Research Articles (University of Pretoria)

Permanent URI for this collectionhttp://hdl.handle.net/2263/121

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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Development of value-added chicken burgers by adding pumpkin peel powder as a sustainable ingredient
(MDPI, 2025-05) Pinna, Nicola; Ianni, Federica; Codini, Michela; Cenci-Goga, Beniamino Terzo; Misuraca, Marco; Costanzi, Egidia; Cossignani, Lina; Blasi, Francesca
Worldwide, there is a growing need to valorize agri-food waste containing bioactive compounds to fit into the circular economy action plan approved in Europe. In this paper, the carotenoids of peel powder of pumpkins (PPP) of five varieties (Hokkaido, Lunga di Napoli, Mantovana, Moscata di Provenza, and Violina rugosa) were characterized by spectrophotometric (antioxidant activity) and chromatographic analyses. PPP from the Hokkaido variety showed high levels of carotenoids (2993.90 μg β-carotene equivalents/g). They were mainly composed of mono- (9065.35 μg zeaxanthin dipalmitate equivalents/g) and di-esterified (1832.74 μg zeaxanthin dipalmitate equivalents/g) xanthophylls. It also showed high antioxidant activity (ABTS 2036.02 μg Trolox equivalents/g). Therefore, it was used as a functional plant ingredient (4%) to prepare chicken burgers (100, 70, and 50% chicken meat). Physical-chemical, microbiological, color, and sensorial analyses of fortified chicken burgers were carried out. The product with 70% chicken meat and 4% PPP obtained the highest overall acceptability score (5.95 ± 0.25). The results confirm that the addition of PPP could represent a valid approach to increasing the health properties and acceptability of burgers, even if a larger assessor size is necessary.
Biotic pressure outweighs the influence of resource availability on physical defence investment in a tropical tree
(Oxford University Press, 2025-06) Babah Daouda, Bio Barriou; Kouagou, M'Mouyohoun; Assede, Emeline Sessi Pelagie; Gaoue, Orou G.
Plants have long-lasting and complex interactions with herbivores, including insects and mammals. In response to high herbivory rates, plants either tolerate biomass loss or develop several defence mechanisms, such as physical defence. The resource availability hypothesis (RAH) predicts that plant defence investment is dependent on resource availability and plant's life history. However, the effect of resource availability on plant investment in defence is mediated through biotic pressure. We tested the effects of soil qualities and browsing pressure on the physical defence and reproductive investments in Acacia sieberiana at the Pendjari Biosphere Reserve in West Africa. We selected six populations, including three in the Pendjari River floodplain where soil moisture is high but with high elephant browsing pressure, and three populations on the plateau in the hunting zone where soils are drier and relatively poorer with a lower density of elephants. We found greater investment in physical defence for trees in the floodplain. Furthermore, A. sieberiana trees produced less fruit in the floodplain than in the plateau. Contrary to the predictions of the RAH, we found more and longer thorns in populations in the richer floodplains than on the plateau. This was linked to higher elephant browsing pressure in the floodplains. This physical defence was probably induced to cope with the episodic but high levels of herbivory observed in this environment. Surprisingly, the negative influence of thorn number and size on the likelihood of elephant damage was observed only in the rich floodplains and not in plateau sites. Altogether, our study demonstrates that the influence of resource availability (soil moisture, pH, and fertility) in shaping plant physical defence can be outweighed by high herbivory pressure.
