bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated determination of magnitude and source length of large earthquakes using backprojection andPwave amplitudes
Authors: Wang Dun , Kawakatsu Hitoshi , Zhuang Jiancang , Mori Jim , Maeda Takuto , Tsuruoka Hiroshi , Zhao Xu 
Published: May 2017

AbstractFast estimates of magnitude and source extent of large earthquakes are fundamental for disaster mitigation. However, resolving these estimates within 10–20 min after origin time remains challenging. Here we propose a robust algorithm to resolve magnitude and source length of large earthquakes using seismic data recorded by regional arrays and global stations. We estimate source length and source duration by backprojecting seismic array data. Then the source duration and the maximum amplitude of the teleseismicPwave displacement waveforms are used jointly to estimate magnitude. We apply this method to 74 shallow earthquakes that occurred within epicentral distances of 30–85° to Hi‐net (2004–2014). The estimated magnitudes are similar to moment magnitudes estimated from W‐phase inversions (U.S. Geological Survey), with standard deviations of 0.14–0.19 depending on the global station distributions. Application of this method to multiple regional seismic arrays could benefit tsunami warning systems and emergency response to large global earthquakes.
Relationship between aerodynamic roughness length and bulk sedge leaf area index in a mixed‐species boreal mire complex
Authors: Alekseychik P. K. , Korrensalo A. , Mammarella I. , Vesala T. , Tuittila E.‐S. 
Published: May 2017

AbstractLeaf area index (LAI) is an important parameter in natural ecosystems, representing the seasonal development of vegetation and photosynthetic potential. However, direct measurement techniques require labor‐intensive field campaigns that are usually limited in time, while remote sensing approaches often do not yield reliable estimates. Here we propose that the bulk LAI of sedges (LAIs) can be estimated alternatively from a micrometeorological parameter, the aerodynamic roughness length for momentum (z0). z0 can be readily calculated from high‐response turbulence and other meteorological data, typically measured continuously and routinely available at ecosystem research sites. The regressions of LAI versus z0 were obtained using the data from two Finnish natural sites representative of boreal fen and bog ecosystems. LAIs was found to be well correlated with z0 and sedge canopy height. Superior method performance was demonstrated in the fen ecosystem where the sedges make a bigger contribution to overall surface roughness than in bogs.
Growth and nonlinear saturation of electromagnetic ion cyclotron waves in multi‐ion species magnetospheric plasma
Authors: Ofman L. , Denton R. E. , Bortnik J. , An X. , Glocer A. , Komar C. 
Published: May 2017

AbstractThe growth and saturation of electromagnetic ion cyclotron (EMIC) waves is essential to the magnetospheric dynamics. Determining and isolating the effects of multiple ion parameters such as temperatures, anisotropies, and relative abundances is important for quantifying these processes in the magnetospheric plasma. In order to study these process, we utilize a 2.5‐D hybrid model (where ions are modeled with the particle‐in‐cell (PIC) method, and electrons are modeled as background neutralizing fluid) to study the nonlinear electromagnetic wave‐particle interactions of hot H+, cold H+, cold He+, and cold or hot O+ ions for a broad range of typical magnetospheric parameters. The excitation of EMIC waves is driven by the temperature anisotropy of hot H+ in our model. As a result, we quantify the parametric dependence of the linear growth, the nonlinear saturation level of perpendicular magnetic fluctuations, and the temporal evolution of the ion temperature anisotropies. We establish the relation between key plasma parameters and the saturated EMIC wave power, using either power law fits or a nonlinear regression method. We construct the dispersion relation of the waves using the results of the model and investigate the energy content in the various branches of the dispersion (k∥−ω space), showing that the different modes can generate wave power in different regions of k space. We find that large O+ concentration reduces the growth and saturated amplitude of the waves; but the waves are less sensitive to the temperature of the O+ in the temperature range relevant to the magnetosphere.
Have Chinese water pricing reforms reduced urban residential water demand?
Authors: Zhang B. , Fang K. H. , Baerenklau K. A. 
Published: June 2017

