Assessment and monitoring of land degradation using remote sensing and geographic information systems (GIS): a case study of Qoqodala within the Wit-Kei catchment in the Eastern Cape, South Africa
- Ngcofe, Luncedo Dalithemba Sanelisiwe
- Authors: Ngcofe, Luncedo Dalithemba Sanelisiwe
- Date: 2009
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , Remote sensing -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4818 , http://hdl.handle.net/10962/d1005492 , Geographic information systems -- South Africa -- Eastern Cape , Remote sensing -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape
- Description: Land degradation is a global problem affecting many countries including South Africa. This study was conducted in order to assess and monitor the nature and extent of land degradation within Qoqodala in the Eastern Cape Province, of South Africa. The study used GIS and Remote Sensing techniques together with household interviews in determining extent, spatial characteristics and nature of land degradation within the study area. Vegetation cover and bare-ground change were the land degradation indicators assessed and monitored by this study. Through RGB band combination, Tasselled Cap Analysis and Unsupervised ISODATA classification techniques, Landsat images over the past eighteen years (1984, 1993, 1996, 2000 and 2002) have been analysed. The results showed that there is vegetation cover and bare-ground increase in the study area. The vegetation increase has been seen as a sign of land degradation increase due to the encroachment of indigenous vegetation by Euryops species (also known as Lapesi by the local community). The bare-ground land degradation indicator has also increased. The analyses of slope showed the spatial characteristics of bare-ground occurring on moderate to flat slopes while vegetation cover occurs on steep to very steep slopes. Furthermore the photographs captured during field visits show rills and gullies or dongas occurring on bare-ground. The interviewed respondents indicated that decline in food production, increase in dongas and vast increase in Euryops and a decline in grassland are the indicators of degradation that are observed in the study area. The occurrence of erosion features (rills and dongas) on bare-ground and the increase of vegetation shown by GIS and Remote Sensing techniques showed a positive correlation with field and household survey towards establishing the nature of land degradation. In this study Landsat images together with interviews proved to be a very useful tool for land degradation research. However the suggestion of a higher spatial resolution satellite image on small catchment studies is recommended
- Full Text:
- Date Issued: 2009
- Authors: Ngcofe, Luncedo Dalithemba Sanelisiwe
- Date: 2009
- Subjects: Geographic information systems -- South Africa -- Eastern Cape , Remote sensing -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4818 , http://hdl.handle.net/10962/d1005492 , Geographic information systems -- South Africa -- Eastern Cape , Remote sensing -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape
- Description: Land degradation is a global problem affecting many countries including South Africa. This study was conducted in order to assess and monitor the nature and extent of land degradation within Qoqodala in the Eastern Cape Province, of South Africa. The study used GIS and Remote Sensing techniques together with household interviews in determining extent, spatial characteristics and nature of land degradation within the study area. Vegetation cover and bare-ground change were the land degradation indicators assessed and monitored by this study. Through RGB band combination, Tasselled Cap Analysis and Unsupervised ISODATA classification techniques, Landsat images over the past eighteen years (1984, 1993, 1996, 2000 and 2002) have been analysed. The results showed that there is vegetation cover and bare-ground increase in the study area. The vegetation increase has been seen as a sign of land degradation increase due to the encroachment of indigenous vegetation by Euryops species (also known as Lapesi by the local community). The bare-ground land degradation indicator has also increased. The analyses of slope showed the spatial characteristics of bare-ground occurring on moderate to flat slopes while vegetation cover occurs on steep to very steep slopes. Furthermore the photographs captured during field visits show rills and gullies or dongas occurring on bare-ground. The interviewed respondents indicated that decline in food production, increase in dongas and vast increase in Euryops and a decline in grassland are the indicators of degradation that are observed in the study area. The occurrence of erosion features (rills and dongas) on bare-ground and the increase of vegetation shown by GIS and Remote Sensing techniques showed a positive correlation with field and household survey towards establishing the nature of land degradation. In this study Landsat images together with interviews proved to be a very useful tool for land degradation research. However the suggestion of a higher spatial resolution satellite image on small catchment studies is recommended
- Full Text:
- Date Issued: 2009
Attitudes and perceptions towards TB in Grahamstown East in a time of HIV/AIDS
- Authors: Ndoro, Tinashe T. R
- Date: 2009
- Subjects: Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3030 , http://hdl.handle.net/10962/d1002539 , Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Description: Tuberculosis (TB) has become a serious South African health problem because it is the most common opportunistic disease that leads to death in people with HIV/AIDS. Due to the airborne nature of the disease it can easily be spread to anyone including healthy people. A lack of compliance to treatment by TB patients explains why prevalence rates of the disease are high and why there is an emergence of drug resistant strains such as XDR-TB and MDR-TB. Information on existing knowledge, attitudes and perceptions regarding TB can provide a crucial foundation for the development of educational programmes and interventions aimed at reducing the further spread of the disease. This study aimed at understanding the knowledge, attitudes and perceptions towards TB and relating these to the current prevalence of HIV/AIDS. A face-to-face interview survey was conducted among adult Grahamstown East residents (n=1020). The Health Belief Model (Rosenstock et al., 1994) and Bandura’s (1986) Social Cognitive Theory formed the theoretical framework of the data collection and analysis. The data generated from the field work was first descriptively analysed providing frequency tables. Thereafter cross tabulations were calculated for relevant items using independent variables, namely gender, level of education, and experience of dealing with TB. The results of the study show that, in general, knowledge concerning TB was sufficient to provide a foundation for the adoption of healthier behaviours in the female respondents. Few of the respondents reported feeling personally susceptible although the majority of the respondents acknowledged the severity of the disease. The cues to action lacked the influence to persuade people to adopt positive health related behaviours. The perceived benefits of adopting preventative behaviour were not very influential in the adoption of healthier behavioural changes in the respondents. Disease stigma regarding the dual association of TB and HIV/AIDS was the main barrier for the adoption of healthier behavioural attitudes. Perceived self-efficacy in preventative behaviours was generally low in the less educated respondents. Recommendations regarding areas for future research and change interventions are provided.
- Full Text:
- Date Issued: 2009
- Authors: Ndoro, Tinashe T. R
- Date: 2009
- Subjects: Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3030 , http://hdl.handle.net/10962/d1002539 , Tuberculosis -- South Africa -- Grahamstown , AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown , HIV (Viruses) -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Social aspects -- South Africa -- Grahamstown , Tuberculosis -- Prevention -- South Africa -- Grahamstown , AIDS (Disease) -- South Africa -- Grahamstown -- Public opinion , Tuberculosis -- South Africa -- Grahamstown -- Public opinion , Health surveys -- South Africa -- Grahamstown
- Description: Tuberculosis (TB) has become a serious South African health problem because it is the most common opportunistic disease that leads to death in people with HIV/AIDS. Due to the airborne nature of the disease it can easily be spread to anyone including healthy people. A lack of compliance to treatment by TB patients explains why prevalence rates of the disease are high and why there is an emergence of drug resistant strains such as XDR-TB and MDR-TB. Information on existing knowledge, attitudes and perceptions regarding TB can provide a crucial foundation for the development of educational programmes and interventions aimed at reducing the further spread of the disease. This study aimed at understanding the knowledge, attitudes and perceptions towards TB and relating these to the current prevalence of HIV/AIDS. A face-to-face interview survey was conducted among adult Grahamstown East residents (n=1020). The Health Belief Model (Rosenstock et al., 1994) and Bandura’s (1986) Social Cognitive Theory formed the theoretical framework of the data collection and analysis. The data generated from the field work was first descriptively analysed providing frequency tables. Thereafter cross tabulations were calculated for relevant items using independent variables, namely gender, level of education, and experience of dealing with TB. The results of the study show that, in general, knowledge concerning TB was sufficient to provide a foundation for the adoption of healthier behaviours in the female respondents. Few of the respondents reported feeling personally susceptible although the majority of the respondents acknowledged the severity of the disease. The cues to action lacked the influence to persuade people to adopt positive health related behaviours. The perceived benefits of adopting preventative behaviour were not very influential in the adoption of healthier behavioural changes in the respondents. Disease stigma regarding the dual association of TB and HIV/AIDS was the main barrier for the adoption of healthier behavioural attitudes. Perceived self-efficacy in preventative behaviours was generally low in the less educated respondents. Recommendations regarding areas for future research and change interventions are provided.
- Full Text:
- Date Issued: 2009
Automating the conversion of natural language fiction to multi-modal 3D animated virtual environments
- Authors: Glass, Kevin Robert
- Date: 2009
- Subjects: Virtual computer systems , Virtual storage (Computer science) , Virtual reality , Computer animation , Fiction -- Computer programs , Narration (Rhetoric) -- Computer simulation , Animation (Cinematography) , Natural language processing (Computer Science)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4632 , http://hdl.handle.net/10962/d1006518
- Description: Popular fiction books describe rich visual environments that contain characters, objects, and behaviour. This research develops automated processes for converting text sourced from fiction books into animated virtual environments and multi-modal films. This involves the analysis of unrestricted natural language fiction to identify appropriate visual descriptions, and the interpretation of the identified descriptions for constructing animated 3D virtual environments. The goal of the text analysis stage is the creation of annotated fiction text, which identifies visual descriptions in a structured manner. A hierarchical rule-based learning system is created that induces patterns from example annotations provided by a human, and uses these for the creation of additional annotations. Patterns are expressed as tree structures that abstract the input text on different levels according to structural (token, sentence) and syntactic (parts-of-speech, syntactic function) categories. Patterns are generalized using pair-wise merging, where dissimilar sub-trees are replaced with wild-cards. The result is a small set of generalized patterns that are able to create correct annotations. A set of generalized patterns represents a model of an annotator's mental process regarding a particular annotation category. Annotated text is interpreted automatically for constructing detailed scene descriptions. This includes identifying which scenes to visualize, and identifying the contents and behaviour in each scene. Entity behaviour in a 3D virtual environment is formulated using time-based constraints that are automatically derived from annotations. Constraints are expressed as non-linear symbolic functions that restrict the trajectories of a pair of entities over a continuous interval of time. Solutions to these constraints specify precise behaviour. We create an innovative quantified constraint optimizer for locating sound solutions, which uses interval arithmetic for treating time and space as contiguous quantities. This optimization method uses a technique of constraint relaxation and tightening that allows solution approximations to be located where constraint systems are inconsistent (an ability not previously explored in interval-based quantified constraint solving). 3D virtual environments are populated by automatically selecting geometric models or procedural geometry-creation methods from a library. 3D models are animated according to trajectories derived from constraint solutions. The final animated film is sequenced using a range of modalities including animated 3D graphics, textual subtitles, audio narrations, and foleys. Hierarchical rule-based learning is evaluated over a range of annotation categories. Models are induced for different categories of annotation without modifying the core learning algorithms, and these models are shown to be applicable to different types of books. Models are induced automatically with accuracies ranging between 51.4% and 90.4%, depending on the category. We show that models are refined if further examples are provided, and this supports a boot-strapping process for training the learning mechanism. The task of interpreting annotated fiction text and populating 3D virtual environments is successfully automated using our described techniques. Detailed scene descriptions are created accurately, where between 83% and 96% of the automatically generated descriptions require no manual modification (depending on the type of description). The interval-based quantified constraint optimizer fully automates the behaviour specification process. Sample animated multi-modal 3D films are created using extracts from fiction books that are unrestricted in terms of complexity or subject matter (unlike existing text-to-graphics systems). These examples demonstrate that: behaviour is visualized that corresponds to the descriptions in the original text; appropriate geometry is selected (or created) for visualizing entities in each scene; sequences of scenes are created for a film-like presentation of the story; and that multiple modalities are combined to create a coherent multi-modal representation of the fiction text. This research demonstrates that visual descriptions in fiction text can be automatically identified, and that these descriptions can be converted into corresponding animated virtual environments. Unlike existing text-to-graphics systems, we describe techniques that function over unrestricted natural language text and perform the conversion process without the need for manually constructed repositories of world knowledge. This enables the rapid production of animated 3D virtual environments, allowing the human designer to focus on creative aspects.
