Ecological role of free-living bacteria in the microbial food web of the temporarily open/closed East Kleinemonde Estuary, South Africa
- Authors: Allan, Elizabeth Louise
- Date: 2008
- Subjects: Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5666 , http://hdl.handle.net/10962/d1005351 , Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Description: The main aim of this study was to assess the “top-down” and “bottom-up” control of bacterial production in the small temporarily open/closed East Kleinemonde Estuary, situated on the south-eastern coastline of southern Africa. Spatial and temporal patterns in bacterial abundance, biomass and production and the importance of abiotic and biotic factors were investigated over the period May 2006 to April 2007. The trophic interactions between bacteria, phytoplankton, nanoflagellates (< 20 μm), microzooplankton (< 200 μm) and mesozooplankton (< 2 000 μm) were investigated during winter and summer. Bacterial abundance, biomass and production ranged between 1.00 × 10⁹ and 4.93 × 10⁹ cells 1⁻¹, 32.4 and 109 μg C 1⁻¹ and 0.01 and 1.99 μg C 1⁻¹ h⁻¹, respectively. With a few exceptions there were no spatial patterns in the values. Bacterial abundance, biomass and production, however, demonstrated a distinct temporal pattern with the lowest values consistently recorded during the winter months. Nanoflagellate and bacterial abundances were significantly correlated to one another (lower reaches: r = 0.818, p < 0.001; middle reaches: r = 0.628, p < 0.001; upper reaches: r = 0.484, p < 0.05) suggesting a strong predator-prey relationship. The frequency of visibly infected bacterial cells and the mean number of virus particles within each bacterial cell during this study demonstrated no temporal or spatial patterns and ranged from 0.5 to 6.1 % and 12.0 to 37.5 virus particles per bacterium, respectively. Viral infection and lysis was thus a constant source of bacterial mortality throughout the year. The estimated percentage of bacterial production removed by viral lysis ranged between 7.8 and 88.9% of the total which suggests that viral lysis represented a very important source of bacterial mortality during this study. The biological interactions between the selected components of the plankton community demonstrated that among the heterotrophic components of the plankton, the nanoflagellates were identified as the most important consumers of bacteria and small phytoplankton cells (< 20 μm). In the presence of microzooplankton the impact of the nanoflagellates on both the bacteria and phytoplankton was reduced, indicating that larger heterotrophs were preying upon the nanoflagellates. Mesozooplankton, however, appeared to exert the greatest impact on nanoflagellates. In the cascading experiments, the data suggest that mesozooplankton consume nanoflagellates, which resulted in a decrease in the predation impact of these organisms on the bacteria. This result is consistent with predator-prey cascades. The presence of the larger heterotrophs therefore, mediates the interactions between the primary bacterivores, the nanoflagellates, and the bacteria within the temporarily open/closed East Kleinemonde Estuary.
- Full Text:
- Date Issued: 2008
- Authors: Allan, Elizabeth Louise
- Date: 2008
- Subjects: Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5666 , http://hdl.handle.net/10962/d1005351 , Bacterial growth -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Microbial ecology -- South Africa -- Eastern Cape , Nutrient cycles -- South Africa -- Eastern Cape , Food chains (Ecology)
- Description: The main aim of this study was to assess the “top-down” and “bottom-up” control of bacterial production in the small temporarily open/closed East Kleinemonde Estuary, situated on the south-eastern coastline of southern Africa. Spatial and temporal patterns in bacterial abundance, biomass and production and the importance of abiotic and biotic factors were investigated over the period May 2006 to April 2007. The trophic interactions between bacteria, phytoplankton, nanoflagellates (< 20 μm), microzooplankton (< 200 μm) and mesozooplankton (< 2 000 μm) were investigated during winter and summer. Bacterial abundance, biomass and production ranged between 1.00 × 10⁹ and 4.93 × 10⁹ cells 1⁻¹, 32.4 and 109 μg C 1⁻¹ and 0.01 and 1.99 μg C 1⁻¹ h⁻¹, respectively. With a few exceptions there were no spatial patterns in the values. Bacterial abundance, biomass and production, however, demonstrated a distinct temporal pattern with the lowest values consistently recorded during the winter months. Nanoflagellate and bacterial abundances were significantly correlated to one another (lower reaches: r = 0.818, p < 0.001; middle reaches: r = 0.628, p < 0.001; upper reaches: r = 0.484, p < 0.05) suggesting a strong predator-prey relationship. The frequency of visibly infected bacterial cells and the mean number of virus particles within each bacterial cell during this study demonstrated no temporal or spatial patterns and ranged from 0.5 to 6.1 % and 12.0 to 37.5 virus particles per bacterium, respectively. Viral infection and lysis was thus a constant source of bacterial mortality throughout the year. The estimated percentage of bacterial production removed by viral lysis ranged between 7.8 and 88.9% of the total which suggests that viral lysis represented a very important source of bacterial mortality during this study. The biological interactions between the selected components of the plankton community demonstrated that among the heterotrophic components of the plankton, the nanoflagellates were identified as the most important consumers of bacteria and small phytoplankton cells (< 20 μm). In the presence of microzooplankton the impact of the nanoflagellates on both the bacteria and phytoplankton was reduced, indicating that larger heterotrophs were preying upon the nanoflagellates. Mesozooplankton, however, appeared to exert the greatest impact on nanoflagellates. In the cascading experiments, the data suggest that mesozooplankton consume nanoflagellates, which resulted in a decrease in the predation impact of these organisms on the bacteria. This result is consistent with predator-prey cascades. The presence of the larger heterotrophs therefore, mediates the interactions between the primary bacterivores, the nanoflagellates, and the bacteria within the temporarily open/closed East Kleinemonde Estuary.
- Full Text:
- Date Issued: 2008
Ecological thinking: Schopenhauer, J M Coetzee and who we are in the world
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
Economic valuation of communal rangelands in the Eastern Cape Province of South Africa
- Authors: Gombakomba, Gift
- Date: 2008
- Subjects: Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11166 , http://hdl.handle.net/10353/351 , Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Description: The exploitation and conversion of rangeland ecosystems is often explained by economists as being the result of an undervaluation of the goods and services provided by the rangelands. Undervaluation of rangelands may contribute to their mismanagement or their transformation to monoculture, such as livestock or gathering. Similarly, this may lead to inappropriate policy recommendations and prescriptions. This study undertakes a valuation exercise in an effort to address causes of undervaluation. The objective of the study is to estimate the annual direct, indirect and non-use values per household of communal rangelands in the Eastern Cape Province, based on both primary and secondary data. The exercise incorporates the two major direct uses, both marketed and non-marketed, of rangelands - livestock and gathering. Contingent valuation method based on stated preferences by individual household was used to value the indirect and non-use values of the communal rangelands (e.g. erosion protection and burial sites). Data was collected using PRAs, structured questionnaires and interviews by trained enumerators. The study shows that half of the households owned livestock, which is the main economic use of the rangelands and gathering of natural resources also made an economic contribution. Every household was involved in collection of range resources such as fuel wood, wild fruits, thatch grass, building poles, hunting, fishing make a significant contribution to the direct use values: in the case of gathering it shows that there is “hidden harvest” of many of the natural resources from the rangelands. Indirect and non-use values are shown to be important in the communal areas but are difficult to quantify; the results of these are based on qualitative analysis. Keywords: communal rangelands, demand curve, direct use values, indirect use values, individuals’ preferences, non-use values, willingness-to-accept and willingness-to-pay.
- Full Text:
- Date Issued: 2008
- Authors: Gombakomba, Gift
- Date: 2008
- Subjects: Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11166 , http://hdl.handle.net/10353/351 , Rangelands -- South Africa -- Eastern Cape -- Evaluation , Rural development -- South Africa -- Eastern Cape -- Evaluation , Commons -- South Africa -- Eastern Cape
- Description: The exploitation and conversion of rangeland ecosystems is often explained by economists as being the result of an undervaluation of the goods and services provided by the rangelands. Undervaluation of rangelands may contribute to their mismanagement or their transformation to monoculture, such as livestock or gathering. Similarly, this may lead to inappropriate policy recommendations and prescriptions. This study undertakes a valuation exercise in an effort to address causes of undervaluation. The objective of the study is to estimate the annual direct, indirect and non-use values per household of communal rangelands in the Eastern Cape Province, based on both primary and secondary data. The exercise incorporates the two major direct uses, both marketed and non-marketed, of rangelands - livestock and gathering. Contingent valuation method based on stated preferences by individual household was used to value the indirect and non-use values of the communal rangelands (e.g. erosion protection and burial sites). Data was collected using PRAs, structured questionnaires and interviews by trained enumerators. The study shows that half of the households owned livestock, which is the main economic use of the rangelands and gathering of natural resources also made an economic contribution. Every household was involved in collection of range resources such as fuel wood, wild fruits, thatch grass, building poles, hunting, fishing make a significant contribution to the direct use values: in the case of gathering it shows that there is “hidden harvest” of many of the natural resources from the rangelands. Indirect and non-use values are shown to be important in the communal areas but are difficult to quantify; the results of these are based on qualitative analysis. Keywords: communal rangelands, demand curve, direct use values, indirect use values, individuals’ preferences, non-use values, willingness-to-accept and willingness-to-pay.
