Sperm morphology in four species of African platypleurine cicadas (Hemiptera: Cicadomorpha: Cicadidae)
- Chawanji, A S, Hodgson, Alan N, Villet, Martin H
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6917 , http://hdl.handle.net/10962/d1011880
- Description: Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.
- Full Text:
- Date Issued: 2005
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6917 , http://hdl.handle.net/10962/d1011880
- Description: Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.
- Full Text:
- Date Issued: 2005
Strategic leadership within the Duke of Edinburgh's International Award Association between 1988 and 2004
- Authors: Andrew, Craig Bruce
- Date: 2005
- Subjects: Duke of Edinburgh's Award (Organization) Duke of Edinburgh's Award -- History Nonprofit organizations -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:764 , http://hdl.handle.net/10962/d1003885
- Description: Providing strategic leadership for global Not-for-Profit organisations poses great challenges to the leadership structures of these voluntary organisations. This study looks at the phenomenon of strategic leadership in the Duke of Edinburgh’s (DOE) International Award Association (IAA) as a global Not-for-Profit Organisation (NPO). The main aim of the research was an in-depth examination of the processes involved in leadership at the top level in a global NPO. Eight strategic leaders from the top management team were interviewed. Further information was generated from a study of the Annual Reports spanning the 15 year period (1988/9 – 2003/4), and key strategic documents were used as supporting material. The research was conducted in a phenomenological paradigm, using the case study research method. Care was taken to minimize possible researcher bias and interpretations, as the researcher has been associated with this organisation for the past 18 years. It was found that the Royal Family play extremely valuable and multifaceted roles in the organisation. The triumvirate of The Royals; The Secretary General’s; and The Trustees; works well as individual ‘great groups’ yet when necessary, they form a collective collaborative grouping to effect strategic leadership for the IAA. The two main themes to emerge from the findings were the nature of the DOE as a global NPO and the role of strategic leadership in the DOE Award. The DOE Award has demonstrated that it has many unique strategic leadership features and is using these features to become more business-like in the application of its new strategic vision. The individual ‘great groups’ offer sound leadership throughout the process of overseeing and running the business of the DOE Award yet, when necessary and appropriate, these great groups appear to work collectively, perhaps in an unstructured manner, as the triumvirate of power. Their collective collaborative leadership is a unique feature of the DOE Award. The highly interactive role of the Royal Family is unique and sets the DOE Award apart from other similar youth organisations globally. The nature of the loose association of National Award Authorities all subscribing to the rules and conditions of association is also a very unique feature of this NPO. The DOE Award is not a movement organisation but is guided by its service ethic. The DOE Award is a service organisation in which the strategic leadership plays a crucial role yet the constitutional power resides with the International Award Association membership. This IAA membership meets every three years at the World Forum Triennium to approve all new policy and procedures.
- Full Text:
- Date Issued: 2005
- Authors: Andrew, Craig Bruce
- Date: 2005
- Subjects: Duke of Edinburgh's Award (Organization) Duke of Edinburgh's Award -- History Nonprofit organizations -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:764 , http://hdl.handle.net/10962/d1003885
- Description: Providing strategic leadership for global Not-for-Profit organisations poses great challenges to the leadership structures of these voluntary organisations. This study looks at the phenomenon of strategic leadership in the Duke of Edinburgh’s (DOE) International Award Association (IAA) as a global Not-for-Profit Organisation (NPO). The main aim of the research was an in-depth examination of the processes involved in leadership at the top level in a global NPO. Eight strategic leaders from the top management team were interviewed. Further information was generated from a study of the Annual Reports spanning the 15 year period (1988/9 – 2003/4), and key strategic documents were used as supporting material. The research was conducted in a phenomenological paradigm, using the case study research method. Care was taken to minimize possible researcher bias and interpretations, as the researcher has been associated with this organisation for the past 18 years. It was found that the Royal Family play extremely valuable and multifaceted roles in the organisation. The triumvirate of The Royals; The Secretary General’s; and The Trustees; works well as individual ‘great groups’ yet when necessary, they form a collective collaborative grouping to effect strategic leadership for the IAA. The two main themes to emerge from the findings were the nature of the DOE as a global NPO and the role of strategic leadership in the DOE Award. The DOE Award has demonstrated that it has many unique strategic leadership features and is using these features to become more business-like in the application of its new strategic vision. The individual ‘great groups’ offer sound leadership throughout the process of overseeing and running the business of the DOE Award yet, when necessary and appropriate, these great groups appear to work collectively, perhaps in an unstructured manner, as the triumvirate of power. Their collective collaborative leadership is a unique feature of the DOE Award. The highly interactive role of the Royal Family is unique and sets the DOE Award apart from other similar youth organisations globally. The nature of the loose association of National Award Authorities all subscribing to the rules and conditions of association is also a very unique feature of this NPO. The DOE Award is not a movement organisation but is guided by its service ethic. The DOE Award is a service organisation in which the strategic leadership plays a crucial role yet the constitutional power resides with the International Award Association membership. This IAA membership meets every three years at the World Forum Triennium to approve all new policy and procedures.
- Full Text:
- Date Issued: 2005
Strategies engaged by a South African beverage organisation entering African markets
- Authors: Brink, Andries Petrus
- Date: 2005
- Subjects: International business enterprises , Coca-cola Sabco (Firm) , Soft drink industry -- South Africa , International trade
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8544 , http://hdl.handle.net/10948/410 , International business enterprises , Coca-cola Sabco (Firm) , Soft drink industry -- South Africa , International trade
- Description: Africa is acknowledged as a vast, untapped market for consumer goods as trade barriers are coming down and economies are starting to develop. The need for consumer goods arises with economic activity. This poses the following question, which will be addressed by this research: How can potential African consumer markets be successfully unlocked by a South African beverage organisation, thereby reducing risk of failure and eliminating the cost of a hit-and-miss approach? The secondary study focused on evaluating the aspects involved with risks and the modes of entry into foreign markets. The macro-environmental factors affecting the expansion into foreign markets were investigated to determine what influence they had on the entry mode chosen for a specific country targeted for expansion. Finally the marketing factors influencing the entry mode were analysed. The significance of trade blocs together with the advantages thereof was included in the study. The primary study was based on the theory and principles of existing literature. The Coca-Cola Sabco organisation was taken as a case study. Four countries, namely Kenya, Uganda, Mozambique and Namibia, were investigated. Questionnaires containing a set of questions to satisfy the sub-problems were sent to the various country managers and their first layers of management. Likewise, interviews were conducted with Coca-Cola Sabco head office strategic management. The empirical results obtained, indicated a strong concurrence, with the theory of entry modes and the influences of macro-environmental factors. In certain aspects, however, some contradictions with the theory pertaining to the Coca-Cola Sabco organisation, were observed. The findings concurred with the theory in that risk were minimised by the acquisition of a going concern that already possessed the infrastructure and logistics such as raw material procurement, manufacturing staff skills, distribution networks and political contacts. The empirical results contradict theory with respect to location economies and scale economies, as the Coca-Cola Company’s franchise agreement excludes the exporting of beverage products. Furthermore, Coca-Cola Sabco becomes involved in expansion initiatives only in reaction to an invitation from the Coca-Cola Company and not of its own desire. Therefore, market surveys are conducted subsequent to an invitation from the Coca-Cola Company. South African organisations planning expansion initiatives into emerging African markets need to take the specific macro- environmental factors of the country in question into consideration in order to minimise risk. A franchise agreement restricting exporting as in the case of Coco-Cola Company or any other restrictive agreement, might cause a deviation from contemporary theory, for example, where markets will be assessed for purposes of location and scale economies. Deviations from contemporary theory could also occur where a franchise opportunity is offered in a specific country that may not be the preferred market choice, due to its lack of growth potential.
- Full Text:
- Date Issued: 2005
- Authors: Brink, Andries Petrus
- Date: 2005
- Subjects: International business enterprises , Coca-cola Sabco (Firm) , Soft drink industry -- South Africa , International trade
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8544 , http://hdl.handle.net/10948/410 , International business enterprises , Coca-cola Sabco (Firm) , Soft drink industry -- South Africa , International trade
- Description: Africa is acknowledged as a vast, untapped market for consumer goods as trade barriers are coming down and economies are starting to develop. The need for consumer goods arises with economic activity. This poses the following question, which will be addressed by this research: How can potential African consumer markets be successfully unlocked by a South African beverage organisation, thereby reducing risk of failure and eliminating the cost of a hit-and-miss approach? The secondary study focused on evaluating the aspects involved with risks and the modes of entry into foreign markets. The macro-environmental factors affecting the expansion into foreign markets were investigated to determine what influence they had on the entry mode chosen for a specific country targeted for expansion. Finally the marketing factors influencing the entry mode were analysed. The significance of trade blocs together with the advantages thereof was included in the study. The primary study was based on the theory and principles of existing literature. The Coca-Cola Sabco organisation was taken as a case study. Four countries, namely Kenya, Uganda, Mozambique and Namibia, were investigated. Questionnaires containing a set of questions to satisfy the sub-problems were sent to the various country managers and their first layers of management. Likewise, interviews were conducted with Coca-Cola Sabco head office strategic management. The empirical results obtained, indicated a strong concurrence, with the theory of entry modes and the influences of macro-environmental factors. In certain aspects, however, some contradictions with the theory pertaining to the Coca-Cola Sabco organisation, were observed. The findings concurred with the theory in that risk were minimised by the acquisition of a going concern that already possessed the infrastructure and logistics such as raw material procurement, manufacturing staff skills, distribution networks and political contacts. The empirical results contradict theory with respect to location economies and scale economies, as the Coca-Cola Company’s franchise agreement excludes the exporting of beverage products. Furthermore, Coca-Cola Sabco becomes involved in expansion initiatives only in reaction to an invitation from the Coca-Cola Company and not of its own desire. Therefore, market surveys are conducted subsequent to an invitation from the Coca-Cola Company. South African organisations planning expansion initiatives into emerging African markets need to take the specific macro- environmental factors of the country in question into consideration in order to minimise risk. A franchise agreement restricting exporting as in the case of Coco-Cola Company or any other restrictive agreement, might cause a deviation from contemporary theory, for example, where markets will be assessed for purposes of location and scale economies. Deviations from contemporary theory could also occur where a franchise opportunity is offered in a specific country that may not be the preferred market choice, due to its lack of growth potential.
- Full Text:
- Date Issued: 2005
Strategies for sustaining family business through succession planning and family creed
- Authors: Gwiliza, Nwabisa
- Date: 2005
- Subjects: Family-owned business enterprises -- South Africa -- Succession , Family corporations -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8537 , http://hdl.handle.net/10948/193 , Family-owned business enterprises -- South Africa -- Succession , Family corporations -- South Africa -- Management
- Description: Family business literature reveals that the majority of family businesses do not make it to the second generation, and quite a few are fortunate to be passed onto the third generation. Succession planning is the critical issue that enhances continuity of the family business. Relational influences indicate that the balancing of family systems and business systems is more likely to encourage high quality succession. The development of effective practical governance systems can help the family business achieve its strategy. External influences indicate that owner role adjustment, defined as the predecessor’s “letting go” in the firm, as well as the development and mentoring of the successor, shape the effectiveness of succession in the family business.
- Full Text:
- Date Issued: 2005
- Authors: Gwiliza, Nwabisa
- Date: 2005
- Subjects: Family-owned business enterprises -- South Africa -- Succession , Family corporations -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8537 , http://hdl.handle.net/10948/193 , Family-owned business enterprises -- South Africa -- Succession , Family corporations -- South Africa -- Management
- Description: Family business literature reveals that the majority of family businesses do not make it to the second generation, and quite a few are fortunate to be passed onto the third generation. Succession planning is the critical issue that enhances continuity of the family business. Relational influences indicate that the balancing of family systems and business systems is more likely to encourage high quality succession. The development of effective practical governance systems can help the family business achieve its strategy. External influences indicate that owner role adjustment, defined as the predecessor’s “letting go” in the firm, as well as the development and mentoring of the successor, shape the effectiveness of succession in the family business.
- Full Text:
- Date Issued: 2005
Strategies used by subject advisors and facilitators to support lesson planning with an environmental learning focus : a case study of the Eastern Cape Neep-Get cluster
- Authors: Mbambisa, Nomaledi Peggy
- Date: 2005
- Subjects: Educational change -- South Africa Education and state -- South Africa Environmental education -- South Africa Competency-based education Curriculum change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1926 , http://hdl.handle.net/10962/d1007586
- Description: Over the past ten years, South Africa has undergone substantial changes, following the advent of democracy. Key amongst these changes being the transformation of educational policy. These policy changes have introduced new structural frameworks within which we operate (including myself as a subject advisor) and new roles for educators. These policy changes affect all the levels of the education system, and have an impact at school level, where teachers are now responsible for learning programme development (including a focus on lesson planning). Lesson planning in an outcomes-based education framework is a challenging aspect of policy implementation. South Africa is faced with the challenges associated with policy change and implementation. The role of the subject advisors and facilitators who support the teachers to make sense of the curriculum is crucial, as they provide the interface between policy and practice. They are the people who work most with teachers, and have a responsibility for curriculum implementation. This study aimed to explore the strategies which are used by subject advisors and facilitators to support teachers develop lesson plans with an environmental learning focus. A qualitative case study was conducted in which I looked at how the support processes were provided by the subject advisors and facilitators in the Eastern Cape in particular the NEEP-GET cluster in the Makana district. The study employed a range of data producing techniques such as questionnaires, interviews, document analysis and observation. The data was analysed to report the findings. The research indicates that some strategies are used to provide curriculum and pedagogical support and guidance, but that these are superficially treated and others have not been attempted at all. This therefore shows that further growth in this area is possible amongst the subject advisors. Recommendations relevant to both the subject advisors and the Department of Education so as to enhance the support processes and professional development of subject advisors have been made.
- Full Text:
- Date Issued: 2005
- Authors: Mbambisa, Nomaledi Peggy
- Date: 2005
- Subjects: Educational change -- South Africa Education and state -- South Africa Environmental education -- South Africa Competency-based education Curriculum change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1926 , http://hdl.handle.net/10962/d1007586
- Description: Over the past ten years, South Africa has undergone substantial changes, following the advent of democracy. Key amongst these changes being the transformation of educational policy. These policy changes have introduced new structural frameworks within which we operate (including myself as a subject advisor) and new roles for educators. These policy changes affect all the levels of the education system, and have an impact at school level, where teachers are now responsible for learning programme development (including a focus on lesson planning). Lesson planning in an outcomes-based education framework is a challenging aspect of policy implementation. South Africa is faced with the challenges associated with policy change and implementation. The role of the subject advisors and facilitators who support the teachers to make sense of the curriculum is crucial, as they provide the interface between policy and practice. They are the people who work most with teachers, and have a responsibility for curriculum implementation. This study aimed to explore the strategies which are used by subject advisors and facilitators to support teachers develop lesson plans with an environmental learning focus. A qualitative case study was conducted in which I looked at how the support processes were provided by the subject advisors and facilitators in the Eastern Cape in particular the NEEP-GET cluster in the Makana district. The study employed a range of data producing techniques such as questionnaires, interviews, document analysis and observation. The data was analysed to report the findings. The research indicates that some strategies are used to provide curriculum and pedagogical support and guidance, but that these are superficially treated and others have not been attempted at all. This therefore shows that further growth in this area is possible amongst the subject advisors. Recommendations relevant to both the subject advisors and the Department of Education so as to enhance the support processes and professional development of subject advisors have been made.
- Full Text:
- Date Issued: 2005
Stress, coping resources and adjustment of married mothers in the teaching profession
- Authors: Nell, Reinette Deidre
- Date: 2005
- Subjects: Women teachers -- Life skills assessment -- South Africa , Work and family -- South Africa -- Psychological aspects , Life skills , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9851 , http://hdl.handle.net/10948/387 , Women teachers -- Life skills assessment -- South Africa , Work and family -- South Africa -- Psychological aspects , Life skills , Stress (Psychology)
- Description: The changes that have taken place in the South African educational system over the past few years have placed teachers under increasing stress. While abundant overseas literature is available regarding teacher stress, limited studies have focused specifically on South African samples. Female teachers, and working mothers, often experience additional stressors to men. Studies on women’s health have received little attention in comparison with the magnitude of research conducted on men’s health. The aim of the current study was to explore and describe the stress, coping resources and adjustment of married mothers in the teaching profession, and to explore and describe the patterns of stress and coping resources of these women. A non-experimental, exploratory descriptive study was employed. A biographical questionnaire and three paper-and-pencil measures, namely the Experience of Work and Life Questionnaire, the Coping Resources Inventory and the Personal, Home, Social and Formal Relations Questionnaire, were administered to 31 full-time primary school teachers who are married mothers of dependent children under the age of 14 years. A non-probability convenience sampling technique was employed. Descriptive statistics and cluster analysis were used in the data analysis. The results of the WLQ for this sample indicated that the mean score for the total level of stress fell within the high range, but with regards to the mode, the majority of the participants had average scores. The results of the CRI indicated an average level of coping resources for the present sample. The sample scored slightly above average on seven of the eleven components of the adjustment areas of the PHSF and slightly below average on the other four components. The participants in cluster one had average levels of stress and an average level of coping resources. The participants in cluster two scored very high levels of stress and average levels of coping resources. The participants in cluster three had very high levels of stress and low levels of coping resources. Suggestions were made for future research involving the stress, coping resources and adjustment of married mothers in the teaching profession. Finally, the limitations as well as the value of the research were outlined.
- Full Text:
- Date Issued: 2005
- Authors: Nell, Reinette Deidre
- Date: 2005
- Subjects: Women teachers -- Life skills assessment -- South Africa , Work and family -- South Africa -- Psychological aspects , Life skills , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9851 , http://hdl.handle.net/10948/387 , Women teachers -- Life skills assessment -- South Africa , Work and family -- South Africa -- Psychological aspects , Life skills , Stress (Psychology)
- Description: The changes that have taken place in the South African educational system over the past few years have placed teachers under increasing stress. While abundant overseas literature is available regarding teacher stress, limited studies have focused specifically on South African samples. Female teachers, and working mothers, often experience additional stressors to men. Studies on women’s health have received little attention in comparison with the magnitude of research conducted on men’s health. The aim of the current study was to explore and describe the stress, coping resources and adjustment of married mothers in the teaching profession, and to explore and describe the patterns of stress and coping resources of these women. A non-experimental, exploratory descriptive study was employed. A biographical questionnaire and three paper-and-pencil measures, namely the Experience of Work and Life Questionnaire, the Coping Resources Inventory and the Personal, Home, Social and Formal Relations Questionnaire, were administered to 31 full-time primary school teachers who are married mothers of dependent children under the age of 14 years. A non-probability convenience sampling technique was employed. Descriptive statistics and cluster analysis were used in the data analysis. The results of the WLQ for this sample indicated that the mean score for the total level of stress fell within the high range, but with regards to the mode, the majority of the participants had average scores. The results of the CRI indicated an average level of coping resources for the present sample. The sample scored slightly above average on seven of the eleven components of the adjustment areas of the PHSF and slightly below average on the other four components. The participants in cluster one had average levels of stress and an average level of coping resources. The participants in cluster two scored very high levels of stress and average levels of coping resources. The participants in cluster three had very high levels of stress and low levels of coping resources. Suggestions were made for future research involving the stress, coping resources and adjustment of married mothers in the teaching profession. Finally, the limitations as well as the value of the research were outlined.
- Full Text:
- Date Issued: 2005
Stress-inducible protein 1: a bioinformatic analysis of the human, mouse and yeast STI1 gene structure
- Authors: Aken, Bronwen Louise
- Date: 2005
- Subjects: Molecular chaperones , Proteins -- Analysis , Heat shock proteins , Bioinformatics , Genetics -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3990 , http://hdl.handle.net/10962/d1004049 , Molecular chaperones , Proteins -- Analysis , Heat shock proteins , Bioinformatics , Genetics -- Data processing
- Description: Stress-inducible protein 1 (Sti1) is a 60 kDa eukaryotic protein that is important under stress and non-stress conditions. Human Sti1 is also known as the Hsp70/Hsp90 organising protein (Hop) that coordinates the functional cooperation of heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) during the folding of various transcription factors and kinases, including certain oncogenic proteins and prion proteins. Limited studies have been conducted on the STI1 gene structure. Thus, the aim of this study was to develop a comprehensive description of human STI1 (hSTI1), mouse STI1 (mSTI1), and yeast STI1 (ySTI1) genes, using a bioinformatic approach. Genes encoded near the STI1 loci were identified for the three organisms using National Centre for Biotechnology Information (NCBI) MapViewer and the Saccharomyces Genome Database. Exon/intron boundaries were predicted using Hidden Markov model gene prediction software (HMMGene) and Genscan, and by alignment of the mRNA sequence with the genomic DNA sequence. Transcription factor binding sites (TFBS) were predicted by scanning the region 1000 base pairs (bp) upstream of the STI1 orthologues’ transcription start site (TSS) with Alibaba, Transcription element search software (TESS) and Transcription factor search (TFSearch). The promoter region was defined by comparing the number, type and position of TFBS across the orthologous STI1 genes. Additional putative TFBS were identified for ySTI1 by searching with software that aligns nucleic acid conserved elements (AlignACE) for over-represented motifs in the region upstream of the TSS of genes thought to be co-regulated with ySTI1. This study showed that hSTI1 and mSTI1 occur in a region of synteny with a number of genes of related function. Both hSTI1 and mSTI1 comprised 14 putative exons, while ySTI1 was encoded on a single exon. Human and mouse STI1 shared a perfectly conserved 55 bp region spanning their predicted TSS, although their TATA boxes were not conserved. A putative CpG island was identified in the region from -500 to +100 bp relative to the hSTI1 and mSTI1 TSS. This region overlapped with a region of high TFBS density, suggesting that the core promoter region was located in the region approximately 100 to 200 bp upstream of the TSS. Several conserved clusters of TFBS were also identified upstream of this promoter region, including binding sites for stimulatory protein 1 (Sp1), heat shock factor (HSF), nuclear factor kappa B (NF-kappaB), and the cAMP/enhancer binding protein (C/EBP). Microarray data suggested that ySTI1 was co-regulated with several heat shock proteins and substrates of the Hsp70/Hsp90 heterocomplex, and several putative regulatory elements were identified in the upstream region of these co-regulated genes, including a motif for HSF binding. The results of this research suggest several avenues of future experimental work, including the confirmation of the proposed core promoter, upstream regulatory elements, and CpG island, and the investigation into the co-regulation of mammalian STI1 with its surrounding genes. These results could also be used to inform STI1 gene knockout experiments in mice, to assess the biological importance of mammalian STI1.
- Full Text:
- Date Issued: 2005
- Authors: Aken, Bronwen Louise
- Date: 2005
- Subjects: Molecular chaperones , Proteins -- Analysis , Heat shock proteins , Bioinformatics , Genetics -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3990 , http://hdl.handle.net/10962/d1004049 , Molecular chaperones , Proteins -- Analysis , Heat shock proteins , Bioinformatics , Genetics -- Data processing
- Description: Stress-inducible protein 1 (Sti1) is a 60 kDa eukaryotic protein that is important under stress and non-stress conditions. Human Sti1 is also known as the Hsp70/Hsp90 organising protein (Hop) that coordinates the functional cooperation of heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) during the folding of various transcription factors and kinases, including certain oncogenic proteins and prion proteins. Limited studies have been conducted on the STI1 gene structure. Thus, the aim of this study was to develop a comprehensive description of human STI1 (hSTI1), mouse STI1 (mSTI1), and yeast STI1 (ySTI1) genes, using a bioinformatic approach. Genes encoded near the STI1 loci were identified for the three organisms using National Centre for Biotechnology Information (NCBI) MapViewer and the Saccharomyces Genome Database. Exon/intron boundaries were predicted using Hidden Markov model gene prediction software (HMMGene) and Genscan, and by alignment of the mRNA sequence with the genomic DNA sequence. Transcription factor binding sites (TFBS) were predicted by scanning the region 1000 base pairs (bp) upstream of the STI1 orthologues’ transcription start site (TSS) with Alibaba, Transcription element search software (TESS) and Transcription factor search (TFSearch). The promoter region was defined by comparing the number, type and position of TFBS across the orthologous STI1 genes. Additional putative TFBS were identified for ySTI1 by searching with software that aligns nucleic acid conserved elements (AlignACE) for over-represented motifs in the region upstream of the TSS of genes thought to be co-regulated with ySTI1. This study showed that hSTI1 and mSTI1 occur in a region of synteny with a number of genes of related function. Both hSTI1 and mSTI1 comprised 14 putative exons, while ySTI1 was encoded on a single exon. Human and mouse STI1 shared a perfectly conserved 55 bp region spanning their predicted TSS, although their TATA boxes were not conserved. A putative CpG island was identified in the region from -500 to +100 bp relative to the hSTI1 and mSTI1 TSS. This region overlapped with a region of high TFBS density, suggesting that the core promoter region was located in the region approximately 100 to 200 bp upstream of the TSS. Several conserved clusters of TFBS were also identified upstream of this promoter region, including binding sites for stimulatory protein 1 (Sp1), heat shock factor (HSF), nuclear factor kappa B (NF-kappaB), and the cAMP/enhancer binding protein (C/EBP). Microarray data suggested that ySTI1 was co-regulated with several heat shock proteins and substrates of the Hsp70/Hsp90 heterocomplex, and several putative regulatory elements were identified in the upstream region of these co-regulated genes, including a motif for HSF binding. The results of this research suggest several avenues of future experimental work, including the confirmation of the proposed core promoter, upstream regulatory elements, and CpG island, and the investigation into the co-regulation of mammalian STI1 with its surrounding genes. These results could also be used to inform STI1 gene knockout experiments in mice, to assess the biological importance of mammalian STI1.
