Optical limiting response of multi-walled carbon nanotube-phthalocyanine nanocomposite in solution and when in poly (acrylic acid)
- Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188628 , vital:44770 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.03.067"
- Description: Bis{23-(3,4-di-yloxybenzoic acid)-(2(3), 9(10), 16(17), 23(24)-(hexakis-pyridin-3-yloxy phthalocyaninato)} dineodymium (III) acetate (3) is linked to amino-functionalized multi-walled carbon nanotubes (MWCNT) to form 3-MWCNT. Z-scan technique was employed to experimentally determine the nonlinear absorption coefficient from the open-aperture data. The limiting threshold values as low as 0.045 J cm−2 were found in solution. The conjugate (3-MWCNT) gave better optical limiting behavior than complex 3 alone.
- Full Text:
- Date Issued: 2016
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188628 , vital:44770 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.03.067"
- Description: Bis{23-(3,4-di-yloxybenzoic acid)-(2(3), 9(10), 16(17), 23(24)-(hexakis-pyridin-3-yloxy phthalocyaninato)} dineodymium (III) acetate (3) is linked to amino-functionalized multi-walled carbon nanotubes (MWCNT) to form 3-MWCNT. Z-scan technique was employed to experimentally determine the nonlinear absorption coefficient from the open-aperture data. The limiting threshold values as low as 0.045 J cm−2 were found in solution. The conjugate (3-MWCNT) gave better optical limiting behavior than complex 3 alone.
- Full Text:
- Date Issued: 2016
Optically active BODIPYs
- Lu, Hua, Mack, John, Nyokong, Tebello, Kobayashi, Nagao, Shen, Zhen
- Authors: Lu, Hua , Mack, John , Nyokong, Tebello , Kobayashi, Nagao , Shen, Zhen
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240421 , vital:50833 , xlink:href="https://doi.org/10.1016/j.ccr.2016.03.015"
- Description: This review highlights and summarizes various optically active BODIPY molecules and describes the analysis of their circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopy, to provide a platform for the rational design of novel optically active BODIPY structures and the development of new chiroptical applications. Possible future research directions are also discussed.
- Full Text:
- Date Issued: 2016
- Authors: Lu, Hua , Mack, John , Nyokong, Tebello , Kobayashi, Nagao , Shen, Zhen
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240421 , vital:50833 , xlink:href="https://doi.org/10.1016/j.ccr.2016.03.015"
- Description: This review highlights and summarizes various optically active BODIPY molecules and describes the analysis of their circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopy, to provide a platform for the rational design of novel optically active BODIPY structures and the development of new chiroptical applications. Possible future research directions are also discussed.
- Full Text:
- Date Issued: 2016
Optimising design and effort for environmental surveys using dung beetles (Coleoptera: Scarabaeidae):
- Tocco, Claudia, Quinn, Danielle, Midgley, John M, Villet, Martin H
- Authors: Tocco, Claudia , Quinn, Danielle , Midgley, John M , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140670 , vital:37908 , DOI: 10.4039/tce.2016.48
- Description: In biological monitoring, deploying an effective standardised quantitative sampling method, optimised by trap design and sampling effort, is an essential consideration. To exemplify this using dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae and Aphodiinae) communities, three pitfall trap designs (un-baited (TN), baited at ground level (flat trap, TF), and baited above the trap (hanging trap, TH)), employed with varying levels of sampling effort (number of traps = 1, 2, 3… 10; number of days = 1, 2, 3), were evaluated for sampling completeness and efficiency in the Eastern Cape, South Africa. Modelling and resampling simulation approaches were used to suggest optimal sampling protocols across environmentally diverse sites. Overall, TF recovered the greatest abundance and species richness of dung beetles, but behavioural guilds showed conflicting trends: endocoprids preferred TH while paracoprids and telocoprids preferred TF. Resampling simulation of trap type and the two components of sampling effort suggested that six TF traps left for three days was most efficient in obtaining a representative sample and allowed differentiation between trap types, allowing the improved efficiency to be recognised. The effect of trap type on non-target specimens, particularly ants, was also investigated. TF and TH caught almost no by-catch, which is ethically desirable.
- Full Text:
- Date Issued: 2016
- Authors: Tocco, Claudia , Quinn, Danielle , Midgley, John M , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140670 , vital:37908 , DOI: 10.4039/tce.2016.48
- Description: In biological monitoring, deploying an effective standardised quantitative sampling method, optimised by trap design and sampling effort, is an essential consideration. To exemplify this using dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae and Aphodiinae) communities, three pitfall trap designs (un-baited (TN), baited at ground level (flat trap, TF), and baited above the trap (hanging trap, TH)), employed with varying levels of sampling effort (number of traps = 1, 2, 3… 10; number of days = 1, 2, 3), were evaluated for sampling completeness and efficiency in the Eastern Cape, South Africa. Modelling and resampling simulation approaches were used to suggest optimal sampling protocols across environmentally diverse sites. Overall, TF recovered the greatest abundance and species richness of dung beetles, but behavioural guilds showed conflicting trends: endocoprids preferred TH while paracoprids and telocoprids preferred TF. Resampling simulation of trap type and the two components of sampling effort suggested that six TF traps left for three days was most efficient in obtaining a representative sample and allowed differentiation between trap types, allowing the improved efficiency to be recognised. The effect of trap type on non-target specimens, particularly ants, was also investigated. TF and TH caught almost no by-catch, which is ethically desirable.
- 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
Partial cold treatment of citrus fruit for export risk mitigation for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as part of a systems approach
- Moore, Sean D, Kirkman, Wayne, Albertyn, Sonnica, Love, C N, Coetzee, Julie A, Hattingh, V
- Authors: Moore, Sean D , Kirkman, Wayne , Albertyn, Sonnica , Love, C N , Coetzee, Julie A , Hattingh, V
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423796 , vital:72094 , xlink:href="https://doi.org/10.1093/jee/tow138"
- Description: Some of South Africa’s citrus export markets require mandatory postharvest cold treatment of citrus fruit as a phytosanitary risk mitigation treatment for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to this may be partial cold treatment as one of the final steps in a systems approach to mitigate phytosanitary risk. Consequently, the efficacy of such partial cold treatments was evaluated. It was first determined that a 2C cold treatment was significantly more effective against fourth and fifth instars (the most cold-tolerant instars) than treatments at 3C and 4C for a duration of 18 d. Secondly, it was determined that 2C for 18 d and 1C for 16 d were similarly effective, but both treatments were significantly more effective than 1C for 14 d. Mean mortality of fourth and fifth instars treated with 2C for 18 d in seven replicates from four trials was 99.94%. Finally, it was determined that the inability of the majority of surviving larvae to develop to adulthood would further increase the efficacy of a 2C for 18 d treatment to 99.96%. Inclusion of reproductive nonviability of survivors increased mortality to 99.99%.
- Full Text:
- Date Issued: 2016
- Authors: Moore, Sean D , Kirkman, Wayne , Albertyn, Sonnica , Love, C N , Coetzee, Julie A , Hattingh, V
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423796 , vital:72094 , xlink:href="https://doi.org/10.1093/jee/tow138"
- Description: Some of South Africa’s citrus export markets require mandatory postharvest cold treatment of citrus fruit as a phytosanitary risk mitigation treatment for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to this may be partial cold treatment as one of the final steps in a systems approach to mitigate phytosanitary risk. Consequently, the efficacy of such partial cold treatments was evaluated. It was first determined that a 2C cold treatment was significantly more effective against fourth and fifth instars (the most cold-tolerant instars) than treatments at 3C and 4C for a duration of 18 d. Secondly, it was determined that 2C for 18 d and 1C for 16 d were similarly effective, but both treatments were significantly more effective than 1C for 14 d. Mean mortality of fourth and fifth instars treated with 2C for 18 d in seven replicates from four trials was 99.94%. Finally, it was determined that the inability of the majority of surviving larvae to develop to adulthood would further increase the efficacy of a 2C for 18 d treatment to 99.96%. Inclusion of reproductive nonviability of survivors increased mortality to 99.99%.
- Full Text:
- Date Issued: 2016
Partnerships and parents–relationships in tutorial programmes
- Layton, Delia M, McKenna, Sioux
- Authors: Layton, Delia M , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66699 , vital:28983 , ISSN 1469-8366 , https://doi.org/10.1080/07294360.2015.1087471
- Description: The tutorial system is considered to be a useful pedagogical intervention to improve student retention, particularly in the context of a first-year student’s experience of entering university. For these novice students to achieve academic success, it is important that they are given access to the subject-specific knowledge and practices in their different disciplines, that is, that they acquire ‘epistemological access’. A recent study of the tutorial system in a South African university (Layton, D.M. [2013]. A social realist account of the tutorial system at the University of Johannesburg (Unpublished doctoral dissertation). Rhodes University, Grahamstown), sought to discover to what extent tutorials were discursively constructed as being about the enablement of epistemological access. This paper focuses on two discourses that emerged from the study – the parent discourse and the partnership discourse. Both discourses were concerned with relationships between key stakeholders in the tutorial programme. Given that tutorials are considered to be spaces in which more intimate learning can take place than in the anonymous environment of the large lecture hall, an interrogation of the relationships fostered in tutorials is important. The parent discourse, in which students were positioned as ‘kids’ needing care, was supportive of new students but ran the risk of being patronising and reductionist. The partnerships discourse, in which tutors and academics were seen to be working together towards the common goal of student success, was seen to be enabling of epistemological access. But it required a commitment to teaching endeavours that was in tension with the institutional focus on research. Through a social realist analysis of the two discourses constructing relationships in the tutorial system, we conclude that these discourses have the power to both constrain and enable the extent to which the tutorial system can be a site of epistemological access.
- Full Text: false
- Date Issued: 2016
- Authors: Layton, Delia M , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66699 , vital:28983 , ISSN 1469-8366 , https://doi.org/10.1080/07294360.2015.1087471
- Description: The tutorial system is considered to be a useful pedagogical intervention to improve student retention, particularly in the context of a first-year student’s experience of entering university. For these novice students to achieve academic success, it is important that they are given access to the subject-specific knowledge and practices in their different disciplines, that is, that they acquire ‘epistemological access’. A recent study of the tutorial system in a South African university (Layton, D.M. [2013]. A social realist account of the tutorial system at the University of Johannesburg (Unpublished doctoral dissertation). Rhodes University, Grahamstown), sought to discover to what extent tutorials were discursively constructed as being about the enablement of epistemological access. This paper focuses on two discourses that emerged from the study – the parent discourse and the partnership discourse. Both discourses were concerned with relationships between key stakeholders in the tutorial programme. Given that tutorials are considered to be spaces in which more intimate learning can take place than in the anonymous environment of the large lecture hall, an interrogation of the relationships fostered in tutorials is important. The parent discourse, in which students were positioned as ‘kids’ needing care, was supportive of new students but ran the risk of being patronising and reductionist. The partnerships discourse, in which tutors and academics were seen to be working together towards the common goal of student success, was seen to be enabling of epistemological access. But it required a commitment to teaching endeavours that was in tension with the institutional focus on research. Through a social realist analysis of the two discourses constructing relationships in the tutorial system, we conclude that these discourses have the power to both constrain and enable the extent to which the tutorial system can be a site of epistemological access.
- Full Text: false
- Date Issued: 2016
Pathogens, disease, and the social-ecological resilience of protected areas
- de Vos, Alta, Cumming, Graeme S, Cumming, David M, Ament, Judith M, Baum, Julia, Clements, Hayley S, Grewar, John D, Maciejewski, Kristine, Moore, Christine
- Authors: de Vos, Alta , Cumming, Graeme S , Cumming, David M , Ament, Judith M , Baum, Julia , Clements, Hayley S , Grewar, John D , Maciejewski, Kristine , Moore, Christine
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416360 , vital:71341 , xlink:href="http://dx.doi.org/10.5751/ES-07984-210120"
- Description: It is extremely important for biodiversity conservation that protected areas are resilient to a range of potential future perturbations. One of the least studied influences on protected area resilience is that of disease. We argue that wildlife disease (1) is a social-ecological problem that must be approached from an interdisciplinary perspective; (2) has the potential to lead to changes in the identity of protected areas, possibly transforming them; and (3) interacts with conservation both directly (via impacts on wild animals, livestock, and people) and indirectly (via the public, conservation management, and veterinary responses). We use southern African protected areas as a case study to test a framework for exploring the connections between conservation, endemic disease, and socialecological resilience. We first define a set of criteria for the social-ecological identity of protected areas. We then use these criteria to explore the potential impacts of selected diseases (foot-and-mouth disease, anthrax, malaria, rabies, rift valley fever, trypanosomiasis, and canine distemper) on protected area resilience. Although endemic diseases may have a number of direct impacts on both wild animals and domestic animals and people, the indirect pathways by which diseases influence social-ecological resilience also emerge as potentially important. The majority of endemic pathogens found in protected areas do not kill large numbers of wild animals or infect many people, and may even play valuable ecological roles; but occasional disease outbreaks and mortalities can have a large impact on public perceptions and disease management, potentially making protected areas unviable in one or more of their stated aims. Neighboring landowners also have a significant impact on park management decisions. The indirect effects triggered by disease in the human social and economic components of protected areas and surrounding landscapes may ultimately have a greater influence on protected area resilience than the direct ecological perturbations caused by disease.
- Full Text:
- Date Issued: 2016
- Authors: de Vos, Alta , Cumming, Graeme S , Cumming, David M , Ament, Judith M , Baum, Julia , Clements, Hayley S , Grewar, John D , Maciejewski, Kristine , Moore, Christine
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416360 , vital:71341 , xlink:href="http://dx.doi.org/10.5751/ES-07984-210120"
- Description: It is extremely important for biodiversity conservation that protected areas are resilient to a range of potential future perturbations. One of the least studied influences on protected area resilience is that of disease. We argue that wildlife disease (1) is a social-ecological problem that must be approached from an interdisciplinary perspective; (2) has the potential to lead to changes in the identity of protected areas, possibly transforming them; and (3) interacts with conservation both directly (via impacts on wild animals, livestock, and people) and indirectly (via the public, conservation management, and veterinary responses). We use southern African protected areas as a case study to test a framework for exploring the connections between conservation, endemic disease, and socialecological resilience. We first define a set of criteria for the social-ecological identity of protected areas. We then use these criteria to explore the potential impacts of selected diseases (foot-and-mouth disease, anthrax, malaria, rabies, rift valley fever, trypanosomiasis, and canine distemper) on protected area resilience. Although endemic diseases may have a number of direct impacts on both wild animals and domestic animals and people, the indirect pathways by which diseases influence social-ecological resilience also emerge as potentially important. The majority of endemic pathogens found in protected areas do not kill large numbers of wild animals or infect many people, and may even play valuable ecological roles; but occasional disease outbreaks and mortalities can have a large impact on public perceptions and disease management, potentially making protected areas unviable in one or more of their stated aims. Neighboring landowners also have a significant impact on park management decisions. The indirect effects triggered by disease in the human social and economic components of protected areas and surrounding landscapes may ultimately have a greater influence on protected area resilience than the direct ecological perturbations caused by disease.
- Full Text:
- Date Issued: 2016
Pedagogy for fostering criticality, reflectivity and praxis in a course on teaching for lecturers
- Quinn, Lynn, Vorster, Jo-Anne
- Authors: Quinn, Lynn , Vorster, Jo-Anne
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66590 , vital:28967 , https://doi.org/10.1080/02602938.2015.1066756
- Description: publisher version , Using the concepts of criticality, reflectivity and praxis, the paper presents an analysis of our reflections on participants’ responses to the assessment requirements for a course for lecturers on teaching. The context in which the course is being taught has changed considerably in the last few years in terms of the mode of delivery, as well as the number and diversity of participants. Our analysis has generated insights into ways in which the course is not meeting all the learning needs of the participants, nor preparing them adequately to demonstrate, in writing, their learning. Using insights gained, we suggest pedagogic processes and strategies for ensuring that the course focuses on both writing to learn and learning to write; and for assisting participants to acquire the practices to demonstrate their learning in written assessment tasks, using the requisite literacy including criticality, reflectivity and praxis.
- Full Text: false
- Date Issued: 2016
- Authors: Quinn, Lynn , Vorster, Jo-Anne
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66590 , vital:28967 , https://doi.org/10.1080/02602938.2015.1066756
- Description: publisher version , Using the concepts of criticality, reflectivity and praxis, the paper presents an analysis of our reflections on participants’ responses to the assessment requirements for a course for lecturers on teaching. The context in which the course is being taught has changed considerably in the last few years in terms of the mode of delivery, as well as the number and diversity of participants. Our analysis has generated insights into ways in which the course is not meeting all the learning needs of the participants, nor preparing them adequately to demonstrate, in writing, their learning. Using insights gained, we suggest pedagogic processes and strategies for ensuring that the course focuses on both writing to learn and learning to write; and for assisting participants to acquire the practices to demonstrate their learning in written assessment tasks, using the requisite literacy including criticality, reflectivity and praxis.
- Full Text: false
- Date Issued: 2016
Peer tutors as learning and teaching partners: a cumulative approach to building peer tutoring capacity in higher education
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61335 , vital:28016 , http://cristal.epubs.ac.za/index.php/cristal/article/view/69
- Description: Peer tutors in higher education are frequently given vital teaching and learning work to do, but the training or professional development and support opportunities they are offered vary, and more often than not peer tutors are under-supported. In order to create and sustain teaching and learning environments that are better able to facilitate students’ engagement with knowledge and learning, the role of peer tutors needs to be recognised differently, as that of learning and teaching partners to both lecturers and students. Tutors then need to be offered opportunities for more in-depth professional academic development in order to fully realise this role. This paper explores a tutor development programme within a South African writing centre that aimed at offering tutors such ongoing and cumulative opportunities for learning and growth using a balanced approach, which included scholarly research and practice-based training. Using narrative data tutors provided in reflective written reports, the paper explores the kinds of development in tutors’ thinking and action that are possible when training and development is theoretically informed, coherent, and oriented towards improving practice.
- Full Text:
- Date Issued: 2016
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61335 , vital:28016 , http://cristal.epubs.ac.za/index.php/cristal/article/view/69
- Description: Peer tutors in higher education are frequently given vital teaching and learning work to do, but the training or professional development and support opportunities they are offered vary, and more often than not peer tutors are under-supported. In order to create and sustain teaching and learning environments that are better able to facilitate students’ engagement with knowledge and learning, the role of peer tutors needs to be recognised differently, as that of learning and teaching partners to both lecturers and students. Tutors then need to be offered opportunities for more in-depth professional academic development in order to fully realise this role. This paper explores a tutor development programme within a South African writing centre that aimed at offering tutors such ongoing and cumulative opportunities for learning and growth using a balanced approach, which included scholarly research and practice-based training. Using narrative data tutors provided in reflective written reports, the paper explores the kinds of development in tutors’ thinking and action that are possible when training and development is theoretically informed, coherent, and oriented towards improving practice.
- Full Text:
- Date Issued: 2016
Photophysical properties of tetraphenylporphyrinsubphthalocyanine conjugates
- Managa, Muthumuni, Mack, John, Remiro-Buenamañana, Sonia, Tshangana, Charmaine, Cammidge, Andrew N, Nyokong, Tebello
- Authors: Managa, Muthumuni , Mack, John , Remiro-Buenamañana, Sonia , Tshangana, Charmaine , Cammidge, Andrew N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240766 , vital:50869 , xlink:href="https://doi.org/10.1142/S1088424615500959"
- Description: Novel tetraphenylporphyrin-subphthalocyanine conjugates have been prepared and characterized. An analysis of their optical spectroscopy and electronic structures using fluorescence emission and magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations, demonstrates that the two chromophores do not interact to any significant extent.
- Full Text:
- Date Issued: 2016
- Authors: Managa, Muthumuni , Mack, John , Remiro-Buenamañana, Sonia , Tshangana, Charmaine , Cammidge, Andrew N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240766 , vital:50869 , xlink:href="https://doi.org/10.1142/S1088424615500959"
- Description: Novel tetraphenylporphyrin-subphthalocyanine conjugates have been prepared and characterized. An analysis of their optical spectroscopy and electronic structures using fluorescence emission and magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations, demonstrates that the two chromophores do not interact to any significant extent.
- Full Text:
- Date Issued: 2016
Photophysicochemical properties of nanoconjugates of zinc (II) 2 (3)-mono-2-(4-oxy) phenoxy) acetic acid phthalocyanine with cysteamine capped silver and silver–gold nanoparticles
- Oluwole, David O, Prinsloo, Earl, Nyokong, Tebello
- Authors: Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188552 , vital:44764 , xlink:href="https://doi.org/10.1016/j.poly.2016.09.034"
- Description: A novel asymmetrical zinc(II) 2(3)-mono-2-(4-oxy)phenoxy)acetic acid phthalocyanine (complex 1) was synthesized and subsequently linked to cysteamine capped silver (AgNPs) and silver–gold (AgAuNPs) nanoparticles (NPs) via amide bonds. The photophysicochemical properties and in vitro photodynamic therapy activity of complex 1 and its nanoconjugates were investigated. The nanoconjugates showed improved photophysical properties compared to complex 1 alone. The fluorescence, triplet and singlet quantum yields of complex 1 were found to be 20%, 48%, and 43% respectively. Complex 1 showed in vitro dark cytotoxicity, but the dark toxicity was reduced for the combination of complex 1 with AgAuNPs, this combination also gave the best photodynamic therapy activity when compared to complex 1 and its conjugate with AgNPs without AuNPs.
- Full Text:
- Date Issued: 2016
- Authors: Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188552 , vital:44764 , xlink:href="https://doi.org/10.1016/j.poly.2016.09.034"
- Description: A novel asymmetrical zinc(II) 2(3)-mono-2-(4-oxy)phenoxy)acetic acid phthalocyanine (complex 1) was synthesized and subsequently linked to cysteamine capped silver (AgNPs) and silver–gold (AgAuNPs) nanoparticles (NPs) via amide bonds. The photophysicochemical properties and in vitro photodynamic therapy activity of complex 1 and its nanoconjugates were investigated. The nanoconjugates showed improved photophysical properties compared to complex 1 alone. The fluorescence, triplet and singlet quantum yields of complex 1 were found to be 20%, 48%, and 43% respectively. Complex 1 showed in vitro dark cytotoxicity, but the dark toxicity was reduced for the combination of complex 1 with AgAuNPs, this combination also gave the best photodynamic therapy activity when compared to complex 1 and its conjugate with AgNPs without AuNPs.
- Full Text:
- Date Issued: 2016
Physicochemical and antimicrobial photodynamic chemotherapy of unsymmetrical indium phthalocyanines alone or in the presence of magnetic nanoparticles
- Osifeko, Olawale L, Uddin, Imran, Mashazi, Philani N, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Uddin, Imran , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189121 , vital:44818 , xlink:href="https://doi.org/10.1039/C5NJ01922B"
- Description: An AB3 type photosensitiser, consisting of 4-pyridylsulfanyl units (denoted as B3) and one aminophenoxy (denoted as A) group (complex 3) was synthesized. Complex 3 was then quaternized to form complex 4. The aminophenoxy substituent of complex 3 was used for the formation of the amide linkage with the carboxylic functionalised magnetic nanoparticles. Complexes 3 and 4 and their conjugates with magnetic nanoparticles were then used for photodynamic antimicrobial chemotherapy on E. coli. The cationic photosensitiser 4 showed a high efficiency for photodynamic antimicrobial chemotherapy at a very low concentration compared to its conjugate on E. coli.
- Full Text:
- Date Issued: 2016
- Authors: Osifeko, Olawale L , Uddin, Imran , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189121 , vital:44818 , xlink:href="https://doi.org/10.1039/C5NJ01922B"
- Description: An AB3 type photosensitiser, consisting of 4-pyridylsulfanyl units (denoted as B3) and one aminophenoxy (denoted as A) group (complex 3) was synthesized. Complex 3 was then quaternized to form complex 4. The aminophenoxy substituent of complex 3 was used for the formation of the amide linkage with the carboxylic functionalised magnetic nanoparticles. Complexes 3 and 4 and their conjugates with magnetic nanoparticles were then used for photodynamic antimicrobial chemotherapy on E. coli. The cationic photosensitiser 4 showed a high efficiency for photodynamic antimicrobial chemotherapy at a very low concentration compared to its conjugate on E. coli.
- Full Text:
- Date Issued: 2016
Planning adaptation to climate change in fast-warming marine regions with seafood-dependent coastal communities
- Hobday, Alistair J, Cochrane, Kevern, Howard, James, Aswani, Shankar, Byfield, Val, Duggan, Greg, Duna, Elethu, Dutra, Leo X, Frusher, Stewart D, Fulton, Elizabeth A, Gammage, Louise, Gasalla, Maria A, Griffiths, Chevon, Guissamulo, Almeida, Haward, Marcus, Jarre, Astrid, Jennings, Sarah M, Jordan, Tia, Joyner, Jessica, Ramani, Narayana K, Shanmugasundaram, Swathi L P, Malherbe, Willem, Ortega-Cisneros, Kelly, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva E, Popova, Ekaterina E, Razafindrainibe, Haja, Roberts, Michael, Rohit, Prathiba, Sainulabdeen, Shyam S, Sauer, Warwick H H, Valappil, Sathianandan T, Zacharia, Paryiappanal U, Van Putten, E Ingrid
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
Planning adaptation to climate change in fast-warming marine regions with seafood-dependent coastal communities
- Hobday, Alistair J, Cochrane, Kevern L, Downey-Breedt, Nicola, Howard, James, Aswani, Shankar, Byfield, Val, Duna, Elethu, Dutra, Leo X, Frusher, Elizabeth A, Fulton, Elizabeth A, Gammage, Louise, Gasalla, Maria A, Griffiths, Chevon, Guissamulo, Almeida, Haward, Marcus, Jarre, Astrid, Jennings, Sarah, Jordan, Tia, Joyner, Jessica, Ramani, Narayana Kumar, Shanmugasundaram, Swathi L, Malherbe, Willem, Cisneros, Kelly, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva E, Popova, Ekaterina E, Razafindrainibe, Haja, K, Roberts, Michael, Rohit, Prathiba, Sainulabdeen, Shyam S, Sauer, Warwick H H, Valappil, Sathianandan T, Zacharia, Paryiappanal U, van Putten, Ingrid E
- Authors: Hobday, Alistair J , Cochrane, Kevern L , Downey-Breedt, Nicola , Howard, James , Aswani, Shankar , Byfield, Val , Duna, Elethu , Dutra, Leo X , Frusher, Elizabeth A , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah , Jordan, Tia , Joyner, Jessica , Ramani, Narayana Kumar , Shanmugasundaram, Swathi L , Malherbe, Willem , Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja, K , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , van Putten, Ingrid E
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422081 , vital:71909 , xlink:href="https://doi.org/10.1007/s11160-016-9419-0"
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and co-developing adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
- Authors: Hobday, Alistair J , Cochrane, Kevern L , Downey-Breedt, Nicola , Howard, James , Aswani, Shankar , Byfield, Val , Duna, Elethu , Dutra, Leo X , Frusher, Elizabeth A , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah , Jordan, Tia , Joyner, Jessica , Ramani, Narayana Kumar , Shanmugasundaram, Swathi L , Malherbe, Willem , Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja, K , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , van Putten, Ingrid E
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422081 , vital:71909 , xlink:href="https://doi.org/10.1007/s11160-016-9419-0"
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and co-developing adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
Plasmodium falciparum Hep1 is required to prevent the self aggregation of PfHsp70-3
- Nyakundi, David O, Vuko, Loyiso A M, Bentley, Stephen J, Hoppe, Heinrich C, Blatch, Gregory L, Boshoff, Aileen
- Authors: Nyakundi, David O , Vuko, Loyiso A M , Bentley, Stephen J , Hoppe, Heinrich C , Blatch, Gregory L , Boshoff, Aileen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66109 , vital:28903 , https://doi.org/10.1371/journal.pone.0156446
- Description: publisher version , The majority of mitochondrial proteins are encoded in the nucleus and need to be imported from the cytosol into the mitochondria, and molecular chaperones play a key role in the efficient translocation and proper folding of these proteins in the matrix. One such molecular chaperone is the eukaryotic mitochondrial heat shock protein 70 (Hsp70); however, it is prone to self-aggregation and requires the presence of an essential zinc-finger protein, Hsp70-escort protein 1 (Hep1), to maintain its structure and function. PfHsp70-3, the only Hsp70 predicted to localize in the mitochondria of P. falciparum, may also rely on a Hep1 orthologue to prevent self-aggregation. In this study, we identified a putative Hep1 orthologue in P. falciparum and co-expression of PfHsp70-3 and PfHep1 enhanced the solubility of PfHsp70-3. PfHep1 suppressed the thermally induced aggregation of PfHsp70-3 but not the aggregation of malate dehydrogenase or citrate synthase, thus showing specificity for PfHsp70-3. Zinc ions were indeed essential for maintaining the function of PfHep1, as EDTA chelation abrogated its abilities to suppress the aggregation of PfHsp70-3. Soluble and functional PfHsp70-3, acquired by co-expression with PfHep-1, will facilitate the biochemical characterisation of this particular Hsp70 protein and its evaluation as a drug target for the treatment of malaria. , This work was funded by grants from the National Research Foundation (NRF); grant number 87663 and Deutsche Forschungsgemeinschaft (DFG); grant number LI 402/14-1. D.O.N. is the recipient of academic development and training funds from Mwenge Catholic University, Moshi, Tanzania. S.J.B. is the recipient of an NRF Doctoral Innovation Scholarship.
- Full Text:
- Date Issued: 2016
- Authors: Nyakundi, David O , Vuko, Loyiso A M , Bentley, Stephen J , Hoppe, Heinrich C , Blatch, Gregory L , Boshoff, Aileen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66109 , vital:28903 , https://doi.org/10.1371/journal.pone.0156446
- Description: publisher version , The majority of mitochondrial proteins are encoded in the nucleus and need to be imported from the cytosol into the mitochondria, and molecular chaperones play a key role in the efficient translocation and proper folding of these proteins in the matrix. One such molecular chaperone is the eukaryotic mitochondrial heat shock protein 70 (Hsp70); however, it is prone to self-aggregation and requires the presence of an essential zinc-finger protein, Hsp70-escort protein 1 (Hep1), to maintain its structure and function. PfHsp70-3, the only Hsp70 predicted to localize in the mitochondria of P. falciparum, may also rely on a Hep1 orthologue to prevent self-aggregation. In this study, we identified a putative Hep1 orthologue in P. falciparum and co-expression of PfHsp70-3 and PfHep1 enhanced the solubility of PfHsp70-3. PfHep1 suppressed the thermally induced aggregation of PfHsp70-3 but not the aggregation of malate dehydrogenase or citrate synthase, thus showing specificity for PfHsp70-3. Zinc ions were indeed essential for maintaining the function of PfHep1, as EDTA chelation abrogated its abilities to suppress the aggregation of PfHsp70-3. Soluble and functional PfHsp70-3, acquired by co-expression with PfHep-1, will facilitate the biochemical characterisation of this particular Hsp70 protein and its evaluation as a drug target for the treatment of malaria. , This work was funded by grants from the National Research Foundation (NRF); grant number 87663 and Deutsche Forschungsgemeinschaft (DFG); grant number LI 402/14-1. D.O.N. is the recipient of academic development and training funds from Mwenge Catholic University, Moshi, Tanzania. S.J.B. is the recipient of an NRF Doctoral Innovation Scholarship.
- Full Text:
- Date Issued: 2016
Politics at a distance from the state: radical, South African and Zimbabwean praxis today
- Helliker, Kirk D, van der Walt, Lucien
- Authors: Helliker, Kirk D , van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71364 , vital:29837 , https://doi.org/10.1080/02589001.2016.1240792
- Description: For decades, most anti-capitalist and anti-imperialist movements identified radical social transformation with the capture of state power. The collapse of supposedly enabling states led recently to a crisis of left and working class politics. But this has also opened space for the rediscovery of society-centred, anti-capitalist modes of bottom-up change, labelled as ‘at a distance’ politics. These modes have registered important successes in practice, such as the Zapatistas in Mexico, and have involved strands of anarchism and syndicalism, and autonomist Marxism. This article, an introduction to a collection of papers emerging from a 2012 conference of academics and activists in South Africa, aims to help articulate an understanding of social transformation from below that has been analytically and politically side-lined not only in South Africa (and Zimbabwe), but globally. In doing so, it provides a preliminary attempt to map and create a dialogue between three major positions within the broad category of ‘at a distance’ politics.
- Full Text: false
- Date Issued: 2016
- Authors: Helliker, Kirk D , van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71364 , vital:29837 , https://doi.org/10.1080/02589001.2016.1240792
- Description: For decades, most anti-capitalist and anti-imperialist movements identified radical social transformation with the capture of state power. The collapse of supposedly enabling states led recently to a crisis of left and working class politics. But this has also opened space for the rediscovery of society-centred, anti-capitalist modes of bottom-up change, labelled as ‘at a distance’ politics. These modes have registered important successes in practice, such as the Zapatistas in Mexico, and have involved strands of anarchism and syndicalism, and autonomist Marxism. This article, an introduction to a collection of papers emerging from a 2012 conference of academics and activists in South Africa, aims to help articulate an understanding of social transformation from below that has been analytically and politically side-lined not only in South Africa (and Zimbabwe), but globally. In doing so, it provides a preliminary attempt to map and create a dialogue between three major positions within the broad category of ‘at a distance’ politics.
- Full Text: false
- Date Issued: 2016
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
Post-apartheid nostalgia and the sadomasochistic pleasures of archival art:
- Authors: Nsele, Zamansele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145598 , vital:38450 , DOI : 10.4314/eia.v43i3.6
- Description: The burgeoning genre of archival art practice in post-apartheid South Africa has catalysed the evocation of nostalgia in abundance. The archive has been at the centre of numerous exhibitions in contemporary art. This paper explores the meaning of an emerging nostalgic turn in post-apartheid South Africa. The discussion considers the pleasure afforded by the sentimentality underpinning nostalgia and attends to the manner in which nostalgia coheres with the creative and aesthetic techniques of archival art. Scopophilia and the covert function of the sadomasochistic gaze are outlined. It is suggested that such acts of retrieval and repetition generally override ethical considerations in part because they unfold from the realm of the unconscious. The paper draws on psychoanalysis by way of Frantz Fanon.
- Full Text:
- Date Issued: 2016
- Authors: Nsele, Zamansele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145598 , vital:38450 , DOI : 10.4314/eia.v43i3.6
- Description: The burgeoning genre of archival art practice in post-apartheid South Africa has catalysed the evocation of nostalgia in abundance. The archive has been at the centre of numerous exhibitions in contemporary art. This paper explores the meaning of an emerging nostalgic turn in post-apartheid South Africa. The discussion considers the pleasure afforded by the sentimentality underpinning nostalgia and attends to the manner in which nostalgia coheres with the creative and aesthetic techniques of archival art. Scopophilia and the covert function of the sadomasochistic gaze are outlined. It is suggested that such acts of retrieval and repetition generally override ethical considerations in part because they unfold from the realm of the unconscious. The paper draws on psychoanalysis by way of Frantz Fanon.
- Full Text:
- Date Issued: 2016
Preference for C4 shade grasses increases hatchling performance in the butterfly, Bicyclus safitza
- Nokelainen, Ossi, Ripley, Bradford Sherman, Van Bergen, Erik, Osborne, Colin P, Brakefield, Paul M
- Authors: Nokelainen, Ossi , Ripley, Bradford Sherman , Van Bergen, Erik , Osborne, Colin P , Brakefield, Paul M
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61424 , vital:28025 , http://onlinelibrary.wiley.com/doi/10.1002/ece3.2235/full
- Description: The Miocene radiation of C4 grasses under high-temperature and low ambient CO2 levels occurred alongside the transformation of a largely forested landscape into savanna. This inevitably changed the host plant regime of herbivores, and the simultaneous diversification of many consumer lineages, including Bicyclus butterflies in Africa, suggests that the radiations of grasses and grazers may be evolutionary linked. We examined mechanisms for this plant–herbivore interaction with the grass-feeding Bicyclus safitza in South Africa. In a controlled environment, we tested oviposition preference and hatchling performance on local grasses with C3 or C4 photosynthetic pathways that grow either in open or shaded habitats. We predicted preference for C3 plants due to a hypothesized lower processing cost and higher palatability to herbivores. In contrast, we found that females preferred C4 shade grasses rather than either C4 grasses from open habitats or C3 grasses. The oviposition preference broadly followed hatchling performance, although hatchling survival was equally good on C4 or C3 shade grasses. This finding was explained by leaf toughness; shade grasses were softer than grasses from open habitats. Field monitoring revealed a preference of adults for shaded habitats, and stable isotope analysis of field-sampled individuals confirmed their preference for C4 grasses as host plants. Our findings suggest that plant–herbivore interactions can influence the direction of selection in a grass-feeding butterfly. Based on this work, we postulate future research to test whether these interactions more generally contribute to radiations in herbivorous insects via expansions into new, unexploited ecological niches.
