Biological activity of extracellular and intracellular polysaccharides from Pleurotus tuber-regium hybrid and mutant strains
- Bamigboye, Comfort Olukemi, Oloke, Julius Kola, Dames, Joanna Felicity
- Authors: Bamigboye, Comfort Olukemi , Oloke, Julius Kola , Dames, Joanna Felicity
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69056 , vital:29376 , http://pubs.sciepub.com/jfnr/4/7/2/
- Description: Publisher version , Pleurotus tuber-regium (Fr.) Singer (1951) is a unique sclerotium-forming edible and medicinal mushroom. Interestingly, both the sclerotium and mushroom are edible and are often used for curing various ailments. Previous studies have focused on the antimicrobial and antioxidant activity of the extracellular polysaccharide (EPS) from wild P. tuber-regium. There has been no report on the intracellular polysaccharide (IPS) of the wild mycelia, likewise there is very meager information on the improvement of the perceived potentials of P. tuber-regium. This research study analysed the EPS and IPS fractions of P. tuber-regium hybrid and mutant strains. The antimicrobial potential of the IPS and EPS fractions, their scavenging activity on 1, 1-diphenyl–2picryhydrazyl (DPPH) and Hydroxyl radicals were also determined. Both IPS and EPS fractions of P. tuber-regium hybrids and mutants showed increased DPPH and hydroxyl scavenging activity over the wild P. tuber-regium with an EC50 mostly 1 mg/ml. The antimicrobial activity of the IPS from a mutant strain had an IC50 of 15.6 mg/ml compared to the wild type (18.75 mg /ml). This study showed that selected mutant and hybrids of P. tuber-regium had increased radical scavenging activity indicating potentially increased biological activity that could offer increased benefit as a neutraceutical.
- Full Text: false
- Date Issued: 2016
- Authors: Bamigboye, Comfort Olukemi , Oloke, Julius Kola , Dames, Joanna Felicity
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69056 , vital:29376 , http://pubs.sciepub.com/jfnr/4/7/2/
- Description: Publisher version , Pleurotus tuber-regium (Fr.) Singer (1951) is a unique sclerotium-forming edible and medicinal mushroom. Interestingly, both the sclerotium and mushroom are edible and are often used for curing various ailments. Previous studies have focused on the antimicrobial and antioxidant activity of the extracellular polysaccharide (EPS) from wild P. tuber-regium. There has been no report on the intracellular polysaccharide (IPS) of the wild mycelia, likewise there is very meager information on the improvement of the perceived potentials of P. tuber-regium. This research study analysed the EPS and IPS fractions of P. tuber-regium hybrid and mutant strains. The antimicrobial potential of the IPS and EPS fractions, their scavenging activity on 1, 1-diphenyl–2picryhydrazyl (DPPH) and Hydroxyl radicals were also determined. Both IPS and EPS fractions of P. tuber-regium hybrids and mutants showed increased DPPH and hydroxyl scavenging activity over the wild P. tuber-regium with an EC50 mostly 1 mg/ml. The antimicrobial activity of the IPS from a mutant strain had an IC50 of 15.6 mg/ml compared to the wild type (18.75 mg /ml). This study showed that selected mutant and hybrids of P. tuber-regium had increased radical scavenging activity indicating potentially increased biological activity that could offer increased benefit as a neutraceutical.
- Full Text: false
- Date Issued: 2016
Nonlinear optical response of a low symmetry phthalocyanine in the presence of gold nanoparticles when in solution or embedded in poly acrylic acid polymer thin films
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188719 , vital:44779 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.12.014"
- Description: In this article, we explored the photophysical and nonlinear optical (NLO) characterizations of low symmetry phthalocyanine (ZnPc-NH2) covalently linked to MPA-capped AuNPs (ZnPc-NH2-AuNPs) and poly acrylic acid (ZnPc-NH2-PAA). Nonlinear optical (NLO) properties of the samples were evaluated using Z-scan technique at 532 nm and 10 ns pulsed duration. We observed enhanced photophysical and nonlinear optical behaviour for the ZnPc-NH2 in presence of AuNPs. By virtue of the magnitude of absorption coefficients and other NLO optical parameters estimated in this work, ZnPc-NH2-AuNPs was found to exhibit improved nonlinear optical response compared to the ZnPc-NH2 and ZnPc-NH2-PAA. Both ZnPc-NH2-AuNPs and ZnPc-NH2 doped in PAA possess strong nonlinear absorption coefficients and very low limiting thresholds than when measured in solution.
- Full Text:
- Date Issued: 2016
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188719 , vital:44779 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.12.014"
- Description: In this article, we explored the photophysical and nonlinear optical (NLO) characterizations of low symmetry phthalocyanine (ZnPc-NH2) covalently linked to MPA-capped AuNPs (ZnPc-NH2-AuNPs) and poly acrylic acid (ZnPc-NH2-PAA). Nonlinear optical (NLO) properties of the samples were evaluated using Z-scan technique at 532 nm and 10 ns pulsed duration. We observed enhanced photophysical and nonlinear optical behaviour for the ZnPc-NH2 in presence of AuNPs. By virtue of the magnitude of absorption coefficients and other NLO optical parameters estimated in this work, ZnPc-NH2-AuNPs was found to exhibit improved nonlinear optical response compared to the ZnPc-NH2 and ZnPc-NH2-PAA. Both ZnPc-NH2-AuNPs and ZnPc-NH2 doped in PAA possess strong nonlinear absorption coefficients and very low limiting thresholds than when measured in solution.
