A geopolitical analysis of long term internet network telescope traffic
- Irwin, Barry V W, Pilkington, Nik, Barnett, Richard J, Friedman, Blake
- Authors: Irwin, Barry V W , Pilkington, Nik , Barnett, Richard J , Friedman, Blake
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428142 , vital:72489 , https://www.researchgate.net/profile/Barry-Ir-win/publication/228848896_A_geopolitical_analysis_of_long_term_internet_network_telescope_traffic/links/53e9c5190cf2fb1b9b672aee/A-geopolitical-analysis-of-long-term-internet-network-telescope-traffic.pdf
- Description: This paper presents results form the analysis of twelve months of net-work telescope traffic spanning 2005 and 2006, and details some of the tools developed. The most significant results of the analysis are high-lighted. In particular the bulk of traffic analysed had its source in the China from a volume perspective, but Eastern United States, and North Western Europe were shown to be primary sources when the number of unique hosts were considered. Traffic from African states (South Af-rica in particular) was also found to be surprisingly high. This unex-pected result may be due to the network locality preference of many automated agents. Both statistical and graphical analysis are present-ed. It is found that a country with a high penetration of broadband con-nectivity is likley to feature highly in Network telescope traffic, as are networks logically close to the telescope network.
- Full Text:
- Date Issued: 2007
- Authors: Irwin, Barry V W , Pilkington, Nik , Barnett, Richard J , Friedman, Blake
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428142 , vital:72489 , https://www.researchgate.net/profile/Barry-Ir-win/publication/228848896_A_geopolitical_analysis_of_long_term_internet_network_telescope_traffic/links/53e9c5190cf2fb1b9b672aee/A-geopolitical-analysis-of-long-term-internet-network-telescope-traffic.pdf
- Description: This paper presents results form the analysis of twelve months of net-work telescope traffic spanning 2005 and 2006, and details some of the tools developed. The most significant results of the analysis are high-lighted. In particular the bulk of traffic analysed had its source in the China from a volume perspective, but Eastern United States, and North Western Europe were shown to be primary sources when the number of unique hosts were considered. Traffic from African states (South Af-rica in particular) was also found to be surprisingly high. This unex-pected result may be due to the network locality preference of many automated agents. Both statistical and graphical analysis are present-ed. It is found that a country with a high penetration of broadband con-nectivity is likley to feature highly in Network telescope traffic, as are networks logically close to the telescope network.
- Full Text:
- Date Issued: 2007
A literature review of the factors impacting on objectivity in news journalism
- Authors: Yat, Gai Thurbil
- Date: 2007
- Subjects: Journalism -- Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8376 , http://hdl.handle.net/10948/872 , Journalism -- Objectivity
- Description: Objectivity has been the most debatable issue in the history of journalism and there are, therefore, many different ways of looking at it. Media academics such as Gans (1979) and Tuchman (2000) refer to objectivity as an examination of contents of collected news materials. Glasser (1992) points out that objectivity is a balance of beliefs restructured by a journalist and presented against independent thinking. It is difficult to test the objectivity of journalists because it is the credibility of facts gathered by a journalist that lies at the heart of objectivity. In Glasser’s opinion, the “notion” of objectivity is flawed against the newsman’s mandate of reporting responsibly. Objectivity is therefore professional principle through which journalists write news responsibly and present it to their audience as a final product (Glasser, 1992). This study will discuss objectivity also in reference to the problems that journalists face when they cover news stories. It may be that journalists may have problems searching for stories not because they do not embrace journalistic principles of fairness, clarity and objectivity, but because of the way in which facts are presented to them by news sources (Fred and Wellman, 2003). There have been some cases whereby media audiences have wrongly been made to think that journalists are biased in their coverage. 2 For example, the 2003 Iraq invasion by US-led forces, where correspondents were made to practice embedded journalism is a good example of how circumstances could force a journalist to succumb to soldiers’ demands of keeping their war causalities away from their cameras. It is worth noting, however, that being biased for a journalist in such a war situation could be circumstantial in the sense that an American journalist covering a story in Iraqi’s capital, Baghdad, would be regarded as a spy by Iraqi’s troops. Likewise, an Iraqi journalist chasing stories in the coalition force’s camps in Iraqi’s capital would be treated as a traitor by the Iraqi people (Fred and Wellman, 2003:21). There is no doubt that in the situations described above objectivity in journalism can be affected. It is against such background that this study will investigate the factors that affect objectivity in the print media. It is vitally important to bear in mind that bias should not be confused with editorial columns that express the opinion of publishers, or editors for that matter. The question of objectivity goes back to the gatekeepers, whereby the editors as gatekeepers decide what to publish and what news stories reporters should gather. So the question of objectivity in the news can be dealt with by the editors who decide which story should be run by their respective newspapers. According to Fred and Wellman (2003:32), editors and media owners are the decision makers in the field of journalism.
- Full Text:
- Date Issued: 2007
- Authors: Yat, Gai Thurbil
- Date: 2007
- Subjects: Journalism -- Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8376 , http://hdl.handle.net/10948/872 , Journalism -- Objectivity
- Description: Objectivity has been the most debatable issue in the history of journalism and there are, therefore, many different ways of looking at it. Media academics such as Gans (1979) and Tuchman (2000) refer to objectivity as an examination of contents of collected news materials. Glasser (1992) points out that objectivity is a balance of beliefs restructured by a journalist and presented against independent thinking. It is difficult to test the objectivity of journalists because it is the credibility of facts gathered by a journalist that lies at the heart of objectivity. In Glasser’s opinion, the “notion” of objectivity is flawed against the newsman’s mandate of reporting responsibly. Objectivity is therefore professional principle through which journalists write news responsibly and present it to their audience as a final product (Glasser, 1992). This study will discuss objectivity also in reference to the problems that journalists face when they cover news stories. It may be that journalists may have problems searching for stories not because they do not embrace journalistic principles of fairness, clarity and objectivity, but because of the way in which facts are presented to them by news sources (Fred and Wellman, 2003). There have been some cases whereby media audiences have wrongly been made to think that journalists are biased in their coverage. 2 For example, the 2003 Iraq invasion by US-led forces, where correspondents were made to practice embedded journalism is a good example of how circumstances could force a journalist to succumb to soldiers’ demands of keeping their war causalities away from their cameras. It is worth noting, however, that being biased for a journalist in such a war situation could be circumstantial in the sense that an American journalist covering a story in Iraqi’s capital, Baghdad, would be regarded as a spy by Iraqi’s troops. Likewise, an Iraqi journalist chasing stories in the coalition force’s camps in Iraqi’s capital would be treated as a traitor by the Iraqi people (Fred and Wellman, 2003:21). There is no doubt that in the situations described above objectivity in journalism can be affected. It is against such background that this study will investigate the factors that affect objectivity in the print media. It is vitally important to bear in mind that bias should not be confused with editorial columns that express the opinion of publishers, or editors for that matter. The question of objectivity goes back to the gatekeepers, whereby the editors as gatekeepers decide what to publish and what news stories reporters should gather. So the question of objectivity in the news can be dealt with by the editors who decide which story should be run by their respective newspapers. According to Fred and Wellman (2003:32), editors and media owners are the decision makers in the field of journalism.
- Full Text:
- Date Issued: 2007
A methodology for measuring and monitoring IT risk
- Authors: Tansley, Natalie Vanessa
- Date: 2007
- Subjects: Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9781 , http://hdl.handle.net/10948/772 , Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Description: The primary objective of the research is to develop a methodology for monitoring and measuring IT risks, strictly focusing on internal controls. The research delivers a methodology whereby an organization can measure its system of internal controls, providing assurance that the risks are at an acceptable level. To achieve the primary objective a number of secondary objectives were addressed: What are the drivers forcing organizations to better corporate governance in managing risk? What is IT risk management, specifically focusing on operational risk. What is internal control and specifically focusing on COSO’s internal control process. Investigation of measurement methods, such as, Balance Scorecards, Critical Success Factors, Maturity Models, Key Performance Indicators and Key Goal Indicators. Investigation of various frameworks such as CobiT, COSO and ISO 17799, ITIL and BS 7799 as to how they manage IT risk relating to internal control.
- Full Text:
- Date Issued: 2007
- Authors: Tansley, Natalie Vanessa
- Date: 2007
- Subjects: Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9781 , http://hdl.handle.net/10948/772 , Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Description: The primary objective of the research is to develop a methodology for monitoring and measuring IT risks, strictly focusing on internal controls. The research delivers a methodology whereby an organization can measure its system of internal controls, providing assurance that the risks are at an acceptable level. To achieve the primary objective a number of secondary objectives were addressed: What are the drivers forcing organizations to better corporate governance in managing risk? What is IT risk management, specifically focusing on operational risk. What is internal control and specifically focusing on COSO’s internal control process. Investigation of measurement methods, such as, Balance Scorecards, Critical Success Factors, Maturity Models, Key Performance Indicators and Key Goal Indicators. Investigation of various frameworks such as CobiT, COSO and ISO 17799, ITIL and BS 7799 as to how they manage IT risk relating to internal control.
- Full Text:
- Date Issued: 2007
A model for a context aware machine-based personal memory manager and its implementation using a visual programming environment
- Authors: Tsegaye, Melekam Asrat
- Date: 2007
- Subjects: Visual programming (Computer science) Memory management (Computer science) Memory -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4640 , http://hdl.handle.net/10962/d1006563
- Description: Memory is a part of cognition. It is essential for an individual to function normally in society. It encompasses an individual's lifetime experience, thus defining his identity. This thesis develops the concept of a machine-based personal memory manager which captures and manages an individual's day-to-day external memories. Rather than accumulating large amounts of data which has to be mined for useful memories, the machine-based memory manager automatically organizes memories as they are captured to enable their quick retrieval and use. The main functions of the machine-based memory manager envisioned in this thesis are the support and the augmentation of an individual's biological memory system. In the thesis, a model for a machine-based memory manager is developed. A visual programming environment, which can be used to build context aware applications as well as a proof-of-concept machine-based memory manager, is conceptualized and implemented. An experimental machine-based memory manager is implemented and evaluated. The model describes a machine-based memory manager which manages an individual's external memories by context. It addresses the management of external memories which accumulate over long periods of time by proposing a context aware file system which automatically organizes external memories by context. It describes how personal memory management can be facilitated by machine using six entities (life streams, memory producers, memory consumers, a memory manager, memory fragments and context descriptors) and the processes in which these entities participate (memory capture, memory encoding and decoding, memory decoding and retrieval). The visual programming environment represents a development tool which contains facilities that support context aware application programming. For example, it provides facilities which enable the definition and use of virtual sensors. It enables rapid programming with a focus on component re-use and dynamic composition of applications through a visual interface. The experimental machine-based memory manager serves as an example implementation of the machine-based memory manager which is described by the model developed in this thesis. The hardware used in its implementation consists of widely available components such as a camera, microphone and sub-notebook computer which are assembled in the form of a wearable computer. The software is constructed using the visual programming environment developed in this thesis. It contains multiple sensor drivers, context interpreters, a context aware file system as well as memory retrieval and presentation interfaces. The evaluation of the machine-based memory manager shows that it is possible to create a machine which monitors the states of an individual and his environment, and manages his external memories, thus supporting and augmenting his biological memory.
- Full Text:
- Date Issued: 2007
- Authors: Tsegaye, Melekam Asrat
- Date: 2007
- Subjects: Visual programming (Computer science) Memory management (Computer science) Memory -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4640 , http://hdl.handle.net/10962/d1006563
- Description: Memory is a part of cognition. It is essential for an individual to function normally in society. It encompasses an individual's lifetime experience, thus defining his identity. This thesis develops the concept of a machine-based personal memory manager which captures and manages an individual's day-to-day external memories. Rather than accumulating large amounts of data which has to be mined for useful memories, the machine-based memory manager automatically organizes memories as they are captured to enable their quick retrieval and use. The main functions of the machine-based memory manager envisioned in this thesis are the support and the augmentation of an individual's biological memory system. In the thesis, a model for a machine-based memory manager is developed. A visual programming environment, which can be used to build context aware applications as well as a proof-of-concept machine-based memory manager, is conceptualized and implemented. An experimental machine-based memory manager is implemented and evaluated. The model describes a machine-based memory manager which manages an individual's external memories by context. It addresses the management of external memories which accumulate over long periods of time by proposing a context aware file system which automatically organizes external memories by context. It describes how personal memory management can be facilitated by machine using six entities (life streams, memory producers, memory consumers, a memory manager, memory fragments and context descriptors) and the processes in which these entities participate (memory capture, memory encoding and decoding, memory decoding and retrieval). The visual programming environment represents a development tool which contains facilities that support context aware application programming. For example, it provides facilities which enable the definition and use of virtual sensors. It enables rapid programming with a focus on component re-use and dynamic composition of applications through a visual interface. The experimental machine-based memory manager serves as an example implementation of the machine-based memory manager which is described by the model developed in this thesis. The hardware used in its implementation consists of widely available components such as a camera, microphone and sub-notebook computer which are assembled in the form of a wearable computer. The software is constructed using the visual programming environment developed in this thesis. It contains multiple sensor drivers, context interpreters, a context aware file system as well as memory retrieval and presentation interfaces. The evaluation of the machine-based memory manager shows that it is possible to create a machine which monitors the states of an individual and his environment, and manages his external memories, thus supporting and augmenting his biological memory.
- Full Text:
- Date Issued: 2007
A model for adaptive multimodal mobile notification
- Authors: Brander, William
- Date: 2007
- Subjects: Mobile computing , Context-aware computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10473 , http://hdl.handle.net/10948/699 , Mobile computing , Context-aware computing
- Description: Information is useless unless it is used whilst still applicable. Having a system that notifies the user of important messages using the most appropriate medium and device will benefit users that rely on time critical information. There are several existing systems and models for mobile notification as well as for adaptive mobile notification using context awareness. Current models and systems are typically designed for a specific set of mobile devices, modes and services. Communication however, can take place in many different modes, across many different devices and may originate from many different sources. The aim of this research was to develop a model for adaptive mobile notification using context awareness. An extensive literature study was performed into existing models for adaptive mobile notification systems using context awareness. The literature study identified several potential models but no way to evaluate and compare the models. A set of requirements to evaluate these models was developed and the models were evaluated against these criteria. The model satisfying the most requirements was adapted so as to satisfy the remaining criteria. The proposed model is extensible in terms of the modes, devices and notification sources supported. The proposed model determines the importance of a message, the appropriate device and mode (or modes) of communication based on the user‘s context, and alerts the user of the message using these modes. A prototype was developed as a proof-of-concept of the proposed model and evaluated by conducting an extensive field study. The field study highlighted the fact that most users did not choose the most suitable mode for the context during their initial subscription to the service. The field study also showed that more research needs to be done on an appropriate filtering mechanism for notifications. Users found that the notifications became intrusive and less useful the longer they used them.
- Full Text:
- Date Issued: 2007
- Authors: Brander, William
- Date: 2007
- Subjects: Mobile computing , Context-aware computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10473 , http://hdl.handle.net/10948/699 , Mobile computing , Context-aware computing
- Description: Information is useless unless it is used whilst still applicable. Having a system that notifies the user of important messages using the most appropriate medium and device will benefit users that rely on time critical information. There are several existing systems and models for mobile notification as well as for adaptive mobile notification using context awareness. Current models and systems are typically designed for a specific set of mobile devices, modes and services. Communication however, can take place in many different modes, across many different devices and may originate from many different sources. The aim of this research was to develop a model for adaptive mobile notification using context awareness. An extensive literature study was performed into existing models for adaptive mobile notification systems using context awareness. The literature study identified several potential models but no way to evaluate and compare the models. A set of requirements to evaluate these models was developed and the models were evaluated against these criteria. The model satisfying the most requirements was adapted so as to satisfy the remaining criteria. The proposed model is extensible in terms of the modes, devices and notification sources supported. The proposed model determines the importance of a message, the appropriate device and mode (or modes) of communication based on the user‘s context, and alerts the user of the message using these modes. A prototype was developed as a proof-of-concept of the proposed model and evaluated by conducting an extensive field study. The field study highlighted the fact that most users did not choose the most suitable mode for the context during their initial subscription to the service. The field study also showed that more research needs to be done on an appropriate filtering mechanism for notifications. Users found that the notifications became intrusive and less useful the longer they used them.
- Full Text:
- Date Issued: 2007
A model for integrating information security into the software development life cycle
- Authors: Futcher, Lynn Ann
- Date: 2007
- Subjects: Computer security , Software maintenance
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9737 , http://hdl.handle.net/10948/506 , Computer security , Software maintenance
- Description: It is within highly integrated technology environments that information security is becoming a focal point for designing, developing and deploying software applications. Ensuring a high level of trust in the security and quality of these applications is crucial to their ultimate success. Therefore, information security has become a core requirement for software applications, driven by the need to protect critical assets and the need to build and preserve widespread trust in computing. However, a common weakness that is inherent in the traditional software development methodologies is the lack of attention given to the security aspects of software development. Most of these methodologies do not explicitly include a standardised method for incorporating information security into their life cycles. Meaningful security can be achieved when information security issues are considered as part of a routine development process, and security safeguards are integrated into the software application throughout its life cycle. This, in turn, will lead to users being more confident to use software applications, and to entrust today's computer systems with their personal information. To build better or more secure software, an improved software development process is required. Security of a software application must be based on the risk associated with the application. In order to understand this risk, the relevant information assets need to be identified together with their threats and vulnerabilities. Therefore, security considerations provide input into every phase of the Software Development Life Cycle (SDLC), from requirements gathering to design, implementation, testing and deployment. This research project presents a Secure Software Development Model (SecSDM) for incorporating information security into all phases of the SDLC, from requirements gathering to systems maintenance. The SecSDM is based on many of the recommendations provided by relevant international standards and best practices, for example, the ISO 7498-2 (1989) standard which addresses the underlying security services and mechanisms that form an integral part of the model.
- Full Text:
- Date Issued: 2007
- Authors: Futcher, Lynn Ann
- Date: 2007
- Subjects: Computer security , Software maintenance
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9737 , http://hdl.handle.net/10948/506 , Computer security , Software maintenance
- Description: It is within highly integrated technology environments that information security is becoming a focal point for designing, developing and deploying software applications. Ensuring a high level of trust in the security and quality of these applications is crucial to their ultimate success. Therefore, information security has become a core requirement for software applications, driven by the need to protect critical assets and the need to build and preserve widespread trust in computing. However, a common weakness that is inherent in the traditional software development methodologies is the lack of attention given to the security aspects of software development. Most of these methodologies do not explicitly include a standardised method for incorporating information security into their life cycles. Meaningful security can be achieved when information security issues are considered as part of a routine development process, and security safeguards are integrated into the software application throughout its life cycle. This, in turn, will lead to users being more confident to use software applications, and to entrust today's computer systems with their personal information. To build better or more secure software, an improved software development process is required. Security of a software application must be based on the risk associated with the application. In order to understand this risk, the relevant information assets need to be identified together with their threats and vulnerabilities. Therefore, security considerations provide input into every phase of the Software Development Life Cycle (SDLC), from requirements gathering to design, implementation, testing and deployment. This research project presents a Secure Software Development Model (SecSDM) for incorporating information security into all phases of the SDLC, from requirements gathering to systems maintenance. The SecSDM is based on many of the recommendations provided by relevant international standards and best practices, for example, the ISO 7498-2 (1989) standard which addresses the underlying security services and mechanisms that form an integral part of the model.
- Full Text:
- Date Issued: 2007
A multiple case study of parent involvement with grade 8 learners of mathematics
- Authors: Govender, Vasuthavan Gopaul
- Date: 2007
- Subjects: Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9556 , http://hdl.handle.net/10948/511 , http://hdl.handle.net/10948/d1011913 , Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
- Description: The learning of mathematics is a worldwide concern. International studies over the last decade place South African learners amongst the lowest achievers. Although various initiatives have been tried there does not seem to be any improvement. In the USA and UK initiatives include the involvement of parents and these have been implemented with great success. One of the parent involvement programmes from the USA, the Family Maths Programme has been in South Africa since 1996. This programme has been successful in South Africa but is confined to parents of grades 4-7 children. However, there is no programme for parents of high school learners. As grade 8 is usually the first high school year in South Africa, this study focuses on parents of grade 8 children and their involvement in their children’s mathematics learning. It consists of an initial survey of grade 8 parents’ (from an urban school) mathematical backgrounds and experiences and their involvement in their children’s education. Using key points from the survey and elements from the literature review and other sources, the researcher designed a parent assistance programme for mathematics which was conducted with three groups of parents of grade 8 children from the same high school. Each group of parents was exclusive and the same set of procedures was applied to each group, making this study a qualitative multiple case study, within the interpretive research paradigm. The parent-assistance programme consists of a parents’ workshop and completion of journals over a 7-week period. Parents documented their interactions with their children in structured journals, a process known as participant journaling. After this journaling period, parents and children were surveyed on this interaction by means of follow-up questionnaires. This was followed later in interviews with the parents and mathematics teachers, separately. After the completion of all three case studies parents and children participated in focus group discussions to discuss and share experiences of the programme. The interrogation of the data, on two levels, suggests parents’ and children’s perceptions of mathematics were likely to be positively influenced. The data also suggest that children were likely to become more confident and to improve in mathematics.
- Full Text:
- Date Issued: 2007
- Authors: Govender, Vasuthavan Gopaul
- Date: 2007
- Subjects: Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9556 , http://hdl.handle.net/10948/511 , http://hdl.handle.net/10948/d1011913 , Education, Secondary -- Parent participation , Parent-teacher relationships , Mathematics -- Study and teaching (Secondary)
- Description: The learning of mathematics is a worldwide concern. International studies over the last decade place South African learners amongst the lowest achievers. Although various initiatives have been tried there does not seem to be any improvement. In the USA and UK initiatives include the involvement of parents and these have been implemented with great success. One of the parent involvement programmes from the USA, the Family Maths Programme has been in South Africa since 1996. This programme has been successful in South Africa but is confined to parents of grades 4-7 children. However, there is no programme for parents of high school learners. As grade 8 is usually the first high school year in South Africa, this study focuses on parents of grade 8 children and their involvement in their children’s mathematics learning. It consists of an initial survey of grade 8 parents’ (from an urban school) mathematical backgrounds and experiences and their involvement in their children’s education. Using key points from the survey and elements from the literature review and other sources, the researcher designed a parent assistance programme for mathematics which was conducted with three groups of parents of grade 8 children from the same high school. Each group of parents was exclusive and the same set of procedures was applied to each group, making this study a qualitative multiple case study, within the interpretive research paradigm. The parent-assistance programme consists of a parents’ workshop and completion of journals over a 7-week period. Parents documented their interactions with their children in structured journals, a process known as participant journaling. After this journaling period, parents and children were surveyed on this interaction by means of follow-up questionnaires. This was followed later in interviews with the parents and mathematics teachers, separately. After the completion of all three case studies parents and children participated in focus group discussions to discuss and share experiences of the programme. The interrogation of the data, on two levels, suggests parents’ and children’s perceptions of mathematics were likely to be positively influenced. The data also suggest that children were likely to become more confident and to improve in mathematics.
- Full Text:
- Date Issued: 2007
A novel biosensor for the detection and monitoring of -d-galactosidase of faecal origin in water
- Wutor, V C, Togo, C A, Limson, Janice L, Pletschke, Brett I
- Authors: Wutor, V C , Togo, C A , Limson, Janice L , Pletschke, Brett I
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6468 , http://hdl.handle.net/10962/d1005797 , http://dx.doi.org/10.1016/j.enzmictec.2006.10.039
- Description: A voltammetric sensor prepared by the immobilization of metallophthalocyanine complexes onto a glassy carbon electrode has been developed for the detection of β-d-galactosidase (B-GAL) of faecal origin in water. Electrooxidation of chlorophenol red, a breakdown product of the chromogenic substrate chlorophenol red β-d-galactopyranoside, was used as a measure of β-d-galactosidase activity. At metallophthalocyanine modified electrodes, in particular copper(II) phthalocyanine, a decrease in electrode fouling was observed. The sensor was sensitive to fluctuations in pH, not significantly affected by temperature variations and could detect one colony forming unit/100 mL in 15 min. Loss of 40% sensitivity was observed over a period of 30 days. A strong correlation between sensor sensitivity and colony forming units was observed. The sensor is capable of detecting viable but nonculturable bacteria, overcoming this drawback of the use of culture media for detection of coliforms.
- Full Text:
- Date Issued: 2007
- Authors: Wutor, V C , Togo, C A , Limson, Janice L , Pletschke, Brett I
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6468 , http://hdl.handle.net/10962/d1005797 , http://dx.doi.org/10.1016/j.enzmictec.2006.10.039
- Description: A voltammetric sensor prepared by the immobilization of metallophthalocyanine complexes onto a glassy carbon electrode has been developed for the detection of β-d-galactosidase (B-GAL) of faecal origin in water. Electrooxidation of chlorophenol red, a breakdown product of the chromogenic substrate chlorophenol red β-d-galactopyranoside, was used as a measure of β-d-galactosidase activity. At metallophthalocyanine modified electrodes, in particular copper(II) phthalocyanine, a decrease in electrode fouling was observed. The sensor was sensitive to fluctuations in pH, not significantly affected by temperature variations and could detect one colony forming unit/100 mL in 15 min. Loss of 40% sensitivity was observed over a period of 30 days. A strong correlation between sensor sensitivity and colony forming units was observed. The sensor is capable of detecting viable but nonculturable bacteria, overcoming this drawback of the use of culture media for detection of coliforms.
- Full Text:
- Date Issued: 2007
A preliminary examination of selected biological links between four Eastern Cape estuaries and the inshore marine environment
- Authors: Vorwerk, Paul D
- Date: 2007
- Subjects: Estuaries -- South Africa -- Eastern Cape Marine fishes -- South Africa -- Eastern Cape Marine ecology -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5747 , http://hdl.handle.net/10962/d1005434
- Description: The coastal transition zone (CTZ), which links the terrestrial and marine environments, has been identified as a region of high biological diversity and elevated production. Results of studies conducted in the northern hemisphere indicate that the links between estuaries and the adjacent marine environment is critical to ecological functioning within the CTZ. This study assessed the influence of selected estuaries with different hydrodynamic characteristics on the adjacent marine environment along the south-eastern coastline of southern Africa. Four estuaries were examined, including two permanently open systems, the fresh water deprived Kariega and fresh water dominated Great Fish, and two temporarily open/closed estuaries (TOCE), the Kasouga and East Kleinemonde. Results of the study indicated that outflow of estuarine water from the Great Fish Estuary contributed to a plume of less saline water being evident within the adjacent marine environment. The plume of water was associated with increased zooplankton biomass and particulate organic matter (POM) and chlorophyll-a concentrations. Adjacent to the Kariega Estuary, no evidence of fresh water outflow into the marine environment was observed. However, in the sea directly opposite the mouth of the estuary an increase in zooplankton abundance and biomass was evident. Results of numerical analyses indicated that the increase in zooplankton abundance observed adjacent to the mouth of both permanently open estuaries could not be attributed to the export of zooplankton from the estuary, but rather the accumulation of marine species within the region. The mechanisms responsible for this accumulation were not determined, but it was thought to be associated with increased food availability in the estuarine frontal zone. A similar, but less dramatic biological response was also observed in the marine environment adjacent to the two TOCEs. It is suggested that the increase in biological activity within these regions could be ascribed to seepage of estuarine or ground water through the sand bar that separates these estuaries from the sea. Results of stable carbon isotope analyses indicated that both the Great Fish and Kariega estuaries exported carbon to the nearshore marine environment. The area influenced by estuarine derived carbon was dependent on the volume of estuarine outflow to the marine environment. Adjacent to the fresh water dominated Great Fish Estuary, estuarine derived carbon was recorded up to 12km from the mouth, while adjacent to the fresh water deprived Kariega, estuarine derived carbon was only evident directly opposite the mouth. The recruitment of macrozooplankton (> 2cm) into the fresh water deprived Kariega Estuary was in the range recorded for other permanently open southern African estuaries with higher fresh water flow rates. This indicates that the mechanisms which allow estuarine dependent larvae to locate and enter estuaries are not related to fresh water inflow. In conclusion, this study has demonstrated that despite their small size relative to European and North American systems, South African permanently open and temporarily open/closed estuaries also influence biological activity within the adjacent nearshore marine environment.
- Full Text:
- Date Issued: 2007
- Authors: Vorwerk, Paul D
- Date: 2007
- Subjects: Estuaries -- South Africa -- Eastern Cape Marine fishes -- South Africa -- Eastern Cape Marine ecology -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5747 , http://hdl.handle.net/10962/d1005434
- Description: The coastal transition zone (CTZ), which links the terrestrial and marine environments, has been identified as a region of high biological diversity and elevated production. Results of studies conducted in the northern hemisphere indicate that the links between estuaries and the adjacent marine environment is critical to ecological functioning within the CTZ. This study assessed the influence of selected estuaries with different hydrodynamic characteristics on the adjacent marine environment along the south-eastern coastline of southern Africa. Four estuaries were examined, including two permanently open systems, the fresh water deprived Kariega and fresh water dominated Great Fish, and two temporarily open/closed estuaries (TOCE), the Kasouga and East Kleinemonde. Results of the study indicated that outflow of estuarine water from the Great Fish Estuary contributed to a plume of less saline water being evident within the adjacent marine environment. The plume of water was associated with increased zooplankton biomass and particulate organic matter (POM) and chlorophyll-a concentrations. Adjacent to the Kariega Estuary, no evidence of fresh water outflow into the marine environment was observed. However, in the sea directly opposite the mouth of the estuary an increase in zooplankton abundance and biomass was evident. Results of numerical analyses indicated that the increase in zooplankton abundance observed adjacent to the mouth of both permanently open estuaries could not be attributed to the export of zooplankton from the estuary, but rather the accumulation of marine species within the region. The mechanisms responsible for this accumulation were not determined, but it was thought to be associated with increased food availability in the estuarine frontal zone. A similar, but less dramatic biological response was also observed in the marine environment adjacent to the two TOCEs. It is suggested that the increase in biological activity within these regions could be ascribed to seepage of estuarine or ground water through the sand bar that separates these estuaries from the sea. Results of stable carbon isotope analyses indicated that both the Great Fish and Kariega estuaries exported carbon to the nearshore marine environment. The area influenced by estuarine derived carbon was dependent on the volume of estuarine outflow to the marine environment. Adjacent to the fresh water dominated Great Fish Estuary, estuarine derived carbon was recorded up to 12km from the mouth, while adjacent to the fresh water deprived Kariega, estuarine derived carbon was only evident directly opposite the mouth. The recruitment of macrozooplankton (> 2cm) into the fresh water deprived Kariega Estuary was in the range recorded for other permanently open southern African estuaries with higher fresh water flow rates. This indicates that the mechanisms which allow estuarine dependent larvae to locate and enter estuaries are not related to fresh water inflow. In conclusion, this study has demonstrated that despite their small size relative to European and North American systems, South African permanently open and temporarily open/closed estuaries also influence biological activity within the adjacent nearshore marine environment.
- Full Text:
- Date Issued: 2007
A preliminary perspective on the Office of the Vice-Chancellor and appeals related to exclusions and admissions
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7644 , http://hdl.handle.net/10962/d1015772
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7644 , http://hdl.handle.net/10962/d1015772
- Full Text:
- Date Issued: 2007
A proposed strategy for the implementation of total productive maintenance at Continental Tyre South Africa
- Authors: Olivier, Christie
- Date: 2007
- Subjects: Continental Tyre South Africa (Firm) , Total productive maintenance , Manufacturing industries
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8576 , http://hdl.handle.net/10948/799 , Continental Tyre South Africa (Firm) , Total productive maintenance , Manufacturing industries
- Description: For a tyre manufacturing company to compete nationally and internationally, the maximum utilization of their equipment is extremely important. Thus, having a maintenance system in place that will ensure this will be essential. In today’s competitive environment, the need to go further than just scheduling maintenance in accordance with manufacturer’s recommendations as a method of improving productivity and product quality was quickly recognized by those companies who were committed to total quality management programmes. The objective of this study was to propose an appropriate strategy for the implementation of Total Productive Maintenance at Continental Tyre South Africa. To achieve this, the current Total Productive Maintenance (TPM) programme, in the steel stock preparation division in affiliated Continental plants in Otrokovice in the Czech Republic and Puchov in the Slovak Republic was evaluated. A comprehensive literature study was performed on Total Productive Maintenance programmes. A questionnaire was designed based on the guidelines in the literature study in order to establish the effectiveness of implemented TPM programmes. The researcher used the random sampling method of selection and distributed the questionnaire to 62 potential respondents via hand-outs from each plant’s respective heads of departments. 56 completed questionnaires were returned and these were processed and analyzed using Microsoft Office Excel 2003, running on the Windows XP suite of computer packages. The opinions of the various respondents were compared with the guidelines provided in the literature survey, in order to identify how to answer two main questions the author wanted to use as part of selecting an appropriate implementation approach for TPM at Continental Tyre South Africa. These were: • How much are the employees involved and empowered to perform their TPM tasks?; and • How effective is the implemented TPM programme? The following were the main recommendations and conclusions: • The experiences gained by plants like Otrokovice and Puchov must be used as a guideline for introduction and implementation; • The employees that will be required to perform the TPM tasks must be properly trained and they should receive the necessary tools to perform their tasks; • It is essential that everyone throughout the entire manufacturing organization is involved from the start in the development, improvement and maintenance of the TPM programme and that the driving force behind it should be a combination of maintenance, production and quality; and • TPM will achieve it’s objectives if: • The equipment effectiveness can be improved; • Autonomous maintenance is achieved; • Planned maintenance is in place; • Staff are trained in relevant maintenance skills; and • Early equipment management can be achieved.
- Full Text:
- Date Issued: 2007
- Authors: Olivier, Christie
- Date: 2007
- Subjects: Continental Tyre South Africa (Firm) , Total productive maintenance , Manufacturing industries
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8576 , http://hdl.handle.net/10948/799 , Continental Tyre South Africa (Firm) , Total productive maintenance , Manufacturing industries
- Description: For a tyre manufacturing company to compete nationally and internationally, the maximum utilization of their equipment is extremely important. Thus, having a maintenance system in place that will ensure this will be essential. In today’s competitive environment, the need to go further than just scheduling maintenance in accordance with manufacturer’s recommendations as a method of improving productivity and product quality was quickly recognized by those companies who were committed to total quality management programmes. The objective of this study was to propose an appropriate strategy for the implementation of Total Productive Maintenance at Continental Tyre South Africa. To achieve this, the current Total Productive Maintenance (TPM) programme, in the steel stock preparation division in affiliated Continental plants in Otrokovice in the Czech Republic and Puchov in the Slovak Republic was evaluated. A comprehensive literature study was performed on Total Productive Maintenance programmes. A questionnaire was designed based on the guidelines in the literature study in order to establish the effectiveness of implemented TPM programmes. The researcher used the random sampling method of selection and distributed the questionnaire to 62 potential respondents via hand-outs from each plant’s respective heads of departments. 56 completed questionnaires were returned and these were processed and analyzed using Microsoft Office Excel 2003, running on the Windows XP suite of computer packages. The opinions of the various respondents were compared with the guidelines provided in the literature survey, in order to identify how to answer two main questions the author wanted to use as part of selecting an appropriate implementation approach for TPM at Continental Tyre South Africa. These were: • How much are the employees involved and empowered to perform their TPM tasks?; and • How effective is the implemented TPM programme? The following were the main recommendations and conclusions: • The experiences gained by plants like Otrokovice and Puchov must be used as a guideline for introduction and implementation; • The employees that will be required to perform the TPM tasks must be properly trained and they should receive the necessary tools to perform their tasks; • It is essential that everyone throughout the entire manufacturing organization is involved from the start in the development, improvement and maintenance of the TPM programme and that the driving force behind it should be a combination of maintenance, production and quality; and • TPM will achieve it’s objectives if: • The equipment effectiveness can be improved; • Autonomous maintenance is achieved; • Planned maintenance is in place; • Staff are trained in relevant maintenance skills; and • Early equipment management can be achieved.
- Full Text:
- Date Issued: 2007
A railway terminus for the inner city of Port Elizabeth
- Authors: Scriba, Marco W
- Date: 2007
- Subjects: Railroad terminals -- South Africa -- Port Elizabeth -- Designs and plans , Terminals (Transportation) -- South Africa -- Port Elizabeth -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: vital:8154 , http://hdl.handle.net/10948/d1016497
- Description: In the late 1980s people and businesses started to move out of Port Elizabeth's Central District (CBD). Businesses moved to the city's edge establishing new business zones, which in turn threatened the existence of the original CBD. Most inner city buildings became derelict and property prices dropped accordingly. Buildings were neglected and vandalized. This resulted in spaces which were unfit for human habitation and encouraged areas characterized by crime. The regeneration of Port Elizabeth's CDB is very important bacause of its historical value and key position. To build the Metropol the historical ideals of the CDB need to be revitalized, giving the city a administrative and cultural core which is both friendly and safe. A few proposals have been introduced to help uplift areas in the CDB. The latest initiative is the upgrading of Govan Mbeki Street lead by the firm The Matrix. Their aim is to create architecture that creates a more interactive, habitable environment. This would be achieved by more pedestrian orientated spaces, natural landscaping and facilitating vendors and craft markets. Future proposals are the removal of railway lines, the Tank Farm and finally the Ore Dumps to allow the city to expand eastwards. This will allow the city to grow and connect with the seafront and the existing harbour. Consequently the development of a new Railway Terminus is central to the establishment of a bay which is consistent with international standards of key marine cities in the modern world. The old station has a beautiful sense of place in Strand Street, as does the Campanile, which is at the gateway to the harbour. Together they offer a unique experience in this historiacal precinct. This offers new opportunities for tourism and trade and the old station would therefore form part of Port Elizabeth's CDB rejuvenation.
- Full Text:
- Date Issued: 2007
- Authors: Scriba, Marco W
- Date: 2007
- Subjects: Railroad terminals -- South Africa -- Port Elizabeth -- Designs and plans , Terminals (Transportation) -- South Africa -- Port Elizabeth -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: vital:8154 , http://hdl.handle.net/10948/d1016497
- Description: In the late 1980s people and businesses started to move out of Port Elizabeth's Central District (CBD). Businesses moved to the city's edge establishing new business zones, which in turn threatened the existence of the original CBD. Most inner city buildings became derelict and property prices dropped accordingly. Buildings were neglected and vandalized. This resulted in spaces which were unfit for human habitation and encouraged areas characterized by crime. The regeneration of Port Elizabeth's CDB is very important bacause of its historical value and key position. To build the Metropol the historical ideals of the CDB need to be revitalized, giving the city a administrative and cultural core which is both friendly and safe. A few proposals have been introduced to help uplift areas in the CDB. The latest initiative is the upgrading of Govan Mbeki Street lead by the firm The Matrix. Their aim is to create architecture that creates a more interactive, habitable environment. This would be achieved by more pedestrian orientated spaces, natural landscaping and facilitating vendors and craft markets. Future proposals are the removal of railway lines, the Tank Farm and finally the Ore Dumps to allow the city to expand eastwards. This will allow the city to grow and connect with the seafront and the existing harbour. Consequently the development of a new Railway Terminus is central to the establishment of a bay which is consistent with international standards of key marine cities in the modern world. The old station has a beautiful sense of place in Strand Street, as does the Campanile, which is at the gateway to the harbour. Together they offer a unique experience in this historiacal precinct. This offers new opportunities for tourism and trade and the old station would therefore form part of Port Elizabeth's CDB rejuvenation.
- Full Text:
- Date Issued: 2007
A review of stakeholder interests and participation in the sustainable use of communal wetlands: the case of the Lake Fundudzi catchment in Limpopo Province, South Africa
- Authors: Silima, Vhangani
- Date: 2007
- Subjects: Wetland ecology -- South Africa -- Limpopo Wetland management -- South Africa -- Limpopo Natural resources -- Management -- South Africa -- Limpopo Conservation of natural resources -- South Africa -- Limpopo Conservation of natural resources -- Citizen participation -- South Africa -- Limpopo Sustainable development -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1745 , http://hdl.handle.net/10962/d1003629
- Description: Many rural South African people depend on natural resources for their survival. Wetlands provide some of those natural resources. These are presently are under pressure due to high demand, overexploitation and poor land management. The history of South Africa has been characterised by exclusion of local communities in the process of decision-making and general management of natural resources. Participation of all stakeholders is crucial for successful sustainable natural resource management. Various South African departments are engaged in a number of strategies for promoting meaningful participation of local communities. The South African laws promoting protection and sustainable use of natural resources incorporate democratic principles that require high level of participation from resource users, local communities in particular. Most of the participation techniques used are focused on satisfying political mandates and do not respond to the social context of the resource users. The aim of the study was to review the participation of stakeholders in the project of promoting the sustainable use and protection of the Lake Fundudzi catchment. The idea was to probe stakeholder interests more carefully, and to research tensions that arise in the participation process, using qualitative methodologies. Through the use of questionnaires, observations and document analysis stakeholders’ interests were identified to assess their influence in the process of participation of local stakeholders. The review of stakeholders’ participation in the Lake Fundudzi Project showed that stakeholders’ interests are crucial for meaningful local community participation, communication and education influence. They enable meaningful participation and empowerment. A multi-stakeholders approach enables stakeholders to share roles and responsibilities and the participation process offers an opportunity for local stakeholders to participate democratically in the Project. Power relations affect stakeholder participation, capital dependant participatory initiatives are likely to be at risk, participatory processes are likely to promote the empowerment and knowledge exchange amongst stakeholders, the views of local stakeholders are not always considered by outside support organisation and multi-stakeholder participatory approaches enable the initiative/activity/project to achieve its objectives.
- Full Text:
- Date Issued: 2007
- Authors: Silima, Vhangani
- Date: 2007
- Subjects: Wetland ecology -- South Africa -- Limpopo Wetland management -- South Africa -- Limpopo Natural resources -- Management -- South Africa -- Limpopo Conservation of natural resources -- South Africa -- Limpopo Conservation of natural resources -- Citizen participation -- South Africa -- Limpopo Sustainable development -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1745 , http://hdl.handle.net/10962/d1003629
- Description: Many rural South African people depend on natural resources for their survival. Wetlands provide some of those natural resources. These are presently are under pressure due to high demand, overexploitation and poor land management. The history of South Africa has been characterised by exclusion of local communities in the process of decision-making and general management of natural resources. Participation of all stakeholders is crucial for successful sustainable natural resource management. Various South African departments are engaged in a number of strategies for promoting meaningful participation of local communities. The South African laws promoting protection and sustainable use of natural resources incorporate democratic principles that require high level of participation from resource users, local communities in particular. Most of the participation techniques used are focused on satisfying political mandates and do not respond to the social context of the resource users. The aim of the study was to review the participation of stakeholders in the project of promoting the sustainable use and protection of the Lake Fundudzi catchment. The idea was to probe stakeholder interests more carefully, and to research tensions that arise in the participation process, using qualitative methodologies. Through the use of questionnaires, observations and document analysis stakeholders’ interests were identified to assess their influence in the process of participation of local stakeholders. The review of stakeholders’ participation in the Lake Fundudzi Project showed that stakeholders’ interests are crucial for meaningful local community participation, communication and education influence. They enable meaningful participation and empowerment. A multi-stakeholders approach enables stakeholders to share roles and responsibilities and the participation process offers an opportunity for local stakeholders to participate democratically in the Project. Power relations affect stakeholder participation, capital dependant participatory initiatives are likely to be at risk, participatory processes are likely to promote the empowerment and knowledge exchange amongst stakeholders, the views of local stakeholders are not always considered by outside support organisation and multi-stakeholder participatory approaches enable the initiative/activity/project to achieve its objectives.
- Full Text:
- Date Issued: 2007
A social realist account of the emergence of a formal academic staff development programme at a South African university
- Authors: Quinn, Lynn
- Date: 2007
- Subjects: Teachers -- Training of -- South Africa Education, Higher -- South Africa Graduate students -- South Africa Universities and colleges -- South Africa -- Graduate work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1321 , http://hdl.handle.net/10962/d1003954
- Description: Using social realist theory and particularly the morphogenetic/morphostatic methodology advocated by Margaret Archer, this study offers a critical examination of the emergence of a formal academic staff development programme at a small South African university (SSAU). Archer’s morphogenetic approach enabled an investigation of the interface between culture, structure and agency (at macro, mezo and micro levels) in order to theorize about the material, ideational and agential conditions that obtained and which in turn enabled the emergence of the Postgraduate Diploma of Higher Education (PGDHE) at the SSAU. The study therefore advances concrete propositions about the cultural, structural and agential conditions for transformation which existed at a particular time in the history of higher education (and the subfield of educational development) which enabled the introduction of the PGDHE. Analysis of the data suggests that what occurred at SSAU was a disruption of the morphostatic synchrony between structure and culture brought about by new discourses and structures emanating from the broader international and national higher education context. In particular, it seems that attempts at reconciling the constraining contradictions between the discourses and structures related to quality assurance on the one hand and educational development on the other resulted in a conjunction between transformation at the levels of both the cultural system and social structure. This conjunction, along with the actions of key Institutional agents and the morphogenesis of the staff of the Educational Development Unit, created sufficiently enabling conditions in the Institution for the introduction of the PGDHE. The research adds to knowledge through insights into the contribution that the ideas, beliefs, values, ideologies and theories about higher education broadly and about educational development specifically make to enabling or constraining conditions for the professionalization of academic staff in higher education institutions. It uncovers how relevant structures at the international, national and institutional levels can shape the practice of educational development and specifically staff development. It has generated insights into how the relevant people and the positions they hold can impact on staff development practices. In summary, the research could contribute towards emancipatory knowledge which could be used by SSAU and educational development practitioners elsewhere to inform future planning and decision making in relation to educational development and more specifically staff development practices in their contexts.
- Full Text:
- Date Issued: 2007
- Authors: Quinn, Lynn
- Date: 2007
- Subjects: Teachers -- Training of -- South Africa Education, Higher -- South Africa Graduate students -- South Africa Universities and colleges -- South Africa -- Graduate work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1321 , http://hdl.handle.net/10962/d1003954
- Description: Using social realist theory and particularly the morphogenetic/morphostatic methodology advocated by Margaret Archer, this study offers a critical examination of the emergence of a formal academic staff development programme at a small South African university (SSAU). Archer’s morphogenetic approach enabled an investigation of the interface between culture, structure and agency (at macro, mezo and micro levels) in order to theorize about the material, ideational and agential conditions that obtained and which in turn enabled the emergence of the Postgraduate Diploma of Higher Education (PGDHE) at the SSAU. The study therefore advances concrete propositions about the cultural, structural and agential conditions for transformation which existed at a particular time in the history of higher education (and the subfield of educational development) which enabled the introduction of the PGDHE. Analysis of the data suggests that what occurred at SSAU was a disruption of the morphostatic synchrony between structure and culture brought about by new discourses and structures emanating from the broader international and national higher education context. In particular, it seems that attempts at reconciling the constraining contradictions between the discourses and structures related to quality assurance on the one hand and educational development on the other resulted in a conjunction between transformation at the levels of both the cultural system and social structure. This conjunction, along with the actions of key Institutional agents and the morphogenesis of the staff of the Educational Development Unit, created sufficiently enabling conditions in the Institution for the introduction of the PGDHE. The research adds to knowledge through insights into the contribution that the ideas, beliefs, values, ideologies and theories about higher education broadly and about educational development specifically make to enabling or constraining conditions for the professionalization of academic staff in higher education institutions. It uncovers how relevant structures at the international, national and institutional levels can shape the practice of educational development and specifically staff development. It has generated insights into how the relevant people and the positions they hold can impact on staff development practices. In summary, the research could contribute towards emancipatory knowledge which could be used by SSAU and educational development practitioners elsewhere to inform future planning and decision making in relation to educational development and more specifically staff development practices in their contexts.
- Full Text:
- Date Issued: 2007
A sociological analysis of intermediary non-governmental organizations and land reform in contemporary Zimbabwe
- Authors: Helliker, Kirk David
- Date: 2007
- Subjects: Non-governmental organizations -- Zimbabwe Land reform -- Zimbabwe Land use -- Zimbabwe Sociology -- Philosophy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3303 , http://hdl.handle.net/10962/d1003091
- Description: The thesis offers an original sociological understanding of intermediary Non-Governmental Organizations (NGOs) in the modern world. This is pursued through a study of NGOs and land reform in contemporary Zimbabwe. The prevailing literature on NGOs is marked by a sociological behaviourism that analyses NGOs in terms of external relations and the object-subject dualism. This behaviourism has both ‘structuralist’ and ‘empiricist’ trends that lead to instrumentalist and functionalist forms of argumentation. The thesis details an alternative conceptual corpus that draws upon the epistemological and theoretical insights of Marx and Weber. The epistemological reasoning of Marx involves processes of deconstruction and reconstruction. This entails conceptualizing NGOs as social forms that embody contradictory relations and, for analytical purposes, the thesis privileges the contradiction between ‘the global’ and ‘the local’. In this regard, it speaks about processes of ‘glocalization’ and ‘glocal modernities’ in which NGOs become immersed. The social field of NGOs is marked by ambiguities and tensions, and NGOs seek to ‘negotiate’ and manoeuvre their way through this field by a variety of organizational practices. Understanding these practices necessitates studying NGOs ‘from within’ and drawing specifically on Weber’s notion of ‘meaning’. These practices often entail activities that stabilize and simplify the world and work of NGOs, and this involves NGOs in prioritizing their own organizational sustainability. In handling the tension between ‘the global’ and ‘the local’, NGOs also tend to privilege global trajectories over local initiatives. The thesis illustrates these points in relation to the work of intermediary NGOs in Zimbabwe over the past ten years. Since the year 2000, a radical restructuring of agrarian relations has occurred, and this has been based upon the massive redistribution of land. In this respect, local empowering initiatives have dramatically asserted themselves against globalizing trajectories. These changes have posed serious challenges to ‘land’ NGOs, that is, NGOs involved in land reform either as advocates for reform or as rural development NGOs. The thesis shows how a range of diverse ‘land’ NGOs has ‘handled’ the heightened contradictions in their social field in ways that maintain their organizational coherence and integrity.
- Full Text:
- Date Issued: 2007
- Authors: Helliker, Kirk David
- Date: 2007
- Subjects: Non-governmental organizations -- Zimbabwe Land reform -- Zimbabwe Land use -- Zimbabwe Sociology -- Philosophy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3303 , http://hdl.handle.net/10962/d1003091
- Description: The thesis offers an original sociological understanding of intermediary Non-Governmental Organizations (NGOs) in the modern world. This is pursued through a study of NGOs and land reform in contemporary Zimbabwe. The prevailing literature on NGOs is marked by a sociological behaviourism that analyses NGOs in terms of external relations and the object-subject dualism. This behaviourism has both ‘structuralist’ and ‘empiricist’ trends that lead to instrumentalist and functionalist forms of argumentation. The thesis details an alternative conceptual corpus that draws upon the epistemological and theoretical insights of Marx and Weber. The epistemological reasoning of Marx involves processes of deconstruction and reconstruction. This entails conceptualizing NGOs as social forms that embody contradictory relations and, for analytical purposes, the thesis privileges the contradiction between ‘the global’ and ‘the local’. In this regard, it speaks about processes of ‘glocalization’ and ‘glocal modernities’ in which NGOs become immersed. The social field of NGOs is marked by ambiguities and tensions, and NGOs seek to ‘negotiate’ and manoeuvre their way through this field by a variety of organizational practices. Understanding these practices necessitates studying NGOs ‘from within’ and drawing specifically on Weber’s notion of ‘meaning’. These practices often entail activities that stabilize and simplify the world and work of NGOs, and this involves NGOs in prioritizing their own organizational sustainability. In handling the tension between ‘the global’ and ‘the local’, NGOs also tend to privilege global trajectories over local initiatives. The thesis illustrates these points in relation to the work of intermediary NGOs in Zimbabwe over the past ten years. Since the year 2000, a radical restructuring of agrarian relations has occurred, and this has been based upon the massive redistribution of land. In this respect, local empowering initiatives have dramatically asserted themselves against globalizing trajectories. These changes have posed serious challenges to ‘land’ NGOs, that is, NGOs involved in land reform either as advocates for reform or as rural development NGOs. The thesis shows how a range of diverse ‘land’ NGOs has ‘handled’ the heightened contradictions in their social field in ways that maintain their organizational coherence and integrity.
- Full Text:
- Date Issued: 2007
A stability-indicating high performance liquid chromatographic (HPLC) assay for the simultaneous determination of atorvastatin and amlodipine in commercial tablets
- Mohammadi, Ali, Rezanour, N, Ansari Dogaheh, M, Ghorbani Bidkorbeh, F, Hashem, M, Walker, Roderick B
- Authors: Mohammadi, Ali , Rezanour, N , Ansari Dogaheh, M , Ghorbani Bidkorbeh, F , Hashem, M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6403 , http://hdl.handle.net/10962/d1006340
- Description: A simple, rapid, precise and accurate isocratic reversed-phase stability-indicating HPLC method was developed and validated for the simultaneous determination of atorvastatin (AT) and amlodipine (AM) in commercial tablets. The method has shown adequate separation for AM, AT from their associated main impurities and their degradation products. Separation was achieved on a Perfectsil® Target ODS-3, 5 μm, 250 mm × 4.6 mm i.d. column using a mobile phase consisting of acetonitrile–0.025 M NaH2PO4 buffer (pH 4.5) (55:45, v/v) at a flow rate of 1 ml/min and UV detection at 237 nm. The drugs were subjected to oxidation, hydrolysis, photolysis and heat to apply stress conditions. The linearity of the proposed method was investigated in the range of 2–30 μg/ml (r = 0.9994) for AT and 1–20 μg/ml (r = 0.9993) for AM. The limits of detection were 0.65 μg/ml and 0.35 μg/ml for AT and AM, respectively. The limits of quantitation were 2 μg/ml and 1 μg/ml for AT and AM, respectively. Degradation products produced as a result of stress studies did not interfere with the detection of AT and AM and the assay can thus be considered stability-indicating.
- Full Text:
- Date Issued: 2007
- Authors: Mohammadi, Ali , Rezanour, N , Ansari Dogaheh, M , Ghorbani Bidkorbeh, F , Hashem, M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6403 , http://hdl.handle.net/10962/d1006340
- Description: A simple, rapid, precise and accurate isocratic reversed-phase stability-indicating HPLC method was developed and validated for the simultaneous determination of atorvastatin (AT) and amlodipine (AM) in commercial tablets. The method has shown adequate separation for AM, AT from their associated main impurities and their degradation products. Separation was achieved on a Perfectsil® Target ODS-3, 5 μm, 250 mm × 4.6 mm i.d. column using a mobile phase consisting of acetonitrile–0.025 M NaH2PO4 buffer (pH 4.5) (55:45, v/v) at a flow rate of 1 ml/min and UV detection at 237 nm. The drugs were subjected to oxidation, hydrolysis, photolysis and heat to apply stress conditions. The linearity of the proposed method was investigated in the range of 2–30 μg/ml (r = 0.9994) for AT and 1–20 μg/ml (r = 0.9993) for AM. The limits of detection were 0.65 μg/ml and 0.35 μg/ml for AT and AM, respectively. The limits of quantitation were 2 μg/ml and 1 μg/ml for AT and AM, respectively. Degradation products produced as a result of stress studies did not interfere with the detection of AT and AM and the assay can thus be considered stability-indicating.
- Full Text:
- Date Issued: 2007
A study of the conflict between maintenance and production functions in a manufacturing organisation in Port Elizabeth
- Authors: Petronio, Riccardo Vinicio
- Date: 2007
- Subjects: Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8737 , http://hdl.handle.net/10948/794 , Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Description: If manufacturing organisations are to improve their competitive positions in the global arena and increase profitability, their operations strategies need to be focused on: reducing cost, improving quality, increasing efficiency, improving the speed of delivery, developing and improving process flexibility, and ensuring that higher service levels are achieved and maintained. One of the critical success factors in implementing these strategies, within manufacturing organisations, is the relationship that exists between the maintenance and production functions. There is sufficient evidence to suggest that in many manufacturing organisations, the relationship that exists between these two functions is usually one of conflict, which if left unmanaged or unresolved has the potential to severely hamper effectiveness, productivity, creativity, and profitability of the organisation. The overall purpose of this research was to identify the interventions that manufacturing organisations can pursue, to effectively manage and resolve the conflict between the production and maintenance functions, in order to improve their competitive position in the global economy. The study was conducted in one particular manufacturing organisation in Port Elizabeth in the Eastern Cape. A research questionnaire was used as a means for collecting empirical data. The research questionnaire included various instruments used by previous conflict researchers, to identify and analyse the following dimensions of conflict within the organisation: conflict management styles used, the types of conflict perceived, and the amount of conflict perceived. The questionnaire was also designed to identify the sources of conflict, collect demographic information, identify issues relating to diversity, and indicate the respondents’ preferences to various organisational reporting structures. The results of the survey revealed key findings, which enabled the researcher to draw meaningful conclusions, and make recommendations as to how organisations can effectively manage and resolve the conflict that exists between maintenance and production functions.
- Full Text:
- Date Issued: 2007
- Authors: Petronio, Riccardo Vinicio
- Date: 2007
- Subjects: Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8737 , http://hdl.handle.net/10948/794 , Conflict management -- South Africa -- Port Elizabeth , Organizational behavior -- South Africa -- Port Elizabeth , Supervision of employees -- South AFrica -- Port Elizabeth
- Description: If manufacturing organisations are to improve their competitive positions in the global arena and increase profitability, their operations strategies need to be focused on: reducing cost, improving quality, increasing efficiency, improving the speed of delivery, developing and improving process flexibility, and ensuring that higher service levels are achieved and maintained. One of the critical success factors in implementing these strategies, within manufacturing organisations, is the relationship that exists between the maintenance and production functions. There is sufficient evidence to suggest that in many manufacturing organisations, the relationship that exists between these two functions is usually one of conflict, which if left unmanaged or unresolved has the potential to severely hamper effectiveness, productivity, creativity, and profitability of the organisation. The overall purpose of this research was to identify the interventions that manufacturing organisations can pursue, to effectively manage and resolve the conflict between the production and maintenance functions, in order to improve their competitive position in the global economy. The study was conducted in one particular manufacturing organisation in Port Elizabeth in the Eastern Cape. A research questionnaire was used as a means for collecting empirical data. The research questionnaire included various instruments used by previous conflict researchers, to identify and analyse the following dimensions of conflict within the organisation: conflict management styles used, the types of conflict perceived, and the amount of conflict perceived. The questionnaire was also designed to identify the sources of conflict, collect demographic information, identify issues relating to diversity, and indicate the respondents’ preferences to various organisational reporting structures. The results of the survey revealed key findings, which enabled the researcher to draw meaningful conclusions, and make recommendations as to how organisations can effectively manage and resolve the conflict that exists between maintenance and production functions.
- Full Text:
- Date Issued: 2007
A study of the summarizing strategies used by ESL first year science students at the University of Botswana
- Authors: Chimbganda, Ambrose Bruce
- Date: 2007
- Subjects: English language -- Study and teaching (Foreign speakers) -- Botswana English language -- Study and teaching (Higher) -- Botswana Science -- Study and teaching (Higher) -- Botswana Language and education -- Botswana College students -- Botswana -- Language
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2341 , http://hdl.handle.net/10962/d1002623
- Description: One of the major problems faced by speakers of English as a second language (ESL) or non-native speakers of English (NNS) is that when they go to college or university, they find themselves without sufficient academic literacy skills to enable them to navigate their learning successfully, such as the ability to summarize textual material. This thesis examines the summarizing strategies used by ESL first year science students at the University of Botswana. Using multiple data collection methods, otherwise known as triangulation or pluralistic research, which is a combination of quantitative and qualitative methods, one hundred and twenty randomly sampled students completed questionnaires and summarized a scientific text. In order to observe the students more closely, nine students (3 high-, 3 average- and 3 low-proficiency) were purposively selected from the sample and wrote a further summary. The nine students were later interviewed in order to find out from them the kinds of strategies they had used in summarizing the texts. To obtain systematic data, the summaries and the taped interview were coded and analyzed using a hybrid scoring classification previously used by other researchers. The results from the Likert type of questionnaire suggest that the ESL first year science students are 'aware' of the appropriate reading, production and self-assessment strategies to use when summarizing. However, when the data from the questionnaire were cross-checked against the strategies they had used in the actual summarization of the text, most of their claims, especially those of the low-proficiency students, were not sustained. As a whole, the results show that high-proficiency students produce more accurate idea units and are more capable of generalizing ideas than low-proficiency students who prefer to "cut and paste" ideas. There are also significant differences between high- and low proficiency students in the manner in which they decode the text: low-proficiency students produce more distortions in their summaries than high-proficiency students who generally give accurate information. Similarly, high-proficiency students are able to sort out global ideas from a labyrinth of localized ideas, unlike average- and low-proficiency students who include trivial information. The same trend is observed with paraphrasing and sentence combinations: high-proficiency students are generally able to recast and coordinate their ideas, unlike low-proficiency students who produce run-on ideas. In terms of the discrete cognitive and meta-cognitive skills preferred by students, low proficiency students are noticeably unable to exploit pre-summarizing cognitive strategies such as discriminating, selecting, note-making, grouping, inferring meanings of new words and using synonyms to convey the intended meanings. There are also greater differences between high- and low-proficiency students when it comes to the use of meta-cognitive strategies. Unlike high-proficiency students who use their reservoir of meta-cognitive skills such as self-judgment, low-proficiency students ostensibly find it difficult to direct their summaries to the demands of the task and are unable to check the accuracy of their summaries. The findings also show that some of the high-proficiency students and many average- and low-proficiency students distort idea units, find it difficult to use their own words and cannot distinguish between main and supporting details. This resulted in the production of circuitous summaries that often failed to capture the gist of the argument. The way the students processed the main ideas also reveals an inherent weakness: most students of different proficiency levels were unable to combine ideas from different paragraphs to produce a coherent text. Not surprising, then, there were too many long summaries produced by both high- and low-proficiency students. To tackle some of the problems related to summarization, pre-reading strategies can be taught, which activate relevant prior knowledge, so that the learning of new knowledge can be facilitated. During the reading process students can become more meta-cognitively aware by monitoring their level of understanding of the text by using, for example, the strategy suggested by Schraw (1998) of "stop, read and think". Text analysis can also be used to help the students identify the main themes or macro-propositions in a text, and hence gain a more global perspective of the content, which is important for selecting the main ideas in a text. A particularly useful approach to fostering a deeper understanding of content is to use a form of reciprocal or peer-mediated teaching, in which students in pairs can articulate to each other their understanding of the main ideas expressed in the text. As part of the solution to the problems faced by students when processing information, we need to take Sewlall's (2000: 170) advice that there should be "a paradigm shift in the learning philosophy from content-based to an emphasis on the acquisition of skills". In this regard, both content and ESL teachers need to train their students in the explicit use of summarizing strategies, and to plan interwoven lessons and learning activities that develop the learners' intellectual ways of dealing with different learning problems so that they can make learning quicker, easier, more effective and exciting.
- Full Text:
- Date Issued: 2007
- Authors: Chimbganda, Ambrose Bruce
- Date: 2007
- Subjects: English language -- Study and teaching (Foreign speakers) -- Botswana English language -- Study and teaching (Higher) -- Botswana Science -- Study and teaching (Higher) -- Botswana Language and education -- Botswana College students -- Botswana -- Language
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2341 , http://hdl.handle.net/10962/d1002623
- Description: One of the major problems faced by speakers of English as a second language (ESL) or non-native speakers of English (NNS) is that when they go to college or university, they find themselves without sufficient academic literacy skills to enable them to navigate their learning successfully, such as the ability to summarize textual material. This thesis examines the summarizing strategies used by ESL first year science students at the University of Botswana. Using multiple data collection methods, otherwise known as triangulation or pluralistic research, which is a combination of quantitative and qualitative methods, one hundred and twenty randomly sampled students completed questionnaires and summarized a scientific text. In order to observe the students more closely, nine students (3 high-, 3 average- and 3 low-proficiency) were purposively selected from the sample and wrote a further summary. The nine students were later interviewed in order to find out from them the kinds of strategies they had used in summarizing the texts. To obtain systematic data, the summaries and the taped interview were coded and analyzed using a hybrid scoring classification previously used by other researchers. The results from the Likert type of questionnaire suggest that the ESL first year science students are 'aware' of the appropriate reading, production and self-assessment strategies to use when summarizing. However, when the data from the questionnaire were cross-checked against the strategies they had used in the actual summarization of the text, most of their claims, especially those of the low-proficiency students, were not sustained. As a whole, the results show that high-proficiency students produce more accurate idea units and are more capable of generalizing ideas than low-proficiency students who prefer to "cut and paste" ideas. There are also significant differences between high- and low proficiency students in the manner in which they decode the text: low-proficiency students produce more distortions in their summaries than high-proficiency students who generally give accurate information. Similarly, high-proficiency students are able to sort out global ideas from a labyrinth of localized ideas, unlike average- and low-proficiency students who include trivial information. The same trend is observed with paraphrasing and sentence combinations: high-proficiency students are generally able to recast and coordinate their ideas, unlike low-proficiency students who produce run-on ideas. In terms of the discrete cognitive and meta-cognitive skills preferred by students, low proficiency students are noticeably unable to exploit pre-summarizing cognitive strategies such as discriminating, selecting, note-making, grouping, inferring meanings of new words and using synonyms to convey the intended meanings. There are also greater differences between high- and low-proficiency students when it comes to the use of meta-cognitive strategies. Unlike high-proficiency students who use their reservoir of meta-cognitive skills such as self-judgment, low-proficiency students ostensibly find it difficult to direct their summaries to the demands of the task and are unable to check the accuracy of their summaries. The findings also show that some of the high-proficiency students and many average- and low-proficiency students distort idea units, find it difficult to use their own words and cannot distinguish between main and supporting details. This resulted in the production of circuitous summaries that often failed to capture the gist of the argument. The way the students processed the main ideas also reveals an inherent weakness: most students of different proficiency levels were unable to combine ideas from different paragraphs to produce a coherent text. Not surprising, then, there were too many long summaries produced by both high- and low-proficiency students. To tackle some of the problems related to summarization, pre-reading strategies can be taught, which activate relevant prior knowledge, so that the learning of new knowledge can be facilitated. During the reading process students can become more meta-cognitively aware by monitoring their level of understanding of the text by using, for example, the strategy suggested by Schraw (1998) of "stop, read and think". Text analysis can also be used to help the students identify the main themes or macro-propositions in a text, and hence gain a more global perspective of the content, which is important for selecting the main ideas in a text. A particularly useful approach to fostering a deeper understanding of content is to use a form of reciprocal or peer-mediated teaching, in which students in pairs can articulate to each other their understanding of the main ideas expressed in the text. As part of the solution to the problems faced by students when processing information, we need to take Sewlall's (2000: 170) advice that there should be "a paradigm shift in the learning philosophy from content-based to an emphasis on the acquisition of skills". In this regard, both content and ESL teachers need to train their students in the explicit use of summarizing strategies, and to plan interwoven lessons and learning activities that develop the learners' intellectual ways of dealing with different learning problems so that they can make learning quicker, easier, more effective and exciting.
- Full Text:
- Date Issued: 2007
A study of the teaching of reading in Grade 1 in the Caprivi region, Namibia
- Authors: Nzwala, Kenneth
- Date: 2007
- Subjects: Reading (Primary) -- Namibia Teachers -- Attitudes -- Namibia Teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1785 , http://hdl.handle.net/10962/d1003670
- Description: This study was conducted in order to understand how Grade 1 teachers teach reading in mother tongue with a focus, firstly, on teacher beliefs and how such beliefs influence teachers’ practice, and secondly, on the methods they use to teach reading. The study was carried out in the Caprivi Region of Namibia. It took the form of an interpretive case study. Three schools were selected for study: one urban, one peri-urban and one rural. The purpose of this sampling was to consider the influence of context on teachers’ practice. The data was gathered by using semi-structured interviews with open ended questions, as well as lesson observations and stimulated recall with the individual teachers after every lesson. This was important in order to have clarity on areas that were not clear during lesson presentations. The key findings are that the teachers I studied taught reading without using books, and there was an absence of shared reading with the learners. Other key findings are: teachers had great love for stories; they had a problem of language, and had no proper understanding of the concept ‘literacy’.
- Full Text:
- Date Issued: 2007
- Authors: Nzwala, Kenneth
- Date: 2007
- Subjects: Reading (Primary) -- Namibia Teachers -- Attitudes -- Namibia Teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1785 , http://hdl.handle.net/10962/d1003670
- Description: This study was conducted in order to understand how Grade 1 teachers teach reading in mother tongue with a focus, firstly, on teacher beliefs and how such beliefs influence teachers’ practice, and secondly, on the methods they use to teach reading. The study was carried out in the Caprivi Region of Namibia. It took the form of an interpretive case study. Three schools were selected for study: one urban, one peri-urban and one rural. The purpose of this sampling was to consider the influence of context on teachers’ practice. The data was gathered by using semi-structured interviews with open ended questions, as well as lesson observations and stimulated recall with the individual teachers after every lesson. This was important in order to have clarity on areas that were not clear during lesson presentations. The key findings are that the teachers I studied taught reading without using books, and there was an absence of shared reading with the learners. Other key findings are: teachers had great love for stories; they had a problem of language, and had no proper understanding of the concept ‘literacy’.
- Full Text:
- Date Issued: 2007
A taxonomic revision of the southern African endemic genus Gazania (Asteraceae) based on morphometric, genetic and phylogeographic data
- Authors: Howis, Seranne
- Date: 2007
- Subjects: Compositae Plant genetics DNA Endemic plants -- South Africa Plant ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4200 , http://hdl.handle.net/10962/d1003769
- Description: Gazania is a small genus of the subtribe Gorteriinae, tribe Arctoteae, that is endemic to southern Africa. The genus was last revised in 1959 by Roessler, who noted that delimitation of the species of Gazania can be “extraordinarily difficult”. Morphometric data was collected to test the reality of the 16 species as delimited by Roessler, who based species boundaries on morphological characters. Only six taxa were found to be morphologically distinct, while the remaining samples showed no species cohesion. DNA sequence data from two nuclear spacer regions (ITS and ETS) and four chloroplast noncoding regions (the trnL and rpS16 introns, and the psbA-trnH and trnL-F spacers) of 43 samples were utilised to create a species level phylogeny and to investigate correlations between genetically delimited units and morphologically defined taxa. DNA sequence data reveal that seven species (as delimited by Roessler) are morphologically and genetically distinct. The remaining nine of Roessler’s species fall into a morphologically and genetically overlapping continuum that forms an ochlospecies. Phylogeographic methods (based on an expanded ITS and ETS DNA sequence data set from 169 samples) were employed to further resolve the limits of species, with special focus on the clades within the ochlospecies. These genetically defined clades were correlated with their geographical distributions, and in combination with molecular dating techniques, used to elucidate the recent climatic or environmental factors that may have shaped the phylogeographic structure of the genus. Phylogeographic patterns and molecular dating reveals that the genus Gazania is an example of a South African endemic clade that has undergone episodic cladogenesis in response to fluctuating climatic conditions over the last seven million years. The ochlospecies within Gazania is a result of repeated cycles of climate driven isolation in refugia and subsequent expansion and hybridization events during the Pliocene and Pleistocene. Comparisons with phylogeographic studies on other organisms reveal a common pattern indicative of the presence and evolutionary importance of an ancestral refugium in the arid Richtersveld / Namib region of southern Africa.
- Full Text:
- Date Issued: 2007
- Authors: Howis, Seranne
- Date: 2007
- Subjects: Compositae Plant genetics DNA Endemic plants -- South Africa Plant ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4200 , http://hdl.handle.net/10962/d1003769
- Description: Gazania is a small genus of the subtribe Gorteriinae, tribe Arctoteae, that is endemic to southern Africa. The genus was last revised in 1959 by Roessler, who noted that delimitation of the species of Gazania can be “extraordinarily difficult”. Morphometric data was collected to test the reality of the 16 species as delimited by Roessler, who based species boundaries on morphological characters. Only six taxa were found to be morphologically distinct, while the remaining samples showed no species cohesion. DNA sequence data from two nuclear spacer regions (ITS and ETS) and four chloroplast noncoding regions (the trnL and rpS16 introns, and the psbA-trnH and trnL-F spacers) of 43 samples were utilised to create a species level phylogeny and to investigate correlations between genetically delimited units and morphologically defined taxa. DNA sequence data reveal that seven species (as delimited by Roessler) are morphologically and genetically distinct. The remaining nine of Roessler’s species fall into a morphologically and genetically overlapping continuum that forms an ochlospecies. Phylogeographic methods (based on an expanded ITS and ETS DNA sequence data set from 169 samples) were employed to further resolve the limits of species, with special focus on the clades within the ochlospecies. These genetically defined clades were correlated with their geographical distributions, and in combination with molecular dating techniques, used to elucidate the recent climatic or environmental factors that may have shaped the phylogeographic structure of the genus. Phylogeographic patterns and molecular dating reveals that the genus Gazania is an example of a South African endemic clade that has undergone episodic cladogenesis in response to fluctuating climatic conditions over the last seven million years. The ochlospecies within Gazania is a result of repeated cycles of climate driven isolation in refugia and subsequent expansion and hybridization events during the Pliocene and Pleistocene. Comparisons with phylogeographic studies on other organisms reveal a common pattern indicative of the presence and evolutionary importance of an ancestral refugium in the arid Richtersveld / Namib region of southern Africa.
- Full Text:
- Date Issued: 2007