Photophysical properties and photodynamic therapy activities of symmetrical and asymmetrical porphyrins embedded into Pluronic polymer micelles and nonlinear optical properties of an asymmetrical phthalocyanine
- Authors: Managa, Muthumuni Elizabeth
- Date: 2019
- Subjects: Porphyrins , Phthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67625 , vital:29122
- Description: This work reports on the synthesis of symmetrical and asymmetrical novel porphyrins that have been incorporated into Pluronic polymers, as well as the synthesis of asymmetrical phthalocyanine. The new compounds were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), mass spectrometry and UV–Visible spectroscopy. The porphyrins that are synthesised were not water soluble but upon incorporating into Pluronic polymer micelles, they became water soluble. The polymer was also modified and linked to folic acid, to enhance selectivity for photodynamic therapy application, where MCF7 breast cancer cells were used. The singlet oxygen quantum yields were lower for the metal free porphyrins as compared to metalled ones due to the heavy atom effect of ClGa, Zn and Cl2Si in the latter which encourages intersystem crossing to the triplet state. Singlet oxygen quantum yields for water soluble derivatives increased upon being encapsulated into the micelles for all. The Stern-Volmer constant (Ksv), binding constant (Kb) and number of binding sites (n) were investigated in order to understand the interaction between the polymer micelles and the porphyrins, and it was showed that the central metals play a role in the manner which the porphyrin interacts with the micelles. The dark toxicity and photodynamic activity of the novel porphyrins upon encapsulating to Pluronic polymer micelles is also reported. There was minimal dark toxicity for all complexes with > 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.
- Full Text:
- Date Issued: 2019
- Authors: Managa, Muthumuni Elizabeth
- Date: 2019
- Subjects: Porphyrins , Phthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67625 , vital:29122
- Description: This work reports on the synthesis of symmetrical and asymmetrical novel porphyrins that have been incorporated into Pluronic polymers, as well as the synthesis of asymmetrical phthalocyanine. The new compounds were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), mass spectrometry and UV–Visible spectroscopy. The porphyrins that are synthesised were not water soluble but upon incorporating into Pluronic polymer micelles, they became water soluble. The polymer was also modified and linked to folic acid, to enhance selectivity for photodynamic therapy application, where MCF7 breast cancer cells were used. The singlet oxygen quantum yields were lower for the metal free porphyrins as compared to metalled ones due to the heavy atom effect of ClGa, Zn and Cl2Si in the latter which encourages intersystem crossing to the triplet state. Singlet oxygen quantum yields for water soluble derivatives increased upon being encapsulated into the micelles for all. The Stern-Volmer constant (Ksv), binding constant (Kb) and number of binding sites (n) were investigated in order to understand the interaction between the polymer micelles and the porphyrins, and it was showed that the central metals play a role in the manner which the porphyrin interacts with the micelles. The dark toxicity and photodynamic activity of the novel porphyrins upon encapsulating to Pluronic polymer micelles is also reported. There was minimal dark toxicity for all complexes with > 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.
- Full Text:
- Date Issued: 2019
Geomorphological connectivity and sensitivity examined in a recently degraded gravel-bed stream: implications for river-floodplain rehabilitation
- Authors: Powell, Rebecca
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/53722 , vital:26313
- Description: The study of river complexity and sensitivity to future human land-use activities and climate change is a fast growing field within the discipline of fluvial geomorphology. Associated with this is a need to improve river rehabilitation and catchment management approach, design and effectiveness. This study aimed to investigate drivers of the recent geomorphological sensitivity of the Baviaanskloof River-floodplain, an upland system in South Africa, by integrating the concepts of geomorphological connectivity and Panarchy. The understanding generated was used to evaluate the approach of the State agency, Working for Wetlands (WfWet), to river-floodplain rehabilitation in the catchment.The concepts of geomorphological connectivity and Panarchy provide useful frameworks for understanding interactions between geomorphological processes and structure across scales of space and time. Geomorphological connectivity explains the degree to which water and sediment is linked in a river landscape, determined by the distribution of erosional and depositional landforms (Brierley et al. 2006; Fryirs et al. 2007a; Fryirs et al. 2007b). Panarchy attempts to explain lagged response to disturbances, non-linear interactions, and sudden shifts in system state, and has been applied largely to ecological systems. Panarchy theory, when combined with the concept of geomorphological connectivity, provides a guiding framework for understanding river complexity in greater depth. The first results chapter of this study investigated river long-term and recent geomorphological history, towards understanding the nature and timing of river geomorphological cycling between erosion and deposition. Optically Stimulated Luminescence dating of alluvial fan and floodplain sedimentary units was conducted, for analysis of river-floodplain long-term history (100s to 1 000s of years). Interviews with 11 local landowners, combined with analysis of historic aerial imagery and river-floodplain topographic surveys, provided a means of describing recent (last few decades) geomorphological dynamics. The results indicated that the Baviaanskloof is naturally a cut- and-fill landscape over scales of several hundred to thousands of years, characterized by the alternation between phases of high fluvial energy and alluvial fan expansion, and low energy conditions associated with floodplain accretion. Recent and widespread river-floodplain degradation was compressed into a short period of approximately 30 years, suggesting that one or more drivers have pushed the system beyond a threshold, resulting in increased water and sediment connectivity. The second results chapter investigated the role of human land-use activities and flooding frequency and magnitude, as drivers of recent river-floodplain degradation. Human impacts were investigated by describing land-use activities for the preceding 80 years, and relating these activities to changes in river-floodplain form and behavior. Temporal trends in flood events of different frequency and magnitude were investigated by analyzing rainfall data, integrated with landowner reports of flood-inducing rainfall magnitudes. The findings indicated that human land-use activities have been an important driver of recent river- floodplain degradation, through the enhancement of water and sediment connectivity across spatial scales of the catchment. Episodic and high magnitude floods synergized with human driven increased connectivity, precipitating stream power and geomorphological threshold breaches, resulting in a shift in river behaviour. The third results chapter investigated the influence of tributary-junction streams and fans on the geomorphological form, behavior and sensitivity of the Baviaanskloof River. Local- scale topographic impacts of tributary fans and streams were described using topographic surveys and geomorphological mapping techniques. Tributary streams form a major control on the behaviour of the river, by influencing the degree of coarse sediment connectivity with the main channel. Although tributary fans buffer the river from disturbances occurring in the wider catchment, they initiate topographic variations along the floodplain, influencing local-scale patterns of deposition and erosion along the river. The main river responds to water and sediment inputs from tributary junction streams by locally adjusting longitudinal slope, maintaining an overall constant slope of 0.0066 m/m. The response of the Baviaanskloof River to tributary junction fans and streams is however variable, and is fashioned by complex interactions between geomorphological and anthropogenic factors. The final two chapters of the thesis evaluate the findings of the study within the context of river-floodplain rehabilitation approaches in South Africa, and within the theoretical, philosophical and methodological context of the research. The first of these two chapters evaluates the approach of the WfWet programme to river-floodplain rehabilitation in the Baviaanskloof. The chapter indicates that the present practice of WfWet is to reinstate a pre-degradation state, which is not suited to the Baviaanskloof River-floodplain, since the river-floodplain has passed a geomorphological threshold, resulting in a new set of interacting processes and landforms. The author presents a conceptual model illustrating the existence of geomorphological adaptive cycles interacting across spatial and temporal scales, thereby attempting to explain a river Panarchy specific to the Baviaanskloof. From this conceptual model, a hierarchical rehabilitation framework, targeting geomorphological processes and structure situated at different spatial and temporal scales of the landscape is suggested. The final chapter discusses the implications of integrating the concepts of geomorphological connectivity and river Panarchy theory in studies of river complexity and sensitivity to geomorphological change. The author suggests that there is scope for further investigation of the application of the two concepts within the discipline of fluvial geomorphology, particularly with regard to developing quantitative approaches to measuring and describing connectivity and Panarchy.
- Full Text:
- Date Issued: 2017
- Authors: Powell, Rebecca
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/53722 , vital:26313
- Description: The study of river complexity and sensitivity to future human land-use activities and climate change is a fast growing field within the discipline of fluvial geomorphology. Associated with this is a need to improve river rehabilitation and catchment management approach, design and effectiveness. This study aimed to investigate drivers of the recent geomorphological sensitivity of the Baviaanskloof River-floodplain, an upland system in South Africa, by integrating the concepts of geomorphological connectivity and Panarchy. The understanding generated was used to evaluate the approach of the State agency, Working for Wetlands (WfWet), to river-floodplain rehabilitation in the catchment.The concepts of geomorphological connectivity and Panarchy provide useful frameworks for understanding interactions between geomorphological processes and structure across scales of space and time. Geomorphological connectivity explains the degree to which water and sediment is linked in a river landscape, determined by the distribution of erosional and depositional landforms (Brierley et al. 2006; Fryirs et al. 2007a; Fryirs et al. 2007b). Panarchy attempts to explain lagged response to disturbances, non-linear interactions, and sudden shifts in system state, and has been applied largely to ecological systems. Panarchy theory, when combined with the concept of geomorphological connectivity, provides a guiding framework for understanding river complexity in greater depth. The first results chapter of this study investigated river long-term and recent geomorphological history, towards understanding the nature and timing of river geomorphological cycling between erosion and deposition. Optically Stimulated Luminescence dating of alluvial fan and floodplain sedimentary units was conducted, for analysis of river-floodplain long-term history (100s to 1 000s of years). Interviews with 11 local landowners, combined with analysis of historic aerial imagery and river-floodplain topographic surveys, provided a means of describing recent (last few decades) geomorphological dynamics. The results indicated that the Baviaanskloof is naturally a cut- and-fill landscape over scales of several hundred to thousands of years, characterized by the alternation between phases of high fluvial energy and alluvial fan expansion, and low energy conditions associated with floodplain accretion. Recent and widespread river-floodplain degradation was compressed into a short period of approximately 30 years, suggesting that one or more drivers have pushed the system beyond a threshold, resulting in increased water and sediment connectivity. The second results chapter investigated the role of human land-use activities and flooding frequency and magnitude, as drivers of recent river-floodplain degradation. Human impacts were investigated by describing land-use activities for the preceding 80 years, and relating these activities to changes in river-floodplain form and behavior. Temporal trends in flood events of different frequency and magnitude were investigated by analyzing rainfall data, integrated with landowner reports of flood-inducing rainfall magnitudes. The findings indicated that human land-use activities have been an important driver of recent river- floodplain degradation, through the enhancement of water and sediment connectivity across spatial scales of the catchment. Episodic and high magnitude floods synergized with human driven increased connectivity, precipitating stream power and geomorphological threshold breaches, resulting in a shift in river behaviour. The third results chapter investigated the influence of tributary-junction streams and fans on the geomorphological form, behavior and sensitivity of the Baviaanskloof River. Local- scale topographic impacts of tributary fans and streams were described using topographic surveys and geomorphological mapping techniques. Tributary streams form a major control on the behaviour of the river, by influencing the degree of coarse sediment connectivity with the main channel. Although tributary fans buffer the river from disturbances occurring in the wider catchment, they initiate topographic variations along the floodplain, influencing local-scale patterns of deposition and erosion along the river. The main river responds to water and sediment inputs from tributary junction streams by locally adjusting longitudinal slope, maintaining an overall constant slope of 0.0066 m/m. The response of the Baviaanskloof River to tributary junction fans and streams is however variable, and is fashioned by complex interactions between geomorphological and anthropogenic factors. The final two chapters of the thesis evaluate the findings of the study within the context of river-floodplain rehabilitation approaches in South Africa, and within the theoretical, philosophical and methodological context of the research. The first of these two chapters evaluates the approach of the WfWet programme to river-floodplain rehabilitation in the Baviaanskloof. The chapter indicates that the present practice of WfWet is to reinstate a pre-degradation state, which is not suited to the Baviaanskloof River-floodplain, since the river-floodplain has passed a geomorphological threshold, resulting in a new set of interacting processes and landforms. The author presents a conceptual model illustrating the existence of geomorphological adaptive cycles interacting across spatial and temporal scales, thereby attempting to explain a river Panarchy specific to the Baviaanskloof. From this conceptual model, a hierarchical rehabilitation framework, targeting geomorphological processes and structure situated at different spatial and temporal scales of the landscape is suggested. The final chapter discusses the implications of integrating the concepts of geomorphological connectivity and river Panarchy theory in studies of river complexity and sensitivity to geomorphological change. The author suggests that there is scope for further investigation of the application of the two concepts within the discipline of fluvial geomorphology, particularly with regard to developing quantitative approaches to measuring and describing connectivity and Panarchy.
