The thermal physiology of Stenopelmus rufinasus and Neohydronomus affinis (Coleoptera: Curculionidae), biological control agents for the invasive alien aquatic weeds Azolla filiculoides and Pistia stratiotes respectively
- Authors: Mvandaba, Sisanda F
- Date: 2018
- Subjects: Beetles -- South Africa , Curculionidae -- South Africa , Azolla filiculoides -- South Africa , Water lettuce -- South Africa , Aquatic weeds -- Biological control -- South Africa , Stenopelmus rufinasus , Neohydronomus affinis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62362 , vital:28158
- Description: Water lettuce, Pistia stratiotes L. (Araceae), and red water fern, Azolla filiculoides Lam. (Azollaceae), are floating aquatic macrophytes that have become problematic invaders in numerous South African waterbodies. Two weevils, Neohydronomus affinis Hustache 1926 (Coleoptera: Curculionidae) and Stenopelmus rufinasus Gyllenhal 1936 (Coleoptera: Curculionidae), are successful biological control agents of these two species, respectively, in South Africa. However, nothing is known about the thermal physiology of these two species Therefore, the aim of this study was to investigate the thermal physiologies of these two species to explain their establishment, distribution and impact in the field. Laboratory based thermal physiology trials showed that both weevils were widely tolerant of cold and warm temperatures. The CTmin of N. affinis was determined to be 5.5 ± 0.312°C and the CTmax was 44 ± 0.697°C, while the CTmin of S. rufinasus was 5.4 ± 0.333°C and the CTmax was 44.5 ± 0.168°C. In addition, the lower lethal temperatures were -9.8 ± 0.053°C and -7.2 ± 0.19°C, and the upper lethal temperatures were 42.8 ± 0.053°C and 41.9 ± 0.19°C respectively. These results suggest that both species should not be limited by cold winter temperatures, as previously thought. This is evident in the field, where S. rufinasus has established widely on A. filiculoides, despite local cold climates in some areas of the plant’s distribution. Even though N. affinis has a similar thermal range, and should therefore theoretically reflect a similar distribution to S. rufinasus throughout South Africa, its distribution is limited by the range of its host, which is restricted to the warmer regions of the country, as is its biocontrol agent. Using the reduced major axis regression method, the development for N. affinis was described using the formulay=12.976x+435.24, while the development of S. rufinasus was described by y=13.6x+222.45. These results showed that S. rufinasus develops much faster, in fact almost twice as quickly, than N. affinis. Using these formulae and temperature data obtained from the South African Weather Service, N. affinis was predicted to complete between 4 and 9 generations per year in South Africa, while S. rufinasus was predicted to complete between 5 and 14 generations per year around the country. This study showed that although the native range of these two species is warm temperate to tropical, they possess sufficient thermal plasticity to not only establish, but also damage their respective host plants in far cooler climates. Thus, in South Africa N. affinis and S. rufinasus are limited by the distribution of their target weeds and not climate.
- Full Text:
- Date Issued: 2018
- Authors: Mvandaba, Sisanda F
- Date: 2018
- Subjects: Beetles -- South Africa , Curculionidae -- South Africa , Azolla filiculoides -- South Africa , Water lettuce -- South Africa , Aquatic weeds -- Biological control -- South Africa , Stenopelmus rufinasus , Neohydronomus affinis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62362 , vital:28158
- Description: Water lettuce, Pistia stratiotes L. (Araceae), and red water fern, Azolla filiculoides Lam. (Azollaceae), are floating aquatic macrophytes that have become problematic invaders in numerous South African waterbodies. Two weevils, Neohydronomus affinis Hustache 1926 (Coleoptera: Curculionidae) and Stenopelmus rufinasus Gyllenhal 1936 (Coleoptera: Curculionidae), are successful biological control agents of these two species, respectively, in South Africa. However, nothing is known about the thermal physiology of these two species Therefore, the aim of this study was to investigate the thermal physiologies of these two species to explain their establishment, distribution and impact in the field. Laboratory based thermal physiology trials showed that both weevils were widely tolerant of cold and warm temperatures. The CTmin of N. affinis was determined to be 5.5 ± 0.312°C and the CTmax was 44 ± 0.697°C, while the CTmin of S. rufinasus was 5.4 ± 0.333°C and the CTmax was 44.5 ± 0.168°C. In addition, the lower lethal temperatures were -9.8 ± 0.053°C and -7.2 ± 0.19°C, and the upper lethal temperatures were 42.8 ± 0.053°C and 41.9 ± 0.19°C respectively. These results suggest that both species should not be limited by cold winter temperatures, as previously thought. This is evident in the field, where S. rufinasus has established widely on A. filiculoides, despite local cold climates in some areas of the plant’s distribution. Even though N. affinis has a similar thermal range, and should therefore theoretically reflect a similar distribution to S. rufinasus throughout South Africa, its distribution is limited by the range of its host, which is restricted to the warmer regions of the country, as is its biocontrol agent. Using the reduced major axis regression method, the development for N. affinis was described using the formulay=12.976x+435.24, while the development of S. rufinasus was described by y=13.6x+222.45. These results showed that S. rufinasus develops much faster, in fact almost twice as quickly, than N. affinis. Using these formulae and temperature data obtained from the South African Weather Service, N. affinis was predicted to complete between 4 and 9 generations per year in South Africa, while S. rufinasus was predicted to complete between 5 and 14 generations per year around the country. This study showed that although the native range of these two species is warm temperate to tropical, they possess sufficient thermal plasticity to not only establish, but also damage their respective host plants in far cooler climates. Thus, in South Africa N. affinis and S. rufinasus are limited by the distribution of their target weeds and not climate.
- Full Text:
- Date Issued: 2018
Knowledge practices and student access and success in General Chemistry at a Large South African University
- Authors: Mtombeni, Thabile Nokuthula
- Date: 2018
- Subjects: Chemistry -- Study and teaching (Higher) -- South Africa , Knowledge management , Education, Higher -- Curricula -- South Africa , Critical realism , Social integration -- South Africa , Educational equalization -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62873 , vital:28305
- Description: This dissertation reports on an investigation into the structuring principles of the General Chemistry curriculum at a Large South African University (LSAU). Student learning in the introductory modules of General Chemistry is critical for access to a range of fields since it is a requisite course for a variety of degree programmes. However, there is ample evidence that success in this subject remains a major challenge, particularly for black students. My quest in this study was to explore how the curriculum could enable greater epistemic access and thus include more students in science programmes at the LSAU. I investigated the organising principles underlying the curriculum practices of the General Chemistry module and explored the effects of the curriculum structure on student learning. Theoretically and conceptually, the study was underpinned by a social realist approach which holds that knowledge is stratified, differentiated, and has real emergent properties, powers and effects. The research question that I attempted to answer in this study was: How do knowledge practices privileged in the General Chemistry curriculum at the LSAU enable or constrain student learning? I adopted an intensive research design approach to conduct a qualitative case study using social realism and LCT as theoretical and analytical lenses. I used empirical data such as curriculum documents and interviews with lecturers to uncover the underlying generative mechanisms of the curriculum. I adopted a multi-layered data analysis process to make visible the underlying organising principles informing knowledge practices in the curriculum so that I could explain their potential effects on student learning. The first level of analysis explored the context of the curriculum and associated knowledge practices, and examined the pedagogic discourse evident in the curriculum. The second level of analysis revealed the inner logic structuring the curriculum and the associated knowledge practices. I used Maton’s Legitimation Code Theory (LCT): Specialisation to identify the specialisation codes, gazes and insights generated by the curriculum. For the third level of analysis, LCT: Semantics was used to generate the semantic profiles of learning activities to determine the extent to which the curriculum structure made cumulative learning possible. From the findings, it is evident that the verticality of knowledge in General Chemistry points to a recontextualising principle that prescribes the selection and arrangement of knowledge, and the special relationship of actors and discourses. As a result, the strong framing of the instructional discourse of General Chemistry curriculum structure is likely to constrain epistemological access for large numbers of students. In order to improve epistemological access to the field, weaker framing of the instructional discourse in introductory science is necessary. Weaker framing of the General Chemistry curriculum would require, in particular, changes to pacing, and that the evaluative criteria are made explicit. This is especially necessary when certain abstract and complex curricular content is taught, especially in the first semester. The findings also indicate that the nature of the organising principles in the curriculum are significant for improving epistemological access to knowledge. In terms of LCT: Specialisation, the General Chemistry curriculum generated a knowledge code and downplayed differences among social categories of students, thus positioning all equally in relation to the knowledge and practices of the field. Therefore, the structuring of the curriculum emphasises and legitimates students who have attained specialist knowledge without considering the nature of the new student coming into the educational setting. Simply, what is privileged is both the object of study (theoretical knowledge) and how it is studied (procedural knowledge). This finding is in line with the general outcomes of Chemistry education. In addition, the purist insight generated by the curriculum further attests to where the emphasis is placed in the curriculum. I argue that the lack of social relations in the curriculum poses a challenge for the holistic development of students as science knowers. The analysis of the learning activities shows rapid code shifts that indicate changes in cognitive demand and modes of thinking required of students. I argue that signposting the changes in complexity of knowledge and in the mode of thinking required could make learning, and thus epistemological access, more possible. Given the imperative of access to powerful knowledge, I contend that the curriculum should be reshaped to enable epistemological access for more students.
