bluuebunny/crossref_metadata_2025_split huggingface dataset:
PATTERNS OF ACTIVITY IN A GLOBAL MODEL OF A SOLAR ACTIVE REGION
Authors: Bradshaw S. J. , Viall N. M. 
Published: April 2016

ABSTRACT
In this work we investigate the global activity patterns predicted from a model active region heated by distributions of nanoflares that have a range of frequencies. What differs is the average frequency of the distributions. The activity patterns are manifested in time lag maps of narrow-band instrument channel pairs. We combine hydrodynamic and forward modeling codes with a magnetic field extrapolation to create a model active region and apply the time lag method to synthetic observations. Our aim is not to reproduce a particular set of observations in detail, but to recover some typical properties and patterns observed in active regions. Our key findings are the following. (1) Cooling dominates the time lag signature and the time lags between the channel pairs are generally consistent with observed values. (2) Shorter coronal loops in the core cool more quickly than longer loops at the periphery. (3) All channel pairs show zero time lag when the line of sight passes through coronal loop footpoints. (4) There is strong evidence that plasma must be re-energized on a timescale comparable to the cooling timescale to reproduce the observed coronal activity, but it is likely that a relatively broad spectrum of heating frequencies are operating across active regions. (5) Due to their highly dynamic nature, we find nanoflare trains produce zero time lags along entire flux tubes in our model active region that are seen between the same channel pairs in observed active regions.
PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION
Authors: Vayner Andrey , Wright Shelley A. , Do Tuan , Larkin James E. , Armus Lee , Gallagher S. C. 
Published: April 2016

ABSTRACT
We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z
Hα
= 2.182) and SDSS J0925+0655 (z
Hα
= 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M
⊙ yr−1 originating from a compact region that is kinematically offset by 290–350 km s−1. For SDSS J0925+0655 we infer a SFR of 29 M
⊙ yr−1 distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M
⊙ yr−1 kpc−2. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M
⊙ yr−1 kpc−2. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if star formation is present in the host (1.4–20 kpc) it would have to occur diffusely with significant extinction and not in compact, clumpy regions.
EVIDENCE FOR REFLECTED LIGHT FROM THE MOST ECCENTRIC EXOPLANET KNOWN
Authors: Kane Stephen R. , Wittenmyer Robert A. , Hinkel Natalie R. , Roy Arpita , Mahadevan Suvrath , Dragomir Diana , Matthews Jaymie M. , Henry Gregory W. , Chakraborty Abhijit , Boyajian Tabetha S. , Wright Jason T. , Ciardi David R. , Fischer Debra A. , Butler R. Paul , Tinney C. G. , Carter Brad D. , Jones Hugh R. A. , Bailey Jeremy , O’Toole Simon J. 
Published: April 2016

ABSTRACT
Planets in highly eccentric orbits form a class of objects not seen within our solar system. The most extreme case known among these objects is the planet orbiting HD 20782, with an orbital period of 597 days and an eccentricity of 0.96. Here we present new data and analysis for this system as part of the Transit Ephemeris Refinement and Monitoring Survey. We obtained CHIRON spectra to perform an independent estimation of the fundamental stellar parameters. New radial velocities from Anglo-Australian Telescope and PARAS observations during periastron passage greatly improve our knowledge of the eccentric nature of the orbit. The combined analysis of our Keplerian orbital and Hipparcos astrometry show that the inclination of the planetary orbit is

>
1
.°
22

, ruling out stellar masses for the companion. Our long-term robotic photometry show that the star is extremely stable over long timescales. Photometric monitoring of the star during predicted transit and periastron times using Microvariability and Oscillations of STars rule out a transit of the planet and reveal evidence of phase variations during periastron. These possible photometric phase variations may be caused by reflected light from the planet’s atmosphere and the dramatic change in star–planet separation surrounding the periastron passage.
SYSTEMATIC AND STOCHASTIC VARIATIONS IN PULSAR DISPERSION MEASURES
Authors: Lam M. T. , Cordes J. M. , Chatterjee S. , Jones M. L. , McLaughlin M. A. , Armstrong J. W. 
Published: April 2016

