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Imbalanced data oversampling through subspace optimization with Bayesian reinforcement
No full textMany real-world machine learning classification problems suffer from imbalanced training data, where the least frequent label has high relevance and significance for the end user, such as equipment breakdowns or various types of process anomalies. This imbalance can negatively impact the learning algorithm and lead to misclassification of minority labels, resulting in erroneous actions and potentially high unexpected costs. Most previous oversampling methods rely only on the minority samples, often ignoring their overall density and distribution in relation to the other classes. In addition, most of them lack in the oversampling method’s explainability. In contrast, this paper proposes a novel oversampling method that considers a subspace of the feature-set for the creation of synthetic minority samples using nonlinear optimization of a class-sensitive objective function. Suitable subspaces for oversampling are identified through a Bayesian reinforcement strategy based on Dirichlet smoothing, which may be useful for explainable-AI. An empirical comparison of the proposed method is performed with 10 existing techniques on 18 real-world datasets using two traditional machine learning classifiers and four evaluation metrics. Statistical analysis of cross-validated runs over the 18 datasets and four metrics (i.e. 72 experiments) reveals that the proposed approach is among the best performing methods in 6 and 2 instances when using random forest classifier and support vector machine classifier, thus placing it at the top. The study also reveals that some feature combinations are more important than others for minority oversampling, and the proposed approach offers a way to identify such features.CC BY 4.0Published online: 10 November 2025Mahesh Kumbhar, [email protected] authors acknowledge the financial support received from KK-stiftelsen (The Knowledge Foundation, Stockholm, Sweden) and VINNOVA (Sweden Innovation Agency, Stockholm, Sweden) for the research projects ‘TOPAZ - Towards Prescriptive Analytics in Virtual Factories through Structured Data Mining and Optimization’ under grant 20200011 and ‘Integrated Manufacturing Analytics Platform for Predictive Maintenance with IoT’ under grant 2021-02537. Open access funding provided by University of Skövde.TOPAZ - Towards Prescriptive Analytics in Virtual Factories through Structured Data Mining and OptimizationIntegrated Manufacturing Analytics Platform for Predictive Maintenance with Io
Aluminoborophosphate glasses and glass-ceramics doped with magnesium oxide : Structural, thermal, in vitro dissolution, and cytotoxicity studies
No full textThis study explores the effects of Mg2+ ion incorporation and nanocrystalline phases formation on the structure and in vitro dissolution behavior of aluminoborophosphate glasses and glass-ceramics. Two series of MgO-doped samples were prepared via melt-quenching, either in water or on a metal plate, yielding amorphous and partially crystalline materials, respectively. Structural and thermal analyses revealed that increasing MgO content enhanced glass transition and crystallization temperatures and promoted nanocrystal formation. In vitro dissolution tests in phosphate-buffered saline showed that the glass-ceramics dissolved up to five times faster than their amorphous counterparts, with calcium phosphate layers, likely apatite-like phases, forming predominantly on high-Mg samples. Cytotoxicity studies using HUVEC cells indicated that the glass samples were non-cytotoxic under all tested conditions, while the glass-ceramics exhibited composition and concentration dependent effects. These findings highlights the potential of Mg2+ doping and partial crystallization to tailor the bioactivity and dissolution behavior of aluminoborophosphate-based materials
Sterile water injections for managing abdominal labour contraction pain : A randomised double blind placebo-controlled trial
No full textBackground: Sterile water injections have been demonstrated to effectively manage back pain experienced during labour with no side effects other than the administration pain. Abdominal labour pain differs to back pain in location and likely physiological derivation. It is not known if sterile water injections would be efficacious in the relief of abdominal labour contraction pain. Objective: To assess the efficacy of sterile water injections to reduce abdominal labour contraction pain. Design: A two-arm superiority randomised placebo-controlled trial. Setting: A referral maternity hospital in Brisbane, Australia. Participants: Women in spontaneous or induced labour at term requesting analgesia. Methods: Between April 2022 and November 2023 consenting participants were assigned (1:1) by an independently generated randomisation schedule to injections of either sterile water or saline placebo. The primary outcome was the difference between groups in self-reported visual analogue pain score at 30 min following allocated treatment. Secondary outcomes included use of pharmacologic analgesia following allocation. Analysis was by intention to treat. Results: 160 women were randomised to sterile water injections (n = 81) or injections of saline placebo (n = 79). Seven participants withdrew prior to treatment. Primary outcome data was provided by 68 women (intervention) and 64 (placebo). The mean visual analogue scores at 30 min were: intervention: 52.13 mm (with 100 mm indicating worst conceivable pain) and placebo: 71.14 mm; mean difference: − 19.00 mm (95 % Confidence interval (CI) − 26.10 to − 11.91). Pain scores in the secondary repeated measures model at 60 min post treatment were (61.28 mm vs.76.15 mm) − 14.84 (95 % CI − 22.23 to − 7.46). There was no difference in pain scores at 90 min, use of other pharmacological analgesia, or maternal or neonatal outcomes. Conclusion: Sterile water injections provided a statistically significant reduction in pain when compared to a placebo for up to 60 min following treatment. However, the use of other pharmacological analgesia such as epidural did not differ between groups. Trial registration: The trial is registered at the Australian and New Zealand Clinical Trials Registry (Trial ID: ACTRN12621001036808). Registration date 5/08/2021. First recruitment 29th April 2022.CC BY 4.0© 2025Correspondence Address: N. Lee; School of Nursing Midwifery and Social Work, Level 3 Chamberlain Building, University of Queensland, St Lucia, 4072, Australia; email: [email protected]; CODEN: IJNUAThe trial was funded by the Medical Research Future Fund (MRFF) Australian Federal Government (2006488). Dr Nigel Lee is supported by a National Health and Medical Research Council Emerging Leadership Fellowship (EL1) (2016432). The funders had no role in the design of the study, the data collection, the data analysis, interpretation of data, or writing of the manuscript.</p
Preliminary insights into the Bronze-to-Iron Age human demographic history of Pella (Jordan) using an ancient DNA approach
No full textIn recent times, the genetic analysis of ancient human remains has contributed significantly to the study of the human past, especially in the subjects of admixture, migrations and social organisation. By utilising distinct methods and source materials, genomic research is adding considerable value to conclusions reached by other disciplines, such as archaeology and history. However, the geographical region of the Levant has only very recently been the subject of genomic research, and the region of Jordan rarely at all, due to poor environmental conditions that hinder DNA preservation and limited access to archaeological excavations and therefore sampling of ancient remains. My Master’s thesis project aimed at generating genome-wide data for 16 Bronze and Iron Age skeletal human remains excavated in the archaeological site of Pella, a multi-period site located in the North Jordan Valley that hasn’t yet been sampled for DNA studies. I also aimed at analysing the resulting data in context with genomic data from the wider region of the Levant, by means of several standard population genetics tests. Additionally, genomic results were interpreted making use of historical and bio-archaeological records specific to the site of Pella. Through an initial assessment of the sequencing data, only six libraries were selected to be included in genome-wide analyses. Surprisingly, the performed tests show two very distinct genomic profiles among the six libraries: four of them have the expected Neolithic-to-Iron Age Levantine profile, while the other two show affinity with ancient and present-day East Asian populations. These results suggest that human mobility in Bronze-to-Iron Age Eurasia could have happened over distances much longer than previously thought. Further target enrichment will provide more power to either reinforce of reject these preliminary results
Finite Element-Based Investigation of Rotor-Bearing-Stator Dynamics
No full textRotating machinery forms the backbone of modern energy conversion, facilitating the transfer of energy between a fluid and a rotating component, the rotor. Mathematical modeling of rotating machinery has become increasingly sophisticated due to growing demands in modern machine design, primarily driven by the increase of angular momentum sustained by the rotor. Thus, the study of rotating machine dynamics has evolved to improve prediction accuracy and ensure operational stability. A rotor typically consists of shafts, disks, and blades, supported by bearings that enable rotation relative to a stationary structure. Bearings are tasked to provide both support and energy dissipation. While rotor-bearing models often suffice for dynamic analysis of rotating machinery, stators—such as casings, housings, and foundations—can influence dynamics through rotor-stator interactions. For example, compliant bearing supports may impair bearing function, while generator stators exert significant electromagnetic forces that impact operational stability. The integrated model of these components is known as a rotor-bearing-stator (RBS) system. While traditional rotor dynamic analysis typically utilizes shaft elements to model the rotor assembly and reduces the stator and bearing to discrete spring elements, a full three-dimensional representation overcomes the kinematic and geometric restrictions of beam theory, enabling the analysis of vastly more complex systems. Furthermore, the increased degrees of freedom lead to greater computational complexity, particularly noticeable for vertical machinery. Unlike horizontal rotors, vertical systems inherently experience large dynamic displacements and lack a stationary point of operation, necessitating the use of nonlinear bearing formulations. Hydropower machinery is generally supported by hydrodynamic journal bearings. This requires tracking the rotor position at each time step and solving equations for fluid-film interaction, further increasing computational demands. This compilation thesis investigates the dynamics of integrated hydropower systems, with emphasis on how to accurately and efficiently model complex, vertical systems by finite element methods. The thesis constitutes three applied studies of vertical RBS-systems, mostly related to hydropower applications. The first paper focuses on a three-dimensional model of a floating-rim synchronous generator, with emphasis on deformation under electromagnetic and centrifugal loads. The second paper explores the interaction between tilting pad journal bearings and an elastic support frame, exploring the potential implementation of nonlinear journal bearing formulations within a three-dimensional finite element framework. Finally, the third paper investigates the impact of a compliant generator-bearing support on the stability of a hydropower rotor-bearing system
Plasmasmältning och centrifugalatomisering av eldfasta legeringar och föreningar
No full textThe development of fabrication technologies suitable for the production of fine, high-quality metallic powders of conventional and novel alloys is crucial to the development of the powder metallurgy route. The plasma-assisted centrifugal atomization process was developed by Metasphere Technology AB for the production of spherical cast tungsten carbide, and subsequently acquired by Höganäs AB. In the standard implementation of the process, feedstock material in the form of crushed powder is fed into a rotating crucible, melted by a transferred plasma arc, and atomized in the form of fine, spherical droplets. The capability to melt alloys and compounds with melting temperatures above 3,000 ᵒC, combined with the extremely rapid solidification of the ejected droplets, allows for the processing of metastable refractory alloys that cannot be obtained otherwise. The main objectives of this work were to (1) better understand the role of the centrifugal atomization mechanism on the microstructure and the mechanical properties of the final powders, and (2) explore the capabilities of a pilot-scale plasma-assisted centrifugal atomization unit for the design and development of novel refractory alloys. The local mechanical characterization of micron-sized powders of hard and brittle compounds is challenging. The use of three-dimensional topography images to measure the residual imprints of microindentation hardness tests has been proposed, ultimately enabling a reliable comparison among CTC powders fabricated by different methods. The microindentation hardness, the micro-pillar compressive strength, and the resistance to cyclic compressive loading of entire particles were extensively investigated in centrifugally-atomized CTC powders subjected to different heat treatments. Suitable processing routes for the fabrication of spherical powders of a compositionally complex Ti-V-Zr-Nb-Mo-Hf-Ta-W refractory high-entropy alloy have been developed. The preparation of pre-alloyed feedstock material by partial sintering followed by cryogenic crushing was considered. Subsequently, the simultaneous melting, alloying, and atomization of a blend of elemental powders was envisaged as an alternative to the time-consuming cryogenic crushing. The microstructure, the indentation hardness, the phase stability, the prospects of consolidation into bulk alloys, and the hydrogenation behavior of the alloys thus produced have been extensively investigated
Interrater, test-retest, and intersession reliability of a test designed to measure tibialis posterior strength with a hand-held dynamometer
No full textBackground: The tibialis posterior muscle has an important role both in stabilizing the foot and in inversion, plantar flexion, and adduction of the foot. Impaired function can lead to tibialis posterior dysfunction. A clinical test that can objectively measure tibialis posterior strength is warranted. Objectives: The aim of this study was to investigate the interrater, test-retest, and intersession reliability of a test designed to measure tibialis posterior strength with a hand-held dynamometer. Design: Interrater, between-day test-retest and intersession reliability. Setting: University laboratory. Participants: The participants comprised 20 healthy individuals (mean age 28.8 years, n = 10 women) without foot problems. Method: A test was designed to test tibialis posterior strength with a hand-held dynamometer (HHD). The test was performed on two occasions 5–15 days apart and was carried out by two raters. The intraclass correlation coefficient (ICC), 95 % confidence interval, standard error of measurement (SEM), and minimal detectable change were calculated. Results: Interrater reliability was good on both occasions (ICC: 0.769, 0.794), test-retest reliability was moderate for both raters (ICC: 0.671, 0.672), and intersession reliability was excellent (ICC: 0.934–0.967). However, the confidence interval had a large variation (-0.027–0.986) and the SEM was relatively high (2.356–3.863 N). Conclusions: This test seems to be reliable, but has some limitations. The results suggest that the current version of the test could be used to compare strength between feet, but that further development of the test is needed to achieve increased interrater and test-retest reliability
Minding mortality : A systematic review of the neural processing of death-related stimuli
No full textThe human relationship with mortality has been widely studied in psychology, with extensive studies suggesting that death-related stimuli impact behavior even without reflective awareness. In recent decades, neuroimaging studies have yielded various contenders for brain regions underlying the online processing of death-related stimuli. To the best of our knowledge, we present here the first systematic review of these findings. We conducted a comprehensive search for studies where participants were presented with death-related and death-unrelated but negatively valenced (unpleasant) stimuli while undergoing functional brain imaging. We found seven functional magnetic resonance imaging studies with a total of 204 participants. Five of six within-group studies found that unpleasant stimuli consistently elicited increased insular activity, but only when it was unrelated to mortality. This novel finding—that insular deactivation alone marks the processing of death-related stimuli—suggests a critical difference between the neural processing of death-related and non-death related, unpleasant stimuli. We argue that preexisting explanatory frameworks fail to unite our results with findings on threat processing mechanisms in the insula or lack evolutionary plausibility. We present an alternative explanation: death might be unique in that it evades the insula's typical threat-assessment mechanisms. Further research is needed to determine whether this neural signature is robust and what its function and consequences may be. A better understanding of how individuals process death-related information promises deeper insight into the human relationship with mortality, with significant implications for individuals and society, not least for mental health interventions and end-of-life care.CC BY 4.0Available online 29 October 2025, 109308Corresponding author [Anna Bengtson] at: Department of Bioscience, University of Skövde, Skövde, 541 28, Sweden. E-mail addresses: [email protected] (A. Bengtson), [email protected] (I. Nordin), [email protected] (J. Parthemore), [email protected] (A. Revonsuo).This research did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors.</p
Sustained impact of higher customer satisfaction on bank revenue
No full textThis study examines the relationship between customer satisfaction and individual-level bank revenue growth, drawing on data from 19,060 Swedish retail banking customers that combine survey responses with objective bank records. Furthermore, we investigate whether the impact of satisfaction on revenue growth is sustained over time, specifically one, two three and four years after the measurement of satisfaction, and whether this effect differs across customer satisfaction levels. The results show that higher satisfaction is associated with greater sustained revenue growth, with more pronounced effects for customers in the medium-high and highest satisfaction groups. By contrast, no significant sustained revenue growth is found for customers with low and low-medium satisfaction. The findings do not support the hypothesis of diminishing returns when moving from medium-high to the highest satisfaction levels, although weak indications suggest scope for further exploration. Overall, the findings demonstrate the long-term revenue growth of satisfied customers and emphasize the importance of targeting customers with lower to medium-low satisfaction to enhance overall revenue performance.QC 20251202</p
Structural determination of self-assembled aggregates formed by a therapeutic cyclical peptide and an ionic surfactant in aqueous solution
No full textAmphiphilic compounds, such as phospholipids or surface-active substances, are present in biological systems and can be part of pharmaceutical formulations. As a consequence, all pharmaceutically active ingredients will encounter amphiphilic compounds, either in the formulation or after administration. With the growing interest in peptide-based pharmaceuticals, there is a need to enhance the understanding of the interactions between peptides and amphiphilic compounds. In this particular study, we have chosen to study mixtures of the comparatively small cyclical octapeptide lanreotide and the conventional anionic surfactant sodium dodecylsulfate (SDS). This was done by examining the self-assembly structures formed in lanreotide-SDS mixtures using light scattering and small-angle X-ray scattering (SAXS). Above the critical micelle concentration (cmc) of SDS, the large excess of SDS could solubilize all lanreotide and form small micelles with lanreotide attached to the interface. Upon dilution to concentrations below the cmc of SDS, a suspension with dispersed solid nanoparticles is formed. The solid nanoparticles grow in size with decreasing concentration and, eventually, precipitate. The precipitated material is arranged in a liquid crystalline micellar phase, consisting of small close-packed SDS micelles with peptide adsorbed at the interface. We were able to conclude that lanreotide does not form mixed micelles with SDS, indicating that it lacks the amphiphilic properties required to integrate fully with SDS behaving as a cosurfactant. In contrast, lanreotide attaches to the interface of SDS micelles, resembling the interactions of polymers, proteins, and nucleic acids with surfactants