Hydrological proceses, chemical variability, and multiple isotopestracing of water flow paths in the Kudumela Wetland- Limpopo Province, South Africa
- Authors: Mekiso, Feleke Abiyo
- Date: 2011
- Subjects: Kudumela Wetland -- South Africa -- Limpopo , Wetland hydrology -- South Africa -- Limpopo , Wetlands -- South Africa -- Limpopo , Wetland conservation -- South Africa -- Limpopo , Wetland management -- South Africa -- Limpopo , Isotopes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6027 , http://hdl.handle.net/10962/d1006153 , Kudumela Wetland -- South Africa -- Limpopo , Wetland hydrology -- South Africa -- Limpopo , Wetlands -- South Africa -- Limpopo , Wetland conservation -- South Africa -- Limpopo , Wetland management -- South Africa -- Limpopo , Isotopes
- Description: The hydrology of the Kudumela Wetland, Limpopo Province of South Africa was studied from November 2005 to April 2007, involving both fieldwork and laboratory analyses. This study presents the results of an investigation of the hydrology of the Kudumela Wetland in South Africa, and its contribution to dry season flow in the Mohlapitsi and Olifants Rivers. Initially, 40 Piezometers were installed along seven transects and water levels monitored in order to understand water table level characteristics (fluctuations) with time. Water levels in transects one, three, the right bank portion of transect four and transect six showed fluctuations. Transect two, the left bank portion of transect four and transect five did not show significant temporal changes. The relationships between piezometer water levels, rainfall in the study area and stream flow observed at a river gauging station are not clear. The river within the wetland is a gaining stream because the water table level elevation is above that of the river. This indicates that the wetland is feeding the river. The northern part of the wetland (T1 and T2) is affected by artificial drains and most of the piezometers closest to the river channel showed the lowest variations. The relationships between rainfall, groundwater, and surface water at this site shows that stream flow did not respond quickly to precipitation as expected, even in months when rainfall increased (for example, 74 and 103mm during 08/02/06 and 18/02/06 respectively), and the groundwater levels did not show fluctuations, indicating that groundwater responds gradually to precipitation, and that the relationship between rainfall, groundwater and surface water is complex. The environmental stable isotopes (deuterium and oxygen-18) and the radioactive isotope (tritium) were analyzed, along with field observations of electrical conductivity (EC), pH, total alkalinity (Talka) and some major and minor dissolved ion analyses for tracing water dynamics in the study area. A total of 39 water samples was taken and analyzed from boreholes, auger holes, right bank and left bank drains, various points along the river and springs in four sampling visits to the wetland. The results did not clearly provide a temporal record of isotope and chemical variations in the various sources. Results from the most extensive sampling survey in April 2007 provide the most comprehensive overview of hydrological relationships. Clustering of the stable isotope data suggests that the water samples of upstream and downstream river, auger holes further south and most drains clustered together suggesting a common water source and almost all samples fall above the global (GMWL) and local (Pretoria MWL) meteoric water lines, while some fall between the global and Pretoria meteoric water lines. Six representative water samples were analyzed for major ion concentration. Both cation (Ca, Mg, K, and Na) and anion (HCO3, SO4, Cl, and NO3) analyses in November 2007 confirmed conclusions reached from field observations. The analysis shows that a single type of water (Ca, Mg-HCO3) is involved in the study area. In almost all major ion plots, the right bank drains, upstream river and downstream river samples grouped together in a single cluster. As the means for reliable river flow measurements were not available, except for the gauging station at the outlet of the valley, rough, semi-quantitative estimates were made during several field visits. These, suggest considerable losses of river flow into the gravel/boulder beds at and below a gabion dam at the head of the valley. Three major and several other left bank springs and right bank drains at transects T1 and T2 contributed to the river flow at all times. Along with the isotopic and chemical evidence, these observations have lead to a hypothesis that river water enters the wetland and flows back to the Mohlapitsi River through boulder beds underlying the wetland and through drains on the surface of the argillaceous aquitard covering the more conductive boulder beds. Deeper dolomitic groundwater does not appear to contribute to the water balance at least in the northern half of the wetland. Although environmental isotope and hydrochemistry results may not unequivocally prove this hypothesis they do not contradict it.
- Full Text:
- Date Issued: 2011
- Authors: Mekiso, Feleke Abiyo
- Date: 2011
- Subjects: Kudumela Wetland -- South Africa -- Limpopo , Wetland hydrology -- South Africa -- Limpopo , Wetlands -- South Africa -- Limpopo , Wetland conservation -- South Africa -- Limpopo , Wetland management -- South Africa -- Limpopo , Isotopes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6027 , http://hdl.handle.net/10962/d1006153 , Kudumela Wetland -- South Africa -- Limpopo , Wetland hydrology -- South Africa -- Limpopo , Wetlands -- South Africa -- Limpopo , Wetland conservation -- South Africa -- Limpopo , Wetland management -- South Africa -- Limpopo , Isotopes
- Description: The hydrology of the Kudumela Wetland, Limpopo Province of South Africa was studied from November 2005 to April 2007, involving both fieldwork and laboratory analyses. This study presents the results of an investigation of the hydrology of the Kudumela Wetland in South Africa, and its contribution to dry season flow in the Mohlapitsi and Olifants Rivers. Initially, 40 Piezometers were installed along seven transects and water levels monitored in order to understand water table level characteristics (fluctuations) with time. Water levels in transects one, three, the right bank portion of transect four and transect six showed fluctuations. Transect two, the left bank portion of transect four and transect five did not show significant temporal changes. The relationships between piezometer water levels, rainfall in the study area and stream flow observed at a river gauging station are not clear. The river within the wetland is a gaining stream because the water table level elevation is above that of the river. This indicates that the wetland is feeding the river. The northern part of the wetland (T1 and T2) is affected by artificial drains and most of the piezometers closest to the river channel showed the lowest variations. The relationships between rainfall, groundwater, and surface water at this site shows that stream flow did not respond quickly to precipitation as expected, even in months when rainfall increased (for example, 74 and 103mm during 08/02/06 and 18/02/06 respectively), and the groundwater levels did not show fluctuations, indicating that groundwater responds gradually to precipitation, and that the relationship between rainfall, groundwater and surface water is complex. The environmental stable isotopes (deuterium and oxygen-18) and the radioactive isotope (tritium) were analyzed, along with field observations of electrical conductivity (EC), pH, total alkalinity (Talka) and some major and minor dissolved ion analyses for tracing water dynamics in the study area. A total of 39 water samples was taken and analyzed from boreholes, auger holes, right bank and left bank drains, various points along the river and springs in four sampling visits to the wetland. The results did not clearly provide a temporal record of isotope and chemical variations in the various sources. Results from the most extensive sampling survey in April 2007 provide the most comprehensive overview of hydrological relationships. Clustering of the stable isotope data suggests that the water samples of upstream and downstream river, auger holes further south and most drains clustered together suggesting a common water source and almost all samples fall above the global (GMWL) and local (Pretoria MWL) meteoric water lines, while some fall between the global and Pretoria meteoric water lines. Six representative water samples were analyzed for major ion concentration. Both cation (Ca, Mg, K, and Na) and anion (HCO3, SO4, Cl, and NO3) analyses in November 2007 confirmed conclusions reached from field observations. The analysis shows that a single type of water (Ca, Mg-HCO3) is involved in the study area. In almost all major ion plots, the right bank drains, upstream river and downstream river samples grouped together in a single cluster. As the means for reliable river flow measurements were not available, except for the gauging station at the outlet of the valley, rough, semi-quantitative estimates were made during several field visits. These, suggest considerable losses of river flow into the gravel/boulder beds at and below a gabion dam at the head of the valley. Three major and several other left bank springs and right bank drains at transects T1 and T2 contributed to the river flow at all times. Along with the isotopic and chemical evidence, these observations have lead to a hypothesis that river water enters the wetland and flows back to the Mohlapitsi River through boulder beds underlying the wetland and through drains on the surface of the argillaceous aquitard covering the more conductive boulder beds. Deeper dolomitic groundwater does not appear to contribute to the water balance at least in the northern half of the wetland. Although environmental isotope and hydrochemistry results may not unequivocally prove this hypothesis they do not contradict it.
- Full Text:
- Date Issued: 2011
Identifying the interdependence between South Africa's monetary policy and the stock market
- Authors: Muroyiwa, Brian
- Date: 2011
- Subjects: Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:982 , http://hdl.handle.net/10962/d1002716 , Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Description: This study estimates the interdependence between South Africa‟s monetary policy and stock market performance, utilising structural vector autoregression (SVAR) methodology. The study finds that a stock price shock which decrease stock prices by 100 basis points leads to 5 basis points decrease in interbank rate. A monetary policy shock that increases the interbank rate by l percent leads to decrease in real stock prices by 1 percent. This result for South Africa is similar to the result by Bjornland and Leteimo (2009) which earlier concluded that there was a high interdependence between interest rate setting and stock prices. However the magnitude of the relationship is relatively lower for South Africa compared to that of the United States of America (USA). The result of the current study is also very much consistent with the argument that the South African stock market is resource-based and so is influenced by external shocks, meaning monetary policy shock does not have as much impact on stock market in South Africa as in the USA. However the SARB may have to consider watching movements in stock prices so that booms in stock markets do not defeat central bank monetary policy thrusts. The stock price market is an essential source of information for monetary policy in South Africa.
- Full Text:
- Date Issued: 2011
- Authors: Muroyiwa, Brian
- Date: 2011
- Subjects: Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:982 , http://hdl.handle.net/10962/d1002716 , Monetary policy -- South Africa , Stock exchanges -- Law and legislation -- South Africa , Interest rates -- South Africa , Securities -- Prices -- South Africa
- Description: This study estimates the interdependence between South Africa‟s monetary policy and stock market performance, utilising structural vector autoregression (SVAR) methodology. The study finds that a stock price shock which decrease stock prices by 100 basis points leads to 5 basis points decrease in interbank rate. A monetary policy shock that increases the interbank rate by l percent leads to decrease in real stock prices by 1 percent. This result for South Africa is similar to the result by Bjornland and Leteimo (2009) which earlier concluded that there was a high interdependence between interest rate setting and stock prices. However the magnitude of the relationship is relatively lower for South Africa compared to that of the United States of America (USA). The result of the current study is also very much consistent with the argument that the South African stock market is resource-based and so is influenced by external shocks, meaning monetary policy shock does not have as much impact on stock market in South Africa as in the USA. However the SARB may have to consider watching movements in stock prices so that booms in stock markets do not defeat central bank monetary policy thrusts. The stock price market is an essential source of information for monetary policy in South Africa.
- Full Text:
- Date Issued: 2011
Identity, belonging and ecological crisis in South African speculative fiction
- Authors: Steenkamp, Elzette Lorna
- Date: 2011
- Subjects: South African fiction -- History and criticism Identity (Philosophical concept) in literature Group identity in literature Ecology in literature Science fiction, South African -- History and criticism Fantasy fiction, South African -- History and criticism Ecofiction -- History and criticism Ecocriticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2219 , http://hdl.handle.net/10962/d1002262
- Description: This study examines a range of South African speculative novels which situate their narratives in futuristic or ‘alternative’ milieus, exploring how these narratives not only address identity formation in a deeply divided and rapidly changing society, but also the ways in which human beings place themselves in relation to Nature and form notions of ‘ecological’ belonging. It offers close readings of these speculative narratives in order to investigate the ways in which they evince concerns which are rooted in the natural, social and political landscapes which inform them. Specific attention is paid to the texts’ treatment of the intertwined issues of identity, belonging and ecological crisis. This dissertation draws on the fields of Ecocriticism, Postcolonial Studies and Science Fiction Studies, and assumes a culturally specific approach to primary texts while investigating possible cross-cultural commonalities between Afrikaans and English speculative narratives, as well as the cross-fertilisation of global SF/speculative features. It is suggested that South African speculative fiction presents a socio-historically situated, rhizomatic approach to ecology – one that is attuned to the tension between humanistic- and ecological concerns.
