An investigation into the principals' leadership roles in selected schools in the Ohangwena Region in Namibia: case study
- Authors: Shitana, Silas Shituleipo
- Date: 2012
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena Management -- Employee participation -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1614 , http://hdl.handle.net/10962/d1003496
- Description: School leadership in Namibia over past centuries was characterized by ‘top down’ administration and typically proceeded without participation of those involved other than the principals who were the sole decision makers. The notion of school leadership through teamwork (team leadership) in Namibia was formalized after the advent of democracy in 1990 and the subsequent reorganization of the education system. The notion of team leadership is embedded in theories that stress participation, teamwork and distributed leadership. It is against this background that this study sought to investigate the current understandings of school leadership and application of team leadership among principals in selected schools in the Ohangwena region in Namibia. The study is an interpretive case study of two secondary schools in the above‐mentioned region in Namibia. The research utilized three quantitative data gathering techniques, namely semi‐structured interviews, observation and document analysis. The research participants were two principals, two teachers and two school board members from each research school. The main findings of this study revealed that the notion of participation of all stakeholders in education is seen as a fundamental aspect of the current leadership thinking. However, the respondents’ vision of leadership is limited and quite traditional in many ways. There is emphasis on the need to control, monitor, and delegate rather than team leadership. Furthermore, where consultation is mentioned it seems the respondents think of the passing down of information – a cascade model ‐ as consultation, a view that is narrow and inaccurate in terms of contemporary leadership theories. While there was an appreciation of the benefits derived from team leadership, challenges facing such leadership pervaded responses. These included lack of understanding of government policies such as ETSIP and NSPIs, resistance to change and implementation of policy. The study recommends that leadership and management programs and teacher leadership development programs be established in Namibia. Finally, the study recommends further research to include Learner Representative Council and Heads of Department. These stakeholders in education may provide new insights into the current school leadership thinking.
- Full Text:
- Authors: Shitana, Silas Shituleipo
- Date: 2012
- Subjects: School management and organization -- Namibia -- Ohangwena School principals -- Namibia -- Ohangwena Educational leadership -- Namibia -- Ohangwena Educational change -- Namibia -- Ohangwena Management -- Employee participation -- Namibia -- Ohangwena
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1614 , http://hdl.handle.net/10962/d1003496
- Description: School leadership in Namibia over past centuries was characterized by ‘top down’ administration and typically proceeded without participation of those involved other than the principals who were the sole decision makers. The notion of school leadership through teamwork (team leadership) in Namibia was formalized after the advent of democracy in 1990 and the subsequent reorganization of the education system. The notion of team leadership is embedded in theories that stress participation, teamwork and distributed leadership. It is against this background that this study sought to investigate the current understandings of school leadership and application of team leadership among principals in selected schools in the Ohangwena region in Namibia. The study is an interpretive case study of two secondary schools in the above‐mentioned region in Namibia. The research utilized three quantitative data gathering techniques, namely semi‐structured interviews, observation and document analysis. The research participants were two principals, two teachers and two school board members from each research school. The main findings of this study revealed that the notion of participation of all stakeholders in education is seen as a fundamental aspect of the current leadership thinking. However, the respondents’ vision of leadership is limited and quite traditional in many ways. There is emphasis on the need to control, monitor, and delegate rather than team leadership. Furthermore, where consultation is mentioned it seems the respondents think of the passing down of information – a cascade model ‐ as consultation, a view that is narrow and inaccurate in terms of contemporary leadership theories. While there was an appreciation of the benefits derived from team leadership, challenges facing such leadership pervaded responses. These included lack of understanding of government policies such as ETSIP and NSPIs, resistance to change and implementation of policy. The study recommends that leadership and management programs and teacher leadership development programs be established in Namibia. Finally, the study recommends further research to include Learner Representative Council and Heads of Department. These stakeholders in education may provide new insights into the current school leadership thinking.
- Full Text:
An investigation into the use of traditional Xhosa dance to teach mathematics: a case study in a Grade 7 class
- Authors: Mbusi, Nokwanda Princess
- Date: 2012
- Subjects: Mathematics -- Study and teaching (Primary) Teaching -- Aids and devices -- Research Xhosa (African people) -- Music Education, Primary -- South Africa -- Eastern Cape , Music in mathematics education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1617 , http://hdl.handle.net/10962/d1003499
- Description: This study seeks to explore mathematical concepts embedded in traditional Xhosa dance and how these concepts can be incorporated into a learning programme for the teaching and learning of mathematics. The study seeks to gain insight into whether learners could benefit from the implementation of such a learning programme. Learners from a Grade 7 class in a rural school performed traditional Xhosa dances and their performances were captured through video recording. The video recordings were then observed and analysed to determine the mathematical concepts embedded in the dances. These concepts were then linked to those found in the Grade 7 mathematics curriculum. A learning programme integrating mathematical concepts from the dance activities with mathematical concepts from the Grade 7 curriculum was then designed. The learning programme contained mathematical problem solving activities that required learners to re-enact the dance performances in order to find the required solutions. The learning programme was then implemented with the learners over a period of three weeks. During the implementation, learners’ behaviour towards the learning experience was observed, their engagement with the problem solving activities as well as their strategies for solving the problems, were carefully observed. Also, their interactions with each other were noted. After the implementation of the learning programme, focus group interviews were held with learners to determine their opinions, attitudes and feelings about their experience of learning mathematics through traditional Xhosa dance. Key findings indicated that traditional Xhosa dance can be used as a medium for learning many concepts in the mathematics curriculum; the use of the dance gave learners an opportunity to learn mathematics from a familiar context and to participate actively and collaboratively in their learning. Also, it emerged that the use of dance to teach mathematics had potential to help improve learners’ attitudes towards mathematics. Conclusions were reached that the dance had potential for use as a means for the meaningful learning of mathematics. However, limitations and challenges with the study were identified, such as its limited replicability in other mathematics classrooms.
- Full Text:
- Authors: Mbusi, Nokwanda Princess
- Date: 2012
- Subjects: Mathematics -- Study and teaching (Primary) Teaching -- Aids and devices -- Research Xhosa (African people) -- Music Education, Primary -- South Africa -- Eastern Cape , Music in mathematics education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1617 , http://hdl.handle.net/10962/d1003499
- Description: This study seeks to explore mathematical concepts embedded in traditional Xhosa dance and how these concepts can be incorporated into a learning programme for the teaching and learning of mathematics. The study seeks to gain insight into whether learners could benefit from the implementation of such a learning programme. Learners from a Grade 7 class in a rural school performed traditional Xhosa dances and their performances were captured through video recording. The video recordings were then observed and analysed to determine the mathematical concepts embedded in the dances. These concepts were then linked to those found in the Grade 7 mathematics curriculum. A learning programme integrating mathematical concepts from the dance activities with mathematical concepts from the Grade 7 curriculum was then designed. The learning programme contained mathematical problem solving activities that required learners to re-enact the dance performances in order to find the required solutions. The learning programme was then implemented with the learners over a period of three weeks. During the implementation, learners’ behaviour towards the learning experience was observed, their engagement with the problem solving activities as well as their strategies for solving the problems, were carefully observed. Also, their interactions with each other were noted. After the implementation of the learning programme, focus group interviews were held with learners to determine their opinions, attitudes and feelings about their experience of learning mathematics through traditional Xhosa dance. Key findings indicated that traditional Xhosa dance can be used as a medium for learning many concepts in the mathematics curriculum; the use of the dance gave learners an opportunity to learn mathematics from a familiar context and to participate actively and collaboratively in their learning. Also, it emerged that the use of dance to teach mathematics had potential to help improve learners’ attitudes towards mathematics. Conclusions were reached that the dance had potential for use as a means for the meaningful learning of mathematics. However, limitations and challenges with the study were identified, such as its limited replicability in other mathematics classrooms.
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An investigation into the use of Visual Technology for the Autonomous Learning of mathematics (VITALmaths) video clips through the medium of cell phones in the teaching of mathematics in selected South African Grade 9 classes: a case study
- Authors: Hyde, Janet Catherine
- Date: 2012
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa Educational innovations -- South Africa Telecommunication in education -- South Africa Teaching -- South Africa -- Aids and devices
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1618 , http://hdl.handle.net/10962/d1003500
- Description: This qualitative study examines the use of Visual Technology for the Autonomous Learning of mathematics (VITALmaths) video clips in three Grade 9 classrooms in the Eastern Cape, South Africa, two of which are in well-resourced ex-Model C schools and one in a semi-rural township school. The rapid development of mobile technology, especially in Africa, has opened up previously unexplored avenues in economy, communication and education (Aker & Mbiti, 2010), with a number of mobile learning initiatives being launched in South Africa (Botha & Ford, 2007; Vosloo & Botha, 2009). The VITALmaths project was developed collaboratively between the University of Applied Sciences Northwestern Switzerland and Rhodes University in South Africa (Linneweber-Lammerskitten, Schäfer and Samson, 2010). As the main platform for dissemination of the video clips is the cell phone, the study looked at the various aspects involved in the use of cell phones by learners in the classroom, as well as the incorporation of the clips into the teaching of three teachers. Consideration was given to whether or not the clips assisted the teachers in teaching, as well as whether or not they encouraged further exploration. The study was divided into six stages during which data was collected and analysed using an interpretive approach throughout. Data collection methods included semistructured interviews, questionnaires, observation, journals and reflective essays. The study revealed the participating teachers, having incorporated the clips into several lessons, found that these had a meaningful effect on their teaching practice, as well as on the engagement of the learners in the lessons. The majority of the learners involved in the study had access to cell phones, either their own or borrowed, and were able to download the video clips onto their phones from the website (www.ru.ac.za/vitalmaths). A number of learners found that the clips helped them find examples of specific mathematical concepts outside of the classroom, thus leading to further enquiry and exploration, while several learners downloaded and viewed additional clips. Overall findings showed that the VITALmaths video clips could be incorporated into teaching with relative ease.
- Full Text:
- Authors: Hyde, Janet Catherine
- Date: 2012
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa Educational innovations -- South Africa Telecommunication in education -- South Africa Teaching -- South Africa -- Aids and devices
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1618 , http://hdl.handle.net/10962/d1003500
- Description: This qualitative study examines the use of Visual Technology for the Autonomous Learning of mathematics (VITALmaths) video clips in three Grade 9 classrooms in the Eastern Cape, South Africa, two of which are in well-resourced ex-Model C schools and one in a semi-rural township school. The rapid development of mobile technology, especially in Africa, has opened up previously unexplored avenues in economy, communication and education (Aker & Mbiti, 2010), with a number of mobile learning initiatives being launched in South Africa (Botha & Ford, 2007; Vosloo & Botha, 2009). The VITALmaths project was developed collaboratively between the University of Applied Sciences Northwestern Switzerland and Rhodes University in South Africa (Linneweber-Lammerskitten, Schäfer and Samson, 2010). As the main platform for dissemination of the video clips is the cell phone, the study looked at the various aspects involved in the use of cell phones by learners in the classroom, as well as the incorporation of the clips into the teaching of three teachers. Consideration was given to whether or not the clips assisted the teachers in teaching, as well as whether or not they encouraged further exploration. The study was divided into six stages during which data was collected and analysed using an interpretive approach throughout. Data collection methods included semistructured interviews, questionnaires, observation, journals and reflective essays. The study revealed the participating teachers, having incorporated the clips into several lessons, found that these had a meaningful effect on their teaching practice, as well as on the engagement of the learners in the lessons. The majority of the learners involved in the study had access to cell phones, either their own or borrowed, and were able to download the video clips onto their phones from the website (www.ru.ac.za/vitalmaths). A number of learners found that the clips helped them find examples of specific mathematical concepts outside of the classroom, thus leading to further enquiry and exploration, while several learners downloaded and viewed additional clips. Overall findings showed that the VITALmaths video clips could be incorporated into teaching with relative ease.
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An investigation of community learning through participation in integrated water resource management practices
- Authors: Phiri, Charles M
- Date: 2012
- Subjects: Water-supply -- Management -- South Africa Water conservation -- South Africa -- Management Water resources development -- South Africa -- Citizen participation Rain and rainfall -- South Africa Water quality management -- South Africa Integrated water development -- South Africa Water -- Management -- South Africa -- Study and teaching Social learning -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1622 , http://hdl.handle.net/10962/d1003504
- Description: South Africa is a semi arid country in which the average rainfall of 450mm/year is well below the world average of about 860mm/year. As a result, South Africa’s water resources are scarce in global terms and limited in extent. Current predictions are that demand will outstrip water availability in the next 15 years. A coordinated approach to improve both water quality and quantity is needed and in order to achieve that, it is crucial to strengthen capacities of local community involvement in identifying the problems that affect them and strategies to solve them. This research was undertaken to develop a deeper understanding of community learning processes in integrated water resources management (IWRM) practices. The study drew on situated and social learning theory which explains that knowledge and skills are learned and embedded in the contexts in which knowledge is obtained and applied in everyday situations. Multiple data collection techniques were used within a case study design and included document analysis, interviews, focus group discussions and field observations. Data analysis was done in three phases and involved uncovering patterns and trends in the data sets. In this context I discovered, through careful observation and interviews with members of the different communities of practice, that people are learning through social learning interactions with other community members as they engage in their daily water management and food production practices. Learning interactions take place through both informal and formal processes such as meetings, training workshops, conversations and interactions with outsiders. I also discovered that people learn from ‘external groups’ or training programmes which bring new knowledge and expertise, but this needs to be contextualised in the local communities of practice. The research has also shown that there are a number of challenges that appear to exist in these learning contexts. For instance it was found that participation and social learning processes and interactions are influenced by a range of causal mechanisms that are contextual. These insights into how communities learn, as well as the tensions and difficulties that are experienced in the learning processes are important for furthering learning and participation in community-based IWRM practices, projects and programmes.
- Full Text:
- Authors: Phiri, Charles M
- Date: 2012
- Subjects: Water-supply -- Management -- South Africa Water conservation -- South Africa -- Management Water resources development -- South Africa -- Citizen participation Rain and rainfall -- South Africa Water quality management -- South Africa Integrated water development -- South Africa Water -- Management -- South Africa -- Study and teaching Social learning -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1622 , http://hdl.handle.net/10962/d1003504
- Description: South Africa is a semi arid country in which the average rainfall of 450mm/year is well below the world average of about 860mm/year. As a result, South Africa’s water resources are scarce in global terms and limited in extent. Current predictions are that demand will outstrip water availability in the next 15 years. A coordinated approach to improve both water quality and quantity is needed and in order to achieve that, it is crucial to strengthen capacities of local community involvement in identifying the problems that affect them and strategies to solve them. This research was undertaken to develop a deeper understanding of community learning processes in integrated water resources management (IWRM) practices. The study drew on situated and social learning theory which explains that knowledge and skills are learned and embedded in the contexts in which knowledge is obtained and applied in everyday situations. Multiple data collection techniques were used within a case study design and included document analysis, interviews, focus group discussions and field observations. Data analysis was done in three phases and involved uncovering patterns and trends in the data sets. In this context I discovered, through careful observation and interviews with members of the different communities of practice, that people are learning through social learning interactions with other community members as they engage in their daily water management and food production practices. Learning interactions take place through both informal and formal processes such as meetings, training workshops, conversations and interactions with outsiders. I also discovered that people learn from ‘external groups’ or training programmes which bring new knowledge and expertise, but this needs to be contextualised in the local communities of practice. The research has also shown that there are a number of challenges that appear to exist in these learning contexts. For instance it was found that participation and social learning processes and interactions are influenced by a range of causal mechanisms that are contextual. These insights into how communities learn, as well as the tensions and difficulties that are experienced in the learning processes are important for furthering learning and participation in community-based IWRM practices, projects and programmes.
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An investigation of how enquiry-based fieldwork develops action competence in Grade 12 Geography: a Namibian case study
- Authors: Simasiku, Frederick
- Date: 2012
- Subjects: Competency-based education -- Namibia -- Hardap Geography -- Study and teaching (Secondary) -- Namibia -- Hardap Student-centered learning -- Namibia -- Hardap Active learning -- Namibia -- Hardap Environmental education -- Namibia -- Hardap Environmental education -- Activity programs -- Namibia -- Hardap
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1629 , http://hdl.handle.net/10962/d1003511
- Description: The goal of the study was twofold: firstly to investigate and describe how senior secondary school geography teachers were implementing enquiry-based learning through fieldwork. Secondly, to investigate and document how enquiry-based learning through fieldwork facilitated the development of action competence amongst learners in a geography classroom. In order to address the first goal, a survey questionnaire was utilised to generate descriptive data from a sample of seven geography teachers in the Hardap region of Namibia. Although teachers engaged learners with enquiry-based fieldwork learning activities it is suggested, based on the findings of data of this goal, that teachers face severe limitations in terms of integrating environmental learning into the geography curriculum. The main limitations of the teachers include: limited practical knowledge of and training in how to teach fieldwork skills; a lack of teaching resource materials; time constraints; heavy personal loads; and lack of school support for environmental education. In addressing the second goal an enquiry-based fieldwork learning unit was planned and implemented in the researcher’s classroom. Observation, focus group interviews, and audio records of learning interactions, were used as data generation methods for this cycle of the study. An indicator framework for identifying action competence in learners was constructed as a data analysis tool. In terms of the findings of goal two it is evident that enquiry-based learning through fieldwork facilitated the development of action competence amongst learners. Six overarching benefits of this type of learning were identified in this study, namely: - It empowered learners to develop contextual knowledge and understanding of issues that they investigated. - It facilitated commitment thus motivated learners to take indirect action. - It promoted social interaction and group cohesion amongst learners thus enhanced their decision-making ability for problem-solving and action taking. - It elicited emotional responses and a greater understanding of learners’ own and others’ attitudes and values towards issues. - It fostered critical thinking thus permitted learners to envisage a future based on their learning experiences. - It enabled learners to plan and take indirect action during the learning process. Based on the research findings, some lessons learned are presented in an attempt to contribute to the effective implementation of enquiry-based fieldwork at the classroom level.
- Full Text:
- Authors: Simasiku, Frederick
- Date: 2012
- Subjects: Competency-based education -- Namibia -- Hardap Geography -- Study and teaching (Secondary) -- Namibia -- Hardap Student-centered learning -- Namibia -- Hardap Active learning -- Namibia -- Hardap Environmental education -- Namibia -- Hardap Environmental education -- Activity programs -- Namibia -- Hardap
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1629 , http://hdl.handle.net/10962/d1003511
- Description: The goal of the study was twofold: firstly to investigate and describe how senior secondary school geography teachers were implementing enquiry-based learning through fieldwork. Secondly, to investigate and document how enquiry-based learning through fieldwork facilitated the development of action competence amongst learners in a geography classroom. In order to address the first goal, a survey questionnaire was utilised to generate descriptive data from a sample of seven geography teachers in the Hardap region of Namibia. Although teachers engaged learners with enquiry-based fieldwork learning activities it is suggested, based on the findings of data of this goal, that teachers face severe limitations in terms of integrating environmental learning into the geography curriculum. The main limitations of the teachers include: limited practical knowledge of and training in how to teach fieldwork skills; a lack of teaching resource materials; time constraints; heavy personal loads; and lack of school support for environmental education. In addressing the second goal an enquiry-based fieldwork learning unit was planned and implemented in the researcher’s classroom. Observation, focus group interviews, and audio records of learning interactions, were used as data generation methods for this cycle of the study. An indicator framework for identifying action competence in learners was constructed as a data analysis tool. In terms of the findings of goal two it is evident that enquiry-based learning through fieldwork facilitated the development of action competence amongst learners. Six overarching benefits of this type of learning were identified in this study, namely: - It empowered learners to develop contextual knowledge and understanding of issues that they investigated. - It facilitated commitment thus motivated learners to take indirect action. - It promoted social interaction and group cohesion amongst learners thus enhanced their decision-making ability for problem-solving and action taking. - It elicited emotional responses and a greater understanding of learners’ own and others’ attitudes and values towards issues. - It fostered critical thinking thus permitted learners to envisage a future based on their learning experiences. - It enabled learners to plan and take indirect action during the learning process. Based on the research findings, some lessons learned are presented in an attempt to contribute to the effective implementation of enquiry-based fieldwork at the classroom level.
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An investigation of how natural sciences teachers mediate learning of chemical reactions in Grade 9: a case study
- Authors: Xipu, Bukelwa
- Date: 2012
- Subjects: Science -- Study and teaching (Secondary) Science -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Chemical reactions Science teachers -- South Africa -- Eastern Cape Science teachers -- Rating of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1631 , http://hdl.handle.net/10962/d1003513
- Description: This research study involves two Grade 9 Natural Sciences teachers from two schools in the Lady Frere District of the Eastern Cape. The reason for selecting these two teachers is that in 2009 they, like me, obtained an Advanced Certificate in Education (Science and Maths) from Rhodes University. As a result, we have a good working relationship. Furthermore, both teachers are actively involved in the Natural Sciences curriculum in the District and their schools are not far from the District Office where I work. The principal objective of this study was to investigate how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9. It was triggered by the transformation in curriculum in South Africa as well as by my experience of working with Natural Sciences teachers in our rural district. The study is informed by an interpretive paradigm using a qualitative case study approach. The data was gathered by administering analysis of documents, semi-structured interviews, observations, field notes and journals. During the data analysis process, patterns and themes were illuminated using the inductive analysis method. Rich data sets in relation to the main research question on how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9 emerged from the analysed data. The conclusions that can be drawn from the study indicate that when teaching chemical reactions, teachers should have adequate content knowledge as well as pedagogical content knowledge. It is thus recommended that teachers consider the prior knowledge of learners, use a variety of teaching and learning approaches including practical activities, to make learning meaningful. The major limitation of this study is that the two selected teachers do not represent the whole population of Grade 9 teachers in the Lady Frere District. Therefore, the findings cannot be generalized to represent the larger population. It is recognised, however, that within the qualitative inquiry, reliability and generalizability play a minor role.
- Full Text:
- Authors: Xipu, Bukelwa
- Date: 2012
- Subjects: Science -- Study and teaching (Secondary) Science -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Chemical reactions Science teachers -- South Africa -- Eastern Cape Science teachers -- Rating of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1631 , http://hdl.handle.net/10962/d1003513
- Description: This research study involves two Grade 9 Natural Sciences teachers from two schools in the Lady Frere District of the Eastern Cape. The reason for selecting these two teachers is that in 2009 they, like me, obtained an Advanced Certificate in Education (Science and Maths) from Rhodes University. As a result, we have a good working relationship. Furthermore, both teachers are actively involved in the Natural Sciences curriculum in the District and their schools are not far from the District Office where I work. The principal objective of this study was to investigate how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9. It was triggered by the transformation in curriculum in South Africa as well as by my experience of working with Natural Sciences teachers in our rural district. The study is informed by an interpretive paradigm using a qualitative case study approach. The data was gathered by administering analysis of documents, semi-structured interviews, observations, field notes and journals. During the data analysis process, patterns and themes were illuminated using the inductive analysis method. Rich data sets in relation to the main research question on how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9 emerged from the analysed data. The conclusions that can be drawn from the study indicate that when teaching chemical reactions, teachers should have adequate content knowledge as well as pedagogical content knowledge. It is thus recommended that teachers consider the prior knowledge of learners, use a variety of teaching and learning approaches including practical activities, to make learning meaningful. The major limitation of this study is that the two selected teachers do not represent the whole population of Grade 9 teachers in the Lady Frere District. Therefore, the findings cannot be generalized to represent the larger population. It is recognised, however, that within the qualitative inquiry, reliability and generalizability play a minor role.
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An investigation of instructional leadership in a Namibian rural school
- Authors: Namukwambi, Nahum
- Date: 2012
- Subjects: Educational leadership -- Namibia -- Omusati Rural schools -- Namibia -- Omusati School management and organization -- Namibia -- Omusati Teachers -- Namibia -- Omusati Effective teaching -- Namibia -- Omusati Learning -- Namibia -- Omusati
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1633 , http://hdl.handle.net/10962/d1003515
- Description: The purpose of this study was to investigate how instructional leadership manifests itself and can be strengthened in a Namibian rural school. As a teacher, head of department and later an education officer, I have long held the view that committed school leadership is essential for the school’s instructional and academic success. Equally, I have always been aware of the impact of the past segregation and the unequal education provided by the colonial government in South Africa and South West Africa/Namibia. The inferior education provided to Africans posed a serious challenge to the leadership and management of schools, as would be principals were not adequately trained to provide the necessary “ingredients” relevant for instructional success. Given this background, I attempted, using a case study of one secondary school, to investigate how instructional leadership is manifesting itself and could be strengthened in a rural school in the Omusati region of Namibia. Research questions that framed the study were: firstly, how does the leadership approach in the school promote teaching and learning; secondly, what is the role of external players in enhancing instructional leadership and thirdly, what are the strengthening and inhibiting factors of instructional leadership. The population of the study was composed of an Inspector of Education, a school principal, a head of department (HOD) and four teachers from a secondary school, located in the Omusati region in Namibia. Data were collected through interviews, document analysis and observation. With regard to data analysis, I first immersed myself in the data. I developed themes that formed the basis of my discussion with my research questions in mind. The analysis revealed that instructional leadership is strongly evidenced at the case study school. However, it emerged that despite the existence of strong instructional leadership at the school, as with all other organisations, there are several challenges that limit the effective implementation of the teaching and learning programme. These challenges vary from indiscipline, poor time management, to lack of teaching and learning resources. Participants also provided a number of possible solutions to the problems identified, including that the principal should be a good role model for the staff and that an enabling environment for both teaching and learning should be created. The study also strongly suggested that participative leadership and management is a cornerstone to the academic success of the school.
- Full Text:
- Authors: Namukwambi, Nahum
- Date: 2012
- Subjects: Educational leadership -- Namibia -- Omusati Rural schools -- Namibia -- Omusati School management and organization -- Namibia -- Omusati Teachers -- Namibia -- Omusati Effective teaching -- Namibia -- Omusati Learning -- Namibia -- Omusati
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1633 , http://hdl.handle.net/10962/d1003515
- Description: The purpose of this study was to investigate how instructional leadership manifests itself and can be strengthened in a Namibian rural school. As a teacher, head of department and later an education officer, I have long held the view that committed school leadership is essential for the school’s instructional and academic success. Equally, I have always been aware of the impact of the past segregation and the unequal education provided by the colonial government in South Africa and South West Africa/Namibia. The inferior education provided to Africans posed a serious challenge to the leadership and management of schools, as would be principals were not adequately trained to provide the necessary “ingredients” relevant for instructional success. Given this background, I attempted, using a case study of one secondary school, to investigate how instructional leadership is manifesting itself and could be strengthened in a rural school in the Omusati region of Namibia. Research questions that framed the study were: firstly, how does the leadership approach in the school promote teaching and learning; secondly, what is the role of external players in enhancing instructional leadership and thirdly, what are the strengthening and inhibiting factors of instructional leadership. The population of the study was composed of an Inspector of Education, a school principal, a head of department (HOD) and four teachers from a secondary school, located in the Omusati region in Namibia. Data were collected through interviews, document analysis and observation. With regard to data analysis, I first immersed myself in the data. I developed themes that formed the basis of my discussion with my research questions in mind. The analysis revealed that instructional leadership is strongly evidenced at the case study school. However, it emerged that despite the existence of strong instructional leadership at the school, as with all other organisations, there are several challenges that limit the effective implementation of the teaching and learning programme. These challenges vary from indiscipline, poor time management, to lack of teaching and learning resources. Participants also provided a number of possible solutions to the problems identified, including that the principal should be a good role model for the staff and that an enabling environment for both teaching and learning should be created. The study also strongly suggested that participative leadership and management is a cornerstone to the academic success of the school.
