Research Articles (University of Pretoria)

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This collection offers open access to the full text of research articles published by staff, students and affiliates of the University of Pretoria. These items are identical in content to their published counterparts. It is linked to the Research Information System and complements the Annual Research Report.

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Corporate earnings announcements and stock market bubbles
Bouri, Elie; Can, Ufuk; Cepni, Oguzhan; Gupta, Rangan (Elsevier, 2026-09)
We examine how corporate earnings announcement shocks influence US stock market bubbles using daily data from January 1990 to June 2025. After identifying positive and negative bubbles, we derive corporate earnings announcement shocks using a heteroskedastic vector autoregression model and estimate their dynamic effects on bubble indicators using local projections, with vector autoregression-based impulse responses reported as a robustness check. Positive earnings shocks boost positive bubbles, particularly at the medium to long-term, while reducing negative bubbles at the short-term. Therefore, favorable earnings news can fuel prolonged speculative episodes by increasing investor optimism, and lead to deep crashes but mild recoveries. HIGHLIGHTS • Link stock bubbles to corporate earnings announcements using local projections. • Apply vector autoregression-based impulse responses as a robustness check. • Positive earnings shocks boost positive bubbles, notably in the medium to long-term. • Positive earnings shocks reduce negative bubbles in the short-term.
Compositional engineering of lignocellulose via selective delignification toward closed-pore-rich hard carbon for high-plateau-capacity sodium storage
Liao, Yunkang; Wang, Qi; Huang, Yongfa; Zhong, Linxin; Li, Tingzhen; Zou, Ren; Dai, Zhenhua; Iwuoha, Emmanuel; Ocakoglu, Kasim; Feleni, Usisipho; Ren, Jianwei; Peng, Xinwen (American Chemical Society, 2026-08)
Hard carbon derived from lignocellulosic biomass is a promising anode candidate for sodium-ion batteries due to its low cost and renewability. However, its practical application is limited by insufficient low-voltage plateau capacity, which is closely related to the closed-pore structure. Herein, we report a green and scalable compositional engineering strategy based on alkaline sulfite pretreatment, an industrially mature pulping process, to convert waste wood into closed-pore-rich hard carbon anodes. By selectively cleaving β-O-4 linkages in lignin, this pretreatment increases the relative cellulose content and fundamentally alters the carbonization pathway, yielding a highly disordered turbostratic structure. The optimized hard carbon (HHC-20) exhibits a doubled closed-pore volume (from 0.073 to 0.178 cm3 g–1) and an expanded interlayer spacing (0.385 nm). Consequently, HHC-20 delivers a high reversible capacity of 347 mAh g–1 at 20 mA g–1, with an outstanding low-voltage plateau capacity of 205 mAh g–1 and an initial Coulombic efficiency of 89.1%. In situ spectroscopic characterizations reveal a sequential sodium storage mechanism involving surface adsorption, interlayer intercalation, and pore filling. This work offers a sustainable and commercially viable pathway for designing high-performance hard carbon anodes for sodium-ion batteries.
The human cost of digitally-driven organisational change in higher education : a phenomenographic study of employee well-being
Lichy, Jessica; Hadleigh-Dunn, Sara (Routledge, 2026)
This study explores the impact on employee well-being in higher education institutions (HEIs) following organisational change as a result of business model innovation. A phenomenographic approach was used involving auto-driven photo-elicitation interviews (PEIs) with 28 instructors in the UK and France, triangulated by focus group discussions with students. The study focused on how digitally-driven organisational change has an impact on the lived experience of occupational health risks and their manifestations (technostress, burnout, etc.) among staff. Findings reveal that digitally-driven organisational change produces a triad of latent stressors, namely technostress, unsustainable workloads, and eroded psychological safety. Critically, ‘health-washing’ emerged as a pervasive risk factor, wherein performative well-being initiatives increase cynicism and disengagement, rather than buffer burnout. Framed by the Job Demands-Resources model, we show how these tensions have direct ramifications for mental health and work-life balance. From this, we advise HEIs to take inspiration from Nordic models of participatory governance and workload transparency to mitigate psychosocial risks. Prioritising employee agency and sustainable business model innovation would foster sustainable work environments.
Beyond [177Lu]Lu-PSMA : a meta-analysis of safety and efficacy of emerging PSMA radioligand therapy agents
Abdlkadir, Ahmed Saad; Al-Adhami, Dhuha; Moghrabi, Serin; Sathekge, Mike Machaba; Kreiss, Michael; Estrada-Lobato, Enrique; Shi, Hongcheng; Al-Ibraheem, Akram (BMC, 2026-03-23)
BACKGROUND: This systematic review and meta-analysis evaluates the safety and efficacy of emerging prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) agents used beyond [¹⁷⁷Lu]Lu-PSMA in metastatic castration-resistant prostate cancer (mCRPC). METHODS: Systematic searches of PubMed, Web of Science, and Scopus were performed from inception until November 3, 2025. Studies reporting objective response rate (ORR), disease control rate (DCR), and/or toxicity outcomes were included. Meta-analytic pooling, assessment of publication bias, heterogeneity analyses, and subgroup evaluations were conducted using Stata software. RESULTS: A total of 33 studies published between 2017 and 2025 met inclusion criteria, encompassing 3625 therapy cycles administered to 1525 patients. The pooled DCR was 86% (95% CI: 82–90%), and the pooled ORR was 57% (95%CI: 50–63%). [²²⁵Ac]Ac-PSMA monotherapy, evaluated in 17 studies, achieved pooled DCR and ORR values of 88% and 62%. Eight studies assessing [¹⁷⁷Lu]Lu/[²²⁵Ac]Ac-PSMA tandem therapy reported pooled DCR and ORR values of 84% and 51%. Five studies on [¹⁶¹Tb]Tb-PSMA demonstrated pooled DCR and ORR values of 81% and 46%. [¹³¹I]PSMA therapy, reported in three studies, resulted in a pooled DCR of 75% and pooled ORR of 48%. Adverse events were documented in 32 studies, with a pooled incidence of 26%. Most events were low-grade and reversible. Xerostomia and anemia were the most frequently reported toxicities, with xerostomia particularly associated with [²²⁵Ac] Ac-PSMA–containing regimens. CONCLUSION: These findings underscore the promising therapeutic potential of emerging PSMA RLT agents beyond [¹⁷⁷Lu]Lu-PSMA, with favorable biochemical responses and manageable safety profiles. Future large-scale prospective studies are essential to define optimal therapeutic roles and expand treatment opportunities for patients with mCRPC.
Measuring the quality of species list governance
Garnett, Stephen T.; Bánki, Olaf; Barik, Saroj Kanta; Berryman, Alex J.; Bouchard, Patrice; Buckeridge, John; Christidis, Les; Cigliano, María Marta; Conix, Stijn; Crawford-Weaver, Haylee; Van Dijk, Peter Paul; Evenhuis, Neil L.; Hilton-Taylor, Craig; Hobern, Donald; Johnston, Claire; Klopper, Ronell Renett; Kroh, Andreas; Le Roux, Marianne; Pape, Thomas; Pyle, Richard L.; Raz, Lauren; Thomas, Philip; Thomson, Scott; Vandepitte, Leen; Wambiji, Nina; Zachos, Frank E.; Lien, Aaron M. (Oxford University Press, 2026-01-28)
Taxonomic lists are important tools for efficient communication about biodiversity. The processes by which they are created and maintained need to be robust, scientifically sound, and transparent. Articulating and scoring a set of governance quality indicators provides a way to assess the relative strengths of list management, gives list users a means to assess the quality of this process, augments the information available to list aggregators, and allows patterns to be measured over time and among forms of life. Based on published principles, we created 12 governance quality indicators which we tested on 16 lists spanning a range of taxonomic groups. Independence of taxonomy from nomenclature scored most strongly, but scores for local and regional involvement were lower. The governance quality indicators may eventually provide a rubric for assessing best practice species list governance but now need a period of further testing, review, and refinement before they are institutionalized.
Comparative analysis of mitochondrial genomes in the Ceratocystidaceae reveals highly conserved gene organization despite substantial genome size variation
Viljoen, Anien; Duong, Tuan A.; Kanzi , Aquillah M.; Wingfield, Brenda D. (BMC, 2026-03-19)
BACKGROUND : Comparative studies of mitochondrial genomes can assist in determining evolutionary and phylogenetic relationships. In the Ceratocystidaceae fungal family, mitochondrial genomes from only two genera are publicly available. In this study, mitochondrial genomes from 10 genera in Ceratocystidaceae were characterised and comparatively analysed. RESULTS : Mitochondrial (mt) genomes were fully assembled and characterized for 18 species and 10 genera of the Ceratocystidaceae. These mt genomes displayed a remarkable level of diversity owing to the variation in the intergenic regions and intron, both in size and number. Despite large variation in size, these mt genomes displayed high levels of synteny and sequence conservation in the oxidative phosphorylation (OXPHOS) genes and the ribosomal RNA and tRNA genes. The genes are found in identical order and orientation in all mt genomes characterized and the coding sequence of all the OXPHOS genes are highly conserved. Phylogenetic analysis of mitochondrial and nuclear DNA sequences reveals significant differences in evolutionary relationships among species and genera of Ceratocystidaceae. CONCLUSION : The remarkable variation in mt genome sizes in species of the Ceratocystidaceae is due to the variation observed in the intergenic regions and intron size and number in the conserved protein-coding genes. The gene order and content are identical across all species investigated.
Winter is coming … how the hoarding behaviour of rodents fosters the persistence of Echinococcus multilocularis
Nagy, Eszter; Bokor, Arpad; Bardos, Boroka; Zam, Izabella; Nagy, Rebeka Rahel; Tari, Tamas; Bokor, Julianna; Moloi, Sibusiso; Abdalrahman, Bawan Mustafa; Nagy, Gabor; Csivincsik, Agnes (Elsevier, 2026-08)
This study aimed to determine whether the interspecific copro-foraging behaviour of potential intermediate host rodents can prevent the summer egg loss of the Arctic-originated cestode parasite, Echinococcus multilocularis. Red fox (Vulpes vulpes) and golden jackal (Canis aureus) scats were used as bait under camera traps to assess rodents’ approach or avoidance activity. Of the 6 detected rodent taxa, common voles (Microtus arvalis) and European wood mice (the morphologically similar species, wood mouse, Apodemus sylvaticus and yellow-necked mouse, A. flavicollis) approached and contacted the baits most frequently, primarily during autumn and winter. A higher seed content in the scat seemed to attract the common voles. Contrary to our hypothesis, autumn hoarding activity appears to foster the transmission of E. multilocularis, while the weakest link in its life cycle, the summer drought, remains less protected. HIGHLIGHTS • Fox and jackal scats were used as bait under camera traps. • Six rodent species had direct contact with wild canine scat. • Wood mice and common vole activity and contacts were highest in fall and winter. • Seed-containing scats attract voles. • Voles' fall hoarding seems to foster the spread of E. multilocularis.
Wild birds as reservoirs of antimicrobial-resistant enterococci : genomic surveillance in Gauteng, South Africa, during the migratory season
Govender, Theevasha; Ueckermann, Veronica; Hamiwe, Thabo; Van der Zel, Gerbrand A.; Makumbi, John Paul; Shirinda, Hlambani; Ehlers, Marthie Magdaleen (Elsevier, 2026-09)
Wild birds, including migratory species, are understudied reservoirs of enterococci in South Africa. This study investigated the resistome, mobilome, virulome and genetic diversity of enterococci from wild birds frequenting water bodies during the migratory season in Gauteng, South Africa. Faecal samples were collected from five sites between November 2023 and March 2024. Enterococci were isolated on selective media and identified with polymerase chain reaction and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry, with 48 isolates undergoing whole-genome sequencing analysis: Enterococcus faecalis (E. faecalis) [56.3% (27/48)], Enterococcus faecium (E. faecium) [18.8% (9/48)] and other enterococci [25.0% (12/48)]. Aminoglycoside resistance genes aph(3′)-III [11.1% (3/27)] and ant(6’)-Ia [7.4% (2/27)] were detected in E. faecalis and linked to Inc18 and RepA_N plasmids. Linezolid resistance was confirmed in an E. faecalis (MIC = 24 μg/mL) and E. faecium (MIC = 8 μg/mL) isolate carrying optrA and rplD_N130K, respectively, with optrA linked to plasmid-derived sequences. A daptomycin resistance-associated liaS_E192G mutation was identified in one E. faecium isolate (MIC = 4 μg/mL). Five potential multidrug-resistant E. faecalis and E. faecium isolates belonged to infrequently described strains. Clinically relevant virulence genes in E. faecalis included: gelE (100%), asa1 [25.9% (7/27)], hylA [59.3% (16/27)], hylB [74.1% (20/27)] and sex-pheromone genes (100%). Phylogenetic analysis revealed wild bird-adapted strains, alongside One Health-relevant E. faecalis ST16 and ST21 and E. faecium ST54 and ST800 lineages, with limited clustering with global isolates. Wild birds harbour enterococcal lineages carrying antimicrobial resistance genes, underscoring surveillance within a One Health framework in low- and middle-income countries. HIGHLIGHTS • Aminoglycoside, linezolid and daptomycin resistance determinants detected. • Linezolid resistance expressed in E. faecalis (optrA) and E. faecium (rplD_N130K). • Mobile genetic elements linked to antimicrobial resistance genes. • Potentially virulent E. faecalis isolates harbouring asa1, gelE and hylAB genes. • Diverse and uncommon STs reflecting wild bird-adapted strains and genome plasticity.
Widespread polyandry in an invasive beetle species (Aethina tumida)
Palonen, Aura K.; Beaurepaire, Alexis L.; Schoch, Robine; Teixeira, Erica Weinstein; Williams, Geoffrey R.; Evans, Jay D.; Posada-Florez, Francisco; Pirk, Christian Walter Werner; Lawrence, Akinwande K.; Sorungbe, Adewale A.; Federico, Giovanni; Formato, Giovanni; Spooner-Hart, Robert; House, Clarissa M.; Neumann, Peter; Papach, Anna (Nature Research, 2026-07-07)
Biological invasions may induce adaptive shifts in traits that increase individual reproductive success, thereby accelerating population growth and amplifying ecological impacts. One such trait is polyandry, i.e. multiple mating by females, which may vary between endemic and invasive populations due to variation in demographic and environmental factors that alter the costs and benefits of multiple mating. Despite polyandry being widespread across taxa, comparative studies among multiple endemic and invasive populations of invasive species remain scarce. Here, we estimated the prevalence of polyandry in two endemic and five invasive populations of small hive beetle (Aethina tumida), a globally invasive parasite affecting bee health. Using DNA microsatellite genotyping of field-sampled females and their offspring to estimate mating frequencies, we show that polyandry varies in SHB populations and females mate with 1–13 males. However, the polyandry levels were not significantly different across the endemic and invasive populations compared. These results suggest that polyandry in SHB may be a stable reproductive trait rather than a plastic response to invasion-related factors. Our work supports further research on how multiple mating may improve both individual reproductive success and population viability in the context of biological invasions.
Why South Africa’s infrastructure maintenance framework has limited practical effect : policy, practice, and comparative lessons from peer countries
Wall, Kevin (University of the Free State, 2026-06-29)
ENGLISH : Despite the National Infrastructure Maintenance Strategy (NIMS), the Government Immovable Asset Management Act (GIAMA), and the National Immovable Asset Maintenance Management (NIAMM) framework, the condition of South African public sector infrastructure remains unsatisfactory, as evidenced by national ‘report cards’ and the three ‘Drop’ reports that appeared in March 2026. The problem is that there has not (until this article) been a study in South Africa that contrasts the high-level NIMS and its associated NIAMM, on the one hand, with the condition of public sector fixed infrastructure, on the other – and has asked why this strategy and this framework have had hardly any practical effect. This article adopts a qualitative, policy- and practice-oriented approach, drawing on documentary evidence, comparative policy review, and practitioner-informed insight. It investigates the adequacy of implementation of South Africa’s infrastructure asset management guidance, and explores whether peer countries achieve better outcomes through alternative mechanisms. Data were collected through a desktop review of relevant overseas strategies, legislation, and guidelines, supplemented by correspondence with practitioners and professional networks in Australia, Canada, New Zealand, and (to a lesser extent) a few other countries, where documents in English could be obtained. Analysis focused on identifying the presence and effectiveness of governance mechanisms, supportive institutions, and enabling cultures that influence infrastructure maintenance outcomes. Findings indicate that, while South Africa possesses documentation or legislation broadly comparable to that of peer countries, the main reason for these countries’ better infrastructure condition is their prioritising accountability, competence, adequate budgets, and supportive organisational cultures. By contrast, South African strategy and frameworks, largely unsupported and unpublicised, have limited impact. The article highlights implications for strengthening infrastructure asset management policy and practice in South Africa. It does not set out an explicit reform blueprint. AFRIKAANS : Ten spyte van die Nasionale Infrastruktuur-onderhoudstrategie (NIMS), die Wet op die Bestuur van Onroerende Bates in die Regering (GIAMA), en die Nasionale Instandhoudingsbestuur van Onroerende Bates (NIAMM) raamwerk, bly die toestand van die Suid-Afrikaanse openbare sektor se infrastruktuur onbevredigend, soos blyk uit nasionale ‘rapportkaarte’ en die drie ‘Drop’-verslae wat in Maart 2026 verskyn het. Die probleem is dat daar (tot hierdie artikel) geen studie in Suid-Afrika was wat die hoëvlak-NIMS en die gepaardgaande NIAMM, aan die een kant, kontrasteer met die toestand van die openbare sektor se vaste infrastruktuur, aan die ander kant nie – en gevra het waarom hierdie strategie en hierdie raamwerk so min praktiese effek gehad het. Hierdie artikel volg ’n kwalitatiewe, beleids- en praktykgerigte benadering, gebaseer op dokumentêre bewyse, vergelykende beleidsoorsig en praktisyn-ingeligte insig. Dit ondersoek die toereikendheid van die implementering van Suid-Afrika se infrastruktuur-batebestuursriglyne, en ondersoek of eweknieë beter uitkomste deur alternatiewe meganismes behaal. Data is ingesamel deur ’n lessenaar-oorsig van relevante oorsese strategieë, wetgewing en riglyne, aangevul deur korrespondensie met praktisyns en professionele netwerke in Australië, Kanada, Nieu-Seeland en (in ’n mindere mate) ’n paar ander lande waar dokumente in Engels verkry kon word. Analise het gefokus op die identifisering van die teenwoordigheid en doeltreffendheid van bestuursmeganismes, ondersteunende instellings en bemagtigende kulture wat die uitkomste van infrastruktuur-instandhouding beïnvloed. Bevindinge dui daarop dat, hoewel Suid-Afrika dokumentasie of wetgewing het wat breedweg vergelykbaar is met dié van eweknieë, die hoofrede vir hierdie lande se beter infrastruktuurtoestand hul prioritisering van verantwoordbaarheid, bevoegdheid, voldoende begrotings en ondersteunende organisatoriese kulture is. In teenstelling hiermee het Suid-Afrikaanse strategie en raamwerke, wat grootliks nie ondersteun en nie gepubliseer word nie, beperkte impak. Die artikel beklemtoon implikasies vir die versterking van infrastruktuur-batebestuursbeleid en -praktyk in Suid-Afrika. Dit stel nie ’n eksplisiete hervormingsbloudruk uiteen nie.