Bayesian nonparametric estimation of differential entropy for toroidal data
(Elsevier, 2025-12) Rad, Najmeh Nakhaei; Arashi, Mohammad; Bekker, Andriette, 1958-; Millard, Sollie M.; najmeh.nakhaeirad@up.ac.za
Entropy is a widely used information-theoretic measure; however, the estimation of entropy for observations of a periodic nature has not received much attention thus far. In this paper, we implement a Bayesian approach to obtain nonparametric estimates of Shannon entropy for toroidal data. This paves the way for its use in protein structure validation through an approach based on information theory and the distribution of backbone dihedral angles in the 3D structure of proteins. In addition, the kernel density estimation proposed in this paper can be applied alongside available parametric models for modeling toroidal observations. Simulation studies and the analysis of real datasets provide insights into this proposed method for protein structure validation. HIGHLIGHTS • Estimation of entropy for observations of a periodic nature specifically toroidal data. • A Bayesian nonparametric density estimator for toroidal data using a Dirichlet infinite mixture model. • Considering the possible dependencies between two circular variables. • An alternative information-theory based method for protein structure validation. • Diagnosing of the disordered pattern of wind direction in univariate case.
What use are ontogenetic data anyway? Challenges in multivariate modelling of primate tooth formation
(Taylor and Francis, 2025-06) Wolfe, Christopher A.; Boughner, Julia C.; Stull, Kyra Elizabeth
BACKGROUND : The development of the permanent dentition provides a reliable substrate to infer ontogenetic patterns within and among species. Multivariate methods offer a promising approach to compare taxon-specific patterns. AIM : This study used multivariate statistical approaches to compare ontogenetic patterns by more comprehensively quantifying variation in crypt and tooth formation scores for the permanent dentition in five catarrhine primate taxa, Homo sapiens, Pan paniscus, Pan troglodytes, Hylobates lar, and Papio anubis. SUBJECTS AND METHODS : Tooth formation was scored according to published standards for each specimen. Multivariate relationships between teeth were modelled according to a Bayesian multivariate cumulative probit model. Relationships among and between teeth were summarised with correlation matrices, variable loadings plots, and the Frobenius norm. Univariate boxplots were used to contextualise and check the biological salience of the multivariate results. RESULTS : H. sapiens results corroborate previous research and show a degree of modularity that separates early forming and later-forming teeth. All four other species may show broad correlative patterns, but clear biological patterns are masked due to small sample sizes and/or sample composition. CONCLUSION : Even with careful application of statistical procedures, ontogenetic inferences are only as good as the data are comprehensive.
Bark investment is key to forest expansion into African savannas by conferring resistance to fire and seasonal drought
(Oxford University Press, 2025-05) Rosell, Julieta A.; Vetter, Susanne; Olson, Mark E.; Greve, Michelle
BACKGROUND AND AIMS : Forest expansion into savannas is widespread even though fire and seasonal drought provide environmental conditions against encroachment by forest specialists. A distinct suite of species can establish under savanna trees, forming bush clumps and facilitating forest establishment. Understanding the functional traits of clump-forming species is crucial for uncovering encroachment mechanisms and devising management strategies. Bark likely plays a key role in enabling clump initiation. Fire resistance can be achieved by accumulation of outer bark thickness (OBT), height and/or stem diameter (SD), while drought resistance may be enhanced by greater inner bark thickness (IBT), associated with water and carbohydrate storage. METHODS : We selected representative savanna, clump-forming and closed-canopy species (ecological categories) at two South African sites experiencing forest expansion and differing in rainfall and fire frequency. We compared OBT–SD and IBT–SD allometries across ecological categories and sites and examined whether categories separated along axes reflecting fire/drought resistance (OBT and IBT) and resource allocation strategy (density and water content, leaf size). KEY RESULTS : OBT–SD scaling of clump-forming species was more similar to savanna than forest species, and savanna species at the more fire-prone savanna had steeper OBT–SD scaling, consistent with high OBT providing fire protection in early clump formation. Similar IBT–SD slope across groups was consistent with similar metabolic needs, while higher intercepts in savanna and clump-forming species indicated higher water storage. ‘Cheap’ low-density tissues in savanna species allow fast accumulation of SD and OBT and resistance to fire topkill. Closed-canopy species had denser tissues and thin stems and bark for a given height, while the clump-forming species were intermediate. CONCLUSIONS : Bark and probably other traits are key in the capacity of some species to form bush clumps. Identifying these traits and the mechanisms underlying clump formation is essential for managing encroached savannas and grasslands.
Can African elephants use leaf colour as a visual cue when making foraging decisions?
(Springer, 2025-06) Peinke, Claire Louise; Shrader, A.M. (Adrian)
Finding food is one of the most important aspects of an animal’s life. Yet, locating it can be challenging as the availability and quality of food varies both spatially and temporarily. To overcome these challenges, mammalian herbivores may use spatial memory or senses such as smell and vision. Recent studies have found that African elephants (Loxodonta africana) use olfactory cues to locate food patches and to select plants to eat within these patches. However, the extent to which they may also use visual cues, such as those associated with leaf colour, a proxy for food quality, when making foraging decisions is unknown. To address this knowledge gap, we tested whether African elephants were able to discriminate differences in leaf colour (i.e., light green: high-quality new growth, dark green: lower quality old growth, brown: poor-quality senesced vegetation) over a range of distances (i.e., 3, 5, 10, 20, 40, 80 m). Testing four semi-tame elephants using visual-based choice experiments between different coloured canvases, we found that the elephants were able to discriminate colour differences at close range (i.e., ≤10 m), but not beyond. This suggests that when feeding within a patch, African elephants may utilise the visual cues associated with leaf colour to help locate high-quality food (e.g., individual trees, branches, and leaves) and thus increase their foraging efficiency. However, as they were unable to discriminate between the different colours over distances > 10 m, it is unlikely that they use colour when making long-range foraging decisions such as selecting feeding patches.
The ATM kinase inhibitor AZD0156 is a potent inhibitor of Plasmodium falciparum phosphatidylinositol 4-kinase (PI4Kβ) and is an attractive candidate for medicinal chemistry optimization against malaria
(Wiley, 2025-07) Woodland, John G.; Coertzen, Dina; Wicht, Kathryn J.; Hidalgo, Virginia Franco; Pasaje, Charisse Flerida A.; Godoy, Luiz C.; Qahash, Tarrick; Mmonwa, Mmakwena M.; Dziwornu, Godwin A.; Wambua, Lynn; Harries, Sarah; Korkor, Constance M.; Njoroge, Mathew; Krugmann, Liezl; Taylor, Dale; Leshabane, Meta Kgaogelo; Langeveld, Henrico; Rabie, Tayla Anne; Reader, Janette; Van der Watt, Mariette Elizabeth; Venter, Nelius; Erlank, Erica; Aswat, Ayesha S.; Koekemoer, Lizette L.; Yeo, Tomas; Jeon, Jin H.; Fidock, David A.; Gamo, Francisco Javier; Wittlin, Sergio; Niles, Jacquin C.; Llinas, Manuel; Coulson, Lauren B.; Birkholtz, Lyn-Marie; Chibale, Kelly; lynmarie.birkholtz@up.ac.za
New compounds targeting human malaria parasites are critical for effective malaria control and elimination. Here, we pursued the imidazoquinolinone AZD0156 (MMV1580483), a human ataxia-telangiectasia mutated (ATM) kinase inhibitor that completed Phase I clinical trials as an anticancer agent. We validated its in vitro activity against the two main forms of the Plasmodium falciparum parasite in the human host, viz. the asexual blood (symptomatic) stage and sexual gametocyte (transmission) stage. Resistance selection, cross-resistance, biochemical, and conditional knockdown studies revealed that AZD0156 inhibits P. falciparum phosphatidylinositol 4-kinase type III beta (PfPI4Kβ), a clinically-validated target for the treatment of malaria. Metabolic perturbations, fixed-ratio isobolograms, killing kinetics and morphological evaluation correlated AZD0156 inhibition with other known PI4Kβ inhibitors. The compound showed favorable in vivo pharmacokinetic properties and 81% antimalarial efficacy (4 × 50 mg kg−1) in a P. berghei mouse malaria infection model. Importantly, a cleaner biochemical profile was measured against human kinases (MAP4K4, MINK1) implicated in embryofoetal developmental toxicity associated with the PfPI4Kβ inhibitor MMV390048. This improved kinase selectivity profile and structural differentiation from other PI4Kβ inhibitors, together with its multistage antiplasmodial activity and favorable pharmacokinetic properties, makes AZD0156 an attractive candidate for target-based drug repositioning against malaria via a medicinal chemistry optimization approach.
Assessing the use of remotely sensed surface water flux to estimate net groundwater storage change in an aquifer predominantly used for irrigation
(Elsevier, 2025-07) Viviers, Cindy; Van der Laan, Michael
Please read abstract in the article.
Assessing extensive pasture-based beef production in South Africa under future climate change conditions
(Elsevier, 2025-10) Magona, Christopher; Hassen, Abubeker; Tesfamariam, Eyob Habte; Mengistu, Michael; Visser, Carina; Oosting, Simon; Van der Linden, Aart; carina.visser@up.ac.za
CONTEXT : Assessing the impact of climate change on extensive pasture-based beef production across varied agro-ecological regions is crucial for designing customized adaptation measures. OBJECTIVE : This study assesses the effects of climate change on extensive pasture-based beef production systems in three South African agro-ecological regions (Bloemfontein, Phalaborwa and Buffalo Berlin) under two climate change scenarios, namely the representative concentration pathways (RCPs) 4.5 and 8.5. METHODS : The LiGAPS-Beef model, previously calibrated for the region, was used to evaluate the impact of climate change on beef cattle production under pasture-based extensive systems. Four breed types, namely Bos taurus, Composite, Zebu indicine and Sanga cattle were included in this study. Genetic parameters for each breed were obtained from SA Stud Book, Livestock Registering Federation (LRF) and literature. Measured historical weather data was obtained from the South African Weather Service for the three agro-ecological regions. An ensemble of eight regional climate model (RCA4) simulations from the CORDEX Africa initiative was used to generate future climate change projection data for the period 2036–2065 under RCP 4.5 and RCP 8.5 scenarios. The future nutritional composition data for forage was collected from studies that simulated and predicted future forage quality under climate change conditions. RESULTS AND CONCLUSION : The study found that the baseline average daily gain (ADG) was significantly higher (0.40 kg/head/day) than the simulated RCP 4.5 (0.21 kg/head/day, −48 %) and RCP 8.5 (0.20 kg/head/day, −51 %) ADGs regardless of breed type when both feed quality and feed quantity limited growth. Although the effect of the climate change scenarios on beef production was agro-ecological region dependent, the performance of Bos taurus declined more than other breeds under future climate scenarios while the Sanga and the Composite types were the most resilient, especially in hot climate areas. Model simulations predict that future climate change will have a greater negative impact on cattle in Buffalo Berlin and Phalaborwa, while those in Bloemfontein will be least affected. The study also highlights that under future climate change scenarios, pasture quality will be the key factor influencing cattle growth in Bloemfontein and Buffalo Berlin, while pasture quantity will be the dominant factor in Phalaborwa if stocking rates remain unchanged. The study highlights the need for nutritional and pasture management interventions for pasture-based extensive system (e.g., feed supplementation, adjusting the stocking rate to match pasture availability, identifying and integrating drought and/or heat tolerant ecotypes, fodder trees that provide shade for the animals) to mitigate the expected decline in beef cattle performance in South African agro-ecological regions. SIGNIFICANCE : Quantifying the impact of anticipated climate change on pasture-based extensive beef production and identifying specific factors that limit beef production per breed type in the different agro-ecological regions is crucial for assessing the potential ramifications on beef production. This information empowers farmers and policy makers to develop targeted mitigation and adaptation strategies that promote resilience of the beef production system in the respective regions. HIGHLIGHTS • Quantifying climate change impact on beef production is vital for coping measures. • Beef cattle growth was simulated under RCP 4.5 and RCP 8.5 in South Africa. • 2050 simulated growth declined by 48 % in RCP 4.5 and 51 % in RCP 8.5 from baseline. • Growth of Bos taurus was most adversely affected, but Sanga was the most resilient. • Location-specific intervention is vital to sustain beef production in South Africa.