- Full Text:
- Date Issued: 2008
Ectomycorrhizas in association with Pinus patula in Sabie, South Africa
- Hawley, Greer L, Taylor, A F S, Dames, Joanna F
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
Editorial: authorship and responsibility [African Entomology]
- Authors: Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6851 , http://hdl.handle.net/10962/d1011132
- Description: Editorial service is a privilege in many senses: editors have a much broader view of disciplinary practices than most of their colleagues; they see work from more institutions; and are privy to manuscripts in all states of fitness for publication. The spectrum of practice is eye-opening, and editors are placed in a position of stewardship, and often mentorship, that inevitably focuses attention on quality assurance and ethics (Lawrence 2003; Bulger 2004; Grieger 2005; Graf et al. 2007). Recently, the Committee on Scholarly Publishing in South Africa, a body within the Academy of Science of South Africa (ASSAf), has drafted Guidelines for best practice in editorial discretion and peer review for South African scholarly journals to assist editors.
- Full Text:
- Date Issued: 2008
- Authors: Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6851 , http://hdl.handle.net/10962/d1011132
- Description: Editorial service is a privilege in many senses: editors have a much broader view of disciplinary practices than most of their colleagues; they see work from more institutions; and are privy to manuscripts in all states of fitness for publication. The spectrum of practice is eye-opening, and editors are placed in a position of stewardship, and often mentorship, that inevitably focuses attention on quality assurance and ethics (Lawrence 2003; Bulger 2004; Grieger 2005; Graf et al. 2007). Recently, the Committee on Scholarly Publishing in South Africa, a body within the Academy of Science of South Africa (ASSAf), has drafted Guidelines for best practice in editorial discretion and peer review for South African scholarly journals to assist editors.
- Full Text:
- Date Issued: 2008
Educated mother-tongue South African English: A corpus approach
- Adendorff, Ralph, de Klerk, Vivian A, de Vos, Mark, Hunt, Sally, Simango, Ronald, Todd, Louise, Niesler, Thomas
- Authors: Adendorff, Ralph , de Klerk, Vivian A , de Vos, Mark , Hunt, Sally , Simango, Ronald , Todd, Louise , Niesler, Thomas
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124352 , vital:35597 , https://doi.org/10.1080/10228190608566261
- Description: South Africa is anecdotally known for its complex system of speech varieties correlating with variables such as ethnicity, first language, class and education. These intuitions (e.g. Lass 1990) require further investigation, especially in the context of a changing South Africa where language variety plays a key role in identifying social, economic and ethnic group membership. Thus, in this research, the extent to which these variables play a role in variety is explored using a corpus approach (the nature of class and race in the corpus is discussed more fully later in the article). The corpus project, focusing primarily on accent, has been undertaken by members of the Department of English Language and Linguistics at Rhodes University in South Africa, collaborating with staff from the Department of Electrical and Electronic Engineering from Stellenbosch University, South Africa. A corpus (the first of its kind) is being compiled, comprising the speech of educated, white, mother-tongue speakers of South African English (as distinct from Afrikaans English, Indian English, and the second language (L2) varieties of English used by speakers of indigenous African languages), and data collection is well under way. This short article aims to describe the aims of the project, and the methodological approach which underpins it, as well as to highlight some of the more problematic aspects of the research.
- Full Text:
- Date Issued: 2008
- Authors: Adendorff, Ralph , de Klerk, Vivian A , de Vos, Mark , Hunt, Sally , Simango, Ronald , Todd, Louise , Niesler, Thomas
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124352 , vital:35597 , https://doi.org/10.1080/10228190608566261
- Description: South Africa is anecdotally known for its complex system of speech varieties correlating with variables such as ethnicity, first language, class and education. These intuitions (e.g. Lass 1990) require further investigation, especially in the context of a changing South Africa where language variety plays a key role in identifying social, economic and ethnic group membership. Thus, in this research, the extent to which these variables play a role in variety is explored using a corpus approach (the nature of class and race in the corpus is discussed more fully later in the article). The corpus project, focusing primarily on accent, has been undertaken by members of the Department of English Language and Linguistics at Rhodes University in South Africa, collaborating with staff from the Department of Electrical and Electronic Engineering from Stellenbosch University, South Africa. A corpus (the first of its kind) is being compiled, comprising the speech of educated, white, mother-tongue speakers of South African English (as distinct from Afrikaans English, Indian English, and the second language (L2) varieties of English used by speakers of indigenous African languages), and data collection is well under way. This short article aims to describe the aims of the project, and the methodological approach which underpins it, as well as to highlight some of the more problematic aspects of the research.
- Full Text:
- Date Issued: 2008
Education in the wetlands and wetlands in the education: a case of contextualizing primary/basic education in Tanzania
- Authors: Hogan, Alice Rosemary
- Date: 2008
- Subjects: Education -- Tanzania Environmental education -- Tanzania Education, Rural -- Tanzania Education -- Curricula -- Tanzania Community and school -- Tanzania
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1504 , http://hdl.handle.net/10962/d1003386
- Description: This dissertation describes an action research case study carried out at a sub-village school at Nyamakurukuru, Utete, Rufiji District, Tanzania. The study was a fully independent research activity funded and led by a female Irish environmental and community specialist who has fifteen years experience of working in rural Tanzania, five of which were in Rufiji District. The aim of the action research was to engage a community of villagers, teachers, students and district officers in a participatory process to adapt a module of a school curriculum to the local context, and teach it in order to describe one way in which contextualization, using local and indigenous knowledge and active discovery teaching-learning processes, can be done. The major research question, which I wished to answer for one specific case, was: Does integrating local environmental cultural knowledge into formal schooling contribute to curriculum relevance? If so, in what way? This document describes the background and context of the research, the motivation and the theoretical basis for the work, the methodology and methods, and the action research process itself. The results are interpreted and discussed in the light of current theoretical perspectives on education and environmental education. The main findings within the case are that: Contextualization improved relevance of education and thus its quality by: • breaking through traditional frames/barriers between teachers and students, students and elders and community and teachers, • allowing formal education to take place outside of the school, • necessitating a change in pedagogy1 to more learner-centered, discovery methods, • allowing indigenous knowledge to come into the classroom, • stimulating creativity and increased confidence, and • bringing local socio-political environmental issues into the classroom. This study provides a case example of how education processes, when engaging local cultural knowledge, can improve the relevance, and thus an aspect of the quality of teaching and learning in school-community contexts, while providing a conduit for integrating environmental education into the formal school curriculum. It provides insights into the key issue of relevance which currently faces educators of children in wetlands in Tanzania. Recommendations were made for the case studied and may be useful beyond the boundaries of the case: • Give more explicit government policy and strategic support for community involvement in educational content–epistemologies and pedagogies. • Weaken framing (hierarchical power positions) to encourage greater partnership between school, home and community to improve relevance. • Investigate the provision of education beyond schools. • Provide practical teacher and community training on use of learner-centered, discovery and active pedagogies. • Provide teacher and community education on biodiversity and the environment. • Provide relevant reference texts and research data on the ecology, biodiversity, vegetation, hydrology, agriculture, sociology, history and other relevant subjects. • Officially nurture a culture that learning should be enjoyable. • Allow the curriculum freedom, in these times of increasing risk for rural tropical wetland communities, to make the curriculum fit the local issues rather than vice versa. • Nurture critical analysis of the curriculum in local pedagogic discourse i.e., at the local contextualization level of the home, community and school.
