Revised parameter estimation methods for the Pitman monthly rainfall-runoff model
- Authors: Kapangaziwiri, Evison
- Date: 2008
- Subjects: Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models , Water supply -- South Africa , Water resources development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6033 , http://hdl.handle.net/10962/d1006172 , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models , Water supply -- South Africa , Water resources development -- South Africa
- Description: In recent years, increased demands have been placed on hydrologists to find the most effective methods of making predictions of hydrologic variables in ungauged basins. A huge part of the southern African region is ungauged and, in gauged basins, the extent to which observed flows represent natural flows is unknown, given unquantified upstream activities. The need to exploit water resources for social and economic development, considered in the light of water scarcity forecasts for the region, makes the reliable quantification of water resources a priority. Contemporary approaches to the problem of hydrological prediction in ungauged basins in the region have relied heavily on calibration against a limited gauged streamflow database and somewhat subjective parameter regionalizations using areas of assumed hydrological similarity. The reliance of these approaches on limited historical records, often of dubious quality, introduces uncertainty in water resources decisions. Thus, it is necessary to develop methods of estimating model parameters that are less reliant on calibration. This thesis addresses the question of whether physical basin properties and the role they play in runoff generation processes can be used directly in the estimation of parameter values of the Pitman monthly rainfall-runoff model. A physically-based approach to estimating the soil moisture accounting and runoff parameters of a conceptual, monthly time-step rainfall-runoff model is proposed. The study investigates the physical meaning of the model parameters, establishes linkages between parameter values and basin physical properties and develops relationships and equations for estimating the parameters taking into account the spatial and temporal scales used in typical model applications. The estimationmethods are then tested in selected gauged basins in southern Africa and the results of model simulations evaluated against historical observed flows. The results of 71 basins chosen from the southern African region suggest that it is possible to directly estimate hydrologically relevant parameters for the Pitman model from physical basin attributes. For South Africa, the statistical and visual fit of the simulations using the revised parameters were at least as good as the current regional sets, albeit the parameter sets being different. In the other countries where no regionalized parameter sets currently exist, simulations were equally good. The availability, within the southern African region, of the appropriate physical basin data and the disparities in the spatial scales and the levels of detail of the data currently available were identified as potential sources of uncertainty. GIS and remote sensing technologies and a widespread use of this revised approach are expected to facilitate access to these data.
- Full Text:
- Authors: Kapangaziwiri, Evison
- Date: 2008
- Subjects: Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models , Water supply -- South Africa , Water resources development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6033 , http://hdl.handle.net/10962/d1006172 , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Hydrology -- Mathematical models , Water supply -- South Africa , Water resources development -- South Africa
- Description: In recent years, increased demands have been placed on hydrologists to find the most effective methods of making predictions of hydrologic variables in ungauged basins. A huge part of the southern African region is ungauged and, in gauged basins, the extent to which observed flows represent natural flows is unknown, given unquantified upstream activities. The need to exploit water resources for social and economic development, considered in the light of water scarcity forecasts for the region, makes the reliable quantification of water resources a priority. Contemporary approaches to the problem of hydrological prediction in ungauged basins in the region have relied heavily on calibration against a limited gauged streamflow database and somewhat subjective parameter regionalizations using areas of assumed hydrological similarity. The reliance of these approaches on limited historical records, often of dubious quality, introduces uncertainty in water resources decisions. Thus, it is necessary to develop methods of estimating model parameters that are less reliant on calibration. This thesis addresses the question of whether physical basin properties and the role they play in runoff generation processes can be used directly in the estimation of parameter values of the Pitman monthly rainfall-runoff model. A physically-based approach to estimating the soil moisture accounting and runoff parameters of a conceptual, monthly time-step rainfall-runoff model is proposed. The study investigates the physical meaning of the model parameters, establishes linkages between parameter values and basin physical properties and develops relationships and equations for estimating the parameters taking into account the spatial and temporal scales used in typical model applications. The estimationmethods are then tested in selected gauged basins in southern Africa and the results of model simulations evaluated against historical observed flows. The results of 71 basins chosen from the southern African region suggest that it is possible to directly estimate hydrologically relevant parameters for the Pitman model from physical basin attributes. For South Africa, the statistical and visual fit of the simulations using the revised parameters were at least as good as the current regional sets, albeit the parameter sets being different. In the other countries where no regionalized parameter sets currently exist, simulations were equally good. The availability, within the southern African region, of the appropriate physical basin data and the disparities in the spatial scales and the levels of detail of the data currently available were identified as potential sources of uncertainty. GIS and remote sensing technologies and a widespread use of this revised approach are expected to facilitate access to these data.
- Full Text:
Rhodes University during the segregation and apartheid eras, 1933 to 1990
- Authors: Greyling, Sean Andrew
- Date: 2008
- Subjects: Rhodes University -- History Post-apartheid era -- South Africa -- History College students -- South Africa -- Political activity South Africa -- Race relations -- History -- 20th century South Africa -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2545 , http://hdl.handle.net/10962/d1002397
- Description: In 2004 Rhodes University celebrated its centenary. At a Critical Tradition Colloquium opportunity was given to explore the university’s past. In particular, its liberal image was questioned and its role during apartheid brought under scrutiny. This thesis investigates the questions raised at the Colloquium. It aims to cover the whole apartheid era in one coherent narrative by addressing the history of Rhodes during that era and how it handled issues of race and politics. It begins in 1933, when the first black student applied to Rhodes, and ends in 1990, when apartheid was drawing to a close.
- Full Text:
- Authors: Greyling, Sean Andrew
- Date: 2008
- Subjects: Rhodes University -- History Post-apartheid era -- South Africa -- History College students -- South Africa -- Political activity South Africa -- Race relations -- History -- 20th century South Africa -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2545 , http://hdl.handle.net/10962/d1002397
- Description: In 2004 Rhodes University celebrated its centenary. At a Critical Tradition Colloquium opportunity was given to explore the university’s past. In particular, its liberal image was questioned and its role during apartheid brought under scrutiny. This thesis investigates the questions raised at the Colloquium. It aims to cover the whole apartheid era in one coherent narrative by addressing the history of Rhodes during that era and how it handled issues of race and politics. It begins in 1933, when the first black student applied to Rhodes, and ends in 1990, when apartheid was drawing to a close.
- Full Text:
Risk assessment and the effects of overhead work - an automotive industry example
- Authors: Elliott, Andrew Brent
- Date: 2008
- Subjects: Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5132 , http://hdl.handle.net/10962/d1005211 , Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Description: The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory individual.
- Full Text:
- Authors: Elliott, Andrew Brent
- Date: 2008
- Subjects: Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5132 , http://hdl.handle.net/10962/d1005211 , Human engineering -- South Africa , Industrial safety -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Automobile industry and trade -- South Africa -- Safety measures , Musculoskeletal system -- Wounds and injuries -- Prevention , Lifting and carrying -- Safety measures , Work measurement , Posture
- Description: The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory individual.
- Full Text:
Spatial and temporal variations in metals in the sediment and water of selected Eastern Cape Estuaries, South Africa
- Authors: Orr, Kyla Kathleen
- Date: 2008
- Subjects: Marine sediments -- South Africa -- Eastern Cape , Metals -- South Africa -- Eastern Cape , Metals -- Environmental aspects , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuarine sediments -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Water pollution -- South Africa -- Eastern Cape , Environmental toxicology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5769 , http://hdl.handle.net/10962/d1005457 , Marine sediments -- South Africa -- Eastern Cape , Metals -- South Africa -- Eastern Cape , Metals -- Environmental aspects , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuarine sediments -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Water pollution -- South Africa -- Eastern Cape , Environmental toxicology -- South Africa -- Eastern Cape
- Description: The spatio-temporal patterns in concentrations of selected metals within the sediment (Cd, Co, Cu, Fe, Pb, Ni and Zn) and water (Cd and Pb) of three permanently open estuaries (Kariega, Kowie, Great Fish) and six temporary open-closed estuaries (Mpekweni, East Kleinemonde, West Kleinemonde, Riet, Kasouga, Boknes) were investigated. The concentrations of metals were influenced by size composition and total organic content of the sediments. Enrichment factors (EFs), using Fe as a reference element, and baseline linear regression models for metals vs. Fe were calculated to assess the extent of metal enrichment in the sediments. The mean concentrations of metals in the sediments(mg·kg⁻¹) showed ranges of 0.28 – 2.31 for Cd, 1.26 – 6.24 Co, 0.69 – 6.93 for Cu, 2119 – 14912 for Fe, 2.29 –14.01 for Ni, 4.81 – 22.20 for Pb and 5.77 – 21.75 for Zn. Mean normalized enrichment factors ranged between 0.75 – 6.19 for Cd, 0.53 – 2.71 for Co, 0.22 – 0.84 for Cu, 0.30 – 1.87 for Ni, 0.99 – 3.17 for Pb and 0.14 – 0.98 for Zn. All nine estuaries had average enrichment factors of greater than 1 for Cd. In general there was no enrichment of Cu and Zn in the sediments of any of the estuaries included in this study (EFs < 1). The Kariega, East Kleinemonde, West Kleinemonde, Riet and Great Fish Estuaries showed some degree of enrichment for Co (1 < EF < 4), Ni (1 < EF < 2) and Pb (1 < EF < 4), while the Mpekweni, Kasouga, Boknes and Kowie Estuaries were unenriched with these metals (EF < 1). Enrichment factors for Cd, Co and Pb typically followed the development gradient along the estuaries, suggesting anthropogenic enrichment. The concentrations of Cd and Pb in the water of the nine estuaries were also determined. The average concentrations of Cd and Pb in the water (μg·ℓ⁻¹) ranged between 0.05 – 3.32 and 0.75 – 34.13 respectively. On average the concentrations of Cd and Pb in the water of all the estuaries were below the South African recommended water quality guidelines for coastal marine waters. Variations in metal concentrations associated with changes in hydrology (wet vs. dry season) were determined in the water and sediment of the Kariega, East Kleinemonde and Riet Estuaries. Cobalt, Pb and Ni enrichment in the Kariega Estuary sediment was significantly higher during the dry season, and the mean concentrations of Pb and Cd in the water column were 19-fold and 66-fold higher in the dry season. The elevated concentration of metals during the dry season could be related to accumulation of diffuse pollution from human activities within the catchment area. Conversely, inflow of fresh water into the estuary had the net effect of reducing the concentration and enrichment of these metals within the Kariega Estuary due to scouring and outflow of estuarine water and sediment into the marine environment. The temporal variations in metal concentrations and enrichment factors were less pronounced in the temporary open-closed estuaries than the permanently open Kariega Estuary. The observed trend can probably be related to the low anthropogenic impact within the catchment areas of these systems, and the relatively smaller size of the catchments. Significant spatial variations existed in metal enrichment in the sediment of both the East Kleinemonde and Riet estuaries, with the highest degrees of enrichment occurring in the sediments from the marine environment and lower reaches.
