bluuebunny/crossref_metadata_2025_split huggingface dataset:
La participation du Portugal à la grande guerre
Authors: Teixeira Nuno Severiano 
Published: April 2018

La participation du Portugal à la Grande Guerre, Nuno Severiano Teixeira.
Le 9 mars 1916, date de la déclaration de guerre de l'Allemagne au Portugal, occulte le fait, méconnu, d'un Portugal en guerre de facto contre l'Allemagne depuis l'été 1914, au Mozambique et en Angola. Cette date masque aussi l'essentiel : d'une part, les raisons qui ont conduit le Portugal à rompre sa neutralité traditionnelle pour entrer en guerre aux côtés de l'Entente ; d'autre part, la conduite d'une guerre marquée, du côté portugais, par le traumatisme de la bataille de la Lys. Aux raisons généralement invoquées à cette entrée en guerre - défense des colonies africaines, volonté de s'assurer une place dans le concert des nations en se démarquant de l'encombrant voisin espagnol resté neutre, Nuno Severiano Teixeira juxtapose la thèse neuve d'une entrée en guerre motivée par des raisons d'ordre interne : la consolidation et la légitimation de la République.
Bilan historiographique des recherches sur l'état nouveau
Authors: Rosas Fernando 
Published: April 2018

Bilan historiographique des recherches sur l'État nouveau, Fernando Rosas.
Vingt-cinq ans après la « révolution des œillets », on peut procéder à un bilan de l'évolution des trois étapes de la recherche consacrée à l'Etat nouveau. Au temps du salazarisme, les recherches en histoire contemporaine, pratiquement inexistantes, étaient suspectées d'esprit partisan. Les rares recours à l'historiographie du 20e siècle portugais servaient à légitimer la résistance et la lutte contre la dictature. Après le processus révolutionnaire, la démocratisation de la société portugaise a permis la découverte et l'appropriation de l'histoire contemporaine. Cette deuxième période a été marquée par une véritable explosion de l'historiographie contemporaine. Plus de vingt ans après 1974, l'historiographie de l'Etat nouveau est non seulement l'un des secteurs les plus dynamiques de la recherche et de la production des sciences sociales portugaises, mais c'est aussi l'une des thématiques les plus populaires auprès du grand public. Ces recherches sont confrontées à des problèmes théoriques et méthodologiques car l'histoire de l'Etat nouveau est une discipline récente au Portugal.
Colors and Shapes of the Irregular Planetary Satellites
Authors: Graykowski Ariel , Jewitt David 
Published: April 2018

Abstract
It is widely recognized that the irregular satellites of the giant planets were captured from initially heliocentric orbits. However, the mechanism of capture and the source region from which they were captured both remain unknown. We present an optical color survey of 43 irregular satellites of the outer planets conducted using the LRIS camera on the 10 m telescope at the Keck Observatory in Hawaii. The measured colors are compared to other planetary bodies in search for similarities and differences that may reflect upon the origin of the satellites. We find that ultrared matter (with color index B–R ≥ 1.6), while abundant in the Kuiper Belt and Centaur populations, is depleted from the irregular satellites. We also use repeated determinations of the absolute magnitudes to make a statistical estimate of the average shape of the irregular satellites. The data provide no evidence that the satellites and the main-belt asteroids are differently shaped, consistent with collisions as the major agent shaping both.
Stellar Variability at the Main-sequence Turnoff of the Intermediate-age LMC Cluster NGC 1846*
Authors: Salinas R. , Pajkos M. A. , Vivas A. K. , Strader J. , Contreras Ramos R. 
Published: April 2018

Abstract
Intermediate-age (IA) star clusters in the Large Magellanic Cloud (LMC) present extended main-sequence turn-offs (MSTO) that have been attributed to either multiple stellar populations or an effect of stellar rotation. Recently it has been proposed that these extended main sequences can also be produced by ill-characterized stellar variability. Here we present Gemini-S/Gemini Multi-Object Spectrometer (GMOS) time series observations of the IA cluster NGC 1846. Using differential image analysis, we identified 73 new variable stars, with 55 of those being of the Delta Scuti type, that is, pulsating variables close the MSTO for the cluster age. Considering completeness and background contamination effects, we estimate the number of δ Sct belonging to the cluster between 40 and 60 members, although this number is based on the detection of a single δ Sct within the cluster half-light radius. This amount of variable stars at the MSTO level will not produce significant broadening of the MSTO, albeit higher-resolution imaging will be needed to rule out variable stars as a major contributor to the extended MSTO phenomenon. Though modest, this amount of δ Sct makes NGC 1846 the star cluster with the highest number of these variables ever discovered. Lastly, our results present a cautionary tale about the adequacy of shallow variability surveys in the LMC (like OGLE) to derive properties of its δ Sct population.
Detecting Weak Spectral Lines in Interferometric Data through Matched Filtering
Authors: Loomis Ryan A. , Öberg Karin I. , Andrews Sean M. , Walsh Catherine , Czekala Ian , Huang Jane , Rosenfeld Katherine A. 
Published: April 2018

Abstract
Modern radio interferometers enable observations of spectral lines with unprecedented spatial resolution and sensitivity. In spite of these technical advances, many lines of interest are still at best weakly detected and therefore necessitate detection and analysis techniques specialized for the low signal-to-noise ratio (S/N) regime. Matched filters can leverage knowledge of the source structure and kinematics to increase sensitivity of spectral line observations. Application of the filter in the native Fourier domain improves S/N while simultaneously avoiding the computational cost and ambiguities associated with imaging, making matched filtering a fast and robust method for weak spectral line detection. We demonstrate how an approximate matched filter can be constructed from a previously observed line or from a model of the source, and we show how this filter can be used to robustly infer a detection significance for weak spectral lines. When applied to ALMA Cycle 2 observations of CH3OH in the protoplanetary disk around TW Hya, the technique yields a ≈53% S/N boost over aperture-based spectral extraction methods, and we show that an even higher boost will be achieved for observations at higher spatial resolution. A Python-based open-source implementation of this technique is available under the MIT license at http://github.com/AstroChem/VISIBLE.
Extraplanar H ii Regions in Spiral Galaxies. II. In Situ Star Formation in the Interstellar Thick Disk of NGC 4013
Authors: Howk J. Christopher , Rueff Katherine M. , Lehner Nicolas , Wotta Christopher B. , Croxall Kevin , Savage Blair D. 
Published: April 2018

Abstract
We present observations of an Hα-emitting knot in the thick disk of NGC 4013, demonstrating it is an H ii region surrounding a cluster of young hot stars z = 860 pc above the plane of this edge-on spiral galaxy. With LBT/MODS spectroscopy we show that this H ii region has an Hα luminosity ∼4–7 times that of the Orion nebula, with an implied ionizing photon production rate log Q
0 ≈ 49.4 (photons s−1). HST/WFPC2 imaging reveals an associated blue continuum source with M

V
= −8.21 ± 0.24. Together, these properties demonstrate that the H ii region is powered by a young cluster of stars formed in situ in the thick disk, with an ionizing photon flux equivalent to ∼6 O7 V stars. If we assume ≈6 other extraplanar Hα-emitting knots are H ii regions, the total thick disk star formation rate of NGC 4013 is ∼5 × 10−4
M
⊙ yr−1. The star formation likely occurs in the dense clouds of the interstellar thick disk seen in optical images of dust extinction and CO emission.
A Model for Negative Ion Chemistry in Titan’s Ionosphere
Authors: Mukundan Vrinda , Bhardwaj Anil 
Published: April 2018

Abstract
We developed a one-dimensional photochemical model for the dayside ionosphere of Titan for calculating the density profiles of negative ions under steady-state photochemical equilibrium condition. We concentrated on the T40 flyby of the Cassini orbiter and used the in situ measurements from instruments on board Cassini as input to the model. Using the latest available reaction rate coefficients and dissociative electron attachment cross sections, the densities of 10 anions are calculated. Our study shows CN− as the dominant anion, followed by C3N−, which agrees with the results of previous calculations. We suggest that H− could be an important anion in Titan’s ionosphere and is the second most abundant anion at altitudes greater than 1200 km. The main production channel of the major ion CN− is the reaction of H− with HCN. The H− also play a major role in the production of anions C2H−, C6H−, and OH−. We present a comparison of the calculated ion density profiles with the relative density profiles derived using recently reported Cassini CAPS/ELS observations.
Extraplanar H ii Regions in Spiral Galaxies. I. Low-metallicity Gas Accreting through the Disk-halo Interface of NGC 4013
Authors: Howk J. Christopher , Rueff Katherine M. , Lehner Nicolas , Wotta Christopher B. , Croxall Kevin , Savage Blair D. 
Published: April 2018

Abstract
The interstellar thick disks of galaxies serve as the interface between the thin star-forming disk, where feedback-driven outflows originate, and the distant halo, the repository for accreted gas. We present optical emission line spectroscopy of a luminous, thick disk H ii region located at z = 860 pc above the plane of the spiral galaxy NGC 4013 taken with the Multi-Object Double Spectrograph on the Large Binocular Telescope. This nebula, with an Hα luminosity ∼4–7 times that of the Orion nebula, surrounds a luminous cluster of young, hot stars that ionize the surrounding interstellar gas of the thick disk, providing a measure of the properties of that gas. We demonstrate that strong emission line methods can provide accurate measures of relative abundances between pairs of H ii regions. From our emission line spectroscopy, we show that the metal content of the thick disk H ii region is a factor of ≈2 lower than gas in H ii regions at the midplane of this galaxy (with the relative abundance of O in the thick disk lower by −0.32 ± 0.09 dex). This implies incomplete mixing of material in the thick disk on small scales (hundreds of parsecs) and that there is accretion of low-metallicity gas through the thick disks of spirals. The inclusion of low-metallicity gas this close to the plane of NGC 4013 is reminiscent of the recently proposed “fountain-driven” accretion models.
Tracers of Stellar Mass-loss. II. Mid-IR Colors and Surface Brightness Fluctuations
Authors: González-Lópezlira Rosa A. 
Published: April 2018

Abstract
I present integrated colors and surface brightness fluctuation magnitudes in the mid-infrared (IR), derived from stellar population synthesis models that include the effects of the dusty envelopes around thermally pulsing asymptotic giant branch (TP-AGB) stars. The models are based on the Bruzual & Charlot CB* isochrones; they are single-burst, range in age from a few Myr to 14 Gyr, and comprise metallicities between Z = 0.0001 and Z = 0.04. I compare these models to mid-IR data of AGB stars and star clusters in the Magellanic Clouds, and study the effects of varying self-consistently the mass-loss rate, the stellar parameters, and the output spectra of the stars plus their dusty envelopes. I find that models with a higher than fiducial mass-loss rate are needed to fit the mid-IR colors of “extreme” single AGB stars in the Large Magellanic Cloud. Surface brightness fluctuation magnitudes are quite sensitive to metallicity for 4.5 μm and longer wavelengths at all stellar population ages, and powerful diagnostics of mass-loss rate in the TP-AGB for intermediate-age populations, between 100 Myr and 2–3 Gyr.
Measuring the Binary Black Hole Mass Spectrum with an Astrophysically Motivated Parameterization
Authors: Talbot Colm , Thrane Eric 
Published: April 2018

Abstract
Gravitational-wave detections have revealed a previously unknown population of stellar mass black holes with masses above 20 M
⊙. These observations provide a new way to test models of stellar evolution for massive stars. By considering the astrophysical processes likely to determine the shape of the binary black hole mass spectrum, we construct a parameterized model to capture key spectral features that relate gravitational-wave data to theoretical stellar astrophysics. In particular, we model the signature of pulsational pair-instability supernovae, which are expected to cause all stars with initial mass 100 M
⊙ ≲ M ≲ 150 M
⊙ to form ∼40 M
⊙ black holes. This would cause a cutoff in the black hole mass spectrum along with an excess of black holes near 40 M
⊙. We carry out a simulated data study to illustrate some of the stellar physics that can be inferred using gravitational-wave measurements of binary black holes and demonstrate several such inferences that might be made in the near future. First, we measure the minimum and maximum stellar black hole mass. Second, we infer the presence of a peak due to pair-instability supernovae. Third, we measure the distribution of black hole mass ratios. Finally, we show how inadequate models of the black hole mass spectrum lead to biased estimates of the merger rate and the amplitude of the stochastic gravitational-wave background.
Detection of [O iii] at z ∼ 3: A Galaxy Above the Main Sequence, Rapidly Assembling Its Stellar Mass
Authors: Vishwas Amit , Ferkinhoff Carl , Nikola Thomas , Parshley Stephen C. , Schoenwald Justin P. , Stacey Gordon J. , Higdon Sarah J. U. , Higdon James L. , Weiss Axel , Güsten Rolf , Menten Karl M. 
Published: April 2018

Abstract
We detect bright emission in the far-infrared (far-IR) fine structure [O iii] 88 μm line from a strong lensing candidate galaxy, H-ATLAS J113526.3-014605, hereafter G12v2.43, at z = 3.127, using the second-generation Redshift (z) and Early Universe Spectrometer (ZEUS-2) at the Atacama Pathfinder Experiment Telescope (APEX). This is only the fifth detection of this far-IR line from a submillimeter galaxy at the epoch of galaxy assembly. The observed [O iii] luminosity of 7.1 × 109

