Postprints (Articles)

Permanent URI for this collectionhttp://hdl.handle.net/2263/51908

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Numerical investigation of heat transfer performance of hybrid nanofluid in porous substrate in microchannel heat sink
(Springer, 2025-07) Oladetan, Jeremiah O.; Fujah, Faridat M.; Omosehin, Oluwasegun S.; Atofarati, Emmanuel O.; Nwabuko, Uzo; Olakoyejo, Olabode T.; Adelaja, Adekunle O.; omosehin.os@up.ac.za
With the increasing integration of integrated circuits (ICs) in electronic devices such as electric vehicles, computer data centers, heat pipe technology, solar energy, and heating ventilation, air conditioning, and refrigeration (HVACR) systems, optimizing heat transfer becomes essential to ensure optimal performance and longevity. This study numerically investigates the thermal and hydraulic performance of a microchannel heat sink (MCHS) enhanced by hybrid nanofluids and porous substrate integration. A two-phase Eulerian–Eulerian model implemented in ANSYS Fluent is employed to simulate Al₂O₃/Cu–water hybrid nanofluid flow at volume concentrations ranging from 0.1 to 3.0%, and flow Reynolds number (200 < Re < 1000) with a porous substrate embedded midway along the flow path. The results reveal that both the nanoparticle concentration and Reynolds number significantly enhance heat transfer, reflected in higher average Nusselt numbers and reduced thermal resistance. The incorporation of a porous substrate further amplifies heat transfer, achieving a maximum enhancement of 80.29% compared to the baseline configuration. Overall, employing hybrid nanofluids and porous substrates improves MCHS performance, offering augmented heat transfer efficiency and thermal performance.
Approaches to modelling spatial data using skewed distributions with an application to disease mapping
(Taylor and Francis, 2025) Ayalew, Kassahun Abere; Manda, S.O.M. (Samuel); Cai, Bo
In disease mapping, estimating spatial patterns is typically done by fitting Gaussian spatial models. However, this assumption may not always be correct, as there is a possibility that the spatial random component could follow a skewed and non-symmetric distribution. We propose two spatial statistics methods based on the skew-normal and skew-Laplace spatial distributions to model the spatial random effects. These approaches leverage the unique properties of skewed distributions to capture the inherent asymmetry in spatial data, providing a more accurate representation of complex disease risk. We compared the performance of our proposed non-normal spatial models with existing methodologies through simulation studies. To demonstrate the applicability of our approach, we analysed adult HIV and infant mortality in South Africa. This demonstration highlights our models' effectiveness and provides valuable insights into their practical relevance in public health research.
Derivation of a multivariate longitudinal causal effects model
(Taylor and Francis, 2025) Twabi, Halima S.; Manda, S.O.M. (Samuel); Small, Dylan S.; Kohler, Hans-Peter
This paper presents a causal inference estimation method for longitudinal observational studies with multiple outcomes. The method uses marginal structural models with inverse probability treatment weights (MSM-IPTWs). In developing the proposed method, we re-define the weights as a product of inverse weights at each time point, accounting for time-varying confounders and treatment exposures and possible correlation between and within (serial) the multiple outcomes. The proposed method is evaluated by simulation studies and with an application to estimate the effect of HIV positivity awareness on condom use and multiple sexual partners using the Malawi Longitudinal Study of Families and Health (MLSFH) data. The simulation study shows that the joint MSM-IPTW performs well with coverage within the expected 95% level for a large sample size (n = 1000) and moderate to strong between and within outcome correlation strength (𝜌𝑗=0.3, 0.75, 𝜌𝑘=0.4, 0.8) when the effects are similar. The joint MSM-IPTW performed relatively the same as the adjusted standard joint model when the treatment effect estimate was the same for the outcomes. In the application, HIV positivity awareness increased the usage of condoms and did not affect the number of sexual partners. We recommend using the proposed MSM-IPTWs to correctly control for time-varying treatment and confounders when estimating causal effects for longitudinal observational studies with multiple outcomes.
