A missing link in the estuarine nitrogen cycle?: coupled nitrification-denitrification mediated by suspended particulate matter
- Zhu, Weijing, Wang, Cheng, Hill, Jaclyn M, He, Yangyang, Tao, Bangyi, Mao, Zhihua, Wu, Weixiang
- Authors: Zhu, Weijing , Wang, Cheng , Hill, Jaclyn M , He, Yangyang , Tao, Bangyi , Mao, Zhihua , Wu, Weixiang
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68368 , vital:29244 , https://0-doi.org.wam.seals.ac.za/10.1038/s41598-018-20688-4
- Description: In estuarine and coastal ecosystems, the majority of previous studies have considered coupled nitrification-denitrification (CND) processes to be exclusively sediment based, with little focus onsuspended particulate matter (SPM) in the water column. Here, we present evidence of CND processes in the water column of Hangzhou Bay, one of the largest macrotidal embayments in the world.
- Full Text:
- Authors: Zhu, Weijing , Wang, Cheng , Hill, Jaclyn M , He, Yangyang , Tao, Bangyi , Mao, Zhihua , Wu, Weixiang
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68368 , vital:29244 , https://0-doi.org.wam.seals.ac.za/10.1038/s41598-018-20688-4
- Description: In estuarine and coastal ecosystems, the majority of previous studies have considered coupled nitrification-denitrification (CND) processes to be exclusively sediment based, with little focus onsuspended particulate matter (SPM) in the water column. Here, we present evidence of CND processes in the water column of Hangzhou Bay, one of the largest macrotidal embayments in the world.
- Full Text:
Developmental and reproductive performance of a specialist herbivore depend on seasonality of, and light conditions experienced by, the host plant
- Zachariades, Uyi O O,, Heshula, L U P, Hill, Martin P
- Authors: Zachariades, Uyi O O, , Heshula, L U P , Hill, Martin P
- Date: 2018
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59845 , vital:27667 , https://doi.org/10.1371/journal.pone.0190700
- Description: Host plant phenology (as influenced by seasonality) and light-mediated changes in the phenotypic and phytochemical properties of leaves have been hypothesised to equivocally influence insect herbivore performance. Here, we examined the effects of seasonality, through host plant phenology (late growth-season = autumn vs flowering-season = winter) and light environment (shade vs full-sun habitat) on the leaf characteristics of the invasive alien plant, Chromolaena odorata. In addition, the performance of a specialist folivore, Pareuchaetes insulata, feeding on leaves obtained from both shaded and full-sun habitats during autumn and winter, was evaluated over two generations. Foliar nitrogen and magnesium contents were generally higher in shaded plants with much higher levels during winter. Leaf water content was higher in shaded and in autumn plants. Total non-structural carbohydrate (TNC) and phosphorus contents did not differ as a function of season, but were higher in shaded foliage compared to full-sun leaves. Leaf toughness was noticeably higher on plants growing in full-sun during winter. With the exception of shaded leaves in autumn that supported the best performance [fastest development, heaviest pupal mass, and highest growth rate and Host Suitability Index (HSI) score], full-sun foliage in autumn surprisingly also supported an improved performance of the moth compared to shaded or full-sun leaves in winter. Our findings suggest that shaded and autumn foliage are nutritionally more suitable for the growth and reproduction of P. insulata. However, the heavier pupal mass, increased number of eggs and higher HSI score in individuals that fed on full-sun foliage in autumn compared to their counterparts that fed on shaded or full-sun foliage in winter suggest that full-sun foliage during autumn is also a suitable food source for larvae of the moth. In sum, our study demonstrates that seasonal and light-modulated changes in leaf characteristics can affect insect folivore performance in ways that are not linear.
- Full Text:
- Authors: Zachariades, Uyi O O, , Heshula, L U P , Hill, Martin P
- Date: 2018
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59845 , vital:27667 , https://doi.org/10.1371/journal.pone.0190700
- Description: Host plant phenology (as influenced by seasonality) and light-mediated changes in the phenotypic and phytochemical properties of leaves have been hypothesised to equivocally influence insect herbivore performance. Here, we examined the effects of seasonality, through host plant phenology (late growth-season = autumn vs flowering-season = winter) and light environment (shade vs full-sun habitat) on the leaf characteristics of the invasive alien plant, Chromolaena odorata. In addition, the performance of a specialist folivore, Pareuchaetes insulata, feeding on leaves obtained from both shaded and full-sun habitats during autumn and winter, was evaluated over two generations. Foliar nitrogen and magnesium contents were generally higher in shaded plants with much higher levels during winter. Leaf water content was higher in shaded and in autumn plants. Total non-structural carbohydrate (TNC) and phosphorus contents did not differ as a function of season, but were higher in shaded foliage compared to full-sun leaves. Leaf toughness was noticeably higher on plants growing in full-sun during winter. With the exception of shaded leaves in autumn that supported the best performance [fastest development, heaviest pupal mass, and highest growth rate and Host Suitability Index (HSI) score], full-sun foliage in autumn surprisingly also supported an improved performance of the moth compared to shaded or full-sun leaves in winter. Our findings suggest that shaded and autumn foliage are nutritionally more suitable for the growth and reproduction of P. insulata. However, the heavier pupal mass, increased number of eggs and higher HSI score in individuals that fed on full-sun foliage in autumn compared to their counterparts that fed on shaded or full-sun foliage in winter suggest that full-sun foliage during autumn is also a suitable food source for larvae of the moth. In sum, our study demonstrates that seasonal and light-modulated changes in leaf characteristics can affect insect folivore performance in ways that are not linear.
- Full Text:
Core-modified rubyrins with phenanthrene-fused pyrrole rings
- Yuan, Xuemei, Li, Minzhi, Meng, Ting, Mack, John, Soy, Rodah, Nyokong, Tebello, Zhu, Weihua, Xu, Haijun, Liang, Xu
- Authors: Yuan, Xuemei , Li, Minzhi , Meng, Ting , Mack, John , Soy, Rodah , Nyokong, Tebello , Zhu, Weihua , Xu, Haijun , Liang, Xu
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234568 , vital:50209 , xlink:href="https://doi.org/10.1016/j.dyepig.2018.05.045"
- Description: Three fused-ring-expanded rubyrins with modified macrocyclic core have been synthesized and characterized. A series of spectroscopic, electrochemical measurements and a set of theoretical calculations demonstrate that the core-modification of the inner core of rubyrins has a large influence on the electronic structure. Colorimetric changes are observe that demonstrate that these core-modified rubyrins could be used as selective Hg2+ ion sensors. These properties can be fine-tuned by introducing lipophilic substituents on the meso-aryl rings.
- Full Text:
- Authors: Yuan, Xuemei , Li, Minzhi , Meng, Ting , Mack, John , Soy, Rodah , Nyokong, Tebello , Zhu, Weihua , Xu, Haijun , Liang, Xu
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234568 , vital:50209 , xlink:href="https://doi.org/10.1016/j.dyepig.2018.05.045"
- Description: Three fused-ring-expanded rubyrins with modified macrocyclic core have been synthesized and characterized. A series of spectroscopic, electrochemical measurements and a set of theoretical calculations demonstrate that the core-modification of the inner core of rubyrins has a large influence on the electronic structure. Colorimetric changes are observe that demonstrate that these core-modified rubyrins could be used as selective Hg2+ ion sensors. These properties can be fine-tuned by introducing lipophilic substituents on the meso-aryl rings.
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Quantitation of zolpidem in biological fluids by electro-driven microextraction combined with HPLC-UV analysis
- Yaripour, Saeid, Mohammadi, Ali, Esfanjani, Isa, Walker, Roderick B, Nojavan, Saeed
- Authors: Yaripour, Saeid , Mohammadi, Ali , Esfanjani, Isa , Walker, Roderick B , Nojavan, Saeed
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184723 , vital:44266 , xlink:href="http://dx.doi.org/10.17179/excli2018-1140"
- Description: In this study, for the first time, an electro-driven microextraction method named electromembrane extraction combined with a simple high performance liquid chromatography and ultraviolet detection was developed and validated for the quantitation of zolpidem in biological samples. Parameters influencing electromembrane extraction were evaluated and optimized. The membrane consisted of 2-ethylhexanol immobilized in the pores of a hollow fiber. As a driving force, a 150 V electric field was applied to facilitate the analyte migration from the sample matrix to an acceptor solution through a supported liquid membrane. The pHs of donor and acceptor solutions were optimized to 6.0 and 2.0, respectively. The enrichment factor was obtained >75 within 15 minutes. The effect of carbon nanotubes (as solid nano-sorbents) on the membrane performance and EME efficiency was evaluated. The method was linear over the range of 10-1000 ng/mL for zolpidem (R2 >0.9991) with repeatability (%RSD) between 0.3 % and 7.3 % (n = 3). The limits of detection and quantitation were 3 and 10 ng/mL, respectively. The sensitivity of HPLC-UV for the determination of zolpidem was enhanced by electromembrane extraction. Finally, the method was employed for the quantitation of zolpidem in biological samples with relative recoveries in the range of 60-79 %.
- Full Text:
- Authors: Yaripour, Saeid , Mohammadi, Ali , Esfanjani, Isa , Walker, Roderick B , Nojavan, Saeed
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184723 , vital:44266 , xlink:href="http://dx.doi.org/10.17179/excli2018-1140"
- Description: In this study, for the first time, an electro-driven microextraction method named electromembrane extraction combined with a simple high performance liquid chromatography and ultraviolet detection was developed and validated for the quantitation of zolpidem in biological samples. Parameters influencing electromembrane extraction were evaluated and optimized. The membrane consisted of 2-ethylhexanol immobilized in the pores of a hollow fiber. As a driving force, a 150 V electric field was applied to facilitate the analyte migration from the sample matrix to an acceptor solution through a supported liquid membrane. The pHs of donor and acceptor solutions were optimized to 6.0 and 2.0, respectively. The enrichment factor was obtained >75 within 15 minutes. The effect of carbon nanotubes (as solid nano-sorbents) on the membrane performance and EME efficiency was evaluated. The method was linear over the range of 10-1000 ng/mL for zolpidem (R2 >0.9991) with repeatability (%RSD) between 0.3 % and 7.3 % (n = 3). The limits of detection and quantitation were 3 and 10 ng/mL, respectively. The sensitivity of HPLC-UV for the determination of zolpidem was enhanced by electromembrane extraction. Finally, the method was employed for the quantitation of zolpidem in biological samples with relative recoveries in the range of 60-79 %.
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Designing writing groups to support postgraduate students’ academic writing: a case study from a South African university
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
Writing groups as transformative spaces
- Wilmot, Kirstin, McKenna, Sioux
- Authors: Wilmot, Kirstin , McKenna, Sioux
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:44576 , xlink:href="https://doi.org/10.1080/07294360.2018.1450361"
- Description: Curriculum transformation is a central concern for higher education in response to rapidly expanding technologies, globalisation and the widening diversity of the student and staff body. This is particularly true for South Africa, which is still grappling with inequalities and pressure for social redress in its universities. Early responses to supporting students took the form of add-on, ‘deficit-model’ approaches which understood poor student retention and success rates as emerging from students’ lack of neutral literacy ‘skills’. Recent initiatives have begun to adopt more socio-cultural understandings of literacy that seek to challenge traditional power structures and cultivate horizontal peer-orientated spaces for learning with a focus on practice rather than on product. Writing groups, as spaces for academic writing development, embrace this orientation and are argued to provide a transformative framework that foregrounds proactive student learning and experience, while still accommodating disciplinary learning through peer engagement. Drawing on the successful implementation of such forms of support at a research-intensive university, this paper argues that writing groups can play a critical role in both personal (student) transformation and broader curriculum transformation. Data include anonymous questionnaires and surveys with participants and coordinators of the writing groups. An inductive, constant comparative analysis indicated that students feel empowered in this space to develop not only their writing practices but also their transforming identities as scholars. Writing groups were found to provide ‘safe spaces’ where academic practices can be made explicit and where they can be challenged. The paper therefore argues that writing groups can play a small but key role in broader transformation efforts.
- Full Text:
- Authors: Wilmot, Kirstin , McKenna, Sioux
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:44576 , xlink:href="https://doi.org/10.1080/07294360.2018.1450361"
- Description: Curriculum transformation is a central concern for higher education in response to rapidly expanding technologies, globalisation and the widening diversity of the student and staff body. This is particularly true for South Africa, which is still grappling with inequalities and pressure for social redress in its universities. Early responses to supporting students took the form of add-on, ‘deficit-model’ approaches which understood poor student retention and success rates as emerging from students’ lack of neutral literacy ‘skills’. Recent initiatives have begun to adopt more socio-cultural understandings of literacy that seek to challenge traditional power structures and cultivate horizontal peer-orientated spaces for learning with a focus on practice rather than on product. Writing groups, as spaces for academic writing development, embrace this orientation and are argued to provide a transformative framework that foregrounds proactive student learning and experience, while still accommodating disciplinary learning through peer engagement. Drawing on the successful implementation of such forms of support at a research-intensive university, this paper argues that writing groups can play a critical role in both personal (student) transformation and broader curriculum transformation. Data include anonymous questionnaires and surveys with participants and coordinators of the writing groups. An inductive, constant comparative analysis indicated that students feel empowered in this space to develop not only their writing practices but also their transforming identities as scholars. Writing groups were found to provide ‘safe spaces’ where academic practices can be made explicit and where they can be challenged. The paper therefore argues that writing groups can play a small but key role in broader transformation efforts.
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Use of a non-hepatic cell line highlights limitations associated with cell-based assessment of metabolically induced toxicity:
- Weyers, Carli, Dingle, Laura M K, Wilhelmi, Brendan S, Edkins, Adrienne L, Veale, Clinton G
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
- Full Text:
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
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HIV/AIDS and other household shocks as catalysts of local commercialization of non-timber forest products in Southern Africa
- Weyer, Dylan J, Shackleton, Charlie M, Adam, Y O
- Authors: Weyer, Dylan J , Shackleton, Charlie M , Adam, Y O
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398223 , vital:69385 , xlink:href="https://doi.org/10.1111/dpr.12261"
- Description: Local trade in non-timber forest products (NTFPs) is increasing globally, yet the causes have been little studied. We examine household shock as a driver of NTFP trade in five southern African countries, with an emphasis on HIV/AIDS-related illness and death. Over the past two years, 95% of trader households experienced at least one shock, with family illness and death recorded for 68% and 42% of households, respectively. Almost 40% had entered the trade because of HIV/AIDS-related shocks. Additional shocks included natural disasters, crop pests or failure and livestock loss. The sale of NTFPs was the third most common coping strategy, after kinship and agricultural adjustments. Coping strategies differed between sites and type of shock.
- Full Text:
- Authors: Weyer, Dylan J , Shackleton, Charlie M , Adam, Y O
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398223 , vital:69385 , xlink:href="https://doi.org/10.1111/dpr.12261"
- Description: Local trade in non-timber forest products (NTFPs) is increasing globally, yet the causes have been little studied. We examine household shock as a driver of NTFP trade in five southern African countries, with an emphasis on HIV/AIDS-related illness and death. Over the past two years, 95% of trader households experienced at least one shock, with family illness and death recorded for 68% and 42% of households, respectively. Almost 40% had entered the trade because of HIV/AIDS-related shocks. Additional shocks included natural disasters, crop pests or failure and livestock loss. The sale of NTFPs was the third most common coping strategy, after kinship and agricultural adjustments. Coping strategies differed between sites and type of shock.
- Full Text:
Extended and Continuous Decline in Effective Population Size Results in Low Genomic Diversity in the World’s Rarest Hyena Species, the Brown Hyena
- Westbury, Michael V, Hartmann, Stefanie, Barlow, Axel, Wiesel, Ingrid, Leo, Viyanna, Welch, Rebecca J, Parker, Daniel M, Sicks, Florian, Ludwig, Arne, Dalén, Love, Hofreiter, Michael
- Authors: Westbury, Michael V , Hartmann, Stefanie , Barlow, Axel , Wiesel, Ingrid , Leo, Viyanna , Welch, Rebecca J , Parker, Daniel M , Sicks, Florian , Ludwig, Arne , Dalén, Love , Hofreiter, Michael
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124482 , vital:35616 , https://doi.org/10.1093/molbev/msy037
- Description: Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of < 10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa.We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started_1Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.
- Full Text:
- Authors: Westbury, Michael V , Hartmann, Stefanie , Barlow, Axel , Wiesel, Ingrid , Leo, Viyanna , Welch, Rebecca J , Parker, Daniel M , Sicks, Florian , Ludwig, Arne , Dalén, Love , Hofreiter, Michael
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124482 , vital:35616 , https://doi.org/10.1093/molbev/msy037
- Description: Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of < 10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa.We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started_1Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.
- Full Text:
Ties that bind: the ambiguous role played by social capital in black working class first-generation South African students’ negotiation of university life
- Vincent, Louise, Hlatshwayo, M
- Authors: Vincent, Louise , Hlatshwayo, M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141722 , vital:37999 , DOI: 10.20853/32-3-2538
- Description: In this article we examine the ambiguous role that social capital plays in first generation Black working class South African students’ negotiation of entry into an elite higher education institutional environment. First generation student experiences have a particular relevance in South Africa where student enrolment increased by 193 000 between 1993 and 2004, with many of the new entrants first-generation students. South African research on first-generation working class Black students has focused on the low proportion of these students who reach university at all and among those who do enter university, the significant number who perform poorly or drop out before completing their degrees. The role played by social capital (social networks, close friends, associations, clubs and other affiliations) in these students’ experiences of negotiating their entry into university has been little explored.
- Full Text:
- Authors: Vincent, Louise , Hlatshwayo, M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141722 , vital:37999 , DOI: 10.20853/32-3-2538
- Description: In this article we examine the ambiguous role that social capital plays in first generation Black working class South African students’ negotiation of entry into an elite higher education institutional environment. First generation student experiences have a particular relevance in South Africa where student enrolment increased by 193 000 between 1993 and 2004, with many of the new entrants first-generation students. South African research on first-generation working class Black students has focused on the low proportion of these students who reach university at all and among those who do enter university, the significant number who perform poorly or drop out before completing their degrees. The role played by social capital (social networks, close friends, associations, clubs and other affiliations) in these students’ experiences of negotiating their entry into university has been little explored.
- Full Text:
“The scales were peeled from my eyes”: South African academics coming to consciousness to become agents of change
- Vincent, Louise, Idahosa, Grace Ese-osa
- Authors: Vincent, Louise , Idahosa, Grace Ese-osa
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141759 , vital:38002 , DOI: 10.18848/2327-0055/cgp/v15i04/13-28
- Description: For postcolonial societies, addressing the impact of the previous oppressive system in a bid to attain equity and social justice necessitates transformation in various spheres and sectors of society. As cradles of learning, research, and knowledge development, higher education institutions are one such sphere with a particular duty to contribute to, and embody, social transformation. However, almost 25 years after the country’s first democratic elections, the institutional cultures and structures of many South African universities still bear the imprimatur of past inequities. Existing research suggests that the success of transformation policies is influenced by the extent to which individual staff members exercise agency to effect transformative practices. But what determines whether an individual becomes an agent of change? This paper draws on the experiences of ten academic staff members who have taken actions that can be said to have contributed to shifting in important ways relations and/or practices at one university in South Africa. It adopts a hermeneutic phenomenological lens to understand the lived experiences of participants of having agency and undertaking transformative actions.
- Full Text:
- Authors: Vincent, Louise , Idahosa, Grace Ese-osa
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141759 , vital:38002 , DOI: 10.18848/2327-0055/cgp/v15i04/13-28
- Description: For postcolonial societies, addressing the impact of the previous oppressive system in a bid to attain equity and social justice necessitates transformation in various spheres and sectors of society. As cradles of learning, research, and knowledge development, higher education institutions are one such sphere with a particular duty to contribute to, and embody, social transformation. However, almost 25 years after the country’s first democratic elections, the institutional cultures and structures of many South African universities still bear the imprimatur of past inequities. Existing research suggests that the success of transformation policies is influenced by the extent to which individual staff members exercise agency to effect transformative practices. But what determines whether an individual becomes an agent of change? This paper draws on the experiences of ten academic staff members who have taken actions that can be said to have contributed to shifting in important ways relations and/or practices at one university in South Africa. It adopts a hermeneutic phenomenological lens to understand the lived experiences of participants of having agency and undertaking transformative actions.
- Full Text:
NMR structural elucidation of channaine, an unusual alkaloid from Sceletium tortuosum:
- Veale, Clinton G L, Chen, Weiyang, Chaudhary, Sushil, Kituyi, Sarah N, Isaacs, Michelle, Hoppe, Heinrich C, Edkins, Adrienne L, Combrinck, Sandra, Mehari, Bewketu, Viljoen, Alvaro
- Authors: Veale, Clinton G L , Chen, Weiyang , Chaudhary, Sushil , Kituyi, Sarah N , Isaacs, Michelle , Hoppe, Heinrich C , Edkins, Adrienne L , Combrinck, Sandra , Mehari, Bewketu , Viljoen, Alvaro
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164345 , vital:41110 , DOI: 10.1016/j.phytol.2017.11.018
- Description: Chemical interrogation of the Sceletium genus and Amaryllidaceae family of plants has yielded a diverse array of aryl-hydroindole containing alkaloids. Included in this class is channaine, which was tentatively identified, without comprehensive structural elucidation from Sceletium tortuosum in 1957. Following its isolation from S. strictum, the structure of channaine was eventually resolved by X-ray crystallographic analysis, which revealed an unusual cage-like ring structure at the interface of two aryl-hydroindole subunits. However, since this report in 1978, channaine has not re-appeared in the literature. In this letter, the full NMR characterisation of channaine, isolated from S. tortuosum collected from St Helena in the Western Cape Province of South Africa, is reported for the first time.
- Full Text:
- Authors: Veale, Clinton G L , Chen, Weiyang , Chaudhary, Sushil , Kituyi, Sarah N , Isaacs, Michelle , Hoppe, Heinrich C , Edkins, Adrienne L , Combrinck, Sandra , Mehari, Bewketu , Viljoen, Alvaro
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164345 , vital:41110 , DOI: 10.1016/j.phytol.2017.11.018
- Description: Chemical interrogation of the Sceletium genus and Amaryllidaceae family of plants has yielded a diverse array of aryl-hydroindole containing alkaloids. Included in this class is channaine, which was tentatively identified, without comprehensive structural elucidation from Sceletium tortuosum in 1957. Following its isolation from S. strictum, the structure of channaine was eventually resolved by X-ray crystallographic analysis, which revealed an unusual cage-like ring structure at the interface of two aryl-hydroindole subunits. However, since this report in 1978, channaine has not re-appeared in the literature. In this letter, the full NMR characterisation of channaine, isolated from S. tortuosum collected from St Helena in the Western Cape Province of South Africa, is reported for the first time.
- Full Text:
Major security incidents since 2014: an African perspective
- Van Heerden, Renier, Von Solms, Sune, Vorster, Johannes
- Authors: Van Heerden, Renier , Von Solms, Sune , Vorster, Johannes
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68291 , vital:29234 , https://ieeexplore.ieee.org/abstract/document/8417326/
- Description: Publisher version , The integration of technology in the modern society provides many benefits, but with increased connectivity comes increased risk where governments, businesses and individuals are vulnerable to a variety of cyber-attacks. Many of the large information security attacks of the last decade can be seen as an attack on 'foreign” systems or individuals when viewed from an African perspective, with no direct impact on an individual in Africa. However, information security experts in Africa states that although some of these attacks might not have had a direct impact of the African individual, but never the less should not be ignored as it does indirectly influence the African individual. The experts state that even if the individuals or businesses are not directly influenced by an attack, it should not be ignored as similar attacks might influence them in the future. They emphasise that these attacks should improve their cybersecurity awareness and behaviour, in order to prevent similar attacks from impacting them.
- Full Text: false
- Authors: Van Heerden, Renier , Von Solms, Sune , Vorster, Johannes
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68291 , vital:29234 , https://ieeexplore.ieee.org/abstract/document/8417326/
- Description: Publisher version , The integration of technology in the modern society provides many benefits, but with increased connectivity comes increased risk where governments, businesses and individuals are vulnerable to a variety of cyber-attacks. Many of the large information security attacks of the last decade can be seen as an attack on 'foreign” systems or individuals when viewed from an African perspective, with no direct impact on an individual in Africa. However, information security experts in Africa states that although some of these attacks might not have had a direct impact of the African individual, but never the less should not be ignored as it does indirectly influence the African individual. The experts state that even if the individuals or businesses are not directly influenced by an attack, it should not be ignored as similar attacks might influence them in the future. They emphasise that these attacks should improve their cybersecurity awareness and behaviour, in order to prevent similar attacks from impacting them.
- Full Text: false
The generation and characterisation of neutralising antibodies against the Theiler’s murine encephalomyelitis virus (TMEV) GDVII capsid reveals the potential binding site of the host cell co-receptor, heparan sulfate:
- Upfold, Nicole, Ross, Caroline J, Tastan Bishop, Özlem, Luke, Garry A, Knox, Caroline M
- Authors: Upfold, Nicole , Ross, Caroline J , Tastan Bishop, Özlem , Luke, Garry A , Knox, Caroline M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148181 , vital:38717 , DOI: 10.1016/j.virusres.2017.11.017
- Description: The early stages of picornavirus capsid assembly and the host factors involved are poorly understood. Since the localisation of viral proteins in infected cells can provide information on their function, antibodies against purified Theiler's murine encephalomyelitis virus (TMEV) GDVII capsids were generated by immunisation of rabbits. The resultant anti-TMEV capsid antibodies recognised a C-terminal region of VP1 but not VP2 or VP3 by Western analysis. Examination of the sites of TMEV capsid assembly by indirect immunofluorescence and confocal microscopy showed that at 5 h post infection, capsid signal was diffusely cytoplasmic with strong perinuclear staining and moved into large punctate structures from 6 to 8 h post infection.
- Full Text:
- Authors: Upfold, Nicole , Ross, Caroline J , Tastan Bishop, Özlem , Luke, Garry A , Knox, Caroline M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148181 , vital:38717 , DOI: 10.1016/j.virusres.2017.11.017
- Description: The early stages of picornavirus capsid assembly and the host factors involved are poorly understood. Since the localisation of viral proteins in infected cells can provide information on their function, antibodies against purified Theiler's murine encephalomyelitis virus (TMEV) GDVII capsids were generated by immunisation of rabbits. The resultant anti-TMEV capsid antibodies recognised a C-terminal region of VP1 but not VP2 or VP3 by Western analysis. Examination of the sites of TMEV capsid assembly by indirect immunofluorescence and confocal microscopy showed that at 5 h post infection, capsid signal was diffusely cytoplasmic with strong perinuclear staining and moved into large punctate structures from 6 to 8 h post infection.
- Full Text:
"Our Voice of Africa": it is less than our voice without a woman's voice
- Authors: Tumusiime, Amanda
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145687 , vital:38458 , https://0-muse.jhu.edu.wam.seals.ac.za/article/695397/pdf
- Description: In her poem Our Voice (Chipasula and Chipasula 1995: 166–67) Noémia de Sousa (1926–2002) speaks about “our voice of Africa” as that voice that is liberative; that voice which opens “up new ways” and “lights up remorse … and burns glimmers of hope in the dark souls of desperate people” who cry out for emancipation from “slavery.” That voice which creates new possibilities by awakening a “cyclone of knowledge.” That voice which can persistently and effectively represent the aspirations of “millions of voices that shout, shout and shout!” for freedom and self-actualization.
- Full Text:
- Authors: Tumusiime, Amanda
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145687 , vital:38458 , https://0-muse.jhu.edu.wam.seals.ac.za/article/695397/pdf
- Description: In her poem Our Voice (Chipasula and Chipasula 1995: 166–67) Noémia de Sousa (1926–2002) speaks about “our voice of Africa” as that voice that is liberative; that voice which opens “up new ways” and “lights up remorse … and burns glimmers of hope in the dark souls of desperate people” who cry out for emancipation from “slavery.” That voice which creates new possibilities by awakening a “cyclone of knowledge.” That voice which can persistently and effectively represent the aspirations of “millions of voices that shout, shout and shout!” for freedom and self-actualization.
- Full Text:
Traditional, indigenous, or leafy?: A definition, typology, and way forward for African vegetables
- Towns, Alexander M, Shackleton, Charlie M
- Authors: Towns, Alexander M , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179791 , vital:43189 , xlink:href="https://doi.org/10.1007/s12231-019-09448-1"
- Description: Around 1000 different species of indigenous and naturalized vegetables contribute to the dietary diversity, food security, and livelihoods of populations across sub-Saharan Africa. These foods are also a part of alimentary traditions and cultural identity, but have suffered as neglected and underutilized species. Slowly, African vegetables are beginning to gain the attention of universities, research centers, and development organizations; however, the terminology used to describe the plants is characterized by widespread disagreement and redundancy. Key terms and concepts used such as indigenous, traditional, and leafy have different interpretations and are used interchangeably, creating a challenge for coordinated research and extension efforts. Through analyzing a broad set of peer-reviewed journal articles on African vegetables, we (1) provide an overview with respect to definitions and terms used in the literature, (2) propose a definition of the term traditional African vegetable (TAV), (3) create a typology to classify the main groups of African vegetables, and (4) identify trends and gaps for further research and extension on African vegetables. We propose not only a unified way to categorize these vegetables but also a way for a more holistic and interdisciplinary systems approach to further the research agenda and practical management of African vegetables.
- Full Text:
- Authors: Towns, Alexander M , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179791 , vital:43189 , xlink:href="https://doi.org/10.1007/s12231-019-09448-1"
- Description: Around 1000 different species of indigenous and naturalized vegetables contribute to the dietary diversity, food security, and livelihoods of populations across sub-Saharan Africa. These foods are also a part of alimentary traditions and cultural identity, but have suffered as neglected and underutilized species. Slowly, African vegetables are beginning to gain the attention of universities, research centers, and development organizations; however, the terminology used to describe the plants is characterized by widespread disagreement and redundancy. Key terms and concepts used such as indigenous, traditional, and leafy have different interpretations and are used interchangeably, creating a challenge for coordinated research and extension efforts. Through analyzing a broad set of peer-reviewed journal articles on African vegetables, we (1) provide an overview with respect to definitions and terms used in the literature, (2) propose a definition of the term traditional African vegetable (TAV), (3) create a typology to classify the main groups of African vegetables, and (4) identify trends and gaps for further research and extension on African vegetables. We propose not only a unified way to categorize these vegetables but also a way for a more holistic and interdisciplinary systems approach to further the research agenda and practical management of African vegetables.
- Full Text:
Trophic preference of southern African dung beetles (Scarabaeoidea: Scarabaeinae and Aphodiinae) and its influence on bioindicator surveys:
- Tocco, Claudia, Balmer, Jonathan P, Villet, Martin H
- Authors: Tocco, Claudia , Balmer, Jonathan P , Villet, Martin H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140796 , vital:37919 , DOI: 10.1111/aje.12523
- Description: Environmental assessments using bioindicators gain value if the interpretability of the indicator used is high, and it is clear how survey methods affect survey comparisons. Because dung beetles are favoured as bioindicators, we studied the trophic preference of a southern African beetle community and its potential effects on surveys of beetle diversity using manual sampling of droppings and pitfall traps baited with carnivore, ruminant or nonruminant dung. Manual sampling showed no significant differences between dung types in either dung beetles abundance or species richness. Generalised linear mixed models of total and endocoprid abundances, species richness and Real Shannon index of trap samples showed higher dung beetle diversity associated with ruminant than with nonruminant dung, which in turn was significantly preferred over carnivore dung.
- Full Text:
- Authors: Tocco, Claudia , Balmer, Jonathan P , Villet, Martin H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140796 , vital:37919 , DOI: 10.1111/aje.12523
- Description: Environmental assessments using bioindicators gain value if the interpretability of the indicator used is high, and it is clear how survey methods affect survey comparisons. Because dung beetles are favoured as bioindicators, we studied the trophic preference of a southern African beetle community and its potential effects on surveys of beetle diversity using manual sampling of droppings and pitfall traps baited with carnivore, ruminant or nonruminant dung. Manual sampling showed no significant differences between dung types in either dung beetles abundance or species richness. Generalised linear mixed models of total and endocoprid abundances, species richness and Real Shannon index of trap samples showed higher dung beetle diversity associated with ruminant than with nonruminant dung, which in turn was significantly preferred over carnivore dung.
- Full Text:
“I slipped into the pages of a book”: intertextuality and literary solidarities in South African writing about London
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68402 , vital:29252 , https://doi.org/10.1080/17533171.2018.1482882
- Description: Publisher version , In this article, I argue that London plays a dual role in South African writing, as a “real” city at a particular moment in history, and as a textual, imaginative space. For many South African writers, London comes to stand metonymically for English culture and literature even if their attitude toward Englishness and Empire may be one of ambivalent critique. The intertexts invoked in South African representations of London forge literary solidarities, and foreground belated postcolonial engagements with modernity that are significantly displaced from the “margin” to the “center” of modernism (and Empire) itself.
- Full Text: false
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68402 , vital:29252 , https://doi.org/10.1080/17533171.2018.1482882
- Description: Publisher version , In this article, I argue that London plays a dual role in South African writing, as a “real” city at a particular moment in history, and as a textual, imaginative space. For many South African writers, London comes to stand metonymically for English culture and literature even if their attitude toward Englishness and Empire may be one of ambivalent critique. The intertexts invoked in South African representations of London forge literary solidarities, and foreground belated postcolonial engagements with modernity that are significantly displaced from the “margin” to the “center” of modernism (and Empire) itself.
- Full Text: false
“Telling freedom” or “telling the spades back home how to behave”? re-examining Peter Abrahams’s writing in London
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68412 , vital:29253 , https://dx.doi.org/10.4314/eia.v45i1.3
- Description: Publisher version , This article considers the notable dearth of recent scholarship on Peter Abrahams’s writing in the context of his exile and his complex, shifting ideological self-positioning throughout his career. To attempt to address this lacuna in South African literary criticism, and to partially explain why Abrahams has been under-researched, I look at key moments during his early career, including the publication of Dark Testament (1942), Song of the City (1945) and Return to Goli (1953). By focusing on texts by Abrahams that were published during his time in London, I also wish to address the significance of the city in the history of South African literature, and in African anti-colonial and anti-racist thinking more broadly.
- Full Text: false
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68412 , vital:29253 , https://dx.doi.org/10.4314/eia.v45i1.3
- Description: Publisher version , This article considers the notable dearth of recent scholarship on Peter Abrahams’s writing in the context of his exile and his complex, shifting ideological self-positioning throughout his career. To attempt to address this lacuna in South African literary criticism, and to partially explain why Abrahams has been under-researched, I look at key moments during his early career, including the publication of Dark Testament (1942), Song of the City (1945) and Return to Goli (1953). By focusing on texts by Abrahams that were published during his time in London, I also wish to address the significance of the city in the history of South African literature, and in African anti-colonial and anti-racist thinking more broadly.
- Full Text: false
The “Pleasure Streets” of exile: queer subjectivities and the body in Arthur Nortje’s London poems
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68432 , vital:29255 , https://doi.org/10.1080/02564718.2018.1447865
- Description: Publisher version , In this article, I aim to expand our understanding of Arthur Nortje as a poet of “exile” by exploring the dialectic between self-loathing and pleasure, as well as between engagement and isolation, which he portrays performatively through his London poetry. While critics have emphasised Nortje’s “marginality” or “liminality”, both as an “exile” and a “coloured” South African, I draw on the critical writing of Zoë Wicomb in order to extend readings of his poetry beyond this tragic paradigm. I furthermore take up Sarah Nuttall’s suggestion that Nortje’s London poetry describes a degree of immersion within the city and that this aspect of his work demands further study. After tracing Nortje’s playful use of literary influences and his reworking of the trope of flânerie, I provide a series of close readings of poems in which Nortje depicts an exploration of queer subjectivities, staged within the city. In his London poetry, Nortje subverts and eludes fixed racial, sexual, national and class identities. Nortje’s London poetry exemplifies how South African literature was developed in response to the alienating condition of exile, but also through engagement with the places where exile occurred.
- Full Text: false
- Authors: Thorpe, Andrea
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68432 , vital:29255 , https://doi.org/10.1080/02564718.2018.1447865
- Description: Publisher version , In this article, I aim to expand our understanding of Arthur Nortje as a poet of “exile” by exploring the dialectic between self-loathing and pleasure, as well as between engagement and isolation, which he portrays performatively through his London poetry. While critics have emphasised Nortje’s “marginality” or “liminality”, both as an “exile” and a “coloured” South African, I draw on the critical writing of Zoë Wicomb in order to extend readings of his poetry beyond this tragic paradigm. I furthermore take up Sarah Nuttall’s suggestion that Nortje’s London poetry describes a degree of immersion within the city and that this aspect of his work demands further study. After tracing Nortje’s playful use of literary influences and his reworking of the trope of flânerie, I provide a series of close readings of poems in which Nortje depicts an exploration of queer subjectivities, staged within the city. In his London poetry, Nortje subverts and eludes fixed racial, sexual, national and class identities. Nortje’s London poetry exemplifies how South African literature was developed in response to the alienating condition of exile, but also through engagement with the places where exile occurred.
- Full Text: false