- Full Text:
- Date Issued: 2005
Students’ engagement with learning theory
- Authors: Schudel, Ingrid J
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6093 , http://hdl.handle.net/10962/d1008615
- Description: This paper reflects on a module on ‘Teaching and Learning Interactions’, presented as part of the Rhodes University Advanced Certificate in Education (Environmental Education).The module is designed to help students use theoretical logic to enhance (not replace) their practical logic of how teaching and learning takes place. Data was analysed from three teaching and learning activities in the module. After the first participatory activity on water and sanitation, students narrated what teaching and learning had taken place using language available from their prior experiences. In a second activity students were introduced to explanations of learning, provided by learning theorists. In the third activity students analysed a case study, using a variety of questions relating to teaching and learning. They then had to consider these same questions in the light of a participatory on-course teaching and learning activity. The paper reflects on how students have used understandings of the nature of reality, the construction of knowledge, the use of language, situated learning, action competence and social change, in order to narrate their teaching and learning experiences on the ACE(EE) course. Through this, the paper trials a reflexive approach to the teaching of learning theory in environmental education.
- Full Text:
- Date Issued: 2005
- Authors: Schudel, Ingrid J
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6093 , http://hdl.handle.net/10962/d1008615
- Description: This paper reflects on a module on ‘Teaching and Learning Interactions’, presented as part of the Rhodes University Advanced Certificate in Education (Environmental Education).The module is designed to help students use theoretical logic to enhance (not replace) their practical logic of how teaching and learning takes place. Data was analysed from three teaching and learning activities in the module. After the first participatory activity on water and sanitation, students narrated what teaching and learning had taken place using language available from their prior experiences. In a second activity students were introduced to explanations of learning, provided by learning theorists. In the third activity students analysed a case study, using a variety of questions relating to teaching and learning. They then had to consider these same questions in the light of a participatory on-course teaching and learning activity. The paper reflects on how students have used understandings of the nature of reality, the construction of knowledge, the use of language, situated learning, action competence and social change, in order to narrate their teaching and learning experiences on the ACE(EE) course. Through this, the paper trials a reflexive approach to the teaching of learning theory in environmental education.
- Full Text:
- Date Issued: 2005
Study of the skincalm filling process at Aspen Pharmacare applying some six sigma principles
- Authors: Marx, Johannes
- Date: 2005
- Subjects: Ointments -- Packaging , Six sigma (Quality control standard)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10369 , http://hdl.handle.net/10948/184 , Ointments -- Packaging , Six sigma (Quality control standard)
- Description: Aspen Pharmacare is listed on the Johannesburg Securities Exchange South Africa (JSE) and is Africa’s largest pharmaceutical manufacturer. The company is a major supplier of branded pharmaceutical and healthcare products to the local and selected international markets. For decades, Aspen has manufactured a basket of affordable, quality, and effective products for the ethical, generic over-the-counter (OTC) and personal care markets. Aspen is also the leading supplier of generic medicines to the public sector, providing comprehensive coverage of the products on the Essential Drug List. Aspen continues to deliver on its commitment toward playing a role in social responsibility diseases such as HIV/AIDS, tuberculosis and malaria. In August 2003 Aspen developed Africa’s first generic anti-retroviral drug, namely Aspen-Stavudine. Aspen’s manufacturing facilities are based in Port Elizabeth (PE) and East London. Aspen has recently completed an Oral Solid Dosage (OSD) manufacturing facility worth approximately R150 million in PE. The Group manufactures approximately 20 tons of product daily and in excess of 400 tons of solid dosage pharmaceuticals, which equates to more than 2 billion tablets. In addition, more than 3 million litres of liquid pharmaceuticals and over 200 tons of pharmaceutical creams and ointments are produced per year [1]. Aspen excels at delivering quality products and services, exceeding customer expectations, complying with international standards in an environment that cultivates technical expertise and innovation. Following this philosophy through to the shop floor areas mean that there are always initiatives in continuous production improvement. One of these improvement projects introduced is called Six Sigma. 8 Ten members of the staff, selected from different expertise fields in the company were trained in Six Sigma. Knowledge gained from the two week training course were applied to different areas in the factory using Six Sigma principles. This dissertation focuses on the study undertaken in one of production areas, namely the filling process of the ointments and creams at the Aspen Port Elizabeth facility.
- Full Text:
- Date Issued: 2005
- Authors: Marx, Johannes
- Date: 2005
- Subjects: Ointments -- Packaging , Six sigma (Quality control standard)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10369 , http://hdl.handle.net/10948/184 , Ointments -- Packaging , Six sigma (Quality control standard)
- Description: Aspen Pharmacare is listed on the Johannesburg Securities Exchange South Africa (JSE) and is Africa’s largest pharmaceutical manufacturer. The company is a major supplier of branded pharmaceutical and healthcare products to the local and selected international markets. For decades, Aspen has manufactured a basket of affordable, quality, and effective products for the ethical, generic over-the-counter (OTC) and personal care markets. Aspen is also the leading supplier of generic medicines to the public sector, providing comprehensive coverage of the products on the Essential Drug List. Aspen continues to deliver on its commitment toward playing a role in social responsibility diseases such as HIV/AIDS, tuberculosis and malaria. In August 2003 Aspen developed Africa’s first generic anti-retroviral drug, namely Aspen-Stavudine. Aspen’s manufacturing facilities are based in Port Elizabeth (PE) and East London. Aspen has recently completed an Oral Solid Dosage (OSD) manufacturing facility worth approximately R150 million in PE. The Group manufactures approximately 20 tons of product daily and in excess of 400 tons of solid dosage pharmaceuticals, which equates to more than 2 billion tablets. In addition, more than 3 million litres of liquid pharmaceuticals and over 200 tons of pharmaceutical creams and ointments are produced per year [1]. Aspen excels at delivering quality products and services, exceeding customer expectations, complying with international standards in an environment that cultivates technical expertise and innovation. Following this philosophy through to the shop floor areas mean that there are always initiatives in continuous production improvement. One of these improvement projects introduced is called Six Sigma. 8 Ten members of the staff, selected from different expertise fields in the company were trained in Six Sigma. Knowledge gained from the two week training course were applied to different areas in the factory using Six Sigma principles. This dissertation focuses on the study undertaken in one of production areas, namely the filling process of the ointments and creams at the Aspen Port Elizabeth facility.
