Abortion as disruption: discourses surrounding abortion in the talk of men
- Authors: Hansjee, Jateen
- Date: 2011
- Subjects: Abortion -- Psychological aspects Abortion -- Social aspects Men -- South Africa -- Language Men -- South Africa -- Attitudes Health attitudes -- South Africa Discourse analysis -- Psychological aspects Discourse analysis -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2984 , http://hdl.handle.net/10962/d1002493
- Description: This research examines men’s talk around abortion using critical discourse analysis. Current literature indicates a dearth of studies addressing the topic of men and abortion in various domains. An understanding of men’s relationship to abortion, however, is crucial to understanding abortion as a social phenomenon. This study utilises the work of Foucault around discourse and power, as well as Butler’s work on gender to create a theoretical framework to approach data. Data were collected in the form of interview groups made up of men, as well as newspaper articles and on-line forum discussions that featured men as the author. What emerged from theses texts was a ‘Familial Discourse’ which posits the nuclear, heterosexual family as a long term relationship between a mother and father, which forms the ideal site to raise children. Discourses that support the family are a discourse of ‘Equal Partnership’ which establishes the man and the woman as being in a heterosexual relationship where each partner is seen to have equal power, and a discourse of ‘Foetal Personhood’ which constructs the foetus as a child in need of a family. Related to the heterosexual matrix, the formation of a family unit comes to be constructed as ‘natural’. Abortion acts as a disruptor to these discourses. By disrupting the formation of the family unit, abortion negatively affects the individuals involved. A relationship where a formation of a family unit was disrupted cannot survive. If the female partner has an abortion without her partner, it is seen as disrupting the equal partnership between the man and the woman. Men in this case see themselves as ‘powerless’ compared to women. From this point a ‘New Man’ discourse emerges, where men position themselves as loving and responsible in the context of a nuclear, heterosexual family unit. Abortion disrupts ‘Foetal Personhood’ and is constructed as murder. In the case of rape the ‘Familial Discourse’ can be invoked either to justify abortion or resist abortion, based on whether or not a family unit can be formed. These discourses reproduce patriarchy.
- Full Text:
- Authors: Hansjee, Jateen
- Date: 2011
- Subjects: Abortion -- Psychological aspects Abortion -- Social aspects Men -- South Africa -- Language Men -- South Africa -- Attitudes Health attitudes -- South Africa Discourse analysis -- Psychological aspects Discourse analysis -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2984 , http://hdl.handle.net/10962/d1002493
- Description: This research examines men’s talk around abortion using critical discourse analysis. Current literature indicates a dearth of studies addressing the topic of men and abortion in various domains. An understanding of men’s relationship to abortion, however, is crucial to understanding abortion as a social phenomenon. This study utilises the work of Foucault around discourse and power, as well as Butler’s work on gender to create a theoretical framework to approach data. Data were collected in the form of interview groups made up of men, as well as newspaper articles and on-line forum discussions that featured men as the author. What emerged from theses texts was a ‘Familial Discourse’ which posits the nuclear, heterosexual family as a long term relationship between a mother and father, which forms the ideal site to raise children. Discourses that support the family are a discourse of ‘Equal Partnership’ which establishes the man and the woman as being in a heterosexual relationship where each partner is seen to have equal power, and a discourse of ‘Foetal Personhood’ which constructs the foetus as a child in need of a family. Related to the heterosexual matrix, the formation of a family unit comes to be constructed as ‘natural’. Abortion acts as a disruptor to these discourses. By disrupting the formation of the family unit, abortion negatively affects the individuals involved. A relationship where a formation of a family unit was disrupted cannot survive. If the female partner has an abortion without her partner, it is seen as disrupting the equal partnership between the man and the woman. Men in this case see themselves as ‘powerless’ compared to women. From this point a ‘New Man’ discourse emerges, where men position themselves as loving and responsible in the context of a nuclear, heterosexual family unit. Abortion disrupts ‘Foetal Personhood’ and is constructed as murder. In the case of rape the ‘Familial Discourse’ can be invoked either to justify abortion or resist abortion, based on whether or not a family unit can be formed. These discourses reproduce patriarchy.
- Full Text:
Above ground woody community attributes, biomass and carbon stocks along a rainfall gradient in the savannas of the central lowveld, South Africa
- Shackleton, Charlie M, Scholes, Robert J
- Authors: Shackleton, Charlie M , Scholes, Robert J
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6658 , http://hdl.handle.net/10962/d1007079
- Description: Enumeration of carbon stocks at benchmark sites is a necessary activity in assessing the potential carbon sequestration and possible generation of credits through restoration of intensively impacted sites. However, there is a lack of empirical studies throughout much of the savannas of sub-Saharan Africa, including South Africa. We report an estimation of species specific and site biomass and carbon stocks, and general vegetation structural attributes from three protected areas along a rainfall gradient in the central lowveld, South Africa. Estimates of biomass and carbon stocks were effected through destructive sampling to establish locally derived allometric equations. There was a gradient of increasing woody density, height of the canopy, number of species, density of regenerative stems and a greater proportion of stems in small size classes from the arid locality to the mesic locality, with the semi-arid locality being intermediate. The proportion of spinescent species decreased with increasing rainfall. The mesic locality was significantly more woody than either the arid or semi-arid sites, having double the biomass, four times the density and 40% higher basal area. Above ground carbon pools were also higher; carbon stocks were approximately 9 t/ha for the arid and semi-arid sites and 18 t/ha for the mesic site.
- Full Text:
- Authors: Shackleton, Charlie M , Scholes, Robert J
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6658 , http://hdl.handle.net/10962/d1007079
- Description: Enumeration of carbon stocks at benchmark sites is a necessary activity in assessing the potential carbon sequestration and possible generation of credits through restoration of intensively impacted sites. However, there is a lack of empirical studies throughout much of the savannas of sub-Saharan Africa, including South Africa. We report an estimation of species specific and site biomass and carbon stocks, and general vegetation structural attributes from three protected areas along a rainfall gradient in the central lowveld, South Africa. Estimates of biomass and carbon stocks were effected through destructive sampling to establish locally derived allometric equations. There was a gradient of increasing woody density, height of the canopy, number of species, density of regenerative stems and a greater proportion of stems in small size classes from the arid locality to the mesic locality, with the semi-arid locality being intermediate. The proportion of spinescent species decreased with increasing rainfall. The mesic locality was significantly more woody than either the arid or semi-arid sites, having double the biomass, four times the density and 40% higher basal area. Above ground carbon pools were also higher; carbon stocks were approximately 9 t/ha for the arid and semi-arid sites and 18 t/ha for the mesic site.
- Full Text:
Action competence and waste management: a case study of learner agency in two Grahamstown eco-schools
- Chiphwanya, Nellie Chimwemwe
- Authors: Chiphwanya, Nellie Chimwemwe
- Date: 2011
- Subjects: Environmental education -- South Africa -- Grahamstown -- Case studies Environmental education -- Study and teaching (Primary) -- South Africa -- Grahamstown -- Case studies Student-centered learning -- South Africa -- Grahamstown -- Case studies Refuse and refuse disposal -- Environmental aspects -- South Africa -- Grahamstown -- Case studies Recycling (Waste, etc) -- South Africa -- Grahamstown -- Case studies Active learning -- South Africa -- Grahamstown -- Case studies Competency based education -- South Africa -- Grahamstown -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1956 , http://hdl.handle.net/10962/d1008308
- Description: There has been a growing need in environmental education to develop students' ability and will to take part in democratic processes that enable them take environmental action in their local environment. This study examined learner action competence in waste management practices in two primary school contexts in the Eastern Cape, South Africa. An interpretive case study design is used to probe how learner participation in Eco-School waste management practices enabled the acquisition of knowledge in purposeful learning and action experiences that developed the vision and agency of informed action. The research was centred on two guiding questions: 1. How informed, purposeful and action-orientated is learner participation in Eco-School waste management activities? 2. What Eco-School waste management activities are fostering active participation towards a learner-led agency? Educators in the two schools were interviewed and Eco-School portfolios were examined for evidence of the learning activities and learner achievement. This provided the contextual data for reviewing focus group interviews to probe what was significant to learners, what they came to know and how they had contributed to the process of developing better waste management in the Eco-School context. The evidence generated in the study was used to identify the roles of the various players, the significant activities and processes that enabled and constrained the emergence of learner-led agency. The main findings in the study were that teacher intentionality and school management ethos were significant in engaging learners in meaningful waste management activities in both cases. The study also revealed that although most of the waste management activities in both cases were teacher-initiated, there were spaces open for learner initiatives. However, it appeared that the activity based waste management practices mostly allowed learners to learn how to do waste management more than allowing them to find out more about the scope and nature of ii the problem of waste. This then resulted in learners talking more about what they were doing with waste than talking about what they knew about waste. There were differences in the way in which learners approached waste in the two cases. In the one case, Kingswood Junior School learners used waste artistically and carried out activities that allowed for better use of waste resources like paper while in the other School, Grahamstown SDA School, learners approached waste as a resource for making money. However, in both cases, learners appeared to enjoy the positive experiences of doing things that contributed to a cleaner environment and were of benefit to others and this gave them a sense of pride to share their experiences with others. This study was significant as it allowed me to probe learner participation and examine the development of their action competence through listening to the voices of the learners themselves and understanding what was important to them about the knowledge they gained and their vision of better waste management.
- Full Text:
- Authors: Chiphwanya, Nellie Chimwemwe
- Date: 2011
- Subjects: Environmental education -- South Africa -- Grahamstown -- Case studies Environmental education -- Study and teaching (Primary) -- South Africa -- Grahamstown -- Case studies Student-centered learning -- South Africa -- Grahamstown -- Case studies Refuse and refuse disposal -- Environmental aspects -- South Africa -- Grahamstown -- Case studies Recycling (Waste, etc) -- South Africa -- Grahamstown -- Case studies Active learning -- South Africa -- Grahamstown -- Case studies Competency based education -- South Africa -- Grahamstown -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1956 , http://hdl.handle.net/10962/d1008308
- Description: There has been a growing need in environmental education to develop students' ability and will to take part in democratic processes that enable them take environmental action in their local environment. This study examined learner action competence in waste management practices in two primary school contexts in the Eastern Cape, South Africa. An interpretive case study design is used to probe how learner participation in Eco-School waste management practices enabled the acquisition of knowledge in purposeful learning and action experiences that developed the vision and agency of informed action. The research was centred on two guiding questions: 1. How informed, purposeful and action-orientated is learner participation in Eco-School waste management activities? 2. What Eco-School waste management activities are fostering active participation towards a learner-led agency? Educators in the two schools were interviewed and Eco-School portfolios were examined for evidence of the learning activities and learner achievement. This provided the contextual data for reviewing focus group interviews to probe what was significant to learners, what they came to know and how they had contributed to the process of developing better waste management in the Eco-School context. The evidence generated in the study was used to identify the roles of the various players, the significant activities and processes that enabled and constrained the emergence of learner-led agency. The main findings in the study were that teacher intentionality and school management ethos were significant in engaging learners in meaningful waste management activities in both cases. The study also revealed that although most of the waste management activities in both cases were teacher-initiated, there were spaces open for learner initiatives. However, it appeared that the activity based waste management practices mostly allowed learners to learn how to do waste management more than allowing them to find out more about the scope and nature of ii the problem of waste. This then resulted in learners talking more about what they were doing with waste than talking about what they knew about waste. There were differences in the way in which learners approached waste in the two cases. In the one case, Kingswood Junior School learners used waste artistically and carried out activities that allowed for better use of waste resources like paper while in the other School, Grahamstown SDA School, learners approached waste as a resource for making money. However, in both cases, learners appeared to enjoy the positive experiences of doing things that contributed to a cleaner environment and were of benefit to others and this gave them a sense of pride to share their experiences with others. This study was significant as it allowed me to probe learner participation and examine the development of their action competence through listening to the voices of the learners themselves and understanding what was important to them about the knowledge they gained and their vision of better waste management.
