Development of an enzyme-synergy based bioreactor system for the beneficiation of apple pomace lignocellulosic waste
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
A morphogenic and laminated system explanation of position-practice systems and professional development training in mainstreaming education for sustainable development in African universities
- Authors: Agbedahin, Adesuwa Vanessa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/584 , vital:19972
- Description: This research focuses on Education for Sustainable Development (ESD) in Higher Education Institutions (HEIs), particularly in Africa. It explores the roles and practices of these institutions, especially their professionals, in the Anthropocene era where increasing concern for contemporary environmental and sustainability issues and risks emerge. The study presents a longitudinal case study of institutions and participants of the Swedish/African/Asian International Training Programme (ITP) on ESD in Higher Education (HE), who are mostly university educators. This thesis however focuses on African ITP participants only. At a macro level, the research sought to examine how African university educators have contributed to the United Nations Decade of Education for Sustainable Development (UNDESD) through their participation in the ITP (which is a change oriented professional development training programme on ESD) and the associated ESD ‘change projects’. The change projects are ITP participants’ direct attempts to mainstream environment and sustainability issues, concerns, and concepts into core university functions and practices: teaching, research, community engagement, and management operations and policy engagement. At a meso level the study sought insight into how educators in national institutions were supported by sub-regional and regional initiatives, institutions and organisations, including the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership programme, especially an initiative supported by the Southern African Development Community Regional Environmental Education Programme to provide (limited) seed funding to three southern African universities to establish what are known as ‘MESA Chairs’, with dedicated time and support for MESA activities in their universities . At a micro level, this research sought to investigate how the position-practice systems and the ITP shape (enable or constrain) effective ESD mainstreaming in higher education, and how the morphogenetic approach and laminated system can be used to understand and explain these dynamics and their relations with meso and macro level engagements. The research sought to understand these dynamics through empirical investigations using survey questionnaires, interviews, document analysis and field visits. The research is constituted as theoretical, conceptual, methodological and analytical exploration using a singular and nested case study research approach, underlaboured by a critical realist ontology, and drawing on a social learning epistemology and social realist morphogenetic interpretive lens. In particular, ontological depth was sought via critical realist laminated system explanation. See Chapter Two for details. This study was carried out in three phases. Phase one encapsulates the investigation of all ITP ESD in higher education alumni who were Asian and African participants from the inception of the ITP to its completion, over a six-year period (2008-2013). This included 280 academics from Asia and Africa in 35 countries in Asia and Africa from 106 institutions in Asia and Africa with their 139 change projects. The outcome of phase one of the research is only included in this thesis as an appendix (see Appendix 3; Agbedahin & Lotz-Sisitka, 2015). However, this phase provided and formed the foundational data that was expanded in phases two and three for the purpose of this study. Phase two of this research concentrated on a less broad population of research participants comprising only all African ITP alumni, from all regions in Africa. The overall data collection and analysis included 162 academics in 23 African countries from 66 institutions with their 81 change projects. The aim was to investigate and provide a morphogenetic explanation of their change projects and how the relationship between participants’ positions and practices (and that of others) may influence ESD mainstreaming in universities. The outcome of this phase two investigation is presented in Chapter Four. In phase three, (nested) case studies of Swaziland, Zambia, and Botswana (in the southern Africa region), which included all the ESD ITP HE participants therein and the three corresponding EE/ESD MESA Chairs, were developed. The population sample in this phase three therefore contained 20 academics, from six institutions with their nine change projects. This phase was characterised by field trips to these countries and in-depth data collection and analysis in order to investigate and deepen the morphogenetic explanations of their change projects and how the relationship between participants’ positions and practices (and that of others) have indeed influenced the ESD mainstreaming in universities. The outcome of this phase three research is presented in Chapters Five, Six and Seven. The final Chapter Eight of this thesis focuses on the seven scalar laminated system perspective and reflections on this research and discussion of these perspectives for supporting the mainstreaming of ESD in African higher education institutions and more specifically in the three case countries and respective institutions presented in Chapters Five, Six, and Seven. The seven scalar laminated system is presented in relation to the position-practice system, and draws on morphogenetic social realist and social learning theory to provide perspective on the actual change processes. Chapter Eight also includes a discussion on social learning and its implication for ESD mainstreaming, and provides recommendations for further research. The outcome of the theoretical exploration underpinning this study provided a potential model for understanding ESD learning and change processes that are facilitated by professional development training programmes in the context of ESD in HE. This study also provides a model for appraising educational changes in time and in space, especially in relation to ESD, or the types of changes that can be brought about by professional development interventions such as those provided by the ITP and how they can be tracked, monitored and documented. For the field of professional or academic development in higher education, this research highlights the significance of the relationship between position-practice systems, professional development interventions and institutional transformation. For the field of ESD in higher education, this study shows the need for in-depth consideration of the position-practice system and sphere of influence of change agents and related stakeholders in and around their institutions in the design and development of professional development programmes. It further sheds light on the laminated system of factors that contextually constrain and/or enable effective ESD mainstreaming at individual, collective, institutional, national, regional and global levels.
- Full Text:
- Authors: Agbedahin, Adesuwa Vanessa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/584 , vital:19972
- Description: This research focuses on Education for Sustainable Development (ESD) in Higher Education Institutions (HEIs), particularly in Africa. It explores the roles and practices of these institutions, especially their professionals, in the Anthropocene era where increasing concern for contemporary environmental and sustainability issues and risks emerge. The study presents a longitudinal case study of institutions and participants of the Swedish/African/Asian International Training Programme (ITP) on ESD in Higher Education (HE), who are mostly university educators. This thesis however focuses on African ITP participants only. At a macro level, the research sought to examine how African university educators have contributed to the United Nations Decade of Education for Sustainable Development (UNDESD) through their participation in the ITP (which is a change oriented professional development training programme on ESD) and the associated ESD ‘change projects’. The change projects are ITP participants’ direct attempts to mainstream environment and sustainability issues, concerns, and concepts into core university functions and practices: teaching, research, community engagement, and management operations and policy engagement. At a meso level the study sought insight into how educators in national institutions were supported by sub-regional and regional initiatives, institutions and organisations, including the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership programme, especially an initiative supported by the Southern African Development Community Regional Environmental Education Programme to provide (limited) seed funding to three southern African universities to establish what are known as ‘MESA Chairs’, with dedicated time and support for MESA activities in their universities . At a micro level, this research sought to investigate how the position-practice systems and the ITP shape (enable or constrain) effective ESD mainstreaming in higher education, and how the morphogenetic approach and laminated system can be used to understand and explain these dynamics and their relations with meso and macro level engagements. The research sought to understand these dynamics through empirical investigations using survey questionnaires, interviews, document analysis and field visits. The research is constituted as theoretical, conceptual, methodological and analytical exploration using a singular and nested case study research approach, underlaboured by a critical realist ontology, and drawing on a social learning epistemology and social realist morphogenetic interpretive lens. In particular, ontological depth was sought via critical realist laminated system explanation. See Chapter Two for details. This study was carried out in three phases. Phase one encapsulates the investigation of all ITP ESD in higher education alumni who were Asian and African participants from the inception of the ITP to its completion, over a six-year period (2008-2013). This included 280 academics from Asia and Africa in 35 countries in Asia and Africa from 106 institutions in Asia and Africa with their 139 change projects. The outcome of phase one of the research is only included in this thesis as an appendix (see Appendix 3; Agbedahin & Lotz-Sisitka, 2015). However, this phase provided and formed the foundational data that was expanded in phases two and three for the purpose of this study. Phase two of this research concentrated on a less broad population of research participants comprising only all African ITP alumni, from all regions in Africa. The overall data collection and analysis included 162 academics in 23 African countries from 66 institutions with their 81 change projects. The aim was to investigate and provide a morphogenetic explanation of their change projects and how the relationship between participants’ positions and practices (and that of others) may influence ESD mainstreaming in universities. The outcome of this phase two investigation is presented in Chapter Four. In phase three, (nested) case studies of Swaziland, Zambia, and Botswana (in the southern Africa region), which included all the ESD ITP HE participants therein and the three corresponding EE/ESD MESA Chairs, were developed. The population sample in this phase three therefore contained 20 academics, from six institutions with their nine change projects. This phase was characterised by field trips to these countries and in-depth data collection and analysis in order to investigate and deepen the morphogenetic explanations of their change projects and how the relationship between participants’ positions and practices (and that of others) have indeed influenced the ESD mainstreaming in universities. The outcome of this phase three research is presented in Chapters Five, Six and Seven. The final Chapter Eight of this thesis focuses on the seven scalar laminated system perspective and reflections on this research and discussion of these perspectives for supporting the mainstreaming of ESD in African higher education institutions and more specifically in the three case countries and respective institutions presented in Chapters Five, Six, and Seven. The seven scalar laminated system is presented in relation to the position-practice system, and draws on morphogenetic social realist and social learning theory to provide perspective on the actual change processes. Chapter Eight also includes a discussion on social learning and its implication for ESD mainstreaming, and provides recommendations for further research. The outcome of the theoretical exploration underpinning this study provided a potential model for understanding ESD learning and change processes that are facilitated by professional development training programmes in the context of ESD in HE. This study also provides a model for appraising educational changes in time and in space, especially in relation to ESD, or the types of changes that can be brought about by professional development interventions such as those provided by the ITP and how they can be tracked, monitored and documented. For the field of professional or academic development in higher education, this research highlights the significance of the relationship between position-practice systems, professional development interventions and institutional transformation. For the field of ESD in higher education, this study shows the need for in-depth consideration of the position-practice system and sphere of influence of change agents and related stakeholders in and around their institutions in the design and development of professional development programmes. It further sheds light on the laminated system of factors that contextually constrain and/or enable effective ESD mainstreaming at individual, collective, institutional, national, regional and global levels.
