bluuebunny/crossref_metadata_2025_split huggingface dataset:
Auroral wave structures and ballooning instabilities in the plasma sheet
Authors: Xing Xiaoyan , Liang Jun , Spanswick Emma , Lyons Larry , Angelopoulos Vassilis 
Published: October 2013

AbstractAuroral wavelike structures extended in the east‐west direction along preexisting arcs are often observed to precede the auroral poleward expansions initiated along that arc. These wave structures are suggested to be the manifestation of ballooning/interchange instabilities in the near‐Earth plasma sheet that may play crucial roles in leading to substorm expansion. The triggering and the development of the ballooning instability in the MHD regime can be evaluated with theory and numerical simulations; however, observations have never shown how these instabilities are initiated in the plasma sheet. In order to examine the instability triggering, we take advantage of the THEMIS ground all‐sky‐imagers and NORSTAR‐NASCAM multiwavelength imagers together with a multi‐spacecraft conjunction to identify the auroral wave structures and to examine the dynamics in the plasma sheet. We show in a case study that the MHD ballooning instability criterion is violated near X = −11 RE in the plasma sheet starting about 1.5 min prior to the initiation of the auroral wave structures. The estimated Alfvénic transit time is slightly larger than 1 min, indicating that the observed auroral signatures are correlated with the ballooning instability developing in the plasma sheet and propagating to the ionosphere along field lines. Magnetic field wavelet analysis shows the initiation of the perpendicular disturbances between 0.01 and 0.02 Hz correlated with the calculated onset of the instability perturbations at the same location, supporting the identification of the localized ballooning instability. At the more tailward region of X ~ −13 RE, enhanced earthward transport toward the unstable region are observed several minutes prior to the instability initiation, which may have modified the pressure spatial distribution and magnetic field topology in the near‐Earth region, leading to the violation of the instability criterion. The further development of the instability may play a crucial role for the aurora explosive expansion.
First results from CSSWE CubeSat: Characteristics of relativistic electrons in the near‐Earth environment during the October 2012 magnetic storms
Authors: Li X. , Schiller Q. , Blum L. , Califf S. , Zhao H. , Tu W. , Turner D. L. , Gerhardt D. , Palo S. , Kanekal S. , Baker D. N. , Fennell J. , Blake J. B. , Looper M. , Reeves G. D. , Spence H. 
Published: October 2013

AbstractMeasurements from the Relativistic Electron and Proton Telescope integrated little experiment (REPTile) on board the Colorado Student Space Weather Experiment (CSSWE) CubeSat mission, which was launched into a highly inclined (65°) low Earth orbit, are analyzed along with measurements from the Relativistic Electron and Proton Telescope (REPT) and the Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the Van Allen Probes, which are in a low inclination (10°) geo‐transfer‐like orbit. Both REPT and MagEIS measure the full distribution of energetic electrons as they traverse the heart of the outer radiation belt. However, due to the small equatorial loss cone (only a few degrees), it is difficult for REPT and MagEIS to directly determine which electrons will precipitate into the atmosphere, a major radiation belt loss process. REPTile, a miniaturized version of REPT, measures the fraction of the total electron population that has small enough equatorial pitch angles to reach the altitude of CSSWE, 480 km × 780 km, thus measuring the precipitating population as well as the trapped and quasi‐trapped populations. These newly available measurements provide an unprecedented opportunity to investigate the source, loss, and energization processes that are responsible for the dynamic behavior of outer radiation belt electrons. The focus of this paper will be on the characteristics of relativistic electrons measured by REPTile during the October 2012 storms; also included are long‐term measurements from the Solar Anomalous and Magnetospheric Particle Explorer to put this study into context.
Diffuse elastic wavefield within a simple crustal model. Some consequences for low and high frequencies
Authors: García‐Jerez Antonio , Luzón Francisco , Sánchez‐Sesma Francisco J. , Lunedei Enrico , Albarello Dario , Santoyo Miguel A. , Almendros Javier 
Published: October 2013