- Full Text:
- Date Issued: 2017
The Kenya National Human Rights Commission and the promotion, protection and monitoring of socio-economic rights in Kenya
- Khayundi, Francis Bulimo Mapati
- Authors: Khayundi, Francis Bulimo Mapati
- Date: 2018
- Subjects: Kenya Human Rights Commission , Economic rights -- Kenya , Social rights -- Kenya , Kenya -- Economic conditions , Kenya -- Social conditions , Kenya -- Politics and government
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60413 , vital:27777
- Description: The promulgation of the 2010 Constitution of Kenya introduced socio-economic rights (SERs) amid widespread poverty and rising inequality. This study seeks to answer the overarching question, what role can the Kenya National Commission on Human Rights (KNCHR) play in promoting, protecting and monitoring SERs in Kenya? Further research questions included whether the KNCHR has the requisite powers to perform its mandate and what lessons could be learned from the South African context. The research sought to understand how the local context affects the ability of KNCHR to carry out its mandate. Likewise, it analyses some of the contributions KNCHR has made in the promotion and protection of SERs while identifying the challenges the Commission faces in carrying out its mandate. Several methodologies were utilised to answer the research questions above. The methodologies included the doctrinal method, analysis of secondary sources and interviews with key informants. A comparative legal research methodology was also employed, with the SAHRC being used as a case study on how NHRIs can promote, protect and monitor SERs. The findings from the research argue that the Paris Principles provide the minimum guidelines on the establishment of NHRIs. Compliance with these Principles has not necessarily guaranteed the effectives of NHRIs. Any assessment of an NHRI should be based on its performance and legitimacy considering the local factors obtaining within its jurisdiction. The domestic protection and judicial enforcement of human rights in Kenya, though crucial to the realisation of SERs, has been fraught with challenges. These challenges have meant that the realisation of SERs has been curtailed and necessitated complementary institutions for human rights to be realised. Given the country’s constitutional architecture, the KNCHR was one such institution that could complement the role of the judiciary given its wide mandate. With SERs a new feature of the 2010 Constitution, the KNCHR had to find ways to promote SERs in the country considering the local peculiarities such as poverty, a highly political climate and lack of political goodwill from the legislature and executive sometime characterised by open hostility. These challenges and the new nature of these rights called for a comparative study with the SAHRC given some similarities between the two jurisdictions. The SAHRC provided valuable lessons having had more experience in dealing with SERs while navigating similar challenges the KNCHR faced or might face. The findings of the research prompted recommendations directed at the KNCHR and other stakeholders, specifically the legislature and executive on how to address the challenges curtailing the performance of the KNCHR in general and particularly ways in which the Commission could go about in promoting, protecting and monitoring SERs.
- Full Text:
- Date Issued: 2018
- Authors: Khayundi, Francis Bulimo Mapati
- Date: 2018
- Subjects: Kenya Human Rights Commission , Economic rights -- Kenya , Social rights -- Kenya , Kenya -- Economic conditions , Kenya -- Social conditions , Kenya -- Politics and government
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60413 , vital:27777
- Description: The promulgation of the 2010 Constitution of Kenya introduced socio-economic rights (SERs) amid widespread poverty and rising inequality. This study seeks to answer the overarching question, what role can the Kenya National Commission on Human Rights (KNCHR) play in promoting, protecting and monitoring SERs in Kenya? Further research questions included whether the KNCHR has the requisite powers to perform its mandate and what lessons could be learned from the South African context. The research sought to understand how the local context affects the ability of KNCHR to carry out its mandate. Likewise, it analyses some of the contributions KNCHR has made in the promotion and protection of SERs while identifying the challenges the Commission faces in carrying out its mandate. Several methodologies were utilised to answer the research questions above. The methodologies included the doctrinal method, analysis of secondary sources and interviews with key informants. A comparative legal research methodology was also employed, with the SAHRC being used as a case study on how NHRIs can promote, protect and monitor SERs. The findings from the research argue that the Paris Principles provide the minimum guidelines on the establishment of NHRIs. Compliance with these Principles has not necessarily guaranteed the effectives of NHRIs. Any assessment of an NHRI should be based on its performance and legitimacy considering the local factors obtaining within its jurisdiction. The domestic protection and judicial enforcement of human rights in Kenya, though crucial to the realisation of SERs, has been fraught with challenges. These challenges have meant that the realisation of SERs has been curtailed and necessitated complementary institutions for human rights to be realised. Given the country’s constitutional architecture, the KNCHR was one such institution that could complement the role of the judiciary given its wide mandate. With SERs a new feature of the 2010 Constitution, the KNCHR had to find ways to promote SERs in the country considering the local peculiarities such as poverty, a highly political climate and lack of political goodwill from the legislature and executive sometime characterised by open hostility. These challenges and the new nature of these rights called for a comparative study with the SAHRC given some similarities between the two jurisdictions. The SAHRC provided valuable lessons having had more experience in dealing with SERs while navigating similar challenges the KNCHR faced or might face. The findings of the research prompted recommendations directed at the KNCHR and other stakeholders, specifically the legislature and executive on how to address the challenges curtailing the performance of the KNCHR in general and particularly ways in which the Commission could go about in promoting, protecting and monitoring SERs.
- Full Text:
- Date Issued: 2018
The efficacy of multi-track diplomacy in resolving intrastate and internationalised conflicts in Africa: the case of the 2007/2008 post-election violence in Kenya
- Authors: Natolooka, Kepha
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63546 , vital:28434
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Natolooka, Kepha
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63546 , vital:28434
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
Exploring and modelling the effects of agricultural land management and climate change on agroecosystem services in the Eastern Cape, South Africa
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
Using a social-ecological systems approach to investigate hillslope seep wetlands ecosystem structure and functionality in the Tsitsa River catchment, Eastern Cape, South Africa
- Authors: Libala, Notiswa
- Date: 2019
- Subjects: Wetland management -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland conservation -- South Africa -- Eastern Cape , Slopes (Physical geography) -- South Africa -- Eastern Cape , Vegetation management -- South Africa -- Tsitsa River Catchment , Land degradation -- Control -- South Africa -- Tsitsa River Catchment , Grazing -- Environmental aspects -- South Africa -- Tsitsa River Catchment , Ecosystem management -- South Africa -- Tsitsa River Catchment , Wetland plants -- Effect of grazing on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115936 , vital:34270
- Description: Wetlands are critical ecosystems that can provide services of great social, economic and environmental value to the society. Yet, in South Africa, hillslope seep wetlands are among the most threatened ecosystems due to human-induced activities and are disappearing rapidly. Further, despite the potential vulnerability of hillslope seep wetland to disturbances, and their criticality in relation to all year round provision of forage for livestock grazing, they are among the most poorly studied wetland systems. Using a social-ecological system framing, and drawing on a range of ecological and social sciences methods, this study shed light on ways in which an integrative approach can contribute to sustainable utilisation of hillslope seep wetlands in the Tsitsa River catchment in the Eastern Cape province of South Africa. The study specific objectives were to i) evaluate the performance of Floristic Quality Assessment Index (FQAI), WET-Health and Floristic Assessment Quotient for Wetlands Index (FQAWet) indices for assessing hillslope seep wetlands ecological health ii) develop a trait-based approach for assessing the potential resilience and vulnerability of hillslope seep wetland plant species to disturbances, iii) assess the role of hillslope seep wetlands in the local communities in relation to livestock, and explore understanding of local people about the value of hillslope seep wetlands, iv) demonstrate collaborative insights emerging from an integrative social-ecological system research process to inform sustainable management of hillslope seep wetlands. A total of 11 hillslope seep wetlands were visually classified based on the level of erosion. Plant species composition within the wetlands was determined along a 100 m line transects across the hillslope wetland sites. 5 quadrats of 0.2m2 were also placed along transect for vegetation collection and cover. The plant species collected were used to calculate (FQAI) and FQAWet scores to evaluate the condition of hillslope seep wetlands. The degree of human disturbances was assessed using the Anthropogenic Activity Index (AAI), an index for qualitatively assessing the degree of human disturbance based on visual inspection of a wetland site. Factors represented in the AAI, include: (i) surrounding land use intensity; (ii) soil disturbance; (iii) hydrological alteration; (iv) habitat alteration within wetland; (v) vegetation community quality. The vegetation samples were collected in summer 2016 and winter 2017. All assessed indices were regressed against AAI to evaluate their performances. All assessed indices FQAI, FQAWet and WET-Health showed that hillslope seep wetland were impacted by human activities. FQAIall and WET-Health showed the strongest response to AAI in winter, while FQAIdom and FAQWet showed a weak response to AAI in all seasons. Overall, the findings of this study suggest that FQAIall and WET-Health are potentially better tools for assessing the biological conditions of hillslope seep wetland in South Africa. A novel trait-based approach was developed using seven plant traits and 27 trait attributes. Based on the developed approach, plant species were grouped into three potentially vulnerable groups in relation to grazing pressure. It was then predicted that species belonging to the highly vulnerable group would be less dominant at the highly disturbed sites, as well as in the winter season when grazing pressure is at its highest. The result corresponds largely with the seasonal predictions; however this was not the case for sites. The approach developed in this study worked and it was useful for predicting the potential responses of plant species in hillslope seep wetlands to grazing pressure. The success of the approach seasonally could be attributed to the careful selection of the traits, reflecting the mechanistic relationship between the grazing mode of stress on vegetation and trait-mediated biotic response. However, this still need to be refined using accurate vegetation cover methods that might have had impact on the lack of correspondence within sites. The results of the present study revealed that communities largely perceive hillslope seep wetlands as important ecosystems for their livelihoods. They recognise that the importance stems from services provided by the wetlands, particularly for livestock grazing during the dry season. Although hillslope seep wetlands are viewed as important ecosystems for livelihoods, the communities also perceive these wetlands as highly eroded ecosystems. Community members indicate willingness to strengthen local natural resource governance systems, which could lead to better management of hillslope seep wetlands. A range of protective strategies for hillslope seep were suggested by community members, including fencing, active herding and rotational grazing. The study suggests that active involvement of local communities is critical to the successful management of natural resources. The study highlights the need to consider the role of local people as influential components within social-ecological systems in order to promote effective management and conservation interventions of hillslope seep wetlands. Overall, the study highlights the criticality of an integrative social-ecological system approach for holistic management of hillslope seep wetlands within the studied catchment.
