Ill at ease in our translated world ecocriticism, language, and the natural environment in the fiction of Michael Ondaatje, Amitav Ghosh, David Malouf and Wilma Stockenström
- Authors: Johnson, Eleanore
- Date: 2011
- Subjects: Ondaatje, Michael, 1943- The English patient Ghosh, Amitav. The hungry tide Malouf, David, 1934- An imaginary life Stockenström, Wilma. The expedition to the Baobab tree Ecocriticism Human ecology in literature Nature in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2234 , http://hdl.handle.net/10962/d1002277
- Description: This thesis explores the thematic desire to establish an ecological human bond with nature in four contemporary novels: The English Patient by Michael Ondaatje, The Hungry Tide by Amitav Ghosh, An Imaginary Life by David Malouf, and The Expedition to The Baobab Tree by Wilma Stockenström. These authors share a concern with the influence that language has on human perception, and one of the most significant ways they attempt to connect with the natural world is through somehow escaping, or transcending, what they perceive to be the divisive tendencies of language. They all suggest that human perception is not steered entirely by a disembodied mind, which constructs reality through linguistic and cultural lenses, but is equally influenced by physical circumstances and embodied experiences. They explore the potential of corporeal reciprocity and empathy as that which enables understanding across cultural barriers, and a sense of ecologically intertwined kinship with nature. They all struggle to reconcile their awareness of the potential danger of relating to nature exclusively through language, with a desire to speak for the natural world in literature. I have examined whether they succeed in doing so, or whether they contradict their thematic suspicion of language with their literary medium. I have prioritised a close ecocritical reading of the novels and loosely situated the authors’ approach to nature and language within the broad theoretical frameworks of radical ecology, structuralism and poststructuralism. I suggest that these novels are best analysed in the context of an ecocritical mediation between poststructuralist conceptions of nature as inaccessible cultural construct, and the naïve conception of unmediated, pre-reflective interaction with the natural world. I draw especially on the phenomenological theories of Maurice Merleau-Ponty, whose insistence that perception is always both embodied and culturally mediated truly renders culture and nature irreducible, intertwined categories. By challenging historical dualisms like mind/body and culture/nature, the selected novels suggest a more fluid and discursive understanding of the perceived conflict between language and nature, whilst problematizing the perception of language as merely a cultural artefact. Moreover, they are examples of the kind of literature that has the potential to positively influence our human conception of nature, and adapt us better to our ecological context on a planet struggling for survival.
- Full Text:
- Date Issued: 2011
- Authors: Johnson, Eleanore
- Date: 2011
- Subjects: Ondaatje, Michael, 1943- The English patient Ghosh, Amitav. The hungry tide Malouf, David, 1934- An imaginary life Stockenström, Wilma. The expedition to the Baobab tree Ecocriticism Human ecology in literature Nature in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2234 , http://hdl.handle.net/10962/d1002277
- Description: This thesis explores the thematic desire to establish an ecological human bond with nature in four contemporary novels: The English Patient by Michael Ondaatje, The Hungry Tide by Amitav Ghosh, An Imaginary Life by David Malouf, and The Expedition to The Baobab Tree by Wilma Stockenström. These authors share a concern with the influence that language has on human perception, and one of the most significant ways they attempt to connect with the natural world is through somehow escaping, or transcending, what they perceive to be the divisive tendencies of language. They all suggest that human perception is not steered entirely by a disembodied mind, which constructs reality through linguistic and cultural lenses, but is equally influenced by physical circumstances and embodied experiences. They explore the potential of corporeal reciprocity and empathy as that which enables understanding across cultural barriers, and a sense of ecologically intertwined kinship with nature. They all struggle to reconcile their awareness of the potential danger of relating to nature exclusively through language, with a desire to speak for the natural world in literature. I have examined whether they succeed in doing so, or whether they contradict their thematic suspicion of language with their literary medium. I have prioritised a close ecocritical reading of the novels and loosely situated the authors’ approach to nature and language within the broad theoretical frameworks of radical ecology, structuralism and poststructuralism. I suggest that these novels are best analysed in the context of an ecocritical mediation between poststructuralist conceptions of nature as inaccessible cultural construct, and the naïve conception of unmediated, pre-reflective interaction with the natural world. I draw especially on the phenomenological theories of Maurice Merleau-Ponty, whose insistence that perception is always both embodied and culturally mediated truly renders culture and nature irreducible, intertwined categories. By challenging historical dualisms like mind/body and culture/nature, the selected novels suggest a more fluid and discursive understanding of the perceived conflict between language and nature, whilst problematizing the perception of language as merely a cultural artefact. Moreover, they are examples of the kind of literature that has the potential to positively influence our human conception of nature, and adapt us better to our ecological context on a planet struggling for survival.
- Full Text:
- Date Issued: 2011
After Baines
- Walters, John Attwood Vereker
- Authors: Walters, John Attwood Vereker
- Date: 2011
- Subjects: Baines, Thomas, 1820-1875 Baines, Thomas, 1820-1875 -- Biography Painting, South African -- Exhibitions Painters -- South Africa -- Biography
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2432 , http://hdl.handle.net/10962/d1004368
- Description: By researching the life and work of Thomas Baines (1820 - 1875) in relation to a broader discourse of painting and the lived experience of being a 'white' male in a post-apartheid South Africa, I explore the ways in which this figure from the past has provoked the three series of artworks I have produced for my Master of Fine Art exhibition. This study has been divided into two parts, represented by the two chapters contained herein. Chapter One includes a critical retelling of Baines' biography and a discussion of the primary ways in which I have engaged with both the life and the working practice of this artist. I also address my own personal complicity in the constructions of 'the figure of Baines' as I have framed him both visually and textually during my work for this degree. Chapter Two describes some of the practicalities of my working process as a visual artist, including how I understand the theoretical and conceptual concerns which I raise in Chapter One to be visually manifest in my work. In this chapter, I also discuss my work in relation to the work of the contemporary South African artists William Kentridge and Johannes Phokela. The artistic practice of one artist imitating another artist's work is also explored as a central conceptual thread which could be seen to weave my verbal and visual production together.
- Full Text:
- Date Issued: 2011
- Authors: Walters, John Attwood Vereker
- Date: 2011
- Subjects: Baines, Thomas, 1820-1875 Baines, Thomas, 1820-1875 -- Biography Painting, South African -- Exhibitions Painters -- South Africa -- Biography
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2432 , http://hdl.handle.net/10962/d1004368
- Description: By researching the life and work of Thomas Baines (1820 - 1875) in relation to a broader discourse of painting and the lived experience of being a 'white' male in a post-apartheid South Africa, I explore the ways in which this figure from the past has provoked the three series of artworks I have produced for my Master of Fine Art exhibition. This study has been divided into two parts, represented by the two chapters contained herein. Chapter One includes a critical retelling of Baines' biography and a discussion of the primary ways in which I have engaged with both the life and the working practice of this artist. I also address my own personal complicity in the constructions of 'the figure of Baines' as I have framed him both visually and textually during my work for this degree. Chapter Two describes some of the practicalities of my working process as a visual artist, including how I understand the theoretical and conceptual concerns which I raise in Chapter One to be visually manifest in my work. In this chapter, I also discuss my work in relation to the work of the contemporary South African artists William Kentridge and Johannes Phokela. The artistic practice of one artist imitating another artist's work is also explored as a central conceptual thread which could be seen to weave my verbal and visual production together.
- Full Text:
- Date Issued: 2011
How an eco-school sanitation community of practice fosters action competence for sanitation management in a rural school : the case of Ramashobohle High School Eco-Schools Community of Practice in Mankweng circuit Polokwane Municipality Capricorn district in Limpopo Province, South Africa
- Authors: Manaka, Ngoanamoshala Maria
- Date: 2011
- Subjects: Sanitation -- South Africa -- Management -- Citizen participation Public utilities -- South Africa -- Management -- Citizen participation Sanitation, Rural -- South Africa Sanitation -- Study and teaching -- South Africa School children -- Health and hygiene -- South Africa School hygiene -- South Africa Sanitation -- Health aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1917 , http://hdl.handle.net/10962/d1007319
- Description: Providing adequate sanitation facilities for the poor remains one of the major challenges in all developing countries. In South Africa, an estimated 11,7% of the schools are without sanitation. The South African government has a constitutional responsibility to ensure that all South Africans have access to adequate sanitation. When sanitation systems fail, or are inadequate, the impact of the health of the community, on the health of others and the negative impact on the environment can be extremely serious. In rural South African schools, many Enviro-Ioo toilets are available today. They are designed to suit a variety of water scarce areas and where there is a high risk of contamination of ground water resources. It is important to realize that any Enviro-Ioo system programme requires an education programme to ensure that the principles of use and maintenance are clearly understood by the user group. Their maintenance requires more responsibility and commitment by users. This study is an interpretive case study that indicates how sanitation in a rural Ramashobohle High School in Polokwane municipality was managed through an EcoSchools Sanitation Community of Practice, and how this developed action competence for sanitation management in the school. The study established that the earlier practice and knowledge of the Ramashobohle Eco-Schools community of practice exercised in maintaining Enviro-Ioo systems was inadequate; unhealthy and unsafe according to the data generated through focus group interviews, observations, interviews, action plan, workshops and reflection interviews. The data generated also indicates that the Eco-Schools community of practice was not committed to maintaining sanitation in their school because they were not sharing sanitation knowledge; they were not communicating and not updating one another concerning Enviro-Ioo systems maintenance as they had no adequate knowledge as to how to maintain the facilities; and the school management was also not supportive and was not taking responsibility. The study shows how this situation was turned around as an Eco-Schools Sanitation Community of Practice focussed on developing action competence in the school community. It provides a case based example of how knowledge and action competence, supported by an Eco-Schools Community of Practice, can find and implement solutions to inadequate sanitation management practices in rural schools, and shows how members of the school community can be engaged in learning how to manage and maintain school sanitation systems through a participatory process that develops action competence. The study points to important dimensions of developing action competence, such as providing knowledge and demonstrations, inviting experts to the school, involving learners in observations and monitoring and in ensuring that adequate facilities are available. In particular, a workshop conducted by Enviro-Ioo consultants, organised and supported by the Eco-Schools Sanitation COP, together with a follow up action plan, provided the main impetus for changes in practice in the school and served to support action competence development. Finally the study provides research findings and recommendations for further research.