- Full Text:
- Date Issued: 2011
- Authors: Steenkamp, Elzette Lorna
- Date: 2011
- Subjects: South African fiction -- History and criticism Identity (Philosophical concept) in literature Group identity in literature Ecology in literature Science fiction, South African -- History and criticism Fantasy fiction, South African -- History and criticism Ecofiction -- History and criticism Ecocriticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2219 , http://hdl.handle.net/10962/d1002262
- Description: This study examines a range of South African speculative novels which situate their narratives in futuristic or ‘alternative’ milieus, exploring how these narratives not only address identity formation in a deeply divided and rapidly changing society, but also the ways in which human beings place themselves in relation to Nature and form notions of ‘ecological’ belonging. It offers close readings of these speculative narratives in order to investigate the ways in which they evince concerns which are rooted in the natural, social and political landscapes which inform them. Specific attention is paid to the texts’ treatment of the intertwined issues of identity, belonging and ecological crisis. This dissertation draws on the fields of Ecocriticism, Postcolonial Studies and Science Fiction Studies, and assumes a culturally specific approach to primary texts while investigating possible cross-cultural commonalities between Afrikaans and English speculative narratives, as well as the cross-fertilisation of global SF/speculative features. It is suggested that South African speculative fiction presents a socio-historically situated, rhizomatic approach to ecology – one that is attuned to the tension between humanistic- and ecological concerns.
- Full Text:
- Date Issued: 2011
Ill at ease in our translated world ecocriticism, language, and the natural environment in the fiction of Michael Ondaatje, Amitav Ghosh, David Malouf and Wilma Stockenström
- Authors: Johnson, Eleanore
- Date: 2011
- Subjects: Ondaatje, Michael, 1943- The English patient Ghosh, Amitav. The hungry tide Malouf, David, 1934- An imaginary life Stockenström, Wilma. The expedition to the Baobab tree Ecocriticism Human ecology in literature Nature in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2234 , http://hdl.handle.net/10962/d1002277
- Description: This thesis explores the thematic desire to establish an ecological human bond with nature in four contemporary novels: The English Patient by Michael Ondaatje, The Hungry Tide by Amitav Ghosh, An Imaginary Life by David Malouf, and The Expedition to The Baobab Tree by Wilma Stockenström. These authors share a concern with the influence that language has on human perception, and one of the most significant ways they attempt to connect with the natural world is through somehow escaping, or transcending, what they perceive to be the divisive tendencies of language. They all suggest that human perception is not steered entirely by a disembodied mind, which constructs reality through linguistic and cultural lenses, but is equally influenced by physical circumstances and embodied experiences. They explore the potential of corporeal reciprocity and empathy as that which enables understanding across cultural barriers, and a sense of ecologically intertwined kinship with nature. They all struggle to reconcile their awareness of the potential danger of relating to nature exclusively through language, with a desire to speak for the natural world in literature. I have examined whether they succeed in doing so, or whether they contradict their thematic suspicion of language with their literary medium. I have prioritised a close ecocritical reading of the novels and loosely situated the authors’ approach to nature and language within the broad theoretical frameworks of radical ecology, structuralism and poststructuralism. I suggest that these novels are best analysed in the context of an ecocritical mediation between poststructuralist conceptions of nature as inaccessible cultural construct, and the naïve conception of unmediated, pre-reflective interaction with the natural world. I draw especially on the phenomenological theories of Maurice Merleau-Ponty, whose insistence that perception is always both embodied and culturally mediated truly renders culture and nature irreducible, intertwined categories. By challenging historical dualisms like mind/body and culture/nature, the selected novels suggest a more fluid and discursive understanding of the perceived conflict between language and nature, whilst problematizing the perception of language as merely a cultural artefact. Moreover, they are examples of the kind of literature that has the potential to positively influence our human conception of nature, and adapt us better to our ecological context on a planet struggling for survival.
- Full Text:
- Date Issued: 2011
- Authors: Johnson, Eleanore
- Date: 2011
- Subjects: Ondaatje, Michael, 1943- The English patient Ghosh, Amitav. The hungry tide Malouf, David, 1934- An imaginary life Stockenström, Wilma. The expedition to the Baobab tree Ecocriticism Human ecology in literature Nature in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2234 , http://hdl.handle.net/10962/d1002277
- Description: This thesis explores the thematic desire to establish an ecological human bond with nature in four contemporary novels: The English Patient by Michael Ondaatje, The Hungry Tide by Amitav Ghosh, An Imaginary Life by David Malouf, and The Expedition to The Baobab Tree by Wilma Stockenström. These authors share a concern with the influence that language has on human perception, and one of the most significant ways they attempt to connect with the natural world is through somehow escaping, or transcending, what they perceive to be the divisive tendencies of language. They all suggest that human perception is not steered entirely by a disembodied mind, which constructs reality through linguistic and cultural lenses, but is equally influenced by physical circumstances and embodied experiences. They explore the potential of corporeal reciprocity and empathy as that which enables understanding across cultural barriers, and a sense of ecologically intertwined kinship with nature. They all struggle to reconcile their awareness of the potential danger of relating to nature exclusively through language, with a desire to speak for the natural world in literature. I have examined whether they succeed in doing so, or whether they contradict their thematic suspicion of language with their literary medium. I have prioritised a close ecocritical reading of the novels and loosely situated the authors’ approach to nature and language within the broad theoretical frameworks of radical ecology, structuralism and poststructuralism. I suggest that these novels are best analysed in the context of an ecocritical mediation between poststructuralist conceptions of nature as inaccessible cultural construct, and the naïve conception of unmediated, pre-reflective interaction with the natural world. I draw especially on the phenomenological theories of Maurice Merleau-Ponty, whose insistence that perception is always both embodied and culturally mediated truly renders culture and nature irreducible, intertwined categories. By challenging historical dualisms like mind/body and culture/nature, the selected novels suggest a more fluid and discursive understanding of the perceived conflict between language and nature, whilst problematizing the perception of language as merely a cultural artefact. Moreover, they are examples of the kind of literature that has the potential to positively influence our human conception of nature, and adapt us better to our ecological context on a planet struggling for survival.
- Full Text:
- Date Issued: 2011
Improved tree species discrimination at leaf level with hyperspectral data combining binary classifiers
- Authors: Dastile, Xolani Collen
- Date: 2011
- Subjects: Mathematical statistics , Analysis of variance , Nearest neighbor analysis (Statistics) , Trees--Classification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5567 , http://hdl.handle.net/10962/d1002807 , Mathematical statistics , Analysis of variance , Nearest neighbor analysis (Statistics) , Trees--Classification
- Description: The purpose of the present thesis is to show that hyperspectral data can be used for discrimination between different tree species. The data set used in this study contains the hyperspectral measurements of leaves of seven savannah tree species. The data is high-dimensional and shows large within-class variability combined with small between-class variability which makes discrimination between the classes challenging. We employ two classification methods: G-nearest neighbour and feed-forward neural networks. For both methods, direct 7-class prediction results in high misclassification rates. However, binary classification works better. We constructed binary classifiers for all possible binary classification problems and combine them with Error Correcting Output Codes. We show especially that the use of 1-nearest neighbour binary classifiers results in no improvement compared to a direct 1-nearest neighbour 7-class predictor. In contrast to this negative result, the use of neural networks binary classifiers improves accuracy by 10% compared to a direct neural networks 7-class predictor, and error rates become acceptable. This can be further improved by choosing only suitable binary classifiers for combination.
- Full Text:
- Date Issued: 2011
- Authors: Dastile, Xolani Collen
- Date: 2011
- Subjects: Mathematical statistics , Analysis of variance , Nearest neighbor analysis (Statistics) , Trees--Classification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5567 , http://hdl.handle.net/10962/d1002807 , Mathematical statistics , Analysis of variance , Nearest neighbor analysis (Statistics) , Trees--Classification
- Description: The purpose of the present thesis is to show that hyperspectral data can be used for discrimination between different tree species. The data set used in this study contains the hyperspectral measurements of leaves of seven savannah tree species. The data is high-dimensional and shows large within-class variability combined with small between-class variability which makes discrimination between the classes challenging. We employ two classification methods: G-nearest neighbour and feed-forward neural networks. For both methods, direct 7-class prediction results in high misclassification rates. However, binary classification works better. We constructed binary classifiers for all possible binary classification problems and combine them with Error Correcting Output Codes. We show especially that the use of 1-nearest neighbour binary classifiers results in no improvement compared to a direct 1-nearest neighbour 7-class predictor. In contrast to this negative result, the use of neural networks binary classifiers improves accuracy by 10% compared to a direct neural networks 7-class predictor, and error rates become acceptable. This can be further improved by choosing only suitable binary classifiers for combination.
- Full Text:
- Date Issued: 2011
Inflation threshold and nonlinearity: implications for inflation targeting in South Africa
- Authors: Morar, Derwina
- Date: 2011
- Subjects: Inflation targeting -- South Africa Interest rates -- Effect of inflation on -- South Africa Monetary policy -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:984 , http://hdl.handle.net/10962/d1002718
- Description: Following many other central banks around the world, the South African Reserve Bank has adopted inflation targeting as its monetary policy framework. The aim of this is to achieve low levels of inflation in order to attain price stability thereby promoting growth. In South Africa, the chosen band to target is 3%–6%. This has been criticised by many trade unions who are calling for the abandonment of inflation targeting. Despite targeting 3%–6%, it is not known whether this is the optimal inflation range for South Africa. Therefore, the aim of this study is to determine the inflation threshold level for South Africa using quarterly data for the period 1983 to 2010. The first section determines whether or not there is a long-run relationship between inflation and growth using the Johansen cointegration method. Exogeneity tests determine the causality between these variables. Vector error correction models are estimated if cointegration is found. The second part determines the threshold level of inflation using the method of conditional least squares. The inflation level that maximises the R-squared value and minimises the residual sum of squares gives an indication of the threshold level. The third part of the study determines whether or not inflation volatility has a significant impact on growth. The first part established that there is long-run comovement between inflation and growth.The causality is bidirectional with both variables being endogenous.Findings regarding the threshold level show that the current inflation targeting band of 3%–6% may be extended up to 9.5%. In addition, the range of inflation from 5.5% to 6.5% promotes economic growth in South Africa. Finally, the evidence suggests that inflation volatility does not have a significant impact on economic growth and the focus of policy should be directed towards the level of inflation as has been the case.
- Full Text:
- Date Issued: 2011
- Authors: Morar, Derwina
- Date: 2011
- Subjects: Inflation targeting -- South Africa Interest rates -- Effect of inflation on -- South Africa Monetary policy -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:984 , http://hdl.handle.net/10962/d1002718
- Description: Following many other central banks around the world, the South African Reserve Bank has adopted inflation targeting as its monetary policy framework. The aim of this is to achieve low levels of inflation in order to attain price stability thereby promoting growth. In South Africa, the chosen band to target is 3%–6%. This has been criticised by many trade unions who are calling for the abandonment of inflation targeting. Despite targeting 3%–6%, it is not known whether this is the optimal inflation range for South Africa. Therefore, the aim of this study is to determine the inflation threshold level for South Africa using quarterly data for the period 1983 to 2010. The first section determines whether or not there is a long-run relationship between inflation and growth using the Johansen cointegration method. Exogeneity tests determine the causality between these variables. Vector error correction models are estimated if cointegration is found. The second part determines the threshold level of inflation using the method of conditional least squares. The inflation level that maximises the R-squared value and minimises the residual sum of squares gives an indication of the threshold level. The third part of the study determines whether or not inflation volatility has a significant impact on growth. The first part established that there is long-run comovement between inflation and growth.The causality is bidirectional with both variables being endogenous.Findings regarding the threshold level show that the current inflation targeting band of 3%–6% may be extended up to 9.5%. In addition, the range of inflation from 5.5% to 6.5% promotes economic growth in South Africa. Finally, the evidence suggests that inflation volatility does not have a significant impact on economic growth and the focus of policy should be directed towards the level of inflation as has been the case.
