bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confocal Analysis of the Distribution and Persistence of Sindbis Virus (TaV-GFP) Infection in Midguts ofAedes aegyptiMosquitoes
Authors: Saredy Jason J. , Chim Florence Y. , Lyski Zoë L. , Ahearn Yani P. , Bowers Doria F. 
Published: March 2020

AbstractBiological transmission of arthropod-borne viruses (arboviruses) to vertebrate hosts by hematophagous insects poses a global threat because such arboviruses can result in a range of serious public health infectious diseases. Sindbis virus (SINV), the prototypeAlphavirus, was used to track infections in the posterior midgut (PMG) ofAedes aegyptiadult mosquitoes. Females were fed viremic blood containing a virus reporter, SINV [Thosea asignavirus-green fluorescent protein (TaV-GFP)], that leaves a fluorescent signal in infected cells. We assessed whole-mount PMGs to identify primary foci, secondary target tissues, distribution, and virus persistence. Following a viremic blood meal, PMGs were dissected and analyzed at various days of post blood-feeding. We report that virus foci indicated by GFP in midgut epithelial cells resulted in a 9.8% PMG infection and a 10.8% dissemination from these infected guts. The number of virus foci ranged from 1 to 3 per individual PMG and was more prevalent in the PMG-middle > PMG-frontal > PMG-caudal regions. SINV TaV-GFP was first observed in the PMG (primary target tissue) at 3 days post blood-feeding, was sequestered in circumscribed foci, replicated in PMG peristaltic muscles (secondary target tissue) following dissemination, and GFP was observed to persist in PMGs for 30 days postinfection.
Shear Wave Splitting and Mantle Flow Beneath Alaska
Authors: McPherson A. M. , Christensen D. H. , Abers G. A. , Tape C. 
Published: March 2020

AbstractShear wave splitting is often assumed to be caused by mantle flow or preexisting lithospheric fabrics. We present 2,389 new SKS shear wave splitting observations from 384 broadband stations deployed in Alaska from January 2010 to August 2017. In Alaska, splitting appears to be controlled by the absolute plate motion (APM) of the North American and Pacific plates, the interaction between the two plates, and the geometry of the subducting Pacific‐Yakutat plate. Outside of the subduction zone's influence, the fast directions in northern Alaska parallel the North American APM direction. Fast directions near the Queen Charlotte‐Fairweather transform margin are parallel to the faults and are likely caused by the strike‐slip deformation extending throughout the lithosphere. In the mantle wedge, fast directions are oriented along the strike of the slab with large splitting times and are caused by along‐strike flow in the mantle wedge as the slab provides a barrier to flow. South of the Alaska Peninsula, the fast directions are parallel to the trench regardless of sea floor fabric, indicating along strike flow under the Pacific plate. Under the Kenai Peninsula, the complex flat slab geometry may cause subslab flow to be parallel to Pacific APM direction or to the North America‐Pacific relative motion.
Seismic Event Coda‐Correlation: Toward Global Coda‐Correlation Tomography
Authors: Wang Sheng , Tkalčić Hrvoje 
Published: March 2020

AbstractSeismic event coda‐correlation is a mathematical manifestation of the seismic wavefield, and it is characterized by many prominent features that are formed due to the similarity between multiple pairs of seismic phases. This new paradigm sets a stage for extracting valuable information about Earth structure. However, earthquake coda‐correlation has a fundamentally different physical mechanism from ambient‐noise correlation and thus cannot be utilized in the same way as the ambient‐noise correlation tomography that has been rigorously studied both in terms of theory and applications. Therefore, we are motivated to devise a new framework for the coda‐correlation tomography, in which relevant features in coda‐correlation are decomposed and separate constituents are individually related to Earth structure to build sensitivity kernels for tomography. Our theoretical framework is verified via a toy‐problem experiment, and we compare the newly proposed method here with the one based on the assumption that an interreceiver response (Green's function) can be obtained. We illustrate that significant differences can arise in the interpretation of results if the Green's function is used instead of the newly proposed framework based on the understanding of the formation of coda‐correlation. The proposed framework paves the way for further detailed and application‐oriented method improvements and exploitation of the coda‐correlation tomography in global and planetary seismology.
The Roles of Elastic Properties, Magmatic Pressure, and Tectonic Stress in Saucer‐Shaped Sill Growth
Authors: Gill S. P. A. , Walker R. J. 
Published: March 2020

AbstractNear‐surface igneous sills commonly exhibit saucer‐like shapes, formed due to interaction with the Earth's surface once some critical sill length is reached relative to its depth. Sill geometry has been strongly linked to the host material conditions, particularly in terms of the elastic properties and shear cohesion of the host rock, operating as primary controls on sill geometry. Here we conduct dynamic numerical simulations for sill growth in the near surface, in which we vary the host rock properties, magma pressure profile internal to the sill ∆P, and the externally applied tectonic stress σr, to consider their contributions to sill geometry. We find that elastic properties alone have little impact on sill geometry. Saucer shapes reflect the additive stress components of the magma overpressure within the sill, and the tectonic stress, controlled by the locus of the maximum energy release rate Gmax. Initially, Gmax is in‐plane with the sill but deflects to ~25° at a critical base length rc relative to depth, due to interaction between the sill and the free surface. Increasing σr decreases this angle and increases rc of the sill. ∆P controls sill growth rate but has little effect on overall geometry. Host rock cohesion and elastic properties control the absolute magnitudes of σr required to effect a change in sill geometry.
The Venusian Atmospheric Oxygen Ion Escape: Extrapolation to the Early Solar System
Authors: Persson M. , Futaana Y. , Ramstad R. , Masunaga K. , Nilsson H. , Hamrin M. , Fedorov A. , Barabash S. 
Published: March 2020

AbstractThe present atmosphere of Venus contains almost no water, but recent measurements indicate that in its early history, Venus had an Earth‐like ocean. Understanding how the Venusian atmosphere evolved is important not only for Venus itself but also for understanding the evolution of other planetary atmospheres. In this study, we quantify the escape rates of oxygen ions from the present Venus to infer the past of the Venusian atmosphere. We show that an extrapolation of the current escape rates back in time leads to the total escape of 0.02–0.6 m of a global equivalent layer of water. This implies that the loss of ions to space, inferred from the present state, cannot account for the loss of an historical Earth‐like ocean. We find that the O+ escape rate increases with solar wind energy flux, where more energy available leads to a higher escape rate. Oppositely, the escape rate decreases slightly with increased extreme ultraviolet radiation (EUV) flux, though the small variation of EUV flux over the measured solar cycle may explain the weak dependency. These results indicate that there is not enough energy transferred from the solar wind to Venus' upper atmosphere that can lead to the escape of the atmosphere over the past 3.9 billion years. This means that the Venusian atmosphere did not have as much water in its atmosphere as previously assumed or the present‐day escape rates do not represent the historical escape rates at Venus. Otherwise, some other mechanisms have acted to more effectively remove the water from the Venusian atmosphere.
Coupled Nitrate and Phosphate Availability Facilitated the Expansion of Eukaryotic Life at Circa 1.56 Ga
Authors: Wang Zhipeng , Wang Xinqiang , Shi Xiaoying , Tang Dongjie , Stüeken Eva E. , Song Huyue 
Published: March 2020

AbstractRecent geochemical and paleontological studies have revealed a significant ocean oxygenation episode and an evolutionary leap of eukaryotes at the onset of the Mesoproterozoic. However, the potential role of nitrogen availability and its interaction with other nutrients in these environmental and biological events have not been investigated. Here we present an integrated study of nitrogen isotopes (δ15N), organic carbon isotopes (δ13Corg), and major and trace element concentrations from Member III of the Gaoyuzhuang Formation in the central North China Craton where the earliest macroscopic multicellular eukaryotic fossils were reported. The enrichments of redox‐sensitive elements (Mo, U, and V), coupled with Mo‐U covariations, δ13Corg, and I/(Ca + Mg), indicate that the Gaoyuzhuang Member III in the study area was deposited in largely suboxic‐anoxic environments with ephemeral occurrences of euxinia. These data reinforce previous inferences of a strongly redox stratified ocean during the early Mesoproterozoic, but a pulsed oxygenation event may have resulted in deepening of the chemocline. The high δ15N values from the study section are interpreted as a result of aerobic N cycling and the presence of a fairly stable nitrate pool in the surface oxic layer, possibly due to the combined effects of oxygenation and low primary productivity. Increased availability of nitrate could have contributed to the expansion of eukaryotic life at this time. However, our data also suggest that nitrate alone was not the only trigger. Instead, this evolutionary leap was likely facilitated by multiple environmental factors, including a rise in O2 levels and increasing supplies of phosphorus and other bio‐essential trace elements.
A Non‐steady State Model Based on Dual Nitrogen and Oxygen Isotopes to Constrain Moss Nitrate Uptake and Reduction
Authors: Liu Xue‐Yan , Wu Di , Song Xin , Dong Yu‐Ping , Chen Chong‐Juan , Song Wei , Liu Cong‐Qiang , Koba Keisuke 
Published: March 2020

AbstractEpilithic mosses are early colonizers of the terrestrial biosphere, which constitute a special ecosystem regulating rock‐atmosphere interactions. Terrestrial mosses can take up nitrate (NO3−), a major form of bioavailable N, from soil substrates. However, the importance of substrate NO3− relative to atmospheric NO3− remains unclear in moss NO3− utilization. This has prevented the understanding of moss NO3− dynamics and their responses to environmental N loadings. This study investigated monthly concentrations, δ15N, and δ18O of NO3− in four epilithic moss species from August 2006 to August 2007 in Guiyang, southwestern China. We developed a non‐steady state isotope mass‐balance model to evaluate fractional contributions of atmospheric NO3− (Фatm) and soil NO3− (Фsoil), moss NO3− uptake flux (Finflux), moss NO3− reduction flux (Freduction), and the percentage of NO3− reduction in moss NO3− uptake (freduced). The monthly Фsoil values averaged 53 ± 13% and the monthly freduced values averaged 50 ± 35%. Both the monthly Freduction and freduced increased as the monthly Finflux increased, particularly when the Фsoil values were higher than Фatm values. However, the amount of annual NO3− reduction (219.7 ± 30.5 μg‐N/g, dw) accounted for only 1.0 ± 0.2% of the bulk N of the mosses. We conclude that half of the NO3− in epilithic mosses is derived from the soil NO3− and that NO3− uptake from the soil induces moss NO3− reduction, but the total NO3− assimilation contributed a low fraction of the total N in the studied mosses. These findings are important for understanding N sources and N dynamics in terrestrial mosses.
Tajik Basin and Southwestern Tian Shan, Northwestern India‐Asia Collision Zone: 1. Structure, Kinematics, and Salt Tectonics in the Tajik Fold‐and‐Thrust Belt of the Western Foreland of the Pamir
Authors: Gągała Łukasz , Ratschbacher Lothar , Ringenbach Jean‐Claude , Kufner Sofia‐Katarina , Schurr Bernd , Dedow Ralf , Abdulhameed Sanaa , Le Garzic Edouard , Gadoev Mustafo , Oimahmadov Ilhomjon 
Published: March 2020

AbstractSurface, seismic, and borehole data characterize the Neogene‐Recent Tajik fold‐and‐thrust belt of the Tajik basin. The basin experienced little sub‐detachment basement deformation, acting as a rigid foreland plate during the Pamir orogeny. The Tajik fold‐and‐thrust belt contains variable thin‐skinned structural styles, changing along and across strike as a function of the thickness and facies of Upper Jurassic evaporites, which constitute the basal detachment, and the influence of the surrounding thick‐skinned belts. The southern Tajik fold‐and‐thrust belt shows regularly spaced, salt‐cored, thrusted detachment anticlines that transition northward into imbricated thrust sheets grouped in oppositely verging stacks facing each other across a common footwall syncline. The width of the fold‐and‐thrust belt decreases northeastward accommodated by the Ilyak fault, a lateral ramp developed over a seismically active dextral basement fault. The southeastern Tajik fold‐and‐thrust belt contains massive subaerial salt sheets, formed by squeezing of preexisting salt diapirs. The salt‐tectonic domain originates from a local depocenter within the Late Jurassic Amu Darya‐Tajik evaporitic basin. Serial cross sections, integrating the structural geometries, yielded minimum thin‐skinned shortening oriented at ~90° to the India‐Asia convergence direction, increasing from ~93 km in the south to ~148 km in the center, and dropping to ~22 km in the northeast; total shortening—including the foreland buttress—is ≥170 km. Most of the shortening in the central‐southern Tajik fold‐and‐thrust belt occurred by hinterland‐vergent, high‐displacement back thrusts. The Pamir played a dominant role in the transfer of shortening to the sedimentary infill of the Tajik basin with the Tian Shan acting as a semi‐passive buttress.
Reformulation of Bayesian Geostatistical Approach on Principal Components
Authors: Zhao Yue , Luo Jian 
Published: March 2020

AbstractIn this note, we reformulate Bayesian geostatistical inverse approach based on principal component analysis of the spatially correlated parameter field to be estimated. The unknown parameter field is described by a latent‐variable model as a realization of projections on its principal component axes. The reformulated geostatistical approach (RGA) achieves substantial dimensionality reduction by estimating the latent variable of projections on truncated principal components instead of directly estimating the parameter field. We provide solutions for best estimates and posterior variances for linear and quasi‐linear inverse problems. The number of normal equations to be solved is reduced to k+p, where k is the number of retained principal components and p is the number of drifts, both independent of the number of observations. To determine the Jacobian matrix for quasi‐linear problems, the number of forward model runs in each iteration is reduced to k+p+1. There is no need to evaluate the Jacobian matrix in terms of the unknown parameter field. RGA unifies the problem setup and computational techniques for large‐dimensional inverse problems introduced previously, which are now naturally built in the reformulated framework. RGA is more efficient and scalable for both large‐dimensional inverse problems and problems with a massive volume of observations. Moreover, conditional realizations of the parameter field can be conveniently generated by generating conditional realizations of latent variables on truncated principal component axes. We also relate the new approach to the classical geostatistical approach formulas. Large‐dimensional hydraulic tomography problems are used to demonstrate the application of the reformulated approach.
Machine‐Learning‐Based Analysis of the Guy‐Greenbrier, Arkansas Earthquakes: A Tale of Two Sequences
Authors: Park Yongsoo , Mousavi S. Mostafa , Zhu Weiqiang , Ellsworth William L. , Beroza Gregory C. 
Published: March 2020

AbstractWe revisited the June 2010 to October 2011 Guy‐Greenbrier earthquake sequence in central Arkansas using PhaseNet, a deep neural network trained to pick P and S arrival times. We applied PhaseNet to continuous waveform data and used phase association and hypocenter relocation to locate nearly 90,000 events. Our catalog suggests that the sequence consists of two adjacent earthquake sequences on the same fault and that the second sequence may be associated with the wastewater disposal well to the west of the Guy‐Greenbrier Fault, rather than the wells to the north and the east that were previously implicated. We find that each sequence is composed of many small clusters that exhibit diffusion along the fault at shorter timescales. Our study demonstrates that machine‐learning‐based earthquake catalog development is now feasible and will yield new insights into earthquake behavior.
Quantitative phosphoproteomic analysis identifies the potential therapeutic target EphA2 for overcoming sorafenib resistance in hepatocellular carcinoma cells
Authors: Chen Chih-Ta , Liao Li-Zhu , Lu Ching-Hui , Huang Yung-Hsuan , Lin Yu-Kie , Lin Jung-Hsin , Chow Lu-Ping 
Published: March 2020

AbstractLimited therapeutic options are available for advanced-stage hepatocellular carcinoma owing to its poor diagnosis. Drug resistance to sorafenib, the only available targeted agent, is commonly reported. The comprehensive elucidation of the mechanisms underlying sorafenib resistance may thus aid in the development of more efficacious therapeutic agents. To clarify the signaling changes contributing to resistance, we applied quantitative phosphoproteomics to analyze the differential phosphorylation changes between parental and sorafenib-resistant HuH-7 cells. Consequently, an average of ~1500 differential phosphoproteins were identified and quantified, among which 533 were significantly upregulated in resistant cells. Further bioinformatic integration via functional categorization annotation, pathway enrichment and interaction linkage analysis led to the discovery of alterations in pathways associated with cell adhesion and motility, cell survival and cell growth and the identification of a novel target, EphA2, in resistant HuH-7Rcells. In vitro functional analysis indicated that the suppression of EphA2 function impairs cell proliferation and motility and, most importantly, overcomes sorafenib resistance. The attenuation of sorafenib resistance may be achieved prior to its development through the modulation of EphA2 and the subsequent inhibition of Akt activity. Binding analyses and in silico modeling revealed a ligand mimic lead compound, prazosin, that could abate the ligand-independent oncogenic activity of EphA2. Finally, data obtained from in vivo animal models verified that the simultaneous inhibition of EphA2 with sorafenib treatment can effectively overcome sorafenib resistance and extend the projected survival of resistant tumor-bearing mice. Thus our findings regarding the targeting of EphA2 may provide an effective approach for overcoming sorafenib resistance and may contribute to the management of advanced hepatocellular carcinoma.
The repertoire of Adhesion G protein-coupled receptors in adipocytes and their functional relevance
Authors: Suchý Tomáš , Zieschang Christian , Popkova Yulia , Kaczmarek Isabell , Weiner Juliane , Liebing Aenne-Dorothea , Çakir Mehmet Volkan , Landgraf Kathrin , Gericke Martin , Pospisilik John Andrew , Körner Antje , Heiker John T. , Dannenberger Dirk , Schiller Jürgen , Schöneberg Torsten , Liebscher Ines , Thor Doreen 
Published: March 2020

Abstract
Background
G protein-coupled receptors (GPCR) are well-characterized regulators of a plethora of physiological functions among them the modulation of adipogenesis and adipocyte function. The class of Adhesion GPCR (aGPCR) and their role in adipose tissue, however, is poorly studied. With respect to the demand for novel targets in obesity treatment, we present a comprehensive study on the expression and function of this enigmatic GPCR class during adipogenesis and in mature adipocytes.

Methods
The expression of all aGPCR representatives was determined by reanalyzing RNA-Seq data and by performing qPCR in different mouse and human adipose tissues under low- and high-fat conditions. The impact of aGPCR expression on adipocyte differentiation and lipid accumulation was studied by siRNA-mediated knockdown of all expressed members of this receptor class. The biological characteristics and function of mature adipocytes lacking selected aGPCR were analyzed by mass spectrometry and biochemical methods (lipolysis, glucose uptake, adiponectin secretion).

Results
More than ten aGPCR are significantly expressed in visceral and subcutaneous adipose tissues and several aGPCR are differentially regulated under high-caloric conditions in human and mouse. Receptor knockdown of six receptors resulted in an impaired adipogenesis indicating their expression is essential for proper adipogenesis. The altered lipid composition was studied in more detail for two representatives, ADGRG2/GPR64 and ADGRG6/GPR126. While GPR126 is mainly involved in adipocyte differentiation, GPR64 has an additional role in mature adipocytes by regulating metabolic processes.

Conclusions
Adhesion GPCR are significantly involved in qualitative and quantitative adipocyte lipid accumulation and can control lipolysis. Factors driving adipocyte formation and function are governed by signaling pathways induced by aGPCR yielding these receptors potential targets for treating obesity.
Drp1 modulates mitochondrial stress responses to mitotic arrest
Authors: Peña-Blanco Aida , Haschka Manuel D. , Jenner Andreas , Zuleger Theresia , Proikas-Cezanne Tassula , Villunger Andreas , García-Sáez Ana J. 
Published: March 2020

AbstractAntimitotic drugs are extensively used in the clinics to treat different types of cancer. They can retain cells in a prolonged mitotic arrest imposing two major fates, mitotic slippage, or mitotic cell death. While the former is molecularly well characterized, the mechanisms that control mitotic cell death remain poorly understood. Here, we performed quantitative proteomics of HeLa cells under mitotic arrest induced with paclitaxel, a microtubule-stabilizer drug, to identify regulators of such cell fate decision. We identified alterations in several apoptosis-related proteins, among which the mitochondrial fission protein Drp1 presented increased levels. We found that Drp1 depletion during prolonged mitotic arrest led to strong mitochondrial depolarization and faster mitotic cell death as well as enhanced mitophagy, a mechanism to remove damaged mitochondria. Our findings support a new role of Drp1 in orchestrating the cellular stress responses during mitosis, where mitochondrial function and distribution into the daughter cells need to be coordinated with cell fate. This novel function of Drp1 in the cell cycle becomes best visible under conditions of prolonged mitotic arrest.
Visible-light promoted regioselective amination and alkylation of remote C(sp3)-H bonds
Authors: Guo Quanping , Peng Qiang , Chai Hongli , Huo Yumei , Wang Shan , Xu Zhaoqing 
Published: March 2020

AbstractThe C-N cross coupling reaction has always been a fundamental task in organic synthesis. However, the direct use of N-H group of aryl amines to generate N-centered radicals which would couple with alkyl radicals to construct C-N bonds is still rare. Here we report a visible light-promoted C-N radical cross coupling for regioselective amination of remote C(sp3)-H bonds. Under visible light irradiation, the N-H groups of aryl amines are converted to N-centered radicals, and are then trapped by alkyl radicals, which are generated from Hofmann-Löffler-Freytag (HLF) type 1,5-hydrogen atom transfer (1,5-HAT). With the same strategy, the regioselective C(sp3)-C(sp3) cross coupling is also realized by using alkyl Hantzsch esters (or nitrile) as radical alkylation reagents. Notably, the α-C(sp3)-H of tertiary amines can be directly alkylated to form the C(sp3)-C(sp3) bonds via C(sp3)-H − C(sp3)-H cross coupling through the same photoredox pathway.