South Africa's chemical and biological warfare programme 1981-1995
- Authors: Gould, Chandré
- Date: 2006
- Subjects: Basson, Wouter, 1950- Basson, Wouter, 1950 -- Trials, litigation, etc Biological warfare -- South Africa Chemical warfare -- South Africa Trials (Political crimes and offenses) -- South Africa South Africa -- Politics and government -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2544 , http://hdl.handle.net/10962/d1002396
- Description: In 1981 the apartheid military initiated a chemical and biological warfare (CBW) programme (code-named Project Coast). The programme, terminated in 1993, was aimed at developing novel irritating and incapacitating agents for internal and external use, covert assassination weapons for use against apartheid opponents, and defensive equipment for use by South African Defence Force (SADF) troops in Angola. The CBW programme was driven by a single individual, Dr Wouter Basson, who reported to a military management committee (the Co-ordinating Management Committee) which comprised a select group of high ranking officers. Practical and financial oversight of the programme was weak which allowed both for the abuse of programme funds and for senior military officers to deny knowledge of aspects of the programme. The biological component of Project Coast was conducted in violation of the commitments of the South African government to the Biological and Toxins Weapons Convention (BTWC). While the state’s commitment to the BTWC was one of the factors considered when initiating the programme, it was not a sufficient constraint to prevent the development of the biological weapons programme, but rather influenced its structure such that the programme could avoid national and international detection. Despite efforts to conceal the military front companies where the chemical and biological warfare (CBW) research and development was undertaken, evidence presented in this thesis shows that the United States had sufficient information about the programme to have been aware of its existence. Yet, it was only in 1993, on the eve of the democratic election in South Africa, that any attempt was made by the US administration to pressure the government to terminate the programme. This thesis considers the factors which influenced the decision to develop Project Coast; the structure and nature of the programme; the motivations of scientists to become involved in the programme and remain involved; the use of chemical and biological agents against opponents of the state, and the factors which influenced the termination of the programme on the eve of the first democratic elections in 1994. It also considers the nature and exent of international support, both tacit and overt, for the programme and argues that the failure of Western nations to call for the termination of the programme before the early 1990s was a function of political expediency and indicates a significant weakness in the ability of international agreements to constrain the development of such programmes.
- Full Text:
- Authors: Gould, Chandré
- Date: 2006
- Subjects: Basson, Wouter, 1950- Basson, Wouter, 1950 -- Trials, litigation, etc Biological warfare -- South Africa Chemical warfare -- South Africa Trials (Political crimes and offenses) -- South Africa South Africa -- Politics and government -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2544 , http://hdl.handle.net/10962/d1002396
- Description: In 1981 the apartheid military initiated a chemical and biological warfare (CBW) programme (code-named Project Coast). The programme, terminated in 1993, was aimed at developing novel irritating and incapacitating agents for internal and external use, covert assassination weapons for use against apartheid opponents, and defensive equipment for use by South African Defence Force (SADF) troops in Angola. The CBW programme was driven by a single individual, Dr Wouter Basson, who reported to a military management committee (the Co-ordinating Management Committee) which comprised a select group of high ranking officers. Practical and financial oversight of the programme was weak which allowed both for the abuse of programme funds and for senior military officers to deny knowledge of aspects of the programme. The biological component of Project Coast was conducted in violation of the commitments of the South African government to the Biological and Toxins Weapons Convention (BTWC). While the state’s commitment to the BTWC was one of the factors considered when initiating the programme, it was not a sufficient constraint to prevent the development of the biological weapons programme, but rather influenced its structure such that the programme could avoid national and international detection. Despite efforts to conceal the military front companies where the chemical and biological warfare (CBW) research and development was undertaken, evidence presented in this thesis shows that the United States had sufficient information about the programme to have been aware of its existence. Yet, it was only in 1993, on the eve of the democratic election in South Africa, that any attempt was made by the US administration to pressure the government to terminate the programme. This thesis considers the factors which influenced the decision to develop Project Coast; the structure and nature of the programme; the motivations of scientists to become involved in the programme and remain involved; the use of chemical and biological agents against opponents of the state, and the factors which influenced the termination of the programme on the eve of the first democratic elections in 1994. It also considers the nature and exent of international support, both tacit and overt, for the programme and argues that the failure of Western nations to call for the termination of the programme before the early 1990s was a function of political expediency and indicates a significant weakness in the ability of international agreements to constrain the development of such programmes.
