bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced emissions of CO2, NOx, and SO2 from U.S. power plants owing to switch from coal to natural gas with combined cycle technology
Authors: de Gouw J. A. , Parrish D. D. , Frost G. J. , Trainer M. 
Published: February 2014

AbstractSince 1997, an increasing fraction of electric power has been generated from natural gas in the United States. Here we use data from continuous emission monitoring systems (CEMS), which measure emissions at the stack of most U.S. electric power generation units, to investigate how this switch affected the emissions of CO2, NOx, and SO2. Per unit of energy produced, natural gas power plants equipped with combined cycle technology emit on an average 44% of the CO2 compared with coal power plants. As a result of the increased use of natural gas, CO2 emissions from U.S. fossil‐fuel power plants were 23% lower in 2012 than they would have been if coal had continued to provide the same fraction of electric power as in 1997. In addition, natural gas power plants with combined cycle technology emit less NOx and far less SO2 per unit of energy produced than coal power plants. Therefore, the increased use of natural gas has led to emission reductions of NOx (40%) and SO2 (44%), in addition to those obtained from the implementation of emission control systems on coal power plants. These benefits to air quality and climate should be weighed against the increase in emissions of methane, volatile organic compounds, and other trace gases that are associated with the production, processing, storage, and transport of natural gas.
High‐resolution lunar gravity fields from the GRAIL Primary and Extended Missions
Authors: Konopliv Alex S. , Park Ryan S. , Yuan Dah‐Ning , Asmar Sami W. , Watkins Michael M. , Williams James G. , Fahnestock Eugene , Kruizinga Gerhard , Paik Meegyeong , Strekalov Dmitry , Harvey Nate , Smith David E. , Zuber Maria T. 
Published: February 2014

AbstractThe resolution and accuracy of the lunar spherical harmonic gravity field have been dramatically improved as a result of the Gravity Recovery and Interior Laboratory (GRAIL) mission. From the Primary Mission, previous harmonic gravity fields resulted in an average n = 420 surface resolution and a Bouguer spectrum to n = 330. The GRAIL Extended Mission improves the resolution due to a lower average 23 km altitude orbit. As a result, new harmonic degree 900 gravity fields (GL0900C and GL0900D) show nearly a factor of 2 improvement with an average surface resolution n = 870 and the Bouguer spectrum extended to n = 550. Since the minimum spacecraft altitude varies spatially between 3 km and 23 km, the surface resolution is variable from near n = 680 for the central farside to near n = 900 for the polar regions. These gravity fields with 0.8 million parameters are by far the highest‐degree fields of any planet ever estimated with a fully dynamic least squares technique using spacecraft tracking data.
On the cause and extent of outer radiation belt losses during the 30 September 2012 dropout event
Authors: Turner D. L. , Angelopoulos V. , Morley S. K. , Henderson M. G. , Reeves G. D. , Li W. , Baker D. N. , Huang C.‐L. , Boyd A. , Spence H. E. , Claudepierre S. G. , Blake J. B. , Rodriguez J. V. 
Published: February 2014

AbstractOn 30 September 2012, a flux “dropout” occurred throughout Earth's outer electron radiation belt during the main phase of a strong geomagnetic storm. Using eight spacecraft from NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) and Van Allen Probes missions and NOAA's Geostationary Operational Environmental Satellites constellation, we examined the full extent and timescales of the dropout based on particle energy, equatorial pitch angle, radial distance, and species. We calculated phase space densities of relativistic electrons, in adiabatic invariant coordinates, which revealed that loss processes during the dropout were > 90% effective throughout the majority of the outer belt and the plasmapause played a key role in limiting the spatial extent of the dropout. THEMIS and the Van Allen Probes observed telltale signatures of loss due to magnetopause shadowing and subsequent outward radial transport, including similar loss of energetic ring current ions. However, Van Allen Probes observations suggest that another loss process played a role for multi‐MeV electrons at lower L shells (L* < ~4).
Dependence of the high‐latitude lower thermospheric wind vertical vorticity and horizontal divergence on the interplanetary magnetic field
Authors: Kwak Y.‐S. , Richmond A. D. 
Published: February 2014