Understanding barriers to pre-exposure prophylaxis (PrEP) uptake among young people in Lower Gweru, Zimbabwe. A qualitative study
(Routledge, 2025) Jimu, Christopher; Nyamaruze, Patrick; Moyo, Freely Tanatswa; Makaye, Jeriphanos
Pre-exposure prophylaxis (PrEP) is a highly effective strategy for preventing HIV infection when taken as prescribed. Most studies have focused on adult populations and other vulnerable groups, such as men who have sex with men (MSM) while few studies have explored the barriers young people face toward PrEP uptake yet they contribute a worrying percentage of new infections and HIV related deaths. We conducted 17 in-depth interviews with young people aged 15–24 years and key informants in Lower Gweru, Zimbabwe. Findings highlighted that young people face numerous barriers such as fear of side effects, pill burden, and lack of PrEP awareness. We concluded that addressing challenges to PrEP uptake requires a multifaceted approach that includes improving accessibility and education, as well as addressing cultural and social barriers. Implementing these recommendations can significantly enhance PrEP uptake, ultimately contributing to national HIV prevention goals and better health outcomes for young populations
Diuresis during 18F-flotufolastat (rhPSMA-7.3) PET/CT improves recurrence detection after prostatectomy : a prospective Phase II trial
(Society of Nuclear Medicine and Molecular Imaging, 2025-02) Lawal, Ismaheel Opeyemi; Mushtaq, Aliza; Jani, Ashesh B.; Rupji, Manali; Dhere, Vishal R.; Patel, Sagar A.; Bilen, Mehmet A.; Patel, Pretesh R.; Sebastian, Nikhil T.; Switchenko, Jeffrey M.; Schuster, David M.; Marcus, Charles
Please read abstract in the article.
Cancer and fertility management : FIGO best practice advice
(Wiley, 2025-10) Purandare, Nikhil; Ruiloba, Francisco; Nguyen-Hoang, Long; Wilailak, Sarikapan; Yanaihara, Nozomu; Chung, Jacqueline P.W.; Malhotra, Jaideep; Mocanu, Edgar; Amant, Frederic; McNally, Orla; Peters, Inge; Flynn, Katie; El Helali, Aya; Maxwell, Cynthia; Adam, Sumaiya; Bergman, Lina; Nanda, Surabhi; Guinto, Valerie Tiempo; McAuliffe, Fionnuala M.; Nelson-Piercy, Catherine; Nana, Melanie; Smith, Graeme; Berek, Jonathan; O'Reilly, Sharleen; O'Brien, Pat; Jacobsson, Bo; Poon, Liona C.
Cancer diagnoses in patients of reproductive age require balancing urgent oncological treatment with the need to preserve fertility. This FIGO Best Practice Advice outlines key considerations for fertility management in this population given the rising cancer incidence among young women and the reproductive risks posed by cancer treatments. The guidance evaluates the impact of chemotherapy, radiotherapy, surgery, and emerging therapies—such as targeted agents and immunotherapies—on gonadal function and fertility. Established fertility preservation methods, including oocyte/embryo cryopreservation, sperm banking, and ovarian tissue freezing, are detailed alongside barriers to their adoption, such as cost and limited access. Early collaborative counseling with oncologists and fertility specialists is central to addressing timelines, psychological impacts, and priorities. Post-treatment pathways, including assisted reproduction and surrogacy, are also explored. The guidance stresses the importance of integrating fertility-sparing interventions and fertility preservation into cancer care while advocating for equitable access to resources. Further research is needed to refine preventive interventions, evaluate long-term outcomes, and expand options for survivors globally. By prioritizing fertility preservation within oncological care, healthcare providers can better support the holistic needs of young individuals facing cancer.
‘Silent losses–silent data’ : reviewing stillbirth data quality in low- and middle-income countries using data quality dimensions
(Wiley, 2025) Pandey, Anuj Kumar; Neogi, Sutapa Bandyopadhyay; Gautam, Diksha; Thomas, M. Benson; Basu, Jayati; Basu, Debashis; Widyastari, Dyah Anantalia
Precise data is crucial for policy decision-making, especially in sensitive outcomes like stillbirth, where each data element have significant effects. Following years of advancement in the healthcare domain, there is a pressing need to improve data-based policymaking by addressing both the social context and emotional dimensions. This holds true for any healthcare condition including stillbirth, which demands the attention of healthcare managers, researchers and policymakers. Conditions such as stillbirth signify more than a birth devoid of vital signs. A mother endures months of discomfort and excruciating labour pain and faces the devastating reality that her baby is no longer alive. The absence of her child's initial cry disrupts her life, causing her to struggle with confusion and sadness on the factors that may have led to this catastrophe. In spite of this significant loss, we typically perceive it as merely one death, often neglecting to acknowledge it adequately. Significant advancements in averting stillbirths can be achieved by viewing it as a loss of life, rather than only perceiving it as the birth of a lifeless infant. Examining stillbirth data and comprehending its causes can aid in formulating strategies to avert future incidents. This publication seeks to compile information on the principal issues associated with the reporting and recording of stillbirths in low- and middle-income countries (LMICs) from the perspective of data quality aspects. Furthermore, it also proposes strategies to enhance each aspect of data quality like harmonising stillbirth definitions, linking routine data systems with surveys, facility audits for better data capture, and increasing funding for stillbirth-related research etc. HIGHLIGHTS • Progress in stillbirth prevention needs robust data for informed decision making. • Concerns in LMIC stillbirth data: no targets, misclassification, fear, stigma etc. • Study recommends better data capture via audits, system links and funding.
Cryphonectria Canker on Eucalyptus in Florida reconsidered
(Wiley, 2025-08) Pham, Nam Q.; Wingfield, Brenda D.; Marincowitz, Seonju; Brawner, Jeremy T.; Hulcr, Jiri; Wingfield, Michael J.; nam.pham@fabi.up.ac.za
Cryphonectria canker is one of the most important diseases of plantation-grown Eucalyptus spp. in the tropics and Southern Hemisphere. The disease has been known in Florida, USA, for many years, and the causal agents are attributed to two known canker pathogens, Chrysoporthe cubensis (≡ Cryphonectria cubensis) and Microthia havanensis (≡ Endothia havanensis). These identifications were based on morphological characteristics, which are inadequate to recognise cryptic species in the Cryphonectriaceae. In this study, we visited various sites in Florida where Eucalyptus grandis and E. amplifolia trees are cultivated and investigated the presence of cankers. Isolations were made from fungal structures on symptomatic tissues associated with cankers. A total of 41 cultures resembling Cryphonectriaceae spp. were isolated. The isolates were identified based on DNA sequences for the ITS region of the rRNA and sections of the β-tubulin gene, and confirmed as the three species of Cryphonectriaceae, namely Microthia havanensis, Chrysoporthe cubensis and Chrysoporthe doradensis. Of these, Chrysoporthe doradensis was discovered for the first time in the USA. In addition, this study represents the first record of any Cryphonectriaceae on E. amplifolia , a Eucalyptus species that is poorly studied in terms of disease. Pathogenicity trials on Eucalyptus showed that all three Cryphonectriaceae species could cause disease on these trees, with Chrysoporthe spp. being more aggressive. These findings highlight the importance of continuous monitoring and surveillance to detect emerging pathogens and safeguard the sustainability of Eucalyptus in non-native forestry systems.
Infection rates of Fasciola spp. in cattle slaughtered at 13 abattoirs in six of nine provinces of South Africa
(Elsevier, 2025-06) Nukeri, Sophy; Malatji, Mokgadi Pulane; Sithole, Msawenkosi I.; Ngcamphalala, Philile I.; Nyagura, Ignore; Tembe, Danisile; Ndlovu, Innocent Siyanda; Chaisi, Mamohale E.; Mukaratirwa, Samson
Fasciolosis or liver fluke infection is a snail-borne disease that affects the productivity of domestic ruminants including liver condemnation especially in cattle. However, there is paucity of information on the burden of infection due to lack of accurate data on liver condemnation related to correct geographical origin of infected animals. This distorts perception of the geographical occurrence of fasciolosis, particularly in South Africa among other countries. We aimed to determine the infection rates of Fasciola spp. in cattle slaughtered at selected abattoirs in South Africa. A total of 13 abattoirs consisting of 10 high throughput and three low throughput abattoirs across six provinces, were visited to screen for liver fluke infection in slaughtered cattle including tracing of the animals' geographical origin. A total of 57 livers from 673 slaughtered cattle (8.5 %) from 10 abattoirs were infected with Fasciola spp.. The highest infection rate from the study sites was 37 % and the lowest 4.5 %. Tracing of infected cattle showed that some abattoirs slaughtered cattle originating from other provinces. Forty-nine percent (29/57) of infected cattle had moderate body condition score (BCS) and recorded the highest intensity of fluke infection (>100 flukes per liver). Furthermore, young animals had high infection rates (51 %; 29/57) compared to adults (49 %; 28/57) and females (54 %; 31/57) compared to males (46 %; 26/57). The overall results highlighted the presence of Fasciola spp. in five provinces of South Africa, represented by more than four agro-ecological zones. Fasciola hepatica occurred in all six provinces while both Fasciola spp. co-occurred in one province. Furthermore, F. hepatica constituted the highest percentage (74 %; 710/960) of Fasciola spp. specimens collected. Fasciola gigantica were collected from abattoirs in one province and constituted 26 % (250/960) of the total collected flukes. Results from the study provide information on the burden of fasciolosis in cattle. This is based on abattoir surveys in South Africa, considering the traced geographical origin of animals slaughtered. Using data from surveys of this nature might support efforts to map the geographical distribution of fasciolosis in South Africa. Thus, contribute towards the development of effective control and treatment programs of fasciolosis to mitigate the burden of the disease in cattle. HIGHLIGHTS • Fasciolosis is prevalent in cattle slaughtered at abattoirs from six provinces of South Africa. • Cattle movement for slaughter distorts the true prevalence at provincial level. • Cattle movement may contribute to introduction of infections to new areas. • Fasciola hepatica was recorded in all six provinces. • Fasciola gigantica co-occurred with F. hepatica in the Limpopo province.
Turing patterns across geometries : a proven DSC-ETDRK4 solver from plane to sphere
(Elsevier, 2025-08) Owolabi, Kolade M.; Pindza, Edson; Mare, Eben
This paper presents a unified and robust numerical framework that combines the Discrete Singular Convolution (DSC) method for spatial discretization with the Exponential Time Differencing Runge–Kutta (ETDRK4) scheme for temporal integration to solve reaction–diffusion systems. Specifically, we investigate the formation of Turing patterns – such as spots, stripes, and mixed structures – in classical models including the Gray–Scott, Brusselator, and Barrio–Varea–Aragón–Maini (BVAM) systems. The DSC method, employing the regularized Shannon’s delta kernel, delivers spectral-like accuracy in computing spatial derivatives on both regular and curved geometries. Coupled with the fourth-order ETDRK method, this approach enables efficient and stable time integration over long simulations. Importantly, we rigorously establish the necessary theoretical results – including convergence, stability, and consistency theorems, along with their proofs – for the combined DSC-ETDRK4 method when applied to both planar and curved surfaces. We demonstrate the capability of the proposed method to accurately reproduce and analyze complex spatiotemporal patterns on a variety of surfaces, including the plane, sphere, torus, and bumpy geometries. Numerical experiments confirm the method’s versatility, high accuracy, and computational efficiency, making it a powerful tool for the study of pattern formation in reaction–diffusion systems on diverse geometries.
Designing an African-context game to entice physiotherapy students to study child developmental milestones
(Taylor and Francis, 2025) Human, Anri; Cochrane, Maria Elizabeth; maria.cochrane-boeyens@up.ac.za
EDUCATIONAL CHALLENGE : Teaching child developmental milestones in undergraduate physiotherapy can be challenging due to the high volume of factual content, which students often find difficult to master. Furthermore, higher education institutions are expected to promote self-directed learning among students. This dual challenge requires innovative methods of teaching and learning to ensure student success. SOLUTION AND IMPLEMENTATION : A narrative-based digital game, called ‘Kidnapped’, was developed using a design-thinking approach. This game was developed in response to the need for interactive, accessible content delivery and to foster self-directed learning among students. The game was intentionally designed to incorporate the principles of learning scaffolding and reinforced learning through repetition, ensuring its educational relevance and alignment with student learning needs. The game was piloted with academic staff to ensure implementation feasibility. LESSONS LEARNED AND NEXT STEPS : A cross-sectional, cross-over study will be conducted towards the end of 2025, combining quantitative and qualitative methods to evaluate the game’s effectiveness. Findings will inform iterative improvements and guide broader implementation across health sciences programmes. Key lessons learned include the value of early stakeholder engagement, the importance of adaptable technology, and the potential of gamification to enhance active learning and learning autonomy in health professions education.
Integrated thinking to address social and environmental grand challenges
(Emerald, 2025) Dimes, Ruth; Grana, Fabrizio; Busco, Cristiano; De Villiers, Charl Johannes
PURPOSE : This paper addresses the urgent need for new approaches and systems of accountability to tackle grand challenges such as climate change, resource scarcity, and inequalities. It explores the role of accounting and accountability practices, as well as the actions of academics, through the lens of Integrated Thinking. DESIGN/METHODOLOGY/APPROACH : The paper employs the three-stage critical framework of Alvesson and Deetz (2000), which includes insight, critique and transformative redefinition. It reviews the current literature on grand challenges and Integrated Thinking, extending the conceptual framework proposed by Granà et al. (2025). It critically reflects on the contributions to this AAAJ Special Issue in the context of Integrated Thinking, suggesting future research directions and actions. FINDINGS : The study highlights the potential of Integrated Thinking to improve connectivity and collaboration across organisational, societal and intertemporal boundaries to drive meaningful change in addressing grand challenges. It emphasises the importance of considering multiple perspectives and integrating various domains of knowledge to make informed decisions that prioritise the whole over its constituent parts. The study proposes that Integrated Thinking may help in developing a virtuous “loop” across organisational, disciplinary and contextual boundaries. ORIGINALITY/VALUE : This paper extends the framework proposed by Granà et al. (2025) to incorporate Integrated Thinking, offering a new perspective on how accounting and accountability practices can address grand challenges. The paper provides a call to action for accounting academics, proposing future research directions and reflections to promote Integrated Thinking across research, teaching, and service activities.
Calcifying odontogenic cyst : a detailed international multicentric study
(Elsevier, 2025-07) Farias Bezerra, Helen Kaline; Dutra, Mateus Jose; Roza, Ana Luiza Oliveira Correa; De Freitas, Stephanie Vargas; Kaminagakura, Estela; Anbinder, Ana Lia; Vazquez-Garduno, Marcela; Rojas-Alcayaga, Gonzalo; Espinoza-Santander, Iris Lucia; Pinto, Ana Veronica Ortega; Farias, Danielle Machado; Carvalho, Elaine Judite de Amorim; De Castro, Jurema Freire Lisboa; Lopes, Marcio Ajudarte; Santos-Silva, Alan Roger; Robinson, Liam; Abrahao, Aline Correa; Romanach, Mario Jose; Van Heerden, Willem Francois Petrus; Mosqueda-Taylor, Adalberto; Vargas, Pablo Agustin; Perez, Danyel Elias da Cruz
OBJECTIVE : To elucidate the histopathological, immunohistochemical, and ultrastructural characteristics of a large series of calcifying odontogenic cysts (COCs). STUDY DESIGN : This was a multicenter cross-sectional retrospective study of seven oral pathology department laboratories from four countries. Clinical, demographic, and radiographic data of the patients were collected. Histopathological, immunohistochemical, and microstructural analyses were based on formalin-fixed, paraffin-embedded tissues. All variables were described, and associations were analyzed using Pearson's chi-square and Fisher's exact tests. RESULTS : A total of 146 cases of COC were analyzed, including 141 central and 5 peripheral cases. Male patients were most involved, with a mean age of 27.8 years. The main clinical presentation was an asymptomatic swelling in the anterior maxilla. Radiographically, most cases appeared as a single well-defined unilocular radiolucency. Forty cases of COC were associated with other odontogenic lesions, including odontoma, ameloblastic fibroma, and odontogenic keratocyst. Immunohistochemical study showed cytoplasmic positivity for CK AE1/AE3, CK14, CK19, and Bcl-2 protein. Nuclear expression of β-catenin was observed in most cases. CONCLUSIONS : COC mainly affects adult males between the second and third decades of life. Asymptomatic maxillary swellings with diverse radiographic and histopathological presentations were noted. Moreover, COC may present associations with other odontogenic lesions, particularly odontomas in younger patients.
