Learning pathways of key occupations relevant to sustainable development in Makana Municipality
- Authors: Mohanoe, Elma Nthabiseng
- Date: 2014
- Subjects: Makana Municipality , Sustainable development -- South Africa -- Grahamstown , Municipal government -- South Africa -- Grahamstown , Environmental education -- South Africa -- Grahamstown , Sustainable development -- Study and teaching -- South Africa -- Grahamstown , Vocational qualifications -- South Africa -- Grahamstown , Organizational learning -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1990 , http://hdl.handle.net/10962/d1013322
- Description: This study presents results to be contributed to the field of Environmental Education. It is a new arena for qualifications development and implementation in the South African Education and Training system. The study is located in the context of a joint research programme focusing on understanding issues of articulation and learning pathways development for sustainable development, established between the South African Qualifications Authority (SAQA) in partnership with Rhodes University, Environmental Learning Research Centre (ELRC). Phase 1 of the SAQA/ELRC research showed that researching workplace learning requires an understanding of learning pathways, if it is to be meaningful. It is for this reason that this research in phase 2 focuses specifically on learning pathways in the context of a local municipality in Makana. Using a case study research approach and qualitative data, this study investigated learning pathways for three occupational categories at different levels in the Makana Municipality: 1) key managerial occupations; 2) key supervisory occupations; and 3) key workers occupations relevant to sustainable development and how they are shaped and experienced. It also identified system and structural factors influencing articulation and access issues relevant to progress in learning pathways relevant to these key occupations. The study was designed using a case study research. Primarily, qualitative research techniques were employed to generate data, including observations, interviews and document analysis. The study used inductive, abductive and retroductive modes of inference to interpret and analyse data, using critical realist and systems perspectives. The findings on worker learning pathways show that there is a discrepancy between the Training Policy and the Environmental Training and Education Strategy of Makana Municipality. The issue of complexity in learning pathways and social structural factors such as inequality emerged as factors that strongly influenced learning pathways for workers. Learning pathways for workers involved in sustainable development practices hardly existed or simply did not exist. Interesting transitions associated with learning pathways such as from home, to work or no schooling in the case of the workers, showed a pattern of emergence. These showed that learning pathways are not accessible and equally available to everyone as can often erroneously be assumed. The findings on supervisor learning pathways show diverse complexities as well as related issues, when compared to the worker’s learning pathways. Issues such as overlapping of study and work emerge as influential to supervisor learning pathways. Lack of support is, however, an influencing factor, but in a different context compared to the workers, and mainly focuses on lack of bursaries, highlighting training policy issues. This aspect was found to also relate to lack of proper resources in order to enable them to learn and do their job better; an issue raised by the workers too. This challenge of lack of support in various forms posed a barrier to learning pathways. Findings related to the manager’s learning pathways show a noticeable gap between the workers, supervisors and managers. The manager’s generally have higher education qualifications related to sustainable development, and in certain cases managers have had exposure to international training related to sustainable development. Factors such as ample opportunities for learning, mentoring, association on professional bodies, and decision making powers influenced the manager’s learning pathways. It was also notable that while managers receive occupationally directed training, it is not necessarily sustainable development related. In theory, the results highlighted a need to understand systems as a whole and how their integration is important in influencing learning pathways. There were also underlying mechanisms and structures identified which needed to be unravelled and understood as these were found to influence learning pathways in this study. The study highlighted critical insights in understanding how learning pathways in a local municipality context (the case of Makana Municipality) are constructed by both systems and structural factors in the workplace, while also identifying ways in which agency of those engaged in learning for sustainable development in workplaces is enabled and /or constrained by such factors. It also showed the persistence of deep-seated inequalities of opportunity, especially for workers, to access and participate in sustainable development learning pathways.
