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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Onderwysers se oortuigings, onderwysers se selfdoeltreffendheid, onderriggehalte en onderrigklarigheid : die verband met Suid-Afrikaanse leerders se wiskundeprestasie
(LitNet, 2024-10) Graham, Marien Alet
AFRIKAANS : Die studie het ten doel om ons begrip van die verhouding tussen onderwysers se oortuigings, selfdoeltreffendheid, onderriggehalte en onderrigklarigheid, en graad 9- Suid-Afrikaanse leerders se wiskundeprestasie te verbreed. Die studie het ’n unieke invalshoek deurdat die onderwerp benader word vanuit die sosiale kognitiewe teorie (Bandura 1986), wat fokus op die wederkerige interaksie tussen persoonlike faktore (soos oortuigings en selfdoeltreffendheid), omgewingsinvloede (soos onderriggehalte) en gedrag (soos wiskundeprestasie). ’n Multivlakanalise met wiskundeprestasie as die afhanklike veranderlike en 15 voorspellers is uitgevoer, terwyl sosio-ekonomiese status en geslag beheer is. ’n Sekondêre data-ontleding met behulp van Trends in International Mathematics and Science Study (TIMSS) se 2019-data is gedoen deur ’n kwantitatiewe benadering te gebruik. Die resultate toon dat onderwysers se voorbereidingstyd ’n sleutelvoorspeller van wiskundeprestasie is, wat die noodsaaklikheid van verbeterde voorbereiding en beplanningsgeleenthede beklemtoon. Beleidmakers en belanghebbendes behoort dit te oorweeg om geteikende opleidingsessies vir onderwysers aan te bied. Hierdie programme kan fokus op effektiewe voorbereidingstegnieke, soos die optimalisering van kurrikulumbronne en die integrasie van tegnologie om lesbeplanning te vaartbelyn. Deur geteikende opleiding te bied, kan opvoeders hul voorbereidingspraktyke verbeter, wat tot verbeterde onderrig- en leergehalte sal lei. Ouers se druk op onderwysers is ook geïdentifiseer as ’n beduidende voorspeller van wiskundeprestasie, wat die belang van ouerlike betrokkenheid beklemtoon. Dit onderstreep die behoefte aan beleide wat ouerlike betrokkenheid by skoolverwante aktiwiteite aanmoedig. Daar is ook gewys op die vooruitgang sedert die implementering van die Suid-Afrikaanse Skolewet van 1996, wat die rol van ouerskap in opvoeding benadruk. Om die potensiaal van hierdie beleidsmaatreëls te ontsluit, word daar aanbeveel dat beleidmakers strategieë implementeer om ouers aktief by skoolaktiwiteite te betrek deur verslae te vereis en inligtingsbronne te versprei. Hierdie samewerkingspogings sal uiteindelik bydra tot ’n meer omvattende opvoedkundige omgewing en verbeterde akademiese uitkomste vir leerders.
Molecular mechanisms underlying tree host-pathogen interactions under drought stress and subsequent rewatering in Eucalyptus grandis
(Elsevier, 2024-12-02) Teshome, Demissew Tesfaye; Zharare, Godfrey Elijah; Ployet, Raphael; Naidoo, Sanushka; sanushka.naidoo@up.ac.za
Abiotic stresses such as drought change plant-pathogen interactions by affecting both hosts and pathogens. Here, we aimed to unravel the molecular mechanisms underlying forest tree-pathogen interactions under drought stress and subsequent rewatering. We conducted glasshouse experiments involving infection by the stem canker-causing fungal pathogen Chrysoporthe austroafricana under drought stress and rewatering in Eucalyptus grandis and investigated host and pathogen transcriptomic changes using RNA-seq data from our current combined stress experiment as well as previous single stress studies. We found that mild drought stress enhances disease progression while, upon rewatering, pathogen infection delays recovery of leaf stomatal conductance. Transcriptomic changes in the host support increased susceptibility to the pathogen while the in planta fungal transcriptome suggests prioritization of survival in the drought-stressed host. Upon rewatering, changes in the host transcriptome suggest allocation of resources to stress responses at the expense of growth and carbohydrate storage while that of the pathogen indicate downregulation of some fungal metabolic pathways potentially because the pathogen takes advantage of changes in the host. Our study identified key molecular processes and genes that provide mechanistic insights into tree-pathogen interactions under abiotic stresses. This enables prediction of tree resilience under a changing climate and contributes towards future tree health improvement endeavours.