- Full Text:
- Date Issued: 2019
- Authors: Libala, Notiswa
- Date: 2019
- Subjects: Wetland management -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland conservation -- South Africa -- Eastern Cape , Slopes (Physical geography) -- South Africa -- Eastern Cape , Vegetation management -- South Africa -- Tsitsa River Catchment , Land degradation -- Control -- South Africa -- Tsitsa River Catchment , Grazing -- Environmental aspects -- South Africa -- Tsitsa River Catchment , Ecosystem management -- South Africa -- Tsitsa River Catchment , Wetland plants -- Effect of grazing on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115936 , vital:34270
- Description: Wetlands are critical ecosystems that can provide services of great social, economic and environmental value to the society. Yet, in South Africa, hillslope seep wetlands are among the most threatened ecosystems due to human-induced activities and are disappearing rapidly. Further, despite the potential vulnerability of hillslope seep wetland to disturbances, and their criticality in relation to all year round provision of forage for livestock grazing, they are among the most poorly studied wetland systems. Using a social-ecological system framing, and drawing on a range of ecological and social sciences methods, this study shed light on ways in which an integrative approach can contribute to sustainable utilisation of hillslope seep wetlands in the Tsitsa River catchment in the Eastern Cape province of South Africa. The study specific objectives were to i) evaluate the performance of Floristic Quality Assessment Index (FQAI), WET-Health and Floristic Assessment Quotient for Wetlands Index (FQAWet) indices for assessing hillslope seep wetlands ecological health ii) develop a trait-based approach for assessing the potential resilience and vulnerability of hillslope seep wetland plant species to disturbances, iii) assess the role of hillslope seep wetlands in the local communities in relation to livestock, and explore understanding of local people about the value of hillslope seep wetlands, iv) demonstrate collaborative insights emerging from an integrative social-ecological system research process to inform sustainable management of hillslope seep wetlands. A total of 11 hillslope seep wetlands were visually classified based on the level of erosion. Plant species composition within the wetlands was determined along a 100 m line transects across the hillslope wetland sites. 5 quadrats of 0.2m2 were also placed along transect for vegetation collection and cover. The plant species collected were used to calculate (FQAI) and FQAWet scores to evaluate the condition of hillslope seep wetlands. The degree of human disturbances was assessed using the Anthropogenic Activity Index (AAI), an index for qualitatively assessing the degree of human disturbance based on visual inspection of a wetland site. Factors represented in the AAI, include: (i) surrounding land use intensity; (ii) soil disturbance; (iii) hydrological alteration; (iv) habitat alteration within wetland; (v) vegetation community quality. The vegetation samples were collected in summer 2016 and winter 2017. All assessed indices were regressed against AAI to evaluate their performances. All assessed indices FQAI, FQAWet and WET-Health showed that hillslope seep wetland were impacted by human activities. FQAIall and WET-Health showed the strongest response to AAI in winter, while FQAIdom and FAQWet showed a weak response to AAI in all seasons. Overall, the findings of this study suggest that FQAIall and WET-Health are potentially better tools for assessing the biological conditions of hillslope seep wetland in South Africa. A novel trait-based approach was developed using seven plant traits and 27 trait attributes. Based on the developed approach, plant species were grouped into three potentially vulnerable groups in relation to grazing pressure. It was then predicted that species belonging to the highly vulnerable group would be less dominant at the highly disturbed sites, as well as in the winter season when grazing pressure is at its highest. The result corresponds largely with the seasonal predictions; however this was not the case for sites. The approach developed in this study worked and it was useful for predicting the potential responses of plant species in hillslope seep wetlands to grazing pressure. The success of the approach seasonally could be attributed to the careful selection of the traits, reflecting the mechanistic relationship between the grazing mode of stress on vegetation and trait-mediated biotic response. However, this still need to be refined using accurate vegetation cover methods that might have had impact on the lack of correspondence within sites. The results of the present study revealed that communities largely perceive hillslope seep wetlands as important ecosystems for their livelihoods. They recognise that the importance stems from services provided by the wetlands, particularly for livestock grazing during the dry season. Although hillslope seep wetlands are viewed as important ecosystems for livelihoods, the communities also perceive these wetlands as highly eroded ecosystems. Community members indicate willingness to strengthen local natural resource governance systems, which could lead to better management of hillslope seep wetlands. A range of protective strategies for hillslope seep were suggested by community members, including fencing, active herding and rotational grazing. The study suggests that active involvement of local communities is critical to the successful management of natural resources. The study highlights the need to consider the role of local people as influential components within social-ecological systems in order to promote effective management and conservation interventions of hillslope seep wetlands. Overall, the study highlights the criticality of an integrative social-ecological system approach for holistic management of hillslope seep wetlands within the studied catchment.
- Full Text:
- Date Issued: 2019
Aiding the education agenda? the role of non-governmental organisations in learner performance and retention in Joza, Grahamstown, South Africa
- Authors: Nomsenge, Sinazo Onela
- Date: 2019
- Subjects: Non-governmental organizations , Non-governmental organizations -- South Africa -- Makhanda , Black people -- Education -- South Africa -- Makhanda , Education -- South Africa -- Makhanda , Joza Youth Hub (Makhanda) , Upstart Youth Development Project (Makhanda) , Village Scribe Association (Makhanda) , Ikamba Youth (Makhanda) , Access Music Project(Makhanda)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76468 , vital:30568
- Description: This thesis describes the network of complexities that characterise the world and work of Non-Governmental Organisations (NGOs). It examines the ways in which organisations navigate different internal, sectoral and contextual intricacies while operating under the command of their chosen developmental mandates. This description is drawn from a sociological analysis of the internal workings of education NGOs, their external affiliations as well as the negotiations which underpin their operations and survival. Collectively, the careful illustration of these underpinnings outlines both the role that NGOs play in the performance and retention of learners in the Grahamstown-east township of Joza and also their position in the town’s basic education sector. Private and non-governmental interveners have, particularly from the closing decades of the 20th century, been conceptually and operationally deployed as panaceas of the socio-economic scarcities which continue to pervade much of the ‘developing’ world. Their involvement in the socio-economic missions of populations living in the Global South has grown both laterally and in the depth of how development is understood and defined, carried out and also measured. NGOs, as widely acclaimed institutional arms of global development imperatives, therefore assume prominent positions in framing policy and implementation models, prescribing performance benchmarks and pronouncing non-compliance. Likewise, education NGOs have obtained normative prescription status in global education policy and practice largely on the back of the Education for All (EFA) objectives, the Millennium Development Goals (MDGs) and the neo-liberal logics which have championed state retreat in favour of private sector ascendance in globalised development. This, in conjunction with the persistent struggles of educational transformation in the Global South, has given NGOs little trouble in legitimising their prominent presence in education and other sectors of socio-economic relief in these parts of the world. Little illusion remains however, in many commentary circles, of the role of NGOs in advancing development ideals, the honesty of their altruistic intents, their ideological leanings as well as their efficacy in carrying out their mandates. As such, the logics which have been used to dethrone developing state structures in order to expand the space for private intervention along with the prevailing and deepening markers of educational underperformance, have been central features of the criticisms levelled against NGOs. This thesis intervenes in these ongoing reflections by describing the role of NGOs in educational outcomes, particularly learner performance and retention in Joza. This analysis demonstrates the organisational, sector-level and broader community forces which influence not only the form which non-state interventions take on and the daily preoccupations of their carriers but broadly, the position they occupy in the town’s overall educational profile. By way of locating NGOs within Grahamstown’s educational landscape, this thesis first demonstrates, the conflicted nature of NGO operations from an international, sectoral, national, local and organisational level. The discussion then illustrates how the preoccupations of NGOs are scattered between the different communities which they occupy within these levels. Their reliance on these players demands that organisations be tactical in guarding both their survival and, at times, the conflicting allegiances which grant them different forms of legitimacy. Internal struggles which characterise this imbalance of forces results in a trade-off which often favours organisational preservation mechanisms over systemic educational overhaul. As such, while non-state interveners can be lauded for extending educational support to those who would otherwise not have such, the gains of NGO intervention are often absorbed by internal urgencies for organisational legitimacy and preservation. This, in a context which possesses a unique set of socio-economic and educational deficits that require, at the very least, radical and unbridled mediation, means that pre-existing inequalities in educational inputs and outcomes along with the resultant inequities in youth socio-economic prospects, can find refuge in the very sector whose support and intervention is sought out and justified for such. This thesis lays out the nuances of these tensions and contradictions and offers this case as a point of reference for further considerations of the persistent markers of underperformance which characterise developing communities that enjoy high concentrations of non-state educational intervention.
