Research Articles (University of Pretoria)

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Quantification of Angora goat beta chain haemoglobin variants using the Sebia Capillarys 2 Flex-Piercing system
Parsons, Sven David Charles; Vermeulen, A.; Hobson, M.; Hooijberg, Emma Henriette (Medpharm Publications, 2025-02)
This study aimed to evaluate the utility of the Sebia Capillarys 2 Flex-Piercing (C2FP) system for the quantification of the major caprine beta chain haemoglobin (Hb) variants, i.e. foetal Hb, neonatal Hb, and adult Hb. Blood samples were collected from six Angora kids at one, 11, and 20 weeks after birth, and analysed using the C2FP instrument and Capillarys Hemoglobin(E) kit. Electropherograms displayed three major peaks which showed consistent changes in relative magnitude as kids aged. At one week old, a peak at position ~75 was identified as foetal Hb, while in older animals, peaks at ~150 and ~170 were identified as neonatal Hb and adult Hb, respectively. In conclusion, this study has confirmed the utility of the Sebia C2FP system for the simple, rapid, and standardised quantification of the major beta chain Hb variants of Angora goats.
First report of a Sporidesmin toxicity (facial eczema) outbreak in a South African dairy herd
Davis, Anthony John; Jordaan, Daniel Du Plessis Scheepers; Myburgh, Jan G. (Medpharm Publications, 2025-03)
Sporidesmin, a toxin released by a saprophytic fungus, Pseudopithomyces chartarum, causes hepatogenous photosensitivity in sheep and cattle, commonly known as Facial Eczema. A recent outbreak in the Eastern Cape Province of South Africa caused significant direct and indirect economic losses to a farmer in the area and highlighted the potential negative consequences of this mycotoxicosis to the dairy industry in this province. The milking herd consisted of 400 cross-bred Jersey/Friesian/Montbilliard cattle. The farmer identified 56 cows showing teat sensitivity/irritability during milking, hypersensitive skin, excessive licking and/or obvious skin lesions on non-pigmented skin areas. Three were culled due to the severity of their skin lesions. Grazing consisted of mixed kikuyu/perennial rye grass pasture under pivot irrigation, alternated with dryland kikuyu/Italian rye and sorghum. Typical clinical signs of severe secondary photosensitivity (skin inflammation and hypersensitivity to touch), very high serum concentrations of Gamma-Glutamyl Transferase (GGT 2143-5177 IU/L) and detection of large numbers of spores on grazed planted pastures supported the clinical diagnosis. Supplementation of zinc oxide (ZnO) powder at 12g per 500 kg cow dosed individually over the concentrates fed in the dairy, effectively reduced the incidence of new cases within two to three weeks. Weight loss, a decrease in milk volume and solids, and increased somatic cell counts were observed during this outbreak. One of these parameters, milk volume loss, was quantified by comparing the financial records of the four years preceding the outbreak to the production figures during the outbreak. The farmer lost approximately R1.5 million in milk volume during this outbreak (November 2020 - April 2021). Long term consequences were also apparent: the culling rate within the clinically affected group of 53 cows was more than 50% higher than the rest of the herd over the following two years. This case study highlights the urgent need to investigate the prevalence and potential economic impact of Sporidesmin Toxicity on the South African pasture-based dairy industry.
Systematic review and meta-analysis of fertility outcome following in vivo insemination with sex-sorted semen in sheep
Nel, J.G.; Thompson, P.N. (Peter N.); Holm, Dietmar Erik (Medpharm Publications, 2025-02)
BACKGROUND : Sex-sorted semen (SS) offers economic benefits to sheep producers, but lower fertility outcome (FO), defined as probability of pregnancy, pregnancy rate or lambing rate, than that following conventional semen (CS) artificial insemination (AI) may limit its use OBJECTIVES : To systematically review the literature, and analyse factors associated with FO following AI in sheep using SS vs CS. METHODS : Available literature was searched using the PRISMA guidelines, resulting in 11 studies with 14 experiments that were reviewed. From these, information from 70 study cohorts representing 13 experiments was used to conduct a meta-analysis which confirmed that FOs for SS and CS AI were 37% (95% CI = 31-43%) and 52% (95% CI = 45-59%), respectively (p < 0.01). RESULTS : FO improved over time, with FO following SS and CS AI improving at the same rate over the period investigated (19972022). In a subgroup analysis, five factors were identified that potentially decrease the FO after SS AI disproportionately. These were sperm dose < 4 χ106 spermatozoa, semen preservation (fresh vs frozen-thawed), oestrus synchronisation using an intravaginal sponge (vs a controlled internal drug release device), presence of gonadotropin-releasing hormone in the synchronisation protocol, and absence of biostimulation using a teaser ram. In a random-effects model analysis, an interaction between sperm dose and SS vs CS, and semen preservation were independent predictors of FO after adjusting for the effect of timing of insemination. CONCLUSION : FO following insemination with SS is 15% lower than that of CS, which can be narrowed by increasing the semen dose for SS inseminations and improving the synchronisation of ovulation with the timing of insemination.