Whole-genome sequences of 240 indigenous African cattle from Egypt, Uganda, and South Africa
Dlamini, Njabulo; Gao, Junxin; Ginja, Catarina; Kantanen, Juha; Ghanem, Nasser; Kugonza, Donald R.; Makgahlela, Mahlako; Elnahas, Ahmed; Zwane, Avhashoni Agnes; Zawedde, Barbara Mugwanya; Nakkazi, Christine; Behabura, Generous; Nxumalo, Khaniysani; Malima, Maano; Radwan, Mohamed Ali; Elsawy, Mohamed Hamada; Agaba, Morris; Fahim, Nadia Hamdi; Khfagy, Rana Atef; Agamy, Rania; Okwasiimire, Rodney; Waibi, Sarah; Lashmar, Simon; Crooijmans, Richard P.M.A. (Nature Research, 2026-06-18)
Indigenous cattle are central to livestock production in Africa, valued for their adaptability to harsh tropical environments despite lower productivity than commercial breeds. Genome analyses offer critical insights into the genetic potential for enhancing both resilience and productive traits, supporting the advancement of worldwide cattle farming systems. Here, we generated whole-genome sequence data for 240 indigenous cattle representing breeds from distinct agro-climatic regions in Egypt, Uganda, and South Africa. The dataset comprises over ten terabytes of paired-end reads generated using the Illumina NovaSeq. 6000 platform, with an average genome coverage of approximately 10×. Post-filtering reads were mapped to the ARS-UCD1.2 reference genome with a mean mapping rate of 99.2% (range: 64.5–99.9%). Variant calling identified ~43 million SNPs and 6 million indels (≤50 bp) unevenly distributed across the genome. Functional annotation indicated that many variants were located within or near known genes. This comprehensive genomic resource provides a foundation for future studies of genetic diversity, breed identity, population structure, local adaptation, breed-specific traits, or strategies for global cattle conservation.
WHO estimates of the global, regional, and national foodborne burdens of 14 invasive parasitic diseases, 2000–21 : an updated data synthesis
Robertson, Lucy J.; Minato, Yuki; Devleesschauwer, Brecht; Di Bari, Carlotta; Vaes, Louise; Keddy, Karen Helena; Sripa, Banchob; Fernandez, Kim; Pires, Sara M.; Majowicz, Shannon E.; Lake, Robin J.; Roberts, Charlee; Nane, Gabriela F.; Kretzschmar, Mirjam E.; Mughini-Gras, Lapo; Rostami, Ali; Carabin, Hélène; Budke, Christine M.; Donadeu, Meritxell; Torgerson, Paul R. (Elsevier, 2026-08)
BACKGROUND : Over 10 years ago, WHO estimates of hazard-specific foodborne disease burdens showed that parasites exert considerable health burdens globally. We updated these estimates, focusing on 14 invasive parasitic diseases. METHODS : Incidences, deaths, and disability-adjusted life-year (DALY) burdens were estimated for each parasitic disease from 2000 to 2021, using data from systematic reviews and the Global Burden of Diseases, Injuries, and Risk Factors Study. For some diseases, structured expert judgement was used to estimate proportions of foodborne infection. Data were pooled via hierarchical meta-regression models with uncertainty propagated through Monte Carlo simulations following disease-specific computational models defined by incidence rates and probability parameters. FINDINGS : We estimated that 277 million illnesses were caused by potentially foodborne invasive parasites, with approximately 171 million attributable to foodborne transmission. Considerable heterogeneity by parasite, in magnitude and uncertainty, was observed. Of 4·89 million foodborne DALYs associated with these diseases, highest contributions were from Taenia solium (1·3 million) and Clonorchis sinensis (0·921 million), both also associated with most foodborne deaths. Burden was greatest in the region of the Americas, predominantly due to Chagas disease, followed by the African region, where neurocysticercosis-associated epilepsy caused most burden. Burdens decreased globally from 2000 to 2021, except in the Western Pacific region, where the burden, predominantly associated with clonorchiasis, is rising. INTERPRETATION : Foodborne parasitoses cause considerable suffering, with some populations and regions particularly at risk. These data provide a baseline by which effects of interventions can be assessed and emphasis directed to those parasites exerting the greatest burden.
WHO estimates of the global, regional, and national burden of 42 foodborne infectious and chemical hazards, 2000–21 : an updated data synthesis
Lake, Robin J.; Devleesschauwer, Brecht; Majowicz, Shannon E.; Robertson, Lucy J.; Jakobsen, Lea Sletting; Agudo, Antonio; Pires, Sara M.; Kirk, Martyn D.; Walter, Elaine Scallan; Keddy, Karen Helena; Di Bari, Carlotta; Vas, Louise; Havelaar, Arie H.; Roberts, Charlee; Gobena, Tesfaye; Kretzschmar, Mirjam E.; Nane, Gabriela F.; Hoffmann, Sandra; Mughini-Gras, Lapo; Sripa, Banchob; Kubota, Kunihiro; Founou, Luria Leslie; Bai, Li; Huthiel, Mohammed Al; Rachmawati, Tety; Estrada-Garcia, Teresa; Kumar, Ashok; Natour, Fadi Al; Jaffee, Steven; Henson, Spencer; Ingenbleek, Luc; Kumapley, Richard; Borghi, Elaine; Minato, Yuki (Elsevier, 2026-08)
BACKGROUND : Foodborne diseases are important causes of illness and death. The first estimates of their burden were published by WHO in 2015. We updated WHO estimates of the global, regional, subregional, and national foodborne disease burden caused by 42 infectious and chemical hazards in 2021, including time trends for 2000–21. METRHODS : We provide a high-level summary of foodborne disease burden, expressed as incidence, deaths, and disability-adjusted life-years (DALYs). Data for burden estimation were provided from a WHO-commissioned series of systematic reviews on the incidence, aetiology, sequelae, and case fatality or mortality of the hazards. Data were analysed using hierarchical meta-regression modelling with geographical clustering and a global linear time trend, disease-specific computational models, and uncertainty propagation through Monte Carlo simulations to calculate 95% uncertainty intervals. Attribution to foodborne transmission was principally based on a structured expert judgement process. Economic impact was measured as lost productivity. FINDINGS : For 2021, foodborne transmission of the 42 hazards caused 866 million (95% uncertainty interval 680–1090) illnesses, 1·52 million (0·783–2·51) deaths, and 57·1 million (39·4–81·1) DALYs. Inorganic arsenic, lead, and non-typhoidal Salmonella enterica (diarrhoeal and invasive disease) resulted in the most DALYs. The greatest burden of foodborne disease was in the African and South-East Asia regions. The incidence in children younger than 5 years was 2·7 times higher than in people aged 5 years or older, resulting in 4·3 times the rate of DALYs. The total burden from all hazards decreased over time. In 2021, these 42 hazards resulted in productivity losses of US$310 billion in nominal terms, and US$647 billion after adjusting for purchasing power parity. INTERPRETATION : Foodborne diseases causes a burden similar to that from tuberculosis, HIV and AIDS, or malaria. The high burden of both communicable and non-communicable foodborne diseases requires countries to prioritise developing strategies to improve the safety of the food supply.
What distinct opportunities could relational wellbeing as framework offer to advance wellbeing research? A purposive review of evidence
Wildschut, Angelique; Abrahams, Hayley; Ntsepe, Yoliswa; Groenewald, Candice; Swartz, Sharlene (Frontiers Media, 2026-07-01)
The notion of wellbeing emerged in resistance to deficit characterizations of people's lives in mental health theory and intervention. It is an approach that rejects compartmentalization and stigmatization, with the aim of centering and presenting a more holistic view of personhood. Informed by a new program of research on youth wellbeing in the Global South, this paper seeks to engage critically with the potential value of an emergent framework called relational wellbeing for advancing research on youth wellbeing. As a formative step, a scoping review was conducted and published in 2024 covering the period 2013–2022. To update and capture possible changes in the literature since then, the authors embarked on a mini review framed by the following two overarching questions: how has relational wellbeing been applied in the more recent academic literature, and to what extent is it being employed as a distinct approach? The mini review confirms that relational wellbeing, understood as a distinct framework, is emergent, but not solidified. The term continues to be used to challenge individualistic models of wellbeing, firmly positioning relationships, culture and context as central to wellbeing. However, the construct continues to lack unified operationalization—used variably as a theoretical lens, analytic framework and still quite strongly as a measurable construct. While this reveals a field conceptually rich and influential, it remains methodologically diffused. Insights across different sections of the review, however, provide guidance for prospective scholars hoping to expand research that applies a relational framework to foster greater understanding and positive impact on youth wellbeing.