- Full Text:
- Date Issued: 2019
- Authors: Nomsenge, Sinazo Onela
- Date: 2019
- Subjects: Non-governmental organizations , Non-governmental organizations -- South Africa -- Makhanda , Black people -- Education -- South Africa -- Makhanda , Education -- South Africa -- Makhanda , Joza Youth Hub (Makhanda) , Upstart Youth Development Project (Makhanda) , Village Scribe Association (Makhanda) , Ikamba Youth (Makhanda) , Access Music Project(Makhanda)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76468 , vital:30568
- Description: This thesis describes the network of complexities that characterise the world and work of Non-Governmental Organisations (NGOs). It examines the ways in which organisations navigate different internal, sectoral and contextual intricacies while operating under the command of their chosen developmental mandates. This description is drawn from a sociological analysis of the internal workings of education NGOs, their external affiliations as well as the negotiations which underpin their operations and survival. Collectively, the careful illustration of these underpinnings outlines both the role that NGOs play in the performance and retention of learners in the Grahamstown-east township of Joza and also their position in the town’s basic education sector. Private and non-governmental interveners have, particularly from the closing decades of the 20th century, been conceptually and operationally deployed as panaceas of the socio-economic scarcities which continue to pervade much of the ‘developing’ world. Their involvement in the socio-economic missions of populations living in the Global South has grown both laterally and in the depth of how development is understood and defined, carried out and also measured. NGOs, as widely acclaimed institutional arms of global development imperatives, therefore assume prominent positions in framing policy and implementation models, prescribing performance benchmarks and pronouncing non-compliance. Likewise, education NGOs have obtained normative prescription status in global education policy and practice largely on the back of the Education for All (EFA) objectives, the Millennium Development Goals (MDGs) and the neo-liberal logics which have championed state retreat in favour of private sector ascendance in globalised development. This, in conjunction with the persistent struggles of educational transformation in the Global South, has given NGOs little trouble in legitimising their prominent presence in education and other sectors of socio-economic relief in these parts of the world. Little illusion remains however, in many commentary circles, of the role of NGOs in advancing development ideals, the honesty of their altruistic intents, their ideological leanings as well as their efficacy in carrying out their mandates. As such, the logics which have been used to dethrone developing state structures in order to expand the space for private intervention along with the prevailing and deepening markers of educational underperformance, have been central features of the criticisms levelled against NGOs. This thesis intervenes in these ongoing reflections by describing the role of NGOs in educational outcomes, particularly learner performance and retention in Joza. This analysis demonstrates the organisational, sector-level and broader community forces which influence not only the form which non-state interventions take on and the daily preoccupations of their carriers but broadly, the position they occupy in the town’s overall educational profile. By way of locating NGOs within Grahamstown’s educational landscape, this thesis first demonstrates, the conflicted nature of NGO operations from an international, sectoral, national, local and organisational level. The discussion then illustrates how the preoccupations of NGOs are scattered between the different communities which they occupy within these levels. Their reliance on these players demands that organisations be tactical in guarding both their survival and, at times, the conflicting allegiances which grant them different forms of legitimacy. Internal struggles which characterise this imbalance of forces results in a trade-off which often favours organisational preservation mechanisms over systemic educational overhaul. As such, while non-state interveners can be lauded for extending educational support to those who would otherwise not have such, the gains of NGO intervention are often absorbed by internal urgencies for organisational legitimacy and preservation. This, in a context which possesses a unique set of socio-economic and educational deficits that require, at the very least, radical and unbridled mediation, means that pre-existing inequalities in educational inputs and outcomes along with the resultant inequities in youth socio-economic prospects, can find refuge in the very sector whose support and intervention is sought out and justified for such. This thesis lays out the nuances of these tensions and contradictions and offers this case as a point of reference for further considerations of the persistent markers of underperformance which characterise developing communities that enjoy high concentrations of non-state educational intervention.
- Full Text:
- Date Issued: 2019
Conceptualisations of and responses to plagiarism in the South African higher education system
- Mphahlele, Martha Matee (Amanda)
- Authors: Mphahlele, Martha Matee (Amanda)
- Date: 2020
- Subjects: Plagiarism , Plagiarism -- Prevention -- South Africa , Education, Higher -- Moral and ethical aspects , Education, Higher -- South Africa , Cheating (Education) -- South Africa , College students -- Legal status, laws, etc. -- South Africa , College discipline -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162642 , vital:40963
- Description: Violations of academic integrity are a cause for concern in universities around the world and plagiarism is one of the most significant examples of these academic integrity issues with which universities are grappling . The approach taken to managing plagiarism depends to a large extent on the understanding of the phenomenon within institutions. This study investigated how plagiarism is conceptualised and responded to in the South African Higher Education system and how this impacts on teaching and learning. Data was collected from 25 out of the 26 South African public universities; the missing university had just been established and did not yet have policies or processes in place. The data was primarily in the form of documents known in these institutions as ‘plagiarism policies’, along with a wealth of other related policies and reports. This was supplemented by interviews as a means of verifying the document analysis with seven plagiarism committee members from across the three institutional types in South Africa, namely: traditional universities, comprehensive universities, and universities of technology. Using Bhaskar’s (2008) critical realism as a metatheory and Archer’s (1995) social realism as both a substantive theory and analytical framework, the experiences and events of plagiarism management were critically examined. Critical realism consider s these experiences and events at the level of the e mpirical and the actual , in order to identify the mechanisms at the l evel of the r eal from which these emerge. Social realism argues that when undertaking such an analysis in the social world, this entails identifying the emergent properties of both the parts (structure and culture) and people (agents). Therefore, the data was analysed using Archer’s analytical dualism to identify structural, cultural and agential mechanisms shaping the understanding of plagiarism and the practices associated with managing the phenomenon. The study found that dominant in the sector was an un derstanding of plagiarism as always being an intentional act, with implications for teaching and learning practices, which then focused on identifying and punishing incidents of plagiarism in student writing. A legal discourse was found to permeate the universities’ plagiarism management systems, such that most procedures replicated the legal framework. This was seen to undermine the identity of universities as teaching and learning spaces and of students as novice members of the disciplinary fields. The study further highlighted that due to plagiarism being perceived as an intentional act, punishment in almost all universities is prioritised as the key means of attending to plagiarism in the se institutions. This emerged as a structural constraint to students’ acquisition of academic writing norms. Such understandings and approaches were seen to be complementary to the risk-aversion of many institutions in a globalised era of university rankings. As increased bureaucracy has been put in place to attend to incidents of plagiarism, including obligatory reporting thereof, an unintentional consequence emerged, where it was at times simpler for academics to ignore incidences of plagiarism than to act on them. Turnitin was frequently referred to across the data as the preferred text - matching tool, but Turnitin together with other text-matching tools , was often used in a way that complemented the understanding of plagiarism as always being an intentional act. The stu dy found that text - matching software was largely misunderstood to be plagiarism software, where the similarity index was perceived to be a measure of plagiarism. This led to an understanding that students needed to paraphrase texts in order to avoid detect ion by the program me, and this may inadvertently encourage plagiarism , as students are taught to write towards the software. The research found that in those instances where educational responses to plagiarism were in place, they often demonstrated a lack of understanding of academic literacies development and the extent to which norms of knowledge production are disciplinary specific. Most (but not all) of the data about educational responses focused on add-on workshops and the signing of a declaration form, indicating that the student has not plagiarised. The workshops were seen to emphasise technical skills, such as the punctuation norms of referencing, and were often offered in a generic format by people outside of the target disciplines. These workshops were found to ignore the connection between the technical skills of referencing and the norms of knowledge construction, with a potential deleterious effect on the development of authorial identity. Finally, the data showed a few instances where particular institutions acknowledged that plagiarism occurs along a continuum, where on one side is intentional plagiarism associated with cheating and requiring punishment, and on the other side is unintentional plagiarism, which is understood to require an educational response , and was seen to emerge from either a lack of understanding of academic literacy norms , or from negligence. Literacy development with regard to taking on the norms of knowledge-making in the academy was seen to be a complex and lengthy process that was fundamental to educational endeavours of facilitating epistemological access, while cases of negligence were seen to be mainly caused by technical oversight rather than a lack of access to the relevant knowledge production norms. The study concludes by arguing that cases of intentional plagiarism require quick and appropriate punishment, but that there also needs to be an institution-wide understanding that unintentional plagiarism often emerges from students failing to access the specific knowledge-making norms of the discipline. There is thus a need for academics to be aware of the complexities related to taking on literacy practices, and who also understand the role of feedback in this process. But it ought not to be assumed that academics would have such insights simply by virtue of their expertise in the discipline. These academics need to have carefully constructed staff development support, as they take on such pedagogical approaches. The study argues that the dominant conceptualisation of plagiarism in the domain of culture as an intentional act and the complementary policies and processes in the domain of structure as focusing on detecting and punishing incidents of plagiarism, fail to address plagiarism in appropriate educational ways.
- Full Text:
- Date Issued: 2020
- Authors: Mphahlele, Martha Matee (Amanda)
- Date: 2020
- Subjects: Plagiarism , Plagiarism -- Prevention -- South Africa , Education, Higher -- Moral and ethical aspects , Education, Higher -- South Africa , Cheating (Education) -- South Africa , College students -- Legal status, laws, etc. -- South Africa , College discipline -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162642 , vital:40963
- Description: Violations of academic integrity are a cause for concern in universities around the world and plagiarism is one of the most significant examples of these academic integrity issues with which universities are grappling . The approach taken to managing plagiarism depends to a large extent on the understanding of the phenomenon within institutions. This study investigated how plagiarism is conceptualised and responded to in the South African Higher Education system and how this impacts on teaching and learning. Data was collected from 25 out of the 26 South African public universities; the missing university had just been established and did not yet have policies or processes in place. The data was primarily in the form of documents known in these institutions as ‘plagiarism policies’, along with a wealth of other related policies and reports. This was supplemented by interviews as a means of verifying the document analysis with seven plagiarism committee members from across the three institutional types in South Africa, namely: traditional universities, comprehensive universities, and universities of technology. Using Bhaskar’s (2008) critical realism as a metatheory and Archer’s (1995) social realism as both a substantive theory and analytical framework, the experiences and events of plagiarism management were critically examined. Critical realism consider s these experiences and events at the level of the e mpirical and the actual , in order to identify the mechanisms at the l evel of the r eal from which these emerge. Social realism argues that when undertaking such an analysis in the social world, this entails identifying the emergent properties of both the parts (structure and culture) and people (agents). Therefore, the data was analysed using Archer’s analytical dualism to identify structural, cultural and agential mechanisms shaping the understanding of plagiarism and the practices associated with managing the phenomenon. The study found that dominant in the sector was an un derstanding of plagiarism as always being an intentional act, with implications for teaching and learning practices, which then focused on identifying and punishing incidents of plagiarism in student writing. A legal discourse was found to permeate the universities’ plagiarism management systems, such that most procedures replicated the legal framework. This was seen to undermine the identity of universities as teaching and learning spaces and of students as novice members of the disciplinary fields. The study further highlighted that due to plagiarism being perceived as an intentional act, punishment in almost all universities is prioritised as the key means of attending to plagiarism in the se institutions. This emerged as a structural constraint to students’ acquisition of academic writing norms. Such understandings and approaches were seen to be complementary to the risk-aversion of many institutions in a globalised era of university rankings. As increased bureaucracy has been put in place to attend to incidents of plagiarism, including obligatory reporting thereof, an unintentional consequence emerged, where it was at times simpler for academics to ignore incidences of plagiarism than to act on them. Turnitin was frequently referred to across the data as the preferred text - matching tool, but Turnitin together with other text-matching tools , was often used in a way that complemented the understanding of plagiarism as always being an intentional act. The stu dy found that text - matching software was largely misunderstood to be plagiarism software, where the similarity index was perceived to be a measure of plagiarism. This led to an understanding that students needed to paraphrase texts in order to avoid detect ion by the program me, and this may inadvertently encourage plagiarism , as students are taught to write towards the software. The research found that in those instances where educational responses to plagiarism were in place, they often demonstrated a lack of understanding of academic literacies development and the extent to which norms of knowledge production are disciplinary specific. Most (but not all) of the data about educational responses focused on add-on workshops and the signing of a declaration form, indicating that the student has not plagiarised. The workshops were seen to emphasise technical skills, such as the punctuation norms of referencing, and were often offered in a generic format by people outside of the target disciplines. These workshops were found to ignore the connection between the technical skills of referencing and the norms of knowledge construction, with a potential deleterious effect on the development of authorial identity. Finally, the data showed a few instances where particular institutions acknowledged that plagiarism occurs along a continuum, where on one side is intentional plagiarism associated with cheating and requiring punishment, and on the other side is unintentional plagiarism, which is understood to require an educational response , and was seen to emerge from either a lack of understanding of academic literacy norms , or from negligence. Literacy development with regard to taking on the norms of knowledge-making in the academy was seen to be a complex and lengthy process that was fundamental to educational endeavours of facilitating epistemological access, while cases of negligence were seen to be mainly caused by technical oversight rather than a lack of access to the relevant knowledge production norms. The study concludes by arguing that cases of intentional plagiarism require quick and appropriate punishment, but that there also needs to be an institution-wide understanding that unintentional plagiarism often emerges from students failing to access the specific knowledge-making norms of the discipline. There is thus a need for academics to be aware of the complexities related to taking on literacy practices, and who also understand the role of feedback in this process. But it ought not to be assumed that academics would have such insights simply by virtue of their expertise in the discipline. These academics need to have carefully constructed staff development support, as they take on such pedagogical approaches. The study argues that the dominant conceptualisation of plagiarism in the domain of culture as an intentional act and the complementary policies and processes in the domain of structure as focusing on detecting and punishing incidents of plagiarism, fail to address plagiarism in appropriate educational ways.