Person-centred HIV care and prevention for youth in rural South Africa : preliminary implementation findings from Thetha Nami ngithethe nawe stepped-wedge trial of peer-navigator mobilization into mobile sexual health services
Busang, Jacob; Ngoma, Nqobile; Zuma, Thembelihle; Herbst, Carina; Okesola, Nonhlanhla; Chimbindi, Natsayi; Dreyer, Jaco; Smit, Theresa; Bird, Kristien; Mtolo, Lucky; Behuhuma, Osee; Hanekom, Willem; Herbst, Kobus; Lebina, Limakatso; Seeley, Janet; Copas, Andrew; Baisley, Kathy; Shahmanesh, Maryam (Wiley, 2025-10)
INTRODUCTION : Despite the efficacy of antiretroviral therapy (ART)-based prevention, population-level impact remains limited because those at high risk of HIV acquisition are not reached by conventional services. We investigated whether youth-centred and tailored HIV prevention, delivered by community-based peer navigators alongside sexual and reproductive health (SRH) services, can mobilize demand for HIV pre-exposure prophylaxis (PrEP) and ART among adolescents and young adults (AYA) in KwaZulu-Natal, South Africa. METHODS : Thetha Nami ngithethe nawe is a cluster-randomized stepped-wedge trial (SWT) in 40 clusters within a rural health and demographic surveillance site. Clusters were randomized to receive the intervention in period 1 (early) or period 2 (delayed). Trained area-based peer navigators conducted needs assessments with youth aged 15-30 years to tailor health promotion, psychosocial support and referrals into nurse-led mobile SRH clinics that also provided HIV testing, and status-neutral ART and oral PrEP. Standard of care was PrEP delivered through primary health clinics. We report SRH service uptake from the 20 intervention clusters during the first period of the SWT (NCT05405582). RESULTS : Between June 2022 and September 2023, peer-navigators reached 9742 (74.9%) of the 13,000 youth in the target population, 46.8% males. Among 9576 individuals with needs assessment, peer-navigators identified 141 (1.5%) with social needs, and 4138 (43.5%) had medium to high health needs. These individuals were referred to mobile clinics, with 2269 (54.8%) attending, including 959 (42.3%) males. HIV testing uptake was high (92.7%; 2103/2269), with 10.1% (212/2103) testing positive for HIV, 62 (29.2%) of whom started ART for the first time. The prevalence of HIV was higher among females compared to males (15.1% vs. 3.3%; p < 0.001). Among clinic attendees, 96.8% were screened for PrEP eligibility, with 38.5% deemed eligible and offered PrEP. Of the 1433 (63.2%) individuals tested for sexually transmitted infections (STIs), 418 (29.2%) tested positive, with females having higher STI prevalence (37.2% vs. 17.9%; p < 0.001). Of these, 385 (92.1%) received STI treatment. Among 1310 females, 769 (58.7%) reported not using any contraception at their initial visit, and 275/769 (35.8%) started contraception during the trial. CONCLUSIONS : Community-based and person-centred approaches delivered through trained peer-navigators can link AYA with SRH and HIV prevention/care needs with mobile SRH services.
Artificial intelligence for HIV care : a global systematic review of current studies and emerging trends
Ngcobo, Sanele; Madela-Mntla, Edith; Shock, Jonathan; Louw, Murray; Mbonambi, Linda; Serite, Thato; Rossouw, Theresa M. (Wiley, 2025-09)
INTRODUCTION : Artificial intelligence (AI) and, in particular, machine learning (ML) have emerged as transformative tools in HIV care, driving advancements in diagnostics, treatment monitoring and patient management. The present review aimed to systematically identify, map and synthesize studies on the use of AI methods across the HIV care continuum, including applications in HIV testing and linkage to care, treatment monitoring, retention in care, and management of clinical and immunological outcomes. METHODS : A comprehensive literature search was conducted across databases, including PubMed and ProQuest Central, Scopus and Web of Science, covering studies published between 2014 and 2024. The review followed PRISMA guidelines, screening 3185 records, of which 47 studies were included in the final analysis. RESULTS : Forty-seven studies were grouped into four thematic areas: (1) HIV testing, AI models improved diagnostic accuracy, with ML achieving up to 100% sensitivity and 98.8% specificity in self-testing and outperforming human interpretation of rapid tests; (2) Retention in care and virological response, ML predicted clinic attendance, viral suppression and virological failure (72-97% accuracy; area under the curve up to 0.76), enabling early identification of high-risk patients; (3) Clinical and immunological outcomes, AI predicted disease progression, immune recovery, comorbidities and HIV complications, achieving up to 97% CD4 status accuracy and outperforming clinicians in tuberculosis diagnosis; (4) Testing and treatment support, AI chatbots improved self-testing uptake, linkage to care and adherence support. Methods included random forests, neural networks, support vector machines, deep learning and many others. DISCUSSION : AI has the potential to transform HIV care by improving early diagnosis, treatment adherence and retention in care. However, challenges such as data quality, infrastructure limitations and ethical considerations must be addressed to ensure successful implementation. CONCLUSIONS : AI has demonstrated immense potential to address gaps in HIV care, improving diagnostic accuracy, enhancing retention strategies and supporting effective treatment monitoring. These advancements contribute towards achieving the UNAIDS 95-95-95 targets. However, challenges such as data quality and integration into healthcare systems remain. Future research should prioritize scalable AI solutions tailored to high-burden, resource-limited settings to maximize their impact on global HIV care.
REPRIEVE final results : what does it mean for guidelines in low- and middle-income countries?
Sokhela, Simiso; Manne-Goehler, Jennifer M.; Lalla-Edward, Samanta; Siedner, Mark J.; Ali, Mohammed K.; Hill, Andrew; Mody, Aaloke; Pozniak, Anton; Nel, Jeremy; Venter, Willem Daniel Francois (Wiley, 2025-06)
INTRODUCTION : The REPRIEVE study demonstrated significant reductions in major adverse cardiovascular events (MACE) with pitavastatin among people living with HIV (PWH) with low to moderate cardiovascular risk. Most MACE events occurred in higher-income countries, raising important considerations for similar primary prevention interventions within HIV programmes in low- and middle-income countries (LMICs) as antiretrovirals become safer and as PWH age. DISCUSSION : Limited data from Africa and within REPRIEVE suggests that MACE may not be as prevalent among PWH as within other geographies. Consequently, there remain questions about the appropriateness of extrapolating REPRIEVE data to the region and whether it should motivate programmatic implementation on the continent. Moreover, glucose and lipid screening used in REPRIEVE raise concerns about additional resources for similar screening, where there is little existing infrastructure and subsequent treatment. Similarly, questions around funding priorities, and health worker resource allocation for MACE prevention, particularly in the context of competing health priorities and limited health financing, need to be addressed. Newer cardiovascular medications, with cardiac, renal, hepatic, diabetes and weight loss benefits, may have greater promise, although cost remains a major concern. Finally, successful implementation with statins or other proven interventions will be unlikely, unless systemic change within non-communicable disease health system delivery programmes occurs first. However, HIV programmes and public health systems more generally have shown themselves to be poor at screening and treating other cardiovascular risk factors, including aspects as simple as raised blood pressure, even in high-income countries, and statins remain grossly under-prescribed for primary and secondary prevention internationally. CONCLUSIONS : REPRIEVE turned a spotlight on how ill-prepared current HIV programmes are to implement the simplest and safest primary care prevention interventions for cardiometabolic disease within LMICs. As data for existing and new interventions become available, HIV delivery systems will need to raise their standard beyond simply prescribing antiretrovirals and taking viral loads.
Advancing entomopathogenic fungi for improved management of Phthorimaea (Tuta) absoluta (Lepidoptera: Gelechiidae)
Kinyanjui, Grace; Mawcha, Kahsay Tadesse; Ndolo, Dennis (Oxford University Press, 2025-09)
Phthorimaea (Tuta) absoluta (Meyrick), a destructive pest of tomato, is currently mainly controlled using chemical insecticides. However, overdependence on chemical control induces resistance among P. absoluta populations and negatively impacts human health and the environment. Therefore, there is a need to adopt complementary pest control methods. Biological control of P. absoluta using integrated pest management (IPM) strategies incorporating entomopathogenic fungi (EPFs) holds great promise for suppressing pest populations and reducing insecticide applications. In this review, we discuss the relevance of EPFs in controlling P. absoluta and highlight their value as an integral component of IPM programs. The review provides an overview of strategies to address the challenges that limit research, development, wide-scale commercialization, and adoption of EPFs, particularly in sub-Saharan Africa. It also highlights technological advances that could improve the insecticidal activity of EPFs to harness their biocontrol potential fully. Further, the review recommends actionable measures for the broad and sustained application of EPFs as components of IPM programs for the control of P. absoluta.
Optimized molecular detection of Cryptosporidium within the water-soil-plant-food nexus : advancing surveillance in agricultural systems
Schipper, Robyn Marijn; Richter-Mouton, Loandi; Korsten, Lise (Elsevier, 2025-08)
Cryptosporidium, a protozoan parasite causing severe diarrheal illness in humans and animals, poses detection challenges due to low parasite concentrations, inhibitors, and inefficient DNA extraction. This study optimized DNA extraction and detection of Cryptosporidium in environmental samples and evaluated their practical use in agriculture. After evaluating 11 DNA extraction methods from spiked phosphate-buffered saline (PBS) sam-ples, three methods for molecular detection of Cryptosporidium in water, soil, and fresh produce were selected and further tested using real-time PCR. A total of 188 artificially contaminated samples were prepared, consist-ing of distilled water (n = 36), environmental water (n = 44), soil (n = 36), and fresh produce (lettuce and spinach; n = 72). Each sample was inoculated with serial dilutions of 12,500 to 5 Cryptosporidium oocysts and tested using real-time PCR and droplet digital PCR (ddPCR) to evaluate detection sensitivity. Results demon-strated that extraction performance varied by matrix, with two spin-column kits excelling for water and another for soil and produce. DNA from as few as five oocysts was occasionally detectable, with ddPCR being less prone to be affected by PCR inhibitors than real-time PCR. These methods were then applied to detect Cryptosporidium in 210 environmental samples (water, soil, produce) from South African small-scale farms. None of the samples tested positive with real-time PCR, while ddPCR detected Cryptosporidium in 13.6% of water, 23.3% of soil, and 34.7% of fresh produce samples. Surface water showed the highest contamination at 28.6%. Soil amended with both fertilizer and manure had a 45% contamination rate. Among vegetables, roots were most affected (46.7%), followed by fruiting (40%) and leafy greens (30.15%). These findings high-light the health risks of Cryptosporidium in food systems and the need for improved detection methods to enhance surveillance and inform future outbreak prevention strategies.
Data-driven insights into road accident severity in sub-Saharan Africa : a multiple correspondence analysis for SDG-aligned policy
Adeliyi, Timothy; Oluwadele, Deborah; Aroba, Oluwasegun J.; Igwe, Kevin (International Information and Engineering Technology Association, 2025-07-31)
In recent years, several impactful studies have provided stakeholders with actionable insights aimed at reducing accident severity, aligning with Sustainable Development Goals 3 and 11, which target a reduction in global deaths and injuries by 2030. Building upon this foundation, the present study applies the Multiple Correspondence Analysis (MCA) technique to uncover complex and latent relationships among categorical variables influencing road accident severity across Sub-Saharan Africa. The dataset comprises 12,316 accident records spanning 2017 to 2020, with 22 carefully selected categorical variables relevant to driver demographics, environmental conditions, vehicle characteristics, and road infrastructure. Through MCA, the dimensionality of the original 182 dimensions was reduced to 29 dimensions based on eigenvalue retention, with the first two dimensions accounting for 60.2% of the total variance. The resulting MCA biplot reveals distinct quadrant-based groupings of variables. The top-right quadrant demonstrates a strong positive correlation among factors such as younger drivers (aged 18-30), vehicle ownership, type of vehicle, service year, presence of medians or lanes, specific accident-prone areas, and weekdays. This cluster suggests that accident severity is significantly influenced by driver age and vehicle characteristics in particular contexts. This study revealed the interrelationships among key features, offering a data-driven foundation upon which policymakers and transport authorities can design and implement targeted interventions. These may include stricter licensing regulations for younger drivers, the enforcement of improved vehicle safety standards, and strategic infrastructural enhancements in identified high-risk zones. The findings provide a strong foundation for the expansion of sustainable road safety strategies and contribute to the growing discourse on mitigating accident severity in Sub-Saharan Africa.
