bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ice water content‐extinction relationships and effective diameter for TTL cirrus derived from in situ measurements during ATTREX 2014
Authors: Thornberry Troy D. , Rollins Andrew W. , Avery Melody A. , Woods Sarah , Lawson R. Paul , Bui Thaopaul V. , Gao Ru‐Shan 
Published: March 2017

AbstractThe NASA Airborne Tropical Tropopause Experiment (ATTREX) deployment in January–March 2014 yielded more than 34 h of cirrus cloud sampling in the tropical tropopause layer (TTL) over the western Pacific. Cirrus were encountered throughout the TTL, at temperatures between 185 and 207 K, with ice water content (IWC) ranging from >10 mg m−3 to below the instrumental detection limit of 1 μg m−3. Geometric optical extinction (σ) values determined from cloud particle probe measurements ranged from 10−3 m−1 to <10−7 m−1. The median effective diameter (Deff) for cirrus sampled at T > 192 K was 40–50 μm and exhibited a weak temperature dependence, while colder than 192 K, Deff decreased more strongly with decreasing T. From the ATTREX data, a new parameterization of the IWC‐σ relationship for TTL cirrus is derived that will improve the estimation of IWC from lidar and optical probe observations of these clouds.
Spatiotemporal evolution of a severe winter dust event in the western Mediterranean: Aerosol optical and physical properties
Authors: Titos G. , Ealo M. , Pandolfi M. , Pérez N. , Sola Y. , Sicard M. , Comerón A. , Querol X. , Alastuey A. 
Published: March 2017

AbstractAn outstanding Saharan dust event affected the Iberian Peninsula during winter 2016 (20 to 25 February). The impact of this event on ambient PM10 surface levels and its spatial and temporal evolution was investigated by means of data from 250 air quality stations across mainland Spain and the Balearic Islands. The event had a significant impact on surface PM10 levels, and on 22 February, 90% of the air quality monitoring sites registered PM10 concentrations above the EU daily limit value of 50 μg/m3. The study of the attenuated backscattering vertical profiles associated with African dust evidenced a complex structure, with a thick aerosol layer that was at higher altitudes over the pre‐Pyrenees compared to the coastal area of Barcelona but closer to the surface than typically observed at both sites. Optical and physical properties of dust particles were investigated at the continental background Global Atmosphere Watch mountain observatory of Montsec (MSA) in the pre‐Pyrenees. Good agreement was found between in situ and passive remote sensing methodologies once the aloft dust layer reached the MSA station. Scattering Ångström exponent values decreased to values close to zero (even below zero for surface in situ measurements) indicating the predominance of coarse particles. On the contrary, absorption Ångström exponent values increased during the Saharan dust outbreak denoting an absorption enhancement at shorter wavelengths, characteristic of mineral dust particles. Furthermore, the performance of NMMB/BSC‐Dust and BSC‐DREAM8b models has been qualitatively evaluated for the dust spatial distribution across Spain and the vertical structure over MSA and Barcelona showing good agreement.
On the use of self‐organizing maps for studying climate extremes
Authors: Gibson Peter B. , Perkins‐Kirkpatrick Sarah E. , Uotila Petteri , Pepler Acacia S. , Alexander Lisa V. 
Published: March 2017

AbstractUnderstanding how climate extremes are sensitive to a changing climate requires characterization of the physical mechanisms behind such events. For this purpose, the application of self‐organizing maps (SOMs) has become popular in the climate science literature. One potential drawback, though not unique to SOMs, is that the background synoptic conditions represented by SOMs may be too generalized to adequately describe the atypical conditions that can co‐occur during the extreme event being considered. In this paper, using the Australian region as a case study, we illustrate how the commonly used SOM training procedure can be readily modified to produce both more accurate patterns and patterns that would otherwise occur too rarely to be represented in the SOM. Even with these improvements, we illustrate that without careful treatment, the synoptic conditions that co‐occur during some types of extreme events (i.e., heavy rainfall and midlatitudinal cyclone occurrence days) risk being poorly represented by the SOM patterns. In contrast, we find that during Australian heat wave events the circulation is indeed well represented by the SOM patterns and that this application can provide additional insight to composite analysis. While these results should not necessarily discourage researchers seeking to apply SOMs to study climate extremes, they highlight the importance of first critically evaluating the features represented by the SOM. This study has provided a methodological framework for such an evaluation which is directly applicable to other weather typing procedures, regions, and types of extreme events.
The 12 September 2016ML5.8 midcrustal earthquake in the Korean Peninsula and its seismic implications
Authors: Hong Tae‐Kyung , Lee Junhyung , Kim Woohan , Hahm In‐Kyeong , Woo Nam Chil , Park Seongjun 
Published: March 2017

AbstractThe seismicity in the Korean Peninsula has increased since the 2011Mw9.0 Tohoku‐Oki megathrust earthquake. Two strike‐slip earthquakes with magnitudes ofML5.1 and 5.8 occurred in the southeastern Korean Peninsula on 12 September 2016. The two events occurred within 48 min. TheML5.8 earthquake was the largest event in the Korean Peninsula since 1978 when national seismic monitoring began. Both events produced strong high‐frequency ground motions. More than 500 aftershocks with local magnitudes greater than or equal to 1.5 followed the events for 2 months. An unreported subsurface strike‐slip fault with a dip of 65° to the east and a strike of N27°E was responsible for the earthquakes. The fault ruptured at depths of 11–16 km, resulting in a rupture plane of ∼26 km2. The aftershock distribution displayed horizontal streaks at a depth of ∼14 km, which was consistent with the focal mechanism solutions from long‐period waveform inversion. The number of aftershocks decreased exponentially with time. The twoML5.1 and 5.8 earthquakes produced regional Coulomb stress changes of −4.9 to 2.5 bar. The spatial distribution of the aftershocks correlated with the Coulomb stress changes. The peak dynamic stress induced by strong ground motions reached 14.2 bar. The groundwater levels changed coseismically in some regions of decreased static stresses. The earthquakes on previously unidentified faults raised attention for the potential seismic hazards by earthquakes with long recurrence intervals.
Two‐dimensional magnetotelluric inversion using reflection seismic data as constraints and application in the COSC project
Authors: Yan Ping , Kalscheuer Thomas , Hedin Peter , Garcia Juanatey Maria A. 
Published: March 2017

AbstractWe present a novel 2‐D magnetotelluric (MT) inversion scheme, in which the local weights of the regularizing smoothness constraints are based on the envelope attribute of a reflection seismic image. The weights resemble those of a previously published seismic modification of the minimum gradient support method. We measure the directional gradients of the seismic envelope to modify the horizontal and vertical smoothness constraints separately. Successful application of the inversion to MT field data of the Collisional Orogeny in the Scandinavian Caledonides (COSC) project using the envelope attribute of the COSC reflection seismic profile helped to reduce the uncertainty of the interpretation of the main décollement by demonstrating that the associated alum shales may be much thinner than suggested by a previous inversion model. Thus, the new model supports the proposed location of a future borehole COSC‐2 which is hoped to penetrate the main décollement and the underlying Precambrian basement.
An 8 month slow slip event triggers progressive nucleation of the 2014 Chile megathrust
Authors: Socquet Anne , Valdes Jesus Piña , Jara Jorge , Cotton Fabrice , Walpersdorf Andrea , Cotte Nathalie , Specht Sebastian , Ortega‐Culaciati Francisco , Carrizo Daniel , Norabuena Edmundo 
Published: March 2017

AbstractThe mechanisms leading to large earthquakes are poorly understood and documented. Here we characterize the long‐term precursory phase of the 1 April 2014 Mw8.1 North Chile megathrust. We show that a group of coastal GPS stations accelerated westward 8 months before the main shock, corresponding to a Mw6.5 slow slip event on the subduction interface, 80% of which was aseismic. Concurrent interface foreshocks underwent a diminution of their radiation at high frequency, as shown by the temporal evolution of Fourier spectra and residuals with respect to ground motions predicted by recent subduction models. Such ground motions change suggests that in response to the slow sliding of the subduction interface, seismic ruptures are progressively becoming smoother and/or slower. The gradual propagation of seismic ruptures beyond seismic asperities into surrounding metastable areas could explain these observations and might be the precursory mechanism eventually leading to the main shock.
A positive correlation between energetic electron butterfly distributions and magnetosonic waves in the radiation belt slot region
Authors: Yang Chang , Su Zhenpeng , Xiao Fuliang , Zheng Huinan , Wang Yuming , Wang Shui , Spence H. E. , Reeves G. D. , Baker D. N. , Blake J. B. , Funsten H. O. 
Published: March 2017