- Full Text:
- Date Issued: 2009
- Authors: Glass, Kevin Robert
- Date: 2009
- Subjects: Virtual computer systems , Virtual storage (Computer science) , Virtual reality , Computer animation , Fiction -- Computer programs , Narration (Rhetoric) -- Computer simulation , Animation (Cinematography) , Natural language processing (Computer Science)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4632 , http://hdl.handle.net/10962/d1006518
- Description: Popular fiction books describe rich visual environments that contain characters, objects, and behaviour. This research develops automated processes for converting text sourced from fiction books into animated virtual environments and multi-modal films. This involves the analysis of unrestricted natural language fiction to identify appropriate visual descriptions, and the interpretation of the identified descriptions for constructing animated 3D virtual environments. The goal of the text analysis stage is the creation of annotated fiction text, which identifies visual descriptions in a structured manner. A hierarchical rule-based learning system is created that induces patterns from example annotations provided by a human, and uses these for the creation of additional annotations. Patterns are expressed as tree structures that abstract the input text on different levels according to structural (token, sentence) and syntactic (parts-of-speech, syntactic function) categories. Patterns are generalized using pair-wise merging, where dissimilar sub-trees are replaced with wild-cards. The result is a small set of generalized patterns that are able to create correct annotations. A set of generalized patterns represents a model of an annotator's mental process regarding a particular annotation category. Annotated text is interpreted automatically for constructing detailed scene descriptions. This includes identifying which scenes to visualize, and identifying the contents and behaviour in each scene. Entity behaviour in a 3D virtual environment is formulated using time-based constraints that are automatically derived from annotations. Constraints are expressed as non-linear symbolic functions that restrict the trajectories of a pair of entities over a continuous interval of time. Solutions to these constraints specify precise behaviour. We create an innovative quantified constraint optimizer for locating sound solutions, which uses interval arithmetic for treating time and space as contiguous quantities. This optimization method uses a technique of constraint relaxation and tightening that allows solution approximations to be located where constraint systems are inconsistent (an ability not previously explored in interval-based quantified constraint solving). 3D virtual environments are populated by automatically selecting geometric models or procedural geometry-creation methods from a library. 3D models are animated according to trajectories derived from constraint solutions. The final animated film is sequenced using a range of modalities including animated 3D graphics, textual subtitles, audio narrations, and foleys. Hierarchical rule-based learning is evaluated over a range of annotation categories. Models are induced for different categories of annotation without modifying the core learning algorithms, and these models are shown to be applicable to different types of books. Models are induced automatically with accuracies ranging between 51.4% and 90.4%, depending on the category. We show that models are refined if further examples are provided, and this supports a boot-strapping process for training the learning mechanism. The task of interpreting annotated fiction text and populating 3D virtual environments is successfully automated using our described techniques. Detailed scene descriptions are created accurately, where between 83% and 96% of the automatically generated descriptions require no manual modification (depending on the type of description). The interval-based quantified constraint optimizer fully automates the behaviour specification process. Sample animated multi-modal 3D films are created using extracts from fiction books that are unrestricted in terms of complexity or subject matter (unlike existing text-to-graphics systems). These examples demonstrate that: behaviour is visualized that corresponds to the descriptions in the original text; appropriate geometry is selected (or created) for visualizing entities in each scene; sequences of scenes are created for a film-like presentation of the story; and that multiple modalities are combined to create a coherent multi-modal representation of the fiction text. This research demonstrates that visual descriptions in fiction text can be automatically identified, and that these descriptions can be converted into corresponding animated virtual environments. Unlike existing text-to-graphics systems, we describe techniques that function over unrestricted natural language text and perform the conversion process without the need for manually constructed repositories of world knowledge. This enables the rapid production of animated 3D virtual environments, allowing the human designer to focus on creative aspects.
- Full Text:
- Date Issued: 2009
Awkward working postures and precision performance as an example of the relationship between ergonomics and production quality
- Ngcamu, Nokubonga Slindele (Sma)
- Authors: Ngcamu, Nokubonga Slindele (Sma)
- Date: 2009
- Subjects: Human engineering , Posture , Posture disorders , Musculoskeletal system -- Diseases , Work -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5105 , http://hdl.handle.net/10962/d1005183 , Human engineering , Posture , Posture disorders , Musculoskeletal system -- Diseases , Work -- Physiological aspects
- Description: Ergonomics aims to improve worker health and enhance productivity and quality. Knowledge and practical evidence of this relationship would be instrumental for optimising organisational performance particularly in industrially developing countries where the discipline is still in its developmental stages. Therefore this thesis set out to analyse the relationship between ergonomics deficiencies and performance. A survey was first conducted to establish the severity of quality problems in the South African manufacturing industry and to determine if these were related to Ergonomic deficiencies. The results indicated that quality problems continue to plague industry, a challenge associated with huge cost implications. Furthermore organisations were not cognisant of the fact that ergonomics deficiencies such as poor workstation design and awkward or constrained working postures are a major contributing factor to poor quality and performance decrements. This demonstrates that much is yet to be done in raising awareness about the benefits of ergonomics in South Africa and other industrially developing countries. However, for this to be effective, tangible evidence of these purported benefits is required. In lieu of this, a laboratory study was then conducted to establish the relationship between awkward working postures and the performance of precision tasks. Acknowledging that the task and the worker are interrelated elements, the impact of precision task demands on the postural strain experienced by the human was also investigated. A high and low precision task quantified positional precision while a force task (combination of pushing and pulling) was utilised to assess the ability to maintain a precise force over time. These three tasks were performed in eight different postures; namely seated, standing, stooping 300 and 600, working overhead, lying supine, and twisting to either side. A combination of the tasks and postures resulted in 24 experimental conditions that were tested on forty eight healthy male and female participants. The performance related dependent variables were movement time, deviation from the centre of the target, and the trend/slope followed by the force exerted. Muscle activity of eight arm, shoulder and back muscles, iii supplemented with heart rate and local ratings of perceived exertion, were utilised to quantify the impact of the tasks and the postures on the individual. The results revealed that awkward working postures do in fact influence performance outcomes. In this regard, awkward working postures (such as overhead work and lying supine and stooping) were evidenced to significantly affect movement time, deviations from the target and the ability to maintain a constant force over time. These variables have a direct relationship with organisational priorities such as productivity and quality. Furthermore, the results indicated that high precision demands augment postural strain elicited through high muscle activity responses and may have negative implications for the precipitation of musculoskeletal disorders. Essentially, the work done on this thesis reflected the complex nature of ergonomics by drawing on both macro and micro-ergonomics approaches. In so doing, challenges perceived to be relevant to industry as reported by organisations formed the foundation for further laboratory studies. Therefore, more collaborative research and knowledge transfer between industry and ergonomics researchers is a necessity particularly in industrially developing countries where ergonomics is still in its developmental stages.
- Full Text:
- Date Issued: 2009
- Authors: Ngcamu, Nokubonga Slindele (Sma)
- Date: 2009
- Subjects: Human engineering , Posture , Posture disorders , Musculoskeletal system -- Diseases , Work -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5105 , http://hdl.handle.net/10962/d1005183 , Human engineering , Posture , Posture disorders , Musculoskeletal system -- Diseases , Work -- Physiological aspects
- Description: Ergonomics aims to improve worker health and enhance productivity and quality. Knowledge and practical evidence of this relationship would be instrumental for optimising organisational performance particularly in industrially developing countries where the discipline is still in its developmental stages. Therefore this thesis set out to analyse the relationship between ergonomics deficiencies and performance. A survey was first conducted to establish the severity of quality problems in the South African manufacturing industry and to determine if these were related to Ergonomic deficiencies. The results indicated that quality problems continue to plague industry, a challenge associated with huge cost implications. Furthermore organisations were not cognisant of the fact that ergonomics deficiencies such as poor workstation design and awkward or constrained working postures are a major contributing factor to poor quality and performance decrements. This demonstrates that much is yet to be done in raising awareness about the benefits of ergonomics in South Africa and other industrially developing countries. However, for this to be effective, tangible evidence of these purported benefits is required. In lieu of this, a laboratory study was then conducted to establish the relationship between awkward working postures and the performance of precision tasks. Acknowledging that the task and the worker are interrelated elements, the impact of precision task demands on the postural strain experienced by the human was also investigated. A high and low precision task quantified positional precision while a force task (combination of pushing and pulling) was utilised to assess the ability to maintain a precise force over time. These three tasks were performed in eight different postures; namely seated, standing, stooping 300 and 600, working overhead, lying supine, and twisting to either side. A combination of the tasks and postures resulted in 24 experimental conditions that were tested on forty eight healthy male and female participants. The performance related dependent variables were movement time, deviation from the centre of the target, and the trend/slope followed by the force exerted. Muscle activity of eight arm, shoulder and back muscles, iii supplemented with heart rate and local ratings of perceived exertion, were utilised to quantify the impact of the tasks and the postures on the individual. The results revealed that awkward working postures do in fact influence performance outcomes. In this regard, awkward working postures (such as overhead work and lying supine and stooping) were evidenced to significantly affect movement time, deviations from the target and the ability to maintain a constant force over time. These variables have a direct relationship with organisational priorities such as productivity and quality. Furthermore, the results indicated that high precision demands augment postural strain elicited through high muscle activity responses and may have negative implications for the precipitation of musculoskeletal disorders. Essentially, the work done on this thesis reflected the complex nature of ergonomics by drawing on both macro and micro-ergonomics approaches. In so doing, challenges perceived to be relevant to industry as reported by organisations formed the foundation for further laboratory studies. Therefore, more collaborative research and knowledge transfer between industry and ergonomics researchers is a necessity particularly in industrially developing countries where ergonomics is still in its developmental stages.
- Full Text:
- Date Issued: 2009
Bank credit extension to the private sector and inflation in South Africa
- Authors: Dlamini, Samuel Nkosinathi
- Date: 2009
- Subjects: Bank loans -- South Africa , Inflation (Finance) -- South Africa , Money supply -- South Africa , Interest rates -- South Africa , Banks and banking -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:959 , http://hdl.handle.net/10962/d1002693 , Bank loans -- South Africa , Inflation (Finance) -- South Africa , Money supply -- South Africa , Interest rates -- South Africa , Banks and banking -- South Africa , Foreign exchange rates -- South Africa
- Description: This study investigates the contribution of bank credit extension to the private sector to inflation in South Africa, covering the period 1970:1-2006:4. The long-run impact of bank credit on inflation is investigated by means of the Johansen co integration model. The short-run ynamics of the inflation is subsequently modelled by means of the Vector Error Correction Model (VECM). Using the Johansen methodology, the study identifies two co integrating equations linking inflation and its eterminants. The results suggest that the long-run relationship between inflation and bank credit to the private sector is negative and statistically significant at 10% level. The determinants that are significant at 5% level are: money supply, real gross domestic product, the money market rate, rand/dollar exchange rate and imports. The results are consistent with previous findings. The speed of adjustment in response to deviation from the equilibrium path was found to be negative at 10.56% per quarter, which is consistent with findings by Ohnsorge and Oomes (2003) for Russia. Both the signs and the magnitude of the coefficients suggest that the co integrating vector describes a long-run inflation equation. The impulse response functions confirm the theoretical expectations except for the import prices. The most persistent and significant shocks observed are on impulse response functions of money supply and bank credit to the private sector. The variance decomposition results also suggest that inflation responds quicker to innovations from money supply and the money market rate. The overall results provide evidence that the surge in inflation is associated with an increase in money supply as well as the instability in exchange rate. The effects of exchange rate fluctuation on inflation are reflected through changes in import prices. Based on the results we conclude that an increase in bank credit during the period 1970:1-2006:4 had a negative mpact on inflation in South Africa.
