Information and communication technology driven teaching and learning opportunities in support of environmental education processes: a case of the eno-environment online programme at Treverton Preparatory School, South Africa
- Authors: Snow, Janet P
- Date: 2008
- Subjects: Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1575 , http://hdl.handle.net/10962/d1003457 , Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Description: This research looks at a global virtual web-based programme for environmental awareness and education for sustainable development (ENO-Environment Online). It is a case study of Treverton Preparatory school in South Africa, one of several schools where the programme is implemented. One of the themes within the programme (“This is our culture”) is highlighted. A mixed method, interpretive case study methodology is used. Research methods include two focus group interviews with a selected group of learners, observations of four computer-based lessons and one practical session, document analysis of the three forms of learners’ submissions (‘blog’ site submission, presentation of material and ‘chat’ session), and two interviews conducted with the Treverton form teacher and ENO programme co-ordinator. The research views the Treverton ENO activities in relation to: academic rigour in Information and Communication Technology (ICT) use, the teacher’s role in ICT pedagogy, and active learning in ICT applications. As the theme is culturally based with a global perspective, the research also considers these activities from the perspectives of education for cultural knowledge (multicultural education) and in terms of mobilising indigenous knowledge and global education. These perspectives on the ENO activities are analysed in relation to dimensions of teaching and learning guidelines pertinent to Education for Sustainable Development in a southern African context. The research shows that the ENO theme supported a variety of learning contexts, a sense of community, modelling of behaviours and actions, debate, sharing of information and improved communication skills. Learners were exposed to cultural diversity, contradictory cultural values, cultural and global inclusivity. Knowledge of social cultural practices and indigenous knowledge was shared. Academic rigour in the ENO theme was noted with reflection being the predominant activity. Based on these key findings, recommendations to the ENO programme, schools and teachers have been made. These include: exploring possibilities for increasing focus on sustainable development actions, improving access to relevant information, encouraging critical debate and critical engagement with cultural diversity.
- Full Text:
- Authors: Snow, Janet P
- Date: 2008
- Subjects: Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1575 , http://hdl.handle.net/10962/d1003457 , Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Description: This research looks at a global virtual web-based programme for environmental awareness and education for sustainable development (ENO-Environment Online). It is a case study of Treverton Preparatory school in South Africa, one of several schools where the programme is implemented. One of the themes within the programme (“This is our culture”) is highlighted. A mixed method, interpretive case study methodology is used. Research methods include two focus group interviews with a selected group of learners, observations of four computer-based lessons and one practical session, document analysis of the three forms of learners’ submissions (‘blog’ site submission, presentation of material and ‘chat’ session), and two interviews conducted with the Treverton form teacher and ENO programme co-ordinator. The research views the Treverton ENO activities in relation to: academic rigour in Information and Communication Technology (ICT) use, the teacher’s role in ICT pedagogy, and active learning in ICT applications. As the theme is culturally based with a global perspective, the research also considers these activities from the perspectives of education for cultural knowledge (multicultural education) and in terms of mobilising indigenous knowledge and global education. These perspectives on the ENO activities are analysed in relation to dimensions of teaching and learning guidelines pertinent to Education for Sustainable Development in a southern African context. The research shows that the ENO theme supported a variety of learning contexts, a sense of community, modelling of behaviours and actions, debate, sharing of information and improved communication skills. Learners were exposed to cultural diversity, contradictory cultural values, cultural and global inclusivity. Knowledge of social cultural practices and indigenous knowledge was shared. Academic rigour in the ENO theme was noted with reflection being the predominant activity. Based on these key findings, recommendations to the ENO programme, schools and teachers have been made. These include: exploring possibilities for increasing focus on sustainable development actions, improving access to relevant information, encouraging critical debate and critical engagement with cultural diversity.
- Full Text:
Information and communication technology in A-level physics teaching and learning at secondary schools in Manicaland Zimbabwe: multiple case studies
- Authors: Mlambo, Watson
- Date: 2008
- Subjects: Information technology -- Zimbabwe Educational technology -- Zimbabwe Education, Secondary -- Zimbabwe Information technology -- Study and teaching (Secondary) -- Zimbabwe Physics -- Study and teaching (Secondary) -- Zimbabwe Computer-assisted instruction -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1576 , http://hdl.handle.net/10962/d1003458
- Description: As personal computers (PCs) and related ICTs become more and more omnipresent than ever before in institutions of education, teachers are faced with the challenge of having to teach in ICT rich environments. Some syllabuses increase this pressure by stipulating where ICT may be applied. While past research efforts have focused on presence of and/or effectiveness of ICTs on achieving various didactic goals, there is limited literature on the extent to which actual practice occurred naturally. It was the aim of this study to determine the extent to which Physics teachers and students used ICT in their usual teaching/learning ambience, referred to as natural settings in this study. Using activity theory as a theoretical lens, multiple case studies were chosen as a strategy using 10 schools, 15 Physics teachers, 20 A-level Physics students and 10 ICT teachers (computer specialists). Questionnaires, observations and informal and focus group interviews were used to elicit responses from students, teachers and computer specialists. It emerged from the case studies that despite the presence of apt ICT infrastructure in the schools and although the teachers had a positive attitude towards the use of ICT for teaching and learning of Physics, teachers were apathetic when it came to the actual use. Some of the reasons militating against use were lack of an ICT policy, school authority, and monopoly of computers enjoyed by computer studies teachers. However among students there were ‘early starters’ who used ICTs outside of school, a situation that tended to change the Physics learning environment. These findings led to a proposal for a post of Computer Specialist (CS) in the schools. The need for developing ICT policy at all levels namely national, Ministry of Education and the school was also proposed. Lastly staff development in the use ICT for Physics teachers was proposed as indispensable.
- Full Text:
- Authors: Mlambo, Watson
- Date: 2008
- Subjects: Information technology -- Zimbabwe Educational technology -- Zimbabwe Education, Secondary -- Zimbabwe Information technology -- Study and teaching (Secondary) -- Zimbabwe Physics -- Study and teaching (Secondary) -- Zimbabwe Computer-assisted instruction -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1576 , http://hdl.handle.net/10962/d1003458
- Description: As personal computers (PCs) and related ICTs become more and more omnipresent than ever before in institutions of education, teachers are faced with the challenge of having to teach in ICT rich environments. Some syllabuses increase this pressure by stipulating where ICT may be applied. While past research efforts have focused on presence of and/or effectiveness of ICTs on achieving various didactic goals, there is limited literature on the extent to which actual practice occurred naturally. It was the aim of this study to determine the extent to which Physics teachers and students used ICT in their usual teaching/learning ambience, referred to as natural settings in this study. Using activity theory as a theoretical lens, multiple case studies were chosen as a strategy using 10 schools, 15 Physics teachers, 20 A-level Physics students and 10 ICT teachers (computer specialists). Questionnaires, observations and informal and focus group interviews were used to elicit responses from students, teachers and computer specialists. It emerged from the case studies that despite the presence of apt ICT infrastructure in the schools and although the teachers had a positive attitude towards the use of ICT for teaching and learning of Physics, teachers were apathetic when it came to the actual use. Some of the reasons militating against use were lack of an ICT policy, school authority, and monopoly of computers enjoyed by computer studies teachers. However among students there were ‘early starters’ who used ICTs outside of school, a situation that tended to change the Physics learning environment. These findings led to a proposal for a post of Computer Specialist (CS) in the schools. The need for developing ICT policy at all levels namely national, Ministry of Education and the school was also proposed. Lastly staff development in the use ICT for Physics teachers was proposed as indispensable.