AbstractEnergetic (hundreds of keV) electrons in the radiation belt slot region have been found to exhibit the butterfly pitch angle distributions. Resonant interactions with magnetosonic and whistler‐mode waves are two potential mechanisms for the formation of these peculiar distributions. Here we perform a statistical study of energetic electron pitch angle distribution characteristics measured by Van Allen Probes in the slot region during a 3 year period from May 2013 to May 2016. Our results show that electron butterfly distributions are closely related to magnetosonic waves rather than to whistler‐mode waves. Both electron butterfly distributions and magnetosonic waves occur more frequently at the geomagnetically active times than at the quiet times. In a statistical sense, more distinct butterfly distributions usually correspond to magnetosonic waves with larger amplitudes and vice versa. The averaged magnetosonic wave amplitude is less than 5 pT in the case of normal and flat‐top distributions with a butterfly index BI =1 but reaches ∼50–95 pT in the case of distinct butterfly distributions with BI >1.3. For magnetosonic waves with amplitudes >50 pT, the occurrence rate of butterfly distribution is above 80%. Our study suggests that energetic electron butterfly distributions in the slot region are primarily caused by magnetosonic waves.
Spacecraft measurements constraining the spatial extent of a magnetopause reconnection X line
Authors: Walsh B. M. , Komar C. M. , Pfau‐Kempf Y. 
Published: March 2017

AbstractMultispacecraft measurements from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission are used to probe the spatial extent of an X line at the dayside magnetopause. A case study from 21 April 2014 is presented where two THEMIS spacecraft have a near‐simultaneous encounter with the equatorial dayside magnetopause separated by 3.9 Earth radii. Both spacecraft observe similar steady inflow conditions with southward interplanetary magnetic field and a high magnetic shear angle at the magnetopause (133°) boundary. One spacecraft observes clear fluid and kinetic signatures of active magnetic reconnection, while the other spacecraft does not observe reconnection. The predicted location of reconnection across the magnetopause is found using several theoretical models and a Block Adaptive Tree Solarwind Roe‐type Upwind Scheme (BATS‐R‐US) MHD simulation. Each model predicts a continuous X line passing close to the two spacecraft, suggesting both would observe reconnection, if active. Using the constraints of the multipoint measurements, the extent or length L of the reconnection is estimated to be 2.4≤L < 5.2 h in local time or 6≤L< 14 RE.
Identification of photovoltaic arrays' maximum power extraction point via dynamic regressor extension and mixing
Authors: Pyrkin Anton , Mancilla‐David Fernando , Ortega Romeo , Bobtsov Alexey , Aranovskiy Stanislav 
Published: March 2017

SummaryThis paper deals with the problem of identification of photovoltaic arrays' maximum power extraction point—information that is encrypted in the current‐voltage characteristic equation. We propose a new parameterisation of the classical 5 parameter models of this function that, combined with the recently introduced identification technique of dynamic regressor extension and mixing, ensures a fast and accurate estimation of all unknown parameters. A concavity property of the current‐voltage characteristic equation is then exploited to directly identify the desired voltage operating point. Realistic numerical examples via computer simulations are presented to assess the performance of the proposed approach.
Palladium‐Nanoparticles‐Catalyzed Oxidative Annulation of Benzamides with Alkynes for the Synthesis of Isoquinolones
Authors: Sharma Nidhi , Saha Rajib , Parveen Naziya , Sekar Govindasamy 
Published: March 2017

AbstractA novel method to synthesize isoquinolones via oxidative annulation of N‐alkoxy benzamides and alkynes using binaphthyl‐stabilized palladium nanoparticles (Pd‐BNP) as catalyst has been developed. This methodology affords various isoquinolone derivatives in good to excellent yields with high regioselectivities in the presence of air as oxidant. N‐Methoxybenzothioamide was also found to undergo oxidative annulation with alkyne successfully and provided a sulfur analogue of isoquinolones in moderate yields. The Pd‐BNP catalyst was easily recovered and reused up to four times without any apparent agglomeration.magnified image
Hypervalent Iodine‐Promoted Aromatization of Exocyclic β‐Enaminones for the Synthesis of meta‐N,N‐Diarylaminophenols
Authors: Bhattacherjee Dhananjay , Thakur Vandna , Shil Arun K. , Das Pralay 
Published: March 2017

AbstractA metal‐ and additive‐free milder cascade approach for the synthesis of meta‐N,N‐diarylaminophenols (DAAP) starting from exocyclic β‐enaminones has been developed. The feasibility of the process is rationalized by the suitable molecular geometry of β‐enaminones for tandem N‐arylative α‐iodination and aromatization under milder basic conditions. Furthermore, the developed strategy has been extended to the synthesis of meta‐N‐benzyl‐N‐arylaminophenols (BAAP). 4‐Ethylpropionyl‐2‐cyclohexenone has been explored to give 7‐diarylaminochroman‐2‐one (DAAC) by employing a similar one‐pot approach. The plausible mechanistic steps were deduced based upon isolation of a stable intermediate and structural identification through X‐ray crystallographic analysis.magnified image
Depression Among Transgender Older Adults: General and Minority Stress
Authors: Hoy‐Ellis Charles P. , Fredriksen‐Goldsen Karen I. 
Published: March 2017

AbstractThis study aims to (a) examine the direct and indirect effects internalized heterosexism, disclosure of gender identity, and perceived general stress in association with depression among transgender older adults; and (b) to assess the relative contribution of each relationship. Secondary analyses of data from a large community‐based study of older sexual and gender minorities were conducted utilizing structural equation modeling with a subsample (n = 174) of transgender adults aged 50 to 86‐years old. Disclosure of gender identity had no significant direct or indirect effects on either perceived general stress or depression. Internalized heterosexism did not have a direct effect on depression, but did have a significant indirect effect through perceived general stress. Finally, perceived general stress had an additional significant direct effect on depression, over and above internalized heterosexism. Total effect sizes appear to be considerable with standardized betas greater than 5.0. Perceived general stress and internalized heterosexism independently and cumulatively have significant direct and indirect effects on depression among transgender older adults. Implications for depression among transgender older adults and the role of community psychology are discussed.
Nitroarenes as the Nitrogen Source in Intermolecular Palladium‐Catalyzed Aryl C–H Bond Aminocarbonylation Reactions
Authors: Zhou Fei , Wang Duo‐Sheng , Guan Xinyu , Driver Tom G. 
Published: March 2017

AbstractA three‐component palladium‐catalyzed aminocarbonylation of aryl and heteroaryl sp2 C−H bonds using nitroarenes as the nitrogen source was achieved using Mo(CO)6 as the reductant and origin of the CO. This intermolecular C−H bond functionalization does not requires any exogenous ligand to be added, and our mechanism experiments indicate that the palladacycle catalyst serves two roles in the aminocarbonylation reaction: reduce the nitroarene to a nitrosoarene and activate the sp2 C−H bond.
Biocatalysis in Silicon Chemistry
Authors: Frampton Mark B. , Zelisko Paul M. 
Published: March 2017

AbstractThe application of biocatalytic or chemoenzymatic techniques in silicon chemistry serves two roles: it provides a greater understanding of the processing of silicon species by natural systems, such as plants, diatoms, and sponges, as well opening up avenues to green methodologies in the field. In the latter case, biocatalytic approaches have been applied to the synthesis of small‐molecule systems and polymeric materials. Often these biocatalytic approaches allow access to molecular structures under mild conditions and, in some cases, molecular structures that are not accessible through traditional chemical methodologies. A review of recent advances in the applications of biocatalysis in silicon chemistry is presented.
Minimum Energy Control of Fractional Descriptor Discrete‐Time Linear Systems with Bounded Inputs Using The DRAZIN Inverse
Authors: Kaczorek Tadeusz 
Published: March 2017

AbstractThe Drazin inverse of matrices is applied to solve the minimum energy control problem of fractional descriptor discrete‐time linear systems with bounded inputs. Necessary and sufficient conditions for the reachability of fractional descriptor linear systems are established. The minimum energy control problem for the fractional descriptor systems with bounded inputs is formulated and solved. A procedure for the computation of the optimal inputs sequence and the minimal value of the performance index is proposed.
Central nervous system involvement of acute promyelocytic leukemia, three case reports
Authors: Furuya Aya , Kawahara Masahiro , Kumode Mina , Ohira Yasuyuki , Usui Asako , Nagai Shiho , Hosoba Sakura , Minamiguchi Hitoshi , Kito Katsuyuki , Andoh Akira 
Published: March 2017

Key Clinical MessageCentral nervous system (CNS) involvement of acute promyelocytic leukemia (APL) causes poor prognosis. Our three cases show that CNS can be involved at the first hematological recurrence, but predicting this is difficult. Triple intrathecal treatment and craniospinal irradiation were effective, while arsenic oxide failed to prevent and improve CNS involvement.
The Role of Various Chlorides on Xylose Conversion to Furfural: Experiments and Kinetic Modeling
Authors: Ershova Olga , Nieminen Kaarlo , Sixta Herbert 
Published: March 2017