- Full Text:
- Date Issued: 2011
Initial investigations into dynamics of mesozooplankton community structure in Algoa Bay, South Africa
- Authors: Dali, Luzuko O'Brian
- Date: 2011
- Subjects: Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5715 , http://hdl.handle.net/10962/d1005401 , Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Description: As part of a long-term monitoring programme initiated by the South African Environmental Observation Network (SAEON) Elwandle Node, the spatio-temporal dynamics of mesozooplankton (200–2000 μm) community structure in Algoa Bay, on the Eastern Cape coastline of southern Africa, was investigated in summer and winter of 2008. Physical-chemical and biological variables were measured at selected sites in the eastern and western sectors of the Bay. During summer, nutrient rich waters upwelling into the eastern sector of the Bay contributed to significant spatial variation in selected physical-chemical variables. During winter, virtually no significant spatial patterns in the physical-chemical variables were observed (P>0.05 in all cases). For the majority of physical-chemical variables, no significant seasonal patterns in values were detected (P>0.05 in all cases). Notable exceptions were water column stability and water temperatures which were highest during summer, and seston, turbidity and ammonium concentrations which attained the highest values in winter. The striking seasonal pattern observed in the water column stability, coupled with the upwelling event, coincided with a strong seasonal pattern in the total surface and integrated chlorophyll-a concentrations within the Bay. During summer, the total surface phytoplankton biomass ranged from 1.87–3.11 μg.L⁻¹ and the integrated biomass values between 44.6 and 89.1 mg chl-a m⁻². In winter, surface chl-a concentrations ranged from 0.49 to 0.55 μg.L⁻¹ and integrated biomass from 13.5 to 13.8 mg chl-a m⁻². During both seasons, the large microphytoplankton (>20 μm) fraction contributed the most (>80%) to the total phytoplankton biomass suggesting that phytoplankton growth is not nutrient limited within the Bay. The total mesozooplankton abundance and biomass values during summer varied between 10088.92 and 28283.21 ind.m⁻³ and between 76.59 and 161.94 mg.m⁻³, respectively. During winter, total abundance and biomass of mesozooplankton within the Bay were significantly lower, ranging from 2392.49 to 11145.29 ind.m⁻³, and from 34.49 to 42.49 mg.m⁻³, respectively (P<0.05). During both seasons, cosmopolitan copepod species 200–500μm in size dominated the total mesozooplankton counts, numerically and in biomass. Hierarchical cluster analyses identified distinct zooplankton groupings within the Bay during both the summer (three groupings) and winter (four groupings) surveys. The different groupings identified during the two seasons were not associated with any specific geographic region or hydrological feature. Nonetheless, a distinct seasonal pattern in the mesozooplankton community was evident, largely reflecting the increased abundance of mesozooplankton during the summer survey. Canonical Correspondence Analyses (CCA) indicated that the zooplankton community structure within Algoa Bay reflected a complex interaction between physical-chemical (e.g. temperature, water column stability, turbidity, and nitrate, dissolved oxygen and nitrite concentrations) and biological factors (e.g. microphytoplankton and picophytoplankton concentrations). These data provide baseline information towards long-term monitoring programs that will be conducted in Algoa Bay, as part of the South African Environmental Observation Network (SAEON), in the near future.
- Full Text:
- Date Issued: 2011
- Authors: Dali, Luzuko O'Brian
- Date: 2011
- Subjects: Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5715 , http://hdl.handle.net/10962/d1005401 , Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Description: As part of a long-term monitoring programme initiated by the South African Environmental Observation Network (SAEON) Elwandle Node, the spatio-temporal dynamics of mesozooplankton (200–2000 μm) community structure in Algoa Bay, on the Eastern Cape coastline of southern Africa, was investigated in summer and winter of 2008. Physical-chemical and biological variables were measured at selected sites in the eastern and western sectors of the Bay. During summer, nutrient rich waters upwelling into the eastern sector of the Bay contributed to significant spatial variation in selected physical-chemical variables. During winter, virtually no significant spatial patterns in the physical-chemical variables were observed (P>0.05 in all cases). For the majority of physical-chemical variables, no significant seasonal patterns in values were detected (P>0.05 in all cases). Notable exceptions were water column stability and water temperatures which were highest during summer, and seston, turbidity and ammonium concentrations which attained the highest values in winter. The striking seasonal pattern observed in the water column stability, coupled with the upwelling event, coincided with a strong seasonal pattern in the total surface and integrated chlorophyll-a concentrations within the Bay. During summer, the total surface phytoplankton biomass ranged from 1.87–3.11 μg.L⁻¹ and the integrated biomass values between 44.6 and 89.1 mg chl-a m⁻². In winter, surface chl-a concentrations ranged from 0.49 to 0.55 μg.L⁻¹ and integrated biomass from 13.5 to 13.8 mg chl-a m⁻². During both seasons, the large microphytoplankton (>20 μm) fraction contributed the most (>80%) to the total phytoplankton biomass suggesting that phytoplankton growth is not nutrient limited within the Bay. The total mesozooplankton abundance and biomass values during summer varied between 10088.92 and 28283.21 ind.m⁻³ and between 76.59 and 161.94 mg.m⁻³, respectively. During winter, total abundance and biomass of mesozooplankton within the Bay were significantly lower, ranging from 2392.49 to 11145.29 ind.m⁻³, and from 34.49 to 42.49 mg.m⁻³, respectively (P<0.05). During both seasons, cosmopolitan copepod species 200–500μm in size dominated the total mesozooplankton counts, numerically and in biomass. Hierarchical cluster analyses identified distinct zooplankton groupings within the Bay during both the summer (three groupings) and winter (four groupings) surveys. The different groupings identified during the two seasons were not associated with any specific geographic region or hydrological feature. Nonetheless, a distinct seasonal pattern in the mesozooplankton community was evident, largely reflecting the increased abundance of mesozooplankton during the summer survey. Canonical Correspondence Analyses (CCA) indicated that the zooplankton community structure within Algoa Bay reflected a complex interaction between physical-chemical (e.g. temperature, water column stability, turbidity, and nitrate, dissolved oxygen and nitrite concentrations) and biological factors (e.g. microphytoplankton and picophytoplankton concentrations). These data provide baseline information towards long-term monitoring programs that will be conducted in Algoa Bay, as part of the South African Environmental Observation Network (SAEON), in the near future.
- Full Text:
- Date Issued: 2011
Intellectualisation of African languages with particular reference to isiXhosa
- Authors: Maseko, Pamela
- Date: 2011
- Subjects: Xhosa language -- Study and teaching -- South Africa , Language and education -- South Africa , African languages
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58035 , vital:27035
- Description: The research explores the relationship between language and education, and motivates for the intellectualisation of African languages, isiXhosa in particular, and for their use in education. The main rationale behind this is that access to, and success in education can largely be realised if that education is mediated in one’s first language. The thesis discusses works of prominent scholars who have written on the subject - relating cognitive abilities and achievement in education to language in which that education is offered. The lack of terminology in new domains in African languages as barrier to mother tongue education is laid bare by looking specifically at the history of intellectualisation of isiXhosa, from the missionaries in the 1820s up to the new endeavours as recently as 2008. Terminologies that were developed during the Bantu Education era, where development of isiXhosa and other indigenous African languages was accelerated in order to respond to the demands of moedertaal-onderwys (mother tongue education) are surveyed, and the process of their development analysed. Three main terminology lists developed during this period are analysed against terminology development principles, approaches and methods that are seen as a measure to ensure quality terminology development. The efforts of the development of isiXhosa during the post-apartheid South Africa, especially the government-driven initiatives, are also critiqued even though these are not as effective and as extensive, especially in education. The result of this analysis is that African languages and isiXhosa in particular, can be used in scientific disciplines and at the highest levels of education. Its grammar is advanced, and its lexicon is extensive such that new concepts that need to be named can be named, using appropriate term creation strategies. There are also technological tools such as WordSmith tools that can be used that can advance its development, ensuring that the concept represented in the newly-created term is precise, concise and appropriate in terms of its discipline. Therefore it is argued that, in the interim, terminologies should be developed, in various subjects, to support learning, which at this stage is mediated in English, for those students who have other languages as mother tongue. Those terminologies that have been developed in the various historical periods should be collated, revised and brought into the classrooms. The thesis argues that real intellectualisation of isiXhosa and other African languages rests on the use of these languages in classrooms and lecture halls, and in the value that all role players place on these languages.
- Full Text:
- Date Issued: 2011
- Authors: Maseko, Pamela
- Date: 2011
- Subjects: Xhosa language -- Study and teaching -- South Africa , Language and education -- South Africa , African languages
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58035 , vital:27035
- Description: The research explores the relationship between language and education, and motivates for the intellectualisation of African languages, isiXhosa in particular, and for their use in education. The main rationale behind this is that access to, and success in education can largely be realised if that education is mediated in one’s first language. The thesis discusses works of prominent scholars who have written on the subject - relating cognitive abilities and achievement in education to language in which that education is offered. The lack of terminology in new domains in African languages as barrier to mother tongue education is laid bare by looking specifically at the history of intellectualisation of isiXhosa, from the missionaries in the 1820s up to the new endeavours as recently as 2008. Terminologies that were developed during the Bantu Education era, where development of isiXhosa and other indigenous African languages was accelerated in order to respond to the demands of moedertaal-onderwys (mother tongue education) are surveyed, and the process of their development analysed. Three main terminology lists developed during this period are analysed against terminology development principles, approaches and methods that are seen as a measure to ensure quality terminology development. The efforts of the development of isiXhosa during the post-apartheid South Africa, especially the government-driven initiatives, are also critiqued even though these are not as effective and as extensive, especially in education. The result of this analysis is that African languages and isiXhosa in particular, can be used in scientific disciplines and at the highest levels of education. Its grammar is advanced, and its lexicon is extensive such that new concepts that need to be named can be named, using appropriate term creation strategies. There are also technological tools such as WordSmith tools that can be used that can advance its development, ensuring that the concept represented in the newly-created term is precise, concise and appropriate in terms of its discipline. Therefore it is argued that, in the interim, terminologies should be developed, in various subjects, to support learning, which at this stage is mediated in English, for those students who have other languages as mother tongue. Those terminologies that have been developed in the various historical periods should be collated, revised and brought into the classrooms. The thesis argues that real intellectualisation of isiXhosa and other African languages rests on the use of these languages in classrooms and lecture halls, and in the value that all role players place on these languages.
- Full Text:
- Date Issued: 2011
Intimate masculinities in the work of Paul Emmanuel
- Authors: Bronner, Irene Enslé
- Date: 2011
- Subjects: Emmanuel, Paul, 1969- Masculinity in art Identity (Psychology) in art Gender identity in art Art, South African -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2397 , http://hdl.handle.net/10962/d1002193
- Description: Paul Emmanuel is a South African artist who produces incised drawings, outdoor installations and prints (particularly intaglio etchings and manière noire lithographs). These focus on the representation of male bodies and experience. Having begun his career as a collaborative printmaker, since 2002, his work has become more ambitious as well as critically acclaimed. In 2010, his most recent body of work, Transitions, was exhibited at the Smithsonian Museum of African Art in Washington D.C. I propose that Emmanuel represents the male body as a presence that either is not easily seen or that actively disappears or erases itself. Its subjectivity, and the viewer’s engagement with it, may be characterised as one of intimacy, exposure, loss and vulnerability. Emmanuel’s work may be said to question conventions and ideals of masculinity while, at the same time, refusing any prescriptive interpretation. To develop this proposition, I examine specifically Emmanuel’s incising drawing technique that ‘holds open’ transitions in male lives. In these liminal moments, Emmanuel represents men as ‘seen’ to change state or status, thereby exposing the ongoing process of building masculine identities. Equally elucidatory is Emmanuel’s imprinting of his own body, which, in his use of “traces” that reveal the vacillation between presence and absence, makes contingently ‘visible’ this gendering process, and has particular implications for the expression of subjectivity in a contemporary South African context.