Decolonising the humanities : reimagining black intellectual life and personhood in Southern African contexts
(PINS-Psychology in Society, 2024-06) Sandwith, Corinne; corinne.sandwith@up.ac.za
This review article explores possibilities for transdisciplinary entanglements between the disciplines of critical psychology and literary criticism through a reading of the volume, ʻFoundational African Writers’, edited by Bhekizizwe Peterson, Khwezi Mkhize and Makhosazana Xaba. In this article, ‘Foundational African Writers’ is approached as a distillation of Peterson’s investment in excavating the world-making activities, writing lives and activities of ordinary people as a central dimension of the project to decolonise the Humanities. As this edited volume attests, Peterson’s creative and critical oeuvre continues to provoke thinking about the ways in which the reading of the African literary archive can assist in the wider project of decolonising and re-imagining intellectual and creative history in the Global South while also providing opportunities for new modes of thinking about personhood and psychic life in contexts of precarity, intergenerational trauma and economic exclusion.
The experiences of race relations amongst student leaders at a historically white South African university
(PINS-Psychology in Society, 2024-12) Selowa, Hlengiwe; Motileng, Benny; benny.motileng@up.ac.za
Recent protest movements such as #Rhodesmustfall and #FeesMustFall have highlighted uneasy race relations at South African universities. Although such incidents are crucial, equally important are the everyday realities of race relations that continue to define student lives in these institutions. The purpose of this study was to provide an understanding of student leaders’ experiences of race relations at a historically white South African university. Guided by a qualitative research approach, Critical Race Theory (CRT) was the framework we used to explore race relations amongst student leaders. Purposive sampling was employed to recruit six student leaders across racial groups. They participated in a forty-five-minute semi-structured interview. Interpretive phenomenological analysis (IPA) was used to analyse the data. The findings suggest that the history and identities of universities as racially segregated in an unequal society, impacts race relations. Racial discrimination and distrust hamper racial integration in the student body and external political factors also affect student leaders’ experiences of race relations. Our findings do show that friendships present an important opportunity to foster positive race relations, even though friendships are largely class dependent. We recommend that universities invest in personnel diversity training and the creation of platforms for intercultural and interracial exchanges.
Framework for contextualising differentiated assessment for learner support in the Nigerian and South African foundation phase school contexts
(Routledge, 2025) Izevbigie, Etinosa; Thuketana, Nkhensani Susan
This paper presents a theory-based conceptual framework the researchers developed to promote differentiated assessment in the Foundation Phase for equitable assessment practices in Nigerian and South African mainstream schools. The literature presents varied assessment frameworks to address injustices and discriminations for the ‘ideal’ learner. However, learners with special educational needs (SEN) remain segregated in the ongoing discourse of equity in classroom assessments. The researchers used the model of modelling in a mixed method approach to develop a framework incorporating Sen’s capability approach, Gardner's theory of multiple intelligences, and Lave and Wenger's community of practice. The framework was tested for reliability by triangulating teachers’ surveys and semi-structured interviews anchored by the three theories to indicate inclusive variable considerations for differentiated assessment. The themes confirmed different knowledge variables about policies and guidelines, transdisciplinary collaboration, skills to align assessments with dominant intelligence crucial for differentiated assessment, and learner support requirements for learning success.
