fish mass a 3 kg fish was calculated to produce 5 fold more eggs per kilogram of body weight than a fish of 1 kg. In addition to producing more eggs per unit weight each year, larger fish also produce significantly larger eggs. Adult emigration and larval dispersal of A. argyrozona from the Tsitsikamma National Park (TNP), South Africa, were investigated using mark-recapture data and Acoustic Doppler Current Profiler measurements of currents. Tagging data showed that adult carpenter were mainly resident, with a small proportion (7%) leaving the TNP in both easterly and westerly directions. No relationship was found between fish movement patterns and fish size or time-at-liberty. Current patterns suggest that eggs and larvae spawned within the TNP are mainly transported eastwards towards established nursery grounds; the median estimated distance moved was 299 km (range 42-561 km) in 30 days (time to flexion). Given this pattern of ichthyoplankton dispersal together with the fact that adult carpenter within the TNP display a high degree of residency and that they are much more abundant than in adjacent fishing grounds (cpue = 23 times greater), it appears that the TNP protects a viable carpenter spawner population capable of seeding adjacent fishing grounds. Fishery independent biomass surveys and commercial linefish catch returns were used to elucidate the spatial patterns of A. argyrozona distributed along the South African continental shelf. Two distinct areas of abundance were determined, one on the central and the other on the eastern Agulhas Bank. Tagging studies revealed little exchange between them. Two distinct nursery areas were identified. These data suggest that in each area juvenile A. argyrozona settle and move inshore, and then move offshore as they grow. Otolith readability and growth rates varied between regions, with fish from the Eastern Cape having the lowest average percentage error and the slowest growth rates, readability decreased westward. L₅₀ varied between the central and eastern Agulhas Bank as did mass at length. Based on the distribution of carpenter, variability in otolith readability, mass at length, variation in growth and size at maturity, it is concluded that carpenter exist as two separate stocks, one on the central Agulhas Bank and the other on the eastern Agulhas Bank. SB/R, fecundity-per-recruit (Egg/R) and yield-per-recruit (Y/R) models were used to model both South African carpenter stocks. Owing to the allometric relationship between annual fecundity and individual size, Egg/R ratios were between 40 and 74% of SB/R at equivalent F. Egg/R ratios account for allometric increases in fecundity with size/age, and are therefore regarded as more accurate estimates of reproductive potential, and biological reference points for per-recruit analysis should wherever possible be based on this quantum. It is shown that the current length at first capture (lc) (250 mm TL) and F (at M = 0.1) will reduce Egg/R to 6.41% of the pristine value in the Eastern Cape and between 6.06 and 14.15% on the central Agulhas Bank, indicating that both stocks are heavily over exploited. An increase in lc from 250 to 350 mm TL and a 70% reduction in commercial fishing effort is recommended to attain a target reference point of 40% Egg/RF=0. Bag frequency analysis indicates that a reduction in daily bag limit from 10 to 4 fish.person¹.day⁻¹ would effect an equivalent reduction in recreational F. The trawl bycatch of carpenter is only 3% of the reported line catch, consequently restrictions to this fishery are not recommended.
- Full Text:
Brain drain, exodus and chicken run : media discourses on emigration
- Authors: Bright, Sue-Ann
- Date: 2005
- Subjects: Mass media and language -- South Africa , Mass media criticism -- South Africa , Discourse analysis -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3163 , http://hdl.handle.net/10962/d1007672 , Mass media and language -- South Africa , Mass media criticism -- South Africa , Discourse analysis -- Social aspects
- Description: This paper explores the discourses of emigration in a South African daily newspaper from 1988 to 2001, and discusses the implications of these discourses on the way in which emigration is constructed within South African society In this paper, Potter and Wetherell 's (1987) approach to discourse analysis is utilized. It makes use of interpretative repertoires, to explore the functions and consequences of the discourses. The discursive framework thereby reveals the different subject positions related to nationalism, race and class. It is argued that economics and notions of culture and social class, do more than provide a useful medium through which the phenomenon of emigration can be understood. They also support the affirmations of certain groups of people above others, by claiming that emigration is unpatriotic and disloyal. This paper concludes by identifying the negative connotations of media discourses in the construction of emigration and acknowledges that many alternate constructions are silenced in this matter.
- Full Text:
- Authors: Bright, Sue-Ann
- Date: 2005
- Subjects: Mass media and language -- South Africa , Mass media criticism -- South Africa , Discourse analysis -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3163 , http://hdl.handle.net/10962/d1007672 , Mass media and language -- South Africa , Mass media criticism -- South Africa , Discourse analysis -- Social aspects
- Description: This paper explores the discourses of emigration in a South African daily newspaper from 1988 to 2001, and discusses the implications of these discourses on the way in which emigration is constructed within South African society In this paper, Potter and Wetherell 's (1987) approach to discourse analysis is utilized. It makes use of interpretative repertoires, to explore the functions and consequences of the discourses. The discursive framework thereby reveals the different subject positions related to nationalism, race and class. It is argued that economics and notions of culture and social class, do more than provide a useful medium through which the phenomenon of emigration can be understood. They also support the affirmations of certain groups of people above others, by claiming that emigration is unpatriotic and disloyal. This paper concludes by identifying the negative connotations of media discourses in the construction of emigration and acknowledges that many alternate constructions are silenced in this matter.