L
⊙ likely arises from H ii regions around massive stars, and the amount of Lyman continuum photons required to support the ionization indicate the presence of (1.2–5.2) × 106

equivalent O5.5 or higher stars, where μ would be the lensing magnification factor. The observed line luminosity also requires a minimum mass of ∼2 × 108

M
⊙ in ionized gas, that is 0.33% of the estimated total molecular gas mass of 6 × 1010

M
⊙. We compile multi-band photometry tracing rest-frame ultraviolet to millimeter continuum emission to further constrain the properties of this dusty high-redshift, star-forming galaxy. Via SED modeling we find G12v2.43 is forming stars at a rate of 916

M
⊙ yr−1 and already has a stellar mass of 8 × 1010

M
⊙. We also constrain the age of the current starburst to be

Myr, making G12v2.43 a gas-rich galaxy lying above the star-forming main sequence at z ∼ 3, undergoing a growth spurt, and it could be on the main sequence within the derived gas depletion timescale of ∼66 Myr.
I. Jet Formation and Evolution Due to 3D Magnetic Reconnection
Authors: González-Avilés J. J. , Guzmán F. S. , Fedun V. , Verth G. , Shelyag S. , Regnier S. 
Published: April 2018

Abstract
Using simulated data-driven, 3D resistive MHD simulations of the solar atmosphere, we show that 3D magnetic reconnection may be responsible for the formation of jets with the characteristics of Type II spicules. We numerically model the photosphere-corona region using the C7 equilibrium atmosphere model. The initial magnetic configuration is a 3D potential magnetic field, extrapolated up to the solar corona region from a dynamic realistic simulation of the solar photospheric magnetoconvection model that mimics the quiet-Sun. In this case, we consider a uniform and constant value of the magnetic resistivity of 12.56 Ω m. We have found that the formation of the jet depends on the Lorentz force, which helps to accelerate the plasma upward. Analyzing various properties of the jet dynamics, we found that the jet structure shows a Doppler shift close to regions with high vorticity. The morphology, the upward velocity covering a range up to 130 km s−1, and the timescale formation of the structure between 60 and 90 s, are similar to those expected for Type II spicules.
Investigating the Response of Loop Plasma to Nanoflare Heating Using RADYN Simulations
Authors: Polito V. , Testa P. , Allred J. , De Pontieu B. , Carlsson M. , Pereira T. M. D. , Gošić Milan , Reale Fabio 
Published: April 2018

Abstract
We present the results of 1D hydrodynamic simulations of coronal loops that are subject to nanoflares, caused by either in situ thermal heating or nonthermal electron (NTE) beams. The synthesized intensity and Doppler shifts can be directly compared with Interface Region Imaging Spectrograph (IRIS) and Atmospheric Imaging Assembly (AIA) observations of rapid variability in the transition region (TR) of coronal loops, associated with transient coronal heating. We find that NTEs with high enough low-energy cutoff (

) deposit energy in the lower TR and chromosphere, causing blueshifts (up to ∼20 km s−1) in the IRIS Si iv lines, which thermal conduction cannot reproduce. The

threshold value for the blueshifts depends on the total energy of the events (≈5 keV for 1024 erg, up to 15 keV for 1025 erg). The observed footpoint emission intensity and flows, combined with the simulations, can provide constraints on both the energy of the heating event and

. The response of the loop plasma to nanoflares depends crucially on the electron density: significant Si iv intensity enhancements and flows are observed only for initially low-density loops (<109 cm−3). This provides a possible explanation of the relative scarcity of observations of significant moss variability. While the TR response to single heating episodes can be clearly observed, the predicted coronal emission (AIA 94 Å) for single strands is below current detectability and can only be observed when several strands are heated closely in time. Finally, we show that the analysis of the IRIS Mg ii chromospheric lines can help further constrain the properties of the heating mechanisms.
Three-dimensional MHD Simulations of Solar Prominence Oscillations in a Magnetic Flux Rope
Authors: Zhou Yu-Hao , Xia C. , Keppens R. , Fang C. , Chen P. F. 
Published: April 2018