- Full Text:
Information technology support for transformation in higher educational institutions in South Africa
- Authors: Roets, Rina Annette
- Date: 2008
- Subjects: Education, Higher -- South Africa Educational change -- South Africa Universities and colleges -- South Africa Universities and colleges -- South Africa -- Administration Information technology -- South Africa Educational technology -- South Africa Education, Higher -- Technological innovations -- South Africa Knowledge management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1145 , http://hdl.handle.net/10962/d1002775
- Description: Higher Education Institutions (HEIs) have been in a state of change, and in South Africa, the term “transformation” is used to describe the changes occurring. These changes have implications for the structure, processes and focus of HEIs, and as such have implications for Information Technology (IS/ICT) support for HEIs. IS/ICT support for organisations is predicated on several factors, such as effective informational and technical support at all levels of the organisation, but especially support for the strategic goals of the organisation (alignment). For organisations in a state of rapid change other issues need to be considered, such as flexibility, and new and diverse information and communication needs. This paper investigates the use of Information Technology to support HEIs in transformation. The research examines factors that make HEIs less amenable to rationalist techniques such as mixed management styles and a “different” value chain. The difficulties for IS/ICT support of HEIs at all managerial levels is discussed, especially the issue of alignment with institutional goals. Thereafter, transformation of HEIs and the possibility of IS/ICT support in achieving the ill-defined goal of transformation is examined. The research uses management and IS/ICT theories such as the widely used and reported Porter’s value chain, Anthony’s information model, and Minzberg’s organisational model to suggest an analysis model for HEIs (Applegate, McFarlan and McKenney, 1996; Minzberg, 1979; Ward and Peppard, 2002). Furthermore, from the analysis of the literature, a model of antecedent factors for successful HEI transformation supported by IS/ICT is proposed. The research makes use of a comparative case study approach in which 3 (three) South African HEIs are investigated through the “lens” of the developed model. The major finding of the research is that the potential use of IS/ICT support for HEIs is not optimal in the three cases examined. Results of the analysis suggest that: • IS/ICT alignment with organisational goals at HEIs is low and holistic IS/ICT strategic management is lacking. The areas of Knowledge Management and Communication Management are conducted informally and Knowledge Management, especially, is not fully exploited. • The greatest area of concern is the lack of IS/ICT support for academic management, where academics are increasingly required to perform administrative and managerial tasks. • The merger/incorporation information needs have not caused major system problems, but other intangible aspects of the mergers/incorporations could be better supported by IS/ICT. The research concludes with a set of actions that should ensure a higher level of support, amongst which are the more holistic management of IS/ICT especially for Academic management needs, and particularly the use of IS/ICT in innovative ways to overcome the challenges of the “transformed” Universities: There are areas of excellence but the full possibilities afforded by technology are not exploited maximally in support of transformation. Research suggests that the reasons for this are mainly the lack of holistic strategic management of IS/ICT.
- Full Text:
Information technology support for transformation in higher educational institutions in South Africa
- Authors: Roets, Rina Annette
- Date: 2008
- Subjects: Education, Higher -- South Africa Educational change -- South Africa Universities and colleges -- South Africa Universities and colleges -- South Africa -- Administration Information technology -- South Africa Educational technology -- South Africa Education, Higher -- Technological innovations -- South Africa Knowledge management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1145 , http://hdl.handle.net/10962/d1002775
- Description: Higher Education Institutions (HEIs) have been in a state of change, and in South Africa, the term “transformation” is used to describe the changes occurring. These changes have implications for the structure, processes and focus of HEIs, and as such have implications for Information Technology (IS/ICT) support for HEIs. IS/ICT support for organisations is predicated on several factors, such as effective informational and technical support at all levels of the organisation, but especially support for the strategic goals of the organisation (alignment). For organisations in a state of rapid change other issues need to be considered, such as flexibility, and new and diverse information and communication needs. This paper investigates the use of Information Technology to support HEIs in transformation. The research examines factors that make HEIs less amenable to rationalist techniques such as mixed management styles and a “different” value chain. The difficulties for IS/ICT support of HEIs at all managerial levels is discussed, especially the issue of alignment with institutional goals. Thereafter, transformation of HEIs and the possibility of IS/ICT support in achieving the ill-defined goal of transformation is examined. The research uses management and IS/ICT theories such as the widely used and reported Porter’s value chain, Anthony’s information model, and Minzberg’s organisational model to suggest an analysis model for HEIs (Applegate, McFarlan and McKenney, 1996; Minzberg, 1979; Ward and Peppard, 2002). Furthermore, from the analysis of the literature, a model of antecedent factors for successful HEI transformation supported by IS/ICT is proposed. The research makes use of a comparative case study approach in which 3 (three) South African HEIs are investigated through the “lens” of the developed model. The major finding of the research is that the potential use of IS/ICT support for HEIs is not optimal in the three cases examined. Results of the analysis suggest that: • IS/ICT alignment with organisational goals at HEIs is low and holistic IS/ICT strategic management is lacking. The areas of Knowledge Management and Communication Management are conducted informally and Knowledge Management, especially, is not fully exploited. • The greatest area of concern is the lack of IS/ICT support for academic management, where academics are increasingly required to perform administrative and managerial tasks. • The merger/incorporation information needs have not caused major system problems, but other intangible aspects of the mergers/incorporations could be better supported by IS/ICT. The research concludes with a set of actions that should ensure a higher level of support, amongst which are the more holistic management of IS/ICT especially for Academic management needs, and particularly the use of IS/ICT in innovative ways to overcome the challenges of the “transformed” Universities: There are areas of excellence but the full possibilities afforded by technology are not exploited maximally in support of transformation. Research suggests that the reasons for this are mainly the lack of holistic strategic management of IS/ICT.
- Full Text:
Interaction between arbuscular mycorrhizal fungi and soil microbial populations in the rhizosphere
- Authors: Ike-Izundu, Nnenna Esther
- Date: 2008
- Subjects: Mycorrhizas , Mycorrhizal fungi , Vesicular-arbuscular mycorrhizas , Soil microbiology , Rhizosphere , Revegetation , Restoration ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3962 , http://hdl.handle.net/10962/d1004021 , Mycorrhizas , Mycorrhizal fungi , Vesicular-arbuscular mycorrhizas , Soil microbiology , Rhizosphere , Revegetation , Restoration ecology
- Description: This study examined the rehabilitation potential of AM fungi with organic and inorganic fertilisers under pot and field trial conditions as well as their interaction with rhizospheric organisms and specific functional groups. In addition, the study highlighted the effects of land-use management on AM fungal populations in soil and the mycorrhizal status of some selected plants from one of the study sites. The study focussed on two sites that differ in operational activities and these included a mined area that was to be rehabilitated and a commercial farming site. A pot trial was conducted using an overburdened soil resulting from kaolin clay mining. Pots were seeded with Cynodon dactylon and treated with either Organic Tea or NPK (3:1:5) fertiliser, with or without AM fungal inoculum. The compatibility of these fertilisers with AM fungi was assessed by plant growth and percentage root colonisation. Maximum shoot height and plant biomass were observed at the 28th week with NPK (3:1:5) fertiliser supporting mycorrhizal colonisation by 80%. The result indicated the potential of AM fungi to be used in rehabilitation with minimal phosphate fertiliser. Similarly, a field trial was set-up using 17 x 17 m[superscript 2] plots in the mining site that were treated with the same organic and inorganic fertilisers as well as with AM fungal inoculum in different combinations. The interaction between AM fungi and soil microbial population was determined using culture dependent and culture independent techniques. The culture dependent technique involved the use of soil dilution and plating on general purpose and selective media. The result showed that there was no change in the total culturable bacterial number in the untreated and AM fungal treated plots, while a change in species composition was observed in the functional groups. Different functional groups identified included nitrogen fixing bacteria, pseudomonads, actinomycetes, phosphate solubilisers and the fungal counterparts. Gram-positive bacteria were observed as the predominant phenotypic type, while nitrogen fixers and actinomycetes were the predominant functional groups. Species identified from each functional group were Pseudomonas fulva, Bacillus megaterium, Streptomyces and actinomycetales bacteria. Meanwhile, fungi such as Ampelomyces, Fusarium, Penicillium, Aspergillus, Cephalosporium and Exserohilium were identified morphologically and molecularly. Furthermore, the mining site had a significantly higher bacterial number than the farming site thereby indicating the effects of land-use management on culturable bacterial numbers. The culture independent technique was carried out by cloning of the bacterial 16S rDNA and sequencing. Identified clones were Bradyrhizobium, Propionibacterium and Sporichthya. A cladogram constructed with the nucleotides sequences of identified functional species, clones and closely related nucleotide sequences from the Genbank indicated that nucleotide sequences differed in terms of the method used. The activity and establishment of the introduced AM fungal population was determined by spore enumeration, infectivity assay, percentage root colonisation and assessment of glomalin concentrations. The results indicated that the two land use types affected AM fungal populations. However, the establishment of AM fungi in the farming site was more successful than in the mining site as indicated by the higher infectivity pontential. Selected host plants, which were collected around the mine area, were observed to be mainly colonised by AM fungi and these were identified as Pentzia incana, Elytropappus rhinocerotis, Euphorbia meloformis, Selago corymbosa, Albuca canadensis and Helichrysum rosum. These plant species were able to thrive under harsh environmental conditions, thereby indicating their potential use as rehabilitation host plants. Generally, the findings of this study has provided an insight into the interaction between arbuscular mycorrhizal fungi and other soil microorganisms in two fields with differing land use management practices.
- Full Text:
- Authors: Ike-Izundu, Nnenna Esther
- Date: 2008
- Subjects: Mycorrhizas , Mycorrhizal fungi , Vesicular-arbuscular mycorrhizas , Soil microbiology , Rhizosphere , Revegetation , Restoration ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3962 , http://hdl.handle.net/10962/d1004021 , Mycorrhizas , Mycorrhizal fungi , Vesicular-arbuscular mycorrhizas , Soil microbiology , Rhizosphere , Revegetation , Restoration ecology
- Description: This study examined the rehabilitation potential of AM fungi with organic and inorganic fertilisers under pot and field trial conditions as well as their interaction with rhizospheric organisms and specific functional groups. In addition, the study highlighted the effects of land-use management on AM fungal populations in soil and the mycorrhizal status of some selected plants from one of the study sites. The study focussed on two sites that differ in operational activities and these included a mined area that was to be rehabilitated and a commercial farming site. A pot trial was conducted using an overburdened soil resulting from kaolin clay mining. Pots were seeded with Cynodon dactylon and treated with either Organic Tea or NPK (3:1:5) fertiliser, with or without AM fungal inoculum. The compatibility of these fertilisers with AM fungi was assessed by plant growth and percentage root colonisation. Maximum shoot height and plant biomass were observed at the 28th week with NPK (3:1:5) fertiliser supporting mycorrhizal colonisation by 80%. The result indicated the potential of AM fungi to be used in rehabilitation with minimal phosphate fertiliser. Similarly, a field trial was set-up using 17 x 17 m[superscript 2] plots in the mining site that were treated with the same organic and inorganic fertilisers as well as with AM fungal inoculum in different combinations. The interaction between AM fungi and soil microbial population was determined using culture dependent and culture independent techniques. The culture dependent technique involved the use of soil dilution and plating on general purpose and selective media. The result showed that there was no change in the total culturable bacterial number in the untreated and AM fungal treated plots, while a change in species composition was observed in the functional groups. Different functional groups identified included nitrogen fixing bacteria, pseudomonads, actinomycetes, phosphate solubilisers and the fungal counterparts. Gram-positive bacteria were observed as the predominant phenotypic type, while nitrogen fixers and actinomycetes were the predominant functional groups. Species identified from each functional group were Pseudomonas fulva, Bacillus megaterium, Streptomyces and actinomycetales bacteria. Meanwhile, fungi such as Ampelomyces, Fusarium, Penicillium, Aspergillus, Cephalosporium and Exserohilium were identified morphologically and molecularly. Furthermore, the mining site had a significantly higher bacterial number than the farming site thereby indicating the effects of land-use management on culturable bacterial numbers. The culture independent technique was carried out by cloning of the bacterial 16S rDNA and sequencing. Identified clones were Bradyrhizobium, Propionibacterium and Sporichthya. A cladogram constructed with the nucleotides sequences of identified functional species, clones and closely related nucleotide sequences from the Genbank indicated that nucleotide sequences differed in terms of the method used. The activity and establishment of the introduced AM fungal population was determined by spore enumeration, infectivity assay, percentage root colonisation and assessment of glomalin concentrations. The results indicated that the two land use types affected AM fungal populations. However, the establishment of AM fungi in the farming site was more successful than in the mining site as indicated by the higher infectivity pontential. Selected host plants, which were collected around the mine area, were observed to be mainly colonised by AM fungi and these were identified as Pentzia incana, Elytropappus rhinocerotis, Euphorbia meloformis, Selago corymbosa, Albuca canadensis and Helichrysum rosum. These plant species were able to thrive under harsh environmental conditions, thereby indicating their potential use as rehabilitation host plants. Generally, the findings of this study has provided an insight into the interaction between arbuscular mycorrhizal fungi and other soil microorganisms in two fields with differing land use management practices.
- Full Text:
Interaction of water-soluble thiol capped CdTe quantum dots and bovine serum albumin
- Idowu, Mopelola, Lamprecht, Emmanuel, Nyokong, Tebello
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
Interest rate risk management : a case study of GBS Mutual Bank
- Authors: Williamson, Gareth Alan
- Date: 2008
- Subjects: GBS Mutual Bank , Interest rates -- Case studies , Interest rate risk -- Case studies , Risk management -- Case studies , Financial risk -- Case studies , Banks and banking -- Case studies
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:986 , http://hdl.handle.net/10962/d1002720 , GBS Mutual Bank , Interest rates -- Case studies , Interest rate risk -- Case studies , Risk management -- Case studies , Financial risk -- Case studies , Banks and banking -- Case studies
- Description: Banks play a pivotal role in the economic growth and development of countries, primarily through the diversification of risk for both themselves and other economic agents. Interest rate risk is regarded as one of the most prominent financial risks faced by a bank. A large portion of private banks’ revenue stems from net interest income that is generated from the difference between various assets and liabilities that are held on the balance sheet. Fluctuations in the interest rate can alter a bank’s interest income and value, making interest rate risk management vital to its success. The asset and liability committee of a bank is the internal committee charged with the duty of managing the bank’s interest rate risk exposure through the use of various hedging strategies and instruments. This thesis uses a case study methodology to analyse GBS Mutual Bank interest rate risk management. Its specific business circumstances, balance sheet structure and the market conditions over a specified period are used to comment on the practicality of a variety of balance sheet positioning strategies and derivative hedging instruments. The thesis also provides recommendations for the bank’s asset and liability committee in terms of its functions and organisation. It is elucidated that the most practical balance sheet hedging strategies are a volume strategy and immunisation, while the most practical derivative hedging instruments are interest rate futures and interest rate collars. It is found that the bank has a well functioning asset and liability committee whose only encumbrance to its functionality is the inadequacy of the informational technology used to measure, control and manage its interest rate risk position. This thesis concludes by summarising the practicality of the various interest rate risk hedging alternatives available to the GBS Mutual Bank. Implementing a particular strategy or instrument depends, of course, on its asset and liability committee’s decision.
- Full Text:
- Authors: Williamson, Gareth Alan
- Date: 2008
- Subjects: GBS Mutual Bank , Interest rates -- Case studies , Interest rate risk -- Case studies , Risk management -- Case studies , Financial risk -- Case studies , Banks and banking -- Case studies
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:986 , http://hdl.handle.net/10962/d1002720 , GBS Mutual Bank , Interest rates -- Case studies , Interest rate risk -- Case studies , Risk management -- Case studies , Financial risk -- Case studies , Banks and banking -- Case studies
- Description: Banks play a pivotal role in the economic growth and development of countries, primarily through the diversification of risk for both themselves and other economic agents. Interest rate risk is regarded as one of the most prominent financial risks faced by a bank. A large portion of private banks’ revenue stems from net interest income that is generated from the difference between various assets and liabilities that are held on the balance sheet. Fluctuations in the interest rate can alter a bank’s interest income and value, making interest rate risk management vital to its success. The asset and liability committee of a bank is the internal committee charged with the duty of managing the bank’s interest rate risk exposure through the use of various hedging strategies and instruments. This thesis uses a case study methodology to analyse GBS Mutual Bank interest rate risk management. Its specific business circumstances, balance sheet structure and the market conditions over a specified period are used to comment on the practicality of a variety of balance sheet positioning strategies and derivative hedging instruments. The thesis also provides recommendations for the bank’s asset and liability committee in terms of its functions and organisation. It is elucidated that the most practical balance sheet hedging strategies are a volume strategy and immunisation, while the most practical derivative hedging instruments are interest rate futures and interest rate collars. It is found that the bank has a well functioning asset and liability committee whose only encumbrance to its functionality is the inadequacy of the informational technology used to measure, control and manage its interest rate risk position. This thesis concludes by summarising the practicality of the various interest rate risk hedging alternatives available to the GBS Mutual Bank. Implementing a particular strategy or instrument depends, of course, on its asset and liability committee’s decision.
- Full Text:
International law before municipal courts: the role of International Court of Justice decisions in domestic court proceedings with specific reference to United States case examples
- Authors: Mangezi, Mutsa
- Date: 2008
- Subjects: International Court of Justice -- Cases Vienna Convention on Consular Relations (1963) International and municipal law -- United States -- Cases International law -- United States -- Cases Jurisdiction (International law) -- Cases
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3711 , http://hdl.handle.net/10962/d1007325
- Description: In the case of LaGrand (Germany v United States), the International Court of Justice held that the United States (US) had violated its international obligation to Germany under the Vienna Convention on Consular Relations when it executed two German nationals without first informing them of their consular rights. The case came before the court after the United States had disregarded a preliminary ruling passed by the IC], which directed the US not to execute the German nationals pending the outcome of the ICJ case. The decision raised the issue of the effect of ICJ decisions in domestic proceedings and the effectiveness of ICJ enforcement mechanisms. This thesis considers the possibility of a role for national courts as active enforcers of ICJ decisions. It is argued that whilst evidence shows that there is no legal obligation on courts to enforce ICJ decisions, there is certainly room in international law to facilitate this development. In support of this argument, the thesis demonstrates how basic presuppositions about international law have shifted over the last few decades. This shift has been both the impetus and the result of globalisation. The case of LaGrand alongside similar cases is used to show how national courts may play an increased role in the enforcement of ICJ decisions.
- Full Text:
- Authors: Mangezi, Mutsa
- Date: 2008
- Subjects: International Court of Justice -- Cases Vienna Convention on Consular Relations (1963) International and municipal law -- United States -- Cases International law -- United States -- Cases Jurisdiction (International law) -- Cases
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3711 , http://hdl.handle.net/10962/d1007325
- Description: In the case of LaGrand (Germany v United States), the International Court of Justice held that the United States (US) had violated its international obligation to Germany under the Vienna Convention on Consular Relations when it executed two German nationals without first informing them of their consular rights. The case came before the court after the United States had disregarded a preliminary ruling passed by the IC], which directed the US not to execute the German nationals pending the outcome of the ICJ case. The decision raised the issue of the effect of ICJ decisions in domestic proceedings and the effectiveness of ICJ enforcement mechanisms. This thesis considers the possibility of a role for national courts as active enforcers of ICJ decisions. It is argued that whilst evidence shows that there is no legal obligation on courts to enforce ICJ decisions, there is certainly room in international law to facilitate this development. In support of this argument, the thesis demonstrates how basic presuppositions about international law have shifted over the last few decades. This shift has been both the impetus and the result of globalisation. The case of LaGrand alongside similar cases is used to show how national courts may play an increased role in the enforcement of ICJ decisions.
- Full Text:
Introduction: Stimela: railway poems of South Africa
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7058 , http://hdl.handle.net/10962/d1007420
- Description: preprint , A collection of railway poems is an unusual undertaking. More than an exercise in nostalgia, this anthology captures a large slice of modern South African life, viewed from different perspectives. Many of South Africa’s best poets have written railway poems. This is unsurprising, for railways hold special meaning for a variety of people – people in all walks of life – who find them not only fascinating but emotionally sympatico. The place of railways in the South African economy is changing rapidly, and it will be interesting to see in the coming years whether the less personal, more streamlined business model that is taking shape will attract the same naïve fascination engendered by South African railways over the past two centuries.
- Full Text:
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7058 , http://hdl.handle.net/10962/d1007420
- Description: preprint , A collection of railway poems is an unusual undertaking. More than an exercise in nostalgia, this anthology captures a large slice of modern South African life, viewed from different perspectives. Many of South Africa’s best poets have written railway poems. This is unsurprising, for railways hold special meaning for a variety of people – people in all walks of life – who find them not only fascinating but emotionally sympatico. The place of railways in the South African economy is changing rapidly, and it will be interesting to see in the coming years whether the less personal, more streamlined business model that is taking shape will attract the same naïve fascination engendered by South African railways over the past two centuries.
- Full Text:
Inventing the Human: Brontosaurus Bloom and “the Shakespeare in us”
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7045 , http://hdl.handle.net/10962/d1007387 , https://www.taylorfrancis.com/books/e/9781351963534/chapters/10.4324%2F9781315264264-15
- Description: preprint , This essay was occasioned by the casual reading of a book called Harold Bloom’s Shakespeare (2002), a collection of responses, pro, ante and puzzled, to Bloom’s Shakespearean magnum opus. The more I browsed in the assembled essays, some of them originally reviews and conference papers, others specially commissioned responses, the more curious I became. On the whole, the contributors seemed not to understand Bloom, at least not to understand him adequately, which is a devastating handicap when the task in hand is to pass judgment. The problem seems to be that few academic commentators take Bloom seriously, accepting that he means what he says; more accurately, they find it hard to entertain with full seriousness matters Bloom intends should be taken entirely seriously. Shakespeareans, locked into their various ways of understanding the world and critical activity, generally try to find Shakespeare (or “Shakespeare”) through reading Bloom, whereas he wants us to find ourselves through reading Shakespeare: to uncover what Emerson called ‘the Shakespeare in us’ (‘Shakespeare, or The Poet’, 256). The difference is stupendous. We ought first to ask in regard to Bloom’s blockbuster the question Bloom tells us he learned from Kenneth Burke, ‘What is the author trying to do for himself or herself by writing this work?’ (Shakespeare, 412).
- Full Text:
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7045 , http://hdl.handle.net/10962/d1007387 , https://www.taylorfrancis.com/books/e/9781351963534/chapters/10.4324%2F9781315264264-15
- Description: preprint , This essay was occasioned by the casual reading of a book called Harold Bloom’s Shakespeare (2002), a collection of responses, pro, ante and puzzled, to Bloom’s Shakespearean magnum opus. The more I browsed in the assembled essays, some of them originally reviews and conference papers, others specially commissioned responses, the more curious I became. On the whole, the contributors seemed not to understand Bloom, at least not to understand him adequately, which is a devastating handicap when the task in hand is to pass judgment. The problem seems to be that few academic commentators take Bloom seriously, accepting that he means what he says; more accurately, they find it hard to entertain with full seriousness matters Bloom intends should be taken entirely seriously. Shakespeareans, locked into their various ways of understanding the world and critical activity, generally try to find Shakespeare (or “Shakespeare”) through reading Bloom, whereas he wants us to find ourselves through reading Shakespeare: to uncover what Emerson called ‘the Shakespeare in us’ (‘Shakespeare, or The Poet’, 256). The difference is stupendous. We ought first to ask in regard to Bloom’s blockbuster the question Bloom tells us he learned from Kenneth Burke, ‘What is the author trying to do for himself or herself by writing this work?’ (Shakespeare, 412).
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Investigating aspects of corporate citizenship on private game farms: the case of Mtshelezi Game Reserve in Makana Municipality, Eastern Cape Province
- Authors: Nyama, Cynthia
- Date: 2008
- Subjects: Tourism -- South Africa -- Eastern Cape , Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions , Social responsibility of business -- South Africa -- Eastern Cape , Ecotourism -- South Africa -- Eastern Cape -- Citizen participation , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:751 , http://hdl.handle.net/10962/d1003872 , Tourism -- South Africa -- Eastern Cape , Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions , Social responsibility of business -- South Africa -- Eastern Cape , Ecotourism -- South Africa -- Eastern Cape -- Citizen participation , Rural development -- South Africa -- Eastern Cape
- Description: Research show that post 1996 period has experienced an unprecedented increase in game based operations. The corporate citizenship or corporate social responsibility of the game reserves is of much interest to this study with a focus on the rights of previous and current occupants of farms, workers’ well-being, job creation, quality of life and poverty alleviation within the game/tourism industry. The research was conducted as a qualitative case study and the tools employed for data gathering include: a review of the relevant literature, interviews (face-to-face), the administering of a questionnaire survey and document analysis from diversity of resources which include the Department of Labour, East Cape Agricultural Research Project, and through use of multiple data sources. The approach taken in this dissertation is to examine to what extent the private game reserves in the Makana Municipality can be labelled as “corporate citizens” and this was done by means of a case study of one private game reserve. The areas that are deemed to be most important in this regard are (i) employment history (ii) educational opportunities (iii) wages (iv) housing (v) land tenure. The study established that younger, better educated people are likely to secure better paying employment on PGR. The nature and conditions of sale of the farm to the PGR can impact on the employment secured by workers in the new dispensation. Workers are tied to these jobs because of the very long hours that prevent them from doing anything else to earn money. Some of the workers had opportunities to learn new skills but the question remains; which people are these and how long will growing differentials in earnings reproduce the poorly educated worker in the next generation. The study also high lightened the need for academics and researchers to come with a common set of corporate citizenship measures such as to measure corporate social impacts.
- Full Text:
- Authors: Nyama, Cynthia
- Date: 2008
- Subjects: Tourism -- South Africa -- Eastern Cape , Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions , Social responsibility of business -- South Africa -- Eastern Cape , Ecotourism -- South Africa -- Eastern Cape -- Citizen participation , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:751 , http://hdl.handle.net/10962/d1003872 , Tourism -- South Africa -- Eastern Cape , Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions , Social responsibility of business -- South Africa -- Eastern Cape , Ecotourism -- South Africa -- Eastern Cape -- Citizen participation , Rural development -- South Africa -- Eastern Cape
- Description: Research show that post 1996 period has experienced an unprecedented increase in game based operations. The corporate citizenship or corporate social responsibility of the game reserves is of much interest to this study with a focus on the rights of previous and current occupants of farms, workers’ well-being, job creation, quality of life and poverty alleviation within the game/tourism industry. The research was conducted as a qualitative case study and the tools employed for data gathering include: a review of the relevant literature, interviews (face-to-face), the administering of a questionnaire survey and document analysis from diversity of resources which include the Department of Labour, East Cape Agricultural Research Project, and through use of multiple data sources. The approach taken in this dissertation is to examine to what extent the private game reserves in the Makana Municipality can be labelled as “corporate citizens” and this was done by means of a case study of one private game reserve. The areas that are deemed to be most important in this regard are (i) employment history (ii) educational opportunities (iii) wages (iv) housing (v) land tenure. The study established that younger, better educated people are likely to secure better paying employment on PGR. The nature and conditions of sale of the farm to the PGR can impact on the employment secured by workers in the new dispensation. Workers are tied to these jobs because of the very long hours that prevent them from doing anything else to earn money. Some of the workers had opportunities to learn new skills but the question remains; which people are these and how long will growing differentials in earnings reproduce the poorly educated worker in the next generation. The study also high lightened the need for academics and researchers to come with a common set of corporate citizenship measures such as to measure corporate social impacts.