- Full Text:
Observational cosmology with imperfect data
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
The chemistry of Algoa Bay ascidians
- Authors: Bromley, Candice Leigh
- Date: 2016
- Subjects: Sea squirts -- South Africa -- Algoa Bay , Marine metabolites , Chemistry, Analytic , Liquid chromatography , Inductively coupled plasma mass spectrometry , Metal ions , Nucleosides , Vanadium
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4560 , http://hdl.handle.net/10962/d1020606
- Description: This thesis investigates the chemistry of 25 ascidian species collected from Algoa Bay, South Africa with a concerted focus on metal accumulation by these ascidians and the possible interaction of these metals with ascidian metabolites. Chapter 2 details the screening techniques employed to establish the presence of nitrogenous metabolites (1H- 15N HMBC), hyper-accumulated metal ions (ICP-MS) and potential metal ion/ ascidian metabolite complexes (LC-ICP-MS/ESI-MS). Unfortunately, exhaustive attempts to detect intact metal ion/ascidian metabolite complexes through the use of liquid chromatography with parallel inductively coupled plasma mass spectrometry/electrospray mass spectrometry (LC-ICPMS/ ESI-MS) were unsuccessful. However, the LC-ICP-MS/ESI-MS data obtained for the crude organic extracts of six of the Algoa Bay ascidian species, Distaplia skoogi, Aplidium monile, Aplidium sp., Didemnum sp., Leptoclindines sp. and Polycitor sp. enabled identification of a number of ten halogenated metabolites, namely the indoles 2.28-2.30, and the tyramine and tyrosine derivatives (2.31-2.33, 2.41, 2.43, 2.44 and 2.46), within the ascidian extracts. This study confirmed that LC-ICP-MS/ESI-MS is a powerful tool for the dereplication of halogenated metabolites in complex mixtures especially where these compounds are present in very small amounts. This study is also the first report of these compounds (eight of which are known) in African ascidians. Compounds 2.32 and 2.46 have not been reported before from a marine source. Compounds 2.28-2.30 and 2.33 were present in sufficient amounts in the respective ascidian extracts to allow their isolation and structure elucidation using standard spectroscopic techniques Chapter 3 explores the ability of ascidians to accumulate a wide range of metal ions at concentrations which are often orders of magnitude higher than those of the surrounding sea water. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the total ion concentrations of 24 metals in 25 Algoa Bay ascidian species. To the best of our knowledge this is the largest and most extensive investigation of metal concentrations in a group of different ascidians occurring in the same area. Hypotheisizing that the metal ion concentrations for each ascidian specimen screened may represent a unique fingerprint for each specimen principal component analysis (PCA) was used in an attempt to establish whether there were spatial, temporal or phylogenetic relationships associated with the metal concentration fingerprints of the ascidians that formed part of this study. The PCA results showed that there were no statistically significant relationships between ascidian metal ion concentrations and either the collection year or the collection site of the ascidians. However, species from the family Didemnidae provided the clearest statistical evidence supporting a phylogenetic relationship between these ascidians and their hyperaccumulated metal ion profiles. Furthermore, these results suggested that ascidian species are indeed actively concentrating metal ions from the surrounding sea water and are not simply sinks for passively accumulated metal ions. Interestingly, the concentration of vanadium in the set of ascidians studied did not appear to correlate with any of the other metals accumulated by these ascidians suggesting that there is possibly a unique method employed for the accumulation of vanadium by ascidians. Chapter 4 investigated this possibility further after the nucleosides 4.10, 4.11, 4.13, 4.15, 4.17 and 4.40 were isolated from the vanadium accumulating ascidian Aplidium monile. Studies into the interactions between nucleosides and vanadyl are unfortunately rare and usually qualitative in nature with limited information provided about the stability or structures of the complexes formed. The vanadyl accumulating aplousobranch ascidians e.g. Aplidium monile dominated our study of Algoa Bay ascidians therefore providing us with the rationale to investigate the relatively little studied binding ability and stability of vandyl-nucleoside complexes. Potentiometric studies were conducted to determine the stability constants of complexes formed between the oxovanadium ion vanadyl (VO2+) and the commercially available nucleosides 4.10-4.14. The data afforded by this analysis clearly confirmed the complexity of the vanadyl/nucleoside complexation and suggested that guanosine (4.12) formed the most stable complex with oxovanadium ions. We were also able to establish a third protonation constant for the hydroxyl moiety in 4.12 with a logK 8.87 which has not been previously reported. Finally, Chapter 5 revisited the cytoxicity two Algoa Bay ascidians, Clavelina sp. and Atriolum marinense the extracts from which produced promising bioactivity results in previous studies against oesophageal cancer cells. The HP-20 fractionated extracts of Clavelina sp. and Atriolum marinense proved to be similalrly cytotoxic to breast cancer cells. With the exception for the 100% acetone(aq)fractions the NMR data for both species suggested that most active non polar fractions were dominated by what appeared to be structurally unremarkable fatty acid glycerides and as such were not pursued further. Purification of the 100% acetone(aq)fraction of A. marinense resulted in the isolation of a styrene trimer, 5.1, common to both ascidian extracts. The NMR simulation software WIN-DAISY was employed to confirm the structure of 5.1. Attempts to establish if 5.1 was an isolation artefact or a product of marine pollution were inconclusive
- Full Text:
- Authors: Bromley, Candice Leigh
- Date: 2016
- Subjects: Sea squirts -- South Africa -- Algoa Bay , Marine metabolites , Chemistry, Analytic , Liquid chromatography , Inductively coupled plasma mass spectrometry , Metal ions , Nucleosides , Vanadium
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4560 , http://hdl.handle.net/10962/d1020606
- Description: This thesis investigates the chemistry of 25 ascidian species collected from Algoa Bay, South Africa with a concerted focus on metal accumulation by these ascidians and the possible interaction of these metals with ascidian metabolites. Chapter 2 details the screening techniques employed to establish the presence of nitrogenous metabolites (1H- 15N HMBC), hyper-accumulated metal ions (ICP-MS) and potential metal ion/ ascidian metabolite complexes (LC-ICP-MS/ESI-MS). Unfortunately, exhaustive attempts to detect intact metal ion/ascidian metabolite complexes through the use of liquid chromatography with parallel inductively coupled plasma mass spectrometry/electrospray mass spectrometry (LC-ICPMS/ ESI-MS) were unsuccessful. However, the LC-ICP-MS/ESI-MS data obtained for the crude organic extracts of six of the Algoa Bay ascidian species, Distaplia skoogi, Aplidium monile, Aplidium sp., Didemnum sp., Leptoclindines sp. and Polycitor sp. enabled identification of a number of ten halogenated metabolites, namely the indoles 2.28-2.30, and the tyramine and tyrosine derivatives (2.31-2.33, 2.41, 2.43, 2.44 and 2.46), within the ascidian extracts. This study confirmed that LC-ICP-MS/ESI-MS is a powerful tool for the dereplication of halogenated metabolites in complex mixtures especially where these compounds are present in very small amounts. This study is also the first report of these compounds (eight of which are known) in African ascidians. Compounds 2.32 and 2.46 have not been reported before from a marine source. Compounds 2.28-2.30 and 2.33 were present in sufficient amounts in the respective ascidian extracts to allow their isolation and structure elucidation using standard spectroscopic techniques Chapter 3 explores the ability of ascidians to accumulate a wide range of metal ions at concentrations which are often orders of magnitude higher than those of the surrounding sea water. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the total ion concentrations of 24 metals in 25 Algoa Bay ascidian species. To the best of our knowledge this is the largest and most extensive investigation of metal concentrations in a group of different ascidians occurring in the same area. Hypotheisizing that the metal ion concentrations for each ascidian specimen screened may represent a unique fingerprint for each specimen principal component analysis (PCA) was used in an attempt to establish whether there were spatial, temporal or phylogenetic relationships associated with the metal concentration fingerprints of the ascidians that formed part of this study. The PCA results showed that there were no statistically significant relationships between ascidian metal ion concentrations and either the collection year or the collection site of the ascidians. However, species from the family Didemnidae provided the clearest statistical evidence supporting a phylogenetic relationship between these ascidians and their hyperaccumulated metal ion profiles. Furthermore, these results suggested that ascidian species are indeed actively concentrating metal ions from the surrounding sea water and are not simply sinks for passively accumulated metal ions. Interestingly, the concentration of vanadium in the set of ascidians studied did not appear to correlate with any of the other metals accumulated by these ascidians suggesting that there is possibly a unique method employed for the accumulation of vanadium by ascidians. Chapter 4 investigated this possibility further after the nucleosides 4.10, 4.11, 4.13, 4.15, 4.17 and 4.40 were isolated from the vanadium accumulating ascidian Aplidium monile. Studies into the interactions between nucleosides and vanadyl are unfortunately rare and usually qualitative in nature with limited information provided about the stability or structures of the complexes formed. The vanadyl accumulating aplousobranch ascidians e.g. Aplidium monile dominated our study of Algoa Bay ascidians therefore providing us with the rationale to investigate the relatively little studied binding ability and stability of vandyl-nucleoside complexes. Potentiometric studies were conducted to determine the stability constants of complexes formed between the oxovanadium ion vanadyl (VO2+) and the commercially available nucleosides 4.10-4.14. The data afforded by this analysis clearly confirmed the complexity of the vanadyl/nucleoside complexation and suggested that guanosine (4.12) formed the most stable complex with oxovanadium ions. We were also able to establish a third protonation constant for the hydroxyl moiety in 4.12 with a logK 8.87 which has not been previously reported. Finally, Chapter 5 revisited the cytoxicity two Algoa Bay ascidians, Clavelina sp. and Atriolum marinense the extracts from which produced promising bioactivity results in previous studies against oesophageal cancer cells. The HP-20 fractionated extracts of Clavelina sp. and Atriolum marinense proved to be similalrly cytotoxic to breast cancer cells. With the exception for the 100% acetone(aq)fractions the NMR data for both species suggested that most active non polar fractions were dominated by what appeared to be structurally unremarkable fatty acid glycerides and as such were not pursued further. Purification of the 100% acetone(aq)fraction of A. marinense resulted in the isolation of a styrene trimer, 5.1, common to both ascidian extracts. The NMR simulation software WIN-DAISY was employed to confirm the structure of 5.1. Attempts to establish if 5.1 was an isolation artefact or a product of marine pollution were inconclusive
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Financial characteristics of the nonprofit organisation: theory and evidence for the assessment of the financial condition of South African public universities
- Authors: Bunting, Mark Bevan
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:923 , http://hdl.handle.net/10962/d1021298 , http://orcid.org/0000-0002-3392-554X
- Description: In this thesis, an analytical framework is developed for the assessment of the financial condition of South African public universities. Foundational constructs of nonprofit economics are applied in the consideration of financial theories of nonprofit organisations in general, and public universities in particular. From this review, a number of hypotheses are developed. Each of these specifies a positive or negative association between a university's financial condition and a particular dimension of its assets, liabilities, equity, revenues, expenses and surplus. From the nonprofit financial analysis literature, ratios and indicators relevant to these hypotheses are selected. Audited data from the annual financial statements of the universities for the seven year period 2007 to 2013 are substantially transformed in mitigation of failures in accounting, auditing and accountability. The adjusted accounting numbers are used to calculate the financial indicators applicable to each university. Exploratory factor analysis is implemented to categorise and organise this large indicator set on the basis of identified associations with a smaller number of factors. It is found that the financial condition of South African public universities is defined by two broad financial characteristics, capital and revenue. Assessment of the capital dimension is informed by a focus on institutional equity, with particular emphasis on expendable equity and its proportionate relationships with surplus, total capital, and total expenses. The revenue dimension is appropriately evaluated in the context of a comparative and interactive consideration of the three main components of South African public university revenue, as well as the proportionate relationship between non-staff operating expenses and total expenses. The framework displays considerable levels of stability and consistency over the seven year review period, and its constructs are, in addition, robust to the application of multiple alternative confirmatory tests involving financial data that are independent of the factor solutions. The financial condition assessment framework developed in this thesis offers a contribution to a broader discourse in nonprofit finance and accounting, with a focus on public university finances.
- Full Text:
- Authors: Bunting, Mark Bevan
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:923 , http://hdl.handle.net/10962/d1021298 , http://orcid.org/0000-0002-3392-554X
- Description: In this thesis, an analytical framework is developed for the assessment of the financial condition of South African public universities. Foundational constructs of nonprofit economics are applied in the consideration of financial theories of nonprofit organisations in general, and public universities in particular. From this review, a number of hypotheses are developed. Each of these specifies a positive or negative association between a university's financial condition and a particular dimension of its assets, liabilities, equity, revenues, expenses and surplus. From the nonprofit financial analysis literature, ratios and indicators relevant to these hypotheses are selected. Audited data from the annual financial statements of the universities for the seven year period 2007 to 2013 are substantially transformed in mitigation of failures in accounting, auditing and accountability. The adjusted accounting numbers are used to calculate the financial indicators applicable to each university. Exploratory factor analysis is implemented to categorise and organise this large indicator set on the basis of identified associations with a smaller number of factors. It is found that the financial condition of South African public universities is defined by two broad financial characteristics, capital and revenue. Assessment of the capital dimension is informed by a focus on institutional equity, with particular emphasis on expendable equity and its proportionate relationships with surplus, total capital, and total expenses. The revenue dimension is appropriately evaluated in the context of a comparative and interactive consideration of the three main components of South African public university revenue, as well as the proportionate relationship between non-staff operating expenses and total expenses. The framework displays considerable levels of stability and consistency over the seven year review period, and its constructs are, in addition, robust to the application of multiple alternative confirmatory tests involving financial data that are independent of the factor solutions. The financial condition assessment framework developed in this thesis offers a contribution to a broader discourse in nonprofit finance and accounting, with a focus on public university finances.
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Ways of seeing over time: the construction and imagination of ‘historic separation’ in Israeli and Palestinian cultures
- Authors: Butler, Nina Melissa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/474 , vital:19962
- Description: There exists an international consensus that Palestinian and Israeli societies are ceaselessly and essentially acrimonious. This thesis argues that the conceptualisation of ‘historic separation’ in Palestine/Israel is supported and nourished by national narratives that follow classic historicism and a linear trajectory of essentialised culture progressing over time. Given these patterns in historiography and cultural expressions, conceptualisations of the future are argued to be dominated by the ‘overdetermined’ and ‘sacralised’ pasts that arrest the ability to conceive of alternative horizons. These national narratives are analysed borrowing from the theorisation of Edward Said on hegemonic culture, and Ranjit Guha’s Subaltern critique of historicism. Zionism is argued to function as a cultural hegemony that operates in a mercurial, selfsustaining and vibrant manner that has the effect of what this thesis terms ‘centrifugal magnetism’ on discourse in the region. Palestinian national narratives are held to be in tangential relation to Zionism (a classic colonial master-narrative), thus entering into a ‘terrible embrace’ of destructive colonial/postcolonial repetition that tends towards violent conflict and the discrimination of minorities. This thesis then proposes a ‘way out’ of this historiographical pattern that is argued to tangibly inform the cultural fabric of the region. By drawing on the later works of Mahmoud Darwish, Mustaffa Hallaj and Said, it is proposed that there are traces of a notion of self and community that can be described as postnational. This demands a reconstruction of narratives of the past in the region in a pluralistic fashion that is based upon shared exilic identity in flux over what Darwish termed an ‘open historical space’. Crucially, this alternative postnational narrative opens up conceptualisations of the future and is founded upon a renewed disposition to temporality. This thesis thus concludes by proposing that an understanding of temporality as ‘ecstatic’ and essential to being (Martin Heidegger) should be included as a crucial consideration for the end to conflict and the attainment of just and equitable futures.
- Full Text:
- Authors: Butler, Nina Melissa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/474 , vital:19962
- Description: There exists an international consensus that Palestinian and Israeli societies are ceaselessly and essentially acrimonious. This thesis argues that the conceptualisation of ‘historic separation’ in Palestine/Israel is supported and nourished by national narratives that follow classic historicism and a linear trajectory of essentialised culture progressing over time. Given these patterns in historiography and cultural expressions, conceptualisations of the future are argued to be dominated by the ‘overdetermined’ and ‘sacralised’ pasts that arrest the ability to conceive of alternative horizons. These national narratives are analysed borrowing from the theorisation of Edward Said on hegemonic culture, and Ranjit Guha’s Subaltern critique of historicism. Zionism is argued to function as a cultural hegemony that operates in a mercurial, selfsustaining and vibrant manner that has the effect of what this thesis terms ‘centrifugal magnetism’ on discourse in the region. Palestinian national narratives are held to be in tangential relation to Zionism (a classic colonial master-narrative), thus entering into a ‘terrible embrace’ of destructive colonial/postcolonial repetition that tends towards violent conflict and the discrimination of minorities. This thesis then proposes a ‘way out’ of this historiographical pattern that is argued to tangibly inform the cultural fabric of the region. By drawing on the later works of Mahmoud Darwish, Mustaffa Hallaj and Said, it is proposed that there are traces of a notion of self and community that can be described as postnational. This demands a reconstruction of narratives of the past in the region in a pluralistic fashion that is based upon shared exilic identity in flux over what Darwish termed an ‘open historical space’. Crucially, this alternative postnational narrative opens up conceptualisations of the future and is founded upon a renewed disposition to temporality. This thesis thus concludes by proposing that an understanding of temporality as ‘ecstatic’ and essential to being (Martin Heidegger) should be included as a crucial consideration for the end to conflict and the attainment of just and equitable futures.