- Full Text:
- Date Issued: 2011
- Authors: Manaka, Ngoanamoshala Maria
- Date: 2011
- Subjects: Sanitation -- South Africa -- Management -- Citizen participation Public utilities -- South Africa -- Management -- Citizen participation Sanitation, Rural -- South Africa Sanitation -- Study and teaching -- South Africa School children -- Health and hygiene -- South Africa School hygiene -- South Africa Sanitation -- Health aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1917 , http://hdl.handle.net/10962/d1007319
- Description: Providing adequate sanitation facilities for the poor remains one of the major challenges in all developing countries. In South Africa, an estimated 11,7% of the schools are without sanitation. The South African government has a constitutional responsibility to ensure that all South Africans have access to adequate sanitation. When sanitation systems fail, or are inadequate, the impact of the health of the community, on the health of others and the negative impact on the environment can be extremely serious. In rural South African schools, many Enviro-Ioo toilets are available today. They are designed to suit a variety of water scarce areas and where there is a high risk of contamination of ground water resources. It is important to realize that any Enviro-Ioo system programme requires an education programme to ensure that the principles of use and maintenance are clearly understood by the user group. Their maintenance requires more responsibility and commitment by users. This study is an interpretive case study that indicates how sanitation in a rural Ramashobohle High School in Polokwane municipality was managed through an EcoSchools Sanitation Community of Practice, and how this developed action competence for sanitation management in the school. The study established that the earlier practice and knowledge of the Ramashobohle Eco-Schools community of practice exercised in maintaining Enviro-Ioo systems was inadequate; unhealthy and unsafe according to the data generated through focus group interviews, observations, interviews, action plan, workshops and reflection interviews. The data generated also indicates that the Eco-Schools community of practice was not committed to maintaining sanitation in their school because they were not sharing sanitation knowledge; they were not communicating and not updating one another concerning Enviro-Ioo systems maintenance as they had no adequate knowledge as to how to maintain the facilities; and the school management was also not supportive and was not taking responsibility. The study shows how this situation was turned around as an Eco-Schools Sanitation Community of Practice focussed on developing action competence in the school community. It provides a case based example of how knowledge and action competence, supported by an Eco-Schools Community of Practice, can find and implement solutions to inadequate sanitation management practices in rural schools, and shows how members of the school community can be engaged in learning how to manage and maintain school sanitation systems through a participatory process that develops action competence. The study points to important dimensions of developing action competence, such as providing knowledge and demonstrations, inviting experts to the school, involving learners in observations and monitoring and in ensuring that adequate facilities are available. In particular, a workshop conducted by Enviro-Ioo consultants, organised and supported by the Eco-Schools Sanitation COP, together with a follow up action plan, provided the main impetus for changes in practice in the school and served to support action competence development. Finally the study provides research findings and recommendations for further research.
- Full Text:
- Date Issued: 2011
Testing the existence and direction of "spill-over" of mussel recruits beyond the boundaries of marine protected areas
- Authors: Ludford, Adam
- Date: 2011
- Subjects: Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5786 , http://hdl.handle.net/10962/d1005474 , Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Description: Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.
- Full Text:
- Date Issued: 2011
- Authors: Ludford, Adam
- Date: 2011
- Subjects: Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5786 , http://hdl.handle.net/10962/d1005474 , Marine parks and reserves -- South Africa -- Transkei , Marine resources conservation -- South Africa -- Transkei , Mussels -- Ecology -- South Africa -- Transkei , Mexilhao mussel -- Reproduction -- South Africa -- Transkei , Mexilhao mussel -- Behavior -- South Africa -- Transkei
- Description: Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.
- Full Text:
- Date Issued: 2011
Identifying the interdependence between South Africa's monetary policy and the stock market
- Authors: Muroyiwa, Brian
- Date: 2011
- Subjects: Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:982 , http://hdl.handle.net/10962/d1002716 , Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Description: This study estimates the interdependence between South Africa‟s monetary policy and stock market performance, utilising structural vector autoregression (SVAR) methodology. The study finds that a stock price shock which decrease stock prices by 100 basis points leads to 5 basis points decrease in interbank rate. A monetary policy shock that increases the interbank rate by l percent leads to decrease in real stock prices by 1 percent. This result for South Africa is similar to the result by Bjornland and Leteimo (2009) which earlier concluded that there was a high interdependence between interest rate setting and stock prices. However the magnitude of the relationship is relatively lower for South Africa compared to that of the United States of America (USA). The result of the current study is also very much consistent with the argument that the South African stock market is resource-based and so is influenced by external shocks, meaning monetary policy shock does not have as much impact on stock market in South Africa as in the USA. However the SARB may have to consider watching movements in stock prices so that booms in stock markets do not defeat central bank monetary policy thrusts. The stock price market is an essential source of information for monetary policy in South Africa.
- Full Text:
- Date Issued: 2011
- Authors: Muroyiwa, Brian
- Date: 2011
- Subjects: Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:982 , http://hdl.handle.net/10962/d1002716 , Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Description: This study estimates the interdependence between South Africa‟s monetary policy and stock market performance, utilising structural vector autoregression (SVAR) methodology. The study finds that a stock price shock which decrease stock prices by 100 basis points leads to 5 basis points decrease in interbank rate. A monetary policy shock that increases the interbank rate by l percent leads to decrease in real stock prices by 1 percent. This result for South Africa is similar to the result by Bjornland and Leteimo (2009) which earlier concluded that there was a high interdependence between interest rate setting and stock prices. However the magnitude of the relationship is relatively lower for South Africa compared to that of the United States of America (USA). The result of the current study is also very much consistent with the argument that the South African stock market is resource-based and so is influenced by external shocks, meaning monetary policy shock does not have as much impact on stock market in South Africa as in the USA. However the SARB may have to consider watching movements in stock prices so that booms in stock markets do not defeat central bank monetary policy thrusts. The stock price market is an essential source of information for monetary policy in South Africa.
- Full Text:
- Date Issued: 2011
Exploring opportunities for action competence development through learners' participation in waste management activities in selected primary schools in Botswana
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
Negotiating the global : how young women in Nairobi shape their local identities in response to aspects of the mexican telenovela, Cuando seas mia
- Authors: Jiwaji, Aamera Hamzaali
- Date: 2011 , 2010-09-15
- Subjects: Cuando seas mia (Television program) , Television soap operas -- Kenya , Motion pictures and youth -- Kenya , Emigration and immigration in motion pictures -- Kenya , Ethnicity in motion pictures -- Kenya , Arts and society -- Kenya
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3532 , http://hdl.handle.net/10962/d1013364
- Description: Latin American telenovelas have been exported to more than a hundred countries across the globe. While they are popular in their country of production because their messages resonate with their audience’s everyday experiences, their popularity amongst global audiences with whom they share neither a social nor a cultural history is unexplained. Kenya has been importing and airing Latin American telenovelas since the early 1990s, and telenovelas have permeated many aspects of Kenyan daily life, when compared to other foreign globally-distributed media products that are aired on Kenyan television. As global media products, telenovelas remain open to criticisms from the media imperialism thesis. This research adopts an ethnographic approach to the study of audiences, and looks at the reception of a Mexican telenovela, Cuando Seas Mia, by a group of young Kenyan women in Nairobi. It reflects upon the media imperialism thesis from an African perspective by investigating the meanings that these women make from Cuando Seas Mia, and how these shape their changing local identities and cultures. The young women in this study, most of whom have moved to the city from the rural areas, are influenced by traditional, patriarchal Kenyan society and by the modern, Western influences of an urban environment. They experience a tension between their evolving rural and urban roles and identities and are drawn to telenovelas because their exploration of rural-urban themes holds a relevance to their own lives. They negotiate their contemporary African youth identities, gender roles and heterosexual relationships in relation to representations in the telenovela, questioning and destabilising African and Western definitions. These women select aspects from their traditional, African cultures and from their modern, Western experiences (and consumption of global media) and reconstruct them into a transitional youth identity which suits their day to day lives as young women living in an urban African environment.