- Full Text:
- Authors: Orr, Kyla Kathleen
- Date: 2008
- Subjects: Marine sediments -- South Africa -- Eastern Cape , Metals -- South Africa -- Eastern Cape , Metals -- Environmental aspects , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuarine sediments -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Water pollution -- South Africa -- Eastern Cape , Environmental toxicology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5769 , http://hdl.handle.net/10962/d1005457 , Marine sediments -- South Africa -- Eastern Cape , Metals -- South Africa -- Eastern Cape , Metals -- Environmental aspects , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuarine sediments -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Water pollution -- South Africa -- Eastern Cape , Environmental toxicology -- South Africa -- Eastern Cape
- Description: The spatio-temporal patterns in concentrations of selected metals within the sediment (Cd, Co, Cu, Fe, Pb, Ni and Zn) and water (Cd and Pb) of three permanently open estuaries (Kariega, Kowie, Great Fish) and six temporary open-closed estuaries (Mpekweni, East Kleinemonde, West Kleinemonde, Riet, Kasouga, Boknes) were investigated. The concentrations of metals were influenced by size composition and total organic content of the sediments. Enrichment factors (EFs), using Fe as a reference element, and baseline linear regression models for metals vs. Fe were calculated to assess the extent of metal enrichment in the sediments. The mean concentrations of metals in the sediments(mg·kg⁻¹) showed ranges of 0.28 – 2.31 for Cd, 1.26 – 6.24 Co, 0.69 – 6.93 for Cu, 2119 – 14912 for Fe, 2.29 –14.01 for Ni, 4.81 – 22.20 for Pb and 5.77 – 21.75 for Zn. Mean normalized enrichment factors ranged between 0.75 – 6.19 for Cd, 0.53 – 2.71 for Co, 0.22 – 0.84 for Cu, 0.30 – 1.87 for Ni, 0.99 – 3.17 for Pb and 0.14 – 0.98 for Zn. All nine estuaries had average enrichment factors of greater than 1 for Cd. In general there was no enrichment of Cu and Zn in the sediments of any of the estuaries included in this study (EFs < 1). The Kariega, East Kleinemonde, West Kleinemonde, Riet and Great Fish Estuaries showed some degree of enrichment for Co (1 < EF < 4), Ni (1 < EF < 2) and Pb (1 < EF < 4), while the Mpekweni, Kasouga, Boknes and Kowie Estuaries were unenriched with these metals (EF < 1). Enrichment factors for Cd, Co and Pb typically followed the development gradient along the estuaries, suggesting anthropogenic enrichment. The concentrations of Cd and Pb in the water of the nine estuaries were also determined. The average concentrations of Cd and Pb in the water (μg·ℓ⁻¹) ranged between 0.05 – 3.32 and 0.75 – 34.13 respectively. On average the concentrations of Cd and Pb in the water of all the estuaries were below the South African recommended water quality guidelines for coastal marine waters. Variations in metal concentrations associated with changes in hydrology (wet vs. dry season) were determined in the water and sediment of the Kariega, East Kleinemonde and Riet Estuaries. Cobalt, Pb and Ni enrichment in the Kariega Estuary sediment was significantly higher during the dry season, and the mean concentrations of Pb and Cd in the water column were 19-fold and 66-fold higher in the dry season. The elevated concentration of metals during the dry season could be related to accumulation of diffuse pollution from human activities within the catchment area. Conversely, inflow of fresh water into the estuary had the net effect of reducing the concentration and enrichment of these metals within the Kariega Estuary due to scouring and outflow of estuarine water and sediment into the marine environment. The temporal variations in metal concentrations and enrichment factors were less pronounced in the temporary open-closed estuaries than the permanently open Kariega Estuary. The observed trend can probably be related to the low anthropogenic impact within the catchment areas of these systems, and the relatively smaller size of the catchments. Significant spatial variations existed in metal enrichment in the sediment of both the East Kleinemonde and Riet estuaries, with the highest degrees of enrichment occurring in the sediments from the marine environment and lower reaches.
- Full Text:
Stakeholders' perceptions of the shift to democratic leadership in a secondary school in the Eastern Cape : a case study
- Authors: Lombo, Mzimkhulu Solomon
- Date: 2008
- Subjects: Education -- South Africa -- Eastern Cape , Education and state -- South Africa -- Eastern Cape , Education -- Political aspects -- South Africa -- Eastern Cape , Education, Secondary -- South Africa -- Eastern Cape -- Case studies , Educational change -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2001 , http://hdl.handle.net/10962/d1015541
- Description: The advent of political democracy in South Africa in 1994 gave rise to new policy in education promoting democratic and participative ways of managing and leading schools. The intention was both to break from the apartheid past which was characterised by an authoritarian, nonparticipative mindset, as well as to point the way for future education development. Principals of schools were expected to develop structures and adopt management and leadership styles which were participative, inclusive and developmental. Many principals would not have been prepared for this shift in mindset, and notions of full participation in governance by parents, and representation of learners through constituted bodies would have been new to them. In this case study of one semi-urban secondary school in the Eastern Cape the researcher sought to establish whether and to what extent the school had moved towards the new management and leadership approaches. The study is interpretive in orientation, and made use of interviews and document analysis. This research has found that the school had democratised its management and leadership to a considerable degree, but that this was not necessarily due to profound changes on the part of the principal 's leadership. The principal emerged as a democratic leader by nature. More significant seem to be the structures which the school had put in place, both officially and internally, to promote widespread participation and the distribution of leadership. This decentralised system of management has contributed to a distinct organisation culture in the school characterised by warmth, openness and ubuntu.
- Full Text:
- Authors: Lombo, Mzimkhulu Solomon
- Date: 2008
- Subjects: Education -- South Africa -- Eastern Cape , Education and state -- South Africa -- Eastern Cape , Education -- Political aspects -- South Africa -- Eastern Cape , Education, Secondary -- South Africa -- Eastern Cape -- Case studies , Educational change -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2001 , http://hdl.handle.net/10962/d1015541
- Description: The advent of political democracy in South Africa in 1994 gave rise to new policy in education promoting democratic and participative ways of managing and leading schools. The intention was both to break from the apartheid past which was characterised by an authoritarian, nonparticipative mindset, as well as to point the way for future education development. Principals of schools were expected to develop structures and adopt management and leadership styles which were participative, inclusive and developmental. Many principals would not have been prepared for this shift in mindset, and notions of full participation in governance by parents, and representation of learners through constituted bodies would have been new to them. In this case study of one semi-urban secondary school in the Eastern Cape the researcher sought to establish whether and to what extent the school had moved towards the new management and leadership approaches. The study is interpretive in orientation, and made use of interviews and document analysis. This research has found that the school had democratised its management and leadership to a considerable degree, but that this was not necessarily due to profound changes on the part of the principal 's leadership. The principal emerged as a democratic leader by nature. More significant seem to be the structures which the school had put in place, both officially and internally, to promote widespread participation and the distribution of leadership. This decentralised system of management has contributed to a distinct organisation culture in the school characterised by warmth, openness and ubuntu.