Endo-exo classification of episodic rock creep in underground mines : implications for forecasting violent rockbursts
Lei, Qinghua; Malan, D.F. (Daniel Francois); Sornette, Didier (Elsevier, 2025-11)
Rock masses in deep underground environments under high in-situ stress often exhibit episodic creep behavior, driven by complex interactions between external perturbation and internal reorganization. The causes of these creep episodes and their link to potential catastrophic failure remain poorly understood. Here, we present a novel “endo-exo” framework for analyzing episodic rock creep in underground mines, capturing the interplay between exogenous triggers (e.g., blasting and excavation) and endogenous processes (e.g., damage and healing within rock masses). The underlying physical mechanism involves cascades of locally triggered rock block movements due to fracturing and sliding. We identify four fundamental types of episodic dynamics, classified by the origin of disturbance (endogenous or exogenous) and the level of criticality (subcritical or critical). All four types exhibit power law relaxations with distinct exponents: 1+θ (exogenous-subcritical), 1-θ (exogenous-critical), 1‒2θ (endogenous-critical), and 0 (endogenous-subcritical), all governed by a single parameter 0 < θ < 1. Our theoretical predictions are examined using the comprehensive dataset of a platinum mine in South Africa, where stopes display episodic closure behavior during successive mining operations. All creep episodes recorded can be accounted for in our classification with θ ≈ 0.35 ± 0.1, providing strong validation of our theory. This θ value is interpreted in terms of a first-passage process driven by anomalous stress diffusion, represented by fractional Brownian motion or Lévy-type processes. Finally, we offer new insights into endo-exo interactions and the system's transition from episodic creep to catastrophic failure, with important implications for forecasting violent rockbursts.
Defining early health technology assessment : building consensus using Delphi technique
Grutters, Janneke P.C.; Bouttell, Janet; Abrishami, Payam; Ahmed, Sulafa. Y.M.; Cole, Amanda; Dawoud, Dalia; Fernández-Barceló, Carla; Frederix, Geert W.J.; Hawkins, Neil; Karnon, Jonathan; Leadbitter, Sharon; McCabe, Christopher; Mueller, Jani; Achiaw, Samuel Owusu; Partington, Andrew; Sampietro-Colom, Laura; Seyahian, Abril; Sucu, Rabia; Tew, Michelle; Van Katwyk, Sasha; Verboven, Yves; Wang, Yi; A Working Group of HTAi (Cambridge University Press, 2025-06)
Although early health technology assessment (HTA) is increasingly being used to guide and inform decisions on product development, a consensus definition is currently lacking. A working group under the HTA International Society was established to develop a consensus-based definition of early HTA. The working group developed a definition using an iterative process that comprised five stages of work and included a two-round Delphi survey with 133 respondents in the first and 99 respondents in the second round of the survey, with various backgrounds and levels of expertise. Following this process, the working group reached the first consensus-based definition of early HTA, which is an HTA conducted to inform decisions about subsequent development, research, and/or investment by explicitly evaluating the potential value of a conceptual or actual health technology. In total, 86 (87 percent) of the 99 panelists who participated in the second round of the Delphi survey either strongly agreed or agreed with this definition. This consensus definition represents an important milestone in early HTA. It will enhance the uniformity of terminology, increasing the visibility of research and policy in this field. We also hope that it will act as a catalyst sparkling further research and developments in this discipline.