COVID-19 pandemic stress and anxiety among South African parents and their children
(Springer, 2025-04) Gaxo, Ezethu; Salie, Muneeb; Bloom, Jenny; Lachman, Anusha; Davids, Eugene Lee; Theron, Linda C.; Pillay, Jace; Seedat, Soraya
The global outbreak of Coronavirus Disease 2019 (COVID-19) significantly impacted the mental health of individuals across all age groups. The Co-SPACE (COVID-19: Supporting Parents, Adolescents, and Children during Epidemics) study conducted in South Africa aimed to explore the impact of the COVID-19 lockdown on the mental health of parents/carers and their children. The online survey involved 257 parents/carers of children (aged 4 to 10 years) and adolescents (aged 11 to 18 years) attending school in Grades R (pre-formal schooling) to 12. The survey assessed the stressors faced by parents/carers, evaluated children’s anxiety levels using the Pandemic Anxiety Scale (PAS), created to measure specific pandemic-related mental health factors, and gathered information on children’s concerns and time allocation. Study findings revealed that the COVID-19 lockdown had a detrimental effect on both parents/carers and their children. The top three sources of stress reported by parents/carers were their work, their child’s future, and their child’s education. Children and adolescents had average anxiety levels of 11.60 ± 6.14 and 14.62 ± 5.56 on the PAS, respectively. Factors such as the child’s age, household income, and family composition were associated with higher anxiety levels. This study highlights the experiences and stress levels faced by parents/carers during the pandemic, as well as the concerns of their children and adolescents. It underscores the importance of identifying vulnerable groups and understanding the factors contributing to their mental health difficulties. This knowledge is crucial for developing effective strategies to address the mental health challenges arising from COVID-19 and future crises. By recognizing and addressing these issues, society can better support families and promote overall well-being.
Abundance, diversity and development of thrips (Thysanoptera) on avocados and macadamias in the Levubu region of Limpopo Province, South Africa
(Wiley, 2025-08) Kibor, Maxwell K.; Sole, Catherine L.; Joubert, Elsje; Weldon, Christopher William; cwweldon@zoology.up.ac.za
Some thrips (Thysanoptera) species are presumed to injure avocado and macadamia trees and fruit when feeding as nymphs and adults. We investigated the abundance and species richness of thrips and monitored fruit and nut set and damage on four avocado (Fuerte, Hass, Maluma and Pinkerton) and macadamia (695, 814, 816 and A4) cultivars. Different stages of avocado fruit (1–3, 4–6 and 7–9 cm) or macadamia nut development (closed racemes, nut set, nut size 1–1.5 cm and nut size 3–4 cm) were sampled over two seasons in the Levubu region of Limpopo Province, South Africa. Thrips development on fruit, nuts and leaf flush was recorded to verify the thrips species causing damage. A total of 15 535 thrips were collected during August–January 2020–2021 and 2021–2022. Six thrips morphotypes were identified across macadamia and avocado orchards: Scirtothrips aurantii Faure (Thripidae), Thrips tenellus Trybom (Thripidae), Haplothrips gowdeyi Franklin (Phlaeothripidae), Frankliniella occidentalis Pergande (Thripidae), Megalurothrips sp. (Thripidae) and Caliothrips sp. (Thripidae). Thrips were less abundant in the 2020/2021 season compared to the 2021/2022 season and in avocados than in macadamias. Pinkerton (2020/2021: 4.9 ± 0.8 and 2021/2022: 13.1 ± 0.2) and Fuerte (2020/2021: 6.9 ± 1.3 and 2021/2022: 7.5 ± 0.1) had the highest damage and fruit set per inflorescence in both seasons. Fruit size 1–3 cm had a mean damage of 3.4 ± 0.8 in 2020/2021 and 4.0 ± 0.7 in 2021/2022, 4–6 cm had 5.3 ± 0.9 and 4.7 ± 0.7 in 2021/2022, and 7–9 cm had 5.2 ± 0.9 in 2020/2021 and 5.0 ± 0.8 in 2021/2022. Macadamia cultivars and developmental stages most affected by thrips were dependent on the season. Our results suggest that damage occurs earlier in fruit or nut development, and Fuerte avocados and Macadamia 695 were the least susceptible to thrips damage. S. aurantii larvae developed from all sampled avocado and macadamia tissues and were able to persist until the adult stage, confirming it as the main damaging thrips species of avocado and macadamia in the Levubu region.