Paired eddy covariance site reveals consistent net C sinks over three growing seasons in an African arid and grassy shrubland
(Elsevier, 2025-09) Maluleke, Amukelani; Feig, Gregor Timothy; Brümmer, Christian; Jaars, Kerneels; Hamilton, Tamryn; Midgley, Guy
Please read abstract in the article. HIGHLIGHTS • African arid and grassy shrubland site reveals consistent net C sinks over three growing seasons. • Savanna site more productive but has lower and more variable water use efficiency than Nama-Karoo site. • Soil moisture observed as a key factor in modulating the relationship between nighttime respiration and soil temperature at both sites.
Alcohol degradation of anhydride-cured epoxy resin insulating materials containing SiO2 filler
(American Institute of Physics, 2025-06) Zhang, Xu; Li, Chengjie; Ye, Xianming; Zhang, Xiaoxing; Maluta, Eric; Wu, Yunjian
Please read abstract in the article.
Kisspeptin fiber and receptor distribution analysis suggests its potential role in central sensorial processing and behavioral state control
(Wiley, 2025-05) Zhang, Limei; Hernandez, Vito Salvador; Zetter, Mario Alberto; Hernandez-Perez, Oscar Rene; Hernandez-Gonzalez, Rafael; Camacho-Arroyo, Ignacio; Eiden, Lee E.; Millar, Robert P.
Kisspeptin (KP) signaling in the brain is defined by the anatomical distribution of KP-producing neurons, their fibers, receptors, and connectivity. Technological advances have prompted a re-evaluation of these chemoanatomical aspects, originally studied in the early years after the discovery of KP and its receptor Kiss1r. Previously, we characterized (Hernández et al. bioRxiv 2024) seven KP neuronal populations in the mouse brain at the mRNA level, including two novel populations, and examined their response to gonadectomy. In this study, we mapped KP fiber distribution in rats and mice using immunohistochemistry under intact as well as short- and long-term post-gonadectomy conditions. Kiss1r mRNA expression was examined via RNAscope, in relation to vesicular GABA transporter (Slc32a1) in whole mouse brain, and to KP and vesicular glutamate transporter 2 (Slc17a6), Kiss1, and Slc32a1 in hypothalamic RP3V and arcuate regions. We identified KP fibers in 118 brain regions, primarily in extra-hypothalamic areas associated with sensorial processing and behavioral state control. KP-immunoreactive fiber density and distribution were largely unchanged by gonadectomy. Kiss1r was expressed prominently in sensorial and state control regions such as the septal nuclei, the suprachiasmatic nucleus, locus coeruleus, hippocampal layers, thalamic nuclei, and cerebellar structures. Co-expression of Kiss1r and Kiss1 was observed in hypothalamic neurons, suggesting both autocrine and paracrine KP signaling mechanisms. These findings enhance our understanding of KP signaling beyond reproductive functions, particularly in sensorial processing and behavioral state regulation. This study opens new avenues for investigating KP's role in controlling complex physiological processes, including those unrelated to reproduction.
Development of a conditional generative adversarial network model for television spectrum radio environment mapping
(Institute of Electrical and Electronics Engineers, 2024-12) Dare, Oluwatobi E.; Okokpujie, Kennedy; Adetiba, Emmanuel; Idowu-Bismark, Olabode; Abayomi, Abdultaofeek; Kala, Raymond Jules; Owolabi, Emmanuel; Ukpong, Udeme C.
To efficiently use the finite wireless communication resource (radio spectrum), a Radio Environment Map (REM) is needed to monitor, analyse and provide rich awareness of spectrum activities in a radio propagating environment. REM shows radio coverage metrics in a geographical region. A REM construction model with few constraints and optimal performance is needed to better support cognitive radio for dynamic spectrum sharing (DSS) and other benefits of REM. This study aims to estimate fine-resolution REM from sparse radio signal strength measurement. In this study, we utilised conditional generative adversarial network (CGAN) to create a television spectrum radio environment map in order to improve cognitive television white space (TVWS) radio performance in real-time propagation environments. Measurement campaign was carried out to acquire a TV-band (470-862MHz) radio frequency and geographical dataset at Covenant University, Ota, Nigeria. A preprocessing procedure which was implemented with Python script was employed to group the dataset using Nigerian Communications Commission TV spectrum channel spacing and to create incomplete spectrograms for 49 channels. Xgboost, SVM, and kriging variogram models were explored to generate ground truth datasets for the CGAN model training, and the best algorithm was employed. A CGAN REM model was developed using U-Net as a generator and PatchGan as a discriminator. The U-Net generator is a 3-channel input, 16-layer architecture while the PatchGan discriminator is a 6-channel input, 7-layer architecture. The model performance was evaluated using mean square error (MSE) and mean absolute error (MAE). 12 different experiments were carried out varying the training parameters of the CGAN architecture to obtain an optimal model. The achieved root mean square error (RMSE) is 0.1145dBm and MAE is 0.0820dBm, which shows the deviation between the ground truth and the generated REM. This low deviation means that the proposed CGAN REM model possesses an improved accuracy in predicting the spectrum activities within the television spectrum which is considered appropriate for DSS technology. This study also revealed that 41 channels within TV-band in Covenant University are totally unoccupied.
Optimal workforce allocation for quality delivery in devOps teams : a case study
(IADIS, 2024) Smuts, Hanlie; Louw, Paul; Smit, Danie; Waechter, Ingo; Sardinha-da Silva, Vanessa
Software development, integration, deployment, and operational management necessitate a diverse array of complex skills. Additionally, there is a growing demand for organizations to expedite the delivery of product-based applications and services compared to traditional software development methods, all while adhering to specific cost, speed, and quality criteria. To address these challenges, IT organizations adopt a DevOps approach, structuring their software teams to integrate development and operations seamlessly. As the complexity varies across different product lines, determining the ideal mix of DevOps workforce becomes important. In this case study, we formulated a generic DevOps workforce profile for product line delivery using stratified systems theory, which considers weighted factors influencing the workforce mix. We then compared this profile with actual workforce data to identify the optimal alignment. Furthermore, qualitative data from 17 product line owners within the organization delineated their key considerations when allocating workforce to DevOps teams. By conducting a thematic analysis of these considerations, we refined the workforce allocation method and proposed a set of systematic guidelines to help organizations better grasp the distribution of DevOps workforce mix, thereby enabling them to staff teams with an optimal balance of expertise, delivery quality, and operational efficiency. This enhanced understanding can further inform talent development and allocation strategies.
Immunogenicity and safety following a homologous booster dose of a SARS-CoV-2 recombinant spike protein vaccine with Matrix-MTM adjuvant (NVX-CoV2373) versus a primary series in people living with and without HIV-1 infection in South Africa : a randomized crossover phase 2a/2b trial
(Taylor and Francis, 2024-12) Shinde, Vivek; Koen, Anthonet Lombard; Hoosain, Zaheer; Archary, Moherndran; Bhorat, Qasim; Fairlie, Lee; Lalloo, Umesh; Masilela, Mduduzi S.L.; Moodley, Dhayendre; Hanley, Sherika; Fouche, Leon Frederik; Louw, Cheryl; Tameris, Michele; Singh, Nishanta; Goga, Ameena; Dheda, Keertan; Grobbelaar, Coert; Joseph, Natasha; Lombaard , Johan J.; Mngqibisa, Rosie; Bhorat, As’ad Ebrahim; Benade, Gabriella; Lalloo, Natasha; Pitsi, Anna; Vollgraaff, Pieter-Louis; Luabeya, Angelique; Esmail, Aliasgar; Petrick, Friedrich G.; Jose, Aylin Oommen; Foulkes, Sharne; Ahmed, Khatija; Thombrayil, Asha; Kalonji, Dishiki; Cloney-Clark, Shane; Zhu, Mingzhu; Bennett, Chijioke; Albert, Gary; Marcheschi, Alex; Plested, Joyce S.; Neal, Susan; Chau, Gordon; Cho, Iksung; Fries, Louis; Glenna, Greg M.; Madhi, Shabir A.
COVID-19 remains a global public health issue and an improved understanding of vaccine performance in immunocompromised individuals, including people living with HIV (PLWH), is needed. Initial data from the present study's pre-crossover/booster phase were previously reported. This phase 2a/b clinical trial in South Africa (2019nCoV-501/NCT04533399) revisits 1:1 randomly assigned HIV-negative adults (18-84 years) and medically stable PLWH (18-64 years) who previously received two NVX-CoV2373 doses (5 μg recombinant Spike protein with 50 μg Matrix-M™ adjuvant) or placebo. During the 6-month blinded crossover/booster phase, NVX-CoV2373 recipients could receive a single NVX-CoV2373 booster dose and placebo recipients a 2-dose NVX-CoV2373 primary series. NVX-CoV2373 safety and immunogenicity were assessed according to prior SARS-CoV-2 infection and HIV status. Post-crossover, 1900/3793 NVX-CoV2373 recipients were assigned another dose, and 1893/3793 placebo recipients were assigned NVX-CoV2373 primary series. Approximately 56% of the participants were SARS-CoV-2-seropositive ("seropositive") at crossover (6% PLWH). In seropositive participants (HIV-negative and PLWH), booster-dose anti-spike IgG, MN50 and hACE2 inhibition responses increased to similar levels, exceeding those in seronegative participants. In primary-series and booster cohorts, seronegative PLWH showed higher neutralizing responses (4.9- to 5.5-fold, respectively) versus peak pre-crossover primary-series responses. The safety profile was similar among the pre-crossover/booster phase groups; solicited and unsolicited adverse events were infrequent in all groups. A single NVX-CoV2373 booster dose substantially increased antibodies. All baseline seropositive participants showed higher immune responses than seronegative participants. These findings support use of NVX-CoV2373, including in immunocompromised individuals.
The impact of COVID-19 pandemic on HIV and AIDS care provision in South Africa : an integrative literature review
(Termedia Publishing House Ltd., 2024-10-30) Seretlo, Raikane James; Ramavhoya, Thifhelimbilu I.; Mulaudzi, Fhumulani Mavis; Gundo, Rodwell; Nesengani, Tintswalo Victoria; Kgatla, Mamoeng N.; Peu, Mmapheko Doriccah
Worldwide, the coronavirus (COVID-19) pandemic has negatively impacted healthcare services, including human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) care. In 2020, the attention shifted from HIV and AIDS to COVID-19, and as a result, there was a decline in using HIV services, such as antiretroviral treatment and pre-exposure prophylaxis. Moreover, people living with HIV cancelled and/or missed their clinic appointments due to fears of contracting the virus. The aim of this paper was to explore the impact of COVID-19 pandemic on HIV and AIDS care provision in South Africa. In this integrative review, Google Scholar, Scopus, EBSCOhost, Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases as well as literature on HIV/AIDS and COVID-19 were searched for publications between 2020 and 2022. Out of 255 publications, 150 were considered irrelevant, 105 were potentially eligible, and 30 were fully screened. In total, only 12 research papers met inclusion criteria. From the literature reviewed, 4 themes and related sub-themes emerged. The findings revealed reduced HIV testing and monitoring, missing and cancellation of appointments, a decline in antiretroviral treatment initiation services and other services, such as antiretroviral treatment collections and adherence, were all affected by the COVID-19 pandemic. COVID-19 had a negative impact in the uptake, HIV monitoring, and adherence to antiretroviral drugs by people living with HIV. The use of telehealth, de-centralization, online classes, and call centers can be some of the innovative strategies that South Africa can adapt, which will help in the prevention of care and avoidance of negative impacts of future pandemics on the health of South Africans.
Pushing the envelope : downturns, wrong directions and additional avenues
(Historical Association of South Africa (HASA), 2024-05) Harris, Karen Leigh; karen.harris@up.ac.za
This article takes a rather unorthodox approach for a presidential address at an academic conference. It looks beyond the windows of the ivory tower to take cognisance of what lies outside the walls of academia to engage with what is really happening and what really matters. It is indeed a case of pushing the envelope - going beyond the limits of what is regarded as the norm and acceptable - and in so doing suggests ways in which we can manoeuvre our discipline to consider embracing a different approach regarding where we are at. While historical research is at the core of what we do and is in effect what keeps our academic institutions afloat, it cannot and must not be an end in itself. What I argue for is that we take account of the situation we find ourselves in in terms of our South African university community and by that, I mean our student cohort, and reflect upon what it is we can and need to do. The article reflects on the downturns, considers the wrong directions and proposes additional avenues.
Where data science and the disciplines meet : innovations in linking doctoral students with masters-level data science education
(Massachusetts Institute of Technology Press, 2024-08-21) Preiss, Doreet; Sperling, Jessica; Huang, Ryan M.; Bradbury, Kyle; Nechyba, Thomas; Calderbank, Robert; Herschlag, Gregory; Borg, Jana Schaich
Although the need for data science methodological training is widely recognized across many disciplines, data science training is often absent from PhD programs. At the same time, master’s-level data science educationa programs have seen incredible growth and investment. In 2018, Duke University initiated a National Science Foundation (NSF)-funded program to determine whether master’s-level data science programs that universities have already invested in could be leveraged to reduce data science education barriers doctoral students face. Doctoral fellows from diverse fields worked with teams of master’s students from Duke’s Master in Interdisciplinary Data Science program on applied capstone projects focused on the doctoral fellows’ own disciplines and dissertation research. Fellows also gained access to the master’s program’s courses and professional development resources. We examined the implementation, experience, and effect of this integration into Master in Data Science program infrastructure using qualitative data collection with doctoral fellows, master’s students, and fellows’ doctoral advisors. Master’s students participating in doctoral-led capstones benefited from their doctoral fellows’ mentorship, project management, and content knowledge. Participating doctoral students showed increased learning of data science techniques and professional skills development. While some fellows’ research was advanced through the capstones, data also showed mismatches between selected master’s program goals and doctoral students’ needs. Overall, this pilot indicated potential promise in harnessing existing Master in Data Science programs to bolster doctoral students’ data science learning and professional readiness while also identifying areas for improving future such efforts.
The commercial meal experience in context : an exploration with frequent travelers
(Elsevier, 2025-09) Stierand, Marc B.; Saunders, Mark N.K.; Eves, Anita
This qualitative-exploratory study is grounded in data obtained from in-depth interviews relating to commercial meal experiences that are essential when dining out near home, during work, and when traveling. Previous studies have examined meal experiences, but have not differentiated in-depth between the dining out contexts described here, particularly the requirements of a meal in the workplace. The interviewees (N = 18) were frequent travelers and therefore had substantial experience of dining out when traveling and in the intercept between traveling and business. Our theorizing from the data suggests that the essence of the commercial meal when dining out near home is an experience of ‘Exotic Familiarity; ’ during work, it is an experience of ‘Diversion from Work’ and ‘Ensuring Confidentiality; ’ and when traveling, it is an experience of ‘Safe Convenience’ and ‘Clichéd Authenticity.’ We conclude by contributing a model of the commercial meal experience, discussing the implications of the findings for theory and practice, and by offering suggestions for future research.
Conflation of reforestation with restoration is widespread : across Africa, vast areas of nonforest are threatened by inappropriate restoration in the form of tree planting
(American Association for the Advancement of Science, 2024-02-16) Parr, Catherine Lucy; Te Beest, Mariska; Stevens, Nicola
No abstract available.

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