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Investigating learning interactions influencing farmers' choices of cultivated food plants
- Authors: Pesanayi, Victor Tichaona
- Date: 2008
- Subjects: Sustainable development -- Africa Poverty -- Africa Environmental education -- Zimbabwe Food supply -- Environmental aspects -- Zimbabwe Farmers -- Education -- Zimbabwe Agriculture -- Study and teaching -- Zimbabwe Plants, cultivated -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1587 , http://hdl.handle.net/10962/d1003469
- Description: The most critical hurdle on the path to sustainable development in Africa and the rest of the so-called Third World is poverty, commonly manifested as food security. A number of factors threaten food security in Zimbabwe, and these include climate change, an unstable socio-political environment and economic depression. The major debates and initiatives on sustainable development often fail to focus on the eradication of poverty in southern Africa. As a result, the trade liberalisation programmes signed by African countries in economic partnership agreements leave smallholder farmers vulnerable to the influx of hybrid seed and genetically modified organisms (GMOs), which threaten local agro-biodiversity. This case study has shown that farmers select seed to plant for food as a result of various learning interactions they engage in, which include inter-generational knowledge transfer, farmer to farmer extension and external training by extension organisations and NGOs. A communities of practice (COPs) (Wenger, 2007) framework was used to gain an understanding of the learning interactions among farmers and their stakeholders in Nyanga and Marange COPs of small grain farmers in Manicaland Province, Zimbabwe, who have been working with Environment Africa (A regional NGO). A critical realist causal analysis was conducted to unravel the various causal factors influencing choice. A number of underlying structures and causal mechanisms were found to influence learning interactions and choices in these communities of practice, and they include ambivalence, which influences the changing domain and practice. Climate change, drought and risk were found to affect farmer practice, while power relations affect the community, its practice, domain, sponsorship and the learning interactions in the COPs. The political economy was also found to have a profound effect on the domain and practice. A space was found for the influence of capacity and knowledge sharing in participatory frameworks of the communities, implying that extension quality can be enhanced to promote locally adapted and diverse seed varieties for food security improvement. The study shows that a deeper understanding of the mechanisms influencing the context of teaching and learning provides a more refined insight into the learning interactions and choices of farmers. This, coupled with the social processes descriptors provided by Wildemeersch (2007) has given me a more detailed understanding of the nature of learning interactions influencing farmer choices.
- Full Text:
- Authors: Pesanayi, Victor Tichaona
- Date: 2008
- Subjects: Sustainable development -- Africa Poverty -- Africa Environmental education -- Zimbabwe Food supply -- Environmental aspects -- Zimbabwe Farmers -- Education -- Zimbabwe Agriculture -- Study and teaching -- Zimbabwe Plants, cultivated -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1587 , http://hdl.handle.net/10962/d1003469
- Description: The most critical hurdle on the path to sustainable development in Africa and the rest of the so-called Third World is poverty, commonly manifested as food security. A number of factors threaten food security in Zimbabwe, and these include climate change, an unstable socio-political environment and economic depression. The major debates and initiatives on sustainable development often fail to focus on the eradication of poverty in southern Africa. As a result, the trade liberalisation programmes signed by African countries in economic partnership agreements leave smallholder farmers vulnerable to the influx of hybrid seed and genetically modified organisms (GMOs), which threaten local agro-biodiversity. This case study has shown that farmers select seed to plant for food as a result of various learning interactions they engage in, which include inter-generational knowledge transfer, farmer to farmer extension and external training by extension organisations and NGOs. A communities of practice (COPs) (Wenger, 2007) framework was used to gain an understanding of the learning interactions among farmers and their stakeholders in Nyanga and Marange COPs of small grain farmers in Manicaland Province, Zimbabwe, who have been working with Environment Africa (A regional NGO). A critical realist causal analysis was conducted to unravel the various causal factors influencing choice. A number of underlying structures and causal mechanisms were found to influence learning interactions and choices in these communities of practice, and they include ambivalence, which influences the changing domain and practice. Climate change, drought and risk were found to affect farmer practice, while power relations affect the community, its practice, domain, sponsorship and the learning interactions in the COPs. The political economy was also found to have a profound effect on the domain and practice. A space was found for the influence of capacity and knowledge sharing in participatory frameworks of the communities, implying that extension quality can be enhanced to promote locally adapted and diverse seed varieties for food security improvement. The study shows that a deeper understanding of the mechanisms influencing the context of teaching and learning provides a more refined insight into the learning interactions and choices of farmers. This, coupled with the social processes descriptors provided by Wildemeersch (2007) has given me a more detailed understanding of the nature of learning interactions influencing farmer choices.
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Investigating the role of portfolios in developing reflective practice : a case study
- Authors: Mbango, Karolina Naango
- Date: 2008
- Subjects: Portfolios in education -- Namibia -- Case studies Student teachers -- Namibia -- Case studies Teachers -- Training of -- Namibia -- Case studies Teacher educators -- Namibia -- Case studies Reflective teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1595 , http://hdl.handle.net/10962/d1003477
- Description: The purpose of this study was to investigate the purpose and role portfolios are playing in developing reflective practice in student teachers and to assess the degree to which this role is being achieved in practice. This study was a interpretive small scale case study. The target groups were 3 student teachers in their final year of study, 3 teacher educators and the vice-rector of the college. Data were obtained through interviews and document analysis. The findings indicated that the students had no meaningful orientation to both the role of portfolio development and reflective skills. The sources of this were the lack of common understanding among teacher educators, lack of support for both teacher educators and student teachers and lack of time, lack of guidelines for construction and clear assessment rubric. The results of this study indicated that the teacher educators were in need of vigorous professional development and considerable implementation strategies are needed to develop the desired reflective skills.
- Full Text:
- Authors: Mbango, Karolina Naango
- Date: 2008
- Subjects: Portfolios in education -- Namibia -- Case studies Student teachers -- Namibia -- Case studies Teachers -- Training of -- Namibia -- Case studies Teacher educators -- Namibia -- Case studies Reflective teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1595 , http://hdl.handle.net/10962/d1003477
- Description: The purpose of this study was to investigate the purpose and role portfolios are playing in developing reflective practice in student teachers and to assess the degree to which this role is being achieved in practice. This study was a interpretive small scale case study. The target groups were 3 student teachers in their final year of study, 3 teacher educators and the vice-rector of the college. Data were obtained through interviews and document analysis. The findings indicated that the students had no meaningful orientation to both the role of portfolio development and reflective skills. The sources of this were the lack of common understanding among teacher educators, lack of support for both teacher educators and student teachers and lack of time, lack of guidelines for construction and clear assessment rubric. The results of this study indicated that the teacher educators were in need of vigorous professional development and considerable implementation strategies are needed to develop the desired reflective skills.
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Isolation and characterization of antiplasmodial metabolites from South African marine alga
- Authors: Afolayan, Anthonia Folake
- Date: 2008
- Subjects: Malaria -- Africa Antimalarials -- Therapeutic use Malaria -- Prevention Malaria -- Drug therapy Marine algae -- Therapeutic use Natural products -- Therapeutic use Plasmodium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3739 , http://hdl.handle.net/10962/d1003063
- Description: Malaria is one of the three most deadly diseases in Africa. Although there are available treatments, their efficacy has been greatly reduced over the past two decades due to the development of resistance to currently available drugs. This has necessitated the search for new and effective antimalarial agents. This project approached the search for new antimalarial compounds in two ways: (i) by screening natural products isolated from marine algae against the Plasmodium parasite and (ii) by modification of selected isolated active compounds to target 1-deoxY-đ-xylulose 5-phosphate reductoisomerase (DXR), an enzyme found in the nonmevalonate isoprenoid biosynthetic pathway of Plasmodium Jalciparum. It was envisaged that such a compound would exhibit dual action on the Plasmodium parasite. Extracts obtained from 22 marine algae were prefractionated by solvent partitioning and were screened for anti plasmodial activity against the chloroquine sensitive (CQS) P. Jalciparum D 10 strain. Overall, 50% of the algae screened produced at least one crude fraction with activity against P. Jalciparum. Extracts of the algae Sargassum heterophyllum, Plocamium cornutum, Amphiroa ephedrea and Pterosiphonia cloiophylla gave the most promising results. Fractionation of S. heterophyllum afforded three tetraprenyltoluquinols (3.1, 3.2 and 3.5) and an all-trans-fucoxanthin (3.6). Three new compounds (4.5, 4.6 and 4.7) and two known halogenated monoterpenes (4.1 and 4.4) were isolated from P. cornutum. Each of the isolated compounds from both S. heterophyllum and P. cornutum showed antiplasmodial activity with IC₅₀ values ranging from 2.0 - 15.3 μM for S. heterophyllum and 13 - 230 μM for P. cornutum. Attempts to synthetically modify halogenated monoterpene 4.4 by dihydroxylation and phosphorylation in order to inhibit the DXR enzyme was unsuccessful. However, the hemiterpene analogue (5.42) of the halogenated monoterpenes was successfully phosphorylated and dihydroxylated to give compound 5.45 which showed promising activity against DXR. The result obtained indicated that the proposed phosphorylation and dihydroxylation of the halogenated monoterpene 4.4 would result in the synthesis of a potent DXR inhibitor and therefore a potential antimalarial agent with dual mode of action on the Plasmodium parasite.
- Full Text:
- Authors: Afolayan, Anthonia Folake
- Date: 2008
- Subjects: Malaria -- Africa Antimalarials -- Therapeutic use Malaria -- Prevention Malaria -- Drug therapy Marine algae -- Therapeutic use Natural products -- Therapeutic use Plasmodium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3739 , http://hdl.handle.net/10962/d1003063
- Description: Malaria is one of the three most deadly diseases in Africa. Although there are available treatments, their efficacy has been greatly reduced over the past two decades due to the development of resistance to currently available drugs. This has necessitated the search for new and effective antimalarial agents. This project approached the search for new antimalarial compounds in two ways: (i) by screening natural products isolated from marine algae against the Plasmodium parasite and (ii) by modification of selected isolated active compounds to target 1-deoxY-đ-xylulose 5-phosphate reductoisomerase (DXR), an enzyme found in the nonmevalonate isoprenoid biosynthetic pathway of Plasmodium Jalciparum. It was envisaged that such a compound would exhibit dual action on the Plasmodium parasite. Extracts obtained from 22 marine algae were prefractionated by solvent partitioning and were screened for anti plasmodial activity against the chloroquine sensitive (CQS) P. Jalciparum D 10 strain. Overall, 50% of the algae screened produced at least one crude fraction with activity against P. Jalciparum. Extracts of the algae Sargassum heterophyllum, Plocamium cornutum, Amphiroa ephedrea and Pterosiphonia cloiophylla gave the most promising results. Fractionation of S. heterophyllum afforded three tetraprenyltoluquinols (3.1, 3.2 and 3.5) and an all-trans-fucoxanthin (3.6). Three new compounds (4.5, 4.6 and 4.7) and two known halogenated monoterpenes (4.1 and 4.4) were isolated from P. cornutum. Each of the isolated compounds from both S. heterophyllum and P. cornutum showed antiplasmodial activity with IC₅₀ values ranging from 2.0 - 15.3 μM for S. heterophyllum and 13 - 230 μM for P. cornutum. Attempts to synthetically modify halogenated monoterpene 4.4 by dihydroxylation and phosphorylation in order to inhibit the DXR enzyme was unsuccessful. However, the hemiterpene analogue (5.42) of the halogenated monoterpenes was successfully phosphorylated and dihydroxylated to give compound 5.45 which showed promising activity against DXR. The result obtained indicated that the proposed phosphorylation and dihydroxylation of the halogenated monoterpene 4.4 would result in the synthesis of a potent DXR inhibitor and therefore a potential antimalarial agent with dual mode of action on the Plasmodium parasite.
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Isolation, purification and characterization of a 'factor' from Fusarium oxysporum responsible for platinum nanoparticle formation
- Authors: Govender, Yageshni
- Date: 2008
- Subjects: Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3923 , http://hdl.handle.net/10962/d1003982 , Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Description: Nanoparticles are microscopic particles in the nanometre range of between 1-100 nm. A wide variety of metal nanoparticles have been found to be produced by prokaryotic and eukaryotic organisms including several fungal species, when exposed to solutions containing metal salts. Previous studies have suggested that this bioreduction of metal particles may occur via an active reductase/hydrogenase enzyme process where H2 is the electron donor and positively charged platinum species act as the electron acceptors becoming reduced to a neutral metal nanoparticle. In view of this on going research, the current study investigated the “factors” in the fungus Fusarium oxysporum which were responsible for platinum nanoparticle formation. The fungus F.oxysporum was used in this study as it has been previously shown to produce a variety of nanoparticles including gold and silver. During exposure of the biomass to H2PtCl6 the initial response to the platinum salts was metal internalisation and subsequent reduction of H2PtCI6 to produce platinum nanoparticles. The observed localization and distribution of platinum precipitates provided some evidence for a hydrogenase mediated bioreduction of platinum salts to produce nanoparticles. Factors secreted by the fungus into the extracellular fluids, were shown to be responsible for platinum nanoparticle formation. From the identification, purification and characterisation studies it was concluded that a hydrogenase and other “factors” were responsible for platinum nanoparticle formation in F.oxysporum. Purification of the hydrogenase by freeze-drying and Sephacryl S200 size exclusion- ion exchange chromatography revealed the enzyme to be a dimer with a 29.4 and 44.5 kDa when analysed by a 10 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 38 °C while it exhibited a poor thermal stability with a half life of 36 minutes. The kinetic parameters Vmax and Km were 3.16 U ml-1 and 3.64 mM respectively. The purified hydrogenase was used in subsequent experiments for the reduction of platinum salts, H2PtCl6 and PtCl2. the results indicated an over 90 % reduction of the platinum salts and TEM micrographs indicated the production of platinum nanoparticles under the various experimental conditions.
- Full Text:
- Authors: Govender, Yageshni
- Date: 2008
- Subjects: Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3923 , http://hdl.handle.net/10962/d1003982 , Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Description: Nanoparticles are microscopic particles in the nanometre range of between 1-100 nm. A wide variety of metal nanoparticles have been found to be produced by prokaryotic and eukaryotic organisms including several fungal species, when exposed to solutions containing metal salts. Previous studies have suggested that this bioreduction of metal particles may occur via an active reductase/hydrogenase enzyme process where H2 is the electron donor and positively charged platinum species act as the electron acceptors becoming reduced to a neutral metal nanoparticle. In view of this on going research, the current study investigated the “factors” in the fungus Fusarium oxysporum which were responsible for platinum nanoparticle formation. The fungus F.oxysporum was used in this study as it has been previously shown to produce a variety of nanoparticles including gold and silver. During exposure of the biomass to H2PtCl6 the initial response to the platinum salts was metal internalisation and subsequent reduction of H2PtCI6 to produce platinum nanoparticles. The observed localization and distribution of platinum precipitates provided some evidence for a hydrogenase mediated bioreduction of platinum salts to produce nanoparticles. Factors secreted by the fungus into the extracellular fluids, were shown to be responsible for platinum nanoparticle formation. From the identification, purification and characterisation studies it was concluded that a hydrogenase and other “factors” were responsible for platinum nanoparticle formation in F.oxysporum. Purification of the hydrogenase by freeze-drying and Sephacryl S200 size exclusion- ion exchange chromatography revealed the enzyme to be a dimer with a 29.4 and 44.5 kDa when analysed by a 10 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 38 °C while it exhibited a poor thermal stability with a half life of 36 minutes. The kinetic parameters Vmax and Km were 3.16 U ml-1 and 3.64 mM respectively. The purified hydrogenase was used in subsequent experiments for the reduction of platinum salts, H2PtCl6 and PtCl2. the results indicated an over 90 % reduction of the platinum salts and TEM micrographs indicated the production of platinum nanoparticles under the various experimental conditions.
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Jantjie v The Minister of Labour Unreported Eastern Cape Division Case No 2193/2006
- Authors: Glover, Graham B , Beard, M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186891 , vital:44545 , xlink:href="///C:/Users/User/Downloads/41DeJure648%20(1).pdf"
- Description: James Joyce once wrote that "mistakes ... are the portals of discovery" (Ulysses (1964) Ch 9). This aptly describes the legal significance of the judgment in Jantjie v Minister of Labour (unreported decision of the High Court, Eastern Cape Division, case no 3193/2006, decided on 2007-06- 14). In this case, Leach J had to deal with a matter of civil procedure that does not seem to have been dealt with in any reported judgment - the effect of an attorney of record mistakenly failing to sign a notice of motion where an application is brought before the High Court.
- Full Text:
- Authors: Glover, Graham B , Beard, M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186891 , vital:44545 , xlink:href="///C:/Users/User/Downloads/41DeJure648%20(1).pdf"
- Description: James Joyce once wrote that "mistakes ... are the portals of discovery" (Ulysses (1964) Ch 9). This aptly describes the legal significance of the judgment in Jantjie v Minister of Labour (unreported decision of the High Court, Eastern Cape Division, case no 3193/2006, decided on 2007-06- 14). In this case, Leach J had to deal with a matter of civil procedure that does not seem to have been dealt with in any reported judgment - the effect of an attorney of record mistakenly failing to sign a notice of motion where an application is brought before the High Court.