- Full Text:
- Date Issued: 2011
- Authors: Jiwaji, Aamera Hamzaali
- Date: 2011 , 2010-09-15
- Subjects: Cuando seas mia (Television program) , Television soap operas -- Kenya , Motion pictures and youth -- Kenya , Emigration and immigration in motion pictures -- Kenya , Ethnicity in motion pictures -- Kenya , Arts and society -- Kenya
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3532 , http://hdl.handle.net/10962/d1013364
- Description: Latin American telenovelas have been exported to more than a hundred countries across the globe. While they are popular in their country of production because their messages resonate with their audience’s everyday experiences, their popularity amongst global audiences with whom they share neither a social nor a cultural history is unexplained. Kenya has been importing and airing Latin American telenovelas since the early 1990s, and telenovelas have permeated many aspects of Kenyan daily life, when compared to other foreign globally-distributed media products that are aired on Kenyan television. As global media products, telenovelas remain open to criticisms from the media imperialism thesis. This research adopts an ethnographic approach to the study of audiences, and looks at the reception of a Mexican telenovela, Cuando Seas Mia, by a group of young Kenyan women in Nairobi. It reflects upon the media imperialism thesis from an African perspective by investigating the meanings that these women make from Cuando Seas Mia, and how these shape their changing local identities and cultures. The young women in this study, most of whom have moved to the city from the rural areas, are influenced by traditional, patriarchal Kenyan society and by the modern, Western influences of an urban environment. They experience a tension between their evolving rural and urban roles and identities and are drawn to telenovelas because their exploration of rural-urban themes holds a relevance to their own lives. They negotiate their contemporary African youth identities, gender roles and heterosexual relationships in relation to representations in the telenovela, questioning and destabilising African and Western definitions. These women select aspects from their traditional, African cultures and from their modern, Western experiences (and consumption of global media) and reconstruct them into a transitional youth identity which suits their day to day lives as young women living in an urban African environment.
- Full Text:
- Date Issued: 2011
An investigation into the state-of-practice of information security within Zambian copper mines: a case study
- Authors: Lukweza, Chishala
- Date: 2011
- Subjects: Computer security -- Zambia -- Management Case studies , Computer networks -- Security measures -- Zambia Case studies , Copper mines and mining -- Computer networks -- Security measures -- Zambia Case studies , Information technology -- Zambia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1146 , http://hdl.handle.net/10962/d1002776 , Computer security -- Zambia -- Management Case studies , Computer networks -- Security measures -- Zambia Case studies , Copper mines and mining -- Computer networks -- Security measures -- Zambia Case studies , Information technology -- Zambia
- Description: Zambian copper mines have embraced the use of information technologies for strategic operations and competitive advantage. This dependence on these technologies has not only been seen in the physical aspects of business operations but also in the use of information systems such as Enterprise Resource Planning Systems (ERPs) for strategic decision making and increased usage of Industrial Control Systems (ICS’) that are meant to enhance operational efficiency in production areas. A survey was conducted to explore leadership perceptions on information security practices in Zambian copper mines and an ISO/IEC 27002 Audit Tool was administered to middle management in a particular mine for an in-depth analysis of their information security practices. Results revealed that although information security controls may have been put in place in these organisations, there are still areas that require attention. Senior management and middle management have different perceptions as to the extent to which information security practices are conducted in these copper mines. This implies that management may not be fully involved in certain aspects of these organisations’ information security practices. The results concluded that management needs to be fully involved and provide support for information security programs. Furthermore, these information security programs should be standardised so as to effectively protect these organisations’ information assets. This should also include the involvement of personnel as key players in the information security process.
- Full Text:
- Date Issued: 2011
- Authors: Lukweza, Chishala
- Date: 2011
- Subjects: Computer security -- Zambia -- Management Case studies , Computer networks -- Security measures -- Zambia Case studies , Copper mines and mining -- Computer networks -- Security measures -- Zambia Case studies , Information technology -- Zambia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1146 , http://hdl.handle.net/10962/d1002776 , Computer security -- Zambia -- Management Case studies , Computer networks -- Security measures -- Zambia Case studies , Copper mines and mining -- Computer networks -- Security measures -- Zambia Case studies , Information technology -- Zambia
- Description: Zambian copper mines have embraced the use of information technologies for strategic operations and competitive advantage. This dependence on these technologies has not only been seen in the physical aspects of business operations but also in the use of information systems such as Enterprise Resource Planning Systems (ERPs) for strategic decision making and increased usage of Industrial Control Systems (ICS’) that are meant to enhance operational efficiency in production areas. A survey was conducted to explore leadership perceptions on information security practices in Zambian copper mines and an ISO/IEC 27002 Audit Tool was administered to middle management in a particular mine for an in-depth analysis of their information security practices. Results revealed that although information security controls may have been put in place in these organisations, there are still areas that require attention. Senior management and middle management have different perceptions as to the extent to which information security practices are conducted in these copper mines. This implies that management may not be fully involved in certain aspects of these organisations’ information security practices. The results concluded that management needs to be fully involved and provide support for information security programs. Furthermore, these information security programs should be standardised so as to effectively protect these organisations’ information assets. This should also include the involvement of personnel as key players in the information security process.
- Full Text:
- Date Issued: 2011
An analysis of the influence of domestic macroeconomic variables on the performance of the South African stock market sectoral indices
- Authors: Hancocks, Ryan Lee
- Date: 2011
- Subjects: Johannesburg Stock Exchange , Stock price indexes -- South Africa , Interest rates -- South Africa , Macroeconomics -- Econometric models
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:954
- Description: An econometric study was undertaken to determine the extent to which selected macroeconomic variables influenced stock market prices on the All-Share, Financial, Mining and Retail Indices of the Johannesburg Stock Exchange in South Africa from 1996:7 to 2008:12. The Johansen cointegration method was used to determine whether cointegrating relationships existed between the macroeconomic variables and the stock market indices. A Vector Error Correction model was estimated and found significant results that money supply, inflation, long and short- run interest rates, and the exchange rate all had an influence on stock market prices. Further, the VECM results for each sector indicated that certain macroeconomic variables had differing influences on each sector of the stock market. Impulse Response tests indicated that the selected macroeconomic variables caused shock to the sectoral indices in the short-run but that the effect was lagged. The Variance Decomposition tests conducted supported earlier evidence that the macroeconomic variables had a strong level of sectoral index determinacy in the long run. The results found that the All-Share and Financial Indices were negatively influenced by inflation and short term interest rates in the long run, while the Financial Index also had a negative relationship with long-run interest rates. Money supply was found to have a positive effect on all the indices. A weakening of the exchange rate was found to have a positive influence on both the Retail and Mining Indices, while it negatively affected the All-Share and Financial Indices. The long-run interest rate had a positive influence on both the Retail and Mining Indices. Overall the study finds that macroeconomic variables are important determinants of stock market prices in South Africa and that it is important to examine each sector of the stock market separately to capture what are different effects. The limitations of the study are that a different measure for exchange rates from the nominal rand/dollar exchange rate used here may yield more decisive results and provide insight into the link between exchange rate behaviour and performance of especially the retail sector.
- Full Text:
- Date Issued: 2011
- Authors: Hancocks, Ryan Lee
- Date: 2011
- Subjects: Johannesburg Stock Exchange , Stock price indexes -- South Africa , Interest rates -- South Africa , Macroeconomics -- Econometric models
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:954
- Description: An econometric study was undertaken to determine the extent to which selected macroeconomic variables influenced stock market prices on the All-Share, Financial, Mining and Retail Indices of the Johannesburg Stock Exchange in South Africa from 1996:7 to 2008:12. The Johansen cointegration method was used to determine whether cointegrating relationships existed between the macroeconomic variables and the stock market indices. A Vector Error Correction model was estimated and found significant results that money supply, inflation, long and short- run interest rates, and the exchange rate all had an influence on stock market prices. Further, the VECM results for each sector indicated that certain macroeconomic variables had differing influences on each sector of the stock market. Impulse Response tests indicated that the selected macroeconomic variables caused shock to the sectoral indices in the short-run but that the effect was lagged. The Variance Decomposition tests conducted supported earlier evidence that the macroeconomic variables had a strong level of sectoral index determinacy in the long run. The results found that the All-Share and Financial Indices were negatively influenced by inflation and short term interest rates in the long run, while the Financial Index also had a negative relationship with long-run interest rates. Money supply was found to have a positive effect on all the indices. A weakening of the exchange rate was found to have a positive influence on both the Retail and Mining Indices, while it negatively affected the All-Share and Financial Indices. The long-run interest rate had a positive influence on both the Retail and Mining Indices. Overall the study finds that macroeconomic variables are important determinants of stock market prices in South Africa and that it is important to examine each sector of the stock market separately to capture what are different effects. The limitations of the study are that a different measure for exchange rates from the nominal rand/dollar exchange rate used here may yield more decisive results and provide insight into the link between exchange rate behaviour and performance of especially the retail sector.