- Full Text:
Characterization of the hydantoin-hydrolysing system of Pseudomonas putida RU-KM3s
- Authors: Matcher, Gwynneth Felicity
- Date: 2005
- Subjects: Hydantoin Hydrolysis Pseudomonas Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3939 , http://hdl.handle.net/10962/d1003998
- Description: The biocatalytic conversion of 5-monosubstituted hydantoin derivatives to optically pure amino acids involves two reaction steps: the hydrolysis of hydantoin to N-carbamylamino acid by an hydantoinase or dihydropyrimidinase enzyme, followed by conversion of the Ncarbamylamino acid to the corresponding amino acid by an N-carbamoylase enzyme. This biocatalytic process has been successfully applied in several industrial processes for the production of enantiomerically pure amino acids used in the synthesis of pharmaceuticals, insecticides, hormones, and food additives. P. putida RU-KM3S was selected for study based on inherent high levels of hydantoinase and N-carbamoylase activity. Subsequent biocatalytic analysis of the enzyme activity within this strain revealed unique properties thus prompting further characterization. The main focus of this research was the isolation of the genes encoding the hydantoin-hydrolysing pathway in RU-KM3S. A genomic library was constructed and screened for heterologous expression of the hydantoin-hydrolysing enzymes. However, this approach was unsuccessful prompting the use of transposon mutagenesis in order to circumvent the drawbacks associated with complementation studies. The enzymes responsible for hydantoin-hydrolysis were identified by insertional inactivation as a dihydropyrimidinase and b-ureidopropionase encoded by dhp and bup respectively. A third open reading frame, encoding a putative transport protein, was identified between the dhp and bup genes and appeared to share a promoter with bup. Analysis of the amino acid sequence deduced from bup and dhp substantiated the distinctive properties and potential industrial application of the L-enantioselective b-ureidopropionase and provided targets for potential optimisation of the substrate-selectivity and activity of the dihydropyrimidinase by site directed mutagenesis. Several transposon-generated mutants with an altered phenotype for growth on minimal medium with hydantoin as the sole source of nitrogen were also isolated. Analysis of the insertion events in these mutants revealed disruptions of genes encoding key elements of the Ntr global regulatory pathway. However, inactivation of these genes had no effect on the dihydropyrimidinase and b-ureidopropionase activity levels. An additional mutant in which the gene coding for the dihydrolipoamide succinyltransferase, which is involved in the TCA cycle, was isolated with reduced levels of both dihydropyrimidinase and b-ureidopropionase activities. These results indicated that the hydantoin-hydrolysis pathway in RU-KM3S is regulated by carbon rather than nitrogen catabolite repression. This was confirmed by the reduction of hydantoin-hydrolysis in cells grown in excess carbon as opposed to nitrogen. Identification of a putative CRP-binding site within the promoter region of these enzymes further supported the regulatory role of carbon catabolite repression (CCR). As CCR in Pseudomonads is poorly understood, elucidation of the mechanism by which the hydantoinhydrolysing pathway in RU-KM3S is regulated would provide valuable insight into this complex process.
- Full Text:
- Authors: Matcher, Gwynneth Felicity
- Date: 2005
- Subjects: Hydantoin Hydrolysis Pseudomonas Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3939 , http://hdl.handle.net/10962/d1003998
- Description: The biocatalytic conversion of 5-monosubstituted hydantoin derivatives to optically pure amino acids involves two reaction steps: the hydrolysis of hydantoin to N-carbamylamino acid by an hydantoinase or dihydropyrimidinase enzyme, followed by conversion of the Ncarbamylamino acid to the corresponding amino acid by an N-carbamoylase enzyme. This biocatalytic process has been successfully applied in several industrial processes for the production of enantiomerically pure amino acids used in the synthesis of pharmaceuticals, insecticides, hormones, and food additives. P. putida RU-KM3S was selected for study based on inherent high levels of hydantoinase and N-carbamoylase activity. Subsequent biocatalytic analysis of the enzyme activity within this strain revealed unique properties thus prompting further characterization. The main focus of this research was the isolation of the genes encoding the hydantoin-hydrolysing pathway in RU-KM3S. A genomic library was constructed and screened for heterologous expression of the hydantoin-hydrolysing enzymes. However, this approach was unsuccessful prompting the use of transposon mutagenesis in order to circumvent the drawbacks associated with complementation studies. The enzymes responsible for hydantoin-hydrolysis were identified by insertional inactivation as a dihydropyrimidinase and b-ureidopropionase encoded by dhp and bup respectively. A third open reading frame, encoding a putative transport protein, was identified between the dhp and bup genes and appeared to share a promoter with bup. Analysis of the amino acid sequence deduced from bup and dhp substantiated the distinctive properties and potential industrial application of the L-enantioselective b-ureidopropionase and provided targets for potential optimisation of the substrate-selectivity and activity of the dihydropyrimidinase by site directed mutagenesis. Several transposon-generated mutants with an altered phenotype for growth on minimal medium with hydantoin as the sole source of nitrogen were also isolated. Analysis of the insertion events in these mutants revealed disruptions of genes encoding key elements of the Ntr global regulatory pathway. However, inactivation of these genes had no effect on the dihydropyrimidinase and b-ureidopropionase activity levels. An additional mutant in which the gene coding for the dihydrolipoamide succinyltransferase, which is involved in the TCA cycle, was isolated with reduced levels of both dihydropyrimidinase and b-ureidopropionase activities. These results indicated that the hydantoin-hydrolysis pathway in RU-KM3S is regulated by carbon rather than nitrogen catabolite repression. This was confirmed by the reduction of hydantoin-hydrolysis in cells grown in excess carbon as opposed to nitrogen. Identification of a putative CRP-binding site within the promoter region of these enzymes further supported the regulatory role of carbon catabolite repression (CCR). As CCR in Pseudomonads is poorly understood, elucidation of the mechanism by which the hydantoinhydrolysing pathway in RU-KM3S is regulated would provide valuable insight into this complex process.
- Full Text: