Economic feasibility of an experimental octopus fishery in South Africa
- Authors: Oosthuizen, Ané
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6760 , http://hdl.handle.net/10962/d1007773
- Description: Octopus vulgaris was identified as a new marine resource to be commercially exploited through an experimental fishery. A recent policy on developing fisheries in South Africa emphasizes the importance of investigating the economic feasibility of a fishery as part of its management framework. The study reported here generated baseline information necessary in the design of the experimental fishery, giving guidelines as to which vessels, fishing gear and markets would be most feasible. The proposed fishery, gear and vessel type, fishing techniques and expected catch rates are described, the results of market research are outlined, and the cost of fishing is estimated. The potential business should consist of small and medium-sized vessels deploying unbaited pots attached to long lines. The longline pot fishery could be economically feasible, provided a 30 percent catch in 6600 pots/month is attained. Only existing, debt-free vessels should be used. The minimum catch per unit effort (CPUE) for various fishing operation scenarios was calculated to determine economic feasibility. This is an estimated minimum CPUE, based on assumptions that cannot be confirmed until the fishery starts. Furthermore, this economic analysis also needs to be assessed by stakeholders with experience of fishery operations , Rhodes Centenary issue of: South African Journal of Science.
- Full Text:
- Date Issued: 2004
- Authors: Oosthuizen, Ané
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6760 , http://hdl.handle.net/10962/d1007773
- Description: Octopus vulgaris was identified as a new marine resource to be commercially exploited through an experimental fishery. A recent policy on developing fisheries in South Africa emphasizes the importance of investigating the economic feasibility of a fishery as part of its management framework. The study reported here generated baseline information necessary in the design of the experimental fishery, giving guidelines as to which vessels, fishing gear and markets would be most feasible. The proposed fishery, gear and vessel type, fishing techniques and expected catch rates are described, the results of market research are outlined, and the cost of fishing is estimated. The potential business should consist of small and medium-sized vessels deploying unbaited pots attached to long lines. The longline pot fishery could be economically feasible, provided a 30 percent catch in 6600 pots/month is attained. Only existing, debt-free vessels should be used. The minimum catch per unit effort (CPUE) for various fishing operation scenarios was calculated to determine economic feasibility. This is an estimated minimum CPUE, based on assumptions that cannot be confirmed until the fishery starts. Furthermore, this economic analysis also needs to be assessed by stakeholders with experience of fishery operations , Rhodes Centenary issue of: South African Journal of Science.
- Full Text:
- Date Issued: 2004
Nuclear translocation of the Hsp70/Hsp90 organizing protein mSTI1 is regulated by cell cycle kinases
- Longshaw, Victoria M, Chapple, J Paul, Cheetham, Michael E, Blatch, Gregory L
- Authors: Longshaw, Victoria M , Chapple, J Paul , Cheetham, Michael E , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6488 , http://hdl.handle.net/10962/d1006271 , https://dx.doi.org/10.1242/jcs.00905
- Description: The co-chaperone murine stress-inducible protein 1 (mSTI1), an Hsp70/Hsp90 organizing protein (Hop) homologue, mediates the assembly of the Hsp70/Hsp90 chaperone heterocomplex. The mSTI1 protein can be phosphorylated in vitro by cell cycle kinases proximal to a putative nuclear localization signal (NLS), which substantiated a predicted casein kinase II (CKII)-cdc2 kinase-NLS (CcN) motif at position 180-239 and suggested that mSTI1 might move between the cytoplasm and the nucleus under certain cell cycle conditions. The mechanism responsible for the cellular localization of mSTI1 was probed using NIH3T3 fibroblasts to investigate the localization of endogenous mSTI1 and enhanced green fluorescent protein (EGFP)-tagged mSTI1 mutants. Localization studies on cell lines stably expressing NLS(mSTI1)-EGFP and EGFP demonstrated that the NLS(mSTI1) was able to promote a nuclear localization of EGFP. The mSTI1 protein was exclusively cytoplasmic in most cells under normal conditions but was present in the nucleus of a subpopulation of cells and accumulated in the nucleus following inhibition of nuclear export (leptomycin B treatment). G1/S-phase arrest (using hydroxyurea) and inhibition of cdc2 kinase (using olomoucine) but not inhibition of casein kinase II (using 5,6-dichlorobenzimidazole riboside), increased the proportion of cells with endogenous mSTI1 nuclear staining. mSTI1-EGFP behaved identically to endogenous mSTI1. The functional importance of key residues was tested using modified mSTI1-EGFP proteins. Inactivation and phosphorylation mimicking of potential phosphorylation sites in mSTI1 altered the nuclear translocation. Mimicking of phosphorylation at the mSTI1 CKII phosphorylation site (S189E) promoted nuclear localization of mSTI1-EGFP. Mimicking phosphorylation at the cdc2 kinase phosphorylation site (T198E) promoted cytoplasmic localization of mSTI1-EGFP at the G1/S-phase transition,whereas removal of this site (T198A) promoted the nuclear localization of mSTI1-EGFP under the same conditions. These data provide the first evidence of nuclear import and export of a major Hsp70/Hsp90 co-chaperone and the regulation of this nuclear-cytoplasmic shuttling by cell cycle status and cell cycle kinases.
