Learning pathways of key occupations relevant to sustainable development in Makana Municipality
- Authors: Mohanoe, Elma Nthabiseng
- Date: 2014
- Subjects: Makana Municipality , Sustainable development -- South Africa -- Grahamstown , Municipal government -- South Africa -- Grahamstown , Environmental education -- South Africa -- Grahamstown , Sustainable development -- Study and teaching -- South Africa -- Grahamstown , Vocational qualifications -- South Africa -- Grahamstown , Organizational learning -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1990 , http://hdl.handle.net/10962/d1013322
- Description: This study presents results to be contributed to the field of Environmental Education. It is a new arena for qualifications development and implementation in the South African Education and Training system. The study is located in the context of a joint research programme focusing on understanding issues of articulation and learning pathways development for sustainable development, established between the South African Qualifications Authority (SAQA) in partnership with Rhodes University, Environmental Learning Research Centre (ELRC). Phase 1 of the SAQA/ELRC research showed that researching workplace learning requires an understanding of learning pathways, if it is to be meaningful. It is for this reason that this research in phase 2 focuses specifically on learning pathways in the context of a local municipality in Makana. Using a case study research approach and qualitative data, this study investigated learning pathways for three occupational categories at different levels in the Makana Municipality: 1) key managerial occupations; 2) key supervisory occupations; and 3) key workers occupations relevant to sustainable development and how they are shaped and experienced. It also identified system and structural factors influencing articulation and access issues relevant to progress in learning pathways relevant to these key occupations. The study was designed using a case study research. Primarily, qualitative research techniques were employed to generate data, including observations, interviews and document analysis. The study used inductive, abductive and retroductive modes of inference to interpret and analyse data, using critical realist and systems perspectives. The findings on worker learning pathways show that there is a discrepancy between the Training Policy and the Environmental Training and Education Strategy of Makana Municipality. The issue of complexity in learning pathways and social structural factors such as inequality emerged as factors that strongly influenced learning pathways for workers. Learning pathways for workers involved in sustainable development practices hardly existed or simply did not exist. Interesting transitions associated with learning pathways such as from home, to work or no schooling in the case of the workers, showed a pattern of emergence. These showed that learning pathways are not accessible and equally available to everyone as can often erroneously be assumed. The findings on supervisor learning pathways show diverse complexities as well as related issues, when compared to the worker’s learning pathways. Issues such as overlapping of study and work emerge as influential to supervisor learning pathways. Lack of support is, however, an influencing factor, but in a different context compared to the workers, and mainly focuses on lack of bursaries, highlighting training policy issues. This aspect was found to also relate to lack of proper resources in order to enable them to learn and do their job better; an issue raised by the workers too. This challenge of lack of support in various forms posed a barrier to learning pathways. Findings related to the manager’s learning pathways show a noticeable gap between the workers, supervisors and managers. The manager’s generally have higher education qualifications related to sustainable development, and in certain cases managers have had exposure to international training related to sustainable development. Factors such as ample opportunities for learning, mentoring, association on professional bodies, and decision making powers influenced the manager’s learning pathways. It was also notable that while managers receive occupationally directed training, it is not necessarily sustainable development related. In theory, the results highlighted a need to understand systems as a whole and how their integration is important in influencing learning pathways. There were also underlying mechanisms and structures identified which needed to be unravelled and understood as these were found to influence learning pathways in this study. The study highlighted critical insights in understanding how learning pathways in a local municipality context (the case of Makana Municipality) are constructed by both systems and structural factors in the workplace, while also identifying ways in which agency of those engaged in learning for sustainable development in workplaces is enabled and /or constrained by such factors. It also showed the persistence of deep-seated inequalities of opportunity, especially for workers, to access and participate in sustainable development learning pathways.
- Full Text:
- Authors: Mohanoe, Elma Nthabiseng
- Date: 2014
- Subjects: Makana Municipality , Sustainable development -- South Africa -- Grahamstown , Municipal government -- South Africa -- Grahamstown , Environmental education -- South Africa -- Grahamstown , Sustainable development -- Study and teaching -- South Africa -- Grahamstown , Vocational qualifications -- South Africa -- Grahamstown , Organizational learning -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1990 , http://hdl.handle.net/10962/d1013322
- Description: This study presents results to be contributed to the field of Environmental Education. It is a new arena for qualifications development and implementation in the South African Education and Training system. The study is located in the context of a joint research programme focusing on understanding issues of articulation and learning pathways development for sustainable development, established between the South African Qualifications Authority (SAQA) in partnership with Rhodes University, Environmental Learning Research Centre (ELRC). Phase 1 of the SAQA/ELRC research showed that researching workplace learning requires an understanding of learning pathways, if it is to be meaningful. It is for this reason that this research in phase 2 focuses specifically on learning pathways in the context of a local municipality in Makana. Using a case study research approach and qualitative data, this study investigated learning pathways for three occupational categories at different levels in the Makana Municipality: 1) key managerial occupations; 2) key supervisory occupations; and 3) key workers occupations relevant to sustainable development and how they are shaped and experienced. It also identified system and structural factors influencing articulation and access issues relevant to progress in learning pathways relevant to these key occupations. The study was designed using a case study research. Primarily, qualitative research techniques were employed to generate data, including observations, interviews and document analysis. The study used inductive, abductive and retroductive modes of inference to interpret and analyse data, using critical realist and systems perspectives. The findings on worker learning pathways show that there is a discrepancy between the Training Policy and the Environmental Training and Education Strategy of Makana Municipality. The issue of complexity in learning pathways and social structural factors such as inequality emerged as factors that strongly influenced learning pathways for workers. Learning pathways for workers involved in sustainable development practices hardly existed or simply did not exist. Interesting transitions associated with learning pathways such as from home, to work or no schooling in the case of the workers, showed a pattern of emergence. These showed that learning pathways are not accessible and equally available to everyone as can often erroneously be assumed. The findings on supervisor learning pathways show diverse complexities as well as related issues, when compared to the worker’s learning pathways. Issues such as overlapping of study and work emerge as influential to supervisor learning pathways. Lack of support is, however, an influencing factor, but in a different context compared to the workers, and mainly focuses on lack of bursaries, highlighting training policy issues. This aspect was found to also relate to lack of proper resources in order to enable them to learn and do their job better; an issue raised by the workers too. This challenge of lack of support in various forms posed a barrier to learning pathways. Findings related to the manager’s learning pathways show a noticeable gap between the workers, supervisors and managers. The manager’s generally have higher education qualifications related to sustainable development, and in certain cases managers have had exposure to international training related to sustainable development. Factors such as ample opportunities for learning, mentoring, association on professional bodies, and decision making powers influenced the manager’s learning pathways. It was also notable that while managers receive occupationally directed training, it is not necessarily sustainable development related. In theory, the results highlighted a need to understand systems as a whole and how their integration is important in influencing learning pathways. There were also underlying mechanisms and structures identified which needed to be unravelled and understood as these were found to influence learning pathways in this study. The study highlighted critical insights in understanding how learning pathways in a local municipality context (the case of Makana Municipality) are constructed by both systems and structural factors in the workplace, while also identifying ways in which agency of those engaged in learning for sustainable development in workplaces is enabled and /or constrained by such factors. It also showed the persistence of deep-seated inequalities of opportunity, especially for workers, to access and participate in sustainable development learning pathways.
- Full Text:
Lignocellulosic waste degradation using enzyme synergy with commercially available enzymes and Clostridium cellulovorans XylanaseA and MannanaseA
- Authors: Morrison, David Graham
- Date: 2014
- Subjects: Lignocellulose -- Biodegradation , Enzymes -- Biotechnology , Agricultural wastes as fuel , Polysaccharides -- Biotechnology , Sugar -- Inversion , Clostridium , Xylanases , Monomers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4119 , http://hdl.handle.net/10962/d1013292
- Description: The launch of national and international initiatives to reduce pollution, reliance on fossil fuels and increase the beneficiation of agricultural wastes has prompted research into sugar monomer production from lignocellulosic wastes. These sugars can subsequently be used in the production of biofuels and environmentally degradable plastics. This study investigated the use of synergistic combinations of commercial and pure enzymes to lower enzyme costs and loadings, while increasing enzyme activity in the hydrolysis of agricultural waste. Pineapple pomace was selected due to its current underutilisation and the substantial quantities of it produced annually, as a by-product of pineapple canning. One of the primary costs in beneficiating agricultural wastes, such as pineapple pomace, is the high cost of enzyme solutions used to generate reducing sugars. This can be lowered through the use of synergistic combinations of enzymes. Studies related to the inclusion of hemicellulose degrading enzymes with commercial enzyme solutions have been limited and investigation of these solutions in select combinations, together with pineapple pomace substrate, allows for novel research. The use of synergistic combinations of purified cellulosomal enzymes has previously been shown to be effective at releasing reducing sugars from agricultural wastes. For the present study, MannanaseA and XylanaseA from Clostridium cellulovorans were heterologously expressed in Escherichia coli BL21 (DE3) cells and purified with immobilised metal affinity chromatography. These enzymes, in addition to two commercially available enzyme solutions (Celluclast 1.5L® and Pectinex® 3XL), were assayed on defined polysaccharides that are present in pineapple pomace to determine their substrate specificities. The degree(s) of synergy and specific activities of selected combinations of these enzymes were tested under both simultaneous and sequential conditions. It was observed that several synergistic combinations of enzyme solutions in select ratios, such as C20P60X20 (20% cellulose, 60% pectinase and 20% xylanse), C20P40X40 (20% cellulose, 40% pectinase and 40% xylanase) and C20P80 (20% cellulose, 80% pectinase) with pineapple pomace could both decrease the protein loading, while raising the level of activity compared to individual enzyme solutions. The highest quantity of reducing sugars to protein weight used on pineapple pomace was recorded at 3, 9 and 18 hours with combinations of Pectinex® 3XL and Celluclast 1.5L®, but for 27 h it was combinations of both these commercial solutions with XynA. The contribution of XynA was significant as C20P60X20 displayed the second highest reducing sugar production of 1.521 mg/mL, at 36 h from 12.875 μg/mL of protein, which was the second lowest protein loading. It was also shown that certain enzyme combinations, such as Pectinex® 3XL, Celluclast 1.5L® and XynA, did not generate synergy when combined in solution at the initial stages of hydrolysis, and instead generated a form of competition called anti-synergy. This was due to Pectinex® 3XL which had anti-synergy relationships in select combinations with the other enzyme solutions assayed. It was also observed that the degree of synergy and specific activity for a combination changed over time. Some solutions displayed the highest levels of synergy at the commencement of hydrolysis, namely Celluclast 1.5L®, ManA and XynA. Other combinations exhibited the highest levels of synergy at the end of the assay period, such as Pectinex® 3XL and Celluclast 1.5L®. Whether greater synergy was generated at the start or end of hydrolysis was a function of the stability of the enzymes in solution and whether enzyme activity increased substrate accessibility or generated competition between enzymes in solution. Sequential synergy studies demonstrated an anti-synergy relationship between Pectinex® 3XL and XynA or ManA, as well as Pectinex® 3 XL and Celluclast 1.5L®. It was found that under sequential synergy conditions with Pectinex® 3 XL, XynA and ManA, that anti-synergy could be negated and high degrees of synergy attained when the enzymes were added in specific loading orders and not inhibited by the presence of other active enzymes. The importance of loading order was demonstrated under sequential synergy conditions when XynA was added before ManA followed by Pectinex® 3 XL, which increased the activity and synergy of the solution by 50%. This equates to a 60% increase in reducing sugar release from the same concentrations of enzymes and emphasises the importance of removing anti-synergy relationships from combinations of enzymes. It can be concluded that a C20P60X20 combination (based on activity) can both synergistically increase the reducing sugar production and lower the protein loading required for pineapple pomace hydrolysis. This study also highlights the importance of reducing anti-synergy in customised enzyme cocktails and how sequential synergy can demonstrate the order in which a lignocellulosic waste is degraded.
