Understanding livelihood strategies of urban women traders : a case of Magaba, Harare in Zimbabwe
- Authors: Chirau, Takunda John
- Date: 2013
- Subjects: Street vendors -- Zimbabwe -- Harare Women -- Zimbabwe -- Harare -- Social conditions Women -- Zimbabwe -- Harare -- Economic conditions Urban poor -- Zimbabwe -- Harare
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3335 , http://hdl.handle.net/10962/d1003742
- Description: This thesis seeks to understand and analyze the livelihood strategies of urban women traders at Magaba in Harare (Zimbabwe) in the context of the contemporary economic and political crisis. The crisis emerged in the 1990s with the introduction of a structural adjustment programme and deepened further with the fast track land reform programme initiated by the Zimbabwean government in the year 2000. The crisis has involved a down-sizing of the Zimbabwean economy and a massive rise in the rate of unemployment in the formal economy. Consequently urban life became increasingly unbearable for poor blacks and informal economic activities blossomed and started to make a significant contribution to household income and livelihoods. The role of women in the informal economy was particularly pronounced. Theoretically, the thesis is underpinned by the sustainable livelihoods framework. In examining the vulnerability context of the Magaba women traders and the institutional interventions which complicate the lives and livelihoods of these traders, I identify and unpack their diverse livelihood activities and strategies and the resources (or assets) they deploy in constructing urban livelihoods. Though their livelihood portfolios complement any earnings from formal employment by household members and though they contribute to their household’s sustenance, there are a number of daily challenges which they face in their trading activities and which they seek to counteract through a range of often ingenious coping mechanisms. The thesis is important for a number of reasons. It fills an important empirical gap in the study of Magaba market specifically, it brings to the fore the gendered character of the informal trading activities in urban Zimbabwe, and it deploys the livelihoods framework in a manner which is sensitive to both structure and agency.
- Full Text:
- Date Issued: 2013
- Authors: Chirau, Takunda John
- Date: 2013
- Subjects: Street vendors -- Zimbabwe -- Harare Women -- Zimbabwe -- Harare -- Social conditions Women -- Zimbabwe -- Harare -- Economic conditions Urban poor -- Zimbabwe -- Harare
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3335 , http://hdl.handle.net/10962/d1003742
- Description: This thesis seeks to understand and analyze the livelihood strategies of urban women traders at Magaba in Harare (Zimbabwe) in the context of the contemporary economic and political crisis. The crisis emerged in the 1990s with the introduction of a structural adjustment programme and deepened further with the fast track land reform programme initiated by the Zimbabwean government in the year 2000. The crisis has involved a down-sizing of the Zimbabwean economy and a massive rise in the rate of unemployment in the formal economy. Consequently urban life became increasingly unbearable for poor blacks and informal economic activities blossomed and started to make a significant contribution to household income and livelihoods. The role of women in the informal economy was particularly pronounced. Theoretically, the thesis is underpinned by the sustainable livelihoods framework. In examining the vulnerability context of the Magaba women traders and the institutional interventions which complicate the lives and livelihoods of these traders, I identify and unpack their diverse livelihood activities and strategies and the resources (or assets) they deploy in constructing urban livelihoods. Though their livelihood portfolios complement any earnings from formal employment by household members and though they contribute to their household’s sustenance, there are a number of daily challenges which they face in their trading activities and which they seek to counteract through a range of often ingenious coping mechanisms. The thesis is important for a number of reasons. It fills an important empirical gap in the study of Magaba market specifically, it brings to the fore the gendered character of the informal trading activities in urban Zimbabwe, and it deploys the livelihoods framework in a manner which is sensitive to both structure and agency.
- Full Text:
- Date Issued: 2013
Teachers’ perception of the integration of environmental education into grade 12 curriculum in East London Education District
- Authors: Damoah, Benjamin
- Date: 2019
- Subjects: Environmental education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16528 , vital:40728
- Description: The study focuses on teachers’ perception of the integration of environmental education into grade 12 curriculum in East London education district. This study is based on empirical research. The theoretical framework of the study is based on Opportunity to Learn (OTL). The concept of OTL was formulated by international Association of Achievements (McDonnell, 1995).OTL is multiplicity of factors that create the conditions for teaching and learning, such as curricula, learning materials, facilities, teachers and instructional experiences. The research study is supported by national and international literatures based on environmental education and integration of environmental education as a component in the school curriculum, and policy documents. The study adopted qualitative research approach, using phenomenological method and interpretivism paradigm respectively. The empirical data was collected from one high school in Mdantsane Township in East London education district. The study sample consisted of 6 high school teachers. Data was collected through semi- structured interviews. According to the findings of the research, grade 12 teachers expressed disparities in their perceptions of environmental education as an integrated component into their subjects. Most of the subject teachers focused on the aspect of knowledge acquisition. According to South African education system, environmental education (EE) has been integrated into all subjects. Although there is environmental education in the GET and FET phase curriculum respectively, however it is not integrated evenly in all subjects. Some subjects like Life sciences, geography have more environmental content than other subjects. Teachers suggested that the approach adopted to integrate environmental education into the school curriculum was not favourable because teachers claimed that what is to be taught as environmental education in the various subjects is not indicated explicitly in the CAPS document. The CAPS document prescribes EE integration into all subjects which makes the teaching of EE a collective responsibility. The main actors of EE integration implementation are themselves a constraint to the success of the integration. The teacher is confronted with many challenges in the process of environmental education integration. This includes lack of teaching and learning resources, time and large class size. The role of teachers in the implementation of environmental education in developing an environmentally literate citizenry is of great significance. The responsibility of the government in ii developing a curriculum with clear goals and content, developing teachers’ capacity in the teaching of environmental education and provision of teaching and learning materials needs to be taken seriously by the government in educational plans and programs. Topics for future research on the integration of EE into grade 12 curriculums were suggested in order to improve on teaching and learning of environmental education
- Full Text:
- Date Issued: 2019
- Authors: Damoah, Benjamin
- Date: 2019
- Subjects: Environmental education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16528 , vital:40728
- Description: The study focuses on teachers’ perception of the integration of environmental education into grade 12 curriculum in East London education district. This study is based on empirical research. The theoretical framework of the study is based on Opportunity to Learn (OTL). The concept of OTL was formulated by international Association of Achievements (McDonnell, 1995).OTL is multiplicity of factors that create the conditions for teaching and learning, such as curricula, learning materials, facilities, teachers and instructional experiences. The research study is supported by national and international literatures based on environmental education and integration of environmental education as a component in the school curriculum, and policy documents. The study adopted qualitative research approach, using phenomenological method and interpretivism paradigm respectively. The empirical data was collected from one high school in Mdantsane Township in East London education district. The study sample consisted of 6 high school teachers. Data was collected through semi- structured interviews. According to the findings of the research, grade 12 teachers expressed disparities in their perceptions of environmental education as an integrated component into their subjects. Most of the subject teachers focused on the aspect of knowledge acquisition. According to South African education system, environmental education (EE) has been integrated into all subjects. Although there is environmental education in the GET and FET phase curriculum respectively, however it is not integrated evenly in all subjects. Some subjects like Life sciences, geography have more environmental content than other subjects. Teachers suggested that the approach adopted to integrate environmental education into the school curriculum was not favourable because teachers claimed that what is to be taught as environmental education in the various subjects is not indicated explicitly in the CAPS document. The CAPS document prescribes EE integration into all subjects which makes the teaching of EE a collective responsibility. The main actors of EE integration implementation are themselves a constraint to the success of the integration. The teacher is confronted with many challenges in the process of environmental education integration. This includes lack of teaching and learning resources, time and large class size. The role of teachers in the implementation of environmental education in developing an environmentally literate citizenry is of great significance. The responsibility of the government in ii developing a curriculum with clear goals and content, developing teachers’ capacity in the teaching of environmental education and provision of teaching and learning materials needs to be taken seriously by the government in educational plans and programs. Topics for future research on the integration of EE into grade 12 curriculums were suggested in order to improve on teaching and learning of environmental education
- Full Text:
- Date Issued: 2019
A case study investigation into drama in education as an effective teaching methodology to support the goals of outcome based education
- Authors: Elliott, Terri Anne
- Date: 2011
- Subjects: Drama in education -- South Africa Competency based education -- South Africa Curriculum planning -- South Africa Student centered learning -- South Africa Critical thinking -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2160 , http://hdl.handle.net/10962/d1008306
- Description: The introduction of outcomes based education (OBE) in the form of Curriculum 2005 (C2005), the National Curriculum Statement (NCS) and the Revised National Curriculum Statement (RNCS) in post-apartheid South Africa resulted in a shift from a content-centred to a learner-centred view on education. This transition took place rapidly as the new government wanted to introduce a democratic education system after the divisive Bantu education system from Apartheid. However, after the changes were implemented, education in South Africa was theoretically outcomes based but practically many educators were still teaching in a content-centred manner. The research puts forward the proposal that drama-in-education (D-i-E) is a useful means by which to align the practical and theoretical goals of OBE within the context of South Africa's current RNCS. This hypothesis drives the main research question: "Can D-i-E be an effective teaching methodology to realise the goals of the RNCS and generate OBE learning environments in a South African high school?" D-i-E is a learner-centred teaching methodology and in practise it meets many of the goals and Critical Cross-Field Outcomes (CCFOs) of OBE. Some of these include the fact that learners can: • Practice problem-solving skills; • Engage with critical and creative thinking; • Grow cultural and aesthetic sensitivity; • Work effectively in groups; and ii. • Learn in inclusive environments that cater for different learning styles and levels. The research examines the use of D-i-E as an outcomes based methodology by which the RNCS could be implemented in the classroom. This is explored through the use of qualitative research in the form of a case study investigation at a South African high school. The case study was conducted with Grade 11 and Grade 12 Dramatic Arts learners and involves an analysis of a D-i-E approach to learning. The conclusion that D-i-E is an effective outcomes based teaching methodology which could assist educators in realising the RNCS was largely reached through participant observation of D-i-E classes and by analysing the learners' journals in which they reflected on D-i-E experiences. The learners' feedback about the experience was generally positive and they reflected that they found D-i-E beneficial because of the fact that it engaged them experientially. They also reflected that D-i-E provided them with a more meaningful and exciting way of learning. These findings are however only generalisable to the type of context (Dramatic Arts learners from a well-resourced girls' high school) in which the research was conducted. The findings provide detailed insight into a specific case study and may be beneficial to educators in South Africa who aim to make use of the same or similar methodologies in their classroom practice. D-i-E also supports many of the underlying tenants of OBE such as learner-centredness, learner diversity and inclusive learning, and can effectively aid educators in implementing the RNCS in an outcomes based way.