- Full Text:
Adjustment of commercial banks' interest rates and the effectiveness of monetary policy: evidence from Anglophone West Africa
- Authors: Bangura, Lamin
- Date: 2011
- Subjects: Monetary policy -- Africa, West , Banks and banking -- Africa, West , Interest rates -- Africa, West
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:951 , http://hdl.handle.net/10962/d1002685 , Monetary policy -- Africa, West , Banks and banking -- Africa, West , Interest rates -- Africa, West
- Description: Most central banks use short-term interest rates as their main instrument of monetary policy. It is assumed that a change in policy rate will influence interest rates set by commercial banks, but this is not usually the case. Commercial banks adjust their interest rates in response to changes in policy rate with lags, which make their interest rates sticky. Stickiness in commercial banks interest rates have been seen as an obstacle to the smooth transmission of monetary policy decisions. Despite the importance of the transmission process, little attention has been given to a systematic measurement of the degree of response of commercial banks‟ interest rates to changes in monetary policy stance in the Anglophone West African countries, specifically within the West African Monetary Zone (WAMZ) economies. Against this backdrop, this study explores the interest rate adjustment dynamics using monthly interest rate series on discount rate, treasury bill rate, commercial banks‟ deposit and lending rates from 1989 to 2009 (for Gambia, Nigeria and Sierra Leone) and from 2000 to 2009 (for Ghana). Specifically, the study set out to examine how lending and deposit rates respond to changes in the official rates and to see whether there is a convergence among the rates over time. Also, to examine the relative adjustment of commercial bank lending rates to changes in the official rate when there is disequilibrium. The analyses were twofold: a full sample period and a rolling window analysis. Following Cottarelli and Kourelis (1994), the study employed cointegration technique and an asymmetric error correction model to obtain the short-run and long-run parameters from which the error correction coefficients, mean adjustment lags and asymmetric mean adjustment lags were estimated. The results for the entire sample period revealed that the long-run pass-through in Nigeria was 81% and 67% for lending rates and deposit rates respectively. In Ghana, it was 66% and 69% for lending and deposit rates respectively. While in Sierra Leone, long-run pass-through was 62% and 72% for lending and deposit rates respectively. In Gambia, it was 50% and 40% for lending and deposit rates respectively. On the other hand, the short-run pass-through was found to be lower compared to the long-run pass-through: in Nigeria it was 66% and 47%; in Gambia, 26% and 29%; in Sierra Leone, 30% and 13%; and in Ghana, -6% and 35% for lending and deposit rates respectively in each country. The pass-through estimates for the rolling windows were mixed for short-run and long-run pass-through. The mean adjustment lags suggest that the speed of adjustment of Lending rates for full sample period were two, two, seven and twelve months in Nigeria, Ghana, Sierra Leone and Gambia respectively. While for deposit rates they were five, six, seven and eighteen for Ghana, Nigeria, Gambia and Sierra Leone respectively. The average speeds of adjustment for the rolling windows were four and five months for lending and deposit rates respectively. Weak evidence of convergence was found in lending and deposit rates in the short-run and long-run pass-through among the countries. However, the results suggest that the magnitude and speed of the pass-through amongst the countries on average were high compared to emerging Asian countries. Significant asymmetric adjustments were found in the lending rates for Gambia and Sierra Leone, while in Gambia and Nigeria there were asymmetries in deposit rates. Based on the evidence provided, interest rate pass-through is high in Nigeria and Ghana compared to Gambia and Sierra Leone and this calls for the harmonization of financial policies on the part of the financial authorities in the WAMZ. Viewed solely from an interest rate pass-through, the lack of convergence among the countries suggests that WAMZ is far from ready for a monetary union. The relatively low pass-through in some of the countries suggests rigidity in the banking system which may be due to underdevelopment of the system. Thus efforts geared toward strengthening the banking system and the financial system as whole would further enhance the prospect of a monetary union among them.
- Full Text:
- Authors: Bangura, Lamin
- Date: 2011
- Subjects: Monetary policy -- Africa, West , Banks and banking -- Africa, West , Interest rates -- Africa, West
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:951 , http://hdl.handle.net/10962/d1002685 , Monetary policy -- Africa, West , Banks and banking -- Africa, West , Interest rates -- Africa, West
- Description: Most central banks use short-term interest rates as their main instrument of monetary policy. It is assumed that a change in policy rate will influence interest rates set by commercial banks, but this is not usually the case. Commercial banks adjust their interest rates in response to changes in policy rate with lags, which make their interest rates sticky. Stickiness in commercial banks interest rates have been seen as an obstacle to the smooth transmission of monetary policy decisions. Despite the importance of the transmission process, little attention has been given to a systematic measurement of the degree of response of commercial banks‟ interest rates to changes in monetary policy stance in the Anglophone West African countries, specifically within the West African Monetary Zone (WAMZ) economies. Against this backdrop, this study explores the interest rate adjustment dynamics using monthly interest rate series on discount rate, treasury bill rate, commercial banks‟ deposit and lending rates from 1989 to 2009 (for Gambia, Nigeria and Sierra Leone) and from 2000 to 2009 (for Ghana). Specifically, the study set out to examine how lending and deposit rates respond to changes in the official rates and to see whether there is a convergence among the rates over time. Also, to examine the relative adjustment of commercial bank lending rates to changes in the official rate when there is disequilibrium. The analyses were twofold: a full sample period and a rolling window analysis. Following Cottarelli and Kourelis (1994), the study employed cointegration technique and an asymmetric error correction model to obtain the short-run and long-run parameters from which the error correction coefficients, mean adjustment lags and asymmetric mean adjustment lags were estimated. The results for the entire sample period revealed that the long-run pass-through in Nigeria was 81% and 67% for lending rates and deposit rates respectively. In Ghana, it was 66% and 69% for lending and deposit rates respectively. While in Sierra Leone, long-run pass-through was 62% and 72% for lending and deposit rates respectively. In Gambia, it was 50% and 40% for lending and deposit rates respectively. On the other hand, the short-run pass-through was found to be lower compared to the long-run pass-through: in Nigeria it was 66% and 47%; in Gambia, 26% and 29%; in Sierra Leone, 30% and 13%; and in Ghana, -6% and 35% for lending and deposit rates respectively in each country. The pass-through estimates for the rolling windows were mixed for short-run and long-run pass-through. The mean adjustment lags suggest that the speed of adjustment of Lending rates for full sample period were two, two, seven and twelve months in Nigeria, Ghana, Sierra Leone and Gambia respectively. While for deposit rates they were five, six, seven and eighteen for Ghana, Nigeria, Gambia and Sierra Leone respectively. The average speeds of adjustment for the rolling windows were four and five months for lending and deposit rates respectively. Weak evidence of convergence was found in lending and deposit rates in the short-run and long-run pass-through among the countries. However, the results suggest that the magnitude and speed of the pass-through amongst the countries on average were high compared to emerging Asian countries. Significant asymmetric adjustments were found in the lending rates for Gambia and Sierra Leone, while in Gambia and Nigeria there were asymmetries in deposit rates. Based on the evidence provided, interest rate pass-through is high in Nigeria and Ghana compared to Gambia and Sierra Leone and this calls for the harmonization of financial policies on the part of the financial authorities in the WAMZ. Viewed solely from an interest rate pass-through, the lack of convergence among the countries suggests that WAMZ is far from ready for a monetary union. The relatively low pass-through in some of the countries suggests rigidity in the banking system which may be due to underdevelopment of the system. Thus efforts geared toward strengthening the banking system and the financial system as whole would further enhance the prospect of a monetary union among them.