EMD empowered neural network for predicting spatio-temporal non-stationary channel in UAV communications
(Springer, 2025-02) Zhang, Qiuyun; Guo, Qiumei; Jiang, Hong; Yin, Xinfan; Mushtaq, Muhammad Umer; Luo, Ying; Wu, Chun
This paper introduces a novel prediction method for spatio-temporal non-stationary channels between unmanned aerial vehicles (UAVs) and ground control vehicles, essential for the fast and accurate acquisition of channel state information (CSI) to support UAV applications in ultra-reliable and low-latency communication (URLLC). Specifically, an empirical mode decomposition (EMD)-empowered spatio-temporal attention neural network is proposed, referred to as EMD-STANN. The STANN sub-module within EMD-STANN is designed to capture the spatial correlation and temporal dependence of CSI. Furthermore, the EMD component is employed to handle the non-stationary and nonlinear dynamic characteristics of the UAV-to-ground control vehicle (U2V) channel, thereby enhancing the feature extraction and refinement capabilities of the STANN and improving the accuracy of CSI prediction. Additionally, we conducted a validation of the proposed EMD-STANN model across multiple datasets. The results indicated that EMD-STANN is capable of effectively adapting to diverse channel conditions and accurately predicting channel states. Compared to existing methods, EMD-STANN exhibited superior predictive performance, as indicated by its reduced root mean square error (RMSE) and mean absolute error (MAE) metrics. Specifically, EMD-STANN achieved a reduction of 24.66% in RMSE and 25.46% in MAE compared to the reference method under our simulation conditions. This improvement in prediction accuracy provides a solid foundation for the implementation of URLLC applications.
Mulching of post-harvest residues and delayed planting improves fungal biodiversity in South African Eucalyptus plantations and enhances plantation productivity
(Elsevier, 2025-06) Bose, Tanay; Roux, Jolanda; Titshall, Louis; Dovey, Steven B.; Hammerbacher, Almuth; tanay.bose@fabi.up.ac.za
Short-rotation Eucalyptus plantations provide essential forest products, with productivity and soil health influenced by residue management and planting strategies. This study examined the effects of burning or mulching post-harvest residue followed by immediate versus delayed planting on soil fungal biodiversity, soil properties, and tree growth across four sites in KwaZulu-Natal, South Africa. Plots were planted either three months ('immediate') or six months ('delayed') after treatment implementation. Volume measurements assessed tree growth, and soil attributes, including moisture, temperature, and nutrient levels, were analyzed. Soil samples were collected in November 2019 and March 2022, and fungal communities were analyzed through high-throughput sequencing targeting the internal transcribed spacer 1 (ITS1) region. Data emerging from this study showed mulched plots had significantly higher tree volume, with delayed planting increasing productivity by 13.6 % at 24–36 months and 25 % at 36–48 months post-planting. Soil moisture was 1.3–2 times higher in mulched plots than in burnt plots. Mulching significantly reduced the maximum soil temperatures by 4.5–6.8 °C. Four months after treatment, burnt plots had higher pH (1.1-fold), carbon (2.2-fold), phosphate (1.6-fold) and manganese (2.5-fold). Initially, mulched plots had lower fungal biodiversity (0.81-fold) than burnt plots but surpassed them after 28 months (1.28-fold increase). Fungal community overlap declined from 83.28 % to 40.64 %, with mulching supporting higher saprotroph (1.3-fold) and symbiotroph (1.25-fold) abundances, while delayed planting increased pathotroph presence by 1.5-fold in burnt plots. These findings highlight the long-term benefits of mulching and delayed planting in enhancing fungal biodiversity, promoting beneficial microbial communities, and improving tree growth, contributing to more sustainable Eucalyptus plantation management.
Exploring anticancer activity and DNA binding of metal (II) salicylaldehyde Schiff base complexes : a convergence of experimental and computational perspectives
(Wiley, 2025-05) Waziri, Ibrahim; Sookai, Sheldon; Yusuf, Tunde Lewis; Olofinsan, Kolawole A.; Muller, Alfred J.
Please read abstract in the article.
Feasibility and optimisation results for elimination by mass trapping in a metapopulation model
(Elsevier, 2025-08) Bliman, Pierre-Alexandre; De la Tousche, Manon; Dumont, Yves
Vector and Pest control is an important issue in terms of Food and Health security all around the World. In this paper, we consider the issue of mass trapping strategies for interconnected areas, where traps can only be deployed in some of them. Assuming linear dispersal between the areas, we consider and study a metapopulation model, and explore the global effect of a linear control, achieved by an (on purpose) increase of the mortality in certain areas. We show that the feasibility of population elimination is determined by an algebraic property on the Jacobian matrix at the origin of a so-called residual system. If elimination is not achievable, we then assess the smallest globally asymptotically stable equilibrium. Conversely when elimination is feasible, we study an optimisation problem consisting in achieving this task while minimising a certain cost function, chosen as a non-decreasing and convex function of the mortality rates added in the controlled areas. We show that such a minimisation problem admits a global minimiser, which is unique in the relevant cases. An interior point algorithm is proposed to compute the solution, using explicit formulas for the Jacobian matrix and the Hessian of the objective function of the unconstrained penalised problem. The results are illustrated and discussed with numerical simulations.
Life cycle external cost assessment of an onshore wind farm in South Africa
(Elsevier, 2025-06) Ibrahim, Hanif Auwal; Thopil, George Alex; george.alexthopil@up.ac.za
Wind power has been crucial in global energy transitions over the past decade. Such transitions are evident in sub-Saharan Africa, where South Africa is a leading player. Onshore wind power is pivotal in South Africa's energy transition, but the comprehensive external costs of the technology remain unexplored. Conducting a life cycle assessment (LCA) of a 138 MW wind farm, this study aims to fill the existing gap in the literature, by assessing greenhouse gas (GHG) and non-GHG impacts, and then converting them into costs. This study provides critical insights into the environmental, health, biodiversity, crops, and materials impact of onshore wind power, contributing towards improving the overall sustainability of offshore wind power. Findings from the study indicate that climate change impacts contribute 26.1 gCO2eq/kWh, while human health impacts emerge as the most significant non-GHG impact. The onshore wind farm's external cost ranges from 5.95 to 9.88 ZAc/kWh (2.9–4.82 €/MWh), with a median of 6.75 ZAc/kWh (3.29 €/MWh), falling within ranges observed in the literature. Climate change and human health jointly account for 89.4 % of the median external costs, primarily associated with the manufacturing and construction phases. This study underscores the importance of including external costs in the comprehensive assessment of wind power, driven by the decreasing technology costs. The findings highlight the need to incorporate climate change and human health costs to better understand the sustainability of onshore wind power across its life cycle.
Practical recommendations for artificial intelligence and machine learning in antimicrobial stewardship for Africa
(Wiley, 2025-04) Dzinamarira, Tafadzwa; Mbunge, Elliot; Steiner, Claire; Moyo, Enos; Akinjeji, Adewale; Yamba, Kaunda; Mwila, Loveday; Muvunyi, Claude Mambo; u19395419@up.ac.za
The challenge of antimicrobial resistance (AMR) represents one of the most pressing global health crises, particularly, in resource-constrained settings like Africa. In this paper, we explore artificial intelligence (AI) and machine learning (ML) potential in transforming the potential for antimicrobial stewardship (AMS) to improve precision, efficiency, and effectiveness of antibiotic use. The deployment of AI-driven solutions presents unprecedented opportunities for optimizing treatment regimens, predicting resistance patterns, and improving clinical workflows. However, successfully integrating these technologies into Africa's health systems faces considerable obstacles, including limited human capacity and expertise, widespread public distrust, insufficient funding, inadequate infrastructure, fragmented data sources, and weak regulatory and policy enforcement. To harness the full potential of AI and ML in AMS, there is a need to first address these foundational barriers. Capacity-building initiatives are essential to equip healthcare professionals with the skills needed to leverage AI technologies effectively. Public trust must be cultivated through community engagement and transparent communication about the benefits and limitations of AI. Furthermore, technological solutions should be tailored to the unique constraints of resource-limited settings, with a focus on developing low-computational, explainable models that can operate with minimal infrastructure. Financial investment is critical to scaling successful pilot projects and integrating them into national health systems. Effective policy development is equally essential to establishing regulatory frameworks that ensure data security, algorithmic fairness, and ethical AI use. This comprehensive approach will not only improve the deployment of AI systems but also address the underlying issues that exacerbate AMR, such as unauthorized antibiotic sales and inadequate enforcement of guidelines. To effectively and sustainably combat AMR, a concerted effort involving governments, health organizations, communities, and technology developers is essential. Through collaborations and sharing a common goal, we can build resilient and effective AMS programs in Africa.
Mesorhizobium salmacidum sp. nov. and Mesorhizobium argentiipisi sp. nov. are symbionts of the dry-land forage legumes Lessertia diffusa and Calobota sericea
(Springer, 2025-03) Muema, Esther K.; Van Lill, Melandre; Venter, S.N. (Stephanus Nicolaas); Chan, Wai Yin; Claassens, Ricu; Steenkamp, Emma Theodora
Legumes Lessertia diffusa and Calobota sericea, indigenous to South Africa, are commonly used as fodder crops with potential for sustainable livestock pasture production. Rhizobia were isolated from their root nodules grown in their respective soils from the Succulent Karoo biome (SKB) in South Africa, identified and characterized using a polyphasic approach. Sequence analysis of the 16S rRNA gene confirmed all isolates as Mesorhizobium members, which were categorized into two distinct lineages using five housekeeping protein-coding genes. Lineage I included 14 strains from both legumes, while Lineage II comprised a single isolate from C. sericea. Differences in phenotypic traits were observed between the lineages and corroborated by average nucleotide identity analyses. While all strains nodulated their original hosts, strains from C. sericea failed to effectively nodulate L. diffusa and vice versa. Phylogenetic analyses of nitrogen fixation (nifH) and nodulation (nodA, nodC) loci grouped all strains in a single clade, suggesting that unique symbiotic loci determine nodulation of these legumes. We designated Lineage I and II as Mesorhizobium salmacidum sp. nov. (Ld1326Ts; GCA_037179605.1Ts) and Mesorhizobium argentiipisi sp. nov. (Cs1330R2N1Ts; GCA_037179585.1Ts), using genome sequences as nomenclatural types according to the Nomenclatural Code for Prokaryotes using Sequence Data, thus avoiding complications with South Africa's biodiversity regulations. Identifying effective microsymbionts of L. diffusa and C. sericea is essential for conservation of Succulent Karoo Biome, where indigenous invasive species like Vachellia karroo and non-native Australian acacia species are present. Furthermore, targeted management practices using effective symbionts of the studied legumes can sustain the biome's socio-economic contribution through fodder provision.
Oxidative stress in the reproduction of mammals
(MDPI, 2025-03) Jacobs, Paul Juan; Bennett, Nigel Charles; pj.jacobs@up.ac.za
No abstract available.