- Full Text:
- Authors: Morrison, David Graham
- Date: 2014
- Subjects: Lignocellulose -- Biodegradation , Enzymes -- Biotechnology , Agricultural wastes as fuel , Polysaccharides -- Biotechnology , Sugar -- Inversion , Clostridium , Xylanases , Monomers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4119 , http://hdl.handle.net/10962/d1013292
- Description: The launch of national and international initiatives to reduce pollution, reliance on fossil fuels and increase the beneficiation of agricultural wastes has prompted research into sugar monomer production from lignocellulosic wastes. These sugars can subsequently be used in the production of biofuels and environmentally degradable plastics. This study investigated the use of synergistic combinations of commercial and pure enzymes to lower enzyme costs and loadings, while increasing enzyme activity in the hydrolysis of agricultural waste. Pineapple pomace was selected due to its current underutilisation and the substantial quantities of it produced annually, as a by-product of pineapple canning. One of the primary costs in beneficiating agricultural wastes, such as pineapple pomace, is the high cost of enzyme solutions used to generate reducing sugars. This can be lowered through the use of synergistic combinations of enzymes. Studies related to the inclusion of hemicellulose degrading enzymes with commercial enzyme solutions have been limited and investigation of these solutions in select combinations, together with pineapple pomace substrate, allows for novel research. The use of synergistic combinations of purified cellulosomal enzymes has previously been shown to be effective at releasing reducing sugars from agricultural wastes. For the present study, MannanaseA and XylanaseA from Clostridium cellulovorans were heterologously expressed in Escherichia coli BL21 (DE3) cells and purified with immobilised metal affinity chromatography. These enzymes, in addition to two commercially available enzyme solutions (Celluclast 1.5L® and Pectinex® 3XL), were assayed on defined polysaccharides that are present in pineapple pomace to determine their substrate specificities. The degree(s) of synergy and specific activities of selected combinations of these enzymes were tested under both simultaneous and sequential conditions. It was observed that several synergistic combinations of enzyme solutions in select ratios, such as C20P60X20 (20% cellulose, 60% pectinase and 20% xylanse), C20P40X40 (20% cellulose, 40% pectinase and 40% xylanase) and C20P80 (20% cellulose, 80% pectinase) with pineapple pomace could both decrease the protein loading, while raising the level of activity compared to individual enzyme solutions. The highest quantity of reducing sugars to protein weight used on pineapple pomace was recorded at 3, 9 and 18 hours with combinations of Pectinex® 3XL and Celluclast 1.5L®, but for 27 h it was combinations of both these commercial solutions with XynA. The contribution of XynA was significant as C20P60X20 displayed the second highest reducing sugar production of 1.521 mg/mL, at 36 h from 12.875 μg/mL of protein, which was the second lowest protein loading. It was also shown that certain enzyme combinations, such as Pectinex® 3XL, Celluclast 1.5L® and XynA, did not generate synergy when combined in solution at the initial stages of hydrolysis, and instead generated a form of competition called anti-synergy. This was due to Pectinex® 3XL which had anti-synergy relationships in select combinations with the other enzyme solutions assayed. It was also observed that the degree of synergy and specific activity for a combination changed over time. Some solutions displayed the highest levels of synergy at the commencement of hydrolysis, namely Celluclast 1.5L®, ManA and XynA. Other combinations exhibited the highest levels of synergy at the end of the assay period, such as Pectinex® 3XL and Celluclast 1.5L®. Whether greater synergy was generated at the start or end of hydrolysis was a function of the stability of the enzymes in solution and whether enzyme activity increased substrate accessibility or generated competition between enzymes in solution. Sequential synergy studies demonstrated an anti-synergy relationship between Pectinex® 3XL and XynA or ManA, as well as Pectinex® 3 XL and Celluclast 1.5L®. It was found that under sequential synergy conditions with Pectinex® 3 XL, XynA and ManA, that anti-synergy could be negated and high degrees of synergy attained when the enzymes were added in specific loading orders and not inhibited by the presence of other active enzymes. The importance of loading order was demonstrated under sequential synergy conditions when XynA was added before ManA followed by Pectinex® 3 XL, which increased the activity and synergy of the solution by 50%. This equates to a 60% increase in reducing sugar release from the same concentrations of enzymes and emphasises the importance of removing anti-synergy relationships from combinations of enzymes. It can be concluded that a C20P60X20 combination (based on activity) can both synergistically increase the reducing sugar production and lower the protein loading required for pineapple pomace hydrolysis. This study also highlights the importance of reducing anti-synergy in customised enzyme cocktails and how sequential synergy can demonstrate the order in which a lignocellulosic waste is degraded.
- Full Text:
Linking satellite and point micrometeorological data to estimate : distributed evapotranspiration modelling based on MODIS LAI, Penman-Monteith and functional convergence theory
- Authors: Weideman, Craig Ivan
- Date: 2014
- Subjects: Plants -- Water requirements -- South Africa , Evaporation (Meteorology) -- Measurement , Satellite meteorology , Micrometeorology , Evapotranspiration , MODIS (Spectroradiometer)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4779 , http://hdl.handle.net/10962/d1012078 , Plants -- Water requirements -- South Africa , Evaporation (Meteorology) -- Measurement , Satellite meteorology , Micrometeorology , Evapotranspiration , MODIS (Spectroradiometer)
- Description: Recent advances in satellite sensor technology and micrometeorological instrumentation for water flux measurement, coupled with the expansion of automatic weather station networks that provide routine measurements of near-surface climate variables, present new opportunities for combining satellite and ground-based instrumentation to obtain distributed estimates of vegetation water use over wide areas in South Africa. In this study, a novel approach is tested, which uses satellite leaf area index (LAI) data retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) to inform the FAO-56 Penman-Monteith equation for calculating reference evaporation (ET₀) of vegetation phenological activity. The model (ETMODIS) was validated at four sites in three different ecosystems across the country, including semi-arid savanna near Skukuza, mixed community grassland at Bellevue, near Pietermaritzburg, and Groenkop, a mixed evergreen indigenous forest near George, to determine potential for application over wider areas of the South African land surface towards meeting water resource management objectives. At Skukuza, evaluated against 170 days of flux data measured at a permanent eddy covariance (EC) flux tower in 2007, the model (ETMODIS) predicted 194.8 mm evapotranspiration relative to 148.9 mm measured fluxes, an overestimate of 31.7 %, (r² = 0.67). At an adjacent site, evaluated against flux data measured on two discrete periods of seven and eight days in February and May of 2005 using a large aperture scintillometer (SLS), ETMODIS predicted 27.4 mm and 6.7 mm evapotranspiration respectively, relative to measured fluxes of 32.5 and 8.2 mm, underestimates of 15.7 % and 18.3 % in each case (r² = 0.67 and 0.34, respectively). At Bellevue, evaluated against 235 days of evapotranspiration data measured using a surface layer scintillometer (SLS) in 2003, ETMODIS predicted 266.9 mm evapotranspiration relative to 460.2 mm measured fluxes, an underestimate of 42 % (r² = 0.67). At Groenkop, evaluated against data measured using a SLS over three discrete periods of four, seven and seven days in February, June and September/October respectively, ETMODIS predicted 9.7 mm, 10.3 mm and 17.0 mm evapotranspiration, relative to measured fluxes of 10.9 mm, 14.6 mm and 23. 9 mm, underestimates of 22.4 %, 11.2 % and 24.1 % in each case (r² = 0.98, 0.43 and 0.80, respectively). Total measured evapotranspiration exceeded total modelled evapotranspiration in all cases, with the exception of the flux tower site at Skukuza, where evapotranspiration was overestimated by ETMODIS by 31.7 % relative to measured (EC) values for the 170 days in 2007 where corresponding modelled and measured data were available. The most significant differences in measured versus predicted data were recorded at the Skukuza flux tower site in 2007 (31.7 % overestimate), and the Bellevue SLS flux site in 2003 (42 % underestimate); coefficients of determination, a measure of the extent to which modelled data are able to explain observed data at validation periods, with just two exceptions, were within a range of 0.67 – 0.98. Several sources of error and uncertainty were identified, relating predominantly to uncertainties in measured flux data used to evaluate ETMODIS, uncertainties in MODIS LAI submitted to ETMODIS, and uncertainties in ETMODIS itself, including model assumptions, and specific uncertainties relating to various inputs; further application of the model is required to test these uncertainties however, and establish confidence limits in performance. Nevertheless, the results of this study suggest that the technique is generally able to produce estimates of vegetation water use to within reasonably close approximations of measurements acquired using micrometeorological instruments, with r² values within the range of other peer-reviewed satellite remote sensing-based approaches.
- Full Text:
- Authors: Weideman, Craig Ivan
- Date: 2014
- Subjects: Plants -- Water requirements -- South Africa , Evaporation (Meteorology) -- Measurement , Satellite meteorology , Micrometeorology , Evapotranspiration , MODIS (Spectroradiometer)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4779 , http://hdl.handle.net/10962/d1012078 , Plants -- Water requirements -- South Africa , Evaporation (Meteorology) -- Measurement , Satellite meteorology , Micrometeorology , Evapotranspiration , MODIS (Spectroradiometer)
- Description: Recent advances in satellite sensor technology and micrometeorological instrumentation for water flux measurement, coupled with the expansion of automatic weather station networks that provide routine measurements of near-surface climate variables, present new opportunities for combining satellite and ground-based instrumentation to obtain distributed estimates of vegetation water use over wide areas in South Africa. In this study, a novel approach is tested, which uses satellite leaf area index (LAI) data retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) to inform the FAO-56 Penman-Monteith equation for calculating reference evaporation (ET₀) of vegetation phenological activity. The model (ETMODIS) was validated at four sites in three different ecosystems across the country, including semi-arid savanna near Skukuza, mixed community grassland at Bellevue, near Pietermaritzburg, and Groenkop, a mixed evergreen indigenous forest near George, to determine potential for application over wider areas of the South African land surface towards meeting water resource management objectives. At Skukuza, evaluated against 170 days of flux data measured at a permanent eddy covariance (EC) flux tower in 2007, the model (ETMODIS) predicted 194.8 mm evapotranspiration relative to 148.9 mm measured fluxes, an overestimate of 31.7 %, (r² = 0.67). At an adjacent site, evaluated against flux data measured on two discrete periods of seven and eight days in February and May of 2005 using a large aperture scintillometer (SLS), ETMODIS predicted 27.4 mm and 6.7 mm evapotranspiration respectively, relative to measured fluxes of 32.5 and 8.2 mm, underestimates of 15.7 % and 18.3 % in each case (r² = 0.67 and 0.34, respectively). At Bellevue, evaluated against 235 days of evapotranspiration data measured using a surface layer scintillometer (SLS) in 2003, ETMODIS predicted 266.9 mm evapotranspiration relative to 460.2 mm measured fluxes, an underestimate of 42 % (r² = 0.67). At Groenkop, evaluated against data measured using a SLS over three discrete periods of four, seven and seven days in February, June and September/October respectively, ETMODIS predicted 9.7 mm, 10.3 mm and 17.0 mm evapotranspiration, relative to measured fluxes of 10.9 mm, 14.6 mm and 23. 9 mm, underestimates of 22.4 %, 11.2 % and 24.1 % in each case (r² = 0.98, 0.43 and 0.80, respectively). Total measured evapotranspiration exceeded total modelled evapotranspiration in all cases, with the exception of the flux tower site at Skukuza, where evapotranspiration was overestimated by ETMODIS by 31.7 % relative to measured (EC) values for the 170 days in 2007 where corresponding modelled and measured data were available. The most significant differences in measured versus predicted data were recorded at the Skukuza flux tower site in 2007 (31.7 % overestimate), and the Bellevue SLS flux site in 2003 (42 % underestimate); coefficients of determination, a measure of the extent to which modelled data are able to explain observed data at validation periods, with just two exceptions, were within a range of 0.67 – 0.98. Several sources of error and uncertainty were identified, relating predominantly to uncertainties in measured flux data used to evaluate ETMODIS, uncertainties in MODIS LAI submitted to ETMODIS, and uncertainties in ETMODIS itself, including model assumptions, and specific uncertainties relating to various inputs; further application of the model is required to test these uncertainties however, and establish confidence limits in performance. Nevertheless, the results of this study suggest that the technique is generally able to produce estimates of vegetation water use to within reasonably close approximations of measurements acquired using micrometeorological instruments, with r² values within the range of other peer-reviewed satellite remote sensing-based approaches.
- Full Text:
Lived bodies: women’s experience of sex and gender
- Authors: Lothian, Julie-Anne
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/69445 , vital:29538
- Description: This thesis will discuss the category of women, as a social group, through a phenomenological understanding of women’s subjective experiences. In arguing for the phenomenological perspective of the lived body, I show the ways in which other conceptions of women’s embodied subjectivity ultimately fail to provide comprehensive accounts of the lived experience of being a woman. I begin with an investigation into how biological determinists hypothesise women’s bodies as sexed. I then move to respond to Judith Butler’s poststructuralist feminist account of the gendered body. Finally, I argue that the embodied experience of being a woman is best explained as an ambiguous relationship between socially constructed expectations of femininity and biological materiality.
- Full Text:
- Authors: Lothian, Julie-Anne
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/69445 , vital:29538
- Description: This thesis will discuss the category of women, as a social group, through a phenomenological understanding of women’s subjective experiences. In arguing for the phenomenological perspective of the lived body, I show the ways in which other conceptions of women’s embodied subjectivity ultimately fail to provide comprehensive accounts of the lived experience of being a woman. I begin with an investigation into how biological determinists hypothesise women’s bodies as sexed. I then move to respond to Judith Butler’s poststructuralist feminist account of the gendered body. Finally, I argue that the embodied experience of being a woman is best explained as an ambiguous relationship between socially constructed expectations of femininity and biological materiality.
- Full Text:
Losing, using, refusing, cruising : first-generation South African women academics narrate the complexity of marginality
- Authors: Idahosa, Grace Ese-Osa
- Date: 2014
- Subjects: Women in higher education -- Research -- South Africa , Women college teachers -- Research -- South Africa , Sex discrimination in higher education -- Research -- South Africa , Feminism and higher education -- South Africa , Marginality, Social -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2880 , http://hdl.handle.net/10962/d1013148
- Description: While existing literature shows a considerable increase in the numbers of women in academia research on the experiences of women in universities has noted their continued occupation of lower status academic positions in relation to their male counterparts. As the ladder gets higher, the number of women seems to drop. These studies indicate the marginalization of women in academic settings, highlighting the various forms of subtle and overt discrimination and exclusion women face in academic work environments. In this study I ask how academic women in South Africa narrate their experience of being ‘outside in’ the teaching machine. It has been argued that intertwined sexist, patriarchal and phallocentric knowledges and practices in academic institutions produce various forms of discrimination, inequality, oppression and marginalization. Academic women report feeling invisible and retreating to the margins so as to avoid victimization and discrimination. Others have pointed to the tension between the ‘tenure clock’ and the ‘biological clock’ as a source of anxiety among academic women. Where a masculinised presentation of the self is adopted as a solution to this dilemma, the devaluation of the feminine in the academic space is confirmed. However, experiences of academic women are not identical. In the context of studies showing the importance of existing personal and social resources, prior experience and having mentors and role models in the negotiation of inequality and discrimination, I document the narratives of women academics who are the first in their families to graduate with a university degree. These first-generation academic women are therefore least likely to have access to social and cultural resources and prior experiences that can render the academic space more hospitable for the marginalised. Employing Spivak’s deconstruction of the concept of marginalisation as my primary interpretive lens, I explore the way in which, in their narratives, first-generation academic women negotiate marginality. These narratives depict a marginality that might be described, following Spivak, as ‘outside/in’, that is, as complex and involving moments of accommodation and resistance, losses and gains, pain and pride.