- Full Text:
- Date Issued: 2009
- Authors: Dlamini, Samuel Nkosinathi
- Date: 2009
- Subjects: Bank loans -- South Africa , Inflation (Finance) -- South Africa , Money supply -- South Africa , Interest rates -- South Africa , Banks and banking -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:959 , http://hdl.handle.net/10962/d1002693 , Bank loans -- South Africa , Inflation (Finance) -- South Africa , Money supply -- South Africa , Interest rates -- South Africa , Banks and banking -- South Africa , Foreign exchange rates -- South Africa
- Description: This study investigates the contribution of bank credit extension to the private sector to inflation in South Africa, covering the period 1970:1-2006:4. The long-run impact of bank credit on inflation is investigated by means of the Johansen co integration model. The short-run ynamics of the inflation is subsequently modelled by means of the Vector Error Correction Model (VECM). Using the Johansen methodology, the study identifies two co integrating equations linking inflation and its eterminants. The results suggest that the long-run relationship between inflation and bank credit to the private sector is negative and statistically significant at 10% level. The determinants that are significant at 5% level are: money supply, real gross domestic product, the money market rate, rand/dollar exchange rate and imports. The results are consistent with previous findings. The speed of adjustment in response to deviation from the equilibrium path was found to be negative at 10.56% per quarter, which is consistent with findings by Ohnsorge and Oomes (2003) for Russia. Both the signs and the magnitude of the coefficients suggest that the co integrating vector describes a long-run inflation equation. The impulse response functions confirm the theoretical expectations except for the import prices. The most persistent and significant shocks observed are on impulse response functions of money supply and bank credit to the private sector. The variance decomposition results also suggest that inflation responds quicker to innovations from money supply and the money market rate. The overall results provide evidence that the surge in inflation is associated with an increase in money supply as well as the instability in exchange rate. The effects of exchange rate fluctuation on inflation are reflected through changes in import prices. Based on the results we conclude that an increase in bank credit during the period 1970:1-2006:4 had a negative mpact on inflation in South Africa.
- Full Text:
- Date Issued: 2009
Between self and author : an autoethnographic approach towards the crafting of reflexive compositions in post graduate drama studies
- Authors: Moyo, Awelani Lena
- Date: 2009
- Subjects: Drama -- Study and teachng (Higher) College and school drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2143 , http://hdl.handle.net/10962/d1002375
- Description: This thesis explores the merits of reflexivity in the processes of creating a performance and of performing research in Drama Studies. In it, I make a case for the validity of autobiographical material as an aid to generating such reflexivity. Through an autoethnographic case study of my work entitled Compositions (a series of performance projects) in which I focus on the theme of migration, I provide an indepth account of my experiences, focusing specifically on the interrelated concerns of body, space and journey in my ritualistic performance. My examination explores the dynamic effects of liminality within identity politics, through which I foreground several issues of concern which I have encountered as an emerging scholar and theatremaker working within an academic institution. I propose that the process of studying drama in a University ultimately requires one to continually negotiate a range of subject positions, whilst finding connections between these various identities that one may take up during the course of one’s studies. By developing an awareness of the overlapping of such identities and inhabiting the spaces in-between subject positions, I demonstrate how taking into account one’s personal lived experience can help illuminate one’s understanding of both the work of art and the research report, as well as the broader contexts in which such practice-based work exists. I illustrate how such an understanding has ultimately maximised the knowledge and learning that I have gathered, and has contributed to the crucial project of developing my authorial voice in writing and performance, which is central to the aims of the Master of Arts degree in Drama.
- Full Text:
- Date Issued: 2009
- Authors: Moyo, Awelani Lena
- Date: 2009
- Subjects: Drama -- Study and teachng (Higher) College and school drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2143 , http://hdl.handle.net/10962/d1002375
- Description: This thesis explores the merits of reflexivity in the processes of creating a performance and of performing research in Drama Studies. In it, I make a case for the validity of autobiographical material as an aid to generating such reflexivity. Through an autoethnographic case study of my work entitled Compositions (a series of performance projects) in which I focus on the theme of migration, I provide an indepth account of my experiences, focusing specifically on the interrelated concerns of body, space and journey in my ritualistic performance. My examination explores the dynamic effects of liminality within identity politics, through which I foreground several issues of concern which I have encountered as an emerging scholar and theatremaker working within an academic institution. I propose that the process of studying drama in a University ultimately requires one to continually negotiate a range of subject positions, whilst finding connections between these various identities that one may take up during the course of one’s studies. By developing an awareness of the overlapping of such identities and inhabiting the spaces in-between subject positions, I demonstrate how taking into account one’s personal lived experience can help illuminate one’s understanding of both the work of art and the research report, as well as the broader contexts in which such practice-based work exists. I illustrate how such an understanding has ultimately maximised the knowledge and learning that I have gathered, and has contributed to the crucial project of developing my authorial voice in writing and performance, which is central to the aims of the Master of Arts degree in Drama.
- Full Text:
- Date Issued: 2009
Bond market development in emerging economies: a case study of the Bond Exchange of South Africa (BESA)
- Authors: Hove, Tagara
- Date: 2009
- Subjects: Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:961 , http://hdl.handle.net/10962/d1002695 , Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Description: This study looks at the development of bond markets in emerging economies and focuses on the development of the Bond Exchange of South Africa (BESA). It explores the history, structure, performance and key issues related to the development of this market within the broader context of domestic, regional and global bond market development. BESA's experience provides valuable lessons for other emerging market economies also seeking to build bond markets. The sophistication of the local bond market is not enough to make it appealing to foreign borrowers. Market development demands an enabling market infrastructure and a background of macroeconomic stability, diversified market participants, deregulation of capital flows and an appropriate regulatory and supervisory environment.
- Full Text:
- Date Issued: 2009
- Authors: Hove, Tagara
- Date: 2009
- Subjects: Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:961 , http://hdl.handle.net/10962/d1002695 , Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Description: This study looks at the development of bond markets in emerging economies and focuses on the development of the Bond Exchange of South Africa (BESA). It explores the history, structure, performance and key issues related to the development of this market within the broader context of domestic, regional and global bond market development. BESA's experience provides valuable lessons for other emerging market economies also seeking to build bond markets. The sophistication of the local bond market is not enough to make it appealing to foreign borrowers. Market development demands an enabling market infrastructure and a background of macroeconomic stability, diversified market participants, deregulation of capital flows and an appropriate regulatory and supervisory environment.
- Full Text:
- Date Issued: 2009
Call centres as a vehicle to improve customer satisfaction in local government: a case study of front line workers in the Nelson Mandela Metropolitan Municipality
- Authors: Magoqwana, Babalwa Mirianda
- Date: 2009
- Subjects: Nelson Mandela Metropolitan Municipality (Eastern Cape, South Africa) Local government -- South Africa -- Eastern Cape -- Case studies Local government -- South Africa -- Eastern Cape -- Case studies Public administration -- South Africa -- Eastern Cape -- Case studies Work environment -- South Africa -- Eastern Cape -- Case studies Customer services -- South Africa -- Eastern Cape -- Case studies Customer satisfaction -- South Africa -- Eastern Cape -- Case studies Municipal services -- South Africa -- Eastern Cape -- Case studies Call center agents -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3340 , http://hdl.handle.net/10962/d1004339
- Description: This dissertation provides an account of 'Batho Pele' (People First) and 'new public management' as applied in two government call-centres in the Eastern Cape. Focusing on the workers at these call-centres, this research examines the workplace organisation of these call-centres based in the Nelson Mandela Metropolitan Municipality. The study involved interviews with managers, call-centre operators and trade unionists. The findings show how the work environment is not conducive to the goals of customer satisfaction as presented in the Batho Pele policies. The research investigates the conditions of workers as one explanatory factor for poor call-centre service. If workers are a key element in the success of the 'new public management', their work environment and conditions have to facilitate their job satisfaction and their improved customer service. The research demonstrated the evident lack of professionalism in the call-centre, customer care designed as a matter of compliance rather the need to change the culture and the persistent lack of discipline and supervision. The call centre operator's experiences include issues of surveillance, stress, emotional labour, lack of training, internal conflicts and bad 'customer service' as perceived by the citizens of the Metro.
- Full Text:
- Date Issued: 2009
- Authors: Magoqwana, Babalwa Mirianda
- Date: 2009
- Subjects: Nelson Mandela Metropolitan Municipality (Eastern Cape, South Africa) Local government -- South Africa -- Eastern Cape -- Case studies Local government -- South Africa -- Eastern Cape -- Case studies Public administration -- South Africa -- Eastern Cape -- Case studies Work environment -- South Africa -- Eastern Cape -- Case studies Customer services -- South Africa -- Eastern Cape -- Case studies Customer satisfaction -- South Africa -- Eastern Cape -- Case studies Municipal services -- South Africa -- Eastern Cape -- Case studies Call center agents -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3340 , http://hdl.handle.net/10962/d1004339
- Description: This dissertation provides an account of 'Batho Pele' (People First) and 'new public management' as applied in two government call-centres in the Eastern Cape. Focusing on the workers at these call-centres, this research examines the workplace organisation of these call-centres based in the Nelson Mandela Metropolitan Municipality. The study involved interviews with managers, call-centre operators and trade unionists. The findings show how the work environment is not conducive to the goals of customer satisfaction as presented in the Batho Pele policies. The research investigates the conditions of workers as one explanatory factor for poor call-centre service. If workers are a key element in the success of the 'new public management', their work environment and conditions have to facilitate their job satisfaction and their improved customer service. The research demonstrated the evident lack of professionalism in the call-centre, customer care designed as a matter of compliance rather the need to change the culture and the persistent lack of discipline and supervision. The call centre operator's experiences include issues of surveillance, stress, emotional labour, lack of training, internal conflicts and bad 'customer service' as perceived by the citizens of the Metro.
- Full Text:
- Date Issued: 2009
Challenging retributivist intuitions
- Authors: Hawkes, Jonathan
- Date: 2009
- Subjects: Lex talionis Punishment -- Philosophy Restorative justice
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2711 , http://hdl.handle.net/10962/d1002841
- Description: Can punishment, a practice which involves the deliberate infliction of suffering, be justified? Retributivists and consequentialists argue that punishment can be justified, whereas abolitionists argue that it cannot. Retributivists argue that punishment is justified because wrongdoers deserve it, whereas punishment is justified for consequentialists because it is beneficial for society. A popular form of abolitionism is restorative justice, which is the view that all those affected by crime (perpetrators, victims and members of society) should be reconciled. In this thesis I argue that retributivist justifications for punishment are mistaken, and argue in favour of a consequentialist view. I also argue that consequentialism can accommodate the valuable features of restorative justice while avoiding the challenges faced by it. My arguments against retributivism will turn on a thought experiment. The experiment is designed to draw out the fundamental retributivist intuition that people who cause harm deserve to suffer harm in return, yet excludes most of the principles retributivists would use to justify the intuition. I will go on to argue that, even if the retributivist considerations did apply to the experiment, they would still not justify the claim that wrongdoers deserve to be punished. Most of the retributivist considerations are, therefore, not necessary for the intuition, and none of the considerations are sufficient for it. The retributivist considerations are, I contend, rationalisations, as the claim that wrongdoers deserve to suffer is based, not on good reasons, but on an unreliable intuition. I shall argue that the consequentialist considerations, while not being necessary, are sufficient for the claim that wrongdoers should be punished, and they should be punished, I maintain, in the interests of preventing greater harm from occurring.
- Full Text:
- Date Issued: 2009
- Authors: Hawkes, Jonathan
- Date: 2009
- Subjects: Lex talionis Punishment -- Philosophy Restorative justice
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2711 , http://hdl.handle.net/10962/d1002841
- Description: Can punishment, a practice which involves the deliberate infliction of suffering, be justified? Retributivists and consequentialists argue that punishment can be justified, whereas abolitionists argue that it cannot. Retributivists argue that punishment is justified because wrongdoers deserve it, whereas punishment is justified for consequentialists because it is beneficial for society. A popular form of abolitionism is restorative justice, which is the view that all those affected by crime (perpetrators, victims and members of society) should be reconciled. In this thesis I argue that retributivist justifications for punishment are mistaken, and argue in favour of a consequentialist view. I also argue that consequentialism can accommodate the valuable features of restorative justice while avoiding the challenges faced by it. My arguments against retributivism will turn on a thought experiment. The experiment is designed to draw out the fundamental retributivist intuition that people who cause harm deserve to suffer harm in return, yet excludes most of the principles retributivists would use to justify the intuition. I will go on to argue that, even if the retributivist considerations did apply to the experiment, they would still not justify the claim that wrongdoers deserve to be punished. Most of the retributivist considerations are, therefore, not necessary for the intuition, and none of the considerations are sufficient for it. The retributivist considerations are, I contend, rationalisations, as the claim that wrongdoers deserve to suffer is based, not on good reasons, but on an unreliable intuition. I shall argue that the consequentialist considerations, while not being necessary, are sufficient for the claim that wrongdoers should be punished, and they should be punished, I maintain, in the interests of preventing greater harm from occurring.
- Full Text:
- Date Issued: 2009
Characterisation of the cellulolytic and hemicellulolytic system of Bacillus Licheniformis SVD1 and the isolation and characterisation of a multi-enzyme complex
- Authors: Van Dyk, Jacoba Susanna
- Date: 2009
- Subjects: Lignocellulose Lignocellulose -- Biotechnology Lignocellulose -- Biodegradation Plant biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3936 , http://hdl.handle.net/10962/d1003995
- Description: The biological degradation of lignocellulose into fermentable sugars for the production of liquid transportation fuels is feasible and sustainable, but equires a variety of enzymes working in synergy as lignocellulose is a complex and recalcitrant substrate. The cellulosome is a multi-enzyme complex (MEC) with a variety of cellulolytic and hemicellulolytic enzymes that appears to facilitate an enhanced synergy and efficiency, as compared to free enzymes, for the degradation of recalcitrant substrates such as lignocellulose and plant cell walls. Most of the studies on cellulosomes have focused on a few organisms; C. thermocellum, C. cellulovorans and C. cellulolyticum, and there is only limited knowledge vailable on similar complexes in other organisms. Some MECs have been identified in aerobic bacteria such as Bacillus circulans and Paenibacillus curdlanolyticus, but the nature of these MECs have not been fully elucidated. This study investigated the cellulolytic and emi-cellulolytic system of Bacillus licheniformis SVD1 with specific reference to the presence of a MEC, which has never been reported in the literature for B. licheniformis. A MEC of approximately 2,000 kDa in size, based on size exclusion chromatography using Sepharose 4B, was purified from a culture of B. licheniformis. When investigating the presence of enzyme activity in the total crude fraction as well as the MEC of a birchwood xylan culture, B. licheniformis was found to display a variety of enzyme activities on a range of substrates, although xylanases were by far the predominant enzyme activity present in both the crude and MEC fractions. Based on zymogram analysis there were three CMCases, seven xylanases, three mannanases and two pectinases in the crude fraction, while the MEC had two CMCases, seven xylanases, two mannanases and one pectinase. The pectinases in the crude could be identified as a pectin methyl esterase and a lyase, while the methyl esterase was absent in the MEC. Seventeen protein species could be detected in the MEC but only nine of these displayed activity on the substrates tested. The possible presence of a β-xylosidase in the crude fraction was deduced from thin layer chromatography (TLC) which demonstrated the production of xylose by the crude fraction. It was furthermore established that B. licheniformis SVD1 was able to regulate levels of enzyme expression based on the substrate the organism was cultured on. It was found that complexed xylanase activity had a pH optimum of between pH 6.0 and 7.0 and a temperature optimum of 55oC. Complexed xylanase activity was found to be slightly inhibited by CaCl2 and inhibited to a greater extent by EDTA. Complexed xylanase activity was further shown to be activated in the presence of xylose and xylobiose, both compounds which are products of enzymatic degradation. Ethanol was found to inhibit complexed xylanase activity. The kinetic parameters for complexed xylanase activity were measured and the Km value was calculated as 2.84 mg/ml while the maximal velocity (Vmax) was calculated as 0.146 U (μmol/min/ml). Binding studies, transmission electron microscopy (TEM) and a bioinformatic analysis was conducted to investigate whether the MEC in B. licheniformis SVD1 was a putative cellulosome. The MEC was found to be unable to bind to Avicel, but was able to bind to insoluble birchwood xylan, indicating the absence of a CBM3a domain common to cellulosomal scaffoldin proteins. TEM micrographs revealed the presence of cell surface structures on cells of B. licheniformis SVD1 cultured on cellobiose and birchwood xylan. However, it could not be established whether these cell surface structures could be ascribed to the presence of the MECs on the cell surface. Bioinformatic analysis was conducted on the available genome sequence of a different strain of B. licheniformis, namely DSM 13 and ATCC 14580. No sequence homology was found with cohesin and dockerin sequences from various cellulosomal species, indicating that these strains most likely do not encode for a cellulosome. This study described and characterised a MEC that was a functional enzyme complex and did not appear to be a mere aggregation of proteins. It displayed a variety of hemi-cellulolytic activities and the available evidence suggests that it is not a cellulosome, but should rather be termed a xylanosome. Further investigation should be carried out to determine the structural basis of this MEC.
- Full Text:
- Date Issued: 2009
- Authors: Van Dyk, Jacoba Susanna
- Date: 2009
- Subjects: Lignocellulose Lignocellulose -- Biotechnology Lignocellulose -- Biodegradation Plant biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3936 , http://hdl.handle.net/10962/d1003995
- Description: The biological degradation of lignocellulose into fermentable sugars for the production of liquid transportation fuels is feasible and sustainable, but equires a variety of enzymes working in synergy as lignocellulose is a complex and recalcitrant substrate. The cellulosome is a multi-enzyme complex (MEC) with a variety of cellulolytic and hemicellulolytic enzymes that appears to facilitate an enhanced synergy and efficiency, as compared to free enzymes, for the degradation of recalcitrant substrates such as lignocellulose and plant cell walls. Most of the studies on cellulosomes have focused on a few organisms; C. thermocellum, C. cellulovorans and C. cellulolyticum, and there is only limited knowledge vailable on similar complexes in other organisms. Some MECs have been identified in aerobic bacteria such as Bacillus circulans and Paenibacillus curdlanolyticus, but the nature of these MECs have not been fully elucidated. This study investigated the cellulolytic and emi-cellulolytic system of Bacillus licheniformis SVD1 with specific reference to the presence of a MEC, which has never been reported in the literature for B. licheniformis. A MEC of approximately 2,000 kDa in size, based on size exclusion chromatography using Sepharose 4B, was purified from a culture of B. licheniformis. When investigating the presence of enzyme activity in the total crude fraction as well as the MEC of a birchwood xylan culture, B. licheniformis was found to display a variety of enzyme activities on a range of substrates, although xylanases were by far the predominant enzyme activity present in both the crude and MEC fractions. Based on zymogram analysis there were three CMCases, seven xylanases, three mannanases and two pectinases in the crude fraction, while the MEC had two CMCases, seven xylanases, two mannanases and one pectinase. The pectinases in the crude could be identified as a pectin methyl esterase and a lyase, while the methyl esterase was absent in the MEC. Seventeen protein species could be detected in the MEC but only nine of these displayed activity on the substrates tested. The possible presence of a β-xylosidase in the crude fraction was deduced from thin layer chromatography (TLC) which demonstrated the production of xylose by the crude fraction. It was furthermore established that B. licheniformis SVD1 was able to regulate levels of enzyme expression based on the substrate the organism was cultured on. It was found that complexed xylanase activity had a pH optimum of between pH 6.0 and 7.0 and a temperature optimum of 55oC. Complexed xylanase activity was found to be slightly inhibited by CaCl2 and inhibited to a greater extent by EDTA. Complexed xylanase activity was further shown to be activated in the presence of xylose and xylobiose, both compounds which are products of enzymatic degradation. Ethanol was found to inhibit complexed xylanase activity. The kinetic parameters for complexed xylanase activity were measured and the Km value was calculated as 2.84 mg/ml while the maximal velocity (Vmax) was calculated as 0.146 U (μmol/min/ml). Binding studies, transmission electron microscopy (TEM) and a bioinformatic analysis was conducted to investigate whether the MEC in B. licheniformis SVD1 was a putative cellulosome. The MEC was found to be unable to bind to Avicel, but was able to bind to insoluble birchwood xylan, indicating the absence of a CBM3a domain common to cellulosomal scaffoldin proteins. TEM micrographs revealed the presence of cell surface structures on cells of B. licheniformis SVD1 cultured on cellobiose and birchwood xylan. However, it could not be established whether these cell surface structures could be ascribed to the presence of the MECs on the cell surface. Bioinformatic analysis was conducted on the available genome sequence of a different strain of B. licheniformis, namely DSM 13 and ATCC 14580. No sequence homology was found with cohesin and dockerin sequences from various cellulosomal species, indicating that these strains most likely do not encode for a cellulosome. This study described and characterised a MEC that was a functional enzyme complex and did not appear to be a mere aggregation of proteins. It displayed a variety of hemi-cellulolytic activities and the available evidence suggests that it is not a cellulosome, but should rather be termed a xylanosome. Further investigation should be carried out to determine the structural basis of this MEC.
- Full Text:
- Date Issued: 2009
Characterisation of the plasmodium falciparum Hsp40 chaperones and their partnerships with Hsp70
- Authors: Botha, Melissa
- Date: 2009
- Subjects: Heat shock proteins Plasmodium falciparum Protein folding Molecular chaperones Malaria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3938 , http://hdl.handle.net/10962/d1003997
- Description: Central to this research, 40 kDa Heat shock proteins (Hsp40s) are known to partner (or cochaperone) 70 kDa Heat shock proteins (Hsp70s), facilitating the selection and transfer of protein substrate to Hsp70 and the stimulation of the protein folding ability of Hsp70. Members of the diverse Hsp70-Hsp40 protein complement of Plasmodium falciparum have been implicated in the cytoprotection of this malaria parasite, and are thought to facilitate the protein folding, assembly and translocation tasks required by the parasite to commandeer the infected human erythrocyte subsequent to invasion. In particular, the parasite has evolved an expanded and specialised 43- member suite of Hsp40 proteins, 19 of which bear an identifiable export motif for secretion into the infected erythrocyte cytoplasm where they potentially interact with human Hsp70. Although type I Hsp40 proteins are representative of typical regulators of Hsp70 activity, only two of these proteins are apparent in the parasite’s Hsp40 complement. These include a characteristic type I Hsp40 termed PfHsp40, and a larger, atypical type I Hsp40 termed Pfj1. Both Hsp40 proteins are predicted to be parasite-resident and are most likely to facilitate the co-chaperone regulation of the highly abundant and stress-inducible Hsp70 homolog, PfHsp70-I. In this work, the co-chaperone functionality of PfHsp40 and Pfj1 was elucidated using in vivo and in vitro assays. Purified recombinant PfHsp40 was shown to stimulate the ATPase activity of PfHsp70-I in in vitro single turnover and steady state ATPase assays, and co-operate with PfHsp70-I in in vitro aggregation suppression assays. In these in vitro assays, heterologous partnerships could be demonstrated between PfHsp70-I and the human Hsp40, Hsj1a, and human Hsp70 and PfHsp40, suggesting a common mode of Hsp70-Hsp40 interaction in the parasite and host organism. The functionality of the signature Hsp40 domain, the Jdomain, of Pfj1 was demonstrated by its ability to replace the equivalent domain of the A. tumefaciens Hsp40, Agt DnaJ, in interactions with the prokaryotic Hsp70, DnaK, in the thermosensitive dnaJ cbpA E. coli OD259 deletion strain. An H33Q mutation introduced into the invariant and crucial HPD tripeptide motif abrogated the functionality of the J-domain in the in vivo complementation system. These findings provide the first evidence for the conservation of the prototypical mode of J-domain based interaction of Hsp40 with Hsp70 in P. falciparum. Immunofluorescence staining revealed the localisation of PfHsp40 to the parasite cytoplasm, and Pfj1 to the parasite cytoplasm and nucleus in cultured intraerythrocytic stage P. falciparum parasites. PfHsp70-I was also shown to localise to the parasite cytoplasm and nucleus in these stages, consistent with the literature. Overall we propose that PfHsp40 and Pfj1 co-localise with and regulate the chaperone activity of PfHsp70-I in P. falciparum. This is the first study to identify and provide evidence for a functional Hsp70-Hsp40 partnership in P. falciparum, and provides a platform for future studies to elucidate the importance of these chaperone partnerships in the establishment and survival of the parasite in the intraerythrocytic-stages of development.
- Full Text:
- Date Issued: 2009
- Authors: Botha, Melissa
- Date: 2009
- Subjects: Heat shock proteins Plasmodium falciparum Protein folding Molecular chaperones Malaria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3938 , http://hdl.handle.net/10962/d1003997
- Description: Central to this research, 40 kDa Heat shock proteins (Hsp40s) are known to partner (or cochaperone) 70 kDa Heat shock proteins (Hsp70s), facilitating the selection and transfer of protein substrate to Hsp70 and the stimulation of the protein folding ability of Hsp70. Members of the diverse Hsp70-Hsp40 protein complement of Plasmodium falciparum have been implicated in the cytoprotection of this malaria parasite, and are thought to facilitate the protein folding, assembly and translocation tasks required by the parasite to commandeer the infected human erythrocyte subsequent to invasion. In particular, the parasite has evolved an expanded and specialised 43- member suite of Hsp40 proteins, 19 of which bear an identifiable export motif for secretion into the infected erythrocyte cytoplasm where they potentially interact with human Hsp70. Although type I Hsp40 proteins are representative of typical regulators of Hsp70 activity, only two of these proteins are apparent in the parasite’s Hsp40 complement. These include a characteristic type I Hsp40 termed PfHsp40, and a larger, atypical type I Hsp40 termed Pfj1. Both Hsp40 proteins are predicted to be parasite-resident and are most likely to facilitate the co-chaperone regulation of the highly abundant and stress-inducible Hsp70 homolog, PfHsp70-I. In this work, the co-chaperone functionality of PfHsp40 and Pfj1 was elucidated using in vivo and in vitro assays. Purified recombinant PfHsp40 was shown to stimulate the ATPase activity of PfHsp70-I in in vitro single turnover and steady state ATPase assays, and co-operate with PfHsp70-I in in vitro aggregation suppression assays. In these in vitro assays, heterologous partnerships could be demonstrated between PfHsp70-I and the human Hsp40, Hsj1a, and human Hsp70 and PfHsp40, suggesting a common mode of Hsp70-Hsp40 interaction in the parasite and host organism. The functionality of the signature Hsp40 domain, the Jdomain, of Pfj1 was demonstrated by its ability to replace the equivalent domain of the A. tumefaciens Hsp40, Agt DnaJ, in interactions with the prokaryotic Hsp70, DnaK, in the thermosensitive dnaJ cbpA E. coli OD259 deletion strain. An H33Q mutation introduced into the invariant and crucial HPD tripeptide motif abrogated the functionality of the J-domain in the in vivo complementation system. These findings provide the first evidence for the conservation of the prototypical mode of J-domain based interaction of Hsp40 with Hsp70 in P. falciparum. Immunofluorescence staining revealed the localisation of PfHsp40 to the parasite cytoplasm, and Pfj1 to the parasite cytoplasm and nucleus in cultured intraerythrocytic stage P. falciparum parasites. PfHsp70-I was also shown to localise to the parasite cytoplasm and nucleus in these stages, consistent with the literature. Overall we propose that PfHsp40 and Pfj1 co-localise with and regulate the chaperone activity of PfHsp70-I in P. falciparum. This is the first study to identify and provide evidence for a functional Hsp70-Hsp40 partnership in P. falciparum, and provides a platform for future studies to elucidate the importance of these chaperone partnerships in the establishment and survival of the parasite in the intraerythrocytic-stages of development.
- Full Text:
- Date Issued: 2009
Characterisation of Trypanosomal Type III and Type IV Hsp40 proteins
- Louw, Cassandra Alexandrovna
- Authors: Louw, Cassandra Alexandrovna
- Date: 2009
- Subjects: Trypanosoma Heat shock proteins African trypanosomiasis Epidemic encephalitis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3926 , http://hdl.handle.net/10962/d1003985
- Description: The heat shock protein-70 (Hsp70) family of molecular chaperones are ubiquitous highly conserved proteins that are critical for the viability of cellular homeostasis. The ATPase activity of Hsp70 proteins is critical to their function as the affinity of a given Hsp70 for non-native substrate is modulated by ATP binding and hydrolysis. When bound to ATP, Hsp70s possess a low affinity for a given substrate protein, while the hydrolysis of ATP to ADP causes a conformational change that results in a high affinity for substrate proteins. The basal ATPase activity of Hsp70s is too low to facilitate their function in vivo, and co-chaperones are essential to modulate the efficient protein folding by Hsp70. Heat shock protein-40 (Hsp40) heat shock proteins are essential for the in vivo function of Hsp70s by stimulating the ATPase activity of these proteins and facilitating transfer of substrates. The Type III class of Hsp40 proteins have not been well characterised due to their poor levels of conservation at the primary sequence level. This is due to the fact that Type III Hsp40s only contain a J-domain and a poorly conserved C-terminal region. The newly identified Type IV class of Hsp40s, contain an abrogated HPD tripeptide motif in the J-domain and have also not been extensively studied. Trypanosoma brucei (T. brucei) is a unicellular flagellated protozoan parasite. It is the causative agent of Human African Trypansomiasis (HAT) which results in thousands of deaths and devastating agricultural losses in many parts of Africa. T. brucei undergoes a complex lifecycle that is characterised by the transition from an insect vector to a mammalian host in markedly different conditions of temperature, pH, nutrient availability and respiratory requirements. It has been proposed that molecular chaperones may enhance the survival of these parasites due to their cytoprotective effect in combating cellular stress. Due to the fact that T. brucei infection is invariably fatal if left untreated, and that no novel treatment regimens have been developed recently, the identification of potential novel drug targets among proteins essential to the parasite’s survival in the host organism is an attractive aspect of T. brucei research. Because Type III Hsp40s are poorly conserved with respect to Hsp40s found in the human host, the identification of any of these proteins found to be essential to T. brucei survival in humans could potentially make attractive novel drug targets. An in depth in silico investigation into the Type III Hsp40 complement as well as partner Hsp70 proteins in T.brucei was performed. T. brucei possesses 65 Hsp40 proteins, of which 47 were classed as Type III and 6 of which were identified as being putative Type IV Hsp40s. A small but significant number (5) of Type III TbHsp40s contained tetratricopeptide (TPR) domains in addition to the J-domain. The J-domains of the Type III TbHsp40 complement were found to be conserved with respect to those of canonical Hsp40 proteins, although the mutation of certain residues that play a key role in Hsp40-Hsp70 interaction was noted. Potential partnerships of these proteins in the parasite was also investigated. The coding regions of three previously uncharacterised TbHsp40s were successfully amplified from T. brucei TREU927 genomic DNA and cloned into an expression vector. Tbj1, a Tcj1 ortholog, was selected for further study and successfully expressed and biochemically characterised. Tbj1 expressed in E. coli was found to be insoluble, but large amounts were recovered with the aid of a denaturing purification followed by refolding elution strategies, and the bulk of the protein recovered was in compact monomeric form as determined by size-exclusion chromatography fast protein liquid chromatography (SEC-FPLC). The addition of Tbj1 to a thermally aggregated substrate resulted in increased levels of aggregation, although Tbj1 was able to assist two Hsp70 proteins in the suppression of aggregation. Tbj1 proved unable to stimulate the ATPase activity of these same Hsp70s, and could not rescue temperature sensitive cells when replacing E.coli DnaJ and CbpA. It was concluded that Tbj1 does not possess independent chaperone activity, but could display Hsp40 co-chaperone properties under certain circumstances. This could allude to a specialised function in the T. brucei parasite. The lack of human orthologues to Tbj1 could result in the attractiveness of this protein as a novel drug target.
- Full Text:
- Date Issued: 2009
- Authors: Louw, Cassandra Alexandrovna
- Date: 2009
- Subjects: Trypanosoma Heat shock proteins African trypanosomiasis Epidemic encephalitis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3926 , http://hdl.handle.net/10962/d1003985
- Description: The heat shock protein-70 (Hsp70) family of molecular chaperones are ubiquitous highly conserved proteins that are critical for the viability of cellular homeostasis. The ATPase activity of Hsp70 proteins is critical to their function as the affinity of a given Hsp70 for non-native substrate is modulated by ATP binding and hydrolysis. When bound to ATP, Hsp70s possess a low affinity for a given substrate protein, while the hydrolysis of ATP to ADP causes a conformational change that results in a high affinity for substrate proteins. The basal ATPase activity of Hsp70s is too low to facilitate their function in vivo, and co-chaperones are essential to modulate the efficient protein folding by Hsp70. Heat shock protein-40 (Hsp40) heat shock proteins are essential for the in vivo function of Hsp70s by stimulating the ATPase activity of these proteins and facilitating transfer of substrates. The Type III class of Hsp40 proteins have not been well characterised due to their poor levels of conservation at the primary sequence level. This is due to the fact that Type III Hsp40s only contain a J-domain and a poorly conserved C-terminal region. The newly identified Type IV class of Hsp40s, contain an abrogated HPD tripeptide motif in the J-domain and have also not been extensively studied. Trypanosoma brucei (T. brucei) is a unicellular flagellated protozoan parasite. It is the causative agent of Human African Trypansomiasis (HAT) which results in thousands of deaths and devastating agricultural losses in many parts of Africa. T. brucei undergoes a complex lifecycle that is characterised by the transition from an insect vector to a mammalian host in markedly different conditions of temperature, pH, nutrient availability and respiratory requirements. It has been proposed that molecular chaperones may enhance the survival of these parasites due to their cytoprotective effect in combating cellular stress. Due to the fact that T. brucei infection is invariably fatal if left untreated, and that no novel treatment regimens have been developed recently, the identification of potential novel drug targets among proteins essential to the parasite’s survival in the host organism is an attractive aspect of T. brucei research. Because Type III Hsp40s are poorly conserved with respect to Hsp40s found in the human host, the identification of any of these proteins found to be essential to T. brucei survival in humans could potentially make attractive novel drug targets. An in depth in silico investigation into the Type III Hsp40 complement as well as partner Hsp70 proteins in T.brucei was performed. T. brucei possesses 65 Hsp40 proteins, of which 47 were classed as Type III and 6 of which were identified as being putative Type IV Hsp40s. A small but significant number (5) of Type III TbHsp40s contained tetratricopeptide (TPR) domains in addition to the J-domain. The J-domains of the Type III TbHsp40 complement were found to be conserved with respect to those of canonical Hsp40 proteins, although the mutation of certain residues that play a key role in Hsp40-Hsp70 interaction was noted. Potential partnerships of these proteins in the parasite was also investigated. The coding regions of three previously uncharacterised TbHsp40s were successfully amplified from T. brucei TREU927 genomic DNA and cloned into an expression vector. Tbj1, a Tcj1 ortholog, was selected for further study and successfully expressed and biochemically characterised. Tbj1 expressed in E. coli was found to be insoluble, but large amounts were recovered with the aid of a denaturing purification followed by refolding elution strategies, and the bulk of the protein recovered was in compact monomeric form as determined by size-exclusion chromatography fast protein liquid chromatography (SEC-FPLC). The addition of Tbj1 to a thermally aggregated substrate resulted in increased levels of aggregation, although Tbj1 was able to assist two Hsp70 proteins in the suppression of aggregation. Tbj1 proved unable to stimulate the ATPase activity of these same Hsp70s, and could not rescue temperature sensitive cells when replacing E.coli DnaJ and CbpA. It was concluded that Tbj1 does not possess independent chaperone activity, but could display Hsp40 co-chaperone properties under certain circumstances. This could allude to a specialised function in the T. brucei parasite. The lack of human orthologues to Tbj1 could result in the attractiveness of this protein as a novel drug target.