- Full Text:
- Date Issued: 2020
Attentive amelioration: developing and evaluating an applied mindfulness programme for psychologists
- Authors: McGarvie, Susan
- Date: 2020
- Subjects: Attentive Amelioration Programme , Mindfulness (Psychology) , Psychotherapy -- Practice , Counseling -- Practice , Medical professionals -- Mental health
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/166186 , vital:41336
- Description: It is readily accepted that healthcare in many third world countries is in crisis, but interestingly, even in wealthy first world countries, many healthcare systems are stretched to their limits, as fewer people choose to follow a career in healthcare and more staff members struggle under the pressures of an overextended system (Krasner, et al., 2009). Ways to improve healthcare practitioner wellbeing is thus a relevant and widely investigated topic (McCann et al., 2013), which has, until recently, been aimed at reducing the negative symptoms associated with poor wellbeing, such as stress and burnout. More recently, there has been burgeoning interest in the effects and potential benefits of mindfulness practice to wellbeing, especially in developed English-speaking countries like the UK, Canada, USA, Australia, as well as in Europe. The aim of this study was to contribute to this body of literature by proposing a more personalised and person-centred means to support and improve wellbeing. It was guided by an overarching research question, about the benefits of a mindfulness-based wellness course for practicing psychologists. This study is a mixed-methods narrative inquiry which employs both Action Research (AR) and Programme Evaluation methods. It involved the design, implementation and evaluation of a mindful-wellness programme, subsequently named the Attentive Amelioration programme. Ten participants were purposively recruited and enrolled in the programme, which ran over eight weeks and included coaching and blended learning facilitation methods, including: an introductory workshop (with a pedagogical mix of lecture, group discussion, practical activities, learners manual and YouTube clips), individual and group coaching sessions, and an online learning programme. The findings suggest that psychologists do experience a great deal of stress and perceived levels of burnout are high, even if the scores on the pre- and post- intervention self-assessment scales do not entirely support this perception. This study found that participants were open to and engaged with mindfulness training and practice and sustained that practice for several months post-intervention. Finally, overall findings suggest that while the Attentive Amelioration programme was effective as a means to cultivate and develop mindfulness, self-compassion and overall wellbeing in the short-term, further investigation is required to determine the sustainability of the effects over the long-term. The findings of this study support the overall aims of the study in that it has found that the participating psychologists found the Attentive Amelioration programme to be beneficial, supportive and even therapeutic. By contributing to and supporting findings of existing research, that suggest that a mindfulness-based coaching programme would be beneficial to psychologist wellbeing and therapeutic proficiency, it serves to advocate for mindfulness as a means to improve and sustain psychologist wellbeing..
- Full Text:
- Date Issued: 2020
Attentive amelioration: developing and evaluating an applied mindfulness programme for psychologists
- Authors: McGarvie, Susan
- Date: 2020
- Subjects: Attentive Amelioration Programme , Mindfulness (Psychology) , Psychotherapy -- Practice , Counseling -- Practice , Medical professionals -- Mental health
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/166186 , vital:41336
- Description: It is readily accepted that healthcare in many third world countries is in crisis, but interestingly, even in wealthy first world countries, many healthcare systems are stretched to their limits, as fewer people choose to follow a career in healthcare and more staff members struggle under the pressures of an overextended system (Krasner, et al., 2009). Ways to improve healthcare practitioner wellbeing is thus a relevant and widely investigated topic (McCann et al., 2013), which has, until recently, been aimed at reducing the negative symptoms associated with poor wellbeing, such as stress and burnout. More recently, there has been burgeoning interest in the effects and potential benefits of mindfulness practice to wellbeing, especially in developed English-speaking countries like the UK, Canada, USA, Australia, as well as in Europe. The aim of this study was to contribute to this body of literature by proposing a more personalised and person-centred means to support and improve wellbeing. It was guided by an overarching research question, about the benefits of a mindfulness-based wellness course for practicing psychologists. This study is a mixed-methods narrative inquiry which employs both Action Research (AR) and Programme Evaluation methods. It involved the design, implementation and evaluation of a mindful-wellness programme, subsequently named the Attentive Amelioration programme. Ten participants were purposively recruited and enrolled in the programme, which ran over eight weeks and included coaching and blended learning facilitation methods, including: an introductory workshop (with a pedagogical mix of lecture, group discussion, practical activities, learners manual and YouTube clips), individual and group coaching sessions, and an online learning programme. The findings suggest that psychologists do experience a great deal of stress and perceived levels of burnout are high, even if the scores on the pre- and post- intervention self-assessment scales do not entirely support this perception. This study found that participants were open to and engaged with mindfulness training and practice and sustained that practice for several months post-intervention. Finally, overall findings suggest that while the Attentive Amelioration programme was effective as a means to cultivate and develop mindfulness, self-compassion and overall wellbeing in the short-term, further investigation is required to determine the sustainability of the effects over the long-term. The findings of this study support the overall aims of the study in that it has found that the participating psychologists found the Attentive Amelioration programme to be beneficial, supportive and even therapeutic. By contributing to and supporting findings of existing research, that suggest that a mindfulness-based coaching programme would be beneficial to psychologist wellbeing and therapeutic proficiency, it serves to advocate for mindfulness as a means to improve and sustain psychologist wellbeing..
- Full Text:
- Date Issued: 2020
Application of machine learning, molecular modelling and structural data mining against antiretroviral drug resistance in HIV-1
- Sheik Amamuddy, Olivier Serge André
- Authors: Sheik Amamuddy, Olivier Serge André
- Date: 2020
- Subjects: Machine learning , Molecules -- Models , Data mining , Neural networks (Computer science) , Antiretroviral agents , Protease inhibitors , Drug resistance , Multidrug resistance , Molecular dynamics , Renin-angiotensin system , HIV (Viruses) -- South Africa , HIV (Viruses) -- Social aspects -- South Africa , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115964 , vital:34282
- Description: Millions are affected with the Human Immunodeficiency Virus (HIV) world wide, even though the death toll is on the decline. Antiretrovirals (ARVs), more specifically protease inhibitors have shown tremendous success since their introduction into therapy since the mid 1990’s by slowing down progression to the Acquired Immune Deficiency Syndrome (AIDS). However, Drug Resistance Mutations (DRMs) are constantly selected for due to viral adaptation, making drugs less effective over time. The current challenge is to manage the infection optimally with a limited set of drugs, with differing associated levels of toxicities in the face of a virus that (1) exists as a quasispecies, (2) may transmit acquired DRMs to drug-naive individuals and (3) that can manifest class-wide resistance due to similarities in design. The presence of latent reservoirs, unawareness of infection status, education and various socio-economic factors make the problem even more complex. Adequate timing and choice of drug prescription together with treatment adherence are very important as drug toxicities, drug failure and sub-optimal treatment regimens leave room for further development of drug resistance. While CD4 cell count and the determination of viral load from patients in resource-limited settings are very helpful to track how well a patient’s immune system is able to keep the virus in check, they can be lengthy in determining whether an ARV is effective. Phenosense assay kits answer this problem using viruses engineered to contain the patient sequences and evaluating their growth in the presence of different ARVs, but this can be expensive and too involved for routine checks. As a cheaper and faster alternative, genotypic assays provide similar information from HIV pol sequences obtained from blood samples, inferring ARV efficacy on the basis of drug resistance mutation patterns. However, these are inherently complex and the various methods of in silico prediction, such as Geno2pheno, REGA and Stanford HIVdb do not always agree in every case, even though this gap decreases as the list of resistance mutations is updated. A major gap in HIV treatment is that the information used for predicting drug resistance is mainly computed from data containing an overwhelming majority of B subtype HIV, when these only comprise about 12% of the worldwide HIV infections. In addition to growing evidence that drug resistance is subtype-related, it is intuitive to hypothesize that as subtyping is a phylogenetic classification, the more divergent a subtype is from the strains used in training prediction models, the less their resistance profiles would correlate. For the aforementioned reasons, we used a multi-faceted approach to attack the virus in multiple ways. This research aimed to (1) improve resistance prediction methods by focusing solely on the available subtype, (2) mine structural information pertaining to resistance in order to find any exploitable weak points and increase knowledge of the mechanistic processes of drug resistance in HIV protease. Finally, (3) we screen for protease inhibitors amongst a database of natural compounds [the South African natural compound database (SANCDB)] to find molecules or molecular properties usable to come up with improved inhibition against the drug target. In this work, structural information was mined using the Anisotropic Network Model, Dynamics Cross-Correlation, Perturbation Response Scanning, residue contact network analysis and the radius of gyration. These methods failed to give any resistance-associated patterns in terms of natural movement, internal correlated motions, residue perturbation response, relational behaviour and global compaction respectively. Applications of drug docking, homology-modelling and energy minimization for generating features suitable for machine-learning were not very promising, and rather suggest that the value of binding energies by themselves from Vina may not be very reliable quantitatively. All these failures lead to a refinement that resulted in a highly sensitive statistically-guided network construction and analysis, which leads to key findings in the early dynamics associated with resistance across all PI drugs. The latter experiment unravelled a conserved lateral expansion motion occurring at the flap elbows, and an associated contraction that drives the base of the dimerization domain towards the catalytic site’s floor in the case of drug resistance. Interestingly, we found that despite the conserved movement, bond angles were degenerate. Alongside, 16 Artificial Neural Network models were optimised for HIV proteases and reverse transcriptase inhibitors, with performances on par with Stanford HIVdb. Finally, we prioritised 9 compounds with potential protease inhibitory activity using virtual screening and molecular dynamics (MD) to additionally suggest a promising modification to one of the compounds. This yielded another molecule inhibiting equally well both opened and closed receptor target conformations, whereby each of the compounds had been selected against an array of multi-drug-resistant receptor variants. While a main hurdle was a lack of non-B subtype data, our findings, especially from the statistically-guided network analysis, may extrapolate to a certain extent to them as the level of conservation was very high within subtype B, despite all the present variations. This network construction method lays down a sensitive approach for analysing a pair of alternate phenotypes for which complex patterns prevail, given a sufficient number of experimental units. During the course of research a weighted contact mapping tool was developed to compare renin-angiotensinogen variants and packaged as part of the MD-TASK tool suite. Finally the functionality, compatibility and performance of the MODE-TASK tool were evaluated and confirmed for both Python2.7.x and Python3.x, for the analysis of normals modes from single protein structures and essential modes from MD trajectories. These techniques and tools collectively add onto the conventional means of MD analysis.
