bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatially Resolving the Kinematics of the ≲100 μas Quasar Broad-line Region Using Spectroastrometry. II. The First Tentative Detection in a Luminous Quasar at z = 2.3
Authors: Bosco Felix , Hennawi Joseph F. , Stern Jonathan , Pott Jörg-Uwe 
Published: September 2021

Abstract
Direct measurements of the masses of supermassive black holes are key to understanding their growth and constraining their symbiotic relationship to their host galaxies. However, current methods used to directly measure black hole masses in active quasars become challenging or impossible beyond z ≳ 0.2. Spectroastrometry (SA) measures the spatial centroid of an object’s spectrum as a function of wavelength, delivering angular resolution far better than the point-spread function (PSF) for high signal-to-noise ratio observations. We observed the luminous quasar SDSS J212329.47–005052.9 at z = 2.279 with the aim of resolving its ∼100 μas Hα broad emission-line region (BLR) and present the first SA constraints on the size and kinematic structure of the BLR. Using a novel pipeline to extract the SA signal and reliable uncertainties, we achieved a centroiding precision of ≃100 μas, or >2000× smaller than the K-band AO-corrected PSF, yielding a tentative 3.2σ detection of an SA signal from the BLR. Modeling the BLR emission as arising from an inclined rotating disk with a mixture of coherent and random motions we constrain

r

BLR

=

454

−
162

+
565

μ
as

(

3.71

−
1.28

+
4.65

pc

), providing a 95% confidence upper limit on the black hole mass

M

BH

sin

2

i
≤
1.8
×

10

9

M

⊙

. Our results agree with the r
BLR–L relation measured for lower-z quasars but expands its dynamic range by an order of magnitude in luminosity. We did not detect the potentially stronger SA signal from the narrow-line region but discuss in detail why it may be absent. Already with existing instrumentation, SA can deliver ∼6× smaller uncertainties (∼15 μas) than achieved here, enabling ∼10% measurements of supermassive black hole masses in high-z quasars.
Gravitational Wave Backgrounds from Coalescing Black Hole Binaries at Cosmic Dawn: An Upper Bound
Authors: Inayoshi Kohei , Kashiyama Kazumi , Visbal Eli , Haiman Zoltán 
Published: September 2021

Abstract
The successive discoveries of binary merger events by Advanced LIGO-Virgo have been revealing the statistical properties of binary black hole (BBH) populations. A stochastic gravitational wave background (GWB) is a useful tool to probe the cosmological evolution of those compact mergers. In this paper, we study the upper bound on a GWB produced by BBH mergers, whose stellar progenitors dominate the reionization process at the cosmic dawn. Since early reionization by those progenitors yields a high optical depth of the universe inconsistent with the Planck measurements, the cumulative mass density is limited to ρ
⋆ ≲ 107
M
⊙ Mpc−3. Even with this upper bound, the amplitude of a GWB owing to the high-z BBH mergers is expected to be as high as

Ω

gw

≃

1.48

−
1.27

+
1.80

×

10

−
9

at f ≃ 25 Hz, while their merger rate at the present day is consistent or lower than the observed GW event rate. This level of GWB is detectable at the design sensitivity of Advanced LIGO-Virgo and would indicate a major contribution of the high-z BBH population to the local GW events. The spectral index is expected to be substantially flatter than the canonical value of ≃2/3 generically produced by lower-redshift and less-massive BBHs. Moreover, if their mass function is more top heavy than in the local universe, the GWB spectrum is even more skewed toward lower frequencies, which would allow us to extract information on the mass function of merging BBHs at high redshifts.
The Highly Self-absorbed Blazar PKS 1351-018
Authors: Punsly Brian , Frey Sándor , Reynolds Cormac , Marziani Paola , Pushkarev Alexander , Chen Sina , Li Shang , Kharb Preeti 
Published: September 2021

Abstract
PKS 1351-018 at a redshift of z = 3.71 is one of the most luminous, steady synchrotron sources with a luminosity >1047 erg s−1. The synchrotron luminosity does not seem to have varied by more than ∼25% over 35 yr. In order to appreciate this remarkable behavior, if it were at z = 0.5, it would have a flux density at 15 GHz in a range of 110–137 Jy over 11 yr. In spite of this steady behavior, two strong γ-ray flares ≲1049 erg s−1 were detected in 2011 and 2016. There is a blazar-like behavior coexisting with the steady behavior. This study is aimed at elucidating the dual nature of this source. We find that the radio source is extremely compact with a bright core and a steep spectrum secondary component, 12 mas away, that appears to be constant in position and flux density in six epochs from 1995–2018. We estimate that a jet with a time averaged power of (5.2 ± 3.2) × 1045 erg s−1 terminates in this lobe, which is advancing ≳0.9c at a deprojected distance of 1–3 kpc from the central engine. This is the rare case of a young (∼6000 yr), very powerful radio source that is viewed a few degrees from the jet axis. We find evidence of a high velocity (4000 km s−1), high ionization wind emanating from a luminous quasar. The young radio jet appears to experience modest bending as it navigates through the intense quasar environment.
Data-constrained Magnetohydrodynamic Simulation of a Long-duration Eruptive Flare
Authors: Guo Yang , Zhong Ze , Ding M. D. , Chen P. F. , Xia Chun , Keppens Rony 
Published: September 2021

Abstract
We perform a zero-β magnetohydrodynamic simulation for the C7.7 class flare initiated at 01:18 UT on 2011 June 21 using the Message Passing Interface Adaptive Mesh Refinement Versatile Advection Code (MPI-AMRVAC). The initial condition for the simulation involves a flux rope, which we realize through the regularized Biot–Savart laws, whose parameters are constrained by observations from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) and the Extreme Ultraviolet Imager (EUVI) on the twin Solar Terrestrial Relations Observatory (STEREO). This data-constrained initial state is then relaxed to a force-free state by the magnetofrictional module in MPI-AMRVAC. The further time-evolving simulation results reproduce the eruption characteristics obtained by SDO/AIA 94 Å, 304 Å, and STEREO/EUVI 304 Å observations fairly well. The simulated flux rope possesses similar eruption direction, height range, and velocity to the observations. In particular, the two phases of slow evolution and fast eruption are reproduced by varying the density distribution in the light of the draining process of the filament material. Our data-constrained simulations also show other advantages, such as a large field of view (about 0.76 R
⊙). We study the twist of the magnetic flux rope and the decay index of the overlying field, and find that in this event, both the magnetic strapping force and the magnetic tension force are sufficiently weaker than the magnetic hoop force, thus allowing the successful eruption of the flux rope. We also find that the anomalous resistivity is necessary to keep the correct morphology of the erupting flux rope.
On the Three-dimensional Structure of Local Molecular Clouds
Authors: Zucker Catherine , Goodman Alyssa , Alves João , Bialy Shmuel , Koch Eric W. , Speagle Joshua S. , Foley Michael M. , Finkbeiner Douglas , Leike Reimar , Enßlin Torsten , Peek Joshua E. G. , Edenhofer Gordian 
Published: September 2021

Abstract
We leverage the 1 pc spatial resolution of the Leike et al. three-dimensional (3D) dust map to characterize the 3D structure of nearby molecular clouds (d ≲ 400 pc). We start by “skeletonizing” the clouds in 3D volume density space to determine their “spines,” which we project on the sky to constrain cloud distances with ≈1% uncertainty. For each cloud, we determine an average radial volume density profile around its 3D spine and fit the profiles using Gaussian and Plummer functions. The radial volume density profiles are well described by a two-component Gaussian function, consistent with clouds having broad, lower-density outer envelopes and narrow, higher-density inner layers. The ratio of the outer to inner envelope widths is ≈3:1. We hypothesize that these two components may be tracing a transition between atomic and diffuse molecular gas or between the unstable and cold neutral medium. Plummer-like models can also provide a good fit, with molecular clouds exhibiting shallow power-law wings with density, n, falling off like n
−2 at large radii. Using Bayesian model selection, we find that parameterizing the clouds’ profiles using a single Gaussian is disfavored. We compare our results with two-dimensional dust extinction maps, finding that the 3D dust recovers the total cloud mass from integrated approaches with fidelity, deviating only at higher levels of extinction (A

V
≳ 2–3 mag). The 3D cloud structure described here will enable comparisons with synthetic clouds generated in simulations, offering unprecedented insight into the origins and fates of molecular clouds in the interstellar medium.
Evaluating and Enhancing Candidate Clocking Systems for CHIME/FRB VLBI Outriggers
Authors: Cary Savannah , Mena-Parra Juan , Leung Calvin , Masui Kiyoshi , Kaczmarek J. F. , Cassanelli Tomas ,   (CHIME/FRB Collaboration)
Published: September 2021

Abstract
As the Canadian Hydrogen Intensity Mapping Experiment (CHIME) has become the leading instrument for detecting Fast Radio Bursts (FRBs), CHIME/FRB Outriggers will use very-long-baseline interferometry (VLBI) to localize FRBs with milliarcsecond precision. The CHIME site uses a passive hydrogen maser frequency standard in order to minimize localization errors due to clock delay. However, not all outrigger stations will have access to a maser. This report presents techniques used to evaluate clocks for use at outrigger sites without a maser. More importantly, the resulting algorithm provides calibration methods for clocks that do not initially meet the stability requirements for VLBI, thus allowing CHIME/FRB Outriggers to remain true to the goal of having milliarcsecond precision.
Le recours croissant aux enseignant·es contractuel·les : vers un effet papillon ?
Authors: Pons Xavier 
Published: September 2021

À première vue, on pourrait considérer que le recours aux enseignant·es contractuel·les ne changerait pas, ou peu, l’enseignement secondaire en France. Non seulement ce phénomène n’est pas récent, mais le statut de titulaire demeure le modèle de recrutement et l’horizon principaux des enseignant·es contractuel·les. Pourtant, l’enquête menée par Xavier Pons sur la gestion des enseignant·es contractuel·les montre en quoi l’augmentation de cette forme d’emploi a des effets organisationnels, professionnels et politiques qui contribuent à transformer le métier. La contractualisation n’est pas une tendance isolée ; elle constitue l’un des rouages d’un ensemble de réformes qui affectent notamment la formation et le recrutement des enseignant·es. Ainsi, Xavier Pons revient sur la néolibéralisation à bas bruit de l’enseignement.
Résister à l’Université néolibérale en Espagne
Authors: García Fernández Javier , Montagnon Marie 
Published: September 2021

La crise financière de 2008 a durablement marqué la société espagnole par des années de politiques d’austérité dans les services publics. La formation d’un gouvernement de coalition entre le Parti Socialiste Ouvrier Espagnol (PSOE) et Unidas Podemos en janvier 2020 a suscité l’espoir d’un virage social en Espagne. Javier García Fernández, docteur en études postcoloniales de l’Université de Coimbra (Portugal), auteur du livre Descolonizar Europa: Ensayos para pensar históricamente desde el sur , est actuellement secrétaire à la formation du Syndicat Andalou des Travailleurs et Travailleuses. Il revient dans cet entretien sur le processus de privatisation de l’université publique espagnole dans le cadre des politiques d’harmonisation de l’enseignement supérieur impulsées par l’Union européenne avec le « plan Bologne ». Il détaille les effets néfastes de la précarisation croissante des enseignant·es et d’une concurrence exacerbée entre chercheur·es, ainsi que les inégalités durablement ancrées dans le monde universitaire espagnol, notamment les inégalités de genre. À partir des résistances syndicales andalouses à la privatisation de ce service public, il retrace aussi plus largement le rôle clé du monde universitaire dans les reconfigurations de la gauche espagnole au cours de la dernière décennie.
Le recours à l’établissement spécialisé : un usage ségrégant du handicap
Authors: Dupont Hugo 
Published: September 2021

Qu’est-ce qui distingue un élève « déviant » d’un élève « en situation de handicap psychique » ? Qu’est-ce qui distingue un élève coupable d’un mauvais comportement, d’un élève victime, en souffrance, incapable de suivre une scolarité ordinaire ? Hugo Dupont montre que le passage d’un registre à l’autre est ce qui permet de légitimer une orientation spécialisée, autrement dit l’exil scolaire de certains élèves vers un établissement hors scolarisation ordinaire. Ici, l’externalisation de l’accompagnement et la médicalisation de problèmes socio-éducatifs permettent de préserver un ordre et une norme scolaires, préservation qui fait obstacle à la flexibilité qu’impliquerait une école réellement inclusive.
Pédagogie de la résistance : les lycées de Tucson et la lutte pour les Mexican-American studies
Authors: Souyri Émilie 
Published: September 2021

Les crispations autour des études postcoloniales et plus largement des enjeux liés à la « race » en éducation en France rendent difficiles des réflexions précises et approfondies sur les pratiques éducatives qui se veulent décoloniales et/ou antiracistes ; de là l’importance d’étudier d’autres contextes. L’article d’Émilie Souyri revient sur les MAC ( Mexican-American Studies ) aux États-Unis, pour montrer la façon dont des programmes intégrant l’histoire et la culture des élèves issu·es de l’immigration et des communautés noires et autochtones peuvent changer le rapport des acteurs à l’École et susciter des débats internes qui visent à davantage d’inclusivité. Toutefois, même dans un tel contexte présentant des résultats positifs et encourageants, les ethnic studies font l’objet d’une diabolisation dans les discours politiques conservateurs et réactionnaires.
La sociologie d’Émile Durkheim (1858-1917) : des pistes pour l’inclusion
Authors: Sembel Nicolas 
Published: September 2021

