bluuebunny/crossref_metadata_2025_split huggingface dataset:
FWIGAN: Full‐Waveform Inversion via a Physics‐Informed Generative Adversarial Network
Authors: Yang Fangshu , Ma Jianwei 
Published: April 2023

AbstractFull‐waveform inversion (FWI) is a powerful geophysical imaging technique that reproduces high‐resolution subsurface physical parameters by iteratively minimizing the misfit between the simulated and observed seismograms. Unfortunately, conventional FWI with a least‐squares loss function suffers from various drawbacks, such as the local‐minima problem and human intervention in the fine‐tuning of parameters. It is particular problematic when applied with noisy data and inadequate starting models. Recent work relying on partial differential equations and neural networks show promising performance in two‐dimensional FWI. Inspired by the competitive learning of generative adversarial networks, we propose an unsupervised learning paradigm that integrates the wave equation with a discriminative network to accurately estimate physically consistent velocity models in a distributional sense (FWIGAN). The introduced framework does not require a labeled training dataset or pretraining of the network; therefore, this framework is flexible and able to achieve inversion with minimal user interaction. We experimentally validate our method for three baseline geological models, and a comparison of the results demonstrates that FWIGAN faithfully recovers the velocity models and consistently outperforms other traditional or deep learning‐based algorithms. A further benefit from the physics‐constrained learning used in this method is that FWIGAN mitigates the local‐minima issue by reducing the sensitivity to initial models or data noise.
Aerosol Impacts on Storm Electrification and Lightning Discharges Under Different Thermodynamic Environments
Authors: Sun Mengyu , Qie Xiushu , Mansell Edward R. , Liu Dongxia , Yair Yoav , Fierro Alexandre O. , Yuan Shanfeng , Lu Jingyu 
Published: April 2023

AbstractThe impacts of aerosol and thermodynamics on electrification and lightning activities have been investigated in detail using the Weather Research and Forecasting Model coupled with a double‐moment microphysics parameterization and an explicit electrification lightning scheme. To obtain a varied combination of convective available potential energy (CAPE) values and aerosol concentrations, a sounding was modified consistently and initiated with five sets of aerosol concentrations that served as cloud condensation nuclei. The simulated electric processes respond to the varying dynamical and microphysical characteristics associated with the different CAPE and aerosol conditions. Under high CAPE circumstances, the augmentation of ice‐phase particle leads to the enhancement of non‐inductive charging primarily through the dynamic processes. Increased aerosol content further invigorates the electrification through microphysical processes. Elevated aerosol loading under low CAPE conditions increases cloud droplet and ice crystal numbers. Larger graupel particle size further leads to the enhanced electric intensity and lightning discharges.
Diverging Ozone Trends Above Western North America: Boundary Layer Decreases Versus Free Tropospheric Increases
Authors: Chang Kai‐Lan , Cooper Owen R. , Rodriguez Gavin , Iraci Laura T. , Yates Emma L. , Johnson Matthew S. , Gaudel Audrey , Jaffe Daniel A. , Bernays Noah , Clark Hannah , Effertz Peter , Leblanc Thierry , Petropavlovskikh Irina , Sauvage Bastien , Tarasick David W. 
Published: April 2023

AbstractThis study has produced an improved percentile and seasonal (median) trend estimate of free tropospheric ozone above western North America (WNA), through a data fusion of ozonesonde, lidar, commercial aircraft, and field campaign measurements. Our method combines heterogeneous data sets according to the consensus data characteristics and inherent uncertainty in order to produce our best fused product. In response to different data collection environments (in situ or ground‐based), we investigate the ozone variability based on a wide range of percentiles, which is preferable for trend detection due to tropospheric ozone's high degree of heteroscedasticity (i.e., inconsistent trends and variability between different ozone percentiles). We then compare the ozone trends and variability above the California sub‐domain to the full WNA region for better understanding of the correlations between different regional scales. In California, the 1995–2021 percentile (from the 5th to 95th) and seasonal trends are clearly positive in terms of high signal‐to‐noise ratios. The magnitude of the trends is generally weaker over WNA compared to California, but reliable positive trends can still be found between the 10th and 70th percentiles, as well as winter and summer, whereas autumn shows a negative trend over the same period. In addition, dozens of rural surface sites across the region are selected to represent the boundary layer variability. In contrast to increasing free tropospheric ozone, we find overall strong negative surface trends since 1995, with the greatest divergence found in summer. Throughout the analysis implications of the COVID‐19 economic downturn on ozone variability are discussed.
Moving Bedforms Control CO2 Production and Distribution in Sandy River Sediments
Authors: Schulz H. , Teitelbaum Y. , Lewandowski J. , Singer G. A. , Arnon S. 
Published: April 2023

AbstractStreams and rivers play an important role in the global carbon cycle. The origins of CO2 in streams are often poorly constrained or neglected, which is especially true for CO2 originating from heterotrophic metabolism in streambeds. We hypothesized that sediment movement will have a direct effect on stream metabolism, and thus, the aim of this study was to quantify the effect of moving bedforms on the production of CO2 in sandy streambeds. We conducted flume experiments where we used planar optodes to measure the distributions of O2 and CO2 under various streambed celerities. We combined these measurements with an assessment of bed morphodynamics and modeling to calculate O2 consumption and CO2 production rates. Our results indicate that sediment transport can strongly influence streambed metabolism and CO2 production. We found that bedform celerity controls the shape of the hyporheic zone and exchange flux, and is directly linked to the spatial and temporal distributions of O2 and CO2. It was also found that the most pronounced change in CO2 production occurred when the bed changed from stationary conditions to a slowly moving bed. A more gradual increase in O2 consumption and CO2 production rates was observed with further increase in celerity. Our study also points out that bedform movement causes hydraulic isolation between the moving and the non‐moving fraction of the streambed that can lead to a transient storage of CO2 in deeper sediments, which may be released in bursts during bed scour.
Rare Event Simulation of Extreme European Winter Rainfall in an Intermediate Complexity Climate Model
Authors: Wouters Jeroen , Schiemann Reinhard K. H. , Shaffrey Len C. 
Published: April 2023

AbstractWe test the application of a rare event simulation (RES) algorithm to accelerate the sampling of extreme winter rainfall over Europe in a climate model. The genealogical particle analysis algorithm, an ensemble method that interrupts the simulation at intermediate times to clone realizations in which an extreme event is developing, is applied to the intermediate complexity general circulation model PlaSim. We show that the algorithm strongly reduces the numerical effort required to estimate probabilities of extremes, demonstrating the potential of RES of seasonal precipitation extremes.
Seasonal Variations of Soil Thermal Conductivity at the InSight Landing Site
Authors: Grott M. , Piqueux S. , Spohn T. , Knollenberg J. , Krause C. , Marteau E. , Hudson T. L. , Forget F. , Lange L. , Müller N. , Golombek M. , Nagihara S. , Morgan P. , Murphy J. P. , Siegler M. , King S. D. , Banfield D. , Smrekar S. E. , Banerdt W. B. 
Published: April 2023

AbstractThe heat flow and physical properties package measured soil thermal conductivity at the landing site in the 0.03–0.37 m depth range. Six measurements spanning solar longitudes from 8.0° to 210.0° were made and atmospheric pressure at the site was simultaneously measured using InSight's Pressure Sensor. We find that soil thermal conductivity strongly correlates with atmospheric pressure. This trend is compatible with predictions of the pressure dependence of thermal conductivity for unconsolidated soils under martian atmospheric conditions, indicating that heat transport through the pore filling gas is a major contributor to the total heat transport. Therefore, any cementation or induration of the soil sampled by the experiments must be minimal and soil surrounding the mole at depths below the duricrust is likely unconsolidated. Thermal conductivity data presented here are the first direct evidence that the atmosphere interacts with the top most meter of material on Mars.
Molecular architecture and gating mechanisms of the Drosophila TRPA1 channel
Authors: Wang Xiaofei , Li Yawen , Wei Hong , Yang Zhisen , Luo Rui , Gao Yongxiang , Zhang Wei , Liu Xin , Sun Linfeng 
Published: April 2023

AbstractThe transient receptor potential channel subfamily A member 1 (TRPA1) ion channel is an evolutionary conserved polymodal sensor responding to noxious temperature or chemical stimuli. Notably, the thermosensitivity of TRPA1 varies among different species or even different isoforms in the same species. However, the underlying molecular basis of its thermo-gating remains largely unknown. Here, we determine the structures of a heat-sensitive isoform of TRPA1 inDrosophila melanogasterin two distinct conformations with cryo-samples prepared at 8 °C. Large conformational changes are observed in the ankyrin repeat domain (ARD) and the coiled-coil domain between the two states. Remarkably, all 17 ankyrin repeats are mapped in the newly resolved conformation, forming a propeller-like architecture. Two intersubunit interfaces are identified in the amino (N)-terminal domain, and play vital roles during both heat and chemical activation as shown by electrophysiological analysis. With cryo-samples prepared at 35 °C, only one conformation is resolved, suggesting possible state transitions during heat responses. These findings provide a basis for further understanding how the ARD regulates channel functions, and insights into the gating mechanism of TRPA1.
Deciphering the genetic structure of the Quebec founder population using genealogies
Authors: Gagnon Laurence , Moreau Claudia , Laprise Catherine , Vézina Hélène , Girard Simon L. 
Published: April 2023

AbstractUsing genealogy to study the demographic history of a population makes it possible to overcome the models and assumptions often used in population genetics. The Quebec founder population is one of the few populations in the world having access to the complete genealogy of the last 400 years. The goal of this study is to follow the evolution of the Quebec population structure over time from the beginning of European colonization until the present day. To do so, we calculated the kinship coefficients of all ancestors’ pairs in the ascending genealogy of 665 subjects from eight regional and ethnocultural groups per 25-year period. We show that the Quebec population structure appeared progressively in the St. Lawrence valley as early as 1750 with the distinction of the Saguenay and Gaspesian groups. At that time, the ancestors of two groups, the Sagueneans and the Acadians from the Gaspé Peninsula, experienced a marked increase in kinship and inbreeding levels which have shaped the structure and led to the contemporary population structure. Interestingly, this structure arose before the colonization of the Saguenay region and at the very beginning of the Gaspé Peninsula settlement. The resulting regional founder effects in these groups led to differences in the present-day identity-by-descent sharing, the Gaspé and North Shore groups sharing more large segments and the Sagueneans more short segments. This is also reflected by the distribution of the number of most recent common ancestors at different generations and their genetic contribution to the studied subjects.
Signature of spin-triplet exciton condensations in LaCoO3 at ultrahigh magnetic fields up to 600 T
Authors: Ikeda Akihiko , Matsuda Yasuhiro H. , Sato Keisuke , Ishii Yuto , Sawabe Hironobu , Nakamura Daisuke , Takeyama Shojiro , Nasu Joji 
Published: April 2023

AbstractBose-Einstein condensation of electron-hole pairs, exciton condensation, has been effortfully investigated since predicted 60 years ago. Irrefutable evidence has still been lacking due to experimental difficulties in verifying the condensation of the charge neutral and non-magnetic spin-singlet excitons. Whilst, condensation of spin-triplet excitons is a promising frontier because spin supercurrent and spin-Seebeck effects will be observable. A canonical cobaltite LaCoO3 under very high magnetic fields is a propitious candidate, yet to be verified. Here, we unveil the exotic phase diagram of LaCoO3 up to 600 T generated using the electromagnetic flux compression method and the state-of-the-art magnetostriction gauge. We found the continuous magnetostriction curves and a bending structure, which suggest the emergence of two distinct spin-triplet exciton condensates. By constructing a phenomenological model, we showed that quantum fluctuations of excitons are crucial for the field-induced successive transitions. The spin-triplet exciton condensation in a cobaltite, which is three-dimensional and thermally equilibrated, opens up a novel venue for spintronics technologies with spin-supercurrent such as a spin Josephson junction.
Unselfish traits and social decision-making patterns characterize six populations of real-world extraordinary altruists
Authors: Rhoads Shawn A. , Vekaria Kruti M. , O’Connell Katherine , Elizabeth Hannah S. , Rand David G. , Kozak Williams Megan N. , Marsh Abigail A. 
Published: April 2023

AbstractActs of extraordinary, costly altruism, in which significant risks or costs are assumed to benefit strangers, have long represented a motivational puzzle. But the features that consistently distinguish individuals who engage in such acts have not been identified. We assess six groups of real-world extraordinary altruists who had performed costly or risky and normatively rare (<0.00005% per capita) altruistic acts: heroic rescues, non-directed and directed kidney donations, liver donations, marrow or hematopoietic stem cell donations, and humanitarian aid work. Here, we show that the features that best distinguish altruists from controls are traits and decision-making patterns indicating unusually high valuation of others’ outcomes: high Honesty-Humility, reduced Social Discounting, and reduced Personal Distress. Two independent samples of adults who were asked what traits would characterize altruists failed to predict this pattern. These findings suggest that theories regarding self-focused motivations for altruism (e.g., self-enhancing reciprocity, reputation enhancement) alone are insufficient explanations for acts of real-world self-sacrifice.
Age-dependent Pdgfrβ signaling drives adipocyte progenitor dysfunction to alter the beige adipogenic niche in male mice
Authors: Benvie Abigail M. , Lee Derek , Steiner Benjamin M. , Xue Siwen , Jiang Yuwei , Berry Daniel C. 
Published: April 2023

AbstractPerivascular adipocyte progenitor cells (APCs) can generate cold temperature-induced thermogenic beige adipocytes within white adipose tissue (WAT), an effect that could counteract excess fat mass and metabolic pathologies. Yet, the ability to generate beige adipocytes declines with age, creating a key challenge for their therapeutic potential. Here we show that ageing beige APCs overexpress platelet derived growth factor receptor beta (Pdgfrβ) to prevent beige adipogenesis. We show that genetically deletingPdgfrβ, in adult male mice, restores beige adipocyte generation whereas activatingPdgfrβin juvenile mice blocks beige fat formation. Mechanistically, we find that Stat1 phosphorylation mediates Pdgfrβ beige APC signaling to suppressIL-33induction, which dampens immunological genes such asIL-13andIL-5. Moreover, pharmacologically targeting Pdgfrβ signaling restores beige adipocyte development by rejuvenating the immunological niche. Thus, targeting Pdgfrβ signaling could be a strategy to restore WAT immune cell function to stimulate beige fat in adult mammals.
Light-driven peristaltic pumping by an actuating splay-bend strip
Authors: Dradrach Klaudia , Zmyślony Michał , Deng Zixuan , Priimagi Arri , Biggins John , Wasylczyk Piotr 
Published: April 2023

AbstractDespite spectacular progress in microfluidics, small-scale liquid manipulation, with few exceptions, is still driven by external pumps and controlled by large-scale valves, increasing cost and size and limiting complexity. By contrast, optofluidics uses light to power, control and monitor liquid manipulation, potentially allowing for small, self-contained microfluidic devices. Here we demonstrate a soft light-propelled actuator made of liquid crystal gel that pumps microlitre volumes of water. The strip of actuating material serves as both a pump and a channel leading to an extremely simple microfluidic architecture that is both powered and controlled by light. The performance of the pump is well explained by a simple theoretical model in which the light-induced bending of the actuator competes with the liquid’s surface tension. The theory highlights that effective pumping requires a threshold light intensity and strip width. The proposed system explores the benefits of shifting the complexity of microfluidic systems from the fabricated device to spatio-temporal control over stimulating light patterns.
Gibberellins promote polar auxin transport to regulate stem cell fate decisions in cambium
Authors: Mäkilä Riikka , Wybouw Brecht , Smetana Ondřej , Vainio Leo , Solé-Gil Anna , Lyu Munan , Ye Lingling , Wang Xin , Siligato Riccardo , Jenness Mark K. , Murphy Angus S. , Mähönen Ari Pekka 
Published: April 2023

AbstractVascular cambium contains bifacial stem cells, which produce secondary xylem to one side and secondary phloem to the other. However, how these fate decisions are regulated is unknown. Here we show that the positioning of an auxin signalling maximum within the cambium determines the fate of stem cell daughters. The position is modulated by gibberellin-regulated, PIN1-dependent polar auxin transport. Gibberellin treatment broadens auxin maximum from the xylem side of the cambium towards the phloem. As a result, xylem-side stem cell daughter preferentially differentiates into xylem, while phloem-side daughter retains stem cell identity. Occasionally, this broadening leads to direct specification of both daughters as xylem, and consequently, adjacent phloem-identity cell reverts to being stem cell. Conversely, reduced gibberellin levels favour specification of phloem-side stem cell daughter as phloem. Together, our data provide a mechanism by which gibberellin regulates the ratio of xylem and phloem production.
Spatial distribution of primary radiation damage in microstructures
Authors: Brand Matthew I. , Obbard Edward G. , Burr Patrick A. 
Published: April 2023

AbstractThe leading theory of primary radiation damage in materials, by Norgett, Robinson, and Torrens (NRT), assumes that materials are homogeneous. This is inadequate for most engineering materials, which have rich microstructures. The lack of alternative theories has led to the widespread assumption that the microstructure only affects defect recombination and not defect production. We extend the NRT formalism to account for microstructural variations and explicitly include the damage caused in a phase by primary knock-on atoms that are produced in another nearby phase. Our approach reveals new insight on the interplay between radiation damage and microstructure, and converges to conventional NRT at suitably large length-scales. Applying it to real two-phase nuclear alloys we discover a reversal of primary radiation damage localisation when grain size is < 1 μm: in some fine-grained superalloys more damage is produced in the matrix than the precipitates, and the opposite is true for coarse-grained superalloys of same composition.
Retrieval practice is costly and is beneficial only when working memory capacity is abundant
Authors: Zheng Yicong , Sun Pengyuan , Liu Xiaonan L. 
Published: April 2023

AbstractNumerous studies have shown that learned information practiced by testing is better retained than that practiced by restudying (the testing effect). However, results are inconsistent regarding the effect of working memory (WM) capacity on the testing effect. Here, we hypothesize that the effect of WM only emerges when task demands challenge WM capacity. We manipulated WM demands by pretraining 30 undergraduate participants in a multi-session visual search task before an associative learning task involving a test/restudy manipulation. The results revealed that, while participants with higher WM capacity showed a consistent testing effect, the benefit of testing only emerged in participants with lower WM capacity when learning familiar stimuli (low WM demands). We simulated the results using a modified source of activation confusion (SAC) model, which implemented a dual-process account of the testing effect. The results suggested that the testing effect only emerges when WM capacity is adequate for both processes.
Rapid loss of complex polymers and pyrogenic carbon in subsoils under whole-soil warming
Authors: Zosso Cyrill U. , Ofiti Nicholas O. E. , Torn Margaret S. , Wiesenberg Guido L. B. , Schmidt Michael W. I. 
Published: April 2023

AbstractSubsoils contain more than half of soil organic carbon (SOC) and are expected to experience rapid warming in the coming decades. Yet our understanding of the stability of this vast carbon pool under global warming is uncertain. In particular, the fate of complex molecular structures (polymers) remains debated. Here we show that 4.5 years of whole-soil warming (+4 °C) resulted in less polymeric SOC (sum of specific polymers contributing to SOC) in the warmed subsoil (20–90 cm) relative to control, with no detectable change in topsoil. Warming stimulated the subsoil loss of lignin phenols (−17 ± 0%) derived from woody plant biomass, hydrolysable lipids cutin and suberin, derived from leaf and woody plant biomass (−28 ± 3%), and pyrogenic carbon (−37 ± 8%) produced during incomplete combustion. Given that these compounds have been proposed for long-term carbon sequestration, it is notable that they were rapidly lost in warmed soils. We conclude that complex polymeric carbon in subsoil is vulnerable to decomposition and propose that molecular structure alone may not protect compounds from degradation under future warming.
High-resolution line-scan Brillouin microscopy for live imaging of mechanical properties during embryo development
Authors: Bevilacqua Carlo , Gomez Juan Manuel , Fiuza Ulla-Maj , Chan Chii Jou , Wang Ling , Hambura Sebastian , Eguren Manuel , Ellenberg Jan , Diz-Muñoz Alba , Leptin Maria , Prevedel Robert 
Published: April 2023

AbstractBrillouin microscopy can assess mechanical properties of biological samples in a three-dimensional (3D), all-optical and hence non-contact fashion, but its weak signals often lead to long imaging times and require an illumination dosage harmful for living organisms. Here, we present a high-resolution line-scanning Brillouin microscope for multiplexed and hence fast 3D imaging of dynamic biological processes with low phototoxicity. The improved background suppression and resolution, in combination with fluorescence light-sheet imaging, enables the visualization of the mechanical properties of cells and tissues over space and time in living organism models such as fruit flies, ascidians and mouse embryos.