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A Change Project story: learning and caring for South Africa’s rivers

- Chetty, Preven

  • Authors: Chetty, Preven
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/391060 , vital:68613 , xlink:href="https://eeasa.org.za/wp-content/uploads/2023/02/Final-EEASA-Bulletin-20212022-Final.pdf"
  • Description: Water quality and scarcity is a major concern in Southern Africa and globally especially as the threat of climate change looms even closer. The current drought in South Africa and worsening rainfall has exposed the brittle nature of this country’s resilience to water shortages. Compounded to this is the fact that most rivers in South Africa are not adequately cared for and are under tremendous strain. Everyone who depends on these rivers whether directly or indirectly will soon be entering a new era where water will no longer be a ubiquitous commodity.
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A critical realist (re-)envisaging of emancipatory research, science and practice

- Schudel, Ingrid J

  • Authors: Schudel, Ingrid J
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/482560 , vital:78666 , https://doi.org/10.1080/14767430.2022.2151142
  • Description: In September 2021, Rhodes University’s Environmental Learning Research Centre, together with WITS’s Centre for Researching Education and Labour (REAL), hosted The 24th annual International Association of Critical Realism conference online. 110 researchers from 30 countries, representing 6 continents participated in the main conference and 57 researchers participated in the pre-conference workshop. Presentations showed the vast application of critical realism in fields such as development and tourism studies, environmental and sustainability sciences, economics, education, philosophy, psychology and sociology. They also showed how critical realism is being used in enriching research methodology as well as trans-disciplinary studies.
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A Decolonial perspective on online media discourses in the context of violence against people with disabilities in South Africa

- Dalvit, Lorenzo

  • Authors: Dalvit, Lorenzo
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/468140 , vital:77022 , DOI: 10.17231/comsoc.41(2022).3722
  • Description: As one of the most violent and unequal societies globally, South Africa is still profoundly shaped by a legacy of segregation and oppression. While race, gender and socio-economic status receive much attention, (dis)ability is an important yet often neglected dimension of inequality. In this article, I adopt a decolonial perspective in discussing online media articles about violence against people with disabilities. By focusing on stories related to issues that received extensive media coverage (e.g. mental health, police brutality and gender-based violence), I problematise the Eurocentric human-rights discourse informing public and scholarly discussions. I also explore the link between current understandings of (dis)ability and the legacy of a violent colonial and apartheid past. As a result of the intersectional nature of (dis)ability, many of the stories involve multiple layers of inequality and different forms of oppression. An explicit focus on extreme forms of institutional and physical violence, while restricting the scope of enquiry, brings the brutality of western modernity and its effects on the people affected into sharp focus. Legal recurse appears to lead to incomplete reparation at best while its failures perpetuate a cycle of marginalisation and oppression. Rather than problematising these structural failures as a result of western modernity and neoliberalism, the media inadvertently obfuscates such links by performing its normative, that is, by identifying and exposing individual culprits or by blaming contextual factors.
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A laminated, emergentist view of skills ecosystems

- Ramsarup, Presha, Lotz-Sisitka, Heila, McGrath, Simon

  • Authors: Ramsarup, Presha , Lotz-Sisitka, Heila , McGrath, Simon
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/370074 , vital:66295 , xlink:href="https://doi.org/10.1080/14767430.2022.2145768"
  • Description: In this paper we present a model of vocational education and training (VET) that can be used to guide decisions relating to VET in Africa today. This model takes the critique of the neoclassical, neoliberal model of VET as its starting point. Guided by Bhaskar's Critical Naturalism, we use immanent critique to consider the adequacy of proposed alternatives to the neoclassical approach, such as: the heterodox approach, which foregrounds explanations based on human capital and political economy; and Hodgson and Spours' social ecosystem model, which addresses some of the limitations of the heterodox account by including, social and ecosystem elements. Finally, we offer a version of the social ecosystem model that, according to our analysis, explains more of the empirical evidence than previous models. Our version of the social ecosystem model differs from earlier versions in terms of its explicit reference to the critical realist ideas of position- practices and emergence.
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A multiscale ONIOM study of the buckminsterfullerene (C60) Diels–Alder reaction: from model design to reaction path analysis

- Isamura, Bienfait K, Lobb, Kevin A

  • Authors: Isamura, Bienfait K , Lobb, Kevin A
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452517 , vital:75140 , xlink:href=" https://link.springer.com/article/10.1007/s00894-022-05319-0"
  • Description: The hybrid ONIOM (Our own N-layered Integrated molecular Orbital and molecular Mechanics) formalism is employed to investigate the Diels–Alder reaction of the buckminsterfullerene C60. Our computa-tions suggest that the ONIOM2(M06-2X/6-31G(d): SVWN/STO3G) mod-el, enclosing both the diene and the pyracyclene fragment of C60 in the higher-layer, provides a reasonable trade-of between accuracy and computational cost as it comes to predicting reaction energetics. Moreover, the frontier molecular orbital (FMO) theory and activation strain model (ASM) are jointly relied on to rationalize the efect of –OH and –CN substituents on the activation barrier of this reaction. Finally, reaction paths are scrutinized to get insight into the various forces un-derpinning the process of cycloadduct formation.
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A simple quinoline-thiophene Schiff base turn-off chemosensor for Hg2+ detection

- Musikavanhu, Brian, Muthusamy, Selvaraj, Zhu, Dongwei, Xue, Zhaoli, Yu, Qian, Chivumba, Choonzo N, Mack, John, Nyokong, Tebello, Wang, Shengjun, Zhao, Long

  • Authors: Musikavanhu, Brian , Muthusamy, Selvaraj , Zhu, Dongwei , Xue, Zhaoli , Yu, Qian , Chivumba, Choonzo N , Mack, John , Nyokong, Tebello , Wang, Shengjun , Zhao, Long
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/230362 , vital:49771 , xlink:href="https://doi.org/10.1016/j.saa.2021.120338"
  • Description: A new Schiff base probe (QT) consisting of 8-aminoquinoline (Q) and thiophene-2-carboxaldehyde (T) moieties has been synthesized. QT undergoes chelation-enhanced fluorescence quenching when exposed to Hg2+ due to coordination by the sulfur and nitrogen atoms of QT thus forming a facile “turn-off” sensor. The formation of the chelation complex was confirmed by UV–visible absorption and emission spectral measurements, 1H NMR titration and density functional theory calculations. These studies revealed that the probe exhibits high selectivity and sensitivity towards Hg2+ in the presence of other common metal ions. A low detection limit of 23.4 nM was determined and a Job plot confirmed a 2:1 stoichiometry between QT and Hg2+. The potential utility of QT as a sensor for Hg2+ ions in human HeLa cells was determined by confocal fluorescence microscopy, and its suitability for use in the field with environmental samples was tested with Whatman filter paper strips.
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A Sn (iv) porphyrin with mitochondria targeting properties for enhanced photodynamic activity against MCF-7 cells

- Babu, Balaji, Mack, John, Nyokong, Tebello

  • Authors: Babu, Balaji , Mack, John , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/230897 , vital:49829 , xlink:href="https://doi.org/10.1039/D2NJ00350C"
  • Description: Two readily synthesized Sn(IV) porphyrins (SnP, SnPH) have been prepared with and without the cationic triphenylphosphonium moiety (TPP+), which have high singlet oxygen quantum yields (ca. 0.72) and long triplet state lifetimes. The Sn(IV) porphyrin with a TPP+ moiety (SnPH) exhibits favorable photodynamic activity against MCF-7 cells with IC50 values of 2.9 μM. SnPH exhibits higher cellular uptake than SnP in MCF-7 cells. A Rhodamine 123 (Rh123) assay showed that SnPH targets mitochondria and induces apoptosis by generating reactive oxygen species. The results demonstrate that this structural modification strategy merits further in-depth study.
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African birds as army ant followers

- Craig, Adrian J F K

  • Authors: Craig, Adrian J F K
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448772 , vital:74759 , https://doi.org/10.1007/s10336-022-01987-0
  • Description: Ant-following birds have been studied extensively in the Neotropics, but much less information is currently available for the Afrotropics. There are published records of 168 African bird species from 37 families foraging in association with driver ants (Dorylus, sub-family Dorylinae). However, of 52 bird species assessed as regular ant-followers, 38 belong to three families, which are disproportionately represented compared to other large Afrotropical bird families: Muscicapidae (18 spp.), Pycnonotidae (13 spp.) and Turdidae (7 spp.). The extent to which these birds are dependent on ants through their annual cycle is not known. African driver ants forage primarily under shaded, humid conditions by day, and may spend a month or longer underground. Conservation assessments of African forest habitats suggest that both driver ants and ant-following birds may be especially sensitive to the loss of forest cover.
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Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost

- Foster, Ryan M, Childs, Amber-Robyn, Mann, Bruce Q, Potts, Warren M

  • Authors: Foster, Ryan M , Childs, Amber-Robyn , Mann, Bruce Q , Potts, Warren M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/443128 , vital:74080 , https://doi.org/10.1080/15627020.2022.2035254
  • Description: The South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern and eastern coasts of South Africa. Monthly biological samples were collected through research spearfishing (n = 170) and augmented by recreational spearfishers’ catches (n = 135). The results indicated that the O. conwayi population sex ratio was skewed towards males (1M:0.6F). The length- and age-frequency distributions were similar between sexes. Oplegnathus conwayi is a relatively slow-growing species, with a maximum-recorded age of 27 years. No significant differences were observed between male and female growth, with the overall population growth curve being best described as L(t) = 697.15(1 − e−0.06(t−6.30)). The slow growth observed in this species is characteristic of a species that is vulnerable to overexploitation, and accordingly a precautionary approach to future management is recommended.
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Agents of Change: Journalism Education as Critical Service-Learning

- Du Toit, Jeanne E

  • Authors: Du Toit, Jeanne E
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/468250 , vital:77036 , ISBN 978-1-80071-188-4 , https://www.emerald.com/insight/content/doi/10.1108/s2055-364120220000046004/full/html
  • Description: The chapter deals with a service-learning course based in the School of Journalism and Media Studies at Rhodes University in South Africa. It provides a backdrop for the case study, describing the context in which the course is based and kind of intervention that it aims to make into this context. It then maps out the theoretical framework that informs the course, explaining how this is informed by the available spectrum of approaches to service-learning. It demonstrates how the course draws on the concept of a ‘communicative ecology’, to provide itself with a language in which to reflect on the social significance of communication. The chapter then reviews the first cycle of the course which took place in 2019, drawing on insights from participants (teachers, students and community partners). It deals, firstly, with the participants’ engagement with the concept of service-learning. Secondly, it describes their experience of service-learning as a communicative process. Finally, it describes their evaluation of this process as an intervention into the local communicative ecology. It is demonstrated that service-learning enables the school to respond strategically to the need for innovative communicative practices both in their immediate environment and within the broader South African context.
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Alignment, scaling and resourcing of citizen-based water quality monitoring Initiatives

- Lotz-Sisitka, Heila, Ward, Mike, Taylor, Jim, Vallabh, Priya, Madiba, Morakane, Graham, P Mark, Louw, Adrienne J, Brownell, Faye

  • Authors: Lotz-Sisitka, Heila , Ward, Mike , Taylor, Jim , Vallabh, Priya , Madiba, Morakane , Graham, P Mark , Louw, Adrienne J , Brownell, Faye
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , report
  • Identifier: http://hdl.handle.net/10962/435729 , vital:73195 , ISBN 978-0-6392-0344-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2854%20final.pdf
  • Description: This action-oriented research project seeks to address the policy-practice contradiction that exists between commit-ments and requirements for citizen engagement and in-volvement in Integrated Water Quality Management (IWQM) and a lack of sustainable support for scaling high quality Citi-zen-based Water Quality Monitoring (CBWQM) practices that exist in South Africa.
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AMADAR: a python-based package for large scale prediction of Diels–Alder transition state geometries and IRC path analysis

- Isamura, Bienfait K, Lobb, Kevin A

  • Authors: Isamura, Bienfait K , Lobb, Kevin A
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/453143 , vital:75226 , xlink:href="https://link.springer.com/article/10.1186/s13321-022-00618-3"
  • Description: Predicting transition state geometries is one of the most challenging tasks in computational chemistry, which often requires expert-based knowledge and permanent human intervention. This short communication reports technical details and preliminary results of a python-based tool (AMADAR) designed to generate any Diels–Alder (DA) transition state geometry (TS) and analyze determined IRC paths in a (quasi-)automated fashion, given the product SMILES. Two modules of the package are devoted to performing, from IRC paths, reaction force analyses (RFA) and atomic (fragment) decompositions of the reaction force F and reaction force constant κ. The performance of the protocol has been assessed using a dataset of 2000 DA cycloadducts retrieved from the ZINC database. The sequential location of the corresponding TSs was achieved with a success rate of 95%. RFA plots confrmed the reaction force constant κ to be a good indicator of the (non)synchronicity of the associated DA reactions. Moreover, the atomic decomposition of κ allows for the rationalization of the (a)synchronicity of each DA reaction in terms of contributions stemming from pairs of interacting atoms. The source code of the AMADAR tool is available on GitHub [CMCDD/AMADAR(github. com)] and can be used directly with minor customizations, mostly regarding the local working environment of the user.
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AMANZI For Food

- Lotz-Sisitka, Heila, Pesanayi, Tichaona, Sisitka, Lawrence, Metelerkamp, Luke, Chakona, Gamuchirai, Van Staden, Wilma, Durr, Sarah, Matiwane, Mandelive, Maqwelane, Lwanda, Conde-Aller, Laura, Shawarire, Patience

An assessment of the medium-term reproductive success of an extralimital white rhinoceros population

- Truter, Anja, Mgqatsa, Nokubonga, Parker, Daniel M

  • Authors: Truter, Anja , Mgqatsa, Nokubonga , Parker, Daniel M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/462570 , vital:76315 , xlink:href="https://doi.org/10.1080/15627020.2022.2132120"
  • Description: The white rhinoceros (Ceratotherium simum) is threatened primarily due to continued poaching for its horns. In South Africa, partly to promote the conservation of the species, white rhinos have been introduced into areas where they did not occur historically (i.e. where they are considered extralimital). Few studies have investigated the conservation contribution of extralimital white rhinos to the overall national herd. We aimed to determine whether the white rhinos introduced to a private game reserve in the Eastern Cape province have been successful from a reproductive perspective. We calculated inter-calving intervals, age at first calving, sex ratios of calves, and recruitment rates for white rhinos at a single site between 1992 and 2019. The average net annual population growth rate for the population was 10%, which is higher than the recommended 5% by the Biodiversity Management Plan for white rhinos. Trends in density-dependent parameters such as age at first calving and inter-calving intervals also indicated that the study population is still well below the density at which ecological constraints may manifest. We demonstrate that an extralimital white rhino population in the Eastern Cape can be successful from a reproductive perspective.
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An evaluation of hand-based algorithms for sign language recognition

- Marais, Marc, Brown, Dane L, Connan, James, Boby, Alden

  • Authors: Marais, Marc , Brown, Dane L , Connan, James , Boby, Alden
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/465124 , vital:76575 , xlink:href="https://ieeexplore.ieee.org/abstract/document/9856310"
  • Description: Sign language recognition is an evolving research field in computer vision, assisting communication between hearing disabled people. Hand gestures contain the majority of the information when signing. Focusing on feature extraction methods to obtain the information stored in hand data in sign language recognition may improve classification accuracy. Pose estimation is a popular method for extracting body and hand landmarks. We implement and compare different feature extraction and segmentation algorithms, focusing on the hands only on the LSA64 dataset. To extract hand landmark coordinates, MediaPipe Holistic is implemented on the sign images. Classification is performed using poplar CNN architectures, namely ResNet and a Pruned VGG network. A separate 1D-CNN is utilised to classify hand landmark coordinates extracted using MediaPipe. The best performance was achieved on the unprocessed raw images using a Pruned VGG network with an accuracy of 95.50%. However, the more computationally efficient model using the hand landmark data and 1D-CNN for classification achieved an accuracy of 94.91%.
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Analysing the Impact of Extended Curriculum Programmes: Implications for Theory, Design and Practice

- Boughey, Chrissie

  • Authors: Boughey, Chrissie
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/434453 , vital:73063 , ISBN 9781991201737 , https://africansunmedia.store.it.si/ZA/book/extended-curriculum-programmes-challenges-and-opportunities/1199327
  • Description: The introduction of ECPs in South African Universities is seen by many as South Africa’s key strategy for addressing the problem of poor patterns of student success and has its basis on the uncontested acceptance that an extended study duration may be necessary to bring some categories of learners to a level of parity with the readiness expectations of their course of study. Even so, this transformative strategic imperative has been plagued by a range of challenges that include poor systems readiness; poor selection mechanisms in the identification of ECP students; poor numeracy and literacy amongst students, and indifferent teacher involvement in ECPs. This volume offers a rare insight into many of the above-recognised challenges and in so doing provides critical matter for thought for educators within the higher education sector.
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Application of gold and palladium nanoparticles supported on polymelamine microspheres in the oxidation of 1-phenylethanol and some other phenyl substituted alcohols

- Storm, Ené, Maggott, Emile D, Mashazi, Philani N, Nyokong, Tebello, Malgas-Enus, Rehana, Mapolie, Selwyn F

  • Authors: Storm, Ené , Maggott, Emile D , Mashazi, Philani N , Nyokong, Tebello , Malgas-Enus, Rehana , Mapolie, Selwyn F
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/299824 , vital:57858 , xlink:href="https://doi.org/10.1016/j.mcat.2022.112456"
  • Description: Melamine formaldehyde and melamine resorcinol formaldehyde microspheres were decorated with Au and Pd nanoparticles and applied as heterogeneous catalysts in the oxidation of 1-phenylethanol. The catalysts showed similar activities irrespective of the support employed. Moderate conversion activities of 48–50% were achieved when using acetonitrile as solvent; however, when employing water as solvent, the supported catalysts formed a three-phase, emulsion system which facilitated the catalytic conversion of 1-phenylethanol to acetophenone at much higher conversions of around 83%. The oxidant, TBHP, decomposed rapidly in acetonitrile, whilst it remained stable in aqueous solution, leading to the enhanced activities observed when using water as solvent. These systems also proved to be recyclable for up to five cycles, with only slight loss of activity observed; this can be attributed to the physical loss of catalyst during the workup procedure conducted between each cycle.
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Aptamer versus antibody as probes for the impedimetric biosensor for human epidermal growth factor receptor

- Centane, Sixolile, Nyokong, Tebello

  • Authors: Centane, Sixolile , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229884 , vital:49720 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2022.111764"
  • Description: In the present work, the performance of aptamer and antibody bioreceptors for the detection of the human epidermal growth factor receptor (HER2) cancer biomarker on a glassy carbon electrode is reported. The carboxylic acid group rich graphene quantum dots (GQDs) modified with gold nanoparticles and a porphyrin binuclear framework (CoP-BNF) were used to modify the glassy carbon electrode. The aptamer and antibody were both amine functionalized and attached to GQDs and CoP-BNF through an amide bond. The designed immunosensors and aptasensors in this work were characterized using electrochemical impedance spectroscopy. The aptasensors, compared to the immunosensors gave better limit of detection values. The aptasensor outperforms the immunosensor in terms of its reusability and storability, while the immunosensor could not be regenerated for subsequent experiments. The potential applicability of all sensors in this work was also investigated, by detection of HER2 in spiked human serum with acceptable results.
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Assessing climate risk to support urban forests in a changing climate

- Esperon-Rodriguez, Manuel, Rymer, Paul D, Power, Sally A, Barton, David N, Cariñanos, Paloma, Dobbs, Cynnamon, Eleuterio, Ana A, Escobedo, Francisco J, Hauer, Richard, Hermy, Martin, Jahani, Ali, Onyekwelu, Jonathan C, Östberg, Johan, Pataki, Diane, Randrup, Thomas B, Rasmussen, Tørres, Roman, Lara A, Russo, Alessio, Shackleton, Charlie M, Solfjeld, Ingjerd, Van Doorn, Natalie S, Wells, Matthew J, Wiström, Björn, Yan, Pengbo, Yang, Jun, Tjoelker, Mark G

Assessing the electrocatalytic activity of a localized push-pull system in cobalt phthalocyanine/graphene quantum dot hybrids

- Nkhahle, Reitumetse, Nyokong, Tebello

  • Authors: Nkhahle, Reitumetse , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229909 , vital:49722 , xlink:href="https://doi.org/10.1016/j.matchemphys.2022.125842"
  • Description: In this study, two cobalt phthalocyanines (asymmetric complex 1) and symmetric (complex 2) were synthesized and conjugated to nitrogen-doped graphene quantum dots (NGQDs) through covalent and non-covalent means to create Co phthalocyanine (CoPc)-NGQDs hybrid systems. The CoPcs and conjugates were applied as electrode modifiers on a glassy carbon electrode in the electrochemical sensing of nitrite. Of the CoPcs alone, complex 1 performed better than complex 2 regarding the limits of detection (LoD) recorded (5.74 μM for 1 and 15.1 μM for 2). Regarding the conjugates/nanocomposites, the π-π stacked conjugate derived from complex 2 (2πNGQDs) demonstrated highly favourable electrochemical potential with an LoD value of 0.70 μM. The nanocomposites fashioned from complex 1 were marred by a reduced loading which rendered the conjugates poor electrochemical sensors. These observations however do not disqualify GQDs as complementary nanomaterials to phthalocyanines but rather shed light on seeking alternative routes to increasing the Pc loading in conjugates (more so in π-π stacked conjugates).
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