- Full Text:
- Date Issued: 2009
Civil society's quest for democracy in Zimbabwe: origins,barriers and prospects, 1900-2008
- Authors: Magure, Booker
- Date: 2009
- Subjects: Civil Society -- Zimbabwe Zimbabwe -- Politics and government -- 1980 Zimbabwe -- Economic conditions Zimbabwe -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2798 , http://hdl.handle.net/10962/d1003008
- Description: This thesis is a critical examination of the origins, barriers and prospects for a working class-led civil society as it sought to democratise Zimbabwe’s post-colonial state. It is an interdisciplinary but historically informed analysis of how advanced capitalist development promoted the emergence of social movement unionism with a potentiality to advance democracy in Zimbabwe. Despite occurring on a much smaller and thinner scale, the evolution of civil society in colonial Zimbabwe was akin to what happened in 19th century Britain where capitalist expansion presented a foundation for democratisation. However, big underlying barriers exist in Zimbabwe, resulting from various forms of authoritarian structures and forcible mobilisation strategies emanating from colonialism and the protracted war of liberation. ZANU PF’s violent reaction to memory contests by non-participants in the war of liberation seeking an alternative political agenda attest to the controversial and polemical nature of struggles over memory and forgetting in contemporary Zimbabwean politics. These structural impediments forestalled the organic growth of civil society in Zimbabwe, thereby explaining its inchoate status and the failure to significantly determine the course of public policy. While recognising the democratic aspirations and capacities of the working class in precipitating political change, this thesis takes into consideration the impact of other factors on state-society relations. These include deepening state barbarism, globalisation, and technological advances in communication, transnational civil society, a dysfunctional economy, migration and remittances. Finally this thesis presents an optimistic scenario about the prospects for civil society and democratisation in Zimbabwe. I argue that the revival of the productive sectors of the economy can possibly strengthen the labour movement and revive its capacities for ushering in a democracy.
- Full Text:
- Date Issued: 2009
- Authors: Magure, Booker
- Date: 2009
- Subjects: Civil Society -- Zimbabwe Zimbabwe -- Politics and government -- 1980 Zimbabwe -- Economic conditions Zimbabwe -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2798 , http://hdl.handle.net/10962/d1003008
- Description: This thesis is a critical examination of the origins, barriers and prospects for a working class-led civil society as it sought to democratise Zimbabwe’s post-colonial state. It is an interdisciplinary but historically informed analysis of how advanced capitalist development promoted the emergence of social movement unionism with a potentiality to advance democracy in Zimbabwe. Despite occurring on a much smaller and thinner scale, the evolution of civil society in colonial Zimbabwe was akin to what happened in 19th century Britain where capitalist expansion presented a foundation for democratisation. However, big underlying barriers exist in Zimbabwe, resulting from various forms of authoritarian structures and forcible mobilisation strategies emanating from colonialism and the protracted war of liberation. ZANU PF’s violent reaction to memory contests by non-participants in the war of liberation seeking an alternative political agenda attest to the controversial and polemical nature of struggles over memory and forgetting in contemporary Zimbabwean politics. These structural impediments forestalled the organic growth of civil society in Zimbabwe, thereby explaining its inchoate status and the failure to significantly determine the course of public policy. While recognising the democratic aspirations and capacities of the working class in precipitating political change, this thesis takes into consideration the impact of other factors on state-society relations. These include deepening state barbarism, globalisation, and technological advances in communication, transnational civil society, a dysfunctional economy, migration and remittances. Finally this thesis presents an optimistic scenario about the prospects for civil society and democratisation in Zimbabwe. I argue that the revival of the productive sectors of the economy can possibly strengthen the labour movement and revive its capacities for ushering in a democracy.
- Full Text:
- Date Issued: 2009
Clem Sunter's transformational leadership discourse: a linguistic analysis
- Authors: Eley, Georgina Jane
- Date: 2009
- Subjects: Linguistics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/61994 , vital:28093
- Description: Since the 1970s, two distinct leadership styles have been recognised in the fields of business and organisational research - transactional and transformational leadership. Transactional leadership is seen to resemble managerial-type leadership where followers fulfil their duties in return for rewards that satisfy their self-interest, such as pay or promotion. Transformational leadership, as the label suggests, is leadership that is seen to transform followers from their everyday selves to their better selves (Yukl 1998). Transformational leaders motivate followers by appealing to their higher-order needs, offering incentives for compliance such as feelings of personal empowerment, a sense of moral self-actualisation and an emphasis on the individual's contribution to the community at large (Harvey 2004). These leaders have been observed to emerge and thrive within contexts fraught with socio-political and economic turbulence, where they maximise the uncertainty of the environment to instigate change. Transformational leaders are seen to be especially adept at using discourse to foster strong, persuasive interpersonal relations with their followers. This research reports on, particularly, the interpersonal dimension of Clem Sunter's transformational discourse; he being a prominent South African scenario planner and business leader. It is essentially a qualitative study that describes Sunter's discourse in three of his texts written in 1996. The end to Apartheid in 1994 and transition from White to Black governance meant that the socio-political climate of 1996 South Africa was conducive to the rise of a transformational leader like Sunter. Although the country was, ostensibly, a democracy in 1996, much social transformation was still needed at the time Sunter produced his texts. The analysis are grounded mainly in Systemic Functional Linguistics, specifically APPRAISAL theory and, to some extent, Critical Discourse Analysis theory. However, the analyses do not follow a classic CDA analysis approach, but draw rather from more recent CDA work (cf. Fairclough 2003), such as the analysis of value assumption types within the texts. This analysis clearly demonstrates that Sunter's discourse is congruent 11 with the principal insights of transformational leadership. More than this, it is argued that these findings suggest a close link between transformational leadership and the goals of the latest social order of new capitalism, a link not made in the relevant research to date. The analysis of modes of operation of ideology in the texts (cf. Thompson 1990), also deriving from CDA, reinforces this, indicating that Sunter's transformational discourse promotes and maintains the kinds of power inequalities that underpin new capitalism. The APPRAISAL analysis of Affect choices in the text reveals a high frequency of disquiet, i.e. Sunter's discourse is seen to generate feelings of insecurity and fear. This feature, interestingly, is completely inconsistent with current transformational leadership theory, but would have been an effective motivational technique given the instability of the South African socio-political context in 1996. In addition, the APPRAISAL analysis of Judgement reveals that Sunter evokes high levels of tenacity and appeals to readers' morality, ethics and feelings of group-efficacy - all higher-order needs. The argument here too is that the socio-political context enabled Sunter to stimulate disquiet and tenacity in an effective configuration to mobilise change in his reader and promote the goals of new capitalism. The thesis concludes with a reflection on the limitations of the study and makes various recommendations for future research.
- Full Text:
- Date Issued: 2009
- Authors: Eley, Georgina Jane
- Date: 2009
- Subjects: Linguistics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/61994 , vital:28093
- Description: Since the 1970s, two distinct leadership styles have been recognised in the fields of business and organisational research - transactional and transformational leadership. Transactional leadership is seen to resemble managerial-type leadership where followers fulfil their duties in return for rewards that satisfy their self-interest, such as pay or promotion. Transformational leadership, as the label suggests, is leadership that is seen to transform followers from their everyday selves to their better selves (Yukl 1998). Transformational leaders motivate followers by appealing to their higher-order needs, offering incentives for compliance such as feelings of personal empowerment, a sense of moral self-actualisation and an emphasis on the individual's contribution to the community at large (Harvey 2004). These leaders have been observed to emerge and thrive within contexts fraught with socio-political and economic turbulence, where they maximise the uncertainty of the environment to instigate change. Transformational leaders are seen to be especially adept at using discourse to foster strong, persuasive interpersonal relations with their followers. This research reports on, particularly, the interpersonal dimension of Clem Sunter's transformational discourse; he being a prominent South African scenario planner and business leader. It is essentially a qualitative study that describes Sunter's discourse in three of his texts written in 1996. The end to Apartheid in 1994 and transition from White to Black governance meant that the socio-political climate of 1996 South Africa was conducive to the rise of a transformational leader like Sunter. Although the country was, ostensibly, a democracy in 1996, much social transformation was still needed at the time Sunter produced his texts. The analysis are grounded mainly in Systemic Functional Linguistics, specifically APPRAISAL theory and, to some extent, Critical Discourse Analysis theory. However, the analyses do not follow a classic CDA analysis approach, but draw rather from more recent CDA work (cf. Fairclough 2003), such as the analysis of value assumption types within the texts. This analysis clearly demonstrates that Sunter's discourse is congruent 11 with the principal insights of transformational leadership. More than this, it is argued that these findings suggest a close link between transformational leadership and the goals of the latest social order of new capitalism, a link not made in the relevant research to date. The analysis of modes of operation of ideology in the texts (cf. Thompson 1990), also deriving from CDA, reinforces this, indicating that Sunter's transformational discourse promotes and maintains the kinds of power inequalities that underpin new capitalism. The APPRAISAL analysis of Affect choices in the text reveals a high frequency of disquiet, i.e. Sunter's discourse is seen to generate feelings of insecurity and fear. This feature, interestingly, is completely inconsistent with current transformational leadership theory, but would have been an effective motivational technique given the instability of the South African socio-political context in 1996. In addition, the APPRAISAL analysis of Judgement reveals that Sunter evokes high levels of tenacity and appeals to readers' morality, ethics and feelings of group-efficacy - all higher-order needs. The argument here too is that the socio-political context enabled Sunter to stimulate disquiet and tenacity in an effective configuration to mobilise change in his reader and promote the goals of new capitalism. The thesis concludes with a reflection on the limitations of the study and makes various recommendations for future research.
