bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution processes of a group of equatorial plasma bubble (EPBs) simultaneously observed by ground‐based and satellite measurements in the equatorial region of China
Authors: Sun Longchang , Xu Jiyao , Wang Wenbin , Yuan Wei , Zhu Yajun 
Published: April 2017

AbstractThis paper for the first time reports conjugate observations of a group of evolving equatorial plasma bubbles (EPBs) generated in the longitudinal sector of China on 4/5 November 2013 using simultaneous airglow and Communication/Navigation Outage Forecasting System (C/NOFS) observations. The airglow depletion structures seen by two all‐sky airglow imagers had the same zonal wavelength as that of the longitudinally periodic electron density depletions observed by the C/NOFS satellite which occurred at almost the same time but at magnetically conjugate latitudes. Data from a VHF radar and a Digisonde were combined to investigate the evolution of the EPB group, including their generation, development, and dissipation. Results indicate that the EPB group developed from the bottomside large‐scale wave‐like structure (LSWS) at about 195–210 km height with a characteristic zonal wavelength and longitudinal extension of about 450 km and 2250 km, respectively. The EPB group also caused periodic bottomside type spread F associated with the LSWS. We found that the development of the EPB group and their associated spread F could be limited by the equatorward motion of equatorial ionization anomaly (EIA) and the southwestward motion of an extremely bright airglow region (SMEBAR). The SMEBAR is a newly discovered structure of plasma density increase but not a plasma blob reported before. Both EIA and SMEBAR could feed high plasma density into an EPB airglow depletion structure that was eventually seen as a bright airglow structure or disappeared. Meanwhile, spread F associated with the EPBs did not evolve from the bottomside type into the strong range type.
New DMSP database of precipitating auroral electrons and ions
Authors: Redmon Robert J. , Denig William F. , Kilcommons Liam M. , Knipp Delores J. 
Published: April 2017

AbstractSince the mid‐1970s, the Defense Meteorological Satellite Program (DMSP) spacecraft have operated instruments for monitoring the space environment from low Earth orbit. As the program evolved, so have the measurement capabilities such that modern DMSP spacecraft include a comprehensive suite of instruments providing estimates of precipitating electron and ion fluxes, cold/bulk plasma composition and moments, the geomagnetic field, and optical emissions in the far and extreme ultraviolet. We describe the creation of a new public database of precipitating electrons and ions from the Special Sensor J (SSJ) instrument, complete with original counts, calibrated differential fluxes adjusted for penetrating radiation, estimates of the total kinetic energy flux and characteristic energy, uncertainty estimates, and accurate ephemerides. These are provided in a common and self‐describing format that covers 30+ years of DMSP spacecraft from F06 (launched in 1982) to F18 (launched in 2009). This new database is accessible at the National Centers for Environmental Information and the Coordinated Data Analysis Web. We describe how the new database is being applied to high‐latitude studies of the colocation of kinetic and electromagnetic energy inputs, ionospheric conductivity variability, field‐aligned currents, and auroral boundary identification. We anticipate that this new database will support a broad range of space science endeavors from single observatory studies to coordinated system science investigations.
Bayesian spectral analysis of chorus subelements from the Van Allen Probes
Authors: Crabtree Chris , Tejero Erik , Ganguli Gurudas , Hospodarsky George B. , Kletzing Craig A. 
Published: April 2017

AbstractWe develop a Bayesian spectral analysis technique that calculates the probability distribution functions of a superposition of wave modes each described by a linear growth rate, a frequency, and a chirp rate. The Bayesian framework has a number of advantages, including (1) reducing the parameter space by integrating over the amplitude and phase of the wave, (2) incorporating the data from each channel to determine the model parameters such as frequency which leads to high‐resolution results in frequency and time, (3) the ability to consider the superposition of waves where the wave parameters are closely spaced, (4) the ability to directly calculate the expectation value of wave parameters without resorting to ensemble averages, and (5) the ability to calculate error bars on model parameters. We examine one rising‐tone chorus element in detail from a disturbed time on 14 November 2012 using burst mode waveform data of the three components of the electric and magnetic field from the EMFISIS instrument on board NASA's Van Allen Probes. The results demonstrate that subelements are likely composed of almost linear waves that are nearly parallel propagating with continuously changing wave parameters such as frequency and wave vector. Between subelements the wave parameters of the dominant mode undergoes a discrete change in frequency and wave vector. Near the boundary of subelements multiple waves are observed such that the evolution of the waves is reminiscent of wave‐wave processes such as parametric decay or nonlinear induced scattering by particles. These nonlinear processes may affect the saturation of the whistler mode chorus instability.
Regional differences of the ionospheric response to the July 2012 geomagnetic storm
Authors: Kuai Jiawei , Liu Libo , Lei Jiuhou , Liu Jing , Zhao Biqiang , Chen Yiding , Le Huijun , Wang Yungang , Hu Lianhuan 
Published: April 2017