- Full Text:
Adoption, use and perception of Australian acacias around the world
- Kull, Christian A, Shackleton, Charlie M, Cunningham, Peter J, Ducatillon, Catherine, Dufour-Dror, Jean-Mark, Esler, Karen J, Friday, James B, Gouveia, António C, Griffin, A R, Marchante, Elizabete, Midgley, Steven J, Pauchard, Aníbal, Rangan, Haripriya, Richardson, David M, Rinaudo, Tony, Tassin, Jacques, Urgenson, Lauren S, van Maltitz, Graham P, Zenni, Rafael D, Zylstra, Matthew J
- Authors: Kull, Christian A , Shackleton, Charlie M , Cunningham, Peter J , Ducatillon, Catherine , Dufour-Dror, Jean-Mark , Esler, Karen J , Friday, James B , Gouveia, António C , Griffin, A R , Marchante, Elizabete , Midgley, Steven J , Pauchard, Aníbal , Rangan, Haripriya , Richardson, David M , Rinaudo, Tony , Tassin, Jacques , Urgenson, Lauren S , van Maltitz, Graham P , Zenni, Rafael D , Zylstra, Matthew J
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182149 , vital:43804 , xlink:href="https://doi.org/10.1111/j.1472-4642.2011.00783.x"
- Description: To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Eighteen landscape-scale case studies around the world, in Vietnam, India, Réunion, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai‘i. Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities.
- Full Text:
- Authors: Kull, Christian A , Shackleton, Charlie M , Cunningham, Peter J , Ducatillon, Catherine , Dufour-Dror, Jean-Mark , Esler, Karen J , Friday, James B , Gouveia, António C , Griffin, A R , Marchante, Elizabete , Midgley, Steven J , Pauchard, Aníbal , Rangan, Haripriya , Richardson, David M , Rinaudo, Tony , Tassin, Jacques , Urgenson, Lauren S , van Maltitz, Graham P , Zenni, Rafael D , Zylstra, Matthew J
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182149 , vital:43804 , xlink:href="https://doi.org/10.1111/j.1472-4642.2011.00783.x"
- Description: To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Eighteen landscape-scale case studies around the world, in Vietnam, India, Réunion, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai‘i. Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities.
- Full Text:
Advances in entomological methods for death time estimation
- Villet, Martin H, Amendt, Jens
- Authors: Villet, Martin H , Amendt, Jens
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441722 , vital:73910 , https://doi.org/10.1007/978-1-61779-249-6_11
- Description: The development of entomological methods for estimating the time of death has been rapid in the last decade, and new methods are on the horizon. These developments are reviewed with specific reference to experimental design, established and new techniques, and mathematical modelling for forensic retrodiction. The techniques include the use of electron microscopy, magnetic resonance imaging, computed tomography, cuticular hydrocarbon profiles, and real-time PCR to estimate the age of immature insects found on corpses, based on their stage of development. Near-infrared spectrograph and pteridine fluorescence techniques can be applied to this task on adult insects. The use of ecological succession in the carrion insect community is also introduced briefly. Finally, the creation and uses of standard techniques in forensic entomology is discussed. We recommend that two steps in this standardisation process are that physiological and ecological studies should be reported in physiological time wherever this is appropriate, and that the type of post-mortem interval being estimated should be stipulated more explicitly than is currently common.
- Full Text:
- Authors: Villet, Martin H , Amendt, Jens
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441722 , vital:73910 , https://doi.org/10.1007/978-1-61779-249-6_11
- Description: The development of entomological methods for estimating the time of death has been rapid in the last decade, and new methods are on the horizon. These developments are reviewed with specific reference to experimental design, established and new techniques, and mathematical modelling for forensic retrodiction. The techniques include the use of electron microscopy, magnetic resonance imaging, computed tomography, cuticular hydrocarbon profiles, and real-time PCR to estimate the age of immature insects found on corpses, based on their stage of development. Near-infrared spectrograph and pteridine fluorescence techniques can be applied to this task on adult insects. The use of ecological succession in the carrion insect community is also introduced briefly. Finally, the creation and uses of standard techniques in forensic entomology is discussed. We recommend that two steps in this standardisation process are that physiological and ecological studies should be reported in physiological time wherever this is appropriate, and that the type of post-mortem interval being estimated should be stipulated more explicitly than is currently common.
- Full Text:
Adventures with abalone : aquaculture, poaching, and fishery restoration
- Authors: Britz, Peter Jacobus, 1959-
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:583 , http://hdl.handle.net/10962/d1018943
- Description: [From the text] Tonight I am going to tell you about my research on a another mollusc, the humble abalone. - In contrast with the highly evolved squid, this marine snail belonging to the ancient archeogastrod lineage which has a much simpler anatomy and lifestyle. It doesn’t posses a proper brain mass, only having 4 ganglia or nerves knots at the front end. Its two simple eye spots which detect light and dark, a tough shell and a large and extremely powerful foot muscle to adhere to rocks. This simple configuration has served well for over 100 million years.
- Full Text:
- Authors: Britz, Peter Jacobus, 1959-
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:583 , http://hdl.handle.net/10962/d1018943
- Description: [From the text] Tonight I am going to tell you about my research on a another mollusc, the humble abalone. - In contrast with the highly evolved squid, this marine snail belonging to the ancient archeogastrod lineage which has a much simpler anatomy and lifestyle. It doesn’t posses a proper brain mass, only having 4 ganglia or nerves knots at the front end. Its two simple eye spots which detect light and dark, a tough shell and a large and extremely powerful foot muscle to adhere to rocks. This simple configuration has served well for over 100 million years.
- Full Text:
Africa: unity, sovereignty and sorrow A book review
- Authors: Matthews, Sally
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142387 , vital:38075 , DOI: 10.1080/02589001.2011.562007
- Description: This ambitious book begins with the statement ‘By and large, the states of sub-Saharan Africa are failures’ (p. 1) and then sets out to explain state failure in Africa and to provide some ‘rational policy fantasies’ in response to this failure. The book builds on the work of scholars like Robert Jackson, William Reno and Jeffrey Herbst, with the particular focus of Englebert's book being on the domestic implications of the unconditional recognition of the sovereignty of African states. African states are internationally recognised despite lacking the features and not being able to perform the functions typically associated with statehood. Englebert's interest is to examine some of the domestic effects of this unconditional international recognition.
- Full Text:
- Authors: Matthews, Sally
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142387 , vital:38075 , DOI: 10.1080/02589001.2011.562007
- Description: This ambitious book begins with the statement ‘By and large, the states of sub-Saharan Africa are failures’ (p. 1) and then sets out to explain state failure in Africa and to provide some ‘rational policy fantasies’ in response to this failure. The book builds on the work of scholars like Robert Jackson, William Reno and Jeffrey Herbst, with the particular focus of Englebert's book being on the domestic implications of the unconditional recognition of the sovereignty of African states. African states are internationally recognised despite lacking the features and not being able to perform the functions typically associated with statehood. Englebert's interest is to examine some of the domestic effects of this unconditional international recognition.
- Full Text:
African carrion ecosystems and their insect communities in relation to forensic entomology
- Authors: Villet, Martin H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442439 , vital:73984 , http://www.globalsciencebooks.info/Online/GSBOnline/OnlinePT_5_1.html
- Description: African carrion communities contain representatives of the same families that occur in carrion communities on other continents. Checklists and identification guides are tabulated, and the natural histories of core members of the terrestrial community are outlined. Because of strong phylogenetic trends in the biology of the families, the species are effectively ecological surrogates of their relatives elsewhere. These phylogenetic trends also allow the definition of a set of guilds of functionally equivalent species that unify the study of carrion communities world-wide, and a revised suite of guilds is described with both synecological and forensic purposes in mind. Although the decomposition process has been arbitrarily subdivided into stages, they have little direct relation to the dynamics of the carrion community, and should be treated as landmarks rather than phases. Community turnover follows a qualitatively predictable succession, with the greatest species richness and diversity around the ecotone-like transition from ‘wet-phase’ to ‘dry-phase’ carrion habitats. These habitats are differentiated along interacting ecological gradients of dietary quality, competition, and risk of predation, which are important to the core guilds. Competition and predation have strong effects on population dynamics of community members, but link particular species only weakly, so that the succession pattern largely reflects the autecology of the individual species. Discrete waves of species are absent, which increases the temporal resolution, and therefore the forensic value, of the succession as a ‘clock’. The forensic significance of various aspects of community and trophic dynamics are discussed, and means of applying ecological theory to investigations are reviewed.
- Full Text:
- Authors: Villet, Martin H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442439 , vital:73984 , http://www.globalsciencebooks.info/Online/GSBOnline/OnlinePT_5_1.html
- Description: African carrion communities contain representatives of the same families that occur in carrion communities on other continents. Checklists and identification guides are tabulated, and the natural histories of core members of the terrestrial community are outlined. Because of strong phylogenetic trends in the biology of the families, the species are effectively ecological surrogates of their relatives elsewhere. These phylogenetic trends also allow the definition of a set of guilds of functionally equivalent species that unify the study of carrion communities world-wide, and a revised suite of guilds is described with both synecological and forensic purposes in mind. Although the decomposition process has been arbitrarily subdivided into stages, they have little direct relation to the dynamics of the carrion community, and should be treated as landmarks rather than phases. Community turnover follows a qualitatively predictable succession, with the greatest species richness and diversity around the ecotone-like transition from ‘wet-phase’ to ‘dry-phase’ carrion habitats. These habitats are differentiated along interacting ecological gradients of dietary quality, competition, and risk of predation, which are important to the core guilds. Competition and predation have strong effects on population dynamics of community members, but link particular species only weakly, so that the succession pattern largely reflects the autecology of the individual species. Discrete waves of species are absent, which increases the temporal resolution, and therefore the forensic value, of the succession as a ‘clock’. The forensic significance of various aspects of community and trophic dynamics are discussed, and means of applying ecological theory to investigations are reviewed.