- Full Text:
- Date Issued: 2011
- Authors: Bronner, Irene Enslé
- Date: 2011
- Subjects: Emmanuel, Paul, 1969- Masculinity in art Identity (Psychology) in art Gender identity in art Art, South African -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2397 , http://hdl.handle.net/10962/d1002193
- Description: Paul Emmanuel is a South African artist who produces incised drawings, outdoor installations and prints (particularly intaglio etchings and manière noire lithographs). These focus on the representation of male bodies and experience. Having begun his career as a collaborative printmaker, since 2002, his work has become more ambitious as well as critically acclaimed. In 2010, his most recent body of work, Transitions, was exhibited at the Smithsonian Museum of African Art in Washington D.C. I propose that Emmanuel represents the male body as a presence that either is not easily seen or that actively disappears or erases itself. Its subjectivity, and the viewer’s engagement with it, may be characterised as one of intimacy, exposure, loss and vulnerability. Emmanuel’s work may be said to question conventions and ideals of masculinity while, at the same time, refusing any prescriptive interpretation. To develop this proposition, I examine specifically Emmanuel’s incising drawing technique that ‘holds open’ transitions in male lives. In these liminal moments, Emmanuel represents men as ‘seen’ to change state or status, thereby exposing the ongoing process of building masculine identities. Equally elucidatory is Emmanuel’s imprinting of his own body, which, in his use of “traces” that reveal the vacillation between presence and absence, makes contingently ‘visible’ this gendering process, and has particular implications for the expression of subjectivity in a contemporary South African context.
- Full Text:
- Date Issued: 2011
Investigating at the grassroots: exploring the origins, purposes journalistic practices and outcomes in two award-winning Daily Dispatch editorial projects
- Authors: Lunga, Carolyne Mande
- Date: 2011
- Subjects: Investigative reporting -- South Africa -- Eastern Cape Citizen journalism -- South Africa -- Eastern Cape Reporters and reporting -- South Africa -- Eastern Cape Journalism -- Social aspects -- South Africa -- Eastern Cape Journalism -- Political aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3452 , http://hdl.handle.net/10962/d1002906
- Description: This thesis explores the origins, purposes, journalistic practices and outcomes of two award-winning projects namely Broken Homes and Slumlords done by Daily Dispatch's Gcina Ntsaluba in 2009. The projects were described by the paper as investigative journalism but interestingly the original idea came from grassroots driven strategies and they were done by adopting alternative news gathering strategies and immersion in the ordinary people, inspired by public journalism. This thesis follows Christians et al's (2009) normative theoretical framework of press roles summarised as the monitorial, facilitative, collaborative and radical roles. It provides normative prescriptions of public and investigative journalism, development and radical journalism. It then draws on sociological theoretical critiques in order to provide an analytical overview of the complex matrix of political, economic and media contexts which influenced the origins, purposes, journalistic practices and outcomes of the two projects. Drawing on a critical realist case study design, the thesis goes on to provide a narrative account of the two projects based on the in-depth interviews exploring the editorial staffs ideas on the origins, purposes, journalistic practices and outcomes of the projects and a qualitative content/thematic analysis of the journalistic texts related to the projects. This primary data is then critically evaluated against normative theories of press performance, especially Nip's (2008) key practices and Haas's (2007) 'public philosophy' of public journalism. It is also evaluated against a normative framework of what constitutes "good investigative journalism" based on Ettema and Glasser (1998), Waisbord (2000) among others. Protess et al 1991's classic mobilisation model is used to interrogate the projects' outcomes. The thesis established that there was a close connection of the monitorial (investigative journalism), facilitative (public journalism) and radical (tabloid journalism) roles at the paper which shows that the roles are not mutually exclusive. The two projects however fell short of the collaborative role (development journalism) which can, partly, be attributed to the adversarial nature of the relationship between the state and the media. The Daily Dispatch also failed to activate a platform for deliberation and public problem solving. There might thus be more scope in adopting a 'facilitative monitorial role' which would not only expose those who violate other people's human rights, corrupt people and institutions that are not performing well. Instead it will also activate civic life and facilitate 'collaboration' between government and the publics in problem solving.
- Full Text:
- Date Issued: 2011
- Authors: Lunga, Carolyne Mande
- Date: 2011
- Subjects: Investigative reporting -- South Africa -- Eastern Cape Citizen journalism -- South Africa -- Eastern Cape Reporters and reporting -- South Africa -- Eastern Cape Journalism -- Social aspects -- South Africa -- Eastern Cape Journalism -- Political aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3452 , http://hdl.handle.net/10962/d1002906
- Description: This thesis explores the origins, purposes, journalistic practices and outcomes of two award-winning projects namely Broken Homes and Slumlords done by Daily Dispatch's Gcina Ntsaluba in 2009. The projects were described by the paper as investigative journalism but interestingly the original idea came from grassroots driven strategies and they were done by adopting alternative news gathering strategies and immersion in the ordinary people, inspired by public journalism. This thesis follows Christians et al's (2009) normative theoretical framework of press roles summarised as the monitorial, facilitative, collaborative and radical roles. It provides normative prescriptions of public and investigative journalism, development and radical journalism. It then draws on sociological theoretical critiques in order to provide an analytical overview of the complex matrix of political, economic and media contexts which influenced the origins, purposes, journalistic practices and outcomes of the two projects. Drawing on a critical realist case study design, the thesis goes on to provide a narrative account of the two projects based on the in-depth interviews exploring the editorial staffs ideas on the origins, purposes, journalistic practices and outcomes of the projects and a qualitative content/thematic analysis of the journalistic texts related to the projects. This primary data is then critically evaluated against normative theories of press performance, especially Nip's (2008) key practices and Haas's (2007) 'public philosophy' of public journalism. It is also evaluated against a normative framework of what constitutes "good investigative journalism" based on Ettema and Glasser (1998), Waisbord (2000) among others. Protess et al 1991's classic mobilisation model is used to interrogate the projects' outcomes. The thesis established that there was a close connection of the monitorial (investigative journalism), facilitative (public journalism) and radical (tabloid journalism) roles at the paper which shows that the roles are not mutually exclusive. The two projects however fell short of the collaborative role (development journalism) which can, partly, be attributed to the adversarial nature of the relationship between the state and the media. The Daily Dispatch also failed to activate a platform for deliberation and public problem solving. There might thus be more scope in adopting a 'facilitative monitorial role' which would not only expose those who violate other people's human rights, corrupt people and institutions that are not performing well. Instead it will also activate civic life and facilitate 'collaboration' between government and the publics in problem solving.
- Full Text:
- Date Issued: 2011
Investigating the popularity of the main news bulletin on Muvi TV, a Zambian television station: a reception study of Lusaka viewers
- Authors: Mbatha, Loisa
- Date: 2011
- Subjects: Television broadcasting of news -- Research -- Zambia Broadcast journalism -- Research -- Zambia Television programs -- Research -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3463 , http://hdl.handle.net/10962/d1002918
- Description: The "tabloid TV" genre, like tabloid newspapers has been chastised for depoliticising the public by causing cynicism, and lowering the standards of rational public discourse. Such criticisms are not always based on a close interrogation of the reasons for the popularity of such a genre amongst its consumers. The "tabloid TV" news genre is a relatively new phenomenon in Zambia and in the African context in general. This study is an investigation of the rise in popularity of the Zambian television station, Muvi TV. It is a reception study of Lusaka (capital city) viewers, particularly the working class community, who make up the majority of the TV stations' audience. Members of this social group who have hitherto been marginalised from mainstream media discourses were interviewed. In particular, the study explores the meanings obtained from the content of Muvi TVs' tabloidised main evening news and its relevance to their everyday lived experiences. The TV station gives prominence to "micro-politics of everyday life", alongside "serious" stories albeit in a more lurid, sensationalised and personalised manner. In undertaking this investigation, the study draws primarily on qualitative in-depth interviews - focus group and individual. These techniques unearth the manner in which the viewers decode the messages and appropriate the meanings into their lived experiences. The study establishes that the popularity of Muvi TV is due to the emphasis on human-interest stories epitomised by tabloid journalism values. The working class majority is able to relate and identify with these stories, and attaches greater believability to the station's news as compared to the public broadcaster, the Zambia National Broadcasting Corporation (ZNBC). As such, Muvi TV can be seen to fulfil a political function despite its sensationalised approach.
- Full Text:
- Date Issued: 2011
- Authors: Mbatha, Loisa
- Date: 2011
- Subjects: Television broadcasting of news -- Research -- Zambia Broadcast journalism -- Research -- Zambia Television programs -- Research -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3463 , http://hdl.handle.net/10962/d1002918
- Description: The "tabloid TV" genre, like tabloid newspapers has been chastised for depoliticising the public by causing cynicism, and lowering the standards of rational public discourse. Such criticisms are not always based on a close interrogation of the reasons for the popularity of such a genre amongst its consumers. The "tabloid TV" news genre is a relatively new phenomenon in Zambia and in the African context in general. This study is an investigation of the rise in popularity of the Zambian television station, Muvi TV. It is a reception study of Lusaka (capital city) viewers, particularly the working class community, who make up the majority of the TV stations' audience. Members of this social group who have hitherto been marginalised from mainstream media discourses were interviewed. In particular, the study explores the meanings obtained from the content of Muvi TVs' tabloidised main evening news and its relevance to their everyday lived experiences. The TV station gives prominence to "micro-politics of everyday life", alongside "serious" stories albeit in a more lurid, sensationalised and personalised manner. In undertaking this investigation, the study draws primarily on qualitative in-depth interviews - focus group and individual. These techniques unearth the manner in which the viewers decode the messages and appropriate the meanings into their lived experiences. The study establishes that the popularity of Muvi TV is due to the emphasis on human-interest stories epitomised by tabloid journalism values. The working class majority is able to relate and identify with these stories, and attaches greater believability to the station's news as compared to the public broadcaster, the Zambia National Broadcasting Corporation (ZNBC). As such, Muvi TV can be seen to fulfil a political function despite its sensationalised approach.
- Full Text:
- Date Issued: 2011
Investigating the relationship between sustainability and farmer decision-making: a qualitative study of maize farmers in Mpumalanga, South Africa
- Authors: Grewar, Robert
- Date: 2011
- Subjects: Sustainable agriculture -- Research -- South Africa Agriculture -- South Africa -- Decision making Corn -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:785 , http://hdl.handle.net/10962/d1003906
- Description: The goal of the research paper was to understand the complex relationship between the issue of sustainability and maize farmers’ decision-making processes. The aim is to shed light on the realities experienced by maize farmers in terms of how sustainability impacts on the decisions they make and how the decisions they make impact on sustainability. The importance of the research lies in the current state of affairs in the world in terms of the current economic recession, overpopulation, dire poverty and hunger, and the poor state of the environment. If humankind is to continue its existence on Earth in a happy, healthy world, something is going to have to give. In order for this to happen, people need to start grappling with the concept of sustainability. Focusing on sustainability as a whole is likely to end in despair. However, breaking the problem down into its component pieces will allow people to influence the particular sector in which they operate. It is therefore imperative for research into sustainability to be undertaken in all sectors of society and the economy. Agriculture presents an excellent research area due to its intrinsic link with the environment, society and the economy. Agriculture and its wellbeing is inextricably tied to environmental health. Healthy plants and animals will not grow in unhealthy conditions. Society is to a large degree dependent on agriculture for food, agriculture therefore has a significant impact on social order and function. Agriculture is one of the primary contributors to GDP, particularly in poor and developing nations. As a result, agriculture has an important role to play in ensuring economic sustainability. In order to engage with sustainability from an agricultural perspective it was decided to engage on the farmer-level. Gaining an understanding of their reality in terms of what motivates their decisions is key to understanding the relationship between agriculture and sustainability. Three maize farmers in Mpumalanga, South Africa, were interviewed with the aim of collecting qualitative data and then analysing the data using thematic analysis. The methodology employed enabled the researcher to uncover patterns in the data that constituted themes across the interviews. The following themes emerged: Theme 1: Economic factors are the primary decision driver. This is primarily due to the extent of the financial risk experienced by farmers as a result of market risk, production risk, finance risk, and rising input costs. This results in economic considerations superseding environmental or social concerns in farmers’ decisions. This has a negative impact on the overall sustainability of the farming operation. Theme 2: There has been a decrease in the number of family-run farms. This is attributable to a number of factors including economic failure, fear of loss of land due to land-reform policies, as well as crime. Family-run farms tend to have a greater focus on sustainability due to the vested interest in the next generation taking over the farm. The corporate farming operations that are taking over the farms tend to be more focussed on short-term gains in order to satisfy shareholders. Theme 3: Mechanisation is preferable to manual labour. There has been an alarming decrease in the number of labourers employed on farms. Farmers say this is due to two factors. Firstly, machines are more efficient than labour. Secondly, restrictive labour laws have made famers less keen to employ people. The net effect of these two factors is that unemployment is rising. This has negative consequences for society, the economy, and the environment. Theme 4: Farmers believe they do very little environmental damage. This results in decisions being made that do not consider environmental wellbeing other than soil health. This is because farmers see healthy soil as an integral input that optimises economic performance. Farmers tend to prioritise economic factors in their decisions more than environmental or social factors. This results in an unsustainable perspective. The only ways in which this is likely to change is if the financial risk associated with agriculture is decreased, or if farmers are given financial incentive to change their ways. In order to deal with this issue it is necessary for further research to be conducted. Research needs to be conducted to confirm the results of this study. It is important to know whether the results pertain only to maize farmers in Mpumalanga or whether most farmers in South Africa, and indeed the world, face similar problems. Research should also be conducted to propose policies or procedures to reduce financial risk in agriculture. Research should focus on reducing market risk and reducing input costs, possibly via subsidisation.