AbstractIn this paper, the catalytic activity of thirteen different metal chlorides in aqueous solution for the conversion of xylose into furfural was studied in comparison with both the auto‐ and HCl‐catalyzed reactions. A maximum furfural yield of 60.3 mol % was reached with the addition of FeCl3 to the aqueous xylose solution. However, the catalytic efficiency of FeCl3 decreased on use of birch hydrolysate as a raw material, resulting in 43.5 mol % furfural yield. The obtained experimental results were incorporated in a kinetic modeling study. The assessed reaction rates for xylose dehydration to furfural and xylose decomposition to byproducts, in the presence of AlCl3 and CrCl3 are significantly higher than during acid‐catalyzed conversion. The logarithms of the reaction rates show a linear correlation with the ionization energy as well as with the acidity of the metal ions.
Enzyme‐Promoted Asymmetric Tandem Passerini Reaction
Authors: Żądło‐Dobrowolska Anna , Koszelewski Dominik , Paprocki Daniel , Madej Arleta , Wilk Monika , Ostaszewski Ryszard 
Published: March 2017

AbstractA versatile and highly efficient three‐step, one‐pot, enzyme‐promoted Passerini tandem reaction has been developed. The chemoenzymatic sequence involved simultaneous enzyme catalyzed hydrolysis, subsequent Passerini reaction, and enzymatic kinetic resolution of the Passerini product. This methodology combines the diversity delivered by multicomponent reactions with the selectivity of biocatalysts, which results in efficient synthesis of the target compounds with excellent enantiomeric excesses of up to 99 %. With a small set of substrates, a large library of complex molecules was obtained within a short time by using the developed procedure.
Catalysis of Michael Additions by Covalently Modified G‐Quadruplex DNA
Authors: Dey Surjendu , Rühl Carmen L. , Jäschke Andres 
Published: March 2017

AbstractEnantioselective catalysis utilizing G‐quadruplex DNA‐based artificial metalloenzymes has emerged as a new approach in the field of aqueous‐phase homogeneous catalysis. Recently, a catalytic asymmetric Michael addition employing a covalently modified G‐quadruplex in combination with CuII ions has been reported. Here we assess, by systematic chemical variation and using various spectrometric techniques, a variety of parameters that govern rate acceleration and stereoselectivity of the reaction, such as the position of modification, the topology of the quadruplex, the nature of the ligand, the length of the linker between ligand and DNA, the chemical identity of monovalent ions and transition metal complexes. The DNA quadruplex modified at position 10 (dU10) with hexynyl‐linked bpy ligand showed twice the initial reaction rate as compared with the DNA strand derivatized at position 12 (dU12). The strikingly different dependence of the stereoselectivity on the linker length, and their different spectroscopic properties indicate large differences in the architecture of the catalytic centers between the dU10‐derivatized and the dU12‐modified quadruplexes. Upon addition of CuII, both types of bpy‐derivatized DNA strands form defined 1:1 Cu–DNA complexes stable enough for mass spectrometric analysis, while the underivatized strands exhibit weak and unspecific binding, correlated with much lower catalytic rate acceleration. Both dU10‐ and dU12‐derivatized quadruplexes could be reused ten times without reduction of stereoselectivity.
Hydroxylated Fluorescent Dyes for Live‐Cell Labeling: Synthesis, Spectra and Super‐Resolution STED
Authors: Butkevich Alexey N. , Belov Vladimir N. , Kolmakov Kirill , Sokolov Viktor V. , Shojaei Heydar , Sidenstein Sven C. , Kamin Dirk , Matthias Jessica , Vlijm Rifka , Engelhardt Johann , Hell Stefan W. 
Published: March 2017

AbstractHydroxylated rhodamines, carbopyronines, silico‐ and germanorhodamines with absorption maxima in the range of 530–640 nm were prepared and applied in specific labeling of living cells. The direct and high‐yielding entry to germa‐ and silaxanthones tolerates the presence of protected heteroatoms and may be considered for the syntheses of various sila‐ and germafluoresceins, as well as ‐rhodols. Application in stimulated emission depletion (STED) fluorescence microscopy revealed a resolution of 50–75 nm in one‐ and two‐color imaging of vimentin‐HaloTag fused protein and native tubulin. The established structure–property relationships allow for prediction of the spectral properties and the positions of spirolactone/zwitterion equilibria for the new analogues of rhodamines, carbo‐, silico‐, and germanorhodamines using simple additive schemes.