bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion beams in the plasma sheet boundary layer
Authors: Birn J. , Hesse M. , Runov A. , Zhou X.‐Z. 
Published: August 2015

AbstractWe explore characteristics of energetic particles in the plasma sheet boundary layer associated with dipolarization events, based on simulations and observations. The simulations use the electromagnetic fields of an MHD simulation of magnetotail reconnection and flow bursts as basis for test particle tracing. They are complemented by self‐consistent fully electrodynamic particle‐in‐cell (PIC) simulations. The test particle simulations confirm that crescent‐shaped earthward flowing ion velocity distributions with strong perpendicular anisotropy can be generated as a consequence of near‐tail reconnection, associated with earthward flows and propagating magnetic field dipolarization fronts. Both PIC and test particle simulations show that the ion distribution in the outflow region close to the reconnection site also consist of a beam superposed on an undisturbed population, which, however, does not show strong perpendicular anisotropy. This suggests that the crescent shape is created by quasi‐adiabatic deformation from ion motion along the magnetic field toward higher field strength. The simulation results compare favorably with “Time History of Events and Macroscale Interactions during Substorms” observations.
A case study of typhoon‐induced gravity waves and the orographic impacts related to Typhoon Mindulle (2004) over Taiwan
Authors: Wu J. F. , Xue X. H. , Hoffmann L. , Dou X. K. , Li H. M. , Chen T. D. 
Published: August 2015

AbstractAtmospheric gravity waves (GWs) significantly influence global circulation. Deep convection, particularly that associated with typhoons, is believed to be an important source of gravity waves. Stratospheric gravity waves induced by Typhoon Mindulle (2004) were detected by the Atmospheric Infrared Sounder (AIRS). Semicircular GWs with horizontal wavelengths of 100–400 km were found over Taiwan through an inspection of AIRS radiances at 4.3 μm. Characteristics of the stratospheric gravity waves generated by Typhoon Mindulle were investigated using the Weather Research and Forecasting (WRF) model. The initial and boundary data were determined by the high‐resolution European Center for Medium‐Range Weather Forecasts reanalysis data. The WRF simulation reproduces the main features of Typhoon Mindulle and the significant GWs. The simulated GWs with horizontal wavelengths of 100–400 km match the AIRS observations: they propagate upward and eastward, and the westward components are mostly filtered in the stratosphere. By comparing the measured waves with a WRF simulation in the absent of orography (WRF‐FLAT), we find that the orographic gravity waves (OGWs) generated by the flow of Typhoon Mindulle over the Central Mountain Range (CMR) in Taiwan account for approximately 50% of the total wave momentum flux in the troposphere. The dominant orientation of the OGW wave fronts is parallel to the CMR rideline. When entering into the stratosphere, OGW propagation is determined by the position of the typhoon center relative to the CMR.
Comparison of the effect of high‐latitude and equatorial ionospheric scintillation on GPS signals during the maximum of solar cycle 24
Authors: Jiao Yu , Morton Yu T. 
Published: August 2015

AbstractRadio signal scintillation caused by electron density irregularities in the ionosphere affects the accuracy and integrity of Global Navigation Satellite Systems, especially in the equatorial and high‐latitude regions during solar maxima. Scintillation in these two regions, nevertheless, is usually influenced by different factors and thus has different characteristics that cause different effects on GNSS signals. This paper compares the characteristics of high‐latitude and equatorial scintillation using multifrequency GPS scintillation data collected at Gakona, Alaska, Jicamarca, Peru, and Ascension Island during the 24th solar maximum. Several statistical distributions are established based on the data to characterize the intensity, duration, and occurrence frequency of scintillation. Results show that scintillation in the equatorial region is generally more severe and longer lasting, while high‐latitude scintillation is, in general, more moderate and usually dominated by phase fluctuations. Results also reveal the different impacts of solar activity, geomagnetic activity, and seasons on scintillation in different geographic locations.
Adaptive failure compensation of hysteretic actuators for a class of nonlinear systems via output feedback
Authors: Liu Ye , Yang Zaihua , Lin Yan 
Published: August 2015

SummaryIn this paper, an adaptive output feedback control scheme is proposed for a class of nonlinear systems with possible actuator failures. The system not only involves unknown parameters but also takes nonlinear terms linear in the unmeasured states into account and is preceded by hysteretic actuators whose nonlinearities are characterized by the saturated Prandtl–Ishlinskii model. By developing a high‐gain observer with one dynamic gain, the closed‐loop stability and arbitrarily small tracking error can be guaranteed. Furthermore, by estimating the upper bound of the unknown time‐varying (piecewise constant) parameters caused by the actuator failures, together with an initialization technique, it is proved that the
tracking performance is achievable, which is fundamentally different from the commonly accepted concept that with actuator failures, it is impossible to improve the
tracking performance by using initialization technique. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis and Electrochemical Evaluation of Conductive Polyacrylamide Nanocomposite Hydrogels
Authors: DIDEHBAN KHADIJEH , ABDI MAHTAB , SHARIF FARHAD 
Published: August 2015

ABSTRACTConductive hydrogel nanocomposites containing graphite, graphene oxide (GO), and graphene particles were synthesized by free radical polymerization in aqueous solution. The effect of cross‐linker, initiator, graphite, GO, and graphene concentrations on water absorbency and electrical conductivity of hydrogels was investigated. The synthesized composites were then characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The graphene/polyacrylamide hydrogels showed highest conductivity of about 0.2 S cm−1, and specific capacitance of polyacrylamide/graphene hydrogel in H2SO4 solution was found to be 616 F g−1.
Real‐time fatigue reduction in emergency care clinicians: The SleepTrackTXT randomized trial
Authors: Patterson P. Daniel , Buysse Daniel J. , Weaver Matthew D. , Doman Jack M. , Moore Charity G. , Suffoletto Brian P. , McManigle Kyle L. , Callaway Clifton W. , Yealy Donald M. 
Published: August 2015

BackgroundWe assessed performance characteristics and impact of a mobile phone text‐message intervention for reducing intra‐shift fatigue among emergency clinician shift workers.MethodsWe used a randomized controlled trial of 100 participants. All participants received text‐message assessments at the start, every 4 hr during, and at end of scheduled shifts over a 90‐day period. Text‐message queries measured self‐rated sleepiness, fatigue, and difficulty with concentration. Additional text‐messages were sent to intervention participants to promote alertness. A performance measure of interest was compliance with answering text‐messages.ResultsNinety‐nine participants documented 2,621 shifts and responded to 36,073 of 40,947 text‐messages (88% compliance rate). Intervention participants reported lower mean fatigue and sleepiness at 4 hr, 8 hr, and at the end of 12 hr shifts compared to controls (P < 0.05). Intervention participants reported better sleep quality at 90‐days compared to baseline (P = 0.01).ConclusionsWe showed feasibility and short‐term efficacy of a text‐message based assessment and intervention tool. Am. J. Ind. Med. 58:1098–1113, 2015. © 2015 Wiley Periodicals, Inc.
Patterns of pneumoconiosis mortality in Kentucky: Analysis of death certificate data
Authors: Beggs Jake A. , Slavova Svetla , Bunn Terry L. 
Published: August 2015

BackgroundMortality rates associated with total pneumoconiosis, including coal worker's pneumoconiosis (CWP), have remained elevated.Methods2003–2013 pneumoconiosis mortality data obtained from National Center for Health Statistics and 2011–2013 Kentucky death certificates were analyzed.ResultsTotal pneumoconiosis mortality rates showed significant linear decreases in West Virginia, Pennsylvania, Kentucky, and the U.S. from 2003 to 2013; Pennsylvania and Kentucky had comparable rates in 2003 but while Pennsylvania rates significantly decreased ∼3.0 deaths/million annually, Kentucky rates decreased only 0.5/million annually. Kentucky and Pennsylvania CWP fatality rates were also comparable in 2003 but while Pennsylvania rates decreased 82% over the study period, Kentucky rates decreased only 26%. Kentucky pneumoconiosis deaths primarily occurred in white Appalachian males in‐hospital. Diseases leading to pneumoconiosis death were largely respiratory and cardiovascular, with autopsies rarely performed.ConclusionsCoal worker environmental exposure protection should be enhanced and pneumoconiosis surveillance improvements, including enhanced management of comorbid conditions like COPD, should be considered. Am. J. Ind. Med. 58:1075–1082, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of Multifunctional Alkenes from Substituted Acrylates and Aldehydes via Phosphine‐Catalyzed Wittig Reaction
Authors: Tsai Yi‐Ling , Lin Wenwei 
Published: August 2015

AbstractAn efficient synthesis of multifunctional alkenes starting from substituted acrylates and aldehydes has been developed via phosphine‐catalyzed Wittig reactions. The reactions proceed smoothly even under mild conditions (30–60 °C) via a phosphine/phosphine oxide catalytic cycle using phenyl silane as the reducing agent. According to this simple protocol, the desired products are obtained in moderate to excellent yields as single stereoisomers.
Revisiting the Phenice technique sex classification results reported by MacLaughlin and Bruce (1990)
Authors: McFadden Clare , Oxenham Marc F. 
Published: August 2015

ABSTRACT Phenice (Am J Phys Anthropol 30 (1969):297–301) reported a success rate of 96% for his method of sex determination based on three morphological features of the pelvis. Numerous studies have tested and evaluated the method with affirmative results. The results of the study by MacLaughlin and Bruce (J Forensic Sci 35 (1990):1384–1392) were inconsistent with other studies, reporting far lower rates of accuracy and a greater degree of interobserver error. The authors believe that this may be the result of the inclusion of an “ambiguous” classification category. Revised modelling using forced classification of sex provides much higher classification rates with the implication that the poor results reported by MacLaughlin and Bruce were due to methodological error for the most part. Am J Phys Anthropol 159:182–183, 2016. © 2015 Wiley Periodicals, Inc.
Interpreting adult stature in industrial London
Authors: Hughes‐Morey Gail 
Published: August 2015

ABSTRACTObjectivesThis study examines adult stature and its association with risk of mortality in two skeletal collections from industrializing London, taking sex and socioeconomic status into account as potential sources of heterogeneity in frailty.MethodsMean femur and tibia lengths and the distributions of short femora and tibiae were examined in adult skeletons from the cemeteries at Lower Saint Bride's (low status) and Chelsea Old Church (high status). Cox proportional hazards models were used to determine if stature was associated with risk of mortality and how that relationship varied with sex and socioeconomic status.ResultsHigh‐status females had significantly longer femora, but not tibiae, on average, than low‐status females. There were no status‐based differences in mean element lengths among males. There were sex and status based differences in the distribution of short femora and tibiae, and there was a significant negative association between tibia length and risk of mortality in high‐status females.DiscussionThe results may be explained by differences in subadult mortality, potentially due to variation in infant feeding practices. Low‐status infants were more likely to live in pathogenic environments and less likely to be breastfed, leading to both stature and immunological deficits, thus minimizing the association between adult stature and mortality, as the shortest individuals did not survive into adulthood. The ways in which migration and repeated epidemics of plague may have shaped stature variation during industrialization are also discussed, highlighting the importance of context in understanding the association between stature and mortality. Am J Phys Anthropol 159:126–134, 2016. © 2015 Wiley Periodicals, Inc.
Silicification‐Induced Cell Aggregation for the Sustainable Production of H2 under Aerobic Conditions
Authors: Xiong Wei , Zhao Xiaohong , Zhu Genxing , Shao Changyu , Li Yaling , Ma Weimin , Xu Xurong , Tang Ruikang 
Published: August 2015

AbstractPhotobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification‐induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core–shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar‐driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell–material complexes.
Zinc‐Catalyzed Alkene Cyclopropanation through Zinc Vinyl Carbenoids Generated from Cyclopropenes
Authors: González María J. , González Javier , López Luís A. , Vicente Rubén 
Published: August 2015

AbstractThe zinc‐catalyzed reaction of cyclopropenes with alkenes leading to vinylcyclopropane derivatives is reported. A broad range of alkenes (including highly substituted or functionalized alkenes) is compatible with this protocol. On the basis of trapping experiments and computational studies, this cyclopropanation reaction is proposed to proceed through initial formation of an electrophilic zinc vinyl carbenoid intermediate, which may be involved in a concerted cyclopropanation reaction. The reported protocol represents an unprecedented and simple strategy for the catalytic generation of zinc vinyl carbenoids, which are promising intermediates in organic synthesis.
HAZOP analysis‐based dynamic simulation and its application in chemical processes
Authors: Tian Wende , Du Tingzhao , Mu Shanjun 
Published: August 2015

AbstractHazard and operability analysis (HAZOP) is widely applied in petroleum industry as a scientific and effective safety analysis method, but it is traditionally qualitative in essence and hereby has such shortages as vague conclusions, susceptible to human factor, lack of comprehensive consideration, and so on. This paper proposed a dynamic simulation‐based quantitative HAZOP method that utilizes dynamic simulation to reason deviations to reduce uncertainty in manual analysis. It transforms deviations into quantitative dynamic tasks and uses these tasks to activate dynamic simulation for quantitative deviation reasoning work. The possible consequence and propagation time caused by deviation is probed by analyzing simulation results. In this process, some deviations that appeared seldom or did not at all before can also be simulated and analyzed with the aid of dynamic mechanism model. Case studies in extractive distillation and ammonia synthesis loop showed that this method can present propagation effect of key process parameters on safety state and is useful for iterative and automatic assessment work. It is also found that detailed operation and device data are necessary for initial complex process modeling. In addition, we should improve simulation platform to meet practical requirements when applying this method. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Can a few non‐coding mutations make a human brain?
Authors: Franchini Lucía F. , Pollard Katherine S. 
Published: August 2015

The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human‐specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human‐specific genetic and genomic changes are linked to complex human traits.Also watch the Video Abstract.
Investigation on the interaction of cefpirome sulfate with lysozyme by fluorescence quenching spectroscopy and synchronous fluorescence spectroscopy
Authors: Han Rong , Liu Baosheng , Li Gaixia , Zhang Qiuju 
Published: August 2015

AbstractThe reaction mechanism of cefpirome sulfate with lysozyme at different temperatures (298, 310 and 318 K) was investigated using fluorescence quenching and synchronous fluorescence spectroscopy under simulated physiological conditions. The results clearly demonstrated that cefpirome sulfate caused strong quenching of the fluorescence of lysozyme by a static quenching mechanism. The binding constants obtained using the above methods were of the same order of magnitude and very similar. Static electric forces played a key role in the interaction between cefpirome sulfate and lysozyme, and the number of binding sites in the interaction was close to 1. The values of Hill's coefficients were > 1, indicating that drugs or proteins showed a very weakly positive cooperativity in the system. In addition, the conclusions obtained from the two methods using the same equation were consistent. The results indicated that synchronous fluorescence spectrometry could be used to study the binding mechanism between drug and protein, and was a useful supplement to the fluorescence quenching method. In addition, the effect of cefpirome sulfate on the secondary structure of lysozyme was analyzed using circular dichroism spectroscopy. Copyright © 2015 John Wiley & Sons, Ltd.
Enzymatic Assays Coupled with Mass Spectrometry with or without Embedded Liquid Chromatography
Authors: Burkhardt Therese , Kaufmann Christine M. , Letzel Thomas , Grassmann Johanna 
Published: August 2015

AbstractThis article reviews monitoring strategies for enzymatic assays coupled with mass spectrometric detection. This coupling has already been shown to be helpful in providing versatile and detailed knowledge about enzyme kinetics. Various available publications address two general approaches. 1) The continuous‐flow setup allows real‐time determination of substrate degradation. Simultaneously, resulting product or potential intermediates can be detected. 2) The online coupled continuous‐flow mixing assay allows the direct coupling of an enzymatic assay to chromatographic separation of complex mixtures. The latest efforts in improving the methodology have been made with regard to miniaturization. This is especially advantageous with regard to reducing costly consumption of chemicals. Finally, these developments are applicable for diverse bioanalytical purposes in the realms of pharmaceutical, biotechnological, food, and environmental research.
Carbon Spheres Prepared by Hydrothermal Synthesis—A Support for Bimetallic Iron Cobalt Fischer–Tropsch Catalysts
Authors: Dlamini Mbongiseni W. , Kumi David O. , Phaahlamohlaka Tumelo N. , Lyadov Anton S. , Billing David G. , Jewell Linda L. , Coville Neil J. 
Published: August 2015

AbstractCarbon spheres (CSs) synthesised by the hydrothermal approach were explored as a model support material for a bimetallic Fe–Co Fischer–Tropsch (FT) catalyst. The CSs were characterised by N2 adsorption–desorption, thermogravimetric analysis, FTIR spectroscopy and powder XRD. If annealed at 900 °C for 4 h, the CSs exhibited an improved surface area, thermal stability and crystallinity. A series of Fe–Co bimetallic FT catalysts supported on the annealed CSs were prepared by co‐precipitation. A variety of Fe‐to‐Co ratios were used with the total metal loadings maintained at 10 %. Catalyst reducibility studies were performed by H2 temperature‐programmed reduction and in situ powder XRD. Catalysts with a Fe/Co ratio of 5:5 (w/w) showed Co–Fe alloy formation upon reduction at >450 °C. Interestingly, the presence of this alloy did not correlate with high C5+ selectivities during FT synthesis; rather the Co‐rich/Fe‐poor catalyst gave the best selectivity. The CSs allowed the metal–metal interactions in the bimetallic systems to be monitored because of the weak interaction of the metals with the support.
Co3O4–MnO2–CNT Hybrids Synthesized by HNO3 Vapor Oxidation of Catalytically Grown CNTs as OER Electrocatalysts
Authors: Xie Kunpeng , Masa Justus , Madej Edyta , Yang Fengkai , Weide Philipp , Dong Weiwen , Muhler Martin , Schuhmann Wolfgang , Xia Wei 
Published: August 2015

AbstractAn efficient two‐step gas‐phase method was developed for the synthesis of Co3O4–MnO2–CNT hybrids used as electrocatalysts in the oxygen evolution reaction (OER). Spinel Co–Mn oxide was used for the catalytic growth of multiwalled carbon nanotubes (CNTs) and the amount of metal species remaining in the CNTs was adjusted by varying the growth time. Gas‐phase treatment in HNO3 vapor at 200 °C was performed to 1) open the CNTs, 2) oxidize encapsulated Co nanoparticles to Co3O4 as well as MnO nanoparticles to MnO2, and 3) to create oxygen functional groups on carbon. The hybrid demonstrated excellent OER activity and stability up to 37.5 h under alkaline conditions, with longer exposure to HNO3 vapor up to 72 h beneficial for improved electrocatalytic properties. The excellent OER performance can be assigned to the high oxidation states of the oxide nanoparticles, the strong electrical coupling between these oxides and the CNTs as well as favorable surface properties rendering the hybrids a promising alternative to noble metal based OER catalysts.
Cascade Reaction through Different Microorganisms for Electrochemical Oxidation of Ethanol
Authors: Matsumoto Ryuhei , Fujita Shuji , Goto Yoshio 
Published: August 2015

AbstractThis paper demonstrates that an artificially constructed microbial community extracts 10.4 electrons of 12 electrons from an ethanol molecule, with 87 % coulombic efficiency of the complete oxidation under ambient temperature. Two separately cultured bacteria of Acetobacter aceti (A. aceti) and Escherichia coli (E. coli) are mixed in a micro‐electrolysis cell with an electron‐transfer mediator. The coulombic yield corresponds to the sum of ethanol oxidation with A. aceti and acetate oxidation with E. coli; a microbial cascade reaction occurs within this system. When Gluconobacter oxydans (G. oxydans) was employed instead of A. aceti, 8.4 electrons were extracted from one ethanol molecule. These microbial cascades show examples of highly efficient energy‐conversion systems. Our results suggest that combinations of microorganisms that do not coexist in nature would enable reactions that a single microorganism or an industrial catalyst has not ever established.