- Full Text:
State sovereignty and alternative community in southern Africa: exploring the Zion Christian Church as the building block for deeper notions of regional community
- Authors: Radebe, Zandisiwe
- Date: 2008
- Subjects: Zionist Christian Church Southern African Development Community Community development -- Africa, Southern Regionalism -- Africa, Southern Sovereignty -- Africa, Southern Africa, Southern -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2824 , http://hdl.handle.net/10962/d1003034
- Description: Regional community in southern Africa has been limited to the region’s states. As a result, deeper notions of community emanating from non-state actors, particularly transnational social movements, continue to be ignored. In an attempt to transcend state centrism, this thesis highlights alternative forms of regional community by exploring the Zion Christian Church (ZCC), one of southern Africa’s biggest and fastest growing cross-border movements. The ZCC is a potential agent for developing regional community from the bottom-up, driving a people-oriented regional integration approach in southern Africa. The ZCC, with its extensive following among the region’s poor, offers a compelling example of a grassroots and truly bottom-up approach to regional community. This thesis explores the possibility of the ZCC as a model of alternative community and identity centred on people’s daily experiences and grounded in a shared history and solidarity. It seeks to highlight the significance of transnational movements like the ZCC to policy makers in the region and it argues that grassroots communities are marching ahead of SADC member states and politicians in the area of integration. There exists a transnational cooperation amongst followers of the ZCC and other grassroots communities across the region and this cooperation transcends the traditional notion of state sovereignty, thereby highlighting deeper notions of what it means to be a community at regional level.
- Full Text:
- Authors: Radebe, Zandisiwe
- Date: 2008
- Subjects: Zionist Christian Church Southern African Development Community Community development -- Africa, Southern Regionalism -- Africa, Southern Sovereignty -- Africa, Southern Africa, Southern -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2824 , http://hdl.handle.net/10962/d1003034
- Description: Regional community in southern Africa has been limited to the region’s states. As a result, deeper notions of community emanating from non-state actors, particularly transnational social movements, continue to be ignored. In an attempt to transcend state centrism, this thesis highlights alternative forms of regional community by exploring the Zion Christian Church (ZCC), one of southern Africa’s biggest and fastest growing cross-border movements. The ZCC is a potential agent for developing regional community from the bottom-up, driving a people-oriented regional integration approach in southern Africa. The ZCC, with its extensive following among the region’s poor, offers a compelling example of a grassroots and truly bottom-up approach to regional community. This thesis explores the possibility of the ZCC as a model of alternative community and identity centred on people’s daily experiences and grounded in a shared history and solidarity. It seeks to highlight the significance of transnational movements like the ZCC to policy makers in the region and it argues that grassroots communities are marching ahead of SADC member states and politicians in the area of integration. There exists a transnational cooperation amongst followers of the ZCC and other grassroots communities across the region and this cooperation transcends the traditional notion of state sovereignty, thereby highlighting deeper notions of what it means to be a community at regional level.
- Full Text:
Studies towards the synthesis of novel, coumarin-based HIV-1 protease inhibitors
- Authors: Rashamuse, Thompho Jason
- Date: 2008
- Subjects: Coumarins , Protease Inhibitors , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4359 , http://hdl.handle.net/10962/d1005024 , Coumarins , Protease Inhibitors , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Heterocyclic compounds -- Derivatives
- Description: A series of the Baylis-Hillman adducts have been obtained by reacting protected O-benzylated and unprotected substituted salicylaldehydes with methyl acrylate or tertbutyl acrylate, respectively, using DABCO as catalyst. Treatment of the Baylis-Hillman adducts with HCl in a mixture of acetic acid and acetic anhydride afforded the corresponding 3-(chloromethyl)coumarin derivatives with yields of up to 94%. Similar use of HI afforded the corresponding 3-(iodomethyl)coumarins but, depending on the reaction time, the reduced 3-methyl analogues could also be obtained. Arbuzov reactions of the 3-(halomethyl)coumarin derivatives have been undertaken to afford 4-phosphorylated and 1’-phosphorylated derivatives, regioselectivity being dependent on the halide-leaving group. The 3-(chloromethyl)coumarin derivatives have been subjected to nucleophilic (SN) attack by benzylamine to give the corresponding 3- [(benzylamino)methyl]coumarin derivatives in yields of up to 74%. Further treatment of the 3-[(benzylamino)methyl]coumarin derivatives with chloroacetyl chloride afforded the chloroacetamide derivatives, which exhibit hindered rotation about the amine C(O)-N bond. The acetamide derivatives have also been subjected to Arbuzov reaction conditions to afford the phosphorylated derivatives in yields of up to 86%. In a preliminary modelling study, hydrolysed analogues of the synthesized phosphorylated derivatives have been docked into the active site of the HIV-1 protease enzyme using the Cerius-2 Ligandfit software module to provide an insight into potential receptor-ligand hydrogen bonding interactions.
- Full Text:
- Authors: Rashamuse, Thompho Jason
- Date: 2008
- Subjects: Coumarins , Protease Inhibitors , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4359 , http://hdl.handle.net/10962/d1005024 , Coumarins , Protease Inhibitors , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Heterocyclic compounds -- Derivatives
- Description: A series of the Baylis-Hillman adducts have been obtained by reacting protected O-benzylated and unprotected substituted salicylaldehydes with methyl acrylate or tertbutyl acrylate, respectively, using DABCO as catalyst. Treatment of the Baylis-Hillman adducts with HCl in a mixture of acetic acid and acetic anhydride afforded the corresponding 3-(chloromethyl)coumarin derivatives with yields of up to 94%. Similar use of HI afforded the corresponding 3-(iodomethyl)coumarins but, depending on the reaction time, the reduced 3-methyl analogues could also be obtained. Arbuzov reactions of the 3-(halomethyl)coumarin derivatives have been undertaken to afford 4-phosphorylated and 1’-phosphorylated derivatives, regioselectivity being dependent on the halide-leaving group. The 3-(chloromethyl)coumarin derivatives have been subjected to nucleophilic (SN) attack by benzylamine to give the corresponding 3- [(benzylamino)methyl]coumarin derivatives in yields of up to 74%. Further treatment of the 3-[(benzylamino)methyl]coumarin derivatives with chloroacetyl chloride afforded the chloroacetamide derivatives, which exhibit hindered rotation about the amine C(O)-N bond. The acetamide derivatives have also been subjected to Arbuzov reaction conditions to afford the phosphorylated derivatives in yields of up to 86%. In a preliminary modelling study, hydrolysed analogues of the synthesized phosphorylated derivatives have been docked into the active site of the HIV-1 protease enzyme using the Cerius-2 Ligandfit software module to provide an insight into potential receptor-ligand hydrogen bonding interactions.
- Full Text:
Synthesis, photochemical and photophysical properties of gallium and indium phthalocyanine derivatives
- Authors: Chauke, Vongani Portia
- Date: 2008
- Subjects: Phthalocyanines , Photochemotherapy , Electrochemistry , Gallium , Indium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4375 , http://hdl.handle.net/10962/d1005040 , Phthalocyanines , Photochemotherapy , Electrochemistry , Gallium , Indium
- Description: The syntheses of octasubstituted and unsusbstitituted Gallium(III) chloride and indium(III) chloride phthalocyanines (GaPc and InPc), their photophysical, photochemical and nonlinear optical parameters are hereby presented. The photocatalytic oxidation of 1-hexene using the synthesized GaPc and InPc complexes as well as electrochemical characterization is also presented in this thesis. Fluorescence quantum yields do not vary much among the four Ga complexes, except for complex 21c; therefore it was concluded that the effect of substituents is not significant among them. Solvents however, had an effect on the results. Lower Φ[subscript F] values were obtained in low viscosity solvents like toluene, relative to highly viscous solvents, such as DMSO. The triplet quantum yields were found to be lower in DMSO than in DMF and toluene. The rate constants for fluorescence, intersystem crossing and internal conversion as well as fluorescence and triplet lifetimes are reported. Photodegradation and singlet oxygen quantum yields have also been reported. There was no clear correlation between the latter parameters. It was however established that the four gallium MPcs were stable, within the allowed stability range for phthalocyanines. High quantum yields of triplet state (Φ[subscript T] ranging from 0.70 to 0.91 in dimethysulfoxide, DMSO) and singlet oxygen generation (Φ[subscript greek capital letter delta], ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50 to 60 μs were obtained in DMSO). Calculated non-linear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. The optical limiting threshold intensity (I[subscript lim]) values for the InPc and GaPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The octasubstituted were found to be better optical limiters. Photocatalytic oxidation of 1-hexene by GaPc (21a-c) and InPc (22a-c) derivatives is also presented. The photocatalytic oxidation products for 1-hexene were 1,2- epoxyhexane and 1-hexen-3-ol. The % conversion values of 1-hexene and % selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
- Full Text:
- Authors: Chauke, Vongani Portia
- Date: 2008
- Subjects: Phthalocyanines , Photochemotherapy , Electrochemistry , Gallium , Indium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4375 , http://hdl.handle.net/10962/d1005040 , Phthalocyanines , Photochemotherapy , Electrochemistry , Gallium , Indium