ABSTRACT
We analyze deterministic and random temporal variations in the dispersion measure (DM) from the full three-dimensional velocities of pulsars with respect to the solar system, combined with electron-density variations over a wide range of length scales. Previous treatments have largely ignored pulsars’ changing distances while favoring interpretations involving changes in sky position from transverse motion. Linear trends in pulsar DMs observed over 5–10 year timescales may signify sizable DM gradients in the interstellar medium (ISM) sampled by the changing direction of the line of sight to the pulsar. We show that motions parallel to the line of sight can also account for linear trends, for the apparent excess of DM variance over that extrapolated from scintillation measurements, and for the apparent non-Kolmogorov scalings of DM structure functions inferred in some cases. Pulsar motions through atomic gas may produce bow-shock ionized gas that also contributes to DM variations. We discuss the possible causes of periodic or quasi-periodic changes in DM, including seasonal changes in the ionosphere, annual variations of the solar elongation angle, structure in the heliosphere and ISM boundary, and substructure in the ISM. We assess the solar cycle’s role on the amplitude of ionospheric and solar wind variations. Interstellar refraction can produce cyclic timing variations from the error in transforming arrival times to the solar system barycenter. We apply our methods to DM time series and DM gradient measurements in the literature and assess their consistency with a Kolmogorov medium. Finally, we discuss the implications of DM modeling in precision pulsar timing experiments.
THE CRITICAL MASS RATIO OF DOUBLE WHITE DWARF BINARIES FOR VIOLENT MERGER-INDUCED TYPE IA SUPERNOVA EXPLOSIONS
Authors: Sato Yushi , Nakasato Naohito , Tanikawa Ataru , Nomoto Ken’ichi , Maeda Keiichi , Hachisu Izumi 
Published: April 2016

ABSTRACT
Mergers of carbon–oxygen (CO) white dwarfs (WDs) are considered to be one of the potential progenitors of type Ia supernovae (SNe Ia). Recent hydrodynamical simulations showed that the less massive (secondary) WD violently accretes onto the more massive (primary) one, carbon detonation occurs, the detonation wave propagates through the primary, and the primary finally explodes as a sub-Chandrasekhar mass SN Ia. Such an explosion mechanism is called the violent merger scenario. Based on the smoothed particle hydrodynamics simulations of merging CO WDs, we derived a critical mass ratio (q
cr) leading to the violent merger scenario that is more stringent than previous results. We conclude that this difference mainly comes from the differences in the initial condition of whether or not the WDs are synchronously spinning. Using our new results, we estimated the brightness distribution of SNe Ia in the violent merger scenario and compared it with previous studies. We found that our new q
cr does not significantly affect the brightness distribution. We present the direct outcome immediately following CO WD mergers for various primary masses and mass ratios. We also discussed the final fate of the central system of the bipolar planetary nebula Henize 2-428, which was recently suggested to be a double CO WD system whose total mass exceeds the Chandrasekhar-limiting mass, merging within the Hubble time. Even considering the uncertainties in the proposed binary parameters, we concluded that the final fate of this system is almost certainly a sub-Chandrasekhar mass SN Ia in the violent merger scenario.
De la République romaine à la République française : exemple historique et scénographie
Authors: Maingueneau Dominique 
Published: April 2016

Cet article met en contraste deux exemples historiques (EH) liés à la Révolution française ; bien que séparés par plus de deux siècles, ils participent de la même culture politique. Le premier, un exemple historique verbal, ouvre un discours de Robespierre devant l’Assemblée constituante en faveur de l’abolition de la peine de mort (30 mai 1791) ; le second est emprunté à la profession de foi du candidat José Bové, lors des élections présidentielles de 2007. Cette étude permet de prendre la mesure de la diversité des modes d’inscription de l’EH dans un texte : il peut être localisé et explicite (Robespierre) ou structurer implicitement l’ensemble de l’argumentation (Bové). Elle permet aussi et surtout de montrer que l’EH atteint son rendement maximal quand il peut réfléchir les conditions mêmes de l’énonciation qui le convoque.
Exemple historique, comparaison, analogie, métaphore : sont-ils interchangeables ?
Authors: Koren Roselyne 
Published: April 2016

La lecture de publications scientifiques ou d’argumentaires profanes référant à l’emploi de l’exemple historique (EH) permet d’observer un phénomène inattendu : les auteurs de métadiscours critiques ayant l’EH pour objet cessent fréquemment de distinguer, dans le feu de la démonstration, entre exemple, comparaison, analogie ou encore métaphore historique. Ces notions surgissent alors plus ou moins simultanément sous la plume des auteurs et semblent être perçues comme interchangeables. Dans le registre scientifique, l’analogie est un « terme couvrant » qui englobe les notions de métaphore, de comparaison et d’exemple (Plantin 2011). Par ailleurs, l’EH des « années trente » et de ses crises économiques, politiques et sociales peut servir de cadre à un discours médiatique où ces notions apparaissent sans être clairement distinguées. La présente contribution entend explorer les voies qui mènent d’un argument à l’autre et mettent sur le même plan des figures fondant la structure du réel comme l’EH, l’analogie ou la métaphore et des figures ayant la structure préalable du réel référentiel pour fondement comme la comparaison, argument « quasi-logique ». On analyse deux exemples types, un article consacré à l’accusation de « populisme » et à l’EH des années trente et l’article d’un historien, « Un nazisme tropical », et on propose quelques hypothèses explicatives concernant la porosité de frontières pourtant bien réelles entre l’EH et l’analogie ou la comparaison.
Historia Magistra Vitae : Le topos de « l’Histoire comme maître de la vie » dans les controverses publiques sur la représentation de Soi et de l’Autre
Authors: Forchtner Bernhard 
Published: April 2016

L’idée que « le passé » puisse contribuer à mieux guider le présent est un topos populaire dans les débats publics. En recherchant la manière dont ce topos de la historia magistra vitae peut être utilisé dans des discours, des représentations et leurs conséquences, cet article cherche à voir comment des affirmations qui disent avoir appris « les leçons » du passé peuvent donner un sens à des acteurs, des événements, des objets et des processus contemporains. On pose donc des questions telles que « sur quels passés et quels présents ce topos se base-t-il ? » et « à quelles conclusions possibles accède-t-on dans l’utilisation de ce topos dans des luttes publiques sur la ligne de démarcation entre “eux” et “nous” ? » Au lieu de proposer une étude de cas, cet article offre une typologie abstraite de telles affirmations, en conceptualisant quatre sortes d’utilisation : les rhétoriques de jugement, les rhétoriques de l’échec, les rhétoriques de repentance, et les rhétoriques de jugement-repentance. Ce faisant, il établit une distinction minutieuse entre ces diverses utilisations, et procure un cadre qui permettra de mieux les comprendre à travers une série de cas.
Normal Extensions of Representations of Abelian Semigroups
Authors: Li Boyu 
Published: April 2016

AbstractA commuting family of subnormal operators need not have a commuting normal extension. We study when a representation of an abelian semigroup can be extended to a normal representation, and show that it suffices to extend the set of generators to commuting normals. We also extend a result due to Athavale to representations on abelian lattice ordered semigroups.
Technical Note: Development of chemoinformatic tools to enumerate functional groups in molecules for organic aerosol characterization
Authors: Ruggeri Giulia , Takahama Satoshi 
Published: April 2016

Abstract. Functional groups (FGs) can be used as a reduced representation of organic aerosol composition in both ambient and controlled chamber studies, as they retain a certain chemical specificity. Furthermore, FG composition has been informative for source apportionment, and various models based on a group contribution framework have been developed to calculate physicochemical properties of organic compounds. In this work, we provide a set of validated chemoinformatic patterns that correspond to (1) a complete set of functional groups that can entirely describe the molecules comprised in the α-pinene and 1,3,5-trimethylbenzene MCMv3.2 oxidation schemes, (2) FGs that are measurable by Fourier transform infrared spectroscopy (FTIR), (3) groups incorporated in the SIMPOL.1 vapor pressure estimation model, and (4) bonds necessary for the calculation of carbon oxidation state. We also provide example applications for this set of patterns. We compare available aerosol composition reported by chemical speciation measurements and FTIR for different emission sources, and calculate the FG contribution to the O : C ratio of simulated gas-phase composition generated from α-pinene photooxidation (using the MCMv3.2 oxidation scheme).
Observation of viscosity transition in α-pinene secondary organic aerosol
Authors: Järvinen Emma , Ignatius Karoliina , Nichman Leonid , Kristensen Thomas B. , Fuchs Claudia , Hoyle Christopher R. , Höppel Niko , Corbin Joel C. , Craven Jill , Duplissy Jonathan , Ehrhart Sebastian , El Haddad Imad , Frege Carla , Gordon Hamish , Jokinen Tuija , Kallinger Peter , Kirkby Jasper , Kiselev Alexei , Naumann Karl-Heinz , Petäjä Tuukka , Pinterich Tamara , Prevot Andre S. H. , Saathoff Harald , Schiebel Thea , Sengupta Kamalika , Simon Mario , Slowik Jay G. , Tröstl Jasmin , Virtanen Annele , Vochezer Paul , Vogt Steffen , Wagner Andrea C. , Wagner Robert , Williamson Christina , Winkler Paul M. , Yan Chao , Baltensperger Urs , Donahue Neil M. , Flagan Rick C. , Gallagher Martin , Hansel Armin , Kulmala Markku , Stratmann Frank , Worsnop Douglas R. , Möhler Ottmar , Leisner Thomas , Schnaiter Martin 
Published: April 2016

Abstract. Under certain conditions, secondary organic aerosol (SOA) particles can exist in the atmosphere in an amorphous solid or semi-solid state. To determine their relevance to processes such as ice nucleation or chemistry occurring within particles requires knowledge of the temperature and relative humidity (RH) range for SOA to exist in these states. In the Cosmics Leaving Outdoor Droplets (CLOUD) experiment at The European Organisation for Nuclear Research (CERN), we deployed a new in situ optical method to detect the viscous state of α-pinene SOA particles and measured their transition from the amorphous highly viscous state to states of lower viscosity. The method is based on the depolarising properties of laboratory-produced non-spherical SOA particles and their transformation to non-depolarising spherical particles at relative humidities near the deliquescence point. We found that particles formed and grown in the chamber developed an asymmetric shape through coagulation. A transition to a spherical shape was observed as the RH was increased to between 35 % at −10 °C and 80 % at −38 °C, confirming previous calculations of the viscosity-transition conditions. Consequently, α-pinene SOA particles exist in a viscous state over a wide range of ambient conditions, including the cirrus region of the free troposphere. This has implications for the physical, chemical, and ice-nucleation properties of SOA and SOA-coated particles in the atmosphere.
Global observations and modeling of atmosphere–surface exchange of elemental mercury: a critical review
Authors: Zhu Wei , Lin Che-Jen , Wang Xun , Sommar Jonas , Fu Xuewu , Feng Xinbin 
Published: April 2016

Abstract. Reliable quantification of air–surface fluxes of elemental Hg vapor (Hg0) is crucial for understanding mercury (Hg) global biogeochemical cycles. There have been extensive measurements and modeling efforts devoted to estimating the exchange fluxes between the atmosphere and various surfaces (e.g., soil, canopies, water, snow, etc.) in the past three decades. However, large uncertainties remain due to the complexity of Hg0 bidirectional exchange, limitations of flux quantification techniques and challenges in model parameterization. In this study, we provide a critical review on the state of science in the atmosphere–surface exchange of Hg0. Specifically, the advancement of flux quantification techniques, mechanisms in driving the air–surface Hg exchange and modeling efforts are presented. Due to the semi-volatile nature of Hg0 and redox transformation of Hg in environmental media, Hg deposition and evasion are influenced by multiple environmental variables including seasonality, vegetative coverage and its life cycle, temperature, light, moisture, atmospheric turbulence and the presence of reactants (e.g., O3, radicals, etc.). However, the effects of these processes on flux have not been fundamentally and quantitatively determined, which limits the accuracy of flux modeling. We compile an up-to-date global observational flux database and discuss the implication of flux data on the global Hg budget. Mean Hg0 fluxes obtained by micrometeorological measurements do not appear to be significantly greater than the fluxes measured by dynamic flux chamber methods over unpolluted surfaces (p = 0.16, one-tailed, Mann–Whitney U test). The spatiotemporal coverage of existing Hg0 flux measurements is highly heterogeneous with large data gaps existing in multiple continents (Africa, South Asia, Middle East, South America and Australia). The magnitude of the evasion flux is strongly enhanced by human activities, particularly at contaminated sites. Hg0 flux observations in East Asia are comparatively larger in magnitude than the rest of the world, suggesting substantial re-emission of previously deposited mercury from anthropogenic sources. The Hg0 exchange over pristine surfaces (e.g., background soil and water) and vegetation needs better constraints for global analyses of the atmospheric Hg budget. The existing knowledge gap and the associated research needs for future measurements and modeling efforts for the air–surface exchange of Hg0 are discussed.
Promotion of Osteogenic Differentiation by Amnion/Chorion Membrane Extracts
Authors: Go Yoon Young , Kim Sung Eun , Cho Geum Joon , Chae Sung-Won , Song Jae-Jun 
Published: April 2016

