bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing the Strong Equivalence Principle: Detection of the External Field Effect in Rotationally Supported Galaxies
Authors: Chae Kyu-Hyun , Lelli Federico , Desmond Harry , McGaugh Stacy S. , Li Pengfei , Schombert James M. 
Published: November 2020

Abstract
The strong equivalence principle (SEP) distinguishes general relativity (GR) from other viable theories of gravity. The SEP demands that the internal dynamics of a self-gravitating system under freefall in an external gravitational field should not depend on the external field strength. We test the SEP by investigating the external field effect (EFE) in Milgromian dynamics (MOND), proposed as an alternative to dark matter in interpreting galactic kinematics. We report a detection of this EFE using galaxies from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample together with estimates of the large-scale external gravitational field from an all-sky galaxy catalog. Our detection is threefold: (1) the EFE is individually detected at 8σ to 11σ in “golden” galaxies subjected to exceptionally strong external fields, while it is not detected in exceptionally isolated galaxies, (2) the EFE is statistically detected at more than 4σ from a blind test of 153 SPARC rotating galaxies, giving a mean value of the external field consistent with an independent estimate from the galaxies’ environments, and (3) we detect a systematic downward trend in the weak gravity part of the radial acceleration relation at the right acceleration predicted by the EFE of the MOND modified gravity. Tidal effects from neighboring galaxies in the Λ cold dark matter (CDM) context are not strong enough to explain these phenomena. They are not predicted by existing ΛCDM models of galaxy formation and evolution, adding a new small-scale challenge to the ΛCDM paradigm. Our results point to a breakdown of the SEP, supporting modified gravity theories beyond GR.
Two Portions of the Sagittarius Stream in the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap
Authors: Zhao J. K. , Ye X. H. , Wu H. , Yang M. , Oswalt Terry D. , Xue X. X. , Chen Y. Q. , Zhang J. J. , Zhao G. 
Published: November 2020

Abstract
We constructed a sample of 13,798 stars with T
eff, log g, [Fe/H], radial velocity, proper motions, and parallaxes from LAMOST DR5 and Gaia DR2 in the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) at the Southern Galactic Cap consisting of areas A and B. Using the distributions in both proper motions and radial velocity, we detected very significant overdensities in these two areas. These substructures most likely are portions of the Sagittarius (Sgr) stream. With the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, 220 candidates stream members were identified. Based upon distance to the Sun and published models, 106 of these stars are likely to be the members of the Sgr stream. The abundance pattern of these members using [α/Fe] from Xiang et al. were found to be similar to Galactic field stars with [Fe/H] < −1.5 and deficient to Milky Way populations at similar metallicities with [Fe/H] > −1.0. No vertical and only small radial gradients in metallicity along the orbit of the Sgr stream were found in our Sgr stream candidates.
Two Candidate High-redshift X-Ray Jets without Coincident Radio Jets
Authors: Schwartz D. A. , Siemiginowska A. , Snios B. , Worrall D. M. , Birkinshaw M. , Cheung C. C. , Marshall H. , Migliori G. , Wardle J. F. C. , Gobeille Doug 
Published: November 2020

Abstract
We report the detection of extended X-ray emission from two high-redshift radio quasars. These quasars, J1405+0415 at z = 3.208 and J1610+1811 at z = 3.118, were observed in a Chandra snapshot survey selected from a complete sample of the radio-brightest quasars in the overlap area of the VLA-FIRST radio survey and the Sloan Digital Sky Survey. The extended X-ray emission is located along the line connecting the core to a radio knot or hotspot, favoring the interpretation of X-ray jets. The inferred rest-frame jet X-ray luminosities from 2 to 30 keV would be of order 1045 erg s−1 if emitted isotropically and without relativistic beaming. In the scenario of inverse Compton scattering of the cosmic microwave background (CMB), X-ray jets without a coincident radio counterpart may be common, and should be readily detectable to redshifts even beyond 3.2 due to the (1+z)4 increase of the CMB energy density compensating for the (1+z)−4 cosmological diminution of surface brightness. If these can be X-ray confirmed, they would be the second and third examples of quasar X-ray jets without detection of underlying continuous radio jets.
The Spatially Resolved Bipolar Nebula of Sakurai’s Object. II. Mapping the Planetary Nebula Expansion
Authors: Hinkle Kenneth H. , Joyce Richard R. , Matheson Thomas , Lacy John H. , Richter Matthew J. 
Published: November 2020

Abstract
Observations of the ejecta from the final flash (FF) of helium shell burning in Sakurai’s Object (V4334 Sgr) are presented for 2015–2019, a period ∼20–24 yr after discovery. Adaptive optics images at K

s
trace the expanding debris. While most of the ejecta mass is in ∼200 K dust, a small fraction, ∼0.4%, of the dust mass is at ∼760 K. The 760 K continuum dominates the near-IR images. Spatial-spectral images in He i 10830 Å show an ∼16 diameter bipolar planetary nebula at position angle 21° ± 5° with the SW moving toward us and the NE moving away. Seen in integrated light, the nebula is nearly circular. Near-IR continuum images show ejecta moving radially away from a bright central point source. High-resolution mid-IR spectra reveal molecular hydrocarbon lines with an expansion velocity of 270 ± 5 km s−1 seen in absorption against the dust continuum. The hydrocarbons originate in material produced in the FF. The bipolar nebula and debris clouds are discussed in the context of a highly inclined disk model. The proper motion has been measured placing V4334 Sgr in the thick disk population. There is no evidence that a hot white dwarf Wolf–Rayet ([WR]) wind has emerged; no [WR] spectral features were detected. The possibility of a binary companion involved in the evolution is discussed.
Diversity of Dark Matter Density Profiles in the Galactic Dwarf Spheroidal Satellites
Authors: Hayashi Kohei , Chiba Masashi , Ishiyama Tomoaki 
Published: November 2020

Abstract
The core–cusp problem is one of the controversial issues in the standard paradigm of Λ cold dark matter (ΛCDM) theory. However, under the assumption of conventional spherical symmetry, the strong degeneracy among model parameters makes it unclear whether dwarf spheroidal (dSph) galaxies indeed have cored dark matter density profiles at their centers. In this work, we revisit this problem using nonspherical mass models, which have the advantage of being able to alleviate the degeneracy. Applying our mass models to the currently available kinematic data of the eight classical dSphs, we find that within finite uncertainties, most of these dSphs favor cusped central profiles rather than cored ones. In particular, Draco has a cusped dark matter halo with high probability even considering a prior bias. We also find the diversity of the inner slopes in their dark matter halos. To clarify the origin of this diversity, we investigate the relation between the inner dark matter density slope and stellar-to-halo mass ratio for the sample dSphs and find that this relation is generally in agreement with the predictions from recent ΛCDM and hydrodynamical simulations. We also find that the simulated subhalos have an anticorrelation between the dark matter density at 150 pc and pericenter distance, which is consistent with the observed one. We estimate their astrophysical factors for dark matter indirect searches and circular velocity profiles associated with huge uncertainties. To more precisely estimate their dark matter profiles, wide-field spectroscopic surveys for the dSphs are essential.
How Well Can We Measure the Stellar Mass of a Galaxy: The Impact of the Assumed Star Formation History Model in SED Fitting
Authors: Lower Sidney , Narayanan Desika , Leja Joel , Johnson Benjamin D. , Conroy Charlie , Davé Romeel 
Published: November 2020

Abstract
The primary method for inferring the stellar mass (M
*) of a galaxy is through spectral energy distribution (SED) modeling. However, the technique rests on assumptions such as the galaxy star formation history (SFH) and dust attenuation law that can severely impact the accuracy of derived physical properties from SED modeling. Here we examine the effect that the assumed SFH has on the stellar properties inferred from SED fitting by ground-truthing them against mock observations of high-resolution cosmological hydrodynamic galaxy formation simulations. Classically, SFHs are modeled with simplified parameterized functional forms, but these forms are unlikely to capture the true diversity of galaxy SFHs and may impose systematic biases with underreported uncertainties on results. We demonstrate that flexible nonparametric SFHs outperform traditional parametric forms in capturing variations in galaxy SFHs and, as a result, lead to significantly improved stellar masses in SED fitting. We find a decrease in the average bias of 0.4 dex with a delayed-τ model to a bias under 0.1 dex for the nonparametric model, though this is heavily dependent on the choice of prior for the nonparametric model. Similarly, using nonparametric SFHs in SED fitting results in increased accuracy in recovered galaxy star formation rates and stellar ages.
On a significant slowing-down of the kinetics of fast transient processes in a fast reactor
Authors: Kulikov Gennady G. , Shmelev Anatoly N. , Apse Vladimir A. , Kulikov Evgeny G. 
Published: November 2020