- Full Text:
- Date Issued: 2020
- Authors: Sheik Amamuddy, Olivier Serge André
- Date: 2020
- Subjects: Machine learning , Molecules -- Models , Data mining , Neural networks (Computer science) , Antiretroviral agents , Protease inhibitors , Drug resistance , Multidrug resistance , Molecular dynamics , Renin-angiotensin system , HIV (Viruses) -- South Africa , HIV (Viruses) -- Social aspects -- South Africa , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115964 , vital:34282
- Description: Millions are affected with the Human Immunodeficiency Virus (HIV) world wide, even though the death toll is on the decline. Antiretrovirals (ARVs), more specifically protease inhibitors have shown tremendous success since their introduction into therapy since the mid 1990’s by slowing down progression to the Acquired Immune Deficiency Syndrome (AIDS). However, Drug Resistance Mutations (DRMs) are constantly selected for due to viral adaptation, making drugs less effective over time. The current challenge is to manage the infection optimally with a limited set of drugs, with differing associated levels of toxicities in the face of a virus that (1) exists as a quasispecies, (2) may transmit acquired DRMs to drug-naive individuals and (3) that can manifest class-wide resistance due to similarities in design. The presence of latent reservoirs, unawareness of infection status, education and various socio-economic factors make the problem even more complex. Adequate timing and choice of drug prescription together with treatment adherence are very important as drug toxicities, drug failure and sub-optimal treatment regimens leave room for further development of drug resistance. While CD4 cell count and the determination of viral load from patients in resource-limited settings are very helpful to track how well a patient’s immune system is able to keep the virus in check, they can be lengthy in determining whether an ARV is effective. Phenosense assay kits answer this problem using viruses engineered to contain the patient sequences and evaluating their growth in the presence of different ARVs, but this can be expensive and too involved for routine checks. As a cheaper and faster alternative, genotypic assays provide similar information from HIV pol sequences obtained from blood samples, inferring ARV efficacy on the basis of drug resistance mutation patterns. However, these are inherently complex and the various methods of in silico prediction, such as Geno2pheno, REGA and Stanford HIVdb do not always agree in every case, even though this gap decreases as the list of resistance mutations is updated. A major gap in HIV treatment is that the information used for predicting drug resistance is mainly computed from data containing an overwhelming majority of B subtype HIV, when these only comprise about 12% of the worldwide HIV infections. In addition to growing evidence that drug resistance is subtype-related, it is intuitive to hypothesize that as subtyping is a phylogenetic classification, the more divergent a subtype is from the strains used in training prediction models, the less their resistance profiles would correlate. For the aforementioned reasons, we used a multi-faceted approach to attack the virus in multiple ways. This research aimed to (1) improve resistance prediction methods by focusing solely on the available subtype, (2) mine structural information pertaining to resistance in order to find any exploitable weak points and increase knowledge of the mechanistic processes of drug resistance in HIV protease. Finally, (3) we screen for protease inhibitors amongst a database of natural compounds [the South African natural compound database (SANCDB)] to find molecules or molecular properties usable to come up with improved inhibition against the drug target. In this work, structural information was mined using the Anisotropic Network Model, Dynamics Cross-Correlation, Perturbation Response Scanning, residue contact network analysis and the radius of gyration. These methods failed to give any resistance-associated patterns in terms of natural movement, internal correlated motions, residue perturbation response, relational behaviour and global compaction respectively. Applications of drug docking, homology-modelling and energy minimization for generating features suitable for machine-learning were not very promising, and rather suggest that the value of binding energies by themselves from Vina may not be very reliable quantitatively. All these failures lead to a refinement that resulted in a highly sensitive statistically-guided network construction and analysis, which leads to key findings in the early dynamics associated with resistance across all PI drugs. The latter experiment unravelled a conserved lateral expansion motion occurring at the flap elbows, and an associated contraction that drives the base of the dimerization domain towards the catalytic site’s floor in the case of drug resistance. Interestingly, we found that despite the conserved movement, bond angles were degenerate. Alongside, 16 Artificial Neural Network models were optimised for HIV proteases and reverse transcriptase inhibitors, with performances on par with Stanford HIVdb. Finally, we prioritised 9 compounds with potential protease inhibitory activity using virtual screening and molecular dynamics (MD) to additionally suggest a promising modification to one of the compounds. This yielded another molecule inhibiting equally well both opened and closed receptor target conformations, whereby each of the compounds had been selected against an array of multi-drug-resistant receptor variants. While a main hurdle was a lack of non-B subtype data, our findings, especially from the statistically-guided network analysis, may extrapolate to a certain extent to them as the level of conservation was very high within subtype B, despite all the present variations. This network construction method lays down a sensitive approach for analysing a pair of alternate phenotypes for which complex patterns prevail, given a sufficient number of experimental units. During the course of research a weighted contact mapping tool was developed to compare renin-angiotensinogen variants and packaged as part of the MD-TASK tool suite. Finally the functionality, compatibility and performance of the MODE-TASK tool were evaluated and confirmed for both Python2.7.x and Python3.x, for the analysis of normals modes from single protein structures and essential modes from MD trajectories. These techniques and tools collectively add onto the conventional means of MD analysis.
- Full Text:
- Date Issued: 2020
The impact of South African business on employment relations in Mozambique: a case study of Banco Austral, a subsidiary of ABSA
- Mtyingizana, Beata Nontlahla
- Authors: Mtyingizana, Beata Nontlahla
- Date: 2018
- Subjects: Industrial sociology -- Mozambique , Industrial relations -- Mozambique , Industrial relations -- Cross-cultural studies , Industrial sociology -- Political aspects , Personnel management -- Mozambique , Personnel management -- Political aspects , ABSA Bank , Banco Austral
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60267 , vital:27760
- Description: This thesis examines the impact of South African business on employment relations in Mozambique. The study specifically focuses on a case study of Banco Austral, a subsidiary of the Amalgamated Banks of South Africa (ABSA), to provide a richer and deeper analysis of employment practices. The study examines the extent to which the expansion of South African businesses in Mozambique has influenced the development of employment relations there. It examines whether the employment relations that exist at Banco Austral are a direct result of the influence of its parent firm, ABSA. It assesses whether the prevailing managerial practices at Banco Austral are distinctly local and a product of Mozambican history or whether the employer and employee relations that exist in that bank are an outcome of some form of hybridised host country and parent firm practices. The study is contextualised within the period of transition that both countries underwent. In the South African context, the end of apartheid promised political stability, democracy and racial harmony. It facilitated South Africa’s reinsertion into the international economy and enabled its investors to embark on large-scale penetration of potential markets. It also opened up opportunities for investors to take advantage of the new global order in the rest of Africa and particularly in Mozambique. Similarly, in Mozambique, the transition to capitalism and to liberal democracy in 1994 marked a clear shift of policy from an authoritarian one-party state characterised by a planned socialist economy. In embracing a liberal market economy, Mozambique facilitated a transference of ownership of major state assets to the private sector and opened itself to the private sector’s market-driven business practices and managerial cultures. The study found that the impact of these historical developments on the evolution of employment relations at Banco Austral has been contradictory. ABSA’s ownership of Banco Austral opened as many opportunities as it closed them. On the one hand, it marked an opportunity for the growth and development of the ABSA brand across Mozambique. It presented opportunities for the integration of the Mozambican workforce into the larger ABSA Group and thereby enabling the transference of innovative managerial practices, world class human resources management techniques and advanced banking technology from ABSA and into Banco Austral. ABSA’s acquisition of Banco Austral also opened prospects for the development of skills for the workforce, enhanced the chances of job mobility as well as opened opportunities for Banco Austral workers to take advantage of the newly created jobs. On the other hand, however, the managerial practices and the human resource management techniques transferred from ABSA was reported by Banco Austral workers to be far from innovative. Instead, they resembled traits of past practices characteristic of Mozambique’s colonial workplace regime and South Africa’s apartheid workplace regime. This tilted the balance of power in favour of managers who arbitrarily exercised their authority in ways similar to that of the Portuguese managers in colonial Mozambique and that of the production councils during the post-independence socialist period. Access to senior positions and training opportunities continued to be allocated along national and racial lines. Many Mozambican workers were said to be ABSA-unfit and could not be trained in critical areas to improve their relevance in the larger ABSA Group. Despite these findings however, this study shows that Banco Austral workers were not helpless actors in the employment relationship. Rather, they remained agents of change in their own right, endowed with varying degrees of power, which they used to minimise the impact of arbitrary management practices and influence the direction of the employment relationship to advance their interests. The argument of this thesis is advanced by locating the study within Pierre Bourdieu’s theoretical triad of capital, field and habitus. Bourdieu’s theoretical triad is used as important analytical tools for understanding how ABSA-specific practices evolved and continued to shape the conduct and thoughts of its managers and workers alike. This study also makes special contribution to Marxism by revisiting Marx’s conception of the labour process to expose a number of analytical dilemmas when Marx is applied to bank labour.
