143174 research outputs found
Sort by
Web execution bundles: reproducible, accurate, and archivable web measurements
No full textPreprint versionRecently, reproducibility has become a cornerstone in the security and privacy research community, including artifact evaluations [2, 35, 48] and even a new symposium topic [2]. However, Web measurements lack tools that can be reused across many measurement tasks without modification, while being robust to circumvention, and accurate across the wide range of behaviors in the Web. As a result, most measurement studies use custom tools and varied archival formats, each of unknown correctness and significant limitations, systematically affecting the research's accuracy and reproducibility. To address these limitations, we present WebREC, a Web measurement tool that is, compared against the current stateof-the-art, accurate (i.e., correctly measures and attributes events not possible with existing tools), general (i.e., reusable without modification for a broad range of measurement tasks), and comprehensive (i.e., handling events from all relevant browser behaviors). We also present .web, an archival format for the accurate and reproducible measurement of a wide range of website behaviors. We empirically evaluate We-bREC's accuracy by replicating well-known Web measurement studies and showing that WebREC's results more accurately match our baseline. We then assess if WebREC and .web succeed as general-purpose tools, which could be used to accomplish many Web measurement tasks without modification. We find that this is so: 70% of papers discussed in a 2024 web crawling SoK paper could be conducted using WebREC as is, and a larger number (48%) could be leveraged against .web archives without requiring any new crawling
Retrofit of floor insulation and scaling with robotic technology
No full textRetrofit of contemporary and historical buildings represents a significant challenge with consideration of oft interrelated issues such as energy, moisture, access, costs, value for money, longevity of the intervention as well as whether the task can be undertaken with residents in-situ and skills required. For residential buildings with a ground-floor cavity between 15 and 20% of the energy loss associated with the home can typically be reduced by use of comprehensive underfloor insulation. However, installation of insulation in a void represents a significant undertaking conventionally requiring removal of furniture and flooring and installation of carefully cut insulation boards. The task can also be undertaken by means of a robot fed into an opening between joists that traverses the cavity spraying insulation foam on the underside of the flooring that remains otherwise undisturbed. The use of robots to undertake this form of retrofit building improvement provides a route for scaling and has now been demonstrated on over 5000 homes. With over 10
million buildings in the UK with underfloor voids, and many more worldwide, scaling of such a process is a key
consideration, and use of robots to undertake this form of intervention by retrofit companies is gaining traction
Neurological and neurodevelopmental effects of Covid and MIS-C on children
No full textSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been shown to cause a unique disease phenotype in the paediatric population compared to adults, following the emergence of Multisystem Inflammatory Syndrome of Children (MIS-C) and Paediatric Inflammatory Multisystem Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS). Over the course of the pandemic, neurological symptoms associated with SARS-CoV-2 have been reported in the paediatric population. The neurological and neurodevelopmental sequelae of both acute SARS-CoV-2 infection and MIS-C/PIMS-TS in the paediatric population are not well understood. Little is known about the underlying pathophysiology and the potential neurovirulence of SARS-CoV-2. Further awareness and research are needed on the neurological sequelae and long-term consequences of SARS-CoV-2 on the developing brain
Strength change explanations in quantitative argumentation
No full textIn order to make argumentation-based inference contestable, it is crucial to explain what changes can achieve a desired (instead of the contested) inference result. To this end, we introduce strength change explanations for quantitative (bipolar) argumentation graphs. Strength change explanations describe changes to the initial strengths of a subset of the arguments in a given graph that can achieve a desired ordering based on the final strengths of some (potentially different) subset of arguments. We show that the existing notions of inverse and counterfactual problems can be reduced to strength change explanations. We also prove basic soundness and completeness properties of our strength change explanations, and demonstrate their existence and non-existence in some special cases. Applying a heuristic search, we demonstrate that we can often successfully find strength change explanations for layered graphs that are common in typical application scenarios, although limitations remain for the general problem
Multifidelity modelling of fuel cell power systems for large transport aircraft
No full textLow temperature proton exchange membrane fuel cells (LT-PEMFCs) represent a promising solution for sustainable aviation, but their design for aircraft applications is
hindered the high computational cost of high-fidelity modelling. This study introduces a multi-fidelity optimisation framework that combines multiple LT-PEMFC models at different levels of fidelity within a Non-Myopic Multi-Fidelity Bayesian Optimisation active learning scheme. By formulating the design search as a dynamic decision process, this scheme efficiently allocates computational resources across fidelities, enabling accurate yet tractable exploration of the design space. The proposed multi-fidelity framework identifies high-power
and physically consistent LT-PEMFC configurations at a fraction of the cost of traditional single-fidelity optimisation, providing a scalable pathway for zero-emission aircraft design
Sedimentology and stratigraphy of the fluvial–deltaic Skrinkle Haven member, Tenby formation, Jezero Crater, Mars
No full textIn 2023, the Mars 2020 Perseverance rover investigated the Skrinkle Haven member of the Tenby formation in the > 3.5-billion-year Jezero Crater western fan. This unit was interpreted from orbiter data as bank attached, lateral-accretion bars in a sinuous river on a muddy delta plain. To test that hypothesis, this study applies facies and stratigraphic analyses of both rover and orbiter data. Rover images show that the Skrinkle Haven member is composed of two lithofacies: a fine-grained sandstone and a pebble conglomerate. Both lithofacies are composed of structureless, ungraded, planar-parallel beds that have sharp, nongradational contacts and depositional angles up to ∼ 30°. These characteristics indicate that grain flow was the main depositional process and that the sedimentary bodies were built through downstream accretion. Architectural analysis suggests that the Skrinkle Haven member was deposited primarily as delta foresets and mouth bars, with limited river bar deposition. The sequence stratigraphic analysis identified five maximum-flooding surfaces associated with relative-lake-level increases ranging from 5 to 25 m. In the sequences, deltaic strata prograded during normal and forced regressions. Some sequences have evidence for compensational stacking. Lake levels decreased through time both within sequences and throughout the duration of the Skrinkle Haven member deposition, from at least –2415 m in the oldest sequence to at most –2455 m in the youngest. The elevation range of the Skrinkle Haven member is below the modern Jezero Crater outlet breach, suggesting that the Jezero Crater lake basin was closed at that time. Overall, the Skrinkle Haven member records the deposition of a sandy to conglomeratic deltaic system that prograded into a closed lake basin during both forced and normal regressions. This type of fluvial–deltaic system is significantly different from the muddy delta topsets originally interpreted from orbiter data, because of the different implications for biosignature preservation and the paleohydrology of the Jezero Crater
Validation and application of coupled thermal-hydraulics and neutronics model using sub-channel CFD and SERPENT
No full textThe novel coarse-mesh CFD tool Subchannel-CFD (SubChCFD) is coupled with the Monte Carlo transport code Serpent using a segregated multi-physics coupling algorithm. The multi-physics model is validated using the CASL VERA Core Physics Benchmark Progression Problem #6, showing good agreement of pin powers and exit coolant temperatures. The model is also used to simulate an assembly from the K-SMR soluble‑boron-free small modular reactor, which shows good agreement with a full-scale CFD model from the software STAR-CCM+, with the exception of a small gap region between two large control rod guide tube and burnable poison rods, which induces a periodic flow instability that SubChCFD cannot fully replicate. Nevertheless, the oscillatory characteristics of the instabilities modelled by both codes show some similarity
Unveiling the importance of nonshortest paths in quantum networks
No full textQuantum networks (QNs) exhibit stronger connectivity than predicted by classical percolation, yet the origin of this phenomenon remains unexplored. We apply a statistical physics model—concurrence percolation—to uncover the origin of stronger connectivity on hierarchical scale-free networks, the (U, V) flowers. These networks allow full analytical control over path connectivity through two adjustable path-length parameters, ≤V. This precise control enables us to determine critical exponents well beyond current simulation limits, revealing that classical and concurrence percolations, while both satisfying the hyperscaling relation, fall into distinct universality classes. This distinction arises from how they “superpose” parallel, nonshortest path contributions into overall connectivity. Concurrence percolation, unlike its classical counterpart, is sensitive to nonshortest paths and shows higher resilience to detours as these paths lengthen. This enhanced resilience is also observed in real-world hierarchical, scale-free internet networks. Our findings highlight a crucial principle for QN design: When nonshortest paths are abundant, they notably enhance QN connectivity beyond what is achievable with classical percolation
A diagnostic host-specific transcriptome response for Mycoplasma pneumoniae pneumonia to guide pediatric patient treatment
No full textMycoplasma pneumoniae causes atypical pneumonia in children and young adults. Its lack of a cell wall makes it resistant to beta-lactams, which are the first-line treatment for typical pneumonia. Current diagnostic tests are time-consuming and have low specificity, leading clinicians to administer empirical antibiotics. Using a LASSO regression simulation approach and blood microarray data from 107 children with pneumonia (including 30 M. pneumoniae) we identify eight different transcriptomic signatures, ranging from 3-10 transcripts, that differentiate mycoplasma pneumonia from other bacterial/viral pneumonias with high accuracy (AUC: 0.84–0.95). Additionally, we demonstrate that existing signatures for broadly distinguishing viral/bacterial infections and viral/bacterial pneumonias are ineffective in distinguishing M. pneumoniae from viral pneumonia. The new signatures are successfully validated in an independent RNAseq cohort of children with pneumonia, demonstrating their robustness. The high sensibility of these signatures presents a valuable opportunity to guide the treatment and management of M. pneumoniae pneumonia patients
Deficiency in nucleoside diphosphate kinase B leads to endothelial activation of the hexosamine biosynthesis pathway and cardiac dysfunction
No full textBackground
Nucleoside diphosphate kinase B (NDPKB) deficiency in endothelial cells (ECs) promotes the activation of the hexosamine biosynthesis pathway (HBP), leading to vascular damage in the retina. The aim of this study was to investigate the consequences of NDPKB deficiency in the mouse heart.
Methods
NDPKB deficient mice were used in the study. Echocardiography was employed to assess cardiac function in vivo. Characterization of contractility in hiPSC-derived cardiomyocytes (hiPSC-CMs) was measured with the IonOptix contractility system. Immunoblotting and immunofluorescence were carried out to analyze the expression and localization of proteins in cultured cells and left ventricles (LVs).
Results
NDPKB deficient mice displayed impaired glucose tolerance and increased heart weight compared to controls. Echocardiographic analysis revealed an increase in the diastolic diameter of the left ventricular posterior wall (LVPW), a decrease in the early diastolic mitral valve E and E′ wave, and in the ratios of E/A and E′/A′ in NDPKB deficient hearts, suggesting cardiac hypertrophy and diastolic dysfunction. In line with cardiac dysfunction, the phosphorylation of myocardial phospholamban (PLN) and the expression of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2 (SERCA2) in the NDPKB deficient LVs were significantly reduced. Moreover, the accumulation of collagen, fibronectin as well as the upregulation of transforming growth factor β (TGF-β), were detected in NDPKB deficient LVs. In addition, activation of the HBP and its downstream O-GlcNAc cycle was observed in the LVs and cardiac ECs (CECs) isolated from the NDPKB−/− mice. Furthermore, a bipolar O-GlcNAc regulation was identified in CMs. O-GlcNAc was decreased in NDPKB-depleted CMs, while conditioned medium from NDPKB-depleted ECs significantly increased O-GlcNAc levels, along with contractile and relaxation dysfunction of the hiPSC-CMs, which was attenuated by inhibiting endothelial HBP activation.
Conclusions
Deficiency in NDPKB leads to endothelial activation of the HBP and cardiac dysfunction. Our findings may highlight the crucial role of proper endothelial HBP in maintaining cardiovascular homeostasis