A stable isotope approach to trophic ecology resolving food webs in intertidal ecosystems
- Authors: Hill, Jaclyn Marie
- Date: 2008
- Subjects: Stable isotopes Food chains (Ecology) Stable isotopes in ecological research Intertidal ecology Mussels -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5771 , http://hdl.handle.net/10962/d1005459
- Description: There are broad differences in regional oceanography and primary production around the South African coast, which we might expect to give rise to major differences in trophic pathways. δ⁻¹³C and δ⁻¹⁵N isotopic ratios of suspended particulate matter (SPM), mussels, various intertidal consumers and common macroalgae along the South African coastline were explored using stable isotope analysis to investigate biogeographic and temporal variability of isotopic signatures of marine intertidal consumers and their food sources around the coast of South Africa, with a focus on evaluating the dependence of intertidal mussels on phytoplankton and macroalgal-derived organic carbon. Isotopic equilibration rates of four mussel tissues were determined through laboratory feeding experiments, which established that adductor tissue had the slowest isotopic turnover rate, and was subsequently used as an indication of overall mussel diet. Biogeographic, temporal and nearshore/offshore trends of isotopic ratios of SPM were investigated along 10km transects perpendicular to the coast and SPM exhibited overall trends of carbon depletion when moving from west to east along the coastline and from nearshore to offshore water, in both cases suggesting a shift from macrophyte detritus to a phytoplankton signature. δ⁻¹³C signatures of SPM also revealed temporal and biogeographic variation that had strong ties to local oceanography, being closely correlated to regional hydrographic features and tidal influences. Mixing models indicated filter feeders demonstrated over 50% dependence on nearshore SPM for organic carbon and it was possible to categorize them into geographic groups based on their carbon and nitrogen signatures, suggesting biogeographic shifts in resources. Biogeographic shifts in diet were also seen in some grazers. Difficulties in relating macroalgae to mussel diet led to investigations into the isotopic changes associated with macroalgal decomposition. Variation in photosynthetic fractionation, leaching and microbial mineralization are believed to have resulted from species-specific patterns of degradation. Although the strong links between carbon signatures and local oceanography indicate that stable isotope analysis is a powerful tool for the study of water mixing and coastal hydrography in relation to food-web analyses, substantial variation in fractionation of primary consumers, along with different periods of time integration between consumers and their food sources must be considered in future studies, to resolve trophic links in marine food webs successfully.
- Full Text:
- Date Issued: 2008
- Authors: Hill, Jaclyn Marie
- Date: 2008
- Subjects: Stable isotopes Food chains (Ecology) Stable isotopes in ecological research Intertidal ecology Mussels -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5771 , http://hdl.handle.net/10962/d1005459
- Description: There are broad differences in regional oceanography and primary production around the South African coast, which we might expect to give rise to major differences in trophic pathways. δ⁻¹³C and δ⁻¹⁵N isotopic ratios of suspended particulate matter (SPM), mussels, various intertidal consumers and common macroalgae along the South African coastline were explored using stable isotope analysis to investigate biogeographic and temporal variability of isotopic signatures of marine intertidal consumers and their food sources around the coast of South Africa, with a focus on evaluating the dependence of intertidal mussels on phytoplankton and macroalgal-derived organic carbon. Isotopic equilibration rates of four mussel tissues were determined through laboratory feeding experiments, which established that adductor tissue had the slowest isotopic turnover rate, and was subsequently used as an indication of overall mussel diet. Biogeographic, temporal and nearshore/offshore trends of isotopic ratios of SPM were investigated along 10km transects perpendicular to the coast and SPM exhibited overall trends of carbon depletion when moving from west to east along the coastline and from nearshore to offshore water, in both cases suggesting a shift from macrophyte detritus to a phytoplankton signature. δ⁻¹³C signatures of SPM also revealed temporal and biogeographic variation that had strong ties to local oceanography, being closely correlated to regional hydrographic features and tidal influences. Mixing models indicated filter feeders demonstrated over 50% dependence on nearshore SPM for organic carbon and it was possible to categorize them into geographic groups based on their carbon and nitrogen signatures, suggesting biogeographic shifts in resources. Biogeographic shifts in diet were also seen in some grazers. Difficulties in relating macroalgae to mussel diet led to investigations into the isotopic changes associated with macroalgal decomposition. Variation in photosynthetic fractionation, leaching and microbial mineralization are believed to have resulted from species-specific patterns of degradation. Although the strong links between carbon signatures and local oceanography indicate that stable isotope analysis is a powerful tool for the study of water mixing and coastal hydrography in relation to food-web analyses, substantial variation in fractionation of primary consumers, along with different periods of time integration between consumers and their food sources must be considered in future studies, to resolve trophic links in marine food webs successfully.
- Full Text:
- Date Issued: 2008
A standards-based security model for health information systems
- Authors: Thomson, Steven Michael
- Date: 2008
- Subjects: Computer networks -- Security measures -- Standards -- South Africa , Data protection -- Management -- Standards , Computer security -- South Africa -- Management , Computers -- Access control -- South Africa , Management information systems -- Security measures -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9786 , http://hdl.handle.net/10948/718 , Computer networks -- Security measures -- Standards -- South Africa , Data protection -- Management -- Standards , Computer security -- South Africa -- Management , Computers -- Access control -- South Africa , Management information systems -- Security measures -- South Africa
- Description: In the healthcare environment, various types of patient information are stored in electronic format. This prevents the re-entering of information that was captured previously. In the past this information was stored on paper and kept in large filing cabinets. However, with the technology advancements that have occurred over the years, the idea of storing patient information in electronic systems arose. This led to a number of electronic health information systems being created, which in turn led to an increase in possible security risks. Any organization that stores information of a sensitive nature must apply information security principles in order to ensure that the stored information is kept secure. At a basic level, this entails ensuring the confidentiality, integrity and availability of the information, which is not an easy feat in today’s distributed and networked environments. This paved the way for organized standardization activities in the areas of information security and information security management. Throughout history, there have been practices that were created to help “standardize” industries of all areas, to the extent that there are professional organizations whose main objective it is to create such standards to help connect industries all over the world. This applies equally to the healthcare environment, where standardization took off in the late eighties. Healthcare organizations must follow standardized security measures to ensure that patient information stored in health information systems is kept secure. However, the proliferation in standards makes it difficult to understand, adopt and deploy these standards in a coherent manner. This research, therefore, proposes a standards-based security model for health information systems to ensure that such standards are applied in a manner that contributes to securing the healthcare environment as a whole, rather than in a piecemeal fashion.
- Full Text:
- Date Issued: 2008
- Authors: Thomson, Steven Michael
- Date: 2008
- Subjects: Computer networks -- Security measures -- Standards -- South Africa , Data protection -- Management -- Standards , Computer security -- South Africa -- Management , Computers -- Access control -- South Africa , Management information systems -- Security measures -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9786 , http://hdl.handle.net/10948/718 , Computer networks -- Security measures -- Standards -- South Africa , Data protection -- Management -- Standards , Computer security -- South Africa -- Management , Computers -- Access control -- South Africa , Management information systems -- Security measures -- South Africa
- Description: In the healthcare environment, various types of patient information are stored in electronic format. This prevents the re-entering of information that was captured previously. In the past this information was stored on paper and kept in large filing cabinets. However, with the technology advancements that have occurred over the years, the idea of storing patient information in electronic systems arose. This led to a number of electronic health information systems being created, which in turn led to an increase in possible security risks. Any organization that stores information of a sensitive nature must apply information security principles in order to ensure that the stored information is kept secure. At a basic level, this entails ensuring the confidentiality, integrity and availability of the information, which is not an easy feat in today’s distributed and networked environments. This paved the way for organized standardization activities in the areas of information security and information security management. Throughout history, there have been practices that were created to help “standardize” industries of all areas, to the extent that there are professional organizations whose main objective it is to create such standards to help connect industries all over the world. This applies equally to the healthcare environment, where standardization took off in the late eighties. Healthcare organizations must follow standardized security measures to ensure that patient information stored in health information systems is kept secure. However, the proliferation in standards makes it difficult to understand, adopt and deploy these standards in a coherent manner. This research, therefore, proposes a standards-based security model for health information systems to ensure that such standards are applied in a manner that contributes to securing the healthcare environment as a whole, rather than in a piecemeal fashion.
- Full Text:
- Date Issued: 2008
A study of professionalism and the professionalisation of journalists in Uganda from 1995 to 2008
- Authors: Mayiga, John Bosco
- Date: 2008
- Subjects: Journalists -- Uganda Journalism -- Political aspects -- Uganda Mass media -- Political aspects -- Uganda Journalism -- Sociological aspects -- Uganda Journalism, Commercial -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3461 , http://hdl.handle.net/10962/d1002916
- Description: This study seeks to examine how Ugandan journalists’ and politicians’ views on journalism professionalisation in Uganda relate to the broad theoretical arguments about professionalism within sociology and media studies. It also seeks to examine how such views impact on the democratic role of the media. The study finds out that there are two sets of distinct ideas on journalism professionalisation. The idea espoused by politicians is statutory professionalisation in which the state plays a major role through regulation and control, hence professionalisation is seen primarily as a control system. On the other hand, journalists perceive professionalisation as nurtured by voluntarily and socially inculcated professional values, hence as a value system. The study however, finds that both sets of understandings have their own complexities. While the statutory approach has complexities like how core elements of professionalism such as professional values can be imposed through legislation, the voluntary approach to professionalism also exhibits tensions within, especially stemming from the relationship between the professional and the news organisation regarding what constitutes professionalism. The study concludes that both sets of ideas have implications for the democratic role of the media, with both perceptions of professionalism curtailing this role. Statutory professionalisation in the Ugandan political context where the state is the dominant institution brings media institutions within its control, which leads to suppression of content of democratic value through a number of means. On the other hand, the self-regulatory perception does not protect media professionalism from the assault of commercial imperatives, especially when fused with state patronage in regard to broadcasting licences and placement of advertising.
- Full Text:
- Date Issued: 2008
- Authors: Mayiga, John Bosco
- Date: 2008
- Subjects: Journalists -- Uganda Journalism -- Political aspects -- Uganda Mass media -- Political aspects -- Uganda Journalism -- Sociological aspects -- Uganda Journalism, Commercial -- Uganda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3461 , http://hdl.handle.net/10962/d1002916
- Description: This study seeks to examine how Ugandan journalists’ and politicians’ views on journalism professionalisation in Uganda relate to the broad theoretical arguments about professionalism within sociology and media studies. It also seeks to examine how such views impact on the democratic role of the media. The study finds out that there are two sets of distinct ideas on journalism professionalisation. The idea espoused by politicians is statutory professionalisation in which the state plays a major role through regulation and control, hence professionalisation is seen primarily as a control system. On the other hand, journalists perceive professionalisation as nurtured by voluntarily and socially inculcated professional values, hence as a value system. The study however, finds that both sets of understandings have their own complexities. While the statutory approach has complexities like how core elements of professionalism such as professional values can be imposed through legislation, the voluntary approach to professionalism also exhibits tensions within, especially stemming from the relationship between the professional and the news organisation regarding what constitutes professionalism. The study concludes that both sets of ideas have implications for the democratic role of the media, with both perceptions of professionalism curtailing this role. Statutory professionalisation in the Ugandan political context where the state is the dominant institution brings media institutions within its control, which leads to suppression of content of democratic value through a number of means. On the other hand, the self-regulatory perception does not protect media professionalism from the assault of commercial imperatives, especially when fused with state patronage in regard to broadcasting licences and placement of advertising.
- Full Text:
- Date Issued: 2008
A study of the Amathole District Municipality's settlement plan in the light of the land reform and spatial planning measures
- Authors: Zenzile, Mlamli Lennox
- Date: 2008
- Subjects: Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land use -- Planning -- South Africa , Restitution -- South Africa -- Eastern Cape , Compensation (Law) -- South Africa -- Eastern Cape , Human rights -- South Africa -- Eastern Cape , Right of property -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3700 , http://hdl.handle.net/10962/d1003215 , Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land use -- Planning -- South Africa , Restitution -- South Africa -- Eastern Cape , Compensation (Law) -- South Africa -- Eastern Cape , Human rights -- South Africa -- Eastern Cape , Right of property -- South Africa -- Eastern Cape
- Description: This study concerns the analysis of policy, and the statutory and regulatory impact of spatial planning on the land reform programme with emphasis on the land reform settlement plan (LSRP) of the Amathole District Municipality (ADM). There is a brief historical overview of the effect of the policy of spatial segregation in both rural and urban areas of the ADM. This study demonstrates, inter alia, the challenges faced by the ADM in both consolidating and physically integrating communities that were hitherto divided across racial lines. The critical question is whether the ADM has the ability to produce a Spatial Development Framework (SDF), which will be responsive to the needs of the region and serve as a catalyst in reversing the physical distortions caused by the land-planning legislation of the apartheid past. The greatest challenge lies in meeting the developmental aspirations of the Development Facilitation Act, 1995, the Local Government: Municipal Systems Act, 2000 and the National Spatial Development Perspective, 2003. Chapter 1 deals with the purpose, research problem and the method of research, as well as the definition of terms used in this research and literature review. Chapter 2 deals with the evolution of central themes of spatial planning and land reform, spatial development plans and integrated development plans (IDPs), the alignment of Amathole SDF and Eastern Cape Spatial Development Plan and the co-ordination of spatial frameworks. Chapter 3 deals with the composition of the ADM and the evolution of the LRSP, as well as land-tenure reform programmes impacting on the Amathole Municipality region. This chapter analyses the settlement plan against spatial planning legislation, the issue of institutional arrangements and mechanisms of consolidated local planning processes. Chapter 5 deals with the thorny issue of participation of traditional leaders in municipal planning and the government’s land-reform programme. Despite the existence of legislation in this regard, implementation seems to pose some difficulties. This chapter also deals with the co-operative governance framework. Chapter 6 is a concluding chapter dealing with the gaps discovered in the Amathole Municipality in the light of existing legislation. Reference to cases is made to demonstrate the challenges confronting the ADM. One notable aspect is the issue of urban-rural dichotomy and how the two worlds are positioned in their competition for the use of space. It is evident from this research that the post-1994 policy and legislative framework and implementation machinery lacks capacity to change the current form of the apartheid city-planning paradigm, something which impacts immensely on the sustainability of the current human-settlement development programmes. Population dynamics in terms of migration are hugely driven by search for employment opportunities and better services. The efficiency and ability of the municipal spatial evelopment frameworks in directing and dictating the identification of development nodes in its juristic boundary informed by the overarching national policy and legislative framework is key in building a better South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Zenzile, Mlamli Lennox
- Date: 2008
- Subjects: Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land use -- Planning -- South Africa , Restitution -- South Africa -- Eastern Cape , Compensation (Law) -- South Africa -- Eastern Cape , Human rights -- South Africa -- Eastern Cape , Right of property -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3700 , http://hdl.handle.net/10962/d1003215 , Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Land use -- Planning -- South Africa , Restitution -- South Africa -- Eastern Cape , Compensation (Law) -- South Africa -- Eastern Cape , Human rights -- South Africa -- Eastern Cape , Right of property -- South Africa -- Eastern Cape
- Description: This study concerns the analysis of policy, and the statutory and regulatory impact of spatial planning on the land reform programme with emphasis on the land reform settlement plan (LSRP) of the Amathole District Municipality (ADM). There is a brief historical overview of the effect of the policy of spatial segregation in both rural and urban areas of the ADM. This study demonstrates, inter alia, the challenges faced by the ADM in both consolidating and physically integrating communities that were hitherto divided across racial lines. The critical question is whether the ADM has the ability to produce a Spatial Development Framework (SDF), which will be responsive to the needs of the region and serve as a catalyst in reversing the physical distortions caused by the land-planning legislation of the apartheid past. The greatest challenge lies in meeting the developmental aspirations of the Development Facilitation Act, 1995, the Local Government: Municipal Systems Act, 2000 and the National Spatial Development Perspective, 2003. Chapter 1 deals with the purpose, research problem and the method of research, as well as the definition of terms used in this research and literature review. Chapter 2 deals with the evolution of central themes of spatial planning and land reform, spatial development plans and integrated development plans (IDPs), the alignment of Amathole SDF and Eastern Cape Spatial Development Plan and the co-ordination of spatial frameworks. Chapter 3 deals with the composition of the ADM and the evolution of the LRSP, as well as land-tenure reform programmes impacting on the Amathole Municipality region. This chapter analyses the settlement plan against spatial planning legislation, the issue of institutional arrangements and mechanisms of consolidated local planning processes. Chapter 5 deals with the thorny issue of participation of traditional leaders in municipal planning and the government’s land-reform programme. Despite the existence of legislation in this regard, implementation seems to pose some difficulties. This chapter also deals with the co-operative governance framework. Chapter 6 is a concluding chapter dealing with the gaps discovered in the Amathole Municipality in the light of existing legislation. Reference to cases is made to demonstrate the challenges confronting the ADM. One notable aspect is the issue of urban-rural dichotomy and how the two worlds are positioned in their competition for the use of space. It is evident from this research that the post-1994 policy and legislative framework and implementation machinery lacks capacity to change the current form of the apartheid city-planning paradigm, something which impacts immensely on the sustainability of the current human-settlement development programmes. Population dynamics in terms of migration are hugely driven by search for employment opportunities and better services. The efficiency and ability of the municipal spatial evelopment frameworks in directing and dictating the identification of development nodes in its juristic boundary informed by the overarching national policy and legislative framework is key in building a better South Africa.
- Full Text:
- Date Issued: 2008
A study of the conducivness of the culture at Freeworld Automotive Coatings to the implementation of lean maunfacturing techniques
- Authors: Gray, Alexander George
- Date: 2008
- Subjects: Corporate culture -- South Africa , Organizational behavior -- South Africa , Organizational change -- South Africa , Organizational effectiveness -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8719 , http://hdl.handle.net/10948/910 , Corporate culture -- South Africa , Organizational behavior -- South Africa , Organizational change -- South Africa , Organizational effectiveness -- South Africa
- Description: It is becoming increasingly important for companies to be responsive to global demands and in order to remain competitive, many companies are looking at lean manufacturing to help them achieve this. Lean manufacturing is however more than just a set of tools as it also requires a change in the organisational culture of the company involved. The creation of an organisation that has a culture of continuous improvement and achieving results through its various principles and philosophies is a main factor in Toyota’s Toyota Way Model. It was the aim of this research study to analyse and determine the factors relating to the impact of an organisation’s culture on the concepts of lean manufacturing based on the Toyota Way model. This was achieved by analysing how conducive the current organisational culture at Freeworld Automotive Coatings to the implementation of Lean Manufacturing principles? The method used for the research study was the questionnaire method using a lean culture assessment questionnaire that has been designed by the researcher that was aligned to the principles important to the Toyota Way model. It can be concluded from the research findings of this study indicates that the existing organisational culture of Freeworld Automotive coatings is relatively conducive to the implementation of lean manufacturing principles within the company.
- Full Text:
- Date Issued: 2008
- Authors: Gray, Alexander George
- Date: 2008
- Subjects: Corporate culture -- South Africa , Organizational behavior -- South Africa , Organizational change -- South Africa , Organizational effectiveness -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8719 , http://hdl.handle.net/10948/910 , Corporate culture -- South Africa , Organizational behavior -- South Africa , Organizational change -- South Africa , Organizational effectiveness -- South Africa
- Description: It is becoming increasingly important for companies to be responsive to global demands and in order to remain competitive, many companies are looking at lean manufacturing to help them achieve this. Lean manufacturing is however more than just a set of tools as it also requires a change in the organisational culture of the company involved. The creation of an organisation that has a culture of continuous improvement and achieving results through its various principles and philosophies is a main factor in Toyota’s Toyota Way Model. It was the aim of this research study to analyse and determine the factors relating to the impact of an organisation’s culture on the concepts of lean manufacturing based on the Toyota Way model. This was achieved by analysing how conducive the current organisational culture at Freeworld Automotive Coatings to the implementation of Lean Manufacturing principles? The method used for the research study was the questionnaire method using a lean culture assessment questionnaire that has been designed by the researcher that was aligned to the principles important to the Toyota Way model. It can be concluded from the research findings of this study indicates that the existing organisational culture of Freeworld Automotive coatings is relatively conducive to the implementation of lean manufacturing principles within the company.
- Full Text:
- Date Issued: 2008
A study of the existence of equilibrium in mathematical economics
- Authors: Xotyeni, Zukisa Gqabi
- Date: 2008
- Subjects: Equilibrium (Economics) -- Mathematical models , Macroeconomics -- Mathematical models , Economics -- Mathematical models , Welfare economics -- Mathematical models , Lattice theory , Economics, Mathematical
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5418 , http://hdl.handle.net/10962/d1005232 , Equilibrium (Economics) -- Mathematical models , Macroeconomics -- Mathematical models , Economics -- Mathematical models , Welfare economics -- Mathematical models , Lattice theory , Economics, Mathematical
- Description: In this thesis we define and study the existence of an equilibrium situation in which producers maximize their profits relative to the production vectors in their production sets, consumers satisfy their preferences in their consumption sets under certain budget constraint, and for every commodity total demand equals total supply. This competitive equilibrium situation is referred to as the Walrasian equilibrium. The existence of this equilibrium is investigated from a various mathematical points of view. These include microeconomic theory, simplicial spaces, global analysis and lattice theory.
- Full Text:
- Date Issued: 2008
- Authors: Xotyeni, Zukisa Gqabi
- Date: 2008
- Subjects: Equilibrium (Economics) -- Mathematical models , Macroeconomics -- Mathematical models , Economics -- Mathematical models , Welfare economics -- Mathematical models , Lattice theory , Economics, Mathematical
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5418 , http://hdl.handle.net/10962/d1005232 , Equilibrium (Economics) -- Mathematical models , Macroeconomics -- Mathematical models , Economics -- Mathematical models , Welfare economics -- Mathematical models , Lattice theory , Economics, Mathematical
- Description: In this thesis we define and study the existence of an equilibrium situation in which producers maximize their profits relative to the production vectors in their production sets, consumers satisfy their preferences in their consumption sets under certain budget constraint, and for every commodity total demand equals total supply. This competitive equilibrium situation is referred to as the Walrasian equilibrium. The existence of this equilibrium is investigated from a various mathematical points of view. These include microeconomic theory, simplicial spaces, global analysis and lattice theory.
- Full Text:
- Date Issued: 2008
A study of the reintergration of former child soldiers : the case study of Gusco Northern Uganda
- Authors: Obika, Juliana
- Date: 2008
- Subjects: Children and war -- Uganda -- Gusco , Child soldiers -- Uganda -- Gusco , Soldiers -- Rehabilitation -- Uganda , Lord's Resistance Army
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8256 , http://hdl.handle.net/10948/786 , http://hdl.handle.net/10948/d1012067 , Children and war -- Uganda -- Gusco , Child soldiers -- Uganda -- Gusco , Soldiers -- Rehabilitation -- Uganda , Lord's Resistance Army
- Description: The provision of basic needs such as food, shelter, security, identity and recognition is central in the rebuilding and reconstruction of the war-torn areas of Africa and indeed around the world. The war in northern Uganda, in particular, has taken its toll on the people of that area for more than 20 years and in the process, has witnessed the children facing some of the worst effects of armed conflicts known to man. This study investigated the role played by the Gulu Support the Children Organisation (GUSCO) in the reintegration of former child soldiers in Northern Uganda. GUSCO is however in favour of the term Formerly Abducted Children (FAC) as this is less prone to acts of stigmatisation against those who have faced some of the most horrific abuses known to human kind. It focused on the process of reintegration of the FAC in relation to the human needs theory which has been used as a basis for conflict resolution practices. The researcher conducted extensive face-to-face interviews with the employees of GUSCO who work in various fields as social workers, counsellors, health workers and teachers, who tend to the needs of the FAC daily. The researcher was also able to carryout observations of the activities that take place at the GUSCO reception centre where the children are rehabilitated. The organisation’s official documents were also consulted in order to carryout this triangular study and collect data. The major themes constructed from the study include: the empowerment and development of the FAC through education and skills training; health care provision to meet both physical and psychological needs; community empowerment and development and finally peacebuilding and reconciliation which involves the participation of whole communities to meet their needs and rebuild the war-torn northern Uganda. The researcher highlights some challenges that GUSCO faces in trying to reintegrate the former combatants albeit children into a routine of a community that struggles to recover from a war that continues to persist after twenty years. Several recommendations are made for GUSCO and civil societies who have given themselves the mandate to work towards salvaging the future generations of Uganda and Africa as a whole.
- Full Text:
- Date Issued: 2008
- Authors: Obika, Juliana
- Date: 2008
- Subjects: Children and war -- Uganda -- Gusco , Child soldiers -- Uganda -- Gusco , Soldiers -- Rehabilitation -- Uganda , Lord's Resistance Army
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8256 , http://hdl.handle.net/10948/786 , http://hdl.handle.net/10948/d1012067 , Children and war -- Uganda -- Gusco , Child soldiers -- Uganda -- Gusco , Soldiers -- Rehabilitation -- Uganda , Lord's Resistance Army
- Description: The provision of basic needs such as food, shelter, security, identity and recognition is central in the rebuilding and reconstruction of the war-torn areas of Africa and indeed around the world. The war in northern Uganda, in particular, has taken its toll on the people of that area for more than 20 years and in the process, has witnessed the children facing some of the worst effects of armed conflicts known to man. This study investigated the role played by the Gulu Support the Children Organisation (GUSCO) in the reintegration of former child soldiers in Northern Uganda. GUSCO is however in favour of the term Formerly Abducted Children (FAC) as this is less prone to acts of stigmatisation against those who have faced some of the most horrific abuses known to human kind. It focused on the process of reintegration of the FAC in relation to the human needs theory which has been used as a basis for conflict resolution practices. The researcher conducted extensive face-to-face interviews with the employees of GUSCO who work in various fields as social workers, counsellors, health workers and teachers, who tend to the needs of the FAC daily. The researcher was also able to carryout observations of the activities that take place at the GUSCO reception centre where the children are rehabilitated. The organisation’s official documents were also consulted in order to carryout this triangular study and collect data. The major themes constructed from the study include: the empowerment and development of the FAC through education and skills training; health care provision to meet both physical and psychological needs; community empowerment and development and finally peacebuilding and reconciliation which involves the participation of whole communities to meet their needs and rebuild the war-torn northern Uganda. The researcher highlights some challenges that GUSCO faces in trying to reintegrate the former combatants albeit children into a routine of a community that struggles to recover from a war that continues to persist after twenty years. Several recommendations are made for GUSCO and civil societies who have given themselves the mandate to work towards salvaging the future generations of Uganda and Africa as a whole.
- Full Text:
- Date Issued: 2008
A supplementary coping skills programme for parents of children diagnosed with attention deficit hyperactivity disorder
- Authors: Gomes, Ana Maria
- Date: 2008
- Subjects: Attention-deficit-disordered children -- Family relationships , Children with disabilities -- Education
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9471 , http://hdl.handle.net/10948/686
- Description: Attention Deficit Hyperactivity Disorder (ADHD)-related behaviour difficulties are said to be the cause of much of the disharmony and discord that exists within many families with ADHD-diagnosed children. On the basis of this understanding, a supplementary programme of behaviour modification, referred to as the Coping Skills Programme, was designed and implemented over a designated period of time, as a trial efficiency test, with a view to alleviate some of the family environmental stress caused by the effects of this disorder. There were three main aims to this research project, related to the research questions: Firstly, to establish to what extent this programme helped with the kinds of problems and difficulties being experienced by the parents of ADHD-diagnosed children and by the children themselves; secondly, to make recommendations regarding how to access and use such a programme and learn its skills, and thirdly to determine further ways with which to improve the Coping Skills Programme. The research design was based on Interpretive Theory and was qualitative in nature. An in-depth literature study was undertaken, which together with all the field notes acquired during the course of the study, formed the foundation of the study. A needs analysis was also carried out to ascertain the level and variety of ADHD-related needs that exist within the family unit. This needs analysis took place in the Nelson Mandela Metropole in the Eastern Cape to ascertain the level and variety of ADHD-related needs that exist within the family unit. The sampling selection of participants was both purposeful and dependent on availability, in order obtain as wide a range of information as possible, regarding specific ADHD-related criteria. This data was used as a foundation for the programme’s development. Information was gathered by means of phenomenological interviews, case study analysis, a focus group interview, field notes, observations and an audit trail. Measures were taken to ensure that the study was ethically conducted and trustworthiness maintained. The Coping Skills Programme was implemented with different families with ADHD-diagnosed children, within its designated time, which varied from family to family from between 8 and 10 weeks. Finally, three families were xx selected as case studies to substantiate the findings of this research study. Their selection was based on the range of the children’s age, the variety of their combined needs, the way in which each family dealt with the challenges posed by the programme, the parents’ involvement and the rate of success experienced by each family at the end of the allotted time. At the end of the programme’s implementation period it was found that confusion regarding parental role clarity and the role of the child in the home had a strong bearing on the treatment and management of ADHD-related difficulties. It was also found that the effect of parental unity and/or discord had a direct impact on ADHD-related behaviour. Equally important to the effective management of ADHD-related difficulties were the parental understanding and perceptions regarding their child’s ADHD-related needs and difficulties. The effectiveness of behaviour modification in relation to the level of parental involvement was also salient, as was the use of effective, positive communication to achievement of optimum results. Parental understanding of the role of discipline and how the effective use of this skill benefits the ADHD-diagnosed child became clear, as did the value of consistency in behaviour modification. The conclusion was reached that a programme as flexible as the Coping Skills Programme, when used appropriately and as a supplement to other forms of therapy, may be a significant source of assistance, support, encouragement and empowerment to families with members suffering with ADHD.
- Full Text:
- Date Issued: 2008
- Authors: Gomes, Ana Maria
- Date: 2008
- Subjects: Attention-deficit-disordered children -- Family relationships , Children with disabilities -- Education
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9471 , http://hdl.handle.net/10948/686
- Description: Attention Deficit Hyperactivity Disorder (ADHD)-related behaviour difficulties are said to be the cause of much of the disharmony and discord that exists within many families with ADHD-diagnosed children. On the basis of this understanding, a supplementary programme of behaviour modification, referred to as the Coping Skills Programme, was designed and implemented over a designated period of time, as a trial efficiency test, with a view to alleviate some of the family environmental stress caused by the effects of this disorder. There were three main aims to this research project, related to the research questions: Firstly, to establish to what extent this programme helped with the kinds of problems and difficulties being experienced by the parents of ADHD-diagnosed children and by the children themselves; secondly, to make recommendations regarding how to access and use such a programme and learn its skills, and thirdly to determine further ways with which to improve the Coping Skills Programme. The research design was based on Interpretive Theory and was qualitative in nature. An in-depth literature study was undertaken, which together with all the field notes acquired during the course of the study, formed the foundation of the study. A needs analysis was also carried out to ascertain the level and variety of ADHD-related needs that exist within the family unit. This needs analysis took place in the Nelson Mandela Metropole in the Eastern Cape to ascertain the level and variety of ADHD-related needs that exist within the family unit. The sampling selection of participants was both purposeful and dependent on availability, in order obtain as wide a range of information as possible, regarding specific ADHD-related criteria. This data was used as a foundation for the programme’s development. Information was gathered by means of phenomenological interviews, case study analysis, a focus group interview, field notes, observations and an audit trail. Measures were taken to ensure that the study was ethically conducted and trustworthiness maintained. The Coping Skills Programme was implemented with different families with ADHD-diagnosed children, within its designated time, which varied from family to family from between 8 and 10 weeks. Finally, three families were xx selected as case studies to substantiate the findings of this research study. Their selection was based on the range of the children’s age, the variety of their combined needs, the way in which each family dealt with the challenges posed by the programme, the parents’ involvement and the rate of success experienced by each family at the end of the allotted time. At the end of the programme’s implementation period it was found that confusion regarding parental role clarity and the role of the child in the home had a strong bearing on the treatment and management of ADHD-related difficulties. It was also found that the effect of parental unity and/or discord had a direct impact on ADHD-related behaviour. Equally important to the effective management of ADHD-related difficulties were the parental understanding and perceptions regarding their child’s ADHD-related needs and difficulties. The effectiveness of behaviour modification in relation to the level of parental involvement was also salient, as was the use of effective, positive communication to achievement of optimum results. Parental understanding of the role of discipline and how the effective use of this skill benefits the ADHD-diagnosed child became clear, as did the value of consistency in behaviour modification. The conclusion was reached that a programme as flexible as the Coping Skills Programme, when used appropriately and as a supplement to other forms of therapy, may be a significant source of assistance, support, encouragement and empowerment to families with members suffering with ADHD.
- Full Text:
- Date Issued: 2008
A symptom that defies analysis: is this simply xenophobia?.
- Authors: Kyazze, Sim
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159337 , vital:40289 , https://hdl.handle.net/10520/EJC140106
- Description: On 29 January 29 2007 I travelled on an SAA flight from Entebbe International Airport in Uganda to OR Tambo International in Johannesburg. Somehow, I had forgotten, ignored or failed to travel with my Yellow Fever Certificate and an Immigration Officer let me have it.
- Full Text:
- Date Issued: 2008
- Authors: Kyazze, Sim
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159337 , vital:40289 , https://hdl.handle.net/10520/EJC140106
- Description: On 29 January 29 2007 I travelled on an SAA flight from Entebbe International Airport in Uganda to OR Tambo International in Johannesburg. Somehow, I had forgotten, ignored or failed to travel with my Yellow Fever Certificate and an Immigration Officer let me have it.
- Full Text:
- Date Issued: 2008
A synopsis of the Afrotropical Tricorythidae
- Authors: Barber-James, Helen M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:7003 , http://hdl.handle.net/10962/d1008362
- Description: The Tricorythidae of the Afrotropical Region is currently composed of five described genera, three of which are thought to be restricted to Madagascar (Madecassorythus Elouard and Oliarioniny, Ranorythus Oliarinony and Elouard, and Spinirythus Oliarinony and Elouard), one which is restricted to Africa (Dicercomyzon Demoulin), and one which is thought to be distributed on both landmasses (Tricorythus Eaton). Based on sexual dimorphism, manifest in the relative eye size of mature male and female nymphs and adults and on the structure of the genitalia of adult males, it is proposed that there are two additional genera in Africa, as yet undescribed. One of these genera is represented by a species currently placed in Tricorythus (T. discolor [Burmeister]). Several other undescribed species within South Africa have been identified as belonging to the group. A second lineage is represented by Tricorythus tinctus Kimmins, from Uganda, the only currently described species. There are also several more undescribed species of this group widespread in Africa.
- Full Text:
- Date Issued: 2008
- Authors: Barber-James, Helen M
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:7003 , http://hdl.handle.net/10962/d1008362
- Description: The Tricorythidae of the Afrotropical Region is currently composed of five described genera, three of which are thought to be restricted to Madagascar (Madecassorythus Elouard and Oliarioniny, Ranorythus Oliarinony and Elouard, and Spinirythus Oliarinony and Elouard), one which is restricted to Africa (Dicercomyzon Demoulin), and one which is thought to be distributed on both landmasses (Tricorythus Eaton). Based on sexual dimorphism, manifest in the relative eye size of mature male and female nymphs and adults and on the structure of the genitalia of adult males, it is proposed that there are two additional genera in Africa, as yet undescribed. One of these genera is represented by a species currently placed in Tricorythus (T. discolor [Burmeister]). Several other undescribed species within South Africa have been identified as belonging to the group. A second lineage is represented by Tricorythus tinctus Kimmins, from Uganda, the only currently described species. There are also several more undescribed species of this group widespread in Africa.