- Full Text:
- Date Issued: 2005
Study South Africa
- International Education Association of South Africa (IEASA), Kishun, Roshen
- Authors: International Education Association of South Africa (IEASA) , Kishun, Roshen
- Date: 2005
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65344 , vital:28751 , ISBN 0123218931
- Description: [Message from the President of IEASA, Dr Roshen Kishun]: We salute the thousands of South Africans From diverse racial backgrounds who 50 years ago put forward their vision, encapsulated in the Freedom Charter, to keep doors of education open. As we celebrate the 50th anniversary of this historic event we are aware of the Foundations laid then to allow us to reconnect to the world. In choosing “lessons in diversity' as the theme For the Sth edition of Study South Africa we support the need For South African higher education to keep its doors open in meeting the development challenges of Africa. The year 2005 has been described as critical For Africa because of a number of Factors that have come together. These include the New Partnership For Africa’s Development which spells out action plans to tackle some of the more intractable problems that Africa Faces, the Formation of the African Union with clear guidelines For governance and peace, and the Pan-African Parliament which promotes the concept of working together to solve the continent's problems. The launch of the Southern African Regional Universities Association in early 2005 by 45 of the region’s vice-chancellors recognised that the excellence and sustainability of university education, research and development will be a leading contributor to Future growth and poverty alleviation. Despite the tides of limited resources, external demands and internal policy challenges, the vice-chancellors were unequivocally committed to advancing the development agenda of higher education on the African continent. Critically, in recent years there has been acknowledgement of the ability of higher education to bring about economic and democratic reforms, as evidenced by the commitment and concerted efforts made by Foundations and funding agencies to support the improvement of higher education institutions in Africa. Most important from our perspective is the support for the ’’renewal’’ of higher education institutions as they are considered to be key vehicles For development on the continent. The Commission For Africa report, published in March 2005, endorses the Association of African Universities, Association of Commonwealth Universities and Higher Education South Africa’s joint 10-year partnership programme, Renewing the African University, The partnership programme calls, among other things, For constructive engagement between states and higher education institutions, increasing North-South and South-South collaboration, internationalisation of the curriculum and partnerships between universities and the corporate sector. The Commission makes clear its conviction that higher education's contribution to building professional skills and knowledge is key to achieving Fundamental development changes. The need for centres of excellence in science, technology and engineering is highlighted as key to Future development and growth. Higher education institutions need to be the “breeding ground For the skilled individuals whom the continent needs". The report stresses the need For urgent attention to be given to the management of natural resources, of Forests and water, improving sanitation and strengthening health systems to deal with pandemics such as malaria, tuberculosis and HIV-Aids. Other important developments needed are building the human and institutional capacity for good governance and strengthening leadership in public life, civil society and business. In Focusing on the theme “lessons in diversity’ the Guide captures the richness of the various “diversities ' in the South African higher education landscape. It describes the radical transformation of higher education in South Africa over more than a decade. It identifies South Africa's research system as being “by Far the biggest in Africa” and demonstrates the important role South African higher education can play in meeting the challenges of Africa. I hope that the information provided will allow those interested in South African education to make informed choices. , 5th Edition
- Full Text:
- Date Issued: 2005
- Authors: International Education Association of South Africa (IEASA) , Kishun, Roshen
- Date: 2005
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65344 , vital:28751 , ISBN 0123218931
- Description: [Message from the President of IEASA, Dr Roshen Kishun]: We salute the thousands of South Africans From diverse racial backgrounds who 50 years ago put forward their vision, encapsulated in the Freedom Charter, to keep doors of education open. As we celebrate the 50th anniversary of this historic event we are aware of the Foundations laid then to allow us to reconnect to the world. In choosing “lessons in diversity' as the theme For the Sth edition of Study South Africa we support the need For South African higher education to keep its doors open in meeting the development challenges of Africa. The year 2005 has been described as critical For Africa because of a number of Factors that have come together. These include the New Partnership For Africa’s Development which spells out action plans to tackle some of the more intractable problems that Africa Faces, the Formation of the African Union with clear guidelines For governance and peace, and the Pan-African Parliament which promotes the concept of working together to solve the continent's problems. The launch of the Southern African Regional Universities Association in early 2005 by 45 of the region’s vice-chancellors recognised that the excellence and sustainability of university education, research and development will be a leading contributor to Future growth and poverty alleviation. Despite the tides of limited resources, external demands and internal policy challenges, the vice-chancellors were unequivocally committed to advancing the development agenda of higher education on the African continent. Critically, in recent years there has been acknowledgement of the ability of higher education to bring about economic and democratic reforms, as evidenced by the commitment and concerted efforts made by Foundations and funding agencies to support the improvement of higher education institutions in Africa. Most important from our perspective is the support for the ’’renewal’’ of higher education institutions as they are considered to be key vehicles For development on the continent. The Commission For Africa report, published in March 2005, endorses the Association of African Universities, Association of Commonwealth Universities and Higher Education South Africa’s joint 10-year partnership programme, Renewing the African University, The partnership programme calls, among other things, For constructive engagement between states and higher education institutions, increasing North-South and South-South collaboration, internationalisation of the curriculum and partnerships between universities and the corporate sector. The Commission makes clear its conviction that higher education's contribution to building professional skills and knowledge is key to achieving Fundamental development changes. The need for centres of excellence in science, technology and engineering is highlighted as key to Future development and growth. Higher education institutions need to be the “breeding ground For the skilled individuals whom the continent needs". The report stresses the need For urgent attention to be given to the management of natural resources, of Forests and water, improving sanitation and strengthening health systems to deal with pandemics such as malaria, tuberculosis and HIV-Aids. Other important developments needed are building the human and institutional capacity for good governance and strengthening leadership in public life, civil society and business. In Focusing on the theme “lessons in diversity’ the Guide captures the richness of the various “diversities ' in the South African higher education landscape. It describes the radical transformation of higher education in South Africa over more than a decade. It identifies South Africa's research system as being “by Far the biggest in Africa” and demonstrates the important role South African higher education can play in meeting the challenges of Africa. I hope that the information provided will allow those interested in South African education to make informed choices. , 5th Edition
- Full Text:
- Date Issued: 2005
Supervision : a Foucaultian exploration of institutional and interpersonal power relations between postgraduate supervisors, their students and the university domain
- Authors: Rau, Asta
- Date: 2005
- Subjects: Foucault, Michel, 1926-1984 -- Methodology Foucault, Michel, 1926-1984 -- Criticism and interpretation Graduate students -- Supervision of Dissertations, Academic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1786 , http://hdl.handle.net/10962/d1003671
- Description: Supervision is widely acknowledged as influencing the quality of postgraduate theses, and by association, of postgraduates. Despite this, publications on conducting research offer far less guidance on managing the supervision relationship than on the practicalities of producing a thesis. In-depth, qualitative supervision studies are few and fewer still examine power in the supervision relationship. Michel Foucault’s insights are used to explore the question: How do postgraduate supervisors and their Master’s students experience the supervision relationship and how are the dynamics of interpersonal and institutional power implicated in these relationships? Foucault argues that power relations always involve resistances; these function primarily through institutionalized discourses to produce different forms of knowledge, one form of which is identity or subjectivity. Accordingly, power relations are explored in terms of thesis-as-product, person-as-product and the impact of both on the mediation of knowledge in the educational domain. Four institutionalized discourses in the university domain are examined: · Commercial educational management discourse: targets academics through issues of quality assurance, throughput, publication, research productivity and funding. · Anarchic educational leadership discourse: integrates quantum principles with commercial demands, change management strategies and meaningful participation. · Humanistic discourse: favours a pastoral ethic and is person-centered. · Holistic discourse: cultivates ecological sensibility and values the interconnectedness of all aspects of being-in-the-world. Data collected in sixteen semi-structured interviews with three matched supervisor-student pairs selected from the humanities and education faculties of one South African university, are presented as case studies. Data analysis combines grounded theory techniques with selected aspects of Foucault’s methods. A conceptual model is devised to analyse how participants use resistance strategies to interface their autonomy and dependency with their expectations, abilities, and professional and pastoral care. The research yields rich data in which several thematic correlations in interpersonal and institutional power dynamics are grounded. These include: the significance of supervisor-student matching; links between expectations, abilities, the way participants negotiate power and the quality of professional and pastoral care they experience; the benefit of personal affinity to thesis-as-product and person-as-product; and the impact of commercial demands on participants’ power relations. Participants tend to reproduce the discourses in which they are embedded and adopt or adapt aspects of contesting discourses to this end. Potential avenues are identified for improving supervision practice and for further research.
- Full Text:
- Date Issued: 2005
- Authors: Rau, Asta
- Date: 2005
- Subjects: Foucault, Michel, 1926-1984 -- Methodology Foucault, Michel, 1926-1984 -- Criticism and interpretation Graduate students -- Supervision of Dissertations, Academic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1786 , http://hdl.handle.net/10962/d1003671
- Description: Supervision is widely acknowledged as influencing the quality of postgraduate theses, and by association, of postgraduates. Despite this, publications on conducting research offer far less guidance on managing the supervision relationship than on the practicalities of producing a thesis. In-depth, qualitative supervision studies are few and fewer still examine power in the supervision relationship. Michel Foucault’s insights are used to explore the question: How do postgraduate supervisors and their Master’s students experience the supervision relationship and how are the dynamics of interpersonal and institutional power implicated in these relationships? Foucault argues that power relations always involve resistances; these function primarily through institutionalized discourses to produce different forms of knowledge, one form of which is identity or subjectivity. Accordingly, power relations are explored in terms of thesis-as-product, person-as-product and the impact of both on the mediation of knowledge in the educational domain. Four institutionalized discourses in the university domain are examined: · Commercial educational management discourse: targets academics through issues of quality assurance, throughput, publication, research productivity and funding. · Anarchic educational leadership discourse: integrates quantum principles with commercial demands, change management strategies and meaningful participation. · Humanistic discourse: favours a pastoral ethic and is person-centered. · Holistic discourse: cultivates ecological sensibility and values the interconnectedness of all aspects of being-in-the-world. Data collected in sixteen semi-structured interviews with three matched supervisor-student pairs selected from the humanities and education faculties of one South African university, are presented as case studies. Data analysis combines grounded theory techniques with selected aspects of Foucault’s methods. A conceptual model is devised to analyse how participants use resistance strategies to interface their autonomy and dependency with their expectations, abilities, and professional and pastoral care. The research yields rich data in which several thematic correlations in interpersonal and institutional power dynamics are grounded. These include: the significance of supervisor-student matching; links between expectations, abilities, the way participants negotiate power and the quality of professional and pastoral care they experience; the benefit of personal affinity to thesis-as-product and person-as-product; and the impact of commercial demands on participants’ power relations. Participants tend to reproduce the discourses in which they are embedded and adopt or adapt aspects of contesting discourses to this end. Potential avenues are identified for improving supervision practice and for further research.
