Ethics in context
- Burningham, Kate, Venn, Susan, Hayward, Bronwyn, Aoyagi, Midori, Hasan, Mohammed Mehedi, Mattar, Helio, Schudel, Ingrid J, Yoshida, Aya
- Authors: Burningham, Kate , Venn, Susan , Hayward, Bronwyn , Aoyagi, Midori , Hasan, Mohammed Mehedi , Mattar, Helio , Schudel, Ingrid J , Yoshida, Aya
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294364 , vital:57215 , xlink:href="https://doi.org/10.1080/13645579.2019.1672282"
- Description: Existing literatures have discussed both ethical issues in visual research with young people, and the problems associated with applying ‘universal’ ethical guidelines across varied cultural contexts. There has been little consideration, however, of specific issues raised in projects where visual research is being conducted with young people simultaneously in multiple national contexts. This paper contributes to knowledge in this area. We reflect on our experiences of planning and conducting the International CYCLES project involving photo elicitation with young people in Bangladesh, Brazil, India, Japan, New Zealand, South Africa and the UK. While some issues such as varying access to technology for taking and sharing photos and diverse cultural sensitivities around the use of photography were anticipated in advance, others were more unexpected. Balancing the need for methods to be appropriate, ethical and feasible within each setting with the desire for sufficient consistency across the project is challenging. We argue that an ‘ethics in context’ approach and an attitude of ‘methodological immaturity’ is critical in international visual research projects with young people.
- Full Text:
- Date Issued: 2020
- Authors: Burningham, Kate , Venn, Susan , Hayward, Bronwyn , Aoyagi, Midori , Hasan, Mohammed Mehedi , Mattar, Helio , Schudel, Ingrid J , Yoshida, Aya
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294364 , vital:57215 , xlink:href="https://doi.org/10.1080/13645579.2019.1672282"
- Description: Existing literatures have discussed both ethical issues in visual research with young people, and the problems associated with applying ‘universal’ ethical guidelines across varied cultural contexts. There has been little consideration, however, of specific issues raised in projects where visual research is being conducted with young people simultaneously in multiple national contexts. This paper contributes to knowledge in this area. We reflect on our experiences of planning and conducting the International CYCLES project involving photo elicitation with young people in Bangladesh, Brazil, India, Japan, New Zealand, South Africa and the UK. While some issues such as varying access to technology for taking and sharing photos and diverse cultural sensitivities around the use of photography were anticipated in advance, others were more unexpected. Balancing the need for methods to be appropriate, ethical and feasible within each setting with the desire for sufficient consistency across the project is challenging. We argue that an ‘ethics in context’ approach and an attitude of ‘methodological immaturity’ is critical in international visual research projects with young people.
- Full Text:
- Date Issued: 2020
Evaluating Feruloyl Esterase—Xylanase Synergism for Hydroxycinnamic Acid and Xylo-Oligosaccharide Production from Untreated, Hydrothermally Pre-Treated and Dilute-Acid Pre-Treated Corn Cobs:
- Mkabayi, Lithalethu, Malgas, Samkelo, Wilhelmi, Brendan S, Pletschke, Brett I
- Authors: Mkabayi, Lithalethu , Malgas, Samkelo , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149240 , vital:38818 , https://doi.org/10.3390/agronomy10050688
- Description: Agricultural residues are considered the most promising option as a renewable feedstock for biofuel and high valued-added chemical production due to their availability and low cost. The efficient enzymatic hydrolysis of agricultural residues into value-added products such as sugars and hydroxycinnamic acids is a challenge because of the recalcitrant properties of the native biomass. Development of synergistic enzyme cocktails is required to overcome biomass residue recalcitrance, and achieve high yields of potential value-added products. In this study, the synergistic action of two termite metagenome-derived feruloyl esterases (FAE5 and FAE6), and an endo-xylanase (Xyn11) from Thermomyces lanuginosus, was optimized using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate) and then applied to 1% (w/v) corn cobs for the efficient production of xylo-oligosaccharides (XOS) and hydroxycinnamic acids.
- Full Text:
- Date Issued: 2020
- Authors: Mkabayi, Lithalethu , Malgas, Samkelo , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149240 , vital:38818 , https://doi.org/10.3390/agronomy10050688
- Description: Agricultural residues are considered the most promising option as a renewable feedstock for biofuel and high valued-added chemical production due to their availability and low cost. The efficient enzymatic hydrolysis of agricultural residues into value-added products such as sugars and hydroxycinnamic acids is a challenge because of the recalcitrant properties of the native biomass. Development of synergistic enzyme cocktails is required to overcome biomass residue recalcitrance, and achieve high yields of potential value-added products. In this study, the synergistic action of two termite metagenome-derived feruloyl esterases (FAE5 and FAE6), and an endo-xylanase (Xyn11) from Thermomyces lanuginosus, was optimized using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate) and then applied to 1% (w/v) corn cobs for the efficient production of xylo-oligosaccharides (XOS) and hydroxycinnamic acids.