- Full Text:
- Date Issued: 2018
- Authors: Mtombeni, Thabile Nokuthula
- Date: 2018
- Subjects: Chemistry -- Study and teaching (Higher) -- South Africa , Knowledge management , Education, Higher -- Curricula -- South Africa , Critical realism , Social integration -- South Africa , Educational equalization -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62873 , vital:28305
- Description: This dissertation reports on an investigation into the structuring principles of the General Chemistry curriculum at a Large South African University (LSAU). Student learning in the introductory modules of General Chemistry is critical for access to a range of fields since it is a requisite course for a variety of degree programmes. However, there is ample evidence that success in this subject remains a major challenge, particularly for black students. My quest in this study was to explore how the curriculum could enable greater epistemic access and thus include more students in science programmes at the LSAU. I investigated the organising principles underlying the curriculum practices of the General Chemistry module and explored the effects of the curriculum structure on student learning. Theoretically and conceptually, the study was underpinned by a social realist approach which holds that knowledge is stratified, differentiated, and has real emergent properties, powers and effects. The research question that I attempted to answer in this study was: How do knowledge practices privileged in the General Chemistry curriculum at the LSAU enable or constrain student learning? I adopted an intensive research design approach to conduct a qualitative case study using social realism and LCT as theoretical and analytical lenses. I used empirical data such as curriculum documents and interviews with lecturers to uncover the underlying generative mechanisms of the curriculum. I adopted a multi-layered data analysis process to make visible the underlying organising principles informing knowledge practices in the curriculum so that I could explain their potential effects on student learning. The first level of analysis explored the context of the curriculum and associated knowledge practices, and examined the pedagogic discourse evident in the curriculum. The second level of analysis revealed the inner logic structuring the curriculum and the associated knowledge practices. I used Maton’s Legitimation Code Theory (LCT): Specialisation to identify the specialisation codes, gazes and insights generated by the curriculum. For the third level of analysis, LCT: Semantics was used to generate the semantic profiles of learning activities to determine the extent to which the curriculum structure made cumulative learning possible. From the findings, it is evident that the verticality of knowledge in General Chemistry points to a recontextualising principle that prescribes the selection and arrangement of knowledge, and the special relationship of actors and discourses. As a result, the strong framing of the instructional discourse of General Chemistry curriculum structure is likely to constrain epistemological access for large numbers of students. In order to improve epistemological access to the field, weaker framing of the instructional discourse in introductory science is necessary. Weaker framing of the General Chemistry curriculum would require, in particular, changes to pacing, and that the evaluative criteria are made explicit. This is especially necessary when certain abstract and complex curricular content is taught, especially in the first semester. The findings also indicate that the nature of the organising principles in the curriculum are significant for improving epistemological access to knowledge. In terms of LCT: Specialisation, the General Chemistry curriculum generated a knowledge code and downplayed differences among social categories of students, thus positioning all equally in relation to the knowledge and practices of the field. Therefore, the structuring of the curriculum emphasises and legitimates students who have attained specialist knowledge without considering the nature of the new student coming into the educational setting. Simply, what is privileged is both the object of study (theoretical knowledge) and how it is studied (procedural knowledge). This finding is in line with the general outcomes of Chemistry education. In addition, the purist insight generated by the curriculum further attests to where the emphasis is placed in the curriculum. I argue that the lack of social relations in the curriculum poses a challenge for the holistic development of students as science knowers. The analysis of the learning activities shows rapid code shifts that indicate changes in cognitive demand and modes of thinking required of students. I argue that signposting the changes in complexity of knowledge and in the mode of thinking required could make learning, and thus epistemological access, more possible. Given the imperative of access to powerful knowledge, I contend that the curriculum should be reshaped to enable epistemological access for more students.
- Full Text:
- Date Issued: 2018
Photosensitizer, pH sensing and optical limiting properties of BODIPY dyes
- Authors: May, Aviwe Khanya
- Date: 2018
- Subjects: Dyes and dyeing -- Chemistry , Halogenation , Photochemotherapy , Bromination , Photosensitizing compounds , Nonlinear optics , BODIPY dyes
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63964 , vital:28515
- Description: A series of BODIPY dyes have been successfully synthesised and structurally characterised to examine the effect of halogenation at the 2,6-positions and the introduction of styryl and vinylene groups at the 3,5-positions. The photophysical properties were studied, to assess the effect of the enhancement of the rate of intersystem crossing through halogenation on the fluorescence properties and the generation of reactive oxygen species. This is important in the assessment of the suitability of applying these molecules as photosensitizer dyes for photodynamic therapy and photodynamic antimicrobial chemotherapy. Upon bromination, the dyes showed moderately high singlet oxygen quantum yields. The inclusion of BODIPY dyes into cyclodextrins was explored since it makes them water soluble and hence suitable for biomedical applications, but no singlet oxygen was detected in aqueous media for the inclusion complexes. In order to red-shift the main spectral band of the BODIPY dyes into the therapeutic window, styryl groups were introduced at the 3,5-positions via a modified Knoevenagel condensation reaction. Since the main spectral band lies well above 532 nm, the second harmonic of the Nd:YAG laser, there is relatively weak absorbance at this wavelength. The 3,5-distyryl and 3,5-divinylene BODIPY dyes were assessed for their potential utility for application in nonlinear optics (NLO), and they demonstrated typical nonlinear absorption behaviour characterised by reverse saturable absorption (RSA) in z-scan measurements. Furthermore, the dyes possess excellent optical limiting parameters, such as their third-order suspectibility and hyperpolarizability values, in a wide range of solvents. One dye containing dimethylamino moieties on styryl groups attached at the 3,5-positions was assessed for potential application as an on/off fluorescence sensor. The dye proved to be successful, since intramolecular charge transfer in the S1 state was eliminated in the presence of acid and this results in a fluorescence “turn on” effect. This process was found to be reversible with the addition of a base.
- Full Text:
- Date Issued: 2018
- Authors: May, Aviwe Khanya
- Date: 2018
- Subjects: Dyes and dyeing -- Chemistry , Halogenation , Photochemotherapy , Bromination , Photosensitizing compounds , Nonlinear optics , BODIPY dyes
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63964 , vital:28515
- Description: A series of BODIPY dyes have been successfully synthesised and structurally characterised to examine the effect of halogenation at the 2,6-positions and the introduction of styryl and vinylene groups at the 3,5-positions. The photophysical properties were studied, to assess the effect of the enhancement of the rate of intersystem crossing through halogenation on the fluorescence properties and the generation of reactive oxygen species. This is important in the assessment of the suitability of applying these molecules as photosensitizer dyes for photodynamic therapy and photodynamic antimicrobial chemotherapy. Upon bromination, the dyes showed moderately high singlet oxygen quantum yields. The inclusion of BODIPY dyes into cyclodextrins was explored since it makes them water soluble and hence suitable for biomedical applications, but no singlet oxygen was detected in aqueous media for the inclusion complexes. In order to red-shift the main spectral band of the BODIPY dyes into the therapeutic window, styryl groups were introduced at the 3,5-positions via a modified Knoevenagel condensation reaction. Since the main spectral band lies well above 532 nm, the second harmonic of the Nd:YAG laser, there is relatively weak absorbance at this wavelength. The 3,5-distyryl and 3,5-divinylene BODIPY dyes were assessed for their potential utility for application in nonlinear optics (NLO), and they demonstrated typical nonlinear absorption behaviour characterised by reverse saturable absorption (RSA) in z-scan measurements. Furthermore, the dyes possess excellent optical limiting parameters, such as their third-order suspectibility and hyperpolarizability values, in a wide range of solvents. One dye containing dimethylamino moieties on styryl groups attached at the 3,5-positions was assessed for potential application as an on/off fluorescence sensor. The dye proved to be successful, since intramolecular charge transfer in the S1 state was eliminated in the presence of acid and this results in a fluorescence “turn on” effect. This process was found to be reversible with the addition of a base.
- Full Text:
- Date Issued: 2018
Teacher perspectives on value creation and learning in South African eco-schools: an evaluative review of teacher support processes in an eco-school professional learning community
- Authors: Khan, Anisa
- Date: 2018
- Subjects: Teachers -- In-service training -- South Africa , Environmental education -- Study and teaching -- South Africa , Continuing education , Teachers -- Attitudes , Communities of practice -- South Africa , Integrated Strategic Planning Framework for Teacher Education , Eco-schools
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/62840 , vital:28300
- Description: The study is framed within the broader policy context of teacher professional development and the Department of Basic Education (DBE) and Department of Higher Education (DHET) strategy to support the development of Professional Learning Communities. Teacher Education and Development initiatives in South Africa face multiple challenges, with the Integrated Strategic Planning Framework for Teacher Education in South Africa: 2011-2025 (ISFPTED) (South Africa, DBE, 2011) providing guidance on priority interventions to address these, including guidance on continuous teacher professional development through teacher education support in professional learning communities. The Eco-Schools programme has, over its decade-long history, provided support to teachers in schools registered as Eco-Schools. The value created by the diverse support practices is not well known or understood. The study aimed to shed light on the support teachers in the Eco-Schools programme value and how this contributes to environmental learning and practice. Working with Wenger’s Communities of Practice theory (Wenger, 1998) as a conceptual framework and lens, the study set out to describe and explore the processes of teacher learning amongst a sample of teachers supported to function as a professional learning community within the Eco-Schools programme. The findings and recommendations made are in relation to the research goals which are to explore and describe the value being created by the patterns of teacher support in an Eco-Schools node/cluster. To this end, the evaluative study generated evidence in relation to what teachers derive value from through the support they receive; and assessed evidence on how teaching, learning, and practice are developing through participation in the Eco-Schools Professional Learning Community examined. The study was conducted in 2 phases, the first as a survey of the patterns of support in Eco-School clusters/ nodes. The descriptions enabled a mapping of the patterns of support in the “coordinator supported model” of Eco-Schools to understand how the coordinator supported model of Eco-Schools enables teacher collaboration and supports the development of an environment and sustainability community of practice between teachers from across the cluster/ node. The second part of the study explored teacher’s perspectives of value derived from participation in an expanded model of Eco-Schools support, using an appreciative inquiry methodology to extract teacher narrations of value creation and meaning-making. In relation to goal one, the main findings indicate that the patterns of support enabled teachers to develop confidence and skills for action taking and responding to local socio-economic and environmental challenges. The data also reflected local partnerships with other environmental knowledge organisations, thus adding value to the programme through an expanded network of environmental practice and provision of additional resources. In relation to goal 2 of the study, teachers experienced Eco-School practices as personally meaningful and connected to their identity. Teachers expressed value in the training they had received through the Fundisa for Change programme which deepened their understanding of the implementation requirements of the Curriculum and Assessment Policy Statements (CAPS) and helped to connect knowledge concepts in the curriculum with sustainability practices implemented as part of the Eco-Schools framework. In relation to goal 3, teachers gained confidence in “Teaching Biodiversity” through the Fundisa for Change training. Teachers were better able to understand the Specific Aims of the Biodiversity curriculum (CAPS) and to adapt their teaching methods to support the CAPS content and assessment requirements. Teacher portfolios also showed evidence of teachers developing skills in analysis of learner performance and an awareness of the need to adjust their teaching and assessment strategies to address “gaps” in learner understanding.
