Light on a hill: building the Constitutional Court of South Africa, Bronwyn Law-Viljoen (Ed.): book review
- Authors: Simbao, Ruth K
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147324 , vital:38626 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31011
- Description: Light on a hill : Building the Constitutional Court of South Africa is a visually elegant book that claims to 'reflect the spirit of the Court and be a beautiful object in its own right' (p. 8). Certainly this book is striking, with its rich photographs by Angela Buckland, its fresh, breathable design by Adele Prins, and its broad format with lavish centerfolds. Reading the text is in many ways an enlightening process of understanding the conceptual underpinnings of the buildings that make up the Constitutional Court complex, but this process of reading takes a few twists and turns along the way.
- Full Text:
- Authors: Simbao, Ruth K
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147324 , vital:38626 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31011
- Description: Light on a hill : Building the Constitutional Court of South Africa is a visually elegant book that claims to 'reflect the spirit of the Court and be a beautiful object in its own right' (p. 8). Certainly this book is striking, with its rich photographs by Angela Buckland, its fresh, breathable design by Adele Prins, and its broad format with lavish centerfolds. Reading the text is in many ways an enlightening process of understanding the conceptual underpinnings of the buildings that make up the Constitutional Court complex, but this process of reading takes a few twists and turns along the way.
- Full Text:
Making visible constructions of dis/advantage through genealogical investigation: South African schooled literacies
- Authors: Prinsloo, Jeanne
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147869 , vital:38680 , DOI: 10.1080/02560040701398889
- Description: In this paper I assume the relevance of Foucauldian insights for conducting socio-cultural critique and I argue the significance of genealogical work in relation to understanding the present. Thus, I seek both to establish what could constitute a genealogical investigation and to illustrate this by describing and discussing a study, undertaken within a genealogical frame, into literacy practices within a specifically South African context. I investigated the differing schooled literacies in KwaZulu-Natal province in South Africa over three decades along the language lines of Afrikaans, English and Zulu. The findings propose that the differing sets of literacy practices validate different subjects – and that they are implicated in constructing dis/advantage.
- Full Text:
- Authors: Prinsloo, Jeanne
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147869 , vital:38680 , DOI: 10.1080/02560040701398889
- Description: In this paper I assume the relevance of Foucauldian insights for conducting socio-cultural critique and I argue the significance of genealogical work in relation to understanding the present. Thus, I seek both to establish what could constitute a genealogical investigation and to illustrate this by describing and discussing a study, undertaken within a genealogical frame, into literacy practices within a specifically South African context. I investigated the differing schooled literacies in KwaZulu-Natal province in South Africa over three decades along the language lines of Afrikaans, English and Zulu. The findings propose that the differing sets of literacy practices validate different subjects – and that they are implicated in constructing dis/advantage.
- Full Text:
Mechanisms for multimodality: taking fiction to another dimension
- Glass, Kevin R, Bangay, Shaun D, Alcock, Bruce
- Authors: Glass, Kevin R , Bangay, Shaun D , Alcock, Bruce
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433226 , vital:72953 , https://doi.org/10.1145/1294685.1294708
- Description: We present methods for automatically constructing representations of fiction books in a range of modalities: audibly, graphically and as 3D virtual environments. The correspondence between the sequential ordering of events against the order of events presented in the text is used to correctly resolve the dynamic interactions for each representation. Synthesised audio created from the fiction text is used to calibrate the base time-line against which the other forms of media are correctly aligned. The audio stream is based on speech synthesis using the text of the book, and is enhanced using distinct voices for the different characters in a book. Sound effects are included automatically. The graphical representation represents the text (as subtitles), identifies active characters and provides visual feedback of the content of the story. Dynamic virtual environments conform to the constraints implied by the story, and are used as a source of further visual content. These representations are all aligned to a common time-line, and combined using sequencing facilities to provide a multimodal version of the original text.
- Full Text:
- Authors: Glass, Kevin R , Bangay, Shaun D , Alcock, Bruce
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433226 , vital:72953 , https://doi.org/10.1145/1294685.1294708
- Description: We present methods for automatically constructing representations of fiction books in a range of modalities: audibly, graphically and as 3D virtual environments. The correspondence between the sequential ordering of events against the order of events presented in the text is used to correctly resolve the dynamic interactions for each representation. Synthesised audio created from the fiction text is used to calibrate the base time-line against which the other forms of media are correctly aligned. The audio stream is based on speech synthesis using the text of the book, and is enhanced using distinct voices for the different characters in a book. Sound effects are included automatically. The graphical representation represents the text (as subtitles), identifies active characters and provides visual feedback of the content of the story. Dynamic virtual environments conform to the constraints implied by the story, and are used as a source of further visual content. These representations are all aligned to a common time-line, and combined using sequencing facilities to provide a multimodal version of the original text.
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Microwave synthesis and photophysics of new tetrasulfonated tin (II) macrocycles
- Khene, Samson, Ogunsipe, Abimbola, Antunes, Edith M, Nyokong, Tebello
- Authors: Khene, Samson , Ogunsipe, Abimbola , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281269 , vital:55708 , xlink:href="https://doi.org/10.1142/S108842460700014X"
- Description: This work reports on the microwave synthesis of tetrasulfonated tin phthalocyanine and tetrasulfonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (more than 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The α,β,γ-tetrabenzcorrole complex has lower triplet life times and yields, while the binding constant and quenching (of bovine serum albumin) constant are lower for α,β,γ-tetrabenzcorrole compared to tetrasulfonated tin phthalocyanine.
- Full Text:
- Authors: Khene, Samson , Ogunsipe, Abimbola , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281269 , vital:55708 , xlink:href="https://doi.org/10.1142/S108842460700014X"
- Description: This work reports on the microwave synthesis of tetrasulfonated tin phthalocyanine and tetrasulfonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (more than 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The α,β,γ-tetrabenzcorrole complex has lower triplet life times and yields, while the binding constant and quenching (of bovine serum albumin) constant are lower for α,β,γ-tetrabenzcorrole compared to tetrasulfonated tin phthalocyanine.
- Full Text:
More media for Southern Africa?: the place of politics, economics and convergence in developing media density
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147825 , vital:38676 , https://0-doi.org.wam.seals.ac.za/10.1080/02560240485310041
- Description: In line with global trends, media in Southern Africa in the past decade has been moving slowly towards mergers, partnerships and multi-platform publishing. Driven by politics and facilitated by technology, the process has had to confront the difficulty of establishing viable economic models, the lack of regional integration within Southern African countries, and what is sometimes a difficult political environment. Markets remain largely national or local and economically weak. Print media faces huge hurdles. Broadcast media density is improving, partly through noncommercial mechanisms. News websites are understaffed, lacking in viable survival strategies and skills, and are incompletely integrated with parent media platforms. Economic pressures, however, are likely to force Southern African media operations into greater synergies in search of survival. The various convergences entailed may increase media density.
- Full Text:
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147825 , vital:38676 , https://0-doi.org.wam.seals.ac.za/10.1080/02560240485310041
- Description: In line with global trends, media in Southern Africa in the past decade has been moving slowly towards mergers, partnerships and multi-platform publishing. Driven by politics and facilitated by technology, the process has had to confront the difficulty of establishing viable economic models, the lack of regional integration within Southern African countries, and what is sometimes a difficult political environment. Markets remain largely national or local and economically weak. Print media faces huge hurdles. Broadcast media density is improving, partly through noncommercial mechanisms. News websites are understaffed, lacking in viable survival strategies and skills, and are incompletely integrated with parent media platforms. Economic pressures, however, are likely to force Southern African media operations into greater synergies in search of survival. The various convergences entailed may increase media density.
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Morphological and genetic analyses suggest that southern African crown crabs, Hymenosoma orbiculare, represent five distinct species
- Edkins, M T, Teske, Peter R, Papadopoulos, Isabelle, Griffiths, C L
- Authors: Edkins, M T , Teske, Peter R , Papadopoulos, Isabelle , Griffiths, C L
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445701 , vital:74415 , https://www.jstor.org/stable/20107852
- Description: The crown crab, Hymenosoma orbiculare, occurs all along the coast of southern Africa displays great morphological variation across this range. To determine whether the species c several distinct taxonomic units, H. orbiculare were collected from 18 estuaries and lagoons Walvis Bay in Namibia and Kosi Bay in north-eastern South Africa. Open ocean individua also obtained from False Bay in south-western South Africa. Morphological and genet mitochondrial DNA) comparisons were carried out between individuals from all locatio monophyletic clusters were identified on the basis of genetic data, each confined to specific of the distribution range. Morphological data supported the distinctness of each of these clus typical H. orbiculare, characterized by large size (maximum carapace width 28 mm) and of the characteristic ornamentations of other morphotypes, occurred in estuaries and lag along the west and south coasts. False Bay deep-water individuals were of two forms.
- Full Text:
- Authors: Edkins, M T , Teske, Peter R , Papadopoulos, Isabelle , Griffiths, C L
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445701 , vital:74415 , https://www.jstor.org/stable/20107852
- Description: The crown crab, Hymenosoma orbiculare, occurs all along the coast of southern Africa displays great morphological variation across this range. To determine whether the species c several distinct taxonomic units, H. orbiculare were collected from 18 estuaries and lagoons Walvis Bay in Namibia and Kosi Bay in north-eastern South Africa. Open ocean individua also obtained from False Bay in south-western South Africa. Morphological and genet mitochondrial DNA) comparisons were carried out between individuals from all locatio monophyletic clusters were identified on the basis of genetic data, each confined to specific of the distribution range. Morphological data supported the distinctness of each of these clus typical H. orbiculare, characterized by large size (maximum carapace width 28 mm) and of the characteristic ornamentations of other morphotypes, occurred in estuaries and lag along the west and south coasts. False Bay deep-water individuals were of two forms.
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Negotiating the Good Life
- Authors: Tabensky, Pedro
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/305688 , vital:58604 , xlink:href="http://10.1007/s10677-006-9030-x"
- Description: Book Review: Mark A. Young asks: “Is there a problem with community in America?” (p. 1). Agreeing with Robert Putnam’s views, embodied in Bowling Alone: The Collapse and Revival of American Community (New York: Touchstone Press, 2000), regarding the breakdown of communal values in the US, but not with his nostalgic recommendations regarding the ‘good old days’ of univocal homogenous communities, Young proposes an alternative solution to Putnam’s, starting from Aristotle’s sophisticated account of the self/community relation and drawing important insights from Alasdair MacIntyre, Charles Taylor, Amitai Etzione, Paul Ricoeur, Michael Sandel and especially Hannah Arendt.
- Full Text:
- Authors: Tabensky, Pedro
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/305688 , vital:58604 , xlink:href="http://10.1007/s10677-006-9030-x"
- Description: Book Review: Mark A. Young asks: “Is there a problem with community in America?” (p. 1). Agreeing with Robert Putnam’s views, embodied in Bowling Alone: The Collapse and Revival of American Community (New York: Touchstone Press, 2000), regarding the breakdown of communal values in the US, but not with his nostalgic recommendations regarding the ‘good old days’ of univocal homogenous communities, Young proposes an alternative solution to Putnam’s, starting from Aristotle’s sophisticated account of the self/community relation and drawing important insights from Alasdair MacIntyre, Charles Taylor, Amitai Etzione, Paul Ricoeur, Michael Sandel and especially Hannah Arendt.
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Nesting success and survival rates of suburban Olive Thrushes (Turdus olivaceus olivaceus).
- Authors: Bonnevie, Bo T
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448299 , vital:74720 , https://doi.org/10.2989/OSTRICH.2007.78.2.19.99
- Description: Adult survival rates of suburban Olive Thrushes (Turdus olivaceus) were estimated from the proportion of adults and juveniles in mist-net samples from the Eastern Cape and Western Cape provinces of South Africa. These survival rates were compared to an estimate from recovery data. Reproductive rate, clutch size, nesting success and survival rate of dependent fledglings were estimated from breeding records in the Eastern Cape. These data were used to estimate survival rate of independent fledglings. The estimated adult survival rate in this region was high and the clutch size was small, compared to those of the Blackbird (Turdus merula) in Europe. Dispersal patterns from recapture and recovery data, and the relatively low survival rates of juvenile birds, suggest that fledglings are most vulnerable when they reach independence and leave their natal territories.
- Full Text:
- Authors: Bonnevie, Bo T
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448299 , vital:74720 , https://doi.org/10.2989/OSTRICH.2007.78.2.19.99
- Description: Adult survival rates of suburban Olive Thrushes (Turdus olivaceus) were estimated from the proportion of adults and juveniles in mist-net samples from the Eastern Cape and Western Cape provinces of South Africa. These survival rates were compared to an estimate from recovery data. Reproductive rate, clutch size, nesting success and survival rate of dependent fledglings were estimated from breeding records in the Eastern Cape. These data were used to estimate survival rate of independent fledglings. The estimated adult survival rate in this region was high and the clutch size was small, compared to those of the Blackbird (Turdus merula) in Europe. Dispersal patterns from recapture and recovery data, and the relatively low survival rates of juvenile birds, suggest that fledglings are most vulnerable when they reach independence and leave their natal territories.
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Novel gallium (III) phthalocyanine derivatives–Synthesis, photophysics and photochemistry
- Chauke, Vongani, Ogunsipe, Abimbola, Durmus, Mahmut, Nyokong, Tebello
- Authors: Chauke, Vongani , Ogunsipe, Abimbola , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283118 , vital:55912 , xlink:href="https://doi.org/10.1016/j.poly.2007.01.016"
- Description: The syntheses of gallium(III) chloride phthalocyanine {(Cl)GaPc}, octaphenoxyphthalocyaninato gallium(III) chloride {(Cl)GaOPPc} and octakis(4-tert-butylphenoxy)phthalocyaninato gallium(III) chloride {(Cl)GaOTBPPc}; as well as their photophysical and photochemical parameters are hereby presented. Fluorescence quantum yields do not vary much among the three metallophthalocyanines (MPcs); therefore it was concluded that the effect of the substituents is not significant amongst (Cl)GaPc, (Cl)GaOPPc and (Cl)GaOTBPPc. Solvents effects, however, had an effect on the results. Triplet quantum yields were found to be lower in DMSO than in DMF and toluene. The rate constants for fluorescence, intersystem crossing and internal conversion as well as fluorescence and triplet lifetimes are reported. We have also reported photodegradation and singlet oxygen quantum yields. There was no clear correlation between the later parameters. It was, however, established that the three MPcs were stable.
- Full Text:
- Authors: Chauke, Vongani , Ogunsipe, Abimbola , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283118 , vital:55912 , xlink:href="https://doi.org/10.1016/j.poly.2007.01.016"
- Description: The syntheses of gallium(III) chloride phthalocyanine {(Cl)GaPc}, octaphenoxyphthalocyaninato gallium(III) chloride {(Cl)GaOPPc} and octakis(4-tert-butylphenoxy)phthalocyaninato gallium(III) chloride {(Cl)GaOTBPPc}; as well as their photophysical and photochemical parameters are hereby presented. Fluorescence quantum yields do not vary much among the three metallophthalocyanines (MPcs); therefore it was concluded that the effect of the substituents is not significant amongst (Cl)GaPc, (Cl)GaOPPc and (Cl)GaOTBPPc. Solvents effects, however, had an effect on the results. Triplet quantum yields were found to be lower in DMSO than in DMF and toluene. The rate constants for fluorescence, intersystem crossing and internal conversion as well as fluorescence and triplet lifetimes are reported. We have also reported photodegradation and singlet oxygen quantum yields. There was no clear correlation between the later parameters. It was, however, established that the three MPcs were stable.
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Patriotic history and the politicisation of memory: manipulation of popular music to re-invent the liberation struggle in Zimbabwe
- Authors: Thram, Diane Janell
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147836 , vital:38677 , https://0-doi.org.wam.seals.ac.za/10.1080/02560040608540456
- Description: This paper investigates how the music nationalism promulgated by the ZANU-PF regime's former Minister of Information and Publicity, Jonathan Moyo, appropriated history and culture in its relentless effort to convince the citizenry that the on-going crisis in Zimbabwe is a continuation of the liberation struggle. It documents how Moyo's propagandised ‘patriotic history’ was written into song lyrics and used in frequently televised propaganda videos and CD/cassette releases to create a music nationalism that appropriated the music of the 1970s Second Chimurenga struggle, then performed to resist colonial oppression, and used it as propaganda intended to maintain the current oppressive regime's grip on political power. It argues that the appropriation of indigenous song/dance forms and the ‘chimurenga music’ of the liberation war has failed to achieve unification of the nation; and that rather, the propaganda's manipulation of memory has offended the Shona cultural aesthetic that requires songwriters to speak the truth of their experience in their music.
- Full Text:
- Authors: Thram, Diane Janell
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147836 , vital:38677 , https://0-doi.org.wam.seals.ac.za/10.1080/02560040608540456
- Description: This paper investigates how the music nationalism promulgated by the ZANU-PF regime's former Minister of Information and Publicity, Jonathan Moyo, appropriated history and culture in its relentless effort to convince the citizenry that the on-going crisis in Zimbabwe is a continuation of the liberation struggle. It documents how Moyo's propagandised ‘patriotic history’ was written into song lyrics and used in frequently televised propaganda videos and CD/cassette releases to create a music nationalism that appropriated the music of the 1970s Second Chimurenga struggle, then performed to resist colonial oppression, and used it as propaganda intended to maintain the current oppressive regime's grip on political power. It argues that the appropriation of indigenous song/dance forms and the ‘chimurenga music’ of the liberation war has failed to achieve unification of the nation; and that rather, the propaganda's manipulation of memory has offended the Shona cultural aesthetic that requires songwriters to speak the truth of their experience in their music.
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Photocatalysis of 4-nitrophenol using zinc phthalocyanine complexes
- Marais, Eloïse A, Klein, Rosalyn, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloïse A , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Authors: Marais, Eloïse A , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
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Photochemistry, photophysics and nonlinear optical parameters of phenoxy and tert-butylphenoxy substituted indium (III) phthalocyanines
- Chauke, Vongani, Durmus, Mahmut, Nyokong, Tebello
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268823 , vital:54235 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
- Full Text:
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268823 , vital:54235 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
- Full Text:
Photochemistry, photophysics and nonlinear optical parameters of phenoxy and tert-butylphenoxy substituted indium (III) phthalocyanines
- Chauke, Vongani, Durmus, Mahmut, Nyokong, Tebello
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268787 , vital:54232 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
- Full Text:
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268787 , vital:54232 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
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Photophysical and photochemical properties of zinc and aluminum phthalocyanines in the presence of magnetic fluid
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281298 , vital:55710 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.12.013"
- Description: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching.
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- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281298 , vital:55710 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.12.013"
- Description: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching.
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Photophysical and photochemical studies of long chain-substituted zinc phthalocyanines
- Durmus, Mahmut, Ahsen, Vefa, Nyokong, Tebello
- Authors: Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281310 , vital:55711 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.025"
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetra(13,17-dioxanonacosane-15-hydroxy)-substituted zinc phthalocyanines (1, 2). General trends are described for quantum yields of photodegradation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet quantum yields of these compounds in dimethylformamide (DMF) and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2) are reported.
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- Authors: Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281310 , vital:55711 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.025"
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetra(13,17-dioxanonacosane-15-hydroxy)-substituted zinc phthalocyanines (1, 2). General trends are described for quantum yields of photodegradation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet quantum yields of these compounds in dimethylformamide (DMF) and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2) are reported.
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Photophysical, photochemical and bovine serum albumin binding studies on water-soluble gallium (III) phthalocyanine derivatives
- Ogunsipe, Abimbola, Nyokong, Tebello, Durmus, Mahmut
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello , Durmus, Mahmut
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271239 , vital:54524 , xlink:href="https://doi.org/10.1142/S1088424607000746"
- Description: Spectral, photophysical, photochemical and bovine serum albumin binding studies on some gallium(III) derivatives - {1,(4)-(tetrapyridyloxyphthalocyaninato)gallium(III), (αGaPc); 2,(3)-(tetrapyridyloxyphthalocyaninato)gallium(III), (βGaPc); and their quaternized derivatives: QαGaPc and QβGaPc)} are hereby presented. β-Substituted complexes are more fluorescent, but show lower tendencies to undergo intersystem crossing than the α-substituted, as judged by their fluorescence and triplet quantum yield values. The quaternized derivatives (QGaPc) are water-soluble and non-aggregated, which makes them potential photosensitizers of choice for photodynamic therapy applications; these amphiphilic compounds also bind strongly to bovine serum albumin in 1:1 stoichiometries, and with binding constants (Kb) in the order of 106 M−1.
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- Authors: Ogunsipe, Abimbola , Nyokong, Tebello , Durmus, Mahmut
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271239 , vital:54524 , xlink:href="https://doi.org/10.1142/S1088424607000746"
- Description: Spectral, photophysical, photochemical and bovine serum albumin binding studies on some gallium(III) derivatives - {1,(4)-(tetrapyridyloxyphthalocyaninato)gallium(III), (αGaPc); 2,(3)-(tetrapyridyloxyphthalocyaninato)gallium(III), (βGaPc); and their quaternized derivatives: QαGaPc and QβGaPc)} are hereby presented. β-Substituted complexes are more fluorescent, but show lower tendencies to undergo intersystem crossing than the α-substituted, as judged by their fluorescence and triplet quantum yield values. The quaternized derivatives (QGaPc) are water-soluble and non-aggregated, which makes them potential photosensitizers of choice for photodynamic therapy applications; these amphiphilic compounds also bind strongly to bovine serum albumin in 1:1 stoichiometries, and with binding constants (Kb) in the order of 106 M−1.
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Phylogeographic structure of the caridean shrimp Palaemon peringueyi in South Africa: further evidence for intraspecific genetic units associated with marine biogeographic provinces
- Teske, Peter R, Froneman, P William, Barker, Nigel P, McQuaid, Christopher D
- Authors: Teske, Peter R , Froneman, P William , Barker, Nigel P , McQuaid, Christopher D
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445486 , vital:74392 , https://doi.org/10.2989/AJMS.2007.29.2.9.192
- Description: Recent genetic studies have shown that most widely distributed, passively dispersing invertebrates in southern Africa have regional intraspecific units that are associated with the three main marine biogeographic provinces (cool-temperate, warm-temperate and subtropical). The caridean shrimp Palaemon peringueyi also occurs in all three provinces, but the fact that it can disperse both actively and passively (i.e. larval drifting, adult walking/swimming and potential adult rafting by means of floating objects) suggests that the amount of gene flow between regions may be too high for evolutionary divergence to have taken place. Samples of P. peringueyi were collected throughout South Africa and an intraspecific phylogeny was reconstructed using mitochondrial COI and 16S rRNA sequences. Three major clades were recovered, which were broadly associated with the three biogeographic regions. This suggests that, even though P. peringueyi can disperse actively, the fact that neither larvae nor adults are strong swimmers has resulted in genetic subdivisons comparable to those of passively dispersing coastal invertebrates in southern Africa.
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- Authors: Teske, Peter R , Froneman, P William , Barker, Nigel P , McQuaid, Christopher D
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445486 , vital:74392 , https://doi.org/10.2989/AJMS.2007.29.2.9.192
- Description: Recent genetic studies have shown that most widely distributed, passively dispersing invertebrates in southern Africa have regional intraspecific units that are associated with the three main marine biogeographic provinces (cool-temperate, warm-temperate and subtropical). The caridean shrimp Palaemon peringueyi also occurs in all three provinces, but the fact that it can disperse both actively and passively (i.e. larval drifting, adult walking/swimming and potential adult rafting by means of floating objects) suggests that the amount of gene flow between regions may be too high for evolutionary divergence to have taken place. Samples of P. peringueyi were collected throughout South Africa and an intraspecific phylogeny was reconstructed using mitochondrial COI and 16S rRNA sequences. Three major clades were recovered, which were broadly associated with the three biogeographic regions. This suggests that, even though P. peringueyi can disperse actively, the fact that neither larvae nor adults are strong swimmers has resulted in genetic subdivisons comparable to those of passively dispersing coastal invertebrates in southern Africa.
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Problematising race for journalists: critical reflections on the South African Human Rights Commission Inquiry into media racism
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147913 , vital:38684 , DOI: 10.1080/02560240185310081
- Description: How journalists report race and racism was at the centre of the South African Human Rights Commission (SAHRC) Inquiry into racism in the media. A critical analysis of the conceptual assumptions in the Inquiry's Final Report, however, reveals serious limitations to the enterprise. In particular the flawed conceptualisations, plus the generalised character of the findings are of little help in assisting the momentum of eradicating racism in South African media, and for linking race transformation to issues of class, gender, sexual orientation and xenophobia. This article identifies the problems as race essentialism and a relativism about what constitutes racism. It argues instead that journalists need the concept of racialisation in order to change their reporting. The argument upholds the desired role of the South African media as one that contributes to a non-racial, as opposed to a multi-racial, society.
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- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147913 , vital:38684 , DOI: 10.1080/02560240185310081
- Description: How journalists report race and racism was at the centre of the South African Human Rights Commission (SAHRC) Inquiry into racism in the media. A critical analysis of the conceptual assumptions in the Inquiry's Final Report, however, reveals serious limitations to the enterprise. In particular the flawed conceptualisations, plus the generalised character of the findings are of little help in assisting the momentum of eradicating racism in South African media, and for linking race transformation to issues of class, gender, sexual orientation and xenophobia. This article identifies the problems as race essentialism and a relativism about what constitutes racism. It argues instead that journalists need the concept of racialisation in order to change their reporting. The argument upholds the desired role of the South African media as one that contributes to a non-racial, as opposed to a multi-racial, society.
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Realistic idealism
- Authors: Tabensky, Pedro
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/305700 , vital:58605 , xlink:href="https://doi.org/10.3167/th.2007.5411306"
- Description: Realists found in International Relations (IR) circles explicitly assign relatively minor importance to ethical ideals in their analyses of the international political domain, although a robust ethical ideal of sorts, implicitly for the most part qua ethical ideal, does guide their analysis of the international arena. For them, the key to order in the international arena is the balance of power reached between different nations aiming at asserting their wills, promoting their interests, in what is in effect perceived by IR realists as an international battle of wills guided primarily by the logic of power. As a purely descriptive claim regarding how nations, for the most part, actually behave, I have no axe to grind with the IR realist, or at least I do not have to grind an axe with them on this matter for the purposes of this paper, but the IR realist is committed to more than merely describing the behaviour of the international order. IR realists, implicitly and paradoxically, are forced, by the logic of their own position, to believe that the ethical ideal that ought to be guiding the international order is the balance of power between competing interests guiding the international behaviour of nations in their quest for power and (alleged) survival. The primary moral dictum of their position is that nations ought to pursue their self-interested interests relentlessly, but only to the extent that the fragile balance of power is not upset (which is, at any rate, a central ingredient for promoting national self-interest). IR realists do not altogether explicitly deny the role of ideals, but the role they assign to ideals is limited and, I will argue, ultimately incoherent, for ideals ought to be understood as flowing from the structure of our embodied existences and into every nook and cranny of our lives, understood individually and collectively, nationally and internationally. We are active creatures, as Aristotle observed, and activities are defined as such in relation to a functional ideal, an ideal of operation, which flows from our specific modes of embodiment. The norms or ends guiding the international political order ought to flow from this understanding of the human subject ideally conceived, as opposed to the largely Machiavellian pessimistic understanding of the human situation informing IR realism; a pessimism that stems from the fallacious move from raw observation to normative recommendation. To claim that our ends are Machiavellian, we shall see, is incoherent and this incoherence is at the heart of IR realism. The demands of reason, we shall see, should push us in the direction of a particular variety of optimism. By using a broadly Aristotelian teleological technique of analysis I will show that IR realists cannot be right. Without placing ideals at the centre of our understandings of our political lives we would be unable properly to understand the political domain, including the specific sphere of concern of IR specialists. The purely observational descriptions alluded to above do not provide the grounds for proper understanding. What does provide a proper understanding, we shall see, is observation through a conceptual lens informed by a teleological understanding of the human person (observation in the light of a conception of the good). That I think a robust conception of the good, of the set of ideals that out to be guiding rational human life, is necessary for properly understanding the international arena does not of course mean that I advocate any such conception of the good. As claimed above, the sort that I advocate, following Aristotle’s footsteps, flows from the specific configuration of our embodied lives. I refer to this form of idealism as realistic idealism.
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- Authors: Tabensky, Pedro
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/305700 , vital:58605 , xlink:href="https://doi.org/10.3167/th.2007.5411306"
- Description: Realists found in International Relations (IR) circles explicitly assign relatively minor importance to ethical ideals in their analyses of the international political domain, although a robust ethical ideal of sorts, implicitly for the most part qua ethical ideal, does guide their analysis of the international arena. For them, the key to order in the international arena is the balance of power reached between different nations aiming at asserting their wills, promoting their interests, in what is in effect perceived by IR realists as an international battle of wills guided primarily by the logic of power. As a purely descriptive claim regarding how nations, for the most part, actually behave, I have no axe to grind with the IR realist, or at least I do not have to grind an axe with them on this matter for the purposes of this paper, but the IR realist is committed to more than merely describing the behaviour of the international order. IR realists, implicitly and paradoxically, are forced, by the logic of their own position, to believe that the ethical ideal that ought to be guiding the international order is the balance of power between competing interests guiding the international behaviour of nations in their quest for power and (alleged) survival. The primary moral dictum of their position is that nations ought to pursue their self-interested interests relentlessly, but only to the extent that the fragile balance of power is not upset (which is, at any rate, a central ingredient for promoting national self-interest). IR realists do not altogether explicitly deny the role of ideals, but the role they assign to ideals is limited and, I will argue, ultimately incoherent, for ideals ought to be understood as flowing from the structure of our embodied existences and into every nook and cranny of our lives, understood individually and collectively, nationally and internationally. We are active creatures, as Aristotle observed, and activities are defined as such in relation to a functional ideal, an ideal of operation, which flows from our specific modes of embodiment. The norms or ends guiding the international political order ought to flow from this understanding of the human subject ideally conceived, as opposed to the largely Machiavellian pessimistic understanding of the human situation informing IR realism; a pessimism that stems from the fallacious move from raw observation to normative recommendation. To claim that our ends are Machiavellian, we shall see, is incoherent and this incoherence is at the heart of IR realism. The demands of reason, we shall see, should push us in the direction of a particular variety of optimism. By using a broadly Aristotelian teleological technique of analysis I will show that IR realists cannot be right. Without placing ideals at the centre of our understandings of our political lives we would be unable properly to understand the political domain, including the specific sphere of concern of IR specialists. The purely observational descriptions alluded to above do not provide the grounds for proper understanding. What does provide a proper understanding, we shall see, is observation through a conceptual lens informed by a teleological understanding of the human person (observation in the light of a conception of the good). That I think a robust conception of the good, of the set of ideals that out to be guiding rational human life, is necessary for properly understanding the international arena does not of course mean that I advocate any such conception of the good. As claimed above, the sort that I advocate, following Aristotle’s footsteps, flows from the specific configuration of our embodied lives. I refer to this form of idealism as realistic idealism.
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Reflecting on the 2007 World Environmental Education Congress
- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183047 , vital:43907 , xlink:href="https://doi.org/10.1177/097340820700100207"
- Description: What motivates more than 800 people from 101 countries around the world to meet at a World Environmental Education Congress? And how does one make the most of such an incredible gathering of people, cultures, thoughts and minds? What did people learn and was it worthwhile? These are just some of the questions that have been chasing through my mind in the weeks following the fourth World Environmental Education Congress held in Durban, South Africa, in July 2007. This short paper shares some preliminary reflections on the 2007 WEEC event, noting that in-depth analyses will only become possible as time passes.
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- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183047 , vital:43907 , xlink:href="https://doi.org/10.1177/097340820700100207"
- Description: What motivates more than 800 people from 101 countries around the world to meet at a World Environmental Education Congress? And how does one make the most of such an incredible gathering of people, cultures, thoughts and minds? What did people learn and was it worthwhile? These are just some of the questions that have been chasing through my mind in the weeks following the fourth World Environmental Education Congress held in Durban, South Africa, in July 2007. This short paper shares some preliminary reflections on the 2007 WEEC event, noting that in-depth analyses will only become possible as time passes.
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