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Probabilistic vs Deep Generative Models: A Fairness Centred Evaluation of Synthetic Healthcare Tabular Data
No full textData Availability:
CPRD cardiovascular disease synthetic dataset used in this paper can be requested from CPRD (https://cprd.com/cprd-cardiovascular-disease-synthetic-dataset). The diabetes dataset is publicly available on Kaggle (https://www.kaggle.com/datasets/rabieelkharoua/diabetes-health-datasetanalysis).Code availability:
Not applicable.Springer is providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.A preprint version of the article is available on Research Square at https://doi.org/10.21203/rs.3.rs-7565139/v1 . It has not been certified by peer review.Synthetic data offers a promising avenue for addressing privacy, scarcity, and fairness challenges in healthcare datasets. However, there is limited evaluation of how different generation methods balance fidelity, utility, and fairness, particularly for underrepresented subgroups. This study addresses this gap by comparing representative generative modelling techniques, both probabilistic and deep approaches, that are popular in the research literature. We empirically evaluate BayesBoost, CTGAN, TVAE, CopulaGAN, and DECAF on two healthcare datasets containing numerical, binary, and categorical features. Each modelโs performance is assessed along three axes: data fidelity, machine learning utility, and fairness, using Accuracy Parity, Equalised Odds, and Predictive Rate Parity. Results show that BayesBoost consistently achieved superior fidelity, utility, and fairness preservation, particularly when paired with Random Forest classifiers, achieving around 60โ63% higher downstream utility than GAN-based deep generative baselines (e.g., Random Forest accuracy up to 0.88 with BayesBoost versus 0.54 to โ 0.55 for GAN-based methods). Deep generative models, while effective in capturing complex structures, often degraded fairness, especially for underrepresented groups, with equalised odds deviating by over 100% from the ideal parity value of 1.0 in some settings. The Variational Autoencoder outperformed other deep generative models in fairness preservation, especially for equalised odds, although with some reduction in fidelity and utility. Overall, these findings suggest that synthetic data generation for healthcare must move beyond fidelity evaluations to explicitly assess fairness and subgroup impacts, with probabilistic models such as BayesBoost showing strong potential for ethical deployment, while deep generative models require further adaptation for fairness-sensitive applications.This work was funded by the Regulators Pioneer Fund, Department for Science, Innovation and Technology.
This work was also supported by the UK Regulatory Science and Innovation Networks โ Implementation Phase: Human Health CERSIs programme through the project RADIANT: Regulatory Science Empowering Innovation in Transformative Digital Health and AI (Grant Ref: MCPC24031), funded by the Medical Research Council (MRC) and Innovate UK
Exploring how weight stigma relates to psychological distress, physical activity, and eating behaviors over time: a longitudinal study among young adults in Hong Kong
Full text linkData availability:
The datasets generated during and/or analyzed during the present study are available from the corresponding author upon reasonable request.Supplementary Information is available online at: https://link.springer.com/article/10.1186/s40337-026-01525-w#Sec32 .Plain English summary:
Weight stigma, discrimination due to an individualโs body weight, is a public health concern. It has been found that weight stigma is harmful to an individualโs mental and physical health, and such negative impact may create a harmful cycle. However, there is little clear evidence that the cycle exists, especially among individuals from East Asia. To investigate this issue, a study followed young adults in Hong Kong to examine how weight stigma relates to mental health, eating behaviors, exercise habits, and weight changes. Young adults were surveyed over a one-year period across four timepoints; Time 1 (Tโ; nโ=โ345), Tโ (nโ=โ253), Tโ (nโ=โ233), Tโ (nโ=โ235). Results indicated that relationships existed over time in the connections between (i) perceived stigma (awareness of stigma) and self-stigma (stigma towards oneself), and (ii) between self-stigma and perceived behavioral control. In summary, the rate of change of these variables did not correlate with changes in body mass index (BMI). However, self-stigma showed a negative association with BMI at later timepoints. Findings supported a clearer understanding of weight management and highlighted the harmful impact of stigma. The findings also showed significant issues with weight stigma in Hong Kong, emphasizing the need for improved public education and stigma reduction efforts. Further research is needed to determine whether weight stigma can be influenced by changes in weight.Background:
Many researchers have expressed concerns that weight stigma may cause adverse health effects and worsen weight issues in a vicious cycle. However, empirical evidence evaluating this cycle is scarce, especially among Eastern Asians. The present study investigated the temporal associations among perceived weight stigma, weight-related self-stigma, psychological distress, perceived behavioral control, physical activity, eating behaviors, and body mass index (BMI) changes.
Methods:
A one-year longitudinal survey was carried out to explore if the weight cycle exists among young adults in Hong Kong. The study comprised 345 participants at Time 1 (Tโ), 253 participants at Tโ, 233 participants at Tโ, and 235 participants at Tโ. Participants completed self-reported psychometric instruments in an online survey. The analysis employed parallel process latent growth curve modeling and a random intercept cross-lagged panel model.
Results:
Temporal relationships existed in the connections between perceived stigma and self-stigma, and self-stigma and perceived behavioral control. A negative relationship between self-stigma and future BMI was found, whereas future self-stigma showed no significant association with previous BMI.
Conclusion:
The growth trajectories of the studied variables did not correlate with changes in BMI. However, self-stigma showed a negative association with subsequent BMI in a different model. Further research is needed to clarify whether weight stigma is impacted by changes in BMI.Open access funding provided by National Cheng Kung University. Jian-Han Chen is supported by the E-Da Hospital funding (EDAHP114007)
Crude Microalgae Extract for Increased COโ Capture and Higher Biomass Production in Algal Cultivation Systems
Full text linkData Availability Statement:
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.Efficient inorganic carbon supply is a common limitation in microalgal cultivation, particularly in waste-derived media such as anaerobic digestate. Carbonic anhydrase (CA) accelerates the interconversion of COโ and bicarbonate and may therefore enhance carbon utilisation under conditions where inorganic carbon is abundant but not readily available. In this study, crude CA-containing extracts (aCA) were prepared from Scenedesmus-dominated algal biomass, and CA activity was quantified using an esterase assay (EAA). Although EAA activities varied depending on biomass pretreatment (0.15โ0.47 U gโปยน DW), the physiological response to extract addition was consistent. In batch cultures of Chlorella sorokiniana grown in diluted digestate, aCA supplementation increased the specific growth rate (SGR) by 21โ82%. In contrast, stimulation in a mineral medium was minimal, indicating that the benefit of aCA addition is most apparent under reduced inorganic carbon availability. In semi-continuous cultivation, repeated extract addition sustained a higher biomass productivity over time (rather than a specific growth rate). These results demonstrate that crude microalgal extracts containing CA can improve growth performance in digestate-based cultures and may offer a simple, low-cost approach to enhancing inorganic carbon utilisation in waste-integrated algal production systems.This research was funded by EU, 101084405โCRONUSโHORIZONโCL5-2021-D3-03
Achieving Single Solid Solution in Equimolar AlCrCuFeNi via Rapid Solidification
Full text linkData availability:
No data was used for the research described in the article.This is a PDF of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability. This version will undergo additional copyediting, typesetting and review before it is published in its final form. As such, this version is no longer the Accepted Manuscript, but it is not yet the definitive Version of Record; we are providing this early version to give early visibility of the article. Please note that Elsevierโs sharing policy for the Published Journal Article applies to this version, see: https://www.elsevier.com/about/policies-and-standards/sharing#4-publishedjournal-article. Please also note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.This study investigates the effect of cooling rate on the equimolar AlCrCuFeNi High-Entropy Alloy (HEA) using a 6.5m-tall drop-tube facility. It is found that as-cast AlCrCuFeNi comprises an FCC phase and a B2 phase. However, the AlCrCuFeNi alloy is found to attain a single B2 structure at cooling rates of 10ยฒ K/s and above. The cooling rates achieved in this work are estimated to vary between 112 K/s and 1.13ร10โถ K/s. Phase separation within the dendrites is observed in the as-cast alloy. This phase separation occurs via spinodal decomposition and is inhibited only at the highest achieved cooling rate of around 1.13ร10โถ K/s. As such, with higher cooling rates, simpler microstructures are obtained, extending the solid-solution of the system. This is one of the primary objectives in employing rapid-solidification techniques in HEAs. Finally, the microhardness of the rapidly cooled samples is probed and found to increase with cooling rate. Notable jumps in microhardness are noted and related to changes in morphology
Short-Term Disruptions and Recovery Patterns in Spanish Hotel Activity: Insights from Quantitative and Qualitative Analysis
Full text linkJEL Classification: Z30; C22.A working paper version of this manuscript can be found at Caporale, G.M., Gil-Alana, L.A., Poza, C., Ruiz-Alba, J.L. 2025. The COVID-19 Shock and Spanish Hotel Activity. CESifo Working Paper No. 11985. Available at: https://www.ifo.de/en/cesifo/publications/2025/working-paper/covid-19-shock-and-spanish-hotel-activity (Accessed: 7 February 2026).Purpose: This paper examines the impact of Covid-19 pandemic on Spanish hotel activity to establish whether it has had temporary or permanent effects. Project/methodology/approach: The analysis is based on both quantitative and qualitative approaches. For the former, data from Google Trends and the Spanish Statistical Office (INE) are collected to create a Leading Hotel Activity (LHA) index and fractional integration and cointegration methods are applied. For the latter, online interviews of a focus group in the Spanish hotel sector are conducted. The analysis also distinguishes between the five main source countries for Spain and the main five tourists regions in Spain. Findings: The results show that the impact of Covid-19 shock on Spanish hotel activity was temporary, and that it disappeared at a faster rate in the case of the Balearic Islands and of tourists from Germany. The qualitative evidence indicates a strong linkage between intentions and behaviour in the Spanish tourism sector. Practical implications: The findings indicate that the effects of Covid-19 on Spanish hotel activity were temporary. The Leading Hotel Activity (LHA) index based on Google Trends emerges as a useful tool for anticipating demand and supporting managerial and destination-level planning. Moreover, differences in recovery across regions and source markets underline the importance of targeted strategies, while the strong link between online search intentions and hotel stays highlights the role of confidence-building measures in accelerating demand recovery. Originality/value: This paper combines fractional integration methods with qualitative evidence to analyse the persistence of shocks in Spanish hotel activity. It introduces a novel Leading Hotel Activity (LHA) index based on Google Trends and provides new evidence on the link between online search intentions and hotel stays across source markets and destination regions.Luis A. Gil-Alana gratefully acknowledges financial support from the Grant D2023-149516NB-I00 funded by MCIN/AEI/ 10.13039/501100011033, and also from an internal project of the Universidad Francisco de Vitoria
How international physical presence and infrastructure differences moderate the link between digital internationalization and MNE performance
No full textHighlights:
โข A U-shaped relationship exists between digital internationalization and performance for retail MNEs.