- Full Text:
- Authors: Mohanoe, Elma Nthabiseng
- Date: 2014
- Subjects: Makana Municipality , Sustainable development -- South Africa -- Grahamstown , Municipal government -- South Africa -- Grahamstown , Environmental education -- South Africa -- Grahamstown , Sustainable development -- Study and teaching -- South Africa -- Grahamstown , Vocational qualifications -- South Africa -- Grahamstown , Organizational learning -- South Africa -- Grahamstown , Educational equalization -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1990 , http://hdl.handle.net/10962/d1013322
- Description: This study presents results to be contributed to the field of Environmental Education. It is a new arena for qualifications development and implementation in the South African Education and Training system. The study is located in the context of a joint research programme focusing on understanding issues of articulation and learning pathways development for sustainable development, established between the South African Qualifications Authority (SAQA) in partnership with Rhodes University, Environmental Learning Research Centre (ELRC). Phase 1 of the SAQA/ELRC research showed that researching workplace learning requires an understanding of learning pathways, if it is to be meaningful. It is for this reason that this research in phase 2 focuses specifically on learning pathways in the context of a local municipality in Makana. Using a case study research approach and qualitative data, this study investigated learning pathways for three occupational categories at different levels in the Makana Municipality: 1) key managerial occupations; 2) key supervisory occupations; and 3) key workers occupations relevant to sustainable development and how they are shaped and experienced. It also identified system and structural factors influencing articulation and access issues relevant to progress in learning pathways relevant to these key occupations. The study was designed using a case study research. Primarily, qualitative research techniques were employed to generate data, including observations, interviews and document analysis. The study used inductive, abductive and retroductive modes of inference to interpret and analyse data, using critical realist and systems perspectives. The findings on worker learning pathways show that there is a discrepancy between the Training Policy and the Environmental Training and Education Strategy of Makana Municipality. The issue of complexity in learning pathways and social structural factors such as inequality emerged as factors that strongly influenced learning pathways for workers. Learning pathways for workers involved in sustainable development practices hardly existed or simply did not exist. Interesting transitions associated with learning pathways such as from home, to work or no schooling in the case of the workers, showed a pattern of emergence. These showed that learning pathways are not accessible and equally available to everyone as can often erroneously be assumed. The findings on supervisor learning pathways show diverse complexities as well as related issues, when compared to the worker’s learning pathways. Issues such as overlapping of study and work emerge as influential to supervisor learning pathways. Lack of support is, however, an influencing factor, but in a different context compared to the workers, and mainly focuses on lack of bursaries, highlighting training policy issues. This aspect was found to also relate to lack of proper resources in order to enable them to learn and do their job better; an issue raised by the workers too. This challenge of lack of support in various forms posed a barrier to learning pathways. Findings related to the manager’s learning pathways show a noticeable gap between the workers, supervisors and managers. The manager’s generally have higher education qualifications related to sustainable development, and in certain cases managers have had exposure to international training related to sustainable development. Factors such as ample opportunities for learning, mentoring, association on professional bodies, and decision making powers influenced the manager’s learning pathways. It was also notable that while managers receive occupationally directed training, it is not necessarily sustainable development related. In theory, the results highlighted a need to understand systems as a whole and how their integration is important in influencing learning pathways. There were also underlying mechanisms and structures identified which needed to be unravelled and understood as these were found to influence learning pathways in this study. The study highlighted critical insights in understanding how learning pathways in a local municipality context (the case of Makana Municipality) are constructed by both systems and structural factors in the workplace, while also identifying ways in which agency of those engaged in learning for sustainable development in workplaces is enabled and /or constrained by such factors. It also showed the persistence of deep-seated inequalities of opportunity, especially for workers, to access and participate in sustainable development learning pathways.