A critical assessment of cable rating methods under soil drying out conditions
Khumalo, Ntombifuthi Queeneth; Naidoo, Raj M.; Mbungu, Nsilulu T.; Bansal, Ramesh C. (Wiley, 2025-10)
The design of underground cable systems must account for the risk of soil drying out due to heat dissipation, which can degrade cable performance and lead to environmental concerns. This study investigates a cost-effective cable rating methodology tailored to South African conditions, where native soils are used instead of engineered backfill. Using the IEC 60287 standard, an Excel-based calculation tool is developed to assess the effects of key installation parameters, including soil thermal resistivity, ambient soil temperature and cable laying depth. Soil samples from Sandton, South Africa, revealed thermal resistivity ranging from 0.596 K·m/W, at 14.5% moisture, to 3.72 K·m/W, at 0% moisture, resulting in current ratings from 518.34 A to 224.21 A. Worst-case conditions—high resistivity, increased depth, 1150 mm and elevated soil temperature, 28°C—reduced ampacity by over 45%. The findings underscore the need to incorporate site-specific soil data and worst-case assumptions into cable rating designs to prevent thermal degradation. The developed method offers a practical, locally optimised alternative for utilities in semiarid regions.
Towards including environmental sustainability in health technology assessment
Holtorf, Anke-Peggy; Pegg, Melissa; Mueller, Debjani; McMeekin, Nicola (Cambridge University Press, 2025-09)
INTRODUCTION : The life cycle of health technologies contribute to air pollution, ecotoxicity, and resource depletion, impacting the environment and human health. Increasing healthcare resource use globally increases emissions that accelerate climate change and negatively affect the health of current and future generations. Health Technology Assessment (HTA) should inform decision makers to prioritize the adoption of technologies demonstrating value in terms of health benefits, costs, and other relevant dimensions such as environmental sustainability. This paper reports on a multistakeholder approach to guiding an international working group for Environmental Sustainability in Health Technology Assessment (ESHTA) that has been formed by Health Technology Assessment international. METHODS : A multistakeholder online workshop was held with 32 participants in May 2024 to define the critical issues to be considered. The resulting report underwent consultation among the ESHTA members and in a broader group of 90 additional worldwide stakeholder representatives. RESULTS : The workshop participants recognized defining frameworks, mechanisms, and tools for embedding environmental sustainability into HTA as an opportunity to support sustainable development and quality improvement in healthcare. Achieving this requires (1) consensus on what environmental sustainability in healthcare means, (2) reconcilement with other healthcare and environmental policies, and (3) methods that are useful and applicable within HTA frameworks. CONCLUSION : This novel collaboration aims to align the global HTA community on the role of environmental sustainability in HTA. The report provides a path for the way forward for incorporating environmental sustainability into HTA based on broad perspectives from global multi-stakeholders.
First principles exploration of N-V point defect complexes in graphane : analysis of energetic stabilities and electronic properties
Mapingire, Hezekia; Fwalo, Chewe; Mapasha, Refilwe Edwin (Springer, 2025-02-07)
In this study, we employ first principles calculations within the framework of density functional theory to comprehensively investigate the energetic stabilities and electronic properties of various nitrogen dopant-vacancy complexes: NCVH,  NCVCH,  NCHVH and NCHVCH in the graphane two-dimensional material. The creation of NCVH and NCHVH complexes require less energy than that of NCVCH and NCHVCH, according to the formation energy analysis. The binding energies analysis reveals that all the considered N-vacancy complexes are stable when compared to their isolated counterparts. Based on U-parameter values derivation, it is easier for NCHVH complex (1.09 eV) to undergo transition from one charge state to another as compared to NCVCH (2.52 eV). The N-vacancy complexes induce acceptor and donor states within the graphane band gap, which alters during transition states (0 to −1 or 0 to +1). This comparative study has provided fundamental insights into the possibilities of utilizing nitrogen-vacancy centers in graphane for band gap engineering and nano-technology tailored applications.
