The response of microalgal biomass and community composition to environmental factors in the Sundays Estuary
- Authors: Kotsedi, Daisy
- Date: 2011
- Subjects: Algal blooms -- South Africa -- Sundays River Estuary
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10609 , http://hdl.handle.net/10948/1434 , Algal blooms -- South Africa -- Sundays River Estuary
- Description: The Sundays Estuary is permanently open to the sea and has been described as channel-like along its entire length with a narrow intertidal area (mostly less than 5 - 6 m in width). The estuary experiences regular freshwater inflow with large supplies of nutrients, derived from the Orange River transfer scheme and agricultural return flow. In particular, nitrate concentrations are high as a result of fertilisers used in the Sundays River catchment area. The objectives of this study were to measure microalgal biomass and community composition and relate to flow, water quality and other environmental variables. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10 percent mostly occurred from 12.5 km from the mouth and this was also where the highest water column chlorophyll a (>20 μg l-1) was found. Different groups of microalgae formed phytoplankton blooms for the different sampling sessions, which were correlated with high chlorophyll a. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The dominant diatom (Cyclotella atomus) indicated nutrient-rich conditions. Green algae and diatoms were associated with low salinity water in the upper reaches of the estuary. Flagellates were dominant throughout the estuary particularly when nutrients were low, whereas the dinoflagellate bloom in June 2008 was correlated with high ammonium and pH. Maximum benthic chlorophyll a was found at 12.5 km from the mouth in February, June and August 2008 and was correlated with high sediment organic and moisture content. Benthic diatoms were associated with high temperature whereas some species in June 2008 were associated with high ammonium concentrations. The middle reaches of the estuary characterise a zone of deposition rather than suspension which would favour benthic diatom colonization. Phytoplankton cells settling out on the sediments may account for the high benthic chlorophyll a because maximum water column chlorophyll a was also found in the REI zone (where salinity is less than 10 percent and where high biological activity occurs) in the Sundays Estuary. The estuary was sampled over five consecutive weeks from March to April 2009 to identify environmental factors that support different microalgal bloom species. Phytoplankton blooms, defined as chlorophyll a greater than 20 μg l-1, were found during Weeks 1, 4 and 5 from the middle to the upper reaches of the estuary. Diatom species (Cylindrotheca closterium, Cyclotella atomus and Cyclostephanus dubius) occurred in bloom concentrations during these weeks. These diatom species are cosmopolitan and indicate brackish nutrient-rich water. Flagellates were the dominant group in Weeks 2 to 4, but positive correlations with chlorophyll a were found during Weeks 1 and 2. During the first week of this study the conditions were warm and calm (measured as temperature and wind speed) and there was a well developed bloom (38 μg l-1). There was a strong cold front from 17 to 19 March, which mixed the water column resulting in the decrease of the chlorophyll a levels (<20 μg l-1) and the bloom collapsed during Weeks 2 and 3. However, in Weeks 4 and 5 conditions were again calm and warmer, which appeared to stimulate the phytoplankton bloom. Nanoplankton (2.7 - 20 μm) was dominant during each week sampled and contributed a considerable amount (55 - 79 percent) to the phytoplankton biomass. Once again subtidal benthic chlorophyll a and water column chlorophyll a were highest 12.5 km from the mouth. Deposition of phytoplankton cells from the water column was evident in the benthic samples. The study showed that the Sundays Estuary is eutrophic and characterised by microalgal blooms consisting of different phytoplankton groups.
- Full Text:
- Date Issued: 2011
- Authors: Kotsedi, Daisy
- Date: 2011
- Subjects: Algal blooms -- South Africa -- Sundays River Estuary
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10609 , http://hdl.handle.net/10948/1434 , Algal blooms -- South Africa -- Sundays River Estuary
- Description: The Sundays Estuary is permanently open to the sea and has been described as channel-like along its entire length with a narrow intertidal area (mostly less than 5 - 6 m in width). The estuary experiences regular freshwater inflow with large supplies of nutrients, derived from the Orange River transfer scheme and agricultural return flow. In particular, nitrate concentrations are high as a result of fertilisers used in the Sundays River catchment area. The objectives of this study were to measure microalgal biomass and community composition and relate to flow, water quality and other environmental variables. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10 percent mostly occurred from 12.5 km from the mouth and this was also where the highest water column chlorophyll a (>20 μg l-1) was found. Different groups of microalgae formed phytoplankton blooms for the different sampling sessions, which were correlated with high chlorophyll a. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The dominant diatom (Cyclotella atomus) indicated nutrient-rich conditions. Green algae and diatoms were associated with low salinity water in the upper reaches of the estuary. Flagellates were dominant throughout the estuary particularly when nutrients were low, whereas the dinoflagellate bloom in June 2008 was correlated with high ammonium and pH. Maximum benthic chlorophyll a was found at 12.5 km from the mouth in February, June and August 2008 and was correlated with high sediment organic and moisture content. Benthic diatoms were associated with high temperature whereas some species in June 2008 were associated with high ammonium concentrations. The middle reaches of the estuary characterise a zone of deposition rather than suspension which would favour benthic diatom colonization. Phytoplankton cells settling out on the sediments may account for the high benthic chlorophyll a because maximum water column chlorophyll a was also found in the REI zone (where salinity is less than 10 percent and where high biological activity occurs) in the Sundays Estuary. The estuary was sampled over five consecutive weeks from March to April 2009 to identify environmental factors that support different microalgal bloom species. Phytoplankton blooms, defined as chlorophyll a greater than 20 μg l-1, were found during Weeks 1, 4 and 5 from the middle to the upper reaches of the estuary. Diatom species (Cylindrotheca closterium, Cyclotella atomus and Cyclostephanus dubius) occurred in bloom concentrations during these weeks. These diatom species are cosmopolitan and indicate brackish nutrient-rich water. Flagellates were the dominant group in Weeks 2 to 4, but positive correlations with chlorophyll a were found during Weeks 1 and 2. During the first week of this study the conditions were warm and calm (measured as temperature and wind speed) and there was a well developed bloom (38 μg l-1). There was a strong cold front from 17 to 19 March, which mixed the water column resulting in the decrease of the chlorophyll a levels (<20 μg l-1) and the bloom collapsed during Weeks 2 and 3. However, in Weeks 4 and 5 conditions were again calm and warmer, which appeared to stimulate the phytoplankton bloom. Nanoplankton (2.7 - 20 μm) was dominant during each week sampled and contributed a considerable amount (55 - 79 percent) to the phytoplankton biomass. Once again subtidal benthic chlorophyll a and water column chlorophyll a were highest 12.5 km from the mouth. Deposition of phytoplankton cells from the water column was evident in the benthic samples. The study showed that the Sundays Estuary is eutrophic and characterised by microalgal blooms consisting of different phytoplankton groups.
- Full Text:
- Date Issued: 2011
The response of microalgal biomass and community composition to environmental factors in the Sundays estuary
- Authors: Kotsedi, Daisy
- Date: 2011
- Subjects: Algal blooms -- South Africa -- Sundays River Estuary , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10636 , http://hdl.handle.net/10948/d1013611
- Description: The Sundays Estuary is permanently open to the sea and has been described as channel-like along its entire length with a narrow intertidal area (mostly less than 5 - 6 m in width). The estuary experiences regular freshwater inflow with large supplies of nutrients, derived from the Orange River transfer scheme and agricultural return flow. In particular, nitrate concentrations are high as a result of fertilisers used in the Sundays River catchment area. The objectives of this study were to measure microalgal biomass and community composition and relate to flow, water quality and other environmental variables. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10 percent mostly occurred from 12.5 km from the mouth and this was also where the highest water column chlorophyll a (>20 μg l-1) was found. Different groups of microalgae formed phytoplankton blooms for the different sampling sessions, which were correlated with high chlorophyll a. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The dominant diatom (Cyclotella atomus) indicated nutrient-rich conditions. Green algae and diatoms were associated with low salinity water in the upper reaches of the estuary. Flagellates were dominant throughout the estuary particularly when nutrients were low, whereas the dinoflagellate bloom in June 2008 was correlated with high ammonium and pH. Maximum benthic chlorophyll a was found at 12.5 km from the mouth in February, June and August 2008 and was correlated with high sediment organic and moisture content. Benthic diatoms were associated with high temperature whereas some species in June 2008 were associated with high ammonium concentrations. The middle reaches of the estuary characterise a zone of deposition rather than suspension which would favour benthic diatom colonization. Phytoplankton cells settling out on the sediments may account for the high benthic chlorophyll a because maximum water column chlorophyll a was also found in the REI zone (where salinity is less than 10 percent and where high biological activity occurs) in the Sundays Estuary.