- Full Text:
Journalists' appropriation of ICTs in news-gathering and processing: a case study of Grocott's Mail
- Authors: Dugo, Habtamu Tesfaye
- Date: 2008
- Subjects: Grocott's Mail (Grahamstown, South Africa) Journalism -- South Africa -- Grahamstown Journalists -- South Africa -- Grahamstown Electronic news gathering -- South Africa -- Grahamstown Journalism -- Data processing -- South Africa -- Grahamstown Information technology -- South Africa -- Grahamstown Reporters and reporting -- South Africa -- Grahamstown Communication and technology -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3427 , http://hdl.handle.net/10962/d1002881
- Description: This study set out to investigate Grocott’s Mail journalists’ appropriation of information and communication technologies in news-gathering and processing using the social shaping of technology as a theoretical lens. It mainly focuses on digital ICTs that journalists use in news-gathering and processing including the Internet, electronic mail, and mobile telephony. Grocott’s Mail is a small-scale newspaper based in Grahamstown, South Africa. Using qualitative research method and the case study as its sub-method, the research reveals that Grocott’s Mail journalists’ appropriation of ICTs involves various opportunities and challenges in news-gathering and processing. In terms of the state of the existing technological infrastructure, the study reveals that since it embraced the digital ICTs in 2003, Grocott’s Mail boasts an adequate ICT infrastructure for a small-scale African newspaper with 30 PCs and one laptop, and professional software for 28 permanent employees. On the other hand, the research reveals serious constraints with the existing ICTs: a huge need for staff training and capacity building to fully utilise the ICTs, and the need to look for ways of raising funds to either upgrade or replace the existing ICTs. Grocott’s Mail journalists use the Internet to do background research on news stories, to verify the accuracy of information, and to check competition across other media. These are the merits of the Internet in news-gathering and processing. On the other hand, there are specific unintended consequences of the Internet such as wasting the company’s working time, and its use leading to lazy/press release journalism. Informants unanimously indicate that the main problems of the Internet are heavy dependence on other online news-sources and wasting time on online entertainment. In terms of using email in news-gathering, the research finds email technology as having advantages such as being a tool of flexibility and speed, a tool for email interviews, and as a technology that promotes participatory journalism. On the other hand, challenges related to email include its limitations because of what interviewees view as its supplementary and small-scale use because of its low contextual richness as opposed to face to face interviews. In terms of cellular telephony, the study finds that regardless of the ubiquity of cell phones and cell phone networks, they have not yet been deployed in news-gathering and processing due to various constraints. These are cell phones not being a big factor in reporting, lack of a proper funding and refunding scheme, prevalence of negative attitudes towards cell phones, and lack of a business model. Thus, cellular phones seem to have little or no relevance in news-gathering and processing at Grocott’s Mail presently.
- Full Text:
- Authors: Dugo, Habtamu Tesfaye
- Date: 2008
- Subjects: Grocott's Mail (Grahamstown, South Africa) Journalism -- South Africa -- Grahamstown Journalists -- South Africa -- Grahamstown Electronic news gathering -- South Africa -- Grahamstown Journalism -- Data processing -- South Africa -- Grahamstown Information technology -- South Africa -- Grahamstown Reporters and reporting -- South Africa -- Grahamstown Communication and technology -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3427 , http://hdl.handle.net/10962/d1002881
- Description: This study set out to investigate Grocott’s Mail journalists’ appropriation of information and communication technologies in news-gathering and processing using the social shaping of technology as a theoretical lens. It mainly focuses on digital ICTs that journalists use in news-gathering and processing including the Internet, electronic mail, and mobile telephony. Grocott’s Mail is a small-scale newspaper based in Grahamstown, South Africa. Using qualitative research method and the case study as its sub-method, the research reveals that Grocott’s Mail journalists’ appropriation of ICTs involves various opportunities and challenges in news-gathering and processing. In terms of the state of the existing technological infrastructure, the study reveals that since it embraced the digital ICTs in 2003, Grocott’s Mail boasts an adequate ICT infrastructure for a small-scale African newspaper with 30 PCs and one laptop, and professional software for 28 permanent employees. On the other hand, the research reveals serious constraints with the existing ICTs: a huge need for staff training and capacity building to fully utilise the ICTs, and the need to look for ways of raising funds to either upgrade or replace the existing ICTs. Grocott’s Mail journalists use the Internet to do background research on news stories, to verify the accuracy of information, and to check competition across other media. These are the merits of the Internet in news-gathering and processing. On the other hand, there are specific unintended consequences of the Internet such as wasting the company’s working time, and its use leading to lazy/press release journalism. Informants unanimously indicate that the main problems of the Internet are heavy dependence on other online news-sources and wasting time on online entertainment. In terms of using email in news-gathering, the research finds email technology as having advantages such as being a tool of flexibility and speed, a tool for email interviews, and as a technology that promotes participatory journalism. On the other hand, challenges related to email include its limitations because of what interviewees view as its supplementary and small-scale use because of its low contextual richness as opposed to face to face interviews. In terms of cellular telephony, the study finds that regardless of the ubiquity of cell phones and cell phone networks, they have not yet been deployed in news-gathering and processing due to various constraints. These are cell phones not being a big factor in reporting, lack of a proper funding and refunding scheme, prevalence of negative attitudes towards cell phones, and lack of a business model. Thus, cellular phones seem to have little or no relevance in news-gathering and processing at Grocott’s Mail presently.
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Journalists' perceptions of their roles and identities with regard to the new partnership for Africa's development
- Kanyegirire, Andrew Steve Tumuhirwe
- Authors: Kanyegirire, Andrew Steve Tumuhirwe
- Date: 2008
- Subjects: New Partnership for Africa's Development Journalists -- Africa Journalism -- Africa Mass media -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3443 , http://hdl.handle.net/10962/d1002897
- Description: This qualitative study features in-depth interviews with selected continental African journalists and offers exploratory insights into how they perceive themselves in terms of their journalistic roles and/or sub-identities with regard to the New Partnership for Africa’s Development (NEPAD). The study also examines correlations between their perceptions and their news stories on NEPAD. Grounded in the libertarian and social responsibility theories of journalism, and reading these theories from the standpoint of Africa, this study posits the neutral, watchdog, social agenda and development journalism sub-identities to explain the respondents’ journalistic identifications. Hence, the study explores how the journalists respond to NEPAD’s (pan)-Africanist and development journalism interpellations. The study draws on postcolonial theoretical perspectives to address questions concerning African identity and the wider NEPAD/African context of research. Findings indicated that the journalists perceive a role for themselves as neutral-objectivist information disseminators as well as social agenda enactors that conscientise their readers about NEPAD. Thus, the journalists tend to implicitly portray a pluralistic understanding of their roles that enables them to balance the ideals of journalism against the development and Africanist aspirations of NEPAD. Although the journalists were found to uphold oppositional stances towards NEPAD, they do not question it from outside of its own neo-liberal discourse. In fact, they still represent themselves as aspiring to its Africanism and remaining sympathetic to its development plans. Overall, they exhibit multiple identifications, and yet they often tend to lean towards their neutral-objectivist journalistic sub-identity. Ultimately, they prioritise the dominant libertarian-professional model of journalism over and above NEPAD’s interpellations. The study also examined the journalists’ interpretations of what they do and the apparent translation of this into their stories. Although in both their stories and interviews discourse they showed a broader orientation towards libertarianism, the findings show that the link between the two is not straightforward.
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- Authors: Kanyegirire, Andrew Steve Tumuhirwe
- Date: 2008
- Subjects: New Partnership for Africa's Development Journalists -- Africa Journalism -- Africa Mass media -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3443 , http://hdl.handle.net/10962/d1002897
- Description: This qualitative study features in-depth interviews with selected continental African journalists and offers exploratory insights into how they perceive themselves in terms of their journalistic roles and/or sub-identities with regard to the New Partnership for Africa’s Development (NEPAD). The study also examines correlations between their perceptions and their news stories on NEPAD. Grounded in the libertarian and social responsibility theories of journalism, and reading these theories from the standpoint of Africa, this study posits the neutral, watchdog, social agenda and development journalism sub-identities to explain the respondents’ journalistic identifications. Hence, the study explores how the journalists respond to NEPAD’s (pan)-Africanist and development journalism interpellations. The study draws on postcolonial theoretical perspectives to address questions concerning African identity and the wider NEPAD/African context of research. Findings indicated that the journalists perceive a role for themselves as neutral-objectivist information disseminators as well as social agenda enactors that conscientise their readers about NEPAD. Thus, the journalists tend to implicitly portray a pluralistic understanding of their roles that enables them to balance the ideals of journalism against the development and Africanist aspirations of NEPAD. Although the journalists were found to uphold oppositional stances towards NEPAD, they do not question it from outside of its own neo-liberal discourse. In fact, they still represent themselves as aspiring to its Africanism and remaining sympathetic to its development plans. Overall, they exhibit multiple identifications, and yet they often tend to lean towards their neutral-objectivist journalistic sub-identity. Ultimately, they prioritise the dominant libertarian-professional model of journalism over and above NEPAD’s interpellations. The study also examined the journalists’ interpretations of what they do and the apparent translation of this into their stories. Although in both their stories and interviews discourse they showed a broader orientation towards libertarianism, the findings show that the link between the two is not straightforward.