- Full Text:
- Date Issued: 2011
- Authors: Elliott, Terri Anne
- Date: 2011
- Subjects: Drama in education -- South Africa Competency based education -- South Africa Curriculum planning -- South Africa Student centered learning -- South Africa Critical thinking -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2160 , http://hdl.handle.net/10962/d1008306
- Description: The introduction of outcomes based education (OBE) in the form of Curriculum 2005 (C2005), the National Curriculum Statement (NCS) and the Revised National Curriculum Statement (RNCS) in post-apartheid South Africa resulted in a shift from a content-centred to a learner-centred view on education. This transition took place rapidly as the new government wanted to introduce a democratic education system after the divisive Bantu education system from Apartheid. However, after the changes were implemented, education in South Africa was theoretically outcomes based but practically many educators were still teaching in a content-centred manner. The research puts forward the proposal that drama-in-education (D-i-E) is a useful means by which to align the practical and theoretical goals of OBE within the context of South Africa's current RNCS. This hypothesis drives the main research question: "Can D-i-E be an effective teaching methodology to realise the goals of the RNCS and generate OBE learning environments in a South African high school?" D-i-E is a learner-centred teaching methodology and in practise it meets many of the goals and Critical Cross-Field Outcomes (CCFOs) of OBE. Some of these include the fact that learners can: • Practice problem-solving skills; • Engage with critical and creative thinking; • Grow cultural and aesthetic sensitivity; • Work effectively in groups; and ii. • Learn in inclusive environments that cater for different learning styles and levels. The research examines the use of D-i-E as an outcomes based methodology by which the RNCS could be implemented in the classroom. This is explored through the use of qualitative research in the form of a case study investigation at a South African high school. The case study was conducted with Grade 11 and Grade 12 Dramatic Arts learners and involves an analysis of a D-i-E approach to learning. The conclusion that D-i-E is an effective outcomes based teaching methodology which could assist educators in realising the RNCS was largely reached through participant observation of D-i-E classes and by analysing the learners' journals in which they reflected on D-i-E experiences. The learners' feedback about the experience was generally positive and they reflected that they found D-i-E beneficial because of the fact that it engaged them experientially. They also reflected that D-i-E provided them with a more meaningful and exciting way of learning. These findings are however only generalisable to the type of context (Dramatic Arts learners from a well-resourced girls' high school) in which the research was conducted. The findings provide detailed insight into a specific case study and may be beneficial to educators in South Africa who aim to make use of the same or similar methodologies in their classroom practice. D-i-E also supports many of the underlying tenants of OBE such as learner-centredness, learner diversity and inclusive learning, and can effectively aid educators in implementing the RNCS in an outcomes based way.
- Full Text:
- Date Issued: 2011
Local development : a response to economic challenges in Noordhoek Valley, Cape Town
- Authors: Gibb, Matthew William
- Date: 2004
- Subjects: Deindustrialization -- South Africa -- Western Cape -- Economic aspects Community development -- South Africa -- Western Cape Community development, Urban -- South Africa -- Western Cape Economic development -- South Africa -- Western Cape Economic development projects -- South Africa -- Western Cape Labor supply -- South Africa -- Western Cape Local government -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4869 , http://hdl.handle.net/10962/d1007848
- Description: De-industrialisation and rising unemployment amongst the world's developed countries' manual labourers as well as continued economic stagnation in developing countries has resulted in many localities experiencing mounting economic hardships and uncertain futures. As a direct result, the time has come that localities are being called upon to take charge of their own futures using local resources for local solutions. Local development has appeared in various guises in different countries. Many agents in the developed North favour pro-business interventions that emphasise enterprise development, responsible local government, and investment in skills training. Stakeholders in developing nations however tend to favour bottom-up approaches focusing on participation in self-reliant activities, providing basic needs, and facilitating micro-enterprises. In addition to the actual nature of applied interventions, qualities such as commitment, innovation, co-operation, social capital and entrepreneurship are equally essential for over-all success. South Africa has recently devolved more autonomy to its localities to enable them to conduct local development as a way of coping with local socio-economic difficulties and is applying both pro-growth and pro-poor approaches. The Noordhoek Valley in the City of Cape Town is a locality where a community driven project seeks to promote both economic growth and poverty alleviation. The establishment of a skills training institution has equipped local residents with the skills to find jobs and become entrepreneurs. To date, over 1000 residents have received training and have earned over R5 million for the community. Although locality-based development is relatively new in South Africa, the activities and results achieved in the Noordhoek Valley indicate that with the appropriate approach and mentality local development and skills development are indeed possible.
- Full Text:
- Date Issued: 2004
- Authors: Gibb, Matthew William
- Date: 2004
- Subjects: Deindustrialization -- South Africa -- Western Cape -- Economic aspects Community development -- South Africa -- Western Cape Community development, Urban -- South Africa -- Western Cape Economic development -- South Africa -- Western Cape Economic development projects -- South Africa -- Western Cape Labor supply -- South Africa -- Western Cape Local government -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4869 , http://hdl.handle.net/10962/d1007848
- Description: De-industrialisation and rising unemployment amongst the world's developed countries' manual labourers as well as continued economic stagnation in developing countries has resulted in many localities experiencing mounting economic hardships and uncertain futures. As a direct result, the time has come that localities are being called upon to take charge of their own futures using local resources for local solutions. Local development has appeared in various guises in different countries. Many agents in the developed North favour pro-business interventions that emphasise enterprise development, responsible local government, and investment in skills training. Stakeholders in developing nations however tend to favour bottom-up approaches focusing on participation in self-reliant activities, providing basic needs, and facilitating micro-enterprises. In addition to the actual nature of applied interventions, qualities such as commitment, innovation, co-operation, social capital and entrepreneurship are equally essential for over-all success. South Africa has recently devolved more autonomy to its localities to enable them to conduct local development as a way of coping with local socio-economic difficulties and is applying both pro-growth and pro-poor approaches. The Noordhoek Valley in the City of Cape Town is a locality where a community driven project seeks to promote both economic growth and poverty alleviation. The establishment of a skills training institution has equipped local residents with the skills to find jobs and become entrepreneurs. To date, over 1000 residents have received training and have earned over R5 million for the community. Although locality-based development is relatively new in South Africa, the activities and results achieved in the Noordhoek Valley indicate that with the appropriate approach and mentality local development and skills development are indeed possible.
- Full Text:
- Date Issued: 2004
Master of Education research portfolio
- Authors: Iitula, Helena
- Date: 2006
- Subjects: Education -- Namibia Curriculum planning -- Namibia Education and state -- Namibia Competency-based education -- Namibia Teachers -- Training of -- Namibia Education, Secondary -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1948 , http://hdl.handle.net/10962/d1008196
- Description: This Portfolio was submitted in 2005 to Rhodes University as a Research Portfolio presented in partial fulfilment of the requirements for the degree of Master of Education in General Education Theory and Practice. The Portfolio consists of seven (7) key parts. The reader of this Portfolio is courteously informed that the structure of this portfolio is to some extent differ from the thesis structure. Thus, the reader should be attentive not to weigh against the two. Further more, I hereby declare that this portfolio is my own work and that all the sources that I have used or quoted have been indicated and acknowledged by means of references indicated at the end of each part. Part 2 and 6 are the core parts of the portfolio. The focal point of part 2 is the contextual curriculum analysis of Grade 8-10 Oshindonga Curriculum in order to investigate its implementation in four educational circuits: Oshigambo, Onathinge, Onyaanya and Omuthiya in Oshikoto Region. Based on the findings of this analysis, lack of critical inquiry and reflective practice among Oshindonga teachers was identified as one of the major obstacles that preventing the effective implementation of the curriculum. Most of these teachers are Basic Education Teacher Diploma (BETD) postgraduates. Thus, part 3 and 4 were developed as supplements to inform the main research paper (part 6) which is related to teacher's professionalism in the classroom. The focus of part 3 (literature review) was on the teacher as a reflective practitioner. This is in line with the Namibian Education Policy, which identifies reflective practice as the heart of teacher professionalism. In this part, I explored a variety of views related to the notion of professionalism in teaching. I have also focused on views related to teacher's professional development both on macro and micro levels. These views provided a clarification and an underpinning framework on which to base my analysis of reflective practice as professionalism in education. Part 4 (education theories) focused on the digging of understanding of knowledge as an important theoretical domain of behaviourist and constructivist theories. I have tried to establish how the two theories (Behaviourist and Constructivist) view knowledge and its acquisition and to gain an understanding of how the two theories have been informing the practice. Subsequently, part 6 meant to investigate and assess the extent to which Basic Education Teacher Diploma postgraduate teachers are autonomously applying the theory of critical inquiry and reflective practice in the classroom. Both part 2 and 6 have findings. There is much correlation between the issues and problems in the implementation of the curriculum as identified in part 2 and the findings of the main research paper (part 6). Though critical inquiry and reflective practice is the key journey towards a high level of reflectivity and one of the significant characters of teacher professionalism in the classroom, most issues and problems identified were related to the insufficient practice of critical inquiry and reflective practices. Low correlation was found between critical inquiry and reflective practice theory and teachers' practices in the classroom. Despite to the fact that various rationales were mentioned as to why critical inquiry and reflective practice successful implementation is not taking place, the study positioned an emphasis on team working at school, cluster and circuit base that could contributed to a great extend to making teachers more competent and supporting themselves in mastering the applicable critical inquiry and reflective practice skills.
