Research Articles (University of Pretoria)

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

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Technical performance assessment in an international tele-intensive care unit network
Lezius, Franziska; Steinecke, Karin; Herholz, Anne; Schuurhuis, Stephen; Terentyuk, Vadym; Lisnyy, Ivan; Anvarov, Khkmat; Paruk, Fathima; König, Jens-Peter; Grosse, Joachim; Edel, Andreas; Hechler, Daniel; Spies, Claudia D.; Weiss, Björn (Sage, 2025-12)
BACKGROUND : There is a plethora of technologies used in the rapidly expanding field of telemedicine, with tele-intensive care units (TICUs) being a specialty with rather distinct needs and challenges. Technology is a crucial aspect of TICU collaboration to ensure high-quality telemedicine consultations in clinical routines. METHODS : We conducted a feedback survey to assess the technical performance within our international TICU network. The survey, addressing medical staff that regularly participates in telemedicine rounds, was designed to specifically assess the technical performance of a TICU system. In detail, usability, perception of audio–visual quality, and user acceptance were evaluated. RESULTS : The results show a positive evaluation by the vast majority of participants, with only minor differences between countries. Potential for improvement was identified in multiple domains closely linked to contextual factors. DISCUSSION : The perception of telemedicine technology performance was promising and will guide further research to enhance technological acceptance and optimize TICU networks for widespread use.
Learning to swim in the Dirac sea : Deleuze and the cosmologies of time and chance
Eloff, Aragorn (Radboud University Press, 2025)
In this article, I reflect on Deleuze’s provocative critique of the second law of thermodynamics in Difference and Repetition by drawing his philosophy into conversation with cosmology—specifically quantum physics. In dialogue with the work of the late Bill Ross, whose recent Order and the Virtual represents the most substantial critical engagement with the entropic principle vis-à-vis Deleuze, I turn to the physicist David Bohm’s distinction between explicate and implicate orders, which Ross argues bear strong similarities to Deleuze’s actual and virtual, respectively. Bohm’s theory, as Ross and others have pointed out, entails a recognition of the pluripotent creative potential of the quantum dynamisms that give rise to the spatiotemporal order—what Deleuze would describe as non-exhaustive intensive differences that are only apparently cancelled out in extensity. Here, with reference to Deleuze’s distinction between the divine and human games, and their respective distributions of chance, I propose—following Ross and Bohm, as well as contemporary loop quantum gravity—an alternative to string theory most commonly associated with the physicist Carlo Rovelli: that whereas the emergent regularities of the macroscopic world are inexorably bound to the arrow of time and thus to the law of entropy, this is not the case for the divine game that takes place within the quantum foam, and that it is here that the Eventum tantum takes place in which all of chance—including said laws—are continuously redistributed. Turning to the both non-continuous and continuous nature of this evental dynamism relative to quantum and macrophysical realities respectively, I close by considering Ross’s eschewal of dynamic systems theory in favour of other quantum-theoretic resources and suggest that perhaps both can be usefully employed to think the reciprocal becomings of Deleuze and the philosophy of cosmology
Supporting choices for educational robotics tools for early childhood settings : considerations, characteristics, and categories
Van Rooyen, Annèl; Callaghan, Ronel (Springer, 2025-12)
Educational robotics offers opportunities to young learners in early childhood settings (three to nine years) to learn with robots, whether screen-free or screen-based. Due to the vast variety of educational robotics tools available, educational practitioners need decision support to choose appropriate tools. The task of finding, acquiring and using educational robotics tools for early childhood settings is influenced by material and usage access issues associated with the digital divide. This article presents the findings obtained during an action research study, which involved semi-structured interviews with seven research participants, observations, and the researcher’s action research journal as data gathering instruments. The findings are interpreted through the lens of two theories, namely the types of access associated with the digital divide, and the Technological Pedagogical and Content Knowledge framework. Ten tools for early childhood settings were investigated. This article provides eight practical considerations, three sets of overarching educational robotics tool characteristics, and three categories for decision support when choosing appropriate educational robotics tools.