AbstractThe reliability of usual assumptions regarding the wavefield composition in applications of the Diffuse Field Approach (DFA) to passive seismic prospecting is investigated. Starting from the more general formulation of the DFA for full wavefield (FW), the contribution of each wave to the horizontal‐ and vertical‐component power spectra at surface are analyzed for a simple elastic waveguide representing the continental crust‐upper mantle interface. Special attention is paid to their compositions at low and high frequencies, and the relative powers of each surface wave (SW) type are identified by means of a semianalytical analysis. If body waves are removed from the analysis, the high‐frequency horizontal asymptote of the H/V spectral ratio decreases slightly (from 1.33 for FW to around 1.14 for SW) and shows dependence on both the Poisson's ratio of the crust and the S wave velocity contrast (while FW‐H/V asymptote depends on the former only). Experimental tests in a local broadband network provide H/V curves compatible with any of these values in the band 0.2–1 Hz, approximately, supporting the applicability of the DFA approximation. Coexistence of multiple SW modes produces distortion in the amplitudes of vertical and radial component Aki's coherences, in comparison with the usual predictions based on fundamental modes. At high frequencies, this effect consists of a decrement by a constant scaling factor, being very remarkable in the radial case. Effects on the tangential coherence are severe, including a − π/4 phase shift, slower decay rate of amplitude versus frequency, and contribution of several velocities for large enough distances.
Hidden aftershocks of the 2011Mw9.0 Tohoku, Japan earthquake imaged with the backprojection method
Authors: Kiser Eric , Ishii Miaki 
Published: October 2013

AbstractThe first 25 h of the aftershock sequence following the 11 March 2011Mw9.0 Tohoku, Japan earthquake is investigated using a backprojection method. In total, 600 aftershocks are imaged during this time period. These aftershocks are distributed over a 500 by 300 km area and include many events in the outer rise. The backprojection events are compared with the Japan Meteorological Agency (JMA) catalogue, which is composed of earthquakes recorded by local seismic networks in Japan. Surprisingly, half of the backprojection events are not found in the JMA catalogue. These events cluster near the Japan Trench and in the outer rise and fill in gaps in the spatial distribution of the early aftershock sequence where large main shock slip is thought to have occurred. These results show that the JMA magnitude of completeness is very high near the trench following the 2011 Tohoku main shock, and earthquakes as large as magnitude 6.8 went undetected by local seismic networks.
The Sm:YAG primary fluorescence pressure scale
Authors: Trots Dmytro M. , Kurnosov Alexander , Ballaran Tiziana Boffa , Tkachev Sergey , Zhuravlev Kirill , Prakapenka Vitali , Berkowski Marek , Frost Daniel J. 
Published: October 2013

AbstractPrimary pressure determinations involve the measurement of pressure without recourse to secondary standard materials. These measurements are essential for ensuring the accuracy of pressures measured in gasketed high‐pressure devices. In this study, the wavelength of optical fluorescence bands and the density of single crystal Sm‐doped yttrium aluminum garnet Y3Al5O12 (Sm:YAG) have been calibrated as a primary pressure scale up to 58 GPa. Absolute pressures were obtained by integrating the bulk modulus determined via Brillouin spectroscopy with respect to volumes measured simultaneously by X‐ray diffraction. A third‐order Birch‐Murnaghan equation of state of Sm:YAG yields V0 = 1735.15(26) Å3, KT0 = 185(1.5) GPa, and K` = 4.18(5). The accompanied pressure‐induced shifts of the fluorescence lines Y1 and Y2 of Sm:YAG were calibrated to the primary pressure, thus creating a highly accurate fluorescence pressure scale. These shifts are described as P = (A/B) * {[1 + (Δλ/λ0)]B − 1} with A = 2089.91(23.04), B = −4.43(1.07) for Y1, and A = 2578.22(48.70), B = −15.38(1.62) for Y2 bands, where ∆λ = λ − λ0, λ and λ0 are wavelengths in nanometer at pressure and ambient conditions. The sensitivity in the pressure determination of the Sm:YAG fluorescence shift is 0.32 nm/GPa, which is identical to that of the ruby scale. Sm:YAG can be considered elastically isotropic up to 58 GPa, implying insensitivity of the determined pressure to the crystallographic orientation under nonhydrostatic or quasi‐hydrostatic conditions. The Sm:YAG fluorescence shift is apparently also independent of crystallographic orientation, in contrast to that of ruby. Since the Y fluorescence band of Sm:YAG is insensitive to temperature changes, this material is highly suitable for the measurement of pressure at elevated temperatures.
Extension fracture propagation in rocks with veins: Insight into the crack‐seal process using Discrete Element Method modeling
Authors: Virgo Simon , Abe Steffen , Urai Janos L. 
Published: October 2013