- Full Text:
- Date Issued: 2004
Nuclear translocation of the Hsp70/Hsp90 organizing protein mSTI1 is regulated by cell cycle kinases
- Authors: Longshaw, Victoria M , Chapple, J Paul , Cheetham, Michael E , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6488 , http://hdl.handle.net/10962/d1006271 , https://dx.doi.org/10.1242/jcs.00905
- Description: The co-chaperone murine stress-inducible protein 1 (mSTI1), an Hsp70/Hsp90 organizing protein (Hop) homologue, mediates the assembly of the Hsp70/Hsp90 chaperone heterocomplex. The mSTI1 protein can be phosphorylated in vitro by cell cycle kinases proximal to a putative nuclear localization signal (NLS), which substantiated a predicted casein kinase II (CKII)-cdc2 kinase-NLS (CcN) motif at position 180-239 and suggested that mSTI1 might move between the cytoplasm and the nucleus under certain cell cycle conditions. The mechanism responsible for the cellular localization of mSTI1 was probed using NIH3T3 fibroblasts to investigate the localization of endogenous mSTI1 and enhanced green fluorescent protein (EGFP)-tagged mSTI1 mutants. Localization studies on cell lines stably expressing NLS(mSTI1)-EGFP and EGFP demonstrated that the NLS(mSTI1) was able to promote a nuclear localization of EGFP. The mSTI1 protein was exclusively cytoplasmic in most cells under normal conditions but was present in the nucleus of a subpopulation of cells and accumulated in the nucleus following inhibition of nuclear export (leptomycin B treatment). G1/S-phase arrest (using hydroxyurea) and inhibition of cdc2 kinase (using olomoucine) but not inhibition of casein kinase II (using 5,6-dichlorobenzimidazole riboside), increased the proportion of cells with endogenous mSTI1 nuclear staining. mSTI1-EGFP behaved identically to endogenous mSTI1. The functional importance of key residues was tested using modified mSTI1-EGFP proteins. Inactivation and phosphorylation mimicking of potential phosphorylation sites in mSTI1 altered the nuclear translocation. Mimicking of phosphorylation at the mSTI1 CKII phosphorylation site (S189E) promoted nuclear localization of mSTI1-EGFP. Mimicking phosphorylation at the cdc2 kinase phosphorylation site (T198E) promoted cytoplasmic localization of mSTI1-EGFP at the G1/S-phase transition,whereas removal of this site (T198A) promoted the nuclear localization of mSTI1-EGFP under the same conditions. These data provide the first evidence of nuclear import and export of a major Hsp70/Hsp90 co-chaperone and the regulation of this nuclear-cytoplasmic shuttling by cell cycle status and cell cycle kinases.
- Full Text:
- Date Issued: 2004
Western Alumna inspiring catalyst
- University of Western Ontario
- Authors: University of Western Ontario
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7172 , http://hdl.handle.net/10962/d1006078 , Nyokong, Tebello
- Description: University of Western Ontario President's Report 2004
- Full Text:
- Authors: University of Western Ontario
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7172 , http://hdl.handle.net/10962/d1006078 , Nyokong, Tebello
- Description: University of Western Ontario President's Report 2004
- Full Text:
Vice-Chancellor's Annual Review 2004
- Language: English
- Type: Article
- Identifier: vital:7169 , http://hdl.handle.net/10962/d1006071
- Description: The highlight of 2004 was the award of both the Vice-Chancellor's Senior Research Award and the SABC2 Shoprite-Checkers Woman of the Year Award (Science and Technology) to Professor Tebello Nyokong, whose research on the development of photosensitisers for photodynamic cancer therapy has received considerable attention.
- Full Text:
- Language: English
- Type: Article
- Identifier: vital:7169 , http://hdl.handle.net/10962/d1006071
- Description: The highlight of 2004 was the award of both the Vice-Chancellor's Senior Research Award and the SABC2 Shoprite-Checkers Woman of the Year Award (Science and Technology) to Professor Tebello Nyokong, whose research on the development of photosensitisers for photodynamic cancer therapy has received considerable attention.
- Full Text:
Reduction in transport in wheat (Triticum aestivum) is caused by sustained phloem feeding by the Russian wheat aphid (Diuraphis noxia)
- Botha, Christiaan E J, Matsiliza, Babalwa
- Authors: Botha, Christiaan E J , Matsiliza, Babalwa
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6498 , http://hdl.handle.net/10962/d1004498
- Description: The Russian wheat aphid (Diuraphis noxia) feeds preferentially from the phloem of longitudinal veins of nonresistant wheat leaves. The xenobiotic, 5,6-CFDA was applied to exposed leaf blade mesophyll cells in control and aphid-infested plants. In control plants, the fluorophore moved approximately 5–6cm from the point of application of 5,6-CFDA within 3h of application. The fluorochrome was transported in the sieve tube companion cell complex, including those in the numerous interconnecting transverse veins. Leaf blades on which the Russian wheat aphid had been feeding demonstrated a marked decrease in 5,6-CF transport. Aphids feeding on the leaves formed local sinks and redirected the fluorophore (and presumably associated assimilate) to the aphids’ gut, with little longitudinal translocation of 5,6-CF below inserted stylets or aphid feeding areas. Aniline blue staining revealed massive deposits of wound and reaction callose caused by the aphids, with callose associated with the sieve plates, pore-plasmodesma between the companion cells and their associated sieve tubes, as well as with plasmodesmal aggregates in parenchymatous elements within the vascular bundles. Leaves that had been colonised by aphids but from which the aphids were removed, showed extensive wound callose deposits, which persisted for up to 48h after removal of aphid colonies, suggesting that the damage caused by aphid feeding is a long-term, non-transient event in non-resistant plants.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Christiaan E J , Matsiliza, Babalwa
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6498 , http://hdl.handle.net/10962/d1004498
- Description: The Russian wheat aphid (Diuraphis noxia) feeds preferentially from the phloem of longitudinal veins of nonresistant wheat leaves. The xenobiotic, 5,6-CFDA was applied to exposed leaf blade mesophyll cells in control and aphid-infested plants. In control plants, the fluorophore moved approximately 5–6cm from the point of application of 5,6-CFDA within 3h of application. The fluorochrome was transported in the sieve tube companion cell complex, including those in the numerous interconnecting transverse veins. Leaf blades on which the Russian wheat aphid had been feeding demonstrated a marked decrease in 5,6-CF transport. Aphids feeding on the leaves formed local sinks and redirected the fluorophore (and presumably associated assimilate) to the aphids’ gut, with little longitudinal translocation of 5,6-CF below inserted stylets or aphid feeding areas. Aniline blue staining revealed massive deposits of wound and reaction callose caused by the aphids, with callose associated with the sieve plates, pore-plasmodesma between the companion cells and their associated sieve tubes, as well as with plasmodesmal aggregates in parenchymatous elements within the vascular bundles. Leaves that had been colonised by aphids but from which the aphids were removed, showed extensive wound callose deposits, which persisted for up to 48h after removal of aphid colonies, suggesting that the damage caused by aphid feeding is a long-term, non-transient event in non-resistant plants.
- Full Text:
- Date Issued: 2004
Constructing a cardinal measure of democratic development in a transition polity: the Nigerian example
- Dinneya, Godson E, Tsegaye, Asrat
- Authors: Dinneya, Godson E , Tsegaye, Asrat
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6076 , http://hdl.handle.net/10962/d1003837
- Description: Existing measures of the level of democracy present in a given state treat democracy as a product and therefore place undue emphasis on actual freedoms enjoyed by the citizens of the country. In transition polities where the actual levels of freedom are low despite continuing efforts to democratize, democracy should be seen as a process rather than a product. A measure that dilutes the end product to capture today's struggles against undemocratic structures and policies does so in order to recognize the foundations these inputs lay for future democratic development. Nigeria exemplifies the many polities in transition on the African continent. This essay looks at the major political events that typify the processes of power change, quality of governance, political environment and democratic dividends, and uses them to construct democratization indices to determine the pattern and level of democratization in Nigeria since political independence. This exercise sets the stage for assessing the impacts of various dimensions of democratization on the performance of the Nigerian economy.
- Full Text:
- Date Issued: 2004
- Authors: Dinneya, Godson E , Tsegaye, Asrat
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6076 , http://hdl.handle.net/10962/d1003837
- Description: Existing measures of the level of democracy present in a given state treat democracy as a product and therefore place undue emphasis on actual freedoms enjoyed by the citizens of the country. In transition polities where the actual levels of freedom are low despite continuing efforts to democratize, democracy should be seen as a process rather than a product. A measure that dilutes the end product to capture today's struggles against undemocratic structures and policies does so in order to recognize the foundations these inputs lay for future democratic development. Nigeria exemplifies the many polities in transition on the African continent. This essay looks at the major political events that typify the processes of power change, quality of governance, political environment and democratic dividends, and uses them to construct democratization indices to determine the pattern and level of democratization in Nigeria since political independence. This exercise sets the stage for assessing the impacts of various dimensions of democratization on the performance of the Nigerian economy.
- Full Text:
- Date Issued: 2004
The bells of Jamestown, South Atlantic Ocean
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6177 , http://hdl.handle.net/10962/d1012370 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2004
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6177 , http://hdl.handle.net/10962/d1012370 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2004
Science after a century at Rhodes University
- Authors: Woods, D R
- Date: 2004
- Language: English
- Type: Article , text
- Identifier: vital:7123 , http://hdl.handle.net/10962/d1006584
- Description: Rhodes Centenary issue , The small University of Rhodes (6142 students), in the rural city of Grahamstown, was established in 1904 as a result of a £50 000 grant from the Rhodes Trust in Oxford. It grew out of St Andrew’s College, which provided the first four professors and 41 students. The first paper from Rhodes in the South African Journal of Science (then called the Report of the South African Association for the Advancement of Science) was by Selmar Schonland, one of the university’s founding fathers. Entitled: ‘Biological and ethnological observations on a trip to the N.E. Kalahari’, it appeared in 1904. The following pages provide a glimpse into the growth and achievements of various departments in the faculties of Science and Pharmacy and associated institutes a century after the university was born.
- Full Text:
- Date Issued: 2004
- Authors: Woods, D R
- Date: 2004
- Language: English
- Type: Article , text
- Identifier: vital:7123 , http://hdl.handle.net/10962/d1006584
- Description: Rhodes Centenary issue , The small University of Rhodes (6142 students), in the rural city of Grahamstown, was established in 1904 as a result of a £50 000 grant from the Rhodes Trust in Oxford. It grew out of St Andrew’s College, which provided the first four professors and 41 students. The first paper from Rhodes in the South African Journal of Science (then called the Report of the South African Association for the Advancement of Science) was by Selmar Schonland, one of the university’s founding fathers. Entitled: ‘Biological and ethnological observations on a trip to the N.E. Kalahari’, it appeared in 1904. The following pages provide a glimpse into the growth and achievements of various departments in the faculties of Science and Pharmacy and associated institutes a century after the university was born.
- Full Text:
- Date Issued: 2004
The bells of north western Transkei, South Africa
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6183 , http://hdl.handle.net/10962/d1012379 , http://www.ringingworld.co.uk
- Description: [From Introduction] Few of the many visitors to South Africa journey into the isolated country east of Queenstown and south of Elliot, in the rugged basin and range country of that part of the Transkei. That is largely a forgotten land, hidden south of the Mount Arthur range from the rolling grasslands of the Drakensburg foothills and their commercial farms. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2004
- Authors: Lewis, Colin A
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6183 , http://hdl.handle.net/10962/d1012379 , http://www.ringingworld.co.uk
- Description: [From Introduction] Few of the many visitors to South Africa journey into the isolated country east of Queenstown and south of Elliot, in the rugged basin and range country of that part of the Transkei. That is largely a forgotten land, hidden south of the Mount Arthur range from the rolling grasslands of the Drakensburg foothills and their commercial farms. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2004
Metus in the Roman law of obligations
- Authors: Glover, Graham B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6336 , http://hdl.handle.net/10962/d1012401
- Description: [From the introduction]: An entire title of book four of Justinian’s Digest is devoted to explaining the doctrine of metus as it was understood at the time of the codification of the Roman law. That title begins with the following statement: "The praetor says: 'I will not hold valid what has been done under duress.'" This unequivocal statement of legal principle illustrates, in very general terms, that by the time the Corpus Iuris Civilis was compiled, the Romans disapproved of persons using threats to inspire the creation of legal obligations, and that it was possible to avoid the legal consequences of an obligation because it was induced by metus. The Corpus Iuris Civilis remains our most valuable source of authority with regard to how duress cases were treated in Roman times. But the relevant textual sources pose some fundamental difficulties. Far from containing a coherent, structured analysis of the law, the relevant passages in fact amount to a jigsaw-puzzle of uncoordinated, haphazard, and occasionally contradictory legal propositions
- Full Text:
- Date Issued: 2004
- Authors: Glover, Graham B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6336 , http://hdl.handle.net/10962/d1012401
- Description: [From the introduction]: An entire title of book four of Justinian’s Digest is devoted to explaining the doctrine of metus as it was understood at the time of the codification of the Roman law. That title begins with the following statement: "The praetor says: 'I will not hold valid what has been done under duress.'" This unequivocal statement of legal principle illustrates, in very general terms, that by the time the Corpus Iuris Civilis was compiled, the Romans disapproved of persons using threats to inspire the creation of legal obligations, and that it was possible to avoid the legal consequences of an obligation because it was induced by metus. The Corpus Iuris Civilis remains our most valuable source of authority with regard to how duress cases were treated in Roman times. But the relevant textual sources pose some fundamental difficulties. Far from containing a coherent, structured analysis of the law, the relevant passages in fact amount to a jigsaw-puzzle of uncoordinated, haphazard, and occasionally contradictory legal propositions
- Full Text:
- Date Issued: 2004
‘The Gentle Art of Letting the Other Fellow Have Your Own Way': Viewpoints on a media narrative used to promote the proposed N2 toll road
- Farrington, Katie, Davies, Kate
- Authors: Farrington, Katie , Davies, Kate
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6098 , http://hdl.handle.net/10962/d1008628
- Description: This viewpoint paper is written in response to a South African National Roads Agency (SANRAL) advertorial published in various South African regional newspapers in February 2004. We highlight the importance of developing ‘media literacy’ – reading skills which enable the critical deconstruction of media texts. We explore, more specifically, the public relations strategies used by large corporations, and the media’s role as disseminators of corporate marketing material.We also look at the relevance in identifying the language and discourse positioning the writer, photographer, reader and their choice representative medium.
- Full Text:
- Date Issued: 2004
- Authors: Farrington, Katie , Davies, Kate
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6098 , http://hdl.handle.net/10962/d1008628
- Description: This viewpoint paper is written in response to a South African National Roads Agency (SANRAL) advertorial published in various South African regional newspapers in February 2004. We highlight the importance of developing ‘media literacy’ – reading skills which enable the critical deconstruction of media texts. We explore, more specifically, the public relations strategies used by large corporations, and the media’s role as disseminators of corporate marketing material.We also look at the relevance in identifying the language and discourse positioning the writer, photographer, reader and their choice representative medium.
- Full Text:
- Date Issued: 2004
Particle precipitation effects in the daytime E-region in the South Atlantic Anomaly region
- Authors: Haggard, Raymond
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6794 , http://hdl.handle.net/10962/d1003836
- Description: The behaviour of the normal daytime E-layer over the South Atlantic Anomaly region during 23 days of project ISAAC (29 June to 21 July 1983) has been examined. Enhanced production rates due to precipitated electrons were calculated from the observed data and compared well with the production rates from the mean electron fluxes in the range 0.2–26 keV observed from the satellite Atmosphere Explorer-C during 1973–77, discussed by Gledhill and Hoffman.1 The present study shows that there is evidence of a significant source of extra ionization, in addition to solar ultraviolet and X-radiation, in the South Atlantic Anomaly region.
- Full Text:
- Date Issued: 2004
- Authors: Haggard, Raymond
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6794 , http://hdl.handle.net/10962/d1003836
- Description: The behaviour of the normal daytime E-layer over the South Atlantic Anomaly region during 23 days of project ISAAC (29 June to 21 July 1983) has been examined. Enhanced production rates due to precipitated electrons were calculated from the observed data and compared well with the production rates from the mean electron fluxes in the range 0.2–26 keV observed from the satellite Atmosphere Explorer-C during 1973–77, discussed by Gledhill and Hoffman.1 The present study shows that there is evidence of a significant source of extra ionization, in addition to solar ultraviolet and X-radiation, in the South Atlantic Anomaly region.
- Full Text:
- Date Issued: 2004
Politics, latent and overt, in Hill of Fools
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:7064 , http://hdl.handle.net/10962/d1007430
- Description: [From the text]: R. L. Peteni’s novel Hill of Fools (1976) is a work that benefits greatly when Collingwood’s maxim is observed. The author’s family history and the circumstances surrounding the book’s publication add a dimension of political and social meaning which its surface deliberately occludes. Perhaps more importantly, while the story can readily be enjoyed, the quality of sensibility behind the work is not readily accessed without understanding some of the socio-political background.
- Full Text:
- Date Issued: 2004
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:7064 , http://hdl.handle.net/10962/d1007430
- Description: [From the text]: R. L. Peteni’s novel Hill of Fools (1976) is a work that benefits greatly when Collingwood’s maxim is observed. The author’s family history and the circumstances surrounding the book’s publication add a dimension of political and social meaning which its surface deliberately occludes. Perhaps more importantly, while the story can readily be enjoyed, the quality of sensibility behind the work is not readily accessed without understanding some of the socio-political background.
- Full Text:
- Date Issued: 2004
Evidence for Archaean lamprophyre from the Kaapvaal Craton, South Africa
- Prevec, S A, Anhaeusser, C R, Poujol, M
- Authors: Prevec, S A , Anhaeusser, C R , Poujol, M
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6739 , http://hdl.handle.net/10962/d1007555
- Description: A suite of mafic dykes occurs as a late component in a wellcharacterized trondhjemite–tonalite–diorite–granodiorite assemblage in the Johannesburg Dome of the central Kaapvaal Craton, southern Africa. The dykes have been subdivided into two sets, based on their orientation, and major and trace element geochemistry. Set 1 dykes are characterized by elevated SiO2, Al2O3 and TiO2, and particularly by enriched LILE and HSFE (e.g. Zr > 200 ppm, Nb > 20 ppm, Ba > 300 ppm), higher than in any of the accompanying felsic rocks. REE and trace element values for Set 1 dykes are similar to those for calc-alkaline lamprophyres. The Set 2 dykes have similar trace element distributions, but are significantly less enriched in general, and are broadly tholeiitic in composition, with enriched MgO (>11 wt. percentage) indicative of an olivine–phyric tholeiitic basaltic protolith. Field relationships and available U–Pb zircon geochronology indicate that the dykes are contemporaneous with components of the trondhjemitic host rocks, and with late granodiorites. The geochemical, geochronological and field petrological setting indicates partial melting of basaltic and eclogitic lithosphere at c. 3120 Myr ago in the basal Kaapvaal Craton, and subsequent emplacement into pre-existing c. 3430 Myr tonalitic to dioritic crust.
- Full Text:
- Date Issued: 2004
- Authors: Prevec, S A , Anhaeusser, C R , Poujol, M
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6739 , http://hdl.handle.net/10962/d1007555
- Description: A suite of mafic dykes occurs as a late component in a wellcharacterized trondhjemite–tonalite–diorite–granodiorite assemblage in the Johannesburg Dome of the central Kaapvaal Craton, southern Africa. The dykes have been subdivided into two sets, based on their orientation, and major and trace element geochemistry. Set 1 dykes are characterized by elevated SiO2, Al2O3 and TiO2, and particularly by enriched LILE and HSFE (e.g. Zr > 200 ppm, Nb > 20 ppm, Ba > 300 ppm), higher than in any of the accompanying felsic rocks. REE and trace element values for Set 1 dykes are similar to those for calc-alkaline lamprophyres. The Set 2 dykes have similar trace element distributions, but are significantly less enriched in general, and are broadly tholeiitic in composition, with enriched MgO (>11 wt. percentage) indicative of an olivine–phyric tholeiitic basaltic protolith. Field relationships and available U–Pb zircon geochronology indicate that the dykes are contemporaneous with components of the trondhjemitic host rocks, and with late granodiorites. The geochemical, geochronological and field petrological setting indicates partial melting of basaltic and eclogitic lithosphere at c. 3120 Myr ago in the basal Kaapvaal Craton, and subsequent emplacement into pre-existing c. 3430 Myr tonalitic to dioritic crust.
- Full Text:
- Date Issued: 2004
The V-C's Awards
- Language: English
- Type: Article
- Identifier: vital:7170 , http://hdl.handle.net/10962/d1006074
- Description: Prof Tebello Nyokong, from the Department of Chemistry, receives the V-C' s Senior Distinguished Research Award in 2003 and 2004
- Full Text:
- Language: English
- Type: Article
- Identifier: vital:7170 , http://hdl.handle.net/10962/d1006074
- Description: Prof Tebello Nyokong, from the Department of Chemistry, receives the V-C' s Senior Distinguished Research Award in 2003 and 2004
- Full Text:
Effects of substituents and solvents on the photochemical properties of zinc phthalocyanine complexes and their protonated derivatives
- Ogunsipe, Abimbola Olukayode, Nyokong, Tebello
- Authors: Ogunsipe, Abimbola Olukayode , Nyokong, Tebello
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6585 , http://hdl.handle.net/10962/d1004161
- Description: Zinc phthalocyanine derivatives containing various ring substituents and axial ligands were studied with respect to the effect of substituents on protonation. Aggregation resulted in failure of some of the ZnPc derivatives to protonate. In fact addition of protonating agents to aggregated ZnPc derivatives resulted in increase in aggregation followed by slow degradation. Axial ligands were lost on protonation. Photobleaching, fluorescence and singlet oxygen quantum yields of the protonated derivatives were compared with those of the unprotonated derivatives. In all cases protonation decreases the singlet oxygen and fluorescence quantum yields. However, photobleaching quantum yields decreased (i.e. stability increased) for the protonated derivatives except when axial ligands were present, where protonation resulted in decrease in stability.
- Full Text:
- Date Issued: 2004
- Authors: Ogunsipe, Abimbola Olukayode , Nyokong, Tebello
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6585 , http://hdl.handle.net/10962/d1004161
- Description: Zinc phthalocyanine derivatives containing various ring substituents and axial ligands were studied with respect to the effect of substituents on protonation. Aggregation resulted in failure of some of the ZnPc derivatives to protonate. In fact addition of protonating agents to aggregated ZnPc derivatives resulted in increase in aggregation followed by slow degradation. Axial ligands were lost on protonation. Photobleaching, fluorescence and singlet oxygen quantum yields of the protonated derivatives were compared with those of the unprotonated derivatives. In all cases protonation decreases the singlet oxygen and fluorescence quantum yields. However, photobleaching quantum yields decreased (i.e. stability increased) for the protonated derivatives except when axial ligands were present, where protonation resulted in decrease in stability.
- Full Text:
- Date Issued: 2004
Making sense of science through two languages: a South African case study
- Authors: Probyn, Margie J
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7025 , http://hdl.handle.net/10962/d1007209
- Description: Mzamo Senior Secondary School (not its real name) looks like any typical township school in South Africa: modern face-brick classroom blocks which conceal a serious lack of resources, material and human. Under apartheid the disparities in spending on white and African students meant hugely different teaching and learning contexts - including infrastructure, teacher training, pupil: teacher ratios and teaching materials. Today, 10 years into the new democracy and despite government’s efforts to equalize spending, the historic inequalities persist. The school is surrounded by township houses and shacks that reflect the high poverty levels in the Eastern Cape Province. Students at schools like this face an additional but less obvious problem – that of the language medium. Although in the Eastern Cape, Xhosa is the home language of 83,8% of the population and English speakers comprise only 3.7%, the official language medium in schools is English from the beginning of Grade 4 in the majority of schools. South Africa is a multilingual country with 11 official languages recognized in the Constitution of 1996 – 9 indigenous languages and the two colonial languages, English and Afrikaans.
- Full Text:
- Date Issued: 2004
- Authors: Probyn, Margie J
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7025 , http://hdl.handle.net/10962/d1007209
- Description: Mzamo Senior Secondary School (not its real name) looks like any typical township school in South Africa: modern face-brick classroom blocks which conceal a serious lack of resources, material and human. Under apartheid the disparities in spending on white and African students meant hugely different teaching and learning contexts - including infrastructure, teacher training, pupil: teacher ratios and teaching materials. Today, 10 years into the new democracy and despite government’s efforts to equalize spending, the historic inequalities persist. The school is surrounded by township houses and shacks that reflect the high poverty levels in the Eastern Cape Province. Students at schools like this face an additional but less obvious problem – that of the language medium. Although in the Eastern Cape, Xhosa is the home language of 83,8% of the population and English speakers comprise only 3.7%, the official language medium in schools is English from the beginning of Grade 4 in the majority of schools. South Africa is a multilingual country with 11 official languages recognized in the Constitution of 1996 – 9 indigenous languages and the two colonial languages, English and Afrikaans.
- Full Text:
- Date Issued: 2004
Phenomenology in education : a case study in educational leadership
- Authors: Van der Mescht, Hennie
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6101 , http://hdl.handle.net/10962/d1008665
- Description: [From the introduction]: Overheard during tea at an Education Faculty research design course: “Phenomenology produces interesting and surprising results, but it’s just too much work …” The speaker was a prospective Masters student who had decided against “phenomenological” research, presumably because “it’s just too much work”. Having been deeply involved in phenomenological research myself for some years, I could identify with his reservation. But his first statement is of course equally true: phenomenological research does indeed produce “interesting and surprising results”, as many of my students have found. I should at the outset describe what I mean by phenomenological research more carefully, since, as Schweitzer (2002) has recently pointed out, there is certainly more than one meaning out there. The kind of research I am referring to is not the kind frequently featured in this journal, which Schweitzer (2002) describes as “Husserlian”, but another kind, which he describes as “‘what’s it like for them’ type of studies”. In this paper I present a case for the latter, and consider its appropriateness to the field of education. I argue that this approach to phenomenological research (which Schweitzer refers to as empirical) is a potentially powerful way of making sense of education practitioners’ (and learners’) sense-making, and can lead to startling new insights into the uniquely complex processes of learning, teaching and educational managing and leading.
- Full Text:
- Date Issued: 2004
- Authors: Van der Mescht, Hennie
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6101 , http://hdl.handle.net/10962/d1008665
- Description: [From the introduction]: Overheard during tea at an Education Faculty research design course: “Phenomenology produces interesting and surprising results, but it’s just too much work …” The speaker was a prospective Masters student who had decided against “phenomenological” research, presumably because “it’s just too much work”. Having been deeply involved in phenomenological research myself for some years, I could identify with his reservation. But his first statement is of course equally true: phenomenological research does indeed produce “interesting and surprising results”, as many of my students have found. I should at the outset describe what I mean by phenomenological research more carefully, since, as Schweitzer (2002) has recently pointed out, there is certainly more than one meaning out there. The kind of research I am referring to is not the kind frequently featured in this journal, which Schweitzer (2002) describes as “Husserlian”, but another kind, which he describes as “‘what’s it like for them’ type of studies”. In this paper I present a case for the latter, and consider its appropriateness to the field of education. I argue that this approach to phenomenological research (which Schweitzer refers to as empirical) is a potentially powerful way of making sense of education practitioners’ (and learners’) sense-making, and can lead to startling new insights into the uniquely complex processes of learning, teaching and educational managing and leading.
- Full Text:
- Date Issued: 2004
Pictograms for conveying medicine instructions: comprehension in various South African language groups
- Dowse, Roslind, Ehlers, Martina S
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6354 , http://hdl.handle.net/10962/d1006038
- Description: The comprehension of medicine instructions is essential for the safe and effective use of medicines. In cases where low literacy constitutes a possible barrier to understanding written medicine information fully, the inclusion of pictograms may facilitate comprehension. Twenty-three internationally available pictograms and 23 corresponding locally developed images were evaluated in 304 low-literate respondents from eight different South African language groups. Demographic data were collected and an English literacy test was administered to those respondents who had stated that they could read English. Interviewees were shown the 46 pictograms in random order and were asked for their interpretation. Preference for either the international or local version was assessed. Correct interpretation of individual pictograms ranged from 14% to 97%. Images which had been developed locally were more successful in eliciting correct interpretations than those obtained from an international source (USP pictograms). Only 2 of the 23 USP pictograms achieved the 85% criterion of the American National Standards Institute compared with 12 of 23 locally developed counterparts. Local pictograms were preferred over the American ones in all cases. Standard of education had a significant influence on interpretation, whereas no significant differences in interpretation could be attributed to cultural diversity between the African language groups. Almost all respondents (98%) reacted positively to the idea of having pictograms on their medicine labels. The success of the local pictograms highlighted the value of a rigorous and consultative design and test process. Results from one African language group can reliably be extrapolated to other groups in South Africa.