Effects of anti-pseudomonal agents, individually and in combination, with or without clarithromycin, on growth and biofilm formation by antibiotic-susceptible and -resistant strains of Pseudomonas aeruginosa, and the impact of exposure to cigarette smoke condensate
(MDPI, 2025-03) Cholo, Moloko C.; Feldman, Charles; Anderson, Ronald; Sekalo, Lebogang; Moloko, Naledi; Richards, Guy A.; moloko.cholo@up.ac.za
BACKGROUND/OBJECTIVES : Pseudomonas aeruginosa (Psa) can circumvent antimicrobial chemotherapy, an ability enhanced by cigarette smoking (CS). This study probed potential benefits of combinations of anti-pseudomonal agents, and potential augmentation by a macrolide, in the absence or presence of cigarette smoke condensate (CSC). METHODS : Two susceptible (WT: wild-type and DS: drug-sensitive) and one multidrug-resistant (MDR) strains of Psa were treated with amikacin, cefepime, and ciprofloxacin, individually and in combination, and with and without clarithromycin, followed by the measurement of planktonic growth and biofilm formation by spectrophotometry. Antibiotic interactions were determined using the fractional inhibitory concentration index (FICI) method. Effects on preformed biofilm density were measured following the addition of antibiotics: all procedures were performed in the absence and presence of CSC. RESULTS : The minimal inhibitory concentrations (MICs) of the three agents ranged from 0.125 mg/L to 1 mg/L (WT and DS strains) and 16 mg/L to 64 mg/L (MDR strain), with all resistant to clarithromycin (125 mg/L). MIC values closely correlated with the antibiotic concentrations required to inhibit biofilm formation. FICI revealed synergism between most combinations, with augmentation by clarithromycin. Amikacin had the greatest effect on biofilm density, which was potentiated by combination with the other antibiotics, particularly clarithromycin. Exposure to CSC had variable, albeit modest, effects on bacterial growth and biofilm formation, but low concentrations increased biofilm mass and attenuated synergistic antimicrobial interactions and effects on biofilm density. CONCLUSIONS : Amikacin, cefepime, and ciprofloxacin, especially with clarithromycin, exhibit synergistic anti-pseudomonal activity and decrease preformed biofilm density. CSC attenuated these effects, illustrating the pro-infective potential of CS.
A One Health approach to reducing livestock disease prevalence in developing countries : advances, challenges, and prospects
(Annual Reviews, 2025-02) Lane, Jennifer K.; Kelly, Terra; Bird, Brian; Chenais, Erika; Roug, Annette; Vidal, Gema; Gallardo, Rodrigo; Zhou, Huaijun; Vanhoy, Grace; Smith, Woutrina
Challenges in livestock production in developing countries are often linked to a high disease prevalence and may be related to poor husbandry, feeding, and nutrition practices, as well as to inadequate access to preventive veterinary care. Structural barriers including chronic poverty, gender roles, inadequate supply chains, and limitations in surveillance infrastructure further complicate progress. Despite many challenges, the livestock sector substantially contributes to agricultural GDP, and reducing livestock disease prevalence is a goal for many countries. One Health initiatives that work across disciplines and sectors to reduce livestock diseases are underway around the world and use integrated approaches that consider the connections between humans, animals, and their shared environments. The growing recognition of the role livestock play in sustainability and livelihoods, as well as their involvement in zoonotic disease transmission and global health security, has highlighted the need for disease reduction strategies as described in this review.
'Becoming manly' : white South African defence force veterans negotiating masculinity
(Routledge, 2024) Janak, Raksha; Bhana, Deevia; Marculitis, James; Buccus, Imraan
This study examines how white South African men reflect on their experiences of being and becoming army veterans, while negotiating masculinity. In the context of ‘high apartheid’, Afrikaner domination of the socio-political landscape, ethnic and racialised inequalities, the veterans negotiated being white English-speaking men through reflecting on, critiquing and disassociating from military masculinity. An English South African masculinity was upheld by distancing from Afrikaner domination and values, violence and compulsory heterosexuality. These findings suggest that while a military masculinity offered men a powerful template to assert their authority as white men, such power was nuanced by English South Africans’ relative political impotence, the domination of Afrikaans as a language and illustrates the heterogeneity in the experience of white veteran masculinity under apartheid. At the same time, however, white English veterans were complicit in and benefitted from whiteness and the power accrued in the country by virtue of race, class and history of British colonialism. We argue that the experience of being and becoming conscripts and the reflection on military masculinity directs attention to the ways in which broader social and political contexts have effects for the shaping of masculinity reflecting hierarchies of power and fluidity.
