30793 research outputs found
Sort by
Influence of fluctuating heat sources on multiphase thermal storage process: Thermal performance optimization utilizing the Taguchi method
No full textHighlights:
• Effect of unsteady heat source on two-phase flow and heat transfer during melting is studied.
• The numerical model of CFD-VOF is verified by experiments.
• The parameters of the fluctuating heat source are further optimized by Taguchi method.
• Influence of the change of heat source on average energy storage rate of two media is explored.Data availability:
No data was used for the research described in the article.The application of thermal energy storage technology in scenarios requiring rapid heat storage and release is of critical importance. This study introduces a novel composite thermal energy storage configuration, comprising a solid-phase change material (PCM) in the lower half and water in the upper section. By utilizing density variations induced by PCM phase change, the design facilitates natural convection between the two media, thereby enhancing heat transfer efficiency. The investigation focuses on the impact of unsteady pulsating heat fluxes on heat and mass transfer dynamics during the charging process. A comparative analysis of experimental and numerical results delineates the evolution of the solid–liquid interface within the PCM and the total melting time, validating the proposed thermal model. The findings demonstrate that the amplitude of the pulsating heat flux significantly influences the mean energy storage rate (ESR), while having a negligible effect on the total thermal energy absorbed by both water and PCM. Compared to a reference configuration with a heat source amplitude of 2.5 K, a half-period of 25 s, and a base temperature of 334.15 K, the Taguchi-optimized thermal storage structure exhibits a 28 % and 30 % improvement in the average ESR for the PCM and water, respectively, along with a 20 % reduction in the total melting time.This work was supported by the Key Scientific and Technological Innovation Team of Shaanxi Province (2023-CX-TD-29) and the Scientists and Engineers Team of Shaanxi Province (2022KXJ-052)
The effect of Alzheimer’s biomarker positivity on neuropsychological networks
Get PDFAccepted manuscripts are PDF versions of the author’s final manuscript, as accepted for publication by the journal but prior to copyediting or typesetting. They can be cited using the author(s), article title, journal title, year of online publication, and DOI. They will be replaced by the final typeset articles, which may therefore contain changes. The DOI will remain the same throughout.Supplementary data are available online at: https://academic.oup.com/braincomms/advance-article/doi/10.1093/braincomms/fcag015/8436063#supplementary-data .Although network neuropsychology is a promising approach to the study of clinical profiles, the link between Alzheimer’s disease biomarkers and neuropsychological networks is still undetermined. We hypothesised that network differences would exist between biomarker-positive and biomarker-negative participants, and that these would be driven by network nodes corresponding to performance on tests of episodic memory, as this is the cognitive domain most distinctively affected by Alzheimer’s disease since the earliest clinical stages.
In this case-control study, we investigated sub-cohorts of individuals who had been 1) enrolled in the National Alzheimer’s Coordinating Center initiative, and 2) tested with Version 3 of the Uniform Data Set neuropsychological battery (i.e., consisting of 11 tests). These included 1,263 “β-amyloid positive” (A+), 1,594 “β-amyloid negative” (A-), 442 “β-amyloid and hyperphosphorylated tau positive” (A+T+), and 734 “β -amyloid and hyperphosphorylated tau negative” (A-T-) participants. We first calculated neuropsychological residuals by regressing out age, years of education, sex, Clinical Dementia Rating scores, and timepoint distance between neuropsychological and biomarker assessment. Secondly, we used rank-based correlations to define conditional associations across all pairs of test scores (i.e., the nodes of the network). Thirdly, we imposed a penalty (i.e., via the Least Absolute Shrinkage and Selection Operator method) to control for network sparsity. We then tested for differences in global network metrics and node centrality between A+ and A-, and between A+T+ and A-T- participants using permutation-based inferential models.
Differences were found between biomarker-positive and biomarker-negative sub-cohorts in global network metrics but, contrarily to our hypothesis, no differences were found in relation to episodic memory nodes. A significant node difference, however, was instead found in relation to Category Fluency (i.e., a test of semantic memory), with increased centrality observed among A+ participants. A similar, yet nonsignificant trend was also observed between A+T+ and A-T- participants.
Network neuropsychology can complement and expand the study of cognitive performance carried out via “traditional” univariate approaches. While univariate analyses reveal episodic memory decline in people with Alzheimer’s disease, this is not accompanied by any abnormalities at a neuropsychological network level. Our findings, however, highlight the importance of semantic memory alterations in A+ individuals. The wide set of neural and cognitive resources that sustain semantic memory may play a supportive role in the presence of neuropathology.Alzheimer's Association [grant ref. AARG]: Category Fluency words recall order and clinical evolution of MCI patients
Two AI copyright cases, two very different outcomes – here’s why
Get PDFThis article is republished from The Conversation under a Creative Commons license. Read the original at https://theconversation.com/two-ai-copyright-cases-two-very-different-outcomes-heres-why-270229 .Artificial intelligence companies and the creative industries are locked in an ongoing battle, being played out in the courts. The thread that pulls all these lawsuits together is copyright.Brunel University of London provides funding as a member of The Conversation UK
Academic Freedom as a Contested Public Good: Ideology, Trust and Public Attitudes in the UK and Japan
No full textData Availability Statement:
Full replication data and code are available from the Harvard Dataverse, at https://doi.org/10.7910/DVN/SYXK30.Related Articles:
• Moon Suk Hong, M. S., M. Jeon, and K. J. Ayhan. 2021. “International Scholarship for Social Change? Re-Contextualizing Global Korea Scholarship Alumni's Perceptions of Justice and Diversity in South Korea.” Politics & Policy 49, no. 6: 1359–1390. https://doi.org/10.1111/polp.12435.
• Shala, A., and A. Grajcevci. 2018. “Examining the Role of Socioeconomic Status, Formal and Informal Education on Political Interest Levels among University Students.” Politics & Policy 46, no. 6: 1050–1070. https://doi.org/10.1111/polp.12274.
• Stockemer, D. 2025. “Is the US Moving Toward Autocracy? A Critical Assessment.” Politics & Policy 53, no. 3: e70032. https://doi.org/10.1111/polp.70032.Academic freedom is widely regarded as a cornerstone of democratic society, yet its public legitimacy remains contested. This article examined how citizens in two democracies (Japan and the United Kingdom) understand and evaluate academic freedom across different issue domains. Drawing on original survey data (N = 3352), we explored whether public support for academic freedom is associated with ideological orientation and institutional trust. We proposed a theoretical framework distinguishing between autonomy and accountability logics: while some citizens treat academic freedom as a non-negotiable principle, others view it as contingent on social responsibility or moral alignment. Our analysis showed that support for academic freedom is associated with political polarization: right-leaning respondents consistently favor autonomy, particularly in cases involving controversial research or offensive ideas, whereas left-leaning individuals show greater support for limiting academic freedom in the name of social sensitivity. These patterns are robust across both countries, despite contrasting institutional contexts. We also find that trust in scientists is strongly associated with pro-autonomy attitudes, especially in Japan. By treating academic freedom as a contested public good, this study sheds light on how normative commitments, political ideology, and institutional trust interact to shape public attitudes toward knowledge, expertise, and university governance.摘要 :
学术自由被广泛视为民主社会的基石，但其公众合法性仍存在争议。本文考察了两个民主国家(日本和英国)的公民如何理解和评价不同议题领域的学术自由。基于原创调查数据(N = 3352)，我们探讨了公众对学术自由的支持是否与意识形态倾向以及制度信任相关。我们提出了一个区分自主逻辑和问责逻辑的理论框架:一些公民将学术自由视为一项不可妥协的原则，而另一些公民则认为它取决于社会责任或道德立场。我们的分析表明，对学术自由的支持与政治极化相关:右倾受访者始终倾向于自主，尤其是在涉及争议性研究或冒犯性观点的情况下；而左倾人士则更倾向于以社会敏感性为由限制学术自由。尽管两国的制度背景截然不同，但这些模式在两国都具有稳健性。我们还发现，对科学家的信任与支持自主的态度密切相关，尤其是在日本。本研究将学术自由视为一种存在争议的公共产品，阐明了规范性承诺、政治意识形态和制度信任如何相互作用，从而塑造公众对知识、专业技能和大学治理的态度。Resumen:
La libertad académica se considera ampliamente una piedra angular de la sociedad democrática, pero su legitimidad pública sigue siendo cuestionada. Este artículo examina cómo los ciudadanos de dos democracias (Japón y el Reino Unido) comprenden y evalúan la libertad académica en diferentes ámbitos temáticos. Basándonos en datos originales de la encuesta (N = 3352), exploramos si el apoyo público a la libertad académica está asociado con la orientación ideológica y la confianza institucional. Proponemos un marco teórico que distingue entre las lógicas de autonomía y rendición de cuentas: mientras que algunos ciudadanos tratan la libertad académica como un principio no negociable, otros la ven como contingente a la responsabilidad social o la alineación moral. Nuestro análisis muestra que el apoyo a la libertad académica está asociado con la polarización política: los encuestados de derechas favorecen sistemáticamente la autonomía, especialmente en casos que involucran investigación controvertida o ideas ofensivas, mientras que los individuos de izquierdas muestran un mayor apoyo a limitar la libertad académica en nombre de la sensibilidad social. Estos patrones son robustos en ambos países, a pesar de los contextos institucionales contrastantes. También encontramos que la confianza en los científicos está fuertemente asociada con actitudes proautonomía, especialmente en Japón. Al considerar la libertad académica como un bien público controvertido, este estudio arroja luz sobre cómo los compromisos normativos, la ideología política y la confianza institucional interactúan para moldear las actitudes públicas hacia el conocimiento, la experiencia y la gobernanza universitaria.This project is sponsored by the Japan Society for the Promotion of Science (JSPS, grant reference JPJSJRP 20211704) and the UK Research and Innovation's Economic and Social Research Council (UKRI-ESRC, grant reference ES/W011913/1)
Regulation of biofilm formation and desiccation tolerance in the critical priority pathogen Acinetobacter baumannii
No full textThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe current ’’silent pandemic’’, caused by the increasing levels of antibiotic resistance amongst pathogenic bacteria and fuelled by the lack of new antibiotics, seriously threatens global healthcare systems. Acinetobacter baumannii is the most critical pathogen, for which novel therapeutic interventions are urgently needed. It is highly prevalent in hospitals and more alarmingly in intensive care units, where it can persist on surfaces in the absence of water and nutrients for months. Additionally, the majority of the nosocomial infections caused by this pathogen are biofilm-related. Biofilm formation is a universal bacterial survival strategy that confers protection to cells from harsh environmental conditions. However, majority of the regulatory mechanisms orchestrating biofilm formation and desiccation tolerance in A. baumannii are still elusive.
In this thesis we present the screening of the Manoil lab transposon mutant library for differential biofilm biomass levels. This led to uncovering CavA adenylate cyclase (AC) as a novel negative biofilm mediator. Subsequently we characterise the role of CavA as the dominant AC under the conditions tested and reveal the cAMP signalling cascade in A. baumannii AB5075 strain. We show that cAMP inhibits biofilm formation while enhancing motility, which is exerted via its effector protein Vfr, and inhibits quorum sensing (QS). In addition to QS, we elucidate the hierarchy of signalling cascades that cAMP orchestrates, which also involves the other major second messenger c-di-GMP. We demonstrate that contrary to the current dogma, in A. baumannii cAMP increases intracellular levels of c-di-GMP via transcriptional regulation of DgcC diguanylate cyclase (DGC) and PdeE phosphodiesterase (PDE). Furthermore, we unveil that cAMP modulates virulence and transient antibiotic resistance. We also present that AB5075 strain possesses an additional AC, CavB, and a second potential cAMP effector protein Crp.
In addition, we investigate regulators governing A. baumannii desiccation tolerance. We show that A. baumannii needs low cAMP levels, via CavB AC downregulation and CpdA PDE upregulation, while c-di-GMP related DGC DgcB negatively impacts desiccation tolerance. Moreover, the protective function of A. baumannii type VI secretion system under desiccation is uncovered. Finally, we demonstrate the central role of phenylacetic acid (PAA) catabolism in the desiccation tolerance of this pathogen. Our data shows that accumulation of intracellular PAA drives A. baumannii cells to enter a viable but non-culturable (VBNC) state, which is a persister strategy used by bacteria to withstand unfavourable conditions.
These findings uncover central regulators of fundamental A. baumannii behaviours (formation of biofilms, tolerance to desiccation and VBNC state), which facilitate the survival of this pathogen in patients and hospitals. These new insights uncover targets for the development of novel therapeutics and disinfectants against A. baumannii and will contribute to improved detection and decontamination practices in the future
Search for t-channel scalar and vector leptoquark exchange in the high-mass dimuon and dielectron spectra in proton-proton collisions at √s = 13 TeV
Get PDFData Availability Statement: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS data preservation, re-use and open access policy (https://doi.org/10.7483/OPENDATA.CMS.1BNU.8V1W).Code Availability Statement. The CMS core software is publicly available on GitHub (https://github.com/cms-sw/cmssw).A version of the article is available at arXiv:2503.20023v2 [hep-ex], https://arxiv.org/abs/2503.20023v2 . Comments: Submitted to the Journal of High Energy Physics. All figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-22-013 (CMS Public Pages). This version corrects the link to the HEPData for this paper. Report number: CMS-EXO-22-013, CERN-EP-2024-275. Submission history: From: The CMS Collaboration: [v1] Tue, 25 Mar 2025 19:07:34 UTC (690 KB); [v2] Fri, 9 May 2025 18:42:08 UTC (690 KB); [v3] Tue, 13 Jan 2026 21:11:21 UTC (689 KB).A search for t-channel exchange of leptoquarks (LQs) is performed in dimuon and dielectron spectra using proton-proton collision data collected at √s = 13 TeV with the CMS detector at the CERN LHC. The data correspond to an integrated luminosity of 138 fb⁻¹. Eight scenarios are considered, in which up or down quarks couple to muons or electrons via a scalar or vector LQ exchange, for dilepton invariant masses above 500 GeV. The LQ masses are probed up to 5 TeV, beyond a regime probed by previous pair-production and single-production searches. The differential distributions of dilepton events are fit to templates that model the nonresonant LQ exchange and various standard model background processes. Limits are set on LQ-fermion coupling strengths for scalar and vector LQ masses in the 1–5 TeV range at 95% confidence level, establishing stringent limits on first- and second-generation LQsSCOAP3
The impact of a secondary cognitive task on variables associated with ACL loading during landing: a systematic review and meta-analysis
No full textSupplemental material is available online at: https://www.tandfonline.com/doi/full/10.1080/14763141.2025.2603396# .This article aimed to perform a meta-analysis and systematic review on the effect of dual-task landing on potential ACL loading. Repeated measures assessments of landings with concurrent, unrelated cognitive tasks were included. Databases were searched (SPORTDiscus, ScienceDirect and PubMed, searched June 2023). Results were synthesised and presented using custom R code. Twenty-five articles were included, 12 eligible for the meta-analysis, involving single or double-leg landings alongside various cognitive tasks. Funnel plots, regression testing and selection modelling detected no publication bias. The systematic review identified most authors concluded dual-task landing potentially increased ACL loading, due to small, inconsistent, biomechanical impacts on the trunk and lower extremity consistent with potentially increased ACL loading. However, robust variance estimation showed no significant effect (g = −0.001, 95% CI [−0.093, 0.09], p = 0.97) on frontal or transverse plane knee loading, only identifying a small decrease in IC knee flexion angles (g = −0.13, p = 0.03). Diverse research methodologies make summarising this research area difficult. While dual-task landings can evoke mechanical changes associated with potentially increased ACL loading, this increased loading is not consistently seen. Further research with consistent methodologies is required to clarify this. This paper was registered (PROSPERO: CRD42023425191).The author(s) reported there is no funding associated with the work featured in this article
Impact of Ethanol on Electrostatic Behaviour of Fluorocarbon Pharmaceutical Propellants
Get PDFData Availability Statement:
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding authors.Background/Objectives: Triboelectrification in fluid systems, and specifically in hydrofluorocarbon (HFC)-based propellants, used in pressurised metered-dose inhalers (pMDIs) remains understudied despite its impact on aerosol behaviour and does delivery. This study investigates how ethanol concentration affects charge generation and dissipation in HFC-152a (1,1-difluoroethane; R152a) flowing through low-density polyethylene (LDPE) tubing, a common valve-stem material in pMDIs. Methods: Controlled experiments measured electrical current, charge accumulation, and flow stability for HFC-152a with varying ethanol concentrations in LDPE tubing. Statistical analysis (two-way ANOVA, p < 0.05) assessed the effects of the propellant and material. Comparative tests include R134a (1,1,1,2-tetrafluoroethane) and R227ea (1,1,1,2,3,3,3-heptafluoropropane), and the tubing materials are polybutylene terephthalate (PBT), polyvinyl chloride (VINYL), polyoxymethylene (POM), and LDPE. Results: Increasing ethanol concentration produced larger measured currents, reduced net charge accumulation, and improved flow stability; these effects are attributed to ethanol’s higher dielectric constant and conductivity enhancing charge mobility and dissipation. Significant propellant x material interactions were found (p < 0.05): R152a generated the largest responses with PBT and VINYL (~16 nA and ~5.6 nA, respectively), R227ea showed higher responses with POM and LDPE (~8 nA), and R134a delivered the highest flow rates across materials but exhibited limited electrical responsiveness. Conclusions: Ethanol addition mitigates undesirable electrostatic effects in HFC-based propellants by promoting charge dissipation. The results demonstrate the strong material dependence of triboelectric behaviour and underline the importance of optimising propellant–polymer pairings to minimise the electrostatic adhesion of aerosolised particles and improve pMDI drug delivery performance.The manuscript was written as part of a PhD sponsored financially by Orbia, a division of Advance Corporation S.A.B. de CV (Mexichem, funding number 11270100), and approved by them for publication
Generalized Score Matching: Bridging f-Divergence and Statistical Estimation Under Correlated Noise
Get PDFRelative Fisher information, also known as score matching, is a recently introduced learning method for parameter estimation. Fundamental relations between relative entropy and score matching have been established in the literature for scalar and isotropic Gaussian channels. This paper demonstrates that such relations hold for a much larger class of observation models. We introduce the vector channel where the perturbation is non-isotropic Gaussian noise. For such channels, we derive new representations that connect the f-divergence between two distributions to the estimation loss induced by mismatch at the decoder. This approach not only unifies but also greatly extends existing results from both the isotropic Gaussian and classical relative entropy frameworks. Building on this generalization, we extend De Bruijn's identity to mismatched non-isotropic Gaussian models and demonstrate that the connections to generative models naturally follow as a consequence application of this new result
Experimental Demonstration of Bending Eavesdropping Detection in Optical Communications Using a Physics-Informed Convolutional Network
Get PDFThis paper proposes a physics-informed convolutional network (PICN) scheme to detect bending eavesdropping attacks in dual-polarization coherent optical communication systems. We present a theoretical model for optical signal transmission under bending eavesdropping, analyzing the impact of bending eavesdropping on fiber physical characteristics such as dispersion and nonlinear effect. These physical characteristics are embedded into a convolutional neural network (CNN) to construct PICN, which automatically captures subtle variations of the signal features under bending eavesdropping. To validate the effectiveness of the scheme, we first develop an eavesdropping experimental platform in an 80-km 168 Gbps dual-polarization quadrature phase shift keying (QPSK) coherent optical communication system. Polarization data are then collected under normal transmission, 10.8 mm and 15 mm bending radius. Finally, the detection performance of four classifiers including PICN, random forest (RF), support vector machine (SVM), and K-nearest neighbor (KNN) are evaluated at single and mixed bending radii. Experimental results demonstrate that PICN achieves detection accuracies of 100%, 98.53%, and 99.02% under 10.8 mm, 15 mm, and mixed bending radii, respectively. Our work provides novel theoretical foundations and innovative perspectives for bending eavesdropping detection in optical fiber communication systems
Data sources:
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