Whale killers on the coast of South Africa : killer whale predation on a humpback whale super-group
Seyboth, Elisa; Wilkinson, Christopher; Elwen, Simon Harvey; Barnes, A.; Vermeulen, Els (NISC (Pty) Ltd and Informa UK Limited (trading as Taylor and Francis Group), 2026-06)
In December 2023, a pod of 15–20 killer whales Orcinus orca successfully predated on a likely juvenile (∼10-m long) humpback whale Megaptera novaeangliae that was part of a super-group (defined as feeding groups of 20+ individuals close to each other) on the west coast of South Africa. The event was recorded and photographed in detail by researchers from the University of Pretoria from a 6-m-long semi-rigid research vessel. The killer whales exhibited clear predation behaviour, with females and juveniles trying to drown the humpback whale by pressing their bodies on top of it to prevent it from breathing. Roughly one hour later, two additional male killer whales, which had not been active in the predation event up to this point, joined the pod and had a role in the final killing of the humpback whale. The kill occurred underwater and was inferred to have happened as pieces of blubber floated to the surface approximately a minute after the two males joined the pod. As humpback whales recover from whaling, and because super-groups of the species seem to use the west coast of South Africa over multiple months of the year, interactions between humpback whales and killer whales are likely to become more common.
Visible-light driven photocatalytic degradation of tartrazine using Co@ZIF-8 monoliths
Tshuma, Piwai; Phiri, Arnold; Chaparadza, Mercy; Seimela, Thapelo Ephraim; Diale, M. (Mmantsae Moche); Poshayi, Nicola Vimbainashe; Marazani, Linia Gedi; Mehlana, Gift (Royal Society of Chemistry, 2026-08-12)
Please read abstract in the article.
Viral variant but not host factors associate with SARS-CoV-2 viral kinetics
Hahn, William O.; Fisher, Leigh H.; Ward, Amy; Grant, Shannon; Yen, Catherine; Randhawa, April Kaur; Li, Xiaohong; Ramirez, Shelly; Espy, Nicole; Hural, John; Hanke, Jennifer; Roychoudhury, Pavitra; Kelley, Colleen F.; Rouphael, Nadine; Cantos, Valeria D.; Pinto, Jorge; Cahn, Pedro E.; Manentsa, Mmatsie; Makhema, Joseph; Samaneka, Wadzanai; Bhondai-Mhuri, Muchaneta; Stranix-Chibanda, Lynda; Losso, Marcelo H.; Garcia, Edgar Antonio Ramirez; Innes, Craig; Chinula, Lameck; Lama, Javier R.; Gallardo-Cartagena, Jorge A.; Kabengele, Chishiba; Chilengi, Roma; Nchabeleng, Maphoshane; Tieu, Hong-Van; Hoagland, Brenda; Grinsztejn, Beatriz; Brumskine, William L.; Ahmed, Khatija; Wallis, Carole L.; Greninger, Alexander L.; Corey, Lawrence; Hyrien, Ollivier (Nature Research, 2026-06-17)
BACKGROUND : It is challenging to assess SARS-CoV-2 viral kinetics amidst viral variant evolution and changes in population-level immunity. However, understanding the relationship between host factors and viral replication deepens our understanding of viral fitness. METHODS : In CoVPN 5001, we enrolled N = 953 adults diagnosed with acute SARS-CoV-2 from July 2020 to July 2022 across 51 sites. We confirmed SARS-CoV-2 infection by RT-PCR and identified the variant via viral genome sequencing. Using multivariable linear regression and median regression, we studied the association between host factors and either observed peak viral load (VL) or clinical viral shedding, respectively, accounting for viral variant effects in a demographically and clinically diverse longitudinal cohort. RESULTS : In this observational study, we determine that while host factors, including age, BMI, sex, medical comorbidities, and HIV, have no significant associations with either observed peak VL or clinical viral shedding in the nasopharynx, viral variant is significantly associated with observed peak VL and clinical viral shedding. We show that neither observed peak VL nor shedding duration predict evolutionary success since the dominant variants in the SARS-CoV-2 pandemic did not all align with the variants with the highest peak and longest shedding duration. CONCLUSIONS : Altogether, our work shows that observed peak VL and shedding duration should be cautiously interpreted as predictors of viral fitness. PLAIN LANGUAGE SUMMARY : Over time the virus causing COVID has changed, with these different viruses described as viral variants that have started in specific geographic regions. Many studies of COVID have involved small numbers of people infected with only one or two viral variants. We undertook a study of a large number of people across the USA, Southern Africa, and South America who acquired COVID between 2020 and 2022, a period during which many different viral variants were present. Different viral variants resulted in different amounts of virus being present in the upper-airways. However, a large amount of virus being present did not predict that a variant would outcompete other variants. Better understanding of the impact of viral variants offers potential improvements for public health policy and insight into the COVID pandemic to date
Variational Bayesian algorithms for independent vector analysis with flexible source models
Hanekom, Natalie; Hanekom, Johannes Jurgens (Elsevier, 2026-11-15)
Fully Bayesian independent vector analysis algorithms derived using variational Bayes are proposed for guided source separation, providing control over the type, amount and influence of prior information. Speaker-dependent modelling is enabled by expressive Gaussian mixture models and hidden Markov models, with explicit noise modelling and an arbitrary number of sensors enabling joint separation and noise reduction in environments with dominant sources of interest contaminated by background interference. Maximum likelihood counterparts for the algorithms are also provided. Compared to state-of-the-art baselines, the proposed algorithms achieve stronger suppression of noise and interference, including background interference and other sources of interest. These gains may partially be attributed to enhanced source and noise modelling, and more principled integration of prior information. The framework additionally demonstrated speaker-dependent voice activity detection and closed-set multi-speaker recognition via Bayesian model comparison.
Validating a questionnaire for vocational teachers to monitor classroom-based assessment practices
Setlalekgosi, Mpho; Combrinck, Celeste (Common Ground Research Networks, 2026-03-26)
The challenge of a mismatch between school-based vocational education (VE) and practical work skills exists. Classroom-based assessment (CBA) is one of the tools that play a fundamental role in addressing this gap. However, teachers are confronted with reporting their CBA activities and challenges that can influence evidence-based decision-making. Measuring teachers’ CBA practices and challenges is pivotal for their improvement. With limited tools developed to monitor and evaluate CBA practices and challenges, teachers cannot thoroughly communicate and make improvements. The study developed a CBA questionnaire for teachers to evaluate and improve their CBA practices. The exploratory sequential mixed-methods approach was used to develop and refine items. The qualitative phase guided the instrument design and helped to obtain the needed quantitative data to validate the instrument. A total of 101 vocational teachers in Botswana answered the questionnaire, and the results were analyzed using the Rasch Measurement Model (RMM). Overall, there is sufficient evidence from validation that the developed questionnaire is internally reliable and valid. There was evidence of unidimensionality, with large and significant correlations of constructs as theoretically required. All items of the questionnaire met the model fit except one item. The instrument is suitable for evaluating teachers’ CBA practices and challenges. The study contributes a tool for teachers, lecturers, and educational managers to use in VE, especially in developing contexts. The questionnaire could stimulate more research and support for enhanced CBA. Teachers’ responses to the questionnaire can inform interventions and supportive actions that improve CBA.
Mapping mental health problems in elite female athletes—a scoping review. Emphasising limited research in Africa and South America
Naidoo, Dhavina; Chantler, Jessica; Gouttebarge, Vincent; Janse van Rensburg, Dina Christina; MacMillan, Candice (Elsevier, 2026)
BACKGROUND : Mental health symptoms and disorders are growing concerns among elite athletes facing unique psychological stressors from high-performance competition. While prevalence has been studied in male athletes and regions like Europe and Australia, significant gaps exist regarding elite female athletes from underrepresented regions, including Africa. OBJECTIVES : To conduct a scoping review on the literature of mental health symptoms and disorders in elite female athletes globally, identify geographic research gaps, and summarise key contributing factors and methodologies. DESIGN : Scoping review. METHODS : While focusing on mental health symptoms and disorders among elite female athletes, studies including both female and male participants were considered to provide a comprehensive overview. A search was conducted in PubMed, PsycINFO, CINAHL, and Scopus databases. Two reviewers independently screened studies, extracted data, and charted results on study characteristics, descriptive study-level prevalence estimates, associated factors, and methodologies. RESULTS : Fifty-nine studies were included. Only seven investigated elite female athletes, 22 reported sex-disaggregated prevalence estimates, and 30 presented aggregated results. Most studies (88.1%) were cross-sectional. Only three studies investigated disorders, and the remaining 56 investigated symptoms such as depression, anxiety, and disordered eating. Risk associations included injury, illness, career dissatisfaction, financial stress, and gender. Research originated mainly from Europe (n = 27), with only one study from Africa and three from South America. CONCLUSIONS : Mental health symptoms are prevalent among elite female athletes, yet evidence is skewed toward high-income regions and often lacks female-specific data. More geographically inclusive, longitudinal, and sex-disaggregated research is needed, particularly in Africa and South America, to ensure the development of equitable interventions and policies.

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