- Full Text:
- Date Issued: 2005
Supply-side ecology of the brown mussel, Perna perna: an investigation of spatial and temporal variation in, and coupling between, gamete release and larval supply
- McQuaid, Christopher D, Lawrie, S M
- Authors: McQuaid, Christopher D , Lawrie, S M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6954 , http://hdl.handle.net/10962/d1011987
- Description: Sampling of recruitment-associated variables of Perna perna was done approximately monthly for 14 months at intertidal locations 500 m apart, nested within sites 25 km apart. Paired with intertidal locations were nearshore locations, 600 m to sea. Sampling assessed spawning, densities of larvae in the water column and densities of late plantigrades and juveniles on the shore. Major events in each variable were synchronous over larger scales (10s of kilometres) while subsidiary events were synchronised at smaller scales, varying within sites (100s of metres) or even within locations (metres). This suggests that the processes driving major events operated over large scales while processes operating at much more local scales drove less intense, more localised events. A major spawning event occurred at all locations in May–June 1998. Weaker spawning events occurred at different times in different locations. Larvae were found on 80% of sampling occasions, densities peaking in January–March 1998 and 1999 at all locations. Plantigrades and juveniles showed less clear patterns, with considerable residual variation. There was no sign of strong coupling among variables with few significant direct or cross correlations. The major sources of variability shifted from time to space as one progressed from spawning, to plantigrade density to juvenile density. For spawning, time was the most important source (58%) of heterogeneity and space accounted for little (8%) of the total variance. For larvae and late plantigrades, time was still the most important source of variability (41% and 33%, respectively), but space was a much more substantial component. For juveniles, small-scale (residual) spatial variability dominated total variability (75%). This strongly suggests the importance of hydrography and its effects on variation in delivery of larvae to the intertidal from offshore. These findings also indicate greater spatial heterogeneity as recruits age, reflecting small-scale variations in larval delivery and the increasing importance of post-settlement mortality.
- Full Text:
- Date Issued: 2005
- Authors: McQuaid, Christopher D , Lawrie, S M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6954 , http://hdl.handle.net/10962/d1011987
- Description: Sampling of recruitment-associated variables of Perna perna was done approximately monthly for 14 months at intertidal locations 500 m apart, nested within sites 25 km apart. Paired with intertidal locations were nearshore locations, 600 m to sea. Sampling assessed spawning, densities of larvae in the water column and densities of late plantigrades and juveniles on the shore. Major events in each variable were synchronous over larger scales (10s of kilometres) while subsidiary events were synchronised at smaller scales, varying within sites (100s of metres) or even within locations (metres). This suggests that the processes driving major events operated over large scales while processes operating at much more local scales drove less intense, more localised events. A major spawning event occurred at all locations in May–June 1998. Weaker spawning events occurred at different times in different locations. Larvae were found on 80% of sampling occasions, densities peaking in January–March 1998 and 1999 at all locations. Plantigrades and juveniles showed less clear patterns, with considerable residual variation. There was no sign of strong coupling among variables with few significant direct or cross correlations. The major sources of variability shifted from time to space as one progressed from spawning, to plantigrade density to juvenile density. For spawning, time was the most important source (58%) of heterogeneity and space accounted for little (8%) of the total variance. For larvae and late plantigrades, time was still the most important source of variability (41% and 33%, respectively), but space was a much more substantial component. For juveniles, small-scale (residual) spatial variability dominated total variability (75%). This strongly suggests the importance of hydrography and its effects on variation in delivery of larvae to the intertidal from offshore. These findings also indicate greater spatial heterogeneity as recruits age, reflecting small-scale variations in larval delivery and the increasing importance of post-settlement mortality.
- Full Text:
- Date Issued: 2005
Surface electrochemistry of iron phthalocyanine axially ligated to 4-mercaptopyridine self-assembled monolayers at gold electrode
- Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289282 , vital:56615 , xlink:href="https://doi.org/10.1016/j.jelechem.2005.02.018"
- Description: Surface electrochemical behaviour of a self-immobilised iron phthalocyanine (FePc) ultrathin film, via axial ligation reaction, onto a preformed 4-mercaptopyridine self-assembled monolayer on gold electrode has been described. Electrochemical evidence for the sensor clearly suggested surface-confined, flat “umbrella”-oriented and densely-packed monolayer film structure. The proposed electrochemical sensor exhibited good catalytic activity towards the oxidation of thiocyanate in pH 4.0 medium over a linear range of three decades of concentration (ca. 10−6–10−3 mol dm−3) with a detection limit in the order of ∼10−7 mol dm−3. The sensor exhibited useful potential for the analysis of thiocyanate in human urine and saliva samples. The advantageous properties of this type of electrode as a sensor for thiocyanate lie in its ease of fabrication, excellent catalytic activity, stability, sensitivity and simplicity.
- Full Text:
- Date Issued: 2005
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289282 , vital:56615 , xlink:href="https://doi.org/10.1016/j.jelechem.2005.02.018"
- Description: Surface electrochemical behaviour of a self-immobilised iron phthalocyanine (FePc) ultrathin film, via axial ligation reaction, onto a preformed 4-mercaptopyridine self-assembled monolayer on gold electrode has been described. Electrochemical evidence for the sensor clearly suggested surface-confined, flat “umbrella”-oriented and densely-packed monolayer film structure. The proposed electrochemical sensor exhibited good catalytic activity towards the oxidation of thiocyanate in pH 4.0 medium over a linear range of three decades of concentration (ca. 10−6–10−3 mol dm−3) with a detection limit in the order of ∼10−7 mol dm−3. The sensor exhibited useful potential for the analysis of thiocyanate in human urine and saliva samples. The advantageous properties of this type of electrode as a sensor for thiocyanate lie in its ease of fabrication, excellent catalytic activity, stability, sensitivity and simplicity.
- Full Text:
- Date Issued: 2005
Synthesis and electrocatalytic properties of polymerizable metallophthalocyanines
- Authors: Obirai, Joseph Chinye
- Date: 2005
- Subjects: Phthalocyanines Electrochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4447 , http://hdl.handle.net/10962/d1007733
- Description: The syntheses, spectral and electrochemical characterization of new family electropolymerizable pyrrole, thiophene and mercaptopyrimidin substituted metallophthalocyanine (MPc) complexes are described. Tetraamino substituted chromium and manganese phthalocyanine complexes were also synthesized and characterized. The spectral and electrochemical results are comparable to literature reports. The complexes formed stable films when deposited on electrode surfaces. The MPc films were formed by electropolymerization, drop-dry method and self-assembling. Nickel hydroxide-like electrodes were formed by electrotransformation of nickel-tetra-4- (pyrrol-1-yl)phenoxy phthalocyanine polymer films to the corresponding PcNi-O-NiPc modified electrodes in alkaline solution. The thiophene, mercaptopyrimidine functionalized MPcs and amino group containing complexes formed good self-assembled monolayers (SAMs) on gold electrode. The electrode modification processes were reproducible. The conductivities of the electrode were dependent on the surface concentrations of the complexes as a function of electropolymerization scan numbers. The electrodes showed good catalytic responses toward L-cysteine, nitrite, nitric oxide (NO), glycine, phenol and its derivative and oxygen. The results also suggest that the presence of thio groups on the ring substituents lowers the oxidation potential of Lcysteine more compared to literature values. The stability of the amperometric responses toward the various analytes is used to diagnose the applicability of the materials for electroanalytical purposes. The limits of detection for L-cysteine, nitrite, NO and glycine were in the range of ~10⁻⁷ to 10⁻⁵ mol dm⁻³.