AbstractChina continues to deal with severe levels of water scarcity and water pollution. To help address this situation, the Chinese central government initiated urban water pricing reforms in 2002 that emphasized the adoption of increasing block rate (IBR) price structures in place of existing uniform rate structures. By combining urban water use records with microlevel data from the Chinese Urban Household Survey, this research investigates the effectiveness of this national policy reform. Specifically, we compare household water consumption in 28 cities that adopted IBR pricing structures during 2002–2009, with that of 110 cities that had not yet done so. Based on difference‐in‐differences models, our results show that the policy reform reduced annual residential water demand by 3–4% in the short run and 5% in the longer run. These relatively modest reductions are consistent with the generous nature of the IBR pricing structures that Chinese cities have typically chosen to implement. Our results imply that more efforts are needed to address China's persistent urban water scarcity challenges.
Trimethylpentan (alle Isomere) [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated trimethylpentane (all isomers) [
564‐02‐3
,
540‐84‐1
,
560‐21‐4
,
565‐75‐3
] considering all toxicological endpoints. Available unpublished study reports and publications are described in detail.

The re‐examination determined that it is difficult to draw final conclusions from a carcinogenicity study of a mixture of 542 hydrocarbons and from mechanistical studies with some of their single components. Thus, the assignment to Carcinogen Category 3 A has been withdrawn. The critical effect is the acute effect on the central nervous system in rats. The NOAEC after 60 min inhalation is 500 ml 2,2,4‐trimethylpentane/m
3
. Experimental data from structurally analogous n‐alkanes and iso‐alkanes lead to the assumption that the concentration of 2,2,4‐trimethylpentane in the brain after 8 hours will be about twice as high as after one hour. The short half‐life in the brain, estimated to be about one hour, does not predict an accumulation during the work week. The same assumptions are made for the other trimethylpentane isomers. Thus, taking into consideration uncertainties in the extrapolation of animal to human data, a MAK value of 100 ml/m
3
(470 mg/m
3
) is set for all trimethylpentane isomers. As the critical effect is systemic, trimethylpentane isomers are assigned to Peak Limitation Category II. The excursion factor of 2 is set as the estimated half‐life in the brain is one hour. Prenatal developmental toxicity studies with trimethylpentane isomers are not available. For structurally analogous C8‐isoalkanes the NOAEC for developmental toxicity in rats is more than 1200 ml/m
3
. Acute neurotoxicity is critical, but the consequences of acute neurotoxic effects on in‐utero development of the nervous system are not known and studies on developmental neurotoxicity of C8‐alkanes are not available. Thus, trimethylpentane isomers are classified in Pregnancy Risk Group D. There are no clinical data and no data in animals concerning the sensitizing potential of trimethylpentane isomers. In analogy to n‐heptane, skin contact is not expected to contribute significantly to systemic toxicity.
3‐(3,5‐Di‐tert‐butyl‐4‐hydroxyphenyl)‐N′‐[3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propanoyl]propanhydrazid [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)‐N′‐[3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propanoyl]‐propanehydrazide [
32687‐78‐8
] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. The substance has a low toxicity after repeated oral administration to rats. It is not irritating to skin or eyes. The oral absorption is not known, but is assumed to be significantly less than 100% due to the high molecular mass; however, a MAK value could not be calculated from the oral studies. Therefore, the substance is assigned to Section II b of the List of MAK and BAT Values. No developmental toxicity was observed up to the highest dose of 3000 mg/kg body weight and day in rats. The substance is not genotoxic in vitro or in vivo. Carcinogenicity studies are not available. There are no clinical results on contact sensitization in humans and the substance is not sensitizing in two sensitization test in guinea pigs. Skin absorption was calculated to be so low that it will not contribute significantly to the systemic toxicity.
Methylacrylat [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: May 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of 5 ml/m
3
for methyl acrylate [96‐33‐3] considering the endpoints local and developmental toxicity as well as genotoxicity. Available publications and unpublished study reports are described in detail. The critical effect in a two‐year inhalation study with rats was reserve cell hyperplasia with loss of ciliated and olfactory cells in the transitional nasal epithelium at the lowest concentration of 15 ml/m
3
. In a two‐generation reproduction toxicity study with a NOAEC of 5 ml/m
3
, degeneration with regeneration of the olfactory epithelium, hyperplasia of the transitional epithelium as well as hyperplasia and hypertrophy of the goblet cells were observed. A lower confidence limit of the benchmark dose for an extra risk of 5% increase of the critical effect incidence (BMDL
05
) of 6.8 ml/m
3
as a substitute for a NOAEC was calculated from the data of the two‐year inhalation study. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. According to this approach, the MAK value for methyl acrylate has been lowered to 2 ml/m
3
. As local effects are critical, the assignment to Peak Limitation Category I and the excursion factor of 2 are confirmed, in analogy to ethyl acrylate. The NOAECs for developmental toxicity in rats and rabbits are sufficiently high so that damage to the embryo or foetus is unlikely when the MAK value is not exceeded. Thus, methyl acrylate is classified in Pregnancy Risk Group C. The substance is clastogenic in vitro but not in vivo and was not carcinogenic in a 2‐year inhalation study in rats. There are only a few cases of contact sensitization in humans but there is a positive result in a local lymph node assay. Data on airway sensitization are still not available. Methyl acrylate remains designated with “Sh”. Skin absorption was calculated to contribute significantly to the systemic toxicity and methyl acrylate is designated with an “H”.
InfraredLIDARApplications in Atmospheric Monitoring
Authors: Orr Brian J. 
Published: May 2017

AbstractThe acronym LIDAR stands for LIght Detection And Ranging, an optical analog of RADAR (RAdio Detection And Ranging). The conventional version of LIDAR requires a laser transmitter to launch short pulses of coherent light, which are scattered from atmospheric targets of interest back to an optical receiver, with a time delay that is determined by the range of the target. Optical phenomena in the Earth's atmosphere (e.g. Rayleigh scattering, Raman scattering, Mie scattering, refraction, and resonant absorption) contribute to the amplitude of optical signals returning to the receiver and their characteristic wavelength dependence allows us to measure the concentration and velocity distributions of different atmospheric molecules and aerosol particles. LIDAR backscattering in the infrared (IR) region, on which this article concentrates, is well suited to detecting aerosols (as in clouds or industrial particulate emissions). IR DIAL (DIfferential Absorption Lidar), a variant in which two or more wavelengths are used simultaneously to separate resonant molecular signals from background, enables many molecular species to be monitored by means of their IR absorption spectra. Closely related approaches comprise long‐path IR laser absorption and IPDA (Integrated Path Differential Absorption), with retroreflection from a topographic target (e.g. a strategically located mirror or a hard target, such as the ground in air‐borne applications); these approaches sacrifice optical range information but gain sensitivity because they integrate over all molecules in the optical column between the transmitter/receiver and the reflector or hard target. All of these techniques are vitally dependent on pulsed IR laser technology.
Optimization of the dosimetric leaf gap for use in planning VMAT treatments of spine SABR cases
Authors: Middlebrook Nigel D , Sutherland Bess , Kairn Tanya 
Published: June 2017

AbstractThe dosimetric leaf gap (DLG) is a beam configuration parameter used in the Varian Eclipse treatment planning system, to model the effects of rounded MLC leaf ends. Measuring the DLG using the conventional sliding‐slit technique has been shown to be produce questionable results for some volumetric modulated arc therapy (VMAT) treatments. This study therefore investigated the use of radiochromic film measurements to optimize the DLG specifically for the purpose of producing accurate VMAT plans using a flattening‐filter‐free (FFF) beam, for use in treating vertebral targets using a stereotactic (SABR, also known as SBRT) fractionation schedule. Four test treatments were planned using a VMAT technique, to deliver a prescription of 24 Gy in 3 fractions to four different spine SABR treatment sites. Measurements of the doses delivered by these treatments were acquired using an ionization chamber and radiographic film. These measurements were compared with the doses calculated by the treatment planning system using a range of DLG values, including a DLG identified using the conventional sliding‐slit method (1.1 mm). An optimal DLG value was identified, as the value that produced the closest agreement between the planned and measured doses (1.9 mm). The accuracy of the dose calculations produced using the optimized DLG value was verified using additional radiochromic film measurements in a heterogeneous phantom. This study provided a specific initial DLG (1.9 mm) as well as a film‐based optimization method, which may be used by radiotherapy centers when attempting to commission or improve an FFF VMAT‐based SABR treatment programme.
Selective Recognition of Acidic Amino Acids in Water by Calixpyridinium
Authors: Wang Kui , Cui Jian‐Hua , Xing Si‐Yang , Ren Xiao‐Wei 
Published: May 2017

AbstractHighly selective recognition of acidic amino acids, such as glutamic acid and aspartic acid, by a positively charged calixpyridinium is reported. The complexation behavior of the calixpyridinium host towards a dipeptide containing the glutamic acid residue and a glutamic acid metabolite is also described.
Prediction of Extremely Strong Antiferromagnetic Superexchange in Silver(II) Fluorides: Challenging the Oxocuprates(II)
Authors: Kurzydłowski Dominik , Grochala Wojciech 
Published: May 2017

AbstractStrong magnetic coupling between the spins of unpaired electrons is an essential ingredient of many fascinating physical phenomena. Here we report calculations using the hybrid HSE06 functional of magnetic superexchange constants, J, for a series of low‐dimensional CuII and AgII binary and ternary systems with fluoride and oxide ligands. The calculations correctly reproduce the sign and size of the magnetic superexchange constants for prototypical antiferromagnetic (AFM) 1D (J1D) and 2D (J2D) systems, while overestimating the absolute values of J by about 11 %. We find that [AgF][BF4], a quasi‐1D system with linear infinite [AgIIF+] chains, is predicted to exhibit an unprecedented strong AFM superexchange via one atom (F), with J1D about −300 meV. Compression of [AgF][BF4] to 10 GPa should lead to a further increase in AFM interactions with J1D reaching −360 meV at 10 GPa.
Specific Enhancement of Catalytic Activity by a Dicopper Core: Selective Hydroxylation of Benzene to Phenol with Hydrogen Peroxide
Authors: Tsuji Tomokazu , Zaoputra Antonius Andre , Hitomi Yutaka , Mieda Kaoru , Ogura Takashi , Shiota Yoshihito , Yoshizawa Kazunari , Sato Hiroyasu , Kodera Masahito 
Published: May 2017

AbstractA dicopper(II) complex, stabilized by the bis(tpa) ligand 1,2‐bis[2‐[bis(2‐pyridylmethyl)aminomethyl]‐6‐pyridyl]ethane (6‐hpa), [Cu2(μ‐OH)(6‐hpa)]3+, was synthesized and structurally characterized. This complex catalyzed selective hydroxylation of benzene to phenol using H2O2, thus attaining large turnover numbers (TONs) and high H2O2 efficiency. The TON after 40 hours for the phenol production exceeded 12000 in MeCN at 50 °C under N2, the highest value reported for benzene hydroxylation with H2O2 catalyzed by homogeneous complexes. At 22 % benzene conversion, phenol (95.2 %) and p‐benzoquinone (4.8 %) were produced. The mechanism of H2O2 activation and benzene hydroxylation is proposed.
Structurally Diverse Boron–Nitrogen Heterocycles from an N2O23− Formazanate Ligand
Authors: Barbon Stephanie M. , Staroverov Viktor N. , Gilroy Joe B. 
Published: May 2017

AbstractFive new compounds comprised of unprecedented boron–nitrogen heterocycles have been isolated from a single reaction of a potentially tetradentate N2O23− formazanate ligand with BF3⋅OEt2 and NEt3. Optimized yields for each product were obtained through variation of experimental conditions and rationalized in terms of relative Gibbs free energies of the products as determined by electronic structure calculations. Chemical reduction of two of these compounds resulted in the formation of a stable anion, radical anion, and diradical dianion. Structural and electronic properties of this new family of redox‐active heterocycles were characterized using UV/vis absorption spectroscopy, cyclic voltammetry and X‐ray crystallography.
Iron‐Catalyzed Cyclotrimerization of Terminal Alkynes by Dual Catalyst Activation in the Absence of Reductants
Authors: Brenna Davide , Villa Matteo , Gieshoff Tim N. , Fischer Fabian , Hapke Marko , Jacobi von Wangelin Axel 
Published: May 2017

AbstractCatalyzing C−C bond‐forming reactions with earth‐abundant metals under mild conditions is at the heart of sustainable synthesis. The cyclotrimerization of alkynes is a valuable atom‐efficient reaction in organic synthesis that is enabled by several metal catalysts, including iron. This study reports an effective iron‐catalyzed cyclotrimerization for the regioselective synthesis of 1,2,4‐substituted arenes (1 mol % catalyst, toluene, 20 °C, 5 min). A dual activation mechanism (substrate deprotonation, reductive elimination) renders the simple FeII precatalyst highly active in the absence of any reductant.
Optical Communication among Oscillatory Reactions and Photo‐Excitable Systems: UV and Visible Radiation Can Synchronize Artificial Neuron Models
Authors: Gentili Pier Luigi , Giubila Maria Sole , Germani Raimondo , Romani Aldo , Nicoziani Andrea , Spalletti Anna , Heron B. Mark 
Published: May 2017

AbstractNeuromorphic engineering promises to have a revolutionary impact in our societies. A strategy to develop artificial neurons (ANs) is to use oscillatory and excitable chemical systems. Herein, we use UV and visible radiation as both excitatory and inhibitory signals for the communication among oscillatory reactions, such as the Belousov–Zhabotinsky and the chemiluminescent Orban transformations, and photo‐excitable photochromic and fluorescent species. We present the experimental results and the simulations regarding pairs of ANs communicating by either one or two optical signals, and triads of ANs arranged in both feed‐forward and recurrent networks. We find that the ANs, powered chemically and/or by the energy of electromagnetic radiation, can give rise to the emergent properties of in‐phase, out‐of‐phase, anti‐phase synchronizations and phase‐locking, dynamically mimicking the communication among real neurons.
Chemoselective Modification of Vinyl DNA by Triazolinediones
Authors: Naik Anu , Alzeer Jawad , Triemer Therese , Bujalska Anna , Luedtke Nathan W. 
Published: May 2017

AbstractA new method for the post‐synthetic modification of nucleic acids was developed that involves mixing a phenyl triazolinedione (PTAD) derivative with DNA containing a vinyl nucleobase. The resulting reactions proceeded through step‐wise mechanisms, giving either a formal [4+2] cycloaddition product, or, depending on the context of nucleobase, PTAD addition along with solvent trapping to give a secondary alcohol in water. Catalyst‐free addition between PTAD and the terminal alkene of 5‐vinyl‐2′‐deoxyuridine (VdU) was exceptionally fast, with a second‐order rate constant of 2×103 m−1 s−1. PTAD derivatives selectively reacted with VdU‐containing oligonucleotides in a conformation‐selective manner, with higher yields observed for G‐quadruplex versus duplex DNA. These results demonstrate a new strategy for copper‐free bioconjugation of DNA that can potentially be used to probe nucleic acid conformations in cells.
A Rapid Total Synthesis of Ciprofloxacin Hydrochloride in Continuous Flow
Authors: Lin Hongkun , Dai Chunhui , Jamison Timothy F. , Jensen Klavs F. 
Published: May 2017

AbstractWithin a total residence time of 9 min, the sodium salt of ciprofloxacin was prepared from simple building blocks via a linear sequence of six chemical reactions in five flow reactors. Sequential offline acidifications and filtrations afforded ciprofloxacin and ciprofloxacin hydrochloride. The overall yield of the eight‐step sequence was 60 %. No separation of intermediates was required throughout the synthesis when a single acylation reaction was applied to remove the main byproduct, dimethylamine.