- Full Text:
- Date Issued: 2006
- Authors: Iitula, Helena
- Date: 2006
- Subjects: Education -- Namibia Curriculum planning -- Namibia Education and state -- Namibia Competency-based education -- Namibia Teachers -- Training of -- Namibia Education, Secondary -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1948 , http://hdl.handle.net/10962/d1008196
- Description: This Portfolio was submitted in 2005 to Rhodes University as a Research Portfolio presented in partial fulfilment of the requirements for the degree of Master of Education in General Education Theory and Practice. The Portfolio consists of seven (7) key parts. The reader of this Portfolio is courteously informed that the structure of this portfolio is to some extent differ from the thesis structure. Thus, the reader should be attentive not to weigh against the two. Further more, I hereby declare that this portfolio is my own work and that all the sources that I have used or quoted have been indicated and acknowledged by means of references indicated at the end of each part. Part 2 and 6 are the core parts of the portfolio. The focal point of part 2 is the contextual curriculum analysis of Grade 8-10 Oshindonga Curriculum in order to investigate its implementation in four educational circuits: Oshigambo, Onathinge, Onyaanya and Omuthiya in Oshikoto Region. Based on the findings of this analysis, lack of critical inquiry and reflective practice among Oshindonga teachers was identified as one of the major obstacles that preventing the effective implementation of the curriculum. Most of these teachers are Basic Education Teacher Diploma (BETD) postgraduates. Thus, part 3 and 4 were developed as supplements to inform the main research paper (part 6) which is related to teacher's professionalism in the classroom. The focus of part 3 (literature review) was on the teacher as a reflective practitioner. This is in line with the Namibian Education Policy, which identifies reflective practice as the heart of teacher professionalism. In this part, I explored a variety of views related to the notion of professionalism in teaching. I have also focused on views related to teacher's professional development both on macro and micro levels. These views provided a clarification and an underpinning framework on which to base my analysis of reflective practice as professionalism in education. Part 4 (education theories) focused on the digging of understanding of knowledge as an important theoretical domain of behaviourist and constructivist theories. I have tried to establish how the two theories (Behaviourist and Constructivist) view knowledge and its acquisition and to gain an understanding of how the two theories have been informing the practice. Subsequently, part 6 meant to investigate and assess the extent to which Basic Education Teacher Diploma postgraduate teachers are autonomously applying the theory of critical inquiry and reflective practice in the classroom. Both part 2 and 6 have findings. There is much correlation between the issues and problems in the implementation of the curriculum as identified in part 2 and the findings of the main research paper (part 6). Though critical inquiry and reflective practice is the key journey towards a high level of reflectivity and one of the significant characters of teacher professionalism in the classroom, most issues and problems identified were related to the insufficient practice of critical inquiry and reflective practices. Low correlation was found between critical inquiry and reflective practice theory and teachers' practices in the classroom. Despite to the fact that various rationales were mentioned as to why critical inquiry and reflective practice successful implementation is not taking place, the study positioned an emphasis on team working at school, cluster and circuit base that could contributed to a great extend to making teachers more competent and supporting themselves in mastering the applicable critical inquiry and reflective practice skills.
- Full Text:
- Date Issued: 2006
Studies of the environmental and endocrine control of reproduction in the four striped field mouse, Rhabdomys pumilio
- Authors: Jackson, Claire
- Date: 2003
- Subjects: Microtus Microtus -- South Africa -- Reproduction Mice -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5777 , http://hdl.handle.net/10962/d1005465
- Description: Previous studies of the control of reproduction in Rhabdomys pumilio have shown that day length alone does not inhibit spermatogenesis, that a reduction in food availability and ambient temperature results in an inhibition of gametogenesis, that females are more susceptible to inhibition than are males, and that mice that are able to maintain a body fat store in the face of an energetic challenge, are less likely to show reproductive inhibition than those that lose their fat store. In the present study, field and laboratory experiments were conducted to examine the effects of winter food supplementation on reproduction and population dynamics, and the effects of exogenous GnRH, leptin and mercaptoacetate (MA) on reproductive activity of Rhabdomys pumilio exposed to an energetic challenge. In the field food supplementation experiments in Thomas Baines Nature Reserve (2000, 2001), there was no winter inhibition of reproduction and provision of supplementary food had little effect. While at Mountain Zebra National Park (2002) winter was harsher, females became reproductively inactive, spermatogenesis continued and the provision of extra food resulted in higher rates of individual growth and larger reproductive organs. Treatment of mice that had been exposed to a prolonged energetic challenge, with exogenous GnRH (1µg/mouse/treatment) resulted in an increase in the masses of the testes and epididymides, and in the activity of the reproductive organs. Treatment with exogenous leptin (40µg/mouse/treatment), concurrently with an energetic challenge, countered the negative effects of the energetic challenge, and treated males had larger reproductive organs. MA (600µmol/kg body mass), given concurrently with an energetic challenge, did not inhibit fat metabolism, although the high-fat diet countered the effects of the energetic challenge. Results suggest that the first response of male Rhabdomys pumilio to an energetic challenge is a reduction in the size of the reproductive organs, without an inhibition of spermatogenesis. It is likely that this effect is mediated via white fat and leptin, and leptin’s influence on the hypothalamic-pituitary-gonad axis. Results of the study support the suggestion that females are more sensitive to reproductive inhibition than males and that reproduction in Rhabdomys pumilio is truly opportunistic.
- Full Text:
- Date Issued: 2003
- Authors: Jackson, Claire
- Date: 2003
- Subjects: Microtus Microtus -- South Africa -- Reproduction Mice -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5777 , http://hdl.handle.net/10962/d1005465
- Description: Previous studies of the control of reproduction in Rhabdomys pumilio have shown that day length alone does not inhibit spermatogenesis, that a reduction in food availability and ambient temperature results in an inhibition of gametogenesis, that females are more susceptible to inhibition than are males, and that mice that are able to maintain a body fat store in the face of an energetic challenge, are less likely to show reproductive inhibition than those that lose their fat store. In the present study, field and laboratory experiments were conducted to examine the effects of winter food supplementation on reproduction and population dynamics, and the effects of exogenous GnRH, leptin and mercaptoacetate (MA) on reproductive activity of Rhabdomys pumilio exposed to an energetic challenge. In the field food supplementation experiments in Thomas Baines Nature Reserve (2000, 2001), there was no winter inhibition of reproduction and provision of supplementary food had little effect. While at Mountain Zebra National Park (2002) winter was harsher, females became reproductively inactive, spermatogenesis continued and the provision of extra food resulted in higher rates of individual growth and larger reproductive organs. Treatment of mice that had been exposed to a prolonged energetic challenge, with exogenous GnRH (1µg/mouse/treatment) resulted in an increase in the masses of the testes and epididymides, and in the activity of the reproductive organs. Treatment with exogenous leptin (40µg/mouse/treatment), concurrently with an energetic challenge, countered the negative effects of the energetic challenge, and treated males had larger reproductive organs. MA (600µmol/kg body mass), given concurrently with an energetic challenge, did not inhibit fat metabolism, although the high-fat diet countered the effects of the energetic challenge. Results suggest that the first response of male Rhabdomys pumilio to an energetic challenge is a reduction in the size of the reproductive organs, without an inhibition of spermatogenesis. It is likely that this effect is mediated via white fat and leptin, and leptin’s influence on the hypothalamic-pituitary-gonad axis. Results of the study support the suggestion that females are more sensitive to reproductive inhibition than males and that reproduction in Rhabdomys pumilio is truly opportunistic.
- Full Text:
- Date Issued: 2003
The television teen drama as folktale
- Authors: Jones, Denna Louise
- Date: 2011
- Subjects: Teen television programs , Television and teenagers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8382 , http://hdl.handle.net/10948/1471 , Teen television programs , Television and teenagers
- Description: In 1927 Vladimir Propp published a book in which he defined the characteristics and morphology of fairytales. His work was a groundbreaking one that forced scholars to question the way in which stories and storytelling affect the fabric of society and its ideals. Since 1927 much has changed with regards to the way in which stories are told. Technology has changed the way in which people interact and communicate with each other. Media conglomerates such as Walt Disney, Time Warner Company and News Corporation are driven to create stories and media that will deliver consumers to their advertisers. This paper sought to examine the way in which the teen drama has redefined the fairytale, and to establish whether Propp’s work on the morphology of fairytales can still be seen as valid today. Following an in depth literature review that sought to establish the foundations of fairytales, narratives, Propp’s morphology, the development of television as well as the teen television drama, the findings of this paper were established through a detailed content analysis of the first season of three modern teen television dramas – The O.C., One Tree Hill and Gossip Girl. The research found that while some of Propp’s functions may have been adapted to take on a more modern role and a few others became defunct, the majority of the functions of the dramatis personae could be found almost unchanged within the teen television drama. Gossip Girl, in particular demonstrated that it was highly aware of its allusions to the fairytale analogy with numerous references throughout its first season to fairytales such as Snow White and the Seven Dwarves, Cinderella and Beauty and the Beast. More than any of the other shows, Gossip Girl appeared deliberate in its references to the world of fairytales, a world in which the damsel in distress is always rescued by her knight in shining armour, and where monarchy reigns supreme. While humans have continued to evolve and the modes of storytelling have changed significantly since Propp first published his paper, the teen television drama has not yet redefined the characteristics of Propp’s morphology. At most it has modernised them making them relevant to the 21st century viewer.
- Full Text:
- Date Issued: 2011
- Authors: Jones, Denna Louise
- Date: 2011
- Subjects: Teen television programs , Television and teenagers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8382 , http://hdl.handle.net/10948/1471 , Teen television programs , Television and teenagers
- Description: In 1927 Vladimir Propp published a book in which he defined the characteristics and morphology of fairytales. His work was a groundbreaking one that forced scholars to question the way in which stories and storytelling affect the fabric of society and its ideals. Since 1927 much has changed with regards to the way in which stories are told. Technology has changed the way in which people interact and communicate with each other. Media conglomerates such as Walt Disney, Time Warner Company and News Corporation are driven to create stories and media that will deliver consumers to their advertisers. This paper sought to examine the way in which the teen drama has redefined the fairytale, and to establish whether Propp’s work on the morphology of fairytales can still be seen as valid today. Following an in depth literature review that sought to establish the foundations of fairytales, narratives, Propp’s morphology, the development of television as well as the teen television drama, the findings of this paper were established through a detailed content analysis of the first season of three modern teen television dramas – The O.C., One Tree Hill and Gossip Girl. The research found that while some of Propp’s functions may have been adapted to take on a more modern role and a few others became defunct, the majority of the functions of the dramatis personae could be found almost unchanged within the teen television drama. Gossip Girl, in particular demonstrated that it was highly aware of its allusions to the fairytale analogy with numerous references throughout its first season to fairytales such as Snow White and the Seven Dwarves, Cinderella and Beauty and the Beast. More than any of the other shows, Gossip Girl appeared deliberate in its references to the world of fairytales, a world in which the damsel in distress is always rescued by her knight in shining armour, and where monarchy reigns supreme. While humans have continued to evolve and the modes of storytelling have changed significantly since Propp first published his paper, the teen television drama has not yet redefined the characteristics of Propp’s morphology. At most it has modernised them making them relevant to the 21st century viewer.
- Full Text:
- Date Issued: 2011
An investigation into the formative assessment practices of teachers in selected Fort Beaufort schools: a case study in the Eastern Cape
- Authors: Kuze, Mongezi William
- Date: 2009
- Subjects: Competency-based education -- South Africa , Education and state -- South Africa -- Eastern Cape , Educational planning -- South Africa -- Eastern Cape , Technology -- Study and teaching -- South Africa -- Eastern Cape , Assessment, Evaluation, and Programming System -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16162 , http://hdl.handle.net/10353/226
- Description: South Africa has, since 1994 undergone significant political, social and economic changes and all these changes have had an effect in most of the governmental departments. One department adversely affected in particular, is the Department of Education (DoE). The implementation of a large number of educational policies being developed at national and provincial levels to bring about radical changes, leave much to desire. That has led the researcher to be investigating Teachers’ Formative Assessment Practices in Grade 9 Technology classrooms of selected schools in the Fort Beaufort District of Education. The DoE had explored ways to better educate learners and to improve the entire school performance, hence the introduction of the new methods of assessment, to quote but one, assessment policy No. 19640 of 1998. The new assessment policy in the GET Band is a means of assessing learners in order to enhance individual growth and development; to monitor the progress of learners; and to facilitate their learning. This policy states that assessment and feedback are integral to the teaching and learning process and policy planners and practitioners must be adequately prepared to implement these policies. Assessment is the most powerful lever educators use to influence the way learners respond to teaching and behave as learners. It is crucial that appropriate and effective methods of assessment are employed to ensure effective learning. Therefore, the study examined, within the interpretive paradigm and taking a constructivist approach, experiences and concerns raised by participants concerning the implementation of formative assessment in the case. In order to investigate teachers’ perceptions and the implementation of formative assessment practices, in relation to emerging educational policies, one Grade 9 learning area – Technology - in five schools were purposefully sampled. Data from the participants were mainly collected employing qualitative methods, being in-depth interviews, observations and document studies. The main findings of the study were that participants’ (School Management Team members, teachers and learners) perceptions were not quite clear pertaining to what formative assessment is all about. They did not know how to implement it in their classes and as a result had a negative impact on them. This led to recommending that these practitioners must adequately and rigorously be re-trained in implementing the policy. The DoE ought to outsource such trainings to tertiary institution for certification purposes. In future, the DoE should, before implementing any policy, make sure facilitators know the policy, are adequately and thoroughly trained and skilled before embarking on any further training of policy practitioners.
- Full Text:
- Date Issued: 2009
- Authors: Kuze, Mongezi William
- Date: 2009
- Subjects: Competency-based education -- South Africa , Education and state -- South Africa -- Eastern Cape , Educational planning -- South Africa -- Eastern Cape , Technology -- Study and teaching -- South Africa -- Eastern Cape , Assessment, Evaluation, and Programming System -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16162 , http://hdl.handle.net/10353/226
- Description: South Africa has, since 1994 undergone significant political, social and economic changes and all these changes have had an effect in most of the governmental departments. One department adversely affected in particular, is the Department of Education (DoE). The implementation of a large number of educational policies being developed at national and provincial levels to bring about radical changes, leave much to desire. That has led the researcher to be investigating Teachers’ Formative Assessment Practices in Grade 9 Technology classrooms of selected schools in the Fort Beaufort District of Education. The DoE had explored ways to better educate learners and to improve the entire school performance, hence the introduction of the new methods of assessment, to quote but one, assessment policy No. 19640 of 1998. The new assessment policy in the GET Band is a means of assessing learners in order to enhance individual growth and development; to monitor the progress of learners; and to facilitate their learning. This policy states that assessment and feedback are integral to the teaching and learning process and policy planners and practitioners must be adequately prepared to implement these policies. Assessment is the most powerful lever educators use to influence the way learners respond to teaching and behave as learners. It is crucial that appropriate and effective methods of assessment are employed to ensure effective learning. Therefore, the study examined, within the interpretive paradigm and taking a constructivist approach, experiences and concerns raised by participants concerning the implementation of formative assessment in the case. In order to investigate teachers’ perceptions and the implementation of formative assessment practices, in relation to emerging educational policies, one Grade 9 learning area – Technology - in five schools were purposefully sampled. Data from the participants were mainly collected employing qualitative methods, being in-depth interviews, observations and document studies. The main findings of the study were that participants’ (School Management Team members, teachers and learners) perceptions were not quite clear pertaining to what formative assessment is all about. They did not know how to implement it in their classes and as a result had a negative impact on them. This led to recommending that these practitioners must adequately and rigorously be re-trained in implementing the policy. The DoE ought to outsource such trainings to tertiary institution for certification purposes. In future, the DoE should, before implementing any policy, make sure facilitators know the policy, are adequately and thoroughly trained and skilled before embarking on any further training of policy practitioners.
- Full Text:
- Date Issued: 2009
Distribution of virulence determinants in some members of the ESKAPE pathogens isolated from selected hospital wastewater effluents in the Eastern Cape, South Africa
- Authors: Mapipa, Qaqamba
- Date: 2019
- Subjects: Effluent quality Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14704 , vital:40061
- Description: Members of ESKAPE pathogens are grouped under the acronymn made up of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens, isolated from hospitals and communities, have just been characterized for new pathogenesis and transmission patterns and overcoming the usefulness of available drugs, this leads to infections that tend to increase the rate of disease in a population and death rate and cost our society massively. The distribution of virulence determinants and the antibiotic susceptibility patterns in some members of the ESKAPE pathogens isolated from hospital wastewater facilities that were selected within the Eastern Cape Province, South Africa was evaluated. Water samples from the hospital wastewater facilities were collected fortnightly over a period of three (3) months (February to April). Spread plate technique was employed for the enumeration and isolation of the members of ESKAPE pathogens. A total of 725 presumptive ESKAPE isolates were collected, screened and Polymerase Chain Reaction (PCR) amplification of target determinants was performed. Results showed that Klebsiella pneumoniae tested positive for ninety two (92=35.9%) samples, Enterobacter cloacae fifty seven (57=22.2%) samples tested positive, Pseudomonas aeruginosa fifty four (54=21.09%) isolates tested positive and fifty three (53=20.7%) isolates tested positive for Acinetobacter baumannii making a total of 256 isolates which tested positive for some members of ESKAPE pathogens. The detection of some members of the ESKAPE pathogens in these Hospitals is a cause of concern to public health. A total of 256 ESKAPE isolates that were obtained from the hospital wastewater facilities; were subjected to antibiotic susceptibility test in order to determine their antibiotic-resistant profiles. ESKAPE isolates recovered from the three hospital effluents showing resistance to antimicrobial agents in this study were further evaluated for resistance determinants namely, sulfonamides resistance determinants (sulI and sulII), β-lactams (ampC, blaTEM and blaZ), tetracyclines (tetA, tetB, tetC and tetM), 10 chloramphenicol’s (catI and catII) and aminoglycoside resistance determinants (aacC2, apHAI and apHAII). The resistant determinants targeted have been evaluated through their prevalence and the following distributions were obtained: [β-Lactams; ampC (80%), blaTEM (77%)]; [Tetracyclines; tetA (87%)]; [Sulfonamides; sulI (79%)]; [Aminoglycosides; aacC2 (12%), aphA2 (52%) and aadA (18%)]. With the worldwide increase in these resistant occurrences, the execution of strict infection control policies and treatment with different antimicrobials needs hasty detection. Comprehensive data are therefore needed so that the history of infection, identification of genes present in organisms and monitoring of changes in infection patterns can be traced correctly.
- Full Text:
- Date Issued: 2019
- Authors: Mapipa, Qaqamba
- Date: 2019
- Subjects: Effluent quality Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14704 , vital:40061
- Description: Members of ESKAPE pathogens are grouped under the acronymn made up of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens, isolated from hospitals and communities, have just been characterized for new pathogenesis and transmission patterns and overcoming the usefulness of available drugs, this leads to infections that tend to increase the rate of disease in a population and death rate and cost our society massively. The distribution of virulence determinants and the antibiotic susceptibility patterns in some members of the ESKAPE pathogens isolated from hospital wastewater facilities that were selected within the Eastern Cape Province, South Africa was evaluated. Water samples from the hospital wastewater facilities were collected fortnightly over a period of three (3) months (February to April). Spread plate technique was employed for the enumeration and isolation of the members of ESKAPE pathogens. A total of 725 presumptive ESKAPE isolates were collected, screened and Polymerase Chain Reaction (PCR) amplification of target determinants was performed. Results showed that Klebsiella pneumoniae tested positive for ninety two (92=35.9%) samples, Enterobacter cloacae fifty seven (57=22.2%) samples tested positive, Pseudomonas aeruginosa fifty four (54=21.09%) isolates tested positive and fifty three (53=20.7%) isolates tested positive for Acinetobacter baumannii making a total of 256 isolates which tested positive for some members of ESKAPE pathogens. The detection of some members of the ESKAPE pathogens in these Hospitals is a cause of concern to public health. A total of 256 ESKAPE isolates that were obtained from the hospital wastewater facilities; were subjected to antibiotic susceptibility test in order to determine their antibiotic-resistant profiles. ESKAPE isolates recovered from the three hospital effluents showing resistance to antimicrobial agents in this study were further evaluated for resistance determinants namely, sulfonamides resistance determinants (sulI and sulII), β-lactams (ampC, blaTEM and blaZ), tetracyclines (tetA, tetB, tetC and tetM), 10 chloramphenicol’s (catI and catII) and aminoglycoside resistance determinants (aacC2, apHAI and apHAII). The resistant determinants targeted have been evaluated through their prevalence and the following distributions were obtained: [β-Lactams; ampC (80%), blaTEM (77%)]; [Tetracyclines; tetA (87%)]; [Sulfonamides; sulI (79%)]; [Aminoglycosides; aacC2 (12%), aphA2 (52%) and aadA (18%)]. With the worldwide increase in these resistant occurrences, the execution of strict infection control policies and treatment with different antimicrobials needs hasty detection. Comprehensive data are therefore needed so that the history of infection, identification of genes present in organisms and monitoring of changes in infection patterns can be traced correctly.