- Full Text:
African Languages And ICT Education
- Dalvit, Lorenzo, Murray, Sarah, Terzoli, Alfredo
- Authors: Dalvit, Lorenzo , Murray, Sarah , Terzoli, Alfredo
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431166 , vital:72750 , https://www.scitepress.org/Papers/2011/33507/33507.pdf
- Description: In South Africa, English plays a dominant role compared to African lan-guages in empowering domain. Better access to Education through the use of African languages is an object of heated debate. This paper shows that an intervention involving the use of an African language in the domain of ICT Education can change the attitudes of Black universi-ty students. The methodology used included a survey with preliminary and follow-up questionnaires and interviews and an intervention involv-ing the use of localised software and of an on-line glossary of computer terms translated, explained and exemplified in an African language (isiXhosa). This experience increased the support for the use of African languages as additional LoLT, even in the English-dominated field of study of Computer Science. This is an initial step towards promoting linguistic equality between English and African languages and social equality between their speakers.
- Full Text:
- Authors: Dalvit, Lorenzo , Murray, Sarah , Terzoli, Alfredo
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431166 , vital:72750 , https://www.scitepress.org/Papers/2011/33507/33507.pdf
- Description: In South Africa, English plays a dominant role compared to African lan-guages in empowering domain. Better access to Education through the use of African languages is an object of heated debate. This paper shows that an intervention involving the use of an African language in the domain of ICT Education can change the attitudes of Black universi-ty students. The methodology used included a survey with preliminary and follow-up questionnaires and interviews and an intervention involv-ing the use of localised software and of an on-line glossary of computer terms translated, explained and exemplified in an African language (isiXhosa). This experience increased the support for the use of African languages as additional LoLT, even in the English-dominated field of study of Computer Science. This is an initial step towards promoting linguistic equality between English and African languages and social equality between their speakers.
- Full Text:
African traditional medicine-antiretroviral interactions : effects of Sutherlandia frutescens on the pharmacokinetics of Atazanavir
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
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:
- 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:
Age validation, growth, mortality, and demographic modeling of spotted gully shark (Triakis megalopterus) from the southeast coast of South Africa
- Booth, Anthony J, Foulis, Alan J, Smale, Malcolm J
- Authors: Booth, Anthony J , Foulis, Alan J , Smale, Malcolm J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123630 , vital:35466 , https://spo.nmfs.noaa.gov/sites/default/files/pdf-content/2011/1091/booth.pdf
- Description: This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and f luoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0= –2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate.
- Full Text:
- Authors: Booth, Anthony J , Foulis, Alan J , Smale, Malcolm J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123630 , vital:35466 , https://spo.nmfs.noaa.gov/sites/default/files/pdf-content/2011/1091/booth.pdf
- Description: This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and f luoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0= –2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate.
- Full Text:
Aging, sex, death (and heavy metals)
- Authors: Limson, Janice L
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:589 , http://hdl.handle.net/10962/d1019732
- Description: Vice Chancellor's Distinguished Research Award Lecture August 2011
- Full Text:
- Authors: Limson, Janice L
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:589 , http://hdl.handle.net/10962/d1019732
- Description: Vice Chancellor's Distinguished Research Award Lecture August 2011
- Full Text:
An analysis of sources and predictability of geomagnetic storms
- Authors: Uwamahoro, Jean
- Date: 2011
- Subjects: Ionospheric storms Solar flares Interplanetary magnetic fields Magnetospheric substorms Coronal mass ejections Space environment Neural networks (Computer science)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5451 , http://hdl.handle.net/10962/d1005236
- Description: Solar transient eruptions are the main cause of interplanetary-magnetospheric disturbances leading to the phenomena known as geomagnetic storms. Eruptive solar events such as coronal mass ejections (CMEs) are currently considered the main cause of geomagnetic storms (GMS). GMS are strong perturbations of the Earth’s magnetic field that can affect space-borne and ground-based technological systems. The solar-terrestrial impact on modern technological systems is commonly known as Space Weather. Part of the research study described in this thesis was to investigate and establish a relationship between GMS (periods with Dst ≤ −50 nT) and their associated solar and interplanetary (IP) properties during solar cycle (SC) 23. Solar and IP geoeffective properties associated with or without CMEs were investigated and used to qualitatively characterise both intense and moderate storms. The results of this analysis specifically provide an estimate of the main sources of GMS during an average 11-year solar activity period. This study indicates that during SC 23, the majority of intense GMS (83%) were associated with CMEs, while the non-associated CME storms were dominant among moderate storms. GMS phenomena are the result of a complex and non-linear chaotic system involving the Sun, the IP medium, the magnetosphere and ionosphere, which make the prediction of these phenomena challenging. This thesis also explored the predictability of both the occurrence and strength of GMS. Due to their nonlinear driving mechanisms, the prediction of GMS was attempted by the use of neural network (NN) techniques, known for their non-linear modelling capabilities. To predict the occurrence of storms, a combination of solar and IP parameters were used as inputs in the NN model that proved to predict the occurrence of GMS with a probability of 87%. Using the solar wind (SW) and IP magnetic field (IMF) parameters, a separate NN-based model was developed to predict the storm-time strength as measured by the global Dst and ap geomagnetic indices, as well as by the locally measured K-index. The performance of the models was tested on data sets which were not part of the NN training process. The results obtained indicate that NN models provide a reliable alternative method for empirically predicting the occurrence and strength of GMS on the basis of solar and IP parameters. The demonstrated ability to predict the geoeffectiveness of solar and IP transient events is a key step in the goal towards improving space weather modelling and prediction.
