bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local Source Vp and Vs Tomography in the Mount St. Helens Region With the iMUSH Broadband Array
Authors: Ulberg Carl W. , Creager Kenneth C. , Moran Seth C. , Abers Geoffrey A. , Thelen Weston A. , Levander Alan , Kiser Eric , Schmandt Brandon , Hansen Steven M. , Crosson Robert S. 
Published: February 2020

AbstractWe present new 3‐D P wave and S wave velocity models of the upper 20 km of the Mount St. Helens (MSH) region. These were obtained using local‐source arrival time tomography from earthquakes and explosions recorded at 70 broadband stations deployed as part of the imaging Magma Under St. Helens (iMUSH) project and augmented by several data sets. Principal features of our models include (1) low P wave and S wave velocities along the St. Helens seismic zone to depths of at least 20 km corresponding to high conductivity imaged by iMUSH magnetotelluric studies. This delineates a zone of weakness that magma can exploit at the location of MSH; (2) a 5‐ to 7‐km diameter, 6–15 km deep, 3–6% negative P wave and S wave velocity anomaly beneath MSH, consistent with previous estimates of the source region for recent eruptions. We interpret this as a magma storage region containing up to 15–20 km3 of partial melt, which is about 5 times more than the largest documented eruption at MSH; (3) a broad region of low P wave velocity below 10‐km depth extending between Mount Adams and Mount Rainier along and to the east of the main Cascade arc, which is likely due to high‐temperature arc crust and possible presence of fluids or melt; (4) several anomalies associated with surface‐mapped features, including high‐velocity igneous units such as the Spud Mountain and Spirit Lake plutons and low velocities in the Chehalis sedimentary basin and the Indian Heaven volcanic field. Our results place further constraints on the geometry of these features at depth.
Responses of the Thermosphere and Ionosphere System to Concurrent Solar Flares and Geomagnetic Storms
Authors: Qian Liying , Wang Wenbin , Burns Alan G. , Chamberlin Phillip C. , Solomon Stanley C. 
Published: February 2020

AbstractWe conducted numerical simulations to examine dayside thermosphere and ionosphere responses to concurrent solar flares and a geomagnetic storm during 6–11 September 2017, as well as the interplay of flare and storm effects. We found that E‐region electron density response to the flares was much smaller inside the auroral oval than it was outside the auroral oval due to an extra source of ionization by auroral particle precipitation. During quiet times in this period, flare enhanced ionization, which decreased daytime eastward electric fields, caused an initial weakening of the vertical E × B drifts. This weakening of the vertical E × B drifts was on the order of ~20% for an X8.2 flare in this period. During storm times, flare‐induced initial changes of the vertical plasma drifts varied between being positive and being negative, depending on latitudes, due to storm‐time disturbance dynamo effects. Storm effects also overall weakened flare effects on geopotential height, ionospheric F2 peak height hmF2, and ionospheric F2 peak electron density NmF2. In addition, storm effects changed the latitudinal distributions of flare effects on hmF2, NmF2, vertical plasma drifts, and O/N2. On the other hand, no major X‐class flare occurred shortly before or during the storm. Model simulations indicate that the weaker C‐ and M‐class flares that occurred before and during the storm had a minor effect on the amplitude of the large‐scale traveling atmosphere disturbances generated by the storm.
Auroral Structure and Dynamics From GOLD
Authors: Michell R. G. 
Published: February 2020

AbstractThe Global‐scale Observations of the Limb and Disk (GOLD) mission data contain significant quantitative information about the aurora on a global scale. Here we present techniques for quantifying such information, including the temporal development of the structure within the auroral oval using the GOLD images. These techniques are applied to auroral observations in the GOLD data, in particular showing an example of how the longitudinal structure within the aurora varies over the course of six consecutive days with differing levels of geomagnetic activity. A simple model of the solar‐induced airglow is presented that is used to remove the sunlight contamination from the dayside auroral observations. Comparisons to ground‐based auroral imaging are used for the overall auroral context and to make estimates of the proportionality between the intensities of the green line (557.7 nm) emission in the visible and the 135.6 nm emissions in the GOLD data. These observations are consistent with the intensity of the 135.6 nm auroral emission being on the same order as the intensity of the 557.7 nm auroral emission. They were both found to be around 1 kR for a stable auroral arc on a day with low geomagnetic activity (3 November 2018) and around 10 kR for an active auroral display on a day with higher levels of geomagnetic activity (5 November 2018). This could have important implications for making direct comparisons between space‐based ultraviolet auroral imaging and ground‐based visible‐light auroral imaging and the total energy input estimates that are derived from them.
Ice Shelf Basal Melt and Influence on Dense Water Outflow in the Southern Weddell Sea
Authors: Akhoudas Camille , Sallée Jean‐Baptiste , Reverdin Gilles , Aloisi Giovanni , Benetti Marion , Vignes Lucie , Gelado Maria 
Published: February 2020

AbstractWe use new observations of stable water isotopes from a research cruise in early 2017 to highlight ocean‐ice interactions occurring under Filchner‐Ronne Ice Shelf, the largest Antarctic ice shelf. In particular, we investigate the properties of Ice Shelf Water with temperature lower than the surface freezing point, in the Filchner Depression. We identify two main flavors of Ice Shelf Water emerging from beneath the Filchner Ice Shelf, which originate from High Salinity Shelf Water end members with distinct characteristics. Furthermore, these two High Salinity Shelf Water end members interact with areas of the ice shelves with different basal properties to produce different versions of Ice Shelf Water. These water masses are associated with different rates of basal melting and refreezing, which we quantify. Ice Shelf Water types that flow out of the ice shelf cavity are composed of 0.4% of mass from ice shelf (melt minus freeze) when sampled at the front of Filchner Ice Shelf. The slightly lighter Ice Shelf Water version mixes directly with ambient water masses as it flows northward on the continental shelf. The resulting Ice Shelf Water mixture with temperature below the surface freezing point ultimately sinks along the continental slope into the deep ocean, as a precursor of the Weddell Sea bottom waters.
Exhumation and Surface Evolution of the Western High Atlas and Surrounding Regions as Constrained by Low‐Temperature Thermochronology
Authors: Lanari R. , Fellin M. G. , Faccenna C. , Balestrieri M. L. , Pazzaglia F. J. , Youbi N. , Maden C. 
Published: February 2020

AbstractThe Moroccan High Atlas, the Anti‐Atlas belts, and the Siroua volcanic massif form an orographic system locally risen to elevations over 4 km. Topographic growth of this system occurred by Cenozoic transpressive inversion of Mesozoic rift structures concomitant with volcanic activity and related mantle processes. In order to constrain the topographic growth, we analyze the regional‐scale exhumation pattern, and we compare it to physiographic features. We contribute 35 new mean (U‐Th‐Sm)/He and 24 new fission track ages on apatite from the High Atlas and Anti‐Atlas, which all together range from 196 to 5 Ma. In the Anti‐Atlas, we find that the rate and amount of Cenozoic exhumation are <0.05 km/Ma and ~2 km, respectively. In the High Atlas, our new data together with previous ones show that the axial regions feature the highest topography, relief, channel steepness, and orographic precipitations together with the maximum rate and amount of Cenozoic exhumation, in the range of 0.2–0.3 km/Ma and 4–6 km, respectively. This region is bounded by high‐angle oblique‐slip faults, which display a Neogene vertical motion of a few kilometers. Moreover, the most deeply incised valley in the axial region of the High Atlas shows stepwise cooling and exhumation with a final acceleration after 6 Ma. We conclude that the location in the same region of high river channel steepness, topography, orographic precipitations, and rates and amount of exhumation, together with large vertical offsets along oblique‐slip faults, suggests that crustal deformation may exert a major control on the topographic growth of Atlas orographic swell.
Modeling the Fate of Pharmaceuticals in a Fourth‐Order River Under Competing Assumptions of Transient Storage
Authors: Liu Y. , Zarfl C. , Basu N. B. , Cirpka O. A. 
Published: February 2020

AbstractQuantifying the degradation of micropollutants in streams is important for river‐water quality management. While biodegradation is believed to be enhanced in transient‐storage zones of rivers, it can also occur in the main channel. Photodegradation is restricted to the main channel and surface transient‐storage zones. In this study, we propose a transient‐storage model framework to address the transport and fate of micropollutants in different domains of a river. We fitted the model to nighttime and daytime measurements of a tracer and four pharmaceuticals in River Steinlach, Germany. We could separate the surface and subsurface fractions of the total transient‐storage zone by fitting fluorescein photodegradation at daytime versus conservative nighttime transport. In reactive transport, we tested two model variants, allowing biodegradation in the main channel or restricting it to the transient‐storage zones, obtaining similar model performances but different degradation rate coefficients. Carbamazepine is relatively conservative; photodegradation of metoprolol and venlafaxine can be quantitatively attributed to the main channel and surface transient‐storage zone; metoprolol, venlafaxine, and sulfamethoxazole undergo biodegradation. We projected a decrease of overall pollutant removal under higher flow conditions, regardless of attributing biodegradation to specific river compartments. Our study indicates that model‐based analysis of daytime and nighttime field experiments allows (1) distinguishing photodegradation and biodegradation, (2) reducing equifinality of surface and subsurface transient‐storage, and (3) estimating biodegradation in different domains under different assumptions. However, entirely reducing the equifinality of attributing biodegradation to different compartments is hardly possible in lowland rivers with only limited transient storage.
A Geostatistical Evolution Strategy for Subsurface Characterization: Theory and Validation Through Hypothetical Two‐Dimensional Hydraulic Conductivity Fields
Authors: Park Eungyu 
Published: February 2020

AbstractA novel approach that uses the covariance matrix adaptation evolution strategy in conjunction with geostatistical covariance functions and simultaneous ensemble Kalman filters is introduced to characterize the hydraulic conductivity fields of aquifers. To verify the performance, several similarity measures between the target and estimated fields are used, including the correlation coefficient, least absolute deviation, least squares, and cross‐variance ratio. Three different cases are synthesized through validation with a small‐scale domain (40 × 40), in which the hydraulic conductivity fields are stationary, nonstationary, and stationary with reduced prior information. According to these applications, the developed approach produces excellent estimations whether the field is stationary or nonstationary when the conditioning information is sufficient. With limited conditioning information, the performance of the estimation is slightly but not significantly lower. To validate the scalability, the developed approach is applied to larger domains (100 × 100, 150 × 150, and 200 × 200), and a modified approach based on principal components is used. According to this analysis, the developed approach requires low computational cost by making predictions with a limited number of forward‐model runs and internal computations. Furthermore, the approach requires a small amount of prior information for the estimation. Based on these applications, this approach shows high potential to create cost‐effective estimates that can be used as a reference for the current state‐of‐the‐art geostatistical inversion approaches to improve subsurface characterization.
Microcystin-LR ameliorates pulmonary fibrosis via modulating CD206+ M2-like macrophage polarization
Authors: Wang Jie , Xu Lizhi , Xiang Zou , Ren Yan , Zheng Xiufen , Zhao Qingya , Zhou Qunzhi , Zhou Yuefen , Xu Lin , Wang Yaping 
Published: February 2020

AbstractIdiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by myofibroblast proliferation and extracellular matrix deposition with limited treatment options. Based on our previous observation, we hypothesized microcystin-leucine arginine (LR), an environmental cyanobacterial toxin, could potentially suppress pulmonary fibrosis. In this study, we first demonstrated that chronic exposure of microcystin-LR by oral for weeks indeed attenuated the pulmonary fibrosis both on bleomycin-induced rat and fluorescein isothiocyanate-induced mouse models. Our data further indicated that treatment with microcystin-LR substantially reduced TGF-β1/Smad signaling in rat pulmonary tissues. The experiments in vitro found that microcystin-LR was capable of blocking epithelial–mesenchymal transition (EMT) and fibroblast–myofibroblast transition (FMT) through suppressing the differentiation of CD206+ macrophages. Mechanically, microcystin-LR was found to bind to glucose-regulated protein 78 kDa (GRP78) and suppress endoplasmic reticulum unfolded protein response (UPRER) signaling pathways. These events led to the modulation of M2 polarization of macrophages, which eventually contributed to the alleviation of pulmonary fibrosis. Our results revealed a novel mechanism that may account for therapeutic effect of microcystin-LR on IPF.
Inhibition of bone morphogenetic protein 6 receptors ameliorates Sjögren’s syndrome in mice
Authors: Yin Hongen , Kalra Lovika , Lai Zhennan , Guimaro Maria C. , Aber Lauren , Warner Blake M. , Michael Drew , Zhang Nan , Cabrera-Perez Javier , Karim Arif , Swaim William D. , Afione Sandra , Voigt Alexandria , Nguyen Cuong Q. , Yu Paul B. , Bloch Donald B. , Chiorini John A. 
Published: February 2020

AbstractPrimary Sjögren’s syndrome (pSS) is a chronic autoimmune disease, with only palliative treatments available. Recent work has suggested that increased bone morphogenetic protein 6 (BMP6) expression could alter cell signaling in the salivary gland (SG) and result in the associated salivary hypofunction. We examined the prevalence of elevated BMP6 expression in a large cohort of pSS patients and tested the therapeutic efficacy of BMP signaling inhibitors in two pSS animal models. Increased BMP6 expression was found in the SGs of 54% of pSS patients, and this increased expression was correlated with low unstimulated whole saliva flow rate. In mouse models of SS, inhibition of BMP6 signaling reduced phosphorylation of SMAD1/5/8 in the mouse submandibular glands, and led to a recovery of SG function and a decrease in inflammatory markers in the mice. The recovery of SG function after inhibition of BMP6 signaling suggests cellular plasticity within the salivary gland and a possibility for therapeutic intervention that can reverse the loss of function in pSS.
The impact of colectomy on the risk of cardiovascular disease among patients without colorectal cancer
Authors: Wu Chin-Chia , Hsu Ta-Wen , Yeh Chia-Chou , Lee Cheng-Hung , Lin Mei-Chen , Chang Chun-Ming 
Published: February 2020

AbstractCardiometabolic disorders were discussed and might be changed by microbiota in recent years. Since the colon acts as the primary reservoir of microbiota, we designed the present study to explore the association between colectomy and cardiovascular disease (CVD). We identified a total of 18,424 patients who underwent colectomy between 2000–2012 for reasons other than colorectal cancer from the National Health Insurance Research Database of Taiwan. Patients were matched with 18,424 patients without colectomy using a 1:1 propensity score by age, sex, and comorbidity. Cox proportional-hazards regression was used to assess the risk of CVD. Patients with colectomy were found to be at lower risk of CVD (hazard ratio [HR]: 0.95, 95% confidence interval [CI] = 0.90–0.99) than patients without colectomy. Stratified analysis according to the type of surgery revealed patients who underwent cecectomy and right hemicolectomy were at lower risk of CVD (cecectomy: adjusted HR [aHR] = 0.77, 95% CI = 0.64–0.94; right hemicolectomy: aHR = 0.88, 95% CI = 0.82–0.96). Patients who underwent left hemicolectomy were at higher risk of CVD (aHR = 1.19, 95% CI = 1.08–1.32). Our results indicate that the different colectomy procedures influence the risk for the CVD differently.
Dissociation dynamics of the diamondoid adamantane upon photoionization by XUV femtosecond pulses
Authors: Maclot Sylvain , Lahl Jan , Peschel Jasper , Wikmark Hampus , Rudawski Piotr , Brunner Fabian , Coudert-Alteirac Hélène , Indrajith Suvasthika , Huber Bernd A. , Díaz-Tendero Sergio , Aguirre Néstor F. , Rousseau Patrick , Johnsson Per 
Published: February 2020

AbstractThis work presents a photodissociation study of the diamondoid adamantane using extreme ultraviolet femtosecond pulses. The fragmentation dynamics of the dication is unraveled by the use of advanced ion and electron spectroscopy giving access to the dissociation channels as well as their energetics. To get insight into the fragmentation dynamics, we use a theoretical approach combining potential energy surface determination, statistical fragmentation methods and molecular dynamics simulations. We demonstrate that the dissociation dynamics of adamantane dications takes place in a two-step process: barrierless cage opening followed by Coulomb repulsion-driven fragmentation.
Narciclasine improves outcome in sepsis among neonatal rats via inhibition of calprotectin and alleviating inflammatory responses
Authors: Kingsley Manoj Kumar , Bhat Ballambattu Vishnu , Badhe Bhawana Ashok , Dhas Benet Bosco , Parija Subhash Chandra 
Published: February 2020

AbstractSepsis is associated with exacerbated inflammatory response which subsequently results in multiple organ dysfunction. Sepsis accounts for high mortality and morbidity among newborns worldwide. Narciclasine is a plant alkaloid which has shown to possess anti-inflammatory properties. In this study we investigated the effect and mechanism of action of narciclasine in neonatal sepsis rat models. The excessive release of S100A8/A9 or calprotectin in neonatal sepsis could be detrimental as it could exacerbate the inflammatory responses. We found that narciclasine significantly reduced the plasma levels of S100A8/A9 and also suppressed its expression in the liver and lung. The systemic and local bacterial load was also reduced in the narciclasine treated rats. The systemic and local production of pro-inflammatory cytokines in plasma and organs (liver and lungs) was significantly reduced in the narciclasine treated rats. The histopathological studies showed that narciclasine prevents the organ damage associated with sepsis and improved the survival of neonatal rats. Sepsis increased the phosphorylated NF-κβ p65 protein expression in the liver. Narciclasine suppressed the phosphorylation of NF-κβ p65 and the degradation of NF-κβ inhibitory protein alpha. It could also suppress the expression of adaptor proteins of the toll like receptor signaling pathway viz., myeloid differentiation factor 88 (MyD88), Interleukin-1 receptor-associated kinase 1 (IRAK1) and TNF receptor associated factor 6 (TRAF6). These results suggest that narciclasine protects against sepsis in neonatal rats through the inhibition of calprotectin, pro-inflammatory cytokines and suppression of NF-κβ signaling pathway.
An assessment of measured and computed depth of closure around Japan
Authors: Udo Keiko , Ranasinghe Roshanka , Takeda Yuriko 
Published: February 2020

AbstractThe development of effective coastal adaptation strategies and protection schemes is a major challenge for coastal zone managers and engineers, not only because the coastal zone is the most populated and developed land zone in the world, but also due to projected climate change impacts. A priori knowledge of the so called depth of closure (DoC) is, more often than not, a pre-requisite to understand and model coastal morphological response to wave forcing, which in turn enables the design of appropriate coastal adaption/protection measures. In the absence of long term measurements of coastal profile data, the DoC is often computed using Hallermeier’s formulations or derivatives thereof, for applications around the world. However, there are two major unresolved issues associated with computing the DoC in this way: the accuracy of the wave data required for reliable DoC computations, and the generic applicability of the coefficients used in DoC equations. This study exploits the availability of DoCs derived from multiple measurements of coastal profiles and wave data along the Japanese coast together with wave reanalysis products to evaluate the validity of DoC calculation approaches. Results show that the accuracy of computed DoC values determined using wave reanalysis data is limited, particularly when the spatial resolution of the wave reanalysis data is lower. Furthermore, coefficients of DoC equations proposed in previous and present studies appear to be location specific and points toward the need for a concerted worldwide meta-analysis that compares observed and derived DoC in order to derive a globally applicable formulation for DoC computations.
Recovery of electro-mechanical properties inside self-healing composites through microencapsulation of carbon nanotubes
Authors: Zamal Hasna Hena , Barba David , Aïssa Brahim , Haddad Emile , Rosei Federico 
Published: February 2020

AbstractWe report the successful microencapsulation of multi-walled carbon nanotubes suspended in a 5-ethylidene-2-norbornene (5E2N) self-healing monomer, into poly melamine urea formaldehyde shells through in situ polymerization. The average size of the microcapsules, their size-distribution, shell wall structural integrity and thickness are characterized by optical and scanning electron microscopy. The presence of carbon nanotubes (CNTs) inside the core liquid content, as well as their release after breaking is confirmed by microscopy and spectroscopy analyses. A small amount of CNTs inside the microcapsules is found to have no significant impact on the thermal stability of the system, as determined by thermogravimetric analysis and differential scanning calorimetry. Both the mechanical and the electrical properties of CNT-based self-healing materials can be restored up to 80% when CNT/5E2N microcapsules are incorporated into polymer composites, thus making them highly suitable for applications in aerospace.