- Full Text:
- Date Issued: 2019
Understanding trainee teachers' engagement with prior everyday knowledge and experiences in teaching physical science concepts : a case study
- Authors: Mukwambo, Muzwangowenyu
- Date: 2013
- Subjects: Science -- Study and teaching -- Namibia -- Caprivi -- Case studies Ethnoscience -- Study and teaching -- Namibia -- Caprivi -- Case studies Experiential learning -- Namibia -- Caprivi -- Case studies Experiential learning -- Namibia -- Caprivi -- Case studies Education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1402 , http://hdl.handle.net/10962/d1001874
- Description: The constructivist world view is advocated in the Namibian National Curriculum for Basic Education (NNCBE, 2010) since it encourages teachers to use different knowledge sources. This perspective embraces a multicultural approach to science teaching and learning. Indigenous knowledge (IK) and western science (WS) are some of the knowledge sources that are advocated. Yet, it has been noted that some science textbooks used in school science curricula do not consider IK. It is often diminished and considered of lesser value. The sole use of WS in teaching and learning is often distant from IK sources which can be used as prior knowledge. In this study, I therefore endeavoured to minimize this gap in the science curriculum. Essentially, the study focused on investigating trainee teachers’ engagement with prior everyday knowledge and experiences of natural phenomena in teaching physical science concepts. The rationale behind the study emerged while I was supervising twelve trainee teachers on school based studies (SBS) in the Caprivi Region. Observations revealed that learners frequently asked trainee teachers to relate their IK to WS to contextualize what they were learning. However, most trainee teachers seemed to experience challenges. This pedagogical gap and challenge was investigated using the instruments below. An analysis was done on the Namibian National Curriculum for Basic Education (NNCBE, 2010), extracts of research papers and a chapters on pressure in physical science textbooks. A worksheet was used to orientate trainee teachers with suggestions on how IK could be fused with WS to contextualize teaching and learning. Thereafter, this was followed by the simultaneous use of brainstorming and audio-visual techniques. Base line instruments paved the way for the main data generating techniques; namely, microteaching, audio-visual techniques, critical partners’ observation and focus group interview. There was triangulation of data collection instruments which enhanced validation followed by tabulation and data collation to develop themes. Analysis entailed checking theme repetition, indigenous categories and key words in context techniques. Themes enabled the construction of analytical statements which were discussed with reference to the relevant literature, theory and subsequently aligned to the research questions. Findings from this study include the suggestions that IK can be incorporated into teaching and learning of science concepts through the use of models or practical activities, science language used in the community and some cultural artifacts. The relevance of incorporating such type of knowledge is to contextualize science teaching and learning. The study therefore concluded that the incorporation of IK into teaching and learning of science concepts; (a) broadens the curriculum as it addresses conceptual progression and cohesion; (b) contextualizes concepts taught; (c) empowers teachers to use a practical curriculum and (d) it also creates space for misconceptions that come with IK to be identified and corrected. The study thus recommends that cultural artifacts and the social science jargon used in the community of the trainee teachers can be used to incorporate IK with WS as these types of knowledge are not mutually exclusive but in fact complement one another.
- Full Text:
- Date Issued: 2013
- Authors: Mukwambo, Muzwangowenyu
- Date: 2013
- Subjects: Science -- Study and teaching -- Namibia -- Caprivi -- Case studies Ethnoscience -- Study and teaching -- Namibia -- Caprivi -- Case studies Experiential learning -- Namibia -- Caprivi -- Case studies Experiential learning -- Namibia -- Caprivi -- Case studies Education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1402 , http://hdl.handle.net/10962/d1001874
- Description: The constructivist world view is advocated in the Namibian National Curriculum for Basic Education (NNCBE, 2010) since it encourages teachers to use different knowledge sources. This perspective embraces a multicultural approach to science teaching and learning. Indigenous knowledge (IK) and western science (WS) are some of the knowledge sources that are advocated. Yet, it has been noted that some science textbooks used in school science curricula do not consider IK. It is often diminished and considered of lesser value. The sole use of WS in teaching and learning is often distant from IK sources which can be used as prior knowledge. In this study, I therefore endeavoured to minimize this gap in the science curriculum. Essentially, the study focused on investigating trainee teachers’ engagement with prior everyday knowledge and experiences of natural phenomena in teaching physical science concepts. The rationale behind the study emerged while I was supervising twelve trainee teachers on school based studies (SBS) in the Caprivi Region. Observations revealed that learners frequently asked trainee teachers to relate their IK to WS to contextualize what they were learning. However, most trainee teachers seemed to experience challenges. This pedagogical gap and challenge was investigated using the instruments below. An analysis was done on the Namibian National Curriculum for Basic Education (NNCBE, 2010), extracts of research papers and a chapters on pressure in physical science textbooks. A worksheet was used to orientate trainee teachers with suggestions on how IK could be fused with WS to contextualize teaching and learning. Thereafter, this was followed by the simultaneous use of brainstorming and audio-visual techniques. Base line instruments paved the way for the main data generating techniques; namely, microteaching, audio-visual techniques, critical partners’ observation and focus group interview. There was triangulation of data collection instruments which enhanced validation followed by tabulation and data collation to develop themes. Analysis entailed checking theme repetition, indigenous categories and key words in context techniques. Themes enabled the construction of analytical statements which were discussed with reference to the relevant literature, theory and subsequently aligned to the research questions. Findings from this study include the suggestions that IK can be incorporated into teaching and learning of science concepts through the use of models or practical activities, science language used in the community and some cultural artifacts. The relevance of incorporating such type of knowledge is to contextualize science teaching and learning. The study therefore concluded that the incorporation of IK into teaching and learning of science concepts; (a) broadens the curriculum as it addresses conceptual progression and cohesion; (b) contextualizes concepts taught; (c) empowers teachers to use a practical curriculum and (d) it also creates space for misconceptions that come with IK to be identified and corrected. The study thus recommends that cultural artifacts and the social science jargon used in the community of the trainee teachers can be used to incorporate IK with WS as these types of knowledge are not mutually exclusive but in fact complement one another.
- Full Text:
- Date Issued: 2013
Eluvial chromite resources of the Great Dyke of Zimbabwe
- Authors: Musa, Caston Tamburayi
- Date: 2007
- Subjects: Dikes (Geology) -- Zimbabwe Chromite -- Zimbabwe Geology -- Zimbabwe Olivine Serpentinite Eluvium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5046 , http://hdl.handle.net/10962/d1007731
- Description: Apart from the concentrations of chromite in layers within the Great Dyke and other ultramafic complexes, chromite also occurs as interstitial grains throughout the olivine-bearing rock-types. These olivine-bearing rocks include no rites, gabbros, dunites and pyroxenites. Chromite concentration in these rocks varies from 0.48 to 3.09 per cent of the rock, usually in the form of chromite (Ahrens, 1965; Worst, 1960). A small fraction of this chromite settled to form chromitite layers whilst the remainder is retained within the rock mass as finely disseminated chromite and chromite interstitial to olivine. This retained chromite is much finer grained than layer chromite and is the primary source of eluvial chromite (Cotterill, 1981). During weathering of the serpentine rock and transportation by rainwater, the heavier chromite and magnetite grains are re-deposited along watercourses and vleis or valleys as the speed of the water is retarded sufficiently for the heavier particles to settle. The lighter serpentine material is removed and the chromite concentration in the soil is increased, thus resulting in eluvial chromite (Keech et ai, 1961; Worst, 1960; Prendergast, 1978). The concentration of chromite particles in soil can be up to 15 (or more) Cr₂O₃ %, resulting in economic and exploitable deposits, located primarily along the Great Dyke fiacks. A preliminary evaluation of the eluvials indicate that the Great Dyke could be host to up to 10 million tonnes of potential chromite concentrates which could be processed from such eluvial concentrates. These chromite-rich soils can be mined more cheaply than the traditional seams mining and processed into chromite concentrates through simple mechanical processing techniques of spirals, jigs and heavy media separators. The resultant chromite concentrates are of high quality and can be used to manufacture chromite ore briquettes, which are an alternative to lumpy chromite smelter feed. The main challenges to eluvial mining are the inevitable environmental degradation and coming up with methods that could possibly mitigate against such environmental damage. The distribution of these eluvials over vast plains as thin soil horizons, necessitate use of mobile concentrator plants and hence establishment of extensive infrastructure. These challenges, however, are not insurmountable and test mining and previous production runs have proved profitable. The eluvials are also associated with some lateritic nickel concentrations. The nickel occurs in close association with some oxide such as goethite and garnierite and is associated with iron-manganiferous soil pisolites. The analyses of these pisolites indicate high nickel grades of generally above 1.00 %Ni. Such high nickel-content of Great Dyke laterites warrant, further investigations.
- Full Text:
- Date Issued: 2007
- Authors: Musa, Caston Tamburayi
- Date: 2007
- Subjects: Dikes (Geology) -- Zimbabwe Chromite -- Zimbabwe Geology -- Zimbabwe Olivine Serpentinite Eluvium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5046 , http://hdl.handle.net/10962/d1007731
- Description: Apart from the concentrations of chromite in layers within the Great Dyke and other ultramafic complexes, chromite also occurs as interstitial grains throughout the olivine-bearing rock-types. These olivine-bearing rocks include no rites, gabbros, dunites and pyroxenites. Chromite concentration in these rocks varies from 0.48 to 3.09 per cent of the rock, usually in the form of chromite (Ahrens, 1965; Worst, 1960). A small fraction of this chromite settled to form chromitite layers whilst the remainder is retained within the rock mass as finely disseminated chromite and chromite interstitial to olivine. This retained chromite is much finer grained than layer chromite and is the primary source of eluvial chromite (Cotterill, 1981). During weathering of the serpentine rock and transportation by rainwater, the heavier chromite and magnetite grains are re-deposited along watercourses and vleis or valleys as the speed of the water is retarded sufficiently for the heavier particles to settle. The lighter serpentine material is removed and the chromite concentration in the soil is increased, thus resulting in eluvial chromite (Keech et ai, 1961; Worst, 1960; Prendergast, 1978). The concentration of chromite particles in soil can be up to 15 (or more) Cr₂O₃ %, resulting in economic and exploitable deposits, located primarily along the Great Dyke fiacks. A preliminary evaluation of the eluvials indicate that the Great Dyke could be host to up to 10 million tonnes of potential chromite concentrates which could be processed from such eluvial concentrates. These chromite-rich soils can be mined more cheaply than the traditional seams mining and processed into chromite concentrates through simple mechanical processing techniques of spirals, jigs and heavy media separators. The resultant chromite concentrates are of high quality and can be used to manufacture chromite ore briquettes, which are an alternative to lumpy chromite smelter feed. The main challenges to eluvial mining are the inevitable environmental degradation and coming up with methods that could possibly mitigate against such environmental damage. The distribution of these eluvials over vast plains as thin soil horizons, necessitate use of mobile concentrator plants and hence establishment of extensive infrastructure. These challenges, however, are not insurmountable and test mining and previous production runs have proved profitable. The eluvials are also associated with some lateritic nickel concentrations. The nickel occurs in close association with some oxide such as goethite and garnierite and is associated with iron-manganiferous soil pisolites. The analyses of these pisolites indicate high nickel grades of generally above 1.00 %Ni. Such high nickel-content of Great Dyke laterites warrant, further investigations.
- Full Text:
- Date Issued: 2007
The effect of replacing antibiotic growth promoters with moringa oleifera leaf powder on growth performance, carcass characteristics, immune organ indices, gut microflora, physicochemical and sensory quality of broiler meat
- Nantapo, Carlos Wyson Tawanda
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
Web-based visualisation techniques for reporting zoonotic outbreaks
- Authors: Ncube, Sinini Paul
- Date: 2012
- Subjects: Zoonoses -- Reporting , Communicable diseases -- Reporting , Communication in medicine , Medical telematics , Internet , Information visualization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4664 , http://hdl.handle.net/10962/d1006672 , Zoonoses -- Reporting , Communicable diseases -- Reporting , Communication in medicine , Medical telematics , Internet , Information visualization
- Description: Zoonotic diseases are diseases that are transmitted from animals or vectors to humans and vice versa. The public together with veterinarian authorities should readily access disease information as it is vital in rapidly controlling resultant zoonotic outbreak threats through improved awareness. Currently, the reporting of disease information in South Africa is predominantly limited to traditional methods of Information Communication Technologies (ICTs) like faxes, monthly newspaper reports, radios, phones and televisions. Although these are effective ways of communication, their disadvantage is that the information that most of them offer can only be accessed at specific times during a crisis. New technologies like the internet have become the most efficient way of distributing information in near-real-time. Many developed countries have used web-based reporting platforms to deliver timely information through temporal and geographic visualisation techniques. There has been an attempt in the use of web-based reporting in South Africa but most of these sites are characterised by heavy text which makes them time consuming to use or maintain. As a result most sites have not been updated or have ceased to exist because of the work load involved. The success of web reporting mechanisms in developed countries offers evidence that web-based reporting systems when appropriately visualised can improve the easy understanding of information and efficiency in the analysis of that data. In this thesis, a web-based reporting prototype was proposed after gathering information from different sources: literature related to disease reporting and the visualisation of infectious diseases; the exploration of the currently deployed web systems; and the investigation of user requirements from relevant parties. The proposed prototype system was then developed using Adobe Flash tools, Java and MySQL languages. A focus group then reviewed the developed system to ascertain that the relevant requirements had been incorporated and to obtain additional ideas about the system. This led to the proposal of a new prototype system that can be used by the authorities concerned as a plan to develop a fully functional disease reporting system for South Africa.
- Full Text:
- Date Issued: 2012
- Authors: Ncube, Sinini Paul
- Date: 2012
- Subjects: Zoonoses -- Reporting , Communicable diseases -- Reporting , Communication in medicine , Medical telematics , Internet , Information visualization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4664 , http://hdl.handle.net/10962/d1006672 , Zoonoses -- Reporting , Communicable diseases -- Reporting , Communication in medicine , Medical telematics , Internet , Information visualization
- Description: Zoonotic diseases are diseases that are transmitted from animals or vectors to humans and vice versa. The public together with veterinarian authorities should readily access disease information as it is vital in rapidly controlling resultant zoonotic outbreak threats through improved awareness. Currently, the reporting of disease information in South Africa is predominantly limited to traditional methods of Information Communication Technologies (ICTs) like faxes, monthly newspaper reports, radios, phones and televisions. Although these are effective ways of communication, their disadvantage is that the information that most of them offer can only be accessed at specific times during a crisis. New technologies like the internet have become the most efficient way of distributing information in near-real-time. Many developed countries have used web-based reporting platforms to deliver timely information through temporal and geographic visualisation techniques. There has been an attempt in the use of web-based reporting in South Africa but most of these sites are characterised by heavy text which makes them time consuming to use or maintain. As a result most sites have not been updated or have ceased to exist because of the work load involved. The success of web reporting mechanisms in developed countries offers evidence that web-based reporting systems when appropriately visualised can improve the easy understanding of information and efficiency in the analysis of that data. In this thesis, a web-based reporting prototype was proposed after gathering information from different sources: literature related to disease reporting and the visualisation of infectious diseases; the exploration of the currently deployed web systems; and the investigation of user requirements from relevant parties. The proposed prototype system was then developed using Adobe Flash tools, Java and MySQL languages. A focus group then reviewed the developed system to ascertain that the relevant requirements had been incorporated and to obtain additional ideas about the system. This led to the proposal of a new prototype system that can be used by the authorities concerned as a plan to develop a fully functional disease reporting system for South Africa.
- Full Text:
- Date Issued: 2012
Farm to abattoir conditions and their subsequent effects on behavioural and physiological changes and the quality of beef from extensively-reared Nguni and non-descript steers
- Authors: Njisane, Yonela Zifikile
- Date: 2016
- Subjects: Nguni cattle Beef cattle breeds Beef -- Quality -- South Africa , Slaughtering and slaughter-houses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3143 , vital:28324
- Description: The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.
- Full Text:
- Date Issued: 2016
- Authors: Njisane, Yonela Zifikile
- Date: 2016
- Subjects: Nguni cattle Beef cattle breeds Beef -- Quality -- South Africa , Slaughtering and slaughter-houses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3143 , vital:28324
- Description: The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.
- Full Text:
- Date Issued: 2016
Variability in and coupling of larval availability and settlement of the mussel Perna perna : a spatio-temporal approach
- Authors: Porri, Francesca
- Date: 2004
- Subjects: Mussels -- South Africa Perna -- South Africa Perna -- Spawning Perna -- Larvae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5796 , http://hdl.handle.net/10962/d1005484
- Description: Population dynamics of many intertidal organisms are highly influenced by the abundance and distribution of planktonic larvae in the water column and their arrival on the shore. The brown mussel, Perna perna was used to investigate two of the primary processes that affect population size and dynamics, larval availability and settlement, on the south coast of South Africa. Perna perna is a dominant species on rocky shores of the southern and eastern coasts of South Africa. It creates three-dimensional beds that provide habitats for many other species and hence promotes biodiversity. Larval availability and settlement were examined at different spatial and temporal scales using a nested experimental design. To detect possible relationships between larval availability and settlement, the studies were simultaneous. Two sites, 4km apart, were chosen to investigate mussel settlement patterns. Within each site, three locations (300m from each other) were selected. At each location, five artificial settler collectors were placed at approximately 20cm intervals. Collectors were replaced at a range of time intervals, from daily to seasonal, for 16 months. Each intertidal location was paired with an offshore station, 500m from the shore, where larval availability was measured. At each offshore station, three vertical hauls were collected twice a month using a plankton net. Plankton sampling lasted for 14 months and was designed to examine variability on three temporal scales: seasonal, lunar and daily. The results showed no correlation between the distribution of larvae in the water and settlers on the shore. While larvae were abundant in the water at the start of sampling, they became very rare throughout the rest of the study at both sites and all locations. In contrast, distinct peaks of settler abundance were observed during the seasonal settlement study. In addition to the expected, strong temporal variation that emerged from both studies at all time scales, spatial patterns of variability were also observed. While no spatial effect was detected for the larvae in the water column, there was distinct spatial variation in settlement at the location level: some locations always showed higher settlement than others. These results suggest that, on scales of hundreds of meters to kilometers, larval availability and settlement are very unpredictable in time and that differential delivery of larvae occurs from nearshore waters to the shore. Although the effect of the state of the moon (new or full) was not significant in either study, more settlers seemed to arrive on the shore during new moon. Wind direction did not correlate significantly with settlement. However, the dropping of offshore winds and the prevalence of onshore winds, which are characteristic of summer, may be linked to the start of settlement. Nevertheless, further investigations on tidal or lunar cycles and on the influence of wind on surface currents are required to clarify the effects of moon and wind on settlement.
- Full Text:
- Date Issued: 2004
- Authors: Porri, Francesca
- Date: 2004
- Subjects: Mussels -- South Africa Perna -- South Africa Perna -- Spawning Perna -- Larvae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5796 , http://hdl.handle.net/10962/d1005484
- Description: Population dynamics of many intertidal organisms are highly influenced by the abundance and distribution of planktonic larvae in the water column and their arrival on the shore. The brown mussel, Perna perna was used to investigate two of the primary processes that affect population size and dynamics, larval availability and settlement, on the south coast of South Africa. Perna perna is a dominant species on rocky shores of the southern and eastern coasts of South Africa. It creates three-dimensional beds that provide habitats for many other species and hence promotes biodiversity. Larval availability and settlement were examined at different spatial and temporal scales using a nested experimental design. To detect possible relationships between larval availability and settlement, the studies were simultaneous. Two sites, 4km apart, were chosen to investigate mussel settlement patterns. Within each site, three locations (300m from each other) were selected. At each location, five artificial settler collectors were placed at approximately 20cm intervals. Collectors were replaced at a range of time intervals, from daily to seasonal, for 16 months. Each intertidal location was paired with an offshore station, 500m from the shore, where larval availability was measured. At each offshore station, three vertical hauls were collected twice a month using a plankton net. Plankton sampling lasted for 14 months and was designed to examine variability on three temporal scales: seasonal, lunar and daily. The results showed no correlation between the distribution of larvae in the water and settlers on the shore. While larvae were abundant in the water at the start of sampling, they became very rare throughout the rest of the study at both sites and all locations. In contrast, distinct peaks of settler abundance were observed during the seasonal settlement study. In addition to the expected, strong temporal variation that emerged from both studies at all time scales, spatial patterns of variability were also observed. While no spatial effect was detected for the larvae in the water column, there was distinct spatial variation in settlement at the location level: some locations always showed higher settlement than others. These results suggest that, on scales of hundreds of meters to kilometers, larval availability and settlement are very unpredictable in time and that differential delivery of larvae occurs from nearshore waters to the shore. Although the effect of the state of the moon (new or full) was not significant in either study, more settlers seemed to arrive on the shore during new moon. Wind direction did not correlate significantly with settlement. However, the dropping of offshore winds and the prevalence of onshore winds, which are characteristic of summer, may be linked to the start of settlement. Nevertheless, further investigations on tidal or lunar cycles and on the influence of wind on surface currents are required to clarify the effects of moon and wind on settlement.
