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Item Engineered BaTiO₃/SnIn₄S₈ step-scheme nanocomposite with interfacial coupling for energy-efficient piezo-photocatalytic oxidation of tetracycline(2026-07) Mohlala, TT; Yusuf, TL; Masukume, Mike; Ojijo, Vincent V; Mabuba, NTetracycline hydrochloride (TCH) has been recognized as one of the most problematic pollutants in water systems due to its extensive uses in medical and veterinary systems. Poor removal leads to persistent residues that lead to antibiotic resistance and ecological disruption. The nanosphere-on-nanoflower architecture of BaTiO3/SnIn4S8 (BTO/SIS) was designed and fabricated via solvothermal synthesis using ethanol as a solvent, as an energy-efficient catalyst for piezo-phototronic applications. Characterization such as Mott-Schottky (M-S), scanning electron microscopy (SEM), and XRD were used to substantiate the nanoflower-decorated nanosphere composite heterojunction contact leading to the Step-scheme (S-scheme) band alignment promoting partial recombination through the internal electric field for enhanced charge separation, generation, and migration within the heterostructure. Owing to the synergistic effects of the S-scheme alignment and the hierarchical morphology, BTO/SIS (1:1) ratio achieved the removal of ~85% of the persistent tetracycline hydrochloride (TCH) in 120 minutes with minimal 70 W light illumination and low ultrasonication power of 6.8 W (20 kHz). The optimized BTO/SIS possessed a synergistic factor of 1.74 (>1), way higher than the single photocatalytic and piezocatalytic processes. Photoluminescence (PL), and electrochemical impedance spectroscopy (EIS) indicated longer lifetimes of charge carriers, lower charge transfer resistance, and lower rates of recombination. Interestingly, TCH as an amphoteric molecule was efficiently removed at an optimum pH of 7 where it is at its zwitterionic form. Trapping studies revealed that superoxides (•O2−) were the major oxidants responsible for the degradation caused by efficient electron transfer and via indirect oxidation especially in S-scheme heterojunctions. This study not only demonstrated the energy-efficient 0D/3D BTO/SIS system but also showed that the nanosphere piezoelectric BTO with a photo-active nanoflower in an architecture S-scheme enhances mechanical deformation sensitivity, while maintaining high stability in piezo-photocatalytic degradation of organic pollutants in water.Item Actionable pharmacogenomics and essential Medicines: An analysis of WHO and African lists for safer and efficacious drug use(2026-04) Mazhindu, TA; Nagy, M; Twesigomwe, D; Agesa, G; Scholefield, Janine; Masimirembwa, CThe World Health Organization Model Essential Medicines List and African national essential medicines lists (EMLs) detail drugs intended to be consistently available within national health systems, thereby supporting clinicians and pharmacists in making evidence-based treatment decisions. At present, these EMLs do not account for pharmacogenomics, despite known drug-gene interactions and the considerable genetic diversity found throughout Africa. In the absence of pharmacogenomic considerations, the medicines lead to sub-optimal treatment outcomes, especially across a continent such as Africa which represents more genetic variation that the rest of the world combined. Herein, we review EMLs from the WHO, and from 52 African countries, highlighting systemic medicines for which actionable pharmacogenomic-biomarker testing recommendations exist. Furthermore, we assess the feasibility of PGx-guided dosing in eight African countries by examining the availability of registered drug formulations that facilitate dose adjustment. The 2023 WHO EML comprised 447 unique systemic medicines, with 58 (13%) categorized as medicines with actionable pharmacogenomic biomarkers. African country EMLs collectively featured 774 such medicines, with an average of 294 per country (range: 125–465). On average, for each country one in every eight medicines in the Essential Medicines List was associated with established pharmacogenomic guidance. PGx recommendation. Cumulatively in African EMLS the most frequent drug classes with this designation are anti-infectives (25.6%), immunomodulators/antineoplastics (16.7%), and medicines for mental and behavioral disorders (14.1%). Analysis of eight African countries determined that implementability ranged from 75% to 96% based on product formulation and strength availability to enable drug or dose modification. We provide data that contributes towards a foundation of increasing evidence showing that integrating pharmacogenomic knowledge into the selection processes for essential medicines and ensuring the availability of appropriate drug formulations can enhance treatment safety and efficacy across Africa.Item Global carbon budget 2025(2026-05) Friedlingstein, P; O’Sullivan, M; Jones, MW; Andrew, RM; Bakker, DCE; Hauck, J; Landschützer, P; Le Quéré, CL; Li, H; Djeutchouang, Laique MAccurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesise datasets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy and cement production data. Emissions from land-use change (ELUC) are estimated by bookkeeping models based on land-use data. The global atmospheric CO2 growth rate (GATM) is computed from changes in concentration measured at surface stations. The global net uptake of CO2 by the ocean (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based fCO2-products. The global net uptake of CO2 by the land (SLAND) is estimated with dynamic global vegetation models. Additional lines of evidence are provided by atmospheric inversions, atmospheric oxygen measurements, ocean interior observation-based estimates, and Earth System Models. This year, we introduced corrections on the ELUC, SOCEAN and SLAND estimates. The sum of all sources and sinks results in the carbon budget imbalance (BIM), a measure of imperfect data and incomplete understanding of the contemporary carbon cycle. All uncertainties are reported as ± 1σ.Item Physiological and meat quality responses to phased and continuous hydrolyzed yeast (Saccharomyces cerevisiae) supplementation in densely stocked broiler chickens(2026-12) Moreane, N; Mnisi, CM; Sumanu, VO; Fayemi, OE; Moonsamy, Ghaneshree; Kiarie, EG; Jha, R; Mlambo, VThe transition toward antibiotic-free broiler production has intensified interest in precision nutritional strategies that enhance bird resilience under intensive rearing conditions. Hydrolyzed yeast (HY, Saccharomyces cerevisiae) delivers a complex array of bioactive compounds that support gut function and immune regulation; however, the benefits of HY are likely growth-stage dependent, and continuous supplementation may be economically inefficient. This study evaluated the physiological, gut microbial, and meat quality responses of densely stocked Ross 308 broilers to phase-targeted HY feeding strategies: continuous HY supplementation and HY supplementation restricted to the starter, grower, or finisher phase. Growth performance, haemobiochemical indices, carcass and meat quality, and caecal microbiota composition were assessed. Continuous AGP supplementation yielded the highest (P < 0.05) feed intake, body weight gain, and feed efficiency. In comparison, HY feeding strategies did not improve growth performance (P > 0.05) relative to antibiotics, but did influence physiological and meat quality outcomes when applied continuously or in a phased manner. Phase-specific HY supplementation induced distinct physiological responses (P < 0.05), including changes in nitrogen-related and liver-associated blood indices, with negative impacts on carcass or meat quality. Caecal microbial alpha diversity remained unchanged across treatments (P > 0.05), though selective shifts in microbial composition occurred. Overall, few significant differences were detected between phased and continuous HY supplementation across the measured outcomes, suggesting that phased HY supplementation warrants further investigation as a practical nutritional strategy for antibiotic-free intensive broiler production.Item Dietary supplementation with a multi-strain Bacillus subtilis probiotic improves digestive efficiency, growth performance, and meat quality in densely stocked broilers(2026-06) Mahlangu, Z; Mnisi, CM; Sumanu, VO; Moonsamy, Ghaneshree; Fayem, OE; Jha, R; Mlambo, VBacillus subtilis has attracted attention as a robust probiotic candidate to replace antibiotic growth promoters (AGPs) in poultry, owing to its spore-forming resilience and capacity to modulate gut function. However, inclusion levels and the efficacy of multi-strain B. subtilis mixtures remain underexplored, particularly at high stocking densities, when birds are more susceptible to physiological and environmental stressors. This study evaluated the effects of incremental levels of a multi-strain B. subtilis probiotic mixture on growth performance, nutrient digestibility, physiological responses, carcass traits, and meat quality of broiler chickens reared under intensive conditions. A total of 900 one-day-old Ross 308 broiler chicks were assigned to six dietary treatments in a completely randomized design, with 36 pens (13 birds/0.75 m²) serving as experimental units. Diets comprised a basal diet without additives (PRB0), a positive control containing zinc bacitracin (POSC), and four diets supplemented with 0.3, 0.4, 0.5, or 0.6% of the B. subtilis probiotic mixture (PRB3 – PRB6). Diets were fed from the starter to the finisher phases. Probiotic supplementation influenced growth responses across the graded inclusion levels. Birds receiving the 0.5% inclusion level consistently exhibited the most favourable body weight gain and feed conversion efficiency compared with the other treatments. Probiotic supplementation enhanced the digestibility of organic matter, neutral detergent fibre, and gross energy, whereas crude protein digestibility exhibited a quadratic response. Haemato-biochemical profiles suggested improved physiological status in birds receiving mid-level probiotic inclusions (PRB3 – PRB5). Carcass yield and major meat quality traits were unaffected by dietary treatments, while minor effects on gut morphological indices were observed. Collectively, these findings suggest that a 0.5% inclusion level may be a promising probiotic supplementation strategy for broiler production under high stocking density.Item Waves explain observed similarity scaling of turbulence dissipation in the Southern Ocean(2026-06) Giddy, Isabelle; Whitt, D; Fer, I; Swart, S; Breivik, O; Nicholson, Sarah-AnneWe investigate the turbulence kinetic energy (TKE) budget of the upper ocean and its response to wind and wave forcing in the Southern Ocean, using realistically forced large-eddy simulations (LESs) and in situ microstructure shear observations. The widely used law of the wall similarity scaling assumes that shear production of TKE is balanced by its dissipation. However, our findings reiterate that this assumption is violated under wave forcing: Dissipation is primarily balanced by local Stokes shear production, augmented by almost equal contributions from local Eulerian shear production and nonlocal convergence of TKE transport. Despite this, the canonical law of the wall scaling reasonably describes the vertical distribution of dissipation rates in the boundary layer in both realistically forced LES and observations, even though the underlying physical reasoning does not hold. We propose a modified scaling to account for the nonlocal component of the TKE budget that yields accurate predictions of the TKE budget as well as an interpretation accounting for wave effects. These insights have important implications for interpreting turbulence dissipation rate observations.Item Proteomic profiling of extracellular vesicle-enriched plasma using mag-net for biomarker discovery in pancreatic ductal adenocarcinoma(2026-08) Buthelezi, Sindisiwe G; Elebo, N; Naicker, P; Mokoena, Rethabile J; Dubazana, S; Govender, Ireshyn I; Mamputha, Sipho; Ellero, A; Stoychev, S; Mazibuko, J;Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer and was ranked among the top seven leading causes of cancer-related deaths in South Africa in 2020. Highlighting the urgent need for ongoing research to identify reliable biomarkers to improve clinical outcomes. This study compared the plasma proteomes of patients with PDAC, those with benign biliary pathologies (BBP), and healthy controls (HC). We used Mag-Net, a magnetic-bead-based method that enriches membrane-bound vesicles. Comparative analyses identified distinct and overlapping dysregulated proteins between PDAC, BBP, and HC. PDAC showed enrichment for epithelial-mesenchymal transition, complement activation, hypoxia, glycolysis, and extracellular matrix remodeling pathways, consistent with aggressive tumor biology. Proteins including SPP1, THBS2, PTX3, FBLN2, SDC1, CTSS, and VCAN were significantly increased in PDAC, with LRG1 showing the strongest association with disease severity. Proteins, namely GPNMB, H4C1, SAA1, and CCDC47, demonstrated progressive upregulation across disease comparisons, suggesting potential relevance to disease progression. These findings demonstrate that plasma proteomics provides discriminatory molecular insights and supports the development of population-relevant biomarker panels. While several candidate proteins show promise for inclusion in multianalyte panels, further validation in larger cohorts is necessary to establish their diagnostic and translational utility for early detection, risk stratification, and improved differential diagnosis of PDAC.Item Advances in solid handling for continuous flow synthesis of specialty chemicals and pharmaceuticals(2026-02) Johnston, Z; Peme, T; Mabasa, Tommy F; Len, C; Riley, D; Panayides, Jenny-Lee; Sagandira, Cloudius RContinuous flow chemistry has transformed the synthesis of pharmaceuticals and specialty chemicals by advancing sustainability, efficiency, and process control. Despite these advantages, the management of solids remains a major challenge, often leading to clogging, inefficient mixing, and limitations in scalability. This review discusses recent strategies developed to overcome these obstacles, including the use of continuous stirred-tank reactors, packed-bed reactors with immobilized reagents, reaction design modifications, Pickering emulsions, colloidal nanoparticle suspensions, and specialised equipment such as agitated tubular reactors, spinning disk reactors, and sonicated systems. By critically assessing these developments, we chart the trajectory toward more resilient and robust flow-based manufacturing, consolidating continuous flow chemistry as a cornerstone of modern chemical manufacturing.Item Refining binned aggregation of unevenly spaced, real-time data for visualisation and control(2015-11) Du Toit, Kirsten; Fogwill, Thomas; Maiwashe, T; Van der Westhuizen, MThe resource constrained environment in South Africa has led to an increased interest in the monitoring and control of electricity demand. The associated proliferation of smart meters/sensors and the collection of their data allows for monitoring and control of demand on a much wider scale than previously possible. A homeowner, business or utility may now make use of real-time data to track and control their electricity demand with potentially widespread economic effect. We examine the characteristics that a system must exhibit to excel at high volume, low latency real-time data stream processing to support such applications. A robust, scalable and fast method for real-time processing of streamed electricity demand data is suggested. This method also addresses the problems associated with developing countries in that the data received are sometimes inconsistent, unevenly spaced and interrupted. Processing these unevenly spaced data for visualisation is an important requirement in order for users to more easily understand and analyse their usage trends. Binned aggregation is explored as an effective strategy for minimizing the negative effects of inconsistent data of different frequencies. It is also used to reduce the data to manageable dimension, while real-time processing determines where and how to use the data. A sensor's data are stored in several rolling arrays of differing size that represent different time-frames. We keep the most detailed information for the current time-frame. The format chosen allows for data reduction yet allows redundant data to contribute to the model and refine the aggregation. The reduced amount of data stored allows fast retrieval of those data for visual display and analysis and improved scalability.Item A research agenda for studying evidence-informed practice in urban planning(2026-07) Du Toit, J; Pieterse, AmyThis article reviews empirical studies of evidence-based policy and proposes an agenda for studying evidence-informed practice in planning along three directions and overarching questions: What does ‘evidence’ mean to practitioners in different contexts and how do practitioners prioritize and use different forms of evidence? What is the effect of individual, institutional, systemic and political factors on evidence use? How can pragmatic evidence use be facilitated for deliberative practice, what is the efficacy of different approaches, and what are the procedural outcomes of cases of evidence use? This agenda could contribute towards a more systematic and integrated understanding of evidence-informed practice.Item Performance evaluation of NFPP-Type Sodium-Ion batteries(2026-05) Grobler, Inus; Banderker, Muhammad H; Govindsamy, Reesen; Van der Kolf, GideonThis paper presents a performance evaluation of next-generation sodium-ion cells employing Sodium Iron Pyrophosphate (NFPP) chemistry, which is now commercially available. Building on prior research into early-generation SiB technologies, the study investigates NFPP cells under varied operating conditions, including high and low temperatures, extreme C-rate discharge, and zero-volt storage. Results indicate that NFPP cells deliver exceptional high-power capability, sustaining continuous discharge rates up to 30C without degradation, and they exhibit strong thermal stability at elevated temperatures. While safety features such as zero-volt tolerance remain intact, low-temperature operation continues to pose challenges, particularly for charging, with irreversible capacity loss observed when exceeding manufacturer specifications. Despite a relatively low energy density (~79.75 Wh/kg), NFPP cells demonstrate significant potential for high-power applications requiring reliability and safety in harsh environments. These findings position NFPP chemistry as a critical step toward advancing sodium-ion technology for specialised energy storage solutions.Item Comprehensive validation of novel deep learning architectures to forecast geomagnetic substorms(2026-06) Essop, A; Mbatha, Nkanyiso B; Stephenson, JAEMagnetic substorms are disturbances in the terrestrial magnetosphere that can have significant space weather impacts, although forecasting their onset accurately remains an open problem. In this study, we develop multiple novel machine learning architectures based on convolutional neural networks, long short-term memory networks, extreme gradient boosting, and their hybrid combinations for the probability prediction of magnetic substorm onsets. The best performing models came from hybrids in the following order: two-dimensional convolution, bidirectional long short-term memory, and finally extreme gradient boosting for binary classification probability prediction with an F1 score of 0.8411 across both classes. Notably, a novel modified stratified K-fold cross-validation benchmark is developed for these deep learning models; the F1 scores fell within 79%–85% across model architectures. The results demonstrate the ability of models to unambiguously forecast substorm onsets from upstream solar wind and IMF conditions. Two-hr historical windows of solar wind velocity, proton number density, and three-dimensional interplanetary magnetic field components, sampled at 1-min cadence, are used to forecast the onset probability at the next minute after the window. The input data set was balanced using the SuperMAG list of substorm onsets between 2003 and 2022, with an equal number of non-substorm intervals, to avoid bias. Principal component analysis showed significant overlap in the solar wind and IMF conditions prior to both substorm and non-substorm intervals, indicating that these parameters alone may not be sufficient to forecast all substorms and that internal magnetotail preconditioning and magnetospheric processes are likely critical areas that should be explored further.Item Factors affecting the adoption of mobile-based digital technologies: Evidence from Ethiopia(2026-06) Bule, DL; Ntuli, Herbert; Gandidzanwa, CMobile phones and associated services possess substantial potential to improve household livelihoods. However, there is inadequate access to and use of mobile-based technologies, despite their potential to improve livelihoods in the Hadiya zone, Ethiopia. This study aims to analyse the main factors influencing the adoption of mobile-based technology. The analysis employed an ordered logit model on cross-sectional data collected from 278 respondents. The findings indicate that factors such as gender, education, affordability, access to remittances, social networks, awareness, geographical location, trade access, and type of mobile phone have positively and significantly influenced the likelihood of adopting mobile-based digital technology, except age. The implications suggest that mobile-based technology adoption remains under-utilised for essential activities, with adoption particularly lower among women and rural populations. Targeted interventions, including infrastructure improvements, digital connectivity enhancement, awareness campaigns, skill training, income-raising initiatives, and gender-sensitive digital policies, are essential to promote adoption.Item Ethnobotanical documentation and conservation assessment of medicinal plants in the Bojanala District, North-West Province, South Africa(2026-05) Matlala, ME; Sinorita, C; Kola, E; Ramarumo, Luambo J; Ndhlovu, PTBojanala District in North-West Province of South Africa is home to a diverse array of plant species, many of which are known for their medicinal properties. Despite their historical use, the pharmacological properties of these plants remain largely unexplored. The current study aimed to explore the phytomedicinal practices in Bojanala District by documenting medicinal plants and the associated indigenous knowledge.Item Integrating conductivity in stealth and biomedicine: Role of 3D printable polymers in next-generation technology(2026-07) Bandyopadhyay, Jayita; Ray, Suprakas SRecently, 3D printing has become a transformative force in manufacturing, especially for custom applications. It is reshaping industries like aerospace and healthcare. As technology advances, the demand for advanced functional materials suitable for 3D printing grows. This review focuses on electrically conductive polymers designed for 3D printing, especially fused deposition modeling It discusses their use in stealth and medicine. The review thoroughly examines the necessary criteria for these applications and the polymers and composites with various fillers developed to meet them. Understanding the performance and cost implications is crucial for future material development across many applications, both known and yet-to-be-discovered. Additionally, a perspective on the future of this technology is offered.Item Building the future of biophotonics through experiential education and seasonal schools(2026-06) Mthunzi-Kufa, P; Maphutha, J; Mcotshana, Zenande KS; Mcoyi, Michael PSignificance: Photonics represents a low-hanging fruit and a highly lucrative industry on the global stage, with applications spanning healthcare and biophotonics, energy and environmental photonics, agriculture and food systems, quantum photonics, telecommunications and data communications, among many other sectors. Despite this breadth of opportunity, the availability of structured biophotonics courses and programs remains limited, largely due to the inherently multidisciplinary nature of the field. Compounding this challenge, many schools, particularly in developing countries, lack adequate science laboratories, especially at the secondary level, thereby depriving learners of the practical exposure necessary to grasp fundamental theoretical concepts meaningfully. Aim: These gaps underscore the need for innovative and creative approaches to education and capacity development. Approach: Initiatives such as job-shadowing opportunities, outreach activities, summer schools, and diverse forms of online learning are therefore essential in widening access and building foundational skills. Results: Introducing photonics, optics, and biophotonics at the high-school and undergraduate levels would significantly strengthen the talent pipeline, cultivating scarce and highly sought-after skills. Conclusions: Against this backdrop, this paper highlights the importance of targeted strategies that advance biophotonics education and capacity building as a catalyst for sectoral growth.Item The role of digital technologies in enhancing construction safety: A case study of the George building collapse(2026-05) Molabe, Matshengwane P; Van Reenen, Coralie AIt is no secret that the construction industry faces ongoing safety challenges, with structural failures posing significant risks to lives and property. Digital technologies transform construction safety management by providing dynamic, data-driven alternatives to traditional, static methods. Studies report that 3D and 4D modelling tools enable clear, real‐time visualizations that improve hazard identification and safety planning. Digital platforms often integrated with Virtual and Augmented Reality also enhance worker training and safety communication, shifting the process from reactive, paper‐based approaches to proactive, continuously updated systems. This paper explores the role of digital technologies in improving construction safety by predicting and mitigating risks. A detailed review of existing literature, an analysis of the George building collapse, and an evaluation of BIM's potential contributions provide insight into how digital tools can revolutionize safety protocols in the construction industry.Item Characterisation of heat-treated Ti-rich NiTi fabricated by laser powder bed fusion(2025-11) Motibane, Londiwe P; Tshabalala, Lerato C; Becker, T; Kgomo, Matshela TNitinol (NiTi) is useful for biomedical applications, and laserpowder bed fusion (L-PBF) presents a unique opportunity to fabricate complex and patient-specific implant designs. The processing of nitinol via L-PBF, however presents a challenge as it results in an inhomogeneous microstructure that affects mechanical performance and can limit functional property performance. Moreover, an understanding of Ti-rich NiTi processed via L-PBF is lacking. Post-processing heat treatments are an avenue to alter and tailor the microstructure and thus influence the resulting phase transformations and mechanical performance. This paper presents various heat treatments and the influence of their resultant microstructures, phases and transformation temperature behaviour is characterised.Item Spatiotemporal air quality forecasting in South Africa using the LSTM model(2026-06) Shikwambana, L; Sebake, M; Molefe, M; Havenga, H; Mbatha, Nkanyiso BThis study applies a Long Short-Term Memory (LSTM) model to predict key air pollutants, i.e., sulphur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter (PM2.5), as well as the Air Quality Index (AQI) across South Africa using satellite-derived observations. The analysis focuses on comparing original pollutant fields with model-generated predictions for two consecutive days, highlighting both spatial patterns and predictive performance. Results reveal a persistent and intense pollution hotspot over the Mpumalanga Highveld, driven by coal-fired power generation and industrial activities. Elevated pollutant concentrations in this region translate into AQI levels ranging from Unhealthy to Very Unhealthy, while most other parts of the country remain within the Good category. Spatial comparison between original and predicted fields shows strong agreement, with only minor deviations in areas characterized by steep emission gradients and localized plumes. Quantitative evaluation using RMSE (0.020390) and MSE (0.000416) confirms the high accuracy of the predictive model, with error values remaining extremely low across all pollutants and AQI outputs. PM2.5 exhibits the smallest errors (MSE = 4.230169 × 10−6), while slightly higher values for SO2 (MSE = 2.628 × 10−4) and NO2 (MSE = 1.39541 × 10−4) reflect the difficulty of capturing sharp spatial transitions associated with pointsource emissions. Despite these localized discrepancies, the model demonstrates robust skill in replicating both pollutant magnitudes and AQI classifications. Overall, the findings indicate that machine-learning approaches offer a reliable, high-resolution tool for air-quality prediction in South Africa and have strong potential for supporting operational forecasting, exposure assessment, and environmental policy development.Item Sources of water-soluble organic carbon in aerosols at the Cape Point GAW station(2026-07) Rawatlal, M; Spence, KAM; Smith, Marie E; Labuschagne, C; Altieri, KEAerosols play a major role in climate by influencing both radiative forcing and cloud condensation nuclei (CCN) formation, with organic aerosols comprising a large fraction of the global natural aerosol burden (∼20–70%). Despite this importance, long-term observations of water-soluble organic carbon (WSOC), particularly in size-segregated aerosols from natural sources, remain scarce in the southern hemisphere. Here, we present size-resolved WSOC measurements from an eight-month observational campaign (April to November 2018) at the Cape Point Global Atmosphere Watch (GAW) station, a remote coastal site at the southern tip of Africa, ideally suited for elucidating marine, continental, and mixed aerosol sources. Weekly aerosol samples were classified using air mass back trajectories, radon-222 and carbon monoxide concentrations, wildfire observations, and satellite-derived chlorophyll-a to assess source influences. Across all air mass classifications, WSOC concentrations were consistently higher in the fine mode (<1 μm) than in the coarse mode (>1 μm) aerosols (0.58 ± 0.55 μg/m3 vs 0.20 ± 0.22 μg/m3, respectively). Fine mode WSOC concentrations were highest during periods influenced by biomass burning (0.87 ± 0.49 μg/m3) and continental outflow, while marine and modified marine air masses exhibited lower fine mode WSOC concentrations. However, periods of enhanced marine biological activity were associated with increased fine-mode WSOC concentrations. The observed predominance of WSOC in the fine mode across marine, modified marine, and continental air masses highlights the importance of secondary formation and atmospheric aging processes, rather than direct primary emissions, in controlling WSOC concentrations at Cape Point. Overall, WSOC levels at this coastal site reflect an integration of natural and anthropogenic sources, transport history, and atmospheric processing. These results establish a regional baseline for WSOC aerosols in southern Africa and contribute to a broader understanding of organic aerosol formation in a data-sparse southern hemisphere coastal environment.