Background The amniotic membrane is a favorable biomaterial to apply in the field of tissue engineering because of its unique biological properties. Human amniotic membranes consist of 2-layered sheets containing numerous growth factors, cytokines and other bioactive substances. Methods In this study, we explored the potential of amnion membrane extracts (AME) and amnion/chorion membrane extracts (A/CME) to promote osteogenic differentiation of osteoblast-like (MG-63) cells. MG-63 cells were cultured in osteogenic induction medium (OIM) with or without 100 µg/mL of AME or A/CME. To determine the early and late differentiation of osteogenesis, alkaline phosphatase (ALP) activity and calcium deposition were measured at 3, 7, 10 and 24 days. Expression of specific genes associated with osteogenic differentiation, including osteocalcin (OCN), osteopontin (OPN), runt domain-containing transcription factor (Runx2) and osterix (OSX) was also determined. Results In vitro experiments demonstrated that A/CME increased ALP activity, osteogenic gene expression and mineralization under osteogenic-inducing conditions. Notably, we found that A/CME contained growth factors related to osteogenesis, including fibroblast growth factors and transforming growth factors, which potentially promoted osteogenic differentiation of MG-63 cells to a greater extent than AME. Conclusions These results indicate that A/CME is capable of providing growth factors and other substrates for osteogenic differentiation, which significantly increased the efficacy of osteogenesis in MG-63 cells. Taken together, the results of this study suggest that human A/CME is a promising biomaterial with therapeutic potential in bone regeneration applications.
Association between Manganese Superoxide Dismutase (MnSOD) Polymorphism and Prostate Cancer Susceptibility: A Meta-Analysis
Authors: Li Xiao , Shen Min , Cai Hongzhou , Liu Kang , Liu Yiyang , Huang Zhengkai , Liang Chao , Deng Xiaheng , Ye Jiaxin , Zou Qing , Li Jie 
Published: April 2016

Background Previous studies have investigated the relationship between manganese superoxide dismutase (MnSOD) Val16Ala polymorphism and prostate cancer susceptibility, but the results have remained controversial. This meta-analysis was therefore performed to clarify this association. Methods The databases PubMed, Embase and Web of Science were searched for relevant available studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Publication bias was estimated using Begg's funnel plots and Egger's regression test. Trial sequential analysis was used to reduce the risk of type I error and estimate whether the evidence of the results was sufficient. Results Overall, a significant increased risk of prostate cancer was associated with MnSOD Val16Ala polymorphism for the heterozygote model (OR = 1.14; 95% CI, 1.05-1.24), homozygote model (OR = 1.18; 95% CI, 1.02-1.36), dominant model (OR = 1.24; 95% CI, 1.07-1.44) and recessive model (OR = 1.10; 95% CI, 0.96-1.24). In the subgroup analysis by genotyping method, the results were statistically significant for the TaqMan and PCR-RFLP methods. In addition, when stratified by sample size, statistically significant increased risks were found among both large samples and small samples. Furthermore, when stratified by source of control, significant results were detected in both population-based controls and hospital-based controls. By trial sequential analyses, these findings in the current study were shown to be based on sufficient evidence. Conclusions This meta-analysis indicated that the Ala allele of the MnSOD gene polymorphism increases prostate cancer susceptibility.