- Full Text:
- Authors: Idahosa, Grace Ese-Osa
- Date: 2014
- Subjects: Women in higher education -- Research -- South Africa , Women college teachers -- Research -- South Africa , Sex discrimination in higher education -- Research -- South Africa , Feminism and higher education -- South Africa , Marginality, Social -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2880 , http://hdl.handle.net/10962/d1013148
- Description: While existing literature shows a considerable increase in the numbers of women in academia research on the experiences of women in universities has noted their continued occupation of lower status academic positions in relation to their male counterparts. As the ladder gets higher, the number of women seems to drop. These studies indicate the marginalization of women in academic settings, highlighting the various forms of subtle and overt discrimination and exclusion women face in academic work environments. In this study I ask how academic women in South Africa narrate their experience of being ‘outside in’ the teaching machine. It has been argued that intertwined sexist, patriarchal and phallocentric knowledges and practices in academic institutions produce various forms of discrimination, inequality, oppression and marginalization. Academic women report feeling invisible and retreating to the margins so as to avoid victimization and discrimination. Others have pointed to the tension between the ‘tenure clock’ and the ‘biological clock’ as a source of anxiety among academic women. Where a masculinised presentation of the self is adopted as a solution to this dilemma, the devaluation of the feminine in the academic space is confirmed. However, experiences of academic women are not identical. In the context of studies showing the importance of existing personal and social resources, prior experience and having mentors and role models in the negotiation of inequality and discrimination, I document the narratives of women academics who are the first in their families to graduate with a university degree. These first-generation academic women are therefore least likely to have access to social and cultural resources and prior experiences that can render the academic space more hospitable for the marginalised. Employing Spivak’s deconstruction of the concept of marginalisation as my primary interpretive lens, I explore the way in which, in their narratives, first-generation academic women negotiate marginality. These narratives depict a marginality that might be described, following Spivak, as ‘outside/in’, that is, as complex and involving moments of accommodation and resistance, losses and gains, pain and pride.
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Manager's perceptions of performance appraisal implemented at Kansanshi Mine, Zambia
- Authors: Silimi, Maimbo Mark
- Date: 2014
- Subjects: Employees -- Rating of -- Zambia , Personnel management , Mineral industries -- Employees , Job satisfaction , Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:831 , http://hdl.handle.net/10962/d1013037
- Description: As managers with direct contact with workers on the floor, line managers are responsible for implementation of the performance appraisal system at Kansanshi Mining plc. Commonly, implementation of performance appraisal is affected by how line managers interact with their subordinates before, during and after an appraisal interview. Notably, no study has been conducted at Kansanshi mine to understand how line managers conduct performance appraisals since their introduction. This qualitative study aims to build an understanding of how line managers at Kansanshi conduct performance appraisal interviews and what enablers and barriers they face in this process. In pursuit of the research aim, line managers from all the ten departments of the mine were considered as eligible for the study. Using stratified random sampling, ten of the 30 line managers from all ten departments across the mine site were selected. A total of fifteen semi-structured, in-depth, face-to-face interviews were conducted with ten line managers to gather data. These individual interviews were conducted on the mine site in the interviewees' offices as well as other convenient places such as the Kansanshi main boardroom. On average, each interview took between 45 to 60 minutes. All these interviews were audio recorded, transcribed and thereafter analyzed using open coding and constant comparison technique to induce themes. Findings of the study show a variety of barriers and enablers of line managers in their conduct of performance appraisal interviews at Kansanshi mine in Zambia. All ten line managers unanimously highlighted that (a) lack of clear job descriptions and set of individual targets as well as (b) lack of adequate refresher training on how to conduct performance appraisals affected how they conducted performance appraisals. Eight of the ten line managers highlighted that (c) perceived subjectivity of the system while seven of the ten highlighted that (d) predominant production focus and priority were barriers to them in how they conducted performance appraisals. On the other hand, ten line managers highlighted that (a) top management commitment to the implementation of a performance appraisal system, seven highlighted that (b) employees' hope for rewards and five line managers highlighted that (c) spring for career development and progression were perceived as enablers in their implementation of performance appraisals. This research is of value as it highlights how the conduct of performance is not only impacted by organizational support and other complementary organizational systems but also how the barriers to the conduct of performance appraisals affect both the appraisee and the appraiser.
- Full Text:
- Authors: Silimi, Maimbo Mark
- Date: 2014
- Subjects: Employees -- Rating of -- Zambia , Personnel management , Mineral industries -- Employees , Job satisfaction , Employee motivation
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:831 , http://hdl.handle.net/10962/d1013037
- Description: As managers with direct contact with workers on the floor, line managers are responsible for implementation of the performance appraisal system at Kansanshi Mining plc. Commonly, implementation of performance appraisal is affected by how line managers interact with their subordinates before, during and after an appraisal interview. Notably, no study has been conducted at Kansanshi mine to understand how line managers conduct performance appraisals since their introduction. This qualitative study aims to build an understanding of how line managers at Kansanshi conduct performance appraisal interviews and what enablers and barriers they face in this process. In pursuit of the research aim, line managers from all the ten departments of the mine were considered as eligible for the study. Using stratified random sampling, ten of the 30 line managers from all ten departments across the mine site were selected. A total of fifteen semi-structured, in-depth, face-to-face interviews were conducted with ten line managers to gather data. These individual interviews were conducted on the mine site in the interviewees' offices as well as other convenient places such as the Kansanshi main boardroom. On average, each interview took between 45 to 60 minutes. All these interviews were audio recorded, transcribed and thereafter analyzed using open coding and constant comparison technique to induce themes. Findings of the study show a variety of barriers and enablers of line managers in their conduct of performance appraisal interviews at Kansanshi mine in Zambia. All ten line managers unanimously highlighted that (a) lack of clear job descriptions and set of individual targets as well as (b) lack of adequate refresher training on how to conduct performance appraisals affected how they conducted performance appraisals. Eight of the ten line managers highlighted that (c) perceived subjectivity of the system while seven of the ten highlighted that (d) predominant production focus and priority were barriers to them in how they conducted performance appraisals. On the other hand, ten line managers highlighted that (a) top management commitment to the implementation of a performance appraisal system, seven highlighted that (b) employees' hope for rewards and five line managers highlighted that (c) spring for career development and progression were perceived as enablers in their implementation of performance appraisals. This research is of value as it highlights how the conduct of performance is not only impacted by organizational support and other complementary organizational systems but also how the barriers to the conduct of performance appraisals affect both the appraisee and the appraiser.
- Full Text:
Marikana : taking a subaltern sphere of politics seriously
- Authors: Naicker, Camalita
- Date: 2014
- Subjects: Miners -- South Africa -- Rustenburg -- Social conditions -- 21st century , Mineral industries -- Political aspects -- South Africa , Violence -- South Africa -- Rustenburg , Massacres -- South Africa -- Rustenburg , Strikes and lockouts -- Miners -- South Africa , Political leadership -- South Africa , Industrial relations -- South Africa , Marxist criticism , Marikana (Rustenburg, South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2886 , http://hdl.handle.net/10962/d1015651
- Description: This thesis aims to open up the realm of what counts as political in the context of the Marikana strikes and subsequent massacre. It does primarily by taking into account the social, political and cultural context of Mpondo workers on the mines. Many narrow Marxist and liberal frameworks have circumscribed the conception of the ‘modern’ and the ‘political’ so much so that political organisation which falls outside of this conceptualisation is often regarded as ‘backward’ or ‘archaic’. It will provide an examination of the history, culture and custom of men, who have, for almost a hundred years migrated back and forth between South African mines and Mpondoland. This not only reveals differing modes of organising and engaging in political action, but also that the praxis of democracy takes many forms, some of which are different and opposed to what counts as democratic in Western liberal democracy. By considering what I argue, following some of the insights from the Subaltern Studies collective in India, to be a subaltern sphere of politics and history, it is possible to better understand the way workers organised and acted. The thesis also argues that most labour and nationalist historiography has been silent on the political contributions of women because of how Marxist/liberal analysis frames struggles through disciplined notions of work and resistance. Rather than objectifying workers as representatives of a homogenous and universal class of people devoid of context, the thesis has linked ‘the worker’ to the community from which s/he comes and community specific struggles, which are supported and sustained, often, by the parallel struggles of women in the community.
- Full Text:
- Authors: Naicker, Camalita
- Date: 2014
- Subjects: Miners -- South Africa -- Rustenburg -- Social conditions -- 21st century , Mineral industries -- Political aspects -- South Africa , Violence -- South Africa -- Rustenburg , Massacres -- South Africa -- Rustenburg , Strikes and lockouts -- Miners -- South Africa , Political leadership -- South Africa , Industrial relations -- South Africa , Marxist criticism , Marikana (Rustenburg, South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2886 , http://hdl.handle.net/10962/d1015651
- Description: This thesis aims to open up the realm of what counts as political in the context of the Marikana strikes and subsequent massacre. It does primarily by taking into account the social, political and cultural context of Mpondo workers on the mines. Many narrow Marxist and liberal frameworks have circumscribed the conception of the ‘modern’ and the ‘political’ so much so that political organisation which falls outside of this conceptualisation is often regarded as ‘backward’ or ‘archaic’. It will provide an examination of the history, culture and custom of men, who have, for almost a hundred years migrated back and forth between South African mines and Mpondoland. This not only reveals differing modes of organising and engaging in political action, but also that the praxis of democracy takes many forms, some of which are different and opposed to what counts as democratic in Western liberal democracy. By considering what I argue, following some of the insights from the Subaltern Studies collective in India, to be a subaltern sphere of politics and history, it is possible to better understand the way workers organised and acted. The thesis also argues that most labour and nationalist historiography has been silent on the political contributions of women because of how Marxist/liberal analysis frames struggles through disciplined notions of work and resistance. Rather than objectifying workers as representatives of a homogenous and universal class of people devoid of context, the thesis has linked ‘the worker’ to the community from which s/he comes and community specific struggles, which are supported and sustained, often, by the parallel struggles of women in the community.
- Full Text:
Master's Degree studies at Rhodes University : access and postgraduate readiness
- Authors: Stephenson, Sandra Lisa
- Date: 2014
- Subjects: Rhodes University Universities and colleges -- Graduate work Recognition of prior learning Graduate students Corporate culture
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1967 , http://hdl.handle.net/10962/d1011783
- Description: This mixed method, grounded theory study aimed to explore access to Master's level study at Rhodes University, a small, traditional South African university established in 1904, over the ten year period 1999-2008. It also sought to capture the essence of 'postgraduate readiness': the generic (non-certificated) attributes which academics expect graduates to possess in order to undertake Master's degree study. While the majority of students enter Master's level via the formal route (which at Rhodes is an Honours or 4-year bachelor's degree), a significant number are admitted based on the recognition of prior learning (RPL), a practice which is encouraged in South African higher education national policy as a means of widening access and also of acknowledging that learning can take place in ways other than 'formally'. The findings show that while RPL is well defined nationally at the undergraduate level, the concept of RPL at the postgraduate level is vague and largely left to institutional discretion. No national, and few institutional, guidelines are available on which to base the assessment of potential Master's degree students who do not have Honours degrees. Interviews with Deans, supervisors and policy makers at Rhodes indicated that while there is institutional support for admitting alternative access candidates, there is a general perception of deficit compared to those entering the Master's with formal qualifications. However, the statistical findings showed no significant difference in success rates or time taken to completion between students with and without Honours degrees. In addition, comments from supervisors with extensive experience of alternative access students praised the diversity and rich life experience which such students brought to their studies and their peers. The study concludes that an institutional culture characterized by resistance to change, risk and externally imposed regulations at Rhodes has resulted in weak implementation of the University's RPL policy, little marketing or publicizing of alternative access routes to postgraduate study, and low numbers of RPL enrolments at the Master's level. A framework for the assessment of potential Master's candidates - both RPL and formal admissions - for use at Rhodes University and potentially also at other higher education institutions, is proposed in conclusion.
- Full Text:
- Authors: Stephenson, Sandra Lisa
- Date: 2014
- Subjects: Rhodes University Universities and colleges -- Graduate work Recognition of prior learning Graduate students Corporate culture
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1967 , http://hdl.handle.net/10962/d1011783
- Description: This mixed method, grounded theory study aimed to explore access to Master's level study at Rhodes University, a small, traditional South African university established in 1904, over the ten year period 1999-2008. It also sought to capture the essence of 'postgraduate readiness': the generic (non-certificated) attributes which academics expect graduates to possess in order to undertake Master's degree study. While the majority of students enter Master's level via the formal route (which at Rhodes is an Honours or 4-year bachelor's degree), a significant number are admitted based on the recognition of prior learning (RPL), a practice which is encouraged in South African higher education national policy as a means of widening access and also of acknowledging that learning can take place in ways other than 'formally'. The findings show that while RPL is well defined nationally at the undergraduate level, the concept of RPL at the postgraduate level is vague and largely left to institutional discretion. No national, and few institutional, guidelines are available on which to base the assessment of potential Master's degree students who do not have Honours degrees. Interviews with Deans, supervisors and policy makers at Rhodes indicated that while there is institutional support for admitting alternative access candidates, there is a general perception of deficit compared to those entering the Master's with formal qualifications. However, the statistical findings showed no significant difference in success rates or time taken to completion between students with and without Honours degrees. In addition, comments from supervisors with extensive experience of alternative access students praised the diversity and rich life experience which such students brought to their studies and their peers. The study concludes that an institutional culture characterized by resistance to change, risk and externally imposed regulations at Rhodes has resulted in weak implementation of the University's RPL policy, little marketing or publicizing of alternative access routes to postgraduate study, and low numbers of RPL enrolments at the Master's level. A framework for the assessment of potential Master's candidates - both RPL and formal admissions - for use at Rhodes University and potentially also at other higher education institutions, is proposed in conclusion.