AbstractWe analyze the vertical component of vorticity and the horizontal divergence of the high‐latitude neutral wind field in the lower thermosphere during the southern summer time for different interplanetary magnetic field (IMF) conditions with the aid of the National Center for Atmospheric Research thermosphere ionosphere electrodynamics general circulation model, with the following results. (1) The mean neutral wind pattern in the high‐latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force rather than by horizontally divergent flow. (2) The vertical vorticity depends on the IMF. (3) The difference vertical vorticity, obtained by subtracting values with zero IMF from those with nonzero IMF, is much larger than the difference horizontal divergence for all IMF conditions. (4) The effects of IMF penetrate down to 106 km altitude. To determine the processes forcing strong rotational flow in the high‐latitude lower thermospheric wind fields, a term analysis of the vorticity equation is also performed, with the following results. (1) The primary forcing term that determines variations of the vertical vorticity is ion drag. This forcing is closely related to the flow of field‐aligned current between the ionosphere and magnetosphere. Significant contributions to variations of the vorticity, however, can be made by the horizontal advection term. (2) The effects of the IMF on the ion drag forcing are seen down to around 106 km altitude. (3) The continual forcing of magnetic zonal mean By‐dependent vertical vorticity by ion drag can lead to strong polar vortices.
Characteristics of large‐scale wave structure observed from African and Southeast Asian longitudinal sectors
Authors: Tulasi Ram S. , Yamamoto M. , Tsunoda R. T. , Chau H. D. , Hoang T. L. , Damtie B. , Wassaie M. , Yatini C. Y. , Manik T. , Tsugawa T. 
Published: February 2014

AbstractThe spatial large‐scale wave structure (LSWS) at the base of F layer is the earliest manifestation of seed perturbation for Rayleigh‐Taylor instability, hence, found to play a deterministic role in the development of Equatorial Plasma Bubbles (EPBs). Except for a few case studies, a comprehensive investigation has not been conducted on the characteristics of LSWS because of the complexity involved in detecting the LSWS, particularly, in spatial domain. In this scenario, a comprehensive study is carried out, for the first time, on the spatial and temporal characteristics of LSWS observed in spatial domain over African and Southeast Asian longitudinal sectors during the year 2011. The observations indicate that these wave structures can be detected a few degrees west of E region sunset terminator and found to grow significantly at longitudes past the sunset terminator. The phase fronts of these spatial structures are found to align with the geomagnetic field () lines over a latitudinal belt for at least 5−6° (~500–600 km) centered on dip equator. The zonal wavelengths of these structures are found to vary from 100 to 700 km, which is consistent with the earlier reports, and the EPBs were consistently observed when the amplitudes of LSWS were grown to sufficient strengths. These results would provide better insights on the underlying physical processes involved in excitation of LSWS in terms of important roles being played by E region electrical loading and polarization electric fields induced via spatially varying dynamo current due to neutral wind perturbations associated with atmospheric gravity waves.
Evaluation of ionospheric profilers using topside sounding data
Authors: Verhulst T. , Stankov S. M. 
Published: February 2014

AbstractAn operational system for deducing and imaging the vertical distribution of the electron density in the local ionosphere has been recently developed. The electron density profile is deduced from combined ground‐based measurements of the total electron content, ionospheric vertical incidence soundings, and empirically obtained values of the O+‐H+ ion transition height. The topside profile is permitted to take one of several forms: Exponential, Chapman, or Epstein. An evaluation of the above mentioned ionospheric profilers is needed in order to determine which one of them provides the best representation of the current ionospheric conditions. For this purpose, we use electron density profiles obtained from ionograms recorded by the topside sounders onboard the Alouette and ISIS satellites. Every profile has been fitted with each of the above mentioned theoretical ionospheric profilers and the corresponding approximation errors calculated. The results have been analyzed with respect to local time, geomagnetic latitude, season, magnetic and solar activity, ion transition height, and the ionospheric density peak characteristics. It has been found that, in the majority of cases, the best fit is provided by the exponential profiler, followed by the Chapman profiler. Also, while some influence of the underlying physical drivers on the topside electron density profile is detected, it is the use of ionospheric characteristics that offers more reliable selection criteria for the most appropriate profiler.
Ray entity based postprocessing of ray‐tracing data for continuous modeling of radio channel
Authors: Mataga Nikola , Zentner Radovan , Mucalo Ana Katalinić 
Published: February 2014

AbstractRay‐tracing data are usually given as angles of arrival and departure, transmitter and receiver coordinates, ray length and delay, received power level, and polarity. Usually, these values are given in raw data with some resolution that covers the area of interest where the simulation is performed. There are two main drawbacks of such approach: first, a huge amount of storage capacity is typically needed and second, although the area of interest is covered by a certain resolution, it is nearly impossible to interpolate between sample points and new time, and memory consuming simulations are necessary in order to increase the resolution of the simulations. This paper addresses the two mentioned drawbacks of ray tracing, suggesting a procedure based on the concept of ray entities both to enable continuous interpolation of ray‐tracing data and reduce the memory needed for storing data. Ray entity is a set of rays that all undergo the same series of propagation phenomena (direct ray, diffraction, reflection, or scattering) on the same objects (building walls or edges). The method is given and illustrated for reflection and diffraction phenomena, and diffuse scattering was not included, but discussion is easily extended to this propagation type as well. The paper gives detailed statistics of entities' length and rays' count per simulated receiver point in few illustrative examples and provides an insight on how to interpolate angles of arrival and departure, ray length, and received power level in order to provide a continuous description of the radio environment.
Keogram analysis of ENA images at Saturn
Authors: Carbary J. F. , Mitchell D. G. 
Published: February 2014

AbstractKeograms are constructed from azimuthal profiles of energetic hydrogen atoms (25–55 keV) from Saturn's magnetosphere. The keograms exhibit linear structures or “tracks” that reveal prograde rotational motion of features or “blobs” in the energetic neutral atom (ENA) images. From polynomial fits, the first derivatives of these tracks are used to estimate the rotational speeds of the blobs. The total blob speed consists of plasma convective drift plus gradient drift, so the convective speed can be approximated by subtracting the gradient drift of the protons from which the ENA derive. This subtraction gives plasma convection speeds that are ~28°/h at ~5 RS and decrease to a constant ~21°/h between 10 RS and 20 RS, which are consistently below corotation (~33.3°/h) and in substantial agreement with estimates of plasma convection made in situ. The speeds also show a local time dependence, decreasing as much as 4–6°/h as the blobs move from midnight through noon to midnight.
Crime Type, Perceived Stereotypicality, and Memory Biases: A Contextual Model of Eyewitness Identification
Authors: Osborne Danny , Davies Paul G. 
Published: February 2014

SummaryThe fallibility of eyewitness identifications is well documented. Nevertheless, research has yet to assess the possibility that the type of crime committed systematically influences who eyewitnesses mistakenly identify. We address this oversight by presenting a contextual model of eyewitness identification (CMEI). The CMEI asserts that discrete crimes automatically activate distinct stereotypes about a perpetrator's appearance. Depending on the congruence between these stereotypes and the perpetrator's actual appearance, eyewitnesses will remember the perpetrator as appearing more (or less) representative of his or her group (i.e., higher or lower on perceived stereotypicality). Estimator and system variables are posited to affect identifications at different stages of the identification process. The literatures on stereotype activation, perceived stereotypicality, and stereotype‐consistent memory biases are reviewed to support the CMEI. Our conceptual integration provides a model of eyewitness identification that explains when mistaken identifications are likely to occur and who they are likely to affect. Copyright © 2014 John Wiley & Sons, Ltd.
Health Is not always written in bone: Using a modern comorbidity index to assess disease load in paleopathology
Authors: van Schaik Katherine , Vinichenko Dmitry , Rühli Frank 
Published: February 2014

ABSTRACTPaleopathology has revealed much about disease in the past but is usually limited to conditions with osteological manifestations; this often excludes acute soft tissue infections and causes of death for most individuals in the past and present. Our understanding of the evolution of disease is essential for contextualizing and predicting the epidemiological shifts that are happening in modern society, as high rates of infectious disease coexist alongside high rates of chronic disease in rates unlike those observed previously in human history. Moreover, many physiological states not previously classified as “disease” (obesity) have become pathologized, influencing our conception of disease and what defines health. By using the Galler Collection, a pre‐antibiotic and pre‐chemotherapeutic osteological series with modern autopsy records, our research quantifies disease burden of the past using the Charlson Index (CI), a modern comorbidity index of disease severity. Galler Collection remains and autopsy records were scored with the Charlson Index to correlate bone findings with soft tissue findings, and statistical analysis was performed for cumulative scores and absolute diagnosis counts, with patients stratified by sex and cause of death (pneumonia or cancer). Osteological diagnosis counts were more predictive of soft‐tissue autopsy disease counts than were associated cumulative CI scores. Diagnosis counts and CI scores for osteological data were more closely related to associated soft tissue data for cancer patients than for pneumonia patients. This research indicates how interdisciplinary paleopathological analysis assists in making more reliable assessments of health and mortality in the past, with implications for trending and predicting future epidemiological shifts. Am J Phys Anthropol 154:215–221, 2014. © 2014 Wiley Periodicals, Inc.
Predictive factors to differentiate between allergic and nonallergic rhinitis in children
Authors: Topal Erdem , Bakirtas Arzu , Yılmaz Ozlem , Karagöl Ilbilge Hacer Ertoy , Arslan Umut , Arga Mustafa , Demirsoy Mehmet Sadik , Turktas Ipek 
Published: February 2014

BackgroundAlthough symptoms and signs of allergic rhinitis (AR) and nonallergic rhinitis (NAR) are similar, treatment and follow‐up are different. We aimed to find predictive factors that can be used in primary health care to differentiate AR from NAR.MethodsWe made a retrospective analysis of cases aged 6–18 years old who were diagnosed as having chronic rhinitis within a 1‐year period. Skin‐prick tests were done and severity of rhinitis symptoms was recorded on a visual analog scale in all patients.ResultsThere were 472 cases whose medical records were complete and included in the analysis. The median age was 11 (interquartile range [IQR], 5) years. AR was diagnosed in 363 patients (76.9%) and was different from NAR with respect to: median age (p = 0.042), seasonality of the symptoms (p = 0.002), persistent symptoms (p = 0.003), moderate/severe according to visual analogue scale (VAS) score (p = 0.017), conjunctivitis (p < 0.001), parental history of AR (p = 0.026), rhinorrhea (p < 0.001), sneezing (p = 0.005), mucosal pallor (p = 0.004), and response to antihistamines (p = 0.035). All parameters with a significance of p < 0.1 between AR and NAR were included in logistic regression analysis. Seasonality, sneezing, moderate/severe rhinitis, and response to antihistamines were identified as significant independent parameters to differentiate AR from NAR.ConclusionFeatures of rhinitis patients with seasonality, sneezing, moderate/severe rhinitis, and response to antihistamines may help in differentiation of AR from NAR at the primary care level.
Heteroatom‐freie Arencobalt‐ und Areneisen‐Katalysatoren für Hydrierungen
Authors: Gärtner Dominik , Welther Alice , Rad Babak Rezaei , Wolf Robert , Jacobi von Wangelin Axel 
Published: February 2014

Abstract75 Jahre nach der Entdeckung der Hydroformylierung erleben Cobalt‐Katalysatoren eine Renaissance in Hydrierungen. Wir haben Arenmetallate untersucht, in denen die niedervalente Metallspezies nicht durch Heteroatom‐Liganden, sondern durch einfache π‐Kohlenwasserstoffe stabilisiert ist. Kaliumbis(anthracen)cobaltat 1 und ‐ferrat 2 sind synthetische Vorstufen für quasi‐“nackte” anionische Metallspezies. Eine Aggregation wird durch (labile) Koordination der in Hydrierungen vorhandenen π‐Akzeptoren (Olefine, Arene, Carbonylverbindungen) effektiv unterdrückt. Kinetische Studien, NMR‐Spektroskopie und Vergiftungsexperimente in Alkenhydrierungen bestätigen die Bildung eines homogenen Katalysators aus 1, der durch Ligandenaustausch gebildet und durch Koordination an Alkene stabilisiert wird. Das zugrundeliegende Katalysatorkonzept ist komplementär zur Verwendung von Komplexen mit Heteroatom‐Donorliganden in reduktiven Prozessen.
Interaction with the Surrounding Water Plays a Key Role in Determining the Aggregation Propensity of Proteins
Authors: Chong Song‐Ho , Ham Sihyun 
Published: February 2014