- Full Text:
- Date Issued: 2018
- Authors: Khan, Anisa
- Date: 2018
- Subjects: Teachers -- In-service training -- South Africa , Environmental education -- Study and teaching -- South Africa , Continuing education , Teachers -- Attitudes , Communities of practice -- South Africa , Integrated Strategic Planning Framework for Teacher Education , Eco-schools
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/62840 , vital:28300
- Description: The study is framed within the broader policy context of teacher professional development and the Department of Basic Education (DBE) and Department of Higher Education (DHET) strategy to support the development of Professional Learning Communities. Teacher Education and Development initiatives in South Africa face multiple challenges, with the Integrated Strategic Planning Framework for Teacher Education in South Africa: 2011-2025 (ISFPTED) (South Africa, DBE, 2011) providing guidance on priority interventions to address these, including guidance on continuous teacher professional development through teacher education support in professional learning communities. The Eco-Schools programme has, over its decade-long history, provided support to teachers in schools registered as Eco-Schools. The value created by the diverse support practices is not well known or understood. The study aimed to shed light on the support teachers in the Eco-Schools programme value and how this contributes to environmental learning and practice. Working with Wenger’s Communities of Practice theory (Wenger, 1998) as a conceptual framework and lens, the study set out to describe and explore the processes of teacher learning amongst a sample of teachers supported to function as a professional learning community within the Eco-Schools programme. The findings and recommendations made are in relation to the research goals which are to explore and describe the value being created by the patterns of teacher support in an Eco-Schools node/cluster. To this end, the evaluative study generated evidence in relation to what teachers derive value from through the support they receive; and assessed evidence on how teaching, learning, and practice are developing through participation in the Eco-Schools Professional Learning Community examined. The study was conducted in 2 phases, the first as a survey of the patterns of support in Eco-School clusters/ nodes. The descriptions enabled a mapping of the patterns of support in the “coordinator supported model” of Eco-Schools to understand how the coordinator supported model of Eco-Schools enables teacher collaboration and supports the development of an environment and sustainability community of practice between teachers from across the cluster/ node. The second part of the study explored teacher’s perspectives of value derived from participation in an expanded model of Eco-Schools support, using an appreciative inquiry methodology to extract teacher narrations of value creation and meaning-making. In relation to goal one, the main findings indicate that the patterns of support enabled teachers to develop confidence and skills for action taking and responding to local socio-economic and environmental challenges. The data also reflected local partnerships with other environmental knowledge organisations, thus adding value to the programme through an expanded network of environmental practice and provision of additional resources. In relation to goal 2 of the study, teachers experienced Eco-School practices as personally meaningful and connected to their identity. Teachers expressed value in the training they had received through the Fundisa for Change programme which deepened their understanding of the implementation requirements of the Curriculum and Assessment Policy Statements (CAPS) and helped to connect knowledge concepts in the curriculum with sustainability practices implemented as part of the Eco-Schools framework. In relation to goal 3, teachers gained confidence in “Teaching Biodiversity” through the Fundisa for Change training. Teachers were better able to understand the Specific Aims of the Biodiversity curriculum (CAPS) and to adapt their teaching methods to support the CAPS content and assessment requirements. Teacher portfolios also showed evidence of teachers developing skills in analysis of learner performance and an awareness of the need to adjust their teaching and assessment strategies to address “gaps” in learner understanding.
- Full Text:
- Date Issued: 2018
A mineral systems approach to the development of structural targeting criteria for orogenic gold deposits in the Asankrangwa gold belt of the Kumasi Basin, South-west Ghana
- Authors: Gelber, Benjamin D J
- Date: 2018
- Subjects: Gold ores -- Geology -- Ghana -- Kumasi , Gold mines and mining -- Ghana -- Kumasi , Asankrangwa (Ghana) , Geodynamics -- Ghana -- Kumasi , Prospecting -- Geophysical methods , Orogenic belts -- Ghana -- Kumasi
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63143 , vital:28367
- Description: The Kumasi Basin in South-west Ghana lies at the centre of the best-endowed Paleoproterozoic gold province in the world. The Kumasi Basin and margins of the adjacent volcanic belts are host to six world class gold camps: (1) 62 Moz Obuasi camp, (2) 22 Moz Prestea-Bogoso camp, (3) 11 Moz Asanko Gold Mine camp, (4) 9 Moz Edikan camp, (5) 7 Moz Bibiani camp, (6) 5 Moz Chirano camp, as well as several additional minor gold camps and many more prospects. Cumulatively these camps account for>116 Moz of endowment and contribute to making south-west Ghana the greatest Paleoproterozoic gold province in the world. Gold deposits in the Kumasi Basin are shear zone hosted and mineralisation ranges from disseminated to massive sulphide refractory deposits, to free milling quartz vein style deposits. Structural relationships and age dating indicate that most deposits are genetically related and were formed during a single episode of gold mineralisation during the D4 NNW-SSE crustal shortening deformation event of the Eburnean Orogeny (2125 – 1980 Ma). The understanding of structural controls on mineralisation is critical for exploration success as it allows exploration to focus on areas where these structural controls exist. This study uses a mineral systems approach to understand the relationship between the geodynamic history and structural controls on gold mineralisation in the Kumasi Basin at various scales, and define targeting criteria which can be applied for the purpose of developing predictive exploration models for making new discoveries in the Asanko Gold Mine camp located in the Asankrangwa Belt. The study used a quantitative analysis to establish residual endowment potential in the Asankrangwa Belt, providing the basis for a business model and resulting exploration strategy. Once established, a Fry autocorrelation analysis was applied to identify trends in deposit and camp spatial distribution to which critical geological processes were ascribed. Observed trends were mapped from multi-scale geophysical data sets and through interpretation of existing geophysical structure models, and structural criteria for targeting orogenic gold deposits at the regional and camp scales were developed. Results show that different structural controls on mineralisation act at the regional and camp scale. At the regional scale the distribution of gold camps was found to be controlled by fundamental N-S and NW-SE basement structures with gold camps forming where they intersect NE-SW first and second order structural corridors. At the Asanko Gold Mine camp scale, deposit distribution was found to be related to the intersection between major second order D3 NE-SW shear zones, minor third order D4 NNE-SSW brittle faults, and cryptic NW-SE upward propagating basement structures. In addition to these structural criteria, deposits in the Asanko Gold Mine camp were found to be aligned along a NNE-SSW lineament caused by the interaction between the N-S basement structure and the NE-SW trending Asankrangwa Belt shear corridor.
- Full Text:
- Date Issued: 2018
- Authors: Gelber, Benjamin D J
- Date: 2018
- Subjects: Gold ores -- Geology -- Ghana -- Kumasi , Gold mines and mining -- Ghana -- Kumasi , Asankrangwa (Ghana) , Geodynamics -- Ghana -- Kumasi , Prospecting -- Geophysical methods , Orogenic belts -- Ghana -- Kumasi
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63143 , vital:28367
- Description: The Kumasi Basin in South-west Ghana lies at the centre of the best-endowed Paleoproterozoic gold province in the world. The Kumasi Basin and margins of the adjacent volcanic belts are host to six world class gold camps: (1) 62 Moz Obuasi camp, (2) 22 Moz Prestea-Bogoso camp, (3) 11 Moz Asanko Gold Mine camp, (4) 9 Moz Edikan camp, (5) 7 Moz Bibiani camp, (6) 5 Moz Chirano camp, as well as several additional minor gold camps and many more prospects. Cumulatively these camps account for>116 Moz of endowment and contribute to making south-west Ghana the greatest Paleoproterozoic gold province in the world. Gold deposits in the Kumasi Basin are shear zone hosted and mineralisation ranges from disseminated to massive sulphide refractory deposits, to free milling quartz vein style deposits. Structural relationships and age dating indicate that most deposits are genetically related and were formed during a single episode of gold mineralisation during the D4 NNW-SSE crustal shortening deformation event of the Eburnean Orogeny (2125 – 1980 Ma). The understanding of structural controls on mineralisation is critical for exploration success as it allows exploration to focus on areas where these structural controls exist. This study uses a mineral systems approach to understand the relationship between the geodynamic history and structural controls on gold mineralisation in the Kumasi Basin at various scales, and define targeting criteria which can be applied for the purpose of developing predictive exploration models for making new discoveries in the Asanko Gold Mine camp located in the Asankrangwa Belt. The study used a quantitative analysis to establish residual endowment potential in the Asankrangwa Belt, providing the basis for a business model and resulting exploration strategy. Once established, a Fry autocorrelation analysis was applied to identify trends in deposit and camp spatial distribution to which critical geological processes were ascribed. Observed trends were mapped from multi-scale geophysical data sets and through interpretation of existing geophysical structure models, and structural criteria for targeting orogenic gold deposits at the regional and camp scales were developed. Results show that different structural controls on mineralisation act at the regional and camp scale. At the regional scale the distribution of gold camps was found to be controlled by fundamental N-S and NW-SE basement structures with gold camps forming where they intersect NE-SW first and second order structural corridors. At the Asanko Gold Mine camp scale, deposit distribution was found to be related to the intersection between major second order D3 NE-SW shear zones, minor third order D4 NNE-SSW brittle faults, and cryptic NW-SE upward propagating basement structures. In addition to these structural criteria, deposits in the Asanko Gold Mine camp were found to be aligned along a NNE-SSW lineament caused by the interaction between the N-S basement structure and the NE-SW trending Asankrangwa Belt shear corridor.