- Full Text:
- Date Issued: 2011
- Authors: Kotsedi, Daisy
- Date: 2011
- Subjects: Algal blooms -- South Africa -- Sundays River Estuary , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10636 , http://hdl.handle.net/10948/d1013611
- Description: The Sundays Estuary is permanently open to the sea and has been described as channel-like along its entire length with a narrow intertidal area (mostly less than 5 - 6 m in width). The estuary experiences regular freshwater inflow with large supplies of nutrients, derived from the Orange River transfer scheme and agricultural return flow. In particular, nitrate concentrations are high as a result of fertilisers used in the Sundays River catchment area. The objectives of this study were to measure microalgal biomass and community composition and relate to flow, water quality and other environmental variables. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10 percent mostly occurred from 12.5 km from the mouth and this was also where the highest water column chlorophyll a (>20 μg l-1) was found. Different groups of microalgae formed phytoplankton blooms for the different sampling sessions, which were correlated with high chlorophyll a. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The dominant diatom (Cyclotella atomus) indicated nutrient-rich conditions. Green algae and diatoms were associated with low salinity water in the upper reaches of the estuary. Flagellates were dominant throughout the estuary particularly when nutrients were low, whereas the dinoflagellate bloom in June 2008 was correlated with high ammonium and pH. Maximum benthic chlorophyll a was found at 12.5 km from the mouth in February, June and August 2008 and was correlated with high sediment organic and moisture content. Benthic diatoms were associated with high temperature whereas some species in June 2008 were associated with high ammonium concentrations. The middle reaches of the estuary characterise a zone of deposition rather than suspension which would favour benthic diatom colonization. Phytoplankton cells settling out on the sediments may account for the high benthic chlorophyll a because maximum water column chlorophyll a was also found in the REI zone (where salinity is less than 10 percent and where high biological activity occurs) in the Sundays Estuary.
- Full Text:
- Date Issued: 2011
The right to organise: critiquing the role of trade unions in shaping work relations in post-apartheid South Africa
- Authors: Nyathi, Mthokozisi
- Date: 2011
- Subjects: Labor unions -- South Africa , Apartheid -- South Africa , Industrial relations -- South Africa , Labor unions -- Law and legislation -- South Africa , Labor -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3690 , http://hdl.handle.net/10962/d1003205 , Labor unions -- South Africa , Apartheid -- South Africa , Industrial relations -- South Africa , Labor unions -- Law and legislation -- South Africa , Labor -- South Africa
- Description: Organised labour continues to play a prominent role in shaping employment relations in South Africa. The individual worker is powerless and in a weaker bargaining position against his employer. The advent of democracy was accompanied by numerous interventions to level the historically uneven bargaining field. The trade union movement has made and consolidated significant gains since the advent of democracy. It however faces a plethora of new challenges, such as the negative forces of globalisation, declining membership (often associated with high levels of unemployment and the changing nature of work from standard to atypical employment), the resurfacing of adversarialism in the bargaining process, and numerous shortcomings inherent in forums established to facilitate corporatism. Business is intensifying its calls for investor-friendly policies, which effectively mean a relaxation of labour policies. The trade union movement faces an enormous task of rebuilding confidence and credibility among its members and at the same time showing some commitment to other social actors, government and business, that it is committed to contribute to economic growth and employment creation. The central focus of this thesis will be to highlight the gains made by the trade union movement, the numerous challenges threatening their existence, and how they have attempted to redefine their role in the face of these challenges. It will attempt to offer advice on how trade unions can continue to play a prominent role in shaping relations of work in South Africa. The study begins with a historical overview of trade unionism in South Africa. It then attempts to establish how trade unions have made use of the institution of collective bargaining, the importance of organisational rights to the trade union movement, the effectiveness of industrial action, and the emerging challenges threatening the vibrancy of trade unions. The overall aim is to assess whether the trade union movement is still a force to be reckoned with and its future role in influencing employment relations in South Africa.
- Full Text:
- Date Issued: 2011
- Authors: Nyathi, Mthokozisi
- Date: 2011
- Subjects: Labor unions -- South Africa , Apartheid -- South Africa , Industrial relations -- South Africa , Labor unions -- Law and legislation -- South Africa , Labor -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3690 , http://hdl.handle.net/10962/d1003205 , Labor unions -- South Africa , Apartheid -- South Africa , Industrial relations -- South Africa , Labor unions -- Law and legislation -- South Africa , Labor -- South Africa
- Description: Organised labour continues to play a prominent role in shaping employment relations in South Africa. The individual worker is powerless and in a weaker bargaining position against his employer. The advent of democracy was accompanied by numerous interventions to level the historically uneven bargaining field. The trade union movement has made and consolidated significant gains since the advent of democracy. It however faces a plethora of new challenges, such as the negative forces of globalisation, declining membership (often associated with high levels of unemployment and the changing nature of work from standard to atypical employment), the resurfacing of adversarialism in the bargaining process, and numerous shortcomings inherent in forums established to facilitate corporatism. Business is intensifying its calls for investor-friendly policies, which effectively mean a relaxation of labour policies. The trade union movement faces an enormous task of rebuilding confidence and credibility among its members and at the same time showing some commitment to other social actors, government and business, that it is committed to contribute to economic growth and employment creation. The central focus of this thesis will be to highlight the gains made by the trade union movement, the numerous challenges threatening their existence, and how they have attempted to redefine their role in the face of these challenges. It will attempt to offer advice on how trade unions can continue to play a prominent role in shaping relations of work in South Africa. The study begins with a historical overview of trade unionism in South Africa. It then attempts to establish how trade unions have made use of the institution of collective bargaining, the importance of organisational rights to the trade union movement, the effectiveness of industrial action, and the emerging challenges threatening the vibrancy of trade unions. The overall aim is to assess whether the trade union movement is still a force to be reckoned with and its future role in influencing employment relations in South Africa.
- Full Text:
- Date Issued: 2011
The role of cluster centre principals in the Ohangwena education region in Namibia
- Authors: Nghatanga, Ponny Haggai
- Date: 2011
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1748 , http://hdl.handle.net/10962/d1003632
- Description: The Namibian Ministry of Education introduced the School Clustering System (SCS) in 1996. The system entails the grouping of schools into clusters to facilitate the sharing of resources and expertise. One school in a group is selected to serve as the Cluster Centre and the principal of the centre is identified as the Cluster Centre Principal (CCP). This has created a new level of educational leadership which is still relatively under-researched and the primary purpose of this study is to investigate the perceptions of this new role since it is perceived to be pivotal to the effective functioning of the cluster. This study is an interpretive case study of Cluster Centres in the Komesho Circuit in the Ohangwena Educational Region. Three data collection instruments were used, namely document analysis, observation and interviews. The collected data provided insight into participants' views on the role of Cluster Centre Principals (CCPs), which shed light on the challenges faCing the roles of CCPs. The findings revealed that respondents welcomed the decentralisation of an education system that involves cluster members and parents in decision making. Furthermore, the perceived role of CCPs is perceived as delegation through participative leadership and management approaches. This involves groups in teamwork to enhance the quality of teaching and learning. The study has, however, also exposed tensions surrounding the role and function of CCPs. This is partly because the role has not been formalised and is perceived as existing in a legal vacuum. This study will benefit the Cluster Centre Principals, Inspectors of Education, Advisory Teachers, non-governmental Organisations, the community and the Ministry of Education by placing the role of Cluster Centre Principals in perspective.
- Full Text:
- Date Issued: 2011
- Authors: Nghatanga, Ponny Haggai
- Date: 2011
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1748 , http://hdl.handle.net/10962/d1003632
- Description: The Namibian Ministry of Education introduced the School Clustering System (SCS) in 1996. The system entails the grouping of schools into clusters to facilitate the sharing of resources and expertise. One school in a group is selected to serve as the Cluster Centre and the principal of the centre is identified as the Cluster Centre Principal (CCP). This has created a new level of educational leadership which is still relatively under-researched and the primary purpose of this study is to investigate the perceptions of this new role since it is perceived to be pivotal to the effective functioning of the cluster. This study is an interpretive case study of Cluster Centres in the Komesho Circuit in the Ohangwena Educational Region. Three data collection instruments were used, namely document analysis, observation and interviews. The collected data provided insight into participants' views on the role of Cluster Centre Principals (CCPs), which shed light on the challenges faCing the roles of CCPs. The findings revealed that respondents welcomed the decentralisation of an education system that involves cluster members and parents in decision making. Furthermore, the perceived role of CCPs is perceived as delegation through participative leadership and management approaches. This involves groups in teamwork to enhance the quality of teaching and learning. The study has, however, also exposed tensions surrounding the role and function of CCPs. This is partly because the role has not been formalised and is perceived as existing in a legal vacuum. This study will benefit the Cluster Centre Principals, Inspectors of Education, Advisory Teachers, non-governmental Organisations, the community and the Ministry of Education by placing the role of Cluster Centre Principals in perspective.