- Full Text:
- Date Issued: 2011
Investigation of photosensitising behaviour of Ni, Pd and Pt phthalocyanines towards phenolic pollutants
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
Emplacement of the 2.44 Ga ultramafic layered Kemi intrusion, Finland PGE, geochemical and Sm-Nd isotopic implications
- Authors: Linkermann, Sean Aaron
- Date: 2011
- Subjects: Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4940 , http://hdl.handle.net/10962/d1005552 , Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Description: Europe’s largest chrome deposit is hosted by the 2.44 Ga Kemi ultramafic layered intrusion. The lower half of the intrusion consists of peridotites, pyroxenites and chromitite layers while the upper half consists of websterites, gabbronorites and leucogabbros. The mafic minerals of the lower and upper parts of the intrusion are altered to serpentine, chlorite, talc, amphiboles and carbonates. However, the original mineralogy is still preserved in the middle part of the intrusion. Earlier work on the Kemi intrusion concentrated mainly on the economically important chromitite layers and suggested that these layers were formed through contamination of a single pulse of primitive magma by underlying Archaean basement crustal material. The broad variations of the major element concentrations reflect variations in the mode of the Kemi rocks. The petrology, which shows olivine- and orthopyroxene-dominated rocks in the lower portion of the intrusion to plagioclase- and clinopyroxene-dominated rocks in the upper portion, shows a gross consistency with a fractional crystallization process.The incompatible elements are relatively enriched in the lower portion of the intrusion which is not consistent with a broad fractional crystallization process. These variations suggest that the ultramafic portion of the KemiIntrusion is relatively enriched in trapped liquid compared to the mafic portion.ε2.44 Nd values ranges from +4 (consistent with depleted mantle source) to -10 (indicating a contribution from Archaean crust). The lower peridotites, pyroxenites and websterites have ε2.44 Nd values ranging between depleted mantle signatures and -2, whereas the gabbroic cumulates have ε2.44 Nd values which cover a range from around -5 to -10. Nd isotopic variation in the lower part of the profile is punctuated by distinct spikes to lower ε2.44 Nd corresponding to the chromitite horizons. Both the lower and upper portions of the Kemi Intrusion show enrichment of LREEC1 relative to HREEC1. The LREEC1 enriched values start to increase markedly from about the 1000 meter mark and continue to increase in value towards the roof of the intrusion.The main enrichment of PGE (ΣPPGE = 55 to 148 ppb) occurs approximately 90 to 160 m above the basal contact, beginning within andcontinuing above the main chromitite ore horizon. The mantle-normalized PGE abundances of the main chromitite horizon and the peridotites and pyroxenites below it show enrichment of IPGEPM (Os + Ir + Ru) relative to PPGEPM (Rh + Pd + Pt). In contrast, the overlying rocks are characterised by enrichment of PPGEPM relative to IPGEPM. These PGE-patterns suggest the influence of two distinct controlling processes above and below the main chromitite reef.The isotopic data are consistent with the initial introduction of multiple pulses of depleted mantle-derived magma crystallising olivine and pyroxene. Before the parent magma was fed into the Kemi magma chamber, it underwent crustal contamination and assimilation in a staging chamber within the lower crust. Some of these pulses were “critically crustally contaminated”, inducing chromite saturation and precipitation. The modelling also predicts minor in-situ contamination of the parent magma in the Kemi chamber with its wall and roof rocks. Above the main chromitite layer (about 160 m above the basal contact), the chromite content decreases and the PPGEPM/IPGEPM values increase which is consistent with scavenging of the IPGE into the lowermost layers and/or evolving magma compositions. Above 1000 m, the isotopic and REE data indicate a new magma pulse which has also been extensively contaminated in the staging magma chamber before emplacement into the Kemi magma chamber. The contamination in the staging magma chamber increased which is reflected in a progressively larger crustal component towards the top of the Kemi Intrusion
- Full Text:
- Date Issued: 2011
- Authors: Linkermann, Sean Aaron
- Date: 2011
- Subjects: Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4940 , http://hdl.handle.net/10962/d1005552 , Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Description: Europe’s largest chrome deposit is hosted by the 2.44 Ga Kemi ultramafic layered intrusion. The lower half of the intrusion consists of peridotites, pyroxenites and chromitite layers while the upper half consists of websterites, gabbronorites and leucogabbros. The mafic minerals of the lower and upper parts of the intrusion are altered to serpentine, chlorite, talc, amphiboles and carbonates. However, the original mineralogy is still preserved in the middle part of the intrusion. Earlier work on the Kemi intrusion concentrated mainly on the economically important chromitite layers and suggested that these layers were formed through contamination of a single pulse of primitive magma by underlying Archaean basement crustal material. The broad variations of the major element concentrations reflect variations in the mode of the Kemi rocks. The petrology, which shows olivine- and orthopyroxene-dominated rocks in the lower portion of the intrusion to plagioclase- and clinopyroxene-dominated rocks in the upper portion, shows a gross consistency with a fractional crystallization process.The incompatible elements are relatively enriched in the lower portion of the intrusion which is not consistent with a broad fractional crystallization process. These variations suggest that the ultramafic portion of the KemiIntrusion is relatively enriched in trapped liquid compared to the mafic portion.ε2.44 Nd values ranges from +4 (consistent with depleted mantle source) to -10 (indicating a contribution from Archaean crust). The lower peridotites, pyroxenites and websterites have ε2.44 Nd values ranging between depleted mantle signatures and -2, whereas the gabbroic cumulates have ε2.44 Nd values which cover a range from around -5 to -10. Nd isotopic variation in the lower part of the profile is punctuated by distinct spikes to lower ε2.44 Nd corresponding to the chromitite horizons. Both the lower and upper portions of the Kemi Intrusion show enrichment of LREEC1 relative to HREEC1. The LREEC1 enriched values start to increase markedly from about the 1000 meter mark and continue to increase in value towards the roof of the intrusion.The main enrichment of PGE (ΣPPGE = 55 to 148 ppb) occurs approximately 90 to 160 m above the basal contact, beginning within andcontinuing above the main chromitite ore horizon. The mantle-normalized PGE abundances of the main chromitite horizon and the peridotites and pyroxenites below it show enrichment of IPGEPM (Os + Ir + Ru) relative to PPGEPM (Rh + Pd + Pt). In contrast, the overlying rocks are characterised by enrichment of PPGEPM relative to IPGEPM. These PGE-patterns suggest the influence of two distinct controlling processes above and below the main chromitite reef.The isotopic data are consistent with the initial introduction of multiple pulses of depleted mantle-derived magma crystallising olivine and pyroxene. Before the parent magma was fed into the Kemi magma chamber, it underwent crustal contamination and assimilation in a staging chamber within the lower crust. Some of these pulses were “critically crustally contaminated”, inducing chromite saturation and precipitation. The modelling also predicts minor in-situ contamination of the parent magma in the Kemi chamber with its wall and roof rocks. Above the main chromitite layer (about 160 m above the basal contact), the chromite content decreases and the PPGEPM/IPGEPM values increase which is consistent with scavenging of the IPGE into the lowermost layers and/or evolving magma compositions. Above 1000 m, the isotopic and REE data indicate a new magma pulse which has also been extensively contaminated in the staging magma chamber before emplacement into the Kemi magma chamber. The contamination in the staging magma chamber increased which is reflected in a progressively larger crustal component towards the top of the Kemi Intrusion
- Full Text:
- Date Issued: 2011
The role of Hsp90 in the Wnt pathway of MCF7 breast cancer cells
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
The effect of sewage effluent from De Beers marine diamond mining operations on the expression of cytochrome P450 (CYP1A) and vitellogenin (vtg)
- Authors: De Almeida, Louise
- Date: 2013-09-20
- Subjects: De Beers Consolidated Mines , Sewage disposal in rivers, lakes, etc. -- Namibia , Endocrine disrupting chemicals in water -- Namibia , Merluccius capensis -- Namibia , Merluccius -- Namibia , Water -- Pollution -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4096 , http://hdl.handle.net/10962/d1009440 , De Beers Consolidated Mines , Sewage disposal in rivers, lakes, etc. -- Namibia , Endocrine disrupting chemicals in water -- Namibia , Merluccius capensis -- Namibia , Merluccius -- Namibia , Water -- Pollution -- Namibia