AbstractWe investigate how existing veins interact with extension fractures in rocks using 3‐D Discrete Element Method models with a geometry inspired by tension tests with notched samples. In a sensitivity study, we varied (a) the angle between the vein and the bulk extension direction and (b) the strength ratio between host rock and vein material. Results show a range of vein‐fracture interactions, which fall into different, robust, “structural styles.” Veins, which are weaker than the host rock, tend to localize fracturing into the vein, even at high‐misorientation angles. Veins, which are stronger than the host rock, cause deflection of the fracture tip along the vein‐host rock interface. Fractures are arrested at the interface from weak to stronger material. When propagating from a stronger to a weaker material, macroscopic bifurcation of the fracture is common. Complex interactions are favored by a low angle between the vein and the fracture and by high‐strength contrast. The structural styles in the models show good agreement with microstructures and mesostructures of crack‐seal veins found in natural systems. We propose that these structural styles form the basis for criteria to recognize strength contrasts and stress of crack‐seal systems in nature.
SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounders
Authors: Tegtmeier S. , Hegglin M. I. , Anderson J. , Bourassa A. , Brohede S. , Degenstein D. , Froidevaux L. , Fuller R. , Funke B. , Gille J. , Jones A. , Kasai Y. , Krüger K. , Kyrölä E. , Lingenfelser G. , Lumpe J. , Nardi B. , Neu J. , Pendlebury D. , Remsberg E. , Rozanov A. , Smith L. , Toohey M. , Urban J. , von Clarmann T. , Walker K. A. , Wang R. H. J. 
Published: October 2013

AbstractA comprehensive quality assessment of the ozone products from 18 limb‐viewing satellite instruments is provided by means of a detailed intercomparison. The ozone climatologies in form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I/II/III, UARS‐MLS, HALOE, POAM II/III, SMR, OSIRIS, MIPAS, GOMOS, SCIAMACHY, ACE‐FTS, ACE‐MAESTRO, Aura‐MLS, HIRDLS, and SMILES within 1978–2010. The intercomparisons focus on mean biases of annual zonal mean fields, interannual variability, and seasonal cycles. Additionally, the physical consistency of the data is tested through diagnostics of the quasi‐biennial oscillation and Antarctic ozone hole. The comprehensive evaluations reveal that the uncertainty in our knowledge of the atmospheric ozone mean state is smallest in the tropical and midlatitude middle stratosphere with a 1σ multi‐instrument spread of less than ±5%. While the overall agreement among the climatological data sets is very good for large parts of the stratosphere, individual discrepancies have been identified, including unrealistic month‐to‐month fluctuations, large biases in particular atmospheric regions, or inconsistencies in the seasonal cycle. Notable differences between the data sets exist in the tropical lower stratosphere (with a spread of ±30%) and at high latitudes (±15%). In particular, large relative differences are identified in the Antarctic during the time of the ozone hole, with a spread between the monthly zonal mean fields of ±50%. The evaluations provide guidance on what data sets are the most reliable for applications such as studies of ozone variability, model‐measurement comparisons, detection of long‐term trends, and data‐merging activities.
The potential of commercial microwave networks to monitor dense fog‐feasibility study
Authors: David N. , Alpert P. , Messer H. 
Published: October 2013

AbstractHere we show the potential for dense fog monitoring using existing measurements from wireless communication systems. Communication networks widely deploy commercial microwave links across the terrain at ground level. Operating at frequencies of tens of gigahertz, they are affected by fog and are, practically, an existing, sensor network, spatially distributed worldwide, which can provide crucial information about fog concentration and visibility. The goal of this paper is to show the feasibility for fog identification and intensity estimation. A method is proposed and is demonstrated by two cases of heavy fog that took place in Israel. During these events, fog covered wide areas (tens of kilometers) and caused severe decrease in visibility, dropping as low as several tens of meters. Liquid water content and visibility values were estimated using measurements from tens of microwave links deployed in the observed area for each event. Each of the links provided a single measurement which was taken simultaneously across all of the links in the system. The values were found to be in the range of 0.5–0.8 gr/m3, high concentration values that match the maximum value range observed in field measurements carried out for prior studies in different test areas in the world. The visibility ranges calculated, between 30 and 70 m, fit the visibility assessments from the specialized measuring equipment operating in the observed area at the same time. These results point to the strong potential of the proposed technique.
Unhindered Spatial Processing During Route Memorization is Required to Maximize Both Spatial and Verbal Route Knowledge
Authors: van Doorn Robert R. A. , Blokland Arjan 
Published: October 2013

SummaryTo successfully remember a route in a physical environment, individuals are believed to process and store both verbal and spatial information of that route. The present study tested whether both spatial and verbal contents are necessary to form an effective route memory. For that purpose, route learning was performed in three concurrent task conditions (spatial, verbal and control) and appraised at two moments in time, via three route memory tests (spatial, verbal and spatial–verbal). Results showed that route memory generally improved across time and that spatial information was remembered better than verbal information. The concurrent spatial condition resulted in lower retention scores of both spatial and verbal route knowledge. These results suggest that effective spatial processing forms a scaffold without which long‐term retention lacks detail of both spatial and verbal route knowledge. It is discussed how these findings add to understanding spatial memory of routes. Copyright © 2013 John Wiley & Sons, Ltd.
Misleading Suggestions can Alter Later Memory Reports even Following a Cognitive Interview
Authors: LaPaglia Jessica A. , Wilford Miko M. , Rivard Jillian R. , Chan Jason C. K. , Fisher Ronald P. 
Published: October 2013

SUMMARYTaking an immediate recall test prior to misinformation exposure can increase eyewitness suggestibility—a finding termed retrieval‐enhanced suggestibility. Here, we examined whether retrieval‐enhanced suggestibility would occur when participants were administered an immediate Cognitive Interview (CI). The CI is an investigative interviewing technique that consistently elicits more correct details in memory reports than standard interviews. In this study, participants watched a video of a crime and then completed a distractor task (control condition), a free recall test, or the CI. They then heard misinformation presented in a narrative. Participants produced more accurate memory details in the CI than in free recall despite spending equal time on both tasks. However, the CI also increased the later report of misinformation relative to the control condition. These results show that initial retrieval can increase subsequent suggestibility even when such retrieval occurs under relatively ideal conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Background Sound Impairs Interruption Recovery in Dynamic Task Situations: Procedural Conflict?
Authors: Hodgetts Helen M. , Vachon François , Tremblay Sébastien 
Published: October 2013

SummaryInterruptions impair performance even on simple, static, laboratory‐based tasks, but little research has looked at their impact in more complex and realistic settings that involve dynamically evolving circumstances and other environmental stressors. Using a radar operator task with or without background sound, participants were unexpectedly interrupted to complete another task, which masked the radar screen as the scenario continually evolved. Task efficiency was impaired by interruption: decision‐making time was slower immediately following interruption, this cost being greater and persevered longer in the presence of auditory distraction. Resumption time was also increased with distraction. Eye fixation durations were shorter following interruption, reflecting participants' attempts to rapidly re‐encode and update their model of the situation. These results suggest that those processes involved in task resumption are also susceptible to background sound, and indicate a need for theories of task interruption to better specify the role of attention in interruption recovery. Copyright © 2013 John Wiley & Sons, Ltd.
Taking Charge of Systemic Sclerosis: A Pilot Study to Assess the Effectiveness of an Internet Self‐Management Program
Authors: Poole Janet L. , Mendelson Cindy , Skipper Betty , Khanna Dinesh 
Published: October 2013

