bluuebunny/crossref_metadata_2025 huggingface dataset:
Sentidos Atribuídos ao Mundo do Trabalho pelas Crianças: a Escola como parte desse Processo
Authors: MIRANDA Amanda Antunes , COELHO Raquel Nascimento
Published: October 2019

Several studies demonstrate the importance of articulating children with the phenomenon of work, whereas they already had knowledge and opinions, by starting from their social experiences and the influences produced by socializing institutions. This study aimed to investigate the attributed meanings of work by children, from a private school in the city of Fortaleza – CE, by analyzing the repercussions on the process. Based on Bardin’s Content Analysis to analyze children’s explanatory speeches about their drawings and semi-structured interviews, by demonstrating that the phenomenon of working was denoted as essential for a human to consume and to obtain sustenance and social recognition. The school was pointed out as a way of increasing the future possibilities for this group of children, by showing that the “great” work is the one what would be built through the study. The necessary to expand the interview’s target audience is evidenced in order to discuss, from socially different places, the aspects of labor social division which produces new signification modes of this phenomenon, as well as to construct strategies of intervention which may contribute with the construction process promotes spaces of citizenship and social and political participation.
Recebido em: 17/04/2017.Aprovado em: 01/03/2018
Práticas de Leitura na EJA: Contribuições para a Formação Política de Leitores no Ensino Médio
Authors: ALVES João Paulo da Conceição , PENHA Ana Cláudia Figueiredo Martins
Published: October 2019

The research aimed toanalyse the relevance of reading practices in order to have a larger number of students that actually read more books on adult education.Corresponds a case study of a public school, in Macapá-AP. The data was collected qualitatively through semi-structured interviews with teachers of this modality. Analysing data was the technique used to interpreting the data itself. The results show that just a few teachers develop a variety of reading practices in the school,diversify the materials and its teaching methodology, they propose discussions for the students to expose their point of view,however it is fragile still when it comes to political aspects, due to the lack of: a bibliographic collection, reading habits and a short workload.
Recebido em: 11/12/2016.Aprovado em: 02/04/2018.
The Soul of the Leningrad Blockade: Leonid Chupiatov’s Bogomater of the Protecting Veil
Authors: O'Bell Leslie
Published: October 2019

The present essay is the first article devoted to the religious paintings of the Soviet artist Leonid Chupiatov (1890–1941), with special attention to his Veil of the Mother of God over the Dying City, created during the desolate Leningrad siege winter of 1941-42. Dmitry Likhachev memorably called this work the “soul of the siege.” The article analyzes what it offers the viewer directly, as a modern version of the traditional image. It goes on to place the painting in the context of Chupiatov’s religious production, both during the siege and previous to it and to explore the circumstances which ensured its preservation against all odds. An apocalyptic context which challenges even divine compassion and saving grace, one which recapitulates the forty days of Christ in the desert—such is the immediate context of Chupiatov’s icon of the Protecting Veil in his artistic work from the winter of 1941–42. In the end, the survival of this powerful image becomes comprehensible through the connections of a fragmented religious-philosophical confraternity. The article thus represents a step towards finally acknowledging the presence of the religious image in the artistic response to the Leningrad siege.
Animais exóticos de origem europeia ou africana entre povos indígenas nas terras baixas da América do Sul Notas para pesquisas futuras
Authors: Ferreira Vander Velden Felipe
Published: October 2019

Este artigo busca sugerir um conjunto de novos rumos para a investigação dos fenômenos ligados à introdução, difusão, adaptação, circulação, exploração e uso de animais de origem exótica entre os povos indígenas nas terras baixas sul-americanas, de modo a constituir um mais completo panorama dos impactos materiais e simbólicos desses seres nos contextos ameríndios. Partindo da coleta e análise de informações históricas e etnográficas acerca do aparecimento e da incorporação desses animais – a saber, galinhas, bois, cavalos, cabras, bodes, porcos, cachorros, gatos, coelhos, ratos, pombos e outros – nos mais distintos povos nativos na América do Sul, busca-se extrair uma (ou múltiplas) história(s) alternativa(s) desses adventícios, bem como compreender as linhas gerais que, fundamentadas na ideia de um pensamento ameríndio, podem caracterizar a adoção e aclimatação dessas espécies nas cosmologias e práticas sociais indígenas, configurando novas formas de conhecimento zoológico e mesmo zootécnico e veterinário, bem como construções singulares da domesticidade e de outros conceitos que usualmente descrevem as relações entre humanos e animais. Espera-se aliar os estudos em etnologia americanista com pesquisas antropológicas sobre relações entre humanos e animais, dois campos que, apesar da centralidade dos não humanos nas vidas e cosmologias indígenas, ainda pouco dialogam no campo etnológico americanista.
MARKET KNOWLEDGE AND NEW PRODUCT PERFORMANCE: THE MEDIATING EFFECTS OF NEW PRODUCT CREATIVITY
Authors: Dabrowski Dariusz
Published: October 2019

Market knowledge is recognised as an important predictor of new product performance, which existing studies have proven. However, a missing link in this relationship is creativity, and specifically, as a natural process in product innovation. This study aims to examine a model that includes two mediating mechanisms between market knowledge scope and two new product outcomes, respectively: a new product’s competitive advantage and its commercial success. In both cases two mediators are used that represent dimensions of creativity—i.e. a product’s meaningfulness and novelty. The model was tested on a sample of 374 Polish medium-high- and high-technology companies using structural equation modelling. The results indicated that market knowledge is transferred to both new product outcomes through new product creativity, albeit somewhat differently. The first mediating mechanism, which explains the factor of competitive advantage, operates only through the indirect effects of both the product’s meaningfulness and its novelty. The second mechanism works directly, through the market knowledge’s effect on commercial success, as well as indirectly, through product meaningfulness. Subsequently, theoretical and managerial implications as well as indications for future research are provided based on these findings.
RESEARCH ON RAIL AND MARITIME TRANSPORT INTEROPERABILITY IN THE AREA OF INFORMATION SYSTEMS: THE CASE OF LITHUANIA
Authors: Jarašūnienė Aldona , Čižiūnienė Kristina , Petraška Artūras
Published: October 2019