- Full Text:
- Date Issued: 2018
- Authors: Mtyingizana, Beata Nontlahla
- Date: 2018
- Subjects: Industrial sociology -- Mozambique , Industrial relations -- Mozambique , Industrial relations -- Cross-cultural studies , Industrial sociology -- Political aspects , Personnel management -- Mozambique , Personnel management -- Political aspects , ABSA Bank , Banco Austral
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60267 , vital:27760
- Description: This thesis examines the impact of South African business on employment relations in Mozambique. The study specifically focuses on a case study of Banco Austral, a subsidiary of the Amalgamated Banks of South Africa (ABSA), to provide a richer and deeper analysis of employment practices. The study examines the extent to which the expansion of South African businesses in Mozambique has influenced the development of employment relations there. It examines whether the employment relations that exist at Banco Austral are a direct result of the influence of its parent firm, ABSA. It assesses whether the prevailing managerial practices at Banco Austral are distinctly local and a product of Mozambican history or whether the employer and employee relations that exist in that bank are an outcome of some form of hybridised host country and parent firm practices. The study is contextualised within the period of transition that both countries underwent. In the South African context, the end of apartheid promised political stability, democracy and racial harmony. It facilitated South Africa’s reinsertion into the international economy and enabled its investors to embark on large-scale penetration of potential markets. It also opened up opportunities for investors to take advantage of the new global order in the rest of Africa and particularly in Mozambique. Similarly, in Mozambique, the transition to capitalism and to liberal democracy in 1994 marked a clear shift of policy from an authoritarian one-party state characterised by a planned socialist economy. In embracing a liberal market economy, Mozambique facilitated a transference of ownership of major state assets to the private sector and opened itself to the private sector’s market-driven business practices and managerial cultures. The study found that the impact of these historical developments on the evolution of employment relations at Banco Austral has been contradictory. ABSA’s ownership of Banco Austral opened as many opportunities as it closed them. On the one hand, it marked an opportunity for the growth and development of the ABSA brand across Mozambique. It presented opportunities for the integration of the Mozambican workforce into the larger ABSA Group and thereby enabling the transference of innovative managerial practices, world class human resources management techniques and advanced banking technology from ABSA and into Banco Austral. ABSA’s acquisition of Banco Austral also opened prospects for the development of skills for the workforce, enhanced the chances of job mobility as well as opened opportunities for Banco Austral workers to take advantage of the newly created jobs. On the other hand, however, the managerial practices and the human resource management techniques transferred from ABSA was reported by Banco Austral workers to be far from innovative. Instead, they resembled traits of past practices characteristic of Mozambique’s colonial workplace regime and South Africa’s apartheid workplace regime. This tilted the balance of power in favour of managers who arbitrarily exercised their authority in ways similar to that of the Portuguese managers in colonial Mozambique and that of the production councils during the post-independence socialist period. Access to senior positions and training opportunities continued to be allocated along national and racial lines. Many Mozambican workers were said to be ABSA-unfit and could not be trained in critical areas to improve their relevance in the larger ABSA Group. Despite these findings however, this study shows that Banco Austral workers were not helpless actors in the employment relationship. Rather, they remained agents of change in their own right, endowed with varying degrees of power, which they used to minimise the impact of arbitrary management practices and influence the direction of the employment relationship to advance their interests. The argument of this thesis is advanced by locating the study within Pierre Bourdieu’s theoretical triad of capital, field and habitus. Bourdieu’s theoretical triad is used as important analytical tools for understanding how ABSA-specific practices evolved and continued to shape the conduct and thoughts of its managers and workers alike. This study also makes special contribution to Marxism by revisiting Marx’s conception of the labour process to expose a number of analytical dilemmas when Marx is applied to bank labour.
- Full Text:
- Date Issued: 2018
Transformative ICT education practices in rural secondary schools for developmental needs and realities: the Eastern Cape Province, South Africa
- Authors: Simuja, Clement
- Date: 2020
- Subjects: Education, Secondary -- South Africa -- Data processing , Information technology -- Study and teaching (Secondary) --South Africa , Educational technology -- Developing countries , Rural development -- Developing countries , Computer-assisted instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa , Rural schools -- South Africa -- Eastern Cape , Community and school -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/150631 , vital:38991
- Description: The perceived social development significance of Information and Communication Technology (ICT) has dramatically expanded the domains in which this cluster of ICTs is being discussed and acted upon. The action to promote community development in rural areas in South Africa has made its way into the introduction of ICT education in secondary schools. Since rural secondary schools form part of the framework for rural communities, they are being challenged to provide ICT education that makes a difference in learners’ lives. This requires engaging education practices that inspire learners to construct knowledge of ICT that does not only respond to examination purposes but rather, to the needs and development aspirations of the community. This research examines the experience of engaging learners and communities in socially informed ICT education in rural secondary schools. Specifically, it seeks to develop a critique of current practices involved in ICT education in rural secondary schools, and explores plausible alternatives to such practices that would make ICT education more transformative and structured towards the developmental concerns of communities. The main empirical focus for the research was five rural secondary schools in the Eastern Cape Province in South Africa. The research involved 53 participants that participated in a socially informed ICT training process. The training was designed to inspire participants to share their self-defined ICT education and ICT knowledge experiences. Critical Action Learning and Philosophical Inquiry provided the methodological framework, whilst the theoretical framework draws on Foucault’s philosophical ideas on power-knowledge relations. Through this theoretical analysis, the research examines the dynamic interplay of practices in ICT education with the values, ideals, and knowledge that form the core-life experiences of learners and rural communities. The research findings of this study indicate that current ICT education practices in rural secondary schools are endowed with ideologies that are affecting learners’ identity, social experiences, power, and ownership of the reflective meaning of using ICTs in community development. The contribution of this thesis lies in demonstrating ways that reframe ICT education transformatively, and more specifically its practices in the light of the way power, identity, ownership and social experience construct and offer learners a transformative view of self and the world. This could enable ICT education to fulfil the potential of contributing to social development in rural communities. The thesis culminates by presenting a theoretical framework that articulates the structural and authoritative components of ICT education practices – these relate to learners’ conscious understandings and represented thoughts, sensations and meanings embedded in the context, and actions and locations of using their knowledge of ICT.
- Full Text:
- Date Issued: 2020
- Authors: Simuja, Clement
- Date: 2020
- Subjects: Education, Secondary -- South Africa -- Data processing , Information technology -- Study and teaching (Secondary) --South Africa , Educational technology -- Developing countries , Rural development -- Developing countries , Computer-assisted instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa , Rural schools -- South Africa -- Eastern Cape , Community and school -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/150631 , vital:38991
- Description: The perceived social development significance of Information and Communication Technology (ICT) has dramatically expanded the domains in which this cluster of ICTs is being discussed and acted upon. The action to promote community development in rural areas in South Africa has made its way into the introduction of ICT education in secondary schools. Since rural secondary schools form part of the framework for rural communities, they are being challenged to provide ICT education that makes a difference in learners’ lives. This requires engaging education practices that inspire learners to construct knowledge of ICT that does not only respond to examination purposes but rather, to the needs and development aspirations of the community. This research examines the experience of engaging learners and communities in socially informed ICT education in rural secondary schools. Specifically, it seeks to develop a critique of current practices involved in ICT education in rural secondary schools, and explores plausible alternatives to such practices that would make ICT education more transformative and structured towards the developmental concerns of communities. The main empirical focus for the research was five rural secondary schools in the Eastern Cape Province in South Africa. The research involved 53 participants that participated in a socially informed ICT training process. The training was designed to inspire participants to share their self-defined ICT education and ICT knowledge experiences. Critical Action Learning and Philosophical Inquiry provided the methodological framework, whilst the theoretical framework draws on Foucault’s philosophical ideas on power-knowledge relations. Through this theoretical analysis, the research examines the dynamic interplay of practices in ICT education with the values, ideals, and knowledge that form the core-life experiences of learners and rural communities. The research findings of this study indicate that current ICT education practices in rural secondary schools are endowed with ideologies that are affecting learners’ identity, social experiences, power, and ownership of the reflective meaning of using ICTs in community development. The contribution of this thesis lies in demonstrating ways that reframe ICT education transformatively, and more specifically its practices in the light of the way power, identity, ownership and social experience construct and offer learners a transformative view of self and the world. This could enable ICT education to fulfil the potential of contributing to social development in rural communities. The thesis culminates by presenting a theoretical framework that articulates the structural and authoritative components of ICT education practices – these relate to learners’ conscious understandings and represented thoughts, sensations and meanings embedded in the context, and actions and locations of using their knowledge of ICT.
- Full Text:
- Date Issued: 2020
Application of In Vitro Release Testing (IVRT) and a dermatopharmacokinetic approach (tape stripping) for the assessment of Metronidazole topical formulations
- Rath, Seeprarani Prabirkumar
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
A comprehensive approach to scalability assessment of ICTD projects : a case study of ICT4RED
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
The morphological complexity of L1 Arabic-speaking children
- Authors: Issa, Iyad
- Date: 2019
- Subjects: Cognition in children , Reading , Arabic language -- Orthography and spelling , Arabic language -- Orthography and spelling -- Study and teaching , Arabic language -- Study and teaching , Arabic language -- Phonetics
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92831 , vital:30754
- Description: Spelling poses a challenge to Arabic-speaking learners due to the complexity of the morphological and orthographic system in Arabic. Arabic morphology has been argued to play a critical role in spelling since its morphological operations are built on a system consisting of a root that is interlocking into different patterns of vowels to form different categories of words. In addition, Arabic orthography is considered to be loyal to the morphographic principle (Ravid, 2012), where morphemes correspond to graphic representation regardless of the pronunciation, especially in the non-vowelized texts. This study made a detailed classification of spelling errors in a word dictation task, based on morphological structures, undertaken by 107 Typically-developing learners (TD) and learners with learning disabiities (LD) attending the same schools. All participants ranged in age from 7 years, 3 months to 15 years, 2 months (grades 2 to 8). The spelling task was made up of 400 common words representing all morphological forms in different conjugations and grammatical classes. The results indicated that learners made three types of errors: errors with respect to the root, errors with respect to the word pattern, and errors with respect to both the root and the word pattern. The results also showed that TD and LD learners follow a similar pattern of complexity even though the LD group produced more errors than the TD group. The results revealed that MA and PA exhibited significant positive regression (b= 9.398, 16.106 respectively) with spelling, indicating that learners with higher scores in PA and MA have higher scores in spelling. The results argued for the crucial contribution that morphological awareness makes towards the general spelling abilities among learners and provide additional evidence for the nonlinear growth of morphological knowedge in spelling. In addition, spelling errors suggested that the spelling process goes in a hierarchical way where words can be accessed and processed either according to the root or according to the stem. Intact verbs are processed according to their root and word pattern. Some weak verb forms, whose radicals undergo modifications, are processed according to their stem, while those whose radicals are fully represented in the spoken word, are processed according to their root and word patterns. Therefore, roots or stems are firstly accessed and attached to basic word patterns (the grapheme without diacritics and affixes). Thereafter, prefixes and, then, suffixes are attached to the word pattern and, finally, diacritics are accessed and attached to the word pattern.