- Full Text:
- Date Issued: 2008
- Authors: Hogan, Alice Rosemary
- Date: 2008
- Subjects: Education -- Tanzania Environmental education -- Tanzania Education, Rural -- Tanzania Education -- Curricula -- Tanzania Community and school -- Tanzania
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1504 , http://hdl.handle.net/10962/d1003386
- Description: This dissertation describes an action research case study carried out at a sub-village school at Nyamakurukuru, Utete, Rufiji District, Tanzania. The study was a fully independent research activity funded and led by a female Irish environmental and community specialist who has fifteen years experience of working in rural Tanzania, five of which were in Rufiji District. The aim of the action research was to engage a community of villagers, teachers, students and district officers in a participatory process to adapt a module of a school curriculum to the local context, and teach it in order to describe one way in which contextualization, using local and indigenous knowledge and active discovery teaching-learning processes, can be done. The major research question, which I wished to answer for one specific case, was: Does integrating local environmental cultural knowledge into formal schooling contribute to curriculum relevance? If so, in what way? This document describes the background and context of the research, the motivation and the theoretical basis for the work, the methodology and methods, and the action research process itself. The results are interpreted and discussed in the light of current theoretical perspectives on education and environmental education. The main findings within the case are that: Contextualization improved relevance of education and thus its quality by: • breaking through traditional frames/barriers between teachers and students, students and elders and community and teachers, • allowing formal education to take place outside of the school, • necessitating a change in pedagogy1 to more learner-centered, discovery methods, • allowing indigenous knowledge to come into the classroom, • stimulating creativity and increased confidence, and • bringing local socio-political environmental issues into the classroom. This study provides a case example of how education processes, when engaging local cultural knowledge, can improve the relevance, and thus an aspect of the quality of teaching and learning in school-community contexts, while providing a conduit for integrating environmental education into the formal school curriculum. It provides insights into the key issue of relevance which currently faces educators of children in wetlands in Tanzania. Recommendations were made for the case studied and may be useful beyond the boundaries of the case: • Give more explicit government policy and strategic support for community involvement in educational content–epistemologies and pedagogies. • Weaken framing (hierarchical power positions) to encourage greater partnership between school, home and community to improve relevance. • Investigate the provision of education beyond schools. • Provide practical teacher and community training on use of learner-centered, discovery and active pedagogies. • Provide teacher and community education on biodiversity and the environment. • Provide relevant reference texts and research data on the ecology, biodiversity, vegetation, hydrology, agriculture, sociology, history and other relevant subjects. • Officially nurture a culture that learning should be enjoyable. • Allow the curriculum freedom, in these times of increasing risk for rural tropical wetland communities, to make the curriculum fit the local issues rather than vice versa. • Nurture critical analysis of the curriculum in local pedagogic discourse i.e., at the local contextualization level of the home, community and school.
- Full Text:
- Date Issued: 2008
Educators perceived challenges in dealing with HIV and AIDS orphans and vulnerable children
- Authors: Goba, Linda
- Date: 2008
- Subjects: Children of AIDS patients -- Education -- South Africa , Orphans -- Education -- South Africa , Teachers -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9526 , http://hdl.handle.net/10948/963 , Children of AIDS patients -- Education -- South Africa , Orphans -- Education -- South Africa , Teachers -- South Africa -- Attitudes
- Description: The HIV and AIDS pandemic in South Africa has increased the number of orphans and vulnerable children in the school system. Given the prominent role that teachers can play in ensuring that these children receive a quality education so as to maximise their life opportunities, it is important for teachers to be empowered and equipped to enable them to deal with issues surrounding orphans and vulnerable children (OVC) at schools. This study focuses on how teachers are experiencing the impact of HIV and AIDS in schools as a result of having OVC in their classes. The Department of Education has developed training courses to help teachers cope with the impact of HIV and AIDS, but the effectiveness of these programmes has not yet been evaluated. This study aims to establish how teachers who have attended these programmes feel about the assistance rendered to them to deal with OVC related issues. In order to meet this aim, a qualitative enquiry was conducted among a sample of selected teachers from the Eastern Cape. The findings suggest that, while the training has helped to improve the knowledge and attitudes of the teachers, it has not equipped them with the necessary skills to overcome barriers to implement the training programmes at school level. The findings also suggest that there is a need for ongoing support from the Department of Education and the trainers it contracts to ensure that learning from the training is implemented in the schools. Based on the research findings, the study concludes with recommendations that will help teachers to better cope with OVC related issues at school.
- Full Text:
- Date Issued: 2008
- Authors: Goba, Linda
- Date: 2008
- Subjects: Children of AIDS patients -- Education -- South Africa , Orphans -- Education -- South Africa , Teachers -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9526 , http://hdl.handle.net/10948/963 , Children of AIDS patients -- Education -- South Africa , Orphans -- Education -- South Africa , Teachers -- South Africa -- Attitudes
- Description: The HIV and AIDS pandemic in South Africa has increased the number of orphans and vulnerable children in the school system. Given the prominent role that teachers can play in ensuring that these children receive a quality education so as to maximise their life opportunities, it is important for teachers to be empowered and equipped to enable them to deal with issues surrounding orphans and vulnerable children (OVC) at schools. This study focuses on how teachers are experiencing the impact of HIV and AIDS in schools as a result of having OVC in their classes. The Department of Education has developed training courses to help teachers cope with the impact of HIV and AIDS, but the effectiveness of these programmes has not yet been evaluated. This study aims to establish how teachers who have attended these programmes feel about the assistance rendered to them to deal with OVC related issues. In order to meet this aim, a qualitative enquiry was conducted among a sample of selected teachers from the Eastern Cape. The findings suggest that, while the training has helped to improve the knowledge and attitudes of the teachers, it has not equipped them with the necessary skills to overcome barriers to implement the training programmes at school level. The findings also suggest that there is a need for ongoing support from the Department of Education and the trainers it contracts to ensure that learning from the training is implemented in the schools. Based on the research findings, the study concludes with recommendations that will help teachers to better cope with OVC related issues at school.
- Full Text:
- Date Issued: 2008
Effect of a South African medicinal plant on antiretroviral drug induced abnormalities in rats
- Authors: Van Gend, Tania Anli
- Date: 2008
- Subjects: Medicinal plants -- South Africa , Antiretroviral agents -- South Africa , Materia medica, Vegetable -- South Africa , HIV infections -- Alternative treatment -- South Africa , Rats as laboratory animals , Rats -- Metabolism
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10121 , http://hdl.handle.net/10948/1080 , Medicinal plants -- South Africa , Antiretroviral agents -- South Africa , Materia medica, Vegetable -- South Africa , HIV infections -- Alternative treatment -- South Africa , Rats as laboratory animals , Rats -- Metabolism
- Description: The worldwide AIDS epidemic is known to have had a profoundly negative social, economic and personal impact and has taken a heavy toll on existing health care systems, particularly in developing countries. South Africa is experiencing an HIV epidemic with enormous social and economic consequences. Lopinavir/ritonavir antiretroviral treatment has been accredited with having a significantly positive effect and is a key advance in controlling HIV morbidity and mortality. An indigenous South African medicinal plant, Sutherlandia frutescens, known for its anti-diabetic properties and immune-boosting effects, is used for treating HIV positive patients suffering from opportunistic infections. Despite the use of the medicinal plant extract as homeotherapeutic medication, there is little evidence of toxicity testing that identifies its potential for interaction with antiretroviral drugs. However, scientific data relating to the mechanism through which Sutherlandia frutescens acts on the immune system has not been comprehensively documented. The aim of this study was to investigate lopinavir/ritonavir induced metabolic abnormalities in rats and whether the introduction of a plant extract of Sutherlandia frutescens would counteract the side effects of ARV medication. The results indicated that the rodents did not become insulin resistant, however, biochemical analysis indicated that extended ARV drug treatment would have caused insulin resistance. Significant morphological changes were found in the livers, kidneys and pancreases of rats exposed to the lopinavir/ritonavir. Rats exposed to the Sutherlandia frutescens plant extract showed improved histopathology with minimal abnormalities.
- Full Text:
- Date Issued: 2008
- Authors: Van Gend, Tania Anli
- Date: 2008
- Subjects: Medicinal plants -- South Africa , Antiretroviral agents -- South Africa , Materia medica, Vegetable -- South Africa , HIV infections -- Alternative treatment -- South Africa , Rats as laboratory animals , Rats -- Metabolism
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10121 , http://hdl.handle.net/10948/1080 , Medicinal plants -- South Africa , Antiretroviral agents -- South Africa , Materia medica, Vegetable -- South Africa , HIV infections -- Alternative treatment -- South Africa , Rats as laboratory animals , Rats -- Metabolism
- Description: The worldwide AIDS epidemic is known to have had a profoundly negative social, economic and personal impact and has taken a heavy toll on existing health care systems, particularly in developing countries. South Africa is experiencing an HIV epidemic with enormous social and economic consequences. Lopinavir/ritonavir antiretroviral treatment has been accredited with having a significantly positive effect and is a key advance in controlling HIV morbidity and mortality. An indigenous South African medicinal plant, Sutherlandia frutescens, known for its anti-diabetic properties and immune-boosting effects, is used for treating HIV positive patients suffering from opportunistic infections. Despite the use of the medicinal plant extract as homeotherapeutic medication, there is little evidence of toxicity testing that identifies its potential for interaction with antiretroviral drugs. However, scientific data relating to the mechanism through which Sutherlandia frutescens acts on the immune system has not been comprehensively documented. The aim of this study was to investigate lopinavir/ritonavir induced metabolic abnormalities in rats and whether the introduction of a plant extract of Sutherlandia frutescens would counteract the side effects of ARV medication. The results indicated that the rodents did not become insulin resistant, however, biochemical analysis indicated that extended ARV drug treatment would have caused insulin resistance. Significant morphological changes were found in the livers, kidneys and pancreases of rats exposed to the lopinavir/ritonavir. Rats exposed to the Sutherlandia frutescens plant extract showed improved histopathology with minimal abnormalities.
- Full Text:
- Date Issued: 2008
Effect of salinity on oxygen consumption and growth of juvenile white steenbras, litohognathus lithognathus
- Authors: Kandjou, Kaunahama
- Date: 2008
- Subjects: Lithognathus -- Growth , Salinity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5275 , http://hdl.handle.net/10962/d1005119 , Lithognathus -- Growth , Salinity
- Description: A stress-induced increase in metabolic rate of fish consumes energy within the metabolic scope of a fish that could otherwise be used for such functions as growth and reproduction. By estimating the degree of the metabolic response under given salinity levels and sudden changes thereof, it could be tested whether growth under given culture conditions could be predicted. Using intermittent respirometers, this study investigated the metabolic response of juvenile Lithognathus lithognathus following gradual acclimation to 5, 25 and 35‰ and, as a result of abrupt change from 35‰ to 5‰ or from 35‰ to 25‰ at 20˚C. The main aim of the study was to establish whether the magnitude of such responses could be used to predict growth of juvenile L. lithognathus under culture conditions. Hence, in addition to the respirometry study, two growth studies were conducted at 5, 10, 25 and 35‰ salinities. The baseline metabolic rates of juvenile L. lithognathus were also determined. Oxygen consumption measurements over 24-hours showed that most fish exhibited a diurnal peak in metabolic rates. The standard and active metabolic rates calculated from juvenile L. lithognathus with a diurnal peak in oxygen consumption were 0.06±0.001mgO₂g⁻¹h⁻¹ (mean±SEM, n = 5), and 0.11±0.01mg O₂g⁻¹h⁻¹, respectively. The standard and active metabolic rates of juvenile L lithognathus showing a nocturnal peak in metabolic activities were 0.04±0.001mgO₂g-1h-1 (n = 1), and 0.12±0.003 mg O₂g⁻¹ h⁻¹, respectively. Routine metabolic rate of these fish calculated over a 3-h measurement period was 0.09±0.005mgO₂g⁻¹h⁻¹ (n = 6). Juvenile L. lithognathus showed a relationship between metabolic rate (mo₂) and body weight (W) following the equation: mo₂ = 0.62 W⁻°·⁵³.
- Full Text:
- Date Issued: 2008
- Authors: Kandjou, Kaunahama
- Date: 2008
- Subjects: Lithognathus -- Growth , Salinity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5275 , http://hdl.handle.net/10962/d1005119 , Lithognathus -- Growth , Salinity
- Description: A stress-induced increase in metabolic rate of fish consumes energy within the metabolic scope of a fish that could otherwise be used for such functions as growth and reproduction. By estimating the degree of the metabolic response under given salinity levels and sudden changes thereof, it could be tested whether growth under given culture conditions could be predicted. Using intermittent respirometers, this study investigated the metabolic response of juvenile Lithognathus lithognathus following gradual acclimation to 5, 25 and 35‰ and, as a result of abrupt change from 35‰ to 5‰ or from 35‰ to 25‰ at 20˚C. The main aim of the study was to establish whether the magnitude of such responses could be used to predict growth of juvenile L. lithognathus under culture conditions. Hence, in addition to the respirometry study, two growth studies were conducted at 5, 10, 25 and 35‰ salinities. The baseline metabolic rates of juvenile L. lithognathus were also determined. Oxygen consumption measurements over 24-hours showed that most fish exhibited a diurnal peak in metabolic rates. The standard and active metabolic rates calculated from juvenile L. lithognathus with a diurnal peak in oxygen consumption were 0.06±0.001mgO₂g⁻¹h⁻¹ (mean±SEM, n = 5), and 0.11±0.01mg O₂g⁻¹h⁻¹, respectively. The standard and active metabolic rates of juvenile L lithognathus showing a nocturnal peak in metabolic activities were 0.04±0.001mgO₂g-1h-1 (n = 1), and 0.12±0.003 mg O₂g⁻¹ h⁻¹, respectively. Routine metabolic rate of these fish calculated over a 3-h measurement period was 0.09±0.005mgO₂g⁻¹h⁻¹ (n = 6). Juvenile L. lithognathus showed a relationship between metabolic rate (mo₂) and body weight (W) following the equation: mo₂ = 0.62 W⁻°·⁵³.
- Full Text:
- Date Issued: 2008
Effects of coastal topography on physiology, behaviour and genetics of indigenous (Perna perna) and invasive (Mytilus galloprovincialis) mussels
- Authors: Nicastro, Katy R
- Date: 2008
- Subjects: Mussels -- Ecology -- South Africa , Perna -- Physiology -- South Africa , Perna -- Behavior -- South Africa , Mussels -- Behavior -- Environmental factors -- South Africa , Mussels -- Habitat -- South Africa , Mytilus galloprovincialis , Mytilus galloprovincialis -- Physiology -- South Africa , Mytilus galloprovincialis -- Behavior -- South Africa , Mytilus galloprovincialis -- Genetics -- South Africa , Coastal ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5833 , http://hdl.handle.net/10962/d1008262
- Description: Organisms inhabit environments that have many dimensions, each of which can vary temporally and spatially. The spatial-temporal variations of environmental stressors and disturbances may have major but different effects on indigenous and invasive species, favouring either of them at different times and places. The invasive mussel Mytilus galloprovincialis invaded the South African coast 30 years ago and, on the south coast of South Africa, it now competes and co-exists with the indigenous Perna perna in the lower eulittoral zone (referred to here as the mussel zone) The invasive and indigenous species dominate the upper and the lower mussel zones respectively, while the two co-exist in the mid-zone. My results show that intertidal mussels experience, and respond to, spatial and temporal fluctuations of several biotic and abiotic stressors. The invasive and the indigenous species adopt different strategies when reacting to environmental factors and their physiological and behavioural responses vary in time and in different habitats as different pressures become of overriding importance. Attachment strength of both species decreased in summer and increased in winter, and was higher on the open coast than in bays for both species, showing a strong positive correlation with wave force in time and space. P. perna had significantly higher attachment strength than M. galloprovincialis but, contrary to previous studies, the difference in gonad index between the two species varied according to the habitat. In bay habitats, M. galloprovincialis had a higher maximum reproductive effort than P. perna, however, on the open coast, there was no significant difference between the two species, suggesting that for the invasive species wave action is a limiting factor not only in terms of the attachment strength but also of energy availability for reproductive tissue development. Major spawning events occurred during periods of low wave action while minor spawning coincided with periods of intense hydrodynamic stress. On the open coast, gonad index was negatively correlated with attachment strength for both species while, in bays, there was no correlation between these two factors for either. The two species also showed different behaviour. In the field, M. galloprovincialis moved significantly more than P. perna over a period of six months. The higher mobility of the invasive species was also confirmed in the laboratory where, in general, M. galloprovincialis formed clumps more readily than P. perna. Taken collectively, these results suggest that channelling more energy into attachment strength limits reproductive tissue development and that, while the indigenous species invests more in byssal production, the invasive species adopts a more dynamic strategy looking for aggregation or a safer arrangement. Higher endolithic infestation and a greater expression of heat shock proteins (Hsps) in mussel populations on the open coast than in bays indicate that this habitat is a more stressful environment not only in terms of wave action. Endolith damaged mussels had significantly lower attachment strengths and condition indices than clean mussels, probably due to the need to channel energy into shell repair. The constant shell repair and expression of Hsps typical of open coast populations are energetically demanding processes. These observations suggest that on the open coast, mussels are subjected to more severe energetic constraints than in bay habitats. Wave and sand stress fluctuated seasonally with the former having a greater effect on mussel mortality on the open coast and the latter a higher impact on bay populations. Overall, mussel mortality rates were higher on the open coast than in bays. My results show that populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed the relatively stable bay habitats act as source populations with greater genetic migration rates out of bays than into them. These differences in genetic structure on scales of las of kilometers show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity. Environmental gradients that are key factors in species distribution over large geographical scales can also be responsible for micro-scale distributions. My results show that M. galloprovincialis colonizes the upper mussel zone where temperature is high, but is less tolerant to this stressor and has to maintain a high expression of Hsps. This suggests that temperature is probably a limiting factor in its invasion towards the sub-tropical east coast. There are inter- and intra-specific differences in responses to the environment which highlight the efforts of M. galloprovincialis and P. perna to optimize resource utilization for survival and reproduction. Determining these differences is crucial to understanding patterns of co-existence between competing indigenous and invasive species.
- Full Text:
- Date Issued: 2008
- Authors: Nicastro, Katy R
- Date: 2008
- Subjects: Mussels -- Ecology -- South Africa , Perna -- Physiology -- South Africa , Perna -- Behavior -- South Africa , Mussels -- Behavior -- Environmental factors -- South Africa , Mussels -- Habitat -- South Africa , Mytilus galloprovincialis , Mytilus galloprovincialis -- Physiology -- South Africa , Mytilus galloprovincialis -- Behavior -- South Africa , Mytilus galloprovincialis -- Genetics -- South Africa , Coastal ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5833 , http://hdl.handle.net/10962/d1008262
- Description: Organisms inhabit environments that have many dimensions, each of which can vary temporally and spatially. The spatial-temporal variations of environmental stressors and disturbances may have major but different effects on indigenous and invasive species, favouring either of them at different times and places. The invasive mussel Mytilus galloprovincialis invaded the South African coast 30 years ago and, on the south coast of South Africa, it now competes and co-exists with the indigenous Perna perna in the lower eulittoral zone (referred to here as the mussel zone) The invasive and indigenous species dominate the upper and the lower mussel zones respectively, while the two co-exist in the mid-zone. My results show that intertidal mussels experience, and respond to, spatial and temporal fluctuations of several biotic and abiotic stressors. The invasive and the indigenous species adopt different strategies when reacting to environmental factors and their physiological and behavioural responses vary in time and in different habitats as different pressures become of overriding importance. Attachment strength of both species decreased in summer and increased in winter, and was higher on the open coast than in bays for both species, showing a strong positive correlation with wave force in time and space. P. perna had significantly higher attachment strength than M. galloprovincialis but, contrary to previous studies, the difference in gonad index between the two species varied according to the habitat. In bay habitats, M. galloprovincialis had a higher maximum reproductive effort than P. perna, however, on the open coast, there was no significant difference between the two species, suggesting that for the invasive species wave action is a limiting factor not only in terms of the attachment strength but also of energy availability for reproductive tissue development. Major spawning events occurred during periods of low wave action while minor spawning coincided with periods of intense hydrodynamic stress. On the open coast, gonad index was negatively correlated with attachment strength for both species while, in bays, there was no correlation between these two factors for either. The two species also showed different behaviour. In the field, M. galloprovincialis moved significantly more than P. perna over a period of six months. The higher mobility of the invasive species was also confirmed in the laboratory where, in general, M. galloprovincialis formed clumps more readily than P. perna. Taken collectively, these results suggest that channelling more energy into attachment strength limits reproductive tissue development and that, while the indigenous species invests more in byssal production, the invasive species adopts a more dynamic strategy looking for aggregation or a safer arrangement. Higher endolithic infestation and a greater expression of heat shock proteins (Hsps) in mussel populations on the open coast than in bays indicate that this habitat is a more stressful environment not only in terms of wave action. Endolith damaged mussels had significantly lower attachment strengths and condition indices than clean mussels, probably due to the need to channel energy into shell repair. The constant shell repair and expression of Hsps typical of open coast populations are energetically demanding processes. These observations suggest that on the open coast, mussels are subjected to more severe energetic constraints than in bay habitats. Wave and sand stress fluctuated seasonally with the former having a greater effect on mussel mortality on the open coast and the latter a higher impact on bay populations. Overall, mussel mortality rates were higher on the open coast than in bays. My results show that populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed the relatively stable bay habitats act as source populations with greater genetic migration rates out of bays than into them. These differences in genetic structure on scales of las of kilometers show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity. Environmental gradients that are key factors in species distribution over large geographical scales can also be responsible for micro-scale distributions. My results show that M. galloprovincialis colonizes the upper mussel zone where temperature is high, but is less tolerant to this stressor and has to maintain a high expression of Hsps. This suggests that temperature is probably a limiting factor in its invasion towards the sub-tropical east coast. There are inter- and intra-specific differences in responses to the environment which highlight the efforts of M. galloprovincialis and P. perna to optimize resource utilization for survival and reproduction. Determining these differences is crucial to understanding patterns of co-existence between competing indigenous and invasive species.
- Full Text:
- Date Issued: 2008
Effects of sheep kraal manure and intercropping with maize on growth, nutrient uptake and yield of a vegetable Amaranthus accession in the central region of the Eastern Cape, South Africa
- Authors: Mhlontlo, Simphiwe
- Date: 2008
- Subjects: Intercropping , Amaranths , Traditional farming , Manures
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11864 , http://hdl.handle.net/10353/76 , Intercropping , Amaranths , Traditional farming , Manures
- Description: Amaranthus is among the nutritious indigenous plant species that are gathered from the wild in the Eastern Cape to prepare a traditional meal known as ‘imifino’ or ‘isigwampa’ to supplement the necessary proteins, vitamins and minerals which are poor in maizebased meals. Amaranthus species are adapted to wild conditions unsuitable for exotic vegetables and could be cultivated but information on its fertility requirements, as sole or intercrop, is the key for its domestication and production as a leafy vegetable, particularly where manure is used. Two dry-land and one glasshouse experiments were conducted to study the effects of sheep kraal manure application rate, intercropping with maize and soil type on growth, fresh and dry matter yields, nutrient uptake and grain yield of a local Amaranthus accession that grows wild in the Eastern Cape. Sheep kraal manure rates ranging from 0 to 10 t ha-1 and an NPK {2:3:4(30) + 0.5% Zn} fertilizer as a positive control, applied at rates recommended for spinach, were tested. In the Gqumahashe experiment, where Amaranthus was grown as a sole crop, low manure rates (≤ 2.5 t ha-1) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilized control, whereas higher rates (5 and 10 t ha-1) and recommended NPK fertilizer had higher levels both at 30 and 60 days after transplanting (DAT) at p < 0.05. At 30 DAT, manure application rates of ≥ 2.5 t ha-1 and the NPK fertilizer treatment, produced greater shoot dry-matter yields (29.35, 30.75 and 37.68 g plant-1) than the unfertilized control (17.11 g plant-1) at p < 0.05. Uptake of N and P in the leaves increased with increase in manure application rate with N uptake reaching a maximum (308 mg plant-1) at a manure rate of 2.5 t ha-1 which corresponded with the maximum dry matter yield. There was no effect of manure rate or fertilizer on residual soil N and Ca, whereas P, K, Mg and Zn increased. In a pot experiment with soils from Ntselamanzi and Gqumahashe Villages, manure rates ≥ 2.5 t ha-1 resulted in plant heights and fresh matter yield that compared well with the NPK fertilizer treatment in the Gqumahashe soil whereas only the 10 t ha-1 manure treatment was comparable to the NPK fertilizer treatment in the Ntselamanzi soil. Only treatments with ≥ 5 t ha-1 manure had stem girth (1.00 and 1.07 cm) that compared well to NPK fertilizer (1.03 cm) in the Ntselamanzi soil whereas in the Gqumahashe soil, all manure levels compared well to NPK fertilizer (1.02 cm). However, no significant difference was observed in plant height and stem girth and fresh matter due to soil type. In both soils, the 1.3-10 t ha-1 manure treatments had dry leaf weight comparable to plants fertilized with NPK fertilizer (3.72 g plant-1 for the Ntselamanzi soil and 3.65 g plant-1 for the Gqumahashe soil) and were bigger than the unfertilized control (2.2 g plant-1 for the Ntselamanzi soil and 1.38 g plant-1 for the Gqumahashe soil) at p < 0.05. Uptake of N, P and K increased as result of manure application but nonetheless, it was less when compared to plants fertilized with NPK fertilizer in both soils. In a field intercropping experiment carried out at Ntselamanzi, growth and yield of sole and intercropped Amaranthus plants grown with manure improved when compared to the unfertilized control and compared well to NPK fertilizer. At 30 days after transplanting (DAT), both sole and intercropped plants grown with ≥ 2.5 t ha-1 manure had fresh and dry matter yield comparable to plants fertilized with NPK fertilizer. At 60 DAT, intercropped plants grown with all manure levels had bigger fresh matter yield when compared to unfertilized control (836.0 g plant-1) whereas for sole cropped plants only those grown with ≥ 2.5 t ha-1 compared to NPK fertilizer (1467.7 g plant-1) at p < 0.05. Uptake of N, P, K, Ca and Mg increased with increase in manure application in both sole and intercropped Amaranthus. Whereas Amaranthus did not suffer from the competition in the intercrop, maize biomass and grain yield were severely reduced with the effects being evident after 60 DAT. Based on results of this study, it is therefore suggested that, if Amaranthus is to be intercropped with maize under dry land conditions of the Central Region of the Eastern Cape, sheep manure should at least be applied at rate of ≥ 2.5 t ha-1 and Amaranthus be harvested at 30 DAT.