- Full Text:
- Date Issued: 2005
- Authors: Obirai, Joseph Chinye
- Date: 2005
- Subjects: Phthalocyanines Electrochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4447 , http://hdl.handle.net/10962/d1007733
- Description: The syntheses, spectral and electrochemical characterization of new family electropolymerizable pyrrole, thiophene and mercaptopyrimidin substituted metallophthalocyanine (MPc) complexes are described. Tetraamino substituted chromium and manganese phthalocyanine complexes were also synthesized and characterized. The spectral and electrochemical results are comparable to literature reports. The complexes formed stable films when deposited on electrode surfaces. The MPc films were formed by electropolymerization, drop-dry method and self-assembling. Nickel hydroxide-like electrodes were formed by electrotransformation of nickel-tetra-4- (pyrrol-1-yl)phenoxy phthalocyanine polymer films to the corresponding PcNi-O-NiPc modified electrodes in alkaline solution. The thiophene, mercaptopyrimidine functionalized MPcs and amino group containing complexes formed good self-assembled monolayers (SAMs) on gold electrode. The electrode modification processes were reproducible. The conductivities of the electrode were dependent on the surface concentrations of the complexes as a function of electropolymerization scan numbers. The electrodes showed good catalytic responses toward L-cysteine, nitrite, nitric oxide (NO), glycine, phenol and its derivative and oxygen. The results also suggest that the presence of thio groups on the ring substituents lowers the oxidation potential of Lcysteine more compared to literature values. The stability of the amperometric responses toward the various analytes is used to diagnose the applicability of the materials for electroanalytical purposes. The limits of detection for L-cysteine, nitrite, NO and glycine were in the range of ~10⁻⁷ to 10⁻⁵ mol dm⁻³.
- Full Text:
- Date Issued: 2005
Synthesis and photophysical properties of a covalently linked porphyrin-phthalocyanine conjugate
- Zhao, Zhixin, Ogunsipe, Abimbola O, Maree, M David, Nyokong, Tebello
- Authors: Zhao, Zhixin , Ogunsipe, Abimbola O , Maree, M David , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300358 , vital:57922 , xlink:href="https://doi.org/10.1142/S1088424605000253"
- Description: The synthesis of a phthalocyanine-porphyrin heteropentamer (zinc(II) tetra(5-phenoxy-10,15,20-triphenylporphyrin)) zinc(II) phthalocyanine, (ZnPc-(ZnTPP)4), containing four units of zinc tetraphenylporphyrin linked to a central zinc phthalocyanine macrocycle via an ether linkage is reported. The photophysical parameters of the pentamer are reported in toluene and dimethyl sulfoxide (DMSO). The observed differences in the fluorescence behavior of the pentamer in the two solvents is explained in terms of emission from different states; charge transfer state in DMSO and locally excited state in toluene. The rate constants for fluorescence, intersystem crossing, internal conversion, and of charge and energy transfer are reported for the pentamer. Quantum yields for fluorescence, internal conversion, triplet state and of charge and energy transfer are also reported for the pentamer, ZnPc-(ZnTPP)4 and the mixture of ZnPc and ZnTPP. The latter two parameters are higher in the pentamer compared to a mixture containing ZnPc and ZnTPP.
- Full Text:
- Date Issued: 2005
- Authors: Zhao, Zhixin , Ogunsipe, Abimbola O , Maree, M David , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300358 , vital:57922 , xlink:href="https://doi.org/10.1142/S1088424605000253"
- Description: The synthesis of a phthalocyanine-porphyrin heteropentamer (zinc(II) tetra(5-phenoxy-10,15,20-triphenylporphyrin)) zinc(II) phthalocyanine, (ZnPc-(ZnTPP)4), containing four units of zinc tetraphenylporphyrin linked to a central zinc phthalocyanine macrocycle via an ether linkage is reported. The photophysical parameters of the pentamer are reported in toluene and dimethyl sulfoxide (DMSO). The observed differences in the fluorescence behavior of the pentamer in the two solvents is explained in terms of emission from different states; charge transfer state in DMSO and locally excited state in toluene. The rate constants for fluorescence, intersystem crossing, internal conversion, and of charge and energy transfer are reported for the pentamer. Quantum yields for fluorescence, internal conversion, triplet state and of charge and energy transfer are also reported for the pentamer, ZnPc-(ZnTPP)4 and the mixture of ZnPc and ZnTPP. The latter two parameters are higher in the pentamer compared to a mixture containing ZnPc and ZnTPP.
- Full Text:
- Date Issued: 2005
Synthesis, electrochemical and electrocatalytic behaviour of thiophene-appended cobalt, manganese and zinc phthalocyanine complexes
- Obirai, Joseph, Nyokong, Tebello
- Authors: Obirai, Joseph , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286103 , vital:56238 , xlink:href="https://doi.org/10.1016/j.electacta.2005.03.024"
- Description: This work reports on the syntheses of new thiophene tetra substituted cobalt, manganese and zinc phthalocyanine (CoTETPc, (Cl)MnTETPc and ZnTETPc) complexes. The redox processes due to the thiophene substituent on the ring of the metallophthalocyanines (MPcs) were observed, in addition to Pc ring and metal (for Co and Mn complexes) based redox activity. The electrocatalytic activity of the CoTETPc complex adsorbed on glassy carbon electrode (GCE) by drop/dry-thermal annealing was investigated using L-cysteine. The modified electrode was stable to repetitive use without any signs of deactivation by oxidation products and was used to determine L-cysteine at concentrations between 0.0015 and 1 mM in pH 4 aqueous conditions.
- Full Text:
- Date Issued: 2005
- Authors: Obirai, Joseph , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286103 , vital:56238 , xlink:href="https://doi.org/10.1016/j.electacta.2005.03.024"
- Description: This work reports on the syntheses of new thiophene tetra substituted cobalt, manganese and zinc phthalocyanine (CoTETPc, (Cl)MnTETPc and ZnTETPc) complexes. The redox processes due to the thiophene substituent on the ring of the metallophthalocyanines (MPcs) were observed, in addition to Pc ring and metal (for Co and Mn complexes) based redox activity. The electrocatalytic activity of the CoTETPc complex adsorbed on glassy carbon electrode (GCE) by drop/dry-thermal annealing was investigated using L-cysteine. The modified electrode was stable to repetitive use without any signs of deactivation by oxidation products and was used to determine L-cysteine at concentrations between 0.0015 and 1 mM in pH 4 aqueous conditions.