- Full Text:
- Date Issued: 2011
- Authors: Grewar, Robert
- Date: 2011
- Subjects: Sustainable agriculture -- Research -- South Africa Agriculture -- South Africa -- Decision making Corn -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:785 , http://hdl.handle.net/10962/d1003906
- Description: The goal of the research paper was to understand the complex relationship between the issue of sustainability and maize farmers’ decision-making processes. The aim is to shed light on the realities experienced by maize farmers in terms of how sustainability impacts on the decisions they make and how the decisions they make impact on sustainability. The importance of the research lies in the current state of affairs in the world in terms of the current economic recession, overpopulation, dire poverty and hunger, and the poor state of the environment. If humankind is to continue its existence on Earth in a happy, healthy world, something is going to have to give. In order for this to happen, people need to start grappling with the concept of sustainability. Focusing on sustainability as a whole is likely to end in despair. However, breaking the problem down into its component pieces will allow people to influence the particular sector in which they operate. It is therefore imperative for research into sustainability to be undertaken in all sectors of society and the economy. Agriculture presents an excellent research area due to its intrinsic link with the environment, society and the economy. Agriculture and its wellbeing is inextricably tied to environmental health. Healthy plants and animals will not grow in unhealthy conditions. Society is to a large degree dependent on agriculture for food, agriculture therefore has a significant impact on social order and function. Agriculture is one of the primary contributors to GDP, particularly in poor and developing nations. As a result, agriculture has an important role to play in ensuring economic sustainability. In order to engage with sustainability from an agricultural perspective it was decided to engage on the farmer-level. Gaining an understanding of their reality in terms of what motivates their decisions is key to understanding the relationship between agriculture and sustainability. Three maize farmers in Mpumalanga, South Africa, were interviewed with the aim of collecting qualitative data and then analysing the data using thematic analysis. The methodology employed enabled the researcher to uncover patterns in the data that constituted themes across the interviews. The following themes emerged: Theme 1: Economic factors are the primary decision driver. This is primarily due to the extent of the financial risk experienced by farmers as a result of market risk, production risk, finance risk, and rising input costs. This results in economic considerations superseding environmental or social concerns in farmers’ decisions. This has a negative impact on the overall sustainability of the farming operation. Theme 2: There has been a decrease in the number of family-run farms. This is attributable to a number of factors including economic failure, fear of loss of land due to land-reform policies, as well as crime. Family-run farms tend to have a greater focus on sustainability due to the vested interest in the next generation taking over the farm. The corporate farming operations that are taking over the farms tend to be more focussed on short-term gains in order to satisfy shareholders. Theme 3: Mechanisation is preferable to manual labour. There has been an alarming decrease in the number of labourers employed on farms. Farmers say this is due to two factors. Firstly, machines are more efficient than labour. Secondly, restrictive labour laws have made famers less keen to employ people. The net effect of these two factors is that unemployment is rising. This has negative consequences for society, the economy, and the environment. Theme 4: Farmers believe they do very little environmental damage. This results in decisions being made that do not consider environmental wellbeing other than soil health. This is because farmers see healthy soil as an integral input that optimises economic performance. Farmers tend to prioritise economic factors in their decisions more than environmental or social factors. This results in an unsustainable perspective. The only ways in which this is likely to change is if the financial risk associated with agriculture is decreased, or if farmers are given financial incentive to change their ways. In order to deal with this issue it is necessary for further research to be conducted. Research needs to be conducted to confirm the results of this study. It is important to know whether the results pertain only to maize farmers in Mpumalanga or whether most farmers in South Africa, and indeed the world, face similar problems. Research should also be conducted to propose policies or procedures to reduce financial risk in agriculture. Research should focus on reducing market risk and reducing input costs, possibly via subsidisation.
- Full Text:
- Date Issued: 2011
Investigating the role of heat shock proteins (Hsps) 40, 70 and 90 in the life cycle of Theiler's murine encephalomyelitis virus (TMEV)
- Mutsvunguma, Lorraine Zvichapera
- Authors: Mutsvunguma, Lorraine Zvichapera
- Date: 2011
- Subjects: Heat shock proteins , Picornaviruses , Encephalomyelitis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3966 , http://hdl.handle.net/10962/d1004025 , Heat shock proteins , Picornaviruses , Encephalomyelitis
- Description: Introduction: Picornaviruses are a family of RNA viruses which are economically and clinically significant. Like many other viruses, picornaviruses utilise host cell machinery to facilitate their replication and assembly, including heat shock proteins (Hsps). The aim of this research was to investigate the role of Hsp40, Hsp70 and Hsp90 during picornavirus infection using the cardiovirus, Theiler’s murine encephalomyelitis virus (TMEV), as a study model. Methodology: Picornavirus VP1 capsid proteins were analysed by multiple sequence alignment and multiple structural comparisons. Protein domain architecture was used to analyse Hsp90 cellular and viral client proteins. Effects of Hsp90 inhibitors, novobiocin and geldanamycin, on TMEV growth in BHK-21 cells was observed over a 48hr period. Localisation of Hsp40, Hsp90 and Hsp70 in TMEV-infected BHK-21 cells was investigated by indirect immunofluorescence and confocal microscopy. Results and Discussion: VP1 proteins of picornaviruses are highly divergent within the family at the amino acid level, which might be linked to the protein’s function in determining virus tropism and antibody neutralisation. An eight-stranded anti-parallel beta-barrel structure was found conserved in the VP1 protein structures which might be linked to the highly conserved picornavirus capsid assembly process. Absence of a common protein domain between Hsp90 viral and cellular client proteins that might be functionally connected to Hsp90, suggests that Hsp90 most likely recognises surface features rather than sequence motifs/patterns. The Hsp90 inhibitors, novobiocin and geldanamycin, had a negative effect on virus growth as virus-induced cytopathic effect was not observed in treated cell after 48hrs. TMEV 2C protein was detected by Western analysis in infected cell lysates treated with geldanamycin but not novobiocin, suggesting novobiocin affects the translation or processing of TMEV 2C. Immunofluorescence analysis of TMEV-infected cells showed a relocalisation of Hsp40 into the nucleus during infection. Overlap of Hsp40 and TMEV P1 was observed in the perinuclear region, suggesting colocalisation between these proteins. Hsp70 converged around the replication complex during infection but did not overlap with TMEV 2C. Hsp90 concentrated in the region of the replication complex where it overlapped with TMEV 2C and this redistribution was found to be dependent on the stage of infection. The overlap between Hsp90 and TMEV 2C signals observed, suggested colocalisation between the two proteins. Conclusion: This study identified Hsp90, Hsp70 and Hsp40 as possible host factors required in TMEV replication.
- Full Text:
- Date Issued: 2011
- Authors: Mutsvunguma, Lorraine Zvichapera
- Date: 2011
- Subjects: Heat shock proteins , Picornaviruses , Encephalomyelitis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3966 , http://hdl.handle.net/10962/d1004025 , Heat shock proteins , Picornaviruses , Encephalomyelitis
- Description: Introduction: Picornaviruses are a family of RNA viruses which are economically and clinically significant. Like many other viruses, picornaviruses utilise host cell machinery to facilitate their replication and assembly, including heat shock proteins (Hsps). The aim of this research was to investigate the role of Hsp40, Hsp70 and Hsp90 during picornavirus infection using the cardiovirus, Theiler’s murine encephalomyelitis virus (TMEV), as a study model. Methodology: Picornavirus VP1 capsid proteins were analysed by multiple sequence alignment and multiple structural comparisons. Protein domain architecture was used to analyse Hsp90 cellular and viral client proteins. Effects of Hsp90 inhibitors, novobiocin and geldanamycin, on TMEV growth in BHK-21 cells was observed over a 48hr period. Localisation of Hsp40, Hsp90 and Hsp70 in TMEV-infected BHK-21 cells was investigated by indirect immunofluorescence and confocal microscopy. Results and Discussion: VP1 proteins of picornaviruses are highly divergent within the family at the amino acid level, which might be linked to the protein’s function in determining virus tropism and antibody neutralisation. An eight-stranded anti-parallel beta-barrel structure was found conserved in the VP1 protein structures which might be linked to the highly conserved picornavirus capsid assembly process. Absence of a common protein domain between Hsp90 viral and cellular client proteins that might be functionally connected to Hsp90, suggests that Hsp90 most likely recognises surface features rather than sequence motifs/patterns. The Hsp90 inhibitors, novobiocin and geldanamycin, had a negative effect on virus growth as virus-induced cytopathic effect was not observed in treated cell after 48hrs. TMEV 2C protein was detected by Western analysis in infected cell lysates treated with geldanamycin but not novobiocin, suggesting novobiocin affects the translation or processing of TMEV 2C. Immunofluorescence analysis of TMEV-infected cells showed a relocalisation of Hsp40 into the nucleus during infection. Overlap of Hsp40 and TMEV P1 was observed in the perinuclear region, suggesting colocalisation between these proteins. Hsp70 converged around the replication complex during infection but did not overlap with TMEV 2C. Hsp90 concentrated in the region of the replication complex where it overlapped with TMEV 2C and this redistribution was found to be dependent on the stage of infection. The overlap between Hsp90 and TMEV 2C signals observed, suggested colocalisation between the two proteins. Conclusion: This study identified Hsp90, Hsp70 and Hsp40 as possible host factors required in TMEV replication.
- Full Text:
- Date Issued: 2011
Investigation into the extended capabilities of the new DPS-4D ionosonde
- Authors: Ssessanga, Nicholas
- Date: 2011
- Subjects: Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5472 , http://hdl.handle.net/10962/d1005257 , Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Description: The DPS-4D is the latest version of digital ionosonde developed by the UMLCAR (University of Massachusetts in Lowell Center for Atmospheric Research) in 2008. This new ionosonde has advances in both the hardware and software which allows for the promised advanced capabilities. The aim of this thesis was to present results from an experiment undertaken using the Hermanus DPS-4D (34.4°S 19.2°E, South Africa), the first of this version to be installed globally, to answer a science question outside of the normally expected capabilities of an ionosonde. The science question posed focused on the ability of the DPS-4D to provide information on day-time Pc3 pulsations evident in the ionosphere. Day-time Pc3 ULF waves propagating down through the ionosphere cause oscillations in the Doppler shift of High Frequency (HF) radio transmissions that are correlated with the magnetic pulsations recorded on the ground. Evidence is presented which shows that no correlation exists between the ground magnetic pulsation data and DPS-4D ionospheric data. The conclusion was reached that although the DPS-4D is more advanced in its eld of technology than its predecessors it may not be used to observe Pc3 pulsations.
- Full Text:
- Date Issued: 2011
- Authors: Ssessanga, Nicholas
- Date: 2011
- Subjects: Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5472 , http://hdl.handle.net/10962/d1005257 , Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Description: The DPS-4D is the latest version of digital ionosonde developed by the UMLCAR (University of Massachusetts in Lowell Center for Atmospheric Research) in 2008. This new ionosonde has advances in both the hardware and software which allows for the promised advanced capabilities. The aim of this thesis was to present results from an experiment undertaken using the Hermanus DPS-4D (34.4°S 19.2°E, South Africa), the first of this version to be installed globally, to answer a science question outside of the normally expected capabilities of an ionosonde. The science question posed focused on the ability of the DPS-4D to provide information on day-time Pc3 pulsations evident in the ionosphere. Day-time Pc3 ULF waves propagating down through the ionosphere cause oscillations in the Doppler shift of High Frequency (HF) radio transmissions that are correlated with the magnetic pulsations recorded on the ground. Evidence is presented which shows that no correlation exists between the ground magnetic pulsation data and DPS-4D ionospheric data. The conclusion was reached that although the DPS-4D is more advanced in its eld of technology than its predecessors it may not be used to observe Pc3 pulsations.
- Full Text:
- Date Issued: 2011
Investigation of learning in an environmental skills programme: a case study of workers' training in the Department of Environmental Affairs Expanded Public Works Project
- Authors: Giqwa, Nomfundiso Louisa
- Date: 2011
- Subjects: South Africa -- Department of Environmental Affairs Environmental education -- Study and teaching -- South Africa Environmental education -- Activity programs -- South Africa Environmental education -- Evaluation -- South Africa Environmental education -- Curricula -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1636 , http://hdl.handle.net/10962/d1003518
- Description: This research project examines a case of environmental training for workers in the Expanded Public Works Programme, a poverty relief programme operating in South Africa (EPWP). It is constituted as an interpretive case study, and explores what workers learn and how they learn in an environmental skills programme. The study also examines the context of learning. In accordance with education and training policy, what learners are meant to learn is articulated in unit standards registered on the South African Qualifications Authority website. The unit standards are used to design curricula and learning programmes which are registered as environmental skills programmes by Sector Education and Training Authorities (SETAs). For the conservation sector the SETA is the Tourism and Hospitality Education and Training Authority (THETA). To develop an understanding of what learners learn, I considered the content, concepts, skills, values and attitudes contained in the unit standards, and then considered the actual learning taking place during the training programme focusing on three unit standards. Data was generated from semi-structured interviews with facilitators, focus group interviews with learners, observations of teaching and learning interventions and document analysis of EPWP, training and skills development policy documents, registered unit standards for the skills programme, and learning support materials produced by the provider implementing the training. The study notes that there is learning taking place within the training implemented through environmental skills programmes. The training is influenced by a number of diverse contextual factors namely policy factors, historical contextual factors, the economic context and diverse literacy levels. Learning interactions involve a variety of social interactions, activities and practices between learners and learners, and learners and facilitators. The main finding of the study is that the training programme’s major emphasis is on concepts and content, and social and learning skills, and values and attitudes. The prominence of social skills masks a neglect of practical workplace related skills which make up a strong focus of the unit standards. This, the study shows, is related to a lack of engagement with workplace learning, which in turn is linked to a disjuncture between policy and practice, where workers working in the EPWP programme are meant to benefit from training, but in this case it was found that community members, who were not working in the programme were being offered training. It was therefore not possible for them to develop the applied workplace skills, which were also meant to facilitate increased employability, as this is one of the key objectives of the EPWP programme. Based on the insights raised by the research findings the study made recommendations that the programme consider the following to recover the situation: to develop strategies that allow for longer term training frameworks so that learners can be trained on full qualifications so that they may qualify and benefit more substantively from the training in terms of employability skills. Facilitators in the programme need to be trained so that they can develop materials that address practical skills, values, attitudes, critical reflections and actions. Monitoring of training needs to be given preference both at materials development level and implementation level.
- Full Text:
- Date Issued: 2011
- Authors: Giqwa, Nomfundiso Louisa
- Date: 2011
- Subjects: South Africa -- Department of Environmental Affairs Environmental education -- Study and teaching -- South Africa Environmental education -- Activity programs -- South Africa Environmental education -- Evaluation -- South Africa Environmental education -- Curricula -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1636 , http://hdl.handle.net/10962/d1003518
- Description: This research project examines a case of environmental training for workers in the Expanded Public Works Programme, a poverty relief programme operating in South Africa (EPWP). It is constituted as an interpretive case study, and explores what workers learn and how they learn in an environmental skills programme. The study also examines the context of learning. In accordance with education and training policy, what learners are meant to learn is articulated in unit standards registered on the South African Qualifications Authority website. The unit standards are used to design curricula and learning programmes which are registered as environmental skills programmes by Sector Education and Training Authorities (SETAs). For the conservation sector the SETA is the Tourism and Hospitality Education and Training Authority (THETA). To develop an understanding of what learners learn, I considered the content, concepts, skills, values and attitudes contained in the unit standards, and then considered the actual learning taking place during the training programme focusing on three unit standards. Data was generated from semi-structured interviews with facilitators, focus group interviews with learners, observations of teaching and learning interventions and document analysis of EPWP, training and skills development policy documents, registered unit standards for the skills programme, and learning support materials produced by the provider implementing the training. The study notes that there is learning taking place within the training implemented through environmental skills programmes. The training is influenced by a number of diverse contextual factors namely policy factors, historical contextual factors, the economic context and diverse literacy levels. Learning interactions involve a variety of social interactions, activities and practices between learners and learners, and learners and facilitators. The main finding of the study is that the training programme’s major emphasis is on concepts and content, and social and learning skills, and values and attitudes. The prominence of social skills masks a neglect of practical workplace related skills which make up a strong focus of the unit standards. This, the study shows, is related to a lack of engagement with workplace learning, which in turn is linked to a disjuncture between policy and practice, where workers working in the EPWP programme are meant to benefit from training, but in this case it was found that community members, who were not working in the programme were being offered training. It was therefore not possible for them to develop the applied workplace skills, which were also meant to facilitate increased employability, as this is one of the key objectives of the EPWP programme. Based on the insights raised by the research findings the study made recommendations that the programme consider the following to recover the situation: to develop strategies that allow for longer term training frameworks so that learners can be trained on full qualifications so that they may qualify and benefit more substantively from the training in terms of employability skills. Facilitators in the programme need to be trained so that they can develop materials that address practical skills, values, attitudes, critical reflections and actions. Monitoring of training needs to be given preference both at materials development level and implementation level.
- Full Text:
- Date Issued: 2011
Investigation of photosensitising behaviour of Ni, Pd and Pt phthalocyanines towards phenolic pollutants
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
Investigations of the assessment of bioequivalence of topical clotrimazole products using a dermatopharmacokinetic approach
- Authors: Parfitt, Natalie Rae
- Date: 2011 , 2010-07-05
- Subjects: Dermatopharmacology , Drugs -- Therapeutic equivalency , Antifungal agents , Therapeutics, Cutaneous and external
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3840 , http://hdl.handle.net/10962/d1007659 , Dermatopharmacology , Drugs -- Therapeutic equivalency , Antifungal agents , Therapeutics, Cutaneous and external
- Description: The specialised nature of the stratum corneum makes it an efficient barrier to foreign substances, including drug molecules. Therefore, cutaneous drug absorption is a slow and complex process of which stratum corneum penetration is the rate limiting step. The rate and extent of stratum corneum penetration by a drug compound depends greatly on the presence of penetration enhancing/retarding excipients and therefore the clinical outcomes of a product rely greatly on the components and quality of the formulation. Hence, establishing bioequivalence between topical products is crucial to ensure that patients receiving multisource drug products are assured of the same efficacy and safety as the brand product. Since locally acting topical formulations do not target the systemic circulation, conventional methods of assessing bioequivalence using plasma levels are not appropriate. Consequently, the current regulatory guidelines require comparative clinical trials to be carried out to show bioequivalence between topical products. As these studies are very expensive and time consuming, the development of a more direct and relatively rapid and inexpensive method for determining bioequivalence between topical products is required. Clotrimazole is an anti-fungal agent where the target site of action is in the stratum corneum. In this work, tape stripping, which involves the sampling of stratum corneum, was investigated as a tool for the determination of bioequivalence between topical clotrimazole products. The tape stripping method involved the analysis of each tape strip individually and standardization of stratum corneum thickness between subjects was carried out using TEWL measurements. This approach provided detailed information regarding the amount of clotrimazole present in the stratum corneum as well as the extent of drug penetration. Prior to the tape stripping studies an HPLC method was developed for the quantitative analysis of clotrimazole from the tape strip samples. This method was shown to be accurate and reproducible across the required range. It was also shown to be selective for clotrimazole in the presence of possible interfering substances such as those present in the tape adhesive and also skin components. The bioequivalence studies were conducted using a single “uptake” time point. In order to determine an appropriate dose duration for these studies a novel approach was employed, involving a preliminary dose duration study. For the bioequivalence investigations, Canesten® Topical cream was used as both test and reference products to determine if the method was capable of showing bioequivalence. Subsequently, Canesten® Topical cream was also compared to a 1% gel formulation to determine if the method could detect formulation differences. The conventional BE limits of 0.8 – 1.25 were used for the assessment of BE, however, the clinical relevance of using these limits for dermal studies is debatable since they are derived from oral pharmacokinetic studies. Therefore, the data from the tape stripping investigations were also assessed using more realistic limits of 0.75 – 1.33 and even 0.7 – 1.44. In addition to the tape stripping studies a novel method of determining the amount of drug present in the stratum corneum, the “Residual Method”, was investigated. This method involved assaying the amount of clotrimazole found in the residual formulation after a specified dose duration had elapsed and subtracting that amount from the amount of clotrimazole initially applied. The results of tape stripping investigations showed that, if the study is sufficiently powered, tape stripping may be used to determine bioequivalence according to the conventional limits, as well as possibly detect formulation differences between different clotrimazole products. Bioequivalence assessment using the widened intervals showed that fewer subjects were required to achieve a sufficient statistical power. The variability associated with this method was acceptable and tape stripping may therefore have the potential to be used as a BE tool in a regulatory setting for clotrimazole or other antifungal topical formulations. The “Residual Method” also showed promising results as a bioequivalence tool, but further investigation and extensive validation of this method is required before it can be suggested as a regulatory method. The results of these studies have clearly indicated that tape stripping has the potential to be used as an alternative to comparative clinical trails for the assessment of bioequivalence between clotrimazole formulations and also to assess bioequivalence between other antifungal products.