Another generalised transmuted Rayleigh distribution theory, properties, and inference
Ashiagbor, Albert Ayi; Das, Sonali; Essel-Mensah, Kojo; Lawluvi, Emmanuel (Chinese Society for Science of Science and S&T Policy Research, 2025)
This paper introduces the Another Generalised Transmuted Rayleigh (AGTR) distribution, obtained by embedding the classical Rayleigh law within the Another Generalised Transmuted (AGT) family. The new model inherits the physical interpretability of the Rayleigh distribution while gaining two additional shape parameters that govern skewness and tail weight, enabling it to capture highly skewed and leptokurtic phenomena. We derive closed-form expressions for the probability density, cumulative, survival, hazard, and reverse-hazard functions and establish legitimacy conditions. Further analytical results include quantile and moment functions, R´enyi and Shannon entropies, incomplete moments, Lorenz and Bonferroni inequality curves, and several stochastic orderings. Parameter estimation is addressed via maximum likelihood; the observed-information matrix is provided for inference. A extensive Monte Carlo study, across sample sizes n = 25–1000, demonstrates that the maximum-likelihood estimators are consistent, nearly unbiased, and achieve nominal 95 % coverage with declining RMSE as n increases. Graphical illustrations confirm the AGTR distribution’s ability to reproduce monotone, bathtub, and non-monotone hazard shapes, underscoring its applicability to reliability analysis, survival studies, and risk modelling. The AGTR distribution thus offers a flexible, analytically tractable alternative to existing Rayleighbased extensions and enriches the toolkit for modelling skewed, heavy-tailed data.
Genera of phytopathogenic fungi known from culture : 1-379
Crous, Pedro W.; Groenewald, J.Z.; Bensch, K.; Gene, J.; Guarro, J. (Westerdijk Fungal Biodiversity Institute, 2025-12-03)
Approximately 200000 species of fungi have been described to date, representing nearly 8000 currently recognised genera. Many of these genera are regarded as plant pathogenic, as they include at least one species proven to cause pre- or postharvest plant disease. Following the abandonment of dual nomenclature and the advent of DNA sequencing and phylogenetic approaches, numerous para- and polyphyletic clades were resolved into distinct genera. These genera are now defined based on morphology, ecology, and DNA phylogeny. The present paper represents the first in a series that aims to provide descriptions, classification, illustrations, significant species, disease symptoms, and DNA data for the common genera of phytopathogenic fungi known from culture, including the first treatment of 379 genera. In addition, several new combinations, lecto-, epi-, or neotypes are also proposed.
Enabling leadership behaviours of principals leading rural primary schools in the Ilembe District, South Africa
Ncokwana, Zamokwakhe Thandinkosi; Blose, Sibonelo (Indonesia Approach Education, 2025-08)
This paper flows from a research project that examined the Principals’ lived experiences of leading rural primary schools. It focuses specifically on leadership behaviours enabling the principals in leading rural primary schools against challenging contextual realities. The servant leadership concept was adopted to frame our understanding of and engagement with participants’ experiences. Regarding the research method, we employed the narrative inquiry design to inquire into principals’ experiences. In keeping with this design, we generated field texts using a narrative interview, an unstructured type of interview. The generated field texts were subsequently analyzed through narrative analysis and analysis of narratives. The findings revealed important leadership behaviours that appeared to enable the participating principals in leading rural primary schools; these include embracing all stakeholders as a family, leading a rural school as a servant, and leveraging stakeholder support to benefit learners. In conclusion, we deduce that the participating rural primary school principals keep their schools afloat by setting themselves as servants who show support to all stakeholders and who are willing to go out of their way to solicit charity to expand the support.
Algebraic question types in grade 10 mathematics textbook : a cognitive perspective
Sibiya, Mandlenkosi Richard; Sekao, David; Ogbonnaya, Ugorji Iheanachor (Indonesia Approach Education , 2025-04)
Mathematics education depends on textbooks as the primary source of information for both teachers and learners while providing essential tasks that develop cognitive skills. The types of tasks used in these resources directly affect learners’ cognitive growth and show why textbooks must contain various question types. Current research lacks examination of mathematics textbooks in South African schools, even though learners consistently perform poorly in mathematics. This study investigated whether a widely used Grade 10 Mathematics textbook challenged learners to various question types that help build problem-solving skills and high-level thinking. A deductive content analysis approach evaluated 1 360 questions from the textbook’s algebra content, including algebraic expressions, exponents, equations and inequalities, number patterns, and functions. The research results indicated that most questions (62%) required routine calculations while the content lacked questions that required higher-order cognitive skills such as problem-solving, argumentation and interpretation. The assessed textbook appears to fail learners by not adequately developing critical thinking skills that learners need for both future advanced math classes and practical applications. The study recommends more diverse question types in mathematics textbooks to develop learners’ cognitive skills and problem-solving abilities.