- Full Text:
- Date Issued: 2008
A VLBI study of OH masers in a proto-planetary nebula OH 0.9+1.3
- Authors: McAlpine, Kim
- Date: 2008
- Subjects: Very long baseline interferometry , Proto-planetary nebulae , Masers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5499 , http://hdl.handle.net/10962/d1005285 , Very long baseline interferometry , Proto-planetary nebulae , Masers
- Description: This thesis reports the calibration, imaging and analysis of one epoch of VLBA observations of the 1612 MHz OH maser emission from the protoplanetary nebula OH 0.9+1.3. These are the first polarisation VLBI observations of this source and the spatial morphology of the OH emission is resolved on this scale. Proto-planetary nebulae represent the transition phase in the evolution of stars between the asymptotic giant branch (AGB) phase and their emergence as planetary nebulae. A long-standing astronomical question is how the predominantly spherical circumstellar envelopes of AGB stars evolve into the bipolar and axisymmetric structures that are commonly observed in planetary nebula. Proto-planetary nebulae offer a unique opportunity to study this transformation process. The high-resolution VLBI maps produced in this thesis were used to investigate the morphology and kinematics of OH 0.9+1.3 with a view to gaining insight into the development of asymmetries in the circumstellar material. The OH maser emission of OH 0.9+1.3 has a double-peaked profile with one peak blue-shifted and the other red-shifted with respect to the stellar velocity. The total intensity maser maps demonstrate a considerable degree of asymmetry with the blue- and red-shifted emission located in spatially distinct regions of the envelope. The blue-shifted emission is distributed preferentially along an axis at a projected position angle of » 135± ( North through East). The morphology of this source is not consistent with the standard symmetric thin-shell model and an attempt to fit the traditional OH/IR kinematic model of a simple expanding shell to the maser components was found to be unsatisfactory. No definitive evidence of a bipolar outflow was observed either. The high degree of asymmetry observed in the source is consistent with its status as a proto-planetary nebula. The source was imaged in all four Stokes parameters and the fractional linear and circular polarisations of the maser components were derived from the Stokes parameter maps. In all except one of the components the total fractional polarisation was found to be low ( < 15%). The mean fractional linear and circular polarisation were calculated to be 5.54% and 7.11% respectively. The absence of an identifiable Zeeman pair in the Stokes V map prohibited the estimation of the magnetic field in the circumstellar envelope of this source.
- Full Text:
- Date Issued: 2008
- Authors: McAlpine, Kim
- Date: 2008
- Subjects: Very long baseline interferometry , Proto-planetary nebulae , Masers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5499 , http://hdl.handle.net/10962/d1005285 , Very long baseline interferometry , Proto-planetary nebulae , Masers
- Description: This thesis reports the calibration, imaging and analysis of one epoch of VLBA observations of the 1612 MHz OH maser emission from the protoplanetary nebula OH 0.9+1.3. These are the first polarisation VLBI observations of this source and the spatial morphology of the OH emission is resolved on this scale. Proto-planetary nebulae represent the transition phase in the evolution of stars between the asymptotic giant branch (AGB) phase and their emergence as planetary nebulae. A long-standing astronomical question is how the predominantly spherical circumstellar envelopes of AGB stars evolve into the bipolar and axisymmetric structures that are commonly observed in planetary nebula. Proto-planetary nebulae offer a unique opportunity to study this transformation process. The high-resolution VLBI maps produced in this thesis were used to investigate the morphology and kinematics of OH 0.9+1.3 with a view to gaining insight into the development of asymmetries in the circumstellar material. The OH maser emission of OH 0.9+1.3 has a double-peaked profile with one peak blue-shifted and the other red-shifted with respect to the stellar velocity. The total intensity maser maps demonstrate a considerable degree of asymmetry with the blue- and red-shifted emission located in spatially distinct regions of the envelope. The blue-shifted emission is distributed preferentially along an axis at a projected position angle of » 135± ( North through East). The morphology of this source is not consistent with the standard symmetric thin-shell model and an attempt to fit the traditional OH/IR kinematic model of a simple expanding shell to the maser components was found to be unsatisfactory. No definitive evidence of a bipolar outflow was observed either. The high degree of asymmetry observed in the source is consistent with its status as a proto-planetary nebula. The source was imaged in all four Stokes parameters and the fractional linear and circular polarisations of the maser components were derived from the Stokes parameter maps. In all except one of the components the total fractional polarisation was found to be low ( < 15%). The mean fractional linear and circular polarisation were calculated to be 5.54% and 7.11% respectively. The absence of an identifiable Zeeman pair in the Stokes V map prohibited the estimation of the magnetic field in the circumstellar envelope of this source.
- Full Text:
- Date Issued: 2008
A xylem retrieval pathway in rice leaf blades – evidence of a role for endocytosis?
- Botha, Christiaan E J, Aoki, N, Scofield, G N, Liu, Lin, Furbank, R T, White, R G
- Authors: Botha, Christiaan E J , Aoki, N , Scofield, G N , Liu, Lin , Furbank, R T , White, R G
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6505 , http://hdl.handle.net/10962/d1005930 , http://dx.doi.org/10.1093/jxb/ern150
- Description: The structure and transport properties of pit membranes at the interface between the metaxylem and xylem parenchyma cells and the possible role of these pit membranes in solute transfer to the phloem was investigated. Electron microscopy revealed a fibrillar, almost tubular matrix within the pit membrane structure between the xylem vessels and xylem parenchyma of leaf blade bundles in rice (Oryza sativa). These pits are involved primarily with regulating water flux to the surrounding xylem parenchyma cells. Vascular parenchyma cells contain large mitochondrial populations, numerous dictyosomes, endomembrane complexes and vesicles in close proximity to the pit membrane. Taken collectively this suggests that endocytosis may occur at this interface. A weak solution of 5,6-carboxyfluorescein diacetate (5,6-CFDA) was applied to cut ends of leaves and after a minimum of 45 minutes, the distribution of the fluorescent cleavage product, 5,6-carboxyfluorescein (5,6-CF) was observed using confocal microscopy. Cleavage of 5,6-CFDA occurred within the xylem parenchyma cells and the non-polar 5,6-CF was then symplasmically transported to other parenchyma elements and ultimately, via numerous pore plasmodesmata, to adjacent thick-walled sieve tubes. Application of Lucifer Yellow, and, separately, Texas Red labelled dextran (10 kDa) to the transpiration stream, confirmed that these membrane-impermeant probes could only have been offloaded from the xylem via the xylem vessel-xylem parenchyma pit membranes, suggesting endocytotic transmembrane transfer of these membrane-impermeant fluorophores. Accumulation within the thick-walled sieve tubes, but not in thin-walled sieve tubes, confirms the presence of a symplasmic phloem loading pathway, via pore plasmodesmata between xylem parenchyma and thick-walled sieve tubes, but not thin-walled sieve tubes.
- Full Text:
- Date Issued: 2008
- Authors: Botha, Christiaan E J , Aoki, N , Scofield, G N , Liu, Lin , Furbank, R T , White, R G
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6505 , http://hdl.handle.net/10962/d1005930 , http://dx.doi.org/10.1093/jxb/ern150
- Description: The structure and transport properties of pit membranes at the interface between the metaxylem and xylem parenchyma cells and the possible role of these pit membranes in solute transfer to the phloem was investigated. Electron microscopy revealed a fibrillar, almost tubular matrix within the pit membrane structure between the xylem vessels and xylem parenchyma of leaf blade bundles in rice (Oryza sativa). These pits are involved primarily with regulating water flux to the surrounding xylem parenchyma cells. Vascular parenchyma cells contain large mitochondrial populations, numerous dictyosomes, endomembrane complexes and vesicles in close proximity to the pit membrane. Taken collectively this suggests that endocytosis may occur at this interface. A weak solution of 5,6-carboxyfluorescein diacetate (5,6-CFDA) was applied to cut ends of leaves and after a minimum of 45 minutes, the distribution of the fluorescent cleavage product, 5,6-carboxyfluorescein (5,6-CF) was observed using confocal microscopy. Cleavage of 5,6-CFDA occurred within the xylem parenchyma cells and the non-polar 5,6-CF was then symplasmically transported to other parenchyma elements and ultimately, via numerous pore plasmodesmata, to adjacent thick-walled sieve tubes. Application of Lucifer Yellow, and, separately, Texas Red labelled dextran (10 kDa) to the transpiration stream, confirmed that these membrane-impermeant probes could only have been offloaded from the xylem via the xylem vessel-xylem parenchyma pit membranes, suggesting endocytotic transmembrane transfer of these membrane-impermeant fluorophores. Accumulation within the thick-walled sieve tubes, but not in thin-walled sieve tubes, confirms the presence of a symplasmic phloem loading pathway, via pore plasmodesmata between xylem parenchyma and thick-walled sieve tubes, but not thin-walled sieve tubes.
