Localisation of Theiler's murine encephalomyelitis virus protein 2C to the golgi apparatus using antibodies generated against a peptide region:
- Jauka, Tembisa, Mutsvunguma, Lorraine Z, Boshoff, Aileen, Edkins, Adrienne L, Knox, Caroline M
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010
Male aggression and mating opportunity in a poeciliid fish
- Magellan, Kit, Kaiser, Horst
- Authors: Magellan, Kit , Kaiser, Horst
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447556 , vital:74656 , https://doi.org/10.1080/15627020.2010.11657250
- Description: One function of aggression in animals is to gain access to mates. Aggression may therefore be favoured by sexual selection, the strength of which can be assessed using repeatability of aggressive behaviour. Here, we tested the hypotheses that male swordtails, Xiphophorus sp., are consistent in the aggressive and mating behaviours exhibited and in the time spent at a close distance to females (female attendance), and that aggressive males gain increased opportunity to attempt copulation compared to their less aggressive conspecifics (sneak frequency). As predicted, aggression between males, and male display and sneak frequency were repeatable. However, male aggression was not significantly correlated with sneak frequency. The function of aggression in this species is not clear-cut and may have an indirect female access function through formation of dominance hierarchies or defence of resources. A surprising finding highlighted by this study was the contradictory results for consistency in female contact, with high repeatability scores indicating consistency in behaviour but the within-subjects component of repeated measures ANOVA showing differences in female contact between trials. The possible reasons for this discrepancy are discussed.
- Full Text:
- Date Issued: 2010
- Authors: Magellan, Kit , Kaiser, Horst
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447556 , vital:74656 , https://doi.org/10.1080/15627020.2010.11657250
- Description: One function of aggression in animals is to gain access to mates. Aggression may therefore be favoured by sexual selection, the strength of which can be assessed using repeatability of aggressive behaviour. Here, we tested the hypotheses that male swordtails, Xiphophorus sp., are consistent in the aggressive and mating behaviours exhibited and in the time spent at a close distance to females (female attendance), and that aggressive males gain increased opportunity to attempt copulation compared to their less aggressive conspecifics (sneak frequency). As predicted, aggression between males, and male display and sneak frequency were repeatable. However, male aggression was not significantly correlated with sneak frequency. The function of aggression in this species is not clear-cut and may have an indirect female access function through formation of dominance hierarchies or defence of resources. A surprising finding highlighted by this study was the contradictory results for consistency in female contact, with high repeatability scores indicating consistency in behaviour but the within-subjects component of repeated measures ANOVA showing differences in female contact between trials. The possible reasons for this discrepancy are discussed.
- Full Text:
- Date Issued: 2010
Metallophthalocyanine-based molecular materials as catalysts for electrochemical reactions
- Zagal, José H, Griveau, Sophie J, Silva, Francisco, Nyokong, Tebello, Bedioui, Fethi
- Authors: Zagal, José H , Griveau, Sophie J , Silva, Francisco , Nyokong, Tebello , Bedioui, Fethi
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7239 , http://hdl.handle.net/10962/d1019718
- Description: Metallophthalocyanines confined on the surface of electrodes are active catalysts for a large variety of electrochemical reactions and electrode surfaces modified by these complexes can be obtained by simple adsorption on graphite and carbon. However, more stable electrodes can be achieved by coating their surfaces with electropolymerized layers of the complexes, that show similar activity than their monomer counterparts. In all cases, fundamental studies carried out with adsorbed layers of these complexes have shown that the redox potential is a very good reactivity index for predicting the catalytic activity of the complexes. Volcano-shaped correlations have been found between the electrocatalytic activity (as log I at constant E) versus the Co(II)/(I) formal potential (E°′) of Co-macrocyclics for the oxidation of several thiols, hydrazine and glucose. For the electroreduction of O2 only linear correlations between the electrocatalytic activity versus the M(III)/M(II) formal potential have been found using Cr, Mn, Fe and Co phthalocyanines but it is likely that these correlations are “incomplete volcano” correlations. The volcano correlations strongly suggest that E°′, the formal potential of the complex needs to be in a rather narrow potential window for achieving maximum activity, probably corresponding to surface coverages of an M-molecule adduct equal to 0.5 and to standard free energies of adsorption of the reacting molecule on the complex active site equal to zero. These results indicate that the catalytic activity of metallophthalocyanines for the oxidation of several molecules can be “tuned” by manipulating the E°′ formal potential, using proper groups on the macrocyclic ligand. This review emphasizes once more that metallophthalocyanines are extremely versatile materials with many applications in electrocatalysis, electroanalysis, just to mention a few, and they provide very good models for testing their catalytic activity for several reactions. Even though the earlier applications of these complexes were focused on providing active materials for electroreduction of O2, for making active cathodes for fuel cells, the main trend in the literature nowadays is to use these complexes for making active electrodes for electrochemical sensors. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.001
- Full Text: false
- Date Issued: 2010
- Authors: Zagal, José H , Griveau, Sophie J , Silva, Francisco , Nyokong, Tebello , Bedioui, Fethi
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7239 , http://hdl.handle.net/10962/d1019718
- Description: Metallophthalocyanines confined on the surface of electrodes are active catalysts for a large variety of electrochemical reactions and electrode surfaces modified by these complexes can be obtained by simple adsorption on graphite and carbon. However, more stable electrodes can be achieved by coating their surfaces with electropolymerized layers of the complexes, that show similar activity than their monomer counterparts. In all cases, fundamental studies carried out with adsorbed layers of these complexes have shown that the redox potential is a very good reactivity index for predicting the catalytic activity of the complexes. Volcano-shaped correlations have been found between the electrocatalytic activity (as log I at constant E) versus the Co(II)/(I) formal potential (E°′) of Co-macrocyclics for the oxidation of several thiols, hydrazine and glucose. For the electroreduction of O2 only linear correlations between the electrocatalytic activity versus the M(III)/M(II) formal potential have been found using Cr, Mn, Fe and Co phthalocyanines but it is likely that these correlations are “incomplete volcano” correlations. The volcano correlations strongly suggest that E°′, the formal potential of the complex needs to be in a rather narrow potential window for achieving maximum activity, probably corresponding to surface coverages of an M-molecule adduct equal to 0.5 and to standard free energies of adsorption of the reacting molecule on the complex active site equal to zero. These results indicate that the catalytic activity of metallophthalocyanines for the oxidation of several molecules can be “tuned” by manipulating the E°′ formal potential, using proper groups on the macrocyclic ligand. This review emphasizes once more that metallophthalocyanines are extremely versatile materials with many applications in electrocatalysis, electroanalysis, just to mention a few, and they provide very good models for testing their catalytic activity for several reactions. Even though the earlier applications of these complexes were focused on providing active materials for electroreduction of O2, for making active cathodes for fuel cells, the main trend in the literature nowadays is to use these complexes for making active electrodes for electrochemical sensors. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.001
- Full Text: false
- Date Issued: 2010
Minimum spanning trees for valley and ridge characterization in digital elevation maps
- Bangay, Shaun D, de Bruyn, David, Glass, Kevin R
- Authors: Bangay, Shaun D , de Bruyn, David , Glass, Kevin R
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433247 , vital:72955 , https://doi.org/10.1145/1811158.1811171
- Description: Texture synthesis employs neighbourhood matching to generate appropriate new content. Terrain synthesis has the added constraint that new content must be geographically plausible. The profile recognition and polygon breaking algorithm (PPA) [Chang et al. 1998] provides a robust mechanism for characterizing terrain as systems of valley and ridge lines in digital elevation maps. We exploit this to create a terrain characterization metric that is robust, efficient to compute and is sensitive to terrain properties.
- Full Text:
- Date Issued: 2010
- Authors: Bangay, Shaun D , de Bruyn, David , Glass, Kevin R
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433247 , vital:72955 , https://doi.org/10.1145/1811158.1811171
- Description: Texture synthesis employs neighbourhood matching to generate appropriate new content. Terrain synthesis has the added constraint that new content must be geographically plausible. The profile recognition and polygon breaking algorithm (PPA) [Chang et al. 1998] provides a robust mechanism for characterizing terrain as systems of valley and ridge lines in digital elevation maps. We exploit this to create a terrain characterization metric that is robust, efficient to compute and is sensitive to terrain properties.
- Full Text:
- Date Issued: 2010
Mobile phones, youth radio, citizen journalists: how the news is coming to Grahamstow
- Authors: Dugmore, Harry
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159412 , vital:40295 , https://hdl.handle.net/10520/EJC139343
- Description: Newspapers everywhere are being forced to rethink their role as simply providers of general news of the day. As people can access much more immediate information and news online, from a wide variety of sources, and get to "hear about things" from their friends and contacts through Facebook, Twitter and other "social media", local papers are having to find better ways to provide immediate and more useful information and news.
- Full Text:
- Date Issued: 2010
- Authors: Dugmore, Harry
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159412 , vital:40295 , https://hdl.handle.net/10520/EJC139343
- Description: Newspapers everywhere are being forced to rethink their role as simply providers of general news of the day. As people can access much more immediate information and news online, from a wide variety of sources, and get to "hear about things" from their friends and contacts through Facebook, Twitter and other "social media", local papers are having to find better ways to provide immediate and more useful information and news.
- Full Text:
- Date Issued: 2010
Monitoring perceptions of social progress and pride of place in a South African community
- Moller, Valerie, Radloff, Sarah E
- Authors: Moller, Valerie , Radloff, Sarah E
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68468 , vital:29261 , https://doi.org/10.1007/s11482-010-9092-8 https://doi.org/10.1007/s11482-011-9145-7
- Description: Publisher version , A social indicators community project was conducted in 2007 to monitor living standards and quality of life in Rhini, a low-income suburb of Grahamstown, Makana Municipality, South Africa. Since 1994, under democratic rule, considerable progress has been made in service delivery to the formerly disadvantaged in South African society in terms of access to housing, infrastructure, and a social safety net to mitigate the high rate of unemployment. A representative cross-sectional household study (n 1020) conducted in 2007 in Rhini found that a positive assessment of the household’s situation and personal life satisfaction did not reflect better living conditions. Lack of income and employment opportunities appeared to dilute gains from higher living standards. The project also inquired into attitudes to place names and a proposed name change for the city under discussion at the time of the survey. It is argued that a place name with which one can identify may be as important as service delivery to enhance community satisfaction and overall quality of life. Dissatisfied residents who had limited access to services and expressed less civic pride were more likely than others to opt for a proposed name change for the city of Grahamstown that would better reflect the country’s new identity and multicultural heritage. It is concluded that a useful pursuit for community quality-of-life studies in countries undergoing social transformation will be to inquire into the complex combination of factors that drive perceptions of material and symbolic progress.
- Full Text: false
- Date Issued: 2010
- Authors: Moller, Valerie , Radloff, Sarah E
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68468 , vital:29261 , https://doi.org/10.1007/s11482-010-9092-8 https://doi.org/10.1007/s11482-011-9145-7
- Description: Publisher version , A social indicators community project was conducted in 2007 to monitor living standards and quality of life in Rhini, a low-income suburb of Grahamstown, Makana Municipality, South Africa. Since 1994, under democratic rule, considerable progress has been made in service delivery to the formerly disadvantaged in South African society in terms of access to housing, infrastructure, and a social safety net to mitigate the high rate of unemployment. A representative cross-sectional household study (n 1020) conducted in 2007 in Rhini found that a positive assessment of the household’s situation and personal life satisfaction did not reflect better living conditions. Lack of income and employment opportunities appeared to dilute gains from higher living standards. The project also inquired into attitudes to place names and a proposed name change for the city under discussion at the time of the survey. It is argued that a place name with which one can identify may be as important as service delivery to enhance community satisfaction and overall quality of life. Dissatisfied residents who had limited access to services and expressed less civic pride were more likely than others to opt for a proposed name change for the city of Grahamstown that would better reflect the country’s new identity and multicultural heritage. It is concluded that a useful pursuit for community quality-of-life studies in countries undergoing social transformation will be to inquire into the complex combination of factors that drive perceptions of material and symbolic progress.
- Full Text: false
- Date Issued: 2010
Multiple organ failure - death of consumer protection?
- Authors: Steinman, H A , Jobson, M R
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6436 , http://hdl.handle.net/10962/d1006613
- Description: The enormously profitable complementary medicines, dietary supplements and traditional medicines markets are largely unregulated internationally and South Africa. Attempts to ensure that consumers are not exposed to harmful or ineffective products have met with varying success around the world.
- Full Text:
- Date Issued: 2010
- Authors: Steinman, H A , Jobson, M R
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6436 , http://hdl.handle.net/10962/d1006613
- Description: The enormously profitable complementary medicines, dietary supplements and traditional medicines markets are largely unregulated internationally and South Africa. Attempts to ensure that consumers are not exposed to harmful or ineffective products have met with varying success around the world.
- Full Text:
- Date Issued: 2010
My First Book of Southern African Insects, C. Uys: book review
- Authors: Villet, Martin H
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451749 , vital:75074 , https://hdl.handle.net/10520/EJC32855
- Description: I concur with Antoine de Saint-Exupéry (1943): we are born with a strong appreciation of the world around us that most of us lose as we grow up. While few adults have much empathy with insects, they are a source of fascination for most children, at least until they start school. The problem facing professional entomology is how to sustain and encourage that early attitude so that we recruit passionate and well-prepared people into the profession, and sensitise the remainder of the population to the value of insects.
- Full Text:
- Date Issued: 2010
- Authors: Villet, Martin H
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451749 , vital:75074 , https://hdl.handle.net/10520/EJC32855
- Description: I concur with Antoine de Saint-Exupéry (1943): we are born with a strong appreciation of the world around us that most of us lose as we grow up. While few adults have much empathy with insects, they are a source of fascination for most children, at least until they start school. The problem facing professional entomology is how to sustain and encourage that early attitude so that we recruit passionate and well-prepared people into the profession, and sensitise the remainder of the population to the value of insects.
- Full Text:
- Date Issued: 2010
Natural enemies from South Africa for biological control of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae) in Europe
- Baars, Jan-Robert, Coetzee, Julie A, Martin, Grant D, Hill, Martin P, Caffrey, J M
- Authors: Baars, Jan-Robert , Coetzee, Julie A , Martin, Grant D , Hill, Martin P , Caffrey, J M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76914 , vital:30637 , https://doi.org/10.1007/s10750-010-0427-0
- Description: The non-native invasive plant, Lagarosiphon major (Hydrocharitaceae) is a submersed aquatic macrophyte that poses a significant threat to water bodies in Europe. Dense infestations prove difficult to manage using traditional methods. In order to initiate a biocontrol programme, a survey for natural enemies of Lagarosiphon was conducted in South Africa. Several phytophagous species were recorded for the first time, with at least three showing notable promise as candidate agents. Amongst these, a leaf-mining fly, Hydrellia sp. (Ephydridae) that occurred over a wide distribution causes significant leaf damage despite high levels of parasitism by braconid wasps. Another yet unidentified fly was recorded mining the stem of L. major. Two leaf-feeding and shoot boring weevils, cf. Bagous sp. (Curculionidae) were recorded damaging the shoot tips and stunting the growth of the stem. Several leaf-feeding lepidopteran species (Nymphulinae) were frequently recorded, but are expected to feed on a wide range of plant species and are not considered for importation before other candidates are assessed. The discovery of several natural enemies in the country of origin improves the biological control prospects of L. major in Europe.
- Full Text:
- Date Issued: 2010
- Authors: Baars, Jan-Robert , Coetzee, Julie A , Martin, Grant D , Hill, Martin P , Caffrey, J M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76914 , vital:30637 , https://doi.org/10.1007/s10750-010-0427-0
- Description: The non-native invasive plant, Lagarosiphon major (Hydrocharitaceae) is a submersed aquatic macrophyte that poses a significant threat to water bodies in Europe. Dense infestations prove difficult to manage using traditional methods. In order to initiate a biocontrol programme, a survey for natural enemies of Lagarosiphon was conducted in South Africa. Several phytophagous species were recorded for the first time, with at least three showing notable promise as candidate agents. Amongst these, a leaf-mining fly, Hydrellia sp. (Ephydridae) that occurred over a wide distribution causes significant leaf damage despite high levels of parasitism by braconid wasps. Another yet unidentified fly was recorded mining the stem of L. major. Two leaf-feeding and shoot boring weevils, cf. Bagous sp. (Curculionidae) were recorded damaging the shoot tips and stunting the growth of the stem. Several leaf-feeding lepidopteran species (Nymphulinae) were frequently recorded, but are expected to feed on a wide range of plant species and are not considered for importation before other candidates are assessed. The discovery of several natural enemies in the country of origin improves the biological control prospects of L. major in Europe.
- Full Text:
- Date Issued: 2010
New Possibilities for Mediation in Society: How is Environmental Education Research Responding?
- O’Donoghue, Rob B, Lotz-Sisitka, Heila
- Authors: O’Donoghue, Rob B , Lotz-Sisitka, Heila
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/437354 , vital:73372 , ISBN 978-9460911590 , https://brill.com/display/title/36964?rskey=xymnmAandresult=1
- Description: African universities have, since their inception in the colonial era, been governed by a colonial framing of research agendas and modernist trajectories. Keeley and Scoones (2003), for example, explain how agronomy in the French colonies in Afri-ca was shaped by the ‘particular form of science’that arrived in Mali as the French set about expanding the production of cot-ton. French scientific research, at the time (in the post World War 1 period) emphasized the economic development of the colonies, which introduced scientific ways of improving the par-ticular production of cash crops, dealing with pests and improv-ing varieties, locating early university-based research in pat-terns of bureaucratic and state formation. Expatriate research-ers from universities in France, England and Belgium were brought to the colonies to set the agenda for research, as most of the colonial universities offered research and teaching pro-grammes that were accredited by universities in the ‘mother country’. While the number of expatriate researchers working in African universities may have declined in recent years, with the emphasis now on short-term consultancies (from the ‘donor country’), funding and technical inputs from mother and donor countries continues to shape research. What is of note here is how research agendas are coupled with particular research conventions and processes of administrative and social organ-ization1 that are seldom explicit..
- Full Text:
- Date Issued: 2010
- Authors: O’Donoghue, Rob B , Lotz-Sisitka, Heila
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/437354 , vital:73372 , ISBN 978-9460911590 , https://brill.com/display/title/36964?rskey=xymnmAandresult=1
- Description: African universities have, since their inception in the colonial era, been governed by a colonial framing of research agendas and modernist trajectories. Keeley and Scoones (2003), for example, explain how agronomy in the French colonies in Afri-ca was shaped by the ‘particular form of science’that arrived in Mali as the French set about expanding the production of cot-ton. French scientific research, at the time (in the post World War 1 period) emphasized the economic development of the colonies, which introduced scientific ways of improving the par-ticular production of cash crops, dealing with pests and improv-ing varieties, locating early university-based research in pat-terns of bureaucratic and state formation. Expatriate research-ers from universities in France, England and Belgium were brought to the colonies to set the agenda for research, as most of the colonial universities offered research and teaching pro-grammes that were accredited by universities in the ‘mother country’. While the number of expatriate researchers working in African universities may have declined in recent years, with the emphasis now on short-term consultancies (from the ‘donor country’), funding and technical inputs from mother and donor countries continues to shape research. What is of note here is how research agendas are coupled with particular research conventions and processes of administrative and social organ-ization1 that are seldom explicit..
- Full Text:
- Date Issued: 2010
Newspaper literacy and communication for democracy: is there a crisis in South African journalism?
- Siebörger, Ian, Adendorff, Ralph D
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125304 , vital:35770 , https://doi.org/10.2989/SALALS.2009.27.4.4.1024
- Description: Media theorists such as Barnett (2002), Buckingham (1997 & 2000) and Sampson (1999) describe a perceived crisis hindering the media’s ability to inform citizens for participation in democracy. One of the symptoms and causes of this crisis, they argue, is that the media use language that many citizens cannot understand. This article draws on theories and methodologies from linguistics to investigate whether this claim holds true for South African newspapers. The concept of the crisis in journalism is deconstructed in the light of Street’s (1984) ideological model of literacy. In a pilot study, multiple readability tests were conducted on one article from each of three newspapers, Business Day, The Herald and Daily Sun. The findings of these tests, and a systemic functional grammar analysis of cohesion and lexical density in the three articles, show that all three newspapers tailor their language to fit their target markets. This, triangulated with the rapid growth in readership of the Daily Sun and the more modest growth of The Herald, suggests that many South Africans are better informed for participation in democracy than in the past, although newspapers can do more to help readers learn a plurality of literacy practices.
- Full Text:
- Date Issued: 2010
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125304 , vital:35770 , https://doi.org/10.2989/SALALS.2009.27.4.4.1024
- Description: Media theorists such as Barnett (2002), Buckingham (1997 & 2000) and Sampson (1999) describe a perceived crisis hindering the media’s ability to inform citizens for participation in democracy. One of the symptoms and causes of this crisis, they argue, is that the media use language that many citizens cannot understand. This article draws on theories and methodologies from linguistics to investigate whether this claim holds true for South African newspapers. The concept of the crisis in journalism is deconstructed in the light of Street’s (1984) ideological model of literacy. In a pilot study, multiple readability tests were conducted on one article from each of three newspapers, Business Day, The Herald and Daily Sun. The findings of these tests, and a systemic functional grammar analysis of cohesion and lexical density in the three articles, show that all three newspapers tailor their language to fit their target markets. This, triangulated with the rapid growth in readership of the Daily Sun and the more modest growth of The Herald, suggests that many South Africans are better informed for participation in democracy than in the past, although newspapers can do more to help readers learn a plurality of literacy practices.
- Full Text:
- Date Issued: 2010
Novel, soluble, FluXoro functional substituted zinc phthalocyanines; synthesis, characterization and photophysicochemical properties
- Erdoğmuş, Ali, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261258 , vital:53378 , xlink:href="https://doi.org/10.1016/j.dyepig.2010.01.001"
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041.
- Full Text:
- Date Issued: 2010
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261258 , vital:53378 , xlink:href="https://doi.org/10.1016/j.dyepig.2010.01.001"
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041.
- Full Text:
- Date Issued: 2010
Optical limiting properties of zinc phthalocyanines in solution and solid PMMA composite films
- Tekin, Sezen, Kürüm, Ulaş, Durmus, Mahmut, Yaglioglu, H Gul, Nyokong, Tebello, Elmali, Ayhan
- Authors: Tekin, Sezen , Kürüm, Ulaş , Durmus, Mahmut , Yaglioglu, H Gul , Nyokong, Tebello , Elmali, Ayhan
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249071 , vital:51775 , xlink:href="https://doi.org/10.1016/j.optcom.2010.07.003"
- Description: The nonlinear absorption and optical limiting (OL) performance of tetra- and octasubstituted zinc phthalocyanine complexes were described in solution and in the solid state using the open-aperture Z-scan technique. The measurements were performed using collimated 4 ns pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The polymeric films exhibit a much larger effective nonlinear absorption coefficient in comparison with solution. However, the parameters of the ratio of the excited to ground state absorption cross section and energy-dependent saturation in solution are much better compared to properties in the polymeric film. In terms of the ratio of the excited to ground state absorption cross section, the peripherally substituted complexes show better OL performance than the non-peripherally substituted derivative.
- Full Text:
- Date Issued: 2010
- Authors: Tekin, Sezen , Kürüm, Ulaş , Durmus, Mahmut , Yaglioglu, H Gul , Nyokong, Tebello , Elmali, Ayhan
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249071 , vital:51775 , xlink:href="https://doi.org/10.1016/j.optcom.2010.07.003"
- Description: The nonlinear absorption and optical limiting (OL) performance of tetra- and octasubstituted zinc phthalocyanine complexes were described in solution and in the solid state using the open-aperture Z-scan technique. The measurements were performed using collimated 4 ns pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The polymeric films exhibit a much larger effective nonlinear absorption coefficient in comparison with solution. However, the parameters of the ratio of the excited to ground state absorption cross section and energy-dependent saturation in solution are much better compared to properties in the polymeric film. In terms of the ratio of the excited to ground state absorption cross section, the peripherally substituted complexes show better OL performance than the non-peripherally substituted derivative.
- Full Text:
- Date Issued: 2010
Osmoregulation in freshwater invertebrates in response to exposure to salt pollution
- Holland, Alexandra J, Gordon, Andrew K, Muller, Nikite W J
- Authors: Holland, Alexandra J , Gordon, Andrew K , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437700 , vital:73403 , ISBN 978-1-4312-0075-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1585.pdf
- Description: The South African National Water Act (No. 36 of 1998) provides for an ecological Reserve which is intended to protect fresh water ecosystems and resources from degradation as a result of misuse, and to maintain vital ecological functions within these systems (Palmer et al., 2004). Water quality guidelines are an important tool in the management of these water resources, aiming to adequately balance protec-tion of aquatic ecological systems with sustainable human use needs. Jooste and Rossouw (2002) proposed guidelines or boundary values for inorganic salts to be included in the ecological Reserve. These boundary values for inorganic salts were derived as follows, acute lethality data (LC50s) from the ECOTOX database main-tained by the USEPA were projected to 336 h and the 5th percentile determined as a lethality benchmark, analogous to the Fair/Poor boundary. Similarly, the 5th percen-tile of available sublethal data was determined as the sublethality benchmark and analogous with the Natural/Good boundary value. The Good/Fair boundary was the mean value between Natural/Good and Fair/Poor values. It has been suggested however, that these guidelines might not be entirely appropriate as they were de-rived without including tolerances of South African biota. Furthermore, the accuracy for some salt boundary values have been questioned (Scherman, 2009; Scherman, 2010).
- Full Text:
- Date Issued: 2010
- Authors: Holland, Alexandra J , Gordon, Andrew K , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437700 , vital:73403 , ISBN 978-1-4312-0075-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1585.pdf
- Description: The South African National Water Act (No. 36 of 1998) provides for an ecological Reserve which is intended to protect fresh water ecosystems and resources from degradation as a result of misuse, and to maintain vital ecological functions within these systems (Palmer et al., 2004). Water quality guidelines are an important tool in the management of these water resources, aiming to adequately balance protec-tion of aquatic ecological systems with sustainable human use needs. Jooste and Rossouw (2002) proposed guidelines or boundary values for inorganic salts to be included in the ecological Reserve. These boundary values for inorganic salts were derived as follows, acute lethality data (LC50s) from the ECOTOX database main-tained by the USEPA were projected to 336 h and the 5th percentile determined as a lethality benchmark, analogous to the Fair/Poor boundary. Similarly, the 5th percen-tile of available sublethal data was determined as the sublethality benchmark and analogous with the Natural/Good boundary value. The Good/Fair boundary was the mean value between Natural/Good and Fair/Poor values. It has been suggested however, that these guidelines might not be entirely appropriate as they were de-rived without including tolerances of South African biota. Furthermore, the accuracy for some salt boundary values have been questioned (Scherman, 2009; Scherman, 2010).
- Full Text:
- Date Issued: 2010
Parallel packet classification using GPU co-processors
- Nottingham, Alistair, Irwin, Barry V W
- Authors: Nottingham, Alistair , Irwin, Barry V W
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430250 , vital:72677 , https://doi.org/10.1145/1899503.1899529
- Description: In the domain of network security, packet filtering for classification pur-poses is of significant interest. Packet classification provides a mecha-nism for understanding the composition of packet streams arriving at distinct network interfaces, and is useful in diagnosing threats and un-covering vulnerabilities so as to maximise data integrity and system se-curity. Traditional packet classifiers, such as PCAP, have utilised Con-trol Flow Graphs (CFGs) in representing filter sets, due to both their amenability to optimisation, and their inherent structural applicability to the metaphor of decision-based classification. Unfortunately, CFGs do not map well to cooperative processing implementations, and single-threaded CPU-based implementations have proven too slow for real-time classification against multiple arbitrary filters on next generation networks. In this paper, we consider a novel multithreaded classification algorithm, optimised for execution on GPU co-processors, intended to accelerate classification throughput and maximise processing efficien-cy in a highly parallel execution context.
- Full Text:
- Date Issued: 2010
- Authors: Nottingham, Alistair , Irwin, Barry V W
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430250 , vital:72677 , https://doi.org/10.1145/1899503.1899529
- Description: In the domain of network security, packet filtering for classification pur-poses is of significant interest. Packet classification provides a mecha-nism for understanding the composition of packet streams arriving at distinct network interfaces, and is useful in diagnosing threats and un-covering vulnerabilities so as to maximise data integrity and system se-curity. Traditional packet classifiers, such as PCAP, have utilised Con-trol Flow Graphs (CFGs) in representing filter sets, due to both their amenability to optimisation, and their inherent structural applicability to the metaphor of decision-based classification. Unfortunately, CFGs do not map well to cooperative processing implementations, and single-threaded CPU-based implementations have proven too slow for real-time classification against multiple arbitrary filters on next generation networks. In this paper, we consider a novel multithreaded classification algorithm, optimised for execution on GPU co-processors, intended to accelerate classification throughput and maximise processing efficien-cy in a highly parallel execution context.
- Full Text:
- Date Issued: 2010
Philosophers and the Poor
- Authors: Jones, Ward E
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275671 , vital:55068 , xlink:href="https://doi.org/10.3167/th.2010.5712506"
- Description: This is a programmatic paper, calling for the renewal andmodernisation of the therapeutic approach to philosophy found inEpicureans, Stoics, and Skeptics; and, in particular, for an applicationof the therapeutic approach to the life of poverty. The general assump-tion behind a therapeutic approach to philosophy is that it is possiblefor someone to be exposed to philosophical work which leads her toan improved understanding of herself and her situation, and for herlife to be improved by this understanding. After offering a sketch ofhow, given the current nature of academic philosophy, such work willbe carried out and disseminated, I suggest three areas in which philo-sophical discourse could have a therapeutic affect on the poor.
- Full Text:
- Date Issued: 2010
- Authors: Jones, Ward E
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275671 , vital:55068 , xlink:href="https://doi.org/10.3167/th.2010.5712506"
- Description: This is a programmatic paper, calling for the renewal andmodernisation of the therapeutic approach to philosophy found inEpicureans, Stoics, and Skeptics; and, in particular, for an applicationof the therapeutic approach to the life of poverty. The general assump-tion behind a therapeutic approach to philosophy is that it is possiblefor someone to be exposed to philosophical work which leads her toan improved understanding of herself and her situation, and for herlife to be improved by this understanding. After offering a sketch ofhow, given the current nature of academic philosophy, such work willbe carried out and disseminated, I suggest three areas in which philo-sophical discourse could have a therapeutic affect on the poor.
- Full Text:
- Date Issued: 2010
Photodynamic therapy for the Developing World
- Authors: Songca, S P
- Date: 2010
- Subjects: Skin -- Diseases -- Photochemotherapy Phototherapy Skin -- Diseases -- Treatment
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1056 , vital:30559
- Description: This article contains some of the contributing works to the founding of the prestigious journal Tetrahedron and it describes the total synthesis of chlorophyll-a starting from Knorr's pyrrole synthesis and includes more than forty six stages required to reach the target molecule.
- Full Text:
- Date Issued: 2010
- Authors: Songca, S P
- Date: 2010
- Subjects: Skin -- Diseases -- Photochemotherapy Phototherapy Skin -- Diseases -- Treatment
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1056 , vital:30559
- Description: This article contains some of the contributing works to the founding of the prestigious journal Tetrahedron and it describes the total synthesis of chlorophyll-a starting from Knorr's pyrrole synthesis and includes more than forty six stages required to reach the target molecule.
- Full Text:
- Date Issued: 2010
Photoelectrochemical characterization of electrodeposited ZnO thin films sensitized by octacarboxymetallophthalocyanine derivatives
- Idowu, Mopelola, Loewenstein, Thomas, Hastall, Andreas, Nyokong, Tebello, Schlettwein, Derck
- Authors: Idowu, Mopelola , Loewenstein, Thomas , Hastall, Andreas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262655 , vital:53541 , xlink:href="https://doi.org/10.1142/S1088424610001854"
- Description: Hybrid thin films of crystalline zinc oxide (ZnO) modified by different octacarboxymetallophthalocyanines (MOCPc) were prepared by the readsorption method. Homogeneously blue or green thin films were formed. The photoelectrochemical characteristics of the electrodes were studied by time-resolved photocurrent measurements. Zinc(II) 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine (ZnOCPc) showed considerably large quantum efficiency in sensitization of ZnO, one of the highest quantum efficiencies obtained so far with phthalocyanine-type sensitizers on nanocrystalline ZnO films.
- Full Text:
- Date Issued: 2010
- Authors: Idowu, Mopelola , Loewenstein, Thomas , Hastall, Andreas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262655 , vital:53541 , xlink:href="https://doi.org/10.1142/S1088424610001854"
- Description: Hybrid thin films of crystalline zinc oxide (ZnO) modified by different octacarboxymetallophthalocyanines (MOCPc) were prepared by the readsorption method. Homogeneously blue or green thin films were formed. The photoelectrochemical characteristics of the electrodes were studied by time-resolved photocurrent measurements. Zinc(II) 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine (ZnOCPc) showed considerably large quantum efficiency in sensitization of ZnO, one of the highest quantum efficiencies obtained so far with phthalocyanine-type sensitizers on nanocrystalline ZnO films.
- Full Text:
- Date Issued: 2010
Photophysical and photochemical parameters of octakis (benzylthio) phthalocyaninato zinc, aluminium and tin
- Akpe, Victor, Brismar, Hjalmar, Nyokong, Tebello, Osadebe, Patience Ogoamak
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
Photophysical and photochemical properties of Ni (II), Pd (II) and Pt (II) aryloxo and alkylthio derivatised phthalocyanine
- Ogunbayo, Taofeek B, Nyokong, Tebello
- Authors: Ogunbayo, Taofeek B , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261511 , vital:53416 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.03.047"
- Description: Several aryloxo (3a–6a and 3b–6b) and alkylthio (3d and 3e) derivatised phthalocyanines were synthesized, characterized and the photochemical and photophysical properties investigated along with those of the previously reported (3c–5c, 4d, 5d, 4e and 5e) complexes. The effects of open-shell metals (Ni(II), Pd(II) and Pt(II)) on the photophysical and photochemical properties of the phthalocyanine ligands were investigated. Palladium and platinum improved the triplet quantum yield and singlet oxygen generation capacities of the unmetalated phthalocyanines (3a–3e) making their complexes candidates for further investigation in photocatalysis. Ni(II)Pc analogues gave poor results compared with their Pd(II)Pc and Pt(II)Pc counterparts.
- Full Text:
- Date Issued: 2010
- Authors: Ogunbayo, Taofeek B , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261511 , vital:53416 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.03.047"
- Description: Several aryloxo (3a–6a and 3b–6b) and alkylthio (3d and 3e) derivatised phthalocyanines were synthesized, characterized and the photochemical and photophysical properties investigated along with those of the previously reported (3c–5c, 4d, 5d, 4e and 5e) complexes. The effects of open-shell metals (Ni(II), Pd(II) and Pt(II)) on the photophysical and photochemical properties of the phthalocyanine ligands were investigated. Palladium and platinum improved the triplet quantum yield and singlet oxygen generation capacities of the unmetalated phthalocyanines (3a–3e) making their complexes candidates for further investigation in photocatalysis. Ni(II)Pc analogues gave poor results compared with their Pd(II)Pc and Pt(II)Pc counterparts.
- Full Text:
- Date Issued: 2010