- Full Text:
- Date Issued: 2018
Development and evaluation of a web application employing artificial neural networks to facilitate the prediction of antiretroviral drug resistance in patients infected with HIV-1 subtype B
- Authors: Nabatanzi, Margaret
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63396 , vital:28406
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Nabatanzi, Margaret
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63396 , vital:28406
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
A community–wide trophic structure analysis in intertidal ecosystems on the south coast of South Africa
- Authors: Gusha, Molline Natanah C
- Date: 2018
- Subjects: Food chains (Ecology) , Coastal ecology -- South Africa , Intertidal ecology -- South Africa , Marine animals -- Climatic factors -- South Africa , Marine animals -- Food -- South Africa , Marine animals -- Habitat -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63312 , vital:28392
- Description: Coastal ecosystems are more than microhabitats for marine species. Acting as atmospheric carbon filters, species in coastal environments are directly and/or indirectly associated with transferring organic carbon to species at higher trophic levels. However, the progressing change in global climatic conditions has created the need to assess the consequences of the shifting conditions on both direct and indirect interactions of physical and biological parameters at species and/or community levels. From these perturbations, the effects of biotic homogenization on ecosystem functioning and resilience can also be realised. Herein, I discuss the effects of temperature, nutrients, biotic interactions and habitat characteristics on community dynamics within intertidal rock pool systems on the south coast of South Africa using complementary qualitative and quantitative analytical methods. Seasonality had a significant impact on rock pool species with changes in composition and higher richness in winter than summer. The first two axes of the Canonical Correspondence Analysis (CCA) of the plant and animal communities each explained ~20% of the relationship between physico-chemical parameters and biological variables. The CCA highlighted that seasonal shifts in chlorophyll-a, conductivity, salinity, water depth, surface area and substratum type indirectly influenced species composition. For example, pools with heterogenous substratum comprising a mixture of sand and rock exhibited higher species diversity than homogenously bedded pools. Furthermore, a Bayesian analysis of community structure based on stable isotope ratios was used to assess how trophic pathways of carbon and nitrogen elements reflected community composition and richness. Isotopic biplots showed an increase in food web size, food chain length and the trophic positions of fish and some gastropods in winter compared to summer. There was greater dietary overlap among species in larger pools. In addition, while isotopic nearest neighbour distance and species evenness also showed a positive increase with pool size in summer, the same metrics were almost constant across all pool sizes in winter. These changes in food web packing and species evenness suggest seasonal preferences or migration of species in summer from small pools to larger pools with stable physico-chemical parameters. Furthermore, the presence of fish was seen to promote trophic diversity within some pools. The results from laboratory microcosm grazing experiments demonstrated significant direct and indirect effects of temperature and nutrients within plankton communities. Copepod grazing had an indirect positive influence on phytoplankton biomass and size structure while the interactive effects of temperature and nutrients had contrasting effects on both phytoplankton communities and copepod biomass. Shifts in water chemistry and nutrient treatments were also observed in the presence of copepods. Phosphate addition had a recognisable impact on plankton communities. The presented synthesis of the literature mainly highlighted that positive effects at one trophic level do not always positively cascade into the next trophic level which is evidence of complex interactive biotic, habitat and water chemistry effects within these intertidal ecosystems. Thus, to further understand cascading effects or community structure functioning in general, there may be a need to incorporate and understand species functional traits and how they contribute to trophic diversity, community restructuring and functioning in coastal habitats.
- Full Text:
- Date Issued: 2018
- Authors: Gusha, Molline Natanah C
- Date: 2018
- Subjects: Food chains (Ecology) , Coastal ecology -- South Africa , Intertidal ecology -- South Africa , Marine animals -- Climatic factors -- South Africa , Marine animals -- Food -- South Africa , Marine animals -- Habitat -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63312 , vital:28392
- Description: Coastal ecosystems are more than microhabitats for marine species. Acting as atmospheric carbon filters, species in coastal environments are directly and/or indirectly associated with transferring organic carbon to species at higher trophic levels. However, the progressing change in global climatic conditions has created the need to assess the consequences of the shifting conditions on both direct and indirect interactions of physical and biological parameters at species and/or community levels. From these perturbations, the effects of biotic homogenization on ecosystem functioning and resilience can also be realised. Herein, I discuss the effects of temperature, nutrients, biotic interactions and habitat characteristics on community dynamics within intertidal rock pool systems on the south coast of South Africa using complementary qualitative and quantitative analytical methods. Seasonality had a significant impact on rock pool species with changes in composition and higher richness in winter than summer. The first two axes of the Canonical Correspondence Analysis (CCA) of the plant and animal communities each explained ~20% of the relationship between physico-chemical parameters and biological variables. The CCA highlighted that seasonal shifts in chlorophyll-a, conductivity, salinity, water depth, surface area and substratum type indirectly influenced species composition. For example, pools with heterogenous substratum comprising a mixture of sand and rock exhibited higher species diversity than homogenously bedded pools. Furthermore, a Bayesian analysis of community structure based on stable isotope ratios was used to assess how trophic pathways of carbon and nitrogen elements reflected community composition and richness. Isotopic biplots showed an increase in food web size, food chain length and the trophic positions of fish and some gastropods in winter compared to summer. There was greater dietary overlap among species in larger pools. In addition, while isotopic nearest neighbour distance and species evenness also showed a positive increase with pool size in summer, the same metrics were almost constant across all pool sizes in winter. These changes in food web packing and species evenness suggest seasonal preferences or migration of species in summer from small pools to larger pools with stable physico-chemical parameters. Furthermore, the presence of fish was seen to promote trophic diversity within some pools. The results from laboratory microcosm grazing experiments demonstrated significant direct and indirect effects of temperature and nutrients within plankton communities. Copepod grazing had an indirect positive influence on phytoplankton biomass and size structure while the interactive effects of temperature and nutrients had contrasting effects on both phytoplankton communities and copepod biomass. Shifts in water chemistry and nutrient treatments were also observed in the presence of copepods. Phosphate addition had a recognisable impact on plankton communities. The presented synthesis of the literature mainly highlighted that positive effects at one trophic level do not always positively cascade into the next trophic level which is evidence of complex interactive biotic, habitat and water chemistry effects within these intertidal ecosystems. Thus, to further understand cascading effects or community structure functioning in general, there may be a need to incorporate and understand species functional traits and how they contribute to trophic diversity, community restructuring and functioning in coastal habitats.
- Full Text:
- Date Issued: 2018
The English East India Company and the British Crown: c. 1795-1803, the first occupation at the Cape of Good Hope
- Authors: Jordan, Calvin
- Date: 2018
- Subjects: East India Company , East India Company -- Influence , Cape of Good Hope (Colony) , Cape of Good Hope (South Africa) -- History -- 1795-1872 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , British -- South Africa -- History -- 19th century , Great Britain -- Colonies -- Commerce , Great Britain -- Colonies -- Administration -- History -- 19th century , Merchant marine -- Great Britain -- History
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63164 , vital:28369
- Description: My thesis aims to investigate the relationship between the English East India Company (EEIC) and the British colonial administration at the Cape of Good Hope during the first British occupation (1795 to 1803). Studies and literature that concern the EEIC have rarely gone beyond the surface, detailing the presence of the EEIC at the Cape, and neglecting the Company’s involvement in the administration thereof. My thesis draws on prior works but attempts to address both temporal and spatial gaps in this literature on the Atlantic and Indian Ocean, and the history of the EEIC. This study takes note of the seaborne related activity around the ports, bays and islands at the Cape – including the regulation of these spaces and issues related to securing British trade and colonial possessions more generally. I question the framing of the Cape primarily as a constituent of a national unit by locating the colony within a broader global and maritime context. A key interest is to determine the degree to which the EEIC influenced and participated in the British governance of the Cape, particularly by exploring the maritime dimensions of the relationship between the EEIC and colonial governance during this particular period. This involves understanding the embeddedness of the Cape in British (Crown and Company) networks and the constitution of a ‘British maritime zone’. This study uses archival sources drawn from the British colonial government records, Company records, and the private diaries and letters of Lady Anne Barnard that relate to the Cape. It is shown that a uniquely configured governance convention was constituted to secure the mutual commercial and imperial interests of both Crown and Company. By keeping the Cape secure, the British sought to keep their greater seaborne Empire secure. This study reveals that the EEIC was significantly involved in and influenced the way the British administration governed the Cape.
- Full Text:
- Date Issued: 2018
- Authors: Jordan, Calvin
- Date: 2018
- Subjects: East India Company , East India Company -- Influence , Cape of Good Hope (Colony) , Cape of Good Hope (South Africa) -- History -- 1795-1872 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , British -- South Africa -- History -- 19th century , Great Britain -- Colonies -- Commerce , Great Britain -- Colonies -- Administration -- History -- 19th century , Merchant marine -- Great Britain -- History
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63164 , vital:28369
- Description: My thesis aims to investigate the relationship between the English East India Company (EEIC) and the British colonial administration at the Cape of Good Hope during the first British occupation (1795 to 1803). Studies and literature that concern the EEIC have rarely gone beyond the surface, detailing the presence of the EEIC at the Cape, and neglecting the Company’s involvement in the administration thereof. My thesis draws on prior works but attempts to address both temporal and spatial gaps in this literature on the Atlantic and Indian Ocean, and the history of the EEIC. This study takes note of the seaborne related activity around the ports, bays and islands at the Cape – including the regulation of these spaces and issues related to securing British trade and colonial possessions more generally. I question the framing of the Cape primarily as a constituent of a national unit by locating the colony within a broader global and maritime context. A key interest is to determine the degree to which the EEIC influenced and participated in the British governance of the Cape, particularly by exploring the maritime dimensions of the relationship between the EEIC and colonial governance during this particular period. This involves understanding the embeddedness of the Cape in British (Crown and Company) networks and the constitution of a ‘British maritime zone’. This study uses archival sources drawn from the British colonial government records, Company records, and the private diaries and letters of Lady Anne Barnard that relate to the Cape. It is shown that a uniquely configured governance convention was constituted to secure the mutual commercial and imperial interests of both Crown and Company. By keeping the Cape secure, the British sought to keep their greater seaborne Empire secure. This study reveals that the EEIC was significantly involved in and influenced the way the British administration governed the Cape.
- Full Text:
- Date Issued: 2018
Building IKhwezi, a digital platform to capture everyday Indigenous Knowledge for improving educational outcomes in marginalised communities
- Authors: Ntšekhe, Mathe V K
- Date: 2018
- Subjects: Information technology , Knowledge management , Traditional ecological knowledge , Pedagogical content knowledge , Traditional ecological knowledge -- Technological innovations , IKhwezi , ICT4D , Indigenous Technological Pedagogical Content Knowledge (I-TPACK) , Siyakhula Living Lab
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62505 , vital:28200
- Description: Aptly captured in the name, the broad mandate of Information and Communications Technologies for Development (ICT4D) is to facilitate the use of Information and Communication Technologies (ICTs) in society to support development. Education, as often stated, is the cornerstone for development, imparting knowledge for conceiving and realising development. In this thesis, we explore how everyday Indigenous Knowledge (IK) can be collected digitally, to enhance the educational outcomes of learners from marginalised backgrounds, by stimulating the production of teaching and learning materials that include the local imagery to have resonance with the learners. As part of the exploration, we reviewed a framework known as Technological Pedagogical Content Knowledge (TPACK), which spells out the different kinds of knowledge needed by teachers to teach effectively with ICTs. In this framework, IK is not present explicitly, but through the concept of context(s). Using Afrocentric and Pan-African scholarship, we argue that this logic is linked to colonialism and a critical decolonising pedagogy necessarily demands explication of IK: to make visible the cultures of the learners in the margins (e.g. Black rural learners). On the strength of this argument, we have proposed that TPACK be augumented to become Indigenous Technological Pedagogical Content Knowledge (I-TPACK). Through this augumentation, I-TPACK becomes an Afrocentric framework for a multicultural education in the digital era. The design of the digital platform for capturing IK relevant for formal education, was done in the Siyakhula Living Lab (SLL). The core idea of a Living Lab (LL) is that users must be understood in the context of their lived everyday reality. Further, they must be involved as co-creators in the design and innovation processes. On a methodological level, the LL environment allowed for the fusing together of multiple methods that can help to create a fitting solution. In this thesis, we followed an iterative user-centred methodology rooted in ethnography and phenomenology. Specifically, through long term conversations and interaction with teachers and ethnographic observations, we conceptualized a platform, IKhwezi, that facilitates the collection of context-sensitive content, collaboratively, and with cost and convenience in mind. We implemented this platform using MediaWiki, based on a number of considerations. From the ICT4D disciplinary point of view, a major consideration was being open to the possibility that other forms of innovation—and, not just ‘technovelty’ (i.e. technological/- technical innovation)—can provide a breakthrough or ingenious solution to the problem at hand. In a sense, we were reinforcing the growing sentiment within the discipline that technology is not the goal, but the means to foregrounding the commonality of the human experience in working towards development. Testing confirmed that there is some value in the platform. This is despite the challenges to onboard users, in pursuit of more content that could bolster the value of everyday IK in improving the educational outcomes of all learners.
- Full Text:
- Date Issued: 2018
- Authors: Ntšekhe, Mathe V K
- Date: 2018
- Subjects: Information technology , Knowledge management , Traditional ecological knowledge , Pedagogical content knowledge , Traditional ecological knowledge -- Technological innovations , IKhwezi , ICT4D , Indigenous Technological Pedagogical Content Knowledge (I-TPACK) , Siyakhula Living Lab
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62505 , vital:28200
- Description: Aptly captured in the name, the broad mandate of Information and Communications Technologies for Development (ICT4D) is to facilitate the use of Information and Communication Technologies (ICTs) in society to support development. Education, as often stated, is the cornerstone for development, imparting knowledge for conceiving and realising development. In this thesis, we explore how everyday Indigenous Knowledge (IK) can be collected digitally, to enhance the educational outcomes of learners from marginalised backgrounds, by stimulating the production of teaching and learning materials that include the local imagery to have resonance with the learners. As part of the exploration, we reviewed a framework known as Technological Pedagogical Content Knowledge (TPACK), which spells out the different kinds of knowledge needed by teachers to teach effectively with ICTs. In this framework, IK is not present explicitly, but through the concept of context(s). Using Afrocentric and Pan-African scholarship, we argue that this logic is linked to colonialism and a critical decolonising pedagogy necessarily demands explication of IK: to make visible the cultures of the learners in the margins (e.g. Black rural learners). On the strength of this argument, we have proposed that TPACK be augumented to become Indigenous Technological Pedagogical Content Knowledge (I-TPACK). Through this augumentation, I-TPACK becomes an Afrocentric framework for a multicultural education in the digital era. The design of the digital platform for capturing IK relevant for formal education, was done in the Siyakhula Living Lab (SLL). The core idea of a Living Lab (LL) is that users must be understood in the context of their lived everyday reality. Further, they must be involved as co-creators in the design and innovation processes. On a methodological level, the LL environment allowed for the fusing together of multiple methods that can help to create a fitting solution. In this thesis, we followed an iterative user-centred methodology rooted in ethnography and phenomenology. Specifically, through long term conversations and interaction with teachers and ethnographic observations, we conceptualized a platform, IKhwezi, that facilitates the collection of context-sensitive content, collaboratively, and with cost and convenience in mind. We implemented this platform using MediaWiki, based on a number of considerations. From the ICT4D disciplinary point of view, a major consideration was being open to the possibility that other forms of innovation—and, not just ‘technovelty’ (i.e. technological/- technical innovation)—can provide a breakthrough or ingenious solution to the problem at hand. In a sense, we were reinforcing the growing sentiment within the discipline that technology is not the goal, but the means to foregrounding the commonality of the human experience in working towards development. Testing confirmed that there is some value in the platform. This is despite the challenges to onboard users, in pursuit of more content that could bolster the value of everyday IK in improving the educational outcomes of all learners.
- Full Text:
- Date Issued: 2018
The influence of landscape dis-connectivity on the structure and function of the Krom River, Eastern Cape, South Africa
- Authors: McNamara, Shaun
- Date: 2018
- Subjects: Wetland ecology -- South Africa -- Kromme River (Eastern Cape) , Alluvial fans -- South Africa -- Kromme River (Eastern Cape) , Sedimentation and deposition -- South Africa -- Kromme River (Eastern Cape) , Fluvial geomorphology -- South Africa -- Kromme River (Eastern Cape) , Soil erosion -- South Africa -- Kromme River (Eastern Cape)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63198 , vital:28380
- Description: Given that a broad valley and low longitudinal slope are important pre-requisites for wetland formation in dryland environments, it has been proposed that cut-and-fill cycles are largely responsible for the geomorphic evolution of the Krom River valley-bottom wetlands. Research to support this suggestion has focused extensively on the role of phases of incision. As a result, little is known about where sediment mobilised during phases of incision is being deposited (filling phase). This study aimed to address this question to add to the understanding of how cut-and-fill cycles influence the structure and functioning of the Krom River and its wetlands. This was achieved through a reach-scale appraisal of the degree of longitudinal connectivity of the Krom River. The reach used for this appraisal contained an incised section along which the river channel exists as a large gully, and a section immediately downstream of the gully terminus where the Krom River is un-gullied, and flow is diffuse across most of the width of the valley floor. Quantification of the masses of sediment eroded and deposited within the selected reach of the Krom River during a single recent (2012) flood event revealed that the degree of longitudinal connectivity in the Krom River is generally low. During the flood, much of the sediment mobilised by the cutting of the Krom River channel was deposited immediately downstream of the gully terminus, forming a large floodout feature. Particle size analyses of core samples taken along the floodout feature showed that the coarsest fraction of previously mobilised sediment was deposited at the head of the floodout, while finer sediment fractions were deposited progressively further downstream. Field surveys revealed that the pattern of deposition within the floodout feature led to localised steepening of the studied reach of the Krom River downstream of the gully terminus. Surveys of the recently eroded gully revealed that following incision, the eroded stream bed had a lower longitudinal gradient than both the pre-erosional land surface and the regional slope of the Krom River. The results of this study suggest that floodout formation downstream of gullies may promote the transgression of geomorphic thresholds for erosion, such that the development of floodout features leads to likely initiation of new cutting phases in novel locations along the course of the Krom River. They further suggest that the Krom River is capable of intrinsic longitudinal self-recovery through ongoing cut-and-fill cycles. Finally, it would appear that the current cutting phases responsible for the “destruction” of wetlands within the system are part of a cycle that will lead to prolonged geomorphic stability, such that the system is made more suitable for the long-term re-establishment of wetlands.
- Full Text:
- Date Issued: 2018
- Authors: McNamara, Shaun
- Date: 2018
- Subjects: Wetland ecology -- South Africa -- Kromme River (Eastern Cape) , Alluvial fans -- South Africa -- Kromme River (Eastern Cape) , Sedimentation and deposition -- South Africa -- Kromme River (Eastern Cape) , Fluvial geomorphology -- South Africa -- Kromme River (Eastern Cape) , Soil erosion -- South Africa -- Kromme River (Eastern Cape)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63198 , vital:28380
- Description: Given that a broad valley and low longitudinal slope are important pre-requisites for wetland formation in dryland environments, it has been proposed that cut-and-fill cycles are largely responsible for the geomorphic evolution of the Krom River valley-bottom wetlands. Research to support this suggestion has focused extensively on the role of phases of incision. As a result, little is known about where sediment mobilised during phases of incision is being deposited (filling phase). This study aimed to address this question to add to the understanding of how cut-and-fill cycles influence the structure and functioning of the Krom River and its wetlands. This was achieved through a reach-scale appraisal of the degree of longitudinal connectivity of the Krom River. The reach used for this appraisal contained an incised section along which the river channel exists as a large gully, and a section immediately downstream of the gully terminus where the Krom River is un-gullied, and flow is diffuse across most of the width of the valley floor. Quantification of the masses of sediment eroded and deposited within the selected reach of the Krom River during a single recent (2012) flood event revealed that the degree of longitudinal connectivity in the Krom River is generally low. During the flood, much of the sediment mobilised by the cutting of the Krom River channel was deposited immediately downstream of the gully terminus, forming a large floodout feature. Particle size analyses of core samples taken along the floodout feature showed that the coarsest fraction of previously mobilised sediment was deposited at the head of the floodout, while finer sediment fractions were deposited progressively further downstream. Field surveys revealed that the pattern of deposition within the floodout feature led to localised steepening of the studied reach of the Krom River downstream of the gully terminus. Surveys of the recently eroded gully revealed that following incision, the eroded stream bed had a lower longitudinal gradient than both the pre-erosional land surface and the regional slope of the Krom River. The results of this study suggest that floodout formation downstream of gullies may promote the transgression of geomorphic thresholds for erosion, such that the development of floodout features leads to likely initiation of new cutting phases in novel locations along the course of the Krom River. They further suggest that the Krom River is capable of intrinsic longitudinal self-recovery through ongoing cut-and-fill cycles. Finally, it would appear that the current cutting phases responsible for the “destruction” of wetlands within the system are part of a cycle that will lead to prolonged geomorphic stability, such that the system is made more suitable for the long-term re-establishment of wetlands.
- Full Text:
- Date Issued: 2018
Analysis of the human HSP70-HSP90 organising protein (HOP) gene - characterisation of the promoter and identification of a novel isoform
- Authors: Mattison, Stacey
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62821 , vital:28296
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Mattison, Stacey
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62821 , vital:28296
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
Black woman you’re on your own
- Authors: Ngada, Unathi Ndlelantle
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63110 , vital:28364
- Full Text:
- Date Issued: 2018
- Authors: Ngada, Unathi Ndlelantle
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63110 , vital:28364
- Full Text:
- Date Issued: 2018
On high-altitude and high- latitude frost environments
- Authors: Hansen, Christel Dorothee
- Date: 2018
- Subjects: Frost -- Drakensberg Mountains , Frost -- Prince Edward Islands -- Marion Island , Frost -- Antarctica -- Queen Maud Land , Climatic geomorphology -- Southern Hemisphere , Permafrost -- Southern Hemisphere , Periglacial processes -- Southern Hemisphere , Frost environments -- Southern Hemisphere
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62383 , vital:28169
- Description: Frost environments occur throughout the world, with associated processes occurring across climatic zones. Climatic geomorphology proposes that climatic zones, largely derived from annual average air temperature and precipitation values, have specific landforms and processes active within that zone. This study offers unique insights into the frost environments of three locations in the Southern Hemisphere, namely the Eastern Cape Drakensberg of South Africa, sub-Antarctic Marion Island, and Dronning Maud Land of Antarctica. The Drakensberg ranges from temperate to alpine, Marion Island is hyper-maritime, and Dronning Maud Land a polar desert. Drivers and forcings on the ground frost regime are identified, as are future climatic scenarios. Altitude and latitude were identified as the most important locational drivers, while air temperature showed highest correlation with freezing events. The initiation of a freeze event correlated strongly with maximum ground temperatures. Vegetation cover was found to ameliorate frost cycles, thereby increasing ground temperatures. Dronning Maud Land of Antarctica is characterised by annual frost (permafrost), with limited seasonal thaw in summer. Thawing cycles reflected the depth of the active layer, which ranged from just under 60 cm for Robertskollen (at lowest altitude) to less than 15 cm on Slettfjell (at greatest altitude). Marion Island had the most active frost environment, exhibiting both seasonal frost, and ubiquitous shallow diurnal frost cycles. The Drakensberg were largely frost-free, with limited seasonal frost and few diurnal freeze- thaw events. Diurnal frost processes were found to be azonal, and present at all three study locations. Evidence of landforms derived from diurnal frost processes were evident in each zone. Equifinality/convergence of form was present to a degree. The presence of patterned ground, which was not wholly derived from frost processes, suggests a measure of equifinality. Furthermore, openwork block deposits, of which not all are either blockstreams nor blockfields, are not necessarily the result of frost processes. The periglacial environment is poorly defined and methods to delineate this environment, as well as other climatic zones, should include additional parameters. Delineating zones on annual (and limited) monthly averages based on predominantly temperature, is not sufficient. While concepts of climatic geomorphology may be applied in a general sense, this framework is not suited to working at smaller scales. Specifically, periglacial environments should be delineated using ground moisture, as well as air temperature. Furthermore, vegetation and snow cover are important, as are soil textural properties.
- Full Text:
- Date Issued: 2018
- Authors: Hansen, Christel Dorothee
- Date: 2018
- Subjects: Frost -- Drakensberg Mountains , Frost -- Prince Edward Islands -- Marion Island , Frost -- Antarctica -- Queen Maud Land , Climatic geomorphology -- Southern Hemisphere , Permafrost -- Southern Hemisphere , Periglacial processes -- Southern Hemisphere , Frost environments -- Southern Hemisphere
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62383 , vital:28169
- Description: Frost environments occur throughout the world, with associated processes occurring across climatic zones. Climatic geomorphology proposes that climatic zones, largely derived from annual average air temperature and precipitation values, have specific landforms and processes active within that zone. This study offers unique insights into the frost environments of three locations in the Southern Hemisphere, namely the Eastern Cape Drakensberg of South Africa, sub-Antarctic Marion Island, and Dronning Maud Land of Antarctica. The Drakensberg ranges from temperate to alpine, Marion Island is hyper-maritime, and Dronning Maud Land a polar desert. Drivers and forcings on the ground frost regime are identified, as are future climatic scenarios. Altitude and latitude were identified as the most important locational drivers, while air temperature showed highest correlation with freezing events. The initiation of a freeze event correlated strongly with maximum ground temperatures. Vegetation cover was found to ameliorate frost cycles, thereby increasing ground temperatures. Dronning Maud Land of Antarctica is characterised by annual frost (permafrost), with limited seasonal thaw in summer. Thawing cycles reflected the depth of the active layer, which ranged from just under 60 cm for Robertskollen (at lowest altitude) to less than 15 cm on Slettfjell (at greatest altitude). Marion Island had the most active frost environment, exhibiting both seasonal frost, and ubiquitous shallow diurnal frost cycles. The Drakensberg were largely frost-free, with limited seasonal frost and few diurnal freeze- thaw events. Diurnal frost processes were found to be azonal, and present at all three study locations. Evidence of landforms derived from diurnal frost processes were evident in each zone. Equifinality/convergence of form was present to a degree. The presence of patterned ground, which was not wholly derived from frost processes, suggests a measure of equifinality. Furthermore, openwork block deposits, of which not all are either blockstreams nor blockfields, are not necessarily the result of frost processes. The periglacial environment is poorly defined and methods to delineate this environment, as well as other climatic zones, should include additional parameters. Delineating zones on annual (and limited) monthly averages based on predominantly temperature, is not sufficient. While concepts of climatic geomorphology may be applied in a general sense, this framework is not suited to working at smaller scales. Specifically, periglacial environments should be delineated using ground moisture, as well as air temperature. Furthermore, vegetation and snow cover are important, as are soil textural properties.
- Full Text:
- Date Issued: 2018
Graphene quantum dots and their metallophthalocyanines nanoconjugates as novel photoluminescent nanosensors
- Authors: Achadu, Ojodomo John
- Date: 2018
- Subjects: Quantum dots , Graphene , Phthalocyanines , Nanoconjugates , Novel photoluminescent nanosensors , Metallophthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60719 , vital:27821
- Description: The fabrication and application of graphene quantum dots (GQDs)-based photoluminescent probes for the detection of analytes is presented. GQDs were functionalized with complexes such as metallophthalocyanines (MPcs), metal nanoparticles (Au@Ag NPs), 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO), maleimide and thymine for the sensing of target analytes such as ascorbic acid (AA), biothiols (cysteine, homocysteine and glutathione) and mercury ion (Hg²+). The design strategy and approach was based on the quenching of the fluorescence of the GQDs upon functionalization with the above-mentioned complexes, which could be restored in the presence of the target analytes (due to their specific interaction affinity with the complexes). For the detection of AA, GQDs were covalently and/or non-covalently conjugated to TEMPO-bearing complexes to form GQDs-4A-TEMPO and GQDs-TEMPO-MPc systems with nanomolar limits of detection. For the detection of biothiols, Au@Ag NPs and maleimide-bearing complexes (MPc), which have specific affinity to interact with biothiols, were deployed. Hg²+ detection involved the use of GQDs and/or MPcs with thiol and thymine groups, respectively. In addition, a smart sensing platform was designed for the dual detection of biothiols and Hg²+ using supramolecular hybrid of polyethyleneimine functionalized-GQDs and MPc-Au@Ag conjugate. The probe could detect, in a sequential manner, Hg²+ and biothiols with high sensitivity. Results obtained from the LODs of the probes showed that GQDs sensing performances could be enhanced in the presence of MPcs. The probes designed in this work were successfully deployed in the assays of the target analytes in real samples and the recoveries obtained confirmed the analytical applicability of the probes.
- Full Text:
- Date Issued: 2018
- Authors: Achadu, Ojodomo John
- Date: 2018
- Subjects: Quantum dots , Graphene , Phthalocyanines , Nanoconjugates , Novel photoluminescent nanosensors , Metallophthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60719 , vital:27821
- Description: The fabrication and application of graphene quantum dots (GQDs)-based photoluminescent probes for the detection of analytes is presented. GQDs were functionalized with complexes such as metallophthalocyanines (MPcs), metal nanoparticles (Au@Ag NPs), 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO), maleimide and thymine for the sensing of target analytes such as ascorbic acid (AA), biothiols (cysteine, homocysteine and glutathione) and mercury ion (Hg²+). The design strategy and approach was based on the quenching of the fluorescence of the GQDs upon functionalization with the above-mentioned complexes, which could be restored in the presence of the target analytes (due to their specific interaction affinity with the complexes). For the detection of AA, GQDs were covalently and/or non-covalently conjugated to TEMPO-bearing complexes to form GQDs-4A-TEMPO and GQDs-TEMPO-MPc systems with nanomolar limits of detection. For the detection of biothiols, Au@Ag NPs and maleimide-bearing complexes (MPc), which have specific affinity to interact with biothiols, were deployed. Hg²+ detection involved the use of GQDs and/or MPcs with thiol and thymine groups, respectively. In addition, a smart sensing platform was designed for the dual detection of biothiols and Hg²+ using supramolecular hybrid of polyethyleneimine functionalized-GQDs and MPc-Au@Ag conjugate. The probe could detect, in a sequential manner, Hg²+ and biothiols with high sensitivity. Results obtained from the LODs of the probes showed that GQDs sensing performances could be enhanced in the presence of MPcs. The probes designed in this work were successfully deployed in the assays of the target analytes in real samples and the recoveries obtained confirmed the analytical applicability of the probes.
- Full Text:
- Date Issued: 2018
Regional value chains and development integration in the SADC Region: the case of the pharmaceutical industry
- Authors: Faydherbe, Sean
- Date: 2018
- Subjects: Pharmaceutical industry -- Africa, Southern , Southern African Development Community , Africa, Southern -- Economic integration , Regional value chains (RVCs) , Global value chains (GVCs)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62906 , vital:28309
- Description: This thesis investigates how regional value chains (RVCs) can be used to further development integration in the Southern African Development Community (SADC) region with a focus on the pharmaceutical manufacturing industry. The study is motivated by the apparent lack of attention given to the development of the pharmaceutical manufacturing industry in Southern Africa, the region’s high disease burden and the identification of the industry as economically and socially important by the SADC (2015) Industrialisation Strategy and Roadmap and the Department of Trade and Industry (DTI) (2017a) Industrial Policy Action Plan (IPAP). At the same time, South Africa and other countries in the region are exploring alternative approaches to regional integration, given the failure or stagnation of numerous formal integration arrangements throughout Africa, which have often lead to polarised rather than balanced development. This thesis argues that the development of RVCs within SADC may be an effective tool for development integration in the region, particularly in sectors such as pharmaceuticals. The study employs a value chain framework for the analysis and discusses development integration options, drawing on the East Asian experience with RVCs and on case studies involving India in the case of the pharmaceutical industry. It provides a sector profile of the industry in South Africa, due to its dominant status in the region, and also of Zimbabwe, due to that country’s potential to become a pharmaceutical industry leader in the region once again. The thesis first explores the important theoretical aspects underlying value chain analysis, namely governance and upgrading, while also outlining the rise of global value chains (GVCs). It analyses the complex relationships between RVCs and GVCs, and RVCs and regional integration. From this it concludes that RVCs are a stepping stone to participation in GVCs and that RVCs should be promoted within a development integration framework through strong regional cooperation. Value chain analysis is applied to the entire pharmaceutical manufacturing industry with a focus on SADC. The thesis examines how the sector is evolving with manufacturing multinational corporations (MNCs) outsourcing production and setting up centres of excellence in regional production hubs. The study argues that with the application of recommended policies, RVCs in sectors such as pharmaceutical manufacturing may provide a tool for achieving balanced development in the region. However, the study also finds that the pharmaceutical industry in SADC lags a long way behind the rest of the world and that many countries and firms will need to begin at the bottom of the value chain, with formulation, in order to contribute to the development of RVCs. The thesis concludes with recommendations on what policies are needed to foster the growth and development of pharmaceutical RVCs in the SADC region. These include strengthening public procurement, providing incentives for investment into the industry, incremental production and incremental export volumes, as well as certainty and predictability around the regulatory and business environment. Further, policy should aim to construct synergies and linkages on the ground between health systems and industrial developments; regulate service links important to pharmaceutical manufacturing; develop a coherent regional policy agenda; remove unnecessary non-tariff barriers to trade in the region and, in line with development integration, implement trade policy along with trade infrastructure that is efficient and includes airports, rail, roads and ports, as well as effective access to the internet.
- Full Text:
- Date Issued: 2018
- Authors: Faydherbe, Sean
- Date: 2018
- Subjects: Pharmaceutical industry -- Africa, Southern , Southern African Development Community , Africa, Southern -- Economic integration , Regional value chains (RVCs) , Global value chains (GVCs)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62906 , vital:28309
- Description: This thesis investigates how regional value chains (RVCs) can be used to further development integration in the Southern African Development Community (SADC) region with a focus on the pharmaceutical manufacturing industry. The study is motivated by the apparent lack of attention given to the development of the pharmaceutical manufacturing industry in Southern Africa, the region’s high disease burden and the identification of the industry as economically and socially important by the SADC (2015) Industrialisation Strategy and Roadmap and the Department of Trade and Industry (DTI) (2017a) Industrial Policy Action Plan (IPAP). At the same time, South Africa and other countries in the region are exploring alternative approaches to regional integration, given the failure or stagnation of numerous formal integration arrangements throughout Africa, which have often lead to polarised rather than balanced development. This thesis argues that the development of RVCs within SADC may be an effective tool for development integration in the region, particularly in sectors such as pharmaceuticals. The study employs a value chain framework for the analysis and discusses development integration options, drawing on the East Asian experience with RVCs and on case studies involving India in the case of the pharmaceutical industry. It provides a sector profile of the industry in South Africa, due to its dominant status in the region, and also of Zimbabwe, due to that country’s potential to become a pharmaceutical industry leader in the region once again. The thesis first explores the important theoretical aspects underlying value chain analysis, namely governance and upgrading, while also outlining the rise of global value chains (GVCs). It analyses the complex relationships between RVCs and GVCs, and RVCs and regional integration. From this it concludes that RVCs are a stepping stone to participation in GVCs and that RVCs should be promoted within a development integration framework through strong regional cooperation. Value chain analysis is applied to the entire pharmaceutical manufacturing industry with a focus on SADC. The thesis examines how the sector is evolving with manufacturing multinational corporations (MNCs) outsourcing production and setting up centres of excellence in regional production hubs. The study argues that with the application of recommended policies, RVCs in sectors such as pharmaceutical manufacturing may provide a tool for achieving balanced development in the region. However, the study also finds that the pharmaceutical industry in SADC lags a long way behind the rest of the world and that many countries and firms will need to begin at the bottom of the value chain, with formulation, in order to contribute to the development of RVCs. The thesis concludes with recommendations on what policies are needed to foster the growth and development of pharmaceutical RVCs in the SADC region. These include strengthening public procurement, providing incentives for investment into the industry, incremental production and incremental export volumes, as well as certainty and predictability around the regulatory and business environment. Further, policy should aim to construct synergies and linkages on the ground between health systems and industrial developments; regulate service links important to pharmaceutical manufacturing; develop a coherent regional policy agenda; remove unnecessary non-tariff barriers to trade in the region and, in line with development integration, implement trade policy along with trade infrastructure that is efficient and includes airports, rail, roads and ports, as well as effective access to the internet.
- Full Text:
- Date Issued: 2018
An investigation into the bacterial biosynthetic origins of bioactive natural products isolated from South African latrunculid sponges
- Authors: Waterworth, Samantha Che
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61826 , vital:28065
- Description: Several pyrroloiminoquinone alkaloids exhibiting cytotoxic, anti-tumour activity have been isolated from sponges within the Latrunculiidae family that are endemic to the South African coastline. Other, structurally similar pyrroloiminoquinone compounds have been isolated from geographically distant and phylogenetically distinct marine sponges, as well as terrestrial myxomycetes which suggested that sponge-associated bacteria may be the true biosynthetic origin of pyrroloiminoquinone compounds. Previous studies have shown that there is conservation of spirochete and betaproteobacterial species in the bacterial communities associated with South African Latrunculiidae sponges and it was proposed that these conserved bacteria represented candidate pyrroloiminoquinone-producers. This study aimed to confirm the conserved dominance of betaproteobacteria and spirochetes within bacterial communities associated with South African latrunculid sponges and employed a shotgun metagenomic approach to assess the functional and biosynthetic potential of associated microbiota in Tsitsikamma favus sponges. Clustering of assembled contigs revealed twenty-three putative bacterial genomes, of which, two were identified as representatives of the conserved betaproteobacteria and spirochete species previously identified in Tsitsikamma sponges. It was shown that the spirochete was most likely an obligate symbiont that benefitted the host sponge through possible defence against pathogenic bacteria and/or nutrient acquisition. The putative genome representing the conserved betaproteobacteria was found to be heavily contaminated and further sequencing is required to accurately resolve the genome for functional characterization. Several biosynthetic gene clusters were identified and demonstrated the bioactive potential of Tsitsikamma favus-associated bacteria. A biosynthetic gene cluster was identified on an unclustered contig that included several genetic features that were indicative of possible pyrroloiminoquinone production.
- Full Text:
- Date Issued: 2018
- Authors: Waterworth, Samantha Che
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61826 , vital:28065
- Description: Several pyrroloiminoquinone alkaloids exhibiting cytotoxic, anti-tumour activity have been isolated from sponges within the Latrunculiidae family that are endemic to the South African coastline. Other, structurally similar pyrroloiminoquinone compounds have been isolated from geographically distant and phylogenetically distinct marine sponges, as well as terrestrial myxomycetes which suggested that sponge-associated bacteria may be the true biosynthetic origin of pyrroloiminoquinone compounds. Previous studies have shown that there is conservation of spirochete and betaproteobacterial species in the bacterial communities associated with South African Latrunculiidae sponges and it was proposed that these conserved bacteria represented candidate pyrroloiminoquinone-producers. This study aimed to confirm the conserved dominance of betaproteobacteria and spirochetes within bacterial communities associated with South African latrunculid sponges and employed a shotgun metagenomic approach to assess the functional and biosynthetic potential of associated microbiota in Tsitsikamma favus sponges. Clustering of assembled contigs revealed twenty-three putative bacterial genomes, of which, two were identified as representatives of the conserved betaproteobacteria and spirochete species previously identified in Tsitsikamma sponges. It was shown that the spirochete was most likely an obligate symbiont that benefitted the host sponge through possible defence against pathogenic bacteria and/or nutrient acquisition. The putative genome representing the conserved betaproteobacteria was found to be heavily contaminated and further sequencing is required to accurately resolve the genome for functional characterization. Several biosynthetic gene clusters were identified and demonstrated the bioactive potential of Tsitsikamma favus-associated bacteria. A biosynthetic gene cluster was identified on an unclustered contig that included several genetic features that were indicative of possible pyrroloiminoquinone production.
- Full Text:
- Date Issued: 2018
Beasts we love
- Authors: Masolane, Tseliso Chrisjan
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , Detective and mystery stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63098 , vital:28363
- Description: My thesis is a novella in flash, written as political crime fiction. It is set in contemporary South Africa and tells the story of Rafau Lekopo, a teacher from a little township called Dikgohlong, whose life is changed forever after he finds his wife and the mayor in bed and shoots them both dead. The information contained within the dead mayor's notebook proves to be explosive, showing that the mayor is far more than he seems, and that he is in fact in the employ of a foreign intelligence service. After his release from prison, the embittered Lekopo sets about his revenge against powerful men who abuse their political power. He takes refuge in Lesotho, masterminds a series of heists, car-hijackings and human trafficking, and expands his syndication back in South Africa. Using the contacts and information from the mayor's notebook, he manipulates the Lesotho government into a diplomatic feud with South Africa which treatens to escalate into a military conflict.
- Full Text:
- Date Issued: 2018
- Authors: Masolane, Tseliso Chrisjan
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , Detective and mystery stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63098 , vital:28363
- Description: My thesis is a novella in flash, written as political crime fiction. It is set in contemporary South Africa and tells the story of Rafau Lekopo, a teacher from a little township called Dikgohlong, whose life is changed forever after he finds his wife and the mayor in bed and shoots them both dead. The information contained within the dead mayor's notebook proves to be explosive, showing that the mayor is far more than he seems, and that he is in fact in the employ of a foreign intelligence service. After his release from prison, the embittered Lekopo sets about his revenge against powerful men who abuse their political power. He takes refuge in Lesotho, masterminds a series of heists, car-hijackings and human trafficking, and expands his syndication back in South Africa. Using the contacts and information from the mayor's notebook, he manipulates the Lesotho government into a diplomatic feud with South Africa which treatens to escalate into a military conflict.
- Full Text:
- Date Issued: 2018
Biochemical characterisation and small molecule modulation of the interaction between two cytosolic Hsp70s from Trypanosoma brucei and potential co-chaperones
- Authors: Bentley, Stephen John
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63402 , vital:28407
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Bentley, Stephen John
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63402 , vital:28407
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
Still
- Authors: Hall, Leila
- Date: 2018
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63638 , vital:28450
- Description: This thesis is a novella in fragments set in contemporary Lesotho. It tells the story of a Mosotho woman in her 30s who has spent a long time living out of the country. She returns to search for a former lover who she hasn’t seen for 15 years. The nonlinear narrative follows her journey, exploring a range of themes, including sexuality, gender and class relations, memory and time, relationship to place, non-conformity and defiance in the face of societal pressure and conformism. The style of writing is inspired by a diverse range of writers, including Sonallah Ibrahim for his understated, sparse and minimalist prose, Tina May Hall for her ability to tell a story in fragmented vignettes, Noy Holland for her understanding of time as synchronous and non-linear, and Ayi Kwei Armah for his skill in evoking the feelings, textures and specificities of a place.
- Full Text:
- Date Issued: 2018
- Authors: Hall, Leila
- Date: 2018
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63638 , vital:28450
- Description: This thesis is a novella in fragments set in contemporary Lesotho. It tells the story of a Mosotho woman in her 30s who has spent a long time living out of the country. She returns to search for a former lover who she hasn’t seen for 15 years. The nonlinear narrative follows her journey, exploring a range of themes, including sexuality, gender and class relations, memory and time, relationship to place, non-conformity and defiance in the face of societal pressure and conformism. The style of writing is inspired by a diverse range of writers, including Sonallah Ibrahim for his understated, sparse and minimalist prose, Tina May Hall for her ability to tell a story in fragmented vignettes, Noy Holland for her understanding of time as synchronous and non-linear, and Ayi Kwei Armah for his skill in evoking the feelings, textures and specificities of a place.
- Full Text:
- Date Issued: 2018
Chemical weathering on selected nunataks in western Dronning Maud Land, Antarctica
- Authors: Knox, Jenna Tracy
- Date: 2018
- Subjects: Glacial climates -- Antarctica -- Queen Maud Land , Glaciology -- Antarctica -- Queen Maud Land , Chemical weathering -- Antarctica -- Queen Maud Land , Atmospheric carbon dioxide -- Environmental aspects , Climatic changes -- Antarctica -- Queen Maud Land , Nunataks -- Antarctica -- Queen Maud Land
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61658 , vital:28046
- Description: High latitude areas are sensitive to the impacts of climate change, and it is expected that the impact of greenhouse warming will be much higher in the polar regions than in any other climatic zones, with the most highly affected area being that of the Antarctic rim (Barsch, 1993). Weathering and pedogenic processes respond to variations in climate, with models predicting that chemical weathering may increase synchronously with global carbon dioxide levels increase, due to dissolution rates and the erosional impact of hydrological cycles in warming climates (Anderson & Anderson, 2010). As liquid water becomes more available in Antarctica the potential for chemical weathering, due to a less moisture-limited environment and increased temperatures, increases (Convey et al., 2009). Weathering processes are important for soil formation and the production of fine-grained material, with chemical weathering being an active constituent of this. Increased rates of soil formation are likely to occur, with global climate changes resulting in greater chemical weathering occurring in Antarctica. Opportunistic sampling was conducted during the Austral summer of 2016/2017, whereby rock, snow and meltwater samples were taken at various sites within the western portion of Dronning Maud Land of Antarctica. Rock samples were placed in resin, and cut with a diamond saw to create thin sections. Optical microscopy and scanning transmission electron microscopy (STEM) were used to analyse mineral weight percentage with depth. Twelve soil samples were dried and weighed, sieved and statistically represented according to particle size. Inductively coupled plasma mass spectrometry (ICP-MS) determined the geochemical analysis for 10 water and snow samples. Rock hardness was inferred through the use of an Equotip, with rebound values recorded for multiple rock faces and samples. Thermal regimes of rock temperature was further recorded using a FLIR infrared camera, and documented for each rock face over a 24 hour period at 2 hourly intervals. The products of increased chemical weathering were evident from particle size analysis; samples were very poorly sorted in nature, and undergo in situ weathering, whereby products were not removed by erosional processes. Weathering rinds were found to be siliceous and ferric, depending on parent lithology. Ferric ratios increased in wt.% from the substrate rock to the external surface, creating the red, iron rich crusts noted on the hand specimens. The observable chemical weathering was found adjacent to intrusions through Precambrian dolerites. Geochemical analysis revealed thin, carbonaceous features, with impurity-rich layers, characteristic of speleothem formation. Carbonaceous layers did not follow underlying substrate features, rather deposited at the external surface, upon which, further precipitation growth could occur, creating karst features. Extensive gypsum coatings (>2mm) under BSE imagery were identified, with the abundance of gypsum salts (below surface level) and rock coatings indicating active sulphuric acid weathering, in western Dronning Maud Land, Antarctica. Were mechanical processes faster than chemical, weathering rinds and solution features on silicate rocks would be uncommon in the Antarctic, periglacial landscape. However, this is not the case as the existence of these landforms implies that chemical weathering may occur faster than mechanical weathering processes (Pope et al., 1995). In a changing world, one needs to monitor these processes at a micro-scale in order to fully understand how periglacial environments react to global climatic changes, and the subsequent impacts on these sensitive environments.
- Full Text:
- Date Issued: 2018
- Authors: Knox, Jenna Tracy
- Date: 2018
- Subjects: Glacial climates -- Antarctica -- Queen Maud Land , Glaciology -- Antarctica -- Queen Maud Land , Chemical weathering -- Antarctica -- Queen Maud Land , Atmospheric carbon dioxide -- Environmental aspects , Climatic changes -- Antarctica -- Queen Maud Land , Nunataks -- Antarctica -- Queen Maud Land
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61658 , vital:28046
- Description: High latitude areas are sensitive to the impacts of climate change, and it is expected that the impact of greenhouse warming will be much higher in the polar regions than in any other climatic zones, with the most highly affected area being that of the Antarctic rim (Barsch, 1993). Weathering and pedogenic processes respond to variations in climate, with models predicting that chemical weathering may increase synchronously with global carbon dioxide levels increase, due to dissolution rates and the erosional impact of hydrological cycles in warming climates (Anderson & Anderson, 2010). As liquid water becomes more available in Antarctica the potential for chemical weathering, due to a less moisture-limited environment and increased temperatures, increases (Convey et al., 2009). Weathering processes are important for soil formation and the production of fine-grained material, with chemical weathering being an active constituent of this. Increased rates of soil formation are likely to occur, with global climate changes resulting in greater chemical weathering occurring in Antarctica. Opportunistic sampling was conducted during the Austral summer of 2016/2017, whereby rock, snow and meltwater samples were taken at various sites within the western portion of Dronning Maud Land of Antarctica. Rock samples were placed in resin, and cut with a diamond saw to create thin sections. Optical microscopy and scanning transmission electron microscopy (STEM) were used to analyse mineral weight percentage with depth. Twelve soil samples were dried and weighed, sieved and statistically represented according to particle size. Inductively coupled plasma mass spectrometry (ICP-MS) determined the geochemical analysis for 10 water and snow samples. Rock hardness was inferred through the use of an Equotip, with rebound values recorded for multiple rock faces and samples. Thermal regimes of rock temperature was further recorded using a FLIR infrared camera, and documented for each rock face over a 24 hour period at 2 hourly intervals. The products of increased chemical weathering were evident from particle size analysis; samples were very poorly sorted in nature, and undergo in situ weathering, whereby products were not removed by erosional processes. Weathering rinds were found to be siliceous and ferric, depending on parent lithology. Ferric ratios increased in wt.% from the substrate rock to the external surface, creating the red, iron rich crusts noted on the hand specimens. The observable chemical weathering was found adjacent to intrusions through Precambrian dolerites. Geochemical analysis revealed thin, carbonaceous features, with impurity-rich layers, characteristic of speleothem formation. Carbonaceous layers did not follow underlying substrate features, rather deposited at the external surface, upon which, further precipitation growth could occur, creating karst features. Extensive gypsum coatings (>2mm) under BSE imagery were identified, with the abundance of gypsum salts (below surface level) and rock coatings indicating active sulphuric acid weathering, in western Dronning Maud Land, Antarctica. Were mechanical processes faster than chemical, weathering rinds and solution features on silicate rocks would be uncommon in the Antarctic, periglacial landscape. However, this is not the case as the existence of these landforms implies that chemical weathering may occur faster than mechanical weathering processes (Pope et al., 1995). In a changing world, one needs to monitor these processes at a micro-scale in order to fully understand how periglacial environments react to global climatic changes, and the subsequent impacts on these sensitive environments.
- Full Text:
- Date Issued: 2018