With the acceleration of globalization processes and increased international cooperation, freight transport routes are expanding, which requires new solutions for the most efficient use of various modes of transport. One of the most important factors that may improve the efficiency of the interoperability of different transport modes is information exchange allowing to plan transport flows in advance, exploiting benefits of the maritime and rail transport and minimizing its disadvantages. Precise information allows to find the most efficient mode of transport for the freight transportation chain. Precise information is necessary for effective management of information flows to ensure interoperability between the transport modes. This article analyses the specificity of railway and maritime transport modes, hence research questionnaire of Lithuanian transport companies is performed to present the results to show the most significant elements of railway and maritime transport interoperability. The completed expert evaluation enabled to prioritize the sequence of elements to ensure the efficient interoperability between rail and maritime transport.
Probing the Hill Sphere of (486958) 2014 MU69. II. Hubble Space Telescope Fine Guidance Sensors Observations during the 2018 August 4 Stellar Occultation
Authors: Kammer Joshua A. , Becker Tracy M. , Retherford Kurt D. , Stern S. Alan , Olkin Catherine B. , Buie Marc W. , Spencer John R. , Bosh Amanda S. , Wasserman Lawrence H.
Published: October 2019

We observed the 2018 August 4 stellar occultation by the Kuiper Belt object (486958) 2014 MU69, the first close flyby target of the extended New Horizons mission. Rather than capture a solid-body occultation by the KBO itself, our program aimed to constrain the opacity of rings, moons, or other debris in the nearby environment. We used the Hubble Space Telescope Fine Guidance Sensors (HST FGS) instrument in TRANS F583W mode to collect 40 Hz time resolution photometry of the stellar occultation star for one HST orbit during this observation. We present the results of reduction and calibration of the HST FGS photometry, and set upper limits on τ of ∼0.02–0.08 for rings or other dust opacity within the Hill sphere of (486958) 2014 MU69 at distances ranging from ∼1660 to ∼57,700 km from the main body.
SILVERRUSH. VIII. Spectroscopic Identifications of Early Large-scale Structures with Protoclusters over 200 Mpc at z ∼ 6–7: Strong Associations of Dusty Star-forming Galaxies
Authors: Harikane Yuichi , Ouchi Masami , Ono Yoshiaki , Fujimoto Seiji , Donevski Darko , Shibuya Takatoshi , Faisst Andreas L. , Goto Tomotsugu , Hatsukade Bunyo , Kashikawa Nobunari , Kohno Kotaro , Hashimoto Takuya , Higuchi Ryo , Inoue Akio K. , Lin Yen-Ting , Martin Crystal L. , Overzier Roderik , Smail Ian , Toshikawa Jun , Umehata Hideki , Ao Yiping , Chapman Scott , Clements David L. , Im Myungshin , Jing Yipeng , Kawaguchi Toshihiro , Lee Chien-Hsiu , Lee Minju M. , Lin Lihwai , Matsuoka Yoshiki , Marinello Murilo , Nagao Tohru , Onodera Masato , Toft Sune , Wang Wei-Hao
Published: October 2019

We have obtained three-dimensional maps of the universe in ∼200 × 200 × 80 comoving Mpc3 (cMpc3) volumes each at z = 5.7 and 6.6 based on a spectroscopic sample of 179 galaxies that achieves ≳80% completeness down to the Lyα luminosity of

, based on our Keck and Gemini observations and the literature. The maps reveal filamentary large-scale structures and two remarkable overdensities made out of at least 44 and 12 galaxies at z = 5.692 (z57OD) and z = 6.585 (z66OD), respectively, making z66OD the most distant overdensity spectroscopically confirmed to date, with >10 spectroscopically confirmed galaxies. We compare spatial distributions of submillimeter galaxies at z ≃ 4–6 with our z = 5.7 galaxies forming the large-scale structures, and detect a 99.97% signal of cross-correlation, indicative of a clear coincidence of dusty star-forming galaxy and dust-unobscured galaxy formation at this early epoch. The galaxies in z57OD and z66OD are actively forming stars with star-formation rates (SFRs) ≳5 times higher than the main sequence, and particularly the SFR density in z57OD is 10 times higher than the cosmic average at the redshift (a.k.a. the Madau-Lilly plot). Comparisons with numerical simulations suggest that z57OD and z66OD are protoclusters that are progenitors of the present-day clusters with halo masses of ∼1014
M
⊙.
Turbulence Driven by Stellar Jets, the Possibility and the Efficiency
Authors: Sheikhnezami Somayeh , Abgharian-Afoushteh Mohsen
Published: October 2019