- Description: Sewage effluents disposed into the marine environment from De Beers Marine Namibia diamond mining vessels have the potential to cause endocrine disruptive effects in marine organisms. Endocrine disruption refers to the alteration of the normal functioning of the endocrine system and various chemicals have the ability to mimic hormones, effecting endogenous hormone synthesis, transport, receptor interaction and intracellular signaling. The potential endocrine disruptive effects, caused by the release of different types of sewage effluents into the ocean, on fish species is a concern due to the commercial importance of fish species found in the mining area e.g. hake, sole, horse mackerel. Increased awareness of marine environmental degradation due to the presence of chemical contaminants has resulted in research being done on early warning systems, in the form of biomarkers. Cytochrome P450 monooxygenase 1A (CYP1A) and vitellogenin (vtg) are important proteins found in fish liver and blood, that have been used as biomarkers for the detection of pollutants in fish. CYP1A is a subfamily of the P450 superfamily of enzymes and catalyzes the oxidation, hydrolysis and reduction of exogenous and endogenous compounds (phase I reactions) and thus has the capacity to regulate the metabolism of several organic contaminants. CYP1A expression is altered by exposure to planar xenobiotic compounds e.g. polyaromatic hydrocarbons. Vtg is an important precursor for egg yolk proteins and plays a role in the growth and development of an oocyte. Expression of this protein is altered upon exposure to estrogenic compounds. The aim of this project was to isolate CYP1A from fish liver by differential centrifugation and optimize conditions for the CYP1A-mediated ethoxyresorufin-Odeethylase (EROD) assay and western blot analysis (to assess CYP1A expression). Another aim of this study was to evaluate the potential effects of biologically disruptive chemicals from sewage effluents, discharged into the marine environment, on the expression of CYP1A in two species of hake, Merluccius capensis and M. paradoxus (Cape hake). CYP1A in Cape hake is approximately a 60 kDa protein and the highest EROD activity was detected in the microsomal fraction after differential centrifugation. Optimal EROD assay conditions were observed at pH 7.5, a temperature of 25 °C, 10 μl of sample and a reaction time of 30 seconds. Enzyme stability assays indicated a drastic decrease in enzyme activity after 30 seconds. The EROD assay was not NADPH dependent but was limited by NADPH supply, with an increase of 300% in EROD activity being observed with the addition of 0.1 M exogenous NADPH. The addition of dicumarol (40 μM), a phase II enzyme inhibitor, showed a 232% increase in EROD activity. This is because dicumarol inhibited enzymes with the capacity to metabolize the product (resorufin) of the EROD reaction. With regard to western blot analysis, the optimal primary (rabbit antifish CYP1A peptide) and secondary (anti-mouse/rabbit antibody-horseradish peroxidase conjugate (POD)) antibody dilutions were determined to be 1:1000 and 1:5000, respectively. The comparison of CYP1A expression in Cape hake samples from De Beers Marine mining area and reference sites showed higher EROD activity (16.29 ± 0.91 pmol/min) in fish samples from the mining area in comparison to the reference site (10.42 ± 2.65 pmol/min). Western blot analysis was in agreement with the EROD assay results and a higher CYP1A expression was observed in fish from the mining sites. The increased CYP1A expression observed in fish from the mining area is not definitively an indication of a pollutant effect in the environment, as several environmental and biological factors (e.g. photoperiod and age) must also be considered before reaching this conclusion. Another aim of this study was to purify vtg from Cape hake blood samples. Cape hake vtg was purified from fish plasma by selective precipitation with MgCl2 and EDTA. Precipitated sample was subjected to anion exchange chromatography using fast protein liquid chromatography (FPLC). Vtg eluted as two broad peaks and had a molecular weight above 200 kDa. SDS-PAGE analysis also resolved smaller molecular weight proteins below 70 kDa, which were thought to be vitellogenin cleavage proteins, lipovitellin and phosphovitins. Western blot analysis was performed; however, it did not produce any conclusive results. The purification of vtg enables further studies in characterizing this protein and developing assay aimed at detecting estrogenic pollutants in the marine environment
- Full Text:
- Authors: De Almeida, Louise
- Date: 2013-09-20
- Subjects: De Beers Consolidated Mines , Sewage disposal in rivers, lakes, etc. -- Namibia , Endocrine disrupting chemicals in water -- Namibia , Merluccius capensis -- Namibia , Merluccius -- Namibia , Water -- Pollution -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4096 , http://hdl.handle.net/10962/d1009440 , De Beers Consolidated Mines , Sewage disposal in rivers, lakes, etc. -- Namibia , Endocrine disrupting chemicals in water -- Namibia , Merluccius capensis -- Namibia , Merluccius -- Namibia , Water -- Pollution -- Namibia
- Description: Sewage effluents disposed into the marine environment from De Beers Marine Namibia diamond mining vessels have the potential to cause endocrine disruptive effects in marine organisms. Endocrine disruption refers to the alteration of the normal functioning of the endocrine system and various chemicals have the ability to mimic hormones, effecting endogenous hormone synthesis, transport, receptor interaction and intracellular signaling. The potential endocrine disruptive effects, caused by the release of different types of sewage effluents into the ocean, on fish species is a concern due to the commercial importance of fish species found in the mining area e.g. hake, sole, horse mackerel. Increased awareness of marine environmental degradation due to the presence of chemical contaminants has resulted in research being done on early warning systems, in the form of biomarkers. Cytochrome P450 monooxygenase 1A (CYP1A) and vitellogenin (vtg) are important proteins found in fish liver and blood, that have been used as biomarkers for the detection of pollutants in fish. CYP1A is a subfamily of the P450 superfamily of enzymes and catalyzes the oxidation, hydrolysis and reduction of exogenous and endogenous compounds (phase I reactions) and thus has the capacity to regulate the metabolism of several organic contaminants. CYP1A expression is altered by exposure to planar xenobiotic compounds e.g. polyaromatic hydrocarbons. Vtg is an important precursor for egg yolk proteins and plays a role in the growth and development of an oocyte. Expression of this protein is altered upon exposure to estrogenic compounds. The aim of this project was to isolate CYP1A from fish liver by differential centrifugation and optimize conditions for the CYP1A-mediated ethoxyresorufin-Odeethylase (EROD) assay and western blot analysis (to assess CYP1A expression). Another aim of this study was to evaluate the potential effects of biologically disruptive chemicals from sewage effluents, discharged into the marine environment, on the expression of CYP1A in two species of hake, Merluccius capensis and M. paradoxus (Cape hake). CYP1A in Cape hake is approximately a 60 kDa protein and the highest EROD activity was detected in the microsomal fraction after differential centrifugation. Optimal EROD assay conditions were observed at pH 7.5, a temperature of 25 °C, 10 μl of sample and a reaction time of 30 seconds. Enzyme stability assays indicated a drastic decrease in enzyme activity after 30 seconds. The EROD assay was not NADPH dependent but was limited by NADPH supply, with an increase of 300% in EROD activity being observed with the addition of 0.1 M exogenous NADPH. The addition of dicumarol (40 μM), a phase II enzyme inhibitor, showed a 232% increase in EROD activity. This is because dicumarol inhibited enzymes with the capacity to metabolize the product (resorufin) of the EROD reaction. With regard to western blot analysis, the optimal primary (rabbit antifish CYP1A peptide) and secondary (anti-mouse/rabbit antibody-horseradish peroxidase conjugate (POD)) antibody dilutions were determined to be 1:1000 and 1:5000, respectively. The comparison of CYP1A expression in Cape hake samples from De Beers Marine mining area and reference sites showed higher EROD activity (16.29 ± 0.91 pmol/min) in fish samples from the mining area in comparison to the reference site (10.42 ± 2.65 pmol/min). Western blot analysis was in agreement with the EROD assay results and a higher CYP1A expression was observed in fish from the mining sites. The increased CYP1A expression observed in fish from the mining area is not definitively an indication of a pollutant effect in the environment, as several environmental and biological factors (e.g. photoperiod and age) must also be considered before reaching this conclusion. Another aim of this study was to purify vtg from Cape hake blood samples. Cape hake vtg was purified from fish plasma by selective precipitation with MgCl2 and EDTA. Precipitated sample was subjected to anion exchange chromatography using fast protein liquid chromatography (FPLC). Vtg eluted as two broad peaks and had a molecular weight above 200 kDa. SDS-PAGE analysis also resolved smaller molecular weight proteins below 70 kDa, which were thought to be vitellogenin cleavage proteins, lipovitellin and phosphovitins. Western blot analysis was performed; however, it did not produce any conclusive results. The purification of vtg enables further studies in characterizing this protein and developing assay aimed at detecting estrogenic pollutants in the marine environment
- Full Text:
Exploring how teachers acquire content knowledge of marine and coastal issues to contextualize the natural science curriculum
- Authors: Mbuyazwe, Vuyiswa
- Date: 2011
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:21017 , http://hdl.handle.net/10962/6016
- Description: The transformation process in the South African curriculum has highlighted a need for teachers to change from being passive implementers of curriculum. They are required to interpret the curriculum, adapt materials and develop lesson plans that will be responsive in their own context. They are also required to use materials and mediate learning. This research explores teacher acquisition of content knowledge on marine and coastal issues and probes how teachers work with materials in the development of lesson plans to contextualize the curriculum. A participatory action research process engaged 3 teachers in a contextualizing process of curriculum development. I started to work with the teachers to adapt and re-develop coastal and marine resources to support learning in local context. The research developed in two phases. The first examined existing teacher knowledge of marine and coastal issues and probed how content was integrated into lesson planning. Teachers identified knowledge acquisition as the priority to enable them to work with the materials and curriculum in their context. The second phase set out to enhance teachers’ knowledge of marine and coastal resources through workshops and field trips to improve the adaptation and use of materials. To document these processes and outcomes in the context of this study, I employed a range of data generation strategies including questionnaires, workshops and classroom observations, field notes, focus group discussion and the review of lesson plans, learners’ work and materials used. All participants collaboratively discussed and reflected on the process, but I was responsible for the final interpretation presented here. This study showed that teachers are still entrenched in their normal practice of working with content as facts and definitions, the delivery of abstract propositions that is not aligned with the curriculum goals. The new curriculum required teachers to change their teaching practice by using materials to mediate learning in context. The data revealed a mismatch between teacher practices and what the curriculum required from them.