Nurturing our reflexivity
(Routledge, 2024-01) Dos Santos, Andeline; andeline.dossantos@up.ac.za
No abstract available.
Modeling and analysis of the fractional-order epidemic model to investigate mutual influence in HIV/HCV co-infection
(Springer, 2024-07) Naik, Parvaiz Ahmad; Yeolekar, Bijal M.; Qureshi, Sania; Yeolekar, Mahesh; Madzvamuse, Anotida
Please read abstract in the article.
Possible factors missed while assessing optic nerve sheath diameter and deformability index in patients with severe traumatic brain injury
(Springer, 2025-10) Netteland, Dag Ferner; Aarhus, Mads; Sandset, Else Charlotte; Padayachy, Llewellyn; Helseth, Eirik; Brekken, Reidar
BACKGROUND : Today, invasive intracranial pressure (ICP) measurement remains the standard, but its invasiveness limits availability. Here, we evaluate a novel ultrasound-based optic nerve sheath parameter called the deformability index (DI) and its ability to assess ICP noninvasively. Furthermore, we ask whether combining DI with optic nerve sheath diameter (ONSD), a more established parameter, results in increased diagnostic ability, as compared to using ONSD alone. METHODS : We prospectively included adult patients with traumatic brain injury with invasive ICP monitoring, which served as the reference measurement. Ultrasound images and videos of the optic nerve sheath were acquired. ONSD was measured at the bedside, whereas DI was calculated by semiautomated postprocessing of ultrasound videos. Correlations of ONSD and DI to ICP were explored, and a linear regression model combining ONSD and DI was compared to a linear regression model using ONSD alone. Ability of the noninvasive parameters to distinguish dichotomized ICP was evaluated using receiver operating characteristic curves, and a logistic regression model combining ONSD and DI was compared to a logistic regression model using ONSD alone. RESULTS : Forty-four ultrasound examinations were performed in 26 patients. Both DI (R = − 0.28; 95% confidence interval [CI] R < − 0.03; p = 0.03) and ONSD (R = 0.45; 95% CI R > 0.23; p < 0.01) correlated with ICP. When including both parameters in a combined model, the estimated correlation coefficient increased (R = 0.51; 95% CI R > 0.30; p < 0.01), compared to using ONSD alone, but the model improvement did not reach statistical significance (p = 0.09). Both DI (area under the curve [AUC] 0.69, 95% CI 0.53–0.83) and ONSD (AUC 0.72, 95% CI 0.56–0.86) displayed ability to distinguish ICP dichotomized at ICP ≥ 15 mm Hg. When using both parameters in a combined model, AUC increased (0.80, 95% CI 0.63–0.90), and the model improvement was statistically significant (p = 0.02). CONCLUSIONS : Combining ONSD with DI holds the potential of increasing the ability of optic nerve sheath parameters in the noninvasive assessment of ICP, compared to using ONSD alone, and further study of DI is warranted.
In reply: Possible factors missed while assessing optic nerve sheath diameter and deformability index in patients with severe traumatic brain injury
(Springer, 2024-08) Netteland, Dag Ferner; Aarhus, Mads; Sandset, Else Charlotte; Padayachy, Llewellyn; Helseth, Eirik; Brekken, Reidar
We would like to thank authors Kapoor and Prabhakar for their interest in our article and appreciate their insights in this regard. In their comment, three matters are brought to attention relating to preexisting glaucoma, intercurrent seizure activity, and units of deformability index (DI) measurements. In this study, we aimed to evaluate the diagnostic ability of the DI, alone and in combination with optic nerve sheath diameter (ONSD), in a general traumatic brain injury (TBI) population requiring neurointensive care.

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