- Full Text:
- Date Issued: 2020
Events tourism as a conduit to promote underdeveloped tourist destinations, with specific reference to the Mooiplaas Homecoming Music Event in East London, South Africa
- Mxunyelwa, Siyabonga, Kilani, Khuselwa Busisiwe
- Authors: Mxunyelwa, Siyabonga , Kilani, Khuselwa Busisiwe
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1958 , vital:39809 , https://www.ajhtl.com/uploads/7/1/6/3/7163688/article_9_vol_9_2__2020_wsu.pdf
- Description: Events tourism has demonstrated growth over the years, and has been used as a tool to boost local economies. Hosting such events creates benefits, these include the boost in the local economy, improvement of infrastructure on destinations and job creation. The purpose of this paper was to investigate how events tourism could be utilised as a conduit to promote underdeveloped tourist destinations in Mooiplaas. Secondary data sources were consulted to understand the role of events tourism in the local community of Mooiplaas. This paper utilised a survey questionnaire to collect data. The simple random sampling method was utilised to select the respondents. The findings indicate that 70% of the respondents agreed that they are consulted about the events that promote their community. Furthermore, the findings elucidates that 82% of the respondents concur that events can potentially create entrepreneurial opportunities. These findings contribute significantly in developing the local economic strategies of the municipalities in underdeveloped regions. As such it is recommended that events are planned in a coherent, systematic manner in order to achieve local economic development objectives. Furthermore, the paper provided a foundation on how to plan, organise, lead and control events that can potentially unearth tourism demand particularly in developing tourist destinations. Moreover, it is hoped that the paper will serve as the basis to plan future events in the context of regions such as Mooiplaas that are still engulfed with developmental challenges, these contribute to triple threat of unemployed, poverty and inequality.
- Full Text:
- Date Issued: 2020
- Authors: Mxunyelwa, Siyabonga , Kilani, Khuselwa Busisiwe
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1958 , vital:39809 , https://www.ajhtl.com/uploads/7/1/6/3/7163688/article_9_vol_9_2__2020_wsu.pdf
- Description: Events tourism has demonstrated growth over the years, and has been used as a tool to boost local economies. Hosting such events creates benefits, these include the boost in the local economy, improvement of infrastructure on destinations and job creation. The purpose of this paper was to investigate how events tourism could be utilised as a conduit to promote underdeveloped tourist destinations in Mooiplaas. Secondary data sources were consulted to understand the role of events tourism in the local community of Mooiplaas. This paper utilised a survey questionnaire to collect data. The simple random sampling method was utilised to select the respondents. The findings indicate that 70% of the respondents agreed that they are consulted about the events that promote their community. Furthermore, the findings elucidates that 82% of the respondents concur that events can potentially create entrepreneurial opportunities. These findings contribute significantly in developing the local economic strategies of the municipalities in underdeveloped regions. As such it is recommended that events are planned in a coherent, systematic manner in order to achieve local economic development objectives. Furthermore, the paper provided a foundation on how to plan, organise, lead and control events that can potentially unearth tourism demand particularly in developing tourist destinations. Moreover, it is hoped that the paper will serve as the basis to plan future events in the context of regions such as Mooiplaas that are still engulfed with developmental challenges, these contribute to triple threat of unemployed, poverty and inequality.
- Full Text:
- Date Issued: 2020
Evidence of genetic differentiation in cigar wrasse Cheilio inermis (Labridae) within the western Indian Ocean:
- Mayekiso, Sisanda, Gouws, Gavin, Mwale, Monica, Gon, Ofer
- Authors: Mayekiso, Sisanda , Gouws, Gavin , Mwale, Monica , Gon, Ofer
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163499 , vital:41043 , https://doi.org/10.1139/gen-2019-0185
- Description: Patterns of genetic structure and connectivity of the monotypic cigar wrasse Cheilio inermis within western Indian Ocean (WIO) are poorly understood. Whether the species exists as a single panmictic population across the WIO is unclear. Sequence data were generated from two mitochondrial genes (cytochrome b and ATPase 6) and one nuclear intron (S7 intron I). High levels of haplotype and allelic diversity (h = 0.88–0.98; A = 0.95–0.98), along with low nucleotide diversities were observed across all markers.
- Full Text:
- Date Issued: 2020
- Authors: Mayekiso, Sisanda , Gouws, Gavin , Mwale, Monica , Gon, Ofer
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163499 , vital:41043 , https://doi.org/10.1139/gen-2019-0185
- Description: Patterns of genetic structure and connectivity of the monotypic cigar wrasse Cheilio inermis within western Indian Ocean (WIO) are poorly understood. Whether the species exists as a single panmictic population across the WIO is unclear. Sequence data were generated from two mitochondrial genes (cytochrome b and ATPase 6) and one nuclear intron (S7 intron I). High levels of haplotype and allelic diversity (h = 0.88–0.98; A = 0.95–0.98), along with low nucleotide diversities were observed across all markers.
- Full Text:
- Date Issued: 2020
Evolving an Efficient and Effective Off-the-Shelf Computing Infrastructure for Rural Communities of South Africa
- Siebörger, Ingrid, Terzoli, Alfredo, Hodgkinson-Williams, Cheryl
- Authors: Siebörger, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430990 , vital:72734 , https://doi.org/10.1007/978-3-030-52014-4_5
- Description: Information Communication Technologies (ICTs) have diffused into al-most every area of life for citizens living in the Global North. Data is seen as a key element in the fourth industrial revolution and is the foundation of Information, Knowledge and Wisdom. Knowledge has become the new “make or break” asset and an inability to access the world’s data and technologies that facilitate access, synthesis and inter-rogation of data places one at a disadvantage. In 2013, the Department of Communications in South Africa announced a new national broad-band policy to promote the reduction of a digital divide and sup-port citi-zens and the economy in digital interactions. Implementation has thus far not been successful. Furthermore, the Broadband policy does not address how South Africans are to access the Internet once available. The Siyakhula Living Lab (SLL) provides an example of a computing infrastructure model for the introduction of ICTs into rural communities. Through the deployment of “broadband islands” and low-cost compu-ting infrastructure to promote both knowledge creation and consump-tion, access to the proposed ubiquitous Internet connectivity can be un-locked. However, the initial computing infrastructure deployed to the SLL suffers from a single point of failure. In this paper, we discuss al-ternative computing infrastructure configurations that were tested and deployed within the SLL in order to determine a more appropriate com-puting infrastructure model for the SLL and potentially other rural South African communities; such that learners, teachers and community members can be active contributors and consumers of data, infor-mation, knowledge and wisdom.
- Full Text:
- Date Issued: 2020
- Authors: Siebörger, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430990 , vital:72734 , https://doi.org/10.1007/978-3-030-52014-4_5
- Description: Information Communication Technologies (ICTs) have diffused into al-most every area of life for citizens living in the Global North. Data is seen as a key element in the fourth industrial revolution and is the foundation of Information, Knowledge and Wisdom. Knowledge has become the new “make or break” asset and an inability to access the world’s data and technologies that facilitate access, synthesis and inter-rogation of data places one at a disadvantage. In 2013, the Department of Communications in South Africa announced a new national broad-band policy to promote the reduction of a digital divide and sup-port citi-zens and the economy in digital interactions. Implementation has thus far not been successful. Furthermore, the Broadband policy does not address how South Africans are to access the Internet once available. The Siyakhula Living Lab (SLL) provides an example of a computing infrastructure model for the introduction of ICTs into rural communities. Through the deployment of “broadband islands” and low-cost compu-ting infrastructure to promote both knowledge creation and consump-tion, access to the proposed ubiquitous Internet connectivity can be un-locked. However, the initial computing infrastructure deployed to the SLL suffers from a single point of failure. In this paper, we discuss al-ternative computing infrastructure configurations that were tested and deployed within the SLL in order to determine a more appropriate com-puting infrastructure model for the SLL and potentially other rural South African communities; such that learners, teachers and community members can be active contributors and consumers of data, infor-mation, knowledge and wisdom.
- Full Text:
- Date Issued: 2020
Examining intraspecific multiple predator effects across shifting predator sex ratios:
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Weyl, Olaf L F, Froneman, P William, Callaghan, Amanda, Dick, Jaimie T A
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150119 , vital:38941 , https://doi.org/10.1016/j.baae.2020.03.002
- Description: Predator-predator interactions, or “multiple predator effects” (MPEs), are pervasive in the structuring of communities and complicate predictive quantifications of ecosystem dynamics. The nature of MPEs is also context-dependent, manifesting differently among species, prey densities and habitat structures. However, there has hitherto been a lack of consideration for the implications of intraspecific demographic variation within populations for the strength of MPEs. The present study extends MPE concepts to examine intraspecific interactions among male and female predators across differences in prey densities using a functional response approach. Focusing on a copepod-mosquito model predator-prey system, interaction strengths of different sex ratio pairs of Lovenula raynerae were quantified towards larval Culex pipiens complex prey, with observations compared to both additive and substitutive model predictions.
- Full Text:
- Date Issued: 2020
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150119 , vital:38941 , https://doi.org/10.1016/j.baae.2020.03.002
- Description: Predator-predator interactions, or “multiple predator effects” (MPEs), are pervasive in the structuring of communities and complicate predictive quantifications of ecosystem dynamics. The nature of MPEs is also context-dependent, manifesting differently among species, prey densities and habitat structures. However, there has hitherto been a lack of consideration for the implications of intraspecific demographic variation within populations for the strength of MPEs. The present study extends MPE concepts to examine intraspecific interactions among male and female predators across differences in prey densities using a functional response approach. Focusing on a copepod-mosquito model predator-prey system, interaction strengths of different sex ratio pairs of Lovenula raynerae were quantified towards larval Culex pipiens complex prey, with observations compared to both additive and substitutive model predictions.
- Full Text:
- Date Issued: 2020
Expansive learning in the leadership development of school learners
- Grant, Carolyn, Kajee, Farhana Amod
- Authors: Grant, Carolyn , Kajee, Farhana Amod
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281072 , vital:55689 , xlink:href="https://doi.org/10.1080/13603124.2020.1836405"
- Description: In many countries across the globe, and on the African continent in particular, young people do not have a voice in matters concerning their schooling. By virtue of their minor status, opportunities for participatory decision-making and leadership in schools are restricted, despite national policies to the contrary. This is all-too-often because leadership is (mis)understood as an adult phenomenon. In this article, we present a formative intervention, ‘Learners Lead’, which aimed at developing learner voice and leadership in learners through collective involvement in school change projects. Formulated as a documentary case study, data were generated from 95 research reports, the written assessments of the students registered for the Educational Leadership and Management elective within a postgraduate qualification in a South African university. Analysis drew on the pyramid of learner voice and the theory of expansive learning to examine if, and how, leadership development in learners occurred. The study found that expansive learning’s seven learning actions provided the necessary additional theoretical tools for understanding and unpacking the stages of leadership development as the school change projects unfolded. Implications for practice and research are discussed.
- Full Text:
- Date Issued: 2020
- Authors: Grant, Carolyn , Kajee, Farhana Amod
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281072 , vital:55689 , xlink:href="https://doi.org/10.1080/13603124.2020.1836405"
- Description: In many countries across the globe, and on the African continent in particular, young people do not have a voice in matters concerning their schooling. By virtue of their minor status, opportunities for participatory decision-making and leadership in schools are restricted, despite national policies to the contrary. This is all-too-often because leadership is (mis)understood as an adult phenomenon. In this article, we present a formative intervention, ‘Learners Lead’, which aimed at developing learner voice and leadership in learners through collective involvement in school change projects. Formulated as a documentary case study, data were generated from 95 research reports, the written assessments of the students registered for the Educational Leadership and Management elective within a postgraduate qualification in a South African university. Analysis drew on the pyramid of learner voice and the theory of expansive learning to examine if, and how, leadership development in learners occurred. The study found that expansive learning’s seven learning actions provided the necessary additional theoretical tools for understanding and unpacking the stages of leadership development as the school change projects unfolded. Implications for practice and research are discussed.
- Full Text:
- Date Issued: 2020
Exploring how a genetic attribution to disease relates to stigma experiences of Xhosa patients with schizophrenia in South Africa
- Matshabane, Olivia P, Campbell, Megan, Faure, Marlyn C, Marshall, Patricia A, Mayosi, Bongani M, Stein, Dan J, Appelbaum, Paul S, de Vries, Jantina
- Authors: Matshabane, Olivia P , Campbell, Megan , Faure, Marlyn C , Marshall, Patricia A , Mayosi, Bongani M , Stein, Dan J , Appelbaum, Paul S , de Vries, Jantina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302487 , vital:58201 , xlink:href="https://doi.org/10.1007/s00127-020-01875-z"
- Description: Background: Over the past three decades, a range of international stakeholders have highlighted the possibility that genomic research may impact stigma associated with psychiatric disorders. Limited research has been conducted in Africa to investigate this relation. Method In the present study, using focus group discussions, we explored the relation between genetic attribution and stigma among 36 Xhosa people with schizophrenia. We addressed three main questions: (1) What causal beliefs do Xhosa people with schizophrenia use to explain their illness and to what extent do genetic explanations play a role in these beliefs? (2) What are the internalised stigma experiences of Xhosa people with schizophrenia? (3) How do genetic explanations relate to stigma experiences, if at all? Results Most participants were able to define genetics and some linked genetics to disease causation. Despite adequate knowledge of genetics and an emphasis on genetic explanations of schizophrenia in the study, most participants held a multitude of causal explanations including: psychosocial, environmental, and cultural. Moreover, participants rarely mentioned disease cause when describing their stigma experiences. Discussion For this population group, there was no straight-forward relation between a genetic attribution and stigma. Therefore, we did not fnd evidence that genetic attribution may signifcantly increase stigma. Although North American and European literature provides conficting evidence regarding this relation, there is increased consensus that biomedical explanations for psychiatric disorders may reduce blame. This study found evidence supporting that consensus. This study provides an empirical foundation to inform ongoing work on the psychosocial implications of psychiatric genomics research in non-Western contexts.
- Full Text:
- Date Issued: 2020
- Authors: Matshabane, Olivia P , Campbell, Megan , Faure, Marlyn C , Marshall, Patricia A , Mayosi, Bongani M , Stein, Dan J , Appelbaum, Paul S , de Vries, Jantina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302487 , vital:58201 , xlink:href="https://doi.org/10.1007/s00127-020-01875-z"
- Description: Background: Over the past three decades, a range of international stakeholders have highlighted the possibility that genomic research may impact stigma associated with psychiatric disorders. Limited research has been conducted in Africa to investigate this relation. Method In the present study, using focus group discussions, we explored the relation between genetic attribution and stigma among 36 Xhosa people with schizophrenia. We addressed three main questions: (1) What causal beliefs do Xhosa people with schizophrenia use to explain their illness and to what extent do genetic explanations play a role in these beliefs? (2) What are the internalised stigma experiences of Xhosa people with schizophrenia? (3) How do genetic explanations relate to stigma experiences, if at all? Results Most participants were able to define genetics and some linked genetics to disease causation. Despite adequate knowledge of genetics and an emphasis on genetic explanations of schizophrenia in the study, most participants held a multitude of causal explanations including: psychosocial, environmental, and cultural. Moreover, participants rarely mentioned disease cause when describing their stigma experiences. Discussion For this population group, there was no straight-forward relation between a genetic attribution and stigma. Therefore, we did not fnd evidence that genetic attribution may signifcantly increase stigma. Although North American and European literature provides conficting evidence regarding this relation, there is increased consensus that biomedical explanations for psychiatric disorders may reduce blame. This study found evidence supporting that consensus. This study provides an empirical foundation to inform ongoing work on the psychosocial implications of psychiatric genomics research in non-Western contexts.
- Full Text:
- Date Issued: 2020
Exploring intermolecular contacts in multi-substituted benzaldehyde derivatives: X-ray, Hirshfeld surface and lattice energy analyses
- Hulushe, Siya T, Manyeruke, Meloddy H, Louzada, Marcel, Rigin, Sergei, Hosten, Eric C, Watkins, Gareth M
- Authors: Hulushe, Siya T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
- Authors: Hulushe, Siya T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
F-and F+-band radioluminescence and the influence of annealing on its emission spectra in Al2O3: C, Mg:
- Chithambo, Makaiko L, Kalita, Jitumani M, Finch, A A
- Authors: Chithambo, Makaiko L , Kalita, Jitumani M , Finch, A A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150130 , vital:38942 , https://doi.org/10.1016/j.radmeas.2020.106306
- Description: Radioluminescence spectra of Al2O3:C,Mg monitored at temperatures up to 400 °C is reported. Measurements were made on samples either as received or on ones annealed at 1200 °C. Radioluminescence is observed at 410 nm for the unannealed sample but principally at 330 and 410 nm in the annealed sample with the emission at 330 nm dominant. Both bands are subject to thermal quenching but the change for the F+ band is atypical. Temperature induced effects on these and other bands are discussed, as are complementary measurements of thermoluminescence spectra.
- Full Text:
- Date Issued: 2020
- Authors: Chithambo, Makaiko L , Kalita, Jitumani M , Finch, A A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150130 , vital:38942 , https://doi.org/10.1016/j.radmeas.2020.106306
- Description: Radioluminescence spectra of Al2O3:C,Mg monitored at temperatures up to 400 °C is reported. Measurements were made on samples either as received or on ones annealed at 1200 °C. Radioluminescence is observed at 410 nm for the unannealed sample but principally at 330 and 410 nm in the annealed sample with the emission at 330 nm dominant. Both bands are subject to thermal quenching but the change for the F+ band is atypical. Temperature induced effects on these and other bands are discussed, as are complementary measurements of thermoluminescence spectra.
- Full Text:
- Date Issued: 2020
Fabrication of dye-sensitized solar cells based on push-pull asymmetrical substituted zinc and copper phthalocyanines and reduced graphene oxide nanosheet:
- Chindeka, Francis, Mashazi, Philani N, Britton, Jonathan, Oluwole, David O, Mapukata, Sivuyisiwe, Nyokong, Tebello
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
Fabrication of electrospun fibers from a porphyrin linked to polyacrylonitrile polymer for photocatalytic transformation of phenols
- Jones, Ben, Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Jones, Ben , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186196 , vital:44472 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128191"
- Description: A novel mono-porphyrin (2) was employed for the photodegradation of 4-chlorophenol and 4-n-nonylphenol at pH 10.60. A partially modified polyacrylonitrile (PAN) polymer was utilized only as a support system for the photosensitiser to allow the formation of a covalent linkage. Complex 2 showed singlet oxygen values of 0.70 in dimethyl formamide and when conjugated (2-PAN) showed 0.39 in water. When employed against 4-chlorophenol a degradation efficiency (η) of 29.1% was achieved at 0.20 mol L−1 over a period of 10 min. When employed against 4-n-nonylphenol we obtained a η of 26.7% at 0.17 mol L−1 over a period of 10 min.
- Full Text:
- Date Issued: 2020
- Authors: Jones, Ben , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186196 , vital:44472 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128191"
- Description: A novel mono-porphyrin (2) was employed for the photodegradation of 4-chlorophenol and 4-n-nonylphenol at pH 10.60. A partially modified polyacrylonitrile (PAN) polymer was utilized only as a support system for the photosensitiser to allow the formation of a covalent linkage. Complex 2 showed singlet oxygen values of 0.70 in dimethyl formamide and when conjugated (2-PAN) showed 0.39 in water. When employed against 4-chlorophenol a degradation efficiency (η) of 29.1% was achieved at 0.20 mol L−1 over a period of 10 min. When employed against 4-n-nonylphenol we obtained a η of 26.7% at 0.17 mol L−1 over a period of 10 min.
- Full Text:
- Date Issued: 2020
First candidates for γ vibrational bands built on the [505] 11/2− neutron orbital in odd-A Dy isotopes:
- Majola, S N T, Sithole, M A, Mdletshe, L, Hartley, D, Timár, J, Nyakó, B M, Allmond, J M, Bark, R A, Beausang, C, Bianco, L, Bucher, T D, Bvumbi, S P, Carpenter, M P, Chiara, C J, Cooper, N, Cullen, D M, Curien, D, Dinoko, T S, Gall, B J P, Garrett, P E, Greenlees, P T, Hirvonen, J, Jakobsson, U, Jones, P M, Julin, R, Juutinen, S, Ketelhut, S, Keswa, B V, Kondev, F G, Korichi, A, Kulp, W D, Lauritsen, T, Lawrie, E A, Makhathini, L, Masiteng, P L, Maqabuka, B, McCutchan, E A, Miller, D, Miller, S, Minkova, A, Msebi, L, Mthembu, S H, Ndayishmiye, J, Nieminen, P, Ngcobo, P Z, Ntshamgase, S S, Orce, J N, Peura, P, Rahkila, P, Redon, N, Riedinger, L L, Riley, M A, Roux, D G, Ruotsalainen, P, Piot, J, Saren, J, Sharpey-Schafer, J F, Scholey, C, Shirinda, O, Simpson, J, Sorri, J, Stefansecu, I, Stolze, S, Uusitalo, J, Wang, X, Werner, V, Wood, J L, Yu, C-H, Zhu, S, Zimba, G
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
First record of an indigenous South African parasitoid wasp on an imported biological control agent, the water hyacinth hopper
- Kraus, Emily C, Coetzee, Julie A, van Noort, Simon, Olmi, Massimo
- Authors: Kraus, Emily C , Coetzee, Julie A , van Noort, Simon , Olmi, Massimo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417700 , vital:71479 , xlink:href="https://doi.org/10.1080/09583157.2019.1660306"
- Description: Water hyacinth, Pontederia crassipes (Martius) [≡Eichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy.
- Full Text:
- Date Issued: 2020
- Authors: Kraus, Emily C , Coetzee, Julie A , van Noort, Simon , Olmi, Massimo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417700 , vital:71479 , xlink:href="https://doi.org/10.1080/09583157.2019.1660306"
- Description: Water hyacinth, Pontederia crassipes (Martius) [≡Eichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy.
- Full Text:
- Date Issued: 2020
Flower orientation in Gloriosa superba (Colchicaceae) promotes cross-pollination via butterfly wings:
- Daniels, Ryan J, Johnson, Steven D, Peter, Craig I
- Authors: Daniels, Ryan J , Johnson, Steven D , Peter, Craig I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150141 , vital:38943 , https://0-doi.org.wam.seals.ac.za/10.1093/aob/mcaa048
- Description: Complex modifications of angiosperm flowers often function for precise pollen placement on pollinators and to promote cross-pollination. We explore the functional significance of the unusually elaborate morphology of Gloriosa superba flowers, which are divided into one hermaphrodite meranthium and five male meranthia (functional pollination units of a single flower). We used controlled pollination experiments, floral measurements, pollen load analyses and visitor observations in four populations of G. superba in South Africa to determine the breeding system, mechanism of pollination and role of flower in the promotion of cross-pollination.
- Full Text:
- Date Issued: 2020
- Authors: Daniels, Ryan J , Johnson, Steven D , Peter, Craig I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150141 , vital:38943 , https://0-doi.org.wam.seals.ac.za/10.1093/aob/mcaa048
- Description: Complex modifications of angiosperm flowers often function for precise pollen placement on pollinators and to promote cross-pollination. We explore the functional significance of the unusually elaborate morphology of Gloriosa superba flowers, which are divided into one hermaphrodite meranthium and five male meranthia (functional pollination units of a single flower). We used controlled pollination experiments, floral measurements, pollen load analyses and visitor observations in four populations of G. superba in South Africa to determine the breeding system, mechanism of pollination and role of flower in the promotion of cross-pollination.
- Full Text:
- Date Issued: 2020
Foraging wild food in urban spaces: The contribution of wild foods to urban dietary diversity in South Africa
- Garekae, Hesekia, Shackleton, Charlie M
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176368 , vital:42688 , https://doi.org/10.3390/su12020678
- Description: Globally, approximately one billion people benefit from contributions of wild foods to their food security and dietary diversity. Wild foods are known to be important in rural communities in terms of food and micronutrient provision, diversifying diets, reducing vulnerability to non-communicable diseases and overall health. However, the potential contribution of wild foods towards food security and dietary diversity in urban food systems has been largely overlooked. This study examined the contribution of wild foods to household dietary diversity in two towns in South Africa, based on a survey of 137 households.
- Full Text:
- Date Issued: 2020
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176368 , vital:42688 , https://doi.org/10.3390/su12020678
- Description: Globally, approximately one billion people benefit from contributions of wild foods to their food security and dietary diversity. Wild foods are known to be important in rural communities in terms of food and micronutrient provision, diversifying diets, reducing vulnerability to non-communicable diseases and overall health. However, the potential contribution of wild foods towards food security and dietary diversity in urban food systems has been largely overlooked. This study examined the contribution of wild foods to household dietary diversity in two towns in South Africa, based on a survey of 137 households.
- Full Text:
- Date Issued: 2020
Forays into contemporary South African theatre
- Authors: Krueger, Anton
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229578 , vital:49689 , xlink:href="https://doi.org/10.1080/10137548.2021.1963112"
- Description: Trying to keep up with what is going on in South African theatre today is an endlessly renewing process. The word ‘foray’ has associations of brief incursions into foreign territory. It’s an almost hesitant word, a venture into unexplored terrain. This hesitation feels apt in the sense that (at the time of writing), any description of a pre-Covid theatre is bound to feel strange. The landscape has shifted, and nobody is quite sure how things will look in a year from now. Nevertheless, this is a rich compendium of relatively recent theatre, as seen from within the country and also from the vantage of a global perspective. Almost all of the essays are drawn from a 2017 conference held in Brussels at the Université Libre de Bruxelles, called: ‘New Stage Idioms: South African Drama, Theatre and Performance in the Twenty-first Century.’Although the tone remains scholarly, the inclusion of different kinds of writers – not only academics but activists, playwrights and journalists – prevents the work from becoming overly dry.
- Full Text:
- Date Issued: 2020
- Authors: Krueger, Anton
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229578 , vital:49689 , xlink:href="https://doi.org/10.1080/10137548.2021.1963112"
- Description: Trying to keep up with what is going on in South African theatre today is an endlessly renewing process. The word ‘foray’ has associations of brief incursions into foreign territory. It’s an almost hesitant word, a venture into unexplored terrain. This hesitation feels apt in the sense that (at the time of writing), any description of a pre-Covid theatre is bound to feel strange. The landscape has shifted, and nobody is quite sure how things will look in a year from now. Nevertheless, this is a rich compendium of relatively recent theatre, as seen from within the country and also from the vantage of a global perspective. Almost all of the essays are drawn from a 2017 conference held in Brussels at the Université Libre de Bruxelles, called: ‘New Stage Idioms: South African Drama, Theatre and Performance in the Twenty-first Century.’Although the tone remains scholarly, the inclusion of different kinds of writers – not only academics but activists, playwrights and journalists – prevents the work from becoming overly dry.
- Full Text:
- Date Issued: 2020
Formulation and Characterisation of a Combination Captopril and Hydrochlorothiazide Microparticulate Dosage Form
- Chikukwa, Mellisa T R, Walker, Roderick B, Khamanga, Sandile M
- Authors: Chikukwa, Mellisa T R , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183200 , vital:43926 , xlink:href="https://doi.org/10.3390/pharmaceutics12080712"
- Description: Cardiovascular diseases such as hypertension and cardiac failure in South African children and adolescents are effectively managed long term, using a combination treatment of captopril and hydrochlorothiazide. The majority of commercially available pharmaceutical products are designed for adult patients and require extemporaneous manipulation, prior to administration to paediatric patients. There is a need to develop an age appropriate microparticulate dosing technology that is easy to swallow, dose and alter doses whilst overcoming the pharmacokinetic challenges of short half-life and biphasic pharmacokinetic disposition exhibited by hydrochlorothiazide and captopril. An emulsion solvent evaporation approach using different combinations of polymers was used to manufacture captopril and hydrochlorothiazide microparticles. Design of experiments was used to develop and analyse experimental data, and identifyoptimum formulation and process conditions for the preparation of the microparticles. Characterisation studies to establish encapsulation efficiency, in vitro release, shape, size and morphology of the microparticles were undertaken. The microparticles produced were in the micrometre size range, with an encapsulation efficiency >75% for both hydrochlorothiazide and captopril. The microparticulate technology is able to offer potential resolution to the half-life mediated dosing frequency of captopril as sustained release of the molecule was observed over a 12-h period. The release of hydrochlorothiazide of >80% suggests an improvement in solubility limited dissolution.
- Full Text:
- Date Issued: 2020
- Authors: Chikukwa, Mellisa T R , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183200 , vital:43926 , xlink:href="https://doi.org/10.3390/pharmaceutics12080712"
- Description: Cardiovascular diseases such as hypertension and cardiac failure in South African children and adolescents are effectively managed long term, using a combination treatment of captopril and hydrochlorothiazide. The majority of commercially available pharmaceutical products are designed for adult patients and require extemporaneous manipulation, prior to administration to paediatric patients. There is a need to develop an age appropriate microparticulate dosing technology that is easy to swallow, dose and alter doses whilst overcoming the pharmacokinetic challenges of short half-life and biphasic pharmacokinetic disposition exhibited by hydrochlorothiazide and captopril. An emulsion solvent evaporation approach using different combinations of polymers was used to manufacture captopril and hydrochlorothiazide microparticles. Design of experiments was used to develop and analyse experimental data, and identifyoptimum formulation and process conditions for the preparation of the microparticles. Characterisation studies to establish encapsulation efficiency, in vitro release, shape, size and morphology of the microparticles were undertaken. The microparticles produced were in the micrometre size range, with an encapsulation efficiency >75% for both hydrochlorothiazide and captopril. The microparticulate technology is able to offer potential resolution to the half-life mediated dosing frequency of captopril as sustained release of the molecule was observed over a 12-h period. The release of hydrochlorothiazide of >80% suggests an improvement in solubility limited dissolution.
- Full Text:
- Date Issued: 2020
Formulation optimization of smart thermosetting lamotrigine loaded hydrogels using response surface methodology, box benhken design and artificial neural networks
- Melamane, Siyabonga, Walker, Roderick B, Khamanga, Sandile M
- Authors: Melamane, Siyabonga , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183265 , vital:43936 , xlink:href="https://doi.org/10.1080/03639045.2020.1791163"
- Description: The aim of this research was to develop lamotrigine containing thermosetting hydrogel for intranasal administration to manage and treat generalized epilepsy. Thermosetting hydrogels were prepared using different ratios of poloxamer 407 (L127), poloxamer 188 (L68) and CarbopolVR 974 P NF (C974) using the cold production process. The in situ thermosetting hydrogel was optimized using Box Behken design. Co-solvency approach was used to increase the solubility of lamotrigine by dissolving it in propylene glycol and polyethylene glycol 400 (0.2: 0.8) and the resultant solution was incorporated in the hydrogel to manufacture an LTG hydrogel. The presence of a higher amount of L127 resulted in higher viscosity at 22 0C and 34 0C and decreased the overall release of LTG. An increase in the amount of C974 resulted in a decrease in the pH of the hydrogel. The results show that formulations F10, F12, F13, F14, F15, F16 and F17 exhibited acceptable thermosetting behavior, pH and released adequate Lamotrigine above the minimum effective concentration to treat generalized epilepsy. The optimized formulation exhibited acceptable thermosetting behavior, pH and lamotrigine release but formed a stiff gel at 22 0C. The average LTG content of the optimized hydrogel was 5.00 ± 0.0225mg/ml with % recovery of 99.17%. The amount of LTG released at 12 h from the optimized hydrogel was 3.21 ± 0.0155mg and will be therapeutically effective in the brain after absorption via the olfactory region in the nasal cavity.
- Full Text:
- Date Issued: 2020
- Authors: Melamane, Siyabonga , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183265 , vital:43936 , xlink:href="https://doi.org/10.1080/03639045.2020.1791163"
- Description: The aim of this research was to develop lamotrigine containing thermosetting hydrogel for intranasal administration to manage and treat generalized epilepsy. Thermosetting hydrogels were prepared using different ratios of poloxamer 407 (L127), poloxamer 188 (L68) and CarbopolVR 974 P NF (C974) using the cold production process. The in situ thermosetting hydrogel was optimized using Box Behken design. Co-solvency approach was used to increase the solubility of lamotrigine by dissolving it in propylene glycol and polyethylene glycol 400 (0.2: 0.8) and the resultant solution was incorporated in the hydrogel to manufacture an LTG hydrogel. The presence of a higher amount of L127 resulted in higher viscosity at 22 0C and 34 0C and decreased the overall release of LTG. An increase in the amount of C974 resulted in a decrease in the pH of the hydrogel. The results show that formulations F10, F12, F13, F14, F15, F16 and F17 exhibited acceptable thermosetting behavior, pH and released adequate Lamotrigine above the minimum effective concentration to treat generalized epilepsy. The optimized formulation exhibited acceptable thermosetting behavior, pH and lamotrigine release but formed a stiff gel at 22 0C. The average LTG content of the optimized hydrogel was 5.00 ± 0.0225mg/ml with % recovery of 99.17%. The amount of LTG released at 12 h from the optimized hydrogel was 3.21 ± 0.0155mg and will be therapeutically effective in the brain after absorption via the olfactory region in the nasal cavity.
- Full Text:
- Date Issued: 2020
From the Booth to the Dock: 2018 elections in Zimbabwe and the elusive search for electoral integrity
- Mwonzora, Gift, Xaba, Mzingaye Brilliant
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020