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Predators of aerial insects and riparian cross-boundary trophic dynamics: web-building spiders, dragonflies and damselflies
- Authors: Chari, Lenin Dzibakwe
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55791 , vital:26734
- Description: This thesis characterises the cross-boundary trophic interactions of a relatively small model ecosystem, the Kowie River (Eastern Cape of South Africa), to explore their epistemic implications for systems ecology. Using web-building spiders and odonates (dragonflies and damselflies) as model organisms, I sought to investigate whether the diets of predators of aerial insects could be used to assess the strength of the trophic connectivity between freshwater and terrestrial systems in relation to variables such as stream width, distance from the river and aquatic insect emergence rates and abundances. Predator diet composition was determined by using a combination of diet analysis tools: direct observations of cross-subsidies, naturally-abundant stable (carbon and nitrogen) isotope analysis and fatty acid analysis. I also sought to reveal feeding niches and guilds among riparian aerial predators and investigate how the environment influenced predators’ access to aquatic prey subsidies. As emergent aquatic insect abundances decreased with an increase in distance from the river, and increased with stream width and seasonal changes from winter to summer, stable isotope and fatty acid analyses revealed distinct changes in web-building spider diet composition. Examination of the fatty acid eicosapentaenoic acid, a component commonly used as an indicator of consumer reliance on aquatic nutritional subsidies, showed that aquatic subsidies extended further inland at the wider sections of the river. Spiders and odonates at the wider sections of the Kowie River generally received more subsidies (56 – 70%) than those at the narrower sections (25 – 60%). When terrestrial insect biomass was distinctly low in winter, the benefit of aquatic subsidisation to spiders was relatively lower at the narrower sections of the Kowie River relative to the wide sections. As such, riparian areas adjacent to wide parts of the river were more likely to support larger populations of aerial predators than those at the narrow sections. Apart from the diet changes across time and space, there was evidence of inter-specific niche partitioning in both spiders and odonates, but no differences were observed between males and females of the same species. Results showed odonates of different sizes and hunting strategies had separate dietary niches, hence varied access to aquatic nutritional subsidies. The larger odonate taxa that frequently foraged mid-air had more varied diets and relied less on aquatic emergent insects than the smaller odonates that foraged from perches near the river. There was also evidence of niche partitioning amongst the spiders, as those that built horizontal webs captured more aquatic insects (40 – 78%) than the vertical orb-web builders (20 – 66%). This study showed that the nature and extent of trophic cross-boundary linkages in riparian areas largely depended on the availability of subsidies that varied seasonally and spatially. The width of the stream and seasonal variability emerged as important predictors of emergent insect abundances/biomasses that influenced predator feeding niches. The high mobility of odonates made their reliance on aquatic nutritional subsidies different from the less mobile spiders. The link between the width of the river and the extent of trophic connectivity has implications for riparian area management and definition of riparian buffer zones. However, the variation in diet niches amongst terrestrial consumers makes the results area-specific, and more studies are required that incorporate additional terrestrial predators in other fluvial systems so that we can make some generalizations on the dynamics of riparian trophic cross-boundary links.
- Full Text:
- Authors: Chari, Lenin Dzibakwe
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55791 , vital:26734
- Description: This thesis characterises the cross-boundary trophic interactions of a relatively small model ecosystem, the Kowie River (Eastern Cape of South Africa), to explore their epistemic implications for systems ecology. Using web-building spiders and odonates (dragonflies and damselflies) as model organisms, I sought to investigate whether the diets of predators of aerial insects could be used to assess the strength of the trophic connectivity between freshwater and terrestrial systems in relation to variables such as stream width, distance from the river and aquatic insect emergence rates and abundances. Predator diet composition was determined by using a combination of diet analysis tools: direct observations of cross-subsidies, naturally-abundant stable (carbon and nitrogen) isotope analysis and fatty acid analysis. I also sought to reveal feeding niches and guilds among riparian aerial predators and investigate how the environment influenced predators’ access to aquatic prey subsidies. As emergent aquatic insect abundances decreased with an increase in distance from the river, and increased with stream width and seasonal changes from winter to summer, stable isotope and fatty acid analyses revealed distinct changes in web-building spider diet composition. Examination of the fatty acid eicosapentaenoic acid, a component commonly used as an indicator of consumer reliance on aquatic nutritional subsidies, showed that aquatic subsidies extended further inland at the wider sections of the river. Spiders and odonates at the wider sections of the Kowie River generally received more subsidies (56 – 70%) than those at the narrower sections (25 – 60%). When terrestrial insect biomass was distinctly low in winter, the benefit of aquatic subsidisation to spiders was relatively lower at the narrower sections of the Kowie River relative to the wide sections. As such, riparian areas adjacent to wide parts of the river were more likely to support larger populations of aerial predators than those at the narrow sections. Apart from the diet changes across time and space, there was evidence of inter-specific niche partitioning in both spiders and odonates, but no differences were observed between males and females of the same species. Results showed odonates of different sizes and hunting strategies had separate dietary niches, hence varied access to aquatic nutritional subsidies. The larger odonate taxa that frequently foraged mid-air had more varied diets and relied less on aquatic emergent insects than the smaller odonates that foraged from perches near the river. There was also evidence of niche partitioning amongst the spiders, as those that built horizontal webs captured more aquatic insects (40 – 78%) than the vertical orb-web builders (20 – 66%). This study showed that the nature and extent of trophic cross-boundary linkages in riparian areas largely depended on the availability of subsidies that varied seasonally and spatially. The width of the stream and seasonal variability emerged as important predictors of emergent insect abundances/biomasses that influenced predator feeding niches. The high mobility of odonates made their reliance on aquatic nutritional subsidies different from the less mobile spiders. The link between the width of the river and the extent of trophic connectivity has implications for riparian area management and definition of riparian buffer zones. However, the variation in diet niches amongst terrestrial consumers makes the results area-specific, and more studies are required that incorporate additional terrestrial predators in other fluvial systems so that we can make some generalizations on the dynamics of riparian trophic cross-boundary links.
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The effects of land use on the avifauna and its conservation in a Kenyan coastal forest ecosystem, and the significance of the Arabuko Sokoke Forest to the local community
- Authors: Chiawo, David O
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5950 , http://hdl.handle.net/10962/d1020946
- Description: This study examines the effects of land use on the bird community of Arabuko Sokoke Forest, the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. Bird species diversity in three land use types (primary forest, plantation and farm lands) was compared using multivariate analysis to determine the response of different feeding guilds to habitat characteristics. The effect of habitat characteristics on overall bird diversity and specific feeding guilds was tested using linear mixed models. A total of 2600 bird observations were recorded during point counts, representing 97 bird species including 25 fruit-eating birds, 17 nectar feeders; and 60 species belonging exclusively to other feeding guilds. Land use had a significant effect on overall bird diversity and abundance. The distribution of frugivorous birds was primarily influenced by the presence of fruiting trees rather than land use type, while nectarivores were significantly affected by vertical habitat heterogeneity and vegetation type. Although the distribution of insectivorous birds is influenced by many habitat factors, proximity to natural forest, habitat heterogeneity, and the presence of large trees and fruiting trees appear to be most important to this guild. The natural forest has the greatest avian diversity and a distinctive community compared to plantation and farmlands. Patterns of habitat use by birds in the area suggest that vertical vegetation heterogeneity and complexity is especially significant in sustaining diverse and abundant bird populations, if they are in close proximity to native forests. Improvement of conservation management for the plantation and farmlands is thus critical for connectivity with other remnant primary forest patches in the area. Socio-economic data was collected from 109 forest adjacent households to determine the value of the forest to the local community and their perception of conservation issues. Arabuko Sokoke Forest is important in supplementing the livelihood needs of the local community. However, the community lacks information on the forest management plan and many people have little knowledge of local birds, which could limit their capacity to participate in conservation projects. Drivers for local community participation in conservation projects are primarily a sustainable income and the fulfillment of basic household needs. Community conservation education is needed to promote local knowledge of forest biodiversity, as well as clear frameworks for the active involvement of the local community in forest management. Support of community based projects is vital to achieve both the conservation and livelihood objectives of the Arabuko Sokoke Forest management plan.
- Full Text:
- Authors: Chiawo, David O
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5950 , http://hdl.handle.net/10962/d1020946
- Description: This study examines the effects of land use on the bird community of Arabuko Sokoke Forest, the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. Bird species diversity in three land use types (primary forest, plantation and farm lands) was compared using multivariate analysis to determine the response of different feeding guilds to habitat characteristics. The effect of habitat characteristics on overall bird diversity and specific feeding guilds was tested using linear mixed models. A total of 2600 bird observations were recorded during point counts, representing 97 bird species including 25 fruit-eating birds, 17 nectar feeders; and 60 species belonging exclusively to other feeding guilds. Land use had a significant effect on overall bird diversity and abundance. The distribution of frugivorous birds was primarily influenced by the presence of fruiting trees rather than land use type, while nectarivores were significantly affected by vertical habitat heterogeneity and vegetation type. Although the distribution of insectivorous birds is influenced by many habitat factors, proximity to natural forest, habitat heterogeneity, and the presence of large trees and fruiting trees appear to be most important to this guild. The natural forest has the greatest avian diversity and a distinctive community compared to plantation and farmlands. Patterns of habitat use by birds in the area suggest that vertical vegetation heterogeneity and complexity is especially significant in sustaining diverse and abundant bird populations, if they are in close proximity to native forests. Improvement of conservation management for the plantation and farmlands is thus critical for connectivity with other remnant primary forest patches in the area. Socio-economic data was collected from 109 forest adjacent households to determine the value of the forest to the local community and their perception of conservation issues. Arabuko Sokoke Forest is important in supplementing the livelihood needs of the local community. However, the community lacks information on the forest management plan and many people have little knowledge of local birds, which could limit their capacity to participate in conservation projects. Drivers for local community participation in conservation projects are primarily a sustainable income and the fulfillment of basic household needs. Community conservation education is needed to promote local knowledge of forest biodiversity, as well as clear frameworks for the active involvement of the local community in forest management. Support of community based projects is vital to achieve both the conservation and livelihood objectives of the Arabuko Sokoke Forest management plan.
- Full Text:
An exploration of how consistently and precisely mathematics teachers code-switch in multilingual classrooms
- Authors: Chikiwa, Clemence
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2076 , http://hdl.handle.net/10962/d1021304
- Description: Many education research studies conducted in and outside South Africa encourage teachers to take advantage of the presence of multilingualism in their classrooms and to use it to the advancement of students’ conceptual learning. This study adopts the notion that code switching is a potential resource that teachers can use when teaching multilingual mathematics classes. The aim of this study is to determine how precisely and consistently selected teachers of multilingual mathematics classes code switched during teaching of trigonometry and geometry at secondary school. This study is informed by socio-cultural theory in general and Vygotsky’s work in particular. It focussed specifically on the critical role that language plays in the teaching and cognitive development of mathematics. My study situated within an interpretivist paradigm, used a case study research design and a mixed method research approach. Data were obtained through document collection, observing and interviewing three Grade 11 Mathematics teachers purposively selected from three secondary schools in Grahamstown and King Williamstown education districts of the Eastern Cape Province, South Africa. Data were quantitatively and qualitatively analysed. Findings from this study revealed that the frequency of code switching was not consistent across teachers, topics and lessons. Teachers taught predominantly in the public domain exposing students to compromised mathematical content through their code switching practices. Borrowing code switching was prevalently employed consistently across the participating teachers. Very little transparent code switching, from mainly those mathematical terms commonly used in the foundation and the intermediate phases, was evident in teacher language. No Grade 11 trigonometry and geometry terms in isiXhosa were transparently and consistently code switched. The data suggested that while precision was observed in some cases, it was not consistent. Inconsistencies were caused by lack of planning for code switching, lack of teaching materials in indigenous languages, selective code switching, and ‘safe mode’ code switching strategies which affected teachers’ pedagogical practices. Overall results in this study illustrate that the lack of planning for code switching and the lack of explicit policies and clear-cut official positions on code switching for teaching has contributed to inconsistent and imprecise code switching by the participating teachers. This study concludes that the development of supporting mechanisms, identifying and documenting best practices to encourage transparent, meaningful and beneficial code switching is urgently required to aid and promote conceptual understanding of strongly bounded sub-registers of secondary school mathematics such as trigonometry and geometry. It is anticipated that this study will contribute significantly to the ongoing debate on language use in education and to the institution of best practices for judicious, consistent and precise use of students’ home language during the teaching of mathematics in South Africa.
- Full Text:
- Authors: Chikiwa, Clemence
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2076 , http://hdl.handle.net/10962/d1021304
- Description: Many education research studies conducted in and outside South Africa encourage teachers to take advantage of the presence of multilingualism in their classrooms and to use it to the advancement of students’ conceptual learning. This study adopts the notion that code switching is a potential resource that teachers can use when teaching multilingual mathematics classes. The aim of this study is to determine how precisely and consistently selected teachers of multilingual mathematics classes code switched during teaching of trigonometry and geometry at secondary school. This study is informed by socio-cultural theory in general and Vygotsky’s work in particular. It focussed specifically on the critical role that language plays in the teaching and cognitive development of mathematics. My study situated within an interpretivist paradigm, used a case study research design and a mixed method research approach. Data were obtained through document collection, observing and interviewing three Grade 11 Mathematics teachers purposively selected from three secondary schools in Grahamstown and King Williamstown education districts of the Eastern Cape Province, South Africa. Data were quantitatively and qualitatively analysed. Findings from this study revealed that the frequency of code switching was not consistent across teachers, topics and lessons. Teachers taught predominantly in the public domain exposing students to compromised mathematical content through their code switching practices. Borrowing code switching was prevalently employed consistently across the participating teachers. Very little transparent code switching, from mainly those mathematical terms commonly used in the foundation and the intermediate phases, was evident in teacher language. No Grade 11 trigonometry and geometry terms in isiXhosa were transparently and consistently code switched. The data suggested that while precision was observed in some cases, it was not consistent. Inconsistencies were caused by lack of planning for code switching, lack of teaching materials in indigenous languages, selective code switching, and ‘safe mode’ code switching strategies which affected teachers’ pedagogical practices. Overall results in this study illustrate that the lack of planning for code switching and the lack of explicit policies and clear-cut official positions on code switching for teaching has contributed to inconsistent and imprecise code switching by the participating teachers. This study concludes that the development of supporting mechanisms, identifying and documenting best practices to encourage transparent, meaningful and beneficial code switching is urgently required to aid and promote conceptual understanding of strongly bounded sub-registers of secondary school mathematics such as trigonometry and geometry. It is anticipated that this study will contribute significantly to the ongoing debate on language use in education and to the institution of best practices for judicious, consistent and precise use of students’ home language during the teaching of mathematics in South Africa.
- Full Text:
The relationship between leaders’ emotional intelligence and followers’ motivational behaviour and organisational commitment
- Authors: Chipumuro, Juliet
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/484 , vital:19963
- Description: Over the past few years, emotional intelligence (EI) has generated significant interest and a wealth of research as a possible area of insight into what determines outstanding performance in the workplace (Ashworth, 2013:8; Pillay, Viviers and Mayer, 2013:1). The internal environment of organisations in the labour-intense hospitality industry is complex and dynamic. Given the unpredictability of change, the researcher found the hospitality industry to be an intriguing milieu within which to ascertain the importance of EI in predicting leaders’ effectiveness as a measure of outstanding performance. As employees are the internal customers of any hotel organisation, representing many hotel organisations’ only true competitive advantage, the purpose of this quantitative investigation was to examine the relationship between leaders’ EI and followers’ motivational behaviour and organisational commitment. Despite the intuitive plausibility of the assumption that leaders who exhibit EI competencies contribute to outstanding performance, the issue of followers’ motivational behaviour and organisational commitment as leadership indices has received little empirical attention. This study sets out to integrate prior findings on EI, motivation and organisational commitment, to support these findings in literature, and to incorporate these findings into a comprehensive conceptual framework. Using critical realists’ post-positivistic philosophical assumptions, the researcher used the Emotional and Social Competencies Inventory (ESCI) to assess leaders’ EI. Furthermore, the Motivational Sources Inventory (MSI) was used to assess followers’ motivational behaviour, while Organisational Commitment Scales (OCS) were used to assess followers’ organisational commitment. The survey respondents consisted of 120 leaders and 435 followers from 13 hotels in four prominent hotel groups in South Africa. The quantitative data collected from the surveys was analysed quantitatively using SPSS to reach substantial results with inferences. The analysis of variance revealed an overall positive relationship between demographic variables and Leaders EI, followers’ motivational behaviour and followers’ organisational commitment. The correlational analysis revealed positive relationships between leaders’ EI and followers’ motivational behaviour and organisational commitment (R= 0.05-, p<0.01) except for instrumental motivation. The correlation between leaders’ emotional self-awareness and followers’ intrinsic process motivation was somewhat weak while the relationship between leaders’ emotional self-awareness and instrumental motivation was found to be sufficient, but statistically not significant. The researcher can conclude that generally the results of this study reveal that organisational leaders can positively influence the motivational behaviour and organisational commitment of their followers by enhancing their own EI competencies. The results add to the leadership literature by illuminating possible antecedents to leadership effectiveness. It is believed that this research will help the hospitality industry at large in clarifying the importance of EI competencies in leadership as a means of obtaining positive motivation behaviour and commitment from followers. Furthermore, the findings have both managerial and research implications for hospitality operations strategy formulation in order to gain competitive advantage and improve the financial position of the businesses.
- Full Text:
- Authors: Chipumuro, Juliet
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/484 , vital:19963
- Description: Over the past few years, emotional intelligence (EI) has generated significant interest and a wealth of research as a possible area of insight into what determines outstanding performance in the workplace (Ashworth, 2013:8; Pillay, Viviers and Mayer, 2013:1). The internal environment of organisations in the labour-intense hospitality industry is complex and dynamic. Given the unpredictability of change, the researcher found the hospitality industry to be an intriguing milieu within which to ascertain the importance of EI in predicting leaders’ effectiveness as a measure of outstanding performance. As employees are the internal customers of any hotel organisation, representing many hotel organisations’ only true competitive advantage, the purpose of this quantitative investigation was to examine the relationship between leaders’ EI and followers’ motivational behaviour and organisational commitment. Despite the intuitive plausibility of the assumption that leaders who exhibit EI competencies contribute to outstanding performance, the issue of followers’ motivational behaviour and organisational commitment as leadership indices has received little empirical attention. This study sets out to integrate prior findings on EI, motivation and organisational commitment, to support these findings in literature, and to incorporate these findings into a comprehensive conceptual framework. Using critical realists’ post-positivistic philosophical assumptions, the researcher used the Emotional and Social Competencies Inventory (ESCI) to assess leaders’ EI. Furthermore, the Motivational Sources Inventory (MSI) was used to assess followers’ motivational behaviour, while Organisational Commitment Scales (OCS) were used to assess followers’ organisational commitment. The survey respondents consisted of 120 leaders and 435 followers from 13 hotels in four prominent hotel groups in South Africa. The quantitative data collected from the surveys was analysed quantitatively using SPSS to reach substantial results with inferences. The analysis of variance revealed an overall positive relationship between demographic variables and Leaders EI, followers’ motivational behaviour and followers’ organisational commitment. The correlational analysis revealed positive relationships between leaders’ EI and followers’ motivational behaviour and organisational commitment (R= 0.05-, p<0.01) except for instrumental motivation. The correlation between leaders’ emotional self-awareness and followers’ intrinsic process motivation was somewhat weak while the relationship between leaders’ emotional self-awareness and instrumental motivation was found to be sufficient, but statistically not significant. The researcher can conclude that generally the results of this study reveal that organisational leaders can positively influence the motivational behaviour and organisational commitment of their followers by enhancing their own EI competencies. The results add to the leadership literature by illuminating possible antecedents to leadership effectiveness. It is believed that this research will help the hospitality industry at large in clarifying the importance of EI competencies in leadership as a means of obtaining positive motivation behaviour and commitment from followers. Furthermore, the findings have both managerial and research implications for hospitality operations strategy formulation in order to gain competitive advantage and improve the financial position of the businesses.
- Full Text:
Rural livelihood strategies of female headed households in former Bantustans of post-apartheid South Africa: The case of Cala, Eastern Cape Province.
- Authors: Chirau, Takunda John
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3410 , http://hdl.handle.net/10962/d1021301
- Description: Communal areas in contemporary South Africa (that is, the former Bantustans of apartheid South Africa) continue to bear and endure, albeit in new forms, socio-economic and political vulnerabilities which are negatively affecting household livelihoods. Current studies on rural livelihoods have failed to keep pace in exploring and analysing the lived experiences and ever-changing challenges faced by these rural households. This thesis provides an understanding and explanation of the livelihood activities of specifically de facto and de jure female-headed households in the former Transkei Bantustan, with a specific focus on villages in Cala. This is framed analytically by feminist theories with their emphasis on systems of patriarchy and by a rural livelihoods framework. It uses a multiplicity of research methods, including focus group discussions, in-depth interviews, life histories and survey questionnaires. The major findings of the thesis show that the female-headed households in Cala depend upon agricultural-based activities and non-agriculturally-based activities and income (including social grants) but that they exist under conditions of extreme vulnerability which are subject to fluctuation. In the end, the livelihoods of female-headed households are precarious and unstable as they live under circumstances of poverty. However, the female heads are not mere passive victims of the rural crisis in post-apartheid South Africa, as they demonstrate qualities of ingenuity and resourcefulness including through a range of coping mechanisms. At the same time, rural communities continue to be marked by patriarchal norms and practices, including systems of chieftainship, which disempower women (including female heads), though this affects de jure heads and de facto heads differently. The thesis contributes to an understanding of rural livelihoods in communal areas (or former Bantustans) of present-day South Africa by way of ‘thick descriptions’ of the everyday lives of female heads in Cala. Further, in examining rural livelihoods, it highlights the importance of bringing to bear on the livelihoods framework a feminist perspective in pinpointing the additional livelihood burdens carried by rural women.
- Full Text:
- Authors: Chirau, Takunda John
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3410 , http://hdl.handle.net/10962/d1021301
- Description: Communal areas in contemporary South Africa (that is, the former Bantustans of apartheid South Africa) continue to bear and endure, albeit in new forms, socio-economic and political vulnerabilities which are negatively affecting household livelihoods. Current studies on rural livelihoods have failed to keep pace in exploring and analysing the lived experiences and ever-changing challenges faced by these rural households. This thesis provides an understanding and explanation of the livelihood activities of specifically de facto and de jure female-headed households in the former Transkei Bantustan, with a specific focus on villages in Cala. This is framed analytically by feminist theories with their emphasis on systems of patriarchy and by a rural livelihoods framework. It uses a multiplicity of research methods, including focus group discussions, in-depth interviews, life histories and survey questionnaires. The major findings of the thesis show that the female-headed households in Cala depend upon agricultural-based activities and non-agriculturally-based activities and income (including social grants) but that they exist under conditions of extreme vulnerability which are subject to fluctuation. In the end, the livelihoods of female-headed households are precarious and unstable as they live under circumstances of poverty. However, the female heads are not mere passive victims of the rural crisis in post-apartheid South Africa, as they demonstrate qualities of ingenuity and resourcefulness including through a range of coping mechanisms. At the same time, rural communities continue to be marked by patriarchal norms and practices, including systems of chieftainship, which disempower women (including female heads), though this affects de jure heads and de facto heads differently. The thesis contributes to an understanding of rural livelihoods in communal areas (or former Bantustans) of present-day South Africa by way of ‘thick descriptions’ of the everyday lives of female heads in Cala. Further, in examining rural livelihoods, it highlights the importance of bringing to bear on the livelihoods framework a feminist perspective in pinpointing the additional livelihood burdens carried by rural women.
- Full Text:
A narrative-discursive analysis of abortion decision-making in Zimbabwe
- Authors: Chiweshe, Malvern Tatenda
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/496 , vital:19964
- Description: Most research on abortion decision-making has looked at the factors or influences that are seen to affect abortion decision-making and thus take a health determinants approach. However, this approach is rarely able to account for the complex, multi-faceted nature of abortion decision-making, and it is often not located within a framework that can unpick the complex array of power relations that underpins the process of abortion decision-making. Research on abortion decision-making has rarely examined how women who undergo a termination of pregnancy (TOP) construct micro-narratives of the decision to terminate the pregnancy and also how these women are positioned by the service providers who interact with them. Using a Foucauldian postcolonial feminist approach and narrative-discursive analysis, this study explores abortion decision-making narratives in a Zimbabwean context where abortion laws are restrictive. In this study I elicited the narratives of women who had undergone an abortion about how they came to make the decision and proceeded to terminate the pregnancy. I highlight the discourses employed in constructing these narratives and how women position themselves in these narratives and discourses. These are then compared to the subject positions enabled in health service providers’ narratives on the same topic. These narratives are then linked to the social discourses and power relations that work to enable or constrain reproductive justice. The data were collected from three sites in Harare, Zimbabwe. The three sites were Harare Hospital, Epworth and Mufakose. An adapted version of Wengraf’s (2001) narrative interview was used to elicit narratives from 18 women who had terminated pregnancies (six at each site). Semi-structured interviews were conducted with six service providers (two nurses at Harare Hospital, two village health workers in Epworth and two nurses in Mufakose). All the service providers interviewed have experience working with women who have terminated pregnancies. In narrating their stories about their abortions, the women employed discursive resources around shame, stigma, religion, health and culture. These discursive resources were drawn upon in the construction of the women’s micro-narratives. The women spoke in a socially sanctioned manner where stories were enabled and constrained by particular religious, cultural and gendered discursive resources. In these stories, cultural constructions, gendered understandings of motherhood and femininity constrained reproductive justice for women who have terminated pregnancies. Comparisons of the way women positioned themselves and how they were positioned by health service providers point to the existence of social discourses and power relations that work to constrain reproductive justice. While the women saw themselves as having ‘unsupportable pregnancies’, the service providers positioned them as being evil, selfish and irresponsible. The negative positions deployed by the service providers point to the vilification and blaming of women who have undergone a termination of pregnancy. In these positions, the woman is at fault and there is silence on the role of men in abortion decision-making. In the women’s narratives and the health service providers positioning of the women a ‘reproductive rights’ discourse was absent. This was significant as much of the activism around abortion has centred on the woman’s rights to her body. Where rights were mentioned, it was in reference to foetal rights (using cultural, moralistic religious understandings of abortion as killing). The missing ‘reproductive rights’ discourse points to a need to move from a reproductive rights framework to a reproductive justice framework that can be applied through local understandings of hunhu/ubuntu. By doing this, abortion is not seen as a ‘choice’ that a woman makes but rather as involving broader social and environmental circumstances that make a pregnancy ‘unsupportable’.