- Full Text:
Spatio-temporal patterns in maturation of the chokka squid (Loligo vulgaris reynaudii) off the coast of South Africa
- Olyott, L J H, Sauer, Warwick H H, Booth, Anthony J
- Authors: Olyott, L J H , Sauer, Warwick H H , Booth, Anthony J
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6763 , http://hdl.handle.net/10962/d1007930
- Description: Knowledge of the temporal and spatial characteristics of chokka squid (Loligo vulgaris reynaudii) biology in South African waters is limited, so the possibility of there being a geographically fragmented stock was examined by investigating the distribution of maturity patterns for the species, covering all known spawning areas and using both historical and recent data. Gonadosomatic indices (GSI) varied between year-round consistency and apparent seasonal peaks in both summer and winter; there was no clear spatial pattern. Monthly percentage maturity provided further evidence for two peak reproductive periods each year, although mature squid were present throughout. Sex ratios demonstrated great variability between different areas and life history stages. Male-biased sex ratios were only apparent on the inshore spawning grounds and ranged between 1.118:1 and 4.267:1. Size at sexual maturity was also seasonal, squid maturing smaller in winter/spring than in summer/autumn. Also, squid in the east matured smaller than squid in the west. Although the results from the present study do not provide conclusive evidence of distinct geographic populations, squid likely spawn over a significantly larger area of the Agulhas Bank than previously estimated, and squid on the west coast of South Africa may return to spawn on the western portion of the Agulhas Bank. It remains likely, however, that the east and west coast populations are a single stock and that migration of juveniles to the west coast and their subsequent return as sub-adults is an integral but non-essential and variable part of the life history.
- Full Text:
- Authors: Olyott, L J H , Sauer, Warwick H H , Booth, Anthony J
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6763 , http://hdl.handle.net/10962/d1007930
- Description: Knowledge of the temporal and spatial characteristics of chokka squid (Loligo vulgaris reynaudii) biology in South African waters is limited, so the possibility of there being a geographically fragmented stock was examined by investigating the distribution of maturity patterns for the species, covering all known spawning areas and using both historical and recent data. Gonadosomatic indices (GSI) varied between year-round consistency and apparent seasonal peaks in both summer and winter; there was no clear spatial pattern. Monthly percentage maturity provided further evidence for two peak reproductive periods each year, although mature squid were present throughout. Sex ratios demonstrated great variability between different areas and life history stages. Male-biased sex ratios were only apparent on the inshore spawning grounds and ranged between 1.118:1 and 4.267:1. Size at sexual maturity was also seasonal, squid maturing smaller in winter/spring than in summer/autumn. Also, squid in the east matured smaller than squid in the west. Although the results from the present study do not provide conclusive evidence of distinct geographic populations, squid likely spawn over a significantly larger area of the Agulhas Bank than previously estimated, and squid on the west coast of South Africa may return to spawn on the western portion of the Agulhas Bank. It remains likely, however, that the east and west coast populations are a single stock and that migration of juveniles to the west coast and their subsequent return as sub-adults is an integral but non-essential and variable part of the life history.
- Full Text:
Spatio-temporal variability of larval abundance and settlement of Perna perna: differential delivery of mussels
- Porri, Francesca, McQuaid, Christopher D, Radloff, Sarah E
- Authors: Porri, Francesca , McQuaid, Christopher D , Radloff, Sarah E
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6877 , http://hdl.handle.net/10962/d1011625 , http://dx.doi.org/10.3354/meps315141
- Description: We examined larval availability and settlement of the intertidal mussel Perna perna simultaneously at different spatial and temporal scales using a nested design at 2 sites, 3 km apart on the south coast of South Africa. Each site had 3 locations (300 m apart) where 5 artificial settler collectors were placed about 20 cm apart. Collectors were replaced on temporal scales varying from fortnightly (for 16 mo) to daily (2 series of 15 to 20 d). Each intertidal location was paired with an inshore location (these too were 300 m apart) within 500 m of the shore, where larval availability was measured by 3 vertical plankton hauls collected on the same dates as for settler sampling. There was strong temporal variation in abundances of larvae and settlers, and no correlation (r always < 0.14) was found between the two. Larvae were abundant only at the start of sampling and rare for the rest of the study, while distinct peaks in settler numbers occurred later. No spatial effect was detected for larval availability, while there was strong spatial variation in settlement at the location level. These results indicate that, on scales of 100s of m to km, delivery of larvae from the nearshore water column onto the shore is strongly differential, with some locations consistently receiving more settlers than others. We conclude that, at these sites, the patchiness in settlement observed on scales of 100s of m depends on differential delivery, rather than differential offshore distribution of larvae. We suggest that differential delivery is due to the effect of nearshore bottom topography on local hydrodynamics.
- Full Text:
- Authors: Porri, Francesca , McQuaid, Christopher D , Radloff, Sarah E
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6877 , http://hdl.handle.net/10962/d1011625 , http://dx.doi.org/10.3354/meps315141
- Description: We examined larval availability and settlement of the intertidal mussel Perna perna simultaneously at different spatial and temporal scales using a nested design at 2 sites, 3 km apart on the south coast of South Africa. Each site had 3 locations (300 m apart) where 5 artificial settler collectors were placed about 20 cm apart. Collectors were replaced on temporal scales varying from fortnightly (for 16 mo) to daily (2 series of 15 to 20 d). Each intertidal location was paired with an inshore location (these too were 300 m apart) within 500 m of the shore, where larval availability was measured by 3 vertical plankton hauls collected on the same dates as for settler sampling. There was strong temporal variation in abundances of larvae and settlers, and no correlation (r always < 0.14) was found between the two. Larvae were abundant only at the start of sampling and rare for the rest of the study, while distinct peaks in settler numbers occurred later. No spatial effect was detected for larval availability, while there was strong spatial variation in settlement at the location level. These results indicate that, on scales of 100s of m to km, delivery of larvae from the nearshore water column onto the shore is strongly differential, with some locations consistently receiving more settlers than others. We conclude that, at these sites, the patchiness in settlement observed on scales of 100s of m depends on differential delivery, rather than differential offshore distribution of larvae. We suggest that differential delivery is due to the effect of nearshore bottom topography on local hydrodynamics.
- Full Text:
Sperm morphology in five species of cicadettine cicadas (Hemiptera: Cicadomorpha: Cicadidae)
- Chawanji, A S, Hodgson, Alan N, Villet, Martin H
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6930 , http://hdl.handle.net/10962/d1011948
- Description: Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species.
- Full Text:
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6930 , http://hdl.handle.net/10962/d1011948
- Description: Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species.
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Spotlight on research: 50 years of Pharmaceutical Sciences Research Excellence Faculty of Pharmacy Rhodes University
- Authors: Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184243 , vital:44193 , xlink:href="https://hdl.handle.net/10520/EJC81478"
- Description: This year, the Faculty of Pharmacy at Rhodes University is celebrating its 50th Anniversary. Over 2000 BPharm, 33 BSc honours, 65 MSc and 27 PhD degrees have been conferred since the Faculty’s inception. The diverse research activities and dedicated academic staff have ensured that the Faculty of Pharmacy has high visibility with respect to research outputs, as is evidenced by the appointment of various members of staff to national and international research, regulatory and professional committees, as well as to serving on the editorial boards of a number of international journals. In addition, staff regularly publish in international and local peer-reviewed journals and present their research findings at international and local conferences.
- Full Text:
- Authors: Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184243 , vital:44193 , xlink:href="https://hdl.handle.net/10520/EJC81478"
- Description: This year, the Faculty of Pharmacy at Rhodes University is celebrating its 50th Anniversary. Over 2000 BPharm, 33 BSc honours, 65 MSc and 27 PhD degrees have been conferred since the Faculty’s inception. The diverse research activities and dedicated academic staff have ensured that the Faculty of Pharmacy has high visibility with respect to research outputs, as is evidenced by the appointment of various members of staff to national and international research, regulatory and professional committees, as well as to serving on the editorial boards of a number of international journals. In addition, staff regularly publish in international and local peer-reviewed journals and present their research findings at international and local conferences.
- Full Text:
Stakeholders' perceptions of the cluster system in a secondary school in Rundu, Namibia
- Authors: Topnaar, P E
- Date: 2006
- Subjects: School management and organization -- Namibia -- Rundu Education -- Namibia -- Rundu Educational leadership -- Namibia -- Rundu Educational change -- Namibia -- Rundu
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1853 , http://hdl.handle.net/10962/d1004516
- Description: Since independence in 1990, various efforts have been made to improve the quality and management of Namibian schools, including the Basic Education Project (BEP-Project). In collaboration with the Geselschaft fur Technische Zusammenarbeit (GTZ), the BEP-Project has supported the implementation of important Government programs, such as Lower Primary reform and the cluster system. In 1995 the BEP-Project began to address educational needs in the Rundu education region. It was believed that Rundu had in the past been the most neglected region, especially with regard to education. The school cluster system was devised to facilitate new ways of education service delivery and to address the question of improving education standards. The purpose of this research is to answer the question: "How do the management and staff of a secondary school in the Rundu region of education experience a school cluster system?" To this end, the research seeks to determine what potential the cluster system holds and how that may be realised, and to also establish whether there is any evidence of change in management practices. A case study method has been employed to gain insight into the cluster system as a management tool. Ten respondents, all of whom have been employed at the school in question for a considerable period of time, were interviewed before and after the implementation of the cluster system. The research disclosed that disparities and tension in the school were legacies of the colonial education system, but that the cluster system had bridged the gap and enhanced uniformity and cooperation. Sharing of ideas on educational issues and constant interaction created a conducive environment for academic performance. The case study further disclosed that parental involvement in decision making is still a course for concern and that the cluster system has not yet addressed this issue. The study has shown that decentralisation has taken place and that rural schools are no longer operating in isolation. A lack of innovative ideas has hampered training as a cluster activity. From the research, it is evident that schools have previously operated on an individual basis, but that the cluster system has created the opportunity for schools to interact on a regular basis. This study is timely and of national importance. I anticipate that this study will be of use to policy makers in making decisions for the future development of the cluster system.
- Full Text:
- Authors: Topnaar, P E
- Date: 2006
- Subjects: School management and organization -- Namibia -- Rundu Education -- Namibia -- Rundu Educational leadership -- Namibia -- Rundu Educational change -- Namibia -- Rundu
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1853 , http://hdl.handle.net/10962/d1004516
- Description: Since independence in 1990, various efforts have been made to improve the quality and management of Namibian schools, including the Basic Education Project (BEP-Project). In collaboration with the Geselschaft fur Technische Zusammenarbeit (GTZ), the BEP-Project has supported the implementation of important Government programs, such as Lower Primary reform and the cluster system. In 1995 the BEP-Project began to address educational needs in the Rundu education region. It was believed that Rundu had in the past been the most neglected region, especially with regard to education. The school cluster system was devised to facilitate new ways of education service delivery and to address the question of improving education standards. The purpose of this research is to answer the question: "How do the management and staff of a secondary school in the Rundu region of education experience a school cluster system?" To this end, the research seeks to determine what potential the cluster system holds and how that may be realised, and to also establish whether there is any evidence of change in management practices. A case study method has been employed to gain insight into the cluster system as a management tool. Ten respondents, all of whom have been employed at the school in question for a considerable period of time, were interviewed before and after the implementation of the cluster system. The research disclosed that disparities and tension in the school were legacies of the colonial education system, but that the cluster system had bridged the gap and enhanced uniformity and cooperation. Sharing of ideas on educational issues and constant interaction created a conducive environment for academic performance. The case study further disclosed that parental involvement in decision making is still a course for concern and that the cluster system has not yet addressed this issue. The study has shown that decentralisation has taken place and that rural schools are no longer operating in isolation. A lack of innovative ideas has hampered training as a cluster activity. From the research, it is evident that schools have previously operated on an individual basis, but that the cluster system has created the opportunity for schools to interact on a regular basis. This study is timely and of national importance. I anticipate that this study will be of use to policy makers in making decisions for the future development of the cluster system.
- Full Text:
Stirring the hornet's nest: women's citizenship and childcare in post-apartheid South Africa
- Authors: Alfers, Laura Corrigall
- Date: 2006
- Subjects: Women's rights -- South Africa , Citizenship -- South Africa , Women -- Political activity , Feminist theory -- Political aspects , Child care -- South Africa , Sex discrimination against women
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2757 , http://hdl.handle.net/10962/d1002967 , Women's rights -- South Africa , Citizenship -- South Africa , Women -- Political activity , Feminist theory -- Political aspects , Child care -- South Africa , Sex discrimination against women
- Description: It is a widely acknowledged fact that women’s access to the full rights of citizenship in the liberal state is restricted because of their unequal responsibility for childcare. The South African state, however, despite its theoretical commitment to gender equality, has failed substantially to engage with the issue of childcare and women’s citizenship. This is problematic because in failing to envisage a role for itself in supporting women with their responsibility for childcare, the state has not only neglected its Constitutional commitments to gender equality, but it has also failed to realise the benefits that could potentially accrue to children if women’s access to economic citizenship is not hampered by childcare. Recognising this problem, this thesis attempts to engender some debate as to how the South African state could feasibly correct this failure. In doing so, it uses feminist political theory as a basis and takes a critical view of the two childcare policies that have dominated the debate over women’s citizenship and childcare in Western liberal democracies – socialised care and the neofamilialist model. In concluding it attempts to provide an idea of what feasible, state-based childcare policies could look like in present-day South Africa.
- Full Text:
- Authors: Alfers, Laura Corrigall
- Date: 2006
- Subjects: Women's rights -- South Africa , Citizenship -- South Africa , Women -- Political activity , Feminist theory -- Political aspects , Child care -- South Africa , Sex discrimination against women
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2757 , http://hdl.handle.net/10962/d1002967 , Women's rights -- South Africa , Citizenship -- South Africa , Women -- Political activity , Feminist theory -- Political aspects , Child care -- South Africa , Sex discrimination against women
- Description: It is a widely acknowledged fact that women’s access to the full rights of citizenship in the liberal state is restricted because of their unequal responsibility for childcare. The South African state, however, despite its theoretical commitment to gender equality, has failed substantially to engage with the issue of childcare and women’s citizenship. This is problematic because in failing to envisage a role for itself in supporting women with their responsibility for childcare, the state has not only neglected its Constitutional commitments to gender equality, but it has also failed to realise the benefits that could potentially accrue to children if women’s access to economic citizenship is not hampered by childcare. Recognising this problem, this thesis attempts to engender some debate as to how the South African state could feasibly correct this failure. In doing so, it uses feminist political theory as a basis and takes a critical view of the two childcare policies that have dominated the debate over women’s citizenship and childcare in Western liberal democracies – socialised care and the neofamilialist model. In concluding it attempts to provide an idea of what feasible, state-based childcare policies could look like in present-day South Africa.
- Full Text:
Structure and distribution of the slope fish community in the vicinity of the sub-Antarctic Prince Edward Archipelago
- Pakhomov, Evgeny A, Bushula, T, Kaehler, Sven, Watkins, B P, Leslie, Rob W
- Authors: Pakhomov, Evgeny A , Bushula, T , Kaehler, Sven , Watkins, B P , Leslie, Rob W
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6958 , http://hdl.handle.net/10962/d1012000
- Description: Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200–1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1•1 to 241•2 individuals h 1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500–600 m and 800–900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso- and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub-Antarctic primary production, organic matter sources at the base of deep-sea food webs.
- Full Text:
- Authors: Pakhomov, Evgeny A , Bushula, T , Kaehler, Sven , Watkins, B P , Leslie, Rob W
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6958 , http://hdl.handle.net/10962/d1012000
- Description: Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200–1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1•1 to 241•2 individuals h 1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500–600 m and 800–900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso- and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub-Antarctic primary production, organic matter sources at the base of deep-sea food webs.
- Full Text:
Studies of equivalent fuzzy subgroups of finite abelian p-Groups of rank two and their subgroup lattices
- Authors: Ngcibi, Sakhile Leonard
- Date: 2006
- Subjects: Abelian groups Fuzzy sets Finite groups Group theory Polynomials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5416 , http://hdl.handle.net/10962/d1005230
- Description: We determine the number and nature of distinct equivalence classes of fuzzy subgroups of finite Abelian p-group G of rank two under a natural equivalence relation on fuzzy subgroups. Our discussions embrace the necessary theory from groups with special emphasis on finite p-groups as a step towards the classification of crisp subgroups as well as maximal chains of subgroups. Unique naming of subgroup generators as discussed in this work facilitates counting of subgroups and chains of subgroups from subgroup lattices of the groups. We cover aspects of fuzzy theory including fuzzy (homo-) isomorphism together with operations on fuzzy subgroups. The equivalence characterization as discussed here is finer than isomorphism. We introduce the theory of keychains with a view towards the enumeration of maximal chains as well as fuzzy subgroups under the equivalence relation mentioned above. We discuss a strategy to develop subgroup lattices of the groups used in the discussion, and give examples for specific cases of prime p and positive integers n,m. We derive formulas for both the number of maximal chains as well as the number of distinct equivalence classes of fuzzy subgroups. The results are in the form of polynomials in p (known in the literature as Hall polynomials) with combinatorial coefficients. Finally we give a brief investigation of the results from a graph-theoretic point of view. We view the subgroup lattices of these groups as simple, connected, symmetric graphs.
- Full Text:
- Authors: Ngcibi, Sakhile Leonard
- Date: 2006
- Subjects: Abelian groups Fuzzy sets Finite groups Group theory Polynomials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5416 , http://hdl.handle.net/10962/d1005230
- Description: We determine the number and nature of distinct equivalence classes of fuzzy subgroups of finite Abelian p-group G of rank two under a natural equivalence relation on fuzzy subgroups. Our discussions embrace the necessary theory from groups with special emphasis on finite p-groups as a step towards the classification of crisp subgroups as well as maximal chains of subgroups. Unique naming of subgroup generators as discussed in this work facilitates counting of subgroups and chains of subgroups from subgroup lattices of the groups. We cover aspects of fuzzy theory including fuzzy (homo-) isomorphism together with operations on fuzzy subgroups. The equivalence characterization as discussed here is finer than isomorphism. We introduce the theory of keychains with a view towards the enumeration of maximal chains as well as fuzzy subgroups under the equivalence relation mentioned above. We discuss a strategy to develop subgroup lattices of the groups used in the discussion, and give examples for specific cases of prime p and positive integers n,m. We derive formulas for both the number of maximal chains as well as the number of distinct equivalence classes of fuzzy subgroups. The results are in the form of polynomials in p (known in the literature as Hall polynomials) with combinatorial coefficients. Finally we give a brief investigation of the results from a graph-theoretic point of view. We view the subgroup lattices of these groups as simple, connected, symmetric graphs.
- Full Text:
Study South Africa
- International Education Association of South Africa (IEASA), Higher Education South Africa (Organization), Kishun, Roshen
- Authors: International Education Association of South Africa (IEASA) , Higher Education South Africa (Organization) , Kishun, Roshen
- Date: 2006
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65386 , vital:28754 , ISBN 0620367652
- Description: [Extract from message from Minister of Higher Education, Hon. Naledi Pandor]: It is a great pleasure for me to give a word of support to the sixth edition of Study South Africa: The Guide to South African Higher Education. I am particularly pleased with the effort and level of commitment shown by the International Education Association of South Africa (IEASA) in promoting South African higher education institutions internationally. The internationalisation of our higher education system is an acknowledgement that South African universities have a valuable contribution to make to the global higher education community, and in particular on the African continent. In this regard, I am pleased to note that of the 52,000 international students enrolled in our institutions, the majority come from the African continent. South Africa's higher education institutions offer unique benefits for international students, blending the experience of living in Africa with the opportunity to obtain internationally recognised qualifications at reasonably affordable costs. Also, high quality educational infrastructure, unique research opportunities, and a rich variety of cultures make South Africa one of the favourable study destinations for many international students. More than ever before our institutions are working hard to ensure that they provide high quality education, comparable to the best in the world. Our institutions continue to strive towards excellence and also to encourage international students, particularly those from Africa, upon completion of their studies to go back and make valuable contributions to the socio-economic development of their home countries. IEASA, Higher Education South Africa (HESA) and our universities have played a valuable role in reinforcing South Africa's international relations in academic and research exchange programmes. The Ministry would like to take this opportunity to commend IEASA and HESA for the dedicated efforts and targeted interventions made towards achieving our national priorities. , 6th Edition
- Full Text:
- Authors: International Education Association of South Africa (IEASA) , Higher Education South Africa (Organization) , Kishun, Roshen
- Date: 2006
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65386 , vital:28754 , ISBN 0620367652
- Description: [Extract from message from Minister of Higher Education, Hon. Naledi Pandor]: It is a great pleasure for me to give a word of support to the sixth edition of Study South Africa: The Guide to South African Higher Education. I am particularly pleased with the effort and level of commitment shown by the International Education Association of South Africa (IEASA) in promoting South African higher education institutions internationally. The internationalisation of our higher education system is an acknowledgement that South African universities have a valuable contribution to make to the global higher education community, and in particular on the African continent. In this regard, I am pleased to note that of the 52,000 international students enrolled in our institutions, the majority come from the African continent. South Africa's higher education institutions offer unique benefits for international students, blending the experience of living in Africa with the opportunity to obtain internationally recognised qualifications at reasonably affordable costs. Also, high quality educational infrastructure, unique research opportunities, and a rich variety of cultures make South Africa one of the favourable study destinations for many international students. More than ever before our institutions are working hard to ensure that they provide high quality education, comparable to the best in the world. Our institutions continue to strive towards excellence and also to encourage international students, particularly those from Africa, upon completion of their studies to go back and make valuable contributions to the socio-economic development of their home countries. IEASA, Higher Education South Africa (HESA) and our universities have played a valuable role in reinforcing South Africa's international relations in academic and research exchange programmes. The Ministry would like to take this opportunity to commend IEASA and HESA for the dedicated efforts and targeted interventions made towards achieving our national priorities. , 6th Edition
- Full Text:
Substituted phthalocyanines development and self-assembled monolayer sensor studies
- Authors: Matemadombo, Fungisai
- Date: 2006
- Subjects: Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4364 , http://hdl.handle.net/10962/d1005029 , Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Description: Zinc, cobalt and iron phenylthio substituted phthalocyanines have been synthesized and characterized. Cyclic and square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes respectively for the cobalt and iron phenylthio substituted phthalocyanines. These complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe(I)Pc for reduction of iron phenylthio substituted phthalocyanine and Co(I)Pc for the reduction of cobalt phenylthio substituted phthalocyanine. The spectrum of the former is particularly of importance since such species have not received much attention in literature. Cobalt and iron phenylthio substituted phthalocyanines have been deposited on Au electrode surfaces through the self assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of L-cysteine. Amine substituted cobalt phthalocyanine (CoTAPc) was deposited on gold surfaces by using an interconnecting SAM of mercaptopropionic acid or dithiobis(N-succinimidyl propionate) through the creation of an amide. Reductive and oxidative desorption of the SAMs limit the useful potential window. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. Both SAMs were highly stable and hence will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Authors: Matemadombo, Fungisai
- Date: 2006
- Subjects: Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4364 , http://hdl.handle.net/10962/d1005029 , Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Description: Zinc, cobalt and iron phenylthio substituted phthalocyanines have been synthesized and characterized. Cyclic and square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes respectively for the cobalt and iron phenylthio substituted phthalocyanines. These complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe(I)Pc for reduction of iron phenylthio substituted phthalocyanine and Co(I)Pc for the reduction of cobalt phenylthio substituted phthalocyanine. The spectrum of the former is particularly of importance since such species have not received much attention in literature. Cobalt and iron phenylthio substituted phthalocyanines have been deposited on Au electrode surfaces through the self assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of L-cysteine. Amine substituted cobalt phthalocyanine (CoTAPc) was deposited on gold surfaces by using an interconnecting SAM of mercaptopropionic acid or dithiobis(N-succinimidyl propionate) through the creation of an amide. Reductive and oxidative desorption of the SAMs limit the useful potential window. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. Both SAMs were highly stable and hence will be interesting tools for further research in surface modification and sensor development.
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Supplying lava eruptions in the Karoo Province, South Africa: a geochemical comparison of the volcanic sequence with intrusions in the main Karoo basin
- Marsh, Julian S, Mitha, Vindina R
- Authors: Marsh, Julian S , Mitha, Vindina R
- Date: 2006
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132873 , vital:36901
- Description: Magma supply for lava eruptions remains a poorly understood facet of continental flood volcanism. In the Karoo Province a vast complex of dolerite sheets and dykes is exposed in the main Karoo sedimentary basin underlying the flood basalt remnant of Lesotho (Drakensberg Group) suggesting that lavas were erupted locally from a widely distributed network of fissures.
- Full Text:
- Authors: Marsh, Julian S , Mitha, Vindina R
- Date: 2006
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132873 , vital:36901
- Description: Magma supply for lava eruptions remains a poorly understood facet of continental flood volcanism. In the Karoo Province a vast complex of dolerite sheets and dykes is exposed in the main Karoo sedimentary basin underlying the flood basalt remnant of Lesotho (Drakensberg Group) suggesting that lavas were erupted locally from a widely distributed network of fissures.
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Synthesis and electrochemical characterisation of benzylmercapto and dodecylmercapto tetra substituted cobalt, iron, and zinc phthalocyanines complexes
- Nyokong, Tebello, Ozoemena, Kenneth I, Agboola, Bolade O
- Authors: Nyokong, Tebello , Ozoemena, Kenneth I , Agboola, Bolade O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6580 , http://hdl.handle.net/10962/d1004143
- Description: The work reports on cyclic voltammetry (CV), square wave voltammetry and spectroelectrochemistry of the following complexes: tetrakis (benzyl mercapto) phthalocyanine complexes of Zn(II) (ZnTBMPc, 4a ), Co(II) (CoTBMPc, 5a ), Fe(II) (FeTBMPc 6a ); and tetrakis (dodecylmercapto) phthalocyanine complexes of Zn(II) (ZnTDMPc, 4b), Co(II) (CoTDMPc, 5b) and Fe(II) (FeTDMPc, 6b). More reversible CV couples were observed for complexes 4a, 5a and 6a containing thiol phenyl ring substituents. Complexes 4b, 5b and 6b containing long chain thiol substituents showed less reversible couples. Complexes 6a and 6b showed a relatively large number of redox processes (5 for 6a and 6 for 6b) within the potential window employed in this work. The processes for FePc derivatives (6a) are assigned to FeIIIPc-1/FeIIIPc-2, FeIIIPc-2/FeIIPc-2, FeIIPc-2/FeIPc-2, FeIPc-2/FeIPc-3 and FeIPc-3/FeIPc-4 and for the CoPc derivative (5a) to CoIIIPc-1/CoIIIPc-2, CoIIIPc-2/CoIIPc-2, CoIIPc-2/CoIPc-2 and CoIPc-2/CoIPc-3.
- Full Text:
- Authors: Nyokong, Tebello , Ozoemena, Kenneth I , Agboola, Bolade O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6580 , http://hdl.handle.net/10962/d1004143
- Description: The work reports on cyclic voltammetry (CV), square wave voltammetry and spectroelectrochemistry of the following complexes: tetrakis (benzyl mercapto) phthalocyanine complexes of Zn(II) (ZnTBMPc, 4a ), Co(II) (CoTBMPc, 5a ), Fe(II) (FeTBMPc 6a ); and tetrakis (dodecylmercapto) phthalocyanine complexes of Zn(II) (ZnTDMPc, 4b), Co(II) (CoTDMPc, 5b) and Fe(II) (FeTDMPc, 6b). More reversible CV couples were observed for complexes 4a, 5a and 6a containing thiol phenyl ring substituents. Complexes 4b, 5b and 6b containing long chain thiol substituents showed less reversible couples. Complexes 6a and 6b showed a relatively large number of redox processes (5 for 6a and 6 for 6b) within the potential window employed in this work. The processes for FePc derivatives (6a) are assigned to FeIIIPc-1/FeIIIPc-2, FeIIIPc-2/FeIIPc-2, FeIIPc-2/FeIPc-2, FeIPc-2/FeIPc-3 and FeIPc-3/FeIPc-4 and for the CoPc derivative (5a) to CoIIIPc-1/CoIIIPc-2, CoIIIPc-2/CoIIPc-2, CoIIPc-2/CoIPc-2 and CoIPc-2/CoIPc-3.
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Synthesis and electrochemical characterisation of α-and β-tetra-substituted oxo (phthalocyaninato) titanium (IV) complexes
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283869 , vital:55998 , xlink:href="https://doi.org/10.1016/j.poly.2005.11.025"
- Description: The synthesis, spectroscopic and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (5b); 2,(3)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (6b). Complexes 5a and 5b are substituted at the non-peripheral (α) positions, whereas complexes 6a and 6b are substituted at the peripheral (β) positions. Cyclic voltammograms of all four complexes are similar, with three reversible reduction couples and three quasi-reversible to irreversible oxidations. The first two reductions are two-electron processes, confirmed by spectroelectrochemistry to be due to TiIVPc−2/TiIIPc−3 and TiIIPc−2/TiIPc−3 redox processes. Spectroelectrochemistry showed that upon oxidation, the molecule decomposes. Oxidation is expected to occur at the ring. Chronocoulometry confirmed two electron transfer at the first and second reduction steps; and a one electron transfer at the third reduction.
- Full Text:
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283869 , vital:55998 , xlink:href="https://doi.org/10.1016/j.poly.2005.11.025"
- Description: The synthesis, spectroscopic and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (5b); 2,(3)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (6b). Complexes 5a and 5b are substituted at the non-peripheral (α) positions, whereas complexes 6a and 6b are substituted at the peripheral (β) positions. Cyclic voltammograms of all four complexes are similar, with three reversible reduction couples and three quasi-reversible to irreversible oxidations. The first two reductions are two-electron processes, confirmed by spectroelectrochemistry to be due to TiIVPc−2/TiIIPc−3 and TiIIPc−2/TiIPc−3 redox processes. Spectroelectrochemistry showed that upon oxidation, the molecule decomposes. Oxidation is expected to occur at the ring. Chronocoulometry confirmed two electron transfer at the first and second reduction steps; and a one electron transfer at the third reduction.