- Full Text:
- Date Issued: 2011
- Authors: Mbuyazwe, Vuyiswa
- Date: 2011
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:21017 , http://hdl.handle.net/10962/6016
- Description: The transformation process in the South African curriculum has highlighted a need for teachers to change from being passive implementers of curriculum. They are required to interpret the curriculum, adapt materials and develop lesson plans that will be responsive in their own context. They are also required to use materials and mediate learning. This research explores teacher acquisition of content knowledge on marine and coastal issues and probes how teachers work with materials in the development of lesson plans to contextualize the curriculum. A participatory action research process engaged 3 teachers in a contextualizing process of curriculum development. I started to work with the teachers to adapt and re-develop coastal and marine resources to support learning in local context. The research developed in two phases. The first examined existing teacher knowledge of marine and coastal issues and probed how content was integrated into lesson planning. Teachers identified knowledge acquisition as the priority to enable them to work with the materials and curriculum in their context. The second phase set out to enhance teachers’ knowledge of marine and coastal resources through workshops and field trips to improve the adaptation and use of materials. To document these processes and outcomes in the context of this study, I employed a range of data generation strategies including questionnaires, workshops and classroom observations, field notes, focus group discussion and the review of lesson plans, learners’ work and materials used. All participants collaboratively discussed and reflected on the process, but I was responsible for the final interpretation presented here. This study showed that teachers are still entrenched in their normal practice of working with content as facts and definitions, the delivery of abstract propositions that is not aligned with the curriculum goals. The new curriculum required teachers to change their teaching practice by using materials to mediate learning in context. The data revealed a mismatch between teacher practices and what the curriculum required from them.
- Full Text:
- Date Issued: 2011
Cointegration, causality and international portfolio diversification : investigating potential benefits to a South African investor
- Authors: Msimanga, Nkululeko Lwazi
- Date: 2011
- Subjects: Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:962 , http://hdl.handle.net/10962/d1002696 , Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Description: Research studies on portfolio diversification have tended to focus on developed markets and paid less attention to emerging markets. Traditionally, correlation analysis has been used to determine potential benefits from diversification but current studies have shifted focus from correlation analysis to exploring cointegration analysis and other forms of tests such as the Vector Error Correction Methodology. The research seeks to find if it is beneficial for a South African investor to diversify their portfolio of emerging market equities over a long-term period. Daily weighted share indices for the period of January 1996 to November 2008 were collected and analysed through the application of the Johansen cointegration technique and Vector Error Correction Methodology. Granger Causality tests were also performed to established whether one variable can be useful in forecasting another variable. The study found that there was at least one statistically significant long-run relationship between the emerging markets. After testing for unit roots for all the share indices and their first difference using the Augmented Dickey-Fuller test (ADF), Philips-Perron and Kwiatkowski, Phillips, Schmidt, and Shin (KPSS) unit root tests, similar conclusions were m~de. All the unit root tests and their levels could not be rejected for all the series. However, unit root tests on the first differences were rejected, meaning that all series are of order 1(1) - evidence of cointegration. Simply put, emerging markets tend not to drift apart over time. This suggests that emerging markets offer limited benefits to investors who are looking to add some risk to their portfolios. In addition, the study also found evidence of both unidirectional and bidirectional causality (Granger-Cause tests) between markets. This implies that the conditions for a particular market are exogenous of the other market. The study concludes that emerging markets are gradually adopting the same profile as developed markets.
- Full Text:
- Date Issued: 2011
- Authors: Msimanga, Nkululeko Lwazi
- Date: 2011
- Subjects: Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:962 , http://hdl.handle.net/10962/d1002696 , Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Description: Research studies on portfolio diversification have tended to focus on developed markets and paid less attention to emerging markets. Traditionally, correlation analysis has been used to determine potential benefits from diversification but current studies have shifted focus from correlation analysis to exploring cointegration analysis and other forms of tests such as the Vector Error Correction Methodology. The research seeks to find if it is beneficial for a South African investor to diversify their portfolio of emerging market equities over a long-term period. Daily weighted share indices for the period of January 1996 to November 2008 were collected and analysed through the application of the Johansen cointegration technique and Vector Error Correction Methodology. Granger Causality tests were also performed to established whether one variable can be useful in forecasting another variable. The study found that there was at least one statistically significant long-run relationship between the emerging markets. After testing for unit roots for all the share indices and their first difference using the Augmented Dickey-Fuller test (ADF), Philips-Perron and Kwiatkowski, Phillips, Schmidt, and Shin (KPSS) unit root tests, similar conclusions were m~de. All the unit root tests and their levels could not be rejected for all the series. However, unit root tests on the first differences were rejected, meaning that all series are of order 1(1) - evidence of cointegration. Simply put, emerging markets tend not to drift apart over time. This suggests that emerging markets offer limited benefits to investors who are looking to add some risk to their portfolios. In addition, the study also found evidence of both unidirectional and bidirectional causality (Granger-Cause tests) between markets. This implies that the conditions for a particular market are exogenous of the other market. The study concludes that emerging markets are gradually adopting the same profile as developed markets.
- Full Text:
- Date Issued: 2011
Towards monitoring that makes sense : action research design of a planning, learning and accountability system for a sustainable agriculture programme in Eastern Indonesia
- Authors: Deprez, Stefan Gert Marie
- Date: 2011
- Subjects: Agricultural development projects -- Indonesia Agricultural administration -- Monitoring -- Indonesia Action research -- Case studies Action research in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1801 , http://hdl.handle.net/10962/d1003686
- Description: This study is an account of an action research process to develop a planning, learning and accountability (PLA) system for the sustainable agriculture chain development programme of VECO (Vredeseilanden Country Office) Indonesia. Many monitoring and evaluation (M&E) processes in development programmes are largely carried out to provide information for funding agencies, to meet external accountability requirements and for symbolic protection. This study generates insights into an integrated, learning-oriented monitoring practice which fosters reflective practice, provides feedback to programme stakeholders about performance, progress and results achieved, facilitates improved accountability, and generates information and knowledge useful for the programme stakeholders to take decisions for improved action. It is argued that M&E systems have the potential, if developed well, to serve as a framework or ‘carrier’ for organisational and institutional learning – an essential requirement to respond to the complex nature of development processes. Outcome mapping is presented as a possible approach to be used as the basis for such a M&E system. This study was underpinned by a socially critical orientation to development (programmes) and by an action research method to guide the PLA system design process. The design process was organized around seven steps - which in themselves were a result of the action research process – including specific steps to ensure a learning-oriented M&E system. Based on the agreed purposes and intended uses of the monitoring and learning process, the resulting PLA system is focused around the organizational spaces and rhythms of VECO Indonesia which are central to sharing, debate, learning and decision-making. In this way, the PLA system becomes integral to the thinking and doing of the organization. It is built on the premise that monitoring does not end with gathering data; it also needs to include a process of understanding and deciding how data can best be used and analysed to strengthen concerted action and facilitate decision-making. It highlights the importance of sense-making – interpreting information to make it usable for action. Furthermore, it incorporates an approach to assess and consciously plan for the creation of the necessary organisational conditions to implement and maintain a learning-oriented M&E system. The study is completed by critical reflection on the relevance of VECO’s new PLA system for planning, learning and accountability, combined with the use of a future scenario technique to generate recommendations and identify critical future directions. Further exploration of ‘intelligent’ information-seeking methods and processes is called for; and a practice which moves beyond intra-organisational monitoring – focusing on VECO’s own monitoring needs – towards a monitoring process that facilitates change based on the viewpoints of, and in collaboration with local actors, i.e., institutional monitoring and learning, is recommended. VECO is encouraged to continue developing a mindset and practice whereby the programme team and partners have the ability to leave the safe zone of pre-determined outcomes and actions, and to make sense of the world as they engage in action.
- Full Text:
- Date Issued: 2011
- Authors: Deprez, Stefan Gert Marie
- Date: 2011
- Subjects: Agricultural development projects -- Indonesia Agricultural administration -- Monitoring -- Indonesia Action research -- Case studies Action research in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1801 , http://hdl.handle.net/10962/d1003686
- Description: This study is an account of an action research process to develop a planning, learning and accountability (PLA) system for the sustainable agriculture chain development programme of VECO (Vredeseilanden Country Office) Indonesia. Many monitoring and evaluation (M&E) processes in development programmes are largely carried out to provide information for funding agencies, to meet external accountability requirements and for symbolic protection. This study generates insights into an integrated, learning-oriented monitoring practice which fosters reflective practice, provides feedback to programme stakeholders about performance, progress and results achieved, facilitates improved accountability, and generates information and knowledge useful for the programme stakeholders to take decisions for improved action. It is argued that M&E systems have the potential, if developed well, to serve as a framework or ‘carrier’ for organisational and institutional learning – an essential requirement to respond to the complex nature of development processes. Outcome mapping is presented as a possible approach to be used as the basis for such a M&E system. This study was underpinned by a socially critical orientation to development (programmes) and by an action research method to guide the PLA system design process. The design process was organized around seven steps - which in themselves were a result of the action research process – including specific steps to ensure a learning-oriented M&E system. Based on the agreed purposes and intended uses of the monitoring and learning process, the resulting PLA system is focused around the organizational spaces and rhythms of VECO Indonesia which are central to sharing, debate, learning and decision-making. In this way, the PLA system becomes integral to the thinking and doing of the organization. It is built on the premise that monitoring does not end with gathering data; it also needs to include a process of understanding and deciding how data can best be used and analysed to strengthen concerted action and facilitate decision-making. It highlights the importance of sense-making – interpreting information to make it usable for action. Furthermore, it incorporates an approach to assess and consciously plan for the creation of the necessary organisational conditions to implement and maintain a learning-oriented M&E system. The study is completed by critical reflection on the relevance of VECO’s new PLA system for planning, learning and accountability, combined with the use of a future scenario technique to generate recommendations and identify critical future directions. Further exploration of ‘intelligent’ information-seeking methods and processes is called for; and a practice which moves beyond intra-organisational monitoring – focusing on VECO’s own monitoring needs – towards a monitoring process that facilitates change based on the viewpoints of, and in collaboration with local actors, i.e., institutional monitoring and learning, is recommended. VECO is encouraged to continue developing a mindset and practice whereby the programme team and partners have the ability to leave the safe zone of pre-determined outcomes and actions, and to make sense of the world as they engage in action.