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An investigation of teachers', learners' and parents' understanding and perceptions of a whole school approach to environmental learning in selected schools in the Oshana Region, Namibia
- Authors: Nashilongo, Onesmus
- Date: 2012
- Subjects: Environmental education -- Namibia -- Oshana Environmental education -- Curricula -- Namibia -- Oshana Environmental education -- Parent participation -- Namibia -- Oshana Environmental education -- Study and teaching -- Namibia -- Oshana Supporting Environmental Education in Namibia (SEEN) Sustainable development -- Study and teaching -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1646 , http://hdl.handle.net/10962/d1003528
- Description: This study sought to investigate teacher, learner and parental perceptions and understanding of a whole school approach in environmental education (EE). There were five schools piloting environmental education through a whole school development approach in the Oshana Region of Namibia. The study was conducted in two rural schools in the Oshana Region. The schools were selected because they participated and piloted the infusion of environmental education themes in the curriculum through the whole school approach during the Supporting Environmental Education in Namibia (SEEN) project piloting phase from 2001 to 2005. This study was shaped and informed by international theories, practices and perspectives of a whole school approach as cited in chapter two of this study. In other words a whole school approach has provided theoretical background information and a practical framework on which this study was built. A whole school approach provides a theoretical understanding of how the school community, the biophysical environment, as well as the curriculum can benefit from EE projects through a whole school development approach. The whole school approach, discussed in this study, provides an opportunity to see the link between the whole school approach and ESD in order to understand the role a whole school approach plays in the implementation of ESD in Namibia. The research took the form of an interpretive case study focusing on a study of two teachers, two learners, and two members of the community. Data were collected through semi-structured interviews, document analysis and site observations. This study was undertaken two years later after the Supporting Environmental Education Namibia (SEEN) pilot project phased out. The findings indicate that despite the training and support received by the schools during the operation of the Supporting Environmental Education Namibia (SEEN) pilot project, schools are still experiencing problems with the application of a whole school approach. The findings revealed that the curriculum should provide guidelines and examples to support teachers on how to integrate environmental education in the teaching and learning process. The results of the study indicate that teachers, learners and members of the community have a limited understanding about how a whole school development approach in environmental education is linked to Education Sustainable Development (ESD) and the four dimensions of the environment.
- Full Text:
- Authors: Nashilongo, Onesmus
- Date: 2012
- Subjects: Environmental education -- Namibia -- Oshana Environmental education -- Curricula -- Namibia -- Oshana Environmental education -- Parent participation -- Namibia -- Oshana Environmental education -- Study and teaching -- Namibia -- Oshana Supporting Environmental Education in Namibia (SEEN) Sustainable development -- Study and teaching -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1646 , http://hdl.handle.net/10962/d1003528
- Description: This study sought to investigate teacher, learner and parental perceptions and understanding of a whole school approach in environmental education (EE). There were five schools piloting environmental education through a whole school development approach in the Oshana Region of Namibia. The study was conducted in two rural schools in the Oshana Region. The schools were selected because they participated and piloted the infusion of environmental education themes in the curriculum through the whole school approach during the Supporting Environmental Education in Namibia (SEEN) project piloting phase from 2001 to 2005. This study was shaped and informed by international theories, practices and perspectives of a whole school approach as cited in chapter two of this study. In other words a whole school approach has provided theoretical background information and a practical framework on which this study was built. A whole school approach provides a theoretical understanding of how the school community, the biophysical environment, as well as the curriculum can benefit from EE projects through a whole school development approach. The whole school approach, discussed in this study, provides an opportunity to see the link between the whole school approach and ESD in order to understand the role a whole school approach plays in the implementation of ESD in Namibia. The research took the form of an interpretive case study focusing on a study of two teachers, two learners, and two members of the community. Data were collected through semi-structured interviews, document analysis and site observations. This study was undertaken two years later after the Supporting Environmental Education Namibia (SEEN) pilot project phased out. The findings indicate that despite the training and support received by the schools during the operation of the Supporting Environmental Education Namibia (SEEN) pilot project, schools are still experiencing problems with the application of a whole school approach. The findings revealed that the curriculum should provide guidelines and examples to support teachers on how to integrate environmental education in the teaching and learning process. The results of the study indicate that teachers, learners and members of the community have a limited understanding about how a whole school development approach in environmental education is linked to Education Sustainable Development (ESD) and the four dimensions of the environment.
- Full Text:
An investigation of the learning processes that take place during practical work activities when using electrical circuit boards in grade: a case study
- Authors: Accom, Gerald Charles
- Date: 2012
- Subjects: Competency-based education -- South Africa -- Eastern Cape -- Case studies Educational tests and measurements -- South Africa -- Eastern Cape -- Case studies Education -- Evaluation -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1961 , http://hdl.handle.net/10962/d1009687
- Description: Since the introduction of Outcomes Based Education (OBE) as a preferred method of teaching and learning with Curriculum 2005 in 1997, its existence has come under continuous threat for the past thirteen years. Its teething experiences included a revision in 2004 which saw the introduction of the Revised National Curriculum Statements (RNCS) and most recently, we are now standing on the threshold of the implementation of the Curriculum Assessment Policy Statements (CAPS) in 2012. Throughout the turbulent educational milieu, social constructivism has always been upheld as the preferred teaching and learning methodology and millions of rands have been invested in this regard. This study is thus premised on the concern that now after all the years of actively promoting social constructivist methodologies, the implementation of the CAPS could seriously negate reasonable strides made in this regard. Triggered by these curricular issues, a qualitative case study was conducted at a school in Grahamstown in the Eastern Cape, South Africa, investigating the learning processes occurring in group work sessions during lessons involving practical work in electricity using circuit boards in grade 8. Underpinned by an interpretivist paradigm, the study took place in two phases. The data was mainly generated through audio and video recording of two focus groups. An open coding system was employed to derive analytical categories and frequency tables were used to establish trends. In order to validate the data, two observer teachers were involved throughout the research process and this was followed up with semistructured interviews after the second phase. The two case studies, involving learners fitting a similar profile in respect of mother-tongue and age group, were engaged in a similar activity for almost a year apart. This study anticipated the revelation of the extent to which group practical activities in electricity promoted learning, how knowledge is constructed in group-settings and whether practical activities involving electrical circuit boards in grade 8 enhance learning? The main findings of my study revealed that these practical activities can promote learning and therefore should remain a preferred method of teaching.
- Full Text:
- Authors: Accom, Gerald Charles
- Date: 2012
- Subjects: Competency-based education -- South Africa -- Eastern Cape -- Case studies Educational tests and measurements -- South Africa -- Eastern Cape -- Case studies Education -- Evaluation -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1961 , http://hdl.handle.net/10962/d1009687
- Description: Since the introduction of Outcomes Based Education (OBE) as a preferred method of teaching and learning with Curriculum 2005 in 1997, its existence has come under continuous threat for the past thirteen years. Its teething experiences included a revision in 2004 which saw the introduction of the Revised National Curriculum Statements (RNCS) and most recently, we are now standing on the threshold of the implementation of the Curriculum Assessment Policy Statements (CAPS) in 2012. Throughout the turbulent educational milieu, social constructivism has always been upheld as the preferred teaching and learning methodology and millions of rands have been invested in this regard. This study is thus premised on the concern that now after all the years of actively promoting social constructivist methodologies, the implementation of the CAPS could seriously negate reasonable strides made in this regard. Triggered by these curricular issues, a qualitative case study was conducted at a school in Grahamstown in the Eastern Cape, South Africa, investigating the learning processes occurring in group work sessions during lessons involving practical work in electricity using circuit boards in grade 8. Underpinned by an interpretivist paradigm, the study took place in two phases. The data was mainly generated through audio and video recording of two focus groups. An open coding system was employed to derive analytical categories and frequency tables were used to establish trends. In order to validate the data, two observer teachers were involved throughout the research process and this was followed up with semistructured interviews after the second phase. The two case studies, involving learners fitting a similar profile in respect of mother-tongue and age group, were engaged in a similar activity for almost a year apart. This study anticipated the revelation of the extent to which group practical activities in electricity promoted learning, how knowledge is constructed in group-settings and whether practical activities involving electrical circuit boards in grade 8 enhance learning? The main findings of my study revealed that these practical activities can promote learning and therefore should remain a preferred method of teaching.
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An investigation of the role of physical manipulatives in the teaching and learning of measurement in Grade 8 : a case study using surface area and volume
- Authors: Chiphambo, Shakespear M E K
- Date: 2012
- Subjects: Measurement -- Study and teaching -- Research Mathematics -- Education (Secondary) -- Study and teaching Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1657 , http://hdl.handle.net/10962/d1003540
- Description: The purpose of this study is to investigate the role of physical manipulatives in the teaching and learning of measurement in Grade 8. The study focuses on how the use of physical manipulatives promotes learners' mathematical proficiency in relation to the five strands of Kilpatrick, Swafford and Findell (2001). The basis of the research is a case study in the interpretive paradigm involving 18 out of a cohort of 270 Grade 8 learners in the school where I teach. The data was collected using a range of methods including: (i) baseline assessment tasks, first piloted using 7 Grade 8 learners and then given to the target group; (ii) an intervention programme with intervention tasks; (iii) a post-intervention task; (iv) observations during the intervention; and (v) individual interviews. The results of the baseline assessment and the post-intervention tasks were analysed both quantitatively and qualitatively. My research findings indicate an overall improvement of the performance after learners engaged in using physical manipulatives. The average mark of the learners in the baseline assessment task was 23% and after the intervention programme the average mark was 31 %. The responses from the learners interviewed showed that they were motivated and that the use of physical manipulatives assisted them in understanding the concepts of measurement, in particular surface area and volume. The results of my study thus reveal that the use of physical manipulatives in teaching and learning mathematics has a positive role to play in learners' understanding of surface area and volume at the Grade 8 level. The fmdings of this case study support other research regarding the importance of using physical manipulatives in teaching and learning mathematics. They align with other findings that assert that manipulatives are essential mediating tools in the development of the conceptual and procedural understanding of mathematical concepts, clarifying and helping learners to visualize abstract mathematical concepts.
- Full Text:
- Authors: Chiphambo, Shakespear M E K
- Date: 2012
- Subjects: Measurement -- Study and teaching -- Research Mathematics -- Education (Secondary) -- Study and teaching Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1657 , http://hdl.handle.net/10962/d1003540
- Description: The purpose of this study is to investigate the role of physical manipulatives in the teaching and learning of measurement in Grade 8. The study focuses on how the use of physical manipulatives promotes learners' mathematical proficiency in relation to the five strands of Kilpatrick, Swafford and Findell (2001). The basis of the research is a case study in the interpretive paradigm involving 18 out of a cohort of 270 Grade 8 learners in the school where I teach. The data was collected using a range of methods including: (i) baseline assessment tasks, first piloted using 7 Grade 8 learners and then given to the target group; (ii) an intervention programme with intervention tasks; (iii) a post-intervention task; (iv) observations during the intervention; and (v) individual interviews. The results of the baseline assessment and the post-intervention tasks were analysed both quantitatively and qualitatively. My research findings indicate an overall improvement of the performance after learners engaged in using physical manipulatives. The average mark of the learners in the baseline assessment task was 23% and after the intervention programme the average mark was 31 %. The responses from the learners interviewed showed that they were motivated and that the use of physical manipulatives assisted them in understanding the concepts of measurement, in particular surface area and volume. The results of my study thus reveal that the use of physical manipulatives in teaching and learning mathematics has a positive role to play in learners' understanding of surface area and volume at the Grade 8 level. The fmdings of this case study support other research regarding the importance of using physical manipulatives in teaching and learning mathematics. They align with other findings that assert that manipulatives are essential mediating tools in the development of the conceptual and procedural understanding of mathematical concepts, clarifying and helping learners to visualize abstract mathematical concepts.
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An ion-imprinted polymer for the selective extraction of mercury(II) ions in aqueous media
- Batlokwa, Bareki Shima, Chimuka, Luke, Tshentu, Zenixole R, Cukrowska, Ewa, Torto, Nelson
- Authors: Batlokwa, Bareki Shima , Chimuka, Luke , Tshentu, Zenixole R , Cukrowska, Ewa , Torto, Nelson
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6566 , http://hdl.handle.net/10962/d1004125
- Description: A double-imprinted polymer exhibiting high sensitivity for mercury(II) in aqueous solution is presented. Polymer particles imprinted with mercury(II) were synthesised by copolymerising the functional and cross-linking monomers, N’–[3– (Trimethoxysilyl)–propyl]diethylenetriamine (TPET) and tetraethylorthosilicate (TEOS). A double-imprinting procedure employing hexadecyltrimethylammonium bromide (CTAB), as a second template to improve the efficiency of the polymer, was adopted. The imprinted polymer was characterised by FTIR, scanning electron microscopy (SEM) and the average size determined by screen analysis using standard test sieves. Relative selective coefficients (k`) of the imprinted polymer evaluated from selective binding studies between Hg2+ and Cu2+ or Hg2+ and Cd2+ were 10 588 and 3 147, respectively. These values indicated highly-favoured Hg2+ extractions over the 2 competing ions. The results of spiked and real water samples showed high extraction efficiencies of Hg2+ ions, (over 84%) as evaluated from the detected unextracted Hg2+ ions by ICP-OES. The method exhibited a dynamic response concentration range for Hg2+ between 0.01 and 20 μg/mℓ, with a detection limit (LOD, 3σ) of 0.000036 μg/mℓ (36 ng/ℓ) that meets the monitoring requirements for the USA EPA of 2 000 ng/ℓ for Hg2+ in drinking water. Generally, the data (n=10) had percentage relative standard deviations (%RSD) of less than 4%. Satisfactory results were also obtained when the prepared sorbent was applied for the pre-concentration of Hg2+ from an aqueous certified reference material. These findings indicate that the double-imprinted polymer has potential to be used as an efficient extraction material for the selective pre–concentration of mercury(II) ions in aqueous environments.
- Full Text:
- Authors: Batlokwa, Bareki Shima , Chimuka, Luke , Tshentu, Zenixole R , Cukrowska, Ewa , Torto, Nelson
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6566 , http://hdl.handle.net/10962/d1004125
- Description: A double-imprinted polymer exhibiting high sensitivity for mercury(II) in aqueous solution is presented. Polymer particles imprinted with mercury(II) were synthesised by copolymerising the functional and cross-linking monomers, N’–[3– (Trimethoxysilyl)–propyl]diethylenetriamine (TPET) and tetraethylorthosilicate (TEOS). A double-imprinting procedure employing hexadecyltrimethylammonium bromide (CTAB), as a second template to improve the efficiency of the polymer, was adopted. The imprinted polymer was characterised by FTIR, scanning electron microscopy (SEM) and the average size determined by screen analysis using standard test sieves. Relative selective coefficients (k`) of the imprinted polymer evaluated from selective binding studies between Hg2+ and Cu2+ or Hg2+ and Cd2+ were 10 588 and 3 147, respectively. These values indicated highly-favoured Hg2+ extractions over the 2 competing ions. The results of spiked and real water samples showed high extraction efficiencies of Hg2+ ions, (over 84%) as evaluated from the detected unextracted Hg2+ ions by ICP-OES. The method exhibited a dynamic response concentration range for Hg2+ between 0.01 and 20 μg/mℓ, with a detection limit (LOD, 3σ) of 0.000036 μg/mℓ (36 ng/ℓ) that meets the monitoring requirements for the USA EPA of 2 000 ng/ℓ for Hg2+ in drinking water. Generally, the data (n=10) had percentage relative standard deviations (%RSD) of less than 4%. Satisfactory results were also obtained when the prepared sorbent was applied for the pre-concentration of Hg2+ from an aqueous certified reference material. These findings indicate that the double-imprinted polymer has potential to be used as an efficient extraction material for the selective pre–concentration of mercury(II) ions in aqueous environments.
- Full Text:
An RTSP proxy for implementing the IPTV media function using a streaming server
- Shibeshi, Zelalem S, Terzoli, Alfredo, Bradshaw, Karen L
- Authors: Shibeshi, Zelalem S , Terzoli, Alfredo , Bradshaw, Karen L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429136 , vital:72562 , https://www.informatica.si/index.php/informatica/article/view/383
- Description: Multimedia content delivery in IMS, including IPTV, is handled by a separate unit, the Media Function (MF), made up of media control and media delivery units, which in the case of IPTV are the Media Control Function (MCF) and Media Delivery Function (MDF), respectively. According to the different specifications of an IMS based IPTV architecture, the User Equipment (UE) is expected to use the RTSP protocol as a media control protocol to interact with the MCF, and obtains delivery of media from the MDF using the RTP protocol. This also means that the streaming session needs to be initiated from the media controller on behalf of the user but the delivery of media is sent to the UE from the media deliverer (media server). Due both to the lack of free and open source Media Servers and the availability of free and open source Streaming Servers, the ideal choice for the delivery of multimedia services, including IPTV, by the research community is Streaming Servers. Nevertheless, because of denial of service attacks and other issues, most streaming servers do not allow a different location for the session setup request and the delivery of media in the streaming session. In other words, most streaming servers are not designed to be controlled by some other entity other than the RTSP client that consumes the media. This makes it difficult to have a separate media control unit for IPTV service in IMS if one wanted to use a streaming server as an MDF unit. So, while waiting for streaming servers to work in this manner, it is better to find a work around in order to use streaming servers to develop and test IPTV services in IMS environments. For this purpose we propose another component (an RTSP proxy and relay unit) as part of the IPTV MF and to mediate between the MCF and MDF. This unit correctly relays media control commands from the MCF to the MDF and RTP packets from the MDF to the UE. It also helps in the implementation of other streaming functionalities that are required for IPTV service delivery, but which are not implemented in the current open source streaming servers. Additional services can also be easily implemented with the help of this unit. This will facilitate the development of an IPTV service using readily available open source streaming servers and help researchers to evaluate their proposals on new services they would like to develop. In this paper we show how this RTSP proxy unit can be integrated into the Media Function of the IPTV architecture to ease the media delivery process of an IMS based IPTV service.
- Full Text:
- Authors: Shibeshi, Zelalem S , Terzoli, Alfredo , Bradshaw, Karen L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429136 , vital:72562 , https://www.informatica.si/index.php/informatica/article/view/383
- Description: Multimedia content delivery in IMS, including IPTV, is handled by a separate unit, the Media Function (MF), made up of media control and media delivery units, which in the case of IPTV are the Media Control Function (MCF) and Media Delivery Function (MDF), respectively. According to the different specifications of an IMS based IPTV architecture, the User Equipment (UE) is expected to use the RTSP protocol as a media control protocol to interact with the MCF, and obtains delivery of media from the MDF using the RTP protocol. This also means that the streaming session needs to be initiated from the media controller on behalf of the user but the delivery of media is sent to the UE from the media deliverer (media server). Due both to the lack of free and open source Media Servers and the availability of free and open source Streaming Servers, the ideal choice for the delivery of multimedia services, including IPTV, by the research community is Streaming Servers. Nevertheless, because of denial of service attacks and other issues, most streaming servers do not allow a different location for the session setup request and the delivery of media in the streaming session. In other words, most streaming servers are not designed to be controlled by some other entity other than the RTSP client that consumes the media. This makes it difficult to have a separate media control unit for IPTV service in IMS if one wanted to use a streaming server as an MDF unit. So, while waiting for streaming servers to work in this manner, it is better to find a work around in order to use streaming servers to develop and test IPTV services in IMS environments. For this purpose we propose another component (an RTSP proxy and relay unit) as part of the IPTV MF and to mediate between the MCF and MDF. This unit correctly relays media control commands from the MCF to the MDF and RTP packets from the MDF to the UE. It also helps in the implementation of other streaming functionalities that are required for IPTV service delivery, but which are not implemented in the current open source streaming servers. Additional services can also be easily implemented with the help of this unit. This will facilitate the development of an IPTV service using readily available open source streaming servers and help researchers to evaluate their proposals on new services they would like to develop. In this paper we show how this RTSP proxy unit can be integrated into the Media Function of the IPTV architecture to ease the media delivery process of an IMS based IPTV service.
- Full Text:
Anthropogenic threats to resident and dispersing African wild dogs west and south of the Kruger National Park, South Africa
- Watermeyer, Jessica Patricia
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
- Authors: Watermeyer, Jessica Patricia
- Date: 2012
- Subjects: African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5636 , http://hdl.handle.net/10962/d1005318 , African wild dog -- South Africa -- Kruger National Park , African wild dog -- Effect of human beings on -- South Africa -- Kruger National Park , African wild dog -- Behavior -- South Africa -- Kruger National Park , Endangered species -- South Africa -- Kruger National Park , African wild dog -- Dispersal -- South Africa -- Kruger National Park , African wild dog -- Conservation -- South Africa -- Kruger National Park , Animal populations -- Estimates -- South Africa -- Kruger National Park
- Description: African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
- Full Text:
Are arts events a good way of augmenting the economic impact of sport?: The case of the 2010 FIFA world cup and the national arts festival in South Africa
- Authors: Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71430 , vital:29848 , https://econrsa.org/system/files/publications/working_papers/wp294.pdf
- Description: Despite the debate about whether arts consumers are also sports consumers, many countries have used cultural events to leverage further tourism spending from sports events, the most famous example being the cultural Olympics. This paper reports the findings of research conducted at the 2010 South African National Arts Festival, which was specifically timed to coincide with SoccerWorld Cup matches being played in a nearby city. Of the 600 interviews conducted with Festival-goers, only 23% reported also attending World Cup soccer matches. Regression analysis revealed that, while there is some overlap between arts and sports attendees, their demographics and consumption habits are significantly different. However, consumption outside of major events showed somewhat more overlap. This suggests that staging cultural events at the same time as major sporting events is not an ideal strategy, since they tend to compete with, rather than complement, each other.
- Full Text:
- Authors: Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71430 , vital:29848 , https://econrsa.org/system/files/publications/working_papers/wp294.pdf
- Description: Despite the debate about whether arts consumers are also sports consumers, many countries have used cultural events to leverage further tourism spending from sports events, the most famous example being the cultural Olympics. This paper reports the findings of research conducted at the 2010 South African National Arts Festival, which was specifically timed to coincide with SoccerWorld Cup matches being played in a nearby city. Of the 600 interviews conducted with Festival-goers, only 23% reported also attending World Cup soccer matches. Regression analysis revealed that, while there is some overlap between arts and sports attendees, their demographics and consumption habits are significantly different. However, consumption outside of major events showed somewhat more overlap. This suggests that staging cultural events at the same time as major sporting events is not an ideal strategy, since they tend to compete with, rather than complement, each other.
- Full Text:
Assessing linkages between local ecological knowledge, HIV/AIDS and the commercialisation of natural resources across Southern Africa
- Authors: Weyer, Dylan James
- Date: 2012
- Subjects: AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4769 , http://hdl.handle.net/10962/d1007180 , AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Description: That natural resources (NRs) are important to those experiencing adversity, and, especially, vulnerability associated with HIV/AIDS, is well documented, particularly with respect to food and energy security. What is unclear is where HIV/AIDS ranks in terms of its significance in comparison to other household shocks, the role local ecological knowledge may (LEK) play in households' response to shock, a propos the types of coping strategies that are employed. Consequently, this research aims to bridge the knowledge gap between HIV/AIDS and the degree to which it is contributing to the expansion of NR commercialisation and to explore the unknowns surrounding the influence of LEK on people's choice of coping strategy. A two phase study was designed to provide quantitative rigour with qualitative depth. Phase one was an extensive, rapid survey of NR traders within urban and rural settings in five southern Africa countries. The principle objective was to profile the trade, the livelihoods of those involved and their reasons for entering the trade, to ultimately establish to what degree HIV/AIDS may have been a catalyst for this. Almost one third of the sample entered the trade in response to illness and/or death in their households, with 80% of deaths being of breadwinners. The findings illustrated considerable dependence on the sale of NRs; for almost 60% of the sample it was their household's only source of income. There was evidently increased blurring of the lines between rural and urban NR use with a greater diversity of products being traded in urban areas. Phase two involved in-depth interviews and work with a smaller sample at two sites selected based on the findings from the first phase. It incorporated three groups of households; non-trading, inexperienced trading and experienced trading households. Key areas of focus were household shocks, coping strategies employed in response to these and the role LEK may be playing in the choice of coping strategies. Within a two year period, 95% of households registered at least one shock, of which 80% recorded AIDS-related proxy shocks. Non-trading households were significantly worse-off in this regard, while in the case of non-AIDS proxy shocks, there was no such difference between groups. The most frequently employed coping strategy was the consumption and sale of NRs and was of particular importance when households were faced with AIDS proxy shocks. Trading households emerged as having superior levels of LEK in comparison to non-trading households, even for non-traded NRs, suggesting that prior LEK of NRs opened up opportunities to trade in NR as a coping strategy. Further inspection of the latter group however revealed that the portion of non-trading households who traded on a very ad hoc basis actually had comparable levels of LEK to the trading households. Despite the ad hoc trading households' vulnerable state and their disproportionately high level of AIDS proxy measures, they had at their disposal, sufficient LEK to unlock certain key coping strategies, namely the NR trade. In this sense there are apparent linkages between LEK, HIV/AIDS and the expansion of the commercialisation of NRs.
- Full Text:
- Authors: Weyer, Dylan James
- Date: 2012
- Subjects: AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4769 , http://hdl.handle.net/10962/d1007180 , AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Description: That natural resources (NRs) are important to those experiencing adversity, and, especially, vulnerability associated with HIV/AIDS, is well documented, particularly with respect to food and energy security. What is unclear is where HIV/AIDS ranks in terms of its significance in comparison to other household shocks, the role local ecological knowledge may (LEK) play in households' response to shock, a propos the types of coping strategies that are employed. Consequently, this research aims to bridge the knowledge gap between HIV/AIDS and the degree to which it is contributing to the expansion of NR commercialisation and to explore the unknowns surrounding the influence of LEK on people's choice of coping strategy. A two phase study was designed to provide quantitative rigour with qualitative depth. Phase one was an extensive, rapid survey of NR traders within urban and rural settings in five southern Africa countries. The principle objective was to profile the trade, the livelihoods of those involved and their reasons for entering the trade, to ultimately establish to what degree HIV/AIDS may have been a catalyst for this. Almost one third of the sample entered the trade in response to illness and/or death in their households, with 80% of deaths being of breadwinners. The findings illustrated considerable dependence on the sale of NRs; for almost 60% of the sample it was their household's only source of income. There was evidently increased blurring of the lines between rural and urban NR use with a greater diversity of products being traded in urban areas. Phase two involved in-depth interviews and work with a smaller sample at two sites selected based on the findings from the first phase. It incorporated three groups of households; non-trading, inexperienced trading and experienced trading households. Key areas of focus were household shocks, coping strategies employed in response to these and the role LEK may be playing in the choice of coping strategies. Within a two year period, 95% of households registered at least one shock, of which 80% recorded AIDS-related proxy shocks. Non-trading households were significantly worse-off in this regard, while in the case of non-AIDS proxy shocks, there was no such difference between groups. The most frequently employed coping strategy was the consumption and sale of NRs and was of particular importance when households were faced with AIDS proxy shocks. Trading households emerged as having superior levels of LEK in comparison to non-trading households, even for non-traded NRs, suggesting that prior LEK of NRs opened up opportunities to trade in NR as a coping strategy. Further inspection of the latter group however revealed that the portion of non-trading households who traded on a very ad hoc basis actually had comparable levels of LEK to the trading households. Despite the ad hoc trading households' vulnerable state and their disproportionately high level of AIDS proxy measures, they had at their disposal, sufficient LEK to unlock certain key coping strategies, namely the NR trade. In this sense there are apparent linkages between LEK, HIV/AIDS and the expansion of the commercialisation of NRs.
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Assessing the effect of a laundry detergent ingredient (LAS) on organisms of a rural South African river
- Authors: Gordon, Andrew K
- Date: 2012
- Subjects: Detergent pollution of rivers, lakes, etc. -- Research -- South Africa -- Eastern Cape Water -- Pollution -- Research -- South Africa -- Eastern Cape Stream health -- Research -- South Africa -- Eastern Cape Stream ecology -- Research -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6042 , http://hdl.handle.net/10962/d1006201
- Description: Powdered laundry detergents are consumed in high volumes worldwide. Post use, they are directed toward water resources via wastewater treatment works or, as is the situation in many rural areas of South Africa, they enter the environment directly as a result of laundry washing activity undertaken alongside surface waters. Within wastewater treatment works, the main ingredient in powdered laundry detergents, the narcotic toxin linear alkylbenzene sulfonate (LAS), is mostly removed, rendering the waste stream a negligible risk to the aquatic biota of receiving waters. In contrast, the biological and ecological impacts of direct LAS input to the aquatic environment, as a consequence of near-stream laundry washing, are yet to be fully realised. Consequently, this thesis posed two research questions: 1) 'What are the LAS concentrations in a small rural South African river'? and 2) 'Is the in-stream biological community negatively affected at these concentrations?' The chosen study area, the community of Balfour in the Eastern Cape Province, is like many rural areas of South Africa where inadequate provision of piped water to homesteads necessitates laundry washing alongside the nearby Balfour River. The first research question was addressed in two ways: by predicting LAS concentrations in Balfour River water by assessing detergent consumption and laundry washing behaviour of residents living alongside the river; and measuring actual in- stream LAS concentrations on different days of the week and during different seasons. Results indicated that LAS concentrations were highly variable temporally and spatially. High peak concentrations of LAS occurred infrequently and were limited to the immediate vicinity of near-stream laundry washing activity with the highest measured concentration being 342 μg.L ⁻¹ and the average 21 μg.L ⁻¹ over the sampling period. The second research question was addressed by integrating the chemical evidence, determined from the first research question, with the biological evidence of stress responses measured in macroinvertebrates collected downstream of near-stream laundry washing activity on the Balfour River. Predicted and measured LAS exposure concentrations from the Balfour River were compared to a water quality guideline for LAS (304 μg.L ⁻¹), specifically derived in this thesis. Biological stress responses were measured at different levels of organisation: two sub-cellular responses (lipid peroxidation and cholinesterase activity); three measures of macroinvertebrate tolerance to water quality impairment; five measures of community composition; three measures of community richness; and a surrogate measure of ecosystem function (functional feeding groups). Weight-of-evidence methodology was utilised to assess, integrate and interpret the chemical and biological evidence, and at its conclusion, determined no effect on the in-stream biological community of the Balfour River downstream of laundry washing activity.
- Full Text:
- Authors: Gordon, Andrew K
- Date: 2012
- Subjects: Detergent pollution of rivers, lakes, etc. -- Research -- South Africa -- Eastern Cape Water -- Pollution -- Research -- South Africa -- Eastern Cape Stream health -- Research -- South Africa -- Eastern Cape Stream ecology -- Research -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6042 , http://hdl.handle.net/10962/d1006201
- Description: Powdered laundry detergents are consumed in high volumes worldwide. Post use, they are directed toward water resources via wastewater treatment works or, as is the situation in many rural areas of South Africa, they enter the environment directly as a result of laundry washing activity undertaken alongside surface waters. Within wastewater treatment works, the main ingredient in powdered laundry detergents, the narcotic toxin linear alkylbenzene sulfonate (LAS), is mostly removed, rendering the waste stream a negligible risk to the aquatic biota of receiving waters. In contrast, the biological and ecological impacts of direct LAS input to the aquatic environment, as a consequence of near-stream laundry washing, are yet to be fully realised. Consequently, this thesis posed two research questions: 1) 'What are the LAS concentrations in a small rural South African river'? and 2) 'Is the in-stream biological community negatively affected at these concentrations?' The chosen study area, the community of Balfour in the Eastern Cape Province, is like many rural areas of South Africa where inadequate provision of piped water to homesteads necessitates laundry washing alongside the nearby Balfour River. The first research question was addressed in two ways: by predicting LAS concentrations in Balfour River water by assessing detergent consumption and laundry washing behaviour of residents living alongside the river; and measuring actual in- stream LAS concentrations on different days of the week and during different seasons. Results indicated that LAS concentrations were highly variable temporally and spatially. High peak concentrations of LAS occurred infrequently and were limited to the immediate vicinity of near-stream laundry washing activity with the highest measured concentration being 342 μg.L ⁻¹ and the average 21 μg.L ⁻¹ over the sampling period. The second research question was addressed by integrating the chemical evidence, determined from the first research question, with the biological evidence of stress responses measured in macroinvertebrates collected downstream of near-stream laundry washing activity on the Balfour River. Predicted and measured LAS exposure concentrations from the Balfour River were compared to a water quality guideline for LAS (304 μg.L ⁻¹), specifically derived in this thesis. Biological stress responses were measured at different levels of organisation: two sub-cellular responses (lipid peroxidation and cholinesterase activity); three measures of macroinvertebrate tolerance to water quality impairment; five measures of community composition; three measures of community richness; and a surrogate measure of ecosystem function (functional feeding groups). Weight-of-evidence methodology was utilised to assess, integrate and interpret the chemical and biological evidence, and at its conclusion, determined no effect on the in-stream biological community of the Balfour River downstream of laundry washing activity.
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Assessing the impacts of invasive non-native African sharptooth catfish Clarias Gariepinus
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
- Full Text:
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
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Automated grid fault detection and repair
- Authors: Luyt, Leslie
- Date: 2012 , 2012-05-24
- Subjects: Computational grids (Computer systems) -- Maintenance and repair , Cloud computing -- Maintenance and repair , Computer architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4670 , http://hdl.handle.net/10962/d1006693 , Computational grids (Computer systems) -- Maintenance and repair , Cloud computing -- Maintenance and repair , Computer architecture
- Description: With the rise in interest in the field of grid and cloud computing, it is becoming increasingly necessary for the grid to be easily maintainable. This maintenance of the grid and grid services can be made easier by using an automated system to monitor and repair the grid as necessary. We propose a novel system to perform automated monitoring and repair of grid systems. To the best of our knowledge, no such systems exist. The results show that certain faults can be easily detected and repaired. , TeX , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Authors: Luyt, Leslie
- Date: 2012 , 2012-05-24
- Subjects: Computational grids (Computer systems) -- Maintenance and repair , Cloud computing -- Maintenance and repair , Computer architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4670 , http://hdl.handle.net/10962/d1006693 , Computational grids (Computer systems) -- Maintenance and repair , Cloud computing -- Maintenance and repair , Computer architecture
- Description: With the rise in interest in the field of grid and cloud computing, it is becoming increasingly necessary for the grid to be easily maintainable. This maintenance of the grid and grid services can be made easier by using an automated system to monitor and repair the grid as necessary. We propose a novel system to perform automated monitoring and repair of grid systems. To the best of our knowledge, no such systems exist. The results show that certain faults can be easily detected and repaired. , TeX , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
Baseline isotope data for Spirodela sp.: nutrient differentiation in aquatic systems
- Hill, Jaclyn M, Kaehler, Sven, Hill, Martin P
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444502 , vital:74246 , https://doi.org/10.1016/j.watres.2012.03.063
- Description: The excessive addition of nitrogen to watersheds is recognized as one of the main causes of the global deterioration of aquatic ecosystems and an increasing number of studies have shown that δ15N signatures of macrophytes may reflect the N-loading of the system under investigation. This study investigated isotopic equilibration rates and concentration level effects of KNO3 and cow manure nutrient solutions on the δ15N and δ13C signatures, C/N ratios, % N and % C of Spirodela sp. over time, to determine the feasibility of their use in monitoring anthropogenic N-loading in freshwater systems. Spirodela δ15N signatures clearly distinguished between nutrient types within 2 days of introduction, with plants grown in KNO3 showing extremely depleted δ15N values (−15.00 to −12.00‰) compared to those growing in cow manure (14.00–18.00‰). Isotopic equilibration rates could not be determined with certainty, but plant isotopic differentiation between nutrient regimes became apparent after 2 days and started to equilibrate by day 4. Concentration level effects were also apparent, with Spirodela tissue displaying more depleted and enriched δ15N values in higher concentrations of KNO3 and cow manure respectively.