- Full Text:
Member perspectives on the role of social capital in the success of the Heiveld Cooperative in the Northern Cape, South Africa
- Authors: Carlisle, Juliet Hazel
- Date: 2014
- Subjects: Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:825 , http://hdl.handle.net/10962/d1011734 , Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
- Description: The aim of this qualitative study is to explore the perspectives of current members of the cooperative regarding the role of social capital in the success of the Heiveld Cooperative on the Suid Bokkeveld in the Northern Cape, South Africa (SA). This cooperative has been cited by several researchers as being successful for various reasons, including the existence of a marketable resource, a steady increase in production, and certification through Fairtrade, resulting in an export market. Social capital, as a contributing factor to the success of the cooperative, has not however previously been investigated in depth. In light of the unique success of this cooperative, it is important to obtain an in-depth understanding of the role of social capital, if any, in its success, particularly in the formation and day-to-day operation of the cooperative. With a particular focus on the members’ perspectives of the cooperative, this qualitative research adopted a case study approach to explore and to gain multiple and subjective understanding of the role played by social capital in the success of the Heiveld Cooperative. This may assist the organisation under study, as well as similar initiatives, in strategically harnessing the benefits of social capital as a resource in future. This report has three interrelated sections. The first part is an academic paper, which includes a condensed literature review, research methods, results and discussions. The second part is an expanded literature review, while the third section details the research methods. It is vital to note that these sections are separate, but interrelated. Convenience sampling was used to identify current members of the cooperative who participated in this exploratory qualitative study. Four heterogeneous focus group discussions, with a total of 44 members of the Heiveld Cooperative in the Suid Bokkeveld, were conducted. The focus groups were heterogeneous, as they included ordinary members, founding members and committee members. A guideline with questions based on the theory of social capital was developed, and used to initiate or stimulate discussion among the members of the cooperative in order to address the key research question, namely: What was the role of social capital, if any, in the success of the Heiveld Cooperative in the Northern Cape as perceived by current cooperative members? The primary source of data was collected through focus group discussions, while secondary data was obtained from documents in a form of internal reports and papers written for the Heiveld Cooperative. Data was analysed using open coding and constant comparison techniques in order to induce emerging themes from the data. Findings of this study revealed that social capital played a major and influential role during the inception and also in the successful operation of the Heiveld Cooperative, by bonding and bridging not just between individual members, but also between communities, trading partners and other collaborators. Another key finding of this study is that social capital was also critical in enhancing supportive knowledge sharing, and the promotion of pride and shared identity, which the study identifies as aspects of cognitive social capital. Interestingly, the cognitive dimension of social capital in the Heiveld Cooperative has contributed to the weakening of social capital, as evident in claims related to lack of transparency and procedural injustice. Last, but not least, leveraging the sense of community has also been useful in promoting collective efficacy, strengthening familial togetherness, and enhanced democratisation of decision-making. Diminished trust, based on perceived oligarchy and nepotism is gradually weakening relational social capital. Findings in this study are illuminated using the social capital theory described by Nahapiet and Ghoshal (1998) to depict the social, cognitive and relational aspect of social capital that are at work at Heiveld Cooperative. Additionally, the social network theory by Hoppe and Reinelt (2010) is used to highlight the systemic view of social capital, which embraces the structural, relational and cognitive nature not only internal to but also between networks of the cooperative. Recommendations are provided to ensure social capital is harnessed, rather than undermined. These include the need to promote the processes of learning, monitoring and discussion that have been implemented; harnessing the benefits of bonding and bridging social capital; leveraging the sense of community and applying a more systemic view of social capital; and addressing perverse aspects of social capital such as nepotism and oligarchy that have been identified.
- Full Text:
- Authors: Carlisle, Juliet Hazel
- Date: 2014
- Subjects: Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:825 , http://hdl.handle.net/10962/d1011734 , Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
- Description: The aim of this qualitative study is to explore the perspectives of current members of the cooperative regarding the role of social capital in the success of the Heiveld Cooperative on the Suid Bokkeveld in the Northern Cape, South Africa (SA). This cooperative has been cited by several researchers as being successful for various reasons, including the existence of a marketable resource, a steady increase in production, and certification through Fairtrade, resulting in an export market. Social capital, as a contributing factor to the success of the cooperative, has not however previously been investigated in depth. In light of the unique success of this cooperative, it is important to obtain an in-depth understanding of the role of social capital, if any, in its success, particularly in the formation and day-to-day operation of the cooperative. With a particular focus on the members’ perspectives of the cooperative, this qualitative research adopted a case study approach to explore and to gain multiple and subjective understanding of the role played by social capital in the success of the Heiveld Cooperative. This may assist the organisation under study, as well as similar initiatives, in strategically harnessing the benefits of social capital as a resource in future. This report has three interrelated sections. The first part is an academic paper, which includes a condensed literature review, research methods, results and discussions. The second part is an expanded literature review, while the third section details the research methods. It is vital to note that these sections are separate, but interrelated. Convenience sampling was used to identify current members of the cooperative who participated in this exploratory qualitative study. Four heterogeneous focus group discussions, with a total of 44 members of the Heiveld Cooperative in the Suid Bokkeveld, were conducted. The focus groups were heterogeneous, as they included ordinary members, founding members and committee members. A guideline with questions based on the theory of social capital was developed, and used to initiate or stimulate discussion among the members of the cooperative in order to address the key research question, namely: What was the role of social capital, if any, in the success of the Heiveld Cooperative in the Northern Cape as perceived by current cooperative members? The primary source of data was collected through focus group discussions, while secondary data was obtained from documents in a form of internal reports and papers written for the Heiveld Cooperative. Data was analysed using open coding and constant comparison techniques in order to induce emerging themes from the data. Findings of this study revealed that social capital played a major and influential role during the inception and also in the successful operation of the Heiveld Cooperative, by bonding and bridging not just between individual members, but also between communities, trading partners and other collaborators. Another key finding of this study is that social capital was also critical in enhancing supportive knowledge sharing, and the promotion of pride and shared identity, which the study identifies as aspects of cognitive social capital. Interestingly, the cognitive dimension of social capital in the Heiveld Cooperative has contributed to the weakening of social capital, as evident in claims related to lack of transparency and procedural injustice. Last, but not least, leveraging the sense of community has also been useful in promoting collective efficacy, strengthening familial togetherness, and enhanced democratisation of decision-making. Diminished trust, based on perceived oligarchy and nepotism is gradually weakening relational social capital. Findings in this study are illuminated using the social capital theory described by Nahapiet and Ghoshal (1998) to depict the social, cognitive and relational aspect of social capital that are at work at Heiveld Cooperative. Additionally, the social network theory by Hoppe and Reinelt (2010) is used to highlight the systemic view of social capital, which embraces the structural, relational and cognitive nature not only internal to but also between networks of the cooperative. Recommendations are provided to ensure social capital is harnessed, rather than undermined. These include the need to promote the processes of learning, monitoring and discussion that have been implemented; harnessing the benefits of bonding and bridging social capital; leveraging the sense of community and applying a more systemic view of social capital; and addressing perverse aspects of social capital such as nepotism and oligarchy that have been identified.
- Full Text:
Michael Jackson : a psychobiography
- Authors: Ruiters, Jeremy John
- Date: 2014
- Subjects: Jackson, Michael, 1958-2009 , Psychology -- Biographical methods , Psychoanalysis , African American singers -- Biography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3228 , http://hdl.handle.net/10962/d1013061
- Description: In a psychobiography a psychological theory is used as a framework to uncover the story of an individual. The psychobiographical approach to research tends to be underutilised. The result of this is that an important area for the application of psychobiographical theory and the study of completed lives is neglected. The value of psychobiographical studies has been advocated by many scholars in the field of psychobiographical research for the development and testing of theories relating to human development. The subject under investigation in this psychobiography is Michael Jackson. Although much has been written about Jackson, not much of the existing literature adopts a psychological focus. The sampling procedure was purposive, as the subject was deliberately selected. The aim of this research was to explore and describe the life of Jackson through the use of the psychobiographical case method. Life history material in the form of biographies, newspaper articles, documentaries and interviews aided in creating a biographical sketch of Jackson's life. The progression of Jackson's personality development was analysed using Erikson’s psychosocial development theory. The data collection and analysis were conducted according to Yin's analytical generalisation which consists of two main strategies: (1) using a theoretical framework as a guide to determine what data are relevant, and (2) developing a matrix as a descriptive framework for organising and integrating the data. Furthermore, the process of data analysis was aided by the use of guidelines prepared by Alexander with Erikson’s psychosocial development as the theoretical framework. This research undertaking can be recognised as a positive demonstration of the value of Erikson’s psychosocial developmental theory in understanding the process of Michael Jackson's personality development. Recommendations regarding future research that utilises the psychobiographical research design and methodology have been made.
- Full Text:
- Authors: Ruiters, Jeremy John
- Date: 2014
- Subjects: Jackson, Michael, 1958-2009 , Psychology -- Biographical methods , Psychoanalysis , African American singers -- Biography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3228 , http://hdl.handle.net/10962/d1013061
- Description: In a psychobiography a psychological theory is used as a framework to uncover the story of an individual. The psychobiographical approach to research tends to be underutilised. The result of this is that an important area for the application of psychobiographical theory and the study of completed lives is neglected. The value of psychobiographical studies has been advocated by many scholars in the field of psychobiographical research for the development and testing of theories relating to human development. The subject under investigation in this psychobiography is Michael Jackson. Although much has been written about Jackson, not much of the existing literature adopts a psychological focus. The sampling procedure was purposive, as the subject was deliberately selected. The aim of this research was to explore and describe the life of Jackson through the use of the psychobiographical case method. Life history material in the form of biographies, newspaper articles, documentaries and interviews aided in creating a biographical sketch of Jackson's life. The progression of Jackson's personality development was analysed using Erikson’s psychosocial development theory. The data collection and analysis were conducted according to Yin's analytical generalisation which consists of two main strategies: (1) using a theoretical framework as a guide to determine what data are relevant, and (2) developing a matrix as a descriptive framework for organising and integrating the data. Furthermore, the process of data analysis was aided by the use of guidelines prepared by Alexander with Erikson’s psychosocial development as the theoretical framework. This research undertaking can be recognised as a positive demonstration of the value of Erikson’s psychosocial developmental theory in understanding the process of Michael Jackson's personality development. Recommendations regarding future research that utilises the psychobiographical research design and methodology have been made.
- Full Text:
Mobilising processes of abstraction, experiential learning and representation of traditional ecological knowledge in participatory monitoring of mangroves and fisheries : an approach towards enhancing social learning processes on the eastern coast of Tanzania
- Authors: Sabai, Daniel
- Date: 2014
- Subjects: Traditional ecological knowledge , Environmental education -- Tanzania , Environmental education -- Study and teaching -- Tanzania , Coastal zone management -- Tanzania , Social learning -- Tanzania , Experiential learning -- Tanzania , Mangrove conservation -- Tanzania , Fishery management -- Tanzania
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1979 , http://hdl.handle.net/10962/d1013060
- Description: This study addresses a core problem that was uncovered in records from coastal management monitoring initiatives on the eastern coast of Tanzania associated with the application and use of coastal monitoring indicators developed by external development partners for the coastal zone. These records suggest that local communities, who are key actors in participatory monitoring of coastal and marine resources, face many challenges associated with adapting and applying the said frameworks of indicators and monitoring plans. These indicators tend to be scientifically abstracted and methodologically reified; given prevailing contextual and socio‐cultural realities amongst them. The research project addresses the following key research question: How can processes of abstraction, conceptualisation, and representation of TEK contribute to the development of coastal management indicators that are less reified, more contextually and culturally congruent, and which may potentially be used by resource users in the wider social learning process of detecting trends, threats, changes and conditions of mangrove and fisheries resources? In response to the contextual problem and the research question, the study employs processes of abstraction and experiential learning techniques to unlock knowledge that local communities have, as an input for underlabouring existing scientific indicators on the Eastern coast of Tanzania. The research is constituted as critical realist case study research, involving two communities on the eastern coast of Tanzania, namely the Moa and the Boma communities (in Mkinga coastal district). Overall, the study involved 37 participants in a series of interviews, focus group discussions, and experiential learning processes using visualised data, and an experiential learning intervention workshop, and follow‐ups over a period of 3 years. The study worked with mangroves and fisheries to provide focus to the case study research and to allow for in‐depth engagement with the assumptions and processes associated with indicators development and use. Through the above mentioned data generation processes, critical realist analysis, and experiential learning processes involving abstraction and representation of traditional ecological knowledge held by mangrove restorers and fishers in the study areas, the study uncovers possible challenges of adapting and applying scientific indicators in participatory monitoring of a mangrove ecosystem. Using ampliative modes of inference for data analysis (induction, abduction and retroduction) and a critical realist scientific explanatory framework known as DRRREI(C) (Resolution, Re‐description, Retrodiction, Elimination, Identification, & Correction) the study suggests a new approach that may lead to the development of a framework of indicators that are less reified, more congruent to users (coastal communities), and likely to attract a wider context‐based social learning which favours epistemological access between scientific institutions (universities inclusive), and local communities. It attempts to establish an interface between knowledge that scientific institutions produce and the potential knowledge that exists in local contexts (traditional ecological knowledge), and seeks to widen and improve knowledge sharing and experiential learning practices that may potentially benefit coastal and marine resources in the study area. As mentioned above, the knowledge and abstraction processes related to the indicators development focussed on the mangrove ecosystem and associated fisheries, as engaged in the two participating communities in the eastern coast of Tanzania. The specific findings are therefore limited by the case boundaries, but the methodological process could be replicated and used elsewhere. The study’s contributions are theoretical and methodological, but also social and practice‐centred. The study brings into view the need to consider the contextual relevance of adapted knowledge, the capacity or ability of beneficiaries to adapt and apply scientific models, frameworks or tools, and the potential of local knowledge as an input for enhancing or improving monitoring of mangroves and mangrove‐based fisheries. Finally, the study comes up with a framework of indicators which is regarded by the coastal communities involved in the study as being less reified, more contextually and culturally congruent, and which may potentially be used in detecting environmental trends, threats, changes and conditions of mangrove and fisheries resources, and attract wider social learning processes.
- Full Text:
- Authors: Sabai, Daniel
- Date: 2014
- Subjects: Traditional ecological knowledge , Environmental education -- Tanzania , Environmental education -- Study and teaching -- Tanzania , Coastal zone management -- Tanzania , Social learning -- Tanzania , Experiential learning -- Tanzania , Mangrove conservation -- Tanzania , Fishery management -- Tanzania
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1979 , http://hdl.handle.net/10962/d1013060
- Description: This study addresses a core problem that was uncovered in records from coastal management monitoring initiatives on the eastern coast of Tanzania associated with the application and use of coastal monitoring indicators developed by external development partners for the coastal zone. These records suggest that local communities, who are key actors in participatory monitoring of coastal and marine resources, face many challenges associated with adapting and applying the said frameworks of indicators and monitoring plans. These indicators tend to be scientifically abstracted and methodologically reified; given prevailing contextual and socio‐cultural realities amongst them. The research project addresses the following key research question: How can processes of abstraction, conceptualisation, and representation of TEK contribute to the development of coastal management indicators that are less reified, more contextually and culturally congruent, and which may potentially be used by resource users in the wider social learning process of detecting trends, threats, changes and conditions of mangrove and fisheries resources? In response to the contextual problem and the research question, the study employs processes of abstraction and experiential learning techniques to unlock knowledge that local communities have, as an input for underlabouring existing scientific indicators on the Eastern coast of Tanzania. The research is constituted as critical realist case study research, involving two communities on the eastern coast of Tanzania, namely the Moa and the Boma communities (in Mkinga coastal district). Overall, the study involved 37 participants in a series of interviews, focus group discussions, and experiential learning processes using visualised data, and an experiential learning intervention workshop, and follow‐ups over a period of 3 years. The study worked with mangroves and fisheries to provide focus to the case study research and to allow for in‐depth engagement with the assumptions and processes associated with indicators development and use. Through the above mentioned data generation processes, critical realist analysis, and experiential learning processes involving abstraction and representation of traditional ecological knowledge held by mangrove restorers and fishers in the study areas, the study uncovers possible challenges of adapting and applying scientific indicators in participatory monitoring of a mangrove ecosystem. Using ampliative modes of inference for data analysis (induction, abduction and retroduction) and a critical realist scientific explanatory framework known as DRRREI(C) (Resolution, Re‐description, Retrodiction, Elimination, Identification, & Correction) the study suggests a new approach that may lead to the development of a framework of indicators that are less reified, more congruent to users (coastal communities), and likely to attract a wider context‐based social learning which favours epistemological access between scientific institutions (universities inclusive), and local communities. It attempts to establish an interface between knowledge that scientific institutions produce and the potential knowledge that exists in local contexts (traditional ecological knowledge), and seeks to widen and improve knowledge sharing and experiential learning practices that may potentially benefit coastal and marine resources in the study area. As mentioned above, the knowledge and abstraction processes related to the indicators development focussed on the mangrove ecosystem and associated fisheries, as engaged in the two participating communities in the eastern coast of Tanzania. The specific findings are therefore limited by the case boundaries, but the methodological process could be replicated and used elsewhere. The study’s contributions are theoretical and methodological, but also social and practice‐centred. The study brings into view the need to consider the contextual relevance of adapted knowledge, the capacity or ability of beneficiaries to adapt and apply scientific models, frameworks or tools, and the potential of local knowledge as an input for enhancing or improving monitoring of mangroves and mangrove‐based fisheries. Finally, the study comes up with a framework of indicators which is regarded by the coastal communities involved in the study as being less reified, more contextually and culturally congruent, and which may potentially be used in detecting environmental trends, threats, changes and conditions of mangrove and fisheries resources, and attract wider social learning processes.
- Full Text:
Modelling the spatial and genetic response of the endemic sparid: Polysteganus praeorbitalis (Pisces: Sparidae) to climate change in the Agulhas Current system
- Authors: Isemonger, Devin Neil
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54509 , vital:26576
- Description: The Scotsman Seabream, Polysteganus praeorbitalis, is one of several large, slow-growing members of the Sparidae family of fishes endemic to the Agulhas Current system in the Western Indian Ocean (WIO). Relatively little research has been conducted on this species despite its importance to both recreational and commercial line fisheries in South Africa and the drastic decline in catch per unit effort (CPUE) that has been recorded since the 1940s. Changing sea temperatures as a result of global climate change are further expected to affect the distribution and abundance of many fish species based on their thermal tolerances, life histories and population structures. The ability of these species to shift their distribution and adapt to new environments and thermal conditions will depend to some degree on the levels of genetic variation and gene flow, within and between populations. A combined approach using species distribution modelling and genetic analyses may prove to be a useful tool in investigating the potential effects of climate change on the distribution and genetic diversity of species. An ensemble species distribution model (SDM) based on 205 occurrence records and 30 years of Reynolds Optimum Interpolated (OI) sea surface temperature data was constructed to predict the distributional response of P. praeorbitalis to climate change in the Agulhas Current system. The ensemble SDM displayed a true skill statistic (TSS) of 0.975 and an area under the receiver operating curve (ROC) of 0.999, indicating good model fit. Autumn and winter minimum temperatures, as well as bathymetry, were the most important predictor variables in the majority of models, indicating that these variables may directly constrain the distribution of P. praeorbitalis. In particular, the southern range edge of this species appeared to be constrained by autumn and winter minima, with high model agreement on this range edge. Conversely, the northern range limit showed poor model agreement leading to a gradual reduction in occurrence. This indicates that this range edge may be constrained by other factors not included in the models such as species interactions. The ensemble SDM projected the current range of P. praeorbitalis to be 1500 km², smaller than the published range for this species. The model underestimated the northern range edge of this species by approximately 5° latitude when binary transformed. This is probably due to the rarity of this species in the landings of the Mozambican linefishery, which was assumed to be an indication of low abundance of P. praeorbitalis in these waters. The absence of a specimen to verify the published northern range edge of this species indicates that the northern range edge produced by this model is likely to be closer to the actual range limit of the species. A range contraction of 30% occurring at both the northern and southern edge of P. praeorbitalis’ range and range fragmentation occurring, towards its northern range edge by 2030, was predicted. These changes are modelled to be the results of cooling related to the intensification of the Port Alfred upwelling cell and of warming predicted north of the Natal Bight and in southern Mozambique. Genetic analyses of the nuclear DNA (nDNA) S7 intron 1 and mitochondrial DNA (mtDNA) control region genes were carried out using 118 tissue samples of P. praeorbitalis collected at four main localities: the Eastern Cape, Transkei, southern KwaZulu-Natal and northern KwaZulu-Natal. Analyses of genetic diversity levels revealed relatively low diversity in the mtDNA dataset (Hd = 0.488; π = 0.004) and moderate levels of diversity in the nDNA dataset (Ad = 0.922; π = 0.005). The low levels of diversity observed in the mtDNA dataset might be explained by a number of factors, including high variation in spawning success, the negative effects of over-harvesting, or a recent population bottleneck. The last explanation is supported by characteristic star-shaped haplotype networks and unimodal mismatch distributions displayed by both datasets. These results, in conjunction with a significant (p = 0.005) negative Tajimas D value (-2.029) in the mtDNA dataset and significant (p = 0.0005) negative Fu’s F statistic in both the nDNA (F = -26.5) and mtDNA (F = -11.9) datasets, provide strong evidence for a recent population expansion after a bottleneck event in this species. Spatially, mtDNA diversity was highest in the Eastern Cape and lowest in the middle localities, while nDNA diversity showed the opposite pattern. These results may be indicative of differences in the sex ratio between localities, possibly as a result of the protogynous hermaphroditism that has been postulated for this species. Although pairwise comparisons and exact tests of population differentiation revealed no significant geneticdifferentiation between populations in the mtDNA dataset, there was some evidence of low levels of differentiation in the nDNA dataset. This occurred for comparisons between the Eastern Cape and Transkei (Fst = 0.039; p <0.05), and the northern KwaZulu-Natal (Fst = 0.045; p < 0.05).. This might be the result of one or a combination of factors including the effects of the Port Alfred upwelling cell on dispersal and gene flow, or the possibility of more than one spawning ground for this species promoting sub-structuring. A SAMOVA analyses run on the nDNA dataset maximised variance by grouping the Eastern Cape and southern KwaZulu-Natal together and Transkei and northern KwaZulu-Natal together in two groups. This revealed no evidence of spatial structure (p = 0.36), with only 3.30% of variation explained by this grouping. The removal of individuals below the estimated length at 50% maturity in the nDNA dataset, in order to test for temporal structure, resulted in stronger evidence of differentiation between the Eastern Cape and all other localities: Transkei (Fst = 0.081; p< 0.05), southern KwaZulu-Natal (Fst = 0.031; p<0.05), and northern KwaZulu-Natal (Fst = 0.078; p< 0.05). This indicates that some temporal genetic structure may exist between age classes within this species. The differentiation observed between the Eastern Cape and other localities, coupled with the high percentage of private haplotypes in the mtDNA dataset in this locality, indicates that this area is where P. praeorbitalis is most vulnerable to the potential negative effects of climate change on its genetic diversity. However, the vast majority of this species genetic diversity appears to reside towards the centre of its range where it is most abundant and the lack of strong genetic structure indicates high levels of gene flow. In conclusion, while P. praeorbitalis is vulnerable to range loss as a result of climate change, its genetic diversity is unlikely to be greatly affected.