- Full Text:
- Date Issued: 2011
Surface properties and electrocatalytic applications of metallophthalocyanines confined on electrode surfaces
- Authors: Akinbulu, Isaac Adebayo
- Date: 2011
- Subjects: Phthalocyanines Electrochemistry Electrocatalysis Pesticides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4365 , http://hdl.handle.net/10962/d1005030
- Description: New cobalt (13, 16 19 and 22), manganese (14, 17, 20 and 23) and iron (15, 18, 21 and 24)phthalocyanine complexes were synthesized and characterized. The UV-Vis spectral properties of the complexes were typical of the nature of central metal and position of substituent on the Pc ligand. Their electrochemical behaviors were signatures of the central metals, with varying influences of the nature and position of substituents. Nanocomposite of complex 18 and single walled carbon nanotubes (SWCNTs) (SWCNT-18)was fabricated. Formation of this nano-composite was confirmed by infrared (IR)spectroscopy, X-ray diffraction (XRD) spectroscopy and transmission electron microscopy (TEM). Self-assembled monolayers (SAMs) of SWCNT-18, complexes 13-15, and 20 were electropolymerized on glassy carbon electrodes (GCE). Complex 14 was also electrodeposited on GCE. Surface properties of the SAMs were consistent with the molecular feature of the substituent and the nature of central metal in the adsorbed species, while those of the MnPc modified GCEs were dependent on point of substitution and number of substituent. The SAM-modified gold electrodes were used for the electrocatalytic oxidation of the carbamate insecticide, carbofuran. Amplification of the current signal of the insecticide, at more energetically feasible oxidation potentials, on the SAM-modified gold electrodes, relative to bare gold electrode,justified electrocatalysis. There was enhanced sensitivity (attributed to the presence of SWCNT) of the SWCNT-18-SAM-modified gold electrode towards carbofuran, relative to the signals observed on the other SAMs. Current response of the insecticide,bendiocarb, was also intensified, at more favorable oxidation potentials, on the MnPc (14 and 17) modified GCEs, relative to the response on bare GCE, substantiating electrocatalysis. Also, catalysis of the oxidation of the herbicide, bentazon, was observed on polymeric film of complex 20. The current response of the herbicide on this film was better than that observed on bare GCE. Electrocatalysis of the analytes, on the respective modified electrodes, occurred via closely related mechanisms.
- Full Text:
- Date Issued: 2011
- Authors: Akinbulu, Isaac Adebayo
- Date: 2011
- Subjects: Phthalocyanines Electrochemistry Electrocatalysis Pesticides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4365 , http://hdl.handle.net/10962/d1005030
- Description: New cobalt (13, 16 19 and 22), manganese (14, 17, 20 and 23) and iron (15, 18, 21 and 24)phthalocyanine complexes were synthesized and characterized. The UV-Vis spectral properties of the complexes were typical of the nature of central metal and position of substituent on the Pc ligand. Their electrochemical behaviors were signatures of the central metals, with varying influences of the nature and position of substituents. Nanocomposite of complex 18 and single walled carbon nanotubes (SWCNTs) (SWCNT-18)was fabricated. Formation of this nano-composite was confirmed by infrared (IR)spectroscopy, X-ray diffraction (XRD) spectroscopy and transmission electron microscopy (TEM). Self-assembled monolayers (SAMs) of SWCNT-18, complexes 13-15, and 20 were electropolymerized on glassy carbon electrodes (GCE). Complex 14 was also electrodeposited on GCE. Surface properties of the SAMs were consistent with the molecular feature of the substituent and the nature of central metal in the adsorbed species, while those of the MnPc modified GCEs were dependent on point of substitution and number of substituent. The SAM-modified gold electrodes were used for the electrocatalytic oxidation of the carbamate insecticide, carbofuran. Amplification of the current signal of the insecticide, at more energetically feasible oxidation potentials, on the SAM-modified gold electrodes, relative to bare gold electrode,justified electrocatalysis. There was enhanced sensitivity (attributed to the presence of SWCNT) of the SWCNT-18-SAM-modified gold electrode towards carbofuran, relative to the signals observed on the other SAMs. Current response of the insecticide,bendiocarb, was also intensified, at more favorable oxidation potentials, on the MnPc (14 and 17) modified GCEs, relative to the response on bare GCE, substantiating electrocatalysis. Also, catalysis of the oxidation of the herbicide, bentazon, was observed on polymeric film of complex 20. The current response of the herbicide on this film was better than that observed on bare GCE. Electrocatalysis of the analytes, on the respective modified electrodes, occurred via closely related mechanisms.
- Full Text:
- Date Issued: 2011
Effects of colours, shapes and icons on performance and familiarity
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
- Date Issued: 2011
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
- Date Issued: 2011
The diversity of aquatic insects in the Tsitsikamma region, with implications for aquatic ecosystem conservation
- Authors: Bellingan, Terence Andrew
- Date: 2011
- Subjects: Aquatic insects -- South Africa -- Tsitsikamma , Aquatic insects -- Classification -- South Africa -- Tsitsikamma , Aquatic ecology -- South Africa -- Tsitsikamma , Ecosystem management -- South Africa -- Tsitsikamma , Stream conservation -- South Africa -- Tsitsikamma
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5664 , http://hdl.handle.net/10962/d1005348 , Aquatic insects -- South Africa -- Tsitsikamma , Aquatic insects -- Classification -- South Africa -- Tsitsikamma , Aquatic ecology -- South Africa -- Tsitsikamma , Ecosystem management -- South Africa -- Tsitsikamma , Stream conservation -- South Africa -- Tsitsikamma
- Description: As a result of research carried out within the last decade to assess the diversity of macroinvertebrates of the Salt River in the Western Cape Province, South Africa, surveys of macroinvertebrates of 20 sites on 11 selected rivers from the same mountain range source were undertaken. This was done to make a preliminary assessment of the conservation status of the rivers of this region. Aquatic insects from the orders Ephemeroptera, Odonata, Plecoptera, Megaloptera, Trichoptera and the dipteran family Simuliidae were collected using techniques to maximize the number of taxa found. The insects collected were identified to species level where possible. Water physicochemical parameters were recorded at all sites for each sampling trip to characterize these rivers and to establish a set of baseline data for future comparisons. These parameters included measurements made on site and analysis of the concentrations of all the major ions in water samples in the laboratory. Multivariate analyses including Principle Components Analysis and Canonical Correspondence Analysis were used to reveal patterns within the water physicochemistry and species distributional data. Results include the identification of 123 species from 70 genera and 30 families. A total of 31 species were found to be undescribed, of which 17 were not previously collected and are thus completely new to science. In addition, four of these species could not be placed into any known genus. The analysis of water physicochemistry showed a clear distinction between rivers of Table Mountain sandstone and Bokkeveld shale origin. Downstream effects of anthropogenic influences were discernable too. Distinct macroinvertebrate assemblages were found based upon stream order and water chemistry composition. pH proved to be the most important driver of invertebrate assemblage composition. The high levels of endemism of the macroinvertebrates found within the upper reaches of these rivers and their degree of ecological specialization make these systems a priority for the conservation of aquatic biodiversity on a national and global scale.
- Full Text:
- Date Issued: 2011
- Authors: Bellingan, Terence Andrew
- Date: 2011
- Subjects: Aquatic insects -- South Africa -- Tsitsikamma , Aquatic insects -- Classification -- South Africa -- Tsitsikamma , Aquatic ecology -- South Africa -- Tsitsikamma , Ecosystem management -- South Africa -- Tsitsikamma , Stream conservation -- South Africa -- Tsitsikamma
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5664 , http://hdl.handle.net/10962/d1005348 , Aquatic insects -- South Africa -- Tsitsikamma , Aquatic insects -- Classification -- South Africa -- Tsitsikamma , Aquatic ecology -- South Africa -- Tsitsikamma , Ecosystem management -- South Africa -- Tsitsikamma , Stream conservation -- South Africa -- Tsitsikamma
- Description: As a result of research carried out within the last decade to assess the diversity of macroinvertebrates of the Salt River in the Western Cape Province, South Africa, surveys of macroinvertebrates of 20 sites on 11 selected rivers from the same mountain range source were undertaken. This was done to make a preliminary assessment of the conservation status of the rivers of this region. Aquatic insects from the orders Ephemeroptera, Odonata, Plecoptera, Megaloptera, Trichoptera and the dipteran family Simuliidae were collected using techniques to maximize the number of taxa found. The insects collected were identified to species level where possible. Water physicochemical parameters were recorded at all sites for each sampling trip to characterize these rivers and to establish a set of baseline data for future comparisons. These parameters included measurements made on site and analysis of the concentrations of all the major ions in water samples in the laboratory. Multivariate analyses including Principle Components Analysis and Canonical Correspondence Analysis were used to reveal patterns within the water physicochemistry and species distributional data. Results include the identification of 123 species from 70 genera and 30 families. A total of 31 species were found to be undescribed, of which 17 were not previously collected and are thus completely new to science. In addition, four of these species could not be placed into any known genus. The analysis of water physicochemistry showed a clear distinction between rivers of Table Mountain sandstone and Bokkeveld shale origin. Downstream effects of anthropogenic influences were discernable too. Distinct macroinvertebrate assemblages were found based upon stream order and water chemistry composition. pH proved to be the most important driver of invertebrate assemblage composition. The high levels of endemism of the macroinvertebrates found within the upper reaches of these rivers and their degree of ecological specialization make these systems a priority for the conservation of aquatic biodiversity on a national and global scale.