We investigate the feedback of the stellar jets on the surrounding interstellar gas based on 2D and 3D simulations applying HD and MHD modules of the PLUTO 4.2 code. The main question we address is whether the stellar jet can be considered as a turbulence driver into the interstellar gas. In addition, we investigate the most effective circumstances in which the driven turbulence is larger and can survive for a longer timescale in the ambient gas. We present a case study of different parameter runs including the jet Mach number, the initial jet velocity field, the background magnetic field geometries and the interacting jets. We also study the environmental effects on the jet-gas interaction by considering the non-homogeneous surrounding gas containing the clumps in the model setup. Among different setups, we find (1) a higher jet Mach number, (2) a rotating jet, (3) a jet propagating in a magnetized environment, (4) a jet propagating in a non-homogeneous environment, and (5) the interacting jets produce more fluctuations and random motions in the entrained gas, which can survive for a longer timescale. In addition, we perform the 3D simulations of jet-ambient gas interaction and we find that the amount of (subsonic–supersonic) fluctuation increases compared to the axisymmetric run, and the entrained gas gains higher velocities in a 3D run. In total, we confirm the previous finding that the stellar jets can transfer the turbulence on neighboring regions and are not sufficient drivers of the large-scale supersonic turbulence in molecular clouds.
Relativistic Astronomy. III. Test of Special Relativity via Doppler Effect
Authors: Yang Yuan-Pei , Zhu Jin-Ping , Zhang Bing
Published: October 2019

The “Breakthrough Starshot” program is planning to send transrelativistic probes to travel to nearby stellar systems within decades. Because the probe velocity is designed to be a good fraction of the light speed, Zhang & Li recently proposed that these transrelativistic probes can be used to study astronomical objects and to test special relativity. In this work, we propose some methods to test special relativity and constrain photon mass using the Doppler effect with the images and spectral features of astronomical objects as observed in the transrelativistic probes. We introduce more general theories to set up the framework of testing special relativity, including the parametric general Doppler effect and the Doppler effect with massive photons. We find that by comparing the spectra of a certain astronomical object, one can test Lorentz invariance and constrain photon mass. Additionally, using the imaging and spectrograph capabilities of transrelativistic probes, one can test time dilation and constrain photon mass. For a transrelativistic probe with velocity v ∼ 0.2c, aperture D ∼ 3.5 cm, and spectral resolution R ∼ 100 (or 1000), we find that the probe velocity uncertainty can be constrained to σ

v
 ∼ 0.01c (or 0.001c), and the time dilation factor uncertainty can be constrained to

(or 0.001), where

is the time dilation factor and γ is the Lorentz factor. Meanwhile, the photon mass limit is set to m

γ
 ≲ 10−33 g, which is slightly lower than the energy of the optical photon.
Spectrophotometric Redshifts for z ∼ 1 Galaxies and Predictions for Number Densities with WFIRST and Euclid
Authors: Joshi Bhavin A. , Cohen Seth , Windhorst Rogier A. , Jansen Rolf , Pirzkal Norbert , Hathi Nimish P.
Published: October 2019

We investigate the accuracy of 4000 Å/Balmer-break based redshifts by combining Hubble Space Telescope (HST) grism data with photometry. The grism spectra are from the Probing Evolution And Reionization Spectroscopically survey with HST using the G800L grism on the Advanced Camera for Surveys. The photometric data come from a compilation by the 3D-HST collaboration of imaging from multiple surveys (notably, the Cosmic Assembly Near-infrared Deep Extragalactic Survey (CANDELS) and 3D-HST). We show evidence that spectrophotometric redshifts (SPZs) typically improve the accuracy of photometric redshifts by ∼17%–60%. Our SPZ method is a template-fitting-based routine that accounts for correlated data between neighboring points within grism spectra via the covariance matrix formalism and also accounts for galaxy morphology along the dispersion direction. We show that the robustness of the SPZ is directly related to the fidelity of the D4000 measurement. We also estimate the accuracy of continuum-based redshifts, i.e., for galaxies that do not contain strong emission lines, based on the grism data alone (

). Given that future space-based observatories like Wide Field InfraRed Survey Telescope and Euclid will spend a significant fraction of time on slitless spectroscopic observations, we estimate number densities for objects with

. We predict ∼700–4400 galaxies degree−2 for galaxies with D4000 > 1.1 and

to a limiting depth of i

AB
 = 24 mag. This is especially important in the absence of an accompanying rich photometric data set like the existing one for the CANDELS fields, where redshift accuracy from future surveys will rely only on the presence of a feature like the 4000 Å/Balmer breaks or the presence of emission lines within the grism spectra.
A Triple AGN in a Mid-infrared Selected Late-stage Galaxy Merger
Authors: Pfeifle Ryan W. , Satyapal Shobita , Manzano-King Christina , Cann Jenna , Sexton Remington O. , Rothberg Barry , Canalizo Gabriela , Ricci Claudio , Blecha Laura , Ellison Sara L. , Gliozzi Mario , Secrest Nathan J. , Constantin Anca , Harvey Jenna B.
Published: October 2019

The coevolution of galaxies and the supermassive black holes (SMBHs) at their centers via hierarchical galaxy mergers is a key prediction of ΛCDM cosmology. As gas and dust are funneled to the SMBHs during the merger, the SMBHs light up as active galactic nuclei (AGNs). In some cases, a merger of two galaxies can encounter a third galaxy, leading to a triple merger, which would manifest as a triple AGN if all three SMBHs are simultaneously accreting. Using high spatial resolution X-ray, near-IR, and optical spectroscopic diagnostics, we report here a compelling case of an AGN triplet with mutual separations <10 kpc in the advanced merger SDSS J084905.51+111447.2 at z = 0.077. The system exhibits three nuclear X-ray sources, optical spectroscopic line ratios consistent with AGN in each nucleus, a high excitation near-IR coronal line in one nucleus, and broad Paα detections in two nuclei. Hard X-ray spectral fitting reveals a high column density along the line of sight, consistent with the picture of late-stage mergers hosting heavily absorbed AGNs. Our multiwavelength diagnostics support a triple AGN scenario, and we rule out alternative explanations such as star formation activity, shock-driven emission, and emission from fewer than three AGN. The dynamics of gravitationally bound triple SMBH systems can dramatically reduce binary SMBH inspiral timescales, providing a possible means to surmount the “Final Parsec Problem.” AGN triplets in advanced mergers are the only observational forerunner to bound triple SMBH systems and thus offer a glimpse of the accretion activity and environments of the AGNs prior to the gravitationally bound triple phase.
Toward a Model-independent Measurement of the Halo Mass Function with Observables
Authors: Dong Fuyu , Zhang Jun , Yang Xiaohu , Zhang Jiajun , Luo Wentao
Published: October 2019

In the CDM paradigm, the halo mass function is a sensitive probe of the cosmic structure. In observations, halo mass is typically estimated from its relation with other observables. The resulting halo mass function is subject to systematic bias, such as the Eddington bias, due to the scatter or uncertainty in the observable–mass relation. Exact correction for the bias is not easy, as predictions for the observables are typically model-dependent in simulations. In this paper, we point out an interesting feature in the halo mass function of the concordance ΛCDM model: the total halo mass within each evenly spaced logarithmic mass bin is approximately the same over a large mass range. We show that this property allows us to construct an almost bias-free halo mass function using only an observable (as a halo mass estimator) and stacked weak lensing measurements as long as the scatter between the true halo mass and the observable-inferred mass has a stable form in logarithmic units. The method is not sensitive to the form of the mass–observable relation. We test the idea using cosmological simulations, and show that the method performs very well for realistic observables.
A Tale of Two Clusters: An Analysis of Gas-phase Metallicity and Nebular Gas Conditions in Proto-cluster Galaxies at z ∼ 2
Authors: Alcorn Leo Y. , Gupta Anshu , Tran Kim-Vy , Kacprzak Glenn G. , Yuan Tiantian , Cohn Jonathan , Forrest Ben , Glazebrook Karl , Harshan Anishya , Kewley Lisa J. , Labbé Ivo , Nanayakkara Themiya , Papovich Casey , Spitler Lee R. , Straatman Caroline M. S.
Published: October 2019

The ZFIRE survey has spectroscopically confirmed two proto-clusters using the MOSFIRE instrument on Keck I: one at z = 2.095 in COSMOS and another at z = 1.62 in UKIRT Infrared Deep Sky Survey (UDS). Here, we use an updated ZFIRE data set to derive the properties of ionized gas regions of proto-cluster galaxies by extracting fluxes from emission lines Hβ 4861 Å, [O iii] 5007 Å, Hα 6563 Å, [N ii] 6585 Å, and [S ii] 6716,6731 Å. We measure gas-phase metallicity of members in both proto-clusters using two indicators, including a strong-line indicator relatively independent of the ionization parameter and electron density. Proto-cluster and field galaxies in both UDS and COSMOS lie on the same Mass–Metallicity Relation with both metallicity indicators. We compare our results to recent IllustrisTNG results, which report no significant gas-phase metallicity offset between proto-cluster and field galaxies until z = 1.5. This is in agreement with our observed metallicities, where no offset is measured between proto-cluster and field populations. We measure tentative evidence from stacked spectra that indicate UDS high-mass proto-cluster and field galaxies have differing [O iii]/Hβ ratios; however, these results are dependent on the sample size of the high-mass stacks.
Feature Ranking of Active Region Source Properties in Solar Flare Forecasting and the Uncompromised Stochasticity of Flare Occurrence
Authors: Campi Cristina , Benvenuto Federico , Massone Anna Maria , Bloomfield D. Shaun , Georgoulis Manolis K. , Piana Michele
Published: October 2019

Solar flares originate from magnetically active regions (ARs) but not all solar ARs give rise to a flare. Therefore, the challenge of solar flare prediction benefits from an intelligent computational analysis of physics-based properties extracted from AR observables, most commonly line-of-sight or vector magnetograms of the active region photosphere. For the purpose of flare forecasting, this study utilizes an unprecedented 171 flare-predictive AR properties, mainly inferred by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory (SDO/HMI) in the course of the European Union Horizon 2020 FLARECAST project. Using two different supervised machine-learning methods that allow feature ranking as a function of predictive capability, we show that (i) an objective training and testing process is paramount for the performance of every supervised machine-learning method; (ii) most properties include overlapping information and are therefore highly redundant for flare prediction; (iii) solar flare prediction is still—and will likely remain—a predominantly probabilistic challenge.
SN 2016coi (ASASSN-16fp): An Energetic H-stripped Core-collapse Supernova from a Massive Stellar Progenitor with Large Mass Loss
Authors: Terreran G. , Margutti R. , Bersier D. , Brimacombe J. , Caprioli D. , Challis P. , Chornock R. , Coppejans D. L. , Dong Subo , Guidorzi C. , Hurley K. , Kirshner R. , Migliori G. , Milisavljevic D. , Palmer D. M. , Prieto J. L. , Tomasella L. , Marchant P. , Pastorello A. , Shappee B. J. , Stanek K. Z. , Stritzinger M. D. , Benetti S. , Chen Ping , DeMarchi L. , Elias-Rosa N. , Gall C. , Harmanen J. , Mattila S.
Published: October 2019

We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the γ-ray through optical and radio wavelengths, acquired within the first hours to ∼420 days post explosion. Our observational campaign confirms the identification of He in the supernova (SN) ejecta, which we interpret to be caused by a larger mixing of Ni into the outer ejecta layers. By modeling the broad bolometric light curve, we derive a large ejecta-mass-to-kinetic-energy ratio (M
ej ∼ 4–7 M
⊙, E
k ∼ (7–8) × 1051 erg). The small [Ca ii] λλ7291,7324 to [O i] λλ6300,6364 ratio (∼0.2) observed in our late-time optical spectra is suggestive of a large progenitor core mass at the time of collapse. We find that SN 2016coi is a luminous source of X-rays (L
X > 1039 erg s−1 in the first ∼100 days post explosion) and radio emission (L
8.5 GHz ∼ 7 × 1027 erg s−1 Hz−1 at peak). These values are in line with those of relativistic SNe (2009bb, 2012ap). However, for SN 2016coi, we infer substantial pre-explosion progenitor mass loss with a rate

 ∼ (1–2) × 

and a sub-relativistic shock velocity v
sh ∼ 0.15c, which is in stark contrast with relativistic SNe and similar to normal SNe. Finally, we find no evidence for a SN-associated shock breakout γ-ray pulse with energy E

γ
 > 2 × 1046 erg. While we cannot exclude the presence of a companion in a binary system, taken together, our findings are consistent with a massive single-star progenitor that experienced large mass loss in the years leading up to core collapse, but was unable to achieve complete stripping of its outer layers before explosion.
Exploring Exoplanet Cloud Assumptions in JWST Transmission Spectra
Authors: Mai Chuhong , Line Michael R.
Published: October 2019

Clouds are ubiquitous in extrasolar planet atmospheres and are critical to our understanding of planetary climate and chemistry. They also represent one of the greater challenges to overcome when trying to interpret transit transmission spectra of exoplanet atmospheres as their presence can inhibit precise constraints on atmospheric composition and thermal properties. In this work, we take a phenomenological approach toward understanding (1) our ability to constrain bulk cloud properties and (2) the impact of clouds on constraining various atmospheric properties as obtained through transmission spectroscopy with the James Webb Space Telescope (JWST). We do this by exploring retrievals of atmospheric and cloud properties for a generic “hot Jupiter” as a function of signal-to-noise ratio (S/N), JWST observing modes, and four different cloud parameterizations. We find that most key atmospheric and cloud inferences can be well constrained in the wavelength range (λ = 0.6–11 μm), with NIRCam (λ = 2.5–5 μm) being critical in inferring atmospheric properties and NIRISS + MIRI (λ = 0.6–2.5, 5–11 μm) being necessary for good constraints on cloud parameters. However, constraining the cloud abundance and therefore the total cloud mass requires an observable cloud base in the transit geometry. While higher S/N observations can place tighter constraints on major parameters such as temperature, metallicity, and cloud sedimentation, they are unable to eliminate strong degeneracies among cloud parameters. Our investigation of a generic “warm Neptune” with photochemical haze parameterization also shows promising results in constraining atmospheric and haze properties in the cooler temperature regime.
Chondrule Formation by the Jovian Sweeping Secular Resonance
Authors: Gong 龚 慕 Munan 南 , Zheng 郑 晓 Xiaochen 晨 , Lin 林 Douglas N. C. 潮 , Silsbee Kedron , Baruteau Clement , Mao 毛 淑 Shude 德
Published: October 2019

Chondrules are silicate spheroids found in meteorites, and they serve as important fossil records of the early solar system. In order to form chondrules, chondrule precursors must be heated to temperatures much higher than the typical conditions in the current asteroid belt. One proposed mechanism for chondrule heating is the passage through bow shocks of highly eccentric planetesimals in the protoplanetary disk in the early solar system. However, it is difficult for planetesimals to gain and maintain such high eccentricities. In this paper, we present a new scenario in which planetesimals in the asteroid belt region are excited to high eccentricities by the Jovian sweeping secular resonance in a depleting disk, leading to efficient formation of chondrules. We study the orbital evolution of planetesimals in the disk using semi-analytic models and numerical simulations. We investigate the dependence of eccentricity excitation on the planetesimal’s size, as well as the physical environment and the probability for chondrule formation. We find that 50–2000 km planetesimals can obtain eccentricities larger than 0.6 and cause effective chondrule heating. Most chondrules form in high-velocity shocks, in low-density gas, and in the inner disk. The fraction of chondrule precursors that become chondrules is about 4%–9% between 1.5 and 3 au. Our model implies that the disk depletion timescale is τ
dep ≈ 1 Myr, comparable to the age spread of chondrules, and that Jupiter formed before chondrules, no more than 0.7 Myr after the formation of calcium aluminum inclusions.
The Evolution of O i over 3.2 < z < 6.5: Reionization of the Circumgalactic Medium
Authors: Becker George D. , Pettini Max , Rafelski Marc , D’Odorico Valentina , Boera Elisa , Christensen Lise , Cupani Guido , Ellison Sara L. , Farina Emanuele Paolo , Fumagalli Michele , López Sebastian , Neeleman Marcel , Ryan-Weber Emma V. , Worseck Gábor
Published: October 2019

We present a survey for metal absorption systems traced by neutral oxygen over 3.2 < z < 6.5. Our survey uses Keck/ESI and VLT/X-Shooter spectra of 199 QSOs with redshifts up to 6.6. In total, we detect 74 O i absorbers, of which 57 are separated from the background QSO by more than 5000 km s−1. We use a maximum likelihood approach to fit the distribution of O i λ1302 equivalent widths in bins of redshift and from this determine the evolution in number density of absorbers with W
1302 > 0.05 Å, of which there are 49 nonproximate systems in our sample. We find that the number density does not monotonically increase with decreasing redshift, as would naively be expected from the buildup of metal-enriched circumgalactic gas with time. The number density over 4.9 < z < 5.7 is a factor of 1.7–4.1 lower (68% confidence) than that over 5.7 < z < 6.5, with a lower value at z < 5.7 favored with 99% confidence. This decrease suggests that the fraction of metals in a low-ionization phase is larger at z ∼ 6 than at lower redshifts. Absorption from highly ionized metals traced by C iv is also weaker in higher-redshift O i systems, supporting this picture. The evolution of O i absorbers implies that metal-enriched circumgalactic gas at z ∼ 6 is undergoing an ionization transition driven by a strengthening ultraviolet background. This in turn suggests that the reionization of the diffuse intergalactic medium may still be ongoing at or only recently ended by this epoch.
Brown Dwarf Atmospheres as the Potentially Most Detectable and Abundant Sites for Life
Authors: Lingam Manasvi , Loeb Abraham
Published: October 2019

We show that the total habitable volume in the atmospheres of cool brown dwarfs with effective temperatures of ∼250–350 K is possibly larger by 2 orders of magnitude than that of Earth-like planets. We also study the role of aerosols, nutrients, and photosynthesis in facilitating life in brown dwarf atmospheres. Our predictions might be testable through searches for spectral edges in the near-infrared and chemical disequilibrium in the atmospheres of nearby brown dwarfs that are either free-floating or within several au of stars. For the latter category, we find that the James Webb Space Telescope may be able to achieve a signal-to-noise ratio of ∼5 after a few hours of integration time per source for the detection of biogenic spectral features in ∼103 cool brown dwarfs.
Discovery of an Mg ii Changing-look Active Galactic Nucleus and Its Implications for a Unification Sequence of Changing-look Active Galactic Nuclei
Authors: Guo 郭 Hengxiao 恒潇 , Sun Mouyuan , Liu Xin , Wang Tinggui , Kong Minzhi , Wang Shu , Sheng Zhenfeng , He Zhicheng
Published: October 2019

Changing look (CL) is a rare phenomenon of active galactic nuclei (AGNs) that exhibit emerging or disappearing broad lines accompanied by continuum variations on astrophysically short timescales (≲1 yr to a few decades). While previous studies have found Balmer-line (broad Hα and/or Hβ) CL AGNs, the broad Mg ii line is persistent even in dim states. No unambiguous Mg ii CL AGN has been reported to date. We perform a systematic search of Mg ii CL AGNs using multi-epoch spectra of a special population of Mg ii-emitters (characterized by strong broad Mg ii emission with little evidence for AGNs from other normal indicators such as broad Hα and Hβ or blue power-law continua) from the Sloan Digital Sky Survey Data Release 14. We present the discovery of the first unambiguous case of a Mg ii CL AGN, SDSS J152533.60+292012.1 (at redshift z = 0.449), which is turning off within rest-frame 286 days. The dramatic diminishing of Mg ii equivalent width (from 110 ± 26 Å to being consistent with zero), together with little optical continuum variation (ΔV
max−min = 0.17 ± 0.05 mag) coevally over ∼10 yr, rules out dust extinction or a tidal disruption event. Combined with previously known Hβ CL AGNs, we construct a sequence that represents different temporal stages of CL AGNs. This CL sequence is best explained by the photoionization model of Guo et al. In addition, we present two candidate turn-on Mg ii CL AGNs and a sample of 361 Mg ii-emitters for future Mg ii CL AGN searches.
Formation of Interstellar C60 from Silicon Carbide Circumstellar Grains
Authors: Bernal J. J. , Haenecour P. , Howe J. , Zega T. J. , Amari S. , Ziurys L. M.
Published: October 2019

We have conducted laboratory experiments with analog crystalline silicon carbide (SiC) grains using transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). The 3C polytype of SiC was used—the type commonly produced in the envelopes of asymptotic giant branch (AGB) stars. We rapidly heated small (∼50 nm) synthetic SiC crystals under vacuum to ∼1300 K and bombarded them with 150 keV Xe ions. TEM imaging and EELS spectroscopic mapping show that such heating and bombardment leaches silicon from the SiC surface, creating layered graphitic sheets. Surface defects in the crystals were found to distort the six-membered rings characteristic of graphite, creating hemispherical structures with diameters matching that of C60. Such nonplanar features require the formation of five-membered rings. We also identified a circumstellar grain, preserved inside the Murchison meteorite, that contains the remnant of an SiC core almost fully encased by graphite, contradicting long-standing thermodynamic predictions of material condensation. Our combined laboratory data suggest that C60 can undergo facile formation from shock heating and ion bombardment of circumstellar SiC grains. Such heating/bombardment could occur in the protoplanetary nebula phase, accounting for the observation of C60 in these objects, in planetary nebulae (PNs) and other interstellar sources receiving PN ejecta. The synthesis of C60 in astronomical sources poses challenges, as the assembly of 60 pure carbon atoms in an H-rich environment is difficult. The formation of C60 from the surface decomposition of SiC grains is a viable mechanism that could readily occur in the heterogeneous, hydrogen-dominated gas of evolved circumstellar shells.
Inter - Relationship of Awareness, Knowledge, Attitude, Some Socio-Economic Variables and Osteoporosis in Sample of Egyptian Women
Authors: Hassan Nayera E. , El Shebini Salwa M. , El-Masry Sahar A. , Ahmed Nihad H. , El Sherity Safenaz Y. , Abd el Hamed Enas R. , Aboud Heba T.
Published: October 2019

BACKGROUND: Osteoporosis is a global health problem, and its prevalence is rapidly increasing worldwide.
AIM: The aim was to assess the awareness concerning some nutritional and socio-economic variables causes the disease in a sample of Egyptian women.
METHODS: This study was done among 116 female volunteers. They were divided into two groups, pre and post-menopausal, with a mean age of 42.05 ± 8.25 & 51.13 ± 5.82 years and mean body mass index (BMI) of 30.83 ± 8.18 & 34.24 ± 8.80 kg/m2. A standardised questionnaire, socioeconomic and food frequency chart were used to assess osteoporosis and food intake awareness. Bone mineral density was measured by dual-energy X-ray absorptiometry (DEXA). Statistical analyses were done using simple percentage and Chi-square test.
RESULTS: Data revealed that a low percentage of pre and post-menopausal women were aware of osteoporosis and fracture (16.67% & 12.96% and 30.65% & 19.35%). They had incomplete knowledge about the sources and the beneficial effects of consumption of calcium and vitamin D rich diet. Non-osteoporotic women showed more awareness. Odds ratio predict occupations and educations levels as risk factors for osteoporosis.
CONCLUSION: Awareness about osteoporosis and consumption healthy diet were low among Egyptian women, so it is important to implement special osteoporosis prevention program.
Bataille ! La pastorale ou la scène du monde dans les Pyrénées occidentales
Authors: Heiniger-Castéret Patricia
Published: October 2019

La pastorale est un théâtre psalmodié, chanté et dansé, interprété par des amateurs. Essentiellement jouée dans les Hautes-Pyrénées et les Pyrénées-Atlantiques elle est aujourd’hui très dynamique dans les vallées et le piémont béarnais comme en vallée basque de Soule. Organisée par un village ou un quartier, elle met en scène la vie d’un héros ou d’une héroïne en mêlant réalisme et surnaturel. Deux camps vont s’affronter pendant 4 heures, les bleus contre les rouges ou les bons contre les méchants. La mise en place de ce théâtre ritualisé mobilise la communauté pendant plusieurs mois et réveille les tensions qui la fragilisent. Mais la plus grande bataille sera de gagner un renom vis-à-vis des communautés voisines.
La rencontre avec un écrivain en contexte scolaire québécois : points de vue d’élèves et d’enseignants
Authors: Dezutter Olivier , Beaudry Marie-Christine , Dumouchel Mélissa , Lemonchois Myriam , Falardeau Érick
Published: October 2019

Dans les programmes pour l’enseignement primaire et secondaire au Québec, les expériences culturelles sont valorisées pour permettre le développement de compétences dans le domaine des langues. Les relations directes avec artistes et les écrivains sont identifiées comme des moyens à privilégier pour ouvrir l’élève à la culture et à s’engager dans des démarches créatives. Pour atteindre cet objectif, différents programmes de soutien ont été mis en place. Mais qu’en est-il dans les milieux scolaires ? Qui sont les enseignants qui offrent à leurs élèves de tels espaces de rencontre, dans quel contexte et à quelles fins ? Quel est aussi l’effet de telles rencontres sur les élèves et plus particulièrement sur leur rapport à l’écrit ? L’article lève un coin du voile en présentant les résultats d’une enquête réalisée auprès d’un large échantillon d’enseignants et de mini-entrevues effectuées avec des élèves du dernier cycle du primaire et du secondaire.
Le Plan lecture lillois : évolution des rencontres scolaires avec des auteurs entre 2005 et 2016
Authors: Gaiotti Florence , Hamaide-Jager Éléonore , Lechaux-Hantute Céline
Published: October 2019

Depuis 2005, le plan « Lecture de Lille », inscrit dans un projet éducatif global de la ville, propose des dispositifs de rencontres entre des auteurs-illustrateurs et les classes. Après une présentation précise du plan, l’article propose une analyse des rencontres à partir de l’observation des relations qui s’établissent alors entre artistes, enseignants et élèves et des expériences littéraires ou plus largement artistiques qui ont pu se mettre en place à l’occasion de ces rencontres. Il s’agit de s’interroger non seulement sur la possibilité de modélisation de ce dispositif mais aussi sur la manière dont ces rencontres peuvent constituer des évènements auprès des élèves.
La Quinzaine du Livre jeunesse en Touraine : 40 ans de militantisme et d’émulation ?
Authors: Dardaillon Sylvie , Meunier Christophe
Published: October 2019

Créée en 1971, en Touraine, dans une perspective clairement militante pour développer le gout de la lecture en partenariat avec l’école, la Quinzaine du livre jeunesse en Touraine privilégie dès son origine les rencontres vivantes avec les œuvres et les créateurs. Les auteurs-illustrateurs sont d’abord accueillis pendant le temps d’exposition des ouvrages sélectionnés. Mais peu à peu, des projets sont mis en place afin d’aider les équipes enseignantes à mieux préparer leur venue. Depuis 1974, plus de deux-cents auteurs et illustrateurs ont été invités par la Quinzaine et sont intervenus dans différents établissements scolaires (écoles maternelles, élémentaires et collèges). Cet article propose ainsi une entrée historique et littéraire, quantitative et qualitative. Il analyse l’évolution de la place des auteurs dans la manifestation autant dans sa dimension spatiale que sociale (évolution des classes concernées). Des entretiens menés auprès d’enseignants permettent de compléter une étude sur les traces, les modalités et l’intérêt de la venue d’un créateur dans la classe.
How to empower people to co-create a healthy food system
Authors: Unger K.
Published: October 2019

On a global scale, it is becoming increasingly hard to grow and consume food in a way that is sustainable for the planet and healthy for the people. Edible insects as ingredients can have a positive effect on the ecosystem and on people’s health. But why should people engage in this movement? We provide a human-centred view on our learnings in the insect industry.
Caring: Its Meaning and Place in the Practice of Nursing
Authors: Chipman Yvonne
Published: October 2019