- Full Text:
- Authors: Isemonger, Devin Neil
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54509 , vital:26576
- Description: The Scotsman Seabream, Polysteganus praeorbitalis, is one of several large, slow-growing members of the Sparidae family of fishes endemic to the Agulhas Current system in the Western Indian Ocean (WIO). Relatively little research has been conducted on this species despite its importance to both recreational and commercial line fisheries in South Africa and the drastic decline in catch per unit effort (CPUE) that has been recorded since the 1940s. Changing sea temperatures as a result of global climate change are further expected to affect the distribution and abundance of many fish species based on their thermal tolerances, life histories and population structures. The ability of these species to shift their distribution and adapt to new environments and thermal conditions will depend to some degree on the levels of genetic variation and gene flow, within and between populations. A combined approach using species distribution modelling and genetic analyses may prove to be a useful tool in investigating the potential effects of climate change on the distribution and genetic diversity of species. An ensemble species distribution model (SDM) based on 205 occurrence records and 30 years of Reynolds Optimum Interpolated (OI) sea surface temperature data was constructed to predict the distributional response of P. praeorbitalis to climate change in the Agulhas Current system. The ensemble SDM displayed a true skill statistic (TSS) of 0.975 and an area under the receiver operating curve (ROC) of 0.999, indicating good model fit. Autumn and winter minimum temperatures, as well as bathymetry, were the most important predictor variables in the majority of models, indicating that these variables may directly constrain the distribution of P. praeorbitalis. In particular, the southern range edge of this species appeared to be constrained by autumn and winter minima, with high model agreement on this range edge. Conversely, the northern range limit showed poor model agreement leading to a gradual reduction in occurrence. This indicates that this range edge may be constrained by other factors not included in the models such as species interactions. The ensemble SDM projected the current range of P. praeorbitalis to be 1500 km², smaller than the published range for this species. The model underestimated the northern range edge of this species by approximately 5° latitude when binary transformed. This is probably due to the rarity of this species in the landings of the Mozambican linefishery, which was assumed to be an indication of low abundance of P. praeorbitalis in these waters. The absence of a specimen to verify the published northern range edge of this species indicates that the northern range edge produced by this model is likely to be closer to the actual range limit of the species. A range contraction of 30% occurring at both the northern and southern edge of P. praeorbitalis’ range and range fragmentation occurring, towards its northern range edge by 2030, was predicted. These changes are modelled to be the results of cooling related to the intensification of the Port Alfred upwelling cell and of warming predicted north of the Natal Bight and in southern Mozambique. Genetic analyses of the nuclear DNA (nDNA) S7 intron 1 and mitochondrial DNA (mtDNA) control region genes were carried out using 118 tissue samples of P. praeorbitalis collected at four main localities: the Eastern Cape, Transkei, southern KwaZulu-Natal and northern KwaZulu-Natal. Analyses of genetic diversity levels revealed relatively low diversity in the mtDNA dataset (Hd = 0.488; π = 0.004) and moderate levels of diversity in the nDNA dataset (Ad = 0.922; π = 0.005). The low levels of diversity observed in the mtDNA dataset might be explained by a number of factors, including high variation in spawning success, the negative effects of over-harvesting, or a recent population bottleneck. The last explanation is supported by characteristic star-shaped haplotype networks and unimodal mismatch distributions displayed by both datasets. These results, in conjunction with a significant (p = 0.005) negative Tajimas D value (-2.029) in the mtDNA dataset and significant (p = 0.0005) negative Fu’s F statistic in both the nDNA (F = -26.5) and mtDNA (F = -11.9) datasets, provide strong evidence for a recent population expansion after a bottleneck event in this species. Spatially, mtDNA diversity was highest in the Eastern Cape and lowest in the middle localities, while nDNA diversity showed the opposite pattern. These results may be indicative of differences in the sex ratio between localities, possibly as a result of the protogynous hermaphroditism that has been postulated for this species. Although pairwise comparisons and exact tests of population differentiation revealed no significant geneticdifferentiation between populations in the mtDNA dataset, there was some evidence of low levels of differentiation in the nDNA dataset. This occurred for comparisons between the Eastern Cape and Transkei (Fst = 0.039; p <0.05), and the northern KwaZulu-Natal (Fst = 0.045; p < 0.05).. This might be the result of one or a combination of factors including the effects of the Port Alfred upwelling cell on dispersal and gene flow, or the possibility of more than one spawning ground for this species promoting sub-structuring. A SAMOVA analyses run on the nDNA dataset maximised variance by grouping the Eastern Cape and southern KwaZulu-Natal together and Transkei and northern KwaZulu-Natal together in two groups. This revealed no evidence of spatial structure (p = 0.36), with only 3.30% of variation explained by this grouping. The removal of individuals below the estimated length at 50% maturity in the nDNA dataset, in order to test for temporal structure, resulted in stronger evidence of differentiation between the Eastern Cape and all other localities: Transkei (Fst = 0.081; p< 0.05), southern KwaZulu-Natal (Fst = 0.031; p<0.05), and northern KwaZulu-Natal (Fst = 0.078; p< 0.05). This indicates that some temporal genetic structure may exist between age classes within this species. The differentiation observed between the Eastern Cape and other localities, coupled with the high percentage of private haplotypes in the mtDNA dataset in this locality, indicates that this area is where P. praeorbitalis is most vulnerable to the potential negative effects of climate change on its genetic diversity. However, the vast majority of this species genetic diversity appears to reside towards the centre of its range where it is most abundant and the lack of strong genetic structure indicates high levels of gene flow. In conclusion, while P. praeorbitalis is vulnerable to range loss as a result of climate change, its genetic diversity is unlikely to be greatly affected.
- Full Text:
Molecular phylogeny, phylogeography and evolutionary adaptation of foraging behaviour amongst sympatric patellid limpets along the southern African shoreline
- Authors: Mmonwa, Kolobe Lucas
- Date: 2014
- Subjects: Limpets -- South Africa -- Adaptation , Limpets -- South Africa -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5882 , http://hdl.handle.net/10962/d1013222
- Description: The southern African shoreline is inhabited by a great diversity of patellid limpets of which most are endemic to South Africa. These limpets have evolved foraging mechanisms that partition ecological resources and reduce interspecific competition, resulting in ecological specialists and generalists. The evolution of ecological specialization or generalization remains poorly understood and there is no agreement on how such evolutionary transitions are correlated with levels of genetic diversity. This study investigated evolutionary correlations between territoriality in foraging and genetic structure of southern African patellid limpets (Cymbula and Scutellastra spp.) using stable δ13C and δ15N ratios, mitochondrial and nuclear DNA markers. The outcomes of the study were best rationalized and understood in the context of the scale of analysis in terms of both space and taxonomy. At biogeographic scales and the interspecific level, the stable isotope signatures and genetic structure of these limpets are determined by extrinsic factors such as biogeography and oceanography. However, at the smallest site scales and the intraspecific level, the isotope signatures and genetic diversity of these limpets are significantly correlated to their foraging traits. At large scales, there are no correlations between foraging behaviour and either genetic structure or isotope signature. At smaller scales, territorial Scutellastra foragers display both isotopic enrichment and greater haplotype diversity than congeneric non-territorial foragers. Thus, the isotope signatures and genetic structure of these limpets are determined by intrinsic species-specific response linked to their foraging behaviour. However, this pattern was intriguing as differences between territorial and non-territorial limpets in both isotopic signature and genetic diversity were observed only along the south coast when the same species were compared in other biogeographic regions. The significant interaction effect between foraging behaviour and stable isotope signatures was only observed from the sites within the Agulhas Bank or which are strongly influenced by the Agulhas current. This south enrichment in isotopic ratios is due to the mixing differences between onshore and offshore waters as the Agulhas current moves from east to south. At the generic level, the correlation between foraging behaviour and isotope signatures and genetic structure were particularly profound for Scutellastra species. The molecular phylogeny revealed deep evolutionary divergence between territorial and non-territorial Scutellastra spp. This divergence was concordant with morphological differences in shell shape and radula anatomy between territorial and non-territorial species. A taxonomic review of the scutellastrid spp. is proposed, suggesting possible re-consideration of the genus as two genera characterized by either territoriality or non-territoriality. The divergence between territorial and non-territorial species in both Scutellastra and Cymbula took place approximately in the early Oligocene. Major climatic cooling and decreases in sea level occurred during the Oligocene and this probably exposed much of the lower intertidal zone, increasing new potential habitats and algal availability. The Oligocene exposure of rocky shores and algal abundance in the lower intertidal zone probably elicited resource partitioning amongst these patellid limpets and subsequently, the evolution of territorial and non-territorial species. Analyses of the demographic history of these patellid limpets revealed evidence of post-glacial spatial expansion around the Pleistocene, implying these limpets were at population equilibrium during the dramatic LGM sea temperatures. Thus, these limpets managed to expand their range during dynamic oceanographic oscillations and dramatic sea-level changes in the Pleistocene. This study highlighted the importance of applying ecological traits as a subject to investigate and comprehend the evolutionary ecology of marine herbivores. The foraging traits of these true limpets are reflected in both their stable isotope ratios and genealogy, presumably as an evolutionary consequence of competition.
- Full Text:
- Authors: Mmonwa, Kolobe Lucas
- Date: 2014
- Subjects: Limpets -- South Africa -- Adaptation , Limpets -- South Africa -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5882 , http://hdl.handle.net/10962/d1013222
- Description: The southern African shoreline is inhabited by a great diversity of patellid limpets of which most are endemic to South Africa. These limpets have evolved foraging mechanisms that partition ecological resources and reduce interspecific competition, resulting in ecological specialists and generalists. The evolution of ecological specialization or generalization remains poorly understood and there is no agreement on how such evolutionary transitions are correlated with levels of genetic diversity. This study investigated evolutionary correlations between territoriality in foraging and genetic structure of southern African patellid limpets (Cymbula and Scutellastra spp.) using stable δ13C and δ15N ratios, mitochondrial and nuclear DNA markers. The outcomes of the study were best rationalized and understood in the context of the scale of analysis in terms of both space and taxonomy. At biogeographic scales and the interspecific level, the stable isotope signatures and genetic structure of these limpets are determined by extrinsic factors such as biogeography and oceanography. However, at the smallest site scales and the intraspecific level, the isotope signatures and genetic diversity of these limpets are significantly correlated to their foraging traits. At large scales, there are no correlations between foraging behaviour and either genetic structure or isotope signature. At smaller scales, territorial Scutellastra foragers display both isotopic enrichment and greater haplotype diversity than congeneric non-territorial foragers. Thus, the isotope signatures and genetic structure of these limpets are determined by intrinsic species-specific response linked to their foraging behaviour. However, this pattern was intriguing as differences between territorial and non-territorial limpets in both isotopic signature and genetic diversity were observed only along the south coast when the same species were compared in other biogeographic regions. The significant interaction effect between foraging behaviour and stable isotope signatures was only observed from the sites within the Agulhas Bank or which are strongly influenced by the Agulhas current. This south enrichment in isotopic ratios is due to the mixing differences between onshore and offshore waters as the Agulhas current moves from east to south. At the generic level, the correlation between foraging behaviour and isotope signatures and genetic structure were particularly profound for Scutellastra species. The molecular phylogeny revealed deep evolutionary divergence between territorial and non-territorial Scutellastra spp. This divergence was concordant with morphological differences in shell shape and radula anatomy between territorial and non-territorial species. A taxonomic review of the scutellastrid spp. is proposed, suggesting possible re-consideration of the genus as two genera characterized by either territoriality or non-territoriality. The divergence between territorial and non-territorial species in both Scutellastra and Cymbula took place approximately in the early Oligocene. Major climatic cooling and decreases in sea level occurred during the Oligocene and this probably exposed much of the lower intertidal zone, increasing new potential habitats and algal availability. The Oligocene exposure of rocky shores and algal abundance in the lower intertidal zone probably elicited resource partitioning amongst these patellid limpets and subsequently, the evolution of territorial and non-territorial species. Analyses of the demographic history of these patellid limpets revealed evidence of post-glacial spatial expansion around the Pleistocene, implying these limpets were at population equilibrium during the dramatic LGM sea temperatures. Thus, these limpets managed to expand their range during dynamic oceanographic oscillations and dramatic sea-level changes in the Pleistocene. This study highlighted the importance of applying ecological traits as a subject to investigate and comprehend the evolutionary ecology of marine herbivores. The foraging traits of these true limpets are reflected in both their stable isotope ratios and genealogy, presumably as an evolutionary consequence of competition.
- Full Text:
Molecular systematics and antifreeze biology of sub-Antarctic notothenioid fishes
- Authors: Miya, Tshoanelo Portia
- Date: 2014
- Subjects: Nototheniidae , Antifreeze proteins , Nototheniidae -- Classification -- Molecular aspects , Polyacrylamide gel electrophoresis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5388 , http://hdl.handle.net/10962/d1020938
- Description: Fishes of the perciform suborder Notothenioidei are found in Antarctic and sub-Antarctic waters that are separated by the Antarctic Polar Front (APF), with some species being distributed on both sides of this front. In this wide latitudinal range, these fishes are exposed to different temperatures ranging from -2 °C in the High Antarctic regions to 12 °C in the sub-Antarctic regions. To survive in icy Antarctic waters, the Antarctic notothenioid species have evolved antifreeze glycoproteins (AFGPs) that prevent their body fluids from freezing. The findings of past research on the AFGP attributes of several notothenioid species inhabiting ice-free sub-Antarctic environments have presented a complex picture. Furthermore, previous taxonomic studies split widely distributed notothenioids into different species and/or subspecies, with other studies disagreeing with these splits. To understand the response of the sub-Antarctic notothenioids to warmer, ice-free environments, it is necessary to have a good understanding of their antifreeze biology and systematics. Therefore, this study aimed to determine the association, if any, between the antifreeze attributes of sub-Antarctic notothenioid fishes and their taxonomic status. And more...
- Full Text:
- Authors: Miya, Tshoanelo Portia
- Date: 2014
- Subjects: Nototheniidae , Antifreeze proteins , Nototheniidae -- Classification -- Molecular aspects , Polyacrylamide gel electrophoresis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5388 , http://hdl.handle.net/10962/d1020938
- Description: Fishes of the perciform suborder Notothenioidei are found in Antarctic and sub-Antarctic waters that are separated by the Antarctic Polar Front (APF), with some species being distributed on both sides of this front. In this wide latitudinal range, these fishes are exposed to different temperatures ranging from -2 °C in the High Antarctic regions to 12 °C in the sub-Antarctic regions. To survive in icy Antarctic waters, the Antarctic notothenioid species have evolved antifreeze glycoproteins (AFGPs) that prevent their body fluids from freezing. The findings of past research on the AFGP attributes of several notothenioid species inhabiting ice-free sub-Antarctic environments have presented a complex picture. Furthermore, previous taxonomic studies split widely distributed notothenioids into different species and/or subspecies, with other studies disagreeing with these splits. To understand the response of the sub-Antarctic notothenioids to warmer, ice-free environments, it is necessary to have a good understanding of their antifreeze biology and systematics. Therefore, this study aimed to determine the association, if any, between the antifreeze attributes of sub-Antarctic notothenioid fishes and their taxonomic status. And more...
- Full Text:
Multilingual repertoires and strategic rapport management: a comparative study of South African and Dutch small business discourse.