Abstract
Solar prominences are subject to all kinds of perturbations during their lifetime, and frequently demonstrate oscillations. The study of prominence oscillations provides an alternative way to investigate their internal magnetic and thermal structures because the characteristics of the oscillations depend on their interplay with the solar corona. Prominence oscillations can be classified into longitudinal and transverse types. We perform three-dimensional ideal magnetohydrodynamic simulations of prominence oscillations along a magnetic flux rope, with the aim of comparing the oscillation periods with those predicted by various simplified models and examining the restoring force. We find that the longitudinal oscillation has a period of about 49 minutes, which is in accordance with the pendulum model where the field-aligned component of gravity serves as the restoring force. In contrast, the horizontal transverse oscillation has a period of about 10 minutes and the vertical transverse oscillation has a period of about 14 minutes, and both of them can be nicely fitted with a two-dimensional slab model. We also find that the magnetic tension force dominates most of the time in transverse oscillations, except for the first minute when magnetic pressure overwhelms it.
Les acteurs ruraux dans la constitution de l’image de leur territoire
Authors: Brun Jérémie 
Published: April 2018

La recherche en marketing territorial s’est peu intéressée aux initiatives rurales, alors qu’il existe un nombre important de démarches dans ces territoires. En effet, les acteurs des territoires ruraux ont structuré une gouvernance à partir de la nécessité de collaborer, pour construire une image et un développement cohérent, malgré la crainte des acteurs locaux. C’est notamment ce qu’il est possible d’observer à travers l’étude de deux cas concrets en France, qui montrent deux formes principales de crainte : l’isolement territorial et le manque de moyens financiers.
Un train de plénipotentiaires : les ambassadeurs britanniques et leur équipage en chemin vers le congrès de Cologne (1673)
Authors: Tessier Alexandre 
Published: April 2018

Cette étude se penche sur la dimension matérielle du périple réalisé au printemps 1673 depuis Londres jusqu’à Cologne par Sir Joseph Williamson et Sir Leoline Jenkins, les deux plénipotentiaires britanniques dépêchés au congrès de paix appelé à se tenir dans la ville rhénane. Comment décrire la composition de la délégation ? Quel itinéraire fut choisi, en fonction de quelles contraintes ou de quels intérêts ? Quelles manifestations ou interactions peut-on observer au long du trajet ? L’exploration de ces trois centres d’intérêt, que peut offrir tout train d’ambassadeur, révèle la tension qui sans cesse s’exerce entre la nécessité de présenter un cortège flatteur, et celle de faire face aux lourdes contraintes qu’il entraîne.
Le fœtus mouvementé, la danse et la basse continue de la vie
Authors: Missonnier Sylvain 
Published: April 2018

Le mouvement de l’embryon puis du fœtus constitue pour les professionnels de l’échographie obstétricale une cible sémiologique essentielle.	Simultanément, c’est fréquemment pour les « devenant parents » un jaillissement visuel décisif dans le processus de parentalisation. La motricité fœtale et les pulsations cardiaques y sont interprétées comme la première signature de la vie de l’être conçu avant toute proprioception maternelle et extéroception conjugale.	Cette authentification médicale et parentale de l’immersion de l’enfant virtuel dans la rivière du mouvement ouvre sur les possibles de son épigenèse ontologique dont la mort (l’absence de mouvement) constitue désormais l’ombre indissociable.	La clinique des consultations parents-fœtus/bébé illustre bien l’amplitude des variations de cette chorégraphie périnatale entre Éros et Thanatos.	L’art de la danse en commémore toute la vie durant l’empreinte inaugurale aquatique prénatale du « premier monde » et les avatars aériens postnatal du second.
Les ancrages corporels du langage chez les enfants autistes
Authors: Mazéas Dominique 
Published: April 2018

Les recherches menées par le groupe « Émergences du langage » de la CIPPA invitent à prendre en compte l’importance des ancrages corporels dans le déploiement du langage verbal chez les personnes autistes. Les réflexes toniques et l’utilisation inconsciente des substances corporelles correspondent à une forme d’expression du patient. Le thérapeute cherche à en révéler la signification émotionnelle afin de rendre cette expressivité partageable. Le patient investit alors davantage l’ensemble de son corps dans la rencontre avec l’autre. Les différents mouvements qui animent l’espace de sa bouche se coordonnent plus facilement et l’intégration psychique de cette coordination libère le plaisir de vocaliser. Les gestes ou les commentaires du thérapeute qui permettent un effet de représentation des angoisses de disparition du patient lorsqu’il s’adresse à l’autre, facilitent ensuite le détachement du langage de sa base corporelle.