La rencontre entre une thématique récente comme l’inclusion et un penseur classique comme Durkheim ne va pas de soi, au point de passer pour sans objet ou peu intéressante. Mais une lecture précise et innovante de l’œuvre de Durkheim en éducation ouvre au contraire des pistes stimulantes, notamment par le questionnement par l’inclusion. D’abord pour penser les prémisses enfouies de celle-ci ; ensuite pour alimenter la lecture innovante de Durkheim ; enfin pour revisiter l’histoire du système éducatif français et son universalisme. L’examen du rapport de Durkheim à sa trajectoire scolaire et universitaire (complétée par celui de Bourdieu), offre une lecture ancrée des écrits en sociologie de l’éducation. Ainsi relue, l’Éducation morale de Durkheim est un bréviaire pour un maître qui se révèlerait aujourd’hui acteur de l’inclusion, ouvre vers une sociologie générale de l’éducation, un universalisme et, au final, pose des jalons d’une révolution inclusive.
Pensée et langage chez Karl Popper et Lev Vygotski
Authors: Firode Alain 
Published: September 2021

Durant la dernière période de sa carrière Popper a développé une théorie évolutionniste de l’esprit dont les conclusions sont souvent proches des thèses du psychologue soviétique, Lev Vygotski. Les deux auteurs partagent en effet l’idée que le langage et le monde symbolique en général jouent un rôle déterminant dans la formation de l’esprit humain. Ils soulignent tous deux l’importance, dans le processus du développement mental, des interactions entre le psychisme et l’environnement linguistique et culturel. La théorie de Popper, cependant, fait apparaître une idée qui ne se trouve pas chez Vygotski, à savoir la thèse selon laquelle l’univers symbolique (le « monde 3 ») possède une réalité logique autonome, distincte de la réalité physique, psychologique ou sociale. Cette thèse, inconciliable avec le point de vue dialectique et matérialiste de Vygotski, introduit une différence profonde entre ces deux théories de l’esprit. Il s’ensuit que les analyses poppériennes, contrairement à celles de Vygotski, sont difficilement compatibles avec le paradigme constructiviste qui prévaut actuellement dans les recherches en éducation.
Au seuil de la classe, le maître E régule différentes temporalités
Authors: Ponté Pascale , Thomazet Serge , Mérini Corinne 
Published: September 2021

En France, de nouveaux textes réorganisent le champ de la prise en charge des difficultés scolaires. Ces évolutions ont justifié une recherche que nous menons depuis trois ans sur le travail des maîtres E (enseignants spécialisés chargés de l’aide pédagogique) et ses vecteurs de transformations. Nous en présentons ici une partie centrée sur la gestion des temporalités. La construction de l’objet et la méthodologie ont été structurées en mobilisant la sociologie des organisations et la psychologie ergonomique, avec lesquelles se conjugue la philosophie. Le travail méthodologique a été mené dans un collectif de recherche. L’analyse des documents professionnels nous a permis de repérer des « points de tension professionnels » que nous avons explorés de manière plus détaillée lors d’entretiens d’autoconfrontation et de confrontations croisés. Nos résultats montrent que les maîtres E sont au seuil de la classe mais au cœur du dispositif de travail collaboratif et développent des stratégies propres pour répondre aux conflits de temporalité générés par les prescriptions.
"Te:mos o serra cura::do, temos o ni:sa, temos o serpa do:p." Suggesting products to buy, shaping materiality and multisensoriality in shop encounters
Authors: Mondada Lorenza 
Published: September 2021

Adopting the perspective of multimodal conversation analysis, the paper shows the methodic organization of an action, making suggestions, achieved by sellers in response to customers’ requests for recommendations in shop encounters, and involving the showing and listing of available products. This focus on a specific sequential environment and institutional ecology, enables an exemplary discussion of how this action is multimodally formatted, embedded in its context, and shaped in relation to objects as discursive referents as well as materialities to be pointed at, looked at, touched and sensed in multiple ways. More generally, this focus enables to address two sets of issues: on the one hand, it elucidates the nexus between action, institutionality and materiality, including the role of multisensoriality in engaging with the qualities of buyable objects. On the other hand, it addresses the nexus between action and referential practices for introducing and presenting new referents, within an interactional perspective locating these grammatical practices and their systematic features within their praxeological context. On the basis of video data recorded in a gourmet shop in Lisbon, Portugal, this double focus targets issues of sensoriality and socialization in food culture, as well as issues of grammar in interaction, casting some light on situated uses of the verb ter for introducing new referents.

Keywords: Social Interaction; Shop Encounters; Multimodality and Multisensoriality.
Automated Radiosynthesis, Quality Control, and Biodistribution of Ga-68 Pentixafor
Authors: Watts Ankit , Chutani Surbhi , Arora Diksha , Madivanane Vasanth , Thakur Samiksha , Kamboj Monika , Singh Baljinder 
Published: September 2021

Background:
Chemokine receptor CXCR4 is overexpressed in more than 27 different human tumors that make it a promising target in oncology. Ga-68 Pentixafor is the most promising positron emission tomography tracer for imaging CXCR4 receptors; hence, the present study was carried out to optimize the radiosynthesis of Ga-68-Pentixafor using fully automated method and the quality control (QC) checks were performed before being used as a clinical product. We also studied the normal biodistribution pattern of Ga-68-pentixafor intended for the use in variety of malignancies.

Materials and Methods:
We optimized the automated radio-synthesis of Ga-68 Pentixafor under good manufacturing practice conditions. A total of 62 productions were carried out in a span of 4 years. Extensive QC tests were performed to check for potency, identity, efficacy, and stability of the tracer. Biodistribution of Ga-68 Pentixafor was investigated in a healthy volunteer to determine normal range of standardized uptake valuemaximum (SUVmax) values in various organs.

Results:
The radiotracer was prepared successfully in 57/62 productions with radiochemical purity of >99%. Mean radiolabelling efficiency of 73.1% ± 7.7% (n = 57) was obtained with synthesis time approximatively of 34 min. The radiolabeled complex showed no signs of dissociation up to 4 h at the room temperature. Ga-68 Pentixafor upon incubation with human serum was found to be stable at 37°C for 4 h. The highest normal organ uptake was seen in urinary bladder (SUVmean = 146.0), spleen (SUVmean = 6.80) followed by kidneys (SUVmean = 4.99).

Conclusion:
Using the automated radiosynthesis, Ga-68 Pentixafor exhibited good radiolabelling efficiency with excellent in vitro and in vivo stability and favorable biodistribution showing clinical applicability of the tracer.
Physiologic Testicular Uptake of 18-F Fluorodeoxyglucose in the Indian Population
Authors: Parida Girish Kumar , Muthu Gopal Sonai , Suman Akchata , Kumar Abhishek , Mitra Sujata 
Published: September 2021

Objective:
The objective of the study is to assess the physiologic uptake of testes in patients undergoing 18F-fluoro-2-deoxyglucose (FDG) position emission tomography/computed tomography (PET/CT) scans for various malignancies other than testicular malignancy.

Materials and Methods:
The testicular uptake of 18F-FDG expressed as the standardized uptake value (T) was measured on PET/CT images in 320 men with no known testicular pathology from July 2019 to March 2020 at Tata Main Hospital, Jamshedpur. The ratio of maximum standardized uptake value (SUVmax) of the testis (T) to SUVmax of muscle (M) T/M ratio and to SUVmax of the liver (L) T/L ratio was calculated using SUVmax of right adductor muscle and liver, respectively. Testicular volume was calculated with the measurements taken from the axial, coronal, and sagittal slices of CT images. The correlation of testicular uptake with age, blood serum glucose level, and testicular volume was also analyzed.

Results:
The mean age of 320 men was 57 ± 15 years (range: 10–94) and the mean blood glucose level was 107.7 ± 23.5 mg/dl (range: 64–175). Mean testicular SUVmax in 320 men was 2.48 ± 0.80 (range: 0.67–5.5). The mean testicular volume of 640 testes of 320 men was 18.80 ± 4.83 cm3 (range: 3.85–33.56 cm3). The mean values of (T/M) and (T/L) ratios in the studied population were 3.64 ± 1.21 (range: 1.08–5.58) and 0.97 ± 0.251 (range: 0.34–1.88), respectively. The laterality index (L − R/(L + R) ×2) in 320 men was 0.074 ± 0.050 (0.000–0.308). There was a minimal negative correlation between testicular SUVmax and age (r = −0.136, P = 0.15). Mild negative correlation was noted between T/M ratio and age (r = −0.291, P < 0.0001) and between T/L ratio and age (r = −0.182, P = 0.001) in the studied population.

Conclusion:
The physiological testicular FDG uptake (SUVmax) of testes was 2.48 ± 0.80 (0.67–5.5) among the Indian population in this study, which has a mild negative correlation with age.