- Authors: Lauriks, Sanne
- Date: 2014
- Subjects: Discourse analysis , Business communication -- South Africa , Business communication -- Netherlands , Multilingual communication -- South Africa , Multilingual communication -- Netherlands , Communication in management -- South Africa , Communication in management -- Netherlands , Sociolinguistics -- South Africa , Sociolinguistics -- Netherlands , Language and culture -- South Africa , Language and culture -- Netherlands
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2382 , http://hdl.handle.net/10962/d1013162
- Description: In this era of globalisation and the consequent increase in social, economic and physical mobility, small businesses are transforming into sites of increasing language contact (Harris and Bargiela-Chiappini 2003). This study explores situated language practices within two small multilingual businesses. The first is a bicycle rental and repair shop located in Amsterdam (the Netherlands), which is a city with a dynamic multilingual society. The second is a tyre fitment centre in Grahamstown (South Africa), which is a city characterised by a stable triglossia of English, Xhosa and Afrikaans. Using Linguistic Ethnography (Rampton 2007) as my data collection method, I spent a total of eight weeks in these businesses. For the analysis I draw on Spencer-Oatey’s (2000b; 2011) Rapport Management Framework and sociolinguistics of globalisation (Blommaert 2010). This combination allowed me to explore situated language practices in relation to a contemporary context of increased globalisation. The analysis is structured using Spencer-Oatey’s (2000b) concept of rapport orientations. The orientations are presented as one of the key factors that influence the choice for a certain strategy. The orientations thus seemed a constructive way of showing how the observed strategies were employed by the participants of this study and what function they fulfilled in a certain context. However, difficulties emerged during the analysis with applying this concept to some of the more elaborate and complex data. As a result my argument developed into two different strands. The first demonstrates how individuals turn to their multilingual repertoires to negotiate agency and power relationships in small business discourse. The analysis reveals that people at times deliberately promote and maintains discordant relations, which can be understood as a rational response to the individual’s social and economic context. The second discusses the problems that emerged during my analysis with applying rapport management orientations to my data. I propose theoretical developments, warranted by my data, to create an Enhanced Rapport Management Framework suitable for the analysis of complex small business discourse.
- Full Text:
- Authors: Lauriks, Sanne
- Date: 2014
- Subjects: Discourse analysis , Business communication -- South Africa , Business communication -- Netherlands , Multilingual communication -- South Africa , Multilingual communication -- Netherlands , Communication in management -- South Africa , Communication in management -- Netherlands , Sociolinguistics -- South Africa , Sociolinguistics -- Netherlands , Language and culture -- South Africa , Language and culture -- Netherlands
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2382 , http://hdl.handle.net/10962/d1013162
- Description: In this era of globalisation and the consequent increase in social, economic and physical mobility, small businesses are transforming into sites of increasing language contact (Harris and Bargiela-Chiappini 2003). This study explores situated language practices within two small multilingual businesses. The first is a bicycle rental and repair shop located in Amsterdam (the Netherlands), which is a city with a dynamic multilingual society. The second is a tyre fitment centre in Grahamstown (South Africa), which is a city characterised by a stable triglossia of English, Xhosa and Afrikaans. Using Linguistic Ethnography (Rampton 2007) as my data collection method, I spent a total of eight weeks in these businesses. For the analysis I draw on Spencer-Oatey’s (2000b; 2011) Rapport Management Framework and sociolinguistics of globalisation (Blommaert 2010). This combination allowed me to explore situated language practices in relation to a contemporary context of increased globalisation. The analysis is structured using Spencer-Oatey’s (2000b) concept of rapport orientations. The orientations are presented as one of the key factors that influence the choice for a certain strategy. The orientations thus seemed a constructive way of showing how the observed strategies were employed by the participants of this study and what function they fulfilled in a certain context. However, difficulties emerged during the analysis with applying this concept to some of the more elaborate and complex data. As a result my argument developed into two different strands. The first demonstrates how individuals turn to their multilingual repertoires to negotiate agency and power relationships in small business discourse. The analysis reveals that people at times deliberately promote and maintains discordant relations, which can be understood as a rational response to the individual’s social and economic context. The second discusses the problems that emerged during my analysis with applying rapport management orientations to my data. I propose theoretical developments, warranted by my data, to create an Enhanced Rapport Management Framework suitable for the analysis of complex small business discourse.
- Full Text:
My grandmother breaks her hip
- Authors: Bamjee, Saaleha
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Poetry , South African poetry (English) -- Study and teaching (Higher) , South African poetry (English) -- 21st century , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5998 , http://hdl.handle.net/10962/d1020881
- Description: A collection of narrative and confessional poems. The poems are mostly short, cinematic, physical, imagistic: moments in time. They explore the poet’s own life, body, memories, and family relationships, and the tensions between power, duty, love and faith. Several poems concern the navigation of meaning and belonging in a time when international urban culture often clashes with tradition.
- Full Text:
- Authors: Bamjee, Saaleha
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Poetry , South African poetry (English) -- Study and teaching (Higher) , South African poetry (English) -- 21st century , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5998 , http://hdl.handle.net/10962/d1020881
- Description: A collection of narrative and confessional poems. The poems are mostly short, cinematic, physical, imagistic: moments in time. They explore the poet’s own life, body, memories, and family relationships, and the tensions between power, duty, love and faith. Several poems concern the navigation of meaning and belonging in a time when international urban culture often clashes with tradition.
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Narratives that shape the professional identities of mathematics teachers
- Felix, Clyde Benedict Aurelius
- Authors: Felix, Clyde Benedict Aurelius
- Date: 2014
- Subjects: Mathematics teachers -- South Africa -- Port Elizabeth , Mathematics teachers -- South Africa -- Grahamstown , Mathematics teachers -- Professional relationships , Mathematics teachers -- Training of , Mathematics -- Study and teaching -- South Africa -- Eastern Cape , Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1995 , http://hdl.handle.net/10962/d1013547
- Description: The central position in this study is that the professional identities, and consequently the classroom practices, of mathematics teachers are continuously being shaped by their narratives of past and present experiences. The primary research question explores the narratives that shape the professional identities of seven mathematics teachers; and the secondary research question, how their narratives shape their professional identities. Furthermore, the potential implications of this study for the design and implementation of pre-service teacher education programmes and in-service teacher development initiatives are considered. This study is framed by Socioculturalism; a theoretical perspective of human thinking as social in origin and of learning as participation in social practices. Futhermore, in line with Situated Learning Theory, the key theoretical notions are: identity (or learning as becoming); community (or learning as belonging); practice (or learning as doing); and meaning (or learning as experience). Identity is construed here as a conceptual bridge between learning and its cultural settings; and also between the individual and the social. In this study, the identity-shaping narratives of seven mathematics teachers, all purposively sampled from schools in the Port Elizabeth and Grahamstown education districts of the Eastern Cape Province of South Africa, were accessed via a narrative inquiry; followed by a horizontal analysis to identify common patterns or recurring themes in the narratives of all seven participants; and, a vertical analysis of the narratives of four of the participants to determine how their narratives shape their professional identities. Recurring themes that emerged during the horizontal analysis include the influence of: family support; role models; changing work environments; continuous professional development; professional recognition; religion; and, micro-politics. The vertical analysis demonstrated how, through a process of interpreting the narratives and restorying them into a meaningful core narrative; it is possible to gain insights into how personal narratives shape a professional identity. This study highlights the importance of listening to the narratives of mathematics teachers; because their professional identities, and consequently their teaching practices, are continuously being shaped by their narratives. It is anticipated that this research will be of interest and benefit to researchers, policy-makers, and teachers; especially in the area of Mathematics Education, where both narrative inquiry as a research method and research into teachers’ professional identities are relatively new.
- Full Text:
- Authors: Felix, Clyde Benedict Aurelius
- Date: 2014
- Subjects: Mathematics teachers -- South Africa -- Port Elizabeth , Mathematics teachers -- South Africa -- Grahamstown , Mathematics teachers -- Professional relationships , Mathematics teachers -- Training of , Mathematics -- Study and teaching -- South Africa -- Eastern Cape , Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1995 , http://hdl.handle.net/10962/d1013547
- Description: The central position in this study is that the professional identities, and consequently the classroom practices, of mathematics teachers are continuously being shaped by their narratives of past and present experiences. The primary research question explores the narratives that shape the professional identities of seven mathematics teachers; and the secondary research question, how their narratives shape their professional identities. Furthermore, the potential implications of this study for the design and implementation of pre-service teacher education programmes and in-service teacher development initiatives are considered. This study is framed by Socioculturalism; a theoretical perspective of human thinking as social in origin and of learning as participation in social practices. Futhermore, in line with Situated Learning Theory, the key theoretical notions are: identity (or learning as becoming); community (or learning as belonging); practice (or learning as doing); and meaning (or learning as experience). Identity is construed here as a conceptual bridge between learning and its cultural settings; and also between the individual and the social. In this study, the identity-shaping narratives of seven mathematics teachers, all purposively sampled from schools in the Port Elizabeth and Grahamstown education districts of the Eastern Cape Province of South Africa, were accessed via a narrative inquiry; followed by a horizontal analysis to identify common patterns or recurring themes in the narratives of all seven participants; and, a vertical analysis of the narratives of four of the participants to determine how their narratives shape their professional identities. Recurring themes that emerged during the horizontal analysis include the influence of: family support; role models; changing work environments; continuous professional development; professional recognition; religion; and, micro-politics. The vertical analysis demonstrated how, through a process of interpreting the narratives and restorying them into a meaningful core narrative; it is possible to gain insights into how personal narratives shape a professional identity. This study highlights the importance of listening to the narratives of mathematics teachers; because their professional identities, and consequently their teaching practices, are continuously being shaped by their narratives. It is anticipated that this research will be of interest and benefit to researchers, policy-makers, and teachers; especially in the area of Mathematics Education, where both narrative inquiry as a research method and research into teachers’ professional identities are relatively new.
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Natural resource products contribute to poverty mitigation amongst urbanising communities in sub-saharan Africa
- Shackleton, Charlie M, Schlesinger, Johannes, Kaoma, Humphrey, Davenport, N I, Ward, Catherine D, Evans, Michelle L, Drescher, Axel W
- Authors: Shackleton, Charlie M , Schlesinger, Johannes , Kaoma, Humphrey , Davenport, N I , Ward, Catherine D , Evans, Michelle L , Drescher, Axel W
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:6624 , http://hdl.handle.net/10962/d1016232
- Description: [From Introduction] Urbanisation in sub-Saharan Africa: changing the locus of poverty. Urbanisation is a global phenomenon that is changing the face of the Earth, as well as how people earn a living and secure their livelihoods. In 2006 the number of urban people in the world surpassed the number of rural people, and this gap will continue to grow. In only 16 years (by 2030) just under two-thirds of the world's people will be urban dwellers. Whilst most of the developed world and large parts of Latin America already have more than threequarters of their populations living in cities and towns, most countries in Asia and sub-Saharan Africa are still catching up. This means that they are experiencing massive migrations from rural to urban areas as rural people wish to swap the insecurities of rural living for the allure of secure employment and better services for health, education, sanitation and transport in towns and cities. Sub-Saharan Africa (SSA) is the most rapidly urbanising region of the globe. According to UN-Habitat, in 1990, only 28 % of the region's inhabitants lived in towns and cities; that increased to approximately 32 % in 2001 and 41 % in 2010. The size of the urban population is likely to surpass the rural one around 2025. Contrary to popular belief, most urban residents in SSA (and globally) live in small towns rather than massive megacities; with just over half living in towns of less than 200,000 people and 78 % living in towns of less than 500,000 residents. Only 14 % of urban dwellers live in cities of more than one million people. Many new urban households maintain strong links to relatives and clans in rural areas, with circular migration patterns emerging as the urban transition takes place over several decades. The implications of this extremely rapid urbanisation in SSA countries for livelihoods and poverty are widely debated. UN-Habitat highlights a relatively unique aspect of urbanisation in SSA as being the accompanying high rate of growth in informal settlements or slums. In other words, not all rural migrants to towns and cities find secure incomes or shelter. Some slum areas have become permanent features where inter-generational poverty is reproduced. Although urban areas are producing an increasing share of national wealth in SSA countries, some argue that slowly the nexus of poverty is shifting towards urban areas. Rates of poverty are high in rural areas of SSA, but migration and internal population growth means that in some countries the number of urban poor almost matches the number of rural poor, and it is likely to grow. The informal economy contributes an average of 40 – 45 % of total urban GDP, which is higher than any other region of the world.
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- Authors: Shackleton, Charlie M , Schlesinger, Johannes , Kaoma, Humphrey , Davenport, N I , Ward, Catherine D , Evans, Michelle L , Drescher, Axel W
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:6624 , http://hdl.handle.net/10962/d1016232
- Description: [From Introduction] Urbanisation in sub-Saharan Africa: changing the locus of poverty. Urbanisation is a global phenomenon that is changing the face of the Earth, as well as how people earn a living and secure their livelihoods. In 2006 the number of urban people in the world surpassed the number of rural people, and this gap will continue to grow. In only 16 years (by 2030) just under two-thirds of the world's people will be urban dwellers. Whilst most of the developed world and large parts of Latin America already have more than threequarters of their populations living in cities and towns, most countries in Asia and sub-Saharan Africa are still catching up. This means that they are experiencing massive migrations from rural to urban areas as rural people wish to swap the insecurities of rural living for the allure of secure employment and better services for health, education, sanitation and transport in towns and cities. Sub-Saharan Africa (SSA) is the most rapidly urbanising region of the globe. According to UN-Habitat, in 1990, only 28 % of the region's inhabitants lived in towns and cities; that increased to approximately 32 % in 2001 and 41 % in 2010. The size of the urban population is likely to surpass the rural one around 2025. Contrary to popular belief, most urban residents in SSA (and globally) live in small towns rather than massive megacities; with just over half living in towns of less than 200,000 people and 78 % living in towns of less than 500,000 residents. Only 14 % of urban dwellers live in cities of more than one million people. Many new urban households maintain strong links to relatives and clans in rural areas, with circular migration patterns emerging as the urban transition takes place over several decades. The implications of this extremely rapid urbanisation in SSA countries for livelihoods and poverty are widely debated. UN-Habitat highlights a relatively unique aspect of urbanisation in SSA as being the accompanying high rate of growth in informal settlements or slums. In other words, not all rural migrants to towns and cities find secure incomes or shelter. Some slum areas have become permanent features where inter-generational poverty is reproduced. Although urban areas are producing an increasing share of national wealth in SSA countries, some argue that slowly the nexus of poverty is shifting towards urban areas. Rates of poverty are high in rural areas of SSA, but migration and internal population growth means that in some countries the number of urban poor almost matches the number of rural poor, and it is likely to grow. The informal economy contributes an average of 40 – 45 % of total urban GDP, which is higher than any other region of the world.