- Full Text:
- Authors: Chiweshe, Malvern Tatenda
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/496 , vital:19964
- Description: Most research on abortion decision-making has looked at the factors or influences that are seen to affect abortion decision-making and thus take a health determinants approach. However, this approach is rarely able to account for the complex, multi-faceted nature of abortion decision-making, and it is often not located within a framework that can unpick the complex array of power relations that underpins the process of abortion decision-making. Research on abortion decision-making has rarely examined how women who undergo a termination of pregnancy (TOP) construct micro-narratives of the decision to terminate the pregnancy and also how these women are positioned by the service providers who interact with them. Using a Foucauldian postcolonial feminist approach and narrative-discursive analysis, this study explores abortion decision-making narratives in a Zimbabwean context where abortion laws are restrictive. In this study I elicited the narratives of women who had undergone an abortion about how they came to make the decision and proceeded to terminate the pregnancy. I highlight the discourses employed in constructing these narratives and how women position themselves in these narratives and discourses. These are then compared to the subject positions enabled in health service providers’ narratives on the same topic. These narratives are then linked to the social discourses and power relations that work to enable or constrain reproductive justice. The data were collected from three sites in Harare, Zimbabwe. The three sites were Harare Hospital, Epworth and Mufakose. An adapted version of Wengraf’s (2001) narrative interview was used to elicit narratives from 18 women who had terminated pregnancies (six at each site). Semi-structured interviews were conducted with six service providers (two nurses at Harare Hospital, two village health workers in Epworth and two nurses in Mufakose). All the service providers interviewed have experience working with women who have terminated pregnancies. In narrating their stories about their abortions, the women employed discursive resources around shame, stigma, religion, health and culture. These discursive resources were drawn upon in the construction of the women’s micro-narratives. The women spoke in a socially sanctioned manner where stories were enabled and constrained by particular religious, cultural and gendered discursive resources. In these stories, cultural constructions, gendered understandings of motherhood and femininity constrained reproductive justice for women who have terminated pregnancies. Comparisons of the way women positioned themselves and how they were positioned by health service providers point to the existence of social discourses and power relations that work to constrain reproductive justice. While the women saw themselves as having ‘unsupportable pregnancies’, the service providers positioned them as being evil, selfish and irresponsible. The negative positions deployed by the service providers point to the vilification and blaming of women who have undergone a termination of pregnancy. In these positions, the woman is at fault and there is silence on the role of men in abortion decision-making. In the women’s narratives and the health service providers positioning of the women a ‘reproductive rights’ discourse was absent. This was significant as much of the activism around abortion has centred on the woman’s rights to her body. Where rights were mentioned, it was in reference to foetal rights (using cultural, moralistic religious understandings of abortion as killing). The missing ‘reproductive rights’ discourse points to a need to move from a reproductive rights framework to a reproductive justice framework that can be applied through local understandings of hunhu/ubuntu. By doing this, abortion is not seen as a ‘choice’ that a woman makes but rather as involving broader social and environmental circumstances that make a pregnancy ‘unsupportable’.
- Full Text:
Field evaluation of the use of select entomopathogenic fungal isolates as microbial control agents of the soil-dwelling life stages of a key South African citrus pest, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae)
- Authors: Coombes, Candice Anne
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/507 , vital:19965
- Description: The control of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick, 1912) (Lepidoptera: Tortricidae), in citrus orchards is strongly reliant on the use of integrated pest management as key export markets impose stringent chemical restrictions on exported fruit and have a strict no entry policy towards this phytosanitary pest. Most current, registered control methods target the above-ground life stages of FCM, not the soil-dwelling life stages. As such, entomopathogenic fungi which are ubiquitous, percutaneously infective soil-borne microbes that have been used successfully as control agents worldwide, present ideal candidates as additional control agents. Following an initial identification of 62 fungal entomopathogens isolated from soil collected from citrus orchards in the Eastern Cape Province, South Africa, further laboratory research has highlighted three isolates as having the greatest control potential against FCM subterranean life stages: Metarhizium anisopliae G 11 3 L6 (Ma1), M. anisopliae FCM Ar 23 B3 (Ma2) and Beauveria bassiana G Ar 17 B3 (Bb1). These isolates are capable of causing above 80% laboratory-induced mycosis of FCM fifth instars. Whether this level of efficacy was obtainable under sub-optimal and fluctuating field conditions was unknown. Thus, this thesis aimed to address the following issues with regards to the three most laboratory-virulent fungal isolates: field efficacy, field persistence, optimal application rate, application timing, environmental dependency, compatibility with fungicides and the use of different wetting agents to promote field efficacy. Following fungal application to one hectare treatment blocks in the field, FCM infestation within fruit was reduced by 28.3% to 81.7%. Isolate Bb1 performed best under moderate to high soil moisture whilst Ma2 was more effective under low soil moisture conditions. All isolates, with the exception of Ma2 at one site, were recorded in the soil five months post-application. None of the wetting agents tested were found to be highly toxic to fungal germination and similar physical suspension characteristics were observed. Fungicide toxicity varied amongst isolates and test conditions. However, only Dithane (a.i. mancozeb) was considered incompatible with isolate Ma2. The implication of these results and the way forward is discussed. This study is the first report of the field efficacy of three laboratory-virulent fungal isolates applied to the soil of conventional citrus orchards against FCM soil-dwelling life stages. As such, it provides a foundation on which future research can build to ensure the development and commercialisation of a cost-effective and consistently reliable product.
- Full Text:
- Authors: Coombes, Candice Anne
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/507 , vital:19965
- Description: The control of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick, 1912) (Lepidoptera: Tortricidae), in citrus orchards is strongly reliant on the use of integrated pest management as key export markets impose stringent chemical restrictions on exported fruit and have a strict no entry policy towards this phytosanitary pest. Most current, registered control methods target the above-ground life stages of FCM, not the soil-dwelling life stages. As such, entomopathogenic fungi which are ubiquitous, percutaneously infective soil-borne microbes that have been used successfully as control agents worldwide, present ideal candidates as additional control agents. Following an initial identification of 62 fungal entomopathogens isolated from soil collected from citrus orchards in the Eastern Cape Province, South Africa, further laboratory research has highlighted three isolates as having the greatest control potential against FCM subterranean life stages: Metarhizium anisopliae G 11 3 L6 (Ma1), M. anisopliae FCM Ar 23 B3 (Ma2) and Beauveria bassiana G Ar 17 B3 (Bb1). These isolates are capable of causing above 80% laboratory-induced mycosis of FCM fifth instars. Whether this level of efficacy was obtainable under sub-optimal and fluctuating field conditions was unknown. Thus, this thesis aimed to address the following issues with regards to the three most laboratory-virulent fungal isolates: field efficacy, field persistence, optimal application rate, application timing, environmental dependency, compatibility with fungicides and the use of different wetting agents to promote field efficacy. Following fungal application to one hectare treatment blocks in the field, FCM infestation within fruit was reduced by 28.3% to 81.7%. Isolate Bb1 performed best under moderate to high soil moisture whilst Ma2 was more effective under low soil moisture conditions. All isolates, with the exception of Ma2 at one site, were recorded in the soil five months post-application. None of the wetting agents tested were found to be highly toxic to fungal germination and similar physical suspension characteristics were observed. Fungicide toxicity varied amongst isolates and test conditions. However, only Dithane (a.i. mancozeb) was considered incompatible with isolate Ma2. The implication of these results and the way forward is discussed. This study is the first report of the field efficacy of three laboratory-virulent fungal isolates applied to the soil of conventional citrus orchards against FCM soil-dwelling life stages. As such, it provides a foundation on which future research can build to ensure the development and commercialisation of a cost-effective and consistently reliable product.
- Full Text:
The effect of shaped nanoparticles on the photophysicochemical behaviour of metallophthalocyanines
- Authors: D'Souza, Sarah
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/529 , vital:19967
- Description: The synthesis, spectroscopic characterization and photophysicochemical analysis of novel and known metallophthalocyanines are reported in this thesis. The novel lowsymmetry compounds were extensively studied. Selected phthalocyanines were conjugated to a variety of nanoparticles consisting of silver (AgNPs), gold (AuNPs) and zinc oxide (ZnO NPs) in order to improve their photophysical and photochemical behaviour. As with the phthalocyanines, the nanoparticles and phthalocyaninenanoparticle conjugates were thoroughly investigated. Research on the effect of the solvent used, as well as the influence of nanoparticle composition and shape on the properties of the phthalocyanines, were performed. The findings showed that there was a general increase in triplet quantum yields of the phthalocyanines in the presence of the nanoparticles. It was also noted that the use of different solvents directly affected the photophysicochemical properties. In the case of the nanoparticle conjugates, photophysical and photochemical changes were observed. Of significance were the gold nanostars, which decreased the degree of phthalocyanine aggregation in water, resulting in increased fluorescence lifetimes. The studies also revealed that the effect of the nanoparticle shape on the phthalocyanine properties was highly dependent on the nanoparticle material. The photodynamic antimicrobial activity of selected phthalocyanine-zinc oxide nanoparticle conjugates was investigated against Staphylococcus aureus (S. aureus) in solution. The phthalocyanines alone exhibited remarkable growth inhibition, however the presence of the nanoparticles in the conjugates increased the photoinactivation of S. aureus.
- Full Text:
- Authors: D'Souza, Sarah
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/529 , vital:19967
- Description: The synthesis, spectroscopic characterization and photophysicochemical analysis of novel and known metallophthalocyanines are reported in this thesis. The novel lowsymmetry compounds were extensively studied. Selected phthalocyanines were conjugated to a variety of nanoparticles consisting of silver (AgNPs), gold (AuNPs) and zinc oxide (ZnO NPs) in order to improve their photophysical and photochemical behaviour. As with the phthalocyanines, the nanoparticles and phthalocyaninenanoparticle conjugates were thoroughly investigated. Research on the effect of the solvent used, as well as the influence of nanoparticle composition and shape on the properties of the phthalocyanines, were performed. The findings showed that there was a general increase in triplet quantum yields of the phthalocyanines in the presence of the nanoparticles. It was also noted that the use of different solvents directly affected the photophysicochemical properties. In the case of the nanoparticle conjugates, photophysical and photochemical changes were observed. Of significance were the gold nanostars, which decreased the degree of phthalocyanine aggregation in water, resulting in increased fluorescence lifetimes. The studies also revealed that the effect of the nanoparticle shape on the phthalocyanine properties was highly dependent on the nanoparticle material. The photodynamic antimicrobial activity of selected phthalocyanine-zinc oxide nanoparticle conjugates was investigated against Staphylococcus aureus (S. aureus) in solution. The phthalocyanines alone exhibited remarkable growth inhibition, however the presence of the nanoparticles in the conjugates increased the photoinactivation of S. aureus.