- Full Text:
- Date Issued: 2011
Trophodynamics of the benthic and hyperbenthic communities inhabiting the Sub-Antarctic Prince Edward Islands : stable isotope and fatty acid signatures
- Authors: Allan, Elizabeth Louise
- Date: 2011
- Subjects: Benthos -- Prince Edward Islands Benthos -- Feeding and feeds -- Prince Edward Islands Benthos -- Nutrition -- Prince Edward Islands Prince Edward Islands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5806 , http://hdl.handle.net/10962/d1006350
- Description: The aim of this study was to investigate spatial changes in the trophic and energy pathways of the benthic community in the shallow shelf waters of the sub-Antarctic Prince Edward Islands (PEI). A combination of stable isotope and fatty acid analyses were used to provide a time-integrated view of the assimilated feeding history of selected components of the PEI benthic community. This study forms part of the larger project entitled “Variability in the Southern Ocean ecosystems” and is a contribution to the South African National Antarctic Programme (SANAP). During austral autumn 2009, benthic specimens were collected from 10 stations (from depths of 70 to 295 m) in different regions around the PEI: inter-island shelf (upstream, between and downstream of the islands) and nearshore. Historical data were combined with new data collected during 2009 to assess the long-term trends in the feeding ecology of the benthos in the region of the islands. The stable isotope and fatty acid signatures of the benthic suspension- and deposit-feeding organisms generated during this study suggested that these two communities incorporated both phytoplankton and kelp in their diets. Stable isotope, and to a lesser extent fatty acid signatures, indicated that kelp contributed more to the diets of those organisms in close proximity to the kelp beds (nearshore stations) than those from the inter-island region. Overall, however, pelagic phytoplankton was the dominant food source in the diets of all organisms, even for those living near the kelp beds. Notable exceptions were the sponges and bryozoans, in which kelp and phytoplankton contributed similar proportions to their diets, most likely resulting from a size restricted feeding mode. There were, therefore, no distinct spatial differences in the importance of the various food sources. However, fatty acid compositional data indicated increased food quality between and within the lee of the islands compared to upstream. The organisms collected upstream of the PEI had substantially lower quantities of total fatty acids (TFAs) than organisms of the same species collected from nearshore, open shelf or downstream stations. The increased food quality between and within the lee of the islands was likely a result of the “island mass effect”, which reflects increased phytoplankton concentrations at the PEI. The fatty acid profiles of hyperbenthic shrimp Nauticaris marionis, a key species in the PEI ecosystem, revealed no distinct ontogenetic or spatial patterns. This result is in contrast to the stable isotope analyses, which detected both spatial and ontogenetic differences in the diet of the shrimp. Nearshore shrimp were more ₁₃C-enriched than those from the inter-island region, suggesting increased kelp entering the food web within these regions. In addition, the shrimps demonstrated enrichment in δ₁₃C and δ₁₅N signatures with an increase in size, resulting in a relatively distinct separation of size classes, thus reflecting niche separation through their diets. The fatty acid profiles revealed that the shrimp all contained large proportions of polyunsaturated fatty acids (PUFAs) and essential fatty acids (EFAs), indicating that the quality of food consumed was similar among size class and region despite the niche separation and variation in carbon sources utilised. In addition, diatom and dinoflagellate fatty acids (20:5ω3 and 22:6ω3, respectively) occurred in the highest proportions in N. marionis, highlighting the importance of phytoplankton (indirectly) in their diet. These results represent strong evidence that phytoplankton is an importance food source in the PEI ecosystem. The temporal investigation of isotope signatures in the benthos at the PEI indicated that N. marionis demonstrated an overall depletion in δ₁₃C signatures over the period of 1984 to 2009 (nearshore: -2.55 ‰, inter-island: -2.32 ‰). Overall, the benthic community showed similar depletions in δ13C signatures (from -1.96 to -4.70 ‰), suggesting that shifts have occurred in the carbon signatures at the base of the food web. The depletion in δ₁₃C signatures of the benthos at the PEI most likely reflects increased contributions of smaller slow growing phytoplankton cells (more depleted signatures than large fast growing cells) in the diets of these organisms over time. These diet shifts, in turn, suggest a decrease in productivity has occurred at the islands, likely due to a decreased frequency and intensity of the “island mass effect”. Decreased phytoplankton productivity at the PEI likely results from the southward shift in the average position of the sub-Antarctic Front (SAF), most likely in response to climate change, which in turn promotes flow-through conditions rather than retention at the PEI.
- Full Text:
- Date Issued: 2011
- Authors: Allan, Elizabeth Louise
- Date: 2011
- Subjects: Benthos -- Prince Edward Islands Benthos -- Feeding and feeds -- Prince Edward Islands Benthos -- Nutrition -- Prince Edward Islands Prince Edward Islands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5806 , http://hdl.handle.net/10962/d1006350
- Description: The aim of this study was to investigate spatial changes in the trophic and energy pathways of the benthic community in the shallow shelf waters of the sub-Antarctic Prince Edward Islands (PEI). A combination of stable isotope and fatty acid analyses were used to provide a time-integrated view of the assimilated feeding history of selected components of the PEI benthic community. This study forms part of the larger project entitled “Variability in the Southern Ocean ecosystems” and is a contribution to the South African National Antarctic Programme (SANAP). During austral autumn 2009, benthic specimens were collected from 10 stations (from depths of 70 to 295 m) in different regions around the PEI: inter-island shelf (upstream, between and downstream of the islands) and nearshore. Historical data were combined with new data collected during 2009 to assess the long-term trends in the feeding ecology of the benthos in the region of the islands. The stable isotope and fatty acid signatures of the benthic suspension- and deposit-feeding organisms generated during this study suggested that these two communities incorporated both phytoplankton and kelp in their diets. Stable isotope, and to a lesser extent fatty acid signatures, indicated that kelp contributed more to the diets of those organisms in close proximity to the kelp beds (nearshore stations) than those from the inter-island region. Overall, however, pelagic phytoplankton was the dominant food source in the diets of all organisms, even for those living near the kelp beds. Notable exceptions were the sponges and bryozoans, in which kelp and phytoplankton contributed similar proportions to their diets, most likely resulting from a size restricted feeding mode. There were, therefore, no distinct spatial differences in the importance of the various food sources. However, fatty acid compositional data indicated increased food quality between and within the lee of the islands compared to upstream. The organisms collected upstream of the PEI had substantially lower quantities of total fatty acids (TFAs) than organisms of the same species collected from nearshore, open shelf or downstream stations. The increased food quality between and within the lee of the islands was likely a result of the “island mass effect”, which reflects increased phytoplankton concentrations at the PEI. The fatty acid profiles of hyperbenthic shrimp Nauticaris marionis, a key species in the PEI ecosystem, revealed no distinct ontogenetic or spatial patterns. This result is in contrast to the stable isotope analyses, which detected both spatial and ontogenetic differences in the diet of the shrimp. Nearshore shrimp were more ₁₃C-enriched than those from the inter-island region, suggesting increased kelp entering the food web within these regions. In addition, the shrimps demonstrated enrichment in δ₁₃C and δ₁₅N signatures with an increase in size, resulting in a relatively distinct separation of size classes, thus reflecting niche separation through their diets. The fatty acid profiles revealed that the shrimp all contained large proportions of polyunsaturated fatty acids (PUFAs) and essential fatty acids (EFAs), indicating that the quality of food consumed was similar among size class and region despite the niche separation and variation in carbon sources utilised. In addition, diatom and dinoflagellate fatty acids (20:5ω3 and 22:6ω3, respectively) occurred in the highest proportions in N. marionis, highlighting the importance of phytoplankton (indirectly) in their diet. These results represent strong evidence that phytoplankton is an importance food source in the PEI ecosystem. The temporal investigation of isotope signatures in the benthos at the PEI indicated that N. marionis demonstrated an overall depletion in δ₁₃C signatures over the period of 1984 to 2009 (nearshore: -2.55 ‰, inter-island: -2.32 ‰). Overall, the benthic community showed similar depletions in δ13C signatures (from -1.96 to -4.70 ‰), suggesting that shifts have occurred in the carbon signatures at the base of the food web. The depletion in δ₁₃C signatures of the benthos at the PEI most likely reflects increased contributions of smaller slow growing phytoplankton cells (more depleted signatures than large fast growing cells) in the diets of these organisms over time. These diet shifts, in turn, suggest a decrease in productivity has occurred at the islands, likely due to a decreased frequency and intensity of the “island mass effect”. Decreased phytoplankton productivity at the PEI likely results from the southward shift in the average position of the sub-Antarctic Front (SAF), most likely in response to climate change, which in turn promotes flow-through conditions rather than retention at the PEI.
- Full Text:
- Date Issued: 2011