ABSTRACT

The School of Nursing at which the author is an instructor has decided to revise its curriculum. The new curriculum will use Jean Watson's Theory of Caring as its theoretical base. This qualitative study was undertaken to help clarify the meaning and value of caring in nursing practice as perceived by second-year diploma nursing students. When the data were analyzed, three categories of nurse behaviors emerged that were perceived as caring: giving of self, meeting patients' needs in a timely fashion, and providing comfort measures for patients and their families. The results of this study can be interpreted as a social constructive view of caring in the practice of nursing. These outcomes may help to define and teach caring nurse behaviors in a curriculum based on the Theory of Caring.
Corneal Perforation During Laser Blepharoplasty
Authors: Darlington Jason K. , Lee W. Barry , Schwab Ivan R.
Published: October 2019

A 61-year-old woman presented with photophobia, pain, epiphora, and decreased vision as a result of two iatrogenic corneal perforations sustained during carbon dioxide laser blepharoplasty. The management and course of the case are outlined. Laser blepharoplasty complications are reviewed. This case highlights the potential occurrence of corneal penetration with laser blepharoplasty. Meticulous awareness of the laser effects on periocular tissue must be kept in mind at all times during laser blepharoplasty to avoid unnecessary intraocular side effects and undesirable postoperative outcomes. [Ophthalmic Surg Lasers Imaging 2006;37:327-329.] AUTHORS From the Department of Ophthalmology (JKD, IRS), University of California—Davis, Sacramento, California; and Eye Consultants of Atlanta (WBL), Atlanta, Georgia. Dr. Schwab is supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York. Accepted for publication April 10, 2006. Address reprint requests to W. Barry Lee, MD, 95 Collier Road, Suite 3000, Atlanta, GA 30309.
Engaging with peers, mentors and native speakers as language learning partners in an online environment
Authors: Chakowa Jessica
Published: October 2019

Opportunities to interact in the target language have a major impact on language learning and motivation. This paper is based on empirical research conducted at an Australian university. It identifies factors that encourage beginner learners of French to participate in asynchronous online interactions with learning partners of different language proficiency levels: peers, mentors and native speakers. It then highlights the benefits of providing opportunities to engage with multiple partners in accordance with students' attitudes and preferences, which fluctuate over time. This progressive approach takes form in encouraging students to contribute to a shared knowledge and improve their productions, it enables them to experience comfort and authenticity, and ultimately, prepare for real-life situations. This study demonstrates that the exposure to the three groups of learning partners as a whole worth more than their mere juxtaposition.
El mito fundacional de Andorra: entre el precepto de Carlomagno y la destrucción del castillo de Bragafolls
Authors: Vergés Oliver
Published: October 2019

En el siglo xviii, Andorra se dotó de su propia historia, en
gran medida a través de la publicación del Manual Digest de Antoni Fiter y Rossell.
Según este compendio, y basándose en un falso precepto, habría que
atribuir a Carlomagno la concesión de una idiosincrasia política
propia para Andorra, un mito que ha perdurado hasta tiempos presentes.
En el presente estudio intentaremos mostrar que la leyenda de
Carlomagno tiene una base real, la destrucción del castillo condal de
Bragafolls por parte de los andorranos en el siglo x, el verdadero hecho
fundacional de Andorra. Para demostrarlo, nos acercaremos a la
historia de los valles andorranos de los siglos ix-xiii, al contexto en que fue edificado el
castillo de Bragafolls, a la creación del feudo episcopal andorrano y
a la importancia que en todo ello tuvo la defensa de la tradición,
base para el nacimiento de la leyenda de Carlomagno.
Los caminos de la disidencia : dinámicas del catarismo a través de los Pirineos (siglos XII-XIV)
Authors: Gascón Chopo Carles
Published: October 2019

Durante los siglos XII y XIII, el catarismo
alcanzó un notable grado de implantación en el área occitana,
proyectando su influencia sobre Cataluña por medio de la predicación
itinerante de sus adeptos, que cruzaban periódicamente la cordillera
pirenaica. Aprovechando los flujos de personas, mercancías e
información que vincularon totalmente a Occitania y Cataluña durante
todo el medievo, los cátaros, a través de sus predicaciones, lograron
establecer una sólida red tendida entre ambas vertientes de los
Pirineos.
Modane : une communauté alpine fourrier des armées européennes à l’époque moderne
Authors: Alerini Julien
Published: October 2019

François Ier aurait qualifié le duc de Savoie de
« mauvais portier qui a lasché ses clefs aux Suisses ». Les souverains
savoyards conservent à l’époque moderne cette image de gardiens de
cols alpins, permettant de faire passer ou non les armées européennes
vers l’Italie. C’est pourtant sur les communautés alpines que reposait
la responsabilité matérielle du logement, des vivres et du transport
de ces armées. L’espace alpin offre un terrain d’analyse particulier
de la relation des troupes aux communautés qui les hébergent. Le choix
des routes et donc des communautés d’étape est très largement
conditionné par la nature même du milieu montagnard qui limite le
nombre de routes possibles. Ces communautés ne peuvent quasiment pas
espérer échapper au logement de la soldatesque. C’est en même temps un
espace où la culture politique communale est encore très vivace à
l’époque moderne. Les communautés alpines ne font donc pas que subir
les troupes, elles s’organisent pour les recevoir ou négocier les
passages militaires avec les souverains. Cet article propose d’étudier
l’impact des déplacements militaires sur la communauté de Modane,
prise comme témoin de la logistique savoyarde. Elle entend analyser
sur le temps long le rapport de la communauté à ces passages
militaires et ses constantes adaptations à leurs intensifications, et
ainsi évaluer l’impact de la fonction géostratégique de la Maison de
Savoie sur le communalisme alpin.