- Full Text:
- Date Issued: 2004
Negotiating identity and belonging: perspectives of children living in a disadvantaged community in the Eastern Cape Province
- Authors: Ridley, Tamerin Amy
- Date: 2013
- Subjects: Group identity -- South Africa -- Eastern Cape , Children's rights -- South Africa -- Eastern Cape , Broken homes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11860 , http://hdl.handle.net/10353/d1019871 , Group identity -- South Africa -- Eastern Cape , Children's rights -- South Africa -- Eastern Cape , Broken homes -- South Africa -- Eastern Cape
- Description: Developing an identity with self-esteem and a sense of self-worth is a child’s fundamental right (Vandenbroek, 2001). To encourage identity formation children need to ask and answer questions such as: ‘Who am I?’, ‘Where do I belong?’ and ‘Is it ok to be who I am?’ A child’s identity is shaped largely by his/her experiences with regards to relationships and belonging within communities and familial structures. However, South Africa faces a host of problems, including poverty, violence, HIV/AIDS, all of which contribute to the breakdown of these familial and community structures. Utilising a participatory action framework, this research aims to provide insight into how children living in a disadvantaged community negotiate identity and belonging. This insight into children’s perceptions of identity and belonging is useful for identifying resources within the community which promote a positive sense of identity and belonging, and also to identify areas where support and intervention are required.
- Full Text:
- Date Issued: 2013
- Authors: Ridley, Tamerin Amy
- Date: 2013
- Subjects: Group identity -- South Africa -- Eastern Cape , Children's rights -- South Africa -- Eastern Cape , Broken homes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11860 , http://hdl.handle.net/10353/d1019871 , Group identity -- South Africa -- Eastern Cape , Children's rights -- South Africa -- Eastern Cape , Broken homes -- South Africa -- Eastern Cape
- Description: Developing an identity with self-esteem and a sense of self-worth is a child’s fundamental right (Vandenbroek, 2001). To encourage identity formation children need to ask and answer questions such as: ‘Who am I?’, ‘Where do I belong?’ and ‘Is it ok to be who I am?’ A child’s identity is shaped largely by his/her experiences with regards to relationships and belonging within communities and familial structures. However, South Africa faces a host of problems, including poverty, violence, HIV/AIDS, all of which contribute to the breakdown of these familial and community structures. Utilising a participatory action framework, this research aims to provide insight into how children living in a disadvantaged community negotiate identity and belonging. This insight into children’s perceptions of identity and belonging is useful for identifying resources within the community which promote a positive sense of identity and belonging, and also to identify areas where support and intervention are required.
- Full Text:
- Date Issued: 2013
The human soul (jivatma) and its ultimate goal (moksa) in the context of Taittiriya Upanisad (3.10.5): a study in an aspect of Hindu eschatology
- Authors: Saradananda, Swami
- Date: 1995
- Subjects: Upanishads -- History and criticism , Hindu eschatology , Soul -- Hinduism , Suicide -- Religious aspects -- Hinduism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1304 , http://hdl.handle.net/10962/d1016396
- Description: This research was stimulated by pastoral concerns regarding the high rate of suicide in the South African Hindu community. On the one hand it was found that traumatized individuals contemplating suicide were woefully ill-equipped with helpful religious guidelines and on the other it is known that the primary and authoritative scriptures of Hinduism possess a wealth of information that can promote healing. This work uses the Taittiriya Upanishad (3.10.5) to address this challenge. The early Vedic writings are not systematized nor are they fully explicable except through commentaries. This research surveys the early Vedic and Upanisadic Writings in order to show the literary, social and philosophical conditions under which the texts were produced. The Taittiriya Upanisad is the culminating part of several strands of thought that emerged from the earlier Taittiriya School. In order to interpret the text of this Upanisad it was necessary to link its key concepts with other Upanisads of this period. Further interpretations emerged from later Upanisads. These texts were viewed in the light of several commentators - Shaukara (medieval period), and Vivekananda, Aurobindo and Radhakrishuan of the Neo-Vedanta movements. In the early Vedic period the soul is a metaphysical entity. Upon death it is judged and in accordance with its good or bad actions, heavenly rewards or the punishments of hell are meted out to it. Heaven and hell are final eschatological goals for the soul in the Vedic period. In the later Vedic or Upanisadic period it is found that heaven and hell are temporary eschatological goals. The ultimate goal becomes Liberation which implies the cessation of duality and the realization of non-duality. Correspondingly the Taittiriya Upauisad defines the soul in a manner in which its components have the potential to achieve this later goal. Here the soul is a formulation of five sheaths: body, vital energy, mind, intellect and bliss with an immortal consciousness as its focus. Functioning under the effects of ignorance each sheath binds the soul to suffering and rebiiths either on earth or on other planes (heaven or hell). However, each sheath also possesses an intrinsic capacity to liberate the soul from suffering. Tills work explores these negative and positive capabilities of the sheaths and points out the path by which the soul's divine potential may be realized. The ultimate healing or liberation occurs when the 'focus-consciousness' of the soul is intuitively realized. This consciousness is one with the universal consciousness. This achievement produces the 'liberated soul' who experiences ecstasy at this knowledge of oneness. This research also points out that the Neo-Vedanta movements, unlike their medieval counterparts, have a life-affirming and positive social attitude that seeks to draw from ancient texts for the purposes of healing and social upliftment.
- Full Text:
- Date Issued: 1995
- Authors: Saradananda, Swami
- Date: 1995
- Subjects: Upanishads -- History and criticism , Hindu eschatology , Soul -- Hinduism , Suicide -- Religious aspects -- Hinduism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1304 , http://hdl.handle.net/10962/d1016396
- Description: This research was stimulated by pastoral concerns regarding the high rate of suicide in the South African Hindu community. On the one hand it was found that traumatized individuals contemplating suicide were woefully ill-equipped with helpful religious guidelines and on the other it is known that the primary and authoritative scriptures of Hinduism possess a wealth of information that can promote healing. This work uses the Taittiriya Upanishad (3.10.5) to address this challenge. The early Vedic writings are not systematized nor are they fully explicable except through commentaries. This research surveys the early Vedic and Upanisadic Writings in order to show the literary, social and philosophical conditions under which the texts were produced. The Taittiriya Upanisad is the culminating part of several strands of thought that emerged from the earlier Taittiriya School. In order to interpret the text of this Upanisad it was necessary to link its key concepts with other Upanisads of this period. Further interpretations emerged from later Upanisads. These texts were viewed in the light of several commentators - Shaukara (medieval period), and Vivekananda, Aurobindo and Radhakrishuan of the Neo-Vedanta movements. In the early Vedic period the soul is a metaphysical entity. Upon death it is judged and in accordance with its good or bad actions, heavenly rewards or the punishments of hell are meted out to it. Heaven and hell are final eschatological goals for the soul in the Vedic period. In the later Vedic or Upanisadic period it is found that heaven and hell are temporary eschatological goals. The ultimate goal becomes Liberation which implies the cessation of duality and the realization of non-duality. Correspondingly the Taittiriya Upauisad defines the soul in a manner in which its components have the potential to achieve this later goal. Here the soul is a formulation of five sheaths: body, vital energy, mind, intellect and bliss with an immortal consciousness as its focus. Functioning under the effects of ignorance each sheath binds the soul to suffering and rebiiths either on earth or on other planes (heaven or hell). However, each sheath also possesses an intrinsic capacity to liberate the soul from suffering. Tills work explores these negative and positive capabilities of the sheaths and points out the path by which the soul's divine potential may be realized. The ultimate healing or liberation occurs when the 'focus-consciousness' of the soul is intuitively realized. This consciousness is one with the universal consciousness. This achievement produces the 'liberated soul' who experiences ecstasy at this knowledge of oneness. This research also points out that the Neo-Vedanta movements, unlike their medieval counterparts, have a life-affirming and positive social attitude that seeks to draw from ancient texts for the purposes of healing and social upliftment.
- Full Text:
- Date Issued: 1995
The best a man can get? : an analysis of the representation of men within group situations in the advertising copy of Men’s Health and FHM from December 2006 through May 2007
- Authors: Scott, Robert James
- Date: 2014
- Subjects: Men's health (Magazine) , For Him Magazine (South Africa) , Men in advertising , Sex role in advertising , Discrimination in the advertising industry , Men in mass media , Mass media criticism , Men in popular culture , Sex role in mass media , Discourse analysis -- Social aspects , Masculinity -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3535 , http://hdl.handle.net/10962/d1013576
- Description: This study examines the production of masculinity in the advertisements of South Africa’s two most popular men’s lifestyle magazines, FHM and Men’s Health. I specifically focus on advertisements, as I argue that they play a crucial role in the re‐production of prominent discursive formations. Informed by a poststructuralist framework this study adopts Foucault’s notions of discourse, power and the constitution of the subject. Gender is conceived of within power relations, with a hierarchical relationship between masculinities and femininities. The gendered subject is also viewed as being constantly in process and being constructed performatively through material forms of practice. Focusing on group representations to establish gender hierarchies, I argue that these representations of people are performative acts, hailing the subjects who view them and producing reality through discourse. Hegemonic masculinity, which is argued to be prominent in advertising, is located at the highest point in the gender hierarchy. However, there is not one universal hegemonic masculinity, for it can vary across three discrete political contexts: the local, which is constructed in the immediate face‐to‐face interactions of families, organisations and social structures; the regional, which is constructed at the level of culture or the nation state; and the global, which is constructed in supra‐national locations. In the advertisements of FHM and Men’s Health there is interplay between the latter two as global and regional brands both advertise in these magazines. To investigate the portrayal of masculinities in these publications, this study first undertakes a content analysis to survey the “general landscape” of representation in the advertisements and then performs a critical discourse analysis to uncover “thick description” of the production of masculinity. The content analysis, finds that the advertisements in the sample validate both white and heterosexual forms of masculinity. The sample is comprised mostly of white males, white females and black males, generally proposing forms of hegemonic masculinity, emphasised femininity and complicit masculinity respectively. The representation of white males and black males is different both in terms of the frequency of representations and in the types of representations. I argued that a certain tension inhabits the resulting representations, which try to be inclusive of a multi‐racial South Africa, yet do so within a clearly hierarchical structure. An in‐depth analysis of eight texts, informed by Fairclough’s model of critical discourse analysis and Kress & van Leeuwen’s framework for visual analysis, finds similar results to the content analysis while providing insight into how various discourses produced the representations, particularly within non‐narrative advertisements.