- Full Text:
The effects of a gradual shift rotation and a split shift nap intervention on cognitive, physiological and subjective responses under simulated night shift settings
- Authors: Davy, Jonathan Patrick
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/517 , vital:19966
- Description: Introduction: Shift work, particularly work that occurs at night has been associated with numerous challenges to occupational safety and productivity. This stems from the associated extended wakefulness, circadian disruptions and sleep loss from the inversion of the sleep wake cycle, which predisposes shift workers to reduced alertness, increased fatigue and decrements in performance capacity. These effects may be exacerbated over consecutive night shifts as a result of reductions in sleep length associated with attempting to sleep against the alerting signals of the circadian rhythm during the day. Although a variety of shift work countermeasures exist, new and innovative fatigue management strategies are needed to mitigate the effects of night work. This study proposed two night shift interventions; the Rolling rotation and a split shift nap combination. Aims: The aim of this study was to explore the effects of these interventions to a conventional Fixed night shift arrangement. Selected performance, physiological and subjective measures were applied to track any effects during a five-day shift work study. Methods: The study was laboratory-based and performance was quantified through the application of computer-based perceptual, cognitive and motor tests. Student participants (24 females and 21 males) partook in the study, which adopted a nonrepeated measures design and spanned five consecutive days. During this time, participants were required to perform a simple beading task over five 8-hour shifts. Participants were split according to sex and chronotype between four independent conditions; 1. Fixed night condition required participants to complete one afternoon shift (14h00 – 22h00) and four consecutive night shifts (22h00 - 06h00) 2. Rolling rotation condition gradually “rolled” participants into the night shift by delaying the start and end of an afternoon shift by two hours each day (16h00 – 00h00, 18h00 – 02h00, 20h00 – 04h00, 22h00 – 06h00) until the times matched that of the Fixed night condition. 3. The split shift nap system was made up of two independent groups, both of which completed one afternoon (14h00 to 22h00) and four night shifts. The Nap early condition worked from 20h00 to 08h00, napping between 00h00 and 04h00, while the Nap late condition worked from 00h00 to 12h00 and napped between 04h00 and 08h00 during the night shifts. Napping, the opportunity for which was 200 minutes occurred in the laboratory, but post shift recovery sleep, for all conditions, happened outside the laboratory. During each shift, six test batteries were completed, in which the following measures were taken: 1. Performance: beading output, eye accommodation time, choice reaction time, visual vigilance, simple reaction time, processing speed and object recognition, working memory, motor response time and tracking performance. 2. Physiological: heart rate, heart rate variability (r-MSSD, normalised Low frequency power: LFnu). 3. Self-reported measures: subjective sleepiness and reported sleep length and quality while outside the laboratory. Results: Analyses revealed that: 1. Measures of beading performance, simple reaction time, vigilance and object recognition, working memory, motor response time and control, all physiological measures, except LFnu and subjective sleepiness demonstrated the effects of time of day / fatigue, irrespective of condition. 2. There was no evidence of cumulative fatigue over the four night shifts in the performance and subjective measures and most of the physiological indicators. Beading output decreased significantly over the course of the night shifts, while reported post shift sleep length was significantly reduced with the start of the night shifts, irrespective of condition. 3. The majority of the physiological and performance measures did not differ significantly between conditions. However, there were some effects: the Rolling rotation condition produced the highest beading output compared to the Nap late condition; working memory was significantly lower in the Nap late condition compared to the other conditions. Furthermore, the nap opportunity in both the Nap early and Nap late conditions reduced subjective sleepiness, while napping during the night shift reduced post shift sleep length compared to the Rolling rotation and Fixed night conditions. There was also evidence of sleep inertia following pre-post nap test comparisons, which mainly affected visual perception tasks in both nap conditions. Sleep inertia possibly also accounted for an apparent dissociation between subjective and performance measures. Conclusions: Quantifying and interpreting the effects of night shift work in a laboratory setting has limitations. These stem mainly from the limited ecological validity of the performance outcome measures adopted and the characteristics of the sample that is tested. However, in order to fully understand the efficacy of any shift work countermeasure, the laboratory setting offers a safe, controlled environment in which to do so. The conclusions should thus be considered in light of these limitations. Night shift work negatively affected all elements of human information processing. The combination of reduced physiological arousal, extended wakefulness, increased perceptions of sleepiness and reduced total sleep obtained explained these decrements in performance. While cumulative fatigue has been reported as a challenge associated with night shift work, there was no conclusive evidence of this in the current study. In the case of the Rolling rotation, the gradual introduction to the night shift delayed the inevitable reduction in alertness and performance, which limits the viability of this intervention. The inclusion of the nap interventions was associated with reduced perceptions of sleepiness, which did not translate into improved performance, relative to the Rolling rotation and Fixed night conditions. Apart from considerations of how to manage sleep inertia post nap, the split shift nap intervention can provide an alternative to conventional night shift work arrangements.
- Full Text:
- Authors: Davy, Jonathan Patrick
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/517 , vital:19966
- Description: Introduction: Shift work, particularly work that occurs at night has been associated with numerous challenges to occupational safety and productivity. This stems from the associated extended wakefulness, circadian disruptions and sleep loss from the inversion of the sleep wake cycle, which predisposes shift workers to reduced alertness, increased fatigue and decrements in performance capacity. These effects may be exacerbated over consecutive night shifts as a result of reductions in sleep length associated with attempting to sleep against the alerting signals of the circadian rhythm during the day. Although a variety of shift work countermeasures exist, new and innovative fatigue management strategies are needed to mitigate the effects of night work. This study proposed two night shift interventions; the Rolling rotation and a split shift nap combination. Aims: The aim of this study was to explore the effects of these interventions to a conventional Fixed night shift arrangement. Selected performance, physiological and subjective measures were applied to track any effects during a five-day shift work study. Methods: The study was laboratory-based and performance was quantified through the application of computer-based perceptual, cognitive and motor tests. Student participants (24 females and 21 males) partook in the study, which adopted a nonrepeated measures design and spanned five consecutive days. During this time, participants were required to perform a simple beading task over five 8-hour shifts. Participants were split according to sex and chronotype between four independent conditions; 1. Fixed night condition required participants to complete one afternoon shift (14h00 – 22h00) and four consecutive night shifts (22h00 - 06h00) 2. Rolling rotation condition gradually “rolled” participants into the night shift by delaying the start and end of an afternoon shift by two hours each day (16h00 – 00h00, 18h00 – 02h00, 20h00 – 04h00, 22h00 – 06h00) until the times matched that of the Fixed night condition. 3. The split shift nap system was made up of two independent groups, both of which completed one afternoon (14h00 to 22h00) and four night shifts. The Nap early condition worked from 20h00 to 08h00, napping between 00h00 and 04h00, while the Nap late condition worked from 00h00 to 12h00 and napped between 04h00 and 08h00 during the night shifts. Napping, the opportunity for which was 200 minutes occurred in the laboratory, but post shift recovery sleep, for all conditions, happened outside the laboratory. During each shift, six test batteries were completed, in which the following measures were taken: 1. Performance: beading output, eye accommodation time, choice reaction time, visual vigilance, simple reaction time, processing speed and object recognition, working memory, motor response time and tracking performance. 2. Physiological: heart rate, heart rate variability (r-MSSD, normalised Low frequency power: LFnu). 3. Self-reported measures: subjective sleepiness and reported sleep length and quality while outside the laboratory. Results: Analyses revealed that: 1. Measures of beading performance, simple reaction time, vigilance and object recognition, working memory, motor response time and control, all physiological measures, except LFnu and subjective sleepiness demonstrated the effects of time of day / fatigue, irrespective of condition. 2. There was no evidence of cumulative fatigue over the four night shifts in the performance and subjective measures and most of the physiological indicators. Beading output decreased significantly over the course of the night shifts, while reported post shift sleep length was significantly reduced with the start of the night shifts, irrespective of condition. 3. The majority of the physiological and performance measures did not differ significantly between conditions. However, there were some effects: the Rolling rotation condition produced the highest beading output compared to the Nap late condition; working memory was significantly lower in the Nap late condition compared to the other conditions. Furthermore, the nap opportunity in both the Nap early and Nap late conditions reduced subjective sleepiness, while napping during the night shift reduced post shift sleep length compared to the Rolling rotation and Fixed night conditions. There was also evidence of sleep inertia following pre-post nap test comparisons, which mainly affected visual perception tasks in both nap conditions. Sleep inertia possibly also accounted for an apparent dissociation between subjective and performance measures. Conclusions: Quantifying and interpreting the effects of night shift work in a laboratory setting has limitations. These stem mainly from the limited ecological validity of the performance outcome measures adopted and the characteristics of the sample that is tested. However, in order to fully understand the efficacy of any shift work countermeasure, the laboratory setting offers a safe, controlled environment in which to do so. The conclusions should thus be considered in light of these limitations. Night shift work negatively affected all elements of human information processing. The combination of reduced physiological arousal, extended wakefulness, increased perceptions of sleepiness and reduced total sleep obtained explained these decrements in performance. While cumulative fatigue has been reported as a challenge associated with night shift work, there was no conclusive evidence of this in the current study. In the case of the Rolling rotation, the gradual introduction to the night shift delayed the inevitable reduction in alertness and performance, which limits the viability of this intervention. The inclusion of the nap interventions was associated with reduced perceptions of sleepiness, which did not translate into improved performance, relative to the Rolling rotation and Fixed night conditions. Apart from considerations of how to manage sleep inertia post nap, the split shift nap intervention can provide an alternative to conventional night shift work arrangements.
- Full Text:
The development of a discovery and control environment for networked audio devices based on a study of current audio control protocols
- Authors: Eales, Andrew Arnold
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/539 , vital:19968
- Description: This dissertation develops a standard device model for networked audio devices and introduces a novel discovery and control environment that uses the developed device model. The proposed standard device model is derived from a study of current audio control protocols. Both the functional capabilities and design principles of audio control protocols are investigated with an emphasis on Open Sound Control, SNMP and IEC-62379, AES64, CopperLan and UPnP. An abstract model of networked audio devices is developed, and the model is implemented in each of the previously mentioned control protocols. This model is also used within a novel discovery and control environment designed around a distributed associative memory termed an object space. This environment challenges the accepted notions of the functionality provided by a control protocol. The study concludes by comparing the salient features of the different control protocols encountered in this study. Different approaches to control protocol design are considered, and several design heuristics for control protocols are proposed.
- Full Text:
- Authors: Eales, Andrew Arnold
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/539 , vital:19968
- Description: This dissertation develops a standard device model for networked audio devices and introduces a novel discovery and control environment that uses the developed device model. The proposed standard device model is derived from a study of current audio control protocols. Both the functional capabilities and design principles of audio control protocols are investigated with an emphasis on Open Sound Control, SNMP and IEC-62379, AES64, CopperLan and UPnP. An abstract model of networked audio devices is developed, and the model is implemented in each of the previously mentioned control protocols. This model is also used within a novel discovery and control environment designed around a distributed associative memory termed an object space. This environment challenges the accepted notions of the functionality provided by a control protocol. The study concludes by comparing the salient features of the different control protocols encountered in this study. Different approaches to control protocol design are considered, and several design heuristics for control protocols are proposed.
- Full Text:
Epistemological access in a science foundation course: a social realist perspective
- Authors: Ellery, Karen
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1335 , http://hdl.handle.net/10962/d1021309
- Description: This dissertation examines how educational practices of a multidisciplinary, integrated science foundation course, Introduction to Science Concepts and Methods (ISCM), at Rhodes University in South Africa, enable and/or constrain epistemological access to a range of mainstream science disciplines. Students in the ISCM course are mainly African, working-class, first-generation higher education learners whose home language is seldom English. This study is motivated firstly by poor success of working-class African students in higher education in South Africa in general and in the sciences in particular, and secondly by the need for closely theorised, empirical work to guide necessary transformational change that will contribute to equity and, thus, to greater social justice. Since I teach in ISCM and coordinate the programme in which it is located, I also have a personal and professional interest in improving my own practice. Conceptually the study draws on Morrow’s (2007, 2009) and various literacy theorists interpretations of the concept of epistemological access, which in this study is about becoming and being a participant in an academic practice by virtue of learning both the knowledge as well as the norms, values and beliefs that constitute the practice. Theoretically and analytically the study draws on Maton’s (2014a) Legitimation Code Theory (LCT) and on various aspects of Bernstein’s (2000) code theory work. Codes are the organising principles or ‘rules of the game’ of practices and code theory is premised on the idea that power and control in education systems manifest themselves through the structural and interactional aspects of educational practices, and therefore have the capacity to include or exclude. Analysing educational practices using code theory enables characterisation of the practices, highlights their underpinning principles, and allows for their effects to be considered. This layered approach to analysis indicates that a critical realist depth ontology serves as an underlabourer to code theory. The desired ‘effect’ of educational practices in this study, is students gaining epistemological access to science, or science disciplines, in higher education. The overall approach is a single, in-depth, qualitative case study with a primary focus on what is legitimated in ISCM educational practices (curriculum, pedagogy, assessment) and how students respond to these practices. A lesser focus is how ex-ISCM students are responding to educational practices in the first-year, first-semester Cell Biology, Chemistry, Earth Sciences and Physics mainstream courses, and whether they are attaining epistemological access. To examine educational practices in ISCM and mainstream courses data from document analysis, interviews, observations and critical reflections are analysed through developing external languages of description. The two LCT code dimensions of Specialisation (what or who specialises a practice) and Semantics (how meaning relates to context and empirical referents) are used to examine curriculum, Bernstein’s (2000) framing of the regulative and instructional discourses are drawn on in considering pedagogy, and an adapted cognitive process level model assists in analysing assessment practices. To examine student responses to educational practices Bernstein’s (ibid.) concept of acquisition of recognition and realisation rules is used. Since ISCM serves the dual purpose of developing scientific conceptual knowledge, as well as supporting student learning in an academic context, a complex picture of practices and underpinning codes emerges. Based on epistemological concerns of developing students as scientists, ISCM legitimates an epistemic-context knowledge code and a rhizomatic/worldly curriculum code. If students produce the legitimated epistemic-context scientific ‘text’, they have attained epistemic access. Based on axiological concerns of the learning context, ISCM also legitimates a learning-context knower code. By producing the legitimate learning-context ‘text’ of an autonomous, self-regulated science learner, students demonstrate they have attained learning-context access. Both forms of access are key for student success, and combined they constitute epistemological access. The findings of the study indicate that framing and legitimation of educational practices in ISCM, by most accounts, should be promoting epistemological access. When epistemological access is not attained in ISCM it is suggested this is likely due to both a code clash at the learning-context level and competing code demands between epistemic-context and learning-context concerns. Poor access in mainstream courses appears to be exacerbated by both a narrow-based knowledge code and little or no support for a learning-context knower code. The study concludes by outlining a two-tiered conceptual model of epistemological access in the sciences based on the mutually integrative components of epistemic- and learning-context access. Because of inequitable outcomes in science mainstream courses at Rhodes University based on race and/or class I argue for far-reaching transformative pedagogies throughout the faculty, and in the broader South African science higher education sector, that address and accommodate issues of diversity and difference. This should include, amongst other things, a weakening of epistemic relations to create space for a strengthening of learning-context social relations. This is not a suggestion to move away from a science knowledge code, which I argue is based on powerful knowledge to which all students must gain access, but instead a shift in emphasis to better support previously educationally disenfranchised students and to understand in a more rigorous manner what epistemological access means to them as individuals. In light of the recent disruptive and angry student calls for decolonisation of the curriculum, this is an urgent imperative.