Church unity in post-apartheid South Africa : the formation of the uniting Presbyterian church in southern Africa (1897–1999)
Duncan, Graham A. (Unisa Press, 2025-02-03)
This article seeks to investigate the process that brought the Uniting Presbyterian Church in Southern Africa into being in 1999; how did it happen without comprehensive discussions and agreement under the guise of mutual authentic reconciliation? The union was the end of a movement that took over 100 years to achieve. The discussions between two Presbyterian denominations were dominated by tensions and disagreements throughout the years in a context of increasing racialisation and apartheid. Yet, it was considered to be the appropriate resolution of differences, which had originated in racist South Africa, at the time of the inauguration of the first democratic government in 1994. The political change motivated black churches' confidence to reach out to their white sisters and brothers on an equal basis while churches of European origin, such as the Presbyterian Church in Southern Africa, faced the future with a degree of fear and trepidation. The decisions that were implemented gave the impression of a union carried through in a rush devoid of clear definitive policies for the uniting denomination. Issues of power were at work, including resistance to change, the unacknowledged threat of change, and the continued domination of settler/colonial and missionary influences which enabled the avoidance of serious authentic discussion regarding reconciliation. The article indicates that greater awareness and care need to be taken regarding historical, cultural, economic, pastoral, and political concerns as prerequisites to union and safeguards built into the process of ongoing union. This study is based largely on primary sources. There are detailed records available. The Reformed Presbyterian Church in Southern Africa General Assembly (GA) papers were not published along with their proceedings of the GA. Greater detail is found in the Presbyterian Church of Southern Africa sources, hence the greater number of quotations. However, the minutes of the Special Commission on Union and the closing General Assembly of the PCSA (1999) are not available. This article makes a contribution to ecumenical history of Christianity in South Africa and further afield as it discusses different emphases in similar traditions which became matters of controversy. It also elucidates some of the pitfalls in discussions which may endure beyond union if agreed-upon processes and policies are not put in place before union is consummated. It is interdisciplinary in nature.
Consumers' perceptions of South African clothing retailers' corporate social responsibility : a triple bottom line and gendered perspective
Muller, Gert Daniel; Sonnenberg, Nadine Cynthia; Donoghue, Sune (Wiley, 2026)
This study examines the influence of consumers' perceptions of clothing retailers' corporate social responsibility (CSR) on word-of-mouth (WOM) and purchase intent in the South African emerging market context. Additionally, a gender comparison was conducted to explore potential differences in the relationship between consumers' CSR perceptions, WOM, and purchase intent. An online survey based on validated scales was used to collect data (N = 1293). Partial least squares (PLS-SEM) was applied to specify a reflective-formative model incorporating consumers' CSR perceptions as a higher-order construct composed of social, economic, and environmental dimensions. The social dimension emerged as the most influential in shaping CSR perceptions, with WOM partially mediating the relationship between CSR perceptions and purchase intent. Additionally, a permutation-based multigroup analysis revealed gender differences in the relationship between consumers' CSR perceptions, WOM, and purchase intent, which can form the basis for further exploratory investigation.
A multidisciplinary assessment of endocrine and morphometric correlates of lactation physiology in southern right whales
Shuttleworth, Loraine; Ganswindt, Andre; Vermeulen, Els (Oxford University Press, 2026-03-27)
Reproduction in long-lived, iteroparous mammals requires careful allocation of energetic resources. This is especially true in capital breeding species such as the southern right whale (Eubalaena australis), where reproductive success depends on body condition, as accumulated reserves must fuel the high energetic demands, especially during lactation. Understanding the physiological mechanisms underpinning maternal energy balance is therefore critical for assessing reproductive capacity and maternal investment strategies. This study combined body condition metrics derived from aerial photogrammetry with endocrine correlates (glucocorticoids and triiodothyronine; hormones associated with energy mobilisation and regulation of metabolism) measured in blubber biopsies to establish baseline measures of metabolic function in lactating southern right whales over the calving season (July–September). Analyses revealed a positive correlation between glucocorticoids and triiodothyronine, strongest in lactating females. A clear decline in both hormones was observed toward the end of the calving season, consistent with reduced maternal metabolic activity and corresponding to slowed calf growth rates. No significant differences in hormone concentrations were detected between demographic groups (n = 15 lactating females, n = 8 unaccompanied adults), nor maternal (n = 9 good condition, n = 3 poor condition) or calf body condition categories (n = 5 good condition, n = 7 poor condition), although this may relate to the study’s limited sample size. By linking endocrine profiles with body condition, this study provides novel physiological context for understanding maternal investment strategies in southern right whales. The findings highlight how intra-seasonal energetic demands are hormonally mediated during lactation and demonstrate the feasibility of integrating photogrammetry with endocrine monitoring in free-swimming baleen whales. Establishing these physiological baselines is critical for detecting early indicators of reproductive stress and for informing conservation strategies in recovering populations.
Albion's Arcadia : the topomythopoeia of Spenser and Milton
Prinsloo, Johan Nel (Routledge, 2026)
This article, the latest in a series, examines the transformation of classical topomythopoiesis in England from the late sixteenth to the seventeenth centuries, focusing on the influence of Puritanism in the literary topomythopoeia of Edmund Spenser (The Faerie Queene, 1596) and John Milton (Paradise Lost, 1667). While classical topomythopoiesis flourished in the papal and aristocratic gardens of continental Europe during this period, Protestant England grappled with its idolatrous (and adulterous) iconography. Yet, the very language of myth was employed to envision a Christian landscape of moral purity, productivity and natural regeneration. These Anglo-Arcadian mythlands, in which the gods were often hollowed of their divinity, were to influence the eighteenth-century taste for countrified gardens with simple and edifying allegories.
Strengthening infection prevention in long-term care facilities in low-income and middle-income countries
Iwu, Chidozie Declan; Iwu-Jaja, Chinwe; Patrick, Sean Mark; Okoh, Anthony Ifeanyi; Wiysonge, Charles Shey (Elsevier, 2026-09)
No abstract available.
In-home tongue swab testing for tuberculosis screening among household contacts in South Africa : a prospective cohort study
Medina-Marino, Andrew; Olifant, Sharon; Pieruccini, Maria; Fiphaza, Kuhle; Ngcelwane, Nondumiso; Ruhwald, Morten; Penn-Nicholson, Adam; Fourie, Bernard P. (Elsevier, 2026-07)
BACKGROUND : Household contact investigation for tuberculosis is limited by reliance on clinic-based testing and sputum-dependent diagnostics. To inform household-level screening strategies, we estimated the diagnostic accuracy of in-home molecular testing using tongue swabs compared with sputum, and quantified linkage to care among household contacts with confirmed tuberculosis. METHODS : We conducted a prospective cohort study at 26 government health clinics in South Africa. We recruited index patients with drug-sensitive pulmonary tuberculosis and their household contacts. Participants aged 18 years or older and not on tuberculosis treatment within the past 6 months were eligible. Household contacts provided tongue swabs and, where possible, sputum specimens during household visits. Xpert MTB/RIF Ultra on GeneXpert Omni or Edge devices were used. Tongue swabs were tested individually or in pools of up to three participants, whereas sputa were tested individually. The primary outcome was the estimated diagnostic accuracy (ie, sensitivity and specificity) of tongue swab testing compared with sputum using paired results, irrespective of pooling strategy. Secondary outcomes included performance of pooled tongue swab testing as a household-level screening strategy (defined by conditional detection of tuberculosis by pool size and the residual probability of underlying tuberculosis following a negative pooled result) and linkage to care (defined as the proportion of individuals with a positive sputum result presenting for clinic-based tuberculosis services and their time-to-clinic presentation). FINDINGS : Between June 15, 2021, and Oct 29, 2024, 438 households and 909 household contacts were enrolled. The median age of household contacts was 39 years (IQR 28–55), 570 (62·7%) of 909 were female and 338 (37·2%) were male, 377 (41·5%) were symptomatic, 132 (14·5%) reported living with HIV, and 207 (22·8%) had a previous history of tuberculosis. Tongue swabs were obtained from 901 (99·1%) of 909 household contacts, whereas 292 (32·1%) produced sputum. Among 203 paired tongue swab–sputum results, sensitivity of tongue swab testing was 61·9% (95% CI 38·4–81·9) and specificity was 100% (98·9–100). Among individually tested tongue swabs paired with sputum results (58 paired tests), sensitivity was 100% (95% CI 47·8–100) and specificity was 100% (93·3–100). Among pooled tests in which at least one contributing participant was sputum-positive, five (55·6%) of nine for two-swab pools and three (42·9%) of seven for three-swab pools tested positive. Among pooled tests with a negative result, the residual probability of an underlying sputum-positive case was four (4·4%) of 91 for two-swab pools and four (9·5%) of 42 for three-swab pools. Sputum testing identified 29 (3·2%) of 909 household contacts with tuberculosis (all previously undiagnosed). Following referral, 25 (86·2%) of 29 presented for clinic-based care within a median of 1 day (IQR 1–2). INTERPRETATION : In-home molecular testing using tongue swabs enabled near-universal specimen collection and microbiological testing among household contacts. When implemented as a pooled, household-level screening approach, tongue swab testing identified tuberculosis among contacts unable to produce sputum and reduced the need for universal individual testing. However, pooling was associated with a measurable residual risk of missed disease following negative pooled results. These findings indicate that efficiency gains from pooled tongue swab testing must be balanced against the residual risk of missed cases.
An efficient and sustainable chemoenzymatic synthesis of ethambutol
Maboya, Josephine T.; Butsi, Kamogelo R.; Martins, Suné; Henning, Steffan; Brady, Dean; Pienaar, Daniel P. (Elsevier, 2026-11)
The anti-tuberculosis drug ethambutol remains in high demand, and hence there is a drive to improve the efficiency and sustainability of its production. Critical intermediates in its synthesis potentially include alkyl (S)-2-aminobutyrate esters. Taking advantage of the high enantioselectivity of enzymes, we applied ω-amino transaminases (ATAs) for the enantioselective transamination of two α-keto ester substrates, using isopropylamine as the amine donor, to produce the corresponding α-amino esters in enantiomeric excesses ranging between 94 and 99% and to obtain the desired products in isolated yields of 15-73%, depending on the enzyme variant and reaction conditions. The isopropyl (iPr) ester substrate gave rise to greater enzyme activity compared to the corresponding ethyl (Et) ester substrate. Hence, it was shown that isopropyl (S)-2-aminobutyrate could be synthesised in a good and preparative isolated yield (73%) and in excellent enantiomeric excess (>99%). A novel and potentially industrially feasible synthetic route to (S, S)-ethambutol was subsequently developed, starting from isopropyl (S)-2-aminobutyrate. Oxamidation using oxalyl chloride, followed by a novel borane mediated global reduction protocol, furnished (S, S)-ethambutol as a single stereoisomer in a good albeit unoptimised overall yield. HIGHLIGHTS • ω-Amino transaminases (ATAs) were used to convert inexpensive achiral keto ester substrates into high-value enantiopure amino esters, one of which has been shown to be a novel key building block in the synthesis of ethambutol. • The introduction of new keto ester enzyme substrates with improved enzyme-substrate binding properties to improve enzyme efficiency. • The development of facile, greener and chemoselective oxamidation and subsequent global reduction protocols for the synthesis of enantiopure ethambutol with minimal waste creation.
A review of vehicle wheel misalignment detection techniques
Mashigo, Khutso I.; Ayomoh, Michael Kweneojo; Erasmus, Louwrence; Nenzhelele, Tshifhiwa G. (MDPI, 2026-07-05)
Wheel (mis)alignment is one of the factors influencing vehicle safety, tire wear, and energy efficiency. While alignment procedures are well established in automotive workshops, recent advances in sensing, connectivity, and data-driven methods have led to renewed academic interest. This goes against existing research, which remains fragmented around vehicle types and methodologies. This study conducts a scoping review of wheel alignment monitoring and detection methods, with a focus on passenger vehicles. Guided by PRISMA-ScR, 453 studies were identified, of which 386 were excluded and 13 were duplicates and thus removed, resulting in a small number remaining for thematic analysis. Three dominant methodological approaches emerged: (i) traditional measurement methods, (ii) sensor-based vehicle dynamics analysis, and (iii) data-driven methods employing machine learning and vehicle telemetry. The findings revealed limited research on vehicle applications, especially for intelligent, integrated, and scalable alignment technologies and real-time, in-service monitoring applications. Other challenges included data quality, calibration, and cost-effectiveness. Therefore, the development of an integrated real-time wheel misalignment detection and reporting framework grounded in systems engineering and enterprise architecture principles is proposed.
Assessing the association between combined oral contraceptive use, selected biomarkers, and depressive episodes among premenopausal women : a protocol for a systematic review and meta-analysis
Fabunmi, Oyesanmi A.; Luthuli, Gugulethu P.; Dludla, Phiwayinkosi V.; Nkambule, Bongani B. (BioMed Central, 2026-07-07)
BACKGROUND : Combined oral contraceptives (COCs) are widely used among premenopausal women because of their contraceptive efficacy and favourable safety profile. However, concerns remain regarding their potential association with depressive symptoms and major depressive disorder (MDD), possibly mediated through alterations in neurochemical, inflammatory, and neurotrophic biomarkers. Hence, this study aims to provide a comprehensive synthesis of the available evidence on the link between COC and selected biomarkers associated with MDD risk and to assess whether the reported outcome is associated with the generational type of COC. METHODS : This systematic review protocol was prepared following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) 2015 statement. An extensive search will be conducted on Embase and MEDLINE through the Ovid and EBSCOhost interface. The Cochrane Library will be searched to augment relevant sources of information. Two reviewers will independently screen for eligible studies using a pre-defined criterion. The risk of bias and quality of included studies will be assessed via Cochrane risk of bias tools. The certainty of evidence will be assessed via Grading of Recommendations, Assessment, Development and Evaluation Assessment (GRADE) tool. DISCUSSION : The rate of depression among women of reproductive age remains alarming due to various factors related to childbearing, which may limit their economic contribution and full participation in societal development. As a result, some of these women may opt for the use of available contraceptive choices, such as COC, which are linked to the onset of MDD in high-risk individuals. More so, the change in hormonal milieu influences the secretion and physiologic role of histamine and other neurotransmitters, such as serotonin, among others, thereby contributing to an increased risk of MDD in premenopausal women. Thus, unravelling the role of COC in the secretions of these biomarkers and their contribution to the onset of MDD among premenopausal women is essential in filling the research gap that will provide insight and guidance when making informed decisions about the available contraceptive choices. The uniqueness of our review also extends to the focus on biomarker-based evidence of mood disorder risk in COC users, which may provide mechanistic insight and inform future risk-stratification research to assess the risk of MDD, both in and outside the clinical setting, among high-risk individuals. SYSTEMATIC REVIEW REGISTRATION : PROSPERO CRD42021284745.
A flexible kernel regression decomposition-based hybrid framework for forecasting foreign exchange rates: uncovering symmetric and asymmetric market dynamics
Iftikhar, Hasnain; Shah, Said Farooq; Almuhayfith, Fatimah E.; Rodrigues, Paulo Canas (MDPI, 2026-08-14)
Foreign exchange rate forecasting is difficult, as its time series have complex nonlinear and nonstationary dynamics. To this end, the paper proposes a hybrid forecasting framework based on kernel regression decomposition that combines nonparametric trend extraction with linear and nonlinear forecasting models. In the framework we propose, we decompose each series of exchange rates into a long-run trend component and a short-run fluctuation component, which are modeled separately and then combined to generate forecasts. An empirical study based on five major foreign exchange markets shows that the proposed framework consistently outperforms conventional hybrid and standalone forecasting models in multiple forecasting accuracy measures. The statistical validation of the forecasting improvements is confirmed by the Diebold–Mariano test. Moreover, the decomposition offers an interpretable representation of exchange-rate dynamics by distilling persistent long-run movements from localized short-run nonlinear fluctuations. The results indicate that the proposed framework improves forecasting accuracy and offers insight into the structural behavior of foreign exchange markets.
Price-responsive energy, water, and carbon cost assessment of greenhouse climate control under South African time-of-use tariffs
Ren, Zhiling; Guo, Jia; Hu, Minjie; Lin, Nan; Feng, Yufan; Dong, Yun (Elsevier, 2026-09)
Greenhouse climate control in water-stressed and carbon-intensive regions involves not only energy use and cost, but irrigation-related water demand, CO2 supplementation, and carbon impacts. However, integrated assessment of these coupled energy, water, CO2, and carbon cost factors remains limited. To address this gap, this study develops an optimization and assessment framework under South African time-of-use (TOU) tariffs. The framework captures the coupled dynamics of temperature, relative humidity, CO2 concentration, transmittance, and irrigation-related water demand, and evaluates three operational strategies: Minimum Energy Consumption (MEC), Minimum Energy Cost (MECo), and Minimum Total Cost (MTC). Compared with the MECo strategy, MTC extends the assessment boundary by incorporating groundwater-related penalty cost, CO2 supply cost, and carbon-emission cost into a unified total-cost objective. Under the baseline winter scenario, MTC reduces total cost by 37.01% versus MEC and 39.41% versus MECo, while reducing energy consumption by 13.74% and CO2 supply cost by 89.15% relative to MECo. Supplementary summer simulations show that under cooling-dominated conditions, MTC reduces total cost by 34.69% compared with MECo. Sensitivity analysis indicates that TOU tariffs exert the strongest influence on total cost. Overall, the framework provides a decision-support tool for price-responsive, sustainability-oriented greenhouse operation under coupled energy, water, and carbon considerations. HIGHLIGHTS • A comparative framework is developed for greenhouse climate-control assessment. • Energy, water, CO2, and carbon costs are jointly evaluated under TOU tariffs. • MEC, MECo, and MTC reveal distinct trade-offs in greenhouse operation. • MTC achieves the minimum total cost in both winter and summer scenarios. • TOU tariffs exert the strongest influence on total cost.
A systematic literature review: the influence of technical, operational and structural factors on the adoption of digital agriculture among small-scale farmers in sub-Saharan Africa
Chesi, Abienwi Lem Chemutah; Cho, Moses Azong; Azong Cho, Matilda Ngwe; Ramoelo, Abel (MDPI, 2026-07-02)
This systematic review paper examines how technical, operational, and structural factors influence the adoption of digital agriculture among small-scale farmers in Sub-Saharan Africa. Guided by PRISMA protocols, the study applies a hybrid thematic synthesis across six dimensions: technical, operational, policy and regulatory, governance, social and cultural, and environmental. The findings indicate that digital tools can generate substantial benefits, including yield increases of 10–30% (documented primarily for mobile-based advisory services and precision input management in East African horticulture and West African cocoa value chains) and price gains of 15–25%, with adoption rates of 70–80% in settings characterised by robust infrastructure, strong institutional support, and effective value chain integration. However, these benefits are unevenly distributed and tend to concentrate in “islands of adoption” characterized by robust infrastructure, strong institutional support, and effective value chain integration. While technical (94.9%) and operational (91.5%) factors dominate the literature, their impact is constrained by persistent structural barriers, including weak policy implementation (79.7%), fragmented governance systems (76.3%), and socio-cultural exclusion—such as gender disparities, age-related digital divides, and language misalignment (71.2%). The review identifies five minimum conditions for meaningful adoption: (i) affordable connectivity and access to digital devices; (ii) context-specific digital literacy; (iii) culturally relevant, user-centred design; (iv) robust institutional ecosystems; and (v) enabling policy and financial frameworks. Overall, the findings underscore that digital agriculture adoption is a socio-technical process shaped not only by technological innovation but also by institutional arrangements and user capabilities. Comparative cases, such as Kenya’s Farm.ink and the less successful EZ Farm initiative, further highlight the importance of integrated, context-responsive approaches to ensure that digital agriculture enhances, rather than marginalizes, small-scale farmers.
Does farmer knowledge of soil quality influence input allocation decisions and productivity outcomes? Implications for sustainability
Msukuma, Michael; Mkwanda, Chisomo; Khataza, Robertson R.B.; Mathanda, Harry; Mgomezulu, Wisdom Richard; Makombe, Godswill (MDPI, 2026-07-14)
Land degradation, characterized by declining soil fertility and erosion, is a major constraint of maize productivity in Malawi, where more than half of the arable land is degraded. Although knowledge of soil fertility is critical for efficient input allocation, most smallholder farmers rely on subjective assessments of soil quality, which could potentially lead to imprecise decisions. This study examines how farmers’ perceptions of soil fertility and erosion influence input allocation and maize productivity among smallholder farmers in Malawi. Using plot-level data comprising 6370 maize plots from the Malawi Integrated Household Survey, we apply a Conditional Mixed Process estimator and stochastic frontier analysis to assess input use behaviour and technical efficiency. Results indicate that farmers allocate more labour and inorganic fertilizer to plots perceived as fertile, and adoption of improved maize varieties is lower on plots perceived as poor. Organic manure is more frequently applied on degraded plots to recondition the soils. Mean technical efficiency is estimated at 0.63, indicating substantial inefficiency relative to the production frontier. Further, technical efficiency declines with worsening soil conditions. These findings highlight sustainability risks associated with soil degradation and inefficient input allocation. Improved soil diagnostic services, integrated soil fertility management practices, and targeted extension programmes could promote sustainable land management and efficient matching of inputs to soil conditions.

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