ObjectiveTo assess the effects of an internet self‐management program for systemic sclerosis on self‐efficacy, health efficacy, and management of care, pain, fatigue, functional ability, and depression.MethodsParticipants logged on to a password‐protected web site and completed modules and learning activities at their own pace over 10 weeks. Participants were encouraged to log on to the discussion board, participate in an interactive component of the web site, and respond to questions posted for each module. Participants completed pre‐ and postintervention questionnaires on perceived self‐efficacy, health efficacy, ability to manage care, functional disability, depression, pain, and fatigue. They also completed an 8‐question evaluation form regarding satisfaction with the web site, program content, discussion boards, and learning activities.ResultsSixteen participants completed the study and postintervention measures. There were significant improvements in mean scores for ability to manage care (effect size [ES] 0.62, P = 0.025) and health efficacy (ES 0.72, P = 0.012), and significant decreases in fatigue (ES −0.55, P = 0.045) and depression (ES −0.71, P = 0.013). Self‐efficacy improved, but not significantly. The evaluation of the program revealed mean scores ranging from 4.2 (web site was visually appealing) to 4.9 (information presented clearly) on a 5‐point scale, where 5 is most satisfied.ConclusionThese findings from this pilot study suggest that a self‐management program delivered using an internet format can lead to statistically significant changes in health efficacy and management of care, fatigue, and depression. These results need to be confirmed with a larger randomized controlled trial with a longer followup period.
Nonlinear Optical Bioinspired Peptide Nanostructures
Authors: Handelman Amir , Lavrov Sergey , Kudryavtsev Andrei , Khatchatouriants Artium , Rosenberg Yuri , Mishina Elena , Rosenman Gil 
Published: October 2013

A nonlinear optical effect of a second harmonic generation (SHG) was first observed in quartz and then found in many inorganic materials that have an asymmetric crystalline structure. Second‐order nonlinear responses were also found in organic and biomaterials and are exploited for fundamental studies of helical and chiral biological molecules, such as proteins and amyloid fibrils. Another class of biomaterials is man‐made bioinspired nanostructures, which are composed of chemically synthesized biomolecules and are self‐assembled into supramolecular nanofibrils. Most of these materials have an asymmetric crystalline structure and possess ferroelectric and related phenomena. Here, the SHG effect is studied in bio‐organic peptide nanostructures of different morphologies and symmetries. These nanostructures are self‐assembled in different solvents from peptide precursors with a variable number of phenylalanine (F) amino acid units. A pronounced SHG response is detected in FFF‐nanobelts, FF‐nanotubes, and FFF‐nanospheres. SHG and Raman spectroscopy studies during phase transformation in FF‐nanotubes allow the definition of the intermolecular bonds responsible for SHG. Using two‐photon optical microscopy, orientational molecular ordering in aligned peptide supramolecular structures is found by adapting a generic model developed earlier for diverse biological protein fibrils. Efficient optical frequency conversion from NIR to green and blue light is demonstrated, as well as an effect of nonlinear optical waveguiding. These results suggest these bioinspired nanostructures as promising for a new generation of nonlinear optical nanomaterias, which can be integrated into nanophotonic devices.
Stereoretentive Copper(II)‐Catalyzed Ritter Reactions of Secondary Cycloalkanols
Authors: Al‐huniti Mohammed H. , Lepore Salvatore D. 
Published: October 2013

AbstractA Ritter‐like coupling reaction of cyclic alcohols and both aryl and alkyl nitriles to form amides catalyzed by copper(II) triflate is described. These reactions proceed in good yields under mild and often solvent‐free conditions. With 2‐ and 3‐substituted cycloalkanols, amide products are formed with near complete retention of configuration. This is likely due to fast nucleophilic capture of non‐planar carbocations (hyperconjomers) stabilized by ring hyperconjugation. A critical aspect of this novel catalytic cycle is the in situ activation of the alcohol substrates by thionyl chloride to form chlorosulfites.magnified image