- Full Text:
- Date Issued: 2008
- Authors: Mhlontlo, Simphiwe
- Date: 2008
- Subjects: Intercropping , Amaranths , Traditional farming , Manures
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11864 , http://hdl.handle.net/10353/76 , Intercropping , Amaranths , Traditional farming , Manures
- Description: Amaranthus is among the nutritious indigenous plant species that are gathered from the wild in the Eastern Cape to prepare a traditional meal known as ‘imifino’ or ‘isigwampa’ to supplement the necessary proteins, vitamins and minerals which are poor in maizebased meals. Amaranthus species are adapted to wild conditions unsuitable for exotic vegetables and could be cultivated but information on its fertility requirements, as sole or intercrop, is the key for its domestication and production as a leafy vegetable, particularly where manure is used. Two dry-land and one glasshouse experiments were conducted to study the effects of sheep kraal manure application rate, intercropping with maize and soil type on growth, fresh and dry matter yields, nutrient uptake and grain yield of a local Amaranthus accession that grows wild in the Eastern Cape. Sheep kraal manure rates ranging from 0 to 10 t ha-1 and an NPK {2:3:4(30) + 0.5% Zn} fertilizer as a positive control, applied at rates recommended for spinach, were tested. In the Gqumahashe experiment, where Amaranthus was grown as a sole crop, low manure rates (≤ 2.5 t ha-1) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilized control, whereas higher rates (5 and 10 t ha-1) and recommended NPK fertilizer had higher levels both at 30 and 60 days after transplanting (DAT) at p < 0.05. At 30 DAT, manure application rates of ≥ 2.5 t ha-1 and the NPK fertilizer treatment, produced greater shoot dry-matter yields (29.35, 30.75 and 37.68 g plant-1) than the unfertilized control (17.11 g plant-1) at p < 0.05. Uptake of N and P in the leaves increased with increase in manure application rate with N uptake reaching a maximum (308 mg plant-1) at a manure rate of 2.5 t ha-1 which corresponded with the maximum dry matter yield. There was no effect of manure rate or fertilizer on residual soil N and Ca, whereas P, K, Mg and Zn increased. In a pot experiment with soils from Ntselamanzi and Gqumahashe Villages, manure rates ≥ 2.5 t ha-1 resulted in plant heights and fresh matter yield that compared well with the NPK fertilizer treatment in the Gqumahashe soil whereas only the 10 t ha-1 manure treatment was comparable to the NPK fertilizer treatment in the Ntselamanzi soil. Only treatments with ≥ 5 t ha-1 manure had stem girth (1.00 and 1.07 cm) that compared well to NPK fertilizer (1.03 cm) in the Ntselamanzi soil whereas in the Gqumahashe soil, all manure levels compared well to NPK fertilizer (1.02 cm). However, no significant difference was observed in plant height and stem girth and fresh matter due to soil type. In both soils, the 1.3-10 t ha-1 manure treatments had dry leaf weight comparable to plants fertilized with NPK fertilizer (3.72 g plant-1 for the Ntselamanzi soil and 3.65 g plant-1 for the Gqumahashe soil) and were bigger than the unfertilized control (2.2 g plant-1 for the Ntselamanzi soil and 1.38 g plant-1 for the Gqumahashe soil) at p < 0.05. Uptake of N, P and K increased as result of manure application but nonetheless, it was less when compared to plants fertilized with NPK fertilizer in both soils. In a field intercropping experiment carried out at Ntselamanzi, growth and yield of sole and intercropped Amaranthus plants grown with manure improved when compared to the unfertilized control and compared well to NPK fertilizer. At 30 days after transplanting (DAT), both sole and intercropped plants grown with ≥ 2.5 t ha-1 manure had fresh and dry matter yield comparable to plants fertilized with NPK fertilizer. At 60 DAT, intercropped plants grown with all manure levels had bigger fresh matter yield when compared to unfertilized control (836.0 g plant-1) whereas for sole cropped plants only those grown with ≥ 2.5 t ha-1 compared to NPK fertilizer (1467.7 g plant-1) at p < 0.05. Uptake of N, P, K, Ca and Mg increased with increase in manure application in both sole and intercropped Amaranthus. Whereas Amaranthus did not suffer from the competition in the intercrop, maize biomass and grain yield were severely reduced with the effects being evident after 60 DAT. Based on results of this study, it is therefore suggested that, if Amaranthus is to be intercropped with maize under dry land conditions of the Central Region of the Eastern Cape, sheep manure should at least be applied at rate of ≥ 2.5 t ha-1 and Amaranthus be harvested at 30 DAT.
- Full Text:
- Date Issued: 2008
Effects of temperature on the development, behaviour and geography of blowflies in a forensic context
- Authors: Richards, Cameron Spencer
- Date: 2008
- Subjects: Blowflies Blowflies -- South Africa Diptera -- South Africa Insects -- Development Insects -- Behavior Forensic entomology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5683 , http://hdl.handle.net/10962/d1005369
- Description: The development of immature insects is commonly employed in forensic investigations to estimate time of death, or postmortem interval (PMI), of a corpse on which they are feeding. The bulk of this thesis focuses on factors influencing the accuracy of developmental data, and exploring how and why developmental data differ between studies involving the same species, and between different species. Because carrion feeding insects are ectotherms, temperature may be expected to significantly influence their behaviour, development and distribution, and the remainder of the thesis therefore focuses on the thermal biology and geographical distribution of seven forensically important blowflies. The species include Chrysomya albiceps, C. putoria, C. chloropyga, C. megacephala, C. marginalis, C. inclinata and Calliphora croceipalpis. A robust experimental design for estimating developmental models is outlined and tested. It is recommended that forensic entomologists should involve at least six constant temperatures, starting at about 7°C above the relevant developmental zero (D0) and going to about 10°C above the upper critical temperature, and a temporal sampling interval with a relative precision of about 10%. Using this design, focused experiments consistently provided the most reliable developmental data, while data pooled from different studies yielded inconsistent results. Similarly, developmental data from closely related species differed significantly, and surprisingly so did developmental data from different populations of the same species. Possible explanations for the latter lay in the different methods of data collection but only temporal sampling resolution had a direct influence on the accuracy of developmental data. Consequently, disparities in such data were primarily ascribed to genetic differences and phenotypic plasticity. Comparisons between numerous thermal thresholds of larvae, pupae and adults support this conclusion and suggest a phylogenetic component to the thermal biology of blowflies. Further comparisons were made between these temperature thresholds and the distributions of blowfly species present on two rhinoceros carcasses. These comparisons suggest that blowfly larvae with high upper lethal temperature thresholds dominate in interspecific competition in favorable thermal environments by raising maggot mass temperature above the thresholds of other carrion-feeding blowflies, through maggot-generated heat. Bioclimatic modeling using maximum entropy analysis provided a successful means of predicting whether a species is likely to occur in an area, and whether it would therefore be expected in a local carcass community. It also showed that temperature was less important than moisture in shaping the geographical distribution of African carrion blowflies. Based on these results, several recommendations are made for the practice of forensic entomology.