- Full Text:
- Date Issued: 2011
The role of eutrophication in the biological control of water hyacinth, Eichhornia crassipes, in South Africa
- Coetzee, Julie A, Hill, Martin P
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
The role of Hsp90 in the Wnt pathway of MCF7 breast cancer cells
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
The role of memory, museums and memorials in reconciling the past : the Apartheid Museum and Red Location Museum as case studies
- Authors: Sippel, Elizabeth
- Date: 2011
- Subjects: Apartheid Museum (Johannesburg, South Africa) Red Location Museum (Port Elizabeth, South Africa) Atrocities -- Museums Apartheid and art Apartheid -- History Historical museums Collective memory Memorialization History -- Psychological aspects Memory (Philosophy) Museum exhibits -- Historiography Museums -- Historiography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2440 , http://hdl.handle.net/10962/d1005773
- Description: When South Africa became a democracy, many of its cultural institutions were tainted by the stigma of having been tools for the production and propagation of apartheid ideology. This thesis examines two key facets of post-apartheid museums and memorials. Firstly, how they have repositioned themselves as institutions of cultural and social standing. Secondly, their role as tools of nation building, social change, and creators of national collective memory within the new democratic South Africa. Through an analysis of cultural memory theory pertaining to museology, this study elaborates on the methods employed by museums to incorporate memory into their narratives and in turn, transfer collective memory to their viewers. This thesis provides a comparative study of the architectural, memorial and museological strategies of two post-apartheid museums; the Red Location Museum and the Apartbeid Museum. It examines the contributions of both museums to the introduction of new museological strategies for the successful creation and transmission of South African collective memory. Through this analysis, both the invaluable contributions and the drawbacks of post-apartheid museums as tools for the promotion of new democratic ideologies and philosophies are considered. This thesis does not resolve the arguments and questions which have surfaced regarding cultural institutions as tools for the promotion of reconciliation and the construction of national collective memory within South Africa. As the current climate of memorialisation is one of change and paradox, it is presently impossible to fully quantify post-apartheid museums' roles within South Africa's move toward reconciliation and social change. However, the examination of both the Red Location Museum and the Apartheid Museum reveals the extraordinary change that South African cultural institutions have undergone in addition to their potential to become institutions which facilitate active reconciliation as well as social and cultural growth.
- Full Text:
- Date Issued: 2011
- Authors: Sippel, Elizabeth
- Date: 2011
- Subjects: Apartheid Museum (Johannesburg, South Africa) Red Location Museum (Port Elizabeth, South Africa) Atrocities -- Museums Apartheid and art Apartheid -- History Historical museums Collective memory Memorialization History -- Psychological aspects Memory (Philosophy) Museum exhibits -- Historiography Museums -- Historiography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2440 , http://hdl.handle.net/10962/d1005773
- Description: When South Africa became a democracy, many of its cultural institutions were tainted by the stigma of having been tools for the production and propagation of apartheid ideology. This thesis examines two key facets of post-apartheid museums and memorials. Firstly, how they have repositioned themselves as institutions of cultural and social standing. Secondly, their role as tools of nation building, social change, and creators of national collective memory within the new democratic South Africa. Through an analysis of cultural memory theory pertaining to museology, this study elaborates on the methods employed by museums to incorporate memory into their narratives and in turn, transfer collective memory to their viewers. This thesis provides a comparative study of the architectural, memorial and museological strategies of two post-apartheid museums; the Red Location Museum and the Apartbeid Museum. It examines the contributions of both museums to the introduction of new museological strategies for the successful creation and transmission of South African collective memory. Through this analysis, both the invaluable contributions and the drawbacks of post-apartheid museums as tools for the promotion of new democratic ideologies and philosophies are considered. This thesis does not resolve the arguments and questions which have surfaced regarding cultural institutions as tools for the promotion of reconciliation and the construction of national collective memory within South Africa. As the current climate of memorialisation is one of change and paradox, it is presently impossible to fully quantify post-apartheid museums' roles within South Africa's move toward reconciliation and social change. However, the examination of both the Red Location Museum and the Apartheid Museum reveals the extraordinary change that South African cultural institutions have undergone in addition to their potential to become institutions which facilitate active reconciliation as well as social and cultural growth.
- Full Text:
- Date Issued: 2011
The role of non-timber forest products in household coping strategies in South Africa: the influence of household wealth and gender
- Paumgarten, Fiona, Shackleton, Charlie M
- Authors: Paumgarten, Fiona , Shackleton, Charlie M
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6648 , http://hdl.handle.net/10962/d1006897
- Description: The prevalence and ranking of non-timber forest products (NTFPs) as safety-nets has been well discussed, but rarely quantified. We report on group discussions and household interviews in two South African villages to assess the frequency and nature of shocks and stresses over a 2-year period and the coping strategies employed, stratified by household wealth and gender of the de jure household head. Overall, kinship was the most widely adopted coping strategy, and NTFPs were the fifth most prevalent (employed by 70% of households). There were relatively few differences in the nature of shocks or responses between male- and female-headed households. Wealth influenced the experience of shocks or stresses as well as responses. Poorer households have fewer options with the increased use or sale of NTFPs being the second most commonly adopted strategy. Increased use and sale of NTFPs is a common manifestation of the safety-net function. To reconcile long-term economic development and biodiversity conservation, it is important to understand people’s use of natural resources and the factors that affect this use, including their responses to shocks and stresses.
- Full Text:
- Date Issued: 2011
- Authors: Paumgarten, Fiona , Shackleton, Charlie M
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6648 , http://hdl.handle.net/10962/d1006897
- Description: The prevalence and ranking of non-timber forest products (NTFPs) as safety-nets has been well discussed, but rarely quantified. We report on group discussions and household interviews in two South African villages to assess the frequency and nature of shocks and stresses over a 2-year period and the coping strategies employed, stratified by household wealth and gender of the de jure household head. Overall, kinship was the most widely adopted coping strategy, and NTFPs were the fifth most prevalent (employed by 70% of households). There were relatively few differences in the nature of shocks or responses between male- and female-headed households. Wealth influenced the experience of shocks or stresses as well as responses. Poorer households have fewer options with the increased use or sale of NTFPs being the second most commonly adopted strategy. Increased use and sale of NTFPs is a common manifestation of the safety-net function. To reconcile long-term economic development and biodiversity conservation, it is important to understand people’s use of natural resources and the factors that affect this use, including their responses to shocks and stresses.
- Full Text:
- Date Issued: 2011
The role of small antelope in ecosystem functioning in the Matobo Hills, Zimbabwe
- Authors: Lunt, Nicola
- Date: 2011
- Subjects: Antelopes -- Zimbabwe -- Rhodes Matopos National Park Ecosystem health -- Zimbabwe -- Rhodes Matopos National Park Forest ecology -- Zimbabwe -- Rhodes Matopos National Park Savanna ecology -- Zimbabwe -- Rhodes Matopos National Park Woody plants -- Effect of fires on -- Zimbabwe -- Rhodes Matopos National Park Duikers -- Zimbabwe -- Rhodes Matopos National Park Bushbuck -- Zimbabwe -- Rhodes Matopos National Park Greater kudu -- Zimbabwe -- Rhodes Matopos National Park
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5760 , http://hdl.handle.net/10962/d1005448
- Description: The 28-month study assessed the impacts of five syntopic medium-sized mammalian browsers and one fire event in a woodland savanna in the Matobo Hills, Zimbabwe. Aspects of herbivory, mechanical pressures, seed dispersal and nutrient cycling were investigated for three species of small antelope (common duiker [Sylvicapra grimmia]1, klipspringer [Oreotragus oreotragus] and steenbok [Raphicerus campestris]) and two medium-sized species (bushbuck [Tragelaphus scriptus] and greater kudu [T. strepsiceros]). Focusing on Burkea africana2 woodland, in a system that does not include elephant (Loxodonta africana), effects of browsing antelope on woody and herbaceous vegetation development were investigated using exclusion plots. Browsers regulated woody plant cover (measured as basal stem area), with smaller antelope having a greater impact than larger species. This was linked to feeding height, feeding selectivity and mechanical pressures (e.g. twig breakage and trampling). Fire caused an initial reduction in above-ground standing biomass, but in the presence of fauna, pre-fire equilibria were attained within 15 months. In antelope exclosures, herbaceous biomass increased and woody biomass decreased following fire. Responses by woody vegetation to browsing varied among species, with highly palatable species typically exhibiting compensatory regrowth. Woody species richness and abundance (especially of palatable species) increased in the absence of browsers, but species richness of the herbaceous layer was promoted by moderate disturbance (trampling or fire). Faecal deposition behaviour, primarily the use of latrines by small antelope, resulted in localised soil enrichment within defended territories. Decomposition rates (and therefore return of nutrients to the soil) varied among species and seasons, due to defecation site selection, accessibility to decomposers and desiccation rates of faecal pellets. Controlled seed germination experiments indicated that ingestion by small antelope enhances germination rates of large, hard-seeded fruits such as Sclerocarya birrea. However, germination of savanna seeds may require multiple cues. This study demonstrated the critical roles of small antelope in ecosystem functioning, and highlights the importance of the less visible impacts of frequently overlooked smaller mammalian herbivores. Perturbations to the faunal community, especially small antelope, are predicted to have substantial impacts on woody plant cover.