- Full Text:
- Authors: Ellery, Karen
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1335 , http://hdl.handle.net/10962/d1021309
- Description: This dissertation examines how educational practices of a multidisciplinary, integrated science foundation course, Introduction to Science Concepts and Methods (ISCM), at Rhodes University in South Africa, enable and/or constrain epistemological access to a range of mainstream science disciplines. Students in the ISCM course are mainly African, working-class, first-generation higher education learners whose home language is seldom English. This study is motivated firstly by poor success of working-class African students in higher education in South Africa in general and in the sciences in particular, and secondly by the need for closely theorised, empirical work to guide necessary transformational change that will contribute to equity and, thus, to greater social justice. Since I teach in ISCM and coordinate the programme in which it is located, I also have a personal and professional interest in improving my own practice. Conceptually the study draws on Morrow’s (2007, 2009) and various literacy theorists interpretations of the concept of epistemological access, which in this study is about becoming and being a participant in an academic practice by virtue of learning both the knowledge as well as the norms, values and beliefs that constitute the practice. Theoretically and analytically the study draws on Maton’s (2014a) Legitimation Code Theory (LCT) and on various aspects of Bernstein’s (2000) code theory work. Codes are the organising principles or ‘rules of the game’ of practices and code theory is premised on the idea that power and control in education systems manifest themselves through the structural and interactional aspects of educational practices, and therefore have the capacity to include or exclude. Analysing educational practices using code theory enables characterisation of the practices, highlights their underpinning principles, and allows for their effects to be considered. This layered approach to analysis indicates that a critical realist depth ontology serves as an underlabourer to code theory. The desired ‘effect’ of educational practices in this study, is students gaining epistemological access to science, or science disciplines, in higher education. The overall approach is a single, in-depth, qualitative case study with a primary focus on what is legitimated in ISCM educational practices (curriculum, pedagogy, assessment) and how students respond to these practices. A lesser focus is how ex-ISCM students are responding to educational practices in the first-year, first-semester Cell Biology, Chemistry, Earth Sciences and Physics mainstream courses, and whether they are attaining epistemological access. To examine educational practices in ISCM and mainstream courses data from document analysis, interviews, observations and critical reflections are analysed through developing external languages of description. The two LCT code dimensions of Specialisation (what or who specialises a practice) and Semantics (how meaning relates to context and empirical referents) are used to examine curriculum, Bernstein’s (2000) framing of the regulative and instructional discourses are drawn on in considering pedagogy, and an adapted cognitive process level model assists in analysing assessment practices. To examine student responses to educational practices Bernstein’s (ibid.) concept of acquisition of recognition and realisation rules is used. Since ISCM serves the dual purpose of developing scientific conceptual knowledge, as well as supporting student learning in an academic context, a complex picture of practices and underpinning codes emerges. Based on epistemological concerns of developing students as scientists, ISCM legitimates an epistemic-context knowledge code and a rhizomatic/worldly curriculum code. If students produce the legitimated epistemic-context scientific ‘text’, they have attained epistemic access. Based on axiological concerns of the learning context, ISCM also legitimates a learning-context knower code. By producing the legitimate learning-context ‘text’ of an autonomous, self-regulated science learner, students demonstrate they have attained learning-context access. Both forms of access are key for student success, and combined they constitute epistemological access. The findings of the study indicate that framing and legitimation of educational practices in ISCM, by most accounts, should be promoting epistemological access. When epistemological access is not attained in ISCM it is suggested this is likely due to both a code clash at the learning-context level and competing code demands between epistemic-context and learning-context concerns. Poor access in mainstream courses appears to be exacerbated by both a narrow-based knowledge code and little or no support for a learning-context knower code. The study concludes by outlining a two-tiered conceptual model of epistemological access in the sciences based on the mutually integrative components of epistemic- and learning-context access. Because of inequitable outcomes in science mainstream courses at Rhodes University based on race and/or class I argue for far-reaching transformative pedagogies throughout the faculty, and in the broader South African science higher education sector, that address and accommodate issues of diversity and difference. This should include, amongst other things, a weakening of epistemic relations to create space for a strengthening of learning-context social relations. This is not a suggestion to move away from a science knowledge code, which I argue is based on powerful knowledge to which all students must gain access, but instead a shift in emphasis to better support previously educationally disenfranchised students and to understand in a more rigorous manner what epistemological access means to them as individuals. In light of the recent disruptive and angry student calls for decolonisation of the curriculum, this is an urgent imperative.
- Full Text:
The influence of introduced forest management practices on transformative social learning in a selected social-ecological forest community : a case of PFM and REDD projects at Pugu and Kazimzumbwi Forest Reserves in Tanzania
- Authors: Ferdinand, Victoria Ugulumu
- Date: 2016
- Subjects: Forest management -- Tanzania , Forest reserves -- Tanzania , Transformative learning , Social ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2064 , http://hdl.handle.net/10962/d1020333
- Description: This research investigates the influence of introduced forest management approaches on transformative social learning in the community surrounding the Pugu and Kazimzumbwi forest reserves in Tanzania from 2000 to 2015. The term transformative social learning reflects an understanding of learning processes that emerge through conscious changes in the perspectives of individuals or communities while interacting with forest management practices. The investigation explores the learning (if any) that occurred in the community and how and why the learning occurred. It also explores whether the learning was social and transformative and examines the conditions that enable or constrain transformative social learning at the Pugu and Kazimzumbwi community. Thus, the three concepts of social learning, transformative learning, and social practices are central to the research. Participatory Forest Management (PFM) emerged globally in the early 1980s to mobilise rural capabilities and resources in development and environmental stewardship. The Pugu and Kazimzumbwi community was introduced to Participatory Forest Management (PFM) projects by the late 1990s. The recent global focus on empowering communities around forests has drawn attention towards transformational adaptation to climate change impacts and building resilience capacities. As a result, in 2011 the Pugu and Kazimzumbwi community started working with a project for Reduction of Emissions through Deforestation and forest Degradation (REDD), which forms a key focus in this study as the most recently introduced PFM with embedded social learning assumptions. This research is designed and conducted as a qualitative case study. The research seeks to study the complex object of socially and contextually constructed learning through a systemic exploration of learning,using semi-structured interviews, focus group discussions, analysis of documents and archival records as well as observations and a reflexive workshop. Supportive information throughfield notes and audio voice and video recording was also generated. A contextual profile of the research site was conducted in March 2012, prior to the actual data collection in 2013 and 2014. Field explorations during the contextual profile helped to describe the research site and promote initial understanding of the context. During data collection, field inquiries based on interactive relationships between a researcher and participants stimulated practice memories and people’s living experiences with forestry and the introduced PFM projects under examination. Analysis of data employed analytical modes of induction, abduction and retroduction. Thick descriptions of learning obtained from fieldi based interactionswere produced before re-contextualising data through theoretical lenses. The research employed realist social theory by Archer (1995), under-laboured by critical realism, and practice theory advanced by Schatzki (2012) and Kemmis et al. (2014). The research process as a whole was underlaboured by the layered ontology of critical realism which proposes emergence of phenomena in open systems as shaped by interacting mechanisms which in this study were both material / ecological and social /political /economic /cultural. And more...
- Full Text:
- Authors: Ferdinand, Victoria Ugulumu
- Date: 2016
- Subjects: Forest management -- Tanzania , Forest reserves -- Tanzania , Transformative learning , Social ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2064 , http://hdl.handle.net/10962/d1020333
- Description: This research investigates the influence of introduced forest management approaches on transformative social learning in the community surrounding the Pugu and Kazimzumbwi forest reserves in Tanzania from 2000 to 2015. The term transformative social learning reflects an understanding of learning processes that emerge through conscious changes in the perspectives of individuals or communities while interacting with forest management practices. The investigation explores the learning (if any) that occurred in the community and how and why the learning occurred. It also explores whether the learning was social and transformative and examines the conditions that enable or constrain transformative social learning at the Pugu and Kazimzumbwi community. Thus, the three concepts of social learning, transformative learning, and social practices are central to the research. Participatory Forest Management (PFM) emerged globally in the early 1980s to mobilise rural capabilities and resources in development and environmental stewardship. The Pugu and Kazimzumbwi community was introduced to Participatory Forest Management (PFM) projects by the late 1990s. The recent global focus on empowering communities around forests has drawn attention towards transformational adaptation to climate change impacts and building resilience capacities. As a result, in 2011 the Pugu and Kazimzumbwi community started working with a project for Reduction of Emissions through Deforestation and forest Degradation (REDD), which forms a key focus in this study as the most recently introduced PFM with embedded social learning assumptions. This research is designed and conducted as a qualitative case study. The research seeks to study the complex object of socially and contextually constructed learning through a systemic exploration of learning,using semi-structured interviews, focus group discussions, analysis of documents and archival records as well as observations and a reflexive workshop. Supportive information throughfield notes and audio voice and video recording was also generated. A contextual profile of the research site was conducted in March 2012, prior to the actual data collection in 2013 and 2014. Field explorations during the contextual profile helped to describe the research site and promote initial understanding of the context. During data collection, field inquiries based on interactive relationships between a researcher and participants stimulated practice memories and people’s living experiences with forestry and the introduced PFM projects under examination. Analysis of data employed analytical modes of induction, abduction and retroduction. Thick descriptions of learning obtained from fieldi based interactionswere produced before re-contextualising data through theoretical lenses. The research employed realist social theory by Archer (1995), under-laboured by critical realism, and practice theory advanced by Schatzki (2012) and Kemmis et al. (2014). The research process as a whole was underlaboured by the layered ontology of critical realism which proposes emergence of phenomena in open systems as shaped by interacting mechanisms which in this study were both material / ecological and social /political /economic /cultural. And more...
- Full Text:
Shifting identities: An exploration of the possibilities for a syncretic Afrikaans theatre by means of three case studies – Hex (2003), Lady Anne (2007), Ekspedisies (2008)
- Authors: Gehring, Heike
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2165 , http://hdl.handle.net/10962/d1021269
- Description: This thesis investigates the possibilities for syncretic Afrikaans language theatre within a post-1994 South African society. The research sets out to explore in what manner theatre can be language-specific, while at the same time being able to cross language contexts. This exploration is driven by the wish to develop strategies for creating Afrikaans theatre that is able to reflect on a society “united in diversity”. In this regard it is argued that for theatre to be able to both retain and cross language barriers, processes of bonding and bridging are necessary. The thesis sets out first to explain why these processes are required and then to suggest ways in which such processes can be implemented in practice. A triangular approach is used, in which conceptual and theoretical frameworks are developed to reflect on actual theatre practices. Three of my own productions are used as case studies, namely Hex (2000; 2003), Lady Anne (2007) and Ekspedisies (2008). These productions can be understood to be “boundary objects” in Henk Borgdorff’s (2012: 177) sense of the word, in that they fulfil a dual function: they are artistic productions that can also be reconstituted to serve a research purpose beyond the productions themselves. All three works were first created for public consumption before becoming cases for this thesis. Many of the strategies that were developed and tested in creating these productions are examples of ways in which bonding and bridging in Afrikaans language theatre can be understood. Chapter One of the thesis contextualises the political currents and events that necessitated the impulse towards “bonding and bridging”. In this case the political and ethical impetus behind the practical explorations has been related predominantly to the democratisation of South African society, in which a paradigm shift happened from viewing the Afrikaans language as one over many to one amongst many. Within a multilingual South Africa, concerns are raised about ways in which to create theatre in South African languages other than English (often understood to be the only possible bridging language) that are able to cross language divides. Following this introduction to language-related concerns, Chapter Two explains how the shift from apartheid to democracy made space for shifts in identity – on personal as well as institutional levels: a progression from essentialised notions of culture to the celebration of plurality. This progression is then related to theatre, with an explanation of how the post-1994 theatre landscape demanded a reimagining of the form and function of theatre. In this re-imagination the notion of a “third space” is important; something that is introduced in this chapter as an alternative to polarised identity constructions. The function of the “third space” as an in-between space and a meeting point for diverse people and entities is a strong underlying theme of this thesis and it serves as a reoccurring touchstone to the ideas put forward. Chapter Three discusses the South African arts festival culture and its contribution to the South African theatre landscape. Particular focus is placed on the Klein Karoo National Arts festival (KKNK) as a platform for the development of the Afrikaans language within a post-1994 context. What is emphasized in particular is the attempt by the KKNK festival to be linguistically and culturally exploratory and inclusive in the face of language protectionism. After the contextual background of the first three chapters, the thesis shifts to an analysis of theories related to “hybridity” and “syncretism”. In Chapter Four the argument is put forward that of the various inclusive performance and theatre models that represent a multicultural society, the most responsive forms are those that are syncretic and hybrid. Principles that can contribute to the unification and merging of diverse and polarized societal groups are described, and suggestions are made for possible ways to bring about bonding and bridging within cultural practices. Having introduced these principles, examples are offered of how these theories might be understood in other disciplines, namely, religious studies, anthropology, history and a range of cultural practices. Following this broad discussion, Chapter Five describes syncretism and hybridity more specifically in theatre by means of relevant examples. Taking the discussion further into the realm of application, Chapter Six offers an overview of “workshop theatre”, “translation” and “collage making” as strategies for putting theories of hybridity and syncretism into practice. This is followed (in Chapters Seven, Eight and Nine) by a discussion of the three productions (Hex, Lady Anne and Ekspedisies) as case studies that demonstrate how these theories can be understood in practice. Practical strategies for bridging language divides are foregrounded, such as code switching as an approach for enabling a “co-habitation” of languages; physical theatre as a means for crossing language divides; and the creation of more than one language version of a production as a tactic to accommodate shifting contexts. Following on from the discoveries made in the foregoing chapters, I conclude that theories and practices related to notions of “third space”, “hybridity” and “syncretism” are ideal for creating theatre forms (in the Afrikaans language in particular) that can truly reflect a South African society which is “united in diversity”. The thesis ends by offering suggestions for ways in which new, future identities, can be developed.