- Full Text:
- Authors: Uwamahoro, Jean
- Date: 2011
- Subjects: Ionospheric storms Solar flares Interplanetary magnetic fields Magnetospheric substorms Coronal mass ejections Space environment Neural networks (Computer science)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5451 , http://hdl.handle.net/10962/d1005236
- Description: Solar transient eruptions are the main cause of interplanetary-magnetospheric disturbances leading to the phenomena known as geomagnetic storms. Eruptive solar events such as coronal mass ejections (CMEs) are currently considered the main cause of geomagnetic storms (GMS). GMS are strong perturbations of the Earth’s magnetic field that can affect space-borne and ground-based technological systems. The solar-terrestrial impact on modern technological systems is commonly known as Space Weather. Part of the research study described in this thesis was to investigate and establish a relationship between GMS (periods with Dst ≤ −50 nT) and their associated solar and interplanetary (IP) properties during solar cycle (SC) 23. Solar and IP geoeffective properties associated with or without CMEs were investigated and used to qualitatively characterise both intense and moderate storms. The results of this analysis specifically provide an estimate of the main sources of GMS during an average 11-year solar activity period. This study indicates that during SC 23, the majority of intense GMS (83%) were associated with CMEs, while the non-associated CME storms were dominant among moderate storms. GMS phenomena are the result of a complex and non-linear chaotic system involving the Sun, the IP medium, the magnetosphere and ionosphere, which make the prediction of these phenomena challenging. This thesis also explored the predictability of both the occurrence and strength of GMS. Due to their nonlinear driving mechanisms, the prediction of GMS was attempted by the use of neural network (NN) techniques, known for their non-linear modelling capabilities. To predict the occurrence of storms, a combination of solar and IP parameters were used as inputs in the NN model that proved to predict the occurrence of GMS with a probability of 87%. Using the solar wind (SW) and IP magnetic field (IMF) parameters, a separate NN-based model was developed to predict the storm-time strength as measured by the global Dst and ap geomagnetic indices, as well as by the locally measured K-index. The performance of the models was tested on data sets which were not part of the NN training process. The results obtained indicate that NN models provide a reliable alternative method for empirically predicting the occurrence and strength of GMS on the basis of solar and IP parameters. The demonstrated ability to predict the geoeffectiveness of solar and IP transient events is a key step in the goal towards improving space weather modelling and prediction.
- Full Text:
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:
- 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:
An analysis of the long run comovements between financial system development and mining production in South Africa
- Authors: Ajagbe, Stephen Mayowa
- Date: 2011
- Subjects: Economic development -- South Africa , Econometric models , Mineral industries -- Economic aspects -- South Africa , South Africa -- Economic conditions , South Africa -- Economic policy , Principal components analysis , Cointegration , Stock exchanges -- South Africa , Banks and banking -- South Africa , Foreign exchange rates
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:955 , http://hdl.handle.net/10962/d1002689 , Economic development -- South Africa , Econometric models , Mineral industries -- Economic aspects -- South Africa , South Africa -- Economic conditions , South Africa -- Economic policy , Principal components analysis , Cointegration , Stock exchanges -- South Africa , Banks and banking -- South Africa , Foreign exchange rates
- Description: This study examines the nature of the relationship which exists between mining sector production and development of the financial systems in South Africa. This is particularly important in that the mining sector is considered to be one of the major contributors to the country’s overall economic growth. South Africa is also considered to have a very well developed financial system, to the point where the dominance of one over the other is difficult to identify. Therefore offering insight into the nature of this relationship will assist policy makers in identifying the most effective policies in order to ensure that the developments within the financial systems impact appropriately on the mining sector, and ultimately on the economy. In addition to using the conventional proxies of financial system development, this study utilises the principal component analysis (PCA) to construct an index for the entire financial system. The multivariate cointegration approach as proposed by Johansen (1988) and Johansen and Juselius (1990) was then used to estimate the relationship between the development of the financial systems and the mining sector production for the period 1988-2008. The study reveals mixed results for different measures of financial system development. Those involving the banking system show that a negative relationship exists between total mining production and total credit extended to the private sector, while liquid liabilities has a positive relationship. Similarly, with the stock market system, mixed results are also obtained which reveal a negative relationship between total mining production and stock market capitalisation, while a positive relationship is found with secondary market turnover. Of all the financial system variables, only that of stock market capitalisation was found to be significant. The result with the financial development index reveals that a significant negative relationship exists between financial system development and total mining sector production. Results on the other variables controlled in the estimation show that positive and significant relationships exist between total mining production and both nominal exchange rate and political stability respectively. Increased mining production therefore takes place in periods of appreciating exchange rates, and similarly in the post-apartheid era. On the other hand, negative relationships were found for both trade openness and inflation control variables. The impulse response and variance decomposition analyses showed that total mining production explains the largest amount of shocks within itself. Overall, the study reveals that the mining sector might not have benefited much from the development in the South African financial system.
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- Authors: Ajagbe, Stephen Mayowa
- Date: 2011
- Subjects: Economic development -- South Africa , Econometric models , Mineral industries -- Economic aspects -- South Africa , South Africa -- Economic conditions , South Africa -- Economic policy , Principal components analysis , Cointegration , Stock exchanges -- South Africa , Banks and banking -- South Africa , Foreign exchange rates
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:955 , http://hdl.handle.net/10962/d1002689 , Economic development -- South Africa , Econometric models , Mineral industries -- Economic aspects -- South Africa , South Africa -- Economic conditions , South Africa -- Economic policy , Principal components analysis , Cointegration , Stock exchanges -- South Africa , Banks and banking -- South Africa , Foreign exchange rates
- Description: This study examines the nature of the relationship which exists between mining sector production and development of the financial systems in South Africa. This is particularly important in that the mining sector is considered to be one of the major contributors to the country’s overall economic growth. South Africa is also considered to have a very well developed financial system, to the point where the dominance of one over the other is difficult to identify. Therefore offering insight into the nature of this relationship will assist policy makers in identifying the most effective policies in order to ensure that the developments within the financial systems impact appropriately on the mining sector, and ultimately on the economy. In addition to using the conventional proxies of financial system development, this study utilises the principal component analysis (PCA) to construct an index for the entire financial system. The multivariate cointegration approach as proposed by Johansen (1988) and Johansen and Juselius (1990) was then used to estimate the relationship between the development of the financial systems and the mining sector production for the period 1988-2008. The study reveals mixed results for different measures of financial system development. Those involving the banking system show that a negative relationship exists between total mining production and total credit extended to the private sector, while liquid liabilities has a positive relationship. Similarly, with the stock market system, mixed results are also obtained which reveal a negative relationship between total mining production and stock market capitalisation, while a positive relationship is found with secondary market turnover. Of all the financial system variables, only that of stock market capitalisation was found to be significant. The result with the financial development index reveals that a significant negative relationship exists between financial system development and total mining sector production. Results on the other variables controlled in the estimation show that positive and significant relationships exist between total mining production and both nominal exchange rate and political stability respectively. Increased mining production therefore takes place in periods of appreciating exchange rates, and similarly in the post-apartheid era. On the other hand, negative relationships were found for both trade openness and inflation control variables. The impulse response and variance decomposition analyses showed that total mining production explains the largest amount of shocks within itself. Overall, the study reveals that the mining sector might not have benefited much from the development in the South African financial system.
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An art based support programme for the amelioration of general psychological distress in marginalised children in South Africa
- Authors: Armstrong, Meredith
- Date: 2011 , 2011-06-28
- Subjects: Art therapy for children Child mental health Group psychotherapy for children Abused children -- Mental health
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3096 , http://hdl.handle.net/10962/d1003730
- Description: This study aimed to construct, and implement an in-school "art expression" based programme designed to aid in mitigation of psychological stress, behavioural difficulties, and self-negativity frequently experienced by marginalised children. It was developed for application within schools that cater for children exposed to neglect and/or abuse resulting from poverty in South Africa. This programme outline was developed and implemented through intensive exploration and review of previously effective art therapy, art expressive methods and techniques in similar contexts, together with the knowledge and experience of a qualified art therapist and educational psychologist. Data was collected through open-ended informal qualitative interviews, observations, and photographs of artworks produced during sessions. These were then analysed in conjunction, using the content analysis method, visual interpretive measures and thematic analysis. This enquiry documented the process of art creation through "art expression", and its ability to ameliorate psychological difficulties affecting marginalised children in South Africa. Following the establishment of trust between the researchers and the participants, the results found that the use of different art modalities demonstrated predominantly positive results in varying degrees. It is hoped that this study can be used to further practical interventions of this nature in comparable milieus in South Africa.
- Full Text:
- Authors: Armstrong, Meredith
- Date: 2011 , 2011-06-28
- Subjects: Art therapy for children Child mental health Group psychotherapy for children Abused children -- Mental health
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3096 , http://hdl.handle.net/10962/d1003730
- Description: This study aimed to construct, and implement an in-school "art expression" based programme designed to aid in mitigation of psychological stress, behavioural difficulties, and self-negativity frequently experienced by marginalised children. It was developed for application within schools that cater for children exposed to neglect and/or abuse resulting from poverty in South Africa. This programme outline was developed and implemented through intensive exploration and review of previously effective art therapy, art expressive methods and techniques in similar contexts, together with the knowledge and experience of a qualified art therapist and educational psychologist. Data was collected through open-ended informal qualitative interviews, observations, and photographs of artworks produced during sessions. These were then analysed in conjunction, using the content analysis method, visual interpretive measures and thematic analysis. This enquiry documented the process of art creation through "art expression", and its ability to ameliorate psychological difficulties affecting marginalised children in South Africa. Following the establishment of trust between the researchers and the participants, the results found that the use of different art modalities demonstrated predominantly positive results in varying degrees. It is hoped that this study can be used to further practical interventions of this nature in comparable milieus in South Africa.
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An attempt to constrain the age, duration, and eruptive history of the Karoo flood basalt: Naude's Nek section (South Africa)
- Moulin, Maud, Fluteau, Frédéric, Courtillot, Vincent, Marsh, Julian S, Delpech, Guillaume, Quidelleur, Xavier, Gérard, Martine, Jay, Anne E
- Authors: Moulin, Maud , Fluteau, Frédéric , Courtillot, Vincent , Marsh, Julian S , Delpech, Guillaume , Quidelleur, Xavier , Gérard, Martine , Jay, Anne E
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145022 , vital:38401 , https://doi.org/10.1029/2011JB008210
- Description: We have carried out paleomagnetic sampling of a ∼750 m sequence of the Karoo large igneous province (Naude's Nek Pass, South Africa). K‐Ar dating (Cassignol‐Gillot) has been performed on four samples from the 650 m upper unit (mean age 179.2 ± 1.8 Ma) and a sample from the lower unit (184.8 ± 2.6 Ma). A succession of two phases of volcanism is suggested. The lower 25 flows (115 m thick) have recorded a reversed polarity; the next 23 flows (135 m thick) are transitional and contribute a detailed record of the “Van Zijl” (1962) Jurassic reversal.
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- Authors: Moulin, Maud , Fluteau, Frédéric , Courtillot, Vincent , Marsh, Julian S , Delpech, Guillaume , Quidelleur, Xavier , Gérard, Martine , Jay, Anne E
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145022 , vital:38401 , https://doi.org/10.1029/2011JB008210
- Description: We have carried out paleomagnetic sampling of a ∼750 m sequence of the Karoo large igneous province (Naude's Nek Pass, South Africa). K‐Ar dating (Cassignol‐Gillot) has been performed on four samples from the 650 m upper unit (mean age 179.2 ± 1.8 Ma) and a sample from the lower unit (184.8 ± 2.6 Ma). A succession of two phases of volcanism is suggested. The lower 25 flows (115 m thick) have recorded a reversed polarity; the next 23 flows (135 m thick) are transitional and contribute a detailed record of the “Van Zijl” (1962) Jurassic reversal.
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An ethics of care for health journalists (and their editors): doing journalism.
- Authors: Dugmore, Harry
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454636 , vital:75361 , https://hdl.handle.net/10520/EJC135803
- Description: Health journalists are not immune from pressures to break great stories before the opposition does and, in the digital age, all stories have to be entertaining and enticing to be read. So how do we think about the eth-ics of health journalism in the 21st century? Does health journalism, because it is about health, a special case, require different ethics to that of other subjects covered by journalists?
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- Authors: Dugmore, Harry
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454636 , vital:75361 , https://hdl.handle.net/10520/EJC135803
- Description: Health journalists are not immune from pressures to break great stories before the opposition does and, in the digital age, all stories have to be entertaining and enticing to be read. So how do we think about the eth-ics of health journalism in the 21st century? Does health journalism, because it is about health, a special case, require different ethics to that of other subjects covered by journalists?
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