- Full Text:
- Date Issued: 2011
- Authors: Lunt, Nicola
- Date: 2011
- Subjects: Antelopes -- Zimbabwe -- Rhodes Matopos National Park Ecosystem health -- Zimbabwe -- Rhodes Matopos National Park Forest ecology -- Zimbabwe -- Rhodes Matopos National Park Savanna ecology -- Zimbabwe -- Rhodes Matopos National Park Woody plants -- Effect of fires on -- Zimbabwe -- Rhodes Matopos National Park Duikers -- Zimbabwe -- Rhodes Matopos National Park Bushbuck -- Zimbabwe -- Rhodes Matopos National Park Greater kudu -- Zimbabwe -- Rhodes Matopos National Park
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5760 , http://hdl.handle.net/10962/d1005448
- Description: The 28-month study assessed the impacts of five syntopic medium-sized mammalian browsers and one fire event in a woodland savanna in the Matobo Hills, Zimbabwe. Aspects of herbivory, mechanical pressures, seed dispersal and nutrient cycling were investigated for three species of small antelope (common duiker [Sylvicapra grimmia]1, klipspringer [Oreotragus oreotragus] and steenbok [Raphicerus campestris]) and two medium-sized species (bushbuck [Tragelaphus scriptus] and greater kudu [T. strepsiceros]). Focusing on Burkea africana2 woodland, in a system that does not include elephant (Loxodonta africana), effects of browsing antelope on woody and herbaceous vegetation development were investigated using exclusion plots. Browsers regulated woody plant cover (measured as basal stem area), with smaller antelope having a greater impact than larger species. This was linked to feeding height, feeding selectivity and mechanical pressures (e.g. twig breakage and trampling). Fire caused an initial reduction in above-ground standing biomass, but in the presence of fauna, pre-fire equilibria were attained within 15 months. In antelope exclosures, herbaceous biomass increased and woody biomass decreased following fire. Responses by woody vegetation to browsing varied among species, with highly palatable species typically exhibiting compensatory regrowth. Woody species richness and abundance (especially of palatable species) increased in the absence of browsers, but species richness of the herbaceous layer was promoted by moderate disturbance (trampling or fire). Faecal deposition behaviour, primarily the use of latrines by small antelope, resulted in localised soil enrichment within defended territories. Decomposition rates (and therefore return of nutrients to the soil) varied among species and seasons, due to defecation site selection, accessibility to decomposers and desiccation rates of faecal pellets. Controlled seed germination experiments indicated that ingestion by small antelope enhances germination rates of large, hard-seeded fruits such as Sclerocarya birrea. However, germination of savanna seeds may require multiple cues. This study demonstrated the critical roles of small antelope in ecosystem functioning, and highlights the importance of the less visible impacts of frequently overlooked smaller mammalian herbivores. Perturbations to the faunal community, especially small antelope, are predicted to have substantial impacts on woody plant cover.
- Full Text:
- Date Issued: 2011
The role of teacher cognition in the integration of technology into English teaching: a case study
- Authors: Baron, Elizabeth Mary
- Date: 2011
- Subjects: English teachers -- Effect of technological innovations on English teachers -- Psychology English teachers -- Attitudes Language and languages -- Study and teaching -- Computer-assisted instruction Educational technology Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1753 , http://hdl.handle.net/10962/d1003637
- Description: Technology, in one or more of its various forms, is now a part of everyday life for most South African citizens. Many schools are equipped with various forms of technology, at great cost to sponsors, schools, parents or the government. However, this technology is not always exploited and full use is not made of it. As access is not the issue, other factors needed to be considered: in this case, teachers’ beliefs, attitudes and knowledge. This thesis explores the cognitive factors which affect the acceptance and use of technology. Teacher cognition and the factors which influence teacher cognition were examined. Following Borg, teacher cognition is defined as “the unobservable cognitive dimension of teaching – what teachers know, believe and think” (Borg, 2003, p. 81). Teacher cognition determines whether or not a teacher will use technology, if the external barrier of access is removed. In order to study the various aspect of teacher cognition, a case study was performed, which studied 6 teachers at 4 schools. All the schools in this study had some level of access to technology. Following Borg, initial experiences with the educational system (i.e. the teacher’s experience as a learner), teacher training, the context the teacher worked in (as well as social factors and private use) and classroom experience were all examined in order to discover the factors which most affect technology acceptance in teaching. The findings show that having easy access to well-maintained and functioning technology cannot be underestimated. In the study, support from other teachers, particularly those in leadership roles, led to an increase in technology use. This support needed to be explicit; general support did not seem to be effective. These findings suggest that technology integration needs to happen at a ‘whole school’ level.
- Full Text:
- Date Issued: 2011
- Authors: Baron, Elizabeth Mary
- Date: 2011
- Subjects: English teachers -- Effect of technological innovations on English teachers -- Psychology English teachers -- Attitudes Language and languages -- Study and teaching -- Computer-assisted instruction Educational technology Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1753 , http://hdl.handle.net/10962/d1003637
- Description: Technology, in one or more of its various forms, is now a part of everyday life for most South African citizens. Many schools are equipped with various forms of technology, at great cost to sponsors, schools, parents or the government. However, this technology is not always exploited and full use is not made of it. As access is not the issue, other factors needed to be considered: in this case, teachers’ beliefs, attitudes and knowledge. This thesis explores the cognitive factors which affect the acceptance and use of technology. Teacher cognition and the factors which influence teacher cognition were examined. Following Borg, teacher cognition is defined as “the unobservable cognitive dimension of teaching – what teachers know, believe and think” (Borg, 2003, p. 81). Teacher cognition determines whether or not a teacher will use technology, if the external barrier of access is removed. In order to study the various aspect of teacher cognition, a case study was performed, which studied 6 teachers at 4 schools. All the schools in this study had some level of access to technology. Following Borg, initial experiences with the educational system (i.e. the teacher’s experience as a learner), teacher training, the context the teacher worked in (as well as social factors and private use) and classroom experience were all examined in order to discover the factors which most affect technology acceptance in teaching. The findings show that having easy access to well-maintained and functioning technology cannot be underestimated. In the study, support from other teachers, particularly those in leadership roles, led to an increase in technology use. This support needed to be explicit; general support did not seem to be effective. These findings suggest that technology integration needs to happen at a ‘whole school’ level.
- Full Text:
- Date Issued: 2011
The role of the mite Orthogalumna terebrantis in the biological control programme for water hyacinth, Eichhornia crassipes, in South Africa
- Authors: Marlin, Danica
- Date: 2011
- Subjects: Water hyacinth -- Biological control -- South Africa Aquatic weeds -- South Africa Invasive plants -- South Africa Mites -- South Africa Mites as biological pest control agents -- South Africa Biological pest control agents -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5762 , http://hdl.handle.net/10962/d1005450
- Description: Water hyacinth (Eichhornia crassipes) is an aquatic macrophyte originating from the Amazon basin. Due to its beautiful appearance it has been introduced into numerous countries across the world as an ornamental pond plant. It was introduced into South Africa in the early 1900s and has since reached pest proportions in many of the country’s fresh water bodies, causing significant economic and ecological losses. It is now considered to be the worst aquatic weed in South Africa. Efforts to control the spread of the weed began in the early 1970s and there have been some successes. Biological control has been used widely as an alternative to mechanical and chemical controls because it is cost-effective, self-sustaining and environmentally friendly. To date, six biological control agents have been introduced onto water hyacinth in South Africa. However, due to factors such as cold winter temperatures and interference from chemical control, the agent populations are occasionally knocked-down and thus the impact of biological control on the weed population is variable. In addition, many South African water systems are highly eutrophic, and in these systems the plant growth may be accelerated to such an extent that the negative impact of the agents’ herbivory is mitigated. One of the agents established on the weed is the galumnid mite Orthogalumna terebrantis, which originates from Uruguay. In South Africa, the mite was initially discovered on two water hyacinth infestations in the Mpumalanga Province in 1989 and it is now established at 17 sites across the country. Many biological control researchers believe that the mite is a good biological control agent but, prior to this thesis, little quantitative data existed to confirm the belief. Thus, this thesis is a post-release evaluation of O. terebrantis in which various aspects of the mite-plant relationship were investigated to determine the efficacy of the mite and thus better understand the role of the mite in the biological control programme of water hyacinth in South Africa. From laboratory experiments, in which mite densities were lower than densities occurring in the field, it was found that water hyacinth growth is largely unaffected by mite herbivory, except possibly at very high mite densities. When grown in high nutrient conditions the growth of the plant is so great that any affect the mite has is nullified. Plant growth is thus more affected by nutrients than by mite herbivory. However, mite feeding was also influenced by water nutrient levels and mite herbivory was greatest on plants grown in high nutrient conditions. The presence of the mite had a positive effect on the performance of the mirid Eccritotarsus catarinensis, such that the interactions of the two agents together had a greater negative impact on the plant’s growth than the individual agents had alone. Furthermore, water hyacinth physiological parameters, such as the plant’s photosynthetic ability, were negatively impacted by the mite, even at the very low mite densities used in the study. Plant growth rate is dependent on photosynthetic ability i.e. the rate of photosynthesis, and thus a decrease in the plant’s photosynthetic ability will eventually be translated into decreased plant growth rates which would ultimately result in the overall reduction of water hyacinth populations. In addition, temperature tolerance studies showed that the mite was tolerant of low temperatures. The mite already occurs at some of the coldest sites in South Africa. Therefore, the mite should be able to establish at all of the water hyacinth infestations in the country, but because it is a poor disperser it is unlikely to establish at new sites without human intervention. It is suggested that the mite be used as an additional biological control agent at sites where it does not yet occur, specifically at cold sites where some of the other, less cold-tolerant, agents have failed to establish. Finally, conditions of where, how many and how often the mite should be distributed to water hyacinth infestation in South Africa are discussed.