- Full Text:
- Authors: Gehring, Heike
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2165 , http://hdl.handle.net/10962/d1021269
- Description: This thesis investigates the possibilities for syncretic Afrikaans language theatre within a post-1994 South African society. The research sets out to explore in what manner theatre can be language-specific, while at the same time being able to cross language contexts. This exploration is driven by the wish to develop strategies for creating Afrikaans theatre that is able to reflect on a society “united in diversity”. In this regard it is argued that for theatre to be able to both retain and cross language barriers, processes of bonding and bridging are necessary. The thesis sets out first to explain why these processes are required and then to suggest ways in which such processes can be implemented in practice. A triangular approach is used, in which conceptual and theoretical frameworks are developed to reflect on actual theatre practices. Three of my own productions are used as case studies, namely Hex (2000; 2003), Lady Anne (2007) and Ekspedisies (2008). These productions can be understood to be “boundary objects” in Henk Borgdorff’s (2012: 177) sense of the word, in that they fulfil a dual function: they are artistic productions that can also be reconstituted to serve a research purpose beyond the productions themselves. All three works were first created for public consumption before becoming cases for this thesis. Many of the strategies that were developed and tested in creating these productions are examples of ways in which bonding and bridging in Afrikaans language theatre can be understood. Chapter One of the thesis contextualises the political currents and events that necessitated the impulse towards “bonding and bridging”. In this case the political and ethical impetus behind the practical explorations has been related predominantly to the democratisation of South African society, in which a paradigm shift happened from viewing the Afrikaans language as one over many to one amongst many. Within a multilingual South Africa, concerns are raised about ways in which to create theatre in South African languages other than English (often understood to be the only possible bridging language) that are able to cross language divides. Following this introduction to language-related concerns, Chapter Two explains how the shift from apartheid to democracy made space for shifts in identity – on personal as well as institutional levels: a progression from essentialised notions of culture to the celebration of plurality. This progression is then related to theatre, with an explanation of how the post-1994 theatre landscape demanded a reimagining of the form and function of theatre. In this re-imagination the notion of a “third space” is important; something that is introduced in this chapter as an alternative to polarised identity constructions. The function of the “third space” as an in-between space and a meeting point for diverse people and entities is a strong underlying theme of this thesis and it serves as a reoccurring touchstone to the ideas put forward. Chapter Three discusses the South African arts festival culture and its contribution to the South African theatre landscape. Particular focus is placed on the Klein Karoo National Arts festival (KKNK) as a platform for the development of the Afrikaans language within a post-1994 context. What is emphasized in particular is the attempt by the KKNK festival to be linguistically and culturally exploratory and inclusive in the face of language protectionism. After the contextual background of the first three chapters, the thesis shifts to an analysis of theories related to “hybridity” and “syncretism”. In Chapter Four the argument is put forward that of the various inclusive performance and theatre models that represent a multicultural society, the most responsive forms are those that are syncretic and hybrid. Principles that can contribute to the unification and merging of diverse and polarized societal groups are described, and suggestions are made for possible ways to bring about bonding and bridging within cultural practices. Having introduced these principles, examples are offered of how these theories might be understood in other disciplines, namely, religious studies, anthropology, history and a range of cultural practices. Following this broad discussion, Chapter Five describes syncretism and hybridity more specifically in theatre by means of relevant examples. Taking the discussion further into the realm of application, Chapter Six offers an overview of “workshop theatre”, “translation” and “collage making” as strategies for putting theories of hybridity and syncretism into practice. This is followed (in Chapters Seven, Eight and Nine) by a discussion of the three productions (Hex, Lady Anne and Ekspedisies) as case studies that demonstrate how these theories can be understood in practice. Practical strategies for bridging language divides are foregrounded, such as code switching as an approach for enabling a “co-habitation” of languages; physical theatre as a means for crossing language divides; and the creation of more than one language version of a production as a tactic to accommodate shifting contexts. Following on from the discoveries made in the foregoing chapters, I conclude that theories and practices related to notions of “third space”, “hybridity” and “syncretism” are ideal for creating theatre forms (in the Afrikaans language in particular) that can truly reflect a South African society which is “united in diversity”. The thesis ends by offering suggestions for ways in which new, future identities, can be developed.
- Full Text:
The knowledge-knower structures used in the assessment of graphic design practical work in a multi-campus context
- Authors: Giloi, Susan Louise
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1336 , http://hdl.handle.net/10962/d1021310
- Description: This case study explicates the knowledge-knower structures that are valued in the assessment of Graphic Design (GD) practical work in a multi-campus Private Higher Education (PHE) context. Assessment, which provides the measure for student success and progression, plays a significant role in Higher Education (HE). It is acknowledged that, in addition to increased pressure on educators to deliver high pass and throughput rates, there is often scrutiny of their assessment practice to ensure that it is fair, reliable, valid and transparent. The aspects of reliability and validity are particularly significant in for-profit private higher education institutions, where a strong focus on efficiency may result in added scrutiny of assessment practices. Although the assessment of GD practical work exemplifies these pressures and objectives, its characteristics and practices set it apart from many of the more standard forms of assessment found in HE. Not only is GD practical work predominantly visual rather than text-based, but complex achievements and tacit knowledge are assessed. This form of assessment traditionally relies on panel or group marking by connoisseurs who consider what is commonly termed ‘person’, ‘process’ and ‘product’ when making value judgements. Therefore, in GD assessment knowledge, the design product, the graphic designer and what the graphic designer does may all be valued. GD assessment, where outcomes are not easily stated, relies on the tacit expertise of assessors and can often be perceived to be subjective and unreliable. It therefore sits uncomfortably with results-driven HE and institutional priorities. In light of this context and the complex and social nature of GD assessment, a critical realist approach provided the guiding metatheory for this case study. Critical realism considers the unseen but real mechanisms that exist and interact within a context to create a phenomenon such as an assessment practice. In this case study the knowledge-structuring theories of Basil Bernstein and Karl Maton were used to uncover these mechanisms. Bernstein and Maton propose that new knowledge, the curriculum and pedagogy, which includes assessment, communicate the valued disciplinary knowledge and who controls these communications. For this study the institutional documents and voices of assessors provided insight into the GD assessment practice; data was generated through a lecturer survey, the study guides and assessor conversations at both the formative and summative assessment stages. Given the significance of both knowledge and expertise in GD, Specialisation, one of the Legitimation Code Theory (LCT) dimensions, provided the conceptual tool whereby the generated data were analysed and categorised, and the underlying valued knowledge-knower structures, or specialisation codes, were identified. The identified specialisation codes revealed a number of code clashes, matches and shifts, which highlighted instances of mixed or conflicting communication regarding what was valued and used in GD assessment. These clashes, matches and shifts have significant implications for curriculum design, pedagogy and assessment. As a result the findings may have relevance for students, lecturers and assessors who work in practice-based fields which require the assessment of complex achievements and rely on a specialised gaze to judge standards. Informed by the findings of this study, I argue that there is a fundamental conflict between what is valued within the broader national South African Higher Education system and Private Higher Education institutional context, and the nature of GD assessment. The broader structures, guided by a techno-rationalist approach to assessment and the pressures of massification, success, compliance and institutional efficiencies, value explicitly-stated outcomes and criteria, propositional knowledge and a positivist ideal of one correct mark for any one assessment, while the GD assessment practice values the more social and tacit elements of procedural knowledge and a specialist knower as evidenced in a largely tacit GD gaze that assessors possess and students aim to develop. The uncovering of the knowledge-knower structures used in GD assessment has the potential to make the assessed gaze more explicit to lecturers, assessors and ultimately to students. My findings offer a deeper understanding of the assessment of knower code disciplines which require a specialist gaze for the judgement of student work, and the pressures experienced in this type of assessment in a HE context.
- Full Text:
- Authors: Giloi, Susan Louise
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1336 , http://hdl.handle.net/10962/d1021310
- Description: This case study explicates the knowledge-knower structures that are valued in the assessment of Graphic Design (GD) practical work in a multi-campus Private Higher Education (PHE) context. Assessment, which provides the measure for student success and progression, plays a significant role in Higher Education (HE). It is acknowledged that, in addition to increased pressure on educators to deliver high pass and throughput rates, there is often scrutiny of their assessment practice to ensure that it is fair, reliable, valid and transparent. The aspects of reliability and validity are particularly significant in for-profit private higher education institutions, where a strong focus on efficiency may result in added scrutiny of assessment practices. Although the assessment of GD practical work exemplifies these pressures and objectives, its characteristics and practices set it apart from many of the more standard forms of assessment found in HE. Not only is GD practical work predominantly visual rather than text-based, but complex achievements and tacit knowledge are assessed. This form of assessment traditionally relies on panel or group marking by connoisseurs who consider what is commonly termed ‘person’, ‘process’ and ‘product’ when making value judgements. Therefore, in GD assessment knowledge, the design product, the graphic designer and what the graphic designer does may all be valued. GD assessment, where outcomes are not easily stated, relies on the tacit expertise of assessors and can often be perceived to be subjective and unreliable. It therefore sits uncomfortably with results-driven HE and institutional priorities. In light of this context and the complex and social nature of GD assessment, a critical realist approach provided the guiding metatheory for this case study. Critical realism considers the unseen but real mechanisms that exist and interact within a context to create a phenomenon such as an assessment practice. In this case study the knowledge-structuring theories of Basil Bernstein and Karl Maton were used to uncover these mechanisms. Bernstein and Maton propose that new knowledge, the curriculum and pedagogy, which includes assessment, communicate the valued disciplinary knowledge and who controls these communications. For this study the institutional documents and voices of assessors provided insight into the GD assessment practice; data was generated through a lecturer survey, the study guides and assessor conversations at both the formative and summative assessment stages. Given the significance of both knowledge and expertise in GD, Specialisation, one of the Legitimation Code Theory (LCT) dimensions, provided the conceptual tool whereby the generated data were analysed and categorised, and the underlying valued knowledge-knower structures, or specialisation codes, were identified. The identified specialisation codes revealed a number of code clashes, matches and shifts, which highlighted instances of mixed or conflicting communication regarding what was valued and used in GD assessment. These clashes, matches and shifts have significant implications for curriculum design, pedagogy and assessment. As a result the findings may have relevance for students, lecturers and assessors who work in practice-based fields which require the assessment of complex achievements and rely on a specialised gaze to judge standards. Informed by the findings of this study, I argue that there is a fundamental conflict between what is valued within the broader national South African Higher Education system and Private Higher Education institutional context, and the nature of GD assessment. The broader structures, guided by a techno-rationalist approach to assessment and the pressures of massification, success, compliance and institutional efficiencies, value explicitly-stated outcomes and criteria, propositional knowledge and a positivist ideal of one correct mark for any one assessment, while the GD assessment practice values the more social and tacit elements of procedural knowledge and a specialist knower as evidenced in a largely tacit GD gaze that assessors possess and students aim to develop. The uncovering of the knowledge-knower structures used in GD assessment has the potential to make the assessed gaze more explicit to lecturers, assessors and ultimately to students. My findings offer a deeper understanding of the assessment of knower code disciplines which require a specialist gaze for the judgement of student work, and the pressures experienced in this type of assessment in a HE context.
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