bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total Electron Content Variations During an HSS/SIR‐Driven Geomagnetic Storm at High and Mid Latitudes
Authors: Geethakumari G. P. , Aikio A. T. , Cai L. , Vanhamäki H. , Virtanen I. I. , Coster A. , Marchaudon A. , Blelly P.‐L. , Maute A. , Norberg J. , Oyama S. , Zhang Y. , Kunduri B. S. R. 
Published: December 2024

AbstractTwo interacting high‐speed solar wind streams (HSSs) and associated stream interaction regions (SIR) caused a moderate geomagnetic storm during 14–20 March 2016. The spatio‐temporal evolution of the total electron content (TEC) during the storm is studied by using Global Navigation Satellite System (GNSS) data. The moderate storm caused significant and long‐lasting changes on TEC within the polar cap (70–90 MLAT), at auroral and sub‐auroral latitudes (60–70 MLAT), and at mid‐latitudes (40–60 MLAT). A 25%–50% depletion in TEC was observed for six days in the day, dusk and dawn sectors in the polar cap region and in the day and dusk sectors at the auroral and sub‐auroral latitudes. Sub‐auroral polarization streams observed by the Defense Meteorological Satellite Program satellite contributed to the sub‐auroral dusk TEC decreases. At mid‐latitudes, TEC depletion was observed in all local time sectors 21 hr after the storm onset. It is suggested that ion‐neutral frictional heating causes the TEC depletions, which is further supported by the observed spatial correlation between TEC depletions and O/N2 decreases at mid‐latitudes observed by TIMED/GUVI. The storm induced a prolonged positive phase at mid‐latitudes lasting 9 hr. In the polar cap, enhancements of TEC up to 200% were caused by polar cap patches. TEC increases were the dominant feature in the night and morning sectors within the auroral oval because of particle precipitation and resulted up to regionally averaged 6 TECU (200%) increases.
Complex Crater Collapse: A Comparison of the Block and Melosh Acoustic Fluidization Models of Transient Target Weakening
Authors: Hay Hamish C. F. C. , Collins Gareth S. , Davison Thomas M. , Rajšić Andrea , Johnson Brandon C. 
Published: December 2024

AbstractThe collapse of large impact craters requires a temporary reduction in the resistance to shear deformation of the target rocks. One explanation for such weakening is acoustic fluidization, where impact‐generated pressure fluctuations temporarily and locally relieve overburden pressure facilitating slip. A model of acoustic fluidization widely used in numerical impact simulations is the Block model. Simulations employing the Block model have successfully reproduced large‐scale crater morphometry and structural deformation but fail to predict localized weakening in the rim area and require unrealistically long pressure fluctuation decay times. Here, we modify the iSALE shock physics code to implement an alternative model of acoustic fluidization, which we call the Melosh model, that accounts for regeneration and scattering of acoustic vibrations not considered by the Block model. The Melosh model of acoustic fluidization is shown to be an effective model of dynamic weakening, differing from the Block model in the style of crater collapse and peak ring formation that it promotes. While the Block model facilitates complex crater collapse by weakening rocks deep beneath the crater, the Melosh model results in shallower and more localized weakening. Inclusion of acoustic energy regeneration in the Melosh model reconciles required acoustic energy dissipation rates with those typically derived from crustal seismic wave propagation analysis.
Using the Melosh Model of Acoustic Fluidization to Simulate Impact Crater Collapse on the Earth and Moon
Authors: Rajšić A. , Johnson B. C. , Collins G. S. , Hay H. C. F. C. 
Published: December 2024

AbstractThe formation of complex craters requires some form of transient weakening of target rocks. Acoustic fluidization is one proposed mechanism applied in many numerical simulations of large crater formation. In a companion paper, we describe implementing the Melosh model of acoustic fluidization in the iSALE shock physics code. Here, we explore the effect of Melosh model parameters on crater collapse and determine the range of parameters that reproduce observed crater depth‐to‐diameter trends on the Earth and Moon. Target viscosity in the Melosh model is proportional to the vibrational wavelength, , and the longevity of acoustic vibrations is (—quality factor). Our simulations show that affects the size of the fluidized region, its fluidity, and the magnitude of the vibrations, producing a variety of crater collapse styles. The size of the fluidized region is strongly affected by the . The regeneration factor, , controls the amount of (re)generated acoustic energy and its localization. We find that a decrease in leads to less crater collapse and that there are trade‐offs between and . This trade‐off contributes to the more realistic values than those used in the Block model. The diffusion of vibrations in regions with high stress and strain is controlled by the scattering term, . Compared to the Block model, the Melosh model results in a shallower zone of weakening in complex craters and enhanced strain localization around the crater rim. The parameter set that produces best depth‐diameter trends is = 0.2impactor radius, = 10–50, = 0.025–0.1, and = 10– .
Patterns of Carbon and Nitrogen Accumulation in Seagrass (Posidonia oceanica) Meadows of the Eastern Mediterranean Sea
Authors: Apostolaki Eugenia T. , Lavery Paul S. , Litsi‐Mizan Victoria , Serrano Eduard , Inostroza Karina , Gerakaris Vasilis , Dailianis Thanos , Glampedakis Julius , Holitzki Tara , Johnson Erik , Mateo Miguel A. , Serrano Oscar 
Published: December 2024

AbstractThe variability in stocks and accumulation rates of organic carbon (Corg), nitrogen (N), and carbonate (CaCO3) was studied in fifteen Posidonia oceanica meadows spread throughout the South Aegean Sea (Greece). In addition, the abiotic and biotic drivers determining the pattern of variability in the accumulation rates were assessed by exploring the influence of sediment characteristics, seagrass traits, and environmental settings. The meadows supported on average (±STDEV) 14.6 ± 5.0 kg Corg m−2, 0.47 ± 0.17 kg N m−2, and 249 ± 210 kg CaCO3 m−2 in the top meter of their sediments, with mean accumulation rates over the last 500 years of 33.6 ± 23.6 g Corg m−2 yr−1, 1.00 ± 0.62 g N m−2 yr−1, and 405 ± 336 g CaCO3 m−2 yr−1 across sites. A redundancy analysis (RDA) explained 70% of the variation in Corg, N, and CaCO3 accumulation rates, with three sediment characteristics (i.e., sediment Corg:N and Corg:Cinorg ratios and P. oceanica contribution to the sediment Corg pool) emerging as the primary set of factors shaping the accumulation of matter, followed by seagrass traits (i.e., leaf biomass and rhizome elongation) and environmental variables (i.e., suspended organic matter). The high degree of variability within the region emphasizes the need for fine‐scale assessments to understand the local conditions influencing sequestration. Our findings underscored the critical role of seagrass meadows in carbon and nitrogen sequestration in the region, urging conservation efforts to protect these ecosystems and prevent potential losses of stored carbon and nitrogen following seagrass degradation.
The Averaged Hydrostatic Boussinesq Ocean Equations in Generalized Vertical Coordinates
Authors: Jansen Malte F. , Adcroft Alistair , Griffies Stephen M. , Grooms Ian 
Published: December 2024

AbstractDue to their limited resolution, numerical ocean models need to be interpreted as representing filtered or averaged equations. How to interpret models in terms of formally averaged equations, however, is not always clear, particularly in the case of hybrid or generalized vertical coordinate models, which limits our ability to interpret the model results and to develop parameterizations for the unresolved eddy contributions. We here derive the averaged hydrostatic Boussinesq equations in generalized vertical coordinates for an arbitrary thickness‐weighted average. We then consider various special cases and discuss the extent to which the averaged equations are consistent with existing ocean model formulations. As previously discussed, the momentum equations in existing depth‐coordinate models are best interpreted as representing Eulerian averages (i.e., averages taken at fixed depth), while the tracer equations can be interpreted as either Eulerian or thickness‐weighted isopycnal averages. Instead we find that no averaging is fully consistent with existing formulations of the parameterizations in semi‐Lagrangian discretizations of generalized vertical coordinate ocean models such as MOM6. A coordinate‐following average would require “coordinate‐aware” parameterizations that can account for the changing nature of the eddy terms as the coordinate changes. Alternatively, the model variables can be interpreted as representing either Eulerian or (thickness‐weighted) isopycnal averages, independent of the model coordinate that is being used for the numerical discretization. Existing parameterizations in generalized vertical coordinate models, however, are not always consistent with either of these interpretations, which, respectively, would require a three‐dimensional divergence‐free eddy tracer advection or a form‐stress parameterization in the momentum equations.
Physical Drivers and Biogeochemical Effects of the Projected Decline of the Shelfbreak Jet in the Northwest North Atlantic Ocean
Authors: Garcia‐Suarez Lina , Fennel Katja 
Published: December 2024

AbstractA solid understanding of the mechanisms behind the presently observed, rapid warming of the northwest North Atlantic Continental Shelf and their biogeochemical impacts is lacking. We hypothesize that a weakening of the Labrador Current System (LCS), especially the shelfbreak jet along the Scotian Shelf, is contributing to these changes and that the future evolution of the LCS will be key to accurate projections. Here we analyze the response of a transient simulation of the high‐resolution GFDL Climate Model 2.6 (CM2.6) which realistically simulates the regional circulation but includes only a highly simplified representation of ocean biogeochemistry. Then, we use the CM2.6 to force a medium‐complexity regional biogeochemical ocean model, the Atlantic Canada Model, to obtain projections of nutrient availability on the shelf. In the simulation, the shelfbreak jet weakens because of a reduction of the along‐shelf pressure gradient caused by a buoyancy gain of the upper water column along the shelf edge. This buoyancy gain is the result of warmer waters along the continental slope. Importantly, we find that the temperature‐based criterion used commonly to pinpoint the location of the Gulf Stream is misleading, causing an overestimation of the northward migration of the Gulf Stream. A fixed isotherm may indicate northward movement as a result of basin‐wide warming and not necessarily reflect changes in dynamics. The combination of the weakened shelfbreak jet and a lowering of nutrient concentrations in its source water reduce nutrient availability on the northwest North Atlantic shelf by one third by 2100 in the projection analyzed.
The long-lasting impacts of the COVID-19 pandemic on population-based cancer survival: what are the implications for data analysis?
Authors: Stannard Rachael , Lambert Paul C. , Lyratzopoulos Georgios , Andersson Therese M.-L. , Khan Sam , Rutherford Mark J. 
Published: December 2024

AbstractMonitoring trends of cancer incidence, mortality and survival is vital for the planning and delivery of health services, and the evaluation of diagnostics and treatment at the population level. Furthermore, comparisons are often made between population subgroups to explore inequalities in outcomes. During the COVID-19 pandemic routine delivery of health services were severely disrupted. Resources were redeployed to COVID-19 services and patient risk of COVID-19 infection required serious consideration. Cancer screening services were paused, the availability of healthcare providers was reduced and, in some cases, patients faced difficulty in accessing optimal treatment in a timely manner. Given these major disruptions, much care should be taken when interpreting changes in cancer survival estimates during this period. The impact on cancer incidence and mortality statistics that have already been reported in some jurisdictions should drive further thought on the corresponding impact on cancer survival, and whether any differences observed are real, artificial or a combination of the two. We discuss the likely impact on key cancer metrics, the likely implications for the analysis of cancer registration data impacted by the pandemic and the implications for comparative analyses between population groups and other risk factor groups when using data spanning the pandemic period.
Imaging NRF2 activation in non-small cell lung cancer with positron emission tomography
Authors: Greenwood Hannah E. , Barber Abigail R. , Edwards Richard S. , Tyrrell Will E. , George Madeleine E. , dos Santos Sofia N. , Baark Friedrich , Tanc Muhammet , Khalil Eman , Falzone Aimee , Ward Nathan P. , DeBlasi Janine M. , Torrente Laura , Soni Pritin N. , Pearce David R. , Firth George , Smith Lydia M. , Vilhelmsson Timmermand Oskar , Huebner Ariana , Swanton Charles , Hynds Robert E. , DeNicola Gina M. , Witney Timothy H. 
Published: December 2024

AbstractMutations in the NRF2-KEAP1 pathway are common in non-small cell lung cancer (NSCLC) and confer broad-spectrum therapeutic resistance, leading to poor outcomes. Currently, there is no means to non-invasively identify NRF2 activation in living subjects. Here, we show that positron emission tomography imaging with the system xc− radiotracer, [18F]FSPG, provides a sensitive and specific marker of NRF2 activation in orthotopic, patient-derived, and genetically engineered mouse models of NSCLC. We found a NRF2-related gene expression signature in a large cohort of NSCLC patients, suggesting an opportunity to preselect patients prior to [18F]FSPG imaging. Furthermore, we reveal that system xc− is a metabolic vulnerability that can be therapeutically targeted with an antibody-drug conjugate for sustained tumour growth suppression. Overall, our results establish [18F]FSPG as a predictive marker of therapy resistance in NSCLC and provide the basis for the clinical evaluation of both imaging and therapeutic agents that target this important antioxidant pathway.
Investigating the demineralisation of hydroxyapatite by kombucha and hard seltzer using atomic force microscopy
Authors: Erickson Andy , Rond Emily , Cravens Shannen L. 
Published: December 2024

AbstractWhile the erosive potential of acidic beverages has been known for decades, many new and increasingly popular beverages and food fads have not been evaluated quantitatively for their dental associated risks. In this study, the authors utilise atomic force microscopy to monitor changes in the surface morphology of an enamel mimic, hydroxyapatite (HA), induced by hard seltzer and kombucha. The primary causes of enamel degradation were assessed through a combinatorial investigation probing the impact of carbonation, acid type, acid concentration, and saliva. The average surface roughness of HA discs was determined after successive demineralisation steps. The heterogeneity of the decay process was assessed using multiple spatial replicates per sample. To aid in the interpretation of the HA decay profiles, pH and titratable acidity of each beverage were also measured. The authors find that, in comparison to a reference sample of Coca‐Cola®, kombucha is equally erosive after prolonged exposure while hard seltzer results in relatively minor surface damage. In addition, the presence of saliva was found to eliminate any measurable amounts of decay. Results from this study demonstrate the potential damage more recently popularised beverages can have on dental enamel and the significant dependence of oral health on the presence of saliva.
Hybrid feature‐based moving cast shadow detection
Authors: Dai Jiangyan , Zhang Huihui , Gao Jin , Chen Chunlei , Yi Yugen 
Published: December 2024

AbstractThe accurate detection of moving objects is essential in various applications of artificial intelligence, particularly in the field of intelligent surveillance systems. However, the moving cast shadow detection significantly decreases the precision of moving object detection because they share similar motion characteristics. To address the issue, the authors propose an innovative approach to detect moving cast shadows by combining the hybrid feature with a broad learning system (BLS). The approach involves extracting low‐level features from the input and background images based on colour constancy and texture consistency principles that are shown to be highly effective in moving cast shadow detection. The authors then utilise the BLS to create a hybrid feature and BLS uses the extracted low‐level features as input instead of the original data. BLS is an innovative form of deep learning that can map input to feature nodes and further enhance them by enhancement nodes, resulting in more compact features for classification. Finally, the authors develop an efficient and straightforward post‐processing technique to improve the accuracy of moving object detection. To evaluate the effectiveness and generalisation ability, the authors conduct extensive experiments on public ATON‐CVRR and CDnet datasets to verify the superior performance of our method by comparing with representative approaches.
On future power system digital twins: A vision towards a standard architecture
Authors: Zomerdijk Wouter , Palensky Peter , AlSkaif Tarek , Vergara Pedro P. 
Published: December 2024

AbstractThe energy sector's digital transformation brings mutually dependent communication and energy infrastructure, tightening the relationship between the physical and the digital world. Digital twins (DT) are the key concept for this. This paper initially discusses the evolution of the DT concept across various engineering applications before narrowing its focus to the power systems domain. By reviewing different definitions and applications, the authors present a new definition of DTs specifically tailored to power systems. Based on the proposed definition and extensive deliberations and consultations with distribution system operators, energy traders, and municipalities, the authors introduce a vision of a standard DT ecosystem architecture that offers services beyond real‐time updates and can seamlessly integrate with existing transmission and distribution system operators' processes while reconciling with concepts such as microgrids and local energy communities based on a system‐of‐systems view. The authors also discuss their vision related to the integration of power system DTs into various phases of the system's life cycle, such as long‐term planning, emphasising challenges that remain to be addressed, such as managing measurement and model errors, and uncertainty propagation. Finally, the authors present their vision of how artificial intelligence and machine learning can enhance several power systems DT modules established in the proposed architecture.
Invulnerability invariants for software controlled speculation
Authors: Mathure Nimish , Srinivasan Sudarshan K. , Ponugoti Kushal K. 
Published: December 2024

AbstractSpectre class of transient execution security attacks on modern microprocessors rely on speculative execution. Software Controlled Speculation (SCS) was proposed as a microarchitecture‐level defense in the original Spectre paper and has also been adopted by ARM. The idea with SCS is to allow a mode in the microarchitecture, where instructions that read from memory are not allowed to execute speculatively. Errors or malicious fault‐injections in the implementation of SCS can still render the microarchitecture vulnerable to Spectre attacks. A formal verification method is proposed that can check the correctness of the implementation of SCS and detect any faults. The method has been demonstrated to be very efficient on two sets of benchmarks and provides accurate detection of implementation faults in SCS.
Experimental investigation on ultra‐low power metamaterial for back‐scatter communication through ice
Authors: Yang Haobin , Ding Tongyu , Zhang Shaoqing , Ye Longfang , Zhang Liang 
Published: December 2024

AbstractWireless sensor networks and nodes are faced with severe constraints in power capacity and lifespan, especially in harsh and cold environments. Electromagnetic radiation energy harvesters serve as a promising alternative power source for sensor nodes. However, the power output from reported energy harvesters remains limited, emphasizing the critical need to reduce power consumption in sensor nodes. Here, a miniaturized, low‐voltage, low‐power active frequency selective surface solution is proposed for backscatter communication under ice. It is designed for the 2.4 GHz wireless band and can operate under extreme conditions, such as sub‐ice environments, requiring only a 3.3 V control voltage and consuming approximately 0.3 of energy. Experimental results in sub‐ice scenarios demonstrate its reliable reflection control characteristics, making it particularly suitable for backscatter communication nodes in wireless sensor networks deployed in harsh environments.
Analytical modelling and analysis of magnet eddy current loss in magnet‐surrounded permanent magnet synchronous machine caused by stator slot effect
Authors: Long Yuhang , Song Zhanfeng 
Published: December 2024

AbstractTo improve the machine torque density, this paper proposes a magnet‐surrounded permanent magnet synchronous machine (MSPMSM). As the critical material of MSPMSM, the permanent magnet (PM) will produce significant eddy current loss under the action of eddy current electromotive force. Therefore, it is essential to investigate the change in PM eddy current loss and methods to suppress it. To solve the above problems, a simplified analytical calculation model for the eddy current loss of PMs caused by stator slotting is proposed. The distribution law of eddy current loss of PMs caused by stator slotting is studied. The concept of influence depth is proposed to solve the problem of unclear correspondence between the groove depth on the PM surface and the eddy current loss of PMs. The calculation results of the influence depth are used to guide the single‐side partial grooving method to reduce the eddy current loss of PMs. In addition, a comparative analysis is conducted on the anti‐demagnetisation ability of PMs before and after MSPMSM optimisation. Finally, the experiment verifies the correctness of the analytical calculation and the high torque density of the MSPMSM.