Enhancing the energy yield of Amaranthus hybridus-derived biofuel using alkaline pretreatment : experimental and data-driven investigation
(Elsevier, 2026-02) Adeleke, Oluwatobi; Bamisaye, Abayomi; Ige, Ayodeji Rapheal; Adegoke, Kayode Adesina; Jen, Tien-Chien
he global quest for sustainable and eco-friendly fuel alternatives has spurred interest in biofuels. This study presents an experimental and data-driven framework for investigating the impact of alkaline-pretreatment on the combustion properties of solid-biofuel derived from Amaranthus hybridus. The aim of the study is to enhance the energy content of the biofuel using NaOH-pretreatment and provide data-driven insight into its energy drivers. The experimental analysis involved ultimate and proximate analysis, calorific value (CV) determination, and structural characterization. Advanced data analytics, including correlation analysis, feature importance analysis (FIA), dimensionality reduction using Principal Component Analysis (PCA), and neuro-fuzzy modelling, were developed to explore relationships among biofuel properties. A Grid Partitioning (GP)-clustered Adaptive Neuro-Fuzzy Inference System (ANFIS) tuned with Particle Swarm Optimization (PSO) was developed for CV prediction. NaOH pretreatment increased the CV from 11.38 MJ/kg to 12.79 MJ/kg (a 12.9 % improvement). The FTIR analysis revealed a C–O stretch difference of 4 cm−1, while the SEM analysis revealed morphological restructuring. The correlation-based parameter profiling revealed fixed carbon (FC) as the only positively correlated parameter with CV. The FIA revealed FC as the most influential predictor of energy content with a Gini index of 0.821, while PCA further confirmed FC’s dominance in driving calorific performance. The GP-clustered ANFIS-PSO model with triangular membership functions outperformed other configurations with high accuracy (RMSE = 0.1070, MAPE = 7.354 %, MAD = 0.0828, and MAE = 0.0895). This research contributes valuable insights into optimizing solid biofuel combustion properties through pretreatment strategies, supported by advanced computational, data-driven and neuro-fuzzy techniques. HIGHLIGHTS • Alkaline pretreatment (0.5 % NaOH) improved CV by 12.9 % from 11.38 to 12.79 MJ/kg. • SEM and FTIR confirmed NaOH pretreatment-induced fiber delignification and porosity. • Fixed carbon (FC) emerges as the dominant driver of energy with a GI-value of 0.821. • PCA shows that 98% of the data variance is captured in PC1 with FC as the dominant feature. • GP-ANFIS-PSO model achieved the best CV prediction with RMSE of 0.1070 and R2 of 0.932.
Impact of preschool hearing screening in low-income communities : program outcomes and caregiver perspectives
(American Speech-Language-Hearing Association, 2025-04) Odendaal, Tara; Le Roux, Talita; Swanepoel, De Wet; dewet.swanepoel@up.ac.za
PURPOSE : This study aimed to describe the impact of a preschool hearing screening program in a low- and middle-income country (LMIC) in terms of referral outcomes and caregiver perspectives. METHOD : This study included two components. First, a review of outcomes from a large-scale community-based hearing screening program, facilitated by community health workers (CHWs), for preschool children who failed their hearing screening. Second, telephonic surveys were conducted with (a) 25 caregivers whose children attended follow-up appointments and were diagnosed with hearing loss and (b) 33 caregivers whose children did not attend follow-up appointments. RESULTS : Over 21 months, 13,322 children underwent hearing screening, with an initial referral rate of 6% (809). Follow-up tests at preschools covered 86.2% (697) of children who failed the initial hearing screening, of whom 47.8% (387) presented with hearing loss and were referred for further evaluation. Among the 190 attending follow-up appointments, 54.8% (104) were diagnosed with hearing loss. Of these, 71.1% (74) had conductive hearing loss, 12.5% (13) had sensorineural hearing loss, and 13.5% (14) had mixed hearing loss. Caregivers strongly supported (96%) community-based hearing screening for preschool-aged children. Notably, attendance varied significantly between preschool rescreenings (86.2%) and health care facility follow-up appointments (49.1%). Caregivers highlighted barriers to attend hearing services including work commitments, long waiting times at health care facilities, miscommunication about referrals and appointments, relocations, and COVID-19 appointment cancellations. CONCLUSIONS : This study highlights the effectiveness of community-based hearing screenings in LMICs, led by CHWs. It emphasizes strong caregiver support and the importance of culturally relevant communication. Challenges in follow-up attendance persist, emphasizing the need for improved accessibility and communication within health care systems. Prioritizing caregiver concerns and promoting culturally sensitive education are essential for improving outcomes.
Adsorptive and photocatalytic remediation of greywater in wastewater : a review
(Springer, 2025-03) Sanni, Saheed O.; Pholosi, Agnes; Pakade, Vusumzi E.; Brink, Hendrik Gideon
Bathroom, and laundry greywater (GW) components are considered significant urban wastewater and are classified as hazardous substances that contaminate groundwater resources. Thus, achieving permitted levels for GW before discharging into the environment requires the removal or reduction, which has become a challenge. Various techniques have been developed to decontaminate GW from wastewater, comprising biological, chemical, filtration, adsorption, membrane separation, and photocatalytic degradation. Due to the simplicity, cost-effectiveness, abundance of materials, and capacity for facile scaling-up for remediation purposes, adsorption and photocatalysis technologies have been widely utilized in GW wastewater treatment. This review thus first explains the sources of GW and components found within this particular wastewater, which are critical for removal. The second part reviews various adsorbents or photocatalysts, including materials of macro, micro, and nanosize utilized for GW treatment. The review highlights the significance of activated carbon among all adsorbents under adsorption technology reviewed with the highest removal rate of chemical oxygen demand (COD), and biochemical oxygen demand BOD in GW. Moreover, the doped titanium dioxide photocatalyst also presented significant removal of COD, and BOD in GW within a shorter space of time. The impact of surface area and chemical functionalities of the adsorbent, and whilst aspect of nanostructure and absorptivity of photocatalyst in the visible region of the solar spectrum on the expedited removal of GW was also highlighted. Furthermore, this review emphasizes photocatalyst nanomaterial achieving a complete mineralization of different components present in GW, into mineral products.
Expanding role for gallium-68 PET imaging in oncology
(Elsevier, 2024-11) Kleynhans, Janke; Ebenhan, Thomas; Sathekge, Mike Machaba
Please read abstract in the article.
Prevalence, symptomology, and correlates of curable sexually transmitted infections among pregnant women in Eastern Cape, South Africa
(Sage, 2025-09) Shaetonhodi, Natalie G.; De Voux, Alex; Babalola, Chibuzor M.; Davey, Dvora Joseph; Mdingi, Mandisa M.; Gigi, Ranjana M.S.; Peters, Remco P.H.; Mukomana, Freedom; Klausner, Jeffrey D.; Medina-Marino, Andrew
BACKGROUND: Curable sexually transmitted infections (STIs) contribute to adverse maternal and neonatal outcomes. Syndromic management is standard care in South Africa. We evaluated prevalence, symptomology, and correlates of curable STIs, among pregnant women in Eastern Cape, South Africa. METHODS : We conducted a cross-sectional analysis using baseline data from a randomized controlled trial of pregnant women attending their first antenatal care visit at public clinics in Buffalo City Municipality (2021–2024). Participants were tested for Chlamydia (C.) trachomatis, Neisseria (N.) gonorrhoeae, Trichomonas (T.) vaginalis using GeneXpert point-of-care tests and for syphilis using Alere Determine TP rapid test. Symptoms were self-reported and clinically-observed. Adjusted prevalence ratios were estimated using Poisson regression models with robust standard errors. RESULTS : Among 1491 participants (median age: 28 years (IQR: 24–33); gestational age: 13 weeks (IQR: 8–18); HIV prevalence: 30%), STI prevalence was 27.6% (95% CI: 25.3–29.9): C. trachomatis 14.7%, N. gonorrhea 5%, T. vaginalis 10.2%, syphilis 3.4%. Women with HIV had higher STI prevalence (32.8% vs 25.3%, p = .003), particularly for T. vaginalis (17% vs 7.3%, p < .001); 20.1% of women with C. trachomatis, N. gonorrhea, and/or T. vaginalis were symptomatic, and 63% of symptomatic women tested STI-negative. Younger age, lower education, multiple sex partners and unknown HIV-serostatus of partners were associated with increased STI prevalence. CONCLUSION : We observed a high prevalence of STIs, particularly among women with HIV, with many asymptomatic cases; emphasizing the need for integrated point-of-care testing to ensure timely treatment, reduce antibiotic overuse, and improve maternal and neonatal outcomes.

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