- Full Text:
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444502 , vital:74246 , https://doi.org/10.1016/j.watres.2012.03.063
- Description: The excessive addition of nitrogen to watersheds is recognized as one of the main causes of the global deterioration of aquatic ecosystems and an increasing number of studies have shown that δ15N signatures of macrophytes may reflect the N-loading of the system under investigation. This study investigated isotopic equilibration rates and concentration level effects of KNO3 and cow manure nutrient solutions on the δ15N and δ13C signatures, C/N ratios, % N and % C of Spirodela sp. over time, to determine the feasibility of their use in monitoring anthropogenic N-loading in freshwater systems. Spirodela δ15N signatures clearly distinguished between nutrient types within 2 days of introduction, with plants grown in KNO3 showing extremely depleted δ15N values (−15.00 to −12.00‰) compared to those growing in cow manure (14.00–18.00‰). Isotopic equilibration rates could not be determined with certainty, but plant isotopic differentiation between nutrient regimes became apparent after 2 days and started to equilibrate by day 4. Concentration level effects were also apparent, with Spirodela tissue displaying more depleted and enriched δ15N values in higher concentrations of KNO3 and cow manure respectively.
- Full Text:
Bayliss-Hillman adducts as scaffolds for the construction of novel compounds with medicinal potential
- Authors: Idahosa, Kenudi Christiana
- Date: 2012
- Subjects: Antimalarials -- Research Malaria -- Chemotherapy -- Research AIDS (Disease) -- Treatment -- Research AIDS (Disease) -- Chemotherapy -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4410 , http://hdl.handle.net/10962/d1006763
- Description: This project has focused on exploring the application of Baylis-Hillman (BH) {a.k.a. Morita-Baylis-Hillman (MBH)} scaffolds in the construction of various compounds with medicinal potential. A series of 2-nitrobenzaldehydes has been treated under BH conditions, with two different activated alkenes, viz., (MVK) and methyl acrylate, using (DABCO) or (3-HQ) as catalyst. While most of the BH reactions were carried out at room temperature, some reactions were conducted using microwave irradiation. The resulting BH adducts have been subjected to dehydration, conjugate addition and allylic substitution to obtain appropriate intermediates, which have been used in turn, to synthesize possible lead compounds, viz., cinnamate esters as HIV-1 integrase inhibitors, 3-(aminomethyl)quinolines and quinolones as anti-malarials and cinnamate ester-AZT conjugates as dual-action HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. Conjugate addition reactions of methyl acrylate-derived BH β-hydroxy esters with the amines, piperidine, propargylamine and 2-amino-5-(diethylamino)pentane, has afforded a range of products as diastereomeric mixtures in moderate to excellent yields. Catalytic hydrogenation of the aminomethy β-hydroxy esters derivatives, using a palladium-oncarbon (Pd-C) catalyst, has afforded the corresponding, novel 3-aminomethyl-2- quinolone derivatives in moderate yields. Effective allylic substitution reactions of the MVK-derived BH β-hydroxy ketones (via a conjugate addition-elimination pathway) using in situ-generated HCl has afforded the corresponding α-chloromethyl derivatives, which have been reacted with various amines, including piperidine, piperazine, propargylamine and 2-amino-5-(diethylamino)pentane, to yield α-aminomethyl derivatives. Catalytic hydrogenation of selected α-aminomethyl derivatives, using a Pd-C catalyst, has afforded the corresponding, novel 3- (aminomethyl)-2-methylquinoline derivatives in low to moderate yields. A bioassay, conducted on a 6-hydroxy-2-methyl-3-[(piperidin-1-yl)methyl]quinoline isolated early in the study indicated anti-malarial activity and prompted further efforts in the synthesis of analogous compounds. Reaction of the methyl acrylate-derived BH adducts with POCl3 has provided access to α-(chloromethyl)cinnamate ester derivatives, which have been aminated to afford α- (aminomethyl)cinnamate ester derivatives as potential HIV-1 integrase inhibitors. The α- (propargylaminomethyl)cinnamates were used, in turn, as substrates for the “click chemistry” reaction with 3'-azido-3'-deoxythymidine (AZT– an azide and an established reverse transcriptase HIV-1 inhibitor) to afford cinnamate ester-AZT conjugates as potential dual-action HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. Computer modelling and docking studies of a cinnamate ester-AZT conjugate into the HIV-1 integrase and reverse transcriptase active-sites revealed potential hydrogen-bonding interactions with amino acid residues within the receptor cavities. The isolated products have been appropriately characterized using IR, 1- and 2-D NMR and HRMS techniques, while elucidation of the stereochemistry of the double bond in the BH-derived halomethyl derivatives has been assigned on the basis of NOE, computer modelling and X-ray crystallographic data.
- Full Text:
- Authors: Idahosa, Kenudi Christiana
- Date: 2012
- Subjects: Antimalarials -- Research Malaria -- Chemotherapy -- Research AIDS (Disease) -- Treatment -- Research AIDS (Disease) -- Chemotherapy -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4410 , http://hdl.handle.net/10962/d1006763
- Description: This project has focused on exploring the application of Baylis-Hillman (BH) {a.k.a. Morita-Baylis-Hillman (MBH)} scaffolds in the construction of various compounds with medicinal potential. A series of 2-nitrobenzaldehydes has been treated under BH conditions, with two different activated alkenes, viz., (MVK) and methyl acrylate, using (DABCO) or (3-HQ) as catalyst. While most of the BH reactions were carried out at room temperature, some reactions were conducted using microwave irradiation. The resulting BH adducts have been subjected to dehydration, conjugate addition and allylic substitution to obtain appropriate intermediates, which have been used in turn, to synthesize possible lead compounds, viz., cinnamate esters as HIV-1 integrase inhibitors, 3-(aminomethyl)quinolines and quinolones as anti-malarials and cinnamate ester-AZT conjugates as dual-action HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. Conjugate addition reactions of methyl acrylate-derived BH β-hydroxy esters with the amines, piperidine, propargylamine and 2-amino-5-(diethylamino)pentane, has afforded a range of products as diastereomeric mixtures in moderate to excellent yields. Catalytic hydrogenation of the aminomethy β-hydroxy esters derivatives, using a palladium-oncarbon (Pd-C) catalyst, has afforded the corresponding, novel 3-aminomethyl-2- quinolone derivatives in moderate yields. Effective allylic substitution reactions of the MVK-derived BH β-hydroxy ketones (via a conjugate addition-elimination pathway) using in situ-generated HCl has afforded the corresponding α-chloromethyl derivatives, which have been reacted with various amines, including piperidine, piperazine, propargylamine and 2-amino-5-(diethylamino)pentane, to yield α-aminomethyl derivatives. Catalytic hydrogenation of selected α-aminomethyl derivatives, using a Pd-C catalyst, has afforded the corresponding, novel 3- (aminomethyl)-2-methylquinoline derivatives in low to moderate yields. A bioassay, conducted on a 6-hydroxy-2-methyl-3-[(piperidin-1-yl)methyl]quinoline isolated early in the study indicated anti-malarial activity and prompted further efforts in the synthesis of analogous compounds. Reaction of the methyl acrylate-derived BH adducts with POCl3 has provided access to α-(chloromethyl)cinnamate ester derivatives, which have been aminated to afford α- (aminomethyl)cinnamate ester derivatives as potential HIV-1 integrase inhibitors. The α- (propargylaminomethyl)cinnamates were used, in turn, as substrates for the “click chemistry” reaction with 3'-azido-3'-deoxythymidine (AZT– an azide and an established reverse transcriptase HIV-1 inhibitor) to afford cinnamate ester-AZT conjugates as potential dual-action HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. Computer modelling and docking studies of a cinnamate ester-AZT conjugate into the HIV-1 integrase and reverse transcriptase active-sites revealed potential hydrogen-bonding interactions with amino acid residues within the receptor cavities. The isolated products have been appropriately characterized using IR, 1- and 2-D NMR and HRMS techniques, while elucidation of the stereochemistry of the double bond in the BH-derived halomethyl derivatives has been assigned on the basis of NOE, computer modelling and X-ray crystallographic data.
- Full Text: