bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coronal Magnetic Structure of Earthbound CMEs and In Situ Comparison
Authors: Palmerio E. , Kilpua E. K. J. , Möstl C. , Bothmer V. , James A. W. , Green L. M. , Isavnin A. , Davies J. A. , Harrison R. A. 
Published: March 2018

AbstractPredicting the magnetic field within an Earth‐directed coronal mass ejection (CME) well before its arrival at Earth is one of the most important issues in space weather research. In this article, we compare the intrinsic flux rope type, that is, the CME orientation and handedness during eruption, with the in situ flux rope type for 20 CME events that have been uniquely linked from Sun to Earth through heliospheric imaging. Our study shows that the intrinsic flux rope type can be estimated for CMEs originating from different source regions using a combination of indirect proxies. We find that only 20% of the events studied match strictly between the intrinsic and in situ flux rope types. The percentage rises to 55% when intermediate cases (where the orientation at the Sun and/or in situ is close to 45°) are considered as a match. We also determine the change in the flux rope tilt angle between the Sun and Earth. For the majority of the cases, the rotation is several tens of degrees, while 35% of the events change by more than 90°. While occasionally the intrinsic flux rope type is a good proxy for the magnetic structure impacting Earth, our study highlights the importance of capturing the CME evolution for space weather forecasting purposes. Moreover, we emphasize that determination of the intrinsic flux rope type is a crucial input for CME forecasting models.
Rollback Orogeny Model for the Evolution of the Swiss Alps
Authors: Kissling Edi , Schlunegger Fritz 
Published: March 2018

AbstractThe construction of the European Alps and the Himalayas has been related to the convergence and subsequent collision of two continental plates. Nearly all models of orogeny build on this concept, and all of them relate the stacking of nappes and the buildup of topography to compressional forces at work in response to the collision between two continental plates. For the central European Alps, however, these models fail to explain the first‐order observations of a mountain belt, which particularly includes the striking isostatic imbalance between the low surface topography and the thick crust beneath the Alps. Here we review and synthesize data on the geologic architecture of the central Alps, the chronology and pattern of crustal deformation, and information about the deep crustal structure derived from seismic tomography. Furthermore, we discuss the intrinsic and explicit assumptions in the kinematic models of Alpine evolution in the context of plate tectonic considerations. We combine these views with progress in understanding that has been gained through subduction and collision, isostatic mass and force balancing and with information that has been collected on the modern seismic regime. We conclude that a rollback orogeny model for the European plate offers the most suitable concept to explain the ensemble of surface and deep lithosphere observations. In this model gravity forces drive the evolution of the orogen and the construction of surface topography is accomplished without the requirement of a hard collision between two continents.
An Extended Trajectory Mechanics Approach for Calculating the Path of a Pressure Transient: Derivation and Illustration
Authors: Vasco D. W. 
Published: March 2018

AbstractFollowing an approach used in quantum dynamics, an exponential representation of the hydraulic head transforms the diffusion equation governing pressure propagation into an equivalent set of ordinary differential equations. Using a reservoir simulator to determine one set of dependent variables leaves a reduced set of equations for the path of a pressure transient. Unlike the current approach for computing the path of a transient, based on a high‐frequency asymptotic solution, the trajectories resulting from this new formulation are valid for arbitrary spatial variations in aquifer properties. For a medium containing interfaces and layers with sharp boundaries, the trajectory mechanics approach produces paths that are compatible with travel time fields produced by a numerical simulator, while the asymptotic solution produces paths that bend too strongly into high permeability regions. The breakdown of the conventional asymptotic solution, due to the presence of sharp boundaries, has implications for model parameter sensitivity calculations and the solution of the inverse problem. For example, near an abrupt boundary, trajectories based on the asymptotic approach deviate significantly from regions of high sensitivity observed in numerical computations. In contrast, paths based on the new trajectory mechanics approach coincide with regions of maximum sensitivity to permeability changes.
The Lower Ionospheric VLF/LF Response to the 2017 Great American Solar Eclipse Observed Across the Continent
Authors: Cohen M. B. , Gross N. C. , Higginson‐Rollins M. A. , Marshall R. A. , Gołkowski M. , Liles W. , Rodriguez D. , Rockway J. 
Published: March 2018

AbstractWe present observations from 11 very low frequency (VLF)/low‐frequency (LF) receivers across the continental United States during the 21 August 2017 “Great American Solar Eclipse.” All receivers detected transmissions from VLF/LF beacons below 50 kHz, while seven also recorded LF beacons above 50 kHz, yielding dozens of individual transmitter‐receiver radio links. Our observations show two separable superimposed signatures: (1) a gradual rise and fall in signal levels visible on almost all paths as the eclipse advances and then declines, as VLF attenuation is reduced by the changing ionosphere under an eclipsed Sun, and (2) direct reflective scattering off the narrow 100‐km‐wide totality spot, observed more uniquely when the transmitter or receiver, if not both, are relatively close to the totality spot.
Large‐Scale Structure of Subauroral Polarization Streams During the Main Phase of a Severe Geomagnetic Storm
Authors: He Fei , Zhang Xiao‐Xin , Wang Wenbin , Liu Libo , Ren Zhi‐Peng , Yue Xinan , Hu Lianhuan , Wan Weixing , Wang Hui 
Published: March 2018

AbstractIn this study, we present multisatellite observations of the large‐scale structures of subauroral polarization streams (SAPS) during the main phase of a severe geomagnetic storm that occurred on 31 March 2001. Observations by the Defense Meteorological Satellite Program F12 to F15 satellites indicate that the SAPS were first generated around the dusk sector at the beginning of the main phase. The SAPS channel then expanded toward the midnight sector and moved to lower latitudes as the main phase progressed. The peak velocity, latitudinal width, latitudinal alignment, and longitudinal span of the SAPS channel were highly dynamic during the storm main phase. The large westward velocities of the SAPS were located in the region of low electron densities, associated with low ionospheric conductivity. The large‐scale structures of the SAPS also corresponded closely to those of the region‐2 field‐aligned currents, which were mainly determined by the azimuthal pressure gradient of the ring current.
Forward Modeling of Thermally Activated Single‐Domain Magnetic Particles Applied to First‐Order Reversal Curves
Authors: Lanci Luca , Kent Dennis V. 
Published: March 2018

AbstractTheoretical first‐order reversal curves (FORCs) were generated by numerically solving a thermally activated Stoner‐Wohlfarth model for assemblages of randomly oriented magnetic particles. The thermally activated Stoner‐Wohlfarth model extends previous models based on Preisach theory. The new numerical simulations show that the shapes of reversal curves and the FORC distributions are significantly modified by the effect of the thermal energy only if superparamagnetic particles are predominant. However, most assemblages containing moderate amounts of superparamagnetic particles are hardly distinguishable from stable single‐domain assemblages. The most relevant thermal effect is a reduction of coercivity that translates in a shift of the FORC distribution toward the origin. Not all of the distinctive characteristics previously predicted for superparamagnetic grain assemblages were confirmed by our calculations, and most of the observed modifications due to thermal effects can be considered minor. A direct comparison with hysteresis parameters shows that these simpler experiments can be equally effective in characterizing viscous and superparamagnetic particles.
Coherent Seismic Arrivals in the P Wave Coda of the 2012 Mw 7.2 Sumatra Earthquake: Water Reverberations or an Early Aftershock?
Authors: Fan Wenyuan , Shearer Peter M. 
Published: March 2018

AbstractTeleseismic records of the 2012 Mw 7.2 Sumatra earthquake contain prominent phases in the P wave train, arriving about 50 to 100 s after the direct P arrival. Azimuthal variations in these arrivals, together with back‐projection analysis, led Fan and Shearer (, https://doi.org/10.1002/2016GL067785) to conclude that they originated from early aftershock(s), located ∼150 km northeast of the mainshock and landward of the trench. However, recently, Yue et al. (, https://doi.org/10.1002/2017GL073254) argued that the anomalous arrivals are more likely water reverberations from the mainshock, based mostly on empirical Green's function analysis of a M6 earthquake near the mainshock and a water phase synthetic test. Here we present detailed back‐projection and waveform analyses of three M6 earthquakes within 100 km of the Mw 7.2 earthquake, including the empirical Green's function event analyzed in Yue et al. (, https://doi.org/10.1002/2017GL073254). In addition, we examine the waveforms of three M5.5 reverse‐faulting earthquakes close to the inferred early aftershock location in Fan and Shearer (, https://doi.org/10.1002/2016GL067785). These results suggest that the reverberatory character of the anomalous arrivals in the mainshock coda is consistent with water reverberations, but the origin of this energy is more likely an early aftershock rather than delayed and displaced water reverberations from the mainshock.
The Penetration of Solar Radiation Into Carbon Dioxide Ice
Authors: Chinnery H. E. , Hagermann A. , Kaufmann E. , Lewis S. R. 
Published: March 2018

AbstractIcy surfaces behave differently to rocky or regolith‐covered surfaces in response to irradiation. A key factor is the ability of visible light to penetrate partially into the subsurface. This results in the solid‐state greenhouse effect, as ices can be transparent or translucent to visible and shorter wavelengths, while opaque in the infrared. This can lead to significant differences in shallow subsurface temperature profiles when compared to rocky surfaces. Of particular significance for modeling the solid‐state greenhouse effect is the e‐folding scale, otherwise known as the absorption scale length, or penetration depth, of the ice. While there have been measurements for water ice and snow, pure and with mixtures, to date, there have been no such measurements published for carbon dioxide ice. After an extensive series of measurements we are able to constrain the e‐folding scale of CO2 ice for the cumulative wavelength range 300 to 1,100 nm, which is a vital parameter in heat transfer models for the Martian surface, enabling us to better understand surface‐atmosphere interactions at Mars' polar caps.
Verification of Acuros XB dose algorithm using 3D printed low‐density phantoms for clinical photon beams
Authors: Zavan Rodolfo , McGeachy Philip , Madamesila Joseph , Villarreal‐Barajas Jose‐Eduardo , Khan Rao 
Published: March 2018

AbstractThe transport‐based dose calculation algorithm Acuros XB (AXB) has been shown to accurately account for heterogeneities primarily through comparisons with Monte Carlo simulations. This study aims to provide additional experimental verification of AXB for clinically relevant flattened and unflattened beam energies in low density phantoms of the same material. Polystyrene slabs were created using a bench‐top 3D printer. Six slabs were printed at varying densities from 0.23 to 0.68 g/cm3, corresponding to different density humanoid tissues. The slabs were used to form different single and multilayer geometries. Dose was calculated with Eclipse™ AXB 11.0.31 for 6MV, 15MV flattened and 6FFF (flattening filter free) energies for field sizes of 2 × 2 and 5 × 5 cm2. EBT3 film was inserted into the phantoms, which were irradiated. Absolute dose profiles and 2D Gamma analyses were performed for 96 dose planes. For all single slab configurations and energies, absolute dose differences between the AXB calculation and film measurements remained <3% for both fields in the high‐dose region, however, larger disagreement was seen within the penumbra. For the multilayered phantom, percentage depth dose with AXB was within 5% of discrete film measurements. The Gamma index at 2%/2 mm averaged 98% in all combinations of fields, phantoms and photon energies. The transport‐based dose algorithm AXB is in good agreement with the experimental measurements for small field sizes using 6MV, 6FFF and 15MV beams adjacent to various low‐density heterogeneous media. This work provides preliminary experimental grounds to support the use of AXB for heterogeneous dose calculation purposes.
Seronegative antibody‐mediated neurology after immune checkpoint inhibitors
Authors: Wilson Robert , Menassa David A. , Davies Alexander J. , Michael Sophia , Hester Joanna , Kuker Wilhelm , Collins Graham P. , Cossins Judith , Beeson David , Steven Neil , Maddison Paul , Rinaldi Simon , Jacob Saiju , Irani Sarosh R. 
Published: March 2018

AbstractCheckpoint inhibitor medications have revolutionized oncology practice, but frequently induce immune‐related adverse events. During autoimmune neurology practice over 20 months, we prospectively identified four patients with likely antibody‐mediated neurological diseases after checkpoint inhibitors: longitudinally extensive transverse myelitis, Guillain–Barré syndrome, and myasthenia gravis. All patients shared three characteristics: symptoms commenced 4 weeks after drug administration, responses to conventional immunotherapies were excellent, and autoantibodies traditionally associated with their syndrome were absent. However, serum immunoglobulins from the myelitis and Guillain–Barré syndrome patients showed novel patterns of tissue reactivity. Vigilance is required for antibody‐mediated neurology after checkpoint inhibitor administration. This phenomenon may inform the immunobiology of antibody‐mediated diseases.
Estimation of intrathecal IgG synthesis: simulation of the risk of underestimation
Authors: Bonnan Mickael , Gianoli‐Guillerme Mariana , Courtade Henri , Demasles Stéphanie , Krim Elsa , Marasescu Raluca , Dréau Hervé , Debeugny Stéphane , Barroso Bruno 
Published: March 2018

AbstractObjectiveThe low level of passively diffused IgG through the blood–brain barrier is sufficient to blur the estimation of intrathecal IgG synthesis (ITS). Therefore, this estimation requires a mathematical calculation derived from empirical laws, but the range of normal values in healthy controls is wide enough to prevent a precise calculation. This study investigated the precision of various methods of ITS estimations and their application to two clinical situations: plasma exchange and immune suppression targeting ITS.MethodsBased on a mathematical model of ITS, we constructed a population of healthy controls and applied a tunable ITS.ResultsWe demonstrate the following results: underestimation of ITS is common at individual level but true ITS is well fitted by cohorts; QIgG increases after plasma exchange; IgGLoc calculation based on Qlim falsely increases when QAlb decreases; the sample size required to demonstrate a decrease in ITS increases exponentially with larger QAlb.InterpretationStudies evaluating changes in ITS level should be adjusted to QAlb. Low amounts of ITS could be largely underestimated.
Determining One‐Year Trajectories of Low‐Back–Related Leg Pain in Primary Care Patients: Growth Mixture Modeling of a Prospective Cohort Study
Authors: Ogollah Reuben O. , Konstantinou Kika , Stynes Siobhán , Dunn Kate M. 
Published: March 2018

ObjectiveThe clinical presentation and outcome of patients with back and leg pain in primary care are heterogeneous and may be better understood by identification of homogeneous and clinically meaningful subgroups. Subgroups of patients with different back pain trajectories have been identified, but little is known about the trajectories for patients with back‐related leg pain. This study sought to identify distinct leg pain trajectories, and baseline characteristics associated with membership of each group, in primary care patients.MethodsMonthly data on leg pain intensity were collected over 12 months for 609 patients participating in a prospective cohort study of adult patients seeking health care for low‐back and leg pain, including sciatica, of any duration and severity, from their general practitioner. Growth mixture modeling was used to identify clusters of patients with distinct leg pain trajectories. Trajectories were characterized using baseline demographic and clinical examination data. Multinomial logistic regression was used to predict latent class membership, with a range of covariates.ResultsFour patient clusters were identified: improving mild pain (58%), persistent moderate pain (26%), persistent severe pain (13%), and improving severe pain (3%). Clusters showed statistically significant differences in a number of baseline characteristics.ConclusionFour trajectories of leg pain were identified. Clusters 1, 2, and 3 were generally comparable to back pain trajectories, while cluster 4, with major improvement in pain, is infrequently identified. Awareness of such distinct patient groups improves understanding of the course of leg pain and may provide a basis of classification for intervention.
A modular adaptive control design with ISS analysis for nonminimum phase hypersonic vehicle models
Authors: Mannava A. , Serrani A. 
Published: March 2018

SummaryAir‐breathing hypersonic vehicles typically exhibit a nonminimum phase behavior when altitude is controlled via lift generation. This phenomenon prohibits the use of classical inversion‐based control techniques. Dynamic models of these vehicles are also subject to parametric uncertainties and unmodeled dynamics related to flexible effects of the fuselage. In this paper, we present a modular adaptive control method that achieves asymptotic setpoint tracking in both airspeed and altitude using thrust and elevator deflection as the only control inputs for a generic longitudinal model of a hypersonic cruise. The nonminimum phase problem is overcome through output redefinition, with altitude controlled by pitching moment. The internal dynamics, flight path angle, and altitude are then stabilized by saturating the interconnections and exploiting local stability properties. A new technique for the use of saturation functions in error coordinate is presented. The adaptive controller for altitude uses a pitch rate observer combined with projection. This control augmentation decouples the parameter estimation errors from internal dynamics, allowing for the use of small‐gain arguments. Simulation results from a vehicle model with flexible effects and parametric uncertainty are included to demonstrate control effectiveness.
A model reference tracking based on an active fault tolerant control for LPV systems
Authors: Rabaoui B. , Rodrigues M. , Hamdi H. , BenHadj Braiek N. 
Published: March 2018

SummaryThis work deals with the problem of a model reference tracking based on the design of an active fault tolerant control for linear parameter‐varying systems affected by actuator faults and unknown inputs. Linear parameter‐varying systems are described by a polytopic representation with measurable gain scheduling functions. The main contribution is to design an active fault tolerant controller whose control law is described by an adaptive proportional integral structure. This one requires 3 types of online information, which are reference outputs, measured real outputs, and the fault estimation provided by a model reference, sensors, and an adaptive polytopic observer, respectively. These types of information are used to reconfigure the designed controller, which is able to compensate the fault effects and to make the closed‐loop system able to track reference outputs in spite of the presence of actuator faults and disturbances. The controller and the observer gains are obtained by solving a set of linear matrices inequalities. Performances of the proposed method are compared to another previous method to underline the relevant results.
Molecular Fluorescence and Photoacoustic Imaging in the Second Near‐Infrared Optical Window Using Organic Contrast Agents
Authors: Jiang Yuyan , Pu Kanyi 
Published: March 2018

AbstractNoninvasive near‐infrared (NIR) light ranging from 650 to 1000 nm (NIR‐I) is widely employed in fundamental research and clinical applications; however, a recently discovered second NIR (NIR‐II) window from 1000 to 1700 nm exhibits even better deep‐tissue imaging capability due to reduced photon scattering, minimized tissue autofluorescence, and increased applicable power at longer wavelengths. This review focuses on recent advances of organic contrast agents developed for in vivo fluorescence and photoacoustic imaging in the NIR‐II optical window. The superiority of the NIR‐II over the NIR‐I window for molecular imaging is first discussed in detail, followed by discussion of fluorescence and photoacoustic imaging of cancer, vasculature, and the brain using organic contrast agents in the NIR‐II window. At last, challenges and perspectives of organic contrast agents for NIR‐II in vivo imaging are suggested.
Making Ultrafast High‐Capacity Anodes for Lithium‐Ion Batteries via Antimony Doping of Nanosized Tin Oxide/Graphene Composites
Authors: Zoller Florian , Peters Kristina , Zehetmaier Peter M. , Zeller Patrick , Döblinger Markus , Bein Thomas , Sofer Zdeneˇk , Fattakhova‐Rohlfing Dina 
Published: March 2018

AbstractTin oxide‐based materials attract increasing attention as anodes in lithium‐ion batteries due to their high theoretical capacity, low cost, and high abundance. Composites of such materials with a carbonaceous matrix such as graphene are particularly promising, as they can overcome the limitations of the individual materials. The fabrication of antimony‐doped tin oxide (ATO)/graphene hybrid nanocomposites is described with high reversible capacity and superior rate performance using a microwave assisted in situ synthesis in tert‐butyl alcohol. This reaction enables the growth of ultrasmall ATO nanoparticles with sizes below 3 nm on the surface of graphene, providing a composite anode material with a high electric conductivity and high structural stability. Antimony doping results in greatly increased lithium insertion rates of this conversion‐type anode and an improved cycling stability, presumably due to the increased electrical conductivity. The uniform composites feature gravimetric capacity of 1226 mAh g−1 at the charging rate 1C and still a high capacity of 577 mAh g−1 at very high charging rates of up to 60C, as compared to 93 mAh g−1 at 60C for the undoped composite synthesized in a similar way. At the same time, the antimony‐doped anodes demonstrate excellent stability with a capacity retention of 77% after 1000 cycles.