- Full Text:
- Date Issued: 2019
- Authors: Issa, Iyad
- Date: 2019
- Subjects: Cognition in children , Reading , Arabic language -- Orthography and spelling , Arabic language -- Orthography and spelling -- Study and teaching , Arabic language -- Study and teaching , Arabic language -- Phonetics
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92831 , vital:30754
- Description: Spelling poses a challenge to Arabic-speaking learners due to the complexity of the morphological and orthographic system in Arabic. Arabic morphology has been argued to play a critical role in spelling since its morphological operations are built on a system consisting of a root that is interlocking into different patterns of vowels to form different categories of words. In addition, Arabic orthography is considered to be loyal to the morphographic principle (Ravid, 2012), where morphemes correspond to graphic representation regardless of the pronunciation, especially in the non-vowelized texts. This study made a detailed classification of spelling errors in a word dictation task, based on morphological structures, undertaken by 107 Typically-developing learners (TD) and learners with learning disabiities (LD) attending the same schools. All participants ranged in age from 7 years, 3 months to 15 years, 2 months (grades 2 to 8). The spelling task was made up of 400 common words representing all morphological forms in different conjugations and grammatical classes. The results indicated that learners made three types of errors: errors with respect to the root, errors with respect to the word pattern, and errors with respect to both the root and the word pattern. The results also showed that TD and LD learners follow a similar pattern of complexity even though the LD group produced more errors than the TD group. The results revealed that MA and PA exhibited significant positive regression (b= 9.398, 16.106 respectively) with spelling, indicating that learners with higher scores in PA and MA have higher scores in spelling. The results argued for the crucial contribution that morphological awareness makes towards the general spelling abilities among learners and provide additional evidence for the nonlinear growth of morphological knowedge in spelling. In addition, spelling errors suggested that the spelling process goes in a hierarchical way where words can be accessed and processed either according to the root or according to the stem. Intact verbs are processed according to their root and word pattern. Some weak verb forms, whose radicals undergo modifications, are processed according to their stem, while those whose radicals are fully represented in the spoken word, are processed according to their root and word patterns. Therefore, roots or stems are firstly accessed and attached to basic word patterns (the grapheme without diacritics and affixes). Thereafter, prefixes and, then, suffixes are attached to the word pattern and, finally, diacritics are accessed and attached to the word pattern.
- Full Text:
- Date Issued: 2019
Evaluation of metallophthalocyanine functionalized photocatalytic asymmetric polymer membranes for pollution control and antimicrobial activity
- Mafukidze, Donovan Musizvinoda Chidyamurimi
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
Aquatic–terrestrial trophic linkages via riverine invertebrates in a South African catchment
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
Assessment of the microbial quality of various domestic rainwater harvesting systems and the suitability of a nano based treatment method
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
Synthesis, characterisation and biological evaluation of novel anti-infective compounds bearing ferrocene, arylpyrrole, thiazolidinedione, quinoline and triazole moieties
- Authors: Oderinlo, Ogunyemi Olajide
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/114714 , vital:34016 , 10.21504/10962/114714
- Description: Expected release date-April 2022
- Full Text: false
- Date Issued: 2019
- Authors: Oderinlo, Ogunyemi Olajide
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/114714 , vital:34016 , 10.21504/10962/114714
- Description: Expected release date-April 2022
- Full Text: false
- Date Issued: 2019
Thermal tolerance and the potential effects of climate change on coastal intertidal and estuarine organisms in the Kariega Estuary and adjacent intertitdal coastline, Eastern Cape, South Africa
- Authors: Van der Walt, Kerry-Ann
- Date: 2020
- Subjects: Ectotherms -- Climatic factors , Ectotherms -- Effect of temperature on , Fishes -- Climatic factors , Fishes -- Effect of temperature on , Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/148459 , vital:38741
- Description: Temperature changes due to the effects of climate change are evident on all continents and oceans. As a result, there is a growing concern over how marine ectotherms will respond to extreme or fluctuating environmental temperatures. Temperature changes have strong direct and indirect effects on individual, population, and ecosystem functioning traits. A multi-scale approach determining the thermal tolerance and performance of several marine ectotherms belonging to different coastal habitats is rarely considered in thermal physiology studies but is effective for an integrated ecosystem assessment. As such, for this thesis, I aimed to quantify and compare the thermal tolerance and performance of a range of coastal marine ectotherms (fish and macro-invertebrates) with different biogeographical distributions from estuarine, subtidal and rocky intertidal habitats to available and projected in situ temperature data. This was also undertaken to gauge the local vulnerability of each species across summer and winter in a warm-temperate region of South Africa. This was done using a multi-method physiological approach, which included the dynamic method (CTmax and CTmin), static respirometry and maximum heart rate fHmax). Results of the dynamic method on several fish and macro-invertebrate species indicated that there are differences in thermal tolerance according to taxonomy, biogeography and habitat for both summer and winter. Macro-invertebrate species generally had higher CTmax endpoints, lower CTmin endpoints, higher upper and lower breadths in tolerance, higher upper and lower thermal safety margins and higher thermal scopes than the fish species. This could be a result of the macro-invertebrate species studied being less mobile compared with fish species (which are able to move to more favourable conditions) as well as having broader geographical distributions. In addition, macro-invertebrates from the intertidal rock pool habitat (Palaemon peringueyi; Pernaperna) were more tolerant of high and low temperatures compared with the macro-invertebrates from the estuarine habitat (Clibanarius virescens; Parasesarma catenatum; Upogebia africana). Overall, macro-invertebrates, with the exception of Parechinus angulosus, investigated in this study indicated that current temperatures and projected climate change scenarios across seasons would not have a significant impact on them and that they are highly adaptable to changing temperature regimes. This sign of high tolerance was further supported by the heart rates of P. perna and P. catenatum under an acute increase in temperature (1.0 °C.h-1) which showed individuals of each species physiologically depressing their metabolism until a final Arrhenius breakpoint temperature was reached (TAB). Among the fish species investigated in this study, tropical species (Chaetodon marleyi; Kuhlia mugil) had the highest CTmax and CTmin endpoints when compared with the temperate (Diplodus capensis; Sarpa salpa), warm-water endemic (Chelon dumerili; Rhabdosargus holubi) and cool-water endemic (Chelon richardsonii) fishes. This suggests that due to their lower breadths in tolerance and thermal safety margins being small, tropical species may be less tolerant of cold temperatures and thermal variability, especially in the form of summer upwelling events which are expected to increase in intensity and frequency in this region as a result of anthropogenic climate change effects. On the other hand, however, if a temperature increase of 2.0 - 4.0 °C takes place at the end of the century as predicted by the Intergovernmental Panel on Climate Change (IPCC), it is likely that tropical species such as C. marleyi will become more common. Temperate species such as D. capensis and S. salpa were able to tolerate a wide range of temperatures (wide thermal scope) compared with the other fish species. These findings may suggest that D. capensis and S. salpa are thermally resilient and may be the least vulnerable to climate change effects and temperature variability. When evaluating the different life stages of D. capensis, however, using the dynamic method (juveniles and adults), static respirometry (juveniles) and maximum heart rate (adults), results suggested that juveniles of this temperate species will be more resilient to increases in ocean temperatures compared with the adults because they have a higher thermal tolerance (CTmax/TCRIT) and a greater metabolic scope (TOPT) at higher temperatures. For both juveniles and adults, temperatures beyond 28.0 °C (upper Tpej; Tarr) will have a significant impact on their physiology. Using a multi-scale and multi-method approach thus helped to identify which species or community may be vulnerable to the effects of climate change within shallow coastal environments in this warm-temperate climate change hotspot. Adopting this type of approach will assist policy makers in developing comprehensive climate change management frameworks for coastal ecosystems globally and around South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Van der Walt, Kerry-Ann
- Date: 2020
- Subjects: Ectotherms -- Climatic factors , Ectotherms -- Effect of temperature on , Fishes -- Climatic factors , Fishes -- Effect of temperature on , Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/148459 , vital:38741
- Description: Temperature changes due to the effects of climate change are evident on all continents and oceans. As a result, there is a growing concern over how marine ectotherms will respond to extreme or fluctuating environmental temperatures. Temperature changes have strong direct and indirect effects on individual, population, and ecosystem functioning traits. A multi-scale approach determining the thermal tolerance and performance of several marine ectotherms belonging to different coastal habitats is rarely considered in thermal physiology studies but is effective for an integrated ecosystem assessment. As such, for this thesis, I aimed to quantify and compare the thermal tolerance and performance of a range of coastal marine ectotherms (fish and macro-invertebrates) with different biogeographical distributions from estuarine, subtidal and rocky intertidal habitats to available and projected in situ temperature data. This was also undertaken to gauge the local vulnerability of each species across summer and winter in a warm-temperate region of South Africa. This was done using a multi-method physiological approach, which included the dynamic method (CTmax and CTmin), static respirometry and maximum heart rate fHmax). Results of the dynamic method on several fish and macro-invertebrate species indicated that there are differences in thermal tolerance according to taxonomy, biogeography and habitat for both summer and winter. Macro-invertebrate species generally had higher CTmax endpoints, lower CTmin endpoints, higher upper and lower breadths in tolerance, higher upper and lower thermal safety margins and higher thermal scopes than the fish species. This could be a result of the macro-invertebrate species studied being less mobile compared with fish species (which are able to move to more favourable conditions) as well as having broader geographical distributions. In addition, macro-invertebrates from the intertidal rock pool habitat (Palaemon peringueyi; Pernaperna) were more tolerant of high and low temperatures compared with the macro-invertebrates from the estuarine habitat (Clibanarius virescens; Parasesarma catenatum; Upogebia africana). Overall, macro-invertebrates, with the exception of Parechinus angulosus, investigated in this study indicated that current temperatures and projected climate change scenarios across seasons would not have a significant impact on them and that they are highly adaptable to changing temperature regimes. This sign of high tolerance was further supported by the heart rates of P. perna and P. catenatum under an acute increase in temperature (1.0 °C.h-1) which showed individuals of each species physiologically depressing their metabolism until a final Arrhenius breakpoint temperature was reached (TAB). Among the fish species investigated in this study, tropical species (Chaetodon marleyi; Kuhlia mugil) had the highest CTmax and CTmin endpoints when compared with the temperate (Diplodus capensis; Sarpa salpa), warm-water endemic (Chelon dumerili; Rhabdosargus holubi) and cool-water endemic (Chelon richardsonii) fishes. This suggests that due to their lower breadths in tolerance and thermal safety margins being small, tropical species may be less tolerant of cold temperatures and thermal variability, especially in the form of summer upwelling events which are expected to increase in intensity and frequency in this region as a result of anthropogenic climate change effects. On the other hand, however, if a temperature increase of 2.0 - 4.0 °C takes place at the end of the century as predicted by the Intergovernmental Panel on Climate Change (IPCC), it is likely that tropical species such as C. marleyi will become more common. Temperate species such as D. capensis and S. salpa were able to tolerate a wide range of temperatures (wide thermal scope) compared with the other fish species. These findings may suggest that D. capensis and S. salpa are thermally resilient and may be the least vulnerable to climate change effects and temperature variability. When evaluating the different life stages of D. capensis, however, using the dynamic method (juveniles and adults), static respirometry (juveniles) and maximum heart rate (adults), results suggested that juveniles of this temperate species will be more resilient to increases in ocean temperatures compared with the adults because they have a higher thermal tolerance (CTmax/TCRIT) and a greater metabolic scope (TOPT) at higher temperatures. For both juveniles and adults, temperatures beyond 28.0 °C (upper Tpej; Tarr) will have a significant impact on their physiology. Using a multi-scale and multi-method approach thus helped to identify which species or community may be vulnerable to the effects of climate change within shallow coastal environments in this warm-temperate climate change hotspot. Adopting this type of approach will assist policy makers in developing comprehensive climate change management frameworks for coastal ecosystems globally and around South Africa.
- Full Text:
- Date Issued: 2020