โข The U-shape steepens with greater international physical presence and stronger home than host infrastructure.
โข Extending the IโR framework to digital and physical domains shows how their interplay shapes performance.
โข Managers should pursue hybrid digitalโphysical strategies to optimize digital internationalization performance.Data availability:
The authors do not have permission to share data.Supplementary data are available online at: https://www.sciencedirect.com/science/article/pii/S0024630126000166#appsec1 .While prior work has predominantly studied the performance implications of multinational enterprise (MNE) physical internationalization, research on how MNEs perform when simultaneously coordinating international digital channels and physical presence remains scarce. This challenge is particularly acute in retail, where the strategic convergence of born-digital retailers expanding physically and traditional retailers going digital creates new cross-domain challenges. Nonetheless, the impact of international physical presence and differences in home country physical infrastructure relative to host countries on MNE performance remains unexplored. Drawing on the integration-responsiveness (IR) framework, we suggest that a non-linear, U-shaped pattern governs the relationship between digital internationalization and performance for these retail MNEs, because the costs of integration and responsiveness are dominant at lower levels of internationalization while their advantages become more pronounced with increased internationalization. Further, we argue that the digital internationalization and MNE performance relationship steepens (a) with a higher international physical presence and (b) for firms originating from home countries with superior physical infrastructure relative to their host countries. Utilizing an 11-year panel of some of the largest retail MNEs, our research contributes to international strategy literature by extending the IR framework to a multidomain digital and physical context, stressing the strategic importance of firm- and country-level physical resources and infrastructure in digital internationalization
Experimental and numerical analysis of water condensation in a condensing economiser for heat recovery
Full text linkHighlights:
โข CFD analysis of water vapor condensation on heat exchangerโs external pipe surfaces.
โข Simplified infinite pipe geometry validated with optimized polyhedral mesh.
โข Coupled models capture transition from fluid film to 3D condensed phase.
โข Simulation predicts condensate within 7% of experimental measurements.
โข Approach aids heat recovery design; future work targets full exchanger.Data availability:
The data that has been used is confidential.Condensing heat exchangers play a key role in industrial processes to enable high efficiency waste heat recovery. Various designs exist and they depend on the primary heat source, pollution level, installation location, etc. The physics involved in these components is very complex and usually difficult to investigate experimentally. Therefore, numerical methods, such as CFD (Computational Fluid Dynamics), prove to be a useful tool for investigating specific phenomena. In particular, the condensation phenomenon is probably the most complex since it implies the co-existence of different phases, their mutual interaction and the variations in concentration of these phases. Focusing on these phenomena, a simplified case study was conducted by considering an infinite pipe geometry and investigated by means of the STAR-CCMโฏ+โฏsoftware to develop a novel methodology for the detailed external condensation pro. The geometry considered represents the first tube section of an existing heat exchanger, and the condensation of hot humified air impinging on the cold pipe was analysed using a multiphase multicomponent approach based on VOF (Volume of Fluid Method). A specific optimum mesh was tested with two different flow regimes for the fluid film defined on the condensation surface. Since no condensation regime is known in advance, the Resolved Fluid Film model was used to trigger the condensation on the pipe wall, starting by means of the Fluid Film model, in order to predict the amount of condensate phase and its diffusion into the background region. After that, the VOF condensation model was used to trigger the condensation between the vapor phase and the newly formed water liquid phase. The condensation regime is then controlled by means of three main parameters being the two condensation models (film and VOF) under relaxation factors and the transition threshold, generally raging from 0 to 1 and here fixed to an optimal value. Finally, the total amount of condensate phase was compared with extrapolated values from experimental results. The simulation proved to be a reliable simplified prediction of the average condensation production related to the actual experimental setup, with the spatial distribution showing a net separation between the film and the VOF regimes.The paper was supported by the European Unionโs Horizon 2020 funded project iWAYS (the grant agreement No 958274). Additional information about the project is available at: iWaysโWater closed loop in industrial processesโiWays
On-campus food poverty in England: student hunger and university free food provision
No full textThis report provides summary findings of a 20-month British Academy/ Leverhulme-funded project to examine on-campus free food provision in response to student need. We define free food provision as food that is free at the point of collection and consumption and is based on presumed and/or evidenced student need.British Academy/Leverhulme, New spaces of free food provision: geographies of welfare, need and support among university students
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