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Juvenile population dynamics of Oreochromis mossambicus in an intermittently open estuary at the limit of its natural distribution
- Ellender, Bruce R, Weyl, Olaf L F, Shanyengange, M K, Cowley, Paul D
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Shanyengange, M K , Cowley, Paul D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446893 , vital:74568 , https://doi.org/10.1080/15627020.2008.11657245
- Description: Juvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to the upper reaches in winter. The young of the year in the littoral zone were rapidly depleted and resultant estimates of the instantaneous rate of total mortality (Z) ranged from 5.4/yr to 6.9/yr. High annual rates of juvenile mortality and small adult populations imply that stock recovery after a reduction in adult population numbers, through activities such as fishing, may be slow. This work adds to the knowledge base of O. mossambicus ecology and population dynamics in temperate estuaries at the limit of its natural distribution.
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- Authors: Ellender, Bruce R , Weyl, Olaf L F , Shanyengange, M K , Cowley, Paul D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446893 , vital:74568 , https://doi.org/10.1080/15627020.2008.11657245
- Description: Juvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to the upper reaches in winter. The young of the year in the littoral zone were rapidly depleted and resultant estimates of the instantaneous rate of total mortality (Z) ranged from 5.4/yr to 6.9/yr. High annual rates of juvenile mortality and small adult populations imply that stock recovery after a reduction in adult population numbers, through activities such as fishing, may be slow. This work adds to the knowledge base of O. mossambicus ecology and population dynamics in temperate estuaries at the limit of its natural distribution.
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Knowledge of plant resource use based on location, gender and generation
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181202 , vital:43707 , xlink:href="https://doi.org/10.1016/j.apgeog.2008.07.002"
- Description: The differences in knowledge of biological resource use between societal and demographic groups are often poorly understood; yet they are an important element of sustainability. Differences in gender and generational knowledge of locally useful woody plant species in South African savannas are examined. The results showed that young people and middle-aged females were highly knowledgeable. Over half of the total 267 woody plant species in nine use categories (i.e., medicinal, fruits–seeds, fuelwood, beverage, cultural, furniture, craft, fencing and housing poles) had multiple uses. Therefore, differences in knowledge of resource selection and use between social or demographic groups (for example based on gender and age) may appropriately inform conservation prioritisation, planning and monitoring.
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- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181202 , vital:43707 , xlink:href="https://doi.org/10.1016/j.apgeog.2008.07.002"
- Description: The differences in knowledge of biological resource use between societal and demographic groups are often poorly understood; yet they are an important element of sustainability. Differences in gender and generational knowledge of locally useful woody plant species in South African savannas are examined. The results showed that young people and middle-aged females were highly knowledgeable. Over half of the total 267 woody plant species in nine use categories (i.e., medicinal, fruits–seeds, fuelwood, beverage, cultural, furniture, craft, fencing and housing poles) had multiple uses. Therefore, differences in knowledge of resource selection and use between social or demographic groups (for example based on gender and age) may appropriately inform conservation prioritisation, planning and monitoring.
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Larval fish dynamics in the shallow nearshore of Eastern Algoa Bay with particular emphasis on the effects of currents and swimming abilities on dispersal
- Authors: Pattrick, Paula
- Date: 2008
- Subjects: Fishes -- Larvae -- Eastern Cape -- Algoa Bay , Marine parks and reserves -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Ecology -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Dispersal -- Eastern Cape -- Algoa Bay , Fishes -- Development -- Eastern Cape -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5294 , http://hdl.handle.net/10962/d1005139 , Fishes -- Larvae -- Eastern Cape -- Algoa Bay , Marine parks and reserves -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Ecology -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Dispersal -- Eastern Cape -- Algoa Bay , Fishes -- Development -- Eastern Cape -- Algoa Bay
- Description: The larval fish assemblage in the shallow, nearshore region of a proposed marine protected area (MPA) in eastern Algoa Bay, temperate South Africa was investigated. Current velocities and direction and the swimming abilities of late-stage larvae were further assessed to determine potential larval movement to and from the MPA. In total, 6045 larval fishes were collected along two depth contours (~5m and ~15m) in the shallow nearshore of eastern Algoa Bay using stepped-oblique bongo net tows, twice per season for two years (March 2005 – January 2007). These larvae represented 32 families and 78 species. The Gobiidae, Cynoglossidae, Clupeidae, Engraulidae and Sparidae were the dominant fish families. Catches varied significantly between seasons peaking in spring with a mean of 64 larvae/100m3. Preflexion stage larvae dominated catches (75%). All developmental stages of Diplodus capensis, Engraulis capensis, Heteromycteris capensis, Sardinops sagax and Pomadasys species were found in the study area. It appears that these species use the shallow nearshore as a nursery area. Analysis of 12 months (May 2006 – May 2007) data from a bottom-moored Acoustic Doppler Current Profiler within the study area showed that offshore south eastward (39%) and onshore north westward currents (33%) dominated. The south westward current (15%) and north eastward current (12%) occurred less frequently. Current velocity decreased with depth in the nearshore, with a mean velocity of ~29 cms⁻¹ recorded at a depth of 4 m and a mean velocity of ~11 cms⁻¹ recorded at a depth of 14 m. Understanding the dispersal and movement of marine fish larvae in coastal habitats requires knowledge of active swimming abilities. The critical speed and endurance swimming of late stage larvae of two common inshore species occurring in the study area, Diplodus capensis and Sarpa salpa (Family Sparidae), were measured in a laboratory swimming chamber. The mean U-crit value for D. capensis (18.6 cms⁻¹) was similar to that of S. salpa (18.0 cms⁻¹), whereas mean endurance (km swum) was greater in S. salpa (8.4 km) than D. capensis (5.9 km). These swimming abilities exceed the average current velocities observed in the shallow nearshore providing larvae with the ability to greatly alter their passive dispersal trajectories and ultimately influence their distribution in the nearshore.
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- Authors: Pattrick, Paula
- Date: 2008
- Subjects: Fishes -- Larvae -- Eastern Cape -- Algoa Bay , Marine parks and reserves -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Ecology -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Dispersal -- Eastern Cape -- Algoa Bay , Fishes -- Development -- Eastern Cape -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5294 , http://hdl.handle.net/10962/d1005139 , Fishes -- Larvae -- Eastern Cape -- Algoa Bay , Marine parks and reserves -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Ecology -- Eastern Cape -- Algoa Bay , Fishes -- Larvae -- Dispersal -- Eastern Cape -- Algoa Bay , Fishes -- Development -- Eastern Cape -- Algoa Bay
- Description: The larval fish assemblage in the shallow, nearshore region of a proposed marine protected area (MPA) in eastern Algoa Bay, temperate South Africa was investigated. Current velocities and direction and the swimming abilities of late-stage larvae were further assessed to determine potential larval movement to and from the MPA. In total, 6045 larval fishes were collected along two depth contours (~5m and ~15m) in the shallow nearshore of eastern Algoa Bay using stepped-oblique bongo net tows, twice per season for two years (March 2005 – January 2007). These larvae represented 32 families and 78 species. The Gobiidae, Cynoglossidae, Clupeidae, Engraulidae and Sparidae were the dominant fish families. Catches varied significantly between seasons peaking in spring with a mean of 64 larvae/100m3. Preflexion stage larvae dominated catches (75%). All developmental stages of Diplodus capensis, Engraulis capensis, Heteromycteris capensis, Sardinops sagax and Pomadasys species were found in the study area. It appears that these species use the shallow nearshore as a nursery area. Analysis of 12 months (May 2006 – May 2007) data from a bottom-moored Acoustic Doppler Current Profiler within the study area showed that offshore south eastward (39%) and onshore north westward currents (33%) dominated. The south westward current (15%) and north eastward current (12%) occurred less frequently. Current velocity decreased with depth in the nearshore, with a mean velocity of ~29 cms⁻¹ recorded at a depth of 4 m and a mean velocity of ~11 cms⁻¹ recorded at a depth of 14 m. Understanding the dispersal and movement of marine fish larvae in coastal habitats requires knowledge of active swimming abilities. The critical speed and endurance swimming of late stage larvae of two common inshore species occurring in the study area, Diplodus capensis and Sarpa salpa (Family Sparidae), were measured in a laboratory swimming chamber. The mean U-crit value for D. capensis (18.6 cms⁻¹) was similar to that of S. salpa (18.0 cms⁻¹), whereas mean endurance (km swum) was greater in S. salpa (8.4 km) than D. capensis (5.9 km). These swimming abilities exceed the average current velocities observed in the shallow nearshore providing larvae with the ability to greatly alter their passive dispersal trajectories and ultimately influence their distribution in the nearshore.
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