bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Response of the Martian Atmosphere to Space Weather
Authors: Brain David A. 
Published: July 2018

AbstractMars lacks a global dynamo magnetic field to shield it from the solar wind and solar storms, so may be especially sensitive to changing space weather compared to Earth. Inputs from the Sun and solar wind have been measured continuously at Mars for 20 years, and intermittently for more than 50 years. Observations of the influence of the variable space weather at Mars include compression and reconfiguration of the magnetosphere in response to solar storms, increased likelihood of aurora and increased auroral electron energies, increased particle precipitation and ionospheric densities during flare and energetic particle events, and increased ion escape during coronal mass ejection events. Continuing measurements at Mars provide a useful vantage point for studying space weather propagation into the heliosphere, and are providing insight into the evolution of the Martian atmosphere and the role that planetary magnetic fields play in helping planets to retain habitable conditions near their surface.
Statistical Analysis of Extreme Electron Fluxes in the Radiation Belts
Authors: Lanabere Vanina , Dasso Sergio 
Published: July 2018

AbstractThe main aim of this work is to study the frequency of extreme Space Weather events, in particular to analyse the tails of the daily averaged electron fluxes distribution function for different channels of energy between 0.249–1.192 MeV measured at ~ 600 km of altitude with the particle detector ICARE-NG/CARMEN-1 on board argentinian polar satellite SAC-D. An extreme value theory was applied to estimate the maximum values of the electron flux in the outer radiation belt for different return levels. We found that the cumulative distribution function of the extreme electron fluxes presents a finite upper limit in (1) the core of the outer radiation belt for the lower energy channels and (2) in the inner edge of the outer radiation belt for energy channels larger than 0.653 keV. The results presented in this work are important to characterise Space Weather conditions.
Application of Test Particle Simulations to Solar Energetic Particle Forecasting
Authors: Dalla S. , Swalwell B. , Battarbee M. , Marsh M. S. , Laitinen T. , Proctor S. J. 
Published: July 2018

AbstractModelling of Solar Energetic Particles (SEPs) is usually carried out by means of the 1D focused transport equation and the same approach is adopted within several SEP Space Weather forecasting frameworks. We present an alternative approach, based on test particle simulations, which naturally describes 3D particle propagation. The SPARX forecasting system is an example of how test particle simulations can be used in real time in a Space Weather context. SPARX is currently operational within the COMESEP Alert System. The performance of the system, which is triggered by detection of a solar flare of class >M1.0 is evaluated by comparing forecasts for flare events between 1997 and 2017 with actual SEP data from the GOES spacecraft.
Forecasting Solar Energetic Particle Events and Associated False Alarms
Authors: Swalwell Bill , Dalla Silvia , Walsh Robert 
Published: July 2018

AbstractBecause of the significant dangers they pose, accurate forecasting of Solar Energetic Particle (SEP) events is vital. Whilst it has long been known that SEP-production is associated with high-energy solar events, forecasting algorithms based upon the observation of these types of solar event suffer from high false alarm rates. Here we analyse the parameters of 4 very high energy solar events which were false alarms, with a view to reaching an understanding as to why SEPs were not detected at Earth. We find that in each case at least two factors were present which have been shown to be detrimental to SEP production.
Physics-Based Modeling Activity from the Solar Surface to the Earth's Atmosphere Including Magnetosphere and Ionosphere at NICT
Authors: Ishii Mamoru , Den Mitsue , Jin Hidekatsu , Kubo Yuki , Kubota Yasubumi , Nakamizo Aoi , Shinagawa Hiroyuki , Shiota Daikou , Tanaka Takashi , Tao Chihiro , Watari Shinichi , Yokoyama Tatsuhiro 
Published: July 2018

AbstractWe present the development of physics-based models of solar-terrestrial regions from the solar surface to the Earth’s atmosphere at NICT. Our models consist of three regions: (1) the solar surface and solar wind, (2) the Earth’s magnetosphere-ionosphere, and (3) a model of the whole atmosphere from the troposphere to the ionosphere, called the Ground to Topside Model of Atmosphere and Ionosphere for Aeronomy (GAIA). We also have a solar wind and CME model, Space-weather-forecast-Usable System Anchored by Numerical Operations and Observations (SUSANOO). Furthermore, we have developed a high-resolution plasma bubble model. The coupling of these models is a future work.
The MOTH II Doppler-Magnetographs and Data Calibration Pipeline
Authors: Forte Roberta , Jefferies Stuart M. , Berrilli Francesco , Del Moro Dario , Fleck Bernhard , Giovannelli Luca , Murphy Neil , Pietropaolo Ermanno , Rodgers Wayne 
Published: July 2018

AbstractThe calibration pipeline of the level zero images obtained from the Magneto-Optical filters at Two Heights (MOTH II) instrument is presented. MOTH II consists of two 20 cm aperture instruments, each using a Magneto-Optical Filter (MOF): one at 5896 Å (Na D2-line), the other one at 7700 Å (K I-line). MOTH II instruments thus provide full disk line-of-sight Doppler velocity and magnetic field measurements at two heights in the solar atmosphere. The developed MOTH II pipeline employs a set of standard calibration corrections, a correction for signal leakage, due to the non-ideal behavior of the polarizers, and the geometrical registration between the eight images acquired by four CMOS cameras, relative to two components of the signal in two circular polarization states, in each of the two channels. MOTH II data are used to investigate atmospheric dynamics (e.g., internal gravity waves and magneto-acoustic portals) and Space Weather phenomena. Particularly, flare forecasting algorithms, based on the detection of magnetic active regions (ARs) and associated flare probability estimation, are currently under development. The possible matching of MOTH II data with SDO/HMI and SDO/AIA images into a flux rope model, developed in collaboration between Harvard-Smithsonian CfA and MIT Laboratory for Nuclear Science, is being tested.
SWERTO: a Regional Space Weather Service
Authors: Berrilli Francesco , Casolino Marco , Del Moro Dario , Forte Roberta , Giovannelli Luca , Martucci Matteo , Mergé Matteo , Napoletano Gianluca , Narici Livio , Pietropalo Ermanno , Pucacco Giuseppe , Rizzo Alessandro , Scardigli Stefano , Sparvoli Roberta 
Published: July 2018

AbstractThe Space WEeatherR TOr vergata university (SWERTO) service is an operational Space Weather service based on multi-instrument data from space-based (PAMELA, ALTEA) and ground-based (IBIS, MOTHII) instruments. The service (spaceweather.roma2.infn.it) is located at the Physics Department of the University of Rome Tor Vergata, Italy (UTOV) and will allow registered users to access scientific data from instrumentation available to UTOV researchers through national and international collaborations. It will provide intuitive software for the selection and visualization of such data and results from prototype forecasting codes for flare probability and Solar Energetic Particle (SEP) fluxes. The service is designed to promote access to technical and scientific information by the regional industries which employ technologies vulnerable to Space Weather effects. Basically, SWERTO aims to: i) design and construct a data-base with particle fluxes recorded by space missions and spectro-polarimetric measurements of the solar photosphere; ii) allow an Open Access to the data-base and to prototype forecasts to regional industries involved and exposed to Space Weather effects; iii) implement a tutorial and a FAQ section to help decision makers to became aware of and evaluate the risks from Space Weather events; iv) outreach and customer products. SWERTO has been financed by the Regione Lazio FILAS-RU-2014-1028 grant.
Effects of ICMEs on High Energetic Particles as Observed by the Global Muon Detector Network (GMDN)
Authors: Dal Lago A. , Braga C. R. , de Mendonca R. R. S. , Rockenbach M. , Echer E. , Schuch N. J. , Munakata K. , Kato C. , Kuwabara T. , Kozai M. , Al Jassar H. K. , Sharma M. M. , Tokumaru M. , Duldig M. , Humble J. , Evenson P. , Sabbah I. 
Published: July 2018

AbstractThe Global Muon Detector Network (GMDN) is composed by four ground cosmic ray detectors distributed around the Earth: Nagoya (Japan), Hobart (Australia), Sao Martinho da Serra (Brazil) and Kuwait city (Kuwait). The network has operated since March 2006. It has been upgraded a few times, increasing its detection area. Each detector is sensitive to muons produced by the interactions of ~50 GeV Galactic Cosmic Rays (GCR) with the Earth′s atmosphere. At these energies, GCR are known to be affected by interplanetary disturbances in the vicinity of the earth. Of special interest are the interplanetary counterparts of coronal mass ejections (ICMEs) and their driven shocks because they are known to be the main origins of geomagnetic storms. It has been observed that these ICMEs produce changes in the cosmic ray gradient, which can be measured by GMDN observations. In terms of applications for space weather, some attempts have been made to use GMDN for forecasting ICME arrival at the earth with lead times of the order of few hours. Scientific space weather studies benefit the most from the GMDN network. As an example, studies have been able to determine ICME orientation at the earth using cosmic ray gradient. Such determinations are of crucial importance for southward interplanetary magnetic field estimates, as well as ICME rotation.
METU Data Driven Forecast Models: From the Window of Space Weather IAU Symposium 335
Authors: Tulunay Yurdanur , Tulunay Ersin 
Published: July 2018

AbstractSpace weather processes, in general, are non-linear and time-varying. In such cases ‘data driven models’ such as Neural Network, Fuzzy Logic and Genetic Algorithm based models were proved promising to be used in parallel with the mathematical models based on first physical principles. In particular, with the recent developments in ‘big data’ systems, one of the urgent issues is the development of new signal processing techniques to extract manageable, representative data out of the ‘relevant big data’ to be employed in ‘training’, ‘testing’ and validation phases of model construction. Since 1990, under the EU Frame Work Program Actions, we have developed such models for nowcasting, forecasting, warning and also for filling the data gaps on space weather cases including prediction of orbital spacecraft parameters. In particular, some typical, illustrative examples include the forecasting of the ionospheric critical frequencies foF2, during disturbed conditions, such as solar storms and extreme events; GPS total electon content(TEC); solar flare index during solar maximum and the construction of solar EUV flux variations. The associated input data organisation and the typical errors which have been within the acceptable operational expectations are summarised in terms of absolute values, percent and RMS. The aim of the paper is to show that the data driven approaches are promising for the forecasting of space weather.
Rock Control of River Geometry: The Fraser Canyons
Authors: Rennie Colin D. , Church Michael , Venditti Jeremy G. 
Published: July 2018

AbstractA 524‐km reach of Fraser River, British Columbia, was traversed, where the channel alternates between gravel‐bedded reaches that are incised into semiconsolidated glacial deposits and bedrock‐bound reaches, including Fraser Canyon. Continuous centerline acoustic Doppler current profiler survey and observations of bedrock confinement, supplemented with measurements on air photos, reveal the influence of bedrock on channel properties. The surveyed reach was subdivided into 10 morphological reaches, ranging from dominance by alluvial gravel‐bed channels to dominantly rock‐walled canyons. Measured data were grouped within each reach based on the presence of bedrock on both banks, one bank, or neither bank. From alluvial to mixed to canyon‐dominated reaches, river widths decreased while water depths, flow velocities, water surface slopes, and bed shear stresses increased. Within reaches, subreaches with bedrock on both banks were narrower and deeper with higher bed shear stresses but, at the observed stage, had lower depth‐averaged velocity and water surface slope than partly confined and alluvial (unconfined) subreaches. A conceptual model is presented representing a bedrock river as an alternating series of relatively low gradient, deep, rock‐walled pools and steep semialluvial or alluvial sections. Downstream hydraulic geometry relations have scaling exponents expected for alluvial channels provided that the alluvial and rock‐influenced sections are analyzed separately. In Fraser River, canyons become relatively narrower downstream, apparently in response to increasing rock uplift during the Quaternary period. The observations are compared against prior semitheoretical frameworks established to explain variations in width, slope, and channel shape along rockbound channels.
Dysregulated iron metabolism in polycythemia vera: etiology and consequences
Authors: Ginzburg Yelena Z. , Feola Maria , Zimran Eran , Varkonyi Judit , Ganz Tomas , Hoffman Ronald 
Published: July 2018

AbstractPolycythemia vera (PV) is a chronic myeloproliferative neoplasm. Virtually all PV patients are iron deficient at presentation and/or during the course of their disease. The co-existence of iron deficiency and polycythemia presents a physiological disconnect. Hepcidin, the master regulator of iron metabolism, is regulated by circulating iron levels, erythroblast secretion of erythroferrone, and inflammation. Both decreased circulating iron and increased erythroferrone levels, which occur as a consequence of erythroid hyperplasia in PV, are anticipated to suppress hepcidin and enable recovery from iron deficiency. Inflammation which accompanies PV is likely to counteract hepcidin suppression, but the relatively low serum ferritin levels observed suggest that inflammation is not a major contributor to the dysregulated iron metabolism. Furthermore, potential defects in iron absorption, aberrant hypoxia sensing and signaling, and frequency of bleeding to account for iron deficiency in PV patients have not been fully elucidated. Insufficiently suppressed hepcidin given the degree of iron deficiency in PV patients strongly suggests that disordered iron metabolism is an important component of the pathobiology of PV. Normalization of hematocrit levels using therapeutic phlebotomy is the most common approach for reducing the incidence of thrombotic complications, a therapy which exacerbates iron deficiency, contributing to a variety of non-hematological symptoms. The use of cytoreductive therapy in high-risk PV patients frequently works more effectively to reverse PV-associated symptoms in iron-deficient relative to iron-replete patients. Lastly, differences in iron-related parameters between PV patients and mice with JAK2 V617F and JAK2 exon 12 mutations suggest that specific regions in JAK2 may influence iron metabolism by nuanced changes of erythropoietin receptor signaling. In this review, we comprehensively discuss the clinical consequences of iron deficiency in PV, provide a framework for understanding the potential dysregulation of iron metabolism, and present a rationale for additional therapeutic options for iron-deficient PV patients.
Organoid cultures recapitulate esophageal adenocarcinoma heterogeneity providing a model for clonality studies and precision therapeutics
Authors: Li Xiaodun , Francies Hayley E. , Secrier Maria , Perner Juliane , Miremadi Ahmad , Galeano-Dalmau Núria , Barendt William J. , Letchford Laura , Leyden Genevieve M. , Goffin Emma K. , Barthorpe Andrew , Lightfoot Howard , Chen Elisabeth , Gilbert James , Noorani Ayesha , Devonshire Ginny , Bower Lawrence , Grantham Amber , MacRae Shona , Grehan Nicola , Wedge David C. , Fitzgerald Rebecca C. , Garnett Mathew J. 
Published: July 2018

AbstractEsophageal adenocarcinoma (EAC) incidence is increasing while 5-year survival rates remain less than 15%. A lack of experimental models has hampered progress. We have generated clinically annotated EAC organoid cultures that recapitulate the morphology, genomic, and transcriptomic landscape of the primary tumor including point mutations, copy number alterations, and mutational signatures. Karyotyping of organoid cultures has confirmed polyclonality reflecting the clonal architecture of the primary tumor. Furthermore, subclones underwent clonal selection associated with driver gene status. Medium throughput drug sensitivity testing demonstrates the potential of targeting receptor tyrosine kinases and downstream mediators. EAC organoid cultures provide a pre-clinical tool for studies of clonal evolution and precision therapeutics.
Spontaneous cortical activity transiently organises into frequency specific phase-coupling networks
Authors: Vidaurre Diego , Hunt Laurence T. , Quinn Andrew J. , Hunt Benjamin A. E. , Brookes Matthew J. , Nobre Anna C. , Woolrich Mark W. 
Published: July 2018

AbstractFrequency-specific oscillations and phase-coupling of neuronal populations are essential mechanisms for the coordination of activity between brain areas during cognitive tasks. Therefore, the ongoing activity ascribed to the different functional brain networks should also be able to reorganise and coordinate via similar mechanisms. We develop a novel method for identifying large-scale phase-coupled network dynamics and show that resting networks in magnetoencephalography are well characterised by visits to short-lived transient brain states, with spatially distinct patterns of oscillatory power and coherence in specific frequency bands. Brain states are identified for sensory, motor networks and higher-order cognitive networks. The cognitive networks include a posterior alpha (8–12 Hz) and an anterior delta/theta range (1–7 Hz) network, both exhibiting high power and coherence in areas that correspond to posterior and anterior subdivisions of the default mode network. Our results show that large-scale cortical phase-coupling networks have characteristic signatures in very specific frequency bands, possibly reflecting functional specialisation at different intrinsic timescales.
Transforming ground mica into high-performance biomimetic polymeric mica film
Authors: Pan Xiao-Feng , Gao Huai-Ling , Lu Yang , Wu Chun-Yan , Wu Ya-Dong , Wang Xiang-Ying , Pan Zhi-Qiang , Dong Liang , Song Yong-Hong , Cong Huai-Ping , Yu Shu-Hong 
Published: July 2018

AbstractBiomimetic assembly of high-quality nanosheets into nacre-like structures can produce macroscopic films with favorable mechanical and optical performances due to the intrinsic properties and high level of ordering of the nanoscale building blocks. Natural ground mica is abundant and exhibits great application potential. However, large size and low aspect ratio greatly limit its biomimetic assembly. Moreover, exfoliation of ground mica into high-quality nanosheets remains a significant challenge. Here, we report that large-scale exfoliation of ground mica into mono- or few-layered mica nanosheets with a production rate of ~1.0 g h−1 can be successfully achieved. The mica nanosheets are then assembled into strong biomimetic polymeric mica film that inherits the high electric insulation, excellent visible transmittance, and unique ultraviolet-shielding properties of natural mica. Its overall performance is superior to that of natural sheet mica and other biomimetic films, making the polymeric mica film a suitable substrate for flexible and transparent devices.
Long range electronic phase separation in CaFe3O5
Authors: Hong Ka. H. , Arevalo-Lopez Angel M. , Cumby James , Ritter Clemens , Attfield J. Paul 
Published: July 2018

AbstractIncomplete transformations from ferromagnetic to charge ordered states in manganite perovskites lead to phase-separated microstructures showing colossal magnetoresistances. However, it is unclear whether electronic matter can show spontaneous separation into multiple phases distinct from the high temperature state. Here we show that paramagnetic CaFe3O5 undergoes separation into two phases with different electronic and spin orders below their joint magnetic transition at 302 K. One phase is charge, orbital and trimeron ordered similar to the ground state of magnetite, Fe3O4, while the other has Fe2+/Fe3+charge averaging. Lattice symmetry is unchanged but differing strains from the electronic orders probably drive the phase separation. Complex low symmetry materials like CaFe3O5 where charge can be redistributed between distinct cation sites offer possibilities for the generation and control of electronic phase separated nanostructures.
Evolution of cooperativity in the spin transition of an iron(II) complex on a graphite surface
Authors: Kipgen Lalminthang , Bernien Matthias , Ossinger Sascha , Nickel Fabian , Britton Andrew J. , Arruda Lucas M. , Naggert Holger , Luo Chen , Lotze Christian , Ryll Hanjo , Radu Florin , Schierle Enrico , Weschke Eugen , Tuczek Felix , Kuch Wolfgang 
Published: July 2018

AbstractCooperative effects determine the spin-state bistability of spin-crossover molecules (SCMs). Herein, the ultimate scale limit at which cooperative spin switching becomes effective is investigated in a complex [Fe(H2B(pz)2)2(bipy)] deposited on a highly oriented pyrolytic graphite surface, using x-ray absorption spectroscopy. This system exhibits a complete thermal- and light-induced spin transition at thicknesses ranging from submonolayers to multilayers. On increasing the coverage from 0.35(4) to 10(1) monolayers, the width of the temperature-induced spin transition curve narrows significantly, evidencing the buildup of cooperative effects. While the molecules at the submonolayers exhibit an apparent anticooperative behavior, the multilayers starting from a double-layer exhibit a distinctly cooperative spin switching, with a free-molecule-like behavior indicated at around a monolayer. These observations will serve as useful guidelines in designing SCM-based devices.
Structural insights into SorCS2–Nerve Growth Factor complex formation
Authors: Leloup Nadia , Chataigner Lucas M. P. , Janssen Bert J. C. 
Published: July 2018

AbstractSignaling of SorCS receptors by proneurotrophin ligands regulates neuronal plasticity, induces apoptosis and is associated with mental disorders. The detailed structure of SorCS2 and its extracellular specificity are unresolved. Here we report crystal structures of the SorCS2–NGF complex and unliganded SorCS2 ectodomain, revealing cross-braced SorCS2 homodimers with two NGF dimers bound in a 2:4 stoichiometry. Five out of six SorCS2 domains directly contribute to dimer formation and a C-terminal membrane proximal unreported domain, with an RNA recognition motif fold, locks the dimer in an intermolecular head-to-tail interaction. The complex structure shows an altered SorCS2 conformation indicating substantial structural plasticity. Both NGF dimer chains interact exclusively with the top face of a SorCS2 β-propeller. Biophysical experiments reveal that NGF, proNGF, and proBDNF bind at this site on SorCS2. Taken together, our data reveal a structurally flexible SorCS2 receptor that employs the large β-propeller as a ligand binding platform.