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Synthesis and photophysical properties of octa-substituted phthalocyaninato oxotitanium (IV) derivatives
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
- Full Text:
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
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Synthesis of triprenylated toluquinone and toluhydroquinone metabolites from a marine-derived Penicillium fungus
- Scheepers, Brent A, Klein, Rosalyn, Davies-Coleman, Michael T
- Authors: Scheepers, Brent A , Klein, Rosalyn , Davies-Coleman, Michael T
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6592 , http://hdl.handle.net/10962/d1004341
- Description: Two triprenylated toluquinone and toluhydroquinone marine fungal metabolites, 5-methyl-2-[(2′E,6′E)-3′,7′,11′-trimethyl-2′,6′,10′-dodecatrienyl]-2,5-cyclohexadiene-1,4-dione and 5-methyl-2-[(2′E,6′E)-3,7,11-trimethyl-2′,6′,10′-dodecatrienyl]-1,4-benzenediol, were synthesized in four and five steps, respectively, from 2-methyl-1,4-benzoquinone. The synthesis extends the applicability of the oxidative ether cleavage of hydroquinone dimethyl ethers with argentic oxide under acidic conditions to include the oxidative demethylation of polyprenylated-1,4-dimethoxy-toluhydroquinones with a quantitative survival of the oxidation- and acid-sensitive polyprenyl side chain. Graphical abstract: Marine fungal metabolites 1 and 2 were synthesized from 2-methyl-1,4-benzoquinone in four and five steps, respectively. [For graphic image see full-text version]
- Full Text:
- Authors: Scheepers, Brent A , Klein, Rosalyn , Davies-Coleman, Michael T
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6592 , http://hdl.handle.net/10962/d1004341
- Description: Two triprenylated toluquinone and toluhydroquinone marine fungal metabolites, 5-methyl-2-[(2′E,6′E)-3′,7′,11′-trimethyl-2′,6′,10′-dodecatrienyl]-2,5-cyclohexadiene-1,4-dione and 5-methyl-2-[(2′E,6′E)-3,7,11-trimethyl-2′,6′,10′-dodecatrienyl]-1,4-benzenediol, were synthesized in four and five steps, respectively, from 2-methyl-1,4-benzoquinone. The synthesis extends the applicability of the oxidative ether cleavage of hydroquinone dimethyl ethers with argentic oxide under acidic conditions to include the oxidative demethylation of polyprenylated-1,4-dimethoxy-toluhydroquinones with a quantitative survival of the oxidation- and acid-sensitive polyprenyl side chain. Graphical abstract: Marine fungal metabolites 1 and 2 were synthesized from 2-methyl-1,4-benzoquinone in four and five steps, respectively. [For graphic image see full-text version]
- Full Text:
Take Me to the River:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: isiXhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175339 , vital:42566 , ISBN 9781869285852
- Full Text:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: isiXhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175339 , vital:42566 , ISBN 9781869285852
- Full Text:
Teacher education for Mathematical Literacy: a modelling approach
- Brown, Bruce J L, Schäfer, Marc
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
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Teacher's beliefs regarding the role of extensive reading in English language learning : a case study
- Authors: Kajinga, Gilford
- Date: 2006
- Subjects: Reading Children -- Books and reading Bilingualism in children Education, Bilingual English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1793 , http://hdl.handle.net/10962/d1003678
- Description: Research suggests numerous views to account for the influence on practice of teachers’ beliefs. One view states that teachers’ lived experiences shape their beliefs about practice. Another view attributes the influence to school experiences. This research sets out to gain insight into teachers’ beliefs on the role of extensive reading in second language learning. A case study of 9 teachers from 3 schools in Grahamstown, South Africa selected purposefully and conveniently was utilised. The teachers were viewed to be knowledgeable on this matter by virtue of their profession while the 3 schools were selected to represent a private school, a former Model C and former Department of Education and Training (DET) school. Data was mainly collected by means of semi-structured interviews, which utilised in-depth open-ended questions to yield teachers’ past experiences. The findings revealed the following: all the teachers appeared to believe that extensive reading was invaluable and enhanced language skills. However, white and black teachers differed in terms of their early experiences of reading. Whereas for white teachers early experiences with literacy were encountered in the home, for black teachers the school was where they had their first exposure to literacy. In addition formal training in the form of an ACE (Advanced Certificate in Education) seemed to have influenced black teachers’ beliefs about the subject at hand, whereas the role of teacher education/ training was not as significant for white teachers.
- Full Text:
- Authors: Kajinga, Gilford
- Date: 2006
- Subjects: Reading Children -- Books and reading Bilingualism in children Education, Bilingual English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1793 , http://hdl.handle.net/10962/d1003678
- Description: Research suggests numerous views to account for the influence on practice of teachers’ beliefs. One view states that teachers’ lived experiences shape their beliefs about practice. Another view attributes the influence to school experiences. This research sets out to gain insight into teachers’ beliefs on the role of extensive reading in second language learning. A case study of 9 teachers from 3 schools in Grahamstown, South Africa selected purposefully and conveniently was utilised. The teachers were viewed to be knowledgeable on this matter by virtue of their profession while the 3 schools were selected to represent a private school, a former Model C and former Department of Education and Training (DET) school. Data was mainly collected by means of semi-structured interviews, which utilised in-depth open-ended questions to yield teachers’ past experiences. The findings revealed the following: all the teachers appeared to believe that extensive reading was invaluable and enhanced language skills. However, white and black teachers differed in terms of their early experiences of reading. Whereas for white teachers early experiences with literacy were encountered in the home, for black teachers the school was where they had their first exposure to literacy. In addition formal training in the form of an ACE (Advanced Certificate in Education) seemed to have influenced black teachers’ beliefs about the subject at hand, whereas the role of teacher education/ training was not as significant for white teachers.
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Teacher-community cooperation to promote sustainability of wetlands in Kenya
- Ndaruga, Ayub M, Irwin, Patrick R
- Authors: Ndaruga, Ayub M , Irwin, Patrick R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text:
- Authors: Ndaruga, Ayub M , Irwin, Patrick R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text: