Rhodes University Graduation Ceremony 2011
- Authors: Rhodes University
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:8136 , http://hdl.handle.net/10962/d1007246
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 7 April at 18.00 [and] Friday, 8 April at 10:30; 14:30 & 18:00 [and] Saturday, 9 April at 10:30
- Full Text:
- Date Issued: 2011
- Authors: Rhodes University
- Date: 2011
- Language: English
- Type: text
- Identifier: vital:8136 , http://hdl.handle.net/10962/d1007246
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 7 April at 18.00 [and] Friday, 8 April at 10:30; 14:30 & 18:00 [and] Saturday, 9 April at 10:30
- Full Text:
- Date Issued: 2011
Crystal Structure, Hirshfeld Surface Analysis and Computational Studies of Two Benzo [b][1, 4] Diazepine Derivatives
- Odame, Felix, Madanhire, T, Hosten, Eric C, Lobb, Kevin A
- Authors: Odame, Felix , Madanhire, T , Hosten, Eric C , Lobb, Kevin A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452689 , vital:75162 , xlink:href="https://doi.org/10.1134/S0022476623120041"
- Description: The DFT computational studies, crystal structures and Hirshfeld surface analysis of (E)-4-(2-chlorostyryl)-2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (1) and (E)-4-(2-(2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-4-yl)vinyl)phenol (2) have been presented. The compounds crystallized in the monoclinic space group P21/c with 4 molecules in their unit cells each. The experimental and computed bond lengths and bond angles deviated from each other to some extent but also showed good agreement with each other in some cases. Hirshfeld surface analysis of the compounds provided further information about the structural properties of the compounds.
- Full Text:
- Date Issued: 2023
- Authors: Odame, Felix , Madanhire, T , Hosten, Eric C , Lobb, Kevin A
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452689 , vital:75162 , xlink:href="https://doi.org/10.1134/S0022476623120041"
- Description: The DFT computational studies, crystal structures and Hirshfeld surface analysis of (E)-4-(2-chlorostyryl)-2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (1) and (E)-4-(2-(2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-4-yl)vinyl)phenol (2) have been presented. The compounds crystallized in the monoclinic space group P21/c with 4 molecules in their unit cells each. The experimental and computed bond lengths and bond angles deviated from each other to some extent but also showed good agreement with each other in some cases. Hirshfeld surface analysis of the compounds provided further information about the structural properties of the compounds.
- Full Text:
- Date Issued: 2023
Rhodes University Graduation Ceremony 2008
- Authors: Rhodes University
- Date: 2008
- Language: English
- Type: text
- Identifier: vital:8139 , http://hdl.handle.net/10962/d1007251
- Description: Rhodes University Graduation Ceremony [at the] 1820 Settlers National Monument Thursday, 27 March at 18:00 [and] Friday, 28 March at 10:30; 14:30 & 18:00 [and] Saturday, 29 March at 10:30
- Full Text:
- Date Issued: 2008
- Authors: Rhodes University
- Date: 2008
- Language: English
- Type: text
- Identifier: vital:8139 , http://hdl.handle.net/10962/d1007251
- Description: Rhodes University Graduation Ceremony [at the] 1820 Settlers National Monument Thursday, 27 March at 18:00 [and] Friday, 28 March at 10:30; 14:30 & 18:00 [and] Saturday, 29 March at 10:30
- Full Text:
- Date Issued: 2008
Rhodes University Graduation Ceremony 2012
- Authors: Rhodes University
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:8135 , http://hdl.handle.net/10962/d1007245
- Description: Rhodes University Graduation Ceremonies 2012 [at] 1820 Settlers National Monument Thursday, 12 April at 18.00 [and] Friday, 13 April at 10:30; 14:30 & 18:00 [and] Saturday, 14 April at 10:30 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2012
- Full Text:
- Date Issued: 2012
- Authors: Rhodes University
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:8135 , http://hdl.handle.net/10962/d1007245
- Description: Rhodes University Graduation Ceremonies 2012 [at] 1820 Settlers National Monument Thursday, 12 April at 18.00 [and] Friday, 13 April at 10:30; 14:30 & 18:00 [and] Saturday, 14 April at 10:30 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2012
- Full Text:
- Date Issued: 2012
Rhodes University Graduation Ceremony 2005
- Authors: Rhodes University
- Date: 2005
- Language: English
- Type: text
- Identifier: vital:8142 , http://hdl.handle.net/10962/d1007257
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Thursday, 31 March 2005 at 18.00 [and] Friday, 1 April 2005 at 10:30; 14:30 & 18:00 [and] Saturday, 2 April 2005 at 10:30 , RU East London Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 4 May 2005 at 18:00
- Full Text:
- Date Issued: 2005
- Authors: Rhodes University
- Date: 2005
- Language: English
- Type: text
- Identifier: vital:8142 , http://hdl.handle.net/10962/d1007257
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Thursday, 31 March 2005 at 18.00 [and] Friday, 1 April 2005 at 10:30; 14:30 & 18:00 [and] Saturday, 2 April 2005 at 10:30 , RU East London Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 4 May 2005 at 18:00
- Full Text:
- Date Issued: 2005
Rhodes University Graduation Ceremony 2013
- Authors: Rhodes University
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:8134 , http://hdl.handle.net/10962/d1007241
- Description: Rhodes University 2013 Installation of Lex Mpati as 7th Chancellor of Rhodes University and Graduation Ceremony [at] 1820 Settlers National Monument Thursday, 4 April 2013 at 18.00 , Rhodes University Graduation Ceremony [at] 1820 Settlers National Monument Friday, 5 April at 10.00; 14:30 & 18:00 [and] Saturday, 6 April at 10:00 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2013
- Full Text:
- Date Issued: 2013
- Authors: Rhodes University
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:8134 , http://hdl.handle.net/10962/d1007241
- Description: Rhodes University 2013 Installation of Lex Mpati as 7th Chancellor of Rhodes University and Graduation Ceremony [at] 1820 Settlers National Monument Thursday, 4 April 2013 at 18.00 , Rhodes University Graduation Ceremony [at] 1820 Settlers National Monument Friday, 5 April at 10.00; 14:30 & 18:00 [and] Saturday, 6 April at 10:00 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2013
- Full Text:
- Date Issued: 2013
Critical assessment of the quartz crystal microbalance with dissipation as an analytical tool for biosensor development and fundamental studies
- Fogel, Ronen, Mashazi, Philani N, Nyokong, Tebello, Limson, Janice L
- Authors: Fogel, Ronen , Mashazi, Philani N , Nyokong, Tebello , Limson, Janice L
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271204 , vital:54521 , xlink:href="https://doi.org/10.1016/j.bios.2007.03.012"
- Description: One of the challenges in electrochemical biosensor design is gaining a fundamental knowledge of the processes underlying immobilisation of the molecules onto the electrode surface. This is of particular importance in biocomposite sensors where concerns have arisen as to the nature of the interaction between the biological and synthetic molecules immobilised. We examined the use of the Quartz Crystal Microbalance with Dissipation (QCM-D) as a tool for fundamental analyses of a model sensor constructed by the immobilisation of cobalt(II) phthalocyanine (TCACoPc) and glucose oxidase (GOx) onto a gold-quartz electrode (electrode surface) for the enhanced detection of glucose. The model sensor was constructed in aqueous phase and covalently linked the gold surface to the TCACoPc, and the TCACoPc to the GOx, using the QCM-D. The aqueous metallophthalocyanine (MPc) formed a multi-layer over the surface of the electrode, which could be removed to leave a monolayer with a mass loading that compared favourably to the theoretical value expected. Analysis of frequency and dissipation plots indicated covalent attachment of glucose oxidase onto the metallophthalocyanine layer. The amount of GOx bound using the model system compared favourably to calculations derived from the maximal amperometric functioning of the electrochemical sensor (examined in previously-published literature, Mashazi, P.N., Ozoemena, K.I., Nyokong, T., 2006. Electrochim. Acta 52, 177–186), but not to theoretical values derived from dimensions of GOx as established by crystallography. The strength of the binding of the GOx film with the TCACoPc layer was tested by using 2% SDS as a denaturant/surfactant, and the GOx film was not found to be significantly affected by exposure to this. This paper thus showed that QCM-D can be used in order to model essential processes and interactions that dictate the functional parameters of a biosensor.
- Full Text:
- Date Issued: 2007
- Authors: Fogel, Ronen , Mashazi, Philani N , Nyokong, Tebello , Limson, Janice L
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271204 , vital:54521 , xlink:href="https://doi.org/10.1016/j.bios.2007.03.012"
- Description: One of the challenges in electrochemical biosensor design is gaining a fundamental knowledge of the processes underlying immobilisation of the molecules onto the electrode surface. This is of particular importance in biocomposite sensors where concerns have arisen as to the nature of the interaction between the biological and synthetic molecules immobilised. We examined the use of the Quartz Crystal Microbalance with Dissipation (QCM-D) as a tool for fundamental analyses of a model sensor constructed by the immobilisation of cobalt(II) phthalocyanine (TCACoPc) and glucose oxidase (GOx) onto a gold-quartz electrode (electrode surface) for the enhanced detection of glucose. The model sensor was constructed in aqueous phase and covalently linked the gold surface to the TCACoPc, and the TCACoPc to the GOx, using the QCM-D. The aqueous metallophthalocyanine (MPc) formed a multi-layer over the surface of the electrode, which could be removed to leave a monolayer with a mass loading that compared favourably to the theoretical value expected. Analysis of frequency and dissipation plots indicated covalent attachment of glucose oxidase onto the metallophthalocyanine layer. The amount of GOx bound using the model system compared favourably to calculations derived from the maximal amperometric functioning of the electrochemical sensor (examined in previously-published literature, Mashazi, P.N., Ozoemena, K.I., Nyokong, T., 2006. Electrochim. Acta 52, 177–186), but not to theoretical values derived from dimensions of GOx as established by crystallography. The strength of the binding of the GOx film with the TCACoPc layer was tested by using 2% SDS as a denaturant/surfactant, and the GOx film was not found to be significantly affected by exposure to this. This paper thus showed that QCM-D can be used in order to model essential processes and interactions that dictate the functional parameters of a biosensor.
- Full Text:
- Date Issued: 2007
Exploring recurring dreams as a catalyst for image-making in Visual Art
- Authors: Adams, Demi
- Date: 2021-04
- Subjects: Dreams and the arts , Dreams in motion pictures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52424 , vital:43640
- Description: The purpose of this study was to create a body of work which focused on the recurring dreams I have been experiencing since early childhood. I had dreams about a world which I could access through the back of my bedroom cupboard or a crack in my ceiling. This world is one which never experiences daytime; it is covered in various crystals and has its own inhabitants. I started keeping dream diaries to create my artworks, essentially creating a Paracosm. Paracosm is: “… a detailed imaginary world, especially one created by a child” (Your dictionary, 2020: 1). The problem of this study was thus: was it possible to recreate my Crystal-Lunar World (personal dream narrative) using visual art so others could experience it and which methods should be employed to substantiate these recurring dreams. Thus, the overarching research question is how do recurring personal dreams translate into visual art to sustain a language which manifests in an individual visual narrative. I made use of mixed media paintings and three-dimensional objects to illustrate scenes from my Crystal-Lunar World. I kept Dream Diaries to collect data on my recurring dreams and extract frequencies and group them into themes to create my artworks. The dream diaries also substantiated what I was painting and making. I also kept drawing journals to study the various crystals and to illustrate them and the creatures I see. , Thesis (MA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Adams, Demi
- Date: 2021-04
- Subjects: Dreams and the arts , Dreams in motion pictures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52424 , vital:43640
- Description: The purpose of this study was to create a body of work which focused on the recurring dreams I have been experiencing since early childhood. I had dreams about a world which I could access through the back of my bedroom cupboard or a crack in my ceiling. This world is one which never experiences daytime; it is covered in various crystals and has its own inhabitants. I started keeping dream diaries to create my artworks, essentially creating a Paracosm. Paracosm is: “… a detailed imaginary world, especially one created by a child” (Your dictionary, 2020: 1). The problem of this study was thus: was it possible to recreate my Crystal-Lunar World (personal dream narrative) using visual art so others could experience it and which methods should be employed to substantiate these recurring dreams. Thus, the overarching research question is how do recurring personal dreams translate into visual art to sustain a language which manifests in an individual visual narrative. I made use of mixed media paintings and three-dimensional objects to illustrate scenes from my Crystal-Lunar World. I kept Dream Diaries to collect data on my recurring dreams and extract frequencies and group them into themes to create my artworks. The dream diaries also substantiated what I was painting and making. I also kept drawing journals to study the various crystals and to illustrate them and the creatures I see. , Thesis (MA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
Rhodes University Graduation Ceremony 2014
- Authors: Rhodes University
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:8148 , http://hdl.handle.net/10962/d1009493
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 10 April at 10.00 & 17:00 [and] Friday, 11 April at 10:00; 14:30 & 18:00 [and] Saturday, 12 April at 10:00 , Rhodes University Awards, Scholarships,Bursaries and Prizes 2014
- Full Text:
- Date Issued: 2014
- Authors: Rhodes University
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:8148 , http://hdl.handle.net/10962/d1009493
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 10 April at 10.00 & 17:00 [and] Friday, 11 April at 10:00; 14:30 & 18:00 [and] Saturday, 12 April at 10:00 , Rhodes University Awards, Scholarships,Bursaries and Prizes 2014
- Full Text:
- Date Issued: 2014
Vice-Chancellor's Annual Review 2004
- Language: English
- Type: Article
- Identifier: vital:7169 , http://hdl.handle.net/10962/d1006071
- Description: The highlight of 2004 was the award of both the Vice-Chancellor's Senior Research Award and the SABC2 Shoprite-Checkers Woman of the Year Award (Science and Technology) to Professor Tebello Nyokong, whose research on the development of photosensitisers for photodynamic cancer therapy has received considerable attention.
- Full Text:
- Language: English
- Type: Article
- Identifier: vital:7169 , http://hdl.handle.net/10962/d1006071
- Description: The highlight of 2004 was the award of both the Vice-Chancellor's Senior Research Award and the SABC2 Shoprite-Checkers Woman of the Year Award (Science and Technology) to Professor Tebello Nyokong, whose research on the development of photosensitisers for photodynamic cancer therapy has received considerable attention.
- Full Text:
Key critical realist concepts for environmental educators
- Authors: Price, Leigh
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437022 , vital:73324 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter describes aspects of critical realism that are rele-vant to environmental educators. Critical realism acts an un-derlabourer for the sciences and the practices of human emancipation. In its underlabouring role, critical realism chal-lenges the Humean assumption that correlations (constant conjunctions) are the only way to know causation and offers an alternative, which is that causation is based on the layered, deep nature of reality (the real, actual and empirical). Critical realism explains how higher levels of being are emergent from lower levels; therefore society (structure) is emergent from the activities of people (agency). Environmental educators should take an interest in structure and agency, not least because cer-tain approaches offer questionable power strategies to people and particularly governments. One consequence of the critical realist version of causation is that it becomes possible to en-visage an environmental ethics that is based on an axiology that is neither absolutist nor relativist. To provide a full enough account of causation to achieve one’s purposes, Bhaskar has suggested a model, the seven laminations of scale. Bhaskar also differentiates between the transitive and intransitive realms and explains that there are questionable ideological advantages to failing to make this distinction. The intransi-tive/transitive realms have implications for our use of catego-ries: critical realism explains how we can use categories to prevent oppression. Critical realism also argues against a purely positive, rather than a negative, account of the dialectic: thus change is absenting the constraints on absenting ab-sences. Contrary to a frequent assumption made by both non-critical realists and critical realists alike, critical realism is not a return to positivism.
- Full Text:
- Date Issued: 2015
- Authors: Price, Leigh
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437022 , vital:73324 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter describes aspects of critical realism that are rele-vant to environmental educators. Critical realism acts an un-derlabourer for the sciences and the practices of human emancipation. In its underlabouring role, critical realism chal-lenges the Humean assumption that correlations (constant conjunctions) are the only way to know causation and offers an alternative, which is that causation is based on the layered, deep nature of reality (the real, actual and empirical). Critical realism explains how higher levels of being are emergent from lower levels; therefore society (structure) is emergent from the activities of people (agency). Environmental educators should take an interest in structure and agency, not least because cer-tain approaches offer questionable power strategies to people and particularly governments. One consequence of the critical realist version of causation is that it becomes possible to en-visage an environmental ethics that is based on an axiology that is neither absolutist nor relativist. To provide a full enough account of causation to achieve one’s purposes, Bhaskar has suggested a model, the seven laminations of scale. Bhaskar also differentiates between the transitive and intransitive realms and explains that there are questionable ideological advantages to failing to make this distinction. The intransi-tive/transitive realms have implications for our use of catego-ries: critical realism explains how we can use categories to prevent oppression. Critical realism also argues against a purely positive, rather than a negative, account of the dialectic: thus change is absenting the constraints on absenting ab-sences. Contrary to a frequent assumption made by both non-critical realists and critical realists alike, critical realism is not a return to positivism.
- Full Text:
- Date Issued: 2015
Plasmodium falciparum Hop: detailed analysis on complex formation with Hsp70 and Hsp90
- Hatherley, Rowan, Clitheroe, Crystal-Leigh, Faya, Ngonidzashe, Tastan Bishop, Özlem
- Authors: Hatherley, Rowan , Clitheroe, Crystal-Leigh , Faya, Ngonidzashe , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125708 , vital:35810 , https://doi.10.1016/j.bbrc.2014.11.103
- Description: The heat shock organizing protein (Hop) is important in modulating the activity and co-interaction of two chaperones: heat shock protein 70 and 90 (Hsp70 and Hsp90). Recent research suggested that Plasmodium falciparum Hop (PfHop), PfHsp70 and PfHsp90 form a complex in the trophozoite infective stage. However, there has been little computational research on the malarial Hop protein in complex with other malarial Hsps. Using in silico characterization of the protein, this work showed that individual domains of Hop are evolving at different rates within the protein. Differences between human Hop (HsHop) and PfHop were identified by motif analysis. Homology modeling of PfHop and HsHop in complex with their own cytosolic Hsp90 and Hsp70 C-terminal peptide partners indicated excellent conservation of the Hop concave TPR sites bound to the C-terminal motifs of partner proteins. Further, we analyzed additional binding sites between Hop and Hsp90, and showed, for the first time, that they are distinctly less conserved between human and malaria parasite. These sites are located on the convex surface of Hop TPR2, and involved in interactions with the Hsp90 middle domain. Since the convex sites are less conserved than the concave sites, it makes their potential for malarial inhibitor design extremely attractive (as opposed to the concave sites which have been the focus of previous efforts).
- Full Text:
- Date Issued: 2015
- Authors: Hatherley, Rowan , Clitheroe, Crystal-Leigh , Faya, Ngonidzashe , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125708 , vital:35810 , https://doi.10.1016/j.bbrc.2014.11.103
- Description: The heat shock organizing protein (Hop) is important in modulating the activity and co-interaction of two chaperones: heat shock protein 70 and 90 (Hsp70 and Hsp90). Recent research suggested that Plasmodium falciparum Hop (PfHop), PfHsp70 and PfHsp90 form a complex in the trophozoite infective stage. However, there has been little computational research on the malarial Hop protein in complex with other malarial Hsps. Using in silico characterization of the protein, this work showed that individual domains of Hop are evolving at different rates within the protein. Differences between human Hop (HsHop) and PfHop were identified by motif analysis. Homology modeling of PfHop and HsHop in complex with their own cytosolic Hsp90 and Hsp70 C-terminal peptide partners indicated excellent conservation of the Hop concave TPR sites bound to the C-terminal motifs of partner proteins. Further, we analyzed additional binding sites between Hop and Hsp90, and showed, for the first time, that they are distinctly less conserved between human and malaria parasite. These sites are located on the convex surface of Hop TPR2, and involved in interactions with the Hsp90 middle domain. Since the convex sites are less conserved than the concave sites, it makes their potential for malarial inhibitor design extremely attractive (as opposed to the concave sites which have been the focus of previous efforts).
- Full Text:
- Date Issued: 2015
Playing musement games: Retroduction in social research, with particular reference to indigenous knowledge in environmental and health education
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
- Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
- Full Text:
- Date Issued: 2005
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
- Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
- Full Text:
- Date Issued: 2005
The final instar exuvium of Pycna semiclara Germar, 1834 (Hemiptera Cicadidae)
- Midgley, John M, Bouwer, Nicolette, Villet, Martin H
- Authors: Midgley, John M , Bouwer, Nicolette , Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440695 , vital:73804 , https://hdl.handle.net/10520/EJC136752
- Description: Exuviae of the cicada Pycna semiclara were found next to freshly eclosed adults. The exuvium of Pycna Semiclara is described and illustrated for the first time and a key is presented to distinguish the exuvium of this species from those of Platypleura stridula and Platypleura capensis, the only other species of cicadas from southern Africa for which exuviae have been described.
- Full Text:
- Date Issued: 2013
- Authors: Midgley, John M , Bouwer, Nicolette , Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440695 , vital:73804 , https://hdl.handle.net/10520/EJC136752
- Description: Exuviae of the cicada Pycna semiclara were found next to freshly eclosed adults. The exuvium of Pycna Semiclara is described and illustrated for the first time and a key is presented to distinguish the exuvium of this species from those of Platypleura stridula and Platypleura capensis, the only other species of cicadas from southern Africa for which exuviae have been described.
- Full Text:
- Date Issued: 2013
Characterization of some amino acid derivatives of benzoyl isothiocyanate: Crystal structures and theoretical prediction of their reactivity
- Odame, Felix, Hosten, Eric C, Betz, Richard, Lobb, Kevin A, Tshentu, Zenixole R
- Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447952 , vital:74686 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.05.053"
- Description: The reaction of benzoyl isothiocyanate with L-serine, L-proline, D-methionine and L-alanine gave 2-[(benzoylcarbamothioyl)amino]-3-hydroxypropanoic acid (I), 1-(benzoylcarbamothioyl)pyrrolidine-2-carboxylic acid (II), 2-[(benzoylcarbamothioyl)amino]-4-(methylsulfanyl)butanoic acid (III) and 2-[(benzoylcarbamothioyl)amino]propanoic acid (IV), respectively. The compounds have been characterized by IR, NMR, microanalyses and mass spectrometry. The crystal structures of all the compounds have also been discussed. Compound II showed rotamers in solution. DFT calculations of the frontier orbitals of the compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity of these compounds. The calculations indicated that the carboxylic acid group in these compounds is unreactive hence making the conversion to benzimidazoles via cyclization on the carboxylic acids impractical. This has been further confirmed by the reaction of compounds I–IV, respectively, with o-phenylene diamine which was unsuccessful but gave compound V.
- Full Text:
- Date Issued: 2015
- Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447952 , vital:74686 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.05.053"
- Description: The reaction of benzoyl isothiocyanate with L-serine, L-proline, D-methionine and L-alanine gave 2-[(benzoylcarbamothioyl)amino]-3-hydroxypropanoic acid (I), 1-(benzoylcarbamothioyl)pyrrolidine-2-carboxylic acid (II), 2-[(benzoylcarbamothioyl)amino]-4-(methylsulfanyl)butanoic acid (III) and 2-[(benzoylcarbamothioyl)amino]propanoic acid (IV), respectively. The compounds have been characterized by IR, NMR, microanalyses and mass spectrometry. The crystal structures of all the compounds have also been discussed. Compound II showed rotamers in solution. DFT calculations of the frontier orbitals of the compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity of these compounds. The calculations indicated that the carboxylic acid group in these compounds is unreactive hence making the conversion to benzimidazoles via cyclization on the carboxylic acids impractical. This has been further confirmed by the reaction of compounds I–IV, respectively, with o-phenylene diamine which was unsuccessful but gave compound V.
- Full Text:
- Date Issued: 2015
A comparative study of the effect of different stabilizers on the critical quality attributes of self-assembling nano co-crystals
- Witika, Bwalya A, Smith, Vincent J, Walker, Roderick B
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183224 , vital:43931 , xlink:href=" https://doi.org/10.3390/pharmaceutics12020182"
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) less than 1000 nm, polydispersity index (PDI) less than 0.500 and Zeta potential (ZP) less than −30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183224 , vital:43931 , xlink:href=" https://doi.org/10.3390/pharmaceutics12020182"
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) less than 1000 nm, polydispersity index (PDI) less than 0.500 and Zeta potential (ZP) less than −30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.
- Full Text:
- Date Issued: 2020
Assessment of the host properties of selected optically pure, racemic and achiral compounds
- Authors: Jooste, Daniel Victor
- Date: 2017
- Subjects: Organic compounds -- Synthesis Cyclic compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18826 , vital:28735
- Description: This study focussed on the synthesis and host properties of four different broad categories of potential host compounds, namely optically active and racemic TADDOL [(4R,5R)-α,α,α’,α’-tetraphenyl-1,3-dioxolane-4,5-dimethanol] and derivatives, TTFOL [(3R,4R)-2,2,5,5-tetraphenyltetrahydrofuran-3,4-diol], amino acid ester-derived compounds [(S)-4-(2-amino-3-hydroxy-3,3-diphenylpropyl)phenol], and compounds derived from xanthone [9-amino-9-phenylxanthene and 1,2-bis(9-phenyl-9H-xanthen-9-yl)hydrazine]. The potential hosts were recrystallized from a range of possible guest species and the resulting solids analysed by 1H-NMR spectroscopy. If inclusion was observed by this technique, the complexes were analysed further using single crystal X-ray techniques and thermal experiments where possible. Competition studies were carried out where these were deemed appropriate. Optically active and racemic TADDOLs were synthesized using L-(+) and DL-(±)-tartaric acid respectively. Two further derivatives were prepared whereby the hydroxyl groups were substituted for chlorine and azide in order to assess the effect of this change on the inclusion ability. Both the optically active and racemic TADDOLs displayed similar host abilities, complexing with guests with 1:1 host:guest ratios as determined through 1H-NMR spectroscopy. Competition experiments showed that both forms of TADDOL exhibited similar guest preferences for pyridine and the methylpyridine isomers. Pyridine however was preferred over 2-methylpyridine by optically active TADDOL while the racemic form preferred this methyl-substituted guest over pyridine. Thermal analysis studies showed, surprisingly, that the TADDOL complexes containing pyridine had higher relative thermal stabilities than those containing the methylpyridines, whether the host was optically active or not. The preference order of these hosts for these guests can, therefore, not be used as a predictor for the relative thermal stability of the complexes. TTFOL was found to include only ethanol, 2-methylpyridine and dioxane from the range of guest species used; the complex with dioxane did not produce X-ray quality crystals. The L-tyrosine derivative, (S)-4-(2-amino-3-hydroxy-3,3-diphenylpropyl)phenol, was an ineffective host incapable of including any of the guests used in these experiments. The two xanthone derivatives, 9-amino-9-phenylxanthene and 1,2-bis(9-phenyl-9H-xanthen-9-yl)hydrazine each formed complexes with one guest species (morpholine and DMF, respectively).
- Full Text:
- Date Issued: 2017
- Authors: Jooste, Daniel Victor
- Date: 2017
- Subjects: Organic compounds -- Synthesis Cyclic compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18826 , vital:28735
- Description: This study focussed on the synthesis and host properties of four different broad categories of potential host compounds, namely optically active and racemic TADDOL [(4R,5R)-α,α,α’,α’-tetraphenyl-1,3-dioxolane-4,5-dimethanol] and derivatives, TTFOL [(3R,4R)-2,2,5,5-tetraphenyltetrahydrofuran-3,4-diol], amino acid ester-derived compounds [(S)-4-(2-amino-3-hydroxy-3,3-diphenylpropyl)phenol], and compounds derived from xanthone [9-amino-9-phenylxanthene and 1,2-bis(9-phenyl-9H-xanthen-9-yl)hydrazine]. The potential hosts were recrystallized from a range of possible guest species and the resulting solids analysed by 1H-NMR spectroscopy. If inclusion was observed by this technique, the complexes were analysed further using single crystal X-ray techniques and thermal experiments where possible. Competition studies were carried out where these were deemed appropriate. Optically active and racemic TADDOLs were synthesized using L-(+) and DL-(±)-tartaric acid respectively. Two further derivatives were prepared whereby the hydroxyl groups were substituted for chlorine and azide in order to assess the effect of this change on the inclusion ability. Both the optically active and racemic TADDOLs displayed similar host abilities, complexing with guests with 1:1 host:guest ratios as determined through 1H-NMR spectroscopy. Competition experiments showed that both forms of TADDOL exhibited similar guest preferences for pyridine and the methylpyridine isomers. Pyridine however was preferred over 2-methylpyridine by optically active TADDOL while the racemic form preferred this methyl-substituted guest over pyridine. Thermal analysis studies showed, surprisingly, that the TADDOL complexes containing pyridine had higher relative thermal stabilities than those containing the methylpyridines, whether the host was optically active or not. The preference order of these hosts for these guests can, therefore, not be used as a predictor for the relative thermal stability of the complexes. TTFOL was found to include only ethanol, 2-methylpyridine and dioxane from the range of guest species used; the complex with dioxane did not produce X-ray quality crystals. The L-tyrosine derivative, (S)-4-(2-amino-3-hydroxy-3,3-diphenylpropyl)phenol, was an ineffective host incapable of including any of the guests used in these experiments. The two xanthone derivatives, 9-amino-9-phenylxanthene and 1,2-bis(9-phenyl-9H-xanthen-9-yl)hydrazine each formed complexes with one guest species (morpholine and DMF, respectively).
- Full Text:
- Date Issued: 2017
The crystal structure of caesium permanganate by x-ray diffraction
- Authors: Nassimbeni, L R
- Date: 1963
- Subjects: Permanganates -- Crystallography , X-rays -- Diffraction , Crystals -- Piezoelectricity , Pyroelectricity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4484 , http://hdl.handle.net/10962/d1012942
- Description: The crystal structure of caesium permanganate has been determined. CsMn0₄ crystallises in the orthorhombic space group Pnma. There are four molecules per unit cell with a = 10.0692 Å, b = 5.8080 Å, c = 7.9470 Å. The structure was determined by Fourier syntheses on the (010) and (001) projections and refined by two-dimensional difference syntheses. The structure is similar to that of KMn0₄. The manganese is surrounded by four oxygen atoms at an average distance of 1.629 Å arranged in a slightly distorted tetrahedron. The caesium is surrounded by eight manganese atoms at an average distance of 4.381 Å.
- Full Text:
- Date Issued: 1963
- Authors: Nassimbeni, L R
- Date: 1963
- Subjects: Permanganates -- Crystallography , X-rays -- Diffraction , Crystals -- Piezoelectricity , Pyroelectricity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4484 , http://hdl.handle.net/10962/d1012942
- Description: The crystal structure of caesium permanganate has been determined. CsMn0₄ crystallises in the orthorhombic space group Pnma. There are four molecules per unit cell with a = 10.0692 Å, b = 5.8080 Å, c = 7.9470 Å. The structure was determined by Fourier syntheses on the (010) and (001) projections and refined by two-dimensional difference syntheses. The structure is similar to that of KMn0₄. The manganese is surrounded by four oxygen atoms at an average distance of 1.629 Å arranged in a slightly distorted tetrahedron. The caesium is surrounded by eight manganese atoms at an average distance of 4.381 Å.
- Full Text:
- Date Issued: 1963
The temporal occurrence of flesh flies (Diptera, Sarcophagidae) at carrion-baited traps in Grahamstown, South Africa
- Villet, Martin H, Clitheroe, Crystal-Leigh, Williams, Kirstin A
- Authors: Villet, Martin H , Clitheroe, Crystal-Leigh , Williams, Kirstin A
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59692 , vital:27639 , https://doi.org/10.3897/AfrInvertebr.58.9537
- Description: Eleven species of flesh fly were identified in a sample of 737 specimens captured during fortnightly trapping at three sites in Grahamstown, South Africa, over a year. Sarcophaga africa Wiedemann, 1824, S. inaequalis Austen, 1909, S. exuberans Pandelle, 1896 and S. tibialis Macquart, 1851 showed well-defined peaks between early October 2001 and late April 2002, and only S. africa was trapped at other times of year. These peaks occurred when average minimum and maximum ambient air temperatures were above 12°C and 22°C, respectively, and showed no obvious relationship to rainfall. There were indications of population cycles in all of these species. Sarcophaga hera Zumpt, 1972, S. arno Curran, 1934, S. inzi Curran, 1934, S. langi Curran, 1934, S. freyi Zumpt, 1953, S. nodosa Engel, 1925 and S. samia Curran, 1934 were too scarce to assess their patterns of occurrence rigorously. Insects attending a corpse are reputed to assist forensic entomologists in estimating the time of year when the body died. Some flesh flies provide more precise estimates than others, so several species should be used for cross-validation. Insect activity at a corpse depends on the weather, so that presence of a species indicates particular environmental conditions and not simply calendar dates (particularly if climate changes). Absence of a species is not necessarily evidence of specific conditions because species may not be present at all sites simultaneously, populations cycle even when their members are active, and low population densities may hamper detection of a species.
- Full Text:
- Date Issued: 2017
- Authors: Villet, Martin H , Clitheroe, Crystal-Leigh , Williams, Kirstin A
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59692 , vital:27639 , https://doi.org/10.3897/AfrInvertebr.58.9537
- Description: Eleven species of flesh fly were identified in a sample of 737 specimens captured during fortnightly trapping at three sites in Grahamstown, South Africa, over a year. Sarcophaga africa Wiedemann, 1824, S. inaequalis Austen, 1909, S. exuberans Pandelle, 1896 and S. tibialis Macquart, 1851 showed well-defined peaks between early October 2001 and late April 2002, and only S. africa was trapped at other times of year. These peaks occurred when average minimum and maximum ambient air temperatures were above 12°C and 22°C, respectively, and showed no obvious relationship to rainfall. There were indications of population cycles in all of these species. Sarcophaga hera Zumpt, 1972, S. arno Curran, 1934, S. inzi Curran, 1934, S. langi Curran, 1934, S. freyi Zumpt, 1953, S. nodosa Engel, 1925 and S. samia Curran, 1934 were too scarce to assess their patterns of occurrence rigorously. Insects attending a corpse are reputed to assist forensic entomologists in estimating the time of year when the body died. Some flesh flies provide more precise estimates than others, so several species should be used for cross-validation. Insect activity at a corpse depends on the weather, so that presence of a species indicates particular environmental conditions and not simply calendar dates (particularly if climate changes). Absence of a species is not necessarily evidence of specific conditions because species may not be present at all sites simultaneously, populations cycle even when their members are active, and low population densities may hamper detection of a species.
- Full Text:
- Date Issued: 2017
Weevil borne microbes contribute as much to the reduction of photosynthesis in water hyacinth as does herbivory
- Venter, Nic, Hill, Martin P, Hutchinson, Sarah-Leigh, Ripley, Bradford S
- Authors: Venter, Nic , Hill, Martin P , Hutchinson, Sarah-Leigh , Ripley, Bradford S
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423573 , vital:72073 , xlink:href="https://doi.org/10.1016/j.biocontrol.2012.10.011"
- Description: Arthropods released for weed biocontrol can have effects other than simply removing biomass and frequently decrease photosynthetic rate more than can be attributed to the mere loss of photosynthetic surface area. Some of this effect may result because biological control agents facilitate the transfer and ingress of deleterious microbes into plant tissues on which they feed. We evaluated this facilitation effect using water hyacinth (Eichhornia crassipes) and a weevil (Neochetina eichhorniae) and compared the reductions in photosynthetic rates between leaves subject to herbivory by adult weevils sterilized with 3.5% chlorine bleach, to those that were unsterilized. The results showed that weevils carried both fungi and bacteria, transferred these to leaves on which they fed, and that microbes and biomass removal contributed almost equally to the 37% decrease in photosynthetic productivity. Hence, maximising the effectiveness of using arthropods that damage leaf surfaces for biocontrol requires the presence of microorganisms that are deleterious to plants.
- Full Text:
- Date Issued: 2013
- Authors: Venter, Nic , Hill, Martin P , Hutchinson, Sarah-Leigh , Ripley, Bradford S
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423573 , vital:72073 , xlink:href="https://doi.org/10.1016/j.biocontrol.2012.10.011"
- Description: Arthropods released for weed biocontrol can have effects other than simply removing biomass and frequently decrease photosynthetic rate more than can be attributed to the mere loss of photosynthetic surface area. Some of this effect may result because biological control agents facilitate the transfer and ingress of deleterious microbes into plant tissues on which they feed. We evaluated this facilitation effect using water hyacinth (Eichhornia crassipes) and a weevil (Neochetina eichhorniae) and compared the reductions in photosynthetic rates between leaves subject to herbivory by adult weevils sterilized with 3.5% chlorine bleach, to those that were unsterilized. The results showed that weevils carried both fungi and bacteria, transferred these to leaves on which they fed, and that microbes and biomass removal contributed almost equally to the 37% decrease in photosynthetic productivity. Hence, maximising the effectiveness of using arthropods that damage leaf surfaces for biocontrol requires the presence of microorganisms that are deleterious to plants.
- Full Text:
- Date Issued: 2013