The kinetics of nuclear reactors is determined by the average neutron lifetime. When the inserted reactivity is more than the effective delayed neutron fraction, the reactor kinetics becomes very rapid. It is possible to slow down the fast reactor kinetics by increasing the neutron lifetime. The authors consider the possibility of using the lead isotope, 208Pb, as a neutron reflector with specific properties in a lead-cooled fast reactor. To analyze the emerging effects in a reactor of this type, a point kinetics model was selected, which takes into account neutrons returning from the 208Pb reflector to the reactor core.
Such specific properties of 208Pb as the high atomic weight and weak neutron absorption allow neutrons from the reactor core to penetrate deeply into the 208Pb reflector, slow down in it, and have a noticeable probability to return to the reactor core and affect the chain fission reaction. The neutrons coming back from the 208Pb reflector have a long ‘dead-time’, i.e., the sum of times when neutrons leave the reactor core, entering the 208Pb reflector, and then diffuse back into the reactor core. During the ‘dead-time’, these neutrons cannot affect the chain fission reaction. In terms of the delay time, the neutrons returning from the deep layers of the 208Pb reflector are close to the delayed neutrons. Moreover, the number of the neutrons coming back from the 208Pb reflector considerably exceeds the number of the delayed neutrons.
As a result, the neutron lifetime formed by the prompt neutron lifetime and the ‘dead-time’ of the neutrons from the 208Pb reflector can be substantially increased. This will lead to a longer reactor acceleration period, which will mitigate the effects of prompt supercriticality. Thus, the use of 208Pb as a neutron reflector can significantly improve the fast reactor nuclear safety.
Vues vérifiées, écoute évacuée : la valorisation publicitaire de la musique sur YouTube
Authors: HEUGUET Guillaume 
Published: November 2020

Depuis 2013, YouTube est reconnu comme la « première destination » des auditeurs de musique en France. Fondée par trois anciens employés de PayPal en 2005 comme l’éditrice d’un site de stockage et de publication de vidéos, l’entreprise a peu à peu développé un système technique et un modèle d’affaires qui entendent « monétiser » la musique publiée sur le site en articulant l’écoute « à la demande » avec un système de régie publicitaire. S’appuyant notamment sur une veille sur différents espaces de youtube.com, le blogue YouTube et l’étude de brevets, cet article s’intéresse aux médiations techniques, sémiotiques et symboliques sur lesquelles repose la valorisation marchande de la musique dans un dispositif médiatique généraliste d’abord conçu pour la vidéo. Il analyse l’hétérogénéité des calculs et des signes liés à une mesure d’audience spécifique, la « vue ». Il montre ensuite son statut d’étalon contesté parmi les acteurs du marché de la musique. Il interroge enfin les aspects anthropologiques des normes de l’économie et de la consommation des médias qui structurent l’acceptabilité d’une telle activité de mesure. Entre la prétention de YouTube à se situer au plus près des pratiques musicales des internautes pour les attirer et séduire les annonceurs et un mode de calcul conçu indépendamment de tout rapport spécifique à la musique, la médiation des valeurs de la musique sur YouTube apparaît comme un paradoxe.
Enseigner la guitare sur YouTube. Le tutoriel gratuit et les contradictions de la « numérimorphose » de l’enseignement de l’instrument : le cas de la chaîne MrGalagomusic
Authors: ROTH Raphaël , SWINNEN Laure-Hélène 
Published: November 2020

Cet article présente les résultats d’une étude sur les modalités d’enseignement de la guitare sur YouTube. Il met en lumière une des contradictions propres au Do (Learn) It Yourself et à la gratuité. « Je me demande si je n’ai pas tué le métier de prof de guitare en proposant des contenus gratuits », s’interroge l’auteur de la chaîne MrGalagomusic lors d’un entretien. Comment, alors que la transformation de la consommation de l’écoute musicale intègre une tension qui tend à diminuer, le tutoriel, par sa gratuité, renouvelle-t-il une tension inhérente à la reproductibilité sonore dans le domaine de la transmission des gestes, des savoirs et des connaissances liés à l’apprentissage d’un instrument ? Cette tension est propre à la culture de la convergence qu’analyse Henry Jenkins : la contribution d’une communauté par une intelligence collective de l’apprentissage se confronte toujours au problème de la rémunération du créateur. Que devient donc son statut lorsque l’apprentissage est pluriel ?
La musique québécoise est-elle compatible avec le streaming  ? Usages et représentations de la musique francophone québécoise sur les plateformes de streaming au Québec
Authors: Jamet Romuald , Roberge Jonathan 
Published: November 2020