AbstractThe July 2012 geomagnetic storm is an extreme space weather event in solar cycle 24, which is characterized by a southward interplanetary geomagnetic field lasting for about 30 h below −10 nT. In this work, multiple instrumental observations, including electron density from ionosondes, total electron content (TEC) from Global Positioning System, Jason‐2, and Gravity Recovery and Climate Experiment, and the topside ion concentration observed by the Defense Meteorological Satellite Program spacecraft are used to comprehensively present the regional differences of the ionospheric response to this event. In the Asian‐Australian sector, an intensive negative storm is detected near longitude ~120°E on 16 July, and in the topside ionosphere the negative phase is mainly existed in the equatorial region. The topside and bottomside TEC contribute equally to the depletion in TEC, and the disturbed electric fields make a reasonable contribution. On 15 July, the positive storm effects are stronger in the Eastside than in the Westside. The topside TEC make a major contribution to the enhancement in TEC for the positive phases, showing the important role of the equatorward neutral winds. For the American sector, the equatorial ionization anomaly intensification is stronger in the Westside than in the Eastside and shows the strongest feature in the longitude ~110°W. The combined effects of the disturbed electric fields, composition disturbances, and neutral winds cause the complex storm time features. Both the topside ion concentrations and TEC reveal the remarkable hemispheric asymmetry, which is mainly resulted from the asymmetry in neutral winds and composition disturbances.
Viscous dissipation in a flow with power law, temperature‐dependent rheology: Application to channeled lava flows
Authors: Filippucci Marilena , Tallarico Andrea , Dragoni Michele 
Published: April 2017

AbstractThe cooling and the dynamics of a lava flowing down an inclined channel under the effect of the gravity force is studied through the finite volume method, taking into account the effect of viscous dissipation in the heat equation. The considered rheology is shear thinning and temperature dependent. The numerical solution is tested in order to verify the independence from the mesh. The dynamic and heat problems are addressed obtaining both the stationary and the transient solution. Results indicate that, considering viscous dissipation in the heat equation, a fluid with temperature‐dependent nonlinear viscosity is faster and hotter with respect to the case in which viscous dissipation is neglected. The most important effect of viscous dissipation is on the solid boundaries where the fluid warms up, and the use of a variable Reynolds number allowed us to conclude that areas in which the flow is in the laminar regime and areas in which the flow is in the turbulent regime can coexist inside the fluid. This behavior seems independent of the channel shape and can explain the observed warming back after the initial cooling in the lava flow lobes emplacement on Kilauea Volcano.
Mineralogical and transport controls on the evolution of porous media texture using direct numerical simulation
Authors: Molins Sergi , Trebotich David , Miller Gregory H. , Steefel Carl I. 
Published: April 2017

AbstractThe evolution of porous media due to mineral dissolution and precipitation can change the bulk properties of subsurface materials. The pore‐scale structure of the media, including its physical and mineralogical heterogeneity, exerts controls on porous media evolution via transport limitations to reactive surfaces and mineral accessibility. Here we explore how these controls affect the evolution of the texture in porous media at the pore scale. For this purpose, a pore‐scale flow and reactive transport model is developed that explicitly tracks mineral surfaces as they evolve using a direct numerical simulation approach. Simulations of dissolution in single‐mineral domains provide insights into the transport controls at the pore scale, while the simulation of a fracture surface composed of bands of faster‐dissolving calcite and slower‐dissolving dolomite provides insights into the mineralogical controls on evolution. Transport‐limited conditions at the grain‐pack scale may result in unstable evolution, a situation in which dissolution is focused in a fast‐flowing, fast‐dissolving path. Due to increasing velocities, the evolution in these regions is like that observed under conditions closer to strict surface control at the pore scale. That is, grains evolve to have oblong shapes with their long dimensions aligning with the local flow directions. Another example of an evolving reactive transport regime that affects local rates is seen in the evolution of the fracture surface. As calcite dissolves, the diffusive length between the fracture flow path and the receding calcite surfaces increases. Thus, the calcite dissolution reaction becomes increasingly limited by diffusion.
A Cross‐sectional population‐based investigation into behavioral change in amyotrophic lateral sclerosis: subphenotypes, staging, cognitive predictors, and survival
Authors: Burke Tom , Pinto‐Grau Marta , Lonergan Katie , Bede Peter , O'Sullivan Meabhdh , Heverin Mark , Vajda Alice , McLaughlin Russell L. , Pender Niall , Hardiman Orla 
Published: April 2017

AbstractObjectiveAmyotrophic Lateral Sclerosis (ALS) is a clinically heterogeneous neurodegenerative disorder associated with cognitive and behavioral impairment. The primary aim of this study was to identify behavioral subphenotypes in ALS using a custom designed behavioral assessment tool (Beaumont Behavioural Inventory, BBI). Secondary aims were to (1) investigate the predictive nature of cognitive assessment on behavioral change, (2) report the behavioral profile associated with the C9orf72 expansion, (3) categorize behavioral change through disease staging, and (4) to investigate the relationship between cross‐sectional behavioral classification and survival.MethodsA cross‐sectional population‐based research design was applied to examine behavioral data from ALS patients (n = 317) and healthy controls (n = 66). Patients were screened for the C9orf72 repeat expansion. A subcohort of ALS patients completed an extensive cognitive assessment battery (n = 65), to investigate predictors of behavior change. Principal component analysis (PCA) determined factors associated with altered behavior. Survival data were extracted from the Irish ALS register.ResultsNo behavioral changes were reported in 180 patients (57%); 95 patients had mild‐moderate behavioral change (30%); 42 patients met the cut‐off for Clinically Severe Behavioral Change (13%), suggestive of a bvFTD diagnosis. The most frequently endorsed behaviors in ALS were reduced concern for hygiene (36.8%), irritability (36.2%), new unusual habits (33.4%), and increased apathy (31.1%). Five independent factors were identified through factor analysis. Social cognitive performance was predictive of behavior change (P = 0.031), yielding an R2 = 0.188. Behavioral categorization (mild/moderate/severe) at the time of assessment was not associated with survival (P = 0.198).InterpretationThese data imply the presence of distinct subphenotypes of behavioral change in ALS, which most likely reflect subcategories of extramotor network disruption.
Gold(I)‐Catalyzed Enantioselective Synthesis of Tetrahydrocarbazoles through Dearomative [4+2] Cycloadditions of 3/2‐Substituted 2/3‐Vinylindoles
Authors: Pirovano Valentina , Borri Micol , Abbiati Giorgio , Rizzato Silvia , Rossi Elisabetta 
Published: April 2017

AbstractThe gold‐catalyzed synthesis of tetrahydrocarbazoles through dearomative [4+2] cycloaddition reactions of 3/2‐substituted 2/3‐vinylindoles with allenamides is reported. In particular, we optimized the enantioselective variant of these cycloadditions. Using allenamides as dienophiles 3‐substituted 2‐vinylindoles gave the corresponding carbazoles with high chemo‐, regio‐ and enantioselectivity. Good results were obtained also with 2‐methyl 3‐vinylindoles even if mixtures of (Z) and (E) isomers were isolated in high er and in excellent overall yields.magnified image
Iron oxide nanoparticles decorated oleic acid for high colloidal stability
Authors: Lai Chin Wei , Low Foo Wah , Tai Mun Foong , Abdul Hamid Sharifah Bee 
Published: April 2017

AbstractIn the present study, oleic acid (OA)‐decorated magnetite nanoparticles (MNPs) were synthesized via in situ co‐precipitation method using ammonium hydroxide as a precipitating agent. This study aims to determine the optimum loading amount of OA for improving the MNPs colloidal stability. Based on our results obtained, it was found that the zeta potential values of MNPs increased from −29.8 to −58.1 mV after modification of MNPs with 1.2 wt.% of OA. Indeed, results obtained clearly to show that a maximum colloidal stability of MNPs in a basic medium could be significantly improved. As a result, this resultant colloidal suspension performance was approximately 7 times higher (21 days‐ high colloidal stability against precipitation and agglomeration) than that of the undecorated MNPs sample (3 days). Based on vibrating sample magnetometer (VSM) analysis, the resultant OA‐decorated MNPs exhibited superparamagnetic behavior with slightly lower saturation magnetization (51–69 emu/g) than that of undecorated MNPs sample (80 emu/g) at room temperature. This behavior was attributed to the sufficient carboxylate ions from the outer layer of the bilayer of OA‐decorated MNPs, which promoted the high colloidal stability performance.
Optimierte Bindungsdauer am Zielenzym: Typ‐I‐Inhibitoren der p38α‐MAP‐Kinase mit verbesserter Bindungskinetik durch direkte Interaktion mit der R‐Spine
Authors: Wentsch Heike K. , Walter Niklas M. , Bührmann Mike , Mayer‐Wrangowski Svenja , Rauh Daniel , Zaman Guido J. R. , Willemsen‐Seegers Nicole , Buijsman Rogier C. , Henning Melanie , Dauch Daniel , Zender Lars , Laufer Stefan 
Published: April 2017

AbstractVor kurzem wurde mit Skepinone‐L ein p38α‐MAP‐Kinase‐Inhibitor mit hoher Potenz und ausgezeichneter Selektivität in vitro und in vivo beschrieben. Der Bindemodus dieser Substanzklasse entspricht allerdings dem eines ATP‐kompetitiven Typ‐I‐Inhibitors mit kurzer Verweildauer am Enzym. Nun wurde Skepinone‐L zu den ersten Typ‐I
‐Inhibitoren der p38α‐MAP‐Kinase weiterentwickelt. Typ‐I
‐Inhibitoren stören den Aufbau der R‐Spine, induzieren einen Glycin‐Flip und besetzen beide hydrophobe Bindetaschen, die hydrophobe Region I und II. Dieses Konzept führte zu Inhibitoren mit verlängerter Verweildauer am Enzym, die sowohl die aktive als auch die inaktive Kinase binden. Des Weiteren kennzeichnet sie eine herausragende Selektivität gegenüber anderen Kinasen sowie eine ausgezeichnete Wirkung am isolierten Enzym. Darüber hinaus reicht ihre Hemmwirkung in einem humanen Vollblut‐Assay bis tief in den nanomolaren Bereich. Dieser neue Bindemodus konnte röntgenkristallographisch belegt werden.
Symmetry Breaking in Pyrrolo[3,2‐b]pyrroles: Synthesis, Solvatofluorochromism and Two‐photon Absorption
Authors: Łukasiewicz Łukasz G. , Ryu Hye Gun , Mikhaylov Alexander , Azarias Cloé , Banasiewicz Marzena , Kozankiewicz Bolesław , Ahn Kyo Han , Jacquemin Denis , Rebane Aleksander , Gryko Daniel T. 
Published: April 2017

AbstractFive centrosymmetric and one dipolar pyrrolo[3,2‐b]pyrroles, possessing either two or one strongly electron‐withdrawing nitro group have been synthesized in a straightforward manner from simple building blocks. For the symmetric compounds, the nitroaryl groups induced spontaneous breaking of inversion symmetry in the excited state, thereby leading to large solvatofluorochromism. To study the origin of this effect, the series employed peripheral structural motifs that control the degree of conjugation via altering of dihedral angle between the 4‐nitrophenyl moiety and the electron‐rich core. We observed that for compounds with a larger dihedral angle, the fluorescence quantum yield decreased quickly when exposed to even moderately polar solvents. Reducing the dihedral angle (i.e., placing the nitrobenzene moiety in the same plane as the rest of the molecule) moderated the dependence on solvent polarity so that the dye exhibited significant emission, even in THF. To investigate at what stage the symmetry breaking occurs, we measured two‐photon absorption (2PA) spectra and 2PA cross‐sections (σ2PA) for all six compounds. The 2PA transition profile of the dipolar pyrrolo[3,2‐b]pyrrole, followed the corresponding one‐photon absorption (1PA) spectrum, which provided an estimate of the change of the permanent electric dipole upon transition, ≈18 D. The nominally symmetric compounds displayed an allowed 2PA transition in the wavelength range of 700–900 nm. The expansion via a triple bond resulted in the largest peak value, σ2PA=770 GM, whereas altering the dihedral angle had no effect other than reducing the peak value two‐ or even three‐fold. In the S0→S1 transition region, the symmetric structures also showed a partial overlap between 2PA and 1PA transitions in the long‐wavelength wing of the band, from which a tentative, relatively small dipole moment change, 2–7 D, was deduced, thus suggesting that some small symmetry breaking may be possible in the ground state, even before major symmetry breaking occurs in the excited state.
Evaluation of a transportation system employing autonomous vehicles
Authors: Lam Stanley , Taghia Javad , Katupitiya Jay 
Published: April 2017

SummaryThe problem of studying public transportation systems with autonomous vehicles is challenging because of behavioral differences that make existing models poorly fit and the technical difficulties involved in studying large autonomous systems operating on a grand scale. In this paper, we propose the following: (i) an autonomous transportation network setting; (ii) a method for modeling autonomous vehicles in simulation; and (iii) a high‐performance simulation platform that allows analysis and visualization of transportation technologies. Results from microsimulation confirm theoretical benefits and improvements from employing autonomous systems in an example setting and highlight the platform's general ability to allow researchers to implement novel transportation systems and study the cost benefit variations occurring between them. Copyright © 2017 John Wiley & Sons, Ltd.
Continuous desalting of refolded protein solution improves capturing in ion exchange chromatography: A seamless process
Authors: Walch Nicole , Jungbauer Alois 
Published: April 2017

AbstractTruly continuous biomanufacturing processes enable an uninterrupted feed stream throughout the whole production without the need for holding tanks. We have utilized microporous anion and cation exchangers into which only salts, but not proteins, can penetrate into the pores for desalting of protein solutions, while diafiltration or dilution is usually employed for feed adjustments. Anion exchange and cation exchange chromatography columns were connected in series to remove both anions and cations. To increase operation performance, a continuous process was developed comprised of four columns. Continuous mode was achieved by staggered cycle operation, where one set of columns, consisting of one anion exchange and one cation exchange column, was loaded during the regeneration of the second set. Refolding, desalting and subsequent ion exchange capturing with a scFv as the model protein was demonstrated. The refolding solution was successfully desalted resulting in a consistent conductivity below 0.5 mS/cm from initial values of 10 to 11 mS/cm. With continuous operation process time could be reduced by 39% while productivity was increased to 163% compared to batch operation. Desalting of the protein solution resulted in up to 7‐fold higher binding capacities in the subsequent ion exchange capture step with conventional protein binding resins.
Rapid in vitro screening for the location‐dependent effects of unnatural amino acids on protein expression and activity
Authors: Schinn Song‐Min , Bradley William , Groesbeck Ashtyn , Wu Jeffrey C. , Broadbent Andrew , Bundy Bradley C. 
Published: April 2017

ABSTRACTThe incorporation of unnatural amino acids (uAA) can introduce novel functional groups into proteins site‐specifically, with important applications in basic sciences and protein engineering. However, uAA incorporation can impact protein expression and functional activity depending on its location within the protein—a process that is not yet completely understood and difficult to predict. Therefore, practical applications often necessitate a time‐consuming optimization of uAA location by individual gene cloning, expressions, purification, and evaluations for each location tested. To address this limitation, we introduce a streamlined and versatile in vitro system to rapidly express and screen uAA‐containing proteins without cumbersome cell culturing or purification procedures. We utilized this technology to simultaneously screen 24 different t4‐lysozyme mutants with different uAA incorporation sites in a matter of hours, compared to weeks‐long workflow of conventional methods. Screening data offered a mechanistic explanation to some effects of uAA incorporation on expression and activity. Despite these insights, rational prediction of such effects remained challenging, further confirming the value of a rapid screening approach. Biotechnol. Bioeng. 2017;114: 2412–2417. © 2017 Wiley Periodicals, Inc.