Are endurance runners at higher risk of depression? Screening for depression and risk factors
Scheer, Volker; Valero, David; Thuany, Mabliny; Knechtle, Beat; Viljoen, Carel Thomas; Escolano, Esther Ruescas; Burgos, Encarna Valero (Thieme Gruppe, 2025-01-20)
Depression is an important public health issue. In the general adult population, about 6.7% are affected. Little data are available about endurance runners. We conducted a prospective survey study screening for depression using the Patient Health Questionnaire and investigating potential associated risk factors in endurance runners (≥ 21.1-42.2 km) and ultraendurance runners (≥ 42.2 km). Statistical analysis included descriptive statistics, predictive techniques, and regression analysis. A total of n = 601 runners participated (female n=222 and male n=379; mean age [SD]: 42.8 years [± 10.1]). Overall, 11.3% screened positive for major depression, particularly female runners compared to male runners (p=0.002) and endurance runners compared to ultraendurance runners (p=0.023). No significant differences were observed among performance levels (elite vs. nonelite). Mild depression was observed in 21.6% of runners. Factors associated with a higher risk for screening for major depression included age (p<0.001), particularly runners under the age of 28 years, previous self-reported history of depression (p<0.001), more frequent weekly workouts (4-5/wk; p=0.021), weeks lost to injury (p=0.022), and female sex (p=0.025). A third of endurance and ultraendurance runners screened positive for depression, highlighting the importance of creating awareness for mental health issues and potential screening for athletes and providing access to appropriate support services and education.
You get HIV because there is no hope a rapid qualitative assessment of the HIV vulnerabilities of transgender women in three South African metros
Naidoo, Dhee; Cloete, Allanise; Skinner, Donald; Savva, Helen; Daniels, Danielle; Kose, Zamakayise; Ramatshekgisa, Malebo Gratitude (Taylor and Francis, 2025)
INTRODUCTION : Epidemiological data show that transgender women are disproportionately affected by Human Immunodeficiency Virus (HIV). Data in South Africa on the HIV vulnerabilities of transgender women are sparse. This paper qualitatively explores the structural, personal, and economic factors that contribute to making South African transgender women vulnerable to HIV and other sexually transmitted infections (STIs). METHODS : We conducted a rapid qualitative assessment in the Cape Town, Johannesburg, and Buffalo City metropolitan municipalities to frame the HIV risk vulnerabilities of transgender women. Purposive sampling was used to recruit study participants. We conducted 25 key informant interviews, five focus group discussions, and 26 in-depth interviews with transgender women. Atlas.ti.8 was used to facilitate qualitative data analysis. STUDY FINDINGS : These data illustrate a pervasive theme of social rejection, discrimination, and everyday victimization among transgender women. The ubiquitous presence of stigma and rejection leads to internalized stigmatization, which affects the social and mental well-being of transgender women, who often turn to alcohol and illicit drug use to alleviate negative emotions. We found that transgender women may engage in high-risk sexual activities like sex work where they can express and affirm their gender identity. In this context, transgender women engaging in high-risk sexual activities found it challenging to access pre-exposure prophylaxis (PrEP). Stigma also leads to reluctance to use public healthcare services. Despite experiencing stigma and discrimination, qualitative data highlights the resilience of transgender women in the study. CONCLUSIONS : Qualitative data demonstrate that HIV risk for transgender women is complex. Multi-level community-led interventions grounded in empowerment are also required to address interpersonal, biological, structural, and community risk. Successful interventions should address stigma and draw upon the resilience of transgender women. Peer-driven interventions may motivate personal responsibility to use high-impact HIV prevention and treatment services.
A load-balancing enhancement to schedule-aware bundle routing
Kamps, Jason Jack; Paluncic, Filip; Maharaj, Bodhaswar Tikanath Jugpershad (Wiley, 2025-03)
Delay- and disruption-tolerant networking (DTN) enables communication in networks afflicted by long propagation delays and sporadic connectivity. DTN routing techniques such as schedule-aware bundle routing (SABR) exist to route data bundles in de-terministic networks, such as those found in deep-space environments, where node contacts are predictable. This article begins with an overview of DTN architecture and SABR. SABR's method of final route selection (forwarding rules) is closely examined. The article then addresses a limitation of SABR whereby the algorithm may overlook parallel channels, leading to network congestion. To mitigate this, an enhancement is proposed. This enhancement aims to optimize data bundle distribution across candidate routes in networks with parallel channels, thus alleviating congestion and enhancing overall network performance. This is achieved with simple modifications to SABR's forwarding rules to avoid the concentration of data bundles on a minority of node contacts. The enhancement is demonstrated through simulations in a reference scenario implemented in DtnSim.