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New geochemical constraints on the genesis of the Gamsberg zinc deposit, Namaqualand Metamorphic Province, South Africa
- Authors: Foulkes, Susan Elizabeth
- Date: 2014
- Subjects: Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5054 , http://hdl.handle.net/10962/d1012084 , Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Description: The base metal massive sulfide deposits of the Aggeneys-Gamsberg (A-G) District are hosted within the Mesoproterozoic Bushmanland Group of the Namaqua-Natal Metamorphic Complex in the Northern Cape Province of South Africa. The district displays an apparent eastward trend in the economic concentration of base metals (+ barite) from relatively Cu-Pb-rich, Ba-poor mineralisation at Black Mountain to Zn- and Ba-rich ores at Gamsberg. Base metal sulfides at Gamsberg are restricted to the so called Gams (Iron) Formation which comprises a sulfidic mineralized unit (“B”) enveloped within a sequence of meta-sedimentary units (“A” and “C”). The aim of the study was to shed further light on the genesis and chemical evolution of the sulfide mineralisation at Gamsberg in the context of the entire A-G District, by interrogating further the apparent district-wide trend in base metal distribution. The Gams Iron Formation was sampled and studied from one key drill core intersection (“G1”) which intersects the largest part of it as described elsewhere; a small number of additional samples from a second drill core (“G2”) complemented the main sample suite. Minerals that make up the silicate assemblages across the studied section include quartz, garnet, pyroxene, pyroxenoid, phyllosilicates, carbonates, amphiboles, oxides (chiefly magnetite) and graphite. In a stratigraphic context, the mineralogical variations conform directly to those documented in the relevant literature from the Gamsberg locality. These are coupled, where possible, with mineral-chemical profiles of selected silicate species which replicate those of bulk-rock compositions, particularly with respect to Mn, Fe and Ca in the upper C Unit of the studied section. These signals collectively track the characteristic transition from a terrigenous, siliciclastic sediment-dominated footwall to an exhalative sediment-dominated hanging wall to the sulfide mineralisation as also seen in similar deposits elsewhere, particularly with respect to the characteristic Mn-rich signature increasingly observed in the hanging wall C Unit. The foregoing suggests that the examined section faithfully records the interpreted primary stratigraphy of the deposits, despite the complex structural and metamorphic overprint that characterises the region. This facilitates a stratigraphic analytical approach on the sulfidic Unit B, through a combination of mineral-chemical and stable isotope analyses. Dominant sulfides in Unit B are sphalerite and pyrite, with lesser pyrrhotite and minor galena. Sphalerite shows high and generally invariant contents of Fe (mean 12.18wt%, as FeS) whereas Zn anti-correlates with Mn (mean 5.58wt%, as MnS). Isotopic analyses for S, Fe and Zn in hand-picked sphalerite and pyrite separates were used with a view to providing new evidence for chemical and isotopic variation within the sulfide ore-body in a vertical (i.e. stratigraphic) sense, discuss the implications thereof, and ultimately interpret the new data in light of similar existing data from the A-G District and elsewhere. The δ³⁴S data for pyrite (plus a single pyrrhotite grain) and sphalerite from both cores G1 and G2 show comparable compositional ranges between 22.9 and 30.4‰ and between 27 and 30.1‰ respectively. The δ⁵⁶Fe data for pyrite show a range between -1.85 and 0.19‰, whereas seven sphalerite separates have a very narrow range of δ⁶⁶Zn from 0.06 to 0.20‰. The atypically high sulfur isotope data reported in this study are interpreted to reflect sedimentary deposition of primary sulfide ore at Gamsberg from an isotopically highly evolved seawater sulfate source through large-scale Rayleigh fractionation processes. Thermogenic sulfate reduction is proposed to have been the main reductive mechanism from seawater sulfate to sulfide, given the absence of very low δ³⁴S data for sulfides anywhere in the A-G District. By contrast, the δ⁶⁶Zn values for sphalerite are for all intents and purposes invariant and very close to 0‰, and therefore suggest little Zn isotope fractionation from an original exhalative fluid source. On this evidence alone, Zn isotopes therefore appear to hold little promise as a proxy of the chemical and isotopic evolution of SEDEX deposits in space and time, although this can only be verified through further application in the broader A-G District and similar deposits elsewhere. The apparent decoupling of Zn and S isotopes in the Gamsberg sulfide deposit, however, points towards diverse sources of these two components, i.e. ascending metalliferous brines versus seawater respectively. Finally, pyrite δ⁵⁶Fe data do show a stratigraphic trend of generally declining values up-section, which are interpreted to reflect the influence of broadly coeval precipitation of isotopically heavy Fe-oxides on a broader-scale – now preserved as abundant magnetite through metamorphism. Further work on the iron isotope composition of silicate-and oxide-hosted Fe on a local-to-district scale will assist in testing this interpretation.
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- Authors: Foulkes, Susan Elizabeth
- Date: 2014
- Subjects: Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5054 , http://hdl.handle.net/10962/d1012084 , Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Description: The base metal massive sulfide deposits of the Aggeneys-Gamsberg (A-G) District are hosted within the Mesoproterozoic Bushmanland Group of the Namaqua-Natal Metamorphic Complex in the Northern Cape Province of South Africa. The district displays an apparent eastward trend in the economic concentration of base metals (+ barite) from relatively Cu-Pb-rich, Ba-poor mineralisation at Black Mountain to Zn- and Ba-rich ores at Gamsberg. Base metal sulfides at Gamsberg are restricted to the so called Gams (Iron) Formation which comprises a sulfidic mineralized unit (“B”) enveloped within a sequence of meta-sedimentary units (“A” and “C”). The aim of the study was to shed further light on the genesis and chemical evolution of the sulfide mineralisation at Gamsberg in the context of the entire A-G District, by interrogating further the apparent district-wide trend in base metal distribution. The Gams Iron Formation was sampled and studied from one key drill core intersection (“G1”) which intersects the largest part of it as described elsewhere; a small number of additional samples from a second drill core (“G2”) complemented the main sample suite. Minerals that make up the silicate assemblages across the studied section include quartz, garnet, pyroxene, pyroxenoid, phyllosilicates, carbonates, amphiboles, oxides (chiefly magnetite) and graphite. In a stratigraphic context, the mineralogical variations conform directly to those documented in the relevant literature from the Gamsberg locality. These are coupled, where possible, with mineral-chemical profiles of selected silicate species which replicate those of bulk-rock compositions, particularly with respect to Mn, Fe and Ca in the upper C Unit of the studied section. These signals collectively track the characteristic transition from a terrigenous, siliciclastic sediment-dominated footwall to an exhalative sediment-dominated hanging wall to the sulfide mineralisation as also seen in similar deposits elsewhere, particularly with respect to the characteristic Mn-rich signature increasingly observed in the hanging wall C Unit. The foregoing suggests that the examined section faithfully records the interpreted primary stratigraphy of the deposits, despite the complex structural and metamorphic overprint that characterises the region. This facilitates a stratigraphic analytical approach on the sulfidic Unit B, through a combination of mineral-chemical and stable isotope analyses. Dominant sulfides in Unit B are sphalerite and pyrite, with lesser pyrrhotite and minor galena. Sphalerite shows high and generally invariant contents of Fe (mean 12.18wt%, as FeS) whereas Zn anti-correlates with Mn (mean 5.58wt%, as MnS). Isotopic analyses for S, Fe and Zn in hand-picked sphalerite and pyrite separates were used with a view to providing new evidence for chemical and isotopic variation within the sulfide ore-body in a vertical (i.e. stratigraphic) sense, discuss the implications thereof, and ultimately interpret the new data in light of similar existing data from the A-G District and elsewhere. The δ³⁴S data for pyrite (plus a single pyrrhotite grain) and sphalerite from both cores G1 and G2 show comparable compositional ranges between 22.9 and 30.4‰ and between 27 and 30.1‰ respectively. The δ⁵⁶Fe data for pyrite show a range between -1.85 and 0.19‰, whereas seven sphalerite separates have a very narrow range of δ⁶⁶Zn from 0.06 to 0.20‰. The atypically high sulfur isotope data reported in this study are interpreted to reflect sedimentary deposition of primary sulfide ore at Gamsberg from an isotopically highly evolved seawater sulfate source through large-scale Rayleigh fractionation processes. Thermogenic sulfate reduction is proposed to have been the main reductive mechanism from seawater sulfate to sulfide, given the absence of very low δ³⁴S data for sulfides anywhere in the A-G District. By contrast, the δ⁶⁶Zn values for sphalerite are for all intents and purposes invariant and very close to 0‰, and therefore suggest little Zn isotope fractionation from an original exhalative fluid source. On this evidence alone, Zn isotopes therefore appear to hold little promise as a proxy of the chemical and isotopic evolution of SEDEX deposits in space and time, although this can only be verified through further application in the broader A-G District and similar deposits elsewhere. The apparent decoupling of Zn and S isotopes in the Gamsberg sulfide deposit, however, points towards diverse sources of these two components, i.e. ascending metalliferous brines versus seawater respectively. Finally, pyrite δ⁵⁶Fe data do show a stratigraphic trend of generally declining values up-section, which are interpreted to reflect the influence of broadly coeval precipitation of isotopically heavy Fe-oxides on a broader-scale – now preserved as abundant magnetite through metamorphism. Further work on the iron isotope composition of silicate-and oxide-hosted Fe on a local-to-district scale will assist in testing this interpretation.
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Nonlinear optical studies of metallophtalocyanines and hemiporphyrazines in solution
- Authors: Britton, Jonathan
- Date: 2014
- Subjects: Phthalocyanines Photochemistry Nanoparticles Nanostructured materials Polymers Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4464 , http://hdl.handle.net/10962/d1011608
- Description: This thesis presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (5-12) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tertbutylphenoxy and amino groups in solution and in poly (methyl methacrylate) (PMMA) films. The optical limiting parameters of Pcs were higher for tertbutylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ⁽³⁾]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10⁻¹² to 10⁻¹° esu cm range. Hyperpolarizabilities (γ) ranged from 10⁻³¹ to 10⁻²⁹ esu L for Pc alone or in mixture with QDs. The effect on the optical limiting abilities of twelve embedded phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films was also examined. The effect of forming a covalent link zinc tetraamino phthalocyanine (12) with poly (methyl acrylic acid) (PMAA) and Zn (13) and OHAl (14) octacarboxy phthalocyanines to polyethylenimine (PEI) was also studied. The hyperpolarizability of the twelve phthalocyanines in polymer was found to be in the range of 10⁻²⁶ to 10⁻²⁴ esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution. Non-linear optical (NLO) parameters were determined for phthalocyanine complexes containing In, Ga and Zn as central metals when embedded in PMMA polymer in the presence of quantum dots (QDs). The QDs mainly employed were CdTe-TGA (TGA = thioglylcolic acid). Triplet lifetimes increased as k (excited state (σex) to ground state (σg) absorption cross section ratio) values decreased with the addition of the CdTe-TGA to the phthalocyanines. The saturation energy density (Fsat) values were smaller in the films when compared to the solutions. Complex 7 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS-TGA, CdSe-TGA, fullerenes and single walled carbon nanotubes. There is a general improvement in optical limiting ability of Pc complexes in the presence of nanomaterials (NMs). Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation. 3(4), 15(16)-Bis-(4 -tert-butyl-phenoxy)-10, 22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1, 3, 5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
- Full Text:
- Authors: Britton, Jonathan
- Date: 2014
- Subjects: Phthalocyanines Photochemistry Nanoparticles Nanostructured materials Polymers Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4464 , http://hdl.handle.net/10962/d1011608
- Description: This thesis presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (5-12) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tertbutylphenoxy and amino groups in solution and in poly (methyl methacrylate) (PMMA) films. The optical limiting parameters of Pcs were higher for tertbutylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ⁽³⁾]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10⁻¹² to 10⁻¹° esu cm range. Hyperpolarizabilities (γ) ranged from 10⁻³¹ to 10⁻²⁹ esu L for Pc alone or in mixture with QDs. The effect on the optical limiting abilities of twelve embedded phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films was also examined. The effect of forming a covalent link zinc tetraamino phthalocyanine (12) with poly (methyl acrylic acid) (PMAA) and Zn (13) and OHAl (14) octacarboxy phthalocyanines to polyethylenimine (PEI) was also studied. The hyperpolarizability of the twelve phthalocyanines in polymer was found to be in the range of 10⁻²⁶ to 10⁻²⁴ esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution. Non-linear optical (NLO) parameters were determined for phthalocyanine complexes containing In, Ga and Zn as central metals when embedded in PMMA polymer in the presence of quantum dots (QDs). The QDs mainly employed were CdTe-TGA (TGA = thioglylcolic acid). Triplet lifetimes increased as k (excited state (σex) to ground state (σg) absorption cross section ratio) values decreased with the addition of the CdTe-TGA to the phthalocyanines. The saturation energy density (Fsat) values were smaller in the films when compared to the solutions. Complex 7 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS-TGA, CdSe-TGA, fullerenes and single walled carbon nanotubes. There is a general improvement in optical limiting ability of Pc complexes in the presence of nanomaterials (NMs). Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation. 3(4), 15(16)-Bis-(4 -tert-butyl-phenoxy)-10, 22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1, 3, 5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
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