- Description: The syntheses of octasubstituted and unsusbstitituted Gallium(III) chloride and indium(III) chloride phthalocyanines (GaPc and InPc), their photophysical, photochemical and nonlinear optical parameters are hereby presented. The photocatalytic oxidation of 1-hexene using the synthesized GaPc and InPc complexes as well as electrochemical characterization is also presented in this thesis. Fluorescence quantum yields do not vary much among the four Ga complexes, except for complex 21c; therefore it was concluded that the effect of substituents is not significant among them. Solvents however, had an effect on the results. Lower Φ[subscript F] values were obtained in low viscosity solvents like toluene, relative to highly viscous solvents, such as DMSO. The triplet quantum yields were found to be lower in DMSO than in DMF and toluene. The rate constants for fluorescence, intersystem crossing and internal conversion as well as fluorescence and triplet lifetimes are reported. Photodegradation and singlet oxygen quantum yields have also been reported. There was no clear correlation between the latter parameters. It was however established that the four gallium MPcs were stable, within the allowed stability range for phthalocyanines. High quantum yields of triplet state (Φ[subscript T] ranging from 0.70 to 0.91 in dimethysulfoxide, DMSO) and singlet oxygen generation (Φ[subscript greek capital letter delta], ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50 to 60 μs were obtained in DMSO). Calculated non-linear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. The optical limiting threshold intensity (I[subscript lim]) values for the InPc and GaPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The octasubstituted were found to be better optical limiters. Photocatalytic oxidation of 1-hexene by GaPc (21a-c) and InPc (22a-c) derivatives is also presented. The photocatalytic oxidation products for 1-hexene were 1,2- epoxyhexane and 1-hexen-3-ol. The % conversion values of 1-hexene and % selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
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Synthesis, photophysics and electrochemical study of tin macrocycles
- Authors: Khene, Mielie Samson
- Date: 2008
- Subjects: Electrochemistry , Photochemistry , Phthalocyanines , Macrocyclic compounds , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4376 , http://hdl.handle.net/10962/d1005041 , Electrochemistry , Photochemistry , Phthalocyanines , Macrocyclic compounds , Spectrum analysis
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (35a), octahexyltetrabenzo-5,10,15-triazaporphyrinato dichlorotin(IV) (35b) and octadecylphthalocyaninato dichlorotin(IV) (35c) were synthesized and their photophysical and electrochemical behaviour studied. Complex (35b), containing a CH group in place of one of the aza nitrogen atom of the phthalocyanine core, shows a split Q band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (35a and 35c). In contrast, (35b) shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in THF than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring based redox processes. This thesis also reports on the microwave syntheses of tetrasulphonated tin phthalocyanine and tetrasulphonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (< 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The SnTSTBC complex has lower triplet life times and yields, while binding constant and quenching (of bovine serum albumin) constant are lower for SnTSTBC, compared to SnTSPc. Finally Non-peripherally (α) tetra- (40) and octa-(38a) substituted dodecyl-mercapto tin(IV) phthalocyanines where synthesized and the electrochemical behavior studied. Cyclic voltammetry and spectroelectrochemistry show ring-based reductions for (38a) and (40); the former shows two ring oxidations, while the latter shows only one ring based oxidation. The adsorption kinetics of (38a) and (40) on a gold electrode have been investigated by electrochemical impedance spectroscopy (EIS). The equilibrium constant (K) for the adsorption and the Gibbs free energy ΔG(ads) of the self-assembled monolayer (SAMs) were evaluated based on the Frumkin isotherm. The interaction factor between adsorbate –adsorbate molecules is also discussed.
- Full Text:
- Authors: Khene, Mielie Samson
- Date: 2008
- Subjects: Electrochemistry , Photochemistry , Phthalocyanines , Macrocyclic compounds , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4376 , http://hdl.handle.net/10962/d1005041 , Electrochemistry , Photochemistry , Phthalocyanines , Macrocyclic compounds , Spectrum analysis
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (35a), octahexyltetrabenzo-5,10,15-triazaporphyrinato dichlorotin(IV) (35b) and octadecylphthalocyaninato dichlorotin(IV) (35c) were synthesized and their photophysical and electrochemical behaviour studied. Complex (35b), containing a CH group in place of one of the aza nitrogen atom of the phthalocyanine core, shows a split Q band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (35a and 35c). In contrast, (35b) shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in THF than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring based redox processes. This thesis also reports on the microwave syntheses of tetrasulphonated tin phthalocyanine and tetrasulphonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (< 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The SnTSTBC complex has lower triplet life times and yields, while binding constant and quenching (of bovine serum albumin) constant are lower for SnTSTBC, compared to SnTSPc. Finally Non-peripherally (α) tetra- (40) and octa-(38a) substituted dodecyl-mercapto tin(IV) phthalocyanines where synthesized and the electrochemical behavior studied. Cyclic voltammetry and spectroelectrochemistry show ring-based reductions for (38a) and (40); the former shows two ring oxidations, while the latter shows only one ring based oxidation. The adsorption kinetics of (38a) and (40) on a gold electrode have been investigated by electrochemical impedance spectroscopy (EIS). The equilibrium constant (K) for the adsorption and the Gibbs free energy ΔG(ads) of the self-assembled monolayer (SAMs) were evaluated based on the Frumkin isotherm. The interaction factor between adsorbate –adsorbate molecules is also discussed.
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Teachers' perceptions of participative management in a primary school in Namibia
- Authors: Kambonde, Samuel Angaleni
- Date: 2008
- Subjects: Education, Elementary -- Namibia Teachers -- Namibia School management and organization -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1795 , http://hdl.handle.net/10962/d1003680
- Description: Participative management, a key theme in contemporary management literature, is one of the central aims of the decentralization policy in Namibian education. Current perceptions of participative management on the part of teachers in Namibia are therefore of topical interest. This study set out to explore such perceptions among teachers in a Namibian primary school. The study is an interpretive case study focusing on six individual teachers’ understanding and experience of participative management within their place of work, a primary school in the Oshikoto region of Namibia. Semi-structured interviews, observation and document analysis were used to gather data. The study revealed a strong sense of commitment among the respondents to participative management and its accompanying practices, such as shared decision making and broad stakeholder involvement. Participative management was implemented chiefly through a committee structure for school organisation and government. Respondents also highlighted challenges facing participative management, such as the persistence of autocratic leadership, conflicts of interest in decision making, laziness and unwillingness among staff members, and a lack of understanding among parents concerning their role in the schooling of their children. HIV/AIDS was also seen to pose challenges to the free and frequent participation of stakeholders. The chief recommendation arising from these findings is that school leaders and managers’ understanding of tenets of participative management, such as site-based management and democratic management approaches, requires improvement and development.
- Full Text:
- Authors: Kambonde, Samuel Angaleni
- Date: 2008
- Subjects: Education, Elementary -- Namibia Teachers -- Namibia School management and organization -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1795 , http://hdl.handle.net/10962/d1003680
- Description: Participative management, a key theme in contemporary management literature, is one of the central aims of the decentralization policy in Namibian education. Current perceptions of participative management on the part of teachers in Namibia are therefore of topical interest. This study set out to explore such perceptions among teachers in a Namibian primary school. The study is an interpretive case study focusing on six individual teachers’ understanding and experience of participative management within their place of work, a primary school in the Oshikoto region of Namibia. Semi-structured interviews, observation and document analysis were used to gather data. The study revealed a strong sense of commitment among the respondents to participative management and its accompanying practices, such as shared decision making and broad stakeholder involvement. Participative management was implemented chiefly through a committee structure for school organisation and government. Respondents also highlighted challenges facing participative management, such as the persistence of autocratic leadership, conflicts of interest in decision making, laziness and unwillingness among staff members, and a lack of understanding among parents concerning their role in the schooling of their children. HIV/AIDS was also seen to pose challenges to the free and frequent participation of stakeholders. The chief recommendation arising from these findings is that school leaders and managers’ understanding of tenets of participative management, such as site-based management and democratic management approaches, requires improvement and development.
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Teaching reading in grade 4 Namibian classrooms : a case study
- Authors: Mutenda, Josephine
- Date: 2008
- Subjects: Literacy -- Study and teaching (Elementary) -- Namibia English language -- Study and teaching (Elementary) -- Namibia Reading (Elementary) -- Namibia Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1797 , http://hdl.handle.net/10962/d1003682
- Description: Literacy is currently a topic of great concern in Namibia. Learners in this country have difficulty in reading and writing, and are often functionally illiterate. This study focuses on the beliefs, experiences and practices of teachers of reading in English to second language learners in Grade 4. Grade 4 is the transitional grade from mother tongue to English as the medium of instruction. The switch to English makes teaching reading in that language especially challenging. The study is structured according to the case study mode of enquiry, with the target respondents comprising Grade 4 teachers. Classroom observation, interviews and document analysis were used as means of collecting data. The main findings revealed that beliefs and experience had an impact on the way in which reading was taught in this study. It emerged that the teachers’ childhood experiences of literacy and learning to read are perpetuated in their beliefs, their attitudes, their basic conceptualization of reading and their current practices, all of which directly affect the children in their classes. Although the teachers’ professional training also had some influence on their teaching methods, neither of the two teachers interviewed had received much in-service support on how to teach reading, and they depended to a large extent on their recall of how they had learned to read themselves. Both teachers were taught in a traditional, teacher-centered way, involving phonics, rote-learning and drilling. Because they see themselves as competent readers, they believe that these approaches were effective and worth sustaining. Tentative recommendations arising from analysis of the data indicate possible areas for improvement in the teaching of reading, and offer guidelines to help teachers cope with the challenge.
