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Inhibiting human dipeptidyl peptidase IV using cannabinoids and Leonotis leonurus extracts as a potential therapy for the management of diabetes

  • Authors: Mkabayi, Lithalethu , Viljoen, Zenobia , Lobb, Kevin A , Pletschke, Brett I , Frost, Carminita L
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452745 , vital:75167 , xlink:href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1773924"
  • Description: Diabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM.
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  • Date Issued: 2023

International agreement for the use and exchange of classical biological control genetic resources: a practical proposal

  • Authors: Mason, Peter G , Mc Kay, Fernando , Silvestri, Luciano C , Hill, Martin P , Weyl, Philip S R , Hinz, Hariet L , Brodeur, Jacques , Vitorino, Marcello Diniz , Barratt, Barbara I P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/418025 , vital:71502 , xlink:href="https://doi.org/10.1007/s10526-023-10177-7"
  • Description: The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.
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  • Date Issued: 2023

Introducing VET Africa 4.0

  • Authors: Lotz-Sisitka, Heila , McGrath, Simon
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/434930 , vital:73117 , ISBN 978-1529224634 , https://bristoluniversitypress.co.uk/transitioning-vocational-education-and-training-in-africa
  • Description: This book is about vocational education and training (VET). It is concerned with how the current policy and practice orthodoxy is not working despite the efforts of educators and learners. It is driven by a realization that the futures for which VET is intended to prepare people are ever more precarious at the individual, societal and planetary levels. And it is motivated by a sense that while better futures are possible, VET is poorly positioned to respond to the new skilling needs these will require.
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  • Date Issued: 2023

Invasion of rocky shores by a mytilid mussel reveals an abundant‐centre distribution coupled with moderate increases in densities at its absolute range limits

  • Authors: Ma, Kevin C K , Pulfrich, Andrea , Froneman, P William , McQuaid, Christopher D
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/479253 , vital:78278 , https://doi.org/10.1111/aec.13260
  • Description: Semimytilus patagonicus is an invasive mussel on the coast of southern Africa and has extended its range in recent years. We asked whether its distribution and abundance are consistent with the abundant‐centre hypothesis (ACH). Marginal populations were located by monitoring 33 rocky shore sites in South Africa and southern Namibia in 2021. This revealed no changes to its distributional limits since 2020. At nine of these sites, population demography was measured to allow a comparison of their densities and size structure. Four were central populations on the west coast of South Africa (including the site where the species was first detected in 2009). Four were marginal populations in South Africa: two towards the cold range edge in the north and two towards the warm range edge to the south. The ninth population was in southern Namibia, representing a recent invasion event first detected in 2014. Across the species' South African range, the distribution of its abundance was generally consistent with the ACH, with the greatest abundance at its range centre and a gradual decrease towards the range edges.
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  • Date Issued: 2023

Investigation into response of wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa

  • Authors: Mzileni L S
  • Date: 2023
  • Subjects: Bonanza farms , Wheat , Drought - tolerant plants
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/27732 , vital:69397
  • Description: Wheat is generally one of the dominant crops globally, being mainly used for human food and livestock feed. Due to climate change, drought makes it challenging to produce enough wheat mostly under dryland production regions in South Africa. Drought stress has severely reduced wheat yield by up to 70 percent, and adversely compromised wheat grain quality. The adoption of drought-tolerant cultivars offers a sustainable and low-cost solution for increasing wheat yields and minimise importing the crop to meet national requirements. The main objective of this study was to investigate the response of different wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa. Forty diverse wheat genotypes were evaluated in this study. The specific objectives were: (i) to evaluate the response of wheat genotypes under optimum and drought-stressed field conditions; (ii) to determine the effect of terminal drought stress on wheat grain quality composition; and (iii) to identify appropriate drought tolerance indices that can be used as selection tools under field conditions. This study was conducted in the field using a 5x8 alpha lattice design, replicated twice under two water regimes (drought and optimum) over two consecutive winter seasons of 2020 and 2021 at two different sites namely University of Fort Hare Research Farm in Alice, and Zanyokwe irrigation scheme in Keiskamahoek. Drought stress was imposed from 50% flowering up to physiological maturity. Data on agro-physiological traits such as duration to heading (DTH); flowering (DTF); maturity (DTM); plant height (HT); spike length (SL); number of spikelets per spike (SPS); kernels per spike (KPS); and grain yield (GY (kg/ha)) was subjected to the analysis of variance using Genstat 18th edition. As the study took place over two sites, a combined ANOVA table revealed significant differences (p0.001) among genotypes, and all interactions such as genotype by water regime (GWR); genotype by seasons (GS) for all studied traits. Notably, the extent and severity of drought differed between geographical regions and between seasons. This necessitated the adoption of the additive main effect and multiplicative interaction analysis (AMMI) for the identification of stable genotypes under two different water regimes over two sites. Regarding grain yield, superior and/or stable genotypes included G5 (4334 kg/ha under optimum, and 2871kg/ha under drought), and G22 (4418 kg/ha under optimum, and 2624kg/ha under drought) at the UFH site. G21 (3194 kg/ha under optimum, and 2938 kg/ha under drought), G33 (2552kg/ha under optimum, and 3810 kg/ha under drought), and G35 (2688 kg/ha under optimum, and 3309 kg/ha under drought) at the ZAN site. Stable genotypes across sites included G21 and G33. There were generally weak correlations between agro-physiological traits and grain yield. From the experiment, grain quality traits such as fixed protein (PF); wet gluten (WG); hectolitre mass (HLM); and thousand kernel weight (TKW) were also examined. A combined ANOVA revealed significant differences (p0.001) among the interaction of genotypes by environments (GE) for all traits except PF. This implies that the performance of wheat genotypes across sites was also different, and therefore, necessitated separate analysis of variance for each site. Significant differences (p0.001) among genotypes (G), water regimes (WR), and the interaction of genotypes by water regime (GWR) were observed for all studied quality traits except PF in both sites. GWR showed no significant differences for TKW in the ZAN site. The stability in the performance of genotypes across water regimes was further determined. G38 was stable for wet gluten; G31 and G26 were stable for PF; G36 was stable for HLM; and G11, G15, and G29 were stable for TKW at the UFH site. G6 was stable for both WG and PF; G13 and G15 were stable for HLM; and G35, G21, and G40 were stable for TKW at the ZAN site. These results suggest that the quality of wheat grains was affected under drought stress conditions except PF. Average grain yield data under both stressed (Ys) and optimum (Yp) conditions was used to compute a number of different drought tolerance indices. These include mean productivity (MP); geometric mean productivity (GMP); harmonic mean (HM); Tolerance index (TOL), stress susceptible index (SSI), sensitive drought index (SDI), and stress tolerance index (STI). The aim was to identify appropriate drought tolerance indices that can be used as selection tools under drought stress. MP, GMP, and HM were the more appropriate indices as they had a strong and positive correlation with grain yield under both drought and optimum conditions. However, genotypes G5, G22, G8, and G21 were more tolerant and stable as they showed high mean values. Based on the results, G19, G16, G2, and G20 were more sensitive to drought as they showed low values of MP, GMP, and HM. Overall, genotype: G5, G21, G22, and G33 are recommended for production under drought and optimum conditions, as they showed stable performance across water regimes. Principal component analysis also revealed that MP, GMP, and HM were the only indices that had positive loadings into the first principal component. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
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  • Date Issued: 2023

Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control

  • Authors: Reid, Megan K , Paterson, Iain D , Coetzee, Julie A , Gettys, Lyn A , Hill, Martin P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/423540 , vital:72070 , xlink:href="https://doi.org/10.1016/j.biocontrol.2023.105291"
  • Description: Hybridisation of alien invasive plants complicates efforts to develop biological control, because variations in the genetic makeup of the target plant can impact the survival of host specific agents that have evolved adaptations specific to the original host. To maximise the likelihood of success in a biological control program, potential agents should therefore be collected from populations in the region of origin that are genetically similar to plants in the invaded range. Molecular markers are useful tools to understand genetic contributions in hybrid populations, especially where morphological differentiation is difficult. Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive alien plant in South Africa that is being targeted for biological control, but hybrids with intermediate morphological traits are also present at several sites. In this study, ISSR (inter simple sequence repeats) and ITS (internal transcribed spacer) markers were used to determine which Nymphaea species are likely to be putative parents of these hybrids, and morphological characters were also investigated to determine if genetic and morphological traits matched. Two major hybrid groups were identified, with one group clustering with Nymphaea odorata Aiton and the other clustering with Nymphaea alba L. A third, smaller group clustered with Nymphaea tetragona Georgi, whereas the remaining samples clustered with pure N. mexicana from the native range. Morphological features agreed with deductions drawn from molecular data. These results allow us to focus efforts to find compatible biological control agents and better understand the complicated genetic structure of N. mexicana and Nymphaea hybrids in South Africa.
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  • Date Issued: 2023

Learning Movement Patterns for Improving the Skills of Beginner Level Players in Competitive MOBAs

  • Authors: Brown, Dane L , Bischof, Jonah
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/464161 , vital:76482 , xlink:href="https://link.springer.com/chapter/10.1007/978-981-99-1624-5_45"
  • Description: League of Legends is a massively multiplayer online battle arena (MOBA)—a form of online competitive game in which teams of five players battle to demolish the opponent’s base. Expert players are aware of when to target, how to maximise their gold, and how to make choices. These are some of the talents that distinguish them from novices. The Riot API enables the retrieval of current League of Legends game data. This data is used to construct machine learning models that can benefit amateur players. Kills and goals can assist seasoned players understand how to take advantage of micro- and macro-teams. By understanding how professional players differ from novices, we may build tools to assist novices’ decision-making. 19 of 20 games for training a random forest (RF) and decision tree (DT) regressor produced encouraging results. An unseen game was utilised to evaluate the impartiality of the findings. RF and DT correctly predicted the locations of all game events in Experiment 1 with MSEs of 9.5 and 10.6. The purpose of the previous experiment was to fine-tune when novice players deviate from professional player behaviour and establish a solid commencement for battles. Based on this discrepancy, the system provided the player with reliable recommendations on which quadrant they should be in and which event/objective they should complete. This has shown to be a beneficial method for modelling player behaviour in future research.
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  • Date Issued: 2023

Lessons learned from the translation of the Internalised Stigma of Mental Illness (ISMI) scale into isiXhosa for use with South African Xhosa people with schizophrenia

  • Authors: Matshabane, Olivia P , Appelbaum, Paul S , Faure, Marlyn C , Marshall, Patricia A , Stein, Dan J , de Vries, Jantina , Campbell, Megan M
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/450689 , vital:74974 , xlink:href="https://doi.org/10.1177/13634615231168461"
  • Description: Internalised stigma is highly prevalent among people with mental illness. This is concerning because internalised stigma is often associated with negative consequences affecting individuals’ personal, familial, social, and overall wellbeing, employment opportunities and recovery. Currently, there is no psychometrically validated instrument to measure internalised stigma among Xhosa people in their home language. Our study aimed to translate the Internalised Stigma of Mental Illness (ISMI) scale into isiXhosa. Following WHO guidelines, the ISMI scale was translated using a five-stage translation design which included (i) forward-translation, (ii) back-translation, (iii) committee approach, (iv) quantitative piloting, and (v) qualitative piloting using cognitive interviews. The ISMI isiXhosa version (ISMI-X) underwent psychometric testing to establish utility, within-scale validity, convergent, divergent, and content validity (assessed using frequency of endorsements and cognitive interviewing) with n = 65 Xhosa people with schizophrenia. The resultant ISMI-X scale demonstrated good psychometric utility, internal consistency for the overall scale (α = .90) and most subscales (α > .70, except the Stigma Resistance subscale where α = .57), convergent validity between the ISMI Discrimination Experiences subscale and the Discrimination and Stigma (DISC) scale's Treated Unfairly subscale (r = .34, p = .03) and divergent validity between the ISMI Stigma Resistance and DISC Treated Unfairly subscales (r = .13, p = .49). But more importantly the study provides valuable insights into strengths and limitations of the present translation design. Specifically, validation methods such as assessing frequency of endorsements of scale items and using cognitive interviewing to establish conceptual clarity and relevance of items may be useful in small piloting sample sizes.
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  • Date Issued: 2023

Lifting the ‘knee on the neck’ through virtual collaboration within creative and therapeutic art methodologies

  • Authors: Mokuku, Selloane , Molefe, Butana , Magagula, Noluvuyo
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/469111 , vital:77210 , https://doi.org/10.1386/dtr_00118_1
  • Description: Police brutality towards Black people and People of Colour (POC) has been a thorn for centuries in South Africa and the world. The advent of COVID-19 escalated this struggle to unimaginable heights, illuminating, amongst other things, the epistemological and ontological limitations underpinning modernity . Nevertheless, the killing of George Floyd moved masses across the globe to reflect critically on the injustices that Black people endure. Equally, social media shone a spotlight to mobilize consciousness amidst the pandemic restrictions. Moved by the mood of the time, we (a group of primarily arts practitioners and thinkers) organized virtual ‘intergenerational and intercontinental dialogues’ to explore how the dialogic approaches informed by the principles of applied theatre may catalyse drama therapy approaches. Through conversations that we named ‘epistemological injustice’, we made discoveries that included noticing how the biases we all carry may serve as enablers or constraints in embracing therapeutic encounters across disciplines. This article shares insights from the ‘#Talks’ and generates reflective material for creative arts therapies and applied theatre methodologies.
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  • Date Issued: 2023

Literary Byways in Duncan Brown’s Finding My Way: A Review Essay

  • Authors: Klopper, Dirk
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/458573 , vital:75753 , https://hdl.handle.net/10520/ejc-iseaeng_v50_n2_a5
  • Description: The poetics of Duncan Brown’s Finding My Way: Reflections on South African Literature (2020) is intimated in the title of the book, where the infinitude of ‘finding’ and the provisionality of ‘reflections’ anticipate what, in the introductory chapter “Finding My Way”, is described as an avoidance of the “monumentalising study” in favour of a more “mobile, tentative, suggestive scholarship” that is comfortable with “paradox and open-endedness” (12). The chapters that follow explore ways in which the notion of South African literature and the notion of the literary may be reimagined, and explicate a mode of reading ‘with’ the text, showing how this may be applied to ways of reading belief. They also examine the notion of creative non-fiction, revisit orality in South African literature, describe an autobiographical history with a book, and end with a reflection on postapartheid South African literature as “a place of radical newness and obsessive return” (175). What the book omits in its coverage, but which is nevertheless present in its ways of thinking, is Brown’s environmental concern with ‘wildness’ and ‘rewilding’, described in his book Wilder Lives: Humans and Our Environments (2019), published a year earlier. As is the case with the essays in the earlier book, the essays in Finding My Way speak to one another, disclosing of a way of thinking, of finding one’s way, that is recursive in style and attentive to the thing under scrutiny.
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  • Date Issued: 2023

Local peoples’ knowledge and perceptions of Australian wattle (Acacia) species invasion, ecosystem services and disservices in grassland landscapes, South Africa

  • Authors: Yapi, Thozamile S , Shackleton, Charlie M , Le Maitre, David C , Dziba, Luthando E
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/399791 , vital:69559 , xlink:href="https://doi.org/10.1080/26395916.2023.2177495"
  • Description: Many alien tree species were introduced into grassland ecosystems in South Africa by the commercial forestry industry for paper and timber for furniture. Over decades some of these introduced species escaped into neighbouring farms and community land. Adult trees from these alien species now provide other ecosystem services, notably fuelwood. Depending on the spatio-temporal context, many of these species can also negatively affect ecosystem services. We collected interview data from commercial and communal farmers in the upper Umzimvubu catchment in South Africa to compare farmers’ knowledge and perceptions of invasive wattle species invasion and their associated ecosystem services and disservices. Fuelwood and fencing poles were the most common uses of wattle by commercial (83%; 67%) and communal (99%; 49%) farmers. On the other hand, the reduction of grass cover and loss of grazing land were the most commonly mentioned negative impacts of wattles by commercial (83%; 75%) and communal (92%; 80%) farmers. Although both groups recognise the importance of wattles in providing ecosystem services, most communal farmers perceived wattles to have more negative effects than benefits. The findings demonstrate that both farmer groups highly depend on ecosystem services and are affected by disservices of wattles. However, while large-scale commercial households favour the presence of wattles in the landscape, communal households prefer complete removal of the wattles from the landscape. This may be due to lack of locally available alternative options or inability to replace or purchase ecosystem services affected by wattles from other sources or markets like commercial farmers.
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  • Date Issued: 2023

Looking back to move forward: a scoping review of counselling psychology in South Africa

  • Authors: Haine, Phillipa , Young, Charles S , Booysen, Duane D
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454106 , vital:75310 , xlink:href="https://doi.org/10.1177/00812463221091433"
  • Description: Despite that counselling psychologists represent a substantial group of registered psychologists in South Africa, literature specifically on the sub-speciality within the country is limited. The aim of this scoping review was to provide a comprehensive summary of the literature available on counselling psychology in South Africa and examine the extent to which literature is available from a lifespan or career-stage perspective. Three electronic databases (EBSCOhost, Sabinet®, and PubMed) were searched for articles published between 2000 and 2021. Titles and abstracts were reviewed, and data extracted and synthesised thematically. Of 507 citations identified, 10 met the inclusion criteria. Findings indicate that literature on counselling psychology in South Africa is scarce, subject to methodological limitations, and dominated by a small number of authors conducting multiple analyses on the same sets of data. Furthermore, literature on counselling psychologists at key career stages across the professional lifespan is largely missing from the professional discourse. Emphasis is instead placed on counselling psychology as embedded in the sociopolitical history of South Africa, professional identity, the contemporary status of the profession, professional threats and challenges, and the profession’s future promise. Our review highlights the need for more empirically informed studies making use of different methodologies, involving multiple authors with diverse backgrounds, tracking employment trends, and soliciting first-person accounts of counselling psychologist’s experiences at key career stages. Without doing so, ideas about how best to support and utilise this particular group of practitioners may be misguided, in turn compromising the successful provision of mental health care within the country.
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  • Date Issued: 2023

Love at first bite? Pre-release surveys reveal a novel association between a native weevil and the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) in South Africa

  • Authors: Reid, Megan K , Hill, Martin P , Coetzee, Julie A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/416866 , vital:71392 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v31_n1_a19"
  • Description: Classical biological control aims to suppress alien invasive plant populations by introducing host-specific natural enemies from the native range. This relies on the assumption that invasive plant populations in the invaded range benefit from the release of natural enemies. Pre-release surveys in the invaded range are a useful way to determine if enemy release applies to a particular invasive alien plant, and to determine what other factors may contribute to the invasion. Similarly, pre-release surveys gather information that can be used to compare invaded sites before and after the release of biological control agents and may also identify whether natural enemies have been accidentally introduced into the country. Pre-release surveys were conducted in South Africa on the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) to gather such information about this species, for which a biological control programme is being developed. There was lower diversity and abundance of herbivores in the native range compared to South Africa, suggesting that N. mexicana does experience enemy release at most sites in South Africa. This support for the enemy release hypothesis justifies the investment in biological control for its management. However, a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), was found feeding and reproducing on N. mexicana at three sites, resulting in damage to the leaves and suggesting that a novel association has formed between these species. Bagous longulus may have potential to be distributed to sites of N. mexicana where it is not present, though further investigation is necessary to confirm if its host range is suitable for this to be a safe endeavour. With the exception of sites where B. longulus was present, leaf sizes were large and damage was low, and there is no evidence that any natural enemies have been accidentally introduced from the native range. Findings such as these emphasise the importance of conducting thorough surveys during the development of biological control programmes.
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  • Date Issued: 2023

Male peer talk about menstruation: Discursively bolstering hegemonic masculinities among young men in South Africa

  • Authors: Macleod, Catriona I , Glover, Jonathan M , Makuse, Manase , Kelland, Lindsay , Paphitis, Sharli A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/441253 , vital:73870 , xlink:href="https://doi.org/10.1080/23293691.2022.2057830"
  • Description: In this paper, we show how male peer talk about menstruating women may be used to discursively bolster hegemonic masculinities and denigrate women. Focus group discussions among 37 young isiXhosa-speaking men from two South African schools were facilitated by two young men; statements garnered from a sexuality education class about menstruation conducted in the same schools were used as cues. Data were analyzed using discourse analysis. The interactive talk constructed a bifurcation: “disgusting” menstruating women versus “reasonable” non-menstruating women who abide by idealized feminine behavior and are available sexually. We argue that as the non-menstruating woman cyclically become the other (menstruating woman) in women of particular ages, the trace of disgust inhabits the signifier “woman” for these men. Menstruation also disrupted a core identity strategy of local hegemonic masculinities: virile (hetero)sexuality. Given this, discursive distancing of the self from the very topic of menstruation is necessary. Small moments of resistance to these constructions were quickly closed down, and caring masculinity emerged only in the context of negotiating sex during menstruation. Involving men in menstrual hygiene management programs may provide spaces for resistance to denigrating discourses about menstruation.
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  • Date Issued: 2023

Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands

  • Authors: Gokul, Jarishma K , Matcher, Gwynneth F , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
  • Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
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  • Date Issued: 2023

Mobile communication and urban/rural flows in a South African marginalised community

  • Authors: Dalvit, Lorenzo
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/468162 , vital:77025 , https://doi.org/10.1177/000276422210928
  • Description: This article draws on Castells’ concept of space of flows to explore the role of mobile communication in mediating the flows of ideas, people and resources concerning Dwesa, a rural community in South Africa. While it is the site of an ICT-for-development project fifteen years in the making, Dwesa is representative of many contemporary South African rural realities in terms of lack of infrastructure, endemic poverty and ur-ban migration. Mobile network coverage is almost universal, sustaining a bidirectional flow of people, resources and information between Dwe-sa and urban areas such as Cape Town. A critical review of the sub-stantial body of research conducted in the area, as well as thematic analysis of social media texts and semi-structured interviews with community members, reveal that mobile phones play an important and nuanced role in arranging physical or virtual rendezvous, facilitating transfers of monetary and other resources, and enabling timeless communication and exchange of information across distance.
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  • Date Issued: 2023

Mobile money taxation and informal workers: Evidence from Ghana's E‐levy

  • Authors: Anyidoho, Nana A , Gallien, Max , Rogan, Michael , Van den Boogaard, Vanessa
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/477985 , vital:78144 , https://doi.org/10.1111/dpr.12704
  • Description: In recent years, governments in low-income countries have increasingly introduced taxes on mobile money transfers. These are often explicitly promoted as a way of taxing informal economic activity, but critics have noted their potential negative impact on lower-income groups and specifically those in the informal sector. Yet there is virtually no evidence base on the effects of mobile money taxes on informal workers. This article assesses how informal workers in Accra, Ghana, use mobile money and how they perceive Ghana's Electronic Transfer Levy (E-levy), introduced in May 2022. This provides a particularly interesting case study to explore the equity implications of the tax, as the policy was explicitly justified as a way of taxing the informal economy but also includes measures to limit the tax burden on lower-income groups.
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  • Date Issued: 2023

Molecular characterization of integrons and their associated gene cassettes in multidrug-resistant enterobacteriaceae isolates from environmental sources and the exploration of antibiotic combination against some resistant strains

  • Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
  • Date: 2023
  • Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10353/27809 , vital:69942
  • Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
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  • Date Issued: 2023

Mosquito community composition in Central District, Botswana: insights from a malaria endemic to non-endemic gradient

  • Authors: Buxton, M , Nyamukondiwa, C , Kesamang, M , Wasserman, Ryan J
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452402 , vital:75126 , http://dx.doi.org/10.17159/2254-8854/2022/a13584
  • Description: Spatial distribution of vector mosquitoes plays a critical role in the dynamics of associated diseases' spread across diverse landscapes. In Botswana, six Districts are implicated as malaria endemic zones, one of which is the Central District comprising both malaria endemic and non-endemic sub-districts. Despite being the biggest in the country, mosquito diversity in this District is under-explored, more so in the malaria non-endemic sub-districts. Here, we thus sampled mosquito adults and larvae from the malaria endemic sub-district of Bobirwa and non-endemic sub-districts of Palapye and Serowe, to determine spatial mosquito abundance and diversity in the District.
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  • Date Issued: 2023

Multispectral Plant Disease Detection with Vision Transformer–Convolutional Neural Network Hybrid Approaches

  • Authors: De Silva, Malitha , Brown, Dane L
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/463428 , vital:76408 , xlink:href="https://doi.org/10.3390/s23208531"
  • Description: Plant diseases pose a critical threat to global agricultural productivity, demanding timely detection for effective crop yield management. Traditional methods for disease identification are laborious and require specialised expertise. Leveraging cutting-edge deep learning algorithms, this study explores innovative approaches to plant disease identification, combining Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs) to enhance accuracy. A multispectral dataset was meticulously collected to facilitate this research using six 50 mm filter filters, covering both the visible and several near-infrared (NIR) wavelengths. Among the models employed, ViT-B16 notably achieved the highest test accuracy, precision, recall, and F1 score across all filters, with averages of 83.3%, 90.1%, 90.75%, and 89.5%, respectively. Furthermore, a comparative analysis highlights the pivotal role of balanced datasets in selecting the appropriate wavelength and deep learning model for robust disease identification. These findings promise to advance crop disease management in real-world agricultural applications and contribute to global food security. The study underscores the significance of machine learning in transforming plant disease diagnostics and encourages further research in this field.
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  • Date Issued: 2023
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