AbstractUnderstanding the molecular determinants of the relative propensities of proteins to aggregate in a cellular environment is a central issue for treating protein‐aggregation diseases and developing peptide‐based therapeutics. Despite the expectation that protein aggregation can largely be attributed to direct protein–protein interactions, a crucial role the surrounding water in determining the aggregation propensity of proteins both in vitro and in vivo was identified. The overall protein hydrophobicity, defined solely by the hydration free energy of a protein in its monomeric state sampling its equilibrium structures, was shown to be the predominant determinant of protein aggregation propensity in aqueous solution. Striking discrimination of positively and negatively charged residues by the surrounding water was also found. This effect depends on the protein net charge and plays a crucial role in regulating the solubility of the protein. These results pave the way for the design of aggregation‐resistant proteins as biotherapeutics.
Direct Catalytic Enantio‐ and Diastereoselective Mannich Reaction of Isocyanoacetates and Ketimines
Authors: Ortín Irene , Dixon Darren J. 
Published: February 2014

AbstractA catalytic asymmetric synthesis of imidazolines with a fully substituted β‐carbon atom by a Mannich‐type addition/cyclization reaction of isocyanoacetate pronucleophiles and N‐diphenylphosphinoyl ketimines has been developed. When a combination of a cinchona‐derived aminophosphine precatalyst and silver oxide was employed as a binary catalyst system, good reactivity, high diastereoselectivities (up to 99:1 d.r.), and excellent enantioselectivities (up to 99 % ee) were obtained for a range of substrates.
Supercapacitive Swing Adsorption of Carbon Dioxide
Authors: Kokoszka Berenika , Jarrah Nina K. , Liu Cong , Moore David T. , Landskron Kai 
Published: February 2014

AbstractAn electrical effect, the supercapacitive swing adsorption (SSA) effect is reported, which allows for reversible adsorption and desorption of carbon dioxide by capacitive charge and discharge of electrically conducting porous carbon materials. The SSA effect can be observed when an electrically conducting, nanoporous carbon material is brought into contact with carbon dioxide gas and an aqueous electrolyte. Charging the supercapacitor electrodes initiates the spontaneous organization of electrolyte ions into an electric double layer at the surface of each porous electrode. The presence of this double layer leads to reversible, selective uptake and release of the CO2 as the supercapacitor is charged and discharged.
Dual Stimuli‐Responsive Self‐Assembled Supramolecular Nanoparticles
Authors: Stoffelen Carmen , Voskuhl Jens , Jonkheijm Pascal , Huskens Jurriaan 
Published: February 2014

AbstractSupramolecular nanoparticles (SNPs) encompass multiple copies of different building blocks brought together by specific noncovalent interactions. The inherently multivalent nature of these systems allows control of their size as well as their assembly and disassembly, thus promising potential as biomedical delivery vehicles. Here, dual responsive SNPs have been based on the ternary host–guest complexation between cucurbit[8]uril (CB[8]), a methyl viologen (MV) polymer, and mono‐ and multivalent azobenzene (Azo) functionalized molecules. UV switching of the Azo groups led to fast disruption of the ternary complexes, but to a relatively slow disintegration of the SNPs. Alternating UV and Vis photoisomerization of the Azo groups led to fully reversible SNP disassembly and reassembly. SNPs were only formed with the Azo moieties in the trans and the MV units in the oxidized states, respectively, thus constituting a supramolecular AND logic gate.
Monitoring Conformational Changes in the NDM‐1 Metallo‐β‐lactamase by 19F NMR Spectroscopy
Authors: Rydzik Anna M. , Brem Jürgen , van Berkel Sander S. , Pfeffer Inga , Makena Anne , Claridge Timothy D. W. , Schofield Christopher J. 
Published: February 2014

AbstractThe New Delhi metallo‐β‐lactamase (NDM‐1) is involved in the emerging antibiotic resistance problem. Development of metallo‐β‐lactamases (MBLs) inhibitors has proven challenging, due to their conformational flexibility. Here we report site‐selective labeling of NDM‐1 with 1,1,1‐trifluoro‐3‐bromo acetone (BFA), and its use to study binding events and conformational changes upon ligand–metal binding using 19F NMR spectroscopy. The results demonstrate different modes of binding of known NDM‐1 inhibitors, including L‐ and D‐captopril by monitoring the changing chemical environment of the active‐site loop of NDM‐1. The method described will be applicable to other MBLs and more generally to monitoring ligand‐induced conformational changes.