- Full Text:
- Date Issued: 2008
- Authors: Richards, Cameron Spencer
- Date: 2008
- Subjects: Blowflies Blowflies -- South Africa Diptera -- South Africa Insects -- Development Insects -- Behavior Forensic entomology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5683 , http://hdl.handle.net/10962/d1005369
- Description: The development of immature insects is commonly employed in forensic investigations to estimate time of death, or postmortem interval (PMI), of a corpse on which they are feeding. The bulk of this thesis focuses on factors influencing the accuracy of developmental data, and exploring how and why developmental data differ between studies involving the same species, and between different species. Because carrion feeding insects are ectotherms, temperature may be expected to significantly influence their behaviour, development and distribution, and the remainder of the thesis therefore focuses on the thermal biology and geographical distribution of seven forensically important blowflies. The species include Chrysomya albiceps, C. putoria, C. chloropyga, C. megacephala, C. marginalis, C. inclinata and Calliphora croceipalpis. A robust experimental design for estimating developmental models is outlined and tested. It is recommended that forensic entomologists should involve at least six constant temperatures, starting at about 7°C above the relevant developmental zero (D0) and going to about 10°C above the upper critical temperature, and a temporal sampling interval with a relative precision of about 10%. Using this design, focused experiments consistently provided the most reliable developmental data, while data pooled from different studies yielded inconsistent results. Similarly, developmental data from closely related species differed significantly, and surprisingly so did developmental data from different populations of the same species. Possible explanations for the latter lay in the different methods of data collection but only temporal sampling resolution had a direct influence on the accuracy of developmental data. Consequently, disparities in such data were primarily ascribed to genetic differences and phenotypic plasticity. Comparisons between numerous thermal thresholds of larvae, pupae and adults support this conclusion and suggest a phylogenetic component to the thermal biology of blowflies. Further comparisons were made between these temperature thresholds and the distributions of blowfly species present on two rhinoceros carcasses. These comparisons suggest that blowfly larvae with high upper lethal temperature thresholds dominate in interspecific competition in favorable thermal environments by raising maggot mass temperature above the thresholds of other carrion-feeding blowflies, through maggot-generated heat. Bioclimatic modeling using maximum entropy analysis provided a successful means of predicting whether a species is likely to occur in an area, and whether it would therefore be expected in a local carcass community. It also showed that temperature was less important than moisture in shaping the geographical distribution of African carrion blowflies. Based on these results, several recommendations are made for the practice of forensic entomology.
- Full Text:
- Date Issued: 2008
Electro-catalyzed oxidation of reduced glutathione and 2-mercaptoethanol by cobalt phthalocyanine-containing screen printed graphite electrodes
- Sehlotho, Nthapo, Griveau, Sophie, Ruillé, Nadine, Boujtita, Mohammed, Nyokong, Tebello, Bedioui, Fethi
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Ruillé, Nadine , Boujtita, Mohammed , Nyokong, Tebello , Bedioui, Fethi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265935 , vital:53902 , xlink:href="https://doi.org/10.1016/j.msec.2007.10.054"
- Description: Electro-catalytic behavior of screen printed graphite electrodes modified with cobalt phthalocyanine (CoPc) towards the oxidation of reduced glutathione (GSH) and 2-mercaptoethanol (2-ME) is reported. We find, by using cyclic voltammetry, that the oxidation of 2-ME occurs at 0.2 V vs Ag/AgCl and − 0.3 vs Ag/AgCl V at pH = 7 and pH = 13, respectively and that of GSH occurs at 0.4 V vs Ag/AgCl and 0.0 V vs Ag/AgCl at pH = 7 and 13, respectively. The electro-catalytic activity depends on the method of electrode modification and the amount of catalyst incorporated in the ink used to fabricate the SPCEs. The highest activity was obtained with electrodes prepared with 2.5% (w:w) of CoPc.
- Full Text:
- Date Issued: 2008
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Ruillé, Nadine , Boujtita, Mohammed , Nyokong, Tebello , Bedioui, Fethi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265935 , vital:53902 , xlink:href="https://doi.org/10.1016/j.msec.2007.10.054"
- Description: Electro-catalytic behavior of screen printed graphite electrodes modified with cobalt phthalocyanine (CoPc) towards the oxidation of reduced glutathione (GSH) and 2-mercaptoethanol (2-ME) is reported. We find, by using cyclic voltammetry, that the oxidation of 2-ME occurs at 0.2 V vs Ag/AgCl and − 0.3 vs Ag/AgCl V at pH = 7 and pH = 13, respectively and that of GSH occurs at 0.4 V vs Ag/AgCl and 0.0 V vs Ag/AgCl at pH = 7 and 13, respectively. The electro-catalytic activity depends on the method of electrode modification and the amount of catalyst incorporated in the ink used to fabricate the SPCEs. The highest activity was obtained with electrodes prepared with 2.5% (w:w) of CoPc.
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- Date Issued: 2008
Electrocatalytic and photosensitizing behavior of metallophthalocyanine complexes
- Authors: Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265908 , vital:53899 , xlink:href="https://doi.org/10.1142/S1088424608000388"
- Description: Electrocatalytic or photosensitizing (photocatalytic) properties of metallophthalocyanine (MPc) complexes are dependent on the central metal. Electrocatalytic behavior is observed for electroactive central metals such as Co, Mn and Fe, whereas photosensitizing behavior is observed for diamagnetic metals such as Al, Zn and Si. In the presence of nanoparticles such as quantum dots, the photosensitizing behavior of MPc complexes is improved. Carbon nanotubes enhance the electrocatalytic behavior of MPc complexes.
- Full Text:
- Date Issued: 2008
- Authors: Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265908 , vital:53899 , xlink:href="https://doi.org/10.1142/S1088424608000388"
- Description: Electrocatalytic or photosensitizing (photocatalytic) properties of metallophthalocyanine (MPc) complexes are dependent on the central metal. Electrocatalytic behavior is observed for electroactive central metals such as Co, Mn and Fe, whereas photosensitizing behavior is observed for diamagnetic metals such as Al, Zn and Si. In the presence of nanoparticles such as quantum dots, the photosensitizing behavior of MPc complexes is improved. Carbon nanotubes enhance the electrocatalytic behavior of MPc complexes.
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- Date Issued: 2008
Electrocatalytic detection of amitrole on the multi-walled carbon nanotube–iron (II) tetra-aminophthalocyanine platform
- Siswana, Msimelelo P, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Siswana, Msimelelo P , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265924 , vital:53901 , xlink:href="https://doi.org/10.3390/s8085096"
- Description: It is shown that iron(II) tetra-aminophthalocyanine complex electropolymerized onto a multi-walled carbon nanotube-modified basal plane pyrolytic graphite electrode greatly enhanced the electrocatalytic detetion of amitrole (a toxic herbicide), resulting in a very low detection limit (0.5 nM) and excellent sensitivity of 8.80±0.44 μA/nM, compared to any known work reported so far. The electrocatalytic detection of amitrole at this electrode occurred at less positive potential (~0.3 V vs Ag|ACl) and also revealed a typical coupled chemical reaction. The mechanism for this response is proposed. The electrode gave satisfactory selectivity to amitrole in the presence of other potential interfering pesticides in aqueous solutions.
- Full Text:
- Date Issued: 2008
- Authors: Siswana, Msimelelo P , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265924 , vital:53901 , xlink:href="https://doi.org/10.3390/s8085096"
- Description: It is shown that iron(II) tetra-aminophthalocyanine complex electropolymerized onto a multi-walled carbon nanotube-modified basal plane pyrolytic graphite electrode greatly enhanced the electrocatalytic detetion of amitrole (a toxic herbicide), resulting in a very low detection limit (0.5 nM) and excellent sensitivity of 8.80±0.44 μA/nM, compared to any known work reported so far. The electrocatalytic detection of amitrole at this electrode occurred at less positive potential (~0.3 V vs Ag|ACl) and also revealed a typical coupled chemical reaction. The mechanism for this response is proposed. The electrode gave satisfactory selectivity to amitrole in the presence of other potential interfering pesticides in aqueous solutions.
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- Date Issued: 2008
Electrochemical and electrocatalytic properties of α-substituted manganese and titanium phthalocyanines
- Nombona, Nolwazi, Tau, Prudence, Sehlotho, Nthapo, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Tau, Prudence , Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268587 , vital:54212 , xlink:href="https://doi.org/10.1016/j.electacta.2007.11.046"
- Description: This work reports on the synthesis of manganese and titanium phthalocyanine complexes that are tetra-substituted at four non-peripheral positions with amino ligands. The complexes are investigated for the first time for their electrochemical properties using cyclic voltammetry, rotating disc electrode voltammetry and spectroelectrochemistry. Electropolymerisation on a glassy carbon electrode was performed with ease and the modified electrodes were investigated for electrocatalysis of nitrite oxidation. Nitrite oxidation to nitrate is confirmed from the transfer of a total of two electrons.
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- Date Issued: 2008
- Authors: Nombona, Nolwazi , Tau, Prudence , Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268587 , vital:54212 , xlink:href="https://doi.org/10.1016/j.electacta.2007.11.046"
- Description: This work reports on the synthesis of manganese and titanium phthalocyanine complexes that are tetra-substituted at four non-peripheral positions with amino ligands. The complexes are investigated for the first time for their electrochemical properties using cyclic voltammetry, rotating disc electrode voltammetry and spectroelectrochemistry. Electropolymerisation on a glassy carbon electrode was performed with ease and the modified electrodes were investigated for electrocatalysis of nitrite oxidation. Nitrite oxidation to nitrate is confirmed from the transfer of a total of two electrons.
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- Date Issued: 2008
Electrochemical Characterization of Self-Assembled Monolayer of a Novel Manganese Tetrabenzylthio-Substituted Phthalocyanine and Its Use in Nitrite Oxidation
- Matemadombo, Fungisai, Griveau, Sophie, Bedioui, Fethi, Nyokong, Tebello
- Authors: Matemadombo, Fungisai , Griveau, Sophie , Bedioui, Fethi , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265950 , vital:53903 , xlink:href="https://doi.org/10.1002/elan.200804269"
- Description: Manganese phthalocyanine MnPc(SPh)4 has been synthesized and used to form self assembled monolayers on gold electrodes. The well packed SAM monolayer was characterized by analyzing the blocking of a number of Faradic processes by cyclic voltammetry, evaluating the electrical characteristics of the modified electrode by electrochemical impedance and imaging the modified surface by electrochemical scanning microscopy. Finally, MnPc(SPh)4-SAM modified electrode displayed an electrocatalytic behavior toward the oxidation of nitrite.
- Full Text:
- Date Issued: 2008
- Authors: Matemadombo, Fungisai , Griveau, Sophie , Bedioui, Fethi , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265950 , vital:53903 , xlink:href="https://doi.org/10.1002/elan.200804269"
- Description: Manganese phthalocyanine MnPc(SPh)4 has been synthesized and used to form self assembled monolayers on gold electrodes. The well packed SAM monolayer was characterized by analyzing the blocking of a number of Faradic processes by cyclic voltammetry, evaluating the electrical characteristics of the modified electrode by electrochemical impedance and imaging the modified surface by electrochemical scanning microscopy. Finally, MnPc(SPh)4-SAM modified electrode displayed an electrocatalytic behavior toward the oxidation of nitrite.
- Full Text:
- Date Issued: 2008
Electrooxidation of hydrazine catalyzed by noncovalently functionalized single-walled carbon nanotubes with CoPc
- Geraldo, Daniela A, Togo, Chamunorwa A, Limson, Janice L, Nyokong, Tebello
- Authors: Geraldo, Daniela A , Togo, Chamunorwa A , Limson, Janice L , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265963 , vital:53904 , xlink:href="https://doi.org/10.1016/j.electacta.2008.05.083"
- Description: We report on the electrooxidation of hydrazine catalyzed by single-walled carbon nanotube (SWCNT) functionalized with cobalt phthalocyanine (CoPc) which shows that the presence of the single-walled carbon nanotubes enhances the catalytic activity of the CoPc itself without any change in the reaction mechanism. A synergistic effect, in terms of reactivity when the new nanocomposite material was adsorbed on the GC electrode, was observed. The obtained hybrid electrodes were tested under hydrodynamic conditions, showing two different oxidation processes, which suggest the presence of two different types of active sites on the electrode surface catalyzing the reaction. Electrochemical impedance spectroscopy (EIS) analyses in the presence of [Fe(CN)6]3−/4− as a redox probe revealed that the GC/SWCNT + CoPc showed much lower electron-resistance (Ret) confirming the synergistic effect of the composite mentioned above. Atomic force microscopy (AFM) images showed the clear differences in surface roughness for each film, confirming the different compositions of the hybrid electrodes used in this study.
- Full Text:
- Date Issued: 2008
- Authors: Geraldo, Daniela A , Togo, Chamunorwa A , Limson, Janice L , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265963 , vital:53904 , xlink:href="https://doi.org/10.1016/j.electacta.2008.05.083"
- Description: We report on the electrooxidation of hydrazine catalyzed by single-walled carbon nanotube (SWCNT) functionalized with cobalt phthalocyanine (CoPc) which shows that the presence of the single-walled carbon nanotubes enhances the catalytic activity of the CoPc itself without any change in the reaction mechanism. A synergistic effect, in terms of reactivity when the new nanocomposite material was adsorbed on the GC electrode, was observed. The obtained hybrid electrodes were tested under hydrodynamic conditions, showing two different oxidation processes, which suggest the presence of two different types of active sites on the electrode surface catalyzing the reaction. Electrochemical impedance spectroscopy (EIS) analyses in the presence of [Fe(CN)6]3−/4− as a redox probe revealed that the GC/SWCNT + CoPc showed much lower electron-resistance (Ret) confirming the synergistic effect of the composite mentioned above. Atomic force microscopy (AFM) images showed the clear differences in surface roughness for each film, confirming the different compositions of the hybrid electrodes used in this study.
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- Date Issued: 2008
Employee performance, leadership style and emotional intelligence
- Hayward, Brett A, Amos, Trevor L, Baxter, Jeremy
- Authors: Hayward, Brett A , Amos, Trevor L , Baxter, Jeremy
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270077 , vital:54393 , xlink:href="https://hdl.handle.net/10520/EJC17031"
- Description: Purpose: The purpose of this research is to explore the relationship between employee performance, leadership style and emotional intelligence in the context of a South African parastatal. Problem Investigated: There is a lack of literature and empirical research on the type of leadership required to achieve high levels of employee performance within South African parastatals. Methodology: The Multifactor Leadership Questionnaire (MLQ) was used to determine leadership style, while the Emotional Competency Profiler (ECP) was used to determine the emotional intelligence of the sample of leaders. Employee performance data was provided by the parastatal, based on their performance management system. Data was analysed using correlation analysis, multiple regression analysis, the standard regression ANOVA/F-test, t-tests and Cronbach alpha reliability coefficient. Findings: The findings of the research show that the ECP is a reliable measure of emotional intelligence and that while the MLQ is a reliable measure of transformational leadership, it is not a reliable measure of transactional leadership. The results of the correlation analysis show a positive significant relationship between emotional intelligence and transformational leadership and a negative significant relationship between employee performance and emotional intelligence. The results of regressing employee performance on emotional intelligence and transformational leadership show that emotional intelligence and transformational leadership have no significant effect on employee performance. The results of the regression models of the research could be biased by the lack of variance in employee performance data. Value of the Research: The value of the research lies in it confirming the MLQ as a reliable measure of transformational leadership and the ECP as a reliable measure of emotional intelligence. The finding of a positive significant relationship between emotional intelligence and transformational leadership is a valuable contribution to the literature. Conclusion: Although a positive significant relationship between emotional intelligence and transformational leadership was found, there is a need for further research to determine the type of leadership best suited to achieve high levels of employee performance within the parastatal.
- Full Text:
- Date Issued: 2008
- Authors: Hayward, Brett A , Amos, Trevor L , Baxter, Jeremy
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270077 , vital:54393 , xlink:href="https://hdl.handle.net/10520/EJC17031"
- Description: Purpose: The purpose of this research is to explore the relationship between employee performance, leadership style and emotional intelligence in the context of a South African parastatal. Problem Investigated: There is a lack of literature and empirical research on the type of leadership required to achieve high levels of employee performance within South African parastatals. Methodology: The Multifactor Leadership Questionnaire (MLQ) was used to determine leadership style, while the Emotional Competency Profiler (ECP) was used to determine the emotional intelligence of the sample of leaders. Employee performance data was provided by the parastatal, based on their performance management system. Data was analysed using correlation analysis, multiple regression analysis, the standard regression ANOVA/F-test, t-tests and Cronbach alpha reliability coefficient. Findings: The findings of the research show that the ECP is a reliable measure of emotional intelligence and that while the MLQ is a reliable measure of transformational leadership, it is not a reliable measure of transactional leadership. The results of the correlation analysis show a positive significant relationship between emotional intelligence and transformational leadership and a negative significant relationship between employee performance and emotional intelligence. The results of regressing employee performance on emotional intelligence and transformational leadership show that emotional intelligence and transformational leadership have no significant effect on employee performance. The results of the regression models of the research could be biased by the lack of variance in employee performance data. Value of the Research: The value of the research lies in it confirming the MLQ as a reliable measure of transformational leadership and the ECP as a reliable measure of emotional intelligence. The finding of a positive significant relationship between emotional intelligence and transformational leadership is a valuable contribution to the literature. Conclusion: Although a positive significant relationship between emotional intelligence and transformational leadership was found, there is a need for further research to determine the type of leadership best suited to achieve high levels of employee performance within the parastatal.
- Full Text:
- Date Issued: 2008