- Full Text:
- Date Issued: 2014
- Authors: Scott, Robert James
- Date: 2014
- Subjects: Men's health (Magazine) , For Him Magazine (South Africa) , Men in advertising , Sex role in advertising , Discrimination in the advertising industry , Men in mass media , Mass media criticism , Men in popular culture , Sex role in mass media , Discourse analysis -- Social aspects , Masculinity -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3535 , http://hdl.handle.net/10962/d1013576
- Description: This study examines the production of masculinity in the advertisements of South Africa’s two most popular men’s lifestyle magazines, FHM and Men’s Health. I specifically focus on advertisements, as I argue that they play a crucial role in the re‐production of prominent discursive formations. Informed by a poststructuralist framework this study adopts Foucault’s notions of discourse, power and the constitution of the subject. Gender is conceived of within power relations, with a hierarchical relationship between masculinities and femininities. The gendered subject is also viewed as being constantly in process and being constructed performatively through material forms of practice. Focusing on group representations to establish gender hierarchies, I argue that these representations of people are performative acts, hailing the subjects who view them and producing reality through discourse. Hegemonic masculinity, which is argued to be prominent in advertising, is located at the highest point in the gender hierarchy. However, there is not one universal hegemonic masculinity, for it can vary across three discrete political contexts: the local, which is constructed in the immediate face‐to‐face interactions of families, organisations and social structures; the regional, which is constructed at the level of culture or the nation state; and the global, which is constructed in supra‐national locations. In the advertisements of FHM and Men’s Health there is interplay between the latter two as global and regional brands both advertise in these magazines. To investigate the portrayal of masculinities in these publications, this study first undertakes a content analysis to survey the “general landscape” of representation in the advertisements and then performs a critical discourse analysis to uncover “thick description” of the production of masculinity. The content analysis, finds that the advertisements in the sample validate both white and heterosexual forms of masculinity. The sample is comprised mostly of white males, white females and black males, generally proposing forms of hegemonic masculinity, emphasised femininity and complicit masculinity respectively. The representation of white males and black males is different both in terms of the frequency of representations and in the types of representations. I argued that a certain tension inhabits the resulting representations, which try to be inclusive of a multi‐racial South Africa, yet do so within a clearly hierarchical structure. An in‐depth analysis of eight texts, informed by Fairclough’s model of critical discourse analysis and Kress & van Leeuwen’s framework for visual analysis, finds similar results to the content analysis while providing insight into how various discourses produced the representations, particularly within non‐narrative advertisements.
- Full Text:
- Date Issued: 2014
Structure and functioning of fish assemblages in two South African estuaries, with emphasis on the presence and absence of aquatic macrophyte beds
- Authors: Sheppard, Jill Nicole
- Date: 2010
- Subjects: Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5321 , http://hdl.handle.net/10962/d1005166 , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
- Description: Temporarily open/closed estuaries (TOCEs) are the dominant estuary type in South Africa. These systems are often characterized by extensive beds of submerged macrophytes, which form important foraging and shelter habitats for fishes, especially for estuary-dependent fish species such as the Cape stumpnose Rhabdosargus holubi and Cape moony Monodactylus falciformis that are commonly associated with them. A loss of submerged macrophytes from an estuary has been shown to affect the fish community as well as reducing overall system productivity. The TOC East Kleinemonde Estuary, situated in the warm-temperate biogeographic region of South Africa has been subject to an ongoing long-term fish monitoring project since 1995. During the period 1995 to 2002, this estuary contained large beds of the submerged macrophytes Ruppia cirrhosa and Potamogeton pectinatus. However, subsequent to a major flood event in 2003 these macrophytes have been largely absent from this system. The effect of the loss of submerged macrophytes on the East Kleinemonde fish assemblage was investigated through an analysis of seine and gill net catch data. Seine net catches for a 12 year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, revealed changes in the relative abundance of certain fish species. Vegetation-associated species such as R. holubi and M. falciformis decreased in abundance whereas sediment-associated species, especially members of the family Mugilidae, increased in abundance following loss of the macrophytes in this estuary. The critically endangered pipefish Syngnathus watermeyeri was only recorded in catches during years in which macrophyte beds were present. In addition to the analysis of catch data, the importance of macrophytes as a primary energy source for selected estuarine fishes was explored through the analysis of carbon and nitrogen stable isotopes. Prior to conducting these analyses, common methodological practices to address the presence of carbonates and lipids within isotope samples were evaluated. A subset of samples were either acid washed to remove carbonates, or lipids were removed according to the method of Bligh and Dyer (1959) as both of these compounds have been shown to affect stable carbon and nitrogen isotope ratios. The suitability of the lipid normalization models of Fry (2002) and Post et al. (2007) for samples of estuarine fish muscle were also tested. Based on this evaluation both models are suitable for use with estuarine fish muscle tissue, however since neither carbonate nor lipid content of any of the samples used in this study was high all samples were left untreated in the following analysis. Carbon isotope ratios from a wide range of fish species collected from the East Kleinemonde Estuary during the macrophyte-senescent phase were compared with individuals of the same species from the neighbouring West Kleinemonde Estuary (where extensive beds of R. cirrhosa and P. pectinatus were present) and revealed the influence of submerged macrophyte material in the diet of fishes in the latter system. However, it was apparent that these plants are not directly consumed but rather contribute to the detrital pool that forms a food source for most invertebrate and some fish species. The most significant source of carbon for East Kleinemonde fishes during the macrophyte senescent phase appeared to have a more depleted origin; probably from benthic or pelagic microalgae. In conclusion, while the importance of macrophyte beds as shelter and foraging habitats for estuarine fishes are well documented, their role in terms of the structuring and functioning of fish assemblages in TOCEs remains somewhat uncertain. The findings of this study were possibly masked by the resilience of vegetation-associated species to the loss of this habitat, as well as by life history characteristics of species such as R. holubi that allow their numerical dominance despite habitat change. Nonetheless, macrophyte senescence in the East Kleinemonde Estuary resulted in the loss of at least one species and the reduced abundance of vegetation-associated species, probably reflective of reduced food resources and/or increased vulnerability to predation. As a result, beds of submerged macrophytes are an important habitat within TOCEs.
- Full Text:
- Date Issued: 2010
- Authors: Sheppard, Jill Nicole
- Date: 2010
- Subjects: Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5321 , http://hdl.handle.net/10962/d1005166 , Estuaries -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
- Description: Temporarily open/closed estuaries (TOCEs) are the dominant estuary type in South Africa. These systems are often characterized by extensive beds of submerged macrophytes, which form important foraging and shelter habitats for fishes, especially for estuary-dependent fish species such as the Cape stumpnose Rhabdosargus holubi and Cape moony Monodactylus falciformis that are commonly associated with them. A loss of submerged macrophytes from an estuary has been shown to affect the fish community as well as reducing overall system productivity. The TOC East Kleinemonde Estuary, situated in the warm-temperate biogeographic region of South Africa has been subject to an ongoing long-term fish monitoring project since 1995. During the period 1995 to 2002, this estuary contained large beds of the submerged macrophytes Ruppia cirrhosa and Potamogeton pectinatus. However, subsequent to a major flood event in 2003 these macrophytes have been largely absent from this system. The effect of the loss of submerged macrophytes on the East Kleinemonde fish assemblage was investigated through an analysis of seine and gill net catch data. Seine net catches for a 12 year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, revealed changes in the relative abundance of certain fish species. Vegetation-associated species such as R. holubi and M. falciformis decreased in abundance whereas sediment-associated species, especially members of the family Mugilidae, increased in abundance following loss of the macrophytes in this estuary. The critically endangered pipefish Syngnathus watermeyeri was only recorded in catches during years in which macrophyte beds were present. In addition to the analysis of catch data, the importance of macrophytes as a primary energy source for selected estuarine fishes was explored through the analysis of carbon and nitrogen stable isotopes. Prior to conducting these analyses, common methodological practices to address the presence of carbonates and lipids within isotope samples were evaluated. A subset of samples were either acid washed to remove carbonates, or lipids were removed according to the method of Bligh and Dyer (1959) as both of these compounds have been shown to affect stable carbon and nitrogen isotope ratios. The suitability of the lipid normalization models of Fry (2002) and Post et al. (2007) for samples of estuarine fish muscle were also tested. Based on this evaluation both models are suitable for use with estuarine fish muscle tissue, however since neither carbonate nor lipid content of any of the samples used in this study was high all samples were left untreated in the following analysis. Carbon isotope ratios from a wide range of fish species collected from the East Kleinemonde Estuary during the macrophyte-senescent phase were compared with individuals of the same species from the neighbouring West Kleinemonde Estuary (where extensive beds of R. cirrhosa and P. pectinatus were present) and revealed the influence of submerged macrophyte material in the diet of fishes in the latter system. However, it was apparent that these plants are not directly consumed but rather contribute to the detrital pool that forms a food source for most invertebrate and some fish species. The most significant source of carbon for East Kleinemonde fishes during the macrophyte senescent phase appeared to have a more depleted origin; probably from benthic or pelagic microalgae. In conclusion, while the importance of macrophyte beds as shelter and foraging habitats for estuarine fishes are well documented, their role in terms of the structuring and functioning of fish assemblages in TOCEs remains somewhat uncertain. The findings of this study were possibly masked by the resilience of vegetation-associated species to the loss of this habitat, as well as by life history characteristics of species such as R. holubi that allow their numerical dominance despite habitat change. Nonetheless, macrophyte senescence in the East Kleinemonde Estuary resulted in the loss of at least one species and the reduced abundance of vegetation-associated species, probably reflective of reduced food resources and/or increased vulnerability to predation. As a result, beds of submerged macrophytes are an important habitat within TOCEs.
- Full Text:
- Date Issued: 2010
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