- Full Text:
- Date Issued: 2016
Comparative studies on photophysical and optical limiting characterizations of low symmetry phthalocyanine linked to Fe 3 O 4–Ag core–shell or hybrid nanoparticles
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188788 , vital:44785 , xlink:href="https://doi.org/10.1039/C6NJ01511E"
- Description: Photophysical and nonlinear optical (NLO) behaviours of low symmetry zinc phthalocyanine (1) linked to Fe3O4/Ag core–shell (represented as Fe/Ag) or Fe3O4–Ag hybrid (represented as FeAg) nanoparticles were investigated in DMSO. Triplet quantum yields and NLO parameters of phthalocyanine improved due to the combined effects of magnetic–metallic nanoparticles. A direct relationship between the increased triplet excited state absorptions by already excited molecules and reverse saturable absorption (RSA) was established as the predominant mechanism responsible for nonlinearity of the samples. Our findings show that, at the same approximate concentrations and conditions, 1-FeAg enhanced the OL potentials of 1 more than 1-Fe/Ag.
- Full Text:
- Date Issued: 2016
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188788 , vital:44785 , xlink:href="https://doi.org/10.1039/C6NJ01511E"
- Description: Photophysical and nonlinear optical (NLO) behaviours of low symmetry zinc phthalocyanine (1) linked to Fe3O4/Ag core–shell (represented as Fe/Ag) or Fe3O4–Ag hybrid (represented as FeAg) nanoparticles were investigated in DMSO. Triplet quantum yields and NLO parameters of phthalocyanine improved due to the combined effects of magnetic–metallic nanoparticles. A direct relationship between the increased triplet excited state absorptions by already excited molecules and reverse saturable absorption (RSA) was established as the predominant mechanism responsible for nonlinearity of the samples. Our findings show that, at the same approximate concentrations and conditions, 1-FeAg enhanced the OL potentials of 1 more than 1-Fe/Ag.
- Full Text:
- Date Issued: 2016
Nonlinear optical behavior of alkyne terminated phthalocyanines in solution and when embedded in polysulfone as thin films: effects of aggregation
- Bankole, Owolabi M, Yilmaz, Yusuf, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Yilmaz, Yusuf , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189110 , vital:44817 , xlink:href="https://doi.org/10.1016/j.optmat.2015.11.041"
- Description: We report here for the first time, on the comparative studies of the photophysical and optical limiting behavior of our two novel phthalocyanines namely 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyanines 2, and 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyaninato zinc (II) (3) in solution and thin films. Nonlinear optical (NLO) properties of the samples in solution and contained in polysulfone (PSU) thin films were evaluated using Z-scan technique at 532 nm and 10 ns pulsed duration. Effects of aggregation and disaggregation on the NLO performance of metal-free phthalocyanine are reported in detail. Our findings showed that the prepared Pcs show larger nonlinear absorption coefficient and lower limiting thresholds when embedded in polysulfone films compared to in solutions. The values of nonlinear susceptibility and hyperpolarizability recorded for 3-PSU in this work are respectively, ∼2.09 × 10−8 esu and ∼1.02 × 10−26 esu. These values are among the largest values reported for phthalocyanines and other macrocycles doped on polymer matrices.
- Full Text:
- Date Issued: 2016
- Authors: Bankole, Owolabi M , Yilmaz, Yusuf , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189110 , vital:44817 , xlink:href="https://doi.org/10.1016/j.optmat.2015.11.041"
- Description: We report here for the first time, on the comparative studies of the photophysical and optical limiting behavior of our two novel phthalocyanines namely 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyanines 2, and 2(3), 9(10), 16(17), 23(24)-tetrakis-(4-(5-methylhex-1-yn-3-yloxy)) phthalocyaninato zinc (II) (3) in solution and thin films. Nonlinear optical (NLO) properties of the samples in solution and contained in polysulfone (PSU) thin films were evaluated using Z-scan technique at 532 nm and 10 ns pulsed duration. Effects of aggregation and disaggregation on the NLO performance of metal-free phthalocyanine are reported in detail. Our findings showed that the prepared Pcs show larger nonlinear absorption coefficient and lower limiting thresholds when embedded in polysulfone films compared to in solutions. The values of nonlinear susceptibility and hyperpolarizability recorded for 3-PSU in this work are respectively, ∼2.09 × 10−8 esu and ∼1.02 × 10−26 esu. These values are among the largest values reported for phthalocyanines and other macrocycles doped on polymer matrices.
- Full Text:
- Date Issued: 2016
Enhanced nonlinear optical responses of zinc diaminopyrimidin-2-ylthio phthalocyanine conjugated to AgxAuy alloy nanoparticles
- Bankole, Owolabi M, Osifeko, Olawale, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Osifeko, Olawale , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240382 , vital:50829 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.06.025"
- Description: In this article, the photophysical and nonlinear optical (NLO) characterizations of diaminopyrimidin-2-ylthio phthalocyaninatozinc (II) (2) before and after conjugation to AgxAuy nano-alloys are discussed. Phthalocyanines-AgxAuy (2-AgxAuy) composites showed enhanced triplet state and nonlinear optical behaviour when compared to free phthalocyanine. Optical limiting (OL) responses of the samples were evaluated using Z-scan technique at 532 nm and 10 ns in dimethyl sulfoxide. Reverse saturable absorption (RSA), which is a direct consequence of triplet absorption of already excited molecules was observed as the dominant mechanism responsible for nonlinearity of the samples. By virtue of the magnitude of absorption coefficients and other NLO optical parameters estimated in this work, 2-AgxAuy composites were found to exhibit stronger optical limiting responses than unconjugated phthalocyanine. The large third-order susceptibilities of the composites make them suitable materials for attenuating modern laser radiations, and also found useful in various optical applications.