- Full Text:
- Date Issued: 2011
- Authors: Parfitt, Natalie Rae
- Date: 2011 , 2010-07-05
- Subjects: Dermatopharmacology , Drugs -- Therapeutic equivalency , Antifungal agents , Therapeutics, Cutaneous and external
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3840 , http://hdl.handle.net/10962/d1007659 , Dermatopharmacology , Drugs -- Therapeutic equivalency , Antifungal agents , Therapeutics, Cutaneous and external
- Description: The specialised nature of the stratum corneum makes it an efficient barrier to foreign substances, including drug molecules. Therefore, cutaneous drug absorption is a slow and complex process of which stratum corneum penetration is the rate limiting step. The rate and extent of stratum corneum penetration by a drug compound depends greatly on the presence of penetration enhancing/retarding excipients and therefore the clinical outcomes of a product rely greatly on the components and quality of the formulation. Hence, establishing bioequivalence between topical products is crucial to ensure that patients receiving multisource drug products are assured of the same efficacy and safety as the brand product. Since locally acting topical formulations do not target the systemic circulation, conventional methods of assessing bioequivalence using plasma levels are not appropriate. Consequently, the current regulatory guidelines require comparative clinical trials to be carried out to show bioequivalence between topical products. As these studies are very expensive and time consuming, the development of a more direct and relatively rapid and inexpensive method for determining bioequivalence between topical products is required. Clotrimazole is an anti-fungal agent where the target site of action is in the stratum corneum. In this work, tape stripping, which involves the sampling of stratum corneum, was investigated as a tool for the determination of bioequivalence between topical clotrimazole products. The tape stripping method involved the analysis of each tape strip individually and standardization of stratum corneum thickness between subjects was carried out using TEWL measurements. This approach provided detailed information regarding the amount of clotrimazole present in the stratum corneum as well as the extent of drug penetration. Prior to the tape stripping studies an HPLC method was developed for the quantitative analysis of clotrimazole from the tape strip samples. This method was shown to be accurate and reproducible across the required range. It was also shown to be selective for clotrimazole in the presence of possible interfering substances such as those present in the tape adhesive and also skin components. The bioequivalence studies were conducted using a single “uptake” time point. In order to determine an appropriate dose duration for these studies a novel approach was employed, involving a preliminary dose duration study. For the bioequivalence investigations, Canesten® Topical cream was used as both test and reference products to determine if the method was capable of showing bioequivalence. Subsequently, Canesten® Topical cream was also compared to a 1% gel formulation to determine if the method could detect formulation differences. The conventional BE limits of 0.8 – 1.25 were used for the assessment of BE, however, the clinical relevance of using these limits for dermal studies is debatable since they are derived from oral pharmacokinetic studies. Therefore, the data from the tape stripping investigations were also assessed using more realistic limits of 0.75 – 1.33 and even 0.7 – 1.44. In addition to the tape stripping studies a novel method of determining the amount of drug present in the stratum corneum, the “Residual Method”, was investigated. This method involved assaying the amount of clotrimazole found in the residual formulation after a specified dose duration had elapsed and subtracting that amount from the amount of clotrimazole initially applied. The results of tape stripping investigations showed that, if the study is sufficiently powered, tape stripping may be used to determine bioequivalence according to the conventional limits, as well as possibly detect formulation differences between different clotrimazole products. Bioequivalence assessment using the widened intervals showed that fewer subjects were required to achieve a sufficient statistical power. The variability associated with this method was acceptable and tape stripping may therefore have the potential to be used as a BE tool in a regulatory setting for clotrimazole or other antifungal topical formulations. The “Residual Method” also showed promising results as a bioequivalence tool, but further investigation and extensive validation of this method is required before it can be suggested as a regulatory method. The results of these studies have clearly indicated that tape stripping has the potential to be used as an alternative to comparative clinical trails for the assessment of bioequivalence between clotrimazole formulations and also to assess bioequivalence between other antifungal products.
- Full Text:
- Date Issued: 2011
Learning commercial beekeeping: two cases of social learning in southern African community natural resources management contexts
- Authors: Masara, Christopher
- Date: 2011
- Subjects: Bee culture Bee culture -- Africa, Southern Social learning -- Africa, Southern Natural resources -- Africa, Southern--Management Natural resources, Communal -- Africa, Southern Conservation of natural resources -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1664 , http://hdl.handle.net/10962/d1003547
- Description: Community Based Natural Resources Management (CBNRM) in southern Africa has gained an important role in alleviating poverty and conserving natural resources. The attention and funding CBNRM is receiving from governments, non-governmental organisations and donors is seen as one way to strengthen civil society‟s involvement in decision-making and participating in activities that contribute to a sustainable livelihood, whilst at the same time learning in their social contexts to adapt and care for the ever changing environment characterised by constraints, challenges, contradictions, new opportunities for learning and change. This study focuses on social learning in commercialisation of natural resource products in two case studies of commercial beekeeping in rural southern African contexts. In this study social learning entails a process of qualitative change taking place in a social context for the purpose of personal and social adaptation. This perspective is useful in this study as learning in the two cases, Hluleka in South Africa and Buhera in Zimbabwe involved the transition beekeeping.from traditional honey harvesting practices and subsistence beekeeping to commercial beekeeping. This study is informed by two related theoretical perspectives namely Cultural Historical Activity Theory (CHAT) and Social Learning Theory. CHAT was used as conceptual and methodological framework to inform the first phase of data gathering and analysis processes; as well as second phase data gathering. In the first phase, I gathered data through semistructured interviews, document reviews and observations to identify problems, challenges and critical incidents in learning commercial beekeeping, technically known as tensions and contradictions within the CHAT framework. These tensions and contradictions, surfaced through analysis of first phase data were used as "mirror data‟ in Intervention Workshops within CHAT's process of Developmental Work Research, which supports social learning in response to tensions and contradictions in workplace activity. Use of mirror data provided a basis for dialogue and the modelling of new solutions to identified contradictions. To interpret the social learning processes resulting from these interactions, I drew on Wals' (2007) analytical lenses, through which I was able to monitor social learning processes that emerged from the Intervention Workshop dialogues while beekeepers modelled new solutions to contradictions in learning commercial beekeeping. The findings of the study revealed that social learning in commercial beekeeping is internally and externally influenced by socio-cultural, political and economic complexities. Social learning in Intervention Workshops was supported by different knowledge bases of participants, in this study these are beekeepers, extension officers, trainers and development facilitators. Such knowledge bases were the source of information for learning and constructing model solutions. The study also revealed that learning in CBNRM workplaces can be observed across the development processes, and CHAT as a methodological tool and Wals‟ (2007) analytical tool are complementary and can be used in researching social learning in other CBNRM workplaces. The study contributes in-depth insight into participatory research and learning processes, especially within the context of CBRM in southern Africa. It gives some empirical and explanatory insight into how change-oriented social learning can emerge and be expanded in Education for Sustainable Development. It also provides learning and extension tools to work with contradictions that arise from socio-cultural and historical dimensions of learning commercialisation of natural resources in southern African context. Its other key contribution is that it provides further insight into the mobilisation of human agency and reflexivity in change oriented social learning processes of commercialisation of sustainable natural resources products and poverty alleviation processes that are critical for responding to socioecological issues and risks and development challenges in southern Africa.
- Full Text:
- Date Issued: 2011
- Authors: Masara, Christopher
- Date: 2011
- Subjects: Bee culture Bee culture -- Africa, Southern Social learning -- Africa, Southern Natural resources -- Africa, Southern--Management Natural resources, Communal -- Africa, Southern Conservation of natural resources -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1664 , http://hdl.handle.net/10962/d1003547
- Description: Community Based Natural Resources Management (CBNRM) in southern Africa has gained an important role in alleviating poverty and conserving natural resources. The attention and funding CBNRM is receiving from governments, non-governmental organisations and donors is seen as one way to strengthen civil society‟s involvement in decision-making and participating in activities that contribute to a sustainable livelihood, whilst at the same time learning in their social contexts to adapt and care for the ever changing environment characterised by constraints, challenges, contradictions, new opportunities for learning and change. This study focuses on social learning in commercialisation of natural resource products in two case studies of commercial beekeeping in rural southern African contexts. In this study social learning entails a process of qualitative change taking place in a social context for the purpose of personal and social adaptation. This perspective is useful in this study as learning in the two cases, Hluleka in South Africa and Buhera in Zimbabwe involved the transition beekeeping.from traditional honey harvesting practices and subsistence beekeeping to commercial beekeeping. This study is informed by two related theoretical perspectives namely Cultural Historical Activity Theory (CHAT) and Social Learning Theory. CHAT was used as conceptual and methodological framework to inform the first phase of data gathering and analysis processes; as well as second phase data gathering. In the first phase, I gathered data through semistructured interviews, document reviews and observations to identify problems, challenges and critical incidents in learning commercial beekeeping, technically known as tensions and contradictions within the CHAT framework. These tensions and contradictions, surfaced through analysis of first phase data were used as "mirror data‟ in Intervention Workshops within CHAT's process of Developmental Work Research, which supports social learning in response to tensions and contradictions in workplace activity. Use of mirror data provided a basis for dialogue and the modelling of new solutions to identified contradictions. To interpret the social learning processes resulting from these interactions, I drew on Wals' (2007) analytical lenses, through which I was able to monitor social learning processes that emerged from the Intervention Workshop dialogues while beekeepers modelled new solutions to contradictions in learning commercial beekeeping. The findings of the study revealed that social learning in commercial beekeeping is internally and externally influenced by socio-cultural, political and economic complexities. Social learning in Intervention Workshops was supported by different knowledge bases of participants, in this study these are beekeepers, extension officers, trainers and development facilitators. Such knowledge bases were the source of information for learning and constructing model solutions. The study also revealed that learning in CBNRM workplaces can be observed across the development processes, and CHAT as a methodological tool and Wals‟ (2007) analytical tool are complementary and can be used in researching social learning in other CBNRM workplaces. The study contributes in-depth insight into participatory research and learning processes, especially within the context of CBRM in southern Africa. It gives some empirical and explanatory insight into how change-oriented social learning can emerge and be expanded in Education for Sustainable Development. It also provides learning and extension tools to work with contradictions that arise from socio-cultural and historical dimensions of learning commercialisation of natural resources in southern African context. Its other key contribution is that it provides further insight into the mobilisation of human agency and reflexivity in change oriented social learning processes of commercialisation of sustainable natural resources products and poverty alleviation processes that are critical for responding to socioecological issues and risks and development challenges in southern Africa.
- Full Text:
- Date Issued: 2011
Lumberjacks and hoodrats: negotiating subject positions of lesbian representation in two South African television programmes
- Authors: Donaldson, Natalie
- Date: 2011
- Subjects: Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2964 , http://hdl.handle.net/10962/d1002473 , Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Description: With the inclusion of sexual orientation in the Equality clause of the post-Apartheid constitution which demands equal rights and protection for all individuals regardless of sexual orientation, South Africa has been praised as one of the most liberal countries in the world. Because of this legal equality, gay and lesbian experiences have become a lot more visible in every day South African lives. This includes visibility in South African television programmes and film. Today, a number of South African produced television programmes have included at least one lesbian character in their storyline and many LGBTIQ activist organisations have deemed this increased visibility as a positive step for LGBTIQ rights. However, discriminatory discourses such as same-sex sexualities as 'un-African ' and unnatural, which often result in brutal hate crimes against LGBTIQ individuals (such as corrective rape), contribute to the social and cultural intolerance of same-sex sexualities. South African research into the lives of lesbian women has often related lesbian experience to that of gay men or has focused on lesbian women as victims of corrective rape and oppressive practices at the hands of the dominant heteronormative culture. This research was a discursive reception study, using three focus group discussions with self-identified lesbian audiences (black and white). The study explored how this audience received (interpreted/talked about) the available fictional representations of 'black' lesbian women and 'white' lesbian women in three clips from two South African television programmes, Society and The Mating Game. Using Wetherell's (1998) critical discursive psychology approach, this research focused on examining the 1) Subject positions made available in/by these representations; 2) Interpretive repertoires used by the audience in appropriating and/or negotiating and/or reSisting these subject positions; and 3) Ideological dilemmas experienced by participants in this negotiation process. The predominant subject positions made available in these representations were differentiated according to binary racial categories of white lesbian women and black lesbian women. For example, participants positioned white lesbian women as "lumberjacks" and "tomboys" while black lesbian women were positioned as "township lesbians" and "hood rats". In working with these subject positions, participants drew on interpretative repertoires of othering and otherness as well as interpretative repertoires of survival. In negotiating with these subject positions and others found in the discussions, ideological dilemmas often arose when participants found themselves having to draw on interpretative repertoires which extend from a heteronormative discourse. These kinds of interpretative repertoires included religion, nature, and compromise which contradicted and created a troubled position when used in relation to the participants' lesbian sexualities. Therefore, when the ideological dilemma and troubled position became apparent, participants had to work to repair the troubled position by justifying their use of these heteronormative interpretative repertoires.