- Full Text:
- Date Issued: 2005
Synthesis, photochemical and photophysical properties of phthalocyanine derivatives
- Authors: Maqanda, Weziwe Theorine
- Date: 2005 , 2013-06-18
- Subjects: Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4436 , http://hdl.handle.net/10962/d1007472 , Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Description: Substituted zinc and magnesium phthalocyanine and porphyrazine derivatives were synthesized according to the reported procedures. The magnesium and zinc phthalocyanine and porphyrazine derivatives were synthesized by ring enlargement of subphthalocyanine and statistical condensation of the two phthalonitrile derivatives. Characterization of the complexes involved the use of infrared spectroscopy, nuclear magnetic resonance spectroscopy, ultraviolet and visible spectroscopy, and Maldi-TOF spectroscopy (for selected compounds) and elemental analysis. Photochemical and photophysical properties of the complexes in non-aqueous solution was then investigated. Photobleaching quantum yields are in order of 10⁻⁵ indicating their relative photostability. Complexes containing more electron-donating substituents were more easily oxidized. For complexes 66 and 69 (as these complexes have the same number of substituents but differ in the metal center) photobleaching quantum yield for the ZincPc complex 69 was slightly less than that of the MgPc complex 66. Singlet oxygen quantum yields of the various complexes in DMSO using diphenylisobenzofuran (DPBF) as a quencher in organic solvents were determined. Singlet oxygen quantum yields of the complexes range from 0.23 to 0.67. High values of Φ[subscript]Δ ZnPc complexes was observed compared to the corresponding MgPc, complexes. This was evidenced by complexes 66 and 69 with Φ[subscript]Δ values of Φ[subscript]Δ = 0.26 and 0.40, respectively. Varying number of phenoxy substituents, complex 71 gave significantly large value of Φ[subscript]Δ compared to 70 (that is, the presence of more electron-donating substituted group, gave higher singlet oxygen quantum yields (0 .67 and 0.25 for 71 and 70 repectively). The triplet quantum yields and triplet lifetimes were determined by laser flash photolysis for selected compounds. The triplet quantum yields increase as the number of substituents increases e.g 68 > 67 > 66. Comparing porphyrazine complexes (63, 64 and 65), 63 with benzene attached to the ring, has higher triplet state lifetime (420 μs) compared to 64 and 65 containing long alkyl chain and tertbutyl substituents, 350 and 360 μs,respectively). The observed Φ[subscript]f values for 68 and 63 were quiet suprising, since low values are observed compared to the rest of the complexes (e.g 0.03 and 0.02 respectively). Although these values seem so low, they are sufficient for fluorescence imaging applications. The Φ[subscript]f values for the complexes under study are within the range reported for complexes currently used for PDT. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2005
- Authors: Maqanda, Weziwe Theorine
- Date: 2005 , 2013-06-18
- Subjects: Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4436 , http://hdl.handle.net/10962/d1007472 , Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Description: Substituted zinc and magnesium phthalocyanine and porphyrazine derivatives were synthesized according to the reported procedures. The magnesium and zinc phthalocyanine and porphyrazine derivatives were synthesized by ring enlargement of subphthalocyanine and statistical condensation of the two phthalonitrile derivatives. Characterization of the complexes involved the use of infrared spectroscopy, nuclear magnetic resonance spectroscopy, ultraviolet and visible spectroscopy, and Maldi-TOF spectroscopy (for selected compounds) and elemental analysis. Photochemical and photophysical properties of the complexes in non-aqueous solution was then investigated. Photobleaching quantum yields are in order of 10⁻⁵ indicating their relative photostability. Complexes containing more electron-donating substituents were more easily oxidized. For complexes 66 and 69 (as these complexes have the same number of substituents but differ in the metal center) photobleaching quantum yield for the ZincPc complex 69 was slightly less than that of the MgPc complex 66. Singlet oxygen quantum yields of the various complexes in DMSO using diphenylisobenzofuran (DPBF) as a quencher in organic solvents were determined. Singlet oxygen quantum yields of the complexes range from 0.23 to 0.67. High values of Φ[subscript]Δ ZnPc complexes was observed compared to the corresponding MgPc, complexes. This was evidenced by complexes 66 and 69 with Φ[subscript]Δ values of Φ[subscript]Δ = 0.26 and 0.40, respectively. Varying number of phenoxy substituents, complex 71 gave significantly large value of Φ[subscript]Δ compared to 70 (that is, the presence of more electron-donating substituted group, gave higher singlet oxygen quantum yields (0 .67 and 0.25 for 71 and 70 repectively). The triplet quantum yields and triplet lifetimes were determined by laser flash photolysis for selected compounds. The triplet quantum yields increase as the number of substituents increases e.g 68 > 67 > 66. Comparing porphyrazine complexes (63, 64 and 65), 63 with benzene attached to the ring, has higher triplet state lifetime (420 μs) compared to 64 and 65 containing long alkyl chain and tertbutyl substituents, 350 and 360 μs,respectively). The observed Φ[subscript]f values for 68 and 63 were quiet suprising, since low values are observed compared to the rest of the complexes (e.g 0.03 and 0.02 respectively). Although these values seem so low, they are sufficient for fluorescence imaging applications. The Φ[subscript]f values for the complexes under study are within the range reported for complexes currently used for PDT. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2005
Synthesis, photophysicochemical studies of adjacently tetrasubstituted binaphthalo-phthalocyanines
- Seotsanyana-Mokhosi, Itumeleng, Chen, Ji-Yao, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289294 , vital:56616 , xlink:href="https://doi.org/10.1142/S108842460500040X"
- Description: Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.
- Full Text:
- Date Issued: 2005
- Authors: Seotsanyana-Mokhosi, Itumeleng , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289294 , vital:56616 , xlink:href="https://doi.org/10.1142/S108842460500040X"
- Description: Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.
- Full Text:
- Date Issued: 2005
Talk radio and public debate : a case study of three Ugandan radio stations
- Authors: Ogoso, Erich Opolot
- Date: 2005
- Subjects: Radio stations -- Uganda , Radio broadcasting -- Social aspects -- Uganda , Radio broadcasting -- Political aspects -- Uganda , Radio talk shows -- Uganda , Interviewing on radio -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3514 , http://hdl.handle.net/10962/d1007723 , Radio stations -- Uganda , Radio broadcasting -- Social aspects -- Uganda , Radio broadcasting -- Political aspects -- Uganda , Radio talk shows -- Uganda , Interviewing on radio -- Uganda
- Description: This study is a comparative examination of approaches to talk radio as a genre on three Ugandan radio stations. The aim is to draw conclusions, from observations made about these stations, about the potential of talk radio to encourage public debate around social issues and improve democratic participation despite pertinent challenges in Uganda. The study first outlines a theoretical framework, which is informed by Habermas's theory of the media as a 'public sphere'. This framework is applied to an exploration of traditions of talk radio that have emerged globally in order to assess the potential of these traditions to play a role in contributing to the establishment of such a 'public sphere'. The study then goes on to discuss the historical development of radio in Uganda and the establishment of the current broadcast landscape. The focus is on the way in which this history has been defined by a struggle around public expression, in which government has repeatedly sought ways to control media as a vehicle for public expression. It is proposed that Ugandan talk radio has the potential to play an important role in ensuring broad participation in public expression. It is against this background that the study then describes and analyses the development of the talk genre at three Ugandan radio stations (each one an example of, respectively, a commercial, community and public service station). It is explained that staff on all three stations emphasise the importance of talk radio in encouraging participation, by their audiences, in the public debate of social and political issues. It is argued that, because of limitations that exist within these stations, none of the talk show teams fully realize the potential of the genre for participation in such debate. The picture that emerges is one of unequal access, with those sections of radio audiences in positions of privilege being further empowered, while those on the margins remain excluded from public discussion. The study finally recommends ways to improve public participation on Ugandan talk radio, noting the need to review government support, the problems of organizational culture within the stations, the need for more guidelines on practical arrangements around talk show production and the question of contradictions that exist at policy level.
- Full Text:
- Date Issued: 2005
- Authors: Ogoso, Erich Opolot
- Date: 2005
- Subjects: Radio stations -- Uganda , Radio broadcasting -- Social aspects -- Uganda , Radio broadcasting -- Political aspects -- Uganda , Radio talk shows -- Uganda , Interviewing on radio -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3514 , http://hdl.handle.net/10962/d1007723 , Radio stations -- Uganda , Radio broadcasting -- Social aspects -- Uganda , Radio broadcasting -- Political aspects -- Uganda , Radio talk shows -- Uganda , Interviewing on radio -- Uganda
- Description: This study is a comparative examination of approaches to talk radio as a genre on three Ugandan radio stations. The aim is to draw conclusions, from observations made about these stations, about the potential of talk radio to encourage public debate around social issues and improve democratic participation despite pertinent challenges in Uganda. The study first outlines a theoretical framework, which is informed by Habermas's theory of the media as a 'public sphere'. This framework is applied to an exploration of traditions of talk radio that have emerged globally in order to assess the potential of these traditions to play a role in contributing to the establishment of such a 'public sphere'. The study then goes on to discuss the historical development of radio in Uganda and the establishment of the current broadcast landscape. The focus is on the way in which this history has been defined by a struggle around public expression, in which government has repeatedly sought ways to control media as a vehicle for public expression. It is proposed that Ugandan talk radio has the potential to play an important role in ensuring broad participation in public expression. It is against this background that the study then describes and analyses the development of the talk genre at three Ugandan radio stations (each one an example of, respectively, a commercial, community and public service station). It is explained that staff on all three stations emphasise the importance of talk radio in encouraging participation, by their audiences, in the public debate of social and political issues. It is argued that, because of limitations that exist within these stations, none of the talk show teams fully realize the potential of the genre for participation in such debate. The picture that emerges is one of unequal access, with those sections of radio audiences in positions of privilege being further empowered, while those on the margins remain excluded from public discussion. The study finally recommends ways to improve public participation on Ugandan talk radio, noting the need to review government support, the problems of organizational culture within the stations, the need for more guidelines on practical arrangements around talk show production and the question of contradictions that exist at policy level.
- Full Text:
- Date Issued: 2005
Tanzaniops, replacement name for certain African Baetidae (Ephemeroptera)
- McCafferty, W P, Barber-James, Helen M
- Authors: McCafferty, W P , Barber-James, Helen M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:7009 , http://hdl.handle.net/10962/d1008387
- Description: The name Tanzaniella, proposed for an African baetid mayfly by Gillies (1991) was preoccupied. The name Tanzaniops is provided as a replacement for this homonym.
- Full Text: false
- Date Issued: 2005
- Authors: McCafferty, W P , Barber-James, Helen M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:7009 , http://hdl.handle.net/10962/d1008387
- Description: The name Tanzaniella, proposed for an African baetid mayfly by Gillies (1991) was preoccupied. The name Tanzaniops is provided as a replacement for this homonym.
- Full Text: false
- Date Issued: 2005