- Full Text:
- Authors: Mutenda, Josephine
- Date: 2008
- Subjects: Literacy -- Study and teaching (Elementary) -- Namibia English language -- Study and teaching (Elementary) -- Namibia Reading (Elementary) -- Namibia Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1797 , http://hdl.handle.net/10962/d1003682
- Description: Literacy is currently a topic of great concern in Namibia. Learners in this country have difficulty in reading and writing, and are often functionally illiterate. This study focuses on the beliefs, experiences and practices of teachers of reading in English to second language learners in Grade 4. Grade 4 is the transitional grade from mother tongue to English as the medium of instruction. The switch to English makes teaching reading in that language especially challenging. The study is structured according to the case study mode of enquiry, with the target respondents comprising Grade 4 teachers. Classroom observation, interviews and document analysis were used as means of collecting data. The main findings revealed that beliefs and experience had an impact on the way in which reading was taught in this study. It emerged that the teachers’ childhood experiences of literacy and learning to read are perpetuated in their beliefs, their attitudes, their basic conceptualization of reading and their current practices, all of which directly affect the children in their classes. Although the teachers’ professional training also had some influence on their teaching methods, neither of the two teachers interviewed had received much in-service support on how to teach reading, and they depended to a large extent on their recall of how they had learned to read themselves. Both teachers were taught in a traditional, teacher-centered way, involving phonics, rote-learning and drilling. Because they see themselves as competent readers, they believe that these approaches were effective and worth sustaining. Tentative recommendations arising from analysis of the data indicate possible areas for improvement in the teaching of reading, and offer guidelines to help teachers cope with the challenge.
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Temperature dependence of the HartRAO pointing model
- Authors: Copley, Charles Judd
- Date: 2008
- Subjects: Astronomical instruments , Observatories -- South Africa , Telescopes , Astronomical observatories , Astronomy -- Data processing , Antennas (Electronics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5491 , http://hdl.handle.net/10962/d1005277 , Astronomical instruments , Observatories -- South Africa , Telescopes , Astronomical observatories , Astronomy -- Data processing , Antennas (Electronics)
- Description: This thesis investigates control aspects of the Hartebeeshoek Radio Astronomy Observatory (HartRAO) antenna. The installation of a new 22 GHz receiver has required the pointing accuracy to be improved to less than 4 mdeg. The effect of thermal conditions on the the HartRAO antenna pointing offset is investigated using a variety of modelling techniques including simple geometric modelling, neural networks and Principal Component Analysis (PCA). Convincing results were obtained for the Declination pointing offset, where applying certain model predictions to observations resulted in an improvement in Declination pointing offset from 5.5 mdeg to 3.2 mdeg (≈50%). The Right Ascension pointing model was considerably less convincing with an improvement of approximately from 5.5 mdeg to 4.5 mdeg (≈20%) in the Right Ascension pointing offset. The Declination pointing offset can be modelled sufficiently well to reduce the pointing offset to less than 4 mdeg, however further investigation of the underlying causes is required for the Right Ascension pointing offset.
- Full Text:
- Authors: Copley, Charles Judd
- Date: 2008
- Subjects: Astronomical instruments , Observatories -- South Africa , Telescopes , Astronomical observatories , Astronomy -- Data processing , Antennas (Electronics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5491 , http://hdl.handle.net/10962/d1005277 , Astronomical instruments , Observatories -- South Africa , Telescopes , Astronomical observatories , Astronomy -- Data processing , Antennas (Electronics)
- Description: This thesis investigates control aspects of the Hartebeeshoek Radio Astronomy Observatory (HartRAO) antenna. The installation of a new 22 GHz receiver has required the pointing accuracy to be improved to less than 4 mdeg. The effect of thermal conditions on the the HartRAO antenna pointing offset is investigated using a variety of modelling techniques including simple geometric modelling, neural networks and Principal Component Analysis (PCA). Convincing results were obtained for the Declination pointing offset, where applying certain model predictions to observations resulted in an improvement in Declination pointing offset from 5.5 mdeg to 3.2 mdeg (≈50%). The Right Ascension pointing model was considerably less convincing with an improvement of approximately from 5.5 mdeg to 4.5 mdeg (≈20%) in the Right Ascension pointing offset. The Declination pointing offset can be modelled sufficiently well to reduce the pointing offset to less than 4 mdeg, however further investigation of the underlying causes is required for the Right Ascension pointing offset.
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That-has-been a discussion on the body cast as that which fixes a subject in time, in relation to notions surrounding the photograph
- Authors: Maree, Christine Fae
- Date: 2008
- Subjects: Barthes, Roland. Camera Lucida Photography, Artistic Photography -- Philosophy Photographic criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2412 , http://hdl.handle.net/10962/d1002208
- Description: Much like a photograph, a casts creates a replica of its referent, thereby immobilising the subject in time. While the subject continues in time and hence ages and inevitably dies the replica does not. With this basic notion of fixing a subject, I have built an argument to contextualise my sculptures, which are made using casts of elderly people. In this discussion I have looked at my works through the ideas of different theorists. The main theorist I have cited is Roland Barthes, specifically with regards to his notion of the photograph as discussed in his book Camera Lucida. I have also referenced three particular artists: Rachel Whiteread, Diane Arbus and Churchill Madikida, as I have found each of their works relate to my work in various ways, creating a different reading from each viewpoint.
- Full Text:
- Authors: Maree, Christine Fae
- Date: 2008
- Subjects: Barthes, Roland. Camera Lucida Photography, Artistic Photography -- Philosophy Photographic criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2412 , http://hdl.handle.net/10962/d1002208
- Description: Much like a photograph, a casts creates a replica of its referent, thereby immobilising the subject in time. While the subject continues in time and hence ages and inevitably dies the replica does not. With this basic notion of fixing a subject, I have built an argument to contextualise my sculptures, which are made using casts of elderly people. In this discussion I have looked at my works through the ideas of different theorists. The main theorist I have cited is Roland Barthes, specifically with regards to his notion of the photograph as discussed in his book Camera Lucida. I have also referenced three particular artists: Rachel Whiteread, Diane Arbus and Churchill Madikida, as I have found each of their works relate to my work in various ways, creating a different reading from each viewpoint.
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The "other" Africans : re-examining representations of sexuality in the work of Nicholas Hlobo and Zanele Muholi
- Authors: Makhubu, Nomusa
- Date: 2008
- Subjects: Hlobo, Nicholas Muholi, Zanele Women in art Photography, Artistic Homosexuality in art Sex in art Performance art Art, African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2410 , http://hdl.handle.net/10962/d1002206
- Description: Nicholas Hlobo, a sculptor and performance artist, and Zanele Muholi, a photographer and activist, explore different ways of representing sexuality, particularly homosexuality. It is extremely difficult to discuss African sexuality in light of the stain of colonial attitudes that have exoticised and ascribed hypersexuality to African bodies. Moreover, sexuality is often not discussed in the construction of so-called African traditions and this has contributed to rendering African-ness as an exclusive identity. Tensions within and between categories of African-ness are compounded by constituted regulations. For example, Hlobo investigates the obligation of circumcision which seems to contrast the lifestyle and contexts in which he works and resides, and Muholi represents the existence of homosexual and transgender relations, even within conservative categories. The visual imagery of these two artists investigates the boundaries set by different social constructs. These set boundaries have also affected crimes against bisexual, transgender and homosexual individuals, which are reaching an alarming rate. Hlobo questions the validity of structures that marginalise homosexual individuals through drawing attention to the ambivalence of certain statutes. Muholi seeks to publicise the injustices imposed upon homosexual individuals in order to demonstrate the weight of that crisis. Although the South African legal system condones liberated expressions of sexual identity, due to social prejudices homosexual individuals are still treated as if they are not entitled to basic human rights. As a result, hate-crimes are not reported, and when they are they are not taken seriously. Hlobo and Muholi not only bring these issues to light, but also point out the dilemma inscribed in the social and political history of (South) Africa with regards to collective and individual identities. This thesis seeks to provide an analysis of the visual language used by Hlobo and Muholi to subvert the notion that homosexuality is “un-African” and to complicate concepts of gender, sexuality and identity.
- Full Text:
- Authors: Makhubu, Nomusa
- Date: 2008
- Subjects: Hlobo, Nicholas Muholi, Zanele Women in art Photography, Artistic Homosexuality in art Sex in art Performance art Art, African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2410 , http://hdl.handle.net/10962/d1002206
- Description: Nicholas Hlobo, a sculptor and performance artist, and Zanele Muholi, a photographer and activist, explore different ways of representing sexuality, particularly homosexuality. It is extremely difficult to discuss African sexuality in light of the stain of colonial attitudes that have exoticised and ascribed hypersexuality to African bodies. Moreover, sexuality is often not discussed in the construction of so-called African traditions and this has contributed to rendering African-ness as an exclusive identity. Tensions within and between categories of African-ness are compounded by constituted regulations. For example, Hlobo investigates the obligation of circumcision which seems to contrast the lifestyle and contexts in which he works and resides, and Muholi represents the existence of homosexual and transgender relations, even within conservative categories. The visual imagery of these two artists investigates the boundaries set by different social constructs. These set boundaries have also affected crimes against bisexual, transgender and homosexual individuals, which are reaching an alarming rate. Hlobo questions the validity of structures that marginalise homosexual individuals through drawing attention to the ambivalence of certain statutes. Muholi seeks to publicise the injustices imposed upon homosexual individuals in order to demonstrate the weight of that crisis. Although the South African legal system condones liberated expressions of sexual identity, due to social prejudices homosexual individuals are still treated as if they are not entitled to basic human rights. As a result, hate-crimes are not reported, and when they are they are not taken seriously. Hlobo and Muholi not only bring these issues to light, but also point out the dilemma inscribed in the social and political history of (South) Africa with regards to collective and individual identities. This thesis seeks to provide an analysis of the visual language used by Hlobo and Muholi to subvert the notion that homosexuality is “un-African” and to complicate concepts of gender, sexuality and identity.