- Full Text:
- Date Issued: 2016
- Authors: Nokelainen, Ossi , Ripley, Bradford Sherman , Van Bergen, Erik , Osborne, Colin P , Brakefield, Paul M
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61424 , vital:28025 , http://onlinelibrary.wiley.com/doi/10.1002/ece3.2235/full
- Description: The Miocene radiation of C4 grasses under high-temperature and low ambient CO2 levels occurred alongside the transformation of a largely forested landscape into savanna. This inevitably changed the host plant regime of herbivores, and the simultaneous diversification of many consumer lineages, including Bicyclus butterflies in Africa, suggests that the radiations of grasses and grazers may be evolutionary linked. We examined mechanisms for this plant–herbivore interaction with the grass-feeding Bicyclus safitza in South Africa. In a controlled environment, we tested oviposition preference and hatchling performance on local grasses with C3 or C4 photosynthetic pathways that grow either in open or shaded habitats. We predicted preference for C3 plants due to a hypothesized lower processing cost and higher palatability to herbivores. In contrast, we found that females preferred C4 shade grasses rather than either C4 grasses from open habitats or C3 grasses. The oviposition preference broadly followed hatchling performance, although hatchling survival was equally good on C4 or C3 shade grasses. This finding was explained by leaf toughness; shade grasses were softer than grasses from open habitats. Field monitoring revealed a preference of adults for shaded habitats, and stable isotope analysis of field-sampled individuals confirmed their preference for C4 grasses as host plants. Our findings suggest that plant–herbivore interactions can influence the direction of selection in a grass-feeding butterfly. Based on this work, we postulate future research to test whether these interactions more generally contribute to radiations in herbivorous insects via expansions into new, unexploited ecological niches.
- Full Text:
- Date Issued: 2016
Purification and characterization of β-mannanase from Aspergillus terreus and its applicability in depolymerization of mannans and saccharification of lignocellulosic biomass
- Soni, Hemant, Rawat, Hemant Kumar, Kango, Naveen
- Authors: Soni, Hemant , Rawat, Hemant Kumar , Kango, Naveen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66167 , vital:28912 , https://doi.org/10.1007/s13205-016-0454-2
- Description: publisher version , Aspergillus terreus FBCC 1369 was grown in solid-state culture under statistically optimized conditions. β-Mannanase was purified to apparent homogeneity by ultrafiltration, anion exchange and gel filtration chromatography. A purification factor of 10.3-fold was achieved, with the purified enzyme exhibiting specific activity of 53 U/mg protein. The purified β-mannanase was optimally active at pH 7.0 and 70 °C and displayed stability over a broad pH range of 4.0–8.0 and a 30 min half-life at 80 °C. The molecular weight of β-mannanase was calculated as ~49 kDa by SDS-PAGE. The enzyme exhibited K m and V maxvalues of 5.9 mg/ml and 39.42 µmol/ml/min, respectively. β-Mannanase activity was stimulated by β-mercaptoethanol and strongly inhibited by Hg2+. The β-Mannanase did not hydrolyze mannobiose and mannotriose, but only mannotetraose liberating mannose and mannotriose. This indicated that at least four mannose residues were required for catalytic activity. Oligosaccharide with a degree of polymerization (DP) three was the predominant product in the case of locust bean gum (16.5 %) and guar gum (15.8 %) hydrolysis. However, the enzyme liberated DP4 oligosaccharide (24 %) exclusively from konjac gum. This property can be exploited in oligosaccharides production with DP 3–4. β-Mannanase hydrolyzed pretreated lignocelluloses and liberated reducing sugars (% theoretical yield) from copra meal (30 %). This property is an important factor for the bioconversion of the biomass.
- Full Text: false
- Date Issued: 2016
- Authors: Soni, Hemant , Rawat, Hemant Kumar , Kango, Naveen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66167 , vital:28912 , https://doi.org/10.1007/s13205-016-0454-2
- Description: publisher version , Aspergillus terreus FBCC 1369 was grown in solid-state culture under statistically optimized conditions. β-Mannanase was purified to apparent homogeneity by ultrafiltration, anion exchange and gel filtration chromatography. A purification factor of 10.3-fold was achieved, with the purified enzyme exhibiting specific activity of 53 U/mg protein. The purified β-mannanase was optimally active at pH 7.0 and 70 °C and displayed stability over a broad pH range of 4.0–8.0 and a 30 min half-life at 80 °C. The molecular weight of β-mannanase was calculated as ~49 kDa by SDS-PAGE. The enzyme exhibited K m and V maxvalues of 5.9 mg/ml and 39.42 µmol/ml/min, respectively. β-Mannanase activity was stimulated by β-mercaptoethanol and strongly inhibited by Hg2+. The β-Mannanase did not hydrolyze mannobiose and mannotriose, but only mannotetraose liberating mannose and mannotriose. This indicated that at least four mannose residues were required for catalytic activity. Oligosaccharide with a degree of polymerization (DP) three was the predominant product in the case of locust bean gum (16.5 %) and guar gum (15.8 %) hydrolysis. However, the enzyme liberated DP4 oligosaccharide (24 %) exclusively from konjac gum. This property can be exploited in oligosaccharides production with DP 3–4. β-Mannanase hydrolyzed pretreated lignocelluloses and liberated reducing sugars (% theoretical yield) from copra meal (30 %). This property is an important factor for the bioconversion of the biomass.
- Full Text: false
- Date Issued: 2016