Les plateformes de streaming musical ont inéluctablement transformé l’industrie musicale ainsi que les formes et les pratiques d’écoute des auditeurs. Ceci est des plus perceptible au Québec, notamment concernant la musique locale : alors que l’industrie musicale peine, de par sa structuration historique et politique, à relever les enjeux liés au streaming et aux dernières modalités technologiques de diffusion, les auditeurs, eux, se sont massivement tournés vers ces plateformes et semblent avoir profondément « numérimorphosé » leurs pratiques d’écoute en se détournant au demeurant de la musique francophone québécoise. Quels rapports entretiennent les Québécois envers le streaming et, entre autres, pourquoi la musique québécoise francophone, pourtant disponible sur ces plateformes, y semble de moins en moins écoutée ? À partir des résultats d’une enquête qualitative et exploratoire auprès d’auditeurs québécois (n=20), cet article sera l’occasion de proposer une analyse des rapports complexes et pour le moins ambigus qu’entretiennent les utilisateurs québécois avec les plateformes de streaming.
Ultrasonographic Evaluation of Osteoarthritis-affected Knee Joints
Authors: Singh Abhay Pratap , Saran Sonal , Thukral Brij Bhushan , Kaushik Ravikant 
Published: November 2020

Background:
The objective was to compare ultrasonographic findings with clinical and radiographic findings in osteoarthritis (OA)-affected knee joints.

Methods:
This prospective study was conducted in Subharti Medical College, Meerut, after getting clearance from the ethical committee. Eighty-five symptomatic knees fulfilling American College of Rheumatology criteria for OA were included in the study. Patients with trauma, inflammatory, and infective conditions of the knee and with a history of intra-articular interventions and surgery were excluded. Demographic data, body mass index (BMI), visual analog scale (VAS), and Western Ontario and McMaster Universities Arthritis (WOMAC) questionnaire score were obtained. Kellgren–Lawrence (K-L) score was obtained on radiography. Ultrasonographic findings which were recorded include effusion, meniscal extrusion, femorotrochlear cartilage grading, maximum length of osteophytes at medial and lateral compartments, and presence or absence of Baker cyst.

Results:
A total of 85 consecutive symptomatic knees were examined. The male: female ratio was 22:63, with a mean age of 54.52 ± 9.44 years, mean duration of disease of 24.24 ± 19.14 months, mean BMI of 28.91 ± 3.69 kg/m2, and mean score of VAS and WOMAC pain scale of 6.27 ± 1.45 and 62.45 ± 10.96, respectively. K-L grading of 1, 2, 3, and 4 was reported in 12.9%, 21.2%, 25.9%, and 40% of the knees, respectively. The mean VAS score and WOMAC score showed statistically significant correlation with KL grading (P < 0.05). Knees with the presence of osteophytes, medial meniscal extrusion, effusion, and medial femoral trochlear cartilage grading showed statistically significant correlation with VAS and WOMAC scores (P < 0.05). However, the correlation was not significant for lateral meniscus extrusion and lateral femoral trochlear cartilage grading.

Conclusion:
Our study found that K-L grading and few ultrasonographic criteria showed a significant positive correlation with pain scores, while few other ultrasonographic criteria did not. Both imaging modalities are complementary to each other, rather than one being superior to the other.
Equivariant cohomology of torus orbifolds
Authors: Darby Alastair , Kuroki Shintarô , Song Jongbaek 
Published: November 2020

AbstractWe calculate the integral equivariant cohomology, in terms of generators and relations, of locally standard torus orbifolds whose odd degree ordinary cohomology vanishes. We begin by studying GKM-orbifolds, which are more general, before specializing to half-dimensional torus actions.
¿Discrimina el Código Penal español a las mujeres?
Authors: Pedrosa Albert 
Published: November 2020