- Full Text:
- Date Issued: 2011
- Authors: Marlin, Danica
- Date: 2011
- Subjects: Water hyacinth -- Biological control -- South Africa Aquatic weeds -- South Africa Invasive plants -- South Africa Mites -- South Africa Mites as biological pest control agents -- South Africa Biological pest control agents -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5762 , http://hdl.handle.net/10962/d1005450
- Description: Water hyacinth (Eichhornia crassipes) is an aquatic macrophyte originating from the Amazon basin. Due to its beautiful appearance it has been introduced into numerous countries across the world as an ornamental pond plant. It was introduced into South Africa in the early 1900s and has since reached pest proportions in many of the country’s fresh water bodies, causing significant economic and ecological losses. It is now considered to be the worst aquatic weed in South Africa. Efforts to control the spread of the weed began in the early 1970s and there have been some successes. Biological control has been used widely as an alternative to mechanical and chemical controls because it is cost-effective, self-sustaining and environmentally friendly. To date, six biological control agents have been introduced onto water hyacinth in South Africa. However, due to factors such as cold winter temperatures and interference from chemical control, the agent populations are occasionally knocked-down and thus the impact of biological control on the weed population is variable. In addition, many South African water systems are highly eutrophic, and in these systems the plant growth may be accelerated to such an extent that the negative impact of the agents’ herbivory is mitigated. One of the agents established on the weed is the galumnid mite Orthogalumna terebrantis, which originates from Uruguay. In South Africa, the mite was initially discovered on two water hyacinth infestations in the Mpumalanga Province in 1989 and it is now established at 17 sites across the country. Many biological control researchers believe that the mite is a good biological control agent but, prior to this thesis, little quantitative data existed to confirm the belief. Thus, this thesis is a post-release evaluation of O. terebrantis in which various aspects of the mite-plant relationship were investigated to determine the efficacy of the mite and thus better understand the role of the mite in the biological control programme of water hyacinth in South Africa. From laboratory experiments, in which mite densities were lower than densities occurring in the field, it was found that water hyacinth growth is largely unaffected by mite herbivory, except possibly at very high mite densities. When grown in high nutrient conditions the growth of the plant is so great that any affect the mite has is nullified. Plant growth is thus more affected by nutrients than by mite herbivory. However, mite feeding was also influenced by water nutrient levels and mite herbivory was greatest on plants grown in high nutrient conditions. The presence of the mite had a positive effect on the performance of the mirid Eccritotarsus catarinensis, such that the interactions of the two agents together had a greater negative impact on the plant’s growth than the individual agents had alone. Furthermore, water hyacinth physiological parameters, such as the plant’s photosynthetic ability, were negatively impacted by the mite, even at the very low mite densities used in the study. Plant growth rate is dependent on photosynthetic ability i.e. the rate of photosynthesis, and thus a decrease in the plant’s photosynthetic ability will eventually be translated into decreased plant growth rates which would ultimately result in the overall reduction of water hyacinth populations. In addition, temperature tolerance studies showed that the mite was tolerant of low temperatures. The mite already occurs at some of the coldest sites in South Africa. Therefore, the mite should be able to establish at all of the water hyacinth infestations in the country, but because it is a poor disperser it is unlikely to establish at new sites without human intervention. It is suggested that the mite be used as an additional biological control agent at sites where it does not yet occur, specifically at cold sites where some of the other, less cold-tolerant, agents have failed to establish. Finally, conditions of where, how many and how often the mite should be distributed to water hyacinth infestation in South Africa are discussed.
- Full Text:
- Date Issued: 2011
The role of the press in political conflicts in Kenya : a case study of the performance of the nation and the East African Standard Newspapers
- Authors: Nyambuga, Charles Ongadi
- Date: 2011
- Subjects: Press and politics -- Kenya , Government and the press -- Kenya , Mass media -- Political aspects , Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16135 , http://hdl.handle.net/10948/1449 , Press and politics -- Kenya , Government and the press -- Kenya , Mass media -- Political aspects , Kenya -- Politics and government
- Description: This study focuses on the role of the press in violent political conflicts in Kenya in the period that preceded the 2005 referendum on the draft constitution. Based on media reports, six major thematic areas of concern emerged during constitution making. These were: land tenure, devolution of power, the executive, the legislature, the Bill of Rights, and the provincial administration. These sections of the draft constitution caused a remarkable divergence of opinion. The citizens either supported or opposed the draft constitution on the basis of how the draft had treated those sections in the draft constitution. Besides the major thematic areas, newspapers regularly focused and reported on ethnicity, violence, political leaders‟ utterances, the process of constitution making, and political conflicts. Three main objectives guided the study. The first objective focused on the relationship between media content and different levels of political conflict. The influence of media content and how these may have led to high political conflict, medium political conflict, low political conflict and no political conflict, are tested in this study. The second objective highlighted the kind of coverage that the draft constitution got during the period that preceded the referendum in November, 2005. This objective facilitated interrogation of media content and whether media content focused on aspects of the draft constitution such as land ownership, the executive, devolution, the legislature and religion, as highlighted in the draft constitution of Kenya 2005. The third objective examined the thematic emphasis that the media undertook in the period that preceded the referendum. The themes that were dominant in the period before the referendum could have impacted on readers' perceptions of the critical issues that could have informed the voters' decisions. Three primary questions were addressed in the study: Firstly, was there a link between media content and different levels of political conflict in weak democracies such as Kenya? Secondly, did media content influence ethnicity and did it encourage ethnic conflict in diverse societies? Finally, what were the key thematic areas of coverage by the press, and how were they used during the referendum? In order to study these research objectives, I used a combination of theories to enhance understanding of the interplay between media content and audience in the society. The theories are: agenda setting, two-step flow, priming, framing, and the public sphere. The study adopts a triangulation convergence design in mixed- methods research that involves both qualitative and quantitative methods. A structured questionnaire and content analysis were used to seek responses to the research questions of the study and to meet the stated objectives. The research revealed that the two newspapers under investigation, namely the East African Standard and the Nation, provided more coverage to issues that were not central to the content of the draft constitution, such as political leaders' utterances, violence, ethnicity, and the process of constitution making. This showed that the newspapers tended to sensationalise issues instead of providing objective coverage of political matters. These newspapers used their opinion pages to educate their readers on how the referendum was turning violent. The theme of political leaders' utterances is closely linked to that of violence. This suggests that the violence was influenced by some of the leaders' statements. These utterances, and more so those that touched on ethnicity, could therefore have been a potential cause of the ensuing political conflicts during the 2005 referendum on the draft constitution. The findings reveal that newspaper editors tended to focus on political conflict at the expense of the actual content of the draft constitution. This would have provided insight and knowledge on the document and avoided sensational reporting, which could have contributed to violent political conflicts during the period that preceded the referendum on the draft constitution of Kenya.
- Full Text:
- Date Issued: 2011
- Authors: Nyambuga, Charles Ongadi
- Date: 2011
- Subjects: Press and politics -- Kenya , Government and the press -- Kenya , Mass media -- Political aspects , Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16135 , http://hdl.handle.net/10948/1449 , Press and politics -- Kenya , Government and the press -- Kenya , Mass media -- Political aspects , Kenya -- Politics and government
- Description: This study focuses on the role of the press in violent political conflicts in Kenya in the period that preceded the 2005 referendum on the draft constitution. Based on media reports, six major thematic areas of concern emerged during constitution making. These were: land tenure, devolution of power, the executive, the legislature, the Bill of Rights, and the provincial administration. These sections of the draft constitution caused a remarkable divergence of opinion. The citizens either supported or opposed the draft constitution on the basis of how the draft had treated those sections in the draft constitution. Besides the major thematic areas, newspapers regularly focused and reported on ethnicity, violence, political leaders‟ utterances, the process of constitution making, and political conflicts. Three main objectives guided the study. The first objective focused on the relationship between media content and different levels of political conflict. The influence of media content and how these may have led to high political conflict, medium political conflict, low political conflict and no political conflict, are tested in this study. The second objective highlighted the kind of coverage that the draft constitution got during the period that preceded the referendum in November, 2005. This objective facilitated interrogation of media content and whether media content focused on aspects of the draft constitution such as land ownership, the executive, devolution, the legislature and religion, as highlighted in the draft constitution of Kenya 2005. The third objective examined the thematic emphasis that the media undertook in the period that preceded the referendum. The themes that were dominant in the period before the referendum could have impacted on readers' perceptions of the critical issues that could have informed the voters' decisions. Three primary questions were addressed in the study: Firstly, was there a link between media content and different levels of political conflict in weak democracies such as Kenya? Secondly, did media content influence ethnicity and did it encourage ethnic conflict in diverse societies? Finally, what were the key thematic areas of coverage by the press, and how were they used during the referendum? In order to study these research objectives, I used a combination of theories to enhance understanding of the interplay between media content and audience in the society. The theories are: agenda setting, two-step flow, priming, framing, and the public sphere. The study adopts a triangulation convergence design in mixed- methods research that involves both qualitative and quantitative methods. A structured questionnaire and content analysis were used to seek responses to the research questions of the study and to meet the stated objectives. The research revealed that the two newspapers under investigation, namely the East African Standard and the Nation, provided more coverage to issues that were not central to the content of the draft constitution, such as political leaders' utterances, violence, ethnicity, and the process of constitution making. This showed that the newspapers tended to sensationalise issues instead of providing objective coverage of political matters. These newspapers used their opinion pages to educate their readers on how the referendum was turning violent. The theme of political leaders' utterances is closely linked to that of violence. This suggests that the violence was influenced by some of the leaders' statements. These utterances, and more so those that touched on ethnicity, could therefore have been a potential cause of the ensuing political conflicts during the 2005 referendum on the draft constitution. The findings reveal that newspaper editors tended to focus on political conflict at the expense of the actual content of the draft constitution. This would have provided insight and knowledge on the document and avoided sensational reporting, which could have contributed to violent political conflicts during the period that preceded the referendum on the draft constitution of Kenya.
- Full Text:
- Date Issued: 2011
The role of the principal as school leader in maintaining academic standards in the schooling of at-risk learners: a case study at a school in the northern areas of Port Elizabeth
- Authors: Draai, Karen Ann
- Date: 2011
- Subjects: School management and organization -- South Africa -- Port Elizabeth School principals -- South Africa -- Port Elizabeth Educational leadership -- South Africa -- Port Elizabeth School discipline -- South Africa -- Port Elizabeth Children with social disabilities -- South Africa -- Port Elizabeth Academic achievement -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1955 , http://hdl.handle.net/10962/d1008278
- Description: Many disadvantaged schools in South Africa are characterised by poor performance, which is often linked to the legacy of the apartheid regime. Yet, some disadvantaged schools are surviving and even producing excellent results. Many successful businessmen, politicians and academics can attest to the success of these schools, being a product of such schools. Leadership, which has received a lot of attention in recent years, are often the cause of schools failing to produce the expected results. Previous studies have shown that leadership is the key to academic excellence and that to lead disadvantaged schools to success requires strong leaders with moral purpose, who possess qualities of transformational leaders, but also leaders who can focus on instructional leadership practices. This study focuses on the role of leadership in maintaining academic standards at a school in the northern areas of Port Elizabeth. The school has a proud tradition of good academic performances and has even been labelled as a 'model C school in the northern areas'. It has been found that teachers are committed and hardworking and the principal is perceived as having expecting high expectations for the children of the area. He believes as an educator one should never give up on the children. The study found that the principal is a strong leader who shows characteristics of a transformational leader and has the drive of an instructional leader to lead the school and to maintain academic standards. He is a well-respected leader who leads with moral purpose and who has the desire to uplift the community. The study has the potential to provide guidance and encouragement to school principals, and to inform the Department of Education's leadership training programmes.
- Full Text:
- Date Issued: 2011
- Authors: Draai, Karen Ann
- Date: 2011
- Subjects: School management and organization -- South Africa -- Port Elizabeth School principals -- South Africa -- Port Elizabeth Educational leadership -- South Africa -- Port Elizabeth School discipline -- South Africa -- Port Elizabeth Children with social disabilities -- South Africa -- Port Elizabeth Academic achievement -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1955 , http://hdl.handle.net/10962/d1008278
- Description: Many disadvantaged schools in South Africa are characterised by poor performance, which is often linked to the legacy of the apartheid regime. Yet, some disadvantaged schools are surviving and even producing excellent results. Many successful businessmen, politicians and academics can attest to the success of these schools, being a product of such schools. Leadership, which has received a lot of attention in recent years, are often the cause of schools failing to produce the expected results. Previous studies have shown that leadership is the key to academic excellence and that to lead disadvantaged schools to success requires strong leaders with moral purpose, who possess qualities of transformational leaders, but also leaders who can focus on instructional leadership practices. This study focuses on the role of leadership in maintaining academic standards at a school in the northern areas of Port Elizabeth. The school has a proud tradition of good academic performances and has even been labelled as a 'model C school in the northern areas'. It has been found that teachers are committed and hardworking and the principal is perceived as having expecting high expectations for the children of the area. He believes as an educator one should never give up on the children. The study found that the principal is a strong leader who shows characteristics of a transformational leader and has the drive of an instructional leader to lead the school and to maintain academic standards. He is a well-respected leader who leads with moral purpose and who has the desire to uplift the community. The study has the potential to provide guidance and encouragement to school principals, and to inform the Department of Education's leadership training programmes.
- Full Text:
- Date Issued: 2011
The role of the state and the environment in indigenous livestock farming: a case study of Debe Marela, Middledrift area, Eastern Cape
- Authors: Hashe, Luvuyo E
- Date: 2011
- Subjects: Farmers -- South Africa -- Eastern Cape , Livestock -- South Africa -- Eastern Cape , Traditional farming -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape , Agriculture and politics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11877 , http://hdl.handle.net/10353/372 , Farmers -- South Africa -- Eastern Cape , Livestock -- South Africa -- Eastern Cape , Traditional farming -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape , Agriculture and politics -- South Africa -- Eastern Cape
- Description: The study focused on the role of the State and the environment in indigenous livestock farming in Debe Marela in Middledrift. Although communal farmers in the area used ethnoveterinary medicines to treat and prevent animal diseases, they also widely used conventional medicines, as these often provided a remedy to animal diseases. The livestock farmers believed in indigenous knowledge which empowered them in using herbs to a certain extent, but the latter was preferred. The Department of Agriculture has featured as a support institution and although livestock farmers in the area have participated in and benefitted from state programmes, they believe that they needed more interventions such as visits from veterinary surgeons, Extension Officers and Animal Health Technicians. The study therefore attempts to address the gaps highlighted in the work of other researchers.
- Full Text:
- Date Issued: 2011
- Authors: Hashe, Luvuyo E
- Date: 2011
- Subjects: Farmers -- South Africa -- Eastern Cape , Livestock -- South Africa -- Eastern Cape , Traditional farming -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape , Agriculture and politics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11877 , http://hdl.handle.net/10353/372 , Farmers -- South Africa -- Eastern Cape , Livestock -- South Africa -- Eastern Cape , Traditional farming -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape , Agriculture and politics -- South Africa -- Eastern Cape
- Description: The study focused on the role of the State and the environment in indigenous livestock farming in Debe Marela in Middledrift. Although communal farmers in the area used ethnoveterinary medicines to treat and prevent animal diseases, they also widely used conventional medicines, as these often provided a remedy to animal diseases. The livestock farmers believed in indigenous knowledge which empowered them in using herbs to a certain extent, but the latter was preferred. The Department of Agriculture has featured as a support institution and although livestock farmers in the area have participated in and benefitted from state programmes, they believe that they needed more interventions such as visits from veterinary surgeons, Extension Officers and Animal Health Technicians. The study therefore attempts to address the gaps highlighted in the work of other researchers.