- Full Text:
- Date Issued: 2016
- Authors: Bankole, Owolabi M , Osifeko, Olawale , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240382 , vital:50829 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.06.025"
- Description: In this article, the photophysical and nonlinear optical (NLO) characterizations of diaminopyrimidin-2-ylthio phthalocyaninatozinc (II) (2) before and after conjugation to AgxAuy nano-alloys are discussed. Phthalocyanines-AgxAuy (2-AgxAuy) composites showed enhanced triplet state and nonlinear optical behaviour when compared to free phthalocyanine. Optical limiting (OL) responses of the samples were evaluated using Z-scan technique at 532 nm and 10 ns in dimethyl sulfoxide. Reverse saturable absorption (RSA), which is a direct consequence of triplet absorption of already excited molecules was observed as the dominant mechanism responsible for nonlinearity of the samples. By virtue of the magnitude of absorption coefficients and other NLO optical parameters estimated in this work, 2-AgxAuy composites were found to exhibit stronger optical limiting responses than unconjugated phthalocyanine. The large third-order susceptibilities of the composites make them suitable materials for attenuating modern laser radiations, and also found useful in various optical applications.
- Full Text:
- Date Issued: 2016
Parallel visions: Byron, Géricault and the Medusa
- Authors: Beard, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147792 , vital:38673 , https://doi.org/10.1080/00043389.1999.11761285
- Description: Martin Meisel has noted that Delacroix's 1841 painting A Shipwreck was recognised as uniting Gericault and Byron. for not only does the painting illustrate that moment in Don Juan when lots are drawn for the human sacrifice {2, 75) but it also invokes comparison with Gericault' s 1819 painting entitled Raft of the Medusa(Meisel1988:601).1 would like to argue in this paper that Gericault' s famous painting and Byron's shipwreck stanzas in the second canto of Don Juan have other points of comparison. Gericault used the Savigny and Correard Narrative of a Voyage to Senegal ( 1817) as the primary source of information for his treatment of the Medusa incident (Eitner 1971: 117). Byron used multiple sources when he researched material for his shipwreck stanzas but it is highly probable that the Savigny and Correard text was one of them. Thus, the cause celebre of the wreck of the Medusa is directly treated by Gericault and indirectly by Byron - two artists temperamentally and artistically attuned.
- Full Text:
- Date Issued: 2016
- Authors: Beard, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147792 , vital:38673 , https://doi.org/10.1080/00043389.1999.11761285
- Description: Martin Meisel has noted that Delacroix's 1841 painting A Shipwreck was recognised as uniting Gericault and Byron. for not only does the painting illustrate that moment in Don Juan when lots are drawn for the human sacrifice {2, 75) but it also invokes comparison with Gericault' s 1819 painting entitled Raft of the Medusa(Meisel1988:601).1 would like to argue in this paper that Gericault' s famous painting and Byron's shipwreck stanzas in the second canto of Don Juan have other points of comparison. Gericault used the Savigny and Correard Narrative of a Voyage to Senegal ( 1817) as the primary source of information for his treatment of the Medusa incident (Eitner 1971: 117). Byron used multiple sources when he researched material for his shipwreck stanzas but it is highly probable that the Savigny and Correard text was one of them. Thus, the cause celebre of the wreck of the Medusa is directly treated by Gericault and indirectly by Byron - two artists temperamentally and artistically attuned.
- Full Text:
- Date Issued: 2016
Constructions of roles in studio teaching and learning
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59792 , vital:27651 , https://doi.org/10.1111/jade.12042
- Description: Various constructions of supervisors and students emerge from education literature on art, design and architecture studio pedagogy. Constructions of the supervisor within the studio and during assessment are considered, with a discussion of the threads which underpin them. This is followed by a discussion of some of the current dominant constructions of the student, and possible effects of these roles and relationships on their engagement with learning. As many of these constructions may be inherited or unconscious, a concern for the agency of those involved to rupture, subvert, rescript or resist such constructions motivates this research, while acknowledging that this may be limited by structural and cultural contexts.
- Full Text: false
- Date Issued: 2016
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59792 , vital:27651 , https://doi.org/10.1111/jade.12042
- Description: Various constructions of supervisors and students emerge from education literature on art, design and architecture studio pedagogy. Constructions of the supervisor within the studio and during assessment are considered, with a discussion of the threads which underpin them. This is followed by a discussion of some of the current dominant constructions of the student, and possible effects of these roles and relationships on their engagement with learning. As many of these constructions may be inherited or unconscious, a concern for the agency of those involved to rupture, subvert, rescript or resist such constructions motivates this research, while acknowledging that this may be limited by structural and cultural contexts.
- Full Text: false
- Date Issued: 2016
Influences on the struggle over content: considering two fine art studio practice curricula in developing/ed contexts
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59809 , vital:27653 , http://dx.doi.org/10.1080/13562517.2016.1183617
- Description: This paper considers the influences of curricula content on the nuances of teaching and learning practices, and the ways in such influences are complicated by the contexts within which they are situated. Generated data from within the particularity of two fine art schools, one operating from the developed world in the global ‘north’ and another the developing world in the ‘south’, considers how they have negotiated the contemporary push from the professional community of practice, led by ‘western’ artmaking, towards the discourse-interest of contextualism in fine art practice education, compared to the focus on skills and mastery of more out-dated formalism. Particular emphasis is placed on the significance of such influences and pressures on the structures and cultures of teaching and learning.
- Full Text: false
- Date Issued: 2016
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59809 , vital:27653 , http://dx.doi.org/10.1080/13562517.2016.1183617
- Description: This paper considers the influences of curricula content on the nuances of teaching and learning practices, and the ways in such influences are complicated by the contexts within which they are situated. Generated data from within the particularity of two fine art schools, one operating from the developed world in the global ‘north’ and another the developing world in the ‘south’, considers how they have negotiated the contemporary push from the professional community of practice, led by ‘western’ artmaking, towards the discourse-interest of contextualism in fine art practice education, compared to the focus on skills and mastery of more out-dated formalism. Particular emphasis is placed on the significance of such influences and pressures on the structures and cultures of teaching and learning.
- Full Text: false
- Date Issued: 2016
Playing broken telephone with student feedback: the possibilities and issues of transformation within a South African case of a collegial rationality model of evaluation
- Authors: Belluigi, Dina Z
- Date: 2013
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66943 , vital:29003 , https://doi.org/10.1016/B978-1-84334-655-5.50001-5
- Description: publisher version , Drawing on the case of a small South African university which espouses a social justice approach to transformation, this chapter considers the possibilities and challenges created for student feedback within an institutional context that gives the individual lecturer a large degree of autonomy in evaluation. The chapter looks at some of the dominant perceptions of student feedback in addition to how it is collected and utilised, by referring to the institution’s policies and guideline documents; institutional research conducted with course coordinators; responses elicited from 40 lecturers on the issues outlined in this chapter; the author’s own reflections as a staff developer in the institution; and specific examples of good practice from lecturers situated within social science disciplines. The emerging concerns which structured this discussion are: the impact of student feedback on improving quality; enabling student voice; increasing student ownership; and the educational value of evaluation processes.
- Full Text: false
- Date Issued: 2013
- Authors: Belluigi, Dina Z
- Date: 2013
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66943 , vital:29003 , https://doi.org/10.1016/B978-1-84334-655-5.50001-5
- Description: publisher version , Drawing on the case of a small South African university which espouses a social justice approach to transformation, this chapter considers the possibilities and challenges created for student feedback within an institutional context that gives the individual lecturer a large degree of autonomy in evaluation. The chapter looks at some of the dominant perceptions of student feedback in addition to how it is collected and utilised, by referring to the institution’s policies and guideline documents; institutional research conducted with course coordinators; responses elicited from 40 lecturers on the issues outlined in this chapter; the author’s own reflections as a staff developer in the institution; and specific examples of good practice from lecturers situated within social science disciplines. The emerging concerns which structured this discussion are: the impact of student feedback on improving quality; enabling student voice; increasing student ownership; and the educational value of evaluation processes.
- Full Text: false
- Date Issued: 2013
Possible futures for science and engineering education
- Blackie, Margaret, Le Roux, Kate, McKenna, Sioux
- Authors: Blackie, Margaret , Le Roux, Kate , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66796 , vital:28994 , ISSN 1573-174X , https://doi.org/10.1007/s10734-015-9962-y
- Description: Publisher version , From Introduction: The understanding that the science, engineering, technology and mathematics disciplines (STEM) have a significant and directly causal role to play in economic productivity and innovation has driven an increased focus on these fields in higher education. Innovation in this context is a shorthand for the harnessing of the knowledge economy and the provision of products with novel significant ‘added value’. The assumption in both developed and developing economies alike is that STEM will drive national growth (World Bank 2002; UNESCO 2009), and this impacts on demands that universities provide competent graduates in sufficient numbers. However, exactly what ‘competency’ might mean in this context is open to debate.
- Full Text: false
- Date Issued: 2016
- Authors: Blackie, Margaret , Le Roux, Kate , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66796 , vital:28994 , ISSN 1573-174X , https://doi.org/10.1007/s10734-015-9962-y
- Description: Publisher version , From Introduction: The understanding that the science, engineering, technology and mathematics disciplines (STEM) have a significant and directly causal role to play in economic productivity and innovation has driven an increased focus on these fields in higher education. Innovation in this context is a shorthand for the harnessing of the knowledge economy and the provision of products with novel significant ‘added value’. The assumption in both developed and developing economies alike is that STEM will drive national growth (World Bank 2002; UNESCO 2009), and this impacts on demands that universities provide competent graduates in sufficient numbers. However, exactly what ‘competency’ might mean in this context is open to debate.
- Full Text: false
- Date Issued: 2016
Counting on demographic equity to transform institutional cultures at historically white South African universities?:
- Booi, Masixole, Vincent, Louise, Liccardo, Sabrina
- Authors: Booi, Masixole , Vincent, Louise , Liccardo, Sabrina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141946 , vital:38018 , DOI: 10.1080/07294360.2017.1289155
- Description: The post-apartheid higher education transformation project is faced with the challenge of recruiting and retaining black academics and other senior staff. But when we shift the focus from participation rates to equality–inequality within historically white universities (HWUs), then the discourse changes from demographic equity and redress to institutional culture and diversity. HWUs invoke the need to maintain their position as leading higher education institutions globally, and notions of ‘quality’ and ‘excellence’ have emerged as discursive practices, which serve to perpetuate exclusion. The question then arises as to which forms of capital comprise the Gold Standard at HWUs? Several South African universities have responded to the challenge of recruiting and retaining black academics by initiating programmes for the ‘accelerated development’ of these candidates.
- Full Text:
- Date Issued: 2017
- Authors: Booi, Masixole , Vincent, Louise , Liccardo, Sabrina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141946 , vital:38018 , DOI: 10.1080/07294360.2017.1289155
- Description: The post-apartheid higher education transformation project is faced with the challenge of recruiting and retaining black academics and other senior staff. But when we shift the focus from participation rates to equality–inequality within historically white universities (HWUs), then the discourse changes from demographic equity and redress to institutional culture and diversity. HWUs invoke the need to maintain their position as leading higher education institutions globally, and notions of ‘quality’ and ‘excellence’ have emerged as discursive practices, which serve to perpetuate exclusion. The question then arises as to which forms of capital comprise the Gold Standard at HWUs? Several South African universities have responded to the challenge of recruiting and retaining black academics by initiating programmes for the ‘accelerated development’ of these candidates.
- Full Text:
- Date Issued: 2017
Lives "on hold": the Daily Sun and the South African identity document
- Authors: Boshoff, Priscilla A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143538 , vital:38255 , https://hdl.handle.net/10520/EJC195358
- Description: The relationship between a personal identity and the state-issued Identity Document (ID) is the focus of this article, which examines stories published in the "Horror Affairs" column of the popular South African tabloid, the Daily Sun. These highly emotional stories tell of the despair and desperation felt by individuals at the lack of an ID book, which is blamed on the inefficiency of the state Department of Home Affairs. In order to explicate this relationship I make use of Agamben's notion of "bare life" and the camp in conjunction with Lacan's idea of the Symbolic Order to argue that if the Identity Document provides the means by which the individual is made to signify, the lack of an Identity Document threatens to reduce the individual to "bare life". By publishing the stories of those deprived of the visibility that the ID provides, the Daily Sun, I show, directly engages in this exchange, and, in contrast to Home Affairs, bestows its own even stronger gift of identity by the fact of appearance in its pages.
- Full Text:
- Date Issued: 2016
- Authors: Boshoff, Priscilla A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143538 , vital:38255 , https://hdl.handle.net/10520/EJC195358
- Description: The relationship between a personal identity and the state-issued Identity Document (ID) is the focus of this article, which examines stories published in the "Horror Affairs" column of the popular South African tabloid, the Daily Sun. These highly emotional stories tell of the despair and desperation felt by individuals at the lack of an ID book, which is blamed on the inefficiency of the state Department of Home Affairs. In order to explicate this relationship I make use of Agamben's notion of "bare life" and the camp in conjunction with Lacan's idea of the Symbolic Order to argue that if the Identity Document provides the means by which the individual is made to signify, the lack of an Identity Document threatens to reduce the individual to "bare life". By publishing the stories of those deprived of the visibility that the ID provides, the Daily Sun, I show, directly engages in this exchange, and, in contrast to Home Affairs, bestows its own even stronger gift of identity by the fact of appearance in its pages.
- Full Text:
- Date Issued: 2016
Russian wheat aphids: Breakfast, lunch, and supper. Feasting on small grains in South Africa
- Botha, Christiaan E J, Sacranie, S, Gallagher, Sean, Hill, Jaclyn M
- Authors: Botha, Christiaan E J , Sacranie, S , Gallagher, Sean , Hill, Jaclyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69031 , vital:29374 , https://doi.org/10.1016/j.sajb.2016.12.006
- Description: The Russian Wheat Aphid (Diuraphis noxia, RWA) negatively impacts commercially grown barley and wheat in South Africa. Climate change, the attendant rise in [CO2], and the appearance of new RWA biotypes have the potential to induce severe crop yield loss in agriculturally important wheat and barley cultivars. This study presents data showing changes in relative aphid population numbers, concurrently with assessments of plant damage under controlled environmental conditions, under ambient and elevated (450 ppm) [CO2]. Extensive structural damage to the vascular tissue and disruption to the transport systems were revealed using light, fluorescence and electron microscopy. This, coupled with biotype population studies, demonstrated that RWA has the capacity to inflict severe, potentially permanent damage to vegetative small grain plants. Furthermore, some currently ‘resistant’ cultivars may well lose resistance as a direct result of increasing atmospheric [CO2]. A small (50 ppm) increase in atmospheric [CO2] may result in increased aphid population numbers, potentially serious plant damage and, by implication, a potentially negative impact on yield, as increased aphid density per plant leads to an accelerated disruption of the assimilate and transpiration transport pathways. These outcomes pose a direct threat to the commercial small grain industry of South Africa and by extension, to other small grain production areas elsewhere.
- Full Text: false
- Date Issued: 2016
- Authors: Botha, Christiaan E J , Sacranie, S , Gallagher, Sean , Hill, Jaclyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69031 , vital:29374 , https://doi.org/10.1016/j.sajb.2016.12.006
- Description: The Russian Wheat Aphid (Diuraphis noxia, RWA) negatively impacts commercially grown barley and wheat in South Africa. Climate change, the attendant rise in [CO2], and the appearance of new RWA biotypes have the potential to induce severe crop yield loss in agriculturally important wheat and barley cultivars. This study presents data showing changes in relative aphid population numbers, concurrently with assessments of plant damage under controlled environmental conditions, under ambient and elevated (450 ppm) [CO2]. Extensive structural damage to the vascular tissue and disruption to the transport systems were revealed using light, fluorescence and electron microscopy. This, coupled with biotype population studies, demonstrated that RWA has the capacity to inflict severe, potentially permanent damage to vegetative small grain plants. Furthermore, some currently ‘resistant’ cultivars may well lose resistance as a direct result of increasing atmospheric [CO2]. A small (50 ppm) increase in atmospheric [CO2] may result in increased aphid population numbers, potentially serious plant damage and, by implication, a potentially negative impact on yield, as increased aphid density per plant leads to an accelerated disruption of the assimilate and transpiration transport pathways. These outcomes pose a direct threat to the commercial small grain industry of South Africa and by extension, to other small grain production areas elsewhere.
- Full Text: false
- Date Issued: 2016
Art investment in South Africa: portfolio diversification and art market efficiency
- Botha, Ferdi, Snowball, Jeanette D, Scott, Brett
- Authors: Botha, Ferdi , Snowball, Jeanette D , Scott, Brett
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64794 , vital:28601 , http://www.dx.doi.org/10.17159/2222-3436/2016/v19n3a4
- Description: Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel art price index offered the opportunity to test this theory in the South African context. Moreover, this paper tests whether art prices are efficient. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A vector autoregression of the art price index, Johannesburg stock exchange all-share index, house price index, and South African government bond index were used. Results show that, when there are increased returns on the stock market in a preceding period and wealth increases, there is a change in the Citadel art price index in the same direction. No significant difference was found between the house price index and the art price index, or between the art and government bond price indices. The art market is also found to be inefficient, thereby exacerbating the risk of investing in art. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Ferdi , Snowball, Jeanette D , Scott, Brett
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64794 , vital:28601 , http://www.dx.doi.org/10.17159/2222-3436/2016/v19n3a4
- Description: Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel art price index offered the opportunity to test this theory in the South African context. Moreover, this paper tests whether art prices are efficient. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A vector autoregression of the art price index, Johannesburg stock exchange all-share index, house price index, and South African government bond index were used. Results show that, when there are increased returns on the stock market in a preceding period and wealth increases, there is a change in the Citadel art price index in the same direction. No significant difference was found between the house price index and the art price index, or between the art and government bond price indices. The art market is also found to be inefficient, thereby exacerbating the risk of investing in art. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2016
The good African society index
- Authors: Botha, Ferdi
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396194 , vital:69157 , xlink:href="https://doi.org/10.1007/s11205-015-0891-z"
- Description: This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (1) economic sustainability, (2) democracy and freedom, (3) child well-being, (4) environment and infrastructure, (5) safety and security, (6) health and health systems, (7) integrity and justice, (8) education, and (9) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 indicators. Tunisia ranks highest on the GASI, followed by Cape Verde and Botswana. Chad has the lowest GASI score, followed by Central African Republic and Cote d’Ivoire. The GASI is strongly related to the 2012 Human Development Index and Fragile States Index, to a lesser extent, GNI per capita.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Ferdi
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396194 , vital:69157 , xlink:href="https://doi.org/10.1007/s11205-015-0891-z"
- Description: This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (1) economic sustainability, (2) democracy and freedom, (3) child well-being, (4) environment and infrastructure, (5) safety and security, (6) health and health systems, (7) integrity and justice, (8) education, and (9) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 indicators. Tunisia ranks highest on the GASI, followed by Cape Verde and Botswana. Chad has the lowest GASI score, followed by Central African Republic and Cote d’Ivoire. The GASI is strongly related to the 2012 Human Development Index and Fragile States Index, to a lesser extent, GNI per capita.
- Full Text:
- Date Issued: 2016
Academic literacy and the decontextualised learner
- Boughey, Chrissie, McKenna, Sioux
- Authors: Boughey, Chrissie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64651 , vital:28585 , http://www.DOI:10.14426/cristal.v4i2.80
- Description: The literacy practices that are valued in the university emerge from specific disciplinary histories yet students are often expected to master these as if they were common sense and natural. This article argues that the autonomous model of literacy, which sees language use as the application of a set of neutral skills, continues to dominate in South African universities. This model denies the extent to which taking on disciplinary literacy practices can be difficult and have implications for identity. It also allows disciplinary norms to remain largely opaque and beyond critique. Furthermore, the autonomous model of literacy is often coupled with a discourse of the ‘decontextualised learner’ who is divorced from her social context, with higher education success seen to be resting largely upon attributes inherent in, or lacking from, the individual. Sadly, alternative critical social understandings have not been widely taken up despite their being well researched. Indeed, such understandings have often been misappropriated in ways that draw on critical social terminology to offer autonomous, decontextualised, remedial student interventions. We argue that these issues are implicated in students’ accusations that universities are alienating spaces.
- Full Text:
- Date Issued: 2016
- Authors: Boughey, Chrissie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64651 , vital:28585 , http://www.DOI:10.14426/cristal.v4i2.80
- Description: The literacy practices that are valued in the university emerge from specific disciplinary histories yet students are often expected to master these as if they were common sense and natural. This article argues that the autonomous model of literacy, which sees language use as the application of a set of neutral skills, continues to dominate in South African universities. This model denies the extent to which taking on disciplinary literacy practices can be difficult and have implications for identity. It also allows disciplinary norms to remain largely opaque and beyond critique. Furthermore, the autonomous model of literacy is often coupled with a discourse of the ‘decontextualised learner’ who is divorced from her social context, with higher education success seen to be resting largely upon attributes inherent in, or lacking from, the individual. Sadly, alternative critical social understandings have not been widely taken up despite their being well researched. Indeed, such understandings have often been misappropriated in ways that draw on critical social terminology to offer autonomous, decontextualised, remedial student interventions. We argue that these issues are implicated in students’ accusations that universities are alienating spaces.
- Full Text:
- Date Issued: 2016
Diversity of bacteria isolated from the flies Musca domestica (Muscidae) andChrysomya megacephala (Calliphoridae) with emphasis on vectored pathogens
- Brits, Devon, Brooks, Margot, Villet, Martin H
- Authors: Brits, Devon , Brooks, Margot , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66904 , vital:28998 , ISSN 1021-3589 , https://doi.org/10.4001/003.024.0365
- Description: Publisher version , We evaluated the bacteria occurring externally on Musca domestica and Chrysomya megacephala, the two most common synanthropic flies which may be found at many refuse sites throughout the world. Bacteria cultured from 10 specimens of each species were isolated, Gram-stained and examined microscopically, and divided into morphologically distinct ‘pseudospecies', to avoid excessive duplication of genetic identification. About 350 bp of the 16S ribosomalRNAgene was amplified from genomicDNAextracted from each ‘pseudospecies', sequenced, and bacteria identified using BLASTn. Nineteen different types of colony were identified from M. domestica, with Pseudomonas sp. and Swine Manure Bacterium SP14 being most abundant. Chrysomya megacephala yielded 15 distinct pseudospecies with total colony counts approximating to 10 000 from 10 plates, where 80 % of colonies were non-pathogenic Bacillus pumilus. A total of 18 species were identified genetically: three shared by the fly species; four unique to C. megacephala, and 13 unique to M. domestica. Half of these 18 species were pathogenic, two or three others were food spoilers and the rest were environmental or commensal bacteria from soil or plant matter. This study added three new pathogenic strains of bacteria and one new environmental strain to the list of bacteria reported to be vectored by these flies.
- Full Text: false
- Date Issued: 2016
- Authors: Brits, Devon , Brooks, Margot , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66904 , vital:28998 , ISSN 1021-3589 , https://doi.org/10.4001/003.024.0365
- Description: Publisher version , We evaluated the bacteria occurring externally on Musca domestica and Chrysomya megacephala, the two most common synanthropic flies which may be found at many refuse sites throughout the world. Bacteria cultured from 10 specimens of each species were isolated, Gram-stained and examined microscopically, and divided into morphologically distinct ‘pseudospecies', to avoid excessive duplication of genetic identification. About 350 bp of the 16S ribosomalRNAgene was amplified from genomicDNAextracted from each ‘pseudospecies', sequenced, and bacteria identified using BLASTn. Nineteen different types of colony were identified from M. domestica, with Pseudomonas sp. and Swine Manure Bacterium SP14 being most abundant. Chrysomya megacephala yielded 15 distinct pseudospecies with total colony counts approximating to 10 000 from 10 plates, where 80 % of colonies were non-pathogenic Bacillus pumilus. A total of 18 species were identified genetically: three shared by the fly species; four unique to C. megacephala, and 13 unique to M. domestica. Half of these 18 species were pathogenic, two or three others were food spoilers and the rest were environmental or commensal bacteria from soil or plant matter. This study added three new pathogenic strains of bacteria and one new environmental strain to the list of bacteria reported to be vectored by these flies.
- Full Text: false
- Date Issued: 2016
Improvement of nonlinear optical properties of phthalocyanine bearing diethyleneglycole chains
- Britton, Jonathan, Martynov, Alexander G, Oluwole, David O, Gorbunova, Yulia G, Tsivadze, Yulia G, Nyokong, Tebello
- Authors: Britton, Jonathan , Martynov, Alexander G , Oluwole, David O , Gorbunova, Yulia G , Tsivadze, Yulia G , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239812 , vital:50769 , xlink:href="https://doi.org/10.1142/S1088424616501042"
- Description: This paper reports the successful synthesis of the low symmetry phthalocyanines: metal-free 2,3-bis[2′-(2′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxyphthalocyanine 1H22 and its zinc complex 1Zn along with their nonlinear optical (NLO) behavior in solution and in thin films. 1H NMR investigations evidenced of higher dissymmetry of electronic density in 1H22 in comparison with 1Zn. This dissymmetry is responsible for unusually higher values of Im[χ(3)χ(3)]/αα, βeffβeff, and γγ for 1H22in contrast to 1Zn, where the notable effect of heavy-metal enhancement of ISC was expected. Both compounds showed Im[χ(3)χ(3)]/αα values of the order of 10−11−11 in chloroform which are higher in comparison to the symmetrical octabutoxyphthalocyanine H2[(BuO)8Pc]. NLO properties of 1H22 were improved via its incorporation into polycarbonate polymeric matrix together with CdSe@CdS-TOPO quantum dots. In such composite the value of Im[χ(3)χ(3)]/αα was almost three times higher in comparison with 1H22 solution in chloroform. The obtained composites are expected to be perspective components of optical materials, capable of protection against strong light irradiation
- Full Text:
- Date Issued: 2016
- Authors: Britton, Jonathan , Martynov, Alexander G , Oluwole, David O , Gorbunova, Yulia G , Tsivadze, Yulia G , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239812 , vital:50769 , xlink:href="https://doi.org/10.1142/S1088424616501042"
- Description: This paper reports the successful synthesis of the low symmetry phthalocyanines: metal-free 2,3-bis[2′-(2′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxyphthalocyanine 1H22 and its zinc complex 1Zn along with their nonlinear optical (NLO) behavior in solution and in thin films. 1H NMR investigations evidenced of higher dissymmetry of electronic density in 1H22 in comparison with 1Zn. This dissymmetry is responsible for unusually higher values of Im[χ(3)χ(3)]/αα, βeffβeff, and γγ for 1H22in contrast to 1Zn, where the notable effect of heavy-metal enhancement of ISC was expected. Both compounds showed Im[χ(3)χ(3)]/αα values of the order of 10−11−11 in chloroform which are higher in comparison to the symmetrical octabutoxyphthalocyanine H2[(BuO)8Pc]. NLO properties of 1H22 were improved via its incorporation into polycarbonate polymeric matrix together with CdSe@CdS-TOPO quantum dots. In such composite the value of Im[χ(3)χ(3)]/αα was almost three times higher in comparison with 1H22 solution in chloroform. The obtained composites are expected to be perspective components of optical materials, capable of protection against strong light irradiation
- Full Text:
- Date Issued: 2016
Sport consumption patterns in the Eastern Cape: cricket spectators as sporting univores or omnivores
- Brock, Kelcey, Fraser, Gavin C G, Botha, Ferdi
- Authors: Brock, Kelcey , Fraser, Gavin C G , Botha, Ferdi
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69362 , vital:29508 , https://doi.org/10.4102/jef.v9i3.64
- Description: Since its inception, consumption behaviour theory has developed to account for the important social aspects that underpin or at least to some extent explain consumer behaviour. Empirical studies on consumption behaviour of cultural activities, entertainment and sport have used Bourdieu’s (1984) omnivore/univore theory to investigate consumption of leisure activities. The aim of this study is to investigate whether South African cricket spectators are sporting omnivores or univores. The study was conducted among cricket spectators in the Eastern Cape at four limited overs cricket matches in the 2012/2013 cricket season. The results indicate that consumption behaviour of sport predominantly differs on the grounds of education and race. This suggests that there are aspects of social connotations underpinning sports consumption behaviour within South Africa.
- Full Text:
- Date Issued: 2016
Sport consumption patterns in the Eastern Cape: cricket spectators as sporting univores or omnivores
- Authors: Brock, Kelcey , Fraser, Gavin C G , Botha, Ferdi
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69362 , vital:29508 , https://doi.org/10.4102/jef.v9i3.64
- Description: Since its inception, consumption behaviour theory has developed to account for the important social aspects that underpin or at least to some extent explain consumer behaviour. Empirical studies on consumption behaviour of cultural activities, entertainment and sport have used Bourdieu’s (1984) omnivore/univore theory to investigate consumption of leisure activities. The aim of this study is to investigate whether South African cricket spectators are sporting omnivores or univores. The study was conducted among cricket spectators in the Eastern Cape at four limited overs cricket matches in the 2012/2013 cricket season. The results indicate that consumption behaviour of sport predominantly differs on the grounds of education and race. This suggests that there are aspects of social connotations underpinning sports consumption behaviour within South Africa.
- Full Text:
- Date Issued: 2016
MD-TASK: a software suite for analyzing molecular dynamics trajectories
- Brown, David K, Penkler, David L, Amamuddy, Olivier S, Ross, Caroline J, Atilgan, Ali R, Atilgan, Canan, Tastan Bishop, Özlem
- Authors: Brown, David K , Penkler, David L , Amamuddy, Olivier S , Ross, Caroline J , Atilgan, Ali R , Atilgan, Canan , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125138 , vital:35735 , https://doi.10.1093/bioinformatics/btx349
- Description: Molecular dynamics (MD) determines the physical motions of atoms of a biological macromolecule in a cell-like environment and is an important method in structural bioinformatics. Traditionally, measurements such as root mean square deviation, root mean square fluctuation, radius of gyration, and various energy measures have been used to analyze MD simulations. Here, we present MD-TASK, a novel software suite that employs graph theory techniques, perturbation response scanning, and dynamic cross-correlation to provide unique ways for analyzing MD trajectories.
- Full Text:
- Date Issued: 2017
- Authors: Brown, David K , Penkler, David L , Amamuddy, Olivier S , Ross, Caroline J , Atilgan, Ali R , Atilgan, Canan , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125138 , vital:35735 , https://doi.10.1093/bioinformatics/btx349
- Description: Molecular dynamics (MD) determines the physical motions of atoms of a biological macromolecule in a cell-like environment and is an important method in structural bioinformatics. Traditionally, measurements such as root mean square deviation, root mean square fluctuation, radius of gyration, and various energy measures have been used to analyze MD simulations. Here, we present MD-TASK, a novel software suite that employs graph theory techniques, perturbation response scanning, and dynamic cross-correlation to provide unique ways for analyzing MD trajectories.
- Full Text:
- Date Issued: 2017