- Full Text:
- Date Issued: 2011
- Authors: Donaldson, Natalie
- Date: 2011
- Subjects: Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2964 , http://hdl.handle.net/10962/d1002473 , Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Description: With the inclusion of sexual orientation in the Equality clause of the post-Apartheid constitution which demands equal rights and protection for all individuals regardless of sexual orientation, South Africa has been praised as one of the most liberal countries in the world. Because of this legal equality, gay and lesbian experiences have become a lot more visible in every day South African lives. This includes visibility in South African television programmes and film. Today, a number of South African produced television programmes have included at least one lesbian character in their storyline and many LGBTIQ activist organisations have deemed this increased visibility as a positive step for LGBTIQ rights. However, discriminatory discourses such as same-sex sexualities as 'un-African ' and unnatural, which often result in brutal hate crimes against LGBTIQ individuals (such as corrective rape), contribute to the social and cultural intolerance of same-sex sexualities. South African research into the lives of lesbian women has often related lesbian experience to that of gay men or has focused on lesbian women as victims of corrective rape and oppressive practices at the hands of the dominant heteronormative culture. This research was a discursive reception study, using three focus group discussions with self-identified lesbian audiences (black and white). The study explored how this audience received (interpreted/talked about) the available fictional representations of 'black' lesbian women and 'white' lesbian women in three clips from two South African television programmes, Society and The Mating Game. Using Wetherell's (1998) critical discursive psychology approach, this research focused on examining the 1) Subject positions made available in/by these representations; 2) Interpretive repertoires used by the audience in appropriating and/or negotiating and/or reSisting these subject positions; and 3) Ideological dilemmas experienced by participants in this negotiation process. The predominant subject positions made available in these representations were differentiated according to binary racial categories of white lesbian women and black lesbian women. For example, participants positioned white lesbian women as "lumberjacks" and "tomboys" while black lesbian women were positioned as "township lesbians" and "hood rats". In working with these subject positions, participants drew on interpretative repertoires of othering and otherness as well as interpretative repertoires of survival. In negotiating with these subject positions and others found in the discussions, ideological dilemmas often arose when participants found themselves having to draw on interpretative repertoires which extend from a heteronormative discourse. These kinds of interpretative repertoires included religion, nature, and compromise which contradicted and created a troubled position when used in relation to the participants' lesbian sexualities. Therefore, when the ideological dilemma and troubled position became apparent, participants had to work to repair the troubled position by justifying their use of these heteronormative interpretative repertoires.
- Full Text:
- Date Issued: 2011
Male and female cardiovascular risk in an urban, black working population
- Authors: Jackson, Lindsay May
- Date: 2011
- Subjects: Cardiovascular system -- Diseases -- South Africa -- Grahamstown , Obesity -- South Africa -- Grahamstown , Hypertension -- South Africa -- Grahamstown , Hypercholesteremia -- South Africa -- Grahamstown , Diabetes -- South Africa -- Grahamstown , Lifestyles -- Health aspects -- South Africa -- Grahamstown , Health behavior -- South Africa -- Grahamstown , Health attitudes -- South Africa -- Grahamstown , Black people -- South Africa -- Grahamstown -- Health and hygiene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5127 , http://hdl.handle.net/10962/d1005205 , Cardiovascular system -- Diseases -- South Africa -- Grahamstown , Obesity -- South Africa -- Grahamstown , Hypertension -- South Africa -- Grahamstown , Hypercholesteremia -- South Africa -- Grahamstown , Diabetes -- South Africa -- Grahamstown , Lifestyles -- Health aspects -- South Africa -- Grahamstown , Health behavior -- South Africa -- Grahamstown , Health attitudes -- South Africa -- Grahamstown , Black people -- South Africa -- Grahamstown -- Health and hygiene
- Description: The aim of this research project was to assess and compare cardiovascular disease (CVD) risk in black males and females from an urban, working population in the Makana (Grahamstown) region of the Eastern Cape, South Africa. Two-hundred and ninety one individuals (males: n = 143, females: n = 148) with a mean age of 42.6 (±8.1) years were voluntarily recruited from the greater urban Makana (Grahamstown) area. Eight Cardiovascular disease (CVD) risks were assessed: stature and mass were obtained in order to calculate body mass index (BMI) (mass/stature2). Obesity, defined as a morphological risk, was classified according to the World Health Organisation (WHO) BMI criteria (BMI>30kg.m-2), as well as according to measures of waist circumference (WC) and body composition. Hypertension, hypercholesterolemia and type II diabetes, were grouped as cardiovascular (CV) risks. Hypertension was defined as a blood pressure greater than 140/90mmHg (JNC-7); hypercholesterolemia, as total cholesterol greater than 6.2mmol.L-1 (NCEP); and type II diabetes, as total glucose greater than 12mmol.L-1 (WHO). Physical activity, diet, tobacco use, and alcohol consumption and dependence were grouped as lifestyle-related risks. These were assessed by means of self-reporting through the use of various validated questionnaires. Finally, self-reporting of obesity, hypertension, hypercholesterolemia and type II diabetes was assessed, in addition to perception questions on individuals’ perceived body shape and size (Ziebland figures). Self-reported and perceived responses were then compared to actual measures. Females were significantly (p<0.001) heavier than the males (92.7kg compared to 72.1kg) and had significantly (p<0.001) higher BMIs than their male counterparts (37.6kg.m-2 compared to 25.7 kg.-2). They also recorded significantly (p<0.001) higher waist circumference (WC) values and had significantly (p<0.001) higher percentage and total body fat. Significantly (p<0.001) more females were obese (81%) compared to males (17%). While a higher percentage of males (25 % compared to 22%) presented with stage I hypertension (≥140/90mmHg, <160/95mmHg), significantly (p<0.05) more females (14% compared to 8%) presented with stage II hypertension (>160/95mmHg). The prevalence of hypercholesterolemia at a high level of risk (>6.2mmol.L-1) was relatively low (2.1 % of males, 3.4% of females), but notably more participants (22% of males and 26% of females) presented with the condition at a moderate level of risk (>5mmol.L-1). Type II diabetes was the least prevalent CV risk factor, with no males and only 3% of females presenting with the condition. Males consumed significantly (p<0.05) more in terms of total energy intake (9024 vs. 7234 kJ) and were significantly (p<0.05) more active (3315 compared to 2660 MET-mins.week). A significantly (p<0.05) higher percentage of males smoked (51.1% compared to 3.4%), consumed alcohol (73.4% compared to 46.6%) and were alcohol dependent (40% compared to 33.5%). Both males and females tended to be ignorant of their health status, with both samples under-reporting obesity, hypertension and hypercholesterolemia, while over-reporting type II diabetes. Furthermore, obesity was significantly (p<0.05) underestimated, with both male and female individuals perceiving themselves to be notably smaller than they actually were. Physical activity and diet were important determinants of CVD risk in this black urban sample of individuals. Obesity, in particular central adiposity, was the most notable risk (particularly in females), followed by hypertension (particularly in males). Although some risks presented at a moderate level of risk, a clustering of risk factors was evident in both samples, with 12.6% and 41.2% of males and females presenting with two risk factors, and 2.8% and 8.1% of males and females respectively presenting with three risks.
- Full Text:
- Date Issued: 2011
- Authors: Jackson, Lindsay May
- Date: 2011
- Subjects: Cardiovascular system -- Diseases -- South Africa -- Grahamstown , Obesity -- South Africa -- Grahamstown , Hypertension -- South Africa -- Grahamstown , Hypercholesteremia -- South Africa -- Grahamstown , Diabetes -- South Africa -- Grahamstown , Lifestyles -- Health aspects -- South Africa -- Grahamstown , Health behavior -- South Africa -- Grahamstown , Health attitudes -- South Africa -- Grahamstown , Black people -- South Africa -- Grahamstown -- Health and hygiene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5127 , http://hdl.handle.net/10962/d1005205 , Cardiovascular system -- Diseases -- South Africa -- Grahamstown , Obesity -- South Africa -- Grahamstown , Hypertension -- South Africa -- Grahamstown , Hypercholesteremia -- South Africa -- Grahamstown , Diabetes -- South Africa -- Grahamstown , Lifestyles -- Health aspects -- South Africa -- Grahamstown , Health behavior -- South Africa -- Grahamstown , Health attitudes -- South Africa -- Grahamstown , Black people -- South Africa -- Grahamstown -- Health and hygiene
- Description: The aim of this research project was to assess and compare cardiovascular disease (CVD) risk in black males and females from an urban, working population in the Makana (Grahamstown) region of the Eastern Cape, South Africa. Two-hundred and ninety one individuals (males: n = 143, females: n = 148) with a mean age of 42.6 (±8.1) years were voluntarily recruited from the greater urban Makana (Grahamstown) area. Eight Cardiovascular disease (CVD) risks were assessed: stature and mass were obtained in order to calculate body mass index (BMI) (mass/stature2). Obesity, defined as a morphological risk, was classified according to the World Health Organisation (WHO) BMI criteria (BMI>30kg.m-2), as well as according to measures of waist circumference (WC) and body composition. Hypertension, hypercholesterolemia and type II diabetes, were grouped as cardiovascular (CV) risks. Hypertension was defined as a blood pressure greater than 140/90mmHg (JNC-7); hypercholesterolemia, as total cholesterol greater than 6.2mmol.L-1 (NCEP); and type II diabetes, as total glucose greater than 12mmol.L-1 (WHO). Physical activity, diet, tobacco use, and alcohol consumption and dependence were grouped as lifestyle-related risks. These were assessed by means of self-reporting through the use of various validated questionnaires. Finally, self-reporting of obesity, hypertension, hypercholesterolemia and type II diabetes was assessed, in addition to perception questions on individuals’ perceived body shape and size (Ziebland figures). Self-reported and perceived responses were then compared to actual measures. Females were significantly (p<0.001) heavier than the males (92.7kg compared to 72.1kg) and had significantly (p<0.001) higher BMIs than their male counterparts (37.6kg.m-2 compared to 25.7 kg.-2). They also recorded significantly (p<0.001) higher waist circumference (WC) values and had significantly (p<0.001) higher percentage and total body fat. Significantly (p<0.001) more females were obese (81%) compared to males (17%). While a higher percentage of males (25 % compared to 22%) presented with stage I hypertension (≥140/90mmHg, <160/95mmHg), significantly (p<0.05) more females (14% compared to 8%) presented with stage II hypertension (>160/95mmHg). The prevalence of hypercholesterolemia at a high level of risk (>6.2mmol.L-1) was relatively low (2.1 % of males, 3.4% of females), but notably more participants (22% of males and 26% of females) presented with the condition at a moderate level of risk (>5mmol.L-1). Type II diabetes was the least prevalent CV risk factor, with no males and only 3% of females presenting with the condition. Males consumed significantly (p<0.05) more in terms of total energy intake (9024 vs. 7234 kJ) and were significantly (p<0.05) more active (3315 compared to 2660 MET-mins.week). A significantly (p<0.05) higher percentage of males smoked (51.1% compared to 3.4%), consumed alcohol (73.4% compared to 46.6%) and were alcohol dependent (40% compared to 33.5%). Both males and females tended to be ignorant of their health status, with both samples under-reporting obesity, hypertension and hypercholesterolemia, while over-reporting type II diabetes. Furthermore, obesity was significantly (p<0.05) underestimated, with both male and female individuals perceiving themselves to be notably smaller than they actually were. Physical activity and diet were important determinants of CVD risk in this black urban sample of individuals. Obesity, in particular central adiposity, was the most notable risk (particularly in females), followed by hypertension (particularly in males). Although some risks presented at a moderate level of risk, a clustering of risk factors was evident in both samples, with 12.6% and 41.2% of males and females presenting with two risk factors, and 2.8% and 8.1% of males and females respectively presenting with three risks.
- Full Text:
- Date Issued: 2011