Unlocking hydropower's potential : retrofitting infrastructure and harnessing unconventional sources for clean energy transitions
Van Dijk, Marco; Gezer, Dogan; Rudolf, Pavel (IOP Publishing, 2025)
Hydropower holds a pivotal role within the water-energy nexus for facilitating the clean energy transition, particularly in unconventional and retrofit opportunities. As a renewable energy source, hydropower contributes to decarbonizing the energy sector while simultaneously supporting water management objectives. By integrating hydropower generation into existing infrastructure such as water supply systems, weirs, irrigation networks, and wastewater treatment facilities, synergies can be leveraged to optimize resource utilization and enhance system resilience. This further offers some options for diversifying the electricity mix and speeding up the clean energy transition. However, the complex interaction between water availability and energy production necessitates careful planning and adaptive strategies to mitigate risks associated with climate variability and changing demand patterns. Unlocking the potential of hydropower through these unconventional and retrofitting opportunities is thus instrumental in advancing sustainability goals and ensuring the success of clean energy transitions in the face of various challenges. By leveraging existing infrastructure and exploring innovative solutions, countries stand to significantly enhance its energy resilience and reduce its carbon footprint. Moreover, such initiatives align with broader international objectives, including the Paris Agreement's vision of transitioning to a zero-emission society by 2050 and the European Union's FIT for 55 targets. Under these considerations, this paper seeks to explore the potential of retrofitting existing infrastructure and harnessing unconventional hydropower sources with examples in Czechia, South Africa and Türkiye to address electricity shortages, mitigate carbon emissions, and contribute to the broader clean energy transition agenda. The insights gained from this analysis can inform policy frameworks, investment strategies, and technological innovations aimed at fostering sustainable energy practices.
Y chromosome variation and prostate cancer ancestral disparities
Soh, Pamela X.Y.; Adams, Alice; Bornman, Maria S. (Riana); Jiang, Jue; Stricker, Phillip D.; Mutambirwa, Shingai B.A.; Jaratlerdsiri, Weerachai; Hayes, Vanessa M. (Elsevier, 2025-05-16)
Prostate cancer (PCa) is marked by significant ancestral bias, with African men disproportionately impacted. However, genome profiling studies have yet to explore the mutational landscape and disparity contribution of the male-determining Y chromosome. Using a cohort of 106 African and 57 European PCa cases, biased toward aggressive presenting primary disease, we performed complete Y chromosome interrogation for inherited and somatic variance. Capturing unexplored early-diverged Y-haplogroup substructure, while European men are 3.1-fold more likely to present with a rare potentially deleterious germline variant, a higher proportion of African patients acquired Y chromosome tumorigenic events (26.4% African, 14% European). While somatic copy number alterations were universally more common to aggressive tumors, besides shared alterations impacting DDX3Y and USP9Y, African derived tumors were prone to somatic losses associated with KDM5D, PCDH11Y, and RBMY. This much-needed African inclusive study alludes to possible Y chromosome contribution, at least in part, to treatment resistance and worsened mortality rates in African men.
Lactobacillus-rich cervicovaginal microbiome associated with lower BV, HPV, and cytology outcomes in women
Osei Sekyere, John; Trama, Jason; Adelson, Martin; Trikannad, Charulata; DiBlasi, Desiree; Schuster, Rachel; Yang, Jing Jing; Mordechai, Eli (Elsevier, 2025-10-17)
The cervicovaginal microbiome modulates susceptibility to bacterial vaginosis (BV), high-risk human papillomavirus (hrHPV) infection, and epithelial cell abnormalities that precede cervical cancer. We retrospectively analyzed 15 607 qPCR-profiled cervicovaginal specimens from U.S. women (ages 14–95; 32 states) and integrated microbiome abundances, hrHPV genotyping, Pap-cytology, and demographics. BV was present in 53% and hrHPV in 11% of samples. Lactobacillus crispatus, L. gasseri, and L. jensenii were enriched in BV-negative and cytologically normal (NILM) samples, whereas L. iners and BV-associated anaerobes co-occurred with hrHPV and abnormal cytology. Machine-learning models confirmed age, hrHPV status, and L. crispatus abundance as the strongest multivariate predictors of BV and cytological outcomes (BV AUROC ≈0.97). Interaction analyses revealed synergistic associations between specific hrHPV genotypes and Gardnerella/Fannyhessea that further increased cytological risk. These findings underscore the clinical value of microbiome profiling and support probiotic strategies that promote protective Lactobacillus communities to reduce BV and hrHPV-related cervical pathology.

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