- Full Text:
- Date Issued: 2009
Clustering algorithms and their effect on edge preservation in image compression
- Authors: Ndebele, Nothando Elizabeth
- Date: 2009
- Subjects: Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5576 , http://hdl.handle.net/10962/d1008210 , Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Description: Image compression aims to reduce the amount of data that is stored or transmitted for images. One technique that may be used to this end is vector quantization. Vectors may be used to represent images. Vector quantization reduces the number of vectors required for an image by representing a cluster of similar vectors by one typical vector that is part of a set of vectors referred to as the code book. For compression, for each image vector, only the closest codebook vector is stored or transmitted. For reconstruction, the image vectors are again replaced by the the closest codebook vectors. Hence vector quantization is a lossy compression technique and the quality of the reconstructed image depends strongly on the quality of the codebook. The design of the codebook is therefore an important part of the process. In this thesis we examine three clustering algorithms which can be used for codebook design in image compression: c-means (CM), fuzzy c-means (FCM) and learning vector quantization (LVQ). We give a description of these algorithms and their application to codebook design. Edges are an important part of the visual information contained in an image. It is essential therefore to use codebooks which allow an accurate representation of the edges. One of the shortcomings of using vector quantization is poor edge representation. We therefore carry out experiments using these algorithms to compare their edge preserving qualities. We also investigate the combination of these algorithms with classified vector quantization (CVQ) and the replication method (RM). Both these methods have been suggested as methods for improving edge representation. We use a cross validation approach to estimate the mean squared error to measure the performance of each of the algorithms and the edge preserving methods. The results reflect that the edges are less accurately represented than the non - edge areas when using CM, FCM and LVQ. The advantage of using CVQ is that the time taken for code book design is reduced particularly for CM and FCM. RM is found to be effective where the codebook is trained using a set that has larger proportions of edges than the test set.
- Full Text:
- Date Issued: 2009
- Authors: Ndebele, Nothando Elizabeth
- Date: 2009
- Subjects: Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5576 , http://hdl.handle.net/10962/d1008210 , Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Description: Image compression aims to reduce the amount of data that is stored or transmitted for images. One technique that may be used to this end is vector quantization. Vectors may be used to represent images. Vector quantization reduces the number of vectors required for an image by representing a cluster of similar vectors by one typical vector that is part of a set of vectors referred to as the code book. For compression, for each image vector, only the closest codebook vector is stored or transmitted. For reconstruction, the image vectors are again replaced by the the closest codebook vectors. Hence vector quantization is a lossy compression technique and the quality of the reconstructed image depends strongly on the quality of the codebook. The design of the codebook is therefore an important part of the process. In this thesis we examine three clustering algorithms which can be used for codebook design in image compression: c-means (CM), fuzzy c-means (FCM) and learning vector quantization (LVQ). We give a description of these algorithms and their application to codebook design. Edges are an important part of the visual information contained in an image. It is essential therefore to use codebooks which allow an accurate representation of the edges. One of the shortcomings of using vector quantization is poor edge representation. We therefore carry out experiments using these algorithms to compare their edge preserving qualities. We also investigate the combination of these algorithms with classified vector quantization (CVQ) and the replication method (RM). Both these methods have been suggested as methods for improving edge representation. We use a cross validation approach to estimate the mean squared error to measure the performance of each of the algorithms and the edge preserving methods. The results reflect that the edges are less accurately represented than the non - edge areas when using CM, FCM and LVQ. The advantage of using CVQ is that the time taken for code book design is reduced particularly for CM and FCM. RM is found to be effective where the codebook is trained using a set that has larger proportions of edges than the test set.
- Full Text:
- Date Issued: 2009
Collective forgiving
- Authors: Hamilton, Kelly
- Date: 2009
- Subjects: Forgiveness -- Philosophy Collective behavior -- Philosophy Retribution -- Philosophy Reconciliation -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2709 , http://hdl.handle.net/10962/d1002839
- Description: Forgiveness is traditionally understood as a personal change of heart, in which an individual victim of a wrongdoing overcomes her resentment towards the perpetrator of that wrongdoing. Peter Strawson (1974) famously argued that resentment is a personal participant retributive reactive attitude, and the overcoming of such an attitude through forgiveness is itself a personal reactive attitude – in other words, forgiveness is an affective response to a wrongdoing by an individual victim, that is devoid of a retributive element. Because reactive attitudes are personal, it is argued that collectives – groups of individuals – cannot forgive, since collectives cannot, as collectives, hold reactive attitudes. I argue against this. I show that it is possible for collectives to hold attitudes in a way that is not reducible to individuals holding attitudes as individuals, and yet these attitudes still remain personal. Individuals exist within communities, and are interdependent on one another. Much of an individual‟s beliefs and attitudes depend on the collectives that she is a part of. I argue that an attitude is collective when it is deemed to be the appropriate attitude for members of the collective to hold. Members of the collective will take this attitude on as their own insofar as they identify themselves as members of the collective. Individuals hold the attitude, making the attitude personal, but since the individuals hold the attitude in virtue of their membership to a collective, the attitude is also collective. Given that forgiveness is itself a reactive attitude, and that collectives can hold attitudes, I argue that it is possible for a collective to forgive. Members of a collective will come to forgive when forgiveness is held up as the appropriate attitude for them, and once enough members have taken on the attitude of forgiveness as their own attitude, a collective can be said to have forgiven.
- Full Text:
- Date Issued: 2009
- Authors: Hamilton, Kelly
- Date: 2009
- Subjects: Forgiveness -- Philosophy Collective behavior -- Philosophy Retribution -- Philosophy Reconciliation -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2709 , http://hdl.handle.net/10962/d1002839
- Description: Forgiveness is traditionally understood as a personal change of heart, in which an individual victim of a wrongdoing overcomes her resentment towards the perpetrator of that wrongdoing. Peter Strawson (1974) famously argued that resentment is a personal participant retributive reactive attitude, and the overcoming of such an attitude through forgiveness is itself a personal reactive attitude – in other words, forgiveness is an affective response to a wrongdoing by an individual victim, that is devoid of a retributive element. Because reactive attitudes are personal, it is argued that collectives – groups of individuals – cannot forgive, since collectives cannot, as collectives, hold reactive attitudes. I argue against this. I show that it is possible for collectives to hold attitudes in a way that is not reducible to individuals holding attitudes as individuals, and yet these attitudes still remain personal. Individuals exist within communities, and are interdependent on one another. Much of an individual‟s beliefs and attitudes depend on the collectives that she is a part of. I argue that an attitude is collective when it is deemed to be the appropriate attitude for members of the collective to hold. Members of the collective will take this attitude on as their own insofar as they identify themselves as members of the collective. Individuals hold the attitude, making the attitude personal, but since the individuals hold the attitude in virtue of their membership to a collective, the attitude is also collective. Given that forgiveness is itself a reactive attitude, and that collectives can hold attitudes, I argue that it is possible for a collective to forgive. Members of a collective will come to forgive when forgiveness is held up as the appropriate attitude for them, and once enough members have taken on the attitude of forgiveness as their own attitude, a collective can be said to have forgiven.
- Full Text:
- Date Issued: 2009
Comparing and contrasting liberal, communitarian and feminist approaches to resolving tensions between customary and constitutional law: the case of polygamy in Swaziland
- Authors: Manson, Katherine Elizabeth
- Date: 2009
- Subjects: Human rights -- Swaziland Constitutional law -- Swaziland Customary law -- Swaziland Culture and law -- Swaziland Women's rights -- Swaziland Sex discrimination against women -- Swaziland Polygamy -- Swaziland Liberalism Communitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2801 , http://hdl.handle.net/10962/d1003011
- Description: Tensions between the individual rights and freedoms found in constitutional bills of rights and the traditionally prescribed social roles and positions articulated in African customary law systems have often been characterised as tensions between communitarian and liberal philosophies. In particular, the notion of gender equality, which is often a feature of the protections offered by constitutional bills of rights, is seen to be in direct opposition to the overtly patriarchal character of many African customs and traditions. This thesis looks specifically at polygamy, long and widely considered in the West to be an oppressive practice premised on the assumed inferiority of women. The analysis considers the implications of polygamy in a particular cultural context, that of the Kingdom of Swaziland, where the newly instituted constitution is often seen to be incompatible with many aspects of Swazi customary law. Here, the tension between the constitutional commitment to gender equality and the persistence of polygamy as a seemingly discriminatory cultural practice forms a lens through which to view the debate as a whole. The theoretical analysis is supplemented by empirical research sourced from local media archives and in-depth interviews conducted with twelve Swazi women, both unmarried and married in polygamous relationships. Communitarian and liberal approaches to resolving this tension are compared, contrasted and finally critiqued from a feminist standpoint. The feminist critique of both communitarianism and liberalism implies that neither ideology promises much for women and affirms the relatively recent feminist suggestion that the key to resolving tensions between constitutional and customary law in general, and to uplifting the social/legal status of women in particular lies in the enhancement of women’s democratic participation and the improvement of women’s decision-making powers.
- Full Text:
- Date Issued: 2009
- Authors: Manson, Katherine Elizabeth
- Date: 2009
- Subjects: Human rights -- Swaziland Constitutional law -- Swaziland Customary law -- Swaziland Culture and law -- Swaziland Women's rights -- Swaziland Sex discrimination against women -- Swaziland Polygamy -- Swaziland Liberalism Communitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2801 , http://hdl.handle.net/10962/d1003011
- Description: Tensions between the individual rights and freedoms found in constitutional bills of rights and the traditionally prescribed social roles and positions articulated in African customary law systems have often been characterised as tensions between communitarian and liberal philosophies. In particular, the notion of gender equality, which is often a feature of the protections offered by constitutional bills of rights, is seen to be in direct opposition to the overtly patriarchal character of many African customs and traditions. This thesis looks specifically at polygamy, long and widely considered in the West to be an oppressive practice premised on the assumed inferiority of women. The analysis considers the implications of polygamy in a particular cultural context, that of the Kingdom of Swaziland, where the newly instituted constitution is often seen to be incompatible with many aspects of Swazi customary law. Here, the tension between the constitutional commitment to gender equality and the persistence of polygamy as a seemingly discriminatory cultural practice forms a lens through which to view the debate as a whole. The theoretical analysis is supplemented by empirical research sourced from local media archives and in-depth interviews conducted with twelve Swazi women, both unmarried and married in polygamous relationships. Communitarian and liberal approaches to resolving this tension are compared, contrasted and finally critiqued from a feminist standpoint. The feminist critique of both communitarianism and liberalism implies that neither ideology promises much for women and affirms the relatively recent feminist suggestion that the key to resolving tensions between constitutional and customary law in general, and to uplifting the social/legal status of women in particular lies in the enhancement of women’s democratic participation and the improvement of women’s decision-making powers.
- Full Text:
- Date Issued: 2009
Conflict, contradiction and crisis: an analysis of the politics of AIDS policy in post-Apartheid South Africa
- Authors: Fletcher, Haley Kim
- Date: 2009
- Subjects: AIDS (Disease) -- Political aspects -- Africa, Southern AIDS (Disease) -- Political aspects -- South Africa AIDS (Disease) -- Government policy -- South Africa Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2775 , http://hdl.handle.net/10962/d1002985
- Description: Despite the profound impacts of HIV and AIDS on all sectors of South African society, governmental responses to the AIDS epidemic have been inundated with contradiction, conflict and contestation. Though governmental leaders have justified not funding HIV treatment programs because they believe that poverty needs to be dealt with first, social spending has been slashed as part of an adherence to a neo-liberal economic model. Though it would seem that the government would seem to have everything to gain by establishing a cooperative relationship with non-governmental actors regarding the epidemic, the relationship between the government and non-governmental actors has instead been described as nothing short of hostile. Though the government enthusiastically backed Virodene, a supposed treatment for AIDS that turned out to be no more than an industrial solvent, other ‘scientifically backed’ AIDS treatments have been treated with caution and skepticism – to the point where the government even refused to provide funding for programs to prevent mother to child transmission of the virus. And perhaps the most perplexing is that although widely respected for his intellect and cool demeanor, former President Mbeki chose to risk his political career on the AIDS issue by shunning away from the mainstream consensus on the biomedical causes of the epidemic and instead surrounded himself and sought advice from AIDS ‘dissidents’ This thesis will seek explanations for these apparent contradictions. Using Bourdieu’s (1986) typology of capitals, it will build on an argument put forward by Helen Schneider (2002): from the South African government’s perspective, the contestation regarding HIV and AIDS policy and implementation is over symbolic capital, or the right to legitimately hold and exercise political power regarding the epidemic. Though this argument helps explain the conflictual relationship between the government and non-governmental actors regarding the AIDS crisis, in order to understand the perplexing contradictions within the governmental policy response, the political context of policy formation must first be taken into consideration.
- Full Text:
- Date Issued: 2009
- Authors: Fletcher, Haley Kim
- Date: 2009
- Subjects: AIDS (Disease) -- Political aspects -- Africa, Southern AIDS (Disease) -- Political aspects -- South Africa AIDS (Disease) -- Government policy -- South Africa Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2775 , http://hdl.handle.net/10962/d1002985
- Description: Despite the profound impacts of HIV and AIDS on all sectors of South African society, governmental responses to the AIDS epidemic have been inundated with contradiction, conflict and contestation. Though governmental leaders have justified not funding HIV treatment programs because they believe that poverty needs to be dealt with first, social spending has been slashed as part of an adherence to a neo-liberal economic model. Though it would seem that the government would seem to have everything to gain by establishing a cooperative relationship with non-governmental actors regarding the epidemic, the relationship between the government and non-governmental actors has instead been described as nothing short of hostile. Though the government enthusiastically backed Virodene, a supposed treatment for AIDS that turned out to be no more than an industrial solvent, other ‘scientifically backed’ AIDS treatments have been treated with caution and skepticism – to the point where the government even refused to provide funding for programs to prevent mother to child transmission of the virus. And perhaps the most perplexing is that although widely respected for his intellect and cool demeanor, former President Mbeki chose to risk his political career on the AIDS issue by shunning away from the mainstream consensus on the biomedical causes of the epidemic and instead surrounded himself and sought advice from AIDS ‘dissidents’ This thesis will seek explanations for these apparent contradictions. Using Bourdieu’s (1986) typology of capitals, it will build on an argument put forward by Helen Schneider (2002): from the South African government’s perspective, the contestation regarding HIV and AIDS policy and implementation is over symbolic capital, or the right to legitimately hold and exercise political power regarding the epidemic. Though this argument helps explain the conflictual relationship between the government and non-governmental actors regarding the AIDS crisis, in order to understand the perplexing contradictions within the governmental policy response, the political context of policy formation must first be taken into consideration.
- Full Text:
- Date Issued: 2009
Constructing the intellectually disabled person as a subject of education: a discourse analysis using Q-methodology
- Authors: McKenzie, Judith Anne
- Date: 2009
- Subjects: Foucault, Michel, 1926-1984 Learning disabled -- Education -- South Africa Discourse analysis -- Methodology Discourse analysis Children with mental disabilities -- Education -- South Africa Q technique Special education -- South Africa Children with disabilities -- Education -- South Africa Right to education Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3017 , http://hdl.handle.net/10962/d1002526
- Description: The education of intellectually disabled (ID) people is constructed within mass education systems as a problem requiring specialised intervention, separation from “normal” school contexts and the application of professional expertise. A social model of disability resists these practices from a human rights perspective and underpins an inclusive education approach. In this study, a post-structuralist disability studies theoretical framework, drawing particularly on the work of Foucault, was used to examine discourses that construct the intellectually disabled person as a subject of education. The study was conducted in Buffalo City, South Africa at a time when an inclusive education policy is being implemented in the country. The research questions were: What discourses are deployed in the representation and educational practices of those identified as ID? What are the effects of these discourses in constructing the ID subject and associated educational practice? The study utilises Q-methodology, a factor analytic method that yields whole patterns of responses for analysis. A process of sorting selected statements along the dimension of agree to disagree was completed by three groups of participants, namely adults with ID, parents of people with ID and professionals working with ID. Discourses of representation and of educational practice were identified through statistical and interpretive analysis, following the discourse analysis school of Q-methodology. The findings of this study reveal the operation of power in a medico-psychological gaze that makes ID visible and supervises disability expertise within education. Representations of ID suffused with religious notions support the exercise of pastoral power by disability experts. Human rights discourses in education can marginalise ID people if applied uncritically. Fixed notions of impairment constrain an intellectually disabled subject who is vulnerable and incompetent. This study argues instead for a theory of (poss)ability, underpinned by an understanding of the situational and shared nature of competence and a fluid conception of impairment. Human rights should be supplemented by an ethics of care and belonging in the community (ubuntu). A research agenda supporting this effort would examine the ways in which ID people work on themselves as subjects (subjectivisation) and explore the potential for resistance in this process.
- Full Text:
- Date Issued: 2009
- Authors: McKenzie, Judith Anne
- Date: 2009
- Subjects: Foucault, Michel, 1926-1984 Learning disabled -- Education -- South Africa Discourse analysis -- Methodology Discourse analysis Children with mental disabilities -- Education -- South Africa Q technique Special education -- South Africa Children with disabilities -- Education -- South Africa Right to education Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3017 , http://hdl.handle.net/10962/d1002526
- Description: The education of intellectually disabled (ID) people is constructed within mass education systems as a problem requiring specialised intervention, separation from “normal” school contexts and the application of professional expertise. A social model of disability resists these practices from a human rights perspective and underpins an inclusive education approach. In this study, a post-structuralist disability studies theoretical framework, drawing particularly on the work of Foucault, was used to examine discourses that construct the intellectually disabled person as a subject of education. The study was conducted in Buffalo City, South Africa at a time when an inclusive education policy is being implemented in the country. The research questions were: What discourses are deployed in the representation and educational practices of those identified as ID? What are the effects of these discourses in constructing the ID subject and associated educational practice? The study utilises Q-methodology, a factor analytic method that yields whole patterns of responses for analysis. A process of sorting selected statements along the dimension of agree to disagree was completed by three groups of participants, namely adults with ID, parents of people with ID and professionals working with ID. Discourses of representation and of educational practice were identified through statistical and interpretive analysis, following the discourse analysis school of Q-methodology. The findings of this study reveal the operation of power in a medico-psychological gaze that makes ID visible and supervises disability expertise within education. Representations of ID suffused with religious notions support the exercise of pastoral power by disability experts. Human rights discourses in education can marginalise ID people if applied uncritically. Fixed notions of impairment constrain an intellectually disabled subject who is vulnerable and incompetent. This study argues instead for a theory of (poss)ability, underpinned by an understanding of the situational and shared nature of competence and a fluid conception of impairment. Human rights should be supplemented by an ethics of care and belonging in the community (ubuntu). A research agenda supporting this effort would examine the ways in which ID people work on themselves as subjects (subjectivisation) and explore the potential for resistance in this process.
- Full Text:
- Date Issued: 2009
Contextualizing the NCS through the use of school gardens in the Butterworth area
- Authors: Rasi, Nandi
- Date: 2009
- Subjects: South African National Biodiversity Institute , Environmental education -- South Africa , School gardens -- South Africa -- Butterworth , Gardening -- Study and teaching (Elementary) -- South Africa -- Butterworth , Environmental education -- Study and teaching (Elementary) -- South Africa -- Butterworth , Teacher participation in curriculum planning -- South Africa -- Butterworth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1464 , http://hdl.handle.net/10962/d1003345
- Description: The research focuses on how teachers can use school gardens sponsored by South African National Biodiversity Institute as resource materials for teaching and learning. The study also focused on how teachers can integrate local knowledge into the school curriculum. The setting of the research is Zizamele Senior Primary School situated in Zizamele community in Butterworth in the Eastern Cape. The study is designed in portfolio format. It consists of three separate studies: a contextual profile; a stakeholder analysis; and a small-scale action research project, which build on each other. By developing a contextual profile of the research site, and the school community and school gardens project, I was able to collect information that informed the stakeholder analysis and the action research study. Data for the contextual profile was gathered by using a variety of data gathering techniques like questionnaires and interviews. The findings were that: the study area is characterized by socio-economic issues like poverty, unemployment, drug abuse and crime. This requires that the people of the area take responsibility in addressing some of the problems by being involved and knowing where to report issues. The second study, which is the stakeholder analysis, was done to mobilize stakeholders’ contributions to the gardens project in Zizamele School, sponsored by the South African National Biodiversity Institute. Data was collected at meetings and workshops in the schools through interviews. Findings indicated that different stakeholders had various contributions to make and that they were prepared to work with the school and with each other to develop the school garden and the learning potential of the school garden. This paved the way for the small scale action research case study that would follow. The last study, the small scale action research, was undertaken in the same school, Zizamele School, and focused on investigating ways of integrating local knowledge into the curriculum and how teachers use the gardens as resource for teaching and learning, with reference to Life Orientation Learning Area. Data was collected by interviews, questionnaires and worksheets. The study involved two teachers who worked with me on the action research and Grade 5 and 6 learners, as well as some of the community stakeholders. The main finding of the action researched showed the potential for involving community members in the process of integrating local knowledge as a way of implementing aspects of the Life Orientation curriculum requirements. The three studies link with each other, and show that to start with an action research project, one needs to understand the context, and the roles of different stakeholders, and how they might contribute to the programmes in the school. Findings showed that teachers could use gardens as resource materials for teaching and learning, and that they could bring in local knowledge to the school curriculum.
- Full Text:
- Date Issued: 2009
- Authors: Rasi, Nandi
- Date: 2009
- Subjects: South African National Biodiversity Institute , Environmental education -- South Africa , School gardens -- South Africa -- Butterworth , Gardening -- Study and teaching (Elementary) -- South Africa -- Butterworth , Environmental education -- Study and teaching (Elementary) -- South Africa -- Butterworth , Teacher participation in curriculum planning -- South Africa -- Butterworth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1464 , http://hdl.handle.net/10962/d1003345
- Description: The research focuses on how teachers can use school gardens sponsored by South African National Biodiversity Institute as resource materials for teaching and learning. The study also focused on how teachers can integrate local knowledge into the school curriculum. The setting of the research is Zizamele Senior Primary School situated in Zizamele community in Butterworth in the Eastern Cape. The study is designed in portfolio format. It consists of three separate studies: a contextual profile; a stakeholder analysis; and a small-scale action research project, which build on each other. By developing a contextual profile of the research site, and the school community and school gardens project, I was able to collect information that informed the stakeholder analysis and the action research study. Data for the contextual profile was gathered by using a variety of data gathering techniques like questionnaires and interviews. The findings were that: the study area is characterized by socio-economic issues like poverty, unemployment, drug abuse and crime. This requires that the people of the area take responsibility in addressing some of the problems by being involved and knowing where to report issues. The second study, which is the stakeholder analysis, was done to mobilize stakeholders’ contributions to the gardens project in Zizamele School, sponsored by the South African National Biodiversity Institute. Data was collected at meetings and workshops in the schools through interviews. Findings indicated that different stakeholders had various contributions to make and that they were prepared to work with the school and with each other to develop the school garden and the learning potential of the school garden. This paved the way for the small scale action research case study that would follow. The last study, the small scale action research, was undertaken in the same school, Zizamele School, and focused on investigating ways of integrating local knowledge into the curriculum and how teachers use the gardens as resource for teaching and learning, with reference to Life Orientation Learning Area. Data was collected by interviews, questionnaires and worksheets. The study involved two teachers who worked with me on the action research and Grade 5 and 6 learners, as well as some of the community stakeholders. The main finding of the action researched showed the potential for involving community members in the process of integrating local knowledge as a way of implementing aspects of the Life Orientation curriculum requirements. The three studies link with each other, and show that to start with an action research project, one needs to understand the context, and the roles of different stakeholders, and how they might contribute to the programmes in the school. Findings showed that teachers could use gardens as resource materials for teaching and learning, and that they could bring in local knowledge to the school curriculum.
- Full Text:
- Date Issued: 2009