- Full Text:
- Date Issued: 2004
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6354 , http://hdl.handle.net/10962/d1006038
- Description: The comprehension of medicine instructions is essential for the safe and effective use of medicines. In cases where low literacy constitutes a possible barrier to understanding written medicine information fully, the inclusion of pictograms may facilitate comprehension. Twenty-three internationally available pictograms and 23 corresponding locally developed images were evaluated in 304 low-literate respondents from eight different South African language groups. Demographic data were collected and an English literacy test was administered to those respondents who had stated that they could read English. Interviewees were shown the 46 pictograms in random order and were asked for their interpretation. Preference for either the international or local version was assessed. Correct interpretation of individual pictograms ranged from 14% to 97%. Images which had been developed locally were more successful in eliciting correct interpretations than those obtained from an international source (USP pictograms). Only 2 of the 23 USP pictograms achieved the 85% criterion of the American National Standards Institute compared with 12 of 23 locally developed counterparts. Local pictograms were preferred over the American ones in all cases. Standard of education had a significant influence on interpretation, whereas no significant differences in interpretation could be attributed to cultural diversity between the African language groups. Almost all respondents (98%) reacted positively to the idea of having pictograms on their medicine labels. The success of the local pictograms highlighted the value of a rigorous and consultative design and test process. Results from one African language group can reliably be extrapolated to other groups in South Africa.
- Full Text:
- Date Issued: 2004
A capillary zone electrophoresis (CZE) method for the determination of cyclizine hydrochloride in tablets and suppositories
- Mohammadi, I, Kanfer, Isadore, Walker, Roderick B
- Authors: Mohammadi, I , Kanfer, Isadore , Walker, Roderick B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6406 , http://hdl.handle.net/10962/d1006479
- Description: Current compendial methods of assay for the analysis of cyclizine tablets involve the use of UV spectrophotometry. Since this is a non-selective technique its application to more complex dosage forms, such as suppositories, is unlikely to be appropriate. There is therefore a need for the development of a highly specific quantitative analytical method, such as high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). The latter technique was chosen in view of some specific advantages over HPLC, such as the use of relatively non-toxic aqueous buffers, as opposed to organic solvents, which obviates the use of expensive HPLC grade solvents making CE more cost effective. Cyclizine was analyzed in 50 mM phosphate buffer (pH 2.3) and run at an applied voltage 25 kV. Detection sensitivity was enhanced by using a wavelength of 200 nm and samples were loaded hydrodynamically onto an uncoated fused-silica capillary (60 cm×50 mm i.d.). Chlorcyclizine was used as the internal standard and resolution of both compounds was achieved in less than 7 min. Stress testing was undertaken in order to investigate the appearance of breakdown products. The method has the requisite accuracy, selectivity, sensitivity and precision to assay cyclizine in tablets and suppositories. Degradation products resulting from the stress studies did not interfere with the detection of cyclizine and the assay is thus stability-indicating.
- Full Text:
- Date Issued: 2004
- Authors: Mohammadi, I , Kanfer, Isadore , Walker, Roderick B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6406 , http://hdl.handle.net/10962/d1006479
- Description: Current compendial methods of assay for the analysis of cyclizine tablets involve the use of UV spectrophotometry. Since this is a non-selective technique its application to more complex dosage forms, such as suppositories, is unlikely to be appropriate. There is therefore a need for the development of a highly specific quantitative analytical method, such as high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). The latter technique was chosen in view of some specific advantages over HPLC, such as the use of relatively non-toxic aqueous buffers, as opposed to organic solvents, which obviates the use of expensive HPLC grade solvents making CE more cost effective. Cyclizine was analyzed in 50 mM phosphate buffer (pH 2.3) and run at an applied voltage 25 kV. Detection sensitivity was enhanced by using a wavelength of 200 nm and samples were loaded hydrodynamically onto an uncoated fused-silica capillary (60 cm×50 mm i.d.). Chlorcyclizine was used as the internal standard and resolution of both compounds was achieved in less than 7 min. Stress testing was undertaken in order to investigate the appearance of breakdown products. The method has the requisite accuracy, selectivity, sensitivity and precision to assay cyclizine in tablets and suppositories. Degradation products resulting from the stress studies did not interfere with the detection of cyclizine and the assay is thus stability-indicating.
- Full Text:
- Date Issued: 2004