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Synthetic analogues of marine bisindole alkaloids as potent selective inhibitors of MRSA pyruvate kinase
- Veale, Clinton Gareth Lancaster
- Authors: Veale, Clinton Gareth Lancaster
- Date: 2014 , 2014-04-02
- Subjects: Alkaloids , Pyruvate kinase , Staphylococcus aureus , Antibiotics , Sponges -- South Africa , Imidazoles , Biological assay , Antibacterial agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4563 , http://hdl.handle.net/10962/d1020893
- Description: Globally, methicillin resistant Staphylococcus aureus (MRSA) has become increasingly difficult to manage in the clinic and new antibiotics are required. The structure activity relationship (SAR) study presented in this thesis forms part of an international collaborative effort to identify potent and selective inhibitors of an MRSA pyruvate kinase (PK) enzyme target. In earlier work the known marine natural product bromodeoxytopsentin (1.6), isolated from a South African marine sponge Topsentia pachastrelloides, exhibited selective and significant inhibition of MRSA PK (IC₅₀ 60 nM). Accordingly bromodeoxytopsentin provided the initial chemical scaffold around which our SAR study was developed. Following a comprehensive introduction, providing the necessary background to the research described in subsequent Chapters, this thesis has been divided into three major parts. Part one (Chapter 2) documents the synthesis of two natural imidazole containing topsentin analogues 1.40, 1.46, five new synthetic analogues 1.58—1.61, 2.104. In the process we developed a new method for the synthesis of topsentin derivatives via selenium dioxide mediated oxidation of N-Boc protected 3-acetylindoles to yield glyoxal intermediates which were subsequently cyclized and deprotected to yield the desired products. Interestingly we were able to demonstrate a delicate relationship between the relative equivalents of selenium dioxide and water used during the oxidation step, careful manipulation of which was required to prevent the uncontrolled formation of side products. Synthetic compounds 1.40, 1.46, 1.58—1.61 were found to be potent inhibitors of MRSA PK (IC₅₀ 238, 2.1, 23, 1.4, 6.3 and 3.2 nM respectively) with 1000-10000 fold selectivity for MRSA PK over four human orthologs. In the second part of this thesis (Chapter 3) we report the successful synthesis of a cohort of previously unknown thiazole containing bisindole topsentin analogues 1.62—1.68 via a Hantzsch thiazole synthesis. Bioassay results revealed that these compounds were only moderate inhibitors of MRSA PK (IC₅₀ 5.1—20 μM) which suggested that inhibitory activity was significantly reduced upon substitution of the central imidazole ring of topsentin type analogues with a thiazole type ring. In addition in Chapter 3 we describe unsuccessful attempts to regiospecifically synthesize oxazole and imidazole topsentin analogues through a similar Hantzsch method. As a consequence of our efforts in this regard we investigated three key reactions in depth, namely the synthesis of 2.2, 3.38, 3.40, 3.41 via α-bromination of 3-acetylindole and the synthesis of indolyl-3-carbonylnitriles 2.13, 3.45—3.47 and α-oxo-1H-indole-3-thioacetamides 3.48—3.51. The investigation of the latter led to the isolation and elucidation of two anomalous N,N-dimethyl-1H-indole-3-carboxamides 3.52 and 3.53. Finally the third part of this thesis (Chapter 4) deals with in silico assessment of the binding of both the imidazole and thiazole containing bisindole alkaloids to the MRSA PK protein which initially guided our SAR studies. In this chapter we reveal that there appears to be no correlation between in silico binding predictions and in vitro MRSA PK inhibitory bioassay data. Superficially it seems that binding energy as determined by the docking program used for these studies correlated with the size of the indole substituents and did not reflect IC₅₀ MRSA PK inhibitory data. Although this led us to computationally explore possible alternative binding sites no clear alternative has been identified.
- Full Text:
- Authors: Veale, Clinton Gareth Lancaster
- Date: 2014 , 2014-04-02
- Subjects: Alkaloids , Pyruvate kinase , Staphylococcus aureus , Antibiotics , Sponges -- South Africa , Imidazoles , Biological assay , Antibacterial agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4563 , http://hdl.handle.net/10962/d1020893
- Description: Globally, methicillin resistant Staphylococcus aureus (MRSA) has become increasingly difficult to manage in the clinic and new antibiotics are required. The structure activity relationship (SAR) study presented in this thesis forms part of an international collaborative effort to identify potent and selective inhibitors of an MRSA pyruvate kinase (PK) enzyme target. In earlier work the known marine natural product bromodeoxytopsentin (1.6), isolated from a South African marine sponge Topsentia pachastrelloides, exhibited selective and significant inhibition of MRSA PK (IC₅₀ 60 nM). Accordingly bromodeoxytopsentin provided the initial chemical scaffold around which our SAR study was developed. Following a comprehensive introduction, providing the necessary background to the research described in subsequent Chapters, this thesis has been divided into three major parts. Part one (Chapter 2) documents the synthesis of two natural imidazole containing topsentin analogues 1.40, 1.46, five new synthetic analogues 1.58—1.61, 2.104. In the process we developed a new method for the synthesis of topsentin derivatives via selenium dioxide mediated oxidation of N-Boc protected 3-acetylindoles to yield glyoxal intermediates which were subsequently cyclized and deprotected to yield the desired products. Interestingly we were able to demonstrate a delicate relationship between the relative equivalents of selenium dioxide and water used during the oxidation step, careful manipulation of which was required to prevent the uncontrolled formation of side products. Synthetic compounds 1.40, 1.46, 1.58—1.61 were found to be potent inhibitors of MRSA PK (IC₅₀ 238, 2.1, 23, 1.4, 6.3 and 3.2 nM respectively) with 1000-10000 fold selectivity for MRSA PK over four human orthologs. In the second part of this thesis (Chapter 3) we report the successful synthesis of a cohort of previously unknown thiazole containing bisindole topsentin analogues 1.62—1.68 via a Hantzsch thiazole synthesis. Bioassay results revealed that these compounds were only moderate inhibitors of MRSA PK (IC₅₀ 5.1—20 μM) which suggested that inhibitory activity was significantly reduced upon substitution of the central imidazole ring of topsentin type analogues with a thiazole type ring. In addition in Chapter 3 we describe unsuccessful attempts to regiospecifically synthesize oxazole and imidazole topsentin analogues through a similar Hantzsch method. As a consequence of our efforts in this regard we investigated three key reactions in depth, namely the synthesis of 2.2, 3.38, 3.40, 3.41 via α-bromination of 3-acetylindole and the synthesis of indolyl-3-carbonylnitriles 2.13, 3.45—3.47 and α-oxo-1H-indole-3-thioacetamides 3.48—3.51. The investigation of the latter led to the isolation and elucidation of two anomalous N,N-dimethyl-1H-indole-3-carboxamides 3.52 and 3.53. Finally the third part of this thesis (Chapter 4) deals with in silico assessment of the binding of both the imidazole and thiazole containing bisindole alkaloids to the MRSA PK protein which initially guided our SAR studies. In this chapter we reveal that there appears to be no correlation between in silico binding predictions and in vitro MRSA PK inhibitory bioassay data. Superficially it seems that binding energy as determined by the docking program used for these studies correlated with the size of the indole substituents and did not reflect IC₅₀ MRSA PK inhibitory data. Although this led us to computationally explore possible alternative binding sites no clear alternative has been identified.
- Full Text:
Thermal decomposition of ammonium metavanadate
- Authors: Stewart, Brian Victor
- Date: 1972
- Subjects: Decomposition (Chemistry) , Solids -- Thermal properties , Ammonia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4503 , http://hdl.handle.net/10962/d1013274
- Description: The isothermal, endothermic, stepwise decomposition of ammonium metavanadate (AMV) in inert (argon or nitrogen), oxidising (air or oxygen) and reducing (ammonia) atmospheres as well as under high vacuum (pressure < IOn bar) conditions has been investigated. The reverse reaction, the isothermal recombination of V₂ 0₅ with ammonia and water vapour has also been investigated. The decomposition and recombination reactions were followed by continuously recording the mass loss of the sample with time using a Cahn R.G. Automatic Electrobalance. This enabled small samples ( ~ lOmg) to be used and consequently any self cooling of the sample during the decomposition was minimized. The intermediates and final products formed have been characterized by chemical analysis, X-ray powder diffraction studies, infrared spectroscopy and the mass loss involved in their formation. The changes in the physical properties of the samples during decomposition and recombination have been investigated by surface area measurements (using the BET method and krypton adsorption) and eIectron microscopy. Values for the enthalpy changes involved in the decomposition have been obtained by differential scanning calorimetry. The stoichiometry of the isothermal decomposition of ammonium metavanadate, under the various conditions of surrounding atmosphere has been discussed. Except for the later stages of the decomposition in ammonia, the results correspond well to the gradual reduction of the ratio of "(NH₄)₂ 0" to "V₂0₅" units from the original 1:1 ratio in ammonium metavanadate to pure "V₂0₅" with ammonia and water being evolved throughout the decomposition in the mole ratio of 2:1. The final product of the decomposition in vacuum, argon and air is "V₂0₅" and in ammonia, below 360°, V0₂. The kinetic parameters for each of the stages of the decomposition of AMV in each of the atmospheres studied have been determined. The mechanism of the first stage of the decomposition under the different conditions of surrounding atmosphere has been discussed from both the kinetic and the thermodynamic points of view. The absolute reaction rate theory has been applied to the decomposition in inert atmospheres enabling the formulae of the activated complexes formed during each stage to be calculated. It has also been shown that the detailed atomic movements occurring during the first stage of the decomposition in ammonia can be predicted from a knowledge of the stoichiometry of the reaction and of the detailed crystal structures of the starting and product materials. The kinetics and mechanism of the recombination of "V₂0₅" with ammonia and water vapour to form AMV have also been discussed in detail.
- Full Text:
- Authors: Stewart, Brian Victor
- Date: 1972
- Subjects: Decomposition (Chemistry) , Solids -- Thermal properties , Ammonia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4503 , http://hdl.handle.net/10962/d1013274
- Description: The isothermal, endothermic, stepwise decomposition of ammonium metavanadate (AMV) in inert (argon or nitrogen), oxidising (air or oxygen) and reducing (ammonia) atmospheres as well as under high vacuum (pressure < IOn bar) conditions has been investigated. The reverse reaction, the isothermal recombination of V₂ 0₅ with ammonia and water vapour has also been investigated. The decomposition and recombination reactions were followed by continuously recording the mass loss of the sample with time using a Cahn R.G. Automatic Electrobalance. This enabled small samples ( ~ lOmg) to be used and consequently any self cooling of the sample during the decomposition was minimized. The intermediates and final products formed have been characterized by chemical analysis, X-ray powder diffraction studies, infrared spectroscopy and the mass loss involved in their formation. The changes in the physical properties of the samples during decomposition and recombination have been investigated by surface area measurements (using the BET method and krypton adsorption) and eIectron microscopy. Values for the enthalpy changes involved in the decomposition have been obtained by differential scanning calorimetry. The stoichiometry of the isothermal decomposition of ammonium metavanadate, under the various conditions of surrounding atmosphere has been discussed. Except for the later stages of the decomposition in ammonia, the results correspond well to the gradual reduction of the ratio of "(NH₄)₂ 0" to "V₂0₅" units from the original 1:1 ratio in ammonium metavanadate to pure "V₂0₅" with ammonia and water being evolved throughout the decomposition in the mole ratio of 2:1. The final product of the decomposition in vacuum, argon and air is "V₂0₅" and in ammonia, below 360°, V0₂. The kinetic parameters for each of the stages of the decomposition of AMV in each of the atmospheres studied have been determined. The mechanism of the first stage of the decomposition under the different conditions of surrounding atmosphere has been discussed from both the kinetic and the thermodynamic points of view. The absolute reaction rate theory has been applied to the decomposition in inert atmospheres enabling the formulae of the activated complexes formed during each stage to be calculated. It has also been shown that the detailed atomic movements occurring during the first stage of the decomposition in ammonia can be predicted from a knowledge of the stoichiometry of the reaction and of the detailed crystal structures of the starting and product materials. The kinetics and mechanism of the recombination of "V₂0₅" with ammonia and water vapour to form AMV have also been discussed in detail.
- Full Text:
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