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The African Peer Review Mechanism : towards Africa's governance audit
- Authors: Molete, Nathan Teboho
- Date: 2008
- Subjects: African Peer Review Mechanism New Partnership for Africa's Development Peer review -- Africa Auditing -- Africa Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2867 , http://hdl.handle.net/10962/d1007681
- Description: The concept of accountability has grown to become an integral part of a broader political and socio-economic transformation. Closely associated to it is the concept of "auditing" which has established itself as a main driving force of accountability and a core means of delivering it. The extent of the rise and expansion of "auditing" has subsequently come to influence every aspect of modern life and this has led to a situation in which practices have had to adapt to the principles of "auditing" processes. Auditing has become prevalent in both the public and private spheres and this impact has far reaching consequences. The concept of "auditing" is evident in the African Peer Review Mechanism (APRM) and is central to its review process. This thesis focuses on the concept of "auditing" in order to illustrate how the APRM has borrowed and applied insights from other disciplinary practices so as to enhance an understanding of accountability and transparency as features of "good governance" and to explicate how these concepts are conceived within the framework of the New Partnership for Africa's Development (NEPAD). It also clarifies the relationship that exists between "peer review" and "auditing" and argues that rather than being considered as two poles marked by distance from each other "auditing" and "peer review" are closely related and mutually constitutive.
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- Authors: Molete, Nathan Teboho
- Date: 2008
- Subjects: African Peer Review Mechanism New Partnership for Africa's Development Peer review -- Africa Auditing -- Africa Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2867 , http://hdl.handle.net/10962/d1007681
- Description: The concept of accountability has grown to become an integral part of a broader political and socio-economic transformation. Closely associated to it is the concept of "auditing" which has established itself as a main driving force of accountability and a core means of delivering it. The extent of the rise and expansion of "auditing" has subsequently come to influence every aspect of modern life and this has led to a situation in which practices have had to adapt to the principles of "auditing" processes. Auditing has become prevalent in both the public and private spheres and this impact has far reaching consequences. The concept of "auditing" is evident in the African Peer Review Mechanism (APRM) and is central to its review process. This thesis focuses on the concept of "auditing" in order to illustrate how the APRM has borrowed and applied insights from other disciplinary practices so as to enhance an understanding of accountability and transparency as features of "good governance" and to explicate how these concepts are conceived within the framework of the New Partnership for Africa's Development (NEPAD). It also clarifies the relationship that exists between "peer review" and "auditing" and argues that rather than being considered as two poles marked by distance from each other "auditing" and "peer review" are closely related and mutually constitutive.
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The antecedents of customer satisfaction in a financial institution : a qualitative study
- Authors: Bleske, Adrian
- Date: 2008
- Subjects: Standard Bank Properties , Banks and banking -- South Africa , Banks and banking -- Customer services -- South Africa , Financial services industry -- South Africa , Bank management -- South Africa , Banks and banking -- Customer services -- Effect of marketing on
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:840 , http://hdl.handle.net/10962/d1015482
- Description: The following is a case study report on the Cape Town business unit of Standard Bank Properties. The research project falls within the ambit of services marketing which introduces several unique management challenges for service businesses that sell services as a core offering. The principal aim of the case study is to gain an understanding of why customers bank at the business unit and to discover what aspects are critical to customer satisfaction. A further goal of the research is to examine how the business unit could improve customer satisfaction and to highlight any impediments to further improving customer satisfaction at the business unit. It is generally regarded that quality customer service is essential to building customer relationships and hence the research project emphasis on services marketing and customer satisfaction within a financial services context. The paper commences with an overview of the South African Banking Sector and its unique challenges such as the Financial Service Charter and newly introduced legislation such as Financial Intelligence Centre Act. The case study will specifically investigate the property finance industry and a detailed analysis of the business unit's operations and process flow will also be undertaken. The reason for this background information is to assist the reader to understand how the business unit operates. The research project will investigate four unique differences between goods marketing and services marketing whereafter three theoretical propositions are introduced, namely the dyadic interaction and service encounter, the Service Profit Chain and finally Relationship Marketing. Evidence in the form of a narrative will be led from insights obtained from interviews conducted with customers and staff at the business unit against these propositions with support (or otherwise) from independent surveys and documents from the business unit. The result of this analysis is the identification of several areas of concern specifically: New employees and the service encounter, Problems with FICA, Lack of a customer complaint handling system, Empowerment issues, Turnaround times, Reliance on key staff These insights together with the evidence from the literature review will be analysed and several recommendations made to improve customer service and ultimately customer satisfaction at the business unit. Several recommendations for further research are offered as well as the identification of limitations including but not limited to the specificity of the case study report.
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- Authors: Bleske, Adrian
- Date: 2008
- Subjects: Standard Bank Properties , Banks and banking -- South Africa , Banks and banking -- Customer services -- South Africa , Financial services industry -- South Africa , Bank management -- South Africa , Banks and banking -- Customer services -- Effect of marketing on
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:840 , http://hdl.handle.net/10962/d1015482
- Description: The following is a case study report on the Cape Town business unit of Standard Bank Properties. The research project falls within the ambit of services marketing which introduces several unique management challenges for service businesses that sell services as a core offering. The principal aim of the case study is to gain an understanding of why customers bank at the business unit and to discover what aspects are critical to customer satisfaction. A further goal of the research is to examine how the business unit could improve customer satisfaction and to highlight any impediments to further improving customer satisfaction at the business unit. It is generally regarded that quality customer service is essential to building customer relationships and hence the research project emphasis on services marketing and customer satisfaction within a financial services context. The paper commences with an overview of the South African Banking Sector and its unique challenges such as the Financial Service Charter and newly introduced legislation such as Financial Intelligence Centre Act. The case study will specifically investigate the property finance industry and a detailed analysis of the business unit's operations and process flow will also be undertaken. The reason for this background information is to assist the reader to understand how the business unit operates. The research project will investigate four unique differences between goods marketing and services marketing whereafter three theoretical propositions are introduced, namely the dyadic interaction and service encounter, the Service Profit Chain and finally Relationship Marketing. Evidence in the form of a narrative will be led from insights obtained from interviews conducted with customers and staff at the business unit against these propositions with support (or otherwise) from independent surveys and documents from the business unit. The result of this analysis is the identification of several areas of concern specifically: New employees and the service encounter, Problems with FICA, Lack of a customer complaint handling system, Empowerment issues, Turnaround times, Reliance on key staff These insights together with the evidence from the literature review will be analysed and several recommendations made to improve customer service and ultimately customer satisfaction at the business unit. Several recommendations for further research are offered as well as the identification of limitations including but not limited to the specificity of the case study report.
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The attitudes of isiXhosa-speaking students toward various languages of learning and teaching (LOLT) issues at Rhodes University
- Authors: Aziakpono, Philomina
- Date: 2008
- Subjects: Rhodes University -- Students -- Attitudes Language and education -- South Africa Xhosa language -- Study and teaching (Higher) -- South Africa English language -- Study and teaching (Higher) -- South Africa Education, Bilingual -- South Africa Language policy -- South Africa Language planning -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2339 , http://hdl.handle.net/10962/d1002621
- Description: This study aims at eliciting opinions and beliefs of isiXhosa-speaking students to revealtheir attitudes toward various languages of learning and teaching (LOLT) issues at RhodesUniversity, and to determine the influence of a number of variables (such as age, gender,schooling background, level of study and field of study) on these attitudes. Another aim of the study is to compare the findings of this research to the recent findings on isiXhosaspeaking students’ language attitudes at the University of the Western Cape (Dyers 1999) and the University of Fort Hare (Dalvit 2004). Qualitative and quantitative methods were used: data was gathered using a survey that employed a questionnaire and interviews (individual and focus group). The questionnaire data is analysed through using percentage scores as well as mean values coupled with Chi-square tests, while the interviews are analysed qualitatively to further confirm the results of the quantitative analysis. Results are also compared with other recent surveys at South African universities. The results reveal that respondents had a generally positive attitude toward English as LOLT, based mainly on instrumental motivations. More importantly, there was a positive attitude toward the use of isiXhosa alongside English. The motivations for the use of isiXhosa were both instrumental and integrative in nature. The majority of respondents who supported a bilingual arrangement did not, however, believe that a fully-fledged bilingual policy would be practical, mainly because of the multilingual nature of Rhodes University. They felt, however, that providing English and isiXhosa exam question-papers, bilingual tutor support and isiXhosa definitions of discipline-specific technical terms would facilitate learning. Most of the variables mentioned above had an influence on the relevant language attitudes, often confirming the findings of other studies. For instance, schooling background greatly influenced the language attitudes of respondents. Those from previously advantaged English-only schools showed very positive attitudes toward an English-only policy, while most respondents from formerly disadvantaged DET bilingual schools were favourably disposed toward a bilingual policy of English and isiXhosa at Rhodes University. A comparison of the findings of this study with those of recent findings on isiXhosa students’ language attitudes at other universities reveals that respondents at the University of Fort Hare were most favourable toward a bilingual policy, those at the University of the Western Cape were to some extent favourable toward a bilingual arrangement, while respondents at Rhodes University were least favourable toward a bilingual policy.
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- Authors: Aziakpono, Philomina
- Date: 2008
- Subjects: Rhodes University -- Students -- Attitudes Language and education -- South Africa Xhosa language -- Study and teaching (Higher) -- South Africa English language -- Study and teaching (Higher) -- South Africa Education, Bilingual -- South Africa Language policy -- South Africa Language planning -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2339 , http://hdl.handle.net/10962/d1002621
- Description: This study aims at eliciting opinions and beliefs of isiXhosa-speaking students to revealtheir attitudes toward various languages of learning and teaching (LOLT) issues at RhodesUniversity, and to determine the influence of a number of variables (such as age, gender,schooling background, level of study and field of study) on these attitudes. Another aim of the study is to compare the findings of this research to the recent findings on isiXhosaspeaking students’ language attitudes at the University of the Western Cape (Dyers 1999) and the University of Fort Hare (Dalvit 2004). Qualitative and quantitative methods were used: data was gathered using a survey that employed a questionnaire and interviews (individual and focus group). The questionnaire data is analysed through using percentage scores as well as mean values coupled with Chi-square tests, while the interviews are analysed qualitatively to further confirm the results of the quantitative analysis. Results are also compared with other recent surveys at South African universities. The results reveal that respondents had a generally positive attitude toward English as LOLT, based mainly on instrumental motivations. More importantly, there was a positive attitude toward the use of isiXhosa alongside English. The motivations for the use of isiXhosa were both instrumental and integrative in nature. The majority of respondents who supported a bilingual arrangement did not, however, believe that a fully-fledged bilingual policy would be practical, mainly because of the multilingual nature of Rhodes University. They felt, however, that providing English and isiXhosa exam question-papers, bilingual tutor support and isiXhosa definitions of discipline-specific technical terms would facilitate learning. Most of the variables mentioned above had an influence on the relevant language attitudes, often confirming the findings of other studies. For instance, schooling background greatly influenced the language attitudes of respondents. Those from previously advantaged English-only schools showed very positive attitudes toward an English-only policy, while most respondents from formerly disadvantaged DET bilingual schools were favourably disposed toward a bilingual policy of English and isiXhosa at Rhodes University. A comparison of the findings of this study with those of recent findings on isiXhosa students’ language attitudes at other universities reveals that respondents at the University of Fort Hare were most favourable toward a bilingual policy, those at the University of the Western Cape were to some extent favourable toward a bilingual arrangement, while respondents at Rhodes University were least favourable toward a bilingual policy.
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The cryopreservation potential and ultrastructure of Agulhas sole Austroglossus pectoralis spermatozoa
- Authors: Markovina, Michael Zeljan
- Date: 2008
- Subjects: Spermatozoa , Spermatozoa -- Cryopreservation , Aquaculture , Fishes -- Breeding , Soleidae , Flatfishes , Agulhas Current (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5251 , http://hdl.handle.net/10962/d1005094 , Spermatozoa , Spermatozoa -- Cryopreservation , Aquaculture , Fishes -- Breeding , Soleidae , Flatfishes , Agulhas Current (South Africa)
- Description: As the estimated market demand for the Agulhas sole Austroglossus pectoralis exceeds the annual catch from trawlers, this species is a potential aquaculture candidate. Broodstock conditioning and gamete preservation is part of research and development aiming at establishing a breeding protocol for a new aquaculture species. Based on a literature review of the morphology of pleuronectiform spermatozoa, this study was designed firstly, to contribute to the field of spermatozoan morphology by describing the ultrastructure of A. pectoralis spermatozoa. This was followed by an experiment to cryopreserve mature spermatozoa to provide baseline data for future studies on this and related species. The testis of A. pectoralis was a paired structure encased in a membrane, the tunica albuginea. The primary testis was located on the dorsal surface of the rib cage and the secondary testis on the ventral side. The testis was of an unrestricted spermatogonial type, based upon observations of spermatogonia along the entire length of the lobule. Mature spermatozoa of A. pectoralis had an acrosome-free ovoid head 1.68 ± 1.6μm in length and 1.7 ± 1.6μm in diameter, a short mid-piece of 0.5 ± 0.1μm in length, containing 7 irregularly shaped mitochondria forming a ring-like structure at the base of the nucleus. The flagellae were 47.4 ± 4.8μm in length, most with two plasma membrane lateral fin-like projections. However, some flagellae had either zero or three lateral fin projections. Cross-sections of the flagellae showed an axenome with a 9+2 microtubule configuration. The proximal and distal centriols were coaxal, situated deep within the nuclear fossa. The structure of A. pectoralis spermatozoa conformed to the type 1 ect-aquasperm, also found in externally fertilizing species. This type has been suggested to be the plesiomorphic form in Neopterigians. Finally, this study contributed to a cryopreservation protocol for A. pectoralis spermatozoa by testing the two cryoprotectants dimethyl sulphoxide (DMSO) and glycerol. Glycerol, at a concentration of 10%, offered better cryoprotection than DMSO. This was established using flow cytometry analysis of post-thaw nuclear membrane integrity after 64 days of storage in liquid nitrogen. The toxicity of DMSO to isolated cellular proteins may have resulted in DMSO-treated sperm having the highest percent (35.2% ± 3.2%) of non-viable cells compared with 23.0% ± 2.5% and 27.8% ± 3.4% for glycerol and the control, respectively. The presence of sucrose in the Modified Mounib Medium extender solution may explain why 45.5% ± 5% of the sperm cells were potentially viable in the control treatment. Initially, the white margined sole Dagatichthys marginatus (Soleidae) was selected as the most suitable candidate for flatfish aquaculture in South Africa. Thus, the aim of this study was to investigate the cryogenic potential and ultrastructure of D. marginatus spermatozoa. However, due to a skewed sex ratio, there were not enough males available to study this species. A skewed sex ratio is common amongst soleids, thus, the need to develop effective cryopreservation methods and to develop an understanding of sperm morphology so that the best time for cryopreservation can be chosen. In conclusion, this first description of spermatozan morphology of A. pectoralis contributed to our understanding of soleid sperm ultrastructure. In addition, a comparison of testis appearance between fish sampled just prior to spawning season and fish with mature sperm provided information on the spawning season of this species. The findings from the cryopreservation experiment suggested that glycerol was a feasible cryoprotectant for this species when sperm was prepared under field conditions.
- Full Text:
- Authors: Markovina, Michael Zeljan
- Date: 2008
- Subjects: Spermatozoa , Spermatozoa -- Cryopreservation , Aquaculture , Fishes -- Breeding , Soleidae , Flatfishes , Agulhas Current (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5251 , http://hdl.handle.net/10962/d1005094 , Spermatozoa , Spermatozoa -- Cryopreservation , Aquaculture , Fishes -- Breeding , Soleidae , Flatfishes , Agulhas Current (South Africa)
- Description: As the estimated market demand for the Agulhas sole Austroglossus pectoralis exceeds the annual catch from trawlers, this species is a potential aquaculture candidate. Broodstock conditioning and gamete preservation is part of research and development aiming at establishing a breeding protocol for a new aquaculture species. Based on a literature review of the morphology of pleuronectiform spermatozoa, this study was designed firstly, to contribute to the field of spermatozoan morphology by describing the ultrastructure of A. pectoralis spermatozoa. This was followed by an experiment to cryopreserve mature spermatozoa to provide baseline data for future studies on this and related species. The testis of A. pectoralis was a paired structure encased in a membrane, the tunica albuginea. The primary testis was located on the dorsal surface of the rib cage and the secondary testis on the ventral side. The testis was of an unrestricted spermatogonial type, based upon observations of spermatogonia along the entire length of the lobule. Mature spermatozoa of A. pectoralis had an acrosome-free ovoid head 1.68 ± 1.6μm in length and 1.7 ± 1.6μm in diameter, a short mid-piece of 0.5 ± 0.1μm in length, containing 7 irregularly shaped mitochondria forming a ring-like structure at the base of the nucleus. The flagellae were 47.4 ± 4.8μm in length, most with two plasma membrane lateral fin-like projections. However, some flagellae had either zero or three lateral fin projections. Cross-sections of the flagellae showed an axenome with a 9+2 microtubule configuration. The proximal and distal centriols were coaxal, situated deep within the nuclear fossa. The structure of A. pectoralis spermatozoa conformed to the type 1 ect-aquasperm, also found in externally fertilizing species. This type has been suggested to be the plesiomorphic form in Neopterigians. Finally, this study contributed to a cryopreservation protocol for A. pectoralis spermatozoa by testing the two cryoprotectants dimethyl sulphoxide (DMSO) and glycerol. Glycerol, at a concentration of 10%, offered better cryoprotection than DMSO. This was established using flow cytometry analysis of post-thaw nuclear membrane integrity after 64 days of storage in liquid nitrogen. The toxicity of DMSO to isolated cellular proteins may have resulted in DMSO-treated sperm having the highest percent (35.2% ± 3.2%) of non-viable cells compared with 23.0% ± 2.5% and 27.8% ± 3.4% for glycerol and the control, respectively. The presence of sucrose in the Modified Mounib Medium extender solution may explain why 45.5% ± 5% of the sperm cells were potentially viable in the control treatment. Initially, the white margined sole Dagatichthys marginatus (Soleidae) was selected as the most suitable candidate for flatfish aquaculture in South Africa. Thus, the aim of this study was to investigate the cryogenic potential and ultrastructure of D. marginatus spermatozoa. However, due to a skewed sex ratio, there were not enough males available to study this species. A skewed sex ratio is common amongst soleids, thus, the need to develop effective cryopreservation methods and to develop an understanding of sperm morphology so that the best time for cryopreservation can be chosen. In conclusion, this first description of spermatozan morphology of A. pectoralis contributed to our understanding of soleid sperm ultrastructure. In addition, a comparison of testis appearance between fish sampled just prior to spawning season and fish with mature sperm provided information on the spawning season of this species. The findings from the cryopreservation experiment suggested that glycerol was a feasible cryoprotectant for this species when sperm was prepared under field conditions.
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The development and evaluation of a cohesion-building programme for a South African male collegiate basketball team
- Authors: Razafimbola, Sandimampita
- Date: 2008
- Subjects: Teamwork (Sports) Basketball teams College sports Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3040 , http://hdl.handle.net/10962/d1002549
- Description: There is a general consensus among sport coaches and practitioners that it is better to work with a cohesive team. Research on cohesion has provided positive links between cohesion and performance as well as the overall well-being of the team and its members. The purpose of this study is to develop and evaluate a cohesion-building programme under an Action Research paradigm. The Group Environment Questionnaire, in parallel with focus group discussions were used to assist in the development and evaluation of a cohesion-building programme tailored to the specific needs of the Rhodes University men’s basketball 1st team. The team is known to be a good team but it was missing something that made it become great. Fostering higher cohesiveness was deemed to be the missing link to the chain of success. Various changes were brought to the 1) team structure, 2) team processes, 3) team environment to enhance the team’s cohesiveness levels. It was found that the programme was positive and powerful in that it accelerated the process of cohesion building within the team. It was also found that the programme had the power to transcend demographical barriers and unite people from diverse backgrounds. Finally, the programme increased the team’s performance level and enabled it to achieve objectives that were never achieved by any other men’s basketball team at Rhodes University before. Naturally there are going to be some ups and downs, especially if you have individuals trying to achieve at a high level. But when we stepped in between the lines, we knew what we were capable of doing. When a pressure situation presented itself, we were plugged into one another like a cohesive unit. That’s why we were able to come back so often and win so many close games. And that’s why we were able to beat more talented team. - Michael Jordan (former Chicago Bulls; NBA Hall of Famer).
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- Authors: Razafimbola, Sandimampita
- Date: 2008
- Subjects: Teamwork (Sports) Basketball teams College sports Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3040 , http://hdl.handle.net/10962/d1002549
- Description: There is a general consensus among sport coaches and practitioners that it is better to work with a cohesive team. Research on cohesion has provided positive links between cohesion and performance as well as the overall well-being of the team and its members. The purpose of this study is to develop and evaluate a cohesion-building programme under an Action Research paradigm. The Group Environment Questionnaire, in parallel with focus group discussions were used to assist in the development and evaluation of a cohesion-building programme tailored to the specific needs of the Rhodes University men’s basketball 1st team. The team is known to be a good team but it was missing something that made it become great. Fostering higher cohesiveness was deemed to be the missing link to the chain of success. Various changes were brought to the 1) team structure, 2) team processes, 3) team environment to enhance the team’s cohesiveness levels. It was found that the programme was positive and powerful in that it accelerated the process of cohesion building within the team. It was also found that the programme had the power to transcend demographical barriers and unite people from diverse backgrounds. Finally, the programme increased the team’s performance level and enabled it to achieve objectives that were never achieved by any other men’s basketball team at Rhodes University before. Naturally there are going to be some ups and downs, especially if you have individuals trying to achieve at a high level. But when we stepped in between the lines, we knew what we were capable of doing. When a pressure situation presented itself, we were plugged into one another like a cohesive unit. That’s why we were able to come back so often and win so many close games. And that’s why we were able to beat more talented team. - Michael Jordan (former Chicago Bulls; NBA Hall of Famer).
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The development and evaluation of a custom-built synchronous online learning environment for tertiary education in South Africa
- Authors: Halse, Michelle Louise
- Date: 2008 , 2008-02-23
- Subjects: Education, Higher -- South Africa -- Computer-assisted instruction , Universities and colleges -- Computer networks -- South Africa , Internet in higher education -- South Africa , Distance education -- South Africa -- Computer-assisted instruction , Computer-assisted instruction -- South Africa , Computer science -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4636 , http://hdl.handle.net/10962/d1006545 , Education, Higher -- South Africa -- Computer-assisted instruction , Universities and colleges -- Computer networks -- South Africa , Internet in higher education -- South Africa , Distance education -- South Africa -- Computer-assisted instruction , Computer-assisted instruction -- South Africa , Computer science -- Study and teaching (Higher) -- South Africa
- Description: The Departments of Computer Science and Information Systems at Rhodes University currently share certain honours-level (fourth year) course modules with students from the corresponding departments at the previously disadvantaged University of Fort Hare. These lectures are currently delivered using video-conferencing. This was found to present a number of problems including challenges in terms of implementing desired pedagogical approaches, inequitable learning experiences, student disengagement at the remote venue, and inflexibility of the video-conferencing system. In order to address these problems, various e-learning modes were investigated and synchronous e-learning were found to offer a number of advantages over asynchronous e-learning. Live Virtual Classrooms (LVCs) were identified as synchronous e-learning tools that support the pedagogical principles important to the two universities and to the broader context of South African tertiary education, and commercial LVC applications were investigated and evaluated. Informed by the results of this investigation a small, simple LVC was designed, developed and customised for use in a predominantly academic sphere and deployment in a South African tertiary educational context. Testing and evaluation of this solution was carried out and the results analysed in terms of the LVC’s technical merits and the pedagogical value of the solution as experienced by students and lecturers/facilitators. An evaluation of this solution indicated that the LVC solves a number of the identified problems with video-conferencing and also provides a flexible/customisable/extensible solution that supports highly interactive, collaborative, learner-centred education. The custom LVC solution could be easily adapted to the specific needs of any tertiary educational institute in the country, and results may benefit other tertiary educational institutions involved in or dependant on distance learning.
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- Authors: Halse, Michelle Louise
- Date: 2008 , 2008-02-23
- Subjects: Education, Higher -- South Africa -- Computer-assisted instruction , Universities and colleges -- Computer networks -- South Africa , Internet in higher education -- South Africa , Distance education -- South Africa -- Computer-assisted instruction , Computer-assisted instruction -- South Africa , Computer science -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4636 , http://hdl.handle.net/10962/d1006545 , Education, Higher -- South Africa -- Computer-assisted instruction , Universities and colleges -- Computer networks -- South Africa , Internet in higher education -- South Africa , Distance education -- South Africa -- Computer-assisted instruction , Computer-assisted instruction -- South Africa , Computer science -- Study and teaching (Higher) -- South Africa
- Description: The Departments of Computer Science and Information Systems at Rhodes University currently share certain honours-level (fourth year) course modules with students from the corresponding departments at the previously disadvantaged University of Fort Hare. These lectures are currently delivered using video-conferencing. This was found to present a number of problems including challenges in terms of implementing desired pedagogical approaches, inequitable learning experiences, student disengagement at the remote venue, and inflexibility of the video-conferencing system. In order to address these problems, various e-learning modes were investigated and synchronous e-learning were found to offer a number of advantages over asynchronous e-learning. Live Virtual Classrooms (LVCs) were identified as synchronous e-learning tools that support the pedagogical principles important to the two universities and to the broader context of South African tertiary education, and commercial LVC applications were investigated and evaluated. Informed by the results of this investigation a small, simple LVC was designed, developed and customised for use in a predominantly academic sphere and deployment in a South African tertiary educational context. Testing and evaluation of this solution was carried out and the results analysed in terms of the LVC’s technical merits and the pedagogical value of the solution as experienced by students and lecturers/facilitators. An evaluation of this solution indicated that the LVC solves a number of the identified problems with video-conferencing and also provides a flexible/customisable/extensible solution that supports highly interactive, collaborative, learner-centred education. The custom LVC solution could be easily adapted to the specific needs of any tertiary educational institute in the country, and results may benefit other tertiary educational institutions involved in or dependant on distance learning.
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