Los datos oficiales muestran que en el contexto español se da una realidad hasta ahora poco conocida: las mujeres reciben proporcionalmente más penas de prisión que los hombres. El objetivo de este artículo es tratar de conocer si esto se debe a un fenómeno de discriminación directa, en tanto ciertos colectivos de mujeres son tratados más punitivamente; o a un fenómeno de discriminación indirecta, si el Código Penal castiga más duramente los delitos cometidos por las mujeres. Para comprobar esto se han analizado datos oficiales sobre imposición de penas y delincuencia conocida para el período 2007-15. Los resultados muestran que el alto porcentaje de penas de prisión impuestas a mujeres puede deberse a la poca libertad que otorga el Código Penal para imponer penas alternativas para delitos leves, especialmente en relación a la delincuencia patrimonial, más cometida por las mujeres, apoyando la existencia de un fenómeno de discriminación indirecta.
Torsional Strength in Fused Filament Fabrication 3D Printing
Authors: Ng Nathan , Flowers Kate 
Published: November 2020

Among robotics enthusiasts, fused filament fabrication (FFF) 3D printing has exploded in popularity. The ability to manufacture custom parts allows for a greater degree of freedom during the design phase. For example, mechanisms like the drivetrain, a hotbed of torsion forces, can be easily compressed to make room for additional functionality. However, such specific components are often unavailable for purchase. Therefore, the ability to manufacture custom torsionally resistant parts in an inexpensive manner is essential.
The objective of this study is to determine the FFF 3D printer settings that contribute significantly to a part’s torsional strength. This will be accomplished by altering either infill percentage or wall line count during printing while keeping all other settings constant among 30 individual test parts. Each part will be tested in a custom testing machine that applies a 9:1 gear reduction to simulate the maximum output torque of most hobbyist drivetrains. By measuring the amount of time each test part lasts before snapping, the setting granting the greatest increase in torsional strength can be determined.
Impact of Biosynthesized Silver Nanoparticles on Bacterial Growth
Authors: Basu Jishnu , Grimes Tiffany 
Published: November 2020

Cystic Fibrosis is a genetic disease which causes the production of viscous mucus in airways which limits airflow and creates the perfect conditions for bacterial growth. Unfortunately, deaths due to bacterial infections in Cystic Fibrosis patients have increased as bacterial strains have developed antibiotic resistance. Researchers have found that silver nanoparticles offer a solution to growing antibiotic resistance due to how no resistance has been developed to them in clinical trials. Current research is focusing on the bio-synthesis of silver nanoparticles which does not produce the harmful waste products seen with the industrial production of silver nanoparticles. However, there is a lack of comparative research concerning the effectiveness of silver nanoparticles produced by different microorganisms, which is what the researcher’s work addressed. The researcher’s work primarily focused on determining how effective silver nanoparticles produced by different bacterial species were at inhibiting bacterial growth. Through the collection of nanoparticles via extracellular synthesis, antimicrobial assays were conducted to determine the efficacy of silver nanoparticles produced by different microorganisms. The results indicated that silver nanoparticles produced by B. subtilis were the most effective in inhibiting bacterial growth. This provides a crucial as research in the field should increasingly focus on bacteria which utilize assimilatory nitrate reduction like B. subtilis because of the increased efficacy of silver nanoparticles produced by this method in inhibiting bacterial growth in aerobic conditions. Advances in this area could increase the efficiency of nanoparticle production and make it viable for industrial production.
Pengembangan Teknologi Game Indonesia untuk Game 2D “Heroes of Indonesia” Menggunakan Unity 2D Engine Berbasis Mobile
Authors: Kaurie Fazriyanor , Purwanto Agung , Minarni Minarni 
Published: November 2020

Pengembangan Teknologi Game Indonesia Untuk Game 2D “Heroes Of Indonesia” Menggunakan Unity 2D Engine Berbasis Mobile merupakan game dengan genre Action-Adventure, yang berguna sebagai hiburan serta sarana edukasi pengenalan sejarah kemerdekaan Indonesia kepada para pemainnya yang dirancang untuk smartphone berbasis Android. Penelitian ini dilakukan dengan cara membandingkan game sejenis. Untuk metode perancangannya dimulai dari tahap Analisis Data, Desain Sistem, Pembuatan Program, Pengujian, Implementasi, dan Evaluasi. Simpulan dari skripsi ini adalah perpaduan antara rintangan dan edukasi berupa kuis dalam game “Heroes Of Indonesia” merupakan media yang efektif dan menarik untuk mengenalkan sejarah apa saja yang terjadi dalam tercapainya kemerdekaan Indonesia. Tanggapan dari responden juga terhibur dengan memainkan game “Heroes Of Indonesia”.