bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear Versus Nonlinear Methods for Detecting Magnetospheric and Ionospheric Current Systems Patterns
Authors: Alberti T. , Giannattasio F. , De Michelis P. , Consolini G. 
Published: February 2020

AbstractThere is a growing interest in the development of models and methods of analysis aimed to recognize in the geomagnetic field signals the different contributions coming from the various sources both internal and external to the Earth. Many models describing the geomagnetic field of internal and external origin have been developed. Here, we investigate the possibility to recognize in the magnetic field of external origin the different contributions coming from external sources. We consider the measurements of the vertical component of the geomagnetic field recorded by the European Space Agency (ESA) Swarm A and B satellites at low and mid latitudes during a geomagnetically quiet period. We apply two different methods of analysis: a linear method, that is, the empirical orthogonal function (EOF), and a nonlinear one, that is, the multivariate empirical mode decomposition (MEMD). Due to the high nonlinear behavior of the different external contributions to the magnetic signal the MEMD seems to recognize better than EOF the main intrinsic modes capable of describing the different magnetic spatial structures embedded in the analyzed signal. By applying the MEMD only five modes and a residue are necessary to recognize the different contributions coming from the external sources in the magnetic signal against the 26 modes that are necessary in the case of the EOF. This study is an example of the potential of the MEMD to give new insights into the analysis of the geomagnetic field of external origin and to separate the ionospheric signal from the magnetospheric one in a simple and rapid way.
Recent Progress in Lunar Laser Ranging at Grasse Laser Ranging Station
Authors: Chabé Julien , Courde Clément , Torre Jean‐Marie , Bouquillon Sébastien , Bourgoin Adrien , Aimar Mourad , Albanèse Dominique , Chauvineau Bertrand , Mariey Hervé , Martinot‐Lagarde Grégoire , Maurice Nicolas , Phung Duy‐Hà , Samain Etienne , Viot Hervé 
Published: February 2020

AbstractBased on a fully passive space segment, the lunar laser ranging experiment is the last of the Apollo Lunar Surface Experiments Package to operate. Observations from the Grasse lunar laser ranging station have been made on a daily basis since the first echoes obtained in 1981. In this paper, first, we review the principle and the technical aspects of lunar laser ranging. We then give a brief summary of the progress made at the Grasse laser ranging facility (Observatoire de la Côte d'Azur, Calern Plateau on the French Riviera) since the first echoes. The current performance, driven by the use of an infrared wavelength laser, is presented in the last section for the year 2018.
Global Prompt Proton Sensor Network: Monitoring Solar Energetic Protons Based on GPS Satellite Constellation
Authors: Chen Yue , Morley Steven K. , Carver Matthew R. 
Published: February 2020

AbstractEnergetic particle instruments on board Global Positioning System (GPS) satellites form a powerful global prompt proton sensor network (GPPSn) that provides an unprecedented opportunity to monitor and characterize solar energetic protons targeting the Earth. The medium‐Earth orbits of the GPS constellation have the unique advantage of allowing solar energetic protons to be simultaneously measured from multiple points in both open‐ and closed‐field line regions. Examining two example intervals of solar proton events, we showcase in this study how GPS proton data are prepared, calibrated, and utilized to reveal important features of solar protons, including their source, acceleration/scattering by interplanetary shocks, the relative position of Earth when impinged by these shocks, the shape of solar particle fronts, the access of solar protons inside the dynamic geomagnetic field, and temporally varying proton distributions in both energy and space. By comparing to Van Allen Probes data, GPS proton observations are further demonstrated not only to be useful for qualitatively monitoring the dynamics of solar protons but also for quantitative scientific research including determining cutoff L‐shells. Our results establish that this GPPSn can join forces with other existing solar proton monitors and contribute to observing, warning, understanding, and ultimately forecasting the incoming solar energetic proton events.
A Century of Reduced ENSO Variability During the Medieval Climate Anomaly
Authors: Lawman Allison E. , Quinn Terrence M. , Partin Judson W. , Thirumalai Kaustubh , Taylor Frederick W. , Wu Chung‐Che , Yu Tsai‐Luen , Gorman Meaghan K. , Shen Chuan‐Chou 
Published: February 2020

AbstractClimate model simulations of El Niño–Southern Oscillation (ENSO) behavior for the last millennium demonstrate interdecadal to centennial changes in ENSO variability that can arise purely from stochastic processes internal to the climate system. That said, the instrumental record of ENSO does not have the temporal coverage needed to capture the full range of natural ENSO variability observed in long, unforced climate model simulations. Here we demonstrate a probabilistic framework to quantify changes in ENSO variability via histograms and probability density functions using monthly instrumental and coral‐based sea surface temperature (SST) anomalies from 1900–2005 and 1051–1150 CE. We find that reconstructed SST anomalies from modern corals from the southwest Pacific capture changes in ENSO variability that are consistent with instrumental SST data from the central equatorial Pacific. Fossil coral records indicate 100 years of relatively lower ENSO variability during part of the Medieval Climate Anomaly. Our results demonstrate that periods of reduced ENSO variability can last a century, far longer in duration than modern observations in the instrumental record of ENSO, but consistent with results from unforced climate model simulations.
Evaluation on the Quasi‐Realistic Ionospheric Prediction Using an Ensemble Kalman Filter Data Assimilation Algorithm
Authors: He Jianhui , Yue Xinan , Le Huijun , Ren Zhipeng , Wan Weixing 
Published: February 2020

AbstractIn this work, we evaluated the quasi‐realistic ionosphere forecasting capability by an ensemble Kalman filter (EnKF) ionosphere and thermosphere data assimilation algorithm. The National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model is used as the background model in the system. The slant total electron contents (TECs) from global International Global Navigation Satellite Systems Service ground‐based receivers and from the Constellation Observing System for Meteorology, Ionosphere and Climate are assimilated into the system, and the ionosphere is then predicted in advance during the quiet interval of 23 to 27 March 2010. The predicted ionosphere vertical TEC (VTEC) and the critical frequency foF2 are validated by the Massachusetts Institute of Technology VTEC and global ionosondes network, respectively. We found that the ionosphere forecast quality could be enhanced by optimizing the thermospheric neutral components via the EnKF method. The ionosphere electron density forecast accuracy can be improved by at least 10% for 24 hr. Furthermore, the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) [O/N2] observations are used to validate the predicted thermosphere [O/N2]. The validation shows that the [O/N2] optimized by EnKF has better agreement with the TIMED/GUVI observation. This study further demonstrates the validity of EnKF in enhancing the ionospheric forecast capability in addition to our previous observing system simulation experiments by He et al. (2019, https://doi.org/10.1029/2019JA026554).
Forearc Basin Stratigraphy Resulting From Syntectonic Sedimentation During Accretionary Wedge Growth: Insights From Sandbox Analog Experiments
Authors: Noda Atsushi , Koge Hiroaki , Yamada Yasuhiro , Miyakawa Ayumu , Ashi Juichiro 
Published: February 2020

AbstractForearc basin stratigraphy is expected to record a detailed history of the deformation and growth pattern of an accretionary wedge. However, the relationship between syntectonic basin sedimentation and growth of a wedge remains poorly understood, including how deformation of the wedge modifies the basin stratigraphy and how syntectonic sedimentation influences deformation of the wedge. This study reproduced accretionary wedges with and without syntectonic sedimentation by analog sandbox experiments. The results show that basin stratigraphy varied with changes of the growth pattern of the accretionary wedge. In the case that wedge growth was dominated by frontal accretion phase, the depositional area migrated trenchward. In contrast, underthrusting phase caused the sediment layers to be tilted landward and the depocenter to migrate landward. A prolonged underthrusting can result in combining a retrowedge basin with a wedge top basin and yield a wide area of accommodation space. The occurrence of two types of basin stratigraphy (trenchward and landward migration of the depocenter) reflects the two different types of deformation (frontal accretion phase and underthrusting phase), and these differences possibly depend on a contrast in strength of the basal shear resistance between the inner and outer parts of the wedge due to temporal and spatial variations of sedimentation on the wedge. A change in the magnitude of normal stress acting on the wedge base likely influenced the mode of deformation of the wedge. These results suggest that forearc basin stratigraphy is influenced by the growth pattern of accretionary wedges, which is itself affected by syntectonic sedimentation.
14C‐Dating Model for Groundwater Affected by CO2 Inputs From Deep Underground Formations
Authors: Wang Tao , Chen Jiansheng , Zhang Chenming , Zhan Lucheng , Li Ling 
Published: February 2020

AbstractGroundwater age, defined as the time since recharge, is useful for estimating groundwater renewal rates. Radiocarbon (14C) activity has been widely applied for groundwater age dating since the 1950s. However, this approach can be complicated by other 14C‐free carbon sources, which dilute the 14C content at the time of groundwater recharge. Several corrective models have been introduced to determine the dilution factor using carbon isotopes and chemical mass balances, but these models do not account for the influence of deep crust and/or mantle (endogenic) carbon sources and are hence not applicable for dating groundwater affected by endogenic CO2. Therefore, we developed a new 14C groundwater dating model including three carbon end‐members (biogenically derived sedimentary carbon, carbonate carbon, and deep crust and/or mantle carbon) to quantify the dilution factor. This model was tested by age dating groundwater samples from the United States that were influenced by endogenic carbon (based on their δ13C value), showing that the conventional method overestimated the 14C apparent age by ~19% on average. The average uncertainty for the conventional and new method is approximately 1.58% and 11.2%, respectively. The new method proposed here can be applied to groundwater age dating in other regions where aquifers are influenced by endogenic CO2. However, its application requires a priori identification of local geological, hydrogeological, and geochemical conditions.
Effects of Temperature on Tidally Influenced Coastal Unconfined Aquifers
Authors: Nguyen Thuy T. M. , Yu Xiayang , Pu Li , Xin Pei , Zhang Chenming , Barry D. A. , Li Ling 
Published: February 2020

AbstractAquifer‐ocean temperature contrasts are common worldwide. Their effects on flow and salinity distributions in unconfined coastal aquifers are, however, poorly understood. Based on laboratory experiments and numerical simulations, we examined the responses of flow processes in tidally influenced aquifers to aquifer‐ocean temperature differences. The extent of seawater intrusion and seawater circulation were found to vary with the aquifer‐ocean temperature contrast. Compared with the isothermal case, an increase of up to 40% of the tide‐induced seawater circulation rate in the intertidal zone was observed when seawater is warmer than groundwater. In contrast, saltwater circulation in the lower saltwater wedge declines notably no matter whether the seawater is warmer or colder than groundwater. As the seawater temperature rises, the contribution of tide‐induced circulation to the overall increase of submarine groundwater discharge becomes more important compared with that of density‐driven seawater circulation. Both the upper saline plume and the freshwater discharge zone expand significantly with warmer seawater whereas the lower saltwater wedge contracts.
Mechanically and biologically skin-like elastomers for bio-integrated electronics
Authors: Chen Shuo , Sun Lijie , Zhou Xiaojun , Guo Yifan , Song Jianchun , Qian Sihao , Liu Zenghe , Guan Qingbao , Meade Jeffries Eric , Liu Wenguang , Wang Yadong , He Chuanglong , You Zhengwei 
Published: February 2020

AbstractThe bio-integrated electronics industry is booming and becoming more integrated with biological tissues. To successfully integrate with the soft tissues of the body (eg. skin), the material must possess many of the same properties including compliance, toughness, elasticity, and tear resistance. In this work, we prepare mechanically and biologically skin-like materials (PSeD-U elastomers) by designing a unique physical and covalent hybrid crosslinking structure. The introduction of an optimal amount of hydrogen bonds significantly strengthens the resultant elastomers with 11 times the toughness and 3 times the strength of covalent crosslinked PSeD elastomers, while maintaining a low modulus. Besides, the PSeD-U elastomers show nonlinear mechanical behavior similar to skins. Furthermore, PSeD-U elastomers demonstrate the cytocompatibility and biodegradability to achieve better integration with tissues. Finally, piezocapacitive pressure sensors are fabricated with high pressure sensitivity and rapid response to demonstrate the potential use of PSeD-U elastomers in bio-integrated electronics.
Visualization and molecular characterization of whole-brain vascular networks with capillary resolution
Authors: Miyawaki Takeyuki , Morikawa Shota , Susaki Etsuo A. , Nakashima Ai , Takeuchi Haruki , Yamaguchi Shun , Ueda Hiroki R. , Ikegaya Yuji 
Published: February 2020

AbstractStructural elucidation and molecular scrutiny of cerebral vasculature is crucial for understanding the functions and diseases of the brain. Here, we introduce SeeNet, a method for near-complete three-dimensional visualization of cerebral vascular networks with high signal-to-noise ratios compatible with molecular phenotyping. SeeNet employs perfusion of a multifunctional crosslinker, vascular casting by temperature-controlled polymerization of hybrid hydrogels, and a bile salt-based tissue-clearing technique optimized for observation of vascular connectivity. SeeNet is capable of whole-brain visualization of molecularly characterized cerebral vasculatures at the single-microvessel level. Moreover, SeeNet reveals a hitherto unidentified vascular pathway bridging cerebral and hippocampal vessels, thus serving as a potential tool to evaluate the connectivity of cerebral vasculature.
Multi-resolution localization of causal variants across the genome
Authors: Sesia Matteo , Katsevich Eugene , Bates Stephen , Candès Emmanuel , Sabatti Chiara 
Published: February 2020

AbstractIn the statistical analysis of genome-wide association data, it is challenging to precisely localize the variants that affect complex traits, due to linkage disequilibrium, and to maximize power while limiting spurious findings. Here we report onKnockoffZoom: a flexible method that localizes causal variants at multiple resolutions by testing the conditional associations of genetic segments of decreasing width, while provably controlling the false discovery rate. Our method utilizes artificial genotypes as negative controls and is equally valid for quantitative and binary phenotypes, without requiring any assumptions about their genetic architectures. Instead, we rely on well-established genetic models of linkage disequilibrium. We demonstrate that our method can detect more associations than mixed effects models and achieve fine-mapping precision, at comparable computational cost. Lastly, we applyKnockoffZoomto data from 350k subjects in the UK Biobank and report many new findings.
Cation-controlled wetting properties of vermiculite membranes and its promise for fouling resistant oil–water separation
Authors: Huang K. , Rowe P. , Chi C. , Sreepal V. , Bohn T. , Zhou K.-G. , Su Y. , Prestat E. , Pillai P. Balakrishna , Cherian C. T. , Michaelides A. , Nair R. R. 
Published: February 2020

AbstractManipulating the surface energy, and thereby the wetting properties of solids, has promise for various physical, chemical, biological and industrial processes. Typically, this is achieved by either chemical modification or by controlling the hierarchical structures of surfaces. Here we report a phenomenon whereby the wetting properties of vermiculite laminates are controlled by the hydrated cations on the surface and in the interlamellar space. We find that vermiculite laminates can be tuned from superhydrophilic to hydrophobic simply by exchanging the cations; hydrophilicity decreases with increasing cation hydration free energy, except for lithium. The lithium-exchanged vermiculite laminate is found to provide a superhydrophilic surface due to its anomalous hydrated structure at the vermiculite surface. Building on these findings, we demonstrate the potential application of superhydrophilic lithium exchanged vermiculite as a thin coating layer on microfiltration membranes to resist fouling, and thus, we address a major challenge for oil–water separation technology.
Bismuthene for highly efficient carbon dioxide electroreduction reaction
Authors: Yang Fa , Elnabawy Ahmed O. , Schimmenti Roberto , Song Ping , Wang Jiawei , Peng Zhangquan , Yao Shuang , Deng Ruiping , Song Shuyan , Lin Yue , Mavrikakis Manos , Xu Weilin 
Published: February 2020

AbstractBismuth (Bi) has been known as a highly efficient electrocatalyst for CO2 reduction reaction. Stable free-standing two-dimensional Bi monolayer (Bismuthene) structures have been predicted theoretically, but never realized experimentally. Here, we show the first simple large-scale synthesis of free-standing Bismuthene, to our knowledge, and demonstrate its high electrocatalytic efficiency for formate (HCOO−) formation from CO2 reduction reaction. The catalytic performance is evident by the high Faradaic efficiency (99% at −580 mV vs. Reversible Hydrogen Electrode (RHE)), small onset overpotential (<90 mV) and high durability (no performance decay after 75 h and annealing at 400 °C). Density functional theory calculations show the structure-sensitivity of the CO2 reduction reaction over Bismuthene and thicker nanosheets, suggesting that selective formation of HCOO− indeed can proceed easily on Bismuthene (111) facet due to the unique compressive strain. This work paves the way for the extensive experimental investigation of Bismuthene in many different fields.
Co-existence of leiomyomas, adenomyosis and endometriosis in women with endometrial cancer
Authors: Johnatty Sharon E. , Stewart Colin J. R. , Smith Deborah , Nguyen Anthony , O’ Dwyer John , O’Mara Tracy A. , Webb Penelope M. , Spurdle Amanda B. 
Published: February 2020

AbstractLeiomyomas, adenomyosis, and endometriosis are reported to be risk factors for endometrial carcinoma (EC), and adenomyosis and endometriosis also for ovarian carcinoma (OC). We aimed to describe the prevalence of these conditions in EC patients with or without an OC diagnosis, and to investigate their relationship with EC risk and prognostic factors in these patients. We evaluated the co-existence of these three conditions in 1399 EC patients, and compared the prevalence of epidemiological risk factors and tumor prognostic features in patients with each condition versus not. Prevalence of conditions was also assessed in the subset of patients with prior/concurrent OC. The observed coexistence of leiomyomas, adenomyosis and endometriosis significantly deviated from that expected (P = 1.2 × 10−8). Patients were more likely to: report a younger age at menarche (PTrend = 0.004) if they had leiomyomas; have used oral contraceptives (P = 6.6 × 10−5) or had ≥2 full-term pregnancies (PTrend = 2.0 × 10−9) if they had adenomyosis; be diagnosed with EC at younger age (P = 5.0 × 10−11) if they had endometriosis. Patients with prior/concurrent OC were more likely to be diagnosed at younger age (P = 5.0 × 10−5), have endometriosis (P = 9.9 × 10−7), and present with higher stage EC (PTrend = 6.6 × 10−5). These findings justify further consideration of these gynecologic conditions as independent risk and prognostic factors for EC.
On-farm multi-location evaluation of genotype by environment interactions for seed yield and cooking time in common bean
Authors: Katuuramu Dennis N. , Luyima Gabriel B. , Nkalubo Stanley T. , Wiesinger Jason A. , Kelly James D. , Cichy Karen A. 
Published: February 2020

AbstractCommon bean variety choice by farmers in Uganda is driven by seed yield plus end-use quality traits like market class and cooking time. Limited genotype by environment information is available for traits valued by consumers. This research evaluated yield, seed size, hydration properties, and cooking time of 15 common bean genotypes within market classes recognized by consumers along with three farmers’ checks at nine on-farm locations in Uganda for two seasons. Yield ranged from 71 to 3,216 kg ha−1 and was largely controlled by location (21.5% of Total Sums of Squares [TSS]), plus the interaction between location and season (48.6% of TSS). Cooking time varied from 19 to 271 minutes with the genotypes Cebo Cela and Ervilha consistently cooking fastest in 24 and 27 minutes respectively. Comparatively, the local checks (NABE-4, NABE-15, and Masindi yellow) took 35 to 45 minutes to cook. Cooking time was largely controlled by genotype (40.6% of TSS). A GGE biplot analysis uncovered the presence of two mega-environments for yield and one mega-environment for cooking time. Identification of mega-environments for these traits will help expedite common bean breeding, evaluation, and variety selection through reduction of number of test environments needed for phenotype evaluations. The high yielding and fast cooking genotypes from this study can be targeted as parental materials to improve existing common bean germplasm for these important traits.
Fabrication of sharp silicon arrays to wound Caenorhabditis elegans
Authors: Belougne Jérôme , Ozerov Igor , Caillard Céline , Bedu Frédéric , Ewbank Jonathan J. 
Published: February 2020

AbstractUnderstanding how animals respond to injury and how wounds heal remains a challenge. These questions can be addressed using genetically tractable animals, including the nematode Caenorhabditis elegans. Given its small size, the current methods for inflicting wounds in a controlled manner are demanding. To facilitate and accelerate the procedure, we fabricated regular arrays of pyramidal features ("pins”) sharp enough to pierce the tough nematode cuticle. The pyramids were made from monocrystalline silicon wafers that were micro-structured using optical lithography and alkaline wet etching. The fabrication protocol and the geometry of the pins, determined by electron microscopy, are described in detail. We also used electron microscopy to characterize the different types of injury caused by these pins. Upon wounding, C. elegans expresses genes encoding antimicrobial peptides. A comparison of the induction of antimicrobial peptide gene expression using traditional needles and the pin arrays demonstrates the utility of this new method.