- Full Text:
- Date Issued: 2008
Absenteeism management at Willard Batteries
- Authors: Paul, Gary William
- Date: 2008
- Subjects: Absenteeism (Labor) -- Management , Absenteeism (Labor) -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9383 , http://hdl.handle.net/10948/896 , Absenteeism (Labor) -- Management , Absenteeism (Labor) -- South Africa
- Description: The main research problem in this study centred around the assessment of the impact of an absenteeism monitoring and management system at Willard Batteries. The main research problem had five sub-problems which were addressed through the following actions: A literature study was conducted to identify the causes and impact of absenteeism in the workplace. The researcher also conducted interviews with the Human Resources Manager, line managers and employees at Willard Batteries to obtain their views of the absenteeism management strategies utilised, as well as the effects of absenteeism in their organisation. The insights gained from these interviews were incorporated into the questionnaire. The absenteeism figures of the organisation for the period 2005 to 2008 were analysed and compared against the internationally accepted absenteeism norm of three percent. An absence rate above three percent is considered as unacceptable and would imply that the current absenteeism management system is not effective. The theoretical study also entailed the reviewing of the legal framework within which absenteeism needs to be managed, as well as the literature that deals with strategies for the effective management of absenteeism. These strategies relate to the recording, calculation, analysis, benchmarking and practical management of absenteeism in the workplace. A survey questionnaire was developed to determine the perceptions of managers, supervisors and employees in relation to the impact of absenteeism on the company as well as the extent to which managers and supervisors were utilising selected absenteeism monitoring and management strategies within the company. The results from the empirical study revealed that management and supervisors were more aware of the impact of absenteeism on the organisation than their employees. It can therefore be concluded that employees perceived their absence from work to have little impact on aspects such as employee morale, cost, production and the customer. This could possibly be due to ineffective communication in terms of the cost and other consequences of absenteeism in the organisation. Employees also felt that managers were effective in taking the necessary disciplinary action with regards to absenteeism-related transgressions, but that they were not diligent in the recording and communication of absence information, as well as comparing absenteeism information inter-departmentally. Absenteeism has proven to be globally pervasive, expensive and extremely disruptive to organisations. Managers and supervisors who employ the various absence monitoring and management strategies, could be more effective in improving employee attendance. Their efforts could be further enhanced if employees are made aware of the negative impact that their absence has on the morale of their fellow employees, the cost to the company, the customer, as well as the achievement of production targets and the quality of outputs.
- Full Text:
- Date Issued: 2008
- Authors: Paul, Gary William
- Date: 2008
- Subjects: Absenteeism (Labor) -- Management , Absenteeism (Labor) -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9383 , http://hdl.handle.net/10948/896 , Absenteeism (Labor) -- Management , Absenteeism (Labor) -- South Africa
- Description: The main research problem in this study centred around the assessment of the impact of an absenteeism monitoring and management system at Willard Batteries. The main research problem had five sub-problems which were addressed through the following actions: A literature study was conducted to identify the causes and impact of absenteeism in the workplace. The researcher also conducted interviews with the Human Resources Manager, line managers and employees at Willard Batteries to obtain their views of the absenteeism management strategies utilised, as well as the effects of absenteeism in their organisation. The insights gained from these interviews were incorporated into the questionnaire. The absenteeism figures of the organisation for the period 2005 to 2008 were analysed and compared against the internationally accepted absenteeism norm of three percent. An absence rate above three percent is considered as unacceptable and would imply that the current absenteeism management system is not effective. The theoretical study also entailed the reviewing of the legal framework within which absenteeism needs to be managed, as well as the literature that deals with strategies for the effective management of absenteeism. These strategies relate to the recording, calculation, analysis, benchmarking and practical management of absenteeism in the workplace. A survey questionnaire was developed to determine the perceptions of managers, supervisors and employees in relation to the impact of absenteeism on the company as well as the extent to which managers and supervisors were utilising selected absenteeism monitoring and management strategies within the company. The results from the empirical study revealed that management and supervisors were more aware of the impact of absenteeism on the organisation than their employees. It can therefore be concluded that employees perceived their absence from work to have little impact on aspects such as employee morale, cost, production and the customer. This could possibly be due to ineffective communication in terms of the cost and other consequences of absenteeism in the organisation. Employees also felt that managers were effective in taking the necessary disciplinary action with regards to absenteeism-related transgressions, but that they were not diligent in the recording and communication of absence information, as well as comparing absenteeism information inter-departmentally. Absenteeism has proven to be globally pervasive, expensive and extremely disruptive to organisations. Managers and supervisors who employ the various absence monitoring and management strategies, could be more effective in improving employee attendance. Their efforts could be further enhanced if employees are made aware of the negative impact that their absence has on the morale of their fellow employees, the cost to the company, the customer, as well as the achievement of production targets and the quality of outputs.
- Full Text:
- Date Issued: 2008
Access to educational resources: illustrative examples from rural schools in the Eastern Cape Province
- Authors: Hendricks, Monica
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7020 , http://hdl.handle.net/10962/d1007200
- Description: [Introduction] This chapter looks at the causes and effects of the widely varying degree of access to material resources across schools in the Eastern Cape. Starting with a broad overview of schools and classroom resources across the whole province, I go on to examine the Grahamstown education district. I discuss the inequalities in resource provision between groupings of schools in the district: comparing independent and state schools, and also examining disparities across schools in different localities within the government sector. The role of parents in providing resources for their children’s schooling is also discussed, as are the relationships among the various participants in education, such as non-governmental organisations, officials of the Department of Education, and teachers.
- Full Text:
- Date Issued: 2008
- Authors: Hendricks, Monica
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7020 , http://hdl.handle.net/10962/d1007200
- Description: [Introduction] This chapter looks at the causes and effects of the widely varying degree of access to material resources across schools in the Eastern Cape. Starting with a broad overview of schools and classroom resources across the whole province, I go on to examine the Grahamstown education district. I discuss the inequalities in resource provision between groupings of schools in the district: comparing independent and state schools, and also examining disparities across schools in different localities within the government sector. The role of parents in providing resources for their children’s schooling is also discussed, as are the relationships among the various participants in education, such as non-governmental organisations, officials of the Department of Education, and teachers.
- Full Text:
- Date Issued: 2008
Action research on leadership style, and relationships in an East London law firm
- Authors: Stoltz, Tania
- Date: 2008
- Subjects: Action research Law offices Leadership Law firms--South Africa--East London Law offices--South Africa--East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:798 , http://hdl.handle.net/10962/d1004592
- Description: "Good leadership springs from a genuine passion for the work and a genuine concern for other people. Great Leaders are people who love what they do and want to share that love with others. " (Daft, 2005:20). During an informal discussion with my husband Hugo Daniels, the leader in this Action Research Case Study, it became apparent that lawyers do not attend a single module or complete a single subject during their formal training at university to obtain their law degree that is related to the field of leadership and how to lead, inspire and motivate followers. The discussion centered on the problems the leader was experiencing in his East London law firm, problems he believed to be as a result of his lack of knowledge in the field of leadership. And so this research project began. It was obvious from the start that to intervene in the firm in order to bring about change would need the participation of everyone in the firm. The first step towards facilitating change would be to change the leadership style of the director of the firm. He would be required to gain knowledge in the field of leadership and the effects that different leadership styles have on followers. At the same time staff's perception of the current leadership style would have to be determined, as well as the desired style for their leader. The research process could then begin, based on the needs expressed by the staff and with participation from all levels in the firm. The case involved 27 members of staff made up of three heads of departments, twenty three general staff members and the leader. Data was gathered through formal interviews with the leader and the heads of departments, as well as from personal journals kept by two heads of departments and the leader. General staff members were first asked to complete The Productive Practice Survey (Hall 1987) to determine their perceptions of the current leadership style in the firm and what they thought they needed from their leader if the firm is to move forward. The Productive Practice Survey (Hall 1987) was not used with the intention of gathering quantitative data, but rather as a means of gathering information of staff's perception in general while ensuring anonymity, so as to facilitate a discussion during a feedback session. The Productive Survey's (Hall 1987) content and working is explained in further detail in Chapter 3 on page 44. Initially participants were skeptical of the process and used the survey as a medium to lash out against the firm and Hugo Daniels as a leader, leaving no room for suggestions for improvement, an "it is what it is" approach. During the feedback session general staff members became more open when they realized that change would benefit them, as changes would be suggested by them and implemented with their participation. They became less reluctant about change and provided valuable input during the session. All participants understood that this Participatory Action Research intervention was only the beginning of change in the firm and the sustainability of the changes rests on the firm as a whole, and working towards it would be a continuous process not ending with the Participatory Action Research process.
- Full Text:
- Date Issued: 2008
- Authors: Stoltz, Tania
- Date: 2008
- Subjects: Action research Law offices Leadership Law firms--South Africa--East London Law offices--South Africa--East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:798 , http://hdl.handle.net/10962/d1004592
- Description: "Good leadership springs from a genuine passion for the work and a genuine concern for other people. Great Leaders are people who love what they do and want to share that love with others. " (Daft, 2005:20). During an informal discussion with my husband Hugo Daniels, the leader in this Action Research Case Study, it became apparent that lawyers do not attend a single module or complete a single subject during their formal training at university to obtain their law degree that is related to the field of leadership and how to lead, inspire and motivate followers. The discussion centered on the problems the leader was experiencing in his East London law firm, problems he believed to be as a result of his lack of knowledge in the field of leadership. And so this research project began. It was obvious from the start that to intervene in the firm in order to bring about change would need the participation of everyone in the firm. The first step towards facilitating change would be to change the leadership style of the director of the firm. He would be required to gain knowledge in the field of leadership and the effects that different leadership styles have on followers. At the same time staff's perception of the current leadership style would have to be determined, as well as the desired style for their leader. The research process could then begin, based on the needs expressed by the staff and with participation from all levels in the firm. The case involved 27 members of staff made up of three heads of departments, twenty three general staff members and the leader. Data was gathered through formal interviews with the leader and the heads of departments, as well as from personal journals kept by two heads of departments and the leader. General staff members were first asked to complete The Productive Practice Survey (Hall 1987) to determine their perceptions of the current leadership style in the firm and what they thought they needed from their leader if the firm is to move forward. The Productive Practice Survey (Hall 1987) was not used with the intention of gathering quantitative data, but rather as a means of gathering information of staff's perception in general while ensuring anonymity, so as to facilitate a discussion during a feedback session. The Productive Survey's (Hall 1987) content and working is explained in further detail in Chapter 3 on page 44. Initially participants were skeptical of the process and used the survey as a medium to lash out against the firm and Hugo Daniels as a leader, leaving no room for suggestions for improvement, an "it is what it is" approach. During the feedback session general staff members became more open when they realized that change would benefit them, as changes would be suggested by them and implemented with their participation. They became less reluctant about change and provided valuable input during the session. All participants understood that this Participatory Action Research intervention was only the beginning of change in the firm and the sustainability of the changes rests on the firm as a whole, and working towards it would be a continuous process not ending with the Participatory Action Research process.
- Full Text:
- Date Issued: 2008
Adaptive user interfaces for mobile map-based visualisation
- Authors: Van Tonder, Bradley Paul
- Date: 2008
- Subjects: Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10470 , http://hdl.handle.net/10948/866 , Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Description: Mobile devices today frequently serve as platforms for the visualisation of map-based data. Despite the obvious advantages, mobile map-based visualisation (MMV) systems are often difficult to design and use. Limited screen space, resource constraints and awkward interaction mechanisms are among the many problems with which designers and users have to contend. Adaptive user interfaces (AUIs), which adapt to the individual user, represent a possible means of addressing the problems of MMV. Adaptive MMV systems are, however, generally designed in an ad-hoc fashion, making the benefits achieved difficult to replicate. In addition, existing models for adaptive MMV systems are either conceptual in nature or only address a subset of the possible input variables and adaptation effects. The primary objective of this research was to develop and evaluate an adaptive MMV system using a model-based approach. The Proteus Model was proposed to support the design of MMV systems which adapt in terms of information, visualisation and user interface in response to the user‟s behaviour, tasks and context. The Proteus Model describes the architectural, interface, data and algorithm design of an adaptive MMV system. A prototype adaptive MMV system, called MediaMaps, was designed and implemented based on the Proteus Model. MediaMaps allows users to capture, location-tag, organise and visualise multimedia on their mobile phones. Information adaptation is performed through the use of an algorithm to assist users in sorting media items into collections based on time and location. Visualisation adaptation is performed by adapting various parameters of the map-based visualisations according to user preferences. Interface adaptation is performed through the use of adaptive lists. An international field study of MediaMaps was conducted in which participants were required to use MediaMaps on their personal mobile phones for a period of three weeks. The results of the field study showed that high levels of accuracy were achieved by both the information and interface adaptations. High levels of user satisfaction were reported, with participants rating all three forms of adaptation as highly useful. The successful implementation of MediaMaps provides practical evidence that the model-based design of adaptive MMV systems is feasible. The positive results of the field study clearly show that the adaptations implemented were highly accurate and that participants found these adaptations to be useful, usable and easy to understand. This research thus provides empirical evidence that the use of AUIs can provide significant benefits for the visualisation of map-based information on mobile devices.
- Full Text:
- Date Issued: 2008
- Authors: Van Tonder, Bradley Paul
- Date: 2008
- Subjects: Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10470 , http://hdl.handle.net/10948/866 , Cartography , Maps -- Design , Digital mapping , Geographic information systems , User interfaces (Computer systems) -- Design
- Description: Mobile devices today frequently serve as platforms for the visualisation of map-based data. Despite the obvious advantages, mobile map-based visualisation (MMV) systems are often difficult to design and use. Limited screen space, resource constraints and awkward interaction mechanisms are among the many problems with which designers and users have to contend. Adaptive user interfaces (AUIs), which adapt to the individual user, represent a possible means of addressing the problems of MMV. Adaptive MMV systems are, however, generally designed in an ad-hoc fashion, making the benefits achieved difficult to replicate. In addition, existing models for adaptive MMV systems are either conceptual in nature or only address a subset of the possible input variables and adaptation effects. The primary objective of this research was to develop and evaluate an adaptive MMV system using a model-based approach. The Proteus Model was proposed to support the design of MMV systems which adapt in terms of information, visualisation and user interface in response to the user‟s behaviour, tasks and context. The Proteus Model describes the architectural, interface, data and algorithm design of an adaptive MMV system. A prototype adaptive MMV system, called MediaMaps, was designed and implemented based on the Proteus Model. MediaMaps allows users to capture, location-tag, organise and visualise multimedia on their mobile phones. Information adaptation is performed through the use of an algorithm to assist users in sorting media items into collections based on time and location. Visualisation adaptation is performed by adapting various parameters of the map-based visualisations according to user preferences. Interface adaptation is performed through the use of adaptive lists. An international field study of MediaMaps was conducted in which participants were required to use MediaMaps on their personal mobile phones for a period of three weeks. The results of the field study showed that high levels of accuracy were achieved by both the information and interface adaptations. High levels of user satisfaction were reported, with participants rating all three forms of adaptation as highly useful. The successful implementation of MediaMaps provides practical evidence that the model-based design of adaptive MMV systems is feasible. The positive results of the field study clearly show that the adaptations implemented were highly accurate and that participants found these adaptations to be useful, usable and easy to understand. This research thus provides empirical evidence that the use of AUIs can provide significant benefits for the visualisation of map-based information on mobile devices.
- Full Text:
- Date Issued: 2008
Addressing the barriers to learning in the Helenvale area of Port Elizabeth : a school management perspective
- Authors: Van Heerden, Edward Thomas
- Date: 2008
- Subjects: Students -- South Africa -- Port Alizabeth -- Social conditions , Children with social disabilities -- Education -- South Africa -- Port Elizabeth , Learning disabilities -- South Africa , School management and organization -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9544 , http://hdl.handle.net/10948/676 , Students -- South Africa -- Port Alizabeth -- Social conditions , Children with social disabilities -- Education -- South Africa -- Port Elizabeth , Learning disabilities -- South Africa , School management and organization -- South Africa -- Port Elizabeth
- Description: Educational underachievement is a big problem in all schools, but it is especially prevalent in poverty stricken areas. The main objective of this research was to investigate the possible reasons for, consequences of and strategies to address the problem of educational underachievement in poverty stricken areas. The research conducted was based on the interpretive paradigm and a qualitative approach was used to gather data. A case study approach was used as a research design. The data collection methods were questionnaires, interviews and observations. The study found that the home conditions, individual factors, family and psychological factors are the main reasons for academic underachievement. The main consequences of academic underachievement were found to be unemployment, behavioural problems, a negative self-perception, high failure rates, high drop-out rates and teenage pregnancies. The main strategies to address the problem which the study revealed are: teachers familiarising themselves with the home conditions of the child, addressing the problem of overcrowding, and poverty, involving the parents in the education of their children, enhancing the self-esteem of learners, improving teaching, implementing cooperative learning and providing study facilities for these learners at the school after hours.
- Full Text:
- Date Issued: 2008
- Authors: Van Heerden, Edward Thomas
- Date: 2008
- Subjects: Students -- South Africa -- Port Alizabeth -- Social conditions , Children with social disabilities -- Education -- South Africa -- Port Elizabeth , Learning disabilities -- South Africa , School management and organization -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9544 , http://hdl.handle.net/10948/676 , Students -- South Africa -- Port Alizabeth -- Social conditions , Children with social disabilities -- Education -- South Africa -- Port Elizabeth , Learning disabilities -- South Africa , School management and organization -- South Africa -- Port Elizabeth
- Description: Educational underachievement is a big problem in all schools, but it is especially prevalent in poverty stricken areas. The main objective of this research was to investigate the possible reasons for, consequences of and strategies to address the problem of educational underachievement in poverty stricken areas. The research conducted was based on the interpretive paradigm and a qualitative approach was used to gather data. A case study approach was used as a research design. The data collection methods were questionnaires, interviews and observations. The study found that the home conditions, individual factors, family and psychological factors are the main reasons for academic underachievement. The main consequences of academic underachievement were found to be unemployment, behavioural problems, a negative self-perception, high failure rates, high drop-out rates and teenage pregnancies. The main strategies to address the problem which the study revealed are: teachers familiarising themselves with the home conditions of the child, addressing the problem of overcrowding, and poverty, involving the parents in the education of their children, enhancing the self-esteem of learners, improving teaching, implementing cooperative learning and providing study facilities for these learners at the school after hours.
- Full Text:
- Date Issued: 2008
Adoption of business information systems in an automotive manufacturing environment: a case study
- Authors: Dyer, Shirley
- Date: 2008
- Subjects: Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9772 , http://hdl.handle.net/10948/892 , Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Description: Dorbyl Automotive Technologies (DAT) is a manufacturing company that supplies parts and components to the local and international motor vehicle market. The automotive components’ market is very competitive and customers require more from the industry to stay competitive. Customers require full integration throughout the supply chain. DAT and its Information Systems Department have ensured that the necessary business information systems are available to assist the company in staying competitive. One problem, though, is that the users of these systems are not using and adopting the technologies available. This research examines the reasons for this by making use of a technology acceptance model called the UNIFIED THEORY OF ACCEPTANCE AND USE OF TECHNOLOGY (UTAUT), which is an integrated model based on eight different available acceptance models. The aim is to understand which factors influence the use of systems. The research also proposes a way forward by suggesting a model to assist DAT in new system implementations as well as correcting the current situation. The only way DAT will stay competitive is by ensuring that the company becomes lean. Customers demand this as more and more are moving to just-in-time delivery. This implies that the suppliers must react to changes real-time. The use of business information systems will become the main focus area to react to changes quickly and correctly. Effective and accurate systems depend on users making good use of these systems. Remaining competitive will depend on how effectively Information and Communication Technologies (ICT) are used.
- Full Text:
- Date Issued: 2008
- Authors: Dyer, Shirley
- Date: 2008
- Subjects: Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9772 , http://hdl.handle.net/10948/892 , Management information systems , Technology -- Information services , Information resources management , Business -- Data processing
- Description: Dorbyl Automotive Technologies (DAT) is a manufacturing company that supplies parts and components to the local and international motor vehicle market. The automotive components’ market is very competitive and customers require more from the industry to stay competitive. Customers require full integration throughout the supply chain. DAT and its Information Systems Department have ensured that the necessary business information systems are available to assist the company in staying competitive. One problem, though, is that the users of these systems are not using and adopting the technologies available. This research examines the reasons for this by making use of a technology acceptance model called the UNIFIED THEORY OF ACCEPTANCE AND USE OF TECHNOLOGY (UTAUT), which is an integrated model based on eight different available acceptance models. The aim is to understand which factors influence the use of systems. The research also proposes a way forward by suggesting a model to assist DAT in new system implementations as well as correcting the current situation. The only way DAT will stay competitive is by ensuring that the company becomes lean. Customers demand this as more and more are moving to just-in-time delivery. This implies that the suppliers must react to changes real-time. The use of business information systems will become the main focus area to react to changes quickly and correctly. Effective and accurate systems depend on users making good use of these systems. Remaining competitive will depend on how effectively Information and Communication Technologies (ICT) are used.
- Full Text:
- Date Issued: 2008
Adsorption of 4-nitrophenol onto Amberlite® IRA-900 modified with metallophthalocyanines
- Marais, Eloïse, Nyokong, Tebello
- Authors: Marais, Eloïse , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268576 , vital:54211 , xlink:href="https://doi.org/10.1016/j.jhazmat.2007.06.096"
- Description: The adsorption of 4-nitrophenol using commercially available Amberlite® IRA-900 modified with metal phthalocyanines (MPc) was investigated. The metallophthalocyanines immobilised onto the surface of Amberlite® IRA-900 include Fe (FePcS4), Co (CoPcS4) and Ni (NiPcS4) tetrasulphophthalocyanines, and differently sulphonated phthalocyanine mixtures of Fe (FePcSmix), Co (CoPcSmix) and Ni (NiPcSmix). Adsorption rates were fastest for the modified adsorbents at a loading of 1 × 10−3 g MPc/g Amberlite, at pH 9. The highest amount of 4-NP removal was obtained on FePcSmix modified Amberlite® IRA-900 with Qt = 42.9 mmol g−1 and adsorption efficiency of 86%. The recovery efficiency of 4-NP within 150 min was 76%. Using the Langmuir–Hinshelwood kinetic model, the complexes showed an order of 4-nitrophenol adsorption to be as follows: CoPcSmix > NiPcS4 > NiPcSmix > FePcS4 > FePcSmix > CoPcS4. The MPc modified Amberlite® IRA-900 was used repeatedly, following removal of 4-NP by nitric acid, without any significant loss of activity.
- Full Text:
- Date Issued: 2008
- Authors: Marais, Eloïse , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268576 , vital:54211 , xlink:href="https://doi.org/10.1016/j.jhazmat.2007.06.096"
- Description: The adsorption of 4-nitrophenol using commercially available Amberlite® IRA-900 modified with metal phthalocyanines (MPc) was investigated. The metallophthalocyanines immobilised onto the surface of Amberlite® IRA-900 include Fe (FePcS4), Co (CoPcS4) and Ni (NiPcS4) tetrasulphophthalocyanines, and differently sulphonated phthalocyanine mixtures of Fe (FePcSmix), Co (CoPcSmix) and Ni (NiPcSmix). Adsorption rates were fastest for the modified adsorbents at a loading of 1 × 10−3 g MPc/g Amberlite, at pH 9. The highest amount of 4-NP removal was obtained on FePcSmix modified Amberlite® IRA-900 with Qt = 42.9 mmol g−1 and adsorption efficiency of 86%. The recovery efficiency of 4-NP within 150 min was 76%. Using the Langmuir–Hinshelwood kinetic model, the complexes showed an order of 4-nitrophenol adsorption to be as follows: CoPcSmix > NiPcS4 > NiPcSmix > FePcS4 > FePcSmix > CoPcS4. The MPc modified Amberlite® IRA-900 was used repeatedly, following removal of 4-NP by nitric acid, without any significant loss of activity.
- Full Text:
- Date Issued: 2008
Agathis bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus
- Authors: Gendall, Kierryn Leigh
- Date: 2008
- Subjects: Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5635 , http://hdl.handle.net/10962/d1005317 , Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Description: The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is one of the major pests of citrus in South Africa, the others being mealybug, Mediterranean fruit fly, bollworm and some mites. Due to problems such as the expense of pesticides, insects evolving pesticide resistance (Hogsette 1999), chemical residue on the skin of export fruit and the negative impact of pesticides on the environment, it became necessary to find alternative methods for pest control (Viggiani 2000). Agathis bishopi (Nixon) (Hymenoptera: Braconidae), a larval parasitoid of false codling moth known only from the Sundays River Valley area (Sishuba 2003), offers a means of control for the pest. A total of 11 389 navel oranges were collected from various orchards in the Addo/Kirkwood area, and false codling moth larvae infested 36.09% of the fruit. A single parasitoid species, A. bishopi, was reared from these larvae. In 2006 the highest parasitism rate, 11.43%, was recorded in May and in 2007, the highest parasitism rate, 13.27%, was in April. Agathis bishopi parasitizes larvae in instars 2 and 3, possibly due to the accessibility of these younger instars to the female parasitoid and possibly due to the length of the life cycle of this koinobiont. Second instar hosts yielded the highest number of parasitoids, and there was no emergence of parasitoids from fifth instar larvae. Females of A. bishopi live for 18.5 days (n = 20; S.E. = 3.1) and males for 8.25 days (n = 20; S.E. = 1.23). Females produce an average of 23 offspring in a lifetime, while female false codling moths produce about 800 eggs each. A high number of parasitoids will be required per hectare to reduce the population of false codling moth. Captive rearing of A. bishopi proved difficult due to viral and fungal contamination. Agathis bishopi has potential for use in an integrated pest management programme once the hurdle of mass-rearing has been overcome.
- Full Text:
- Date Issued: 2008
- Authors: Gendall, Kierryn Leigh
- Date: 2008
- Subjects: Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5635 , http://hdl.handle.net/10962/d1005317 , Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Description: The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is one of the major pests of citrus in South Africa, the others being mealybug, Mediterranean fruit fly, bollworm and some mites. Due to problems such as the expense of pesticides, insects evolving pesticide resistance (Hogsette 1999), chemical residue on the skin of export fruit and the negative impact of pesticides on the environment, it became necessary to find alternative methods for pest control (Viggiani 2000). Agathis bishopi (Nixon) (Hymenoptera: Braconidae), a larval parasitoid of false codling moth known only from the Sundays River Valley area (Sishuba 2003), offers a means of control for the pest. A total of 11 389 navel oranges were collected from various orchards in the Addo/Kirkwood area, and false codling moth larvae infested 36.09% of the fruit. A single parasitoid species, A. bishopi, was reared from these larvae. In 2006 the highest parasitism rate, 11.43%, was recorded in May and in 2007, the highest parasitism rate, 13.27%, was in April. Agathis bishopi parasitizes larvae in instars 2 and 3, possibly due to the accessibility of these younger instars to the female parasitoid and possibly due to the length of the life cycle of this koinobiont. Second instar hosts yielded the highest number of parasitoids, and there was no emergence of parasitoids from fifth instar larvae. Females of A. bishopi live for 18.5 days (n = 20; S.E. = 3.1) and males for 8.25 days (n = 20; S.E. = 1.23). Females produce an average of 23 offspring in a lifetime, while female false codling moths produce about 800 eggs each. A high number of parasitoids will be required per hectare to reduce the population of false codling moth. Captive rearing of A. bishopi proved difficult due to viral and fungal contamination. Agathis bishopi has potential for use in an integrated pest management programme once the hurdle of mass-rearing has been overcome.
- Full Text:
- Date Issued: 2008