Health, human rights, and the conduct of clinical research within oppressed populations
- Authors: Mills, E J , Singh, S
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6411 , http://hdl.handle.net/10962/d1006504 , http://dx.doi.org/10.1186/1744-8603-3-10
- Description: Background Clinical trials evaluating interventions for infectious diseases require enrolling participants that are vulnerable to infection. As clinical trials are conducted in increasingly vulnerable populations, issues of protection of these populations become challenging. In settings where populations are forseeably oppressed, the conduct of research requires considerations that go beyond common ethical concerns and into issues of international human rights law. Discussion Using examples of HIV prevention trials in Thailand, hepatitis-E prevention trials in Nepal and malaria therapeutic trials in Burma (Myanmar), we address the inadequacies of current ethical guidelines when conducting research within oppressed populations. We review existing legislature in the United States and United Kingdom that may be used against foreign investigators if trial hardships exist. We conclude by making considerations for research conducted within oppressed populations.
- Full Text:
- Authors: Mills, E J , Singh, S
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6411 , http://hdl.handle.net/10962/d1006504 , http://dx.doi.org/10.1186/1744-8603-3-10
- Description: Background Clinical trials evaluating interventions for infectious diseases require enrolling participants that are vulnerable to infection. As clinical trials are conducted in increasingly vulnerable populations, issues of protection of these populations become challenging. In settings where populations are forseeably oppressed, the conduct of research requires considerations that go beyond common ethical concerns and into issues of international human rights law. Discussion Using examples of HIV prevention trials in Thailand, hepatitis-E prevention trials in Nepal and malaria therapeutic trials in Burma (Myanmar), we address the inadequacies of current ethical guidelines when conducting research within oppressed populations. We review existing legislature in the United States and United Kingdom that may be used against foreign investigators if trial hardships exist. We conclude by making considerations for research conducted within oppressed populations.
- Full Text:
Hermeneutic and empirical analyses of graphically inspired metamathematics that reflect critical consciousness within perspectives of personal and social justice
- Authors: Van Jaarsveld, Pieter Paul
- Date: 2007
- Subjects: Mathematics -- Study and teaching -- South Africa Mathematics -- Study and teaching -- Social aspects -- South Africa Algorithms -- Study and teaching -- South Africa Critical pedagogy Metacognition Hermeneutics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1842 , http://hdl.handle.net/10962/d1004376
- Description: My involvement with mathematics education amongst township educators and learners over the past seven years has highlighted the absence of sustained meaning and meaning making of mathematical concepts. It appears though that this instrumental rather than relational understanding of FET mathematics is not unique to township learners but is encountered amongst learners of all socio-economic classes and is representative of many FET mathematics learners. Given that the language of learning and teaching is a major contributory factor in the South African education system, it appears that the language of mathematics itself is a greater exacerbating factor for many learners of mathematics. The exclusive algorithmic approach to classroom mathematics further seems to alienate many learners from the essence of the meaning of mathematical tasks. This research undertakes to determine whether metateaching and metalearning as forerunners to metacognition facilitates the acquisition of the sustained meaning of mathematical concepts. Metateaching and metalearning refer to the acute and deliberate awareness by educator and learner as to what constitutes concepts. Teaching and learning therefore presupposes the deconstruction of concepts into its subsumed derivative roots. It also assumes an awareness of the tacit degrees of abstraction that characterise tasks and the content of tasks. This in turn has implications for the educator's adopted sequence of topics for instruction. Metacognition implies awareness on the part of the learner (and educator) as to how material is learned and a further awareness as to how that learning can be sustained. Whether we ascribe meaningful learning to radical or social constructivism, or to associationist didactive approaches, or a combination of these, we are making assumptions about how learners acquire and sustain mathematical meaning because mathematics is, by and large a symbolic language often devoid of affective connotation. Furthermore our assessments of learners' tasks amount to clinical corrections of austere formulae wrapped in algorithmic procedures which manifest nothing of a learner's experience of mathematics or the deeper understanding (or misunderstandings) which characterise a learning and/or assessment episode. To this end the research design of this interpretive case study requires learners to expound in textual accounts their thoughts as they describe the evolution of a mathematical process as they approach a solution and eventually interpret it. The textual account exposes the concept definition for what it really is in a learner's understanding of it and it is the expressiveness of language that indicates whether the understanding of a learner is approaching the concept image. The textual accounts vary in richness in terms of mathematical register and this in turn reflects the conceptual depth. The mechanism which seems to promote the conversion from concept definition to concept image is the graphical representation of the mathematical task or procedure, possibly because of its greater concreteness as opposed to the abstraction of its algebraic form.
- Full Text:
- Authors: Van Jaarsveld, Pieter Paul
- Date: 2007
- Subjects: Mathematics -- Study and teaching -- South Africa Mathematics -- Study and teaching -- Social aspects -- South Africa Algorithms -- Study and teaching -- South Africa Critical pedagogy Metacognition Hermeneutics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1842 , http://hdl.handle.net/10962/d1004376
- Description: My involvement with mathematics education amongst township educators and learners over the past seven years has highlighted the absence of sustained meaning and meaning making of mathematical concepts. It appears though that this instrumental rather than relational understanding of FET mathematics is not unique to township learners but is encountered amongst learners of all socio-economic classes and is representative of many FET mathematics learners. Given that the language of learning and teaching is a major contributory factor in the South African education system, it appears that the language of mathematics itself is a greater exacerbating factor for many learners of mathematics. The exclusive algorithmic approach to classroom mathematics further seems to alienate many learners from the essence of the meaning of mathematical tasks. This research undertakes to determine whether metateaching and metalearning as forerunners to metacognition facilitates the acquisition of the sustained meaning of mathematical concepts. Metateaching and metalearning refer to the acute and deliberate awareness by educator and learner as to what constitutes concepts. Teaching and learning therefore presupposes the deconstruction of concepts into its subsumed derivative roots. It also assumes an awareness of the tacit degrees of abstraction that characterise tasks and the content of tasks. This in turn has implications for the educator's adopted sequence of topics for instruction. Metacognition implies awareness on the part of the learner (and educator) as to how material is learned and a further awareness as to how that learning can be sustained. Whether we ascribe meaningful learning to radical or social constructivism, or to associationist didactive approaches, or a combination of these, we are making assumptions about how learners acquire and sustain mathematical meaning because mathematics is, by and large a symbolic language often devoid of affective connotation. Furthermore our assessments of learners' tasks amount to clinical corrections of austere formulae wrapped in algorithmic procedures which manifest nothing of a learner's experience of mathematics or the deeper understanding (or misunderstandings) which characterise a learning and/or assessment episode. To this end the research design of this interpretive case study requires learners to expound in textual accounts their thoughts as they describe the evolution of a mathematical process as they approach a solution and eventually interpret it. The textual account exposes the concept definition for what it really is in a learner's understanding of it and it is the expressiveness of language that indicates whether the understanding of a learner is approaching the concept image. The textual accounts vary in richness in terms of mathematical register and this in turn reflects the conceptual depth. The mechanism which seems to promote the conversion from concept definition to concept image is the graphical representation of the mathematical task or procedure, possibly because of its greater concreteness as opposed to the abstraction of its algebraic form.
- Full Text:
Hermeneutics and memory in selected works by Willem Boshoff
- Authors: Tryon, Denzil Jordan
- Date: 2007
- Subjects: Boshoff, Willem, 1951- Hermeneutics Memory in art Art, Modern -- 20th century -- South Africa Installations (Art) -- South Africa
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2433 , http://hdl.handle.net/10962/d1004453
- Description: From Introduction: Willem Boshoff was born in Vereeniging, South Africa, in 1951. The son of a carpenter, Boshoff developed an early interest in art. Although never taught formally by his father, he nevertheless acquired a knowledge of the craft of carpentry, a skill which he continues to utilize in much of his art-making today. Boshoff studied at the Johannesburg College of Art, and obtained a Master's Diploma in Technology in Fine Art in 1984. He taught at that institution for twelve years, becoming a full-time art practitioner in 1996. He produced some significant works prior to and during the time of his teaching tenure, including his KykAfrikaans visual poetry in 1979-1980, Bangboek between 1977-1986, and the researching and writing of the Dictionary of Perplexing English in 1986 (ending in 1999). In this study I will discuss Willem Boshoff's careful employment of language and materials, througb which he propagates his "study of ignorance" (Williamson and Jamal 1996:148). I will investigate two major works by Boshoff, namely The Writing in the Sand and The Blind Alphabet in Chapters 1 and 2 respectively. Both of these installations are concerned fundamentally with the subversion of power relationships and elitism. As I will show, both works offer an opportunity to investigate their objectives in relation to discourses surrounding language and hermeneutics. My study includes a third chapter, in which I discuss my own work entitled The Bread of the Presence in relation to Boshoff's own methodologies. As will be demonstrated with particular reference to The Blind Alphabet and my own work, a discussion of memory proves to be of some relevance within this dialogue.
- Full Text:
- Authors: Tryon, Denzil Jordan
- Date: 2007
- Subjects: Boshoff, Willem, 1951- Hermeneutics Memory in art Art, Modern -- 20th century -- South Africa Installations (Art) -- South Africa
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2433 , http://hdl.handle.net/10962/d1004453
- Description: From Introduction: Willem Boshoff was born in Vereeniging, South Africa, in 1951. The son of a carpenter, Boshoff developed an early interest in art. Although never taught formally by his father, he nevertheless acquired a knowledge of the craft of carpentry, a skill which he continues to utilize in much of his art-making today. Boshoff studied at the Johannesburg College of Art, and obtained a Master's Diploma in Technology in Fine Art in 1984. He taught at that institution for twelve years, becoming a full-time art practitioner in 1996. He produced some significant works prior to and during the time of his teaching tenure, including his KykAfrikaans visual poetry in 1979-1980, Bangboek between 1977-1986, and the researching and writing of the Dictionary of Perplexing English in 1986 (ending in 1999). In this study I will discuss Willem Boshoff's careful employment of language and materials, througb which he propagates his "study of ignorance" (Williamson and Jamal 1996:148). I will investigate two major works by Boshoff, namely The Writing in the Sand and The Blind Alphabet in Chapters 1 and 2 respectively. Both of these installations are concerned fundamentally with the subversion of power relationships and elitism. As I will show, both works offer an opportunity to investigate their objectives in relation to discourses surrounding language and hermeneutics. My study includes a third chapter, in which I discuss my own work entitled The Bread of the Presence in relation to Boshoff's own methodologies. As will be demonstrated with particular reference to The Blind Alphabet and my own work, a discussion of memory proves to be of some relevance within this dialogue.
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Hippocampus queenslandicus Horne, 2001–a new seahorse species or yet another synonym?
- Teske, Peter R, Lourie, Sara A, Matthee, Conrad A, Green, David M
- Authors: Teske, Peter R , Lourie, Sara A , Matthee, Conrad A , Green, David M
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445666 , vital:74412 , https://www.publish.csiro.au/zo/ZO07021
- Description: During the past six years, 15 new seahorse species (Syngnathidae: Hippocampus) have been described on the basis of morphological characters. This approach is known to be problematic, and most species names in Hippocampus are now considered to be synonyms. Genetic methods have great potential to resolve the confused taxonomy of the genus, but none have yet been incorporated into species descriptions. In the present study, mitochondrial control region and cytochrome b DNA sequences, as well as morphological data from the recently described Queensland seahorse, Hippocampus queenslandicus Horne, 2001, were compared with corresponding data from closely related seahorse species to determine whether there is strong support for distinction of this taxon. The haplotypes of H. queenslandicus were nested among haplotypes belonging to two of the three major Southeast Asian lineages of H. spinosissimus Weber, 1913. Although incomplete lineage sorting characteristic of very recently diverged species cannot be ruled out, the genetic results suggest that H. queenslandicus is paraphyletic. Morphometric analysis further fails to provide strong support for the species status of H. queenslandicus. We conclude that support for the distinctness of H. queenslandicus is weak, and indicate that it is a synonym of H. spinosissimus. The taxonomic validity of other recently described seahorse species should be similarly scrutinised using combined genetic and detailed morphological methods.
- Full Text:
- Authors: Teske, Peter R , Lourie, Sara A , Matthee, Conrad A , Green, David M
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445666 , vital:74412 , https://www.publish.csiro.au/zo/ZO07021
- Description: During the past six years, 15 new seahorse species (Syngnathidae: Hippocampus) have been described on the basis of morphological characters. This approach is known to be problematic, and most species names in Hippocampus are now considered to be synonyms. Genetic methods have great potential to resolve the confused taxonomy of the genus, but none have yet been incorporated into species descriptions. In the present study, mitochondrial control region and cytochrome b DNA sequences, as well as morphological data from the recently described Queensland seahorse, Hippocampus queenslandicus Horne, 2001, were compared with corresponding data from closely related seahorse species to determine whether there is strong support for distinction of this taxon. The haplotypes of H. queenslandicus were nested among haplotypes belonging to two of the three major Southeast Asian lineages of H. spinosissimus Weber, 1913. Although incomplete lineage sorting characteristic of very recently diverged species cannot be ruled out, the genetic results suggest that H. queenslandicus is paraphyletic. Morphometric analysis further fails to provide strong support for the species status of H. queenslandicus. We conclude that support for the distinctness of H. queenslandicus is weak, and indicate that it is a synonym of H. spinosissimus. The taxonomic validity of other recently described seahorse species should be similarly scrutinised using combined genetic and detailed morphological methods.
- Full Text:
How entrepreneurs deal with ethical challenges : an application of the Business Ethics Synergy Star Technique
- Robinson, David A, Davidsson, Per, Van der Mescht, Hennie, Court, Philip
- Authors: Robinson, David A , Davidsson, Per , Van der Mescht, Hennie , Court, Philip
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6079 , http://hdl.handle.net/10962/d1006123
- Description: Entrepreneurs typically live with the ever present threat of business failure arising from limited financial resources and aggressive competition in the marketplace. Under these circumstances, conflicting priorities arise and the entrepreneur is thus faced with certain dilemmas. In seeking to resolve these, entrepreneurs must often rely on their own judgment to determine ‘‘what is right’’. There is thus a need for a technique to assist them decide on a course of action when no precedent or obvious solution exists. This research paper examines how entrepreneurs experience and deal with these dilemmas. The research is based on interviews with seven entrepreneurs in established service-oriented ventures, which gave rise to 26 dilemmas. These dilemmas were analyzed by making use of the Synergy Star technique, which is introduced here as a tool that is useful in defining any dilemma, isolating the ethical component, and resolving the dilemma in a way that is congruent with the entrepreneur’s personal world-view.
- Full Text:
- Authors: Robinson, David A , Davidsson, Per , Van der Mescht, Hennie , Court, Philip
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6079 , http://hdl.handle.net/10962/d1006123
- Description: Entrepreneurs typically live with the ever present threat of business failure arising from limited financial resources and aggressive competition in the marketplace. Under these circumstances, conflicting priorities arise and the entrepreneur is thus faced with certain dilemmas. In seeking to resolve these, entrepreneurs must often rely on their own judgment to determine ‘‘what is right’’. There is thus a need for a technique to assist them decide on a course of action when no precedent or obvious solution exists. This research paper examines how entrepreneurs experience and deal with these dilemmas. The research is based on interviews with seven entrepreneurs in established service-oriented ventures, which gave rise to 26 dilemmas. These dilemmas were analyzed by making use of the Synergy Star technique, which is introduced here as a tool that is useful in defining any dilemma, isolating the ethical component, and resolving the dilemma in a way that is congruent with the entrepreneur’s personal world-view.
- Full Text:
Hydrogenases from sulphate reducing bacteria and their role in the bioremediation of textile effluent
- Mutambanengwe, Cecil Clifford Zvandada
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2007
- Subjects: Bioremediation , Dyes and dyeing -- Waste disposal , Sulfur bacteria , Hydragenase , Factory and trade waste -- Purification , Textile waste
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3960 , http://hdl.handle.net/10962/d1004019 , Bioremediation , Dyes and dyeing -- Waste disposal , Sulfur bacteria , Hydragenase , Factory and trade waste -- Purification , Textile waste
- Description: The continuing industrial development has led to a corresponding increase in the amount of waste water generation leading to a consequential decline in levels and quality of the natural water in the ecosystem. Textile industries consume over 7 x 10[superscript 5] tons of dyes annually and use up to 1 litre of water per kg of dye processed and are third largest polluters in the world, the problem being aggravated by the inefficiencies of the dye houses. An abundance of physio-chemical methods are in use world wide, however, there is increasing concern as to their impact in effectively treating textile effluents as they introduce secondary pollutants during the ‘remediation’ process which are quite costly to run, maintain and clean up. Research on biological treatment has offered simple and cost effective ways of bioremediating textile effluents. While aerobic treatment of textile dyes and their effluents has been reported, its major draw back is commercial up-scaling and as such anaerobic systems have been investigated and shown to degrade azo dyes, which form the bulk of the dyes used world wide. However, the mechanisms involved in the bioremediation of these dyes are poorly understood. The aims of this study were to identify and investigate the role of enzymes produced by sulphate reducing bacteria (SRB) in bioremediating textile dye and their effluents. Sulphate reducing bacteria were used in this study because they are tolerant to harsh environmental conditions and inhibit the proliferance of pathogenic micro-organisms. The appearance of clear zones in agar plates containing azo dye concentrations ranging from 10 – 100 mgl[superscript -1] showed the ability of SRB to decolourize dyes under anaerobic conditions. Assays of enzymes previously reported to decolourise azo dyes were not successful, but led to the identification of hydrogenase enzyme being produced by SRB. The enzyme was found to be localised in the membrane and cytoplasm. A surface response method was used to optimize the extraction of the enzyme from the bacterial cells resulting in approximately 3 fold increase in hydrogenase activity. Maximum hydrogenase activity was found to occur after six days in the absence of dyes but was found to occur after one day in the presence of azo dyes. A decline in hydrogenase activity thereafter, suggested inhibition of enzymatic activity by the putative aromatic amines produced after azo cleavage. Purification of the hydrogenase by freeze drying, poly ethylene glycol, and Sephacryl – 200 size exclusion- ion exchange chromatography revealed the enzyme to have a molecular weight of 38.5 kDa when analyzed by a 12 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 40 °C while it exhibited a poor thermal stability with a half-life of 32 minutes. The kinetic parameters V[subscript max] and K[subscript m] were 21.18 U ml[superscript -1} and 4.57 mM respectively. Application of the cell free extract on commercial dyes was not successful, and only whole SRB cells resulted in decolourisation of the dyes. Consequently trials on the industrial dyes and effluents were carried out with whole cells. Decolourisation rates of up to 96 % were achieved for the commercial dyes and up to 93 % for the industrial dyes over a period of 10 days.
- Full Text:
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2007
- Subjects: Bioremediation , Dyes and dyeing -- Waste disposal , Sulfur bacteria , Hydragenase , Factory and trade waste -- Purification , Textile waste
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3960 , http://hdl.handle.net/10962/d1004019 , Bioremediation , Dyes and dyeing -- Waste disposal , Sulfur bacteria , Hydragenase , Factory and trade waste -- Purification , Textile waste
- Description: The continuing industrial development has led to a corresponding increase in the amount of waste water generation leading to a consequential decline in levels and quality of the natural water in the ecosystem. Textile industries consume over 7 x 10[superscript 5] tons of dyes annually and use up to 1 litre of water per kg of dye processed and are third largest polluters in the world, the problem being aggravated by the inefficiencies of the dye houses. An abundance of physio-chemical methods are in use world wide, however, there is increasing concern as to their impact in effectively treating textile effluents as they introduce secondary pollutants during the ‘remediation’ process which are quite costly to run, maintain and clean up. Research on biological treatment has offered simple and cost effective ways of bioremediating textile effluents. While aerobic treatment of textile dyes and their effluents has been reported, its major draw back is commercial up-scaling and as such anaerobic systems have been investigated and shown to degrade azo dyes, which form the bulk of the dyes used world wide. However, the mechanisms involved in the bioremediation of these dyes are poorly understood. The aims of this study were to identify and investigate the role of enzymes produced by sulphate reducing bacteria (SRB) in bioremediating textile dye and their effluents. Sulphate reducing bacteria were used in this study because they are tolerant to harsh environmental conditions and inhibit the proliferance of pathogenic micro-organisms. The appearance of clear zones in agar plates containing azo dye concentrations ranging from 10 – 100 mgl[superscript -1] showed the ability of SRB to decolourize dyes under anaerobic conditions. Assays of enzymes previously reported to decolourise azo dyes were not successful, but led to the identification of hydrogenase enzyme being produced by SRB. The enzyme was found to be localised in the membrane and cytoplasm. A surface response method was used to optimize the extraction of the enzyme from the bacterial cells resulting in approximately 3 fold increase in hydrogenase activity. Maximum hydrogenase activity was found to occur after six days in the absence of dyes but was found to occur after one day in the presence of azo dyes. A decline in hydrogenase activity thereafter, suggested inhibition of enzymatic activity by the putative aromatic amines produced after azo cleavage. Purification of the hydrogenase by freeze drying, poly ethylene glycol, and Sephacryl – 200 size exclusion- ion exchange chromatography revealed the enzyme to have a molecular weight of 38.5 kDa when analyzed by a 12 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 40 °C while it exhibited a poor thermal stability with a half-life of 32 minutes. The kinetic parameters V[subscript max] and K[subscript m] were 21.18 U ml[superscript -1} and 4.57 mM respectively. Application of the cell free extract on commercial dyes was not successful, and only whole SRB cells resulted in decolourisation of the dyes. Consequently trials on the industrial dyes and effluents were carried out with whole cells. Decolourisation rates of up to 96 % were achieved for the commercial dyes and up to 93 % for the industrial dyes over a period of 10 days.
- Full Text:
Identity in the Siyagruva Series of novels: Toward an intercultural
- Authors: Kaschula, Russell H
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175159 , vital:42548 , DOI: 10.4314/tvl.v44i2.29792
- Description: This article explores the notion of changing South African youth identity and how it is depicted in the Siyagruva [We are Grooving] Series of novels for young adults. The article highlights the need for a broadening of literary theory in order to include an appropriate theoretical approach for new South African youth literature. This theory explores intercultural literary discourse by making use of, for example, the work of intercultural theorists such as Ting-Toomey (1999), Gudykunst (2003) and others. It is argued that this form of literary discourse is now appropriate as a theoretical paradigm within multilingual South Africa where intercultural communication is becoming a reality. There is also reference to intracultural communication where differences are beginning to appear between young people who are perceived to come from the same cultural group, for example, the character Brunette in the Siyagruva Series who is perceived as a “coconut” by her friends, and thus finds herself having to justify her belonging within a particular in-group or culture. The article concentrates on selected novels, though reference is made to many of the twenty three published novels in the Siyagruva Series, twenty in English, and three translated into isiXhosa.
- Full Text:
- Authors: Kaschula, Russell H
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175159 , vital:42548 , DOI: 10.4314/tvl.v44i2.29792
- Description: This article explores the notion of changing South African youth identity and how it is depicted in the Siyagruva [We are Grooving] Series of novels for young adults. The article highlights the need for a broadening of literary theory in order to include an appropriate theoretical approach for new South African youth literature. This theory explores intercultural literary discourse by making use of, for example, the work of intercultural theorists such as Ting-Toomey (1999), Gudykunst (2003) and others. It is argued that this form of literary discourse is now appropriate as a theoretical paradigm within multilingual South Africa where intercultural communication is becoming a reality. There is also reference to intracultural communication where differences are beginning to appear between young people who are perceived to come from the same cultural group, for example, the character Brunette in the Siyagruva Series who is perceived as a “coconut” by her friends, and thus finds herself having to justify her belonging within a particular in-group or culture. The article concentrates on selected novels, though reference is made to many of the twenty three published novels in the Siyagruva Series, twenty in English, and three translated into isiXhosa.
- Full Text:
Immobilization of tetra-amine substituted metallophthalocyanines at gold surfaces modified with mercaptopropionic acid or DTSP-SAMs
- Matemadombo, Fungisai, Westbroek, Philippe, Nyokong, Tebello, Ozoemena, Kenneth, De Clerck, Karen, Kiekens, Paul
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello , Ozoemena, Kenneth , De Clerck, Karen , Kiekens, Paul
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283924 , vital:56003 , xlink:href="https://doi.org/10.1016/j.electacta.2006.08.027"
- Description: This paper shows that amine substituted cobalt phthalocyanine (CoTAPc) can be deposited on gold surfaces by using an interconnecting layer of a self-assembled monolayer (SAM) of mercaptopropionic acid or Lomant's reagent (dithiobis(N-succinimidyl propionate) (DTSP)). In both cases the new bond formed is obtained by the creation of an amide. The layers were characterized by electrochemistry and showed high coverage fractions (near 100%). Reductive and oxidative desorption of the SAMs limit the useful potential window from −0.6 to +0.5 V versus Ag|AgCl. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. The amount of CoTAPc molecules deposited (obtained from the Co central metal ion activity in nitrogen purged solutions) revealed that the CoTAPc molecules are bonded in a perpendicular manner at the surface. Taking into account a surface of 200 Å2 for a flatly bonded MPc, this should result in a four times less amount of deposited CoTAPc compared to the experimental value obtained. Both methods showed good results and promising long-term stability and will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello , Ozoemena, Kenneth , De Clerck, Karen , Kiekens, Paul
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283924 , vital:56003 , xlink:href="https://doi.org/10.1016/j.electacta.2006.08.027"
- Description: This paper shows that amine substituted cobalt phthalocyanine (CoTAPc) can be deposited on gold surfaces by using an interconnecting layer of a self-assembled monolayer (SAM) of mercaptopropionic acid or Lomant's reagent (dithiobis(N-succinimidyl propionate) (DTSP)). In both cases the new bond formed is obtained by the creation of an amide. The layers were characterized by electrochemistry and showed high coverage fractions (near 100%). Reductive and oxidative desorption of the SAMs limit the useful potential window from −0.6 to +0.5 V versus Ag|AgCl. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. The amount of CoTAPc molecules deposited (obtained from the Co central metal ion activity in nitrogen purged solutions) revealed that the CoTAPc molecules are bonded in a perpendicular manner at the surface. Taking into account a surface of 200 Å2 for a flatly bonded MPc, this should result in a four times less amount of deposited CoTAPc compared to the experimental value obtained. Both methods showed good results and promising long-term stability and will be interesting tools for further research in surface modification and sensor development.
- Full Text:
Impact of nutrients and herbivory by Eccritotarsus catarinensis on the biological control of water hyacinth, Eichhornia crassipes
- Coetzee, Julie A, Byrne, Marcus J, Hill, Martin P
- Authors: Coetzee, Julie A , Byrne, Marcus J , Hill, Martin P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6945 , http://hdl.handle.net/10962/d1011973 , https://orcid.org/0000-0003-0579-5298
- Description: Many water hyacinth infestations in South Africa are the symptom of eutrophication, and as a result, biological control of this weed is variable. This study examined the effects of herbivory by the mirid, Eccritotarsus catarinensis, on water hyacinth grown at high, medium and low nitrogen (N) and phosphorus (P) nutrient concentrations. Water nutrient concentration appears to be the overriding factor affecting plant growth parameters of water hyacinth plants—at high nutrient concentrations, leaf and daughter plant production were more than double than at low nutrient concentrations, while stem length was twice as great at high nutrient concentrations compared to low concentrations. Chlorophyll content was also twice as high at high nutrient concentrations than low concentrations. Conversely, flower production at high nutrient concentrations was less than half that at low concentrations. Herbivory by E. catarinensis did not have as great an effect on water hyacinth vigour as nutrient concentration did, although it significantly reduced the production of daughter plants by 23 ± 9%, the length of the second petiole by 13 ± 5%, and chlorophyll content of water hyacinth leaves by 15 ± 6%. In terms of insect numbers, mirids performed better on plants grown under medium nutrient conditions (99 ± 28 S.E.), compared to high nutrient concentrations (52 ± 27 S.E.), and low nutrient concentrations (25 ± 30 S.E.). Thus, these results suggest that the fastest and most significant reduction in water hyacinth proliferation would be reached by lowering the water nutrient concentrations, and herbivory by E. catarinensis alone is not sufficient to reduce all aspects of water hyacinth vigour, especially at very high nutrient concentrations.
- Full Text:
- Authors: Coetzee, Julie A , Byrne, Marcus J , Hill, Martin P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6945 , http://hdl.handle.net/10962/d1011973 , https://orcid.org/0000-0003-0579-5298
- Description: Many water hyacinth infestations in South Africa are the symptom of eutrophication, and as a result, biological control of this weed is variable. This study examined the effects of herbivory by the mirid, Eccritotarsus catarinensis, on water hyacinth grown at high, medium and low nitrogen (N) and phosphorus (P) nutrient concentrations. Water nutrient concentration appears to be the overriding factor affecting plant growth parameters of water hyacinth plants—at high nutrient concentrations, leaf and daughter plant production were more than double than at low nutrient concentrations, while stem length was twice as great at high nutrient concentrations compared to low concentrations. Chlorophyll content was also twice as high at high nutrient concentrations than low concentrations. Conversely, flower production at high nutrient concentrations was less than half that at low concentrations. Herbivory by E. catarinensis did not have as great an effect on water hyacinth vigour as nutrient concentration did, although it significantly reduced the production of daughter plants by 23 ± 9%, the length of the second petiole by 13 ± 5%, and chlorophyll content of water hyacinth leaves by 15 ± 6%. In terms of insect numbers, mirids performed better on plants grown under medium nutrient conditions (99 ± 28 S.E.), compared to high nutrient concentrations (52 ± 27 S.E.), and low nutrient concentrations (25 ± 30 S.E.). Thus, these results suggest that the fastest and most significant reduction in water hyacinth proliferation would be reached by lowering the water nutrient concentrations, and herbivory by E. catarinensis alone is not sufficient to reduce all aspects of water hyacinth vigour, especially at very high nutrient concentrations.
- Full Text:
Implementation of computers in schools: a case study of five schools in the Makana and Somerset East districts
- Authors: Prince, Gilbert Leslie
- Date: 2007
- Subjects: Educational technology , Educational technology -- South Africa -- Eastern Cape , Education, Elementary -- Computer-assisted instruction , Computer-assisted instruction -- South Africa -- Eastern Cape , Computer managed instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1562 , http://hdl.handle.net/10962/d1003444 , Educational technology , Educational technology -- South Africa -- Eastern Cape , Education, Elementary -- Computer-assisted instruction , Computer-assisted instruction -- South Africa -- Eastern Cape , Computer managed instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa -- Eastern Cape
- Description: This case study attempts to explain the implementation of Information Communications Technology (ICT) in primary schools, specifically mentioning the integration of computers into the curriculum. To begin with, the implementation of ICT from an international perspective is explored and subsequently some international and African ICT policies in education are also identified and discussed. Nationally, ICT policies from four provinces in South Africa are examined and analyzed. Provincially, the ICT Projects Coordinator in the Eastern Cape Department of Education (ECDoE) was interviewed to obtain a provincial perspective of ICT in the Eastern Cape. From local schools’ perspective, four primary schools and one secondary school in the Makana and Somerset East Districts were visited and the ICT coordinators at these schools were interviewed. The results reveal that the previously disadvantaged (PD) schools were not utilizing their computers effectively. This is due to a number of factors, including a lack of funds to maintain the computers; unskilled or under skilled teachers in ICT; and under resourced computer facilities. The previously advantaged (PA) schools, on the other hand, have well-resourced computer laboratories, adequate maintenance plans as well as skilled teachers in ICT that enable these schools to effectively integrate the use of computers into the curriculum. Key words: Information communications technology, implementation, integration, previously advantaged, previously disadvantaged, curriculum, primary school, secondary school.
- Full Text:
- Authors: Prince, Gilbert Leslie
- Date: 2007
- Subjects: Educational technology , Educational technology -- South Africa -- Eastern Cape , Education, Elementary -- Computer-assisted instruction , Computer-assisted instruction -- South Africa -- Eastern Cape , Computer managed instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1562 , http://hdl.handle.net/10962/d1003444 , Educational technology , Educational technology -- South Africa -- Eastern Cape , Education, Elementary -- Computer-assisted instruction , Computer-assisted instruction -- South Africa -- Eastern Cape , Computer managed instruction -- South Africa -- Eastern Cape , Internet in education -- South Africa -- Eastern Cape
- Description: This case study attempts to explain the implementation of Information Communications Technology (ICT) in primary schools, specifically mentioning the integration of computers into the curriculum. To begin with, the implementation of ICT from an international perspective is explored and subsequently some international and African ICT policies in education are also identified and discussed. Nationally, ICT policies from four provinces in South Africa are examined and analyzed. Provincially, the ICT Projects Coordinator in the Eastern Cape Department of Education (ECDoE) was interviewed to obtain a provincial perspective of ICT in the Eastern Cape. From local schools’ perspective, four primary schools and one secondary school in the Makana and Somerset East Districts were visited and the ICT coordinators at these schools were interviewed. The results reveal that the previously disadvantaged (PD) schools were not utilizing their computers effectively. This is due to a number of factors, including a lack of funds to maintain the computers; unskilled or under skilled teachers in ICT; and under resourced computer facilities. The previously advantaged (PA) schools, on the other hand, have well-resourced computer laboratories, adequate maintenance plans as well as skilled teachers in ICT that enable these schools to effectively integrate the use of computers into the curriculum. Key words: Information communications technology, implementation, integration, previously advantaged, previously disadvantaged, curriculum, primary school, secondary school.
- Full Text:
Implementation of learner-centred education by Grade 4 BETD in-service teachers in selected Namibia schools
- Authors: Amakali, Amram
- Date: 2007
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1849 , http://hdl.handle.net/10962/d1004457
- Description: Before independence Namibia's education system was predominantly teacher-centred. Soon after its independence Namibia embarked on education restructuring and transformation. A new education system, leamer-centred education, was introduced to cater for the needs of all Namibian learners. It was seen as an effective antidote to the stifling teacher-centred practices of the previous education system. A new programme, the Basic Education Teacher Diploma (BETD) was introduced to prepare teachers to teach in a leamer-centred approach. Research has, however, indicated that many Namibian teachers have a somewhat shallow or naIve understanding oflearner-centred education. This small-scale case study, conducted in Oshikoto region, focuses on two Grade 4 teachers. The study examined the two teachers ' perceptions and experiences oflearnercentred education and the teaching strategies they use to develop learners' understanding. The study uses a qualitative approach in its exploration of teachers ' lived experiences of becoming learner-centred. The data emerging from this case study identify a number of misconceptions and understandings of leamer-centred education and its implementation. The findings suggest that teachers ' misconceptions are caused by a lack of deep understanding about the epistemology and theory of learning which underpins Namibia's reform policies and principles.
- Full Text:
- Authors: Amakali, Amram
- Date: 2007
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1849 , http://hdl.handle.net/10962/d1004457
- Description: Before independence Namibia's education system was predominantly teacher-centred. Soon after its independence Namibia embarked on education restructuring and transformation. A new education system, leamer-centred education, was introduced to cater for the needs of all Namibian learners. It was seen as an effective antidote to the stifling teacher-centred practices of the previous education system. A new programme, the Basic Education Teacher Diploma (BETD) was introduced to prepare teachers to teach in a leamer-centred approach. Research has, however, indicated that many Namibian teachers have a somewhat shallow or naIve understanding oflearner-centred education. This small-scale case study, conducted in Oshikoto region, focuses on two Grade 4 teachers. The study examined the two teachers ' perceptions and experiences oflearnercentred education and the teaching strategies they use to develop learners' understanding. The study uses a qualitative approach in its exploration of teachers ' lived experiences of becoming learner-centred. The data emerging from this case study identify a number of misconceptions and understandings of leamer-centred education and its implementation. The findings suggest that teachers ' misconceptions are caused by a lack of deep understanding about the epistemology and theory of learning which underpins Namibia's reform policies and principles.
- Full Text:
Implementation tensions and challenges in donor funded curriculum projects: a case analysis of environmental and population education projects in Lesotho
- Monaheng, Nkaiseng ̕Mamotšelisi
- Authors: Monaheng, Nkaiseng ̕Mamotšelisi
- Date: 2007
- Subjects: National Curriculum Development Centre (Lesotho) Curriculum planning -- Lesotho Environmental education -- Lesotho Economic assistance -- Lesotho Technical assistance -- Lesotho Sustainable development -- Lesotho
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1568 , http://hdl.handle.net/10962/d1003450
- Description: This study aims to capture the challenges and tensions that arise in donor funded curriculum projects in Lesotho. Through an interpretive case study research design I investigated these challenges and tensions in two projects relevant to Education for Sustainable Development, namely the Lesotho Environmental Support Project (LEESP) and the Population/Family Education (POP/FLE) projects which are donor funded curriculum projects funded by DANIDA and UNFPA respectively. A review of donor funded curriculum projects in the field of environmental education/Education for Sustainable Development was undertaken to provide background and a theoretical context for the study. It highlighted different challenges and implementation tensions experienced by other similar projects in other countries. At the heart of such projects lies a particular political economy, which is based on development assistance to poor countries. Such development assistance is constructed around concepts of need, participation and innovation, and donor-recipient relationships. It is structured around a system of governance and management that normally uses logical framework planning as its main methodology. This political economy has shaped the two donor funded projects that were considered in this study, and has shaped many of the tensions and challenges identified in the study. To investigate the two projects, data for this study was generated through in-depth interviews, document analysis and focus group interviews, with people who had been involved with the projects at the national level. The data generation process did not involve the schools where the projects were ultimately implemented, as it was seeking to identify how local institutions such as the National Curriculum Development Centre could support better synergies between donor funded initiatives and the local context. The findings of the study revealed the ambivalent nature of donor initiatives, and identified that the political economy and donor-recipient relations influence the projects. Aspects such as the design and management of projects, the processes associated with introducing innovation in educational ideas and paradigms, pedagogical issues, and staff contributions and ownership were identified as some of the key tensions that existed in the projects. Other factors such as poor capacity levels of local staff, non-alignment with existing structures, inadequate sustainability mechanisms and the difficulty of the envisaged integration of new paradigm thinking (methods and approaches) into the existing curriculum framework were also significant tensions, given the positivist history of the Lesotho curriculum. The study recommends the need to establish mechanisms for working with donors to tackle the tensions that arise in such projects within longer-term donor assistance. It proposes that government should expedite the development of policy on donor coordination. Both donors and the NCDC need to put mechanisms in place to allow for debate and discussions on innovations brought in by the donors in relation to local needs. The study further recommends that in cases where more than one donor exists, the NCDC and the donors should work towards developing synergies between the different initiatives to avoid duplication and overlap. Finally, there is a need for projects to use bottom-up approaches for the design and formulation of projects to ensure ownership.
- Full Text:
- Authors: Monaheng, Nkaiseng ̕Mamotšelisi
- Date: 2007
- Subjects: National Curriculum Development Centre (Lesotho) Curriculum planning -- Lesotho Environmental education -- Lesotho Economic assistance -- Lesotho Technical assistance -- Lesotho Sustainable development -- Lesotho
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1568 , http://hdl.handle.net/10962/d1003450
- Description: This study aims to capture the challenges and tensions that arise in donor funded curriculum projects in Lesotho. Through an interpretive case study research design I investigated these challenges and tensions in two projects relevant to Education for Sustainable Development, namely the Lesotho Environmental Support Project (LEESP) and the Population/Family Education (POP/FLE) projects which are donor funded curriculum projects funded by DANIDA and UNFPA respectively. A review of donor funded curriculum projects in the field of environmental education/Education for Sustainable Development was undertaken to provide background and a theoretical context for the study. It highlighted different challenges and implementation tensions experienced by other similar projects in other countries. At the heart of such projects lies a particular political economy, which is based on development assistance to poor countries. Such development assistance is constructed around concepts of need, participation and innovation, and donor-recipient relationships. It is structured around a system of governance and management that normally uses logical framework planning as its main methodology. This political economy has shaped the two donor funded projects that were considered in this study, and has shaped many of the tensions and challenges identified in the study. To investigate the two projects, data for this study was generated through in-depth interviews, document analysis and focus group interviews, with people who had been involved with the projects at the national level. The data generation process did not involve the schools where the projects were ultimately implemented, as it was seeking to identify how local institutions such as the National Curriculum Development Centre could support better synergies between donor funded initiatives and the local context. The findings of the study revealed the ambivalent nature of donor initiatives, and identified that the political economy and donor-recipient relations influence the projects. Aspects such as the design and management of projects, the processes associated with introducing innovation in educational ideas and paradigms, pedagogical issues, and staff contributions and ownership were identified as some of the key tensions that existed in the projects. Other factors such as poor capacity levels of local staff, non-alignment with existing structures, inadequate sustainability mechanisms and the difficulty of the envisaged integration of new paradigm thinking (methods and approaches) into the existing curriculum framework were also significant tensions, given the positivist history of the Lesotho curriculum. The study recommends the need to establish mechanisms for working with donors to tackle the tensions that arise in such projects within longer-term donor assistance. It proposes that government should expedite the development of policy on donor coordination. Both donors and the NCDC need to put mechanisms in place to allow for debate and discussions on innovations brought in by the donors in relation to local needs. The study further recommends that in cases where more than one donor exists, the NCDC and the donors should work towards developing synergies between the different initiatives to avoid duplication and overlap. Finally, there is a need for projects to use bottom-up approaches for the design and formulation of projects to ensure ownership.
- Full Text:
Implementing innovative assessment methods in undergraduate Mathematics
- Authors: Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Text
- Identifier: vital:6779 , http://hdl.handle.net/10962/d1006947
- Description: The following challenges associated with teaching undergraduate Mathematics will be discussed: Negative attitudes of students to Mathematics, Student’s reluctance to practise Mathematics, and surface learning. Some (or all) of the ways in which assessment can be used to address these challenges will be discussed. If used strategically assessment methods/tasks can enhance the teaching and learning of mathematics. Some of the unique challenges that we as lecturers face in teaching mathematics can be remedied by selecting appropriate assessment techniques/tasks. Using the tutorial time fruitfully is one of the challenging aspects in teaching mathematics. Not taking tutorials and other formative assessments seriously is not an uncommon student attitude in higher education contexts. Students who are pressured for time often do not see the immediate value of formative assessment or of discussion as a useful learning activity. A collection of case studies which clearly document what has been tried in different contexts is very useful in mathematics as this information is limited in the South African higher education sector. An innovative assessment method (peer-assessment) which was introduced for a Linear Algebra second year course at Rhodes University (South Africa) will be presented: The implementation method, purpose of introducing the assessment method, its advantages, and disadvantages will be examined. A reflection on the assessment method and concluding remarks will be provided.
- Full Text:
- Authors: Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Text
- Identifier: vital:6779 , http://hdl.handle.net/10962/d1006947
- Description: The following challenges associated with teaching undergraduate Mathematics will be discussed: Negative attitudes of students to Mathematics, Student’s reluctance to practise Mathematics, and surface learning. Some (or all) of the ways in which assessment can be used to address these challenges will be discussed. If used strategically assessment methods/tasks can enhance the teaching and learning of mathematics. Some of the unique challenges that we as lecturers face in teaching mathematics can be remedied by selecting appropriate assessment techniques/tasks. Using the tutorial time fruitfully is one of the challenging aspects in teaching mathematics. Not taking tutorials and other formative assessments seriously is not an uncommon student attitude in higher education contexts. Students who are pressured for time often do not see the immediate value of formative assessment or of discussion as a useful learning activity. A collection of case studies which clearly document what has been tried in different contexts is very useful in mathematics as this information is limited in the South African higher education sector. An innovative assessment method (peer-assessment) which was introduced for a Linear Algebra second year course at Rhodes University (South Africa) will be presented: The implementation method, purpose of introducing the assessment method, its advantages, and disadvantages will be examined. A reflection on the assessment method and concluding remarks will be provided.
- Full Text:
Implications of life history for genetic structure and migration rates of southern African coastal invertebrates: planktonic, abbreviated and direct development
- Teske, Peter R, Papadopoulos, Isabelle, Zardi, Gerardo I, McQuaid, Christopher D, Edkins, M T, Griffiths, C L, Barker, Nigel P
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Zardi, Gerardo I , McQuaid, Christopher D , Edkins, M T , Griffiths, C L , Barker, Nigel P
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445447 , vital:74388 , https://doi.org/10.1007/s00227-007-0724-y
- Description: The amount of genetic structure in marine invertebrates is often thought to be negatively correlated with larval duration. However, larval retention may increase genetic structure in species with long-lived planktonic larvae, and rafting provides a means of dispersal for species that lack a larval dispersal phase. We compared genetic structure, demographic histories and levels of gene flow of regional lineages (in most cases defined by biogeographic region) of five southern African coastal invertebrates with three main types of larval development: (1) dispersal by long-lived planktonic larvae (mudprawn Upogebia africana and brown mussel Perna perna), (2) abbreviated larval development (crown crab Hymenosoma orbiculare) and (3) direct development (estuarine isopod Exosphaeroma hylecoetes and estuarine cumacean Iphinoe truncata). We hypothesized that H. orbiculare, having abbreviated larval development, would employ a strategy of larval retention, resulting in genetic structure comparable to that of the direct developers rather than the planktonic dispersers.
- Full Text:
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Zardi, Gerardo I , McQuaid, Christopher D , Edkins, M T , Griffiths, C L , Barker, Nigel P
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445447 , vital:74388 , https://doi.org/10.1007/s00227-007-0724-y
- Description: The amount of genetic structure in marine invertebrates is often thought to be negatively correlated with larval duration. However, larval retention may increase genetic structure in species with long-lived planktonic larvae, and rafting provides a means of dispersal for species that lack a larval dispersal phase. We compared genetic structure, demographic histories and levels of gene flow of regional lineages (in most cases defined by biogeographic region) of five southern African coastal invertebrates with three main types of larval development: (1) dispersal by long-lived planktonic larvae (mudprawn Upogebia africana and brown mussel Perna perna), (2) abbreviated larval development (crown crab Hymenosoma orbiculare) and (3) direct development (estuarine isopod Exosphaeroma hylecoetes and estuarine cumacean Iphinoe truncata). We hypothesized that H. orbiculare, having abbreviated larval development, would employ a strategy of larval retention, resulting in genetic structure comparable to that of the direct developers rather than the planktonic dispersers.
- Full Text:
Inetvis: a graphical aid for the detection and visualisation of network scans
- Irwin, Barry V W, van Riel, Jean-Pierre
- Authors: Irwin, Barry V W , van Riel, Jean-Pierre
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430381 , vital:72687 , https://www.cs.ru.ac.za/research/g02V2468/publications/Irwin-VizSEC2007_draft.pdf
- Description: This paper presents an investigative analysis of network scans and scan detection algorithms. Visualisation is employed to review network telescope traffic and identify incidents of scan activity. Some of the identified phenomena appear to be novel forms of host discovery. The scan detection algorithms of Snort and Bro are critiqued by comparing the visualised scans with alert output. Where human assessment disa-grees with the alert output, explanations are sought after by analysing the detection algorithms. The algorithms of the Snort and Bro intrusion detection systems are based on counting unique connection attempts to destination addresses and ports. For Snort, notable false positive and false negative cases result due to a grossly oversimplified method of counting unique destination addresses and ports.
- Full Text:
- Authors: Irwin, Barry V W , van Riel, Jean-Pierre
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430381 , vital:72687 , https://www.cs.ru.ac.za/research/g02V2468/publications/Irwin-VizSEC2007_draft.pdf
- Description: This paper presents an investigative analysis of network scans and scan detection algorithms. Visualisation is employed to review network telescope traffic and identify incidents of scan activity. Some of the identified phenomena appear to be novel forms of host discovery. The scan detection algorithms of Snort and Bro are critiqued by comparing the visualised scans with alert output. Where human assessment disa-grees with the alert output, explanations are sought after by analysing the detection algorithms. The algorithms of the Snort and Bro intrusion detection systems are based on counting unique connection attempts to destination addresses and ports. For Snort, notable false positive and false negative cases result due to a grossly oversimplified method of counting unique destination addresses and ports.
- Full Text:
Insights into the surface and redox properties of single-walled carbon nanotube—cobalt (II) tetra-aminophthalocyanine self-assembled on gold electrode
- Ozoemena, Kenneth I, Nyokong, Tebello, Nkosi, Duduzile, Chambrier, Isabelle, Cook, Michael J
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello , Nkosi, Duduzile , Chambrier, Isabelle , Cook, Michael J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281258 , vital:55707 , xlink:href="https://doi.org/10.1016/j.electacta.2006.11.039"
- Description: This paper describes for the first time the electrochemical properties of redox-active self-assembled films of single-walled carbon nanotubes (SWCNTs) coordinated to cobalt(II)tetra-aminophthalocyanine (CoTAPc) by sequential self-assembly onto a preformed aminoethanethiol (AET) self-assembled monolayer (SAM) on a gold electrode. Both redox-active SAMs (Au-AET-SWCNT and Au-AET-SWCNT-CoTAPc) exhibited reversible electrochemistry in aqueous (phosphate buffer) solution. X-ray photoelectron spectroscopy (XPS) confirmed the appearance on the gold surface of the various elements found on the SAMs. Atomic force microscopy (AFM) images prove, corroborating the estimated electrochemical surface concentrations, that these SAMs lie normal to the gold surface. Electrochemical impedance spectroscopy (EIS) analyses in the presence of [Fe(CN)6]3−/4− as a redox probe revealed that the Au-AET-SWCNT-CoTAPc showed much lower (∼10 times) electron-transfer resistance (Ret) and much higher (∼10 times) apparent electron-transfer rate constant (kapp) compared to the Au-AET-SWCNT SAM. Interestingly, a preliminary electrocatalytic investigation showed that both SAMs exhibit comparable electrocatalytic responses towards the detection of dopamine in pH 7.4 phosphate buffer solutions (PBS). The electrochemical studies (cyclic voltammetry (CV) and EIS) prove that SWCNT greatly improves the electronic communication between CoTAPc and the Au electrode surface.
- Full Text:
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello , Nkosi, Duduzile , Chambrier, Isabelle , Cook, Michael J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281258 , vital:55707 , xlink:href="https://doi.org/10.1016/j.electacta.2006.11.039"
- Description: This paper describes for the first time the electrochemical properties of redox-active self-assembled films of single-walled carbon nanotubes (SWCNTs) coordinated to cobalt(II)tetra-aminophthalocyanine (CoTAPc) by sequential self-assembly onto a preformed aminoethanethiol (AET) self-assembled monolayer (SAM) on a gold electrode. Both redox-active SAMs (Au-AET-SWCNT and Au-AET-SWCNT-CoTAPc) exhibited reversible electrochemistry in aqueous (phosphate buffer) solution. X-ray photoelectron spectroscopy (XPS) confirmed the appearance on the gold surface of the various elements found on the SAMs. Atomic force microscopy (AFM) images prove, corroborating the estimated electrochemical surface concentrations, that these SAMs lie normal to the gold surface. Electrochemical impedance spectroscopy (EIS) analyses in the presence of [Fe(CN)6]3−/4− as a redox probe revealed that the Au-AET-SWCNT-CoTAPc showed much lower (∼10 times) electron-transfer resistance (Ret) and much higher (∼10 times) apparent electron-transfer rate constant (kapp) compared to the Au-AET-SWCNT SAM. Interestingly, a preliminary electrocatalytic investigation showed that both SAMs exhibit comparable electrocatalytic responses towards the detection of dopamine in pH 7.4 phosphate buffer solutions (PBS). The electrochemical studies (cyclic voltammetry (CV) and EIS) prove that SWCNT greatly improves the electronic communication between CoTAPc and the Au electrode surface.
- Full Text:
Intermediating Africa:
- Authors: Garman, Anthea
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158806 , vital:40230 , https://hdl.handle.net/10520/EJC144693
- Description: In July, Vanity Fair, based in New York, did a unique special edition. Editor Graydon Carter explained how it came about: "Earlier this year, Mark Dowley, a marketing polymath at the Endeavour talent agency who has been involved with Bono's (Red) campaign from the start, called to inquire if I would be interested in having him guest edit an issue of the magazine. Interested? I'll say!".
- Full Text:
- Authors: Garman, Anthea
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158806 , vital:40230 , https://hdl.handle.net/10520/EJC144693
- Description: In July, Vanity Fair, based in New York, did a unique special edition. Editor Graydon Carter explained how it came about: "Earlier this year, Mark Dowley, a marketing polymath at the Endeavour talent agency who has been involved with Bono's (Red) campaign from the start, called to inquire if I would be interested in having him guest edit an issue of the magazine. Interested? I'll say!".
- Full Text:
International trade and environmental disputes : an analysis of Article XX of the General Agreement on Tariffs and Trade (1994) and environmental policies of the developing and developed world
- Authors: Manjoro, Faith Tendayi
- Date: 2007
- Subjects: World Trade Organization General Agreement on Tariffs and Trade (Organization) Environmental protection Environmental degradation Free trade -- Environmental aspects Foreign trade regulation International trade
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3713 , http://hdl.handle.net/10962/d1007444
- Description: A major problem emanating from the trade/environment conflict is the use of trade measures, such as restrictions and sanctions, as tools for environmental protection. Proponents of free trade argue that the use of these measures is tantamount to abuse of environmental standards for protectionist ends. This is particularly so if the imposition of the standard amounts to a unilateral act which blocks the entry of a specified product into the market of another member state for reasons other than environmental protection. Environmentalists at the same time argue that free trade will lead to environmental degradation and therefore advocate for the use of trade-restrictive measures to safeguard against the destruction of the environment. The GATT has proved problematic when it comes to the resolution of trade/environment conflicts. The GATT aims at trade liberalisation yet most environmental policies are enforced through trade-restrictive devices like quotas and licences. Article XX of the GATT is anomalous: it does not explicitly mention the environment, yet member states rely on it as an environmental protection clause. This thesis discusses the various issues emanating from the trade/environmental debate. The history of Article XX is reviewed and the issues that arise in the adjudication of Articles XX (b) and (g) in a trade/environment context are analysed in light of the decisions by the GATTIWTO dispute settlement bodies. The role played by Multilateral Environmental Agreements (MEAs) in protecting the environment is discussed. However, the relationship between MEAs and the WTO is also scrutinised as these rule-making bodies often come into conflict: firstly, because they serve two differing interests - on the one hand, MEAs allow for the use of trade restrictive measures in environmental agreements and on the other, the WTO calls for unrestricted trade unless exceptional circumstances exist; and secondly, member states that are party to both the WTO and MEAs are often forced to subscribe to international trade rules that are incompatible with those in environmental agreements. The trade/environmental debate is important to both the developed and developing worlds. The developed world is in favour of environmental policies which protect the environment from degradation. On the other hand, the developing world is in desperate need of the benefits of trade liberalisation so as to cater for high unemployment rates and poor economic growth. The question thus arises as to whether, when environmental issues are promoted, developing countries will not suffer at the expense of developed nations which may engage in protectionist measures under the pretext of environmental conservation. The divide between developed and developing countries is illustrated in Chapter 5 through case studies on coal mining in the USA and South Africa. The conclusion reached is that total co-operation is essential between developed and developing states for success in safeguarding the environment from degradation. Accordingly, the trade/environmental debate cannot be isolated from the conflicting approaches in developed and developing countries. The conclusions in the final chapter seek to strike a balance between trade liberalisation and environmental protection. Recommendations are made on how the trade/environmental challenges could be dealt with and the regulation of trade restrictive devices to exclude, or at least limit, protectionism.
- Full Text:
- Authors: Manjoro, Faith Tendayi
- Date: 2007
- Subjects: World Trade Organization General Agreement on Tariffs and Trade (Organization) Environmental protection Environmental degradation Free trade -- Environmental aspects Foreign trade regulation International trade
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3713 , http://hdl.handle.net/10962/d1007444
- Description: A major problem emanating from the trade/environment conflict is the use of trade measures, such as restrictions and sanctions, as tools for environmental protection. Proponents of free trade argue that the use of these measures is tantamount to abuse of environmental standards for protectionist ends. This is particularly so if the imposition of the standard amounts to a unilateral act which blocks the entry of a specified product into the market of another member state for reasons other than environmental protection. Environmentalists at the same time argue that free trade will lead to environmental degradation and therefore advocate for the use of trade-restrictive measures to safeguard against the destruction of the environment. The GATT has proved problematic when it comes to the resolution of trade/environment conflicts. The GATT aims at trade liberalisation yet most environmental policies are enforced through trade-restrictive devices like quotas and licences. Article XX of the GATT is anomalous: it does not explicitly mention the environment, yet member states rely on it as an environmental protection clause. This thesis discusses the various issues emanating from the trade/environmental debate. The history of Article XX is reviewed and the issues that arise in the adjudication of Articles XX (b) and (g) in a trade/environment context are analysed in light of the decisions by the GATTIWTO dispute settlement bodies. The role played by Multilateral Environmental Agreements (MEAs) in protecting the environment is discussed. However, the relationship between MEAs and the WTO is also scrutinised as these rule-making bodies often come into conflict: firstly, because they serve two differing interests - on the one hand, MEAs allow for the use of trade restrictive measures in environmental agreements and on the other, the WTO calls for unrestricted trade unless exceptional circumstances exist; and secondly, member states that are party to both the WTO and MEAs are often forced to subscribe to international trade rules that are incompatible with those in environmental agreements. The trade/environmental debate is important to both the developed and developing worlds. The developed world is in favour of environmental policies which protect the environment from degradation. On the other hand, the developing world is in desperate need of the benefits of trade liberalisation so as to cater for high unemployment rates and poor economic growth. The question thus arises as to whether, when environmental issues are promoted, developing countries will not suffer at the expense of developed nations which may engage in protectionist measures under the pretext of environmental conservation. The divide between developed and developing countries is illustrated in Chapter 5 through case studies on coal mining in the USA and South Africa. The conclusion reached is that total co-operation is essential between developed and developing states for success in safeguarding the environment from degradation. Accordingly, the trade/environmental debate cannot be isolated from the conflicting approaches in developed and developing countries. The conclusions in the final chapter seek to strike a balance between trade liberalisation and environmental protection. Recommendations are made on how the trade/environmental challenges could be dealt with and the regulation of trade restrictive devices to exclude, or at least limit, protectionism.
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Investigating grade 10 geography teachers' implementation of a learner-centred approach in selected Namibian schools
- Authors: Angula, Adelheid
- Date: 2007
- Subjects: Geography -- Study and teaching (Secondary) -- Namibia Student-centered learning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1851 , http://hdl.handle.net/10962/d1004459
- Description: Geography, more than other subjects in the curriculum, plays a central role in general education in equipping learners with skills and competencies needed for modern living and global citizenship. A learner-centred education in Namibia was adopted to provide more opportunities for learners to develop the required skills and competencies irrespective of their different cultural background. This small-scale case study investigated three Grade 10 geography teachers' understanding and implementation ofa learner-centred approach to gain insights into how leamer-centred education is being implemented in the context of Geography. The research design adopted a qualitative approach within an interpretative orientation. Data were collected through interviews, classroom observations and documentary analysis. The research was conducted at three selected schools in Oshikoto Region with three Grade 10 geography teachers The findings revealed, firstly, that teachers have a limited understanding of the key ideas ofLCE, such as, prior knowledge, role of questioning, and social interaction in learning; use of resources and the types of assessment activities which comply with the aims of LCE. Seconclly, the findings revealed that the policy documents, such as syllabuses, that are being used by the participants are not in line with the tenets ofLCE. Thirdly, teachers appeared to have limited subject knowledge, as revealed by their lack of understanding of how to translate the aims and assessment objectives into their daily lessons. The study therefore raises some possibilities for improving the implementation of LCE in the selected schools if the gaps as identified by this study are reduced.
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- Authors: Angula, Adelheid
- Date: 2007
- Subjects: Geography -- Study and teaching (Secondary) -- Namibia Student-centered learning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1851 , http://hdl.handle.net/10962/d1004459
- Description: Geography, more than other subjects in the curriculum, plays a central role in general education in equipping learners with skills and competencies needed for modern living and global citizenship. A learner-centred education in Namibia was adopted to provide more opportunities for learners to develop the required skills and competencies irrespective of their different cultural background. This small-scale case study investigated three Grade 10 geography teachers' understanding and implementation ofa learner-centred approach to gain insights into how leamer-centred education is being implemented in the context of Geography. The research design adopted a qualitative approach within an interpretative orientation. Data were collected through interviews, classroom observations and documentary analysis. The research was conducted at three selected schools in Oshikoto Region with three Grade 10 geography teachers The findings revealed, firstly, that teachers have a limited understanding of the key ideas ofLCE, such as, prior knowledge, role of questioning, and social interaction in learning; use of resources and the types of assessment activities which comply with the aims of LCE. Seconclly, the findings revealed that the policy documents, such as syllabuses, that are being used by the participants are not in line with the tenets ofLCE. Thirdly, teachers appeared to have limited subject knowledge, as revealed by their lack of understanding of how to translate the aims and assessment objectives into their daily lessons. The study therefore raises some possibilities for improving the implementation of LCE in the selected schools if the gaps as identified by this study are reduced.
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Investigating the effect of Glomus etunicatum colonization on structure and phloem transport in roots of Eragrostis curvula (Umgeni)
- Authors: Skinner, Amy
- Date: 2007
- Subjects: Glomus (Fungi) , Phloem , Plant translocation , Weeping lovegrass , Vesicular-arbuscular mycorrhizas , Mycorrhizal fungi , Mycorrhizas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4227 , http://hdl.handle.net/10962/d1003796 , Glomus (Fungi) , Phloem , Plant translocation , Weeping lovegrass , Vesicular-arbuscular mycorrhizas , Mycorrhizal fungi , Mycorrhizas
- Description: The symbiotic unit of an arbuscular mycorrhizal fungus and its host is able toachieve and maintain far higher inflow of nutrients than non-mycorrhizal roots. The colonization strategy of the mycobiont within the plant is intrinsic to the symbiosis with respect to both structural adaptations and nutrient exchange. An investigation into the effect of Glomus etunicatum colonization on the structure and phloem transport in Eragrostis curvula (Umgeni) allowed for greater insight into the dynamic of the symbiosis. The combined use of stains (such as Trypan Blue, Chlorazol Black, Safranin and Fast Green), and techniques, (such as freeze-microtome transverse sectioning and permanent slide preparations) contributed to a successful general observation of an intermediate colonization strategy using light microscopy methods. However, clarity into structural detail of mycorrhizal forms required electron microscopy studies. The SEM method used with freeze fracture was a relatively quick and simple method allowing for the observation of surface and internal features. The TEM method allowed for highresolution images providing insight into the variations in the apoplasmic compartmental form, and how this may relate to the function of the symbiosis with regard to fungal coils or arbuscules. The apoplasmic nature of mycorrhizas was substantiated and no symplasmic connections were found between symbionts. Fluorescence studies demonstrated that 5,6-carboxyfluorescein was transported through the phloem into the roots of E. curvula, but remained predominantly in the root phloem. Unloading only occurred in optimal nutrient exchange areas of meristimatic lateral or apical growth regions. It was not possible, using fluorescence techniques and related equipment available, to conclusively establish if there were symplasmic connections between the mycobiont and its host or if bidirectional transfer of nutrients occurred at the same interface.
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- Authors: Skinner, Amy
- Date: 2007
- Subjects: Glomus (Fungi) , Phloem , Plant translocation , Weeping lovegrass , Vesicular-arbuscular mycorrhizas , Mycorrhizal fungi , Mycorrhizas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4227 , http://hdl.handle.net/10962/d1003796 , Glomus (Fungi) , Phloem , Plant translocation , Weeping lovegrass , Vesicular-arbuscular mycorrhizas , Mycorrhizal fungi , Mycorrhizas
- Description: The symbiotic unit of an arbuscular mycorrhizal fungus and its host is able toachieve and maintain far higher inflow of nutrients than non-mycorrhizal roots. The colonization strategy of the mycobiont within the plant is intrinsic to the symbiosis with respect to both structural adaptations and nutrient exchange. An investigation into the effect of Glomus etunicatum colonization on the structure and phloem transport in Eragrostis curvula (Umgeni) allowed for greater insight into the dynamic of the symbiosis. The combined use of stains (such as Trypan Blue, Chlorazol Black, Safranin and Fast Green), and techniques, (such as freeze-microtome transverse sectioning and permanent slide preparations) contributed to a successful general observation of an intermediate colonization strategy using light microscopy methods. However, clarity into structural detail of mycorrhizal forms required electron microscopy studies. The SEM method used with freeze fracture was a relatively quick and simple method allowing for the observation of surface and internal features. The TEM method allowed for highresolution images providing insight into the variations in the apoplasmic compartmental form, and how this may relate to the function of the symbiosis with regard to fungal coils or arbuscules. The apoplasmic nature of mycorrhizas was substantiated and no symplasmic connections were found between symbionts. Fluorescence studies demonstrated that 5,6-carboxyfluorescein was transported through the phloem into the roots of E. curvula, but remained predominantly in the root phloem. Unloading only occurred in optimal nutrient exchange areas of meristimatic lateral or apical growth regions. It was not possible, using fluorescence techniques and related equipment available, to conclusively establish if there were symplasmic connections between the mycobiont and its host or if bidirectional transfer of nutrients occurred at the same interface.
- Full Text: