bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Resistivity on the Efficiency of Magnetic Reconnection in MHD
Authors: Pérez‐Coll Jiménez Judit , Tenfjord Paul , Hesse Michael , Norgren Cecilia , Kwagala Norah , Kolstø Håkon Midthun , Spinnangr Susanne Flø 
Published: May 2022

AbstractUsing a resistive MagnetoHydroDynamic (MHD) simulation, we study how the magnitude and shape of diffusion influence magnetic reconnection. Specifically, we investigate how and why the reconnection rate is influenced by variations in the diffusion distribution and magnitude. By running multiple MHD simulations where we vary the localized resistivity, we find that the properties of the diffusion region greatly influence the rate of reconnection. Increasing the magnitude of the imposed resistivity results in a higher reconnection rate, but the rate saturates at approximately 0.2. We show how a redistribution of the current density, leading to a bifurcated current sheet, play a major role in this limitation. In addition, we investigate the impact of different shapes of resistive region. The shape of the diffusion region also plays a major role in how efficient the reconnection energy conversion can operate. The highest reconnection rate, approximately 0.25, is achieved for an optimal opening angle. Our results imply that reconnection has a speed limit that may depend on properties outside the diffusion region.
Bilateral Heterogeneity in an Upwelling Mantle via Double Subduction of Oceanic Lithosphere
Authors: Dao Nghiem Van , Kitagawa Hiroshi , Nakamura Eizo , Kobayashi Katsura , Ngo Thanh Xuan , Trinh Son Hai 
Published: May 2022

AbstractVietnam is a major field of Cenozoic volcanism in Southeast (SE) Asia. Two contrasting models have been proposed to explain the mantle upwelling and volcanism in this region; collision of the Indian and Eurasian continents or subduction of the Pacific or Indo‐Australian oceanic lithosphere. To place constraints on the origin of the intraplate volcanism in SE Asia, new geochronological and geochemical data for Cenozoic basalts in Vietnam are presented. Based largely on Sr‐Nd‐Pb isotope systematics, it was found that the sources of basalts from Central and Southern Vietnam are chemically distinct forming a sharp boundary at 13.5°N. The basalts north of the boundary show isotopic features similar to Enriched Mantle type 2 (EM2) ocean island basalts. Whereas the basalts south of the boundary show isotopic features similar to Enriched Mantle type 1 (EM1) ocean island basalts. The EM1 and EM2 basalts display positive Sr anomalies and elevated Pb/Ce and Th/La ratios, respectively. Such features suggest the origins of the sources through the recycling of deeply‐subducted crustal lithologies. Furthermore, subduction of dense oceanic lithosphere can induce a convecting cell in the upper mantle. Therefore, we suggest that the chemically different basalts from Central and Southern Vietnam represent the surface expression of melting in two different convecting cells, one is driven by subduction of the Pacific plate and the other by subduction of the Indo‐Australian plate.
X‐Ray Amorphous Sulfur‐Bearing Phases in Sedimentary Rocks of Gale Crater, Mars
Authors: Smith R. J. , McLennan S. M. , Sutter B. , Rampe E. B. , Dehouck E. , Siebach K. L. , Horgan B. H. N. , Sun V. , McAdam A. , Mangold N. , Vaniman D. , Salvatore M. , Thorpe M. T. , Achilles C. N. 
Published: May 2022

AbstractThe Curiosity rover in Gale crater is investigating a mineral transition observed from orbit—an older “clay unit” to a younger “sulfate unit”—hypothesized to reflect the aridification of Mars' climate. Below this transition, the rover detected crystalline Ca‐sulfates with minor Fe‐sulfates but also found that some fraction of a rock's bulk SO3 is often in the poorly constrained X‐ray amorphous component. Here, we characterize the abundances and compositions of the X‐ray amorphous sulfur‐bearing phases in 19 drilled samples using a mass balance approach, and in a subset of 5 samples using evolved SO2 gas measured using the SAM instrument. We find that ∼20–90 wt% of a sample's bulk SO3 is in the X‐ray amorphous state and that X‐ray amorphous sulfur‐bearing phase compositions are consistent with mixtures of Mg‐S, Fe‐S, and possibly Ca‐S phases, likely sulfates or sulfites. These phases reside in the bedrock, perhaps as cementing agents deposited with detrital sediments or during early diagenesis, and in diagenetic alteration halos deposited after lithification during late diagenesis. The likely presence of highly soluble Mg‐sulfates in the rocks suggests negligible fluid flow through the bedrock post‐Mg‐sulfate deposition. The X‐ray amorphous sulfur‐bearing phases probably became amorphous through dehydration in the current Martian atmosphere or inside the CheMin instrument. X‐ray amorphous sulfur‐bearing materials likely contribute to orbital spectral detections of sulfates, and so our results help form multiple hypotheses to be tested in the sulfate unit and are important for understanding the evolution of the Martian surface environment at Gale crater.
A Laboratory Model for a Meandering Zonal Jet
Authors: Stewart K. D. , Macleod F. 
Published: May 2022

AbstractThe meandering jet streams of the Northern Hemisphere influence the weather for more than half of Earth's population, so it is imperative that we improve our understanding of their behavior and how they respond to climate change. Here, we describe a novel laboratory model for a meandering zonal jet. This model comprises a large rotating annulus with a series of topographic ridges, and an imposed radial vorticity flux. Flow interactions with the topographic ridges operate to concentrate the zonal transport into a narrow jet, which supports the development and propagation of Rossby waves. We investigate the dynamics of the jet for a range of rotation rates, imposed radial vorticity fluxes, and topographic ridge configurations. The circulations are classified into two distinct regimes: predominantly zonal or predominantly meandering. The flow regime can be quantified by the ratio of the Ekman dissipation and jet advection timescales, which gives an indication of whether disturbances arising from the flow‐topography interaction are dissipated faster than the time taken to circuit the annulus; if not, these disturbances will reencounter the topography, and thus be reinforced and amplified. For predominantly zonal flows, the radial vorticity flux is split equally between the standing meanders and transient eddies. For predominantly meandering flows, standing meanders perform 79% of the radial vorticity flux, with 18% accommodated by the transient eddies. Our experiments indicate that the Arctic amplification associated with climate change will tend to favor predominantly zonal flow conditions, suggesting a reduced occurrence of atmospheric blocking events caused by the jet streams.
Long‐Term Schumann Resonance Dynamics Based on Horizontal Magnetic Field Data at Mikhnevo Observatory During 2016–2020
Authors: Goncharov E. S. , Lyakhov A. N. , Losseva T. V. 
Published: May 2022

AbstractIt is the first time when we present a significant amount of two‐channel (north‐south and west‐east) absolute magnetic field data in the extremely low frequency (ELF) band for the European Russia. The measurements are evaluated at Mikhnevo geophysical observatory of the Sadovsky Institute of Geosphere Dynamics. We start with a recently proposed unified processing procedure by Rodriguez‐Camacho et al. (2018, https://doi.org/10.1029/2018jd029462) and further elaborate an ELF spectrum calculation technique. The true sequence of the spectrum calculation is presented, including the proper parameters, software requirements, and the use of third‐party libraries. We receive an optimal set of processing parameters for Mikhnevo observatory and discuss the long‐term (2016–2020) Schumann Resonance variations.
Vertical Flux of Trace Elements Associated With Lithogenic and Biogenic Carrier Phases in the Southern Ocean
Authors: Blain S. , Planquette H. , Obernosterer I. , Guéneuguès A. 
Published: May 2022

AbstractTrace elements (TE) are tracers of multiple biotic and abiotic processes in the ocean and some of them are essential for marine life. Vertical export by particles is a major removal process of a large fraction of TE from the surface ocean. However, the seasonal export dynamics and its controlling factors, critical for the understanding of the internal TE cycling, remain poorly constrained. Here, we report and discuss the seasonal export of 15 TE in sinking particles collected by a sediment trap deployed in a highly productive region of the Southern Ocean. Basalt material was the main carrier phase for the export flux of 9 TE, and its dynamic was characterized by a strong decrease over time. TE export driven by biological carriers such as diatom spores and vegetative cells added pulsed seasonal dynamics to the lithogenic signal, while the contribution of fecal pellets was less variable over the season. For each TE, we were able to decipher the biological carrier phases that represent the most dominant export pathway. We discuss this partitioning with regards to the known metabolic functions of the different trace metals or TE of biological interest.
Glacial Warming in the Eastern Pacific Warm Pool
Authors: Meegan Kumar Dervla , Tierney Jessica E. , Bhattacharya Tripti , Zhu Jiang , Murray James W. 
Published: May 2022

AbstractThe Eastern Pacific Warm Pool (EPWP) modulates global climate through its connection with tropical Pacific circulation, but sparse paleoceanographic data from this region limits our understanding of its role in past climate variability. We present a 144 kyr alkenone‐sea surface temperature (SST) reconstruction from core NH22P, located in the northern EPWP, that shows local warming occurred during periods of global cooling. Climate model simulations of the Last Glacial Maximum indicate that both ice sheet and greenhouse gas forcing slowed wind speeds over the EPWP, which attenuated glacial cooling of local SST via the wind‐evaporation‐SST feedback. Spectral analysis further suggests precessional pacing of the warming spikes. Vernal equinox insolation could explain this pacing as direct shortwave heating during boreal spring would have contributed to the early seasonal intensification of the EPWP. This work provides crucial constraints on tropical Pacific glacial climate variability and highlights the unique response of the EPWP to global climate forcings.
Ionospheric Signatures During G2, G3 and G4 Storms in Mid‐Latitude
Authors: Dahal Subodh , Adhikari Binod , Khadka Anil Kumar , Silwal Ashok , Gupta Suresh Prasad , Chapagain Narayan Prasad 
Published: May 2022

AbstractThis paper presents a wavelet‐based analysis of ionospheric irregularities induced by three different geomagnetic storms of varying strength and interplanetary origin over three mid‐latitudes stations, viz. Moscow, Fairford, and Rome. We observed the highest decrease in ionospheric variables (foF2, total electron content (TEC), and NmF2) during the negative phase of the G4 storm. Interestingly, hmF2 exhibits the opposite trend in terms of variation. The maximum ionization height (hmF2) for the G4 event is 500 km (during the main phase) and 150 km (during the recovery phase). Within 2–3 hr of the G4 event, the value of hmF2 is found to decline by 70%. The largest reduction (80%) in critical frequency (foF2) is observed during the negative phase of this event, which is also confirmed by the continuous wavelet transform results. During the negative phase, we observed noticeable power shifts in the signal of the ionospheric parameters toward the lower Fourier period band. During the G4 storm—Particularly during the negative phase—The lowest power linked with the ionospheric parameter's signal was discovered. Additionally, we used detrended cross‐correlation analysis to investigate the correlation and time lag between geomagnetic indices (Symmetric H‐component (SYM‐H) & auroral electrojet) and ionospheric parameters (foF2, NmF2, hmF2 & TEC). The significant association between SYM‐H and ionospheric parameters suggests that the magnetosphere‐ionosphere interaction produces intense electric field disturbances and winds in the mid‐latitudes, resulting in the perturbation of hmF2, foF2, TEC, and NmF2.
AIMP2-DX2 provides therapeutic interface to control KRAS-driven tumorigenesis
Authors: Kim Dae Gyu , Choi Yongseok , Lee Yuno , Lim Semi , Kong Jiwon , Song JaeHa , Roh Younah , Harmalkar Dipesh S. , Lee Kwanshik , Goo Ja-il , Cho Hye Young , Mushtaq Ameeq Ul , Lee Jihye , Park Song Hwa , Kim Doyeun , Min Byung Soh , Lee Kang Young , Jeon Young Ho , Lee Sunkyung , Lee Kyeong , Kim Sunghoon 
Published: May 2022

AbstractRecent development of the chemical inhibitors specific to oncogenic KRAS (Kirsten Rat Sarcoma 2 Viral Oncogene Homolog) mutants revives much interest to control KRAS-driven cancers. Here, we report that AIMP2-DX2, a variant of the tumor suppressor AIMP2 (aminoacyl-tRNA synthetase-interacting multi-functional protein 2), acts as a cancer-specific regulator of KRAS stability, augmenting KRAS-driven tumorigenesis. AIMP2-DX2 specifically binds to the hypervariable region and G-domain of KRAS in the cytosol prior to farnesylation. Then, AIMP2-DX2 competitively blocks the access of Smurf2 (SMAD Ubiquitination Regulatory Factor 2) to KRAS, thus preventing ubiquitin-mediated degradation. Moreover, AIMP2-DX2 levels are positively correlated with KRAS levels in colon and lung cancer cell lines and tissues. We also identified a small molecule that specifically bound to the KRAS-binding region of AIMP2-DX2 and inhibited the interaction between these two factors. Treatment with this compound reduces the cellular levels of KRAS, leading to the suppression of KRAS-dependent cancer cell growth in vitro and in vivo. These results suggest the interface of AIMP2-DX2 and KRAS as a route to control KRAS-driven cancers.
Agrobacterium expressing a type III secretion system delivers Pseudomonas effectors into plant cells to enhance transformation
Authors: Raman Vidhyavathi , Rojas Clemencia M. , Vasudevan Balaji , Dunning Kevin , Kolape Jaydeep , Oh Sunhee , Yun Jianfei , Yang Lishan , Li Guangming , Pant Bikram D. , Jiang Qingzhen , Mysore Kirankumar S. 
Published: May 2022

AbstractAgrobacterium-mediated plant transformation (AMT) is the basis of modern-day plant biotechnology. One major drawback of this technology is the recalcitrance of many plant species/varieties to Agrobacterium infection, most likely caused by elicitation of plant defense responses. Here, we develop a strategy to increase AMT by engineering Agrobacterium tumefaciens to express a type III secretion system (T3SS) from Pseudomonas syringae and individually deliver the P. syringae effectors AvrPto, AvrPtoB, or HopAO1 to suppress host defense responses. Using the engineered Agrobacterium, we demonstrate increase in AMT of wheat, alfalfa and switchgrass by ~250%–400%. We also show that engineered A. tumefaciens expressing a T3SS can deliver a plant protein, histone H2A-1, to enhance AMT. This strategy is of great significance to both basic research and agricultural biotechnology for transient and stable transformation of recalcitrant plant species/varieties and to deliver proteins into plant cells in a non-transgenic manner.
Thioesters provide a plausible prebiotic path to proto-peptides
Authors: Frenkel-Pinter Moran , Bouza Marcos , Fernández Facundo M. , Leman Luke J. , Williams Loren Dean , Hud Nicholas V. , Guzman-Martinez Aikomari 
Published: May 2022

AbstractIt is widely assumed that the condensation of building blocks into oligomers and polymers was important in the origins of life. High activation energies, unfavorable thermodynamics and side reactions are bottlenecks for abiotic peptide formation. All abiotic reactions reported thus far for peptide bond formation via thioester intermediates have relied on high energy molecules, which usually suffer from short half-life in aqueous conditions and therefore require constant replenishment. Here we report plausible prebiotic reactions of mercaptoacids with amino acids that result in the formation of thiodepsipeptides, which contain both peptide and thioester bonds. Thiodepsipeptide formation was achieved under a wide range of pH and temperature by simply drying and heating mercaptoacids with amino acids. Our results offer a robust one-pot prebiotically-plausible pathway for proto-peptide formation. These results support the hypothesis that thiodepsipeptides and thiol-terminated peptides formed readily on prebiotic Earth and were possible contributors to early chemical evolution.
Off-the-shelf CAR natural killer cells secreting IL-15 target spike in treating COVID-19
Authors: Lu Ting , Ma Rui , Dong Wenjuan , Teng Kun-Yu , Kollath Daniel S. , Li Zhiyao , Yi Jinhee , Bustillos Christian , Ma Shoubao , Tian Lei , Mansour Anthony G. , Li Zhenlong , Settles Erik W. , Zhang Jianying , Keim Paul S. , Barker Bridget M. , Caligiuri Michael A. , Yu Jianhua 
Published: May 2022

AbstractEngineered natural killer (NK) cells represent a promising option for immune therapy option due to their immediate availability in allogeneic settings. Severe acute diseases, such as COVID-19, require targeted and immediate intervention. Here we show engineering of NK cells to express (1) soluble interleukin-15 (sIL15) for enhancing their survival and (2) a chimeric antigen receptor (CAR) consisting of an extracellular domain of ACE2, targeting the spike protein of SARS-CoV-2. These CAR NK cells (mACE2-CAR_sIL15 NK cells) bind to VSV-SARS-CoV-2 chimeric viral particles as well as the recombinant SARS-CoV-2 spike protein subunit S1 leading to enhanced NK cell production of TNF-α and IFN-γ and increased in vitro and in vivo cytotoxicity against cells expressing the spike protein. Administration of mACE2-CAR_sIL15 NK cells maintains body weight, reduces viral load, and prolongs survival of transgenic mice expressing human ACE2 upon infection with live SARS-CoV-2. These experiments, and the capacity of mACE2-CAR_sIL15 NK cells to retain their activity following cryopreservation, demonstrate their potential as an allogeneic off-the-shelf therapy for COVID-19 patients who are faced with limited treatment options.
Diamond mirrors for high-power continuous-wave lasers
Authors: Atikian Haig A. , Sinclair Neil , Latawiec Pawel , Xiong Xiao , Meesala Srujan , Gauthier Scarlett , Wintz Daniel , Randi Joseph , Bernot David , DeFrances Sage , Thomas Jeffrey , Roman Michael , Durrant Sean , Capasso Federico , Lončar Marko 
Published: May 2022

AbstractHigh-power continuous-wave (CW) lasers are used in a variety of areas including industry, medicine, communications, and defense. Yet, conventional optics, which are based on multi-layer coatings, are damaged when illuminated by high-power CW laser light, primarily due to thermal loading. This hampers the effectiveness, restricts the scope and utility, and raises the cost and complexity of high-power CW laser applications. Here we demonstrate monolithic and highly reflective mirrors that operate under high-power CW laser irradiation without damage. In contrast to conventional mirrors, ours are realized by etching nanostructures into the surface of single-crystal diamond, a material with exceptional optical and thermal properties. We measure reflectivities of greater than 98% and demonstrate damage-free operation using 10 kW of CW laser light at 1070 nm, focused to a spot of 750 μm diameter. In contrast, we observe damage to a conventional dielectric mirror when illuminated by the same beam. Our results initiate a new category of optics that operate under extreme conditions, which has potential to improve or create new applications of high-power lasers.
Effect of test media on the crevice corrosion of stainless steel by sulfate reducing bacteria
Authors: Javed M. A. , Neil W. C. , Wade S. A. 
Published: May 2022

AbstractThe potential for crevice corrosion of UNS30400 stainless steel in the presence of sulfate-reducing bacteria (SRB) was studied in different media. Immersion studies found crevice corrosion to occur in test media supplemented with high chloride levels and SRB present for crevice gaps of ~3 μm. Electrochemical measurements showed high susceptibility to corrosion in this particular medium, demonstrated by a negative shift of open circuit potential, increased corrosion current and the lowest passivity breakdown potential. Overall, the results showed that test media can play a critical role in the crevice corrosion of stainless steel in the presence of SRB.
A dataset of winter wheat aboveground biomass in China during 2007–2015 based on data assimilation
Authors: Huang Hai , Huang Jianxi , Li Xuecao , Zhuo Wen , Wu Yantong , Niu Quandi , Su Wei , Yuan Wenping 
Published: May 2022

AbstractAs a key variable to characterize the process of crop growth, the aboveground biomass (AGB) plays an important role in crop management and production. Process-based models and remote sensing are two important scientific methods for crop AGB estimation. In this study, we combined observations from agricultural meteorological stations and county-level yield statistics to calibrate a process-based crop growth model for winter wheat. After that, we assimilated a reprocessed temporal-spatial filtered MODIS Leaf Area Index product into the model to derive the 1 km daily AGB dataset of the main winter wheat producing areas in China from 2007 to 2015. The validation using ground measurements also suggests the derived AGB dataset agrees well with the filed observations, i.e., the R2 is above 0.9, and the root mean square error (RMSE) reaches 1,377 kg·ha−1. Compared to county-level statistics during 2007–2015, the ranges of R2, RMSE, and mean absolute percentage error (MAPE) are 0.73~0.89, 953~1,503 kg·ha−1, and 8%~12%, respectively. We believe our dataset can be helpful for relevant studies on regional agricultural production management and yield estimation.
Diagnosis of colour vision deficits using eye movements
Authors: Taore Aryaman , Lobo Gabriel , Turnbull Philip R. , Dakin Steven C. 
Published: May 2022

AbstractWe set out to develop a simple objective test of functional colour vision based on eye movements made in response to moving patterns. We exploit the finding that while the motion of a colour-defined stimulus can be cancelled by adding a low-contrast luminance-defined stimulus moving in the opposite direction, the “equivalent luminance contrast” required for such cancellation is reduced when colour vision is abnormal. We used a consumer-grade infrared eye-tracker to measure eye movements made in response to coloured patterns drifting at different speeds. An automated analysis of these movements estimated individuals’ red-green equiluminant point and their equivalent luminance contrast. We tested 34 participants: 23 colour vision normal controls, 9 deuteranomalous and 2 protanomalous individuals. We obtained reliable estimates of strength of directed eye movements (i.e. combined optokinetic and voluntary tracking) for stimuli moving at 16 deg/s and could use these data to classify participants’ colour vision status with a sensitivity rate of 90.9% and a specificity rate of 91.3%. We conclude that an objective test of functional colour vision combining a motion-nulling technique with an automated analysis of eye movements can diagnose and assess the severity of protanopia and deuteranopia. The test places minimal demands on patients (who simply view a series of moving patterns for less than 90 s), requires modest operator expertise, and can be run on affordable hardware.