- Full Text:
- Date Issued: 2011
The role of the state in rural development: appropriate strategies for the rural development program in Mbhashe municipality in Eastern Cape
- Authors: Futshane, Patrick Sivuyile
- Date: 2011
- Subjects: Rural development -- South Africa -- Eastern Cape , Rural development -- Government policy -- South Africa -- Eastern Cape , Community development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9073 , http://hdl.handle.net/10948/d1008409 , Rural development -- South Africa -- Eastern Cape , Rural development -- Government policy -- South Africa -- Eastern Cape , Community development -- South Africa
- Description: Poverty and inequality in South Africa are a result of the impact of apartheid policy, which inter alia stripped people of their assets, especially land, distorted economic markets and social institutions through racial discrimination, and resulted in violence and destabilization. This has shaped the nature of poverty in South Africa. In view of the above, the South African government has introduced a programme known as the Comprehensive Rural Development Strategy in order to redress the imbalances of the former apartheid regime. In this strategy it is envisaged that vibrant, equitable and sustainable rural communities and food security for all will be achieved. In this study, I investigated the implementation of rural development programmes in the Mbhashe local municipality of the Eastern Cape Province in order to determine appropriate intervention strategies. This study focused on Ward18 of Mbhashe local municipality on a village known as Nkwalini Bafazi. This is a village that has been earmarked by the government to be a pilot site for the Rural Development Programme. This project is at the initial stage of social facilitation. In other words this research project is designed to investigate the process of Rural Development and how it can be implemented in the Mbhashe Local municipality in order to alleviate poverty and underdevelopment. For the purpose of the study, a mixed research approach was chosen. This means that the study used both the qualitative and quantitative approaches for in-depth understanding and verification. Questionnaires and structured interview questions were used to collect the data. Participatory Rural Appraisal (PRA) was also used for the purpose of observing and involving the community in the exercise. Data was collected from residents by conducting surveys, making use of questionnaires. Structured interviews were conducted with government officials (Department of Rural Development and Agrarian Reform) in order to understand the situation better.
- Full Text:
- Date Issued: 2011
- Authors: Futshane, Patrick Sivuyile
- Date: 2011
- Subjects: Rural development -- South Africa -- Eastern Cape , Rural development -- Government policy -- South Africa -- Eastern Cape , Community development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9073 , http://hdl.handle.net/10948/d1008409 , Rural development -- South Africa -- Eastern Cape , Rural development -- Government policy -- South Africa -- Eastern Cape , Community development -- South Africa
- Description: Poverty and inequality in South Africa are a result of the impact of apartheid policy, which inter alia stripped people of their assets, especially land, distorted economic markets and social institutions through racial discrimination, and resulted in violence and destabilization. This has shaped the nature of poverty in South Africa. In view of the above, the South African government has introduced a programme known as the Comprehensive Rural Development Strategy in order to redress the imbalances of the former apartheid regime. In this strategy it is envisaged that vibrant, equitable and sustainable rural communities and food security for all will be achieved. In this study, I investigated the implementation of rural development programmes in the Mbhashe local municipality of the Eastern Cape Province in order to determine appropriate intervention strategies. This study focused on Ward18 of Mbhashe local municipality on a village known as Nkwalini Bafazi. This is a village that has been earmarked by the government to be a pilot site for the Rural Development Programme. This project is at the initial stage of social facilitation. In other words this research project is designed to investigate the process of Rural Development and how it can be implemented in the Mbhashe Local municipality in order to alleviate poverty and underdevelopment. For the purpose of the study, a mixed research approach was chosen. This means that the study used both the qualitative and quantitative approaches for in-depth understanding and verification. Questionnaires and structured interview questions were used to collect the data. Participatory Rural Appraisal (PRA) was also used for the purpose of observing and involving the community in the exercise. Data was collected from residents by conducting surveys, making use of questionnaires. Structured interviews were conducted with government officials (Department of Rural Development and Agrarian Reform) in order to understand the situation better.
- Full Text:
- Date Issued: 2011
The Role of Universities in a Transformed Post School Education and Training System
- Authors: Nzimande, Blade E
- Date: 2011
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/762 , vital:19988
- Description: Over the past two years my Department has been conceptualising and building a single system comprising of all institutions involved in post-school education and training. The inevitable changes have affected some of the institutions and institutional types more than others, but it will inevitably affect all of them, I believe for the better. We are aiming at creating an integrated, accessible, flexible, differentiated and highly articulated system of post school education and training which will benefit our youth, our society more generally and our economy. This lecture talks to the role we see for universities in this transformed system.
- Full Text:
- Date Issued: 2011
- Authors: Nzimande, Blade E
- Date: 2011
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/762 , vital:19988
- Description: Over the past two years my Department has been conceptualising and building a single system comprising of all institutions involved in post-school education and training. The inevitable changes have affected some of the institutions and institutional types more than others, but it will inevitably affect all of them, I believe for the better. We are aiming at creating an integrated, accessible, flexible, differentiated and highly articulated system of post school education and training which will benefit our youth, our society more generally and our economy. This lecture talks to the role we see for universities in this transformed system.
- Full Text:
- Date Issued: 2011
The short-term effect on shareholder wealth of banking mergers and acquisitions during periods of real economic expansion and contraction
- Authors: Kerr, Gordon Roy
- Date: 2011
- Subjects: Bank mergers , Consolidation and merger of corporations , Business cycles , Corporations -- Investor relations , Stockholder wealth , Rate of return
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1108 , http://hdl.handle.net/10962/d1013442
- Description: Controversy currently exists over whether abnormal returns (ARs) are earned by shareholders of bidder and target banks through a Merger and Acquisition (M&A). The state of the economy in which the firms operate is often mentioned as a reason for firms engaging in M&As, however, the extent to which economies influence the ARs of shareholders is unknown. Following MacKinlay (1997), the aim of this study is to determine the average ARs earned or lost by shareholders of several banks around the world during an M&A. The results obtained may indicate that shareholders of bidding firms consider an M&A to be a wealth-destroying event irrespective of the state of the economy. It would seem that target firms’ shareholders consider M&As to be wealth-creating events when they occur during a period of real economic expansion. However, during periods of real economic contraction, target firms’ shareholders consider M&As to be wealth-destroying events. Thus, the state of an economy during an M&A can affect average ARs considerably.
- Full Text:
- Date Issued: 2011
- Authors: Kerr, Gordon Roy
- Date: 2011
- Subjects: Bank mergers , Consolidation and merger of corporations , Business cycles , Corporations -- Investor relations , Stockholder wealth , Rate of return
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1108 , http://hdl.handle.net/10962/d1013442
- Description: Controversy currently exists over whether abnormal returns (ARs) are earned by shareholders of bidder and target banks through a Merger and Acquisition (M&A). The state of the economy in which the firms operate is often mentioned as a reason for firms engaging in M&As, however, the extent to which economies influence the ARs of shareholders is unknown. Following MacKinlay (1997), the aim of this study is to determine the average ARs earned or lost by shareholders of several banks around the world during an M&A. The results obtained may indicate that shareholders of bidding firms consider an M&A to be a wealth-destroying event irrespective of the state of the economy. It would seem that target firms’ shareholders consider M&As to be wealth-creating events when they occur during a period of real economic expansion. However, during periods of real economic contraction, target firms’ shareholders consider M&As to be wealth-destroying events. Thus, the state of an economy during an M&A can affect average ARs considerably.
- Full Text:
- Date Issued: 2011
The simulation of vehicle engine cooling in a climatic chamber
- Authors: Badenhorst, Kenneth Merwin
- Date: 2011
- Subjects: Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9615 , http://hdl.handle.net/10948/1454 , Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Description: The simulation of vehicle engine cooling validation in a Climatic chamber will benefit all vehicle manufacturers that are responsible for the design or the localization of parts used in a vehicle's engine cooling system. The ability to test the vehicle in-house allows testing at any time of the year; it provides repeatable and comparative data, and accelerates component level approval, which in itself reduces program timing and cost. For this dissertation road level testing was conducted in Upington using a TD1200 Superflow towing dynamometer, while the in-house testing was performed on a ROTOTEST chassis dynamometer in a Climatic chamber. All tests were conducted according to GENERAL MOTORS SOUTH AFRICA global testing standards. Statistical analyses of the test data were used to determine the relationship between parameters measured and results obtained. The major contributors to the simulation process was identified and implemented to improve measurement quality and test results. The result was an accurate simulation between road and chamber testing, hence the possibility of moving away from road testing and conduct simulated chamber testing. The presented dissertation is useful for the understanding of basic vehicle cooling testing and the methodology of simulated testing in an environmentally controlled chamber.
- Full Text:
- Date Issued: 2011
- Authors: Badenhorst, Kenneth Merwin
- Date: 2011
- Subjects: Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9615 , http://hdl.handle.net/10948/1454 , Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Description: The simulation of vehicle engine cooling validation in a Climatic chamber will benefit all vehicle manufacturers that are responsible for the design or the localization of parts used in a vehicle's engine cooling system. The ability to test the vehicle in-house allows testing at any time of the year; it provides repeatable and comparative data, and accelerates component level approval, which in itself reduces program timing and cost. For this dissertation road level testing was conducted in Upington using a TD1200 Superflow towing dynamometer, while the in-house testing was performed on a ROTOTEST chassis dynamometer in a Climatic chamber. All tests were conducted according to GENERAL MOTORS SOUTH AFRICA global testing standards. Statistical analyses of the test data were used to determine the relationship between parameters measured and results obtained. The major contributors to the simulation process was identified and implemented to improve measurement quality and test results. The result was an accurate simulation between road and chamber testing, hence the possibility of moving away from road testing and conduct simulated chamber testing. The presented dissertation is useful for the understanding of basic vehicle cooling testing and the methodology of simulated testing in an environmentally controlled chamber.
- Full Text:
- Date Issued: 2011
The spatial evolution of the chemotaxis proteins of the Bacillus subtilis group
- Yssel, Anna Elizabeth Johanna
- Authors: Yssel, Anna Elizabeth Johanna
- Date: 2011
- Subjects: Chemotaxis , Bacillus subtilis , Bacillus (Bacteria) , Homology (Biology) , Plants -- Microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4027 , http://hdl.handle.net/10962/d1004087 , Chemotaxis , Bacillus subtilis , Bacillus (Bacteria) , Homology (Biology) , Plants -- Microbiology
- Description: The aim of this work was to study spatial evolution of the chemotaxis proteins of a group of plant-associated soil-dwelling bacteria vernacularly referred to as the B. subtilis group. This was achieved by creating homology models for the chemotaxis proteins if a suitable template was available, and by analysing the selective forces (positive, purifying or neutral) acting upon the chemotaxis proteins. Chemotaxis is the phenomenon in which bacteria direct their movement towards more favourable conditions, and is critical for processes such as obtaining nutrients, escaping toxic compounds, host colonization and bio-film formation. Members of the B. subtilis group exhibit different preferences for certain host plants, and it is therefore feasible that their chemotactic machinery are fine-tuned to respond optimally to the conditions of the various niches that the strains inhabit. Homology models were inferred for the plant growth promoting B. amyloliquefaciens FZB42 proteins CheB, CheC, CheD, CheR, CheW and CheY. The interactions between: CheC-CheD, the P1 and P2 domains of CheA with CheY and CheB, and the P4 and P5 domains of CheA with CheW were also modelled. The hydrophobic interactions contributing to intra- and inter-protein contacts were analysed. The models of the interactions between CheB and the various domains of CheA are of particular interest, because to date no structures have been solved that show an interaction between a histidine kinase (such as CheA) and a multidomain response regulator (such as CheB). Furthermore, evidence that phospho-CheB may inhibit the formation of phospho-CheY by competitively binding to the P2 domain of CheA is also presented. Proteins were analysed to determine if individual amino acid sites are under positive, neutral or purifying selection. The Methyl Accepting Chemotaxis Proteins (MCPs), CheA and CheV were also analyzed, but due to a lack of suitable templates, no homology models were constructed. Site-specific positive and purifying selection were estimated by comparing the ratios of non-synonymous to synonymous substitutions at each site in the sequences for the chemotaxis proteins as well as for the receptors McpA, McpB, and McpC. Homology models were coloured according to intensity of selective forces. It was found that the chemotaxis proteins of member of the B. subtilis group are under strong evolutionary constraints, hence it is unlikely that positive selection in these proteins are responsible for the differences in habitat preference that these organism exhibit.
- Full Text:
- Date Issued: 2011
- Authors: Yssel, Anna Elizabeth Johanna
- Date: 2011
- Subjects: Chemotaxis , Bacillus subtilis , Bacillus (Bacteria) , Homology (Biology) , Plants -- Microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4027 , http://hdl.handle.net/10962/d1004087 , Chemotaxis , Bacillus subtilis , Bacillus (Bacteria) , Homology (Biology) , Plants -- Microbiology
- Description: The aim of this work was to study spatial evolution of the chemotaxis proteins of a group of plant-associated soil-dwelling bacteria vernacularly referred to as the B. subtilis group. This was achieved by creating homology models for the chemotaxis proteins if a suitable template was available, and by analysing the selective forces (positive, purifying or neutral) acting upon the chemotaxis proteins. Chemotaxis is the phenomenon in which bacteria direct their movement towards more favourable conditions, and is critical for processes such as obtaining nutrients, escaping toxic compounds, host colonization and bio-film formation. Members of the B. subtilis group exhibit different preferences for certain host plants, and it is therefore feasible that their chemotactic machinery are fine-tuned to respond optimally to the conditions of the various niches that the strains inhabit. Homology models were inferred for the plant growth promoting B. amyloliquefaciens FZB42 proteins CheB, CheC, CheD, CheR, CheW and CheY. The interactions between: CheC-CheD, the P1 and P2 domains of CheA with CheY and CheB, and the P4 and P5 domains of CheA with CheW were also modelled. The hydrophobic interactions contributing to intra- and inter-protein contacts were analysed. The models of the interactions between CheB and the various domains of CheA are of particular interest, because to date no structures have been solved that show an interaction between a histidine kinase (such as CheA) and a multidomain response regulator (such as CheB). Furthermore, evidence that phospho-CheB may inhibit the formation of phospho-CheY by competitively binding to the P2 domain of CheA is also presented. Proteins were analysed to determine if individual amino acid sites are under positive, neutral or purifying selection. The Methyl Accepting Chemotaxis Proteins (MCPs), CheA and CheV were also analyzed, but due to a lack of suitable templates, no homology models were constructed. Site-specific positive and purifying selection were estimated by comparing the ratios of non-synonymous to synonymous substitutions at each site in the sequences for the chemotaxis proteins as well as for the receptors McpA, McpB, and McpC. Homology models were coloured according to intensity of selective forces. It was found that the chemotaxis proteins of member of the B. subtilis group are under strong evolutionary constraints, hence it is unlikely that positive selection in these proteins are responsible for the differences in habitat preference that these organism exhibit.
- Full Text:
- Date Issued: 2011
The strategic management of intellectual capital : a case study in the banking and financial services sector in Zambia
- Authors: Banda, Japhet Mathias
- Date: 2011
- Subjects: Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1178 , http://hdl.handle.net/10962/d1002795 , Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Description: Fundamental changes in the global economy are changing the basis of organisational competitive advantage. The challenge in attaining a competitive advantage is characterised by factors such as increased competition, market volatility, geographically dispersed operations, customer awareness, raising workforce diversity and stringent regulatory regimes. These factors have driven, and in turn have been driven by, an increasing complexity of products, services and the processes that create value, resulting in changes in the structural and functional dimensions of the organisation. Business executives and academics recognise the shift in value creating assets from the traditional land, labour and capital to intangible assets such as knowledge and information becoming the most important resources an organisation can muster.The combination and integration of intangible assets such as human resources, structural and relational resources has been grouped under the umbrella of intellectual capital. This study comprises of a single descriptive case study analysis to ascertain how intellectual capital is managed strategically to gain a competitive advantage in an organisation in the banking and financial services sector in Zambia. Based on document review and semi-structured interviews, this thesis investigated the extent to which an organisation in the banking and financial services sector in Zambia leveraged intellectual capital to gain competitive advantage. In this study it was found that there is a low level appreciation of the intellectual capital phenomenon as a strategic management tool in the participating organisation. However, the organisation has adopted aspects of intellectual capital and has implemented them successfully accounting for the organisation‘s competitive edge in the market.
- Full Text:
- Date Issued: 2011
- Authors: Banda, Japhet Mathias
- Date: 2011
- Subjects: Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1178 , http://hdl.handle.net/10962/d1002795 , Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Description: Fundamental changes in the global economy are changing the basis of organisational competitive advantage. The challenge in attaining a competitive advantage is characterised by factors such as increased competition, market volatility, geographically dispersed operations, customer awareness, raising workforce diversity and stringent regulatory regimes. These factors have driven, and in turn have been driven by, an increasing complexity of products, services and the processes that create value, resulting in changes in the structural and functional dimensions of the organisation. Business executives and academics recognise the shift in value creating assets from the traditional land, labour and capital to intangible assets such as knowledge and information becoming the most important resources an organisation can muster.The combination and integration of intangible assets such as human resources, structural and relational resources has been grouped under the umbrella of intellectual capital. This study comprises of a single descriptive case study analysis to ascertain how intellectual capital is managed strategically to gain a competitive advantage in an organisation in the banking and financial services sector in Zambia. Based on document review and semi-structured interviews, this thesis investigated the extent to which an organisation in the banking and financial services sector in Zambia leveraged intellectual capital to gain competitive advantage. In this study it was found that there is a low level appreciation of the intellectual capital phenomenon as a strategic management tool in the participating organisation. However, the organisation has adopted aspects of intellectual capital and has implemented them successfully accounting for the organisation‘s competitive edge in the market.
- Full Text:
- Date Issued: 2011