bluuebunny/crossref_metadata_2025 huggingface dataset:
Photon Ring Symmetries in Simulated Linear Polarization Images of Messier 87*
Authors: Palumbo Daniel C. M. , Wong George N.
Published: April 2022

The Event Horizon Telescope (EHT) recently released the first linearly polarized images of the accretion flow around the supermassive black hole Messier 87*, hereafter M87*. The spiraling polarization pattern found in the EHT images favored magnetically arrested disks as the explanation for the EHT image. With next-generation improvements to very long baseline interferometry on the horizon, understanding similar polarized features in the highly lensed structure known as the “photon ring,” where photons make multiple half orbits about the black hole before reaching the observer, will be critical to the analysis of future images. Recent work has indicated that this image region may be depolarized relative to more direct emission. We expand this observation by decomposing photon half orbits in the EHT library of simulated images of the M 87* accretion system and find that images of magnetically arrested disk simulations show a relative depolarization of the photon ring attributable to destructive interference of oppositely spiraling electric field vectors; this antisymmetry, which arises purely from strong gravitational lensing, can produce up to ∼50% depolarization in the photon ring region with respect to the direct image. In systems that are not magnetically arrested and with the exception of systems with high spin and ions and electrons of equal temperature, we find that highly lensed indirect subimages are almost completely depolarized, causing a modest depolarization of the photon ring region in the complete image. We predict that next-generation EHT observations of M 87* polarization should jointly constrain the black hole spin and the underlying emission and magnetic field geometry.
COSMOS2020: Ubiquitous AGN Activity of Massive Quiescent Galaxies at 0 < z < 5 Revealed by X-Ray and Radio Stacking
Authors: Ito Kei , Tanaka Masayuki , Miyaji Takamitsu , Ilbert Olivier , Kauffmann Olivier B. , Koekemoer Anton M. , Marchesi Stefano , Shuntov Marko , Toft Sune , Valentino Francesco , Weaver John R.
Published: April 2022

We characterize the average X-ray and radio properties of quiescent galaxies (QGs) with

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at 0 < z < 5. QGs are photometrically selected from the latest COSMOS2020 catalog. We conduct the stacking analysis of X-ray images of the Chandra COSMOS Legacy Survey for individually undetected QGs. Thanks to the large sample and deep images, the stacked X-ray signal is significantly detected up to z ∼ 5. The average X-ray luminosity cannot be explained by the X-ray luminosity of X-ray binaries, suggesting that the low-luminosity active galactic nuclei (AGNs) ubiquitously exist in QGs. Moreover, the X-ray AGN luminosity of QGs at z > 1.5 is higher than that of star-forming galaxies (SFGs), derived in the same manner as QGs. The stacking analysis of the VLA-COSMOS images is conducted for the identical sample, and the radio signal for QGs is also detected up to z ∼ 5. We find that the radio AGN luminosity of QGs at z > 1.5 is also higher than SFGs, which is in good agreement with the X-ray analysis. The enhanced AGN activity in QGs suggested by the individual analysis in the X-ray and radio wavelength supports its important role for quenching at high redshift. Their enhanced AGN activity is less obvious at z < 1.5, which can be interpreted as an increasing role of others at lower redshifts, such as environmental quenching.
Theoretical and Observational Evidence for Coriolis Effects in Coronal Magnetic Fields via Direct Current Driven Flaring Events
Authors: Seligman Darryl Z. , Rogers Leslie A. , Feinstein Adina D. , Krumholz Mark R. , Beattie James R. , Federrath Christoph , Adams Fred C. , Fatuzzo Marco , Günther Maximilian N.
Published: April 2022

All stars produce explosive surface events such as flares and coronal mass ejections. These events are driven by the release of energy stored in coronal magnetic fields, generated by the stellar dynamo. However, it remains unclear if the energy deposition in the magnetic fields is driven by direct or alternating currents. Recently, we presented observational measurements of the flare intensity distributions for a sample of ∼105 stars across the main sequence observed by TESS, all of which exhibited power-law distributions similar to those observed in the Sun, albeit with varying slopes. Here we investigate the mechanisms required to produce such a distribution of flaring events via direct current energy deposition, in which coronal magnetic fields braid, reconnect, and produce flares. We adopt a topological model for this process, which produces a power-law distribution of energetic flaring events. We expand this model to include the Coriolis effect, which we demonstrate produces a shallower distribution of flare energies in stars that rotate more rapidly (corresponding to a weaker decline in occurrence rates toward increasing flare energies). We present tentative evidence for the predicted rotation-power-law index correlation in the observations. We advocate for future observations of stellar flares that would improve our measurements of the power-law exponents, and yield key insights into the underlying dynamo mechanisms that underpin the self-similar flare intensity distributions.
Gravitomagnetic Interaction of a Kerr Black Hole with a Magnetic Field as the Source of the Jetted GeV Radiation of Gamma-Ray Bursts
Authors: Rueda J. A. , Ruffini R. , Kerr R. P.
Published: April 2022

We show that the gravitomagnetic interaction of a Kerr black hole (BH) with a surrounding magnetic field induces an electric field that accelerates charged particles to ultra-relativistic energies in the vicinity of the BH. Along the BH rotation axis, these electrons/protons can reach energies of even thousands of petaelectronvolts, so stellar-mass BHs in long gamma-ray bursts (GRBs) and supermassive BHs in active galactic nuclei can contribute to the ultrahigh-energy cosmic rays thorough this mechanism. At off-axis latitudes, the particles accelerate to energies of hundreds of gigaelectronvolts and emit synchrotron radiation at gigaelectronvolt energies. This process occurs within 60° around the BH rotation axis, and due to the equatorial symmetry, it forms a double-cone emission. We outline the theoretical framework describing these acceleration and radiation processes, how they extract the rotational energy of the Kerr BH and the consequences for the astrophysics of GRBs.
Unveiling an Old Disk around a Massive Young Leaking Blueberry in SDSS-IV MaNGA
Authors: Paswan Abhishek , Saha Kanak , Borgohain Anshuman , Leitherer Claus , Dhiwar Suraj
Published: April 2022

Extreme emission-line galaxies, such as blue compact dwarfs (BCDs), Green Peas (GPs), and blueberries in the local universe are potential candidates for understanding the nature of galaxies that reionized the early universe. Being low-mass, metal-poor starburst systems, they are understood to be local analogs of the high-redshift Lyman continuum and Lyα emitters (LAEs). Even with their proximity to us, we know little about their spatially resolved properties; while most blueberries and GPs are indeed compact, they remain unresolved. Here, we report the detection of a disk-like lower-surface-brightness (LSB) stellar host with a very old population around a blueberry LAE system using broad i-band imaging and integral field spectroscopic data from the SDSS and SDSS-IV MaNGA surveys, respectively. The LSB stellar host is structurally similar to that observed around local starburst BCDs. Furthermore, the kinematics of the studied blueberry source bears signs of misalignment between the gas and stellar components. Our findings establish an intriguing thread connecting the blueberry and an LSB disk with an old stellar population and suggest that blueberries and their high-redshift counterparts such as GPs do not represent peculiar cases of dwarf galaxy evolution. In fact, with respect to the structural properties of their host galaxies, they are compatible with a common evolutionary track of the main population of local BCDs.
Factor Related the Use of Respiratory Supports among COVID-19 Patients in Sardjito Hospital Yogyakarta: A Cross-sectional Study
Authors: Putri Imram Radne Rimba , Surismanto Fajar , Sugiarto Sugiarto , Ridwan Edi Sampurno
Published: April 2022

BACKGROUND: In patients with coronavirus disease-19 (COVID-19), respiratory failure is a serious condition that requires immediate respiratory supports. Various clinical conditions can be determinant factors to the need for used of ventilators.

AIM: The aim of the study was to determine factor related to the used of ventilators among COVID-19 patients transferred to intensive care unit Sardjito Hospital.

METHODS: Using a cross-sectional design, a total of 171 of 300 medical records selected in accordance to the inclusion criteria. Association of each clinical characteristics and outcome variable used contingency coefficient and Spearman rank tests, while multivariate logistic regression model was performed for hypothesis testing. The area under curve (AUC) was test to determine model fit of the logistic approach.

RESULTS: There was a significant correlation between age (p = 0.004), blood sugar levels (p < 0.001), and oxygen saturation (p < 0.001), and the used of ventilator. Patients with hypoxia and severe hypoxia had odds of using ventilation supports 5 times and 114 times (OR = 5.623) and (OR = 114.3). The AUC test indicated that null hypothesis was rejected.

CONCLUSION: The clinical characteristics were associated with age, blood sugar levels, and oxygen saturation. Patients with COVID-19 who admitted to hospital with hypoxia and severe hypoxia increased the odds of the use ventilators.
HPLC-FLD analysis of amino acids content in Chrysanthemum morifolium
Authors: Savych Alona , Polonets Olha , Morozova Liubov , Syrovatko Kateryna , Recun Tetiana
Published: April 2022

Chrysanthemum morifolium (Asteraceae family) have long been used as a tonic, antioxidant, antipyretic, analgesic, sedative, antitumor, neuroprotector, hepatoprotector and cardioprotector agent. This species should be reconsidered as possible sources of many biocompounds, especially amino acids. Thus, the aim of this study was to validate the chromatographic method for detection of amino acids and their identification in flowers and leaves of Ch. morifolium of variant Pectoral. HPLC-FLD method was evaluated in terms of linearity, precision, repeatability, accuracy, LOD and LOQ. The calibration curves of all analytical standards of amino acids were linear (R2 > 0.99) over the range of 0.015–0.625 μmol/mL, the LODs and the LOQs were in the range of 0.001–0.096 µg/mL and 0.004–0.321 µg/mL, respectively. During the HPLC-FLD assay ten amino acids in free form and fifteen amino acids after hydrolysis in Ch. morifolium flowers were identified. Besides, twelve amino acids were detected in free form and fourteen amino acids after hydrolysis in Ch. morifolium leaves. The results of HPLC-FLD analysis showed that the predominant amino acid was L-proline in both types of herbal raw materials. Its total content was 31.67±0.02 μg/mg in Ch. morifolium flowers and 18.56±0.02 μg/mg in Ch. morifolium leaves. This phytochemical study confirms that flowers and leaves of Ch. morifolium (Pectoral) are rich sources of amino acids and can exhibit a wide range of pharmacological activities.
Le conte et la construction de soi
Authors: Chouvier Bernard
Published: April 2022

Le conte permet d’actualiser, de métaphoriser et de dépasser une altération traumatogène des vécus familiaux. Sa structure cyclique, sa narrativité spécifique liée à une mobilisation manifeste de l’imaginaire lui confèrent une capacité élaborative suffisante pour engager le sujet dans une mise à l’épreuve identitaire corrélée à un étayage intersubjectif en mesure de lui offrir une ouverture symbolique adéquate. L’analyse du conte russe L’oiseau de feu met en évidence les différentes manières dont dispose le conte pour symboliser les transformations nécessaires à la progression maturative individuelle, au-delà des conflits familiaux rencontrés. L’auteur présente les trois temps du dispositif du groupe-conte au cours desquels se manifestent, à mesure que se développe une processualisation psychique groupale, la mise en jeu des niveaux inter et transgénérationnels ainsi que la résolution des conflits familiaux.
La coconstruction de la narrativité. Trois niveaux dans le développement comme dans le soin
Authors: Golse Bernard
Published: April 2022

Après avoir rappelé quelques définitions concernant les concepts de narrativité, de récit et de narration, l’auteur évoque les différentes racines épistémologiques de la narrativité ainsi que l’ontogénèse de cette fonction dans le cadre du développement du bébé (narrativité sensorielle, narrativité corporelle, narrativité en images mentales et narrativité verbale enfin). Il montre ensuite que l’espace des interactions précoces peut être considéré comme un espace de coconstruction narrative entre l’adulte et l’enfant avant de rapporter les travaux de l’institut Pikler-Lóczy à Budapest et l’organisation de la construction narrative dans le cadre des soins selon trois niveaux (l’enfant, la nurse et la pédagogue) qui rappellent les trois générations nécessaires à la construction d’un sujet.
Maltraitance intrafamiliale et enrôlement « volontaire » d’enfant soldat
Authors: Onguéné Ndongo Théodore
Published: April 2022

L’enrôlement d’enfants dans les groupes armés est une triste réalité. Présents dans plusieurs conflits armés et guerres, ces derniers peuvent être enrôlés de force, mais il faut prendre en compte le phénomène avéré d’enrôlement volontaire. Les raisons de cet enrôlement volontaire sont nombreuses. Cet article se propose d’examiner la place que tient la maltraitance intra-familiale dans l’émergence et la pérennisation de ce phénomène. Il porte sur une étude de cas d’un enfant soldat rencontré lors d’une recherche en République démocratique du Congo. Ce travail montre que l’enrôlement volontaire puise en partie sa source dans la souffrance du lien familial meurtri dans un tel contexte. Ceci se manifeste dans les questions de bonne distance, de partage de l’intimité et la construction de la figure de l’enfant intrus.
« Habiter le temps » de l’amphithéâtre à l’heure des pratiques numériques informelles
Authors: Barry Anna
Published: April 2022

Cet article traite de la recomposition des temps de l’étude à l’université en lien avec le développement de l’usage (ici informel) des technologies de l’information et de la communication. Deux espaces d’analyse sont convoqués : celui d’un groupe Facebook, réunissant 199 étudiants de licence 3 ; celui de l’enseignement présentiel de cette même promotion (60 heures de cours magistral). L’article pose l’hypothèse que la reconfiguration numérique du temps des études gagne à être examinée en amont des dispositifs qui lui sont officiellement dédiés : ceux de la pédagogie universitaire. Les auteurs proposent d’examiner comment les modes de communication numériques spontanément mis en œuvre par les étudiants sur les réseaux sociaux exercent à eux seuls d’importants effets sur la diffusion des savoirs à l’université et participent de ce fait à l’apparition de nouvelles formes de l’étude où les logiques d’immédiateté et de différé interfèrent avec les conditions classiques de l’enseignement magistral.
De la trajectoire scolaire aux « signes » de la vocation : la sélection de l’élève de classe préparatoire littéraire au sein d’un établissement privé catholique
Authors: Laheyne Cédric
Published: April 2022

À partir d’une enquête par entretiens et d’une étude de lettres de motivation d’élèves d’une classe préparatoire littéraire d’un lycée privé catholique (filière « lettres et sciences sociales »), l’article s’intéresse aux catégories de l’entendement professoral qui se manifestent dans le processus de sélection en classe préparatoire. Il évoque dans un premier temps comment elles renvoient à la singularité de l’histoire institutionnelle et aux conceptions de l’éducation propre aux congrégations féminines. Puis, en nous appuyant sur le concept sociologique de vocation, nous montrerons en quoi elles reflètent un mode de sélection basé sur la rencontre entre des dispositions individuelles et des attentes institutionnelles, notamment au profit d’élèves non suffisamment pluridisciplinaires pour s’assurer une place dans cette filière particulièrement sélective.
Bienveillance et exemplarité
Authors: Roelens Camille
Published: April 2022

Nous partons ici du constat d’une tension entre la volonté de former les enseignants à la bienveillance et le sentiment que ces derniers peuvent éprouver de ne pas être traités eux-mêmes avec bienveillance par l’institution scolaire (1). Nous restituons ensuite brièvement une généalogie de cette notion de bienveillance et l’histoire de son émergence contemporaine dans la société et dans l’école, puis présentons deux conceptualisations complémentaires de la bienveillance inscrites dans la société des individus (2). Introduire la notion d’ exemplarité nous permet ensuite d’envisager comment il est possible et peut-être nécessaire pour former à la bienveillance de former avec bienveillance (3). Ces réflexions sont menées d’un point de vue de philosophe de l’éducation inscrit dans le champ des sciences de l’éducation.
La progression de l’enseignement supérieur au Sénégal : des inégalités persistantes
Authors: Goudiaby Jean-Alain , Pilon Marc
Published: April 2022

À l’instar de nombreux autres pays d’Afrique subsaharienne, le Sénégal connaît depuis les années 2000 une très forte croissance de sa population étudiante, mais avec des niveaux de fréquentation du supérieur demeurant encore très faibles. Sur la base de sources de données existantes (statistiques et qualitatives), le texte propose de faire un point sur l’évolution des politiques éducatives, le développement de l’offre (publique et privée) et de la fréquentation du supérieur. Si le développement de l’offre de formation s’est globalement accru, les inégalités régionales demeurent marquées, et différentes selon le sexe. Et si la scolarisation des filles dans le supérieur a progressé, elle reste encore bien inférieure à celle des garçons. Classification JEL : I2, D63
L’immédiateté de Dieu dans l’ordinaire de la vie chrétienne : les charismes au service d’une Église synodale
Authors: Desmazières Agnès
Published: April 2022

La théologie des charismes pâtit jusqu’à aujourd’hui d’une assimilation des charismes à l’« extraordinaire » : Dieu ne pourrait se donner de manière immédiate que dans l’« extraordinaire ». Cet article vise au contraire à mettre en évidence comment les charismes s’inscrivent dans l’ordinaire de la vie vertueuse et se déploient en vocations au service du Royaume. Dans cette perspective, en conjonction avec le sensus fidei , ils contribuent au discernement de l’Esprit à l’œuvre dans l’Église, appelée à être toujours plus authentiquement synodale.
« Rares sont ceux qui voudraient le croire » : hiérarchie et proximité de Dieu selon saint Bonaventure
Authors: Solignac Laure
Published: April 2022

Comment Bonaventure peut-il soutenir sans contradiction la nécessité de médiations (hiérarchies, itinéraire) entre Dieu et l’âme humaine, et la possibilité d’une expérience immédiate de Dieu ? Faut-il y voir une tension entre le ministre général réputé autoritaire et le mystique avide de goûter la présence de Dieu ? Loin de cette caricature, l’examen de sa conception de l’Ordre et de sa doctrine des sens spirituels révèle qu’à ses yeux les médiations n’ont de sens qu’à reconduire l’homme vers l’expérience de la présence de Dieu dans leur vie.
Suicidality in Rural College Students: An Integrative Review
Authors: Johnson Ashlyn M. , Smith Diane L.
Published: April 2022

Suicide, as the third leading cause of death among individuals aged 15 to 24 years, is substantially more frequent in non-metropolitan/rural counties, where college/university students may be at particular risk; however, little is known about risk and protective factors and prevention strategies specific to this population. The current integrated review was completed to explore such factors and evidence-based interventions. A systematic literature search was performed, guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and using computerized databases, for studies published from 2008 to 2021; nine met inclusion criteria. Data were classified into subgroups, which included risk and protective factors for suicidality, stressors and risk factors for psychological distress, and barriers to psychological help-seeking. Key findings included depression as a risk factor, religiosity as a protective factor, decreased social support as a stressor, and various barriers to help-seeking. No evidence-based interventions for this population have been identified in the literature. Research is needed to explore evidence-based interventions for rural college/university students. [Journal of Psychosocial Nursing and Mental Health Services, 60(9), 15–23.]
Achieved and Functional Optical Zone in Myopic Eyes With High Astigmatism After Small Incision Lenticule Extraction
Authors: Liu Shengtao , Gu Xuejun , Zhang Xiaoxue , Zhao Jing , Zhou Xingtao
Published: April 2022

PURPOSE:

To investigate the achieved optical zone and functional optical zone in myopic eyes with high astigmatism after small incision lenticule extraction (SMILE).

METHODS:

Seventy-five eyes of 75 consecutive patients with myopia before SMILE were included and divided into two groups (no astigmatism group: without astigmatism vs high astigmatism group: with astigmatism > 2.00 diopters). The achieved optical zone, functional optical zone, and corneal aberrations were compared using Scheimpflug imaging at 6 months postoperatively. Correlations between corneal aberrations and functional optical zone were analyzed.

RESULTS:

The mean achieved optical zone diameter was smaller in the no astigmatism group than in the high astigmatism group. There were no significant differences in achieved optical zone among the different meridians in each group. The mean functional optical zone diameter was significantly smaller in the no astigmatism group than in the high astigmatism group. Compared with the programmed optical zone, significant reduction of the functional optical zone was found in the two groups. The reduction of the functional optical zone was significantly smaller in the high astigmatism group than in the no astigmatism group, except for the 60°, 90°, and 120° meridians. There were significant correlations between the functional optical zone area and the induced corneal aberrations in the high astigmatism group, except for horizontal coma, whereas significant correlations of functional optical zone with total higher order aberrations and spherical aberration were detected in the no astigmatism group.

CONCLUSIONS:

Myopic eyes with high astigmatism following SMILE had a circular achieved optical zone, but the functional optical zone was oval and larger than in eyes without astigmatism. Moreover, a lower spherical aberration was observed in the patients with high astigmatism.

[
J Refract Surg
. 2022;38(4):243–249.]
The existence results for a class of generalized quasilinear Schrödinger equation with nonlocal term
Authors: Hu Die , Jin Peng , Tang Xianhua
Published: April 2022

In this paper, we discuss the generalized quasilinear Schrödinger equation with nonlocal term:

\begin{document}
$
\begin{align} -\mathrm{div}(g^{2}(u)\nabla u)+g(u)g'(u)|\nabla u|^{2}+V(x)u = \left(|x|^{-\mu}\ast F(u)\right)f( u),\; \; x\in \mathbb{R}^{N}, \;\;\;\;\;\;\;\;({{\rm{P}}})\end{align}
$
\end{document}

where $ N\geq 3 $, $ \mu\in(0, N) $, $ g\in \mathbb{C}^{1}(\mathbb{R}, \mathbb{R}^{+}) $, $ V\in \mathbb{C}^{1}(\mathbb{R}^N, \mathbb{R}) $ and $ f\in \mathbb{C}(\mathbb{R}, \mathbb{R}) $. Under some "Berestycki-Lions type conditions" on the nonlinearity $ f $ which are almost necessary, we prove that problem $ (\rm P) $ has a nontrivial solution $ \bar{u}\in H^{1}(\mathbb{R}^{N}) $ such that $ \bar{v} = G(\bar{u}) $ is a ground state solution of the following problem

\begin{document}
$
\begin{align} - \Delta v+V(x)\frac{G^{-1}(v)}{g(G^{-1}(v))} = \left(|x|^{-\mu}\ast F(G^{-1}(v))\right)f( G^{-1}(v)),\; \; x\in \mathbb{R}^{N}, \;\;\;\;\;\;\;\;({{\rm{\bar P}}})\end{align}
$
\end{document}

where $ G(t): = \int_{0}^{t} g(s) ds $. We also give a minimax characterization for the ground state solution $ \bar{v} $.
Some conditions for the existence and uniqueness of monotonic and positive solutions for nonlinear systems of ordinary differential equations
Authors: Branga Adrian Nicolae
Published: April 2022

In this paper, applying the theory of fixed points in complete gauge spaces, we establish some conditions for the existence and uniqueness of monotonic and positive solutions for nonlinear systems of ordinary differential equations. Moreover, the paper contains an application of the theoretical results to the study of a class of systems of nonlinear ordinary differential equations.
Piecewise discretization of monodromy operators of delay equations on adapted meshes
Authors: Breda Dimitri , Liessi Davide , Vermiglio Rossana
Published: April 2022

Periodic solutions of delay equations are usually approximated as continuous piecewise polynomials on meshes adapted to the solutions' profile. In practical computations this affects the regularity of the (coefficients of the) linearized system and, in turn, the effectiveness of assessing local stability by approximating the Floquet multipliers. To overcome this problem when computing multipliers by collocation, the discretization grid should include the piecewise adapted mesh of the computed periodic solution. By introducing a piecewise version of existing pseudospectral techniques, we explain why and show experimentally that this choice is essential in presence of either strong mesh adaptation or nontrivial multipliers whose eigenfunctions' profile is unrelated to that of the periodic solution.
El camafeo de Júpiter de Girona: una obra imperial reutilizada en la Baja Edad Media
Authors: Oliver Vert Jordi , Parada López de Corselas Manuel
Published: April 2022

En el presente trabajo abordamos el estudio de un camafeo romano de considerable calidad y tamaño (6,2 × 4,8 cm), en sardónice tricolor tallado en tres estratos, con la representación de Júpiter entronizado y que se encuentra reutilizado en la Cruz de las Cofradías en el tesoro de la catedral de Girona. Proponemos la datación en los siglos III-IV d. C. de la pieza a partir de su estudio estilístico e iconográfico y, por otro lado, abordamos su contextualización como ornamentum en la cruz gótica gerundense, analizando las circunstancias en las que se engarzó en ella.
Production and characterization of AA2014-B4C surface-modificated composite via the squeeze casting technique
Authors: Kabil Ahmet , Yüksel Çağlar , Çiğdem Mustafa
Published: April 2022

Metal matrix composite (MMCs) materials provide superiority to monolithic materials in various mechanical properties such as tensile, yield, abrasion resistance, impact resistance by adding reinforcements such as B4C, SiC, Al2O3. While liquid metal processes offer an important advantage, such as low-cost production in high volumes, the heterogeneous clustering of reinforcements in the matrix and the formation of porosity in the area between the reinforcement and matrix pose a problem for composite production. The squeeze casting method stands out in composite production due to its low cost, suitability for mass production, allowing high reinforcement ratio, and ease of homogeneous distribution of reinforcements. In this study, a composite layer reinforced with B4C was produced with a thickness of 1 and 2 mm on a substrate of aluminum 2014 wrought alloy using the squeeze casting method. The mechanical properties of the composite materials produced were characterized via tensile, wear, impact, and hardness tests, and were examined with the help of Scanning Electron Microscopy (SEM). It has been observed that the composite region contains 50 vol.% of B4C reinforcement and the particles of reinforcement were homogeneously distributed into the matrix. All results of the tests mentioned above are better than those obtained in the monolithic 2014 aluminum alloy.
Evaluation of Learning Management Systems
Authors: Yamani Hanaa A. , Alharthi Ahmed D. , Smirani Lassaad Kacem
Published: April 2022

This study examined, by analysis and comparison, two Learning Management Systems (LMS): Blackboard and Brightspace. The field research sample consisted of 513 students at Umm Al-Qura University. The study attempted to answer central questions dealing with the evaluation level of Umm Al-Qura University students for the characteristics of these two LMS. The study concludes that most students agree on the benefits of Blackboard and Brightspace, and according to them, the most common advantages of these LMS are: Help to access shared data and files, record and monitor the learner's performance, help to control and customize the educational process, facilitate the exchange of experiences and scientific concepts with others, the stable interface in controlling and moving among other components, facilitate discussion with the teacher and with students, and interface easy to understand and learn and easy to use. The study revealed that there is a statistically significant difference between the mean scores of students who use the Blackboard system and students who use the Brightspace system in the overall score to evaluate the e-learning system characteristics in favor of students who use the Brightspace system. This means that students who use the Brightspace system are more sensitive to the advantages of an e-learning system compared to students who use the Blackboard system. The findings can be used to assist educators in producing the best process of implementing open and distance learning. The appropriate techniques must be chosen to ensure that no student drops behind and that the teaching and learning process works with sustainability.
Modelling Students’ Adoption of E-Learning During the COVID-19 Pandemic
Authors: Jamalova Maral , Bálint Csaba
Published: April 2022

This research examines the impact of gender and age differences on the attitude towards online education in universities and colleges during the COVID-19 pandemic in Hungary. The answers were evaluated using Partial Least Squares estimation technique by involving age and gender as moderator variables. The research model is based on a modified version of the Technology Acceptance Model (TAM) proposed by Davis, Warshaw, and Bagozzi (1989) and expanded by a good teaching scale. Apart from perceived ease of use, other variables illustrated significant direct relationships. Moderating effect of age and gender of the surveyed Hungarian students influence formulation of attitude towards e-learning. The results illustrate that the gender and age of the respondents influence the perceived usefulness → behavioral intention pathway. Also, the age of respondents has an impact on the relationship between perceived ease of use and perceived usefulness.
Hybridization of Neural Networks and Sine Cosine Algorithm for an Optimal Neural Network Architecture Applied to Prevent Heart Attacks
Authors: Hourri Maryem , Alaa Noureddine
Published: April 2022

Artificial intelligence and deep learning provide very good results, if it is well adjusted. In this work, we will proceed to perform the deep learning results through the optimization of the neural network architecture. For this purpose, especially for supervised algorithms, Hybridization of neural networks and the sinus-cosine algorithm will perform classification problems. The role of this method is to escape the groping method in choosing the optimal architecture of neural networks. The goal of our method is to build an optimal neural network architecture, without falling into an over fitting problem. To demonstrate the effectiveness of our work, an application part with experimental results is included: with an application in medicine especially heart attack. The goal of our work is to develop an efficient hybrid classifier, using machine learning and sine cosine algorithm to detect heart attack and minimize the number of heart attack not predicted. Through this hybridization technique we should have a low error with satisfying classification results. This method of hybridization can be applied for different issues.
Diagnosis of Pulmonary Nodules on CT Images Using YOLOv4
Authors: Bhatt Shital , Soni Himanshu , Pawar Tanmay , Kher Heena
Published: April 2022

In this paper, the Scale-Invariant Feature Transform (SIFT) and Fast Library for Approximate Nearest Neighbors (FLANN) based algorithm is used to detect the abnormalities in the National Lung Screening Trial (NLST) CT scans as the exact clinical nodule locations are not provided in the dataset. These identified nodules on NLST CT Scans are then annotated using LabelImg tool. This process consumes time and so furthermore, the automatic nodule detection, You Only Look Once version 4 (YOLOv4) object detection model is implemented. The YOLOv4 object detection model is provided with total of 4187 labelled images in form of training (70%), validation (20%), and test (10%) datasets. Our YOLOv4 model achieves precision of 95%, sensitivity of 81% and mean Average Precision (mAP) of 89.1%.
Thucydide sous le regard de Raymond Aron
Authors: Foro Philippe
Published: April 2022

Raymond Aron a été un des grands analystes des tragédies, évolutions et grands débats idéologiques du siècle dernier. Lecteur et admirateur de Thucydide, il a mis à contribution l’héritage de l’historien de la Guerre du Péloponnèse pour éclairer sa réflexion sur le xxe siècle. Cette contribution souhaite en souligner quelques aspects.
« Rien dans les mains, rien dans les poches ». Louis Gernet e Jean-Pierre Vernant e lo studio della tirannide in Grecia
Authors: Bonanno Daniela
Published: April 2022

Le présent travail se propose d’examiner la contribution que L. Gernet et J.-P. Vernant fournirent à l’étude de la tyrannie en Grèce et de reconstruire le contexte intellectuel et scientifique dans lequel de telles réflexions se développèrent. Les deux savants ne consacrèrent que deux brefs travaux à ce sujet, réussissant à retracer dans le passé mythique les modèles de comportement dont les tyrans grecs s’inspiraient. Les conclusions auxquelles ils parvinrent et, plus encore, l’approche utilisée pour l’analyse des sources antiques suscitèrent un large débat et eurent des conséquences notables sur les recherches postérieures sur la tyrannie.
Une Promenade italienne de Charles Maurras (1929) : le couple franco-italien au cœur du projet d’« Union latine »
Authors: Valenti Catherine
Published: April 2022

Depuis la seconde moitié du xixe siècle s’est développée en Europe une défense de la « civilisation latine », en réaction contre l’hégémonie économique et culturelle des pays anglo-saxons et de l’Allemagne. Pour ses promoteurs, la latinité ne se limite pas aux seuls pays riverains de la Méditerranée, ni même au seul continent européen, puisqu’elle englobe aussi les pays de l’Amérique du sud que l’on qualifie désormais de « latine ».Ayant forgé sa conscience politique auprès du Félibrige et du mouvement fédéraliste provençal, Charles Maurras adhère au projet d’« Union latine » dès la fin du xixe siècle. Dans son ouvrage Promenade italienne paru en 1929, le leader de l’Action française voit dans l’avènement du régime fasciste en Italie l’occasion de mettre enfin ce projet à exécution, autour du couple franco-italien.
Albert Camus, l’Anabase de Xénophon et la « nouvelle Culture méditerranéenne »
Authors: Demont Paul
Published: April 2022

Albert Camus fait à deux reprises allusion au fameux cri poussé par les mercenaires grecs conduits par Xénophon quand ils aperçurent enfin la mer  : «  La mer  ! La mer  !  », dans la perspective de la «  nouvelle Culture méditerranéenne  » qu’il voulait construire, puis dans le programme d’une nouvelle revue intitulée Rivages. Les écarts par rapport au texte de Xénophon méritent une brève étude. Deux aspects principaux dominent ces allusions  : la condamnation de la Méditerranée latine, Mare nostrum pour le nouvel empire de Mussolini, et le bonheur sensuel du contact avec la mer Méditerranée.
Quand les feuilles du chêne de Dodone se mirent à bruire
Authors: Grand-Clément Adeline , Rey Sarah
Published: April 2022

Le fonctionnement de l’oracle de Dodone reste obscur, mais on lit souvent dans les manuels d’histoire grecque que les pèlerins venaient dans ce sanctuaire épirote consulter la volonté de Zeus en écoutant le bruissement du vent dans le feuillage du chêne sacré. Un examen des sources anciennes révèle toutefois que rien ne vient confirmer cette hypothèse  ; cette dernière repose vraisemblablement sur un amalgame entre des témoignages différents. Nous tentons de comprendre ici les raisons de son succès, en orientant l’enquête du côté de l’origine de l’histoire des religions, autour de la dendrolâtrie attribuée aux Anciens, puis du côté du développement d’une forme de sensibilité écologique chez les modernes.
Qu’est-ce que l’anthropologie historique des savoirs ?
Authors: Jacob Christian
Published: April 2022

Sur le mode réflexif d’une forme d’ego-histoire, cet article essaie de définir la visée, les méthodes, les enjeux d’une approche anthropologique des savoirs antiques, où l’accent est mis moins sur les contenus que sur les modalités de leur construction et de leur énonciation, resituées dans la multi-dimensionnalité des contextes qui en déterminent les significations — matérialité, interactions sociales, opérations des laboratoires discursifs que sont les textes de savoir de l’Antiquité gréco-romaine.
Prendre les dieux grecs au sérieux : Marcel Detienne au miroir de Walter Otto
Authors: Bonnet Corinne , Pirenne-Delforge Vinciane , Pironti Gabriella
Published: April 2022

L’ouvrage de W.F. Otto qui paraît à Bonn en 1929 et s’intitule Die Götter Griechenlands. Das Bild des Göttlichen im Spiegel griechischen Geistes, a fait l’objet d’une édition en langue française en 1981 proposant une préface de M. Detienne, intitulée « Au commencement était le corps des dieux ». Cet article s’attache à retracer la relation intellectuelle paradoxale qui se noue entre ces deux auteurs et leur pensée respective sur le polythéisme grec. Le jeu de miroirs entre deux hommes et deux œuvres, entre proximité et écart, permet de s’interroger sur l’historiographie des dieux grecs au xxe siècle.
L'Enchiridion de Sextus Pomponius, heurs et malheurs d’un manuel juridique antique
Authors: Bur Clément , Lanfranchi Thibaud
Published: April 2022

Parmi les œuvres juridiques léguées par l’Antiquité romaine, l’Enchiridion de Sextus Pomponius occupe une place à part, à la fois parce que c’est une des rares œuvres à nous être parvenues assez complète, mais aussi par sa nature très originale qui lui a valu sa place en tête du Digeste. Cet article se propose de revenir sur les interprétations et éditions de ce texte depuis l’époque moderne pour montrer qu’il a fait l’objet de lectures très contrastées, et pour attirer l’attention sur tout l’intérêt qu’il y aurait à en proposer une édition française commentée.
Lettre sur l’Humanisme et les Humanités
Authors: Hartog François
Published: April 2022

Humanisme est un nom récent. Le latin classique ou médiéval l’ignore, et son usage ne se répand qu’au cours du xixe siècle, à partir de l’Allemagne. On le sait, on le relève parfois, mais, pressé d’arriver à l’Humanisme de la Renaissance, devenu l’éponyme, on ne s’y arrête pas. C’est justement ce que ce texte entend faire : s’arrêter sur cet écart temporel et commencer à interroger cette généalogie moderne de la culture européenne.
L’espace de la représentation (politique) et l’espace de la participation
Authors: Gaudin Jean-Pierre
Published: April 2022

Pour juger pleinement de la participation, il faut la replacer dans les débats d’ensemble portant sur la démocratie. Et tenir compte en particulier de la confrontation entre partisans et critiques de la démocratie parlementaire, confrontation qui est presque toujours sous-jacente aux débats actuels sur la participation. Est-ce que la démocratie parlementaire ne reproduit pas en définitive les défauts des régimes politiques les plus élitistes ? Dès lors que la déception politique devient grande, beaucoup de citoyens rêvent de prendre directement la parole, de faire entendre leurs choix sans passer par des représentants élus. Les parlements et les assemblées seraient-ils donc devenus inutiles ? Sans doute, les deux formes de l’expression politique, la représentative et la participative, ne s’excluent pas par principe. Certains penseurs politiques considèrent même qu’elles se complètent et s’enrichissent mutuellement, dans un mouvement d’approfondissement de la démocratie globale. Mais est-ce à dire qu’elles peuvent simplement s’additionner ? Et qu’elles ne se concurrencent jamais, même lorsque leurs légitimités restent différentes ? Si les agencements concrets des démarches de participation nous apportent certaines garanties de bonne fin, ils ne sauraient faire oublier ni les débats d’idées concernant la représentation politique ni la force de nos imaginaires démocratiques.
The dynamics of metropolitan peripheries: Ongoing changes in residential development in the North-Western corridor of the Madrid region
Authors: Adelfio Marco , Valenzuela Manuel
Published: April 2022

This paper examines the ongoing transformations of residential development underway in the North-Western corridor of the Madrid metropolitan region, which are a consequence of a deconcentration process that has affected the capital of Spain over several decades. It also outlines the historical forces that have paved the way for the contemporary suburbanisation process. This part of the Madrid region, traditionally used for animal husbandry or leisure activities for wealthy social classes, was later occupied by second homes. In recent years we have observed a transformation of these second homes into principal residences, together with a construction of brand-new primary residences. This is linked to the rise in housing prices occurring in central Madrid, which has fostered a centrifugal movement of population. This process has particularly affected single-family housing.
Paul Krugman : (presque) un Nobel de géographie
Authors: Walther Olivier
Published: April 2022

Paul Krugman a reçu le Prix Nobel d’économie pour son analyse des modèles du commerce mondial et de la localisation de l’activité économique. Voilà une nouvelle qui devrait réjouir certains géographes.
Les débuts du tourisme au Grand-Duché de Luxembourg. Au temps où le Luxembourg était à 6 heures 30 de Paris
Authors: Jeck Marc
Published: April 2022

Les débuts de l’industrie touristique au Grand-Duché de Luxembourg se situent au XIXe siècle. Les « touristes romantiques » découvrent le côté « pittoresque » d’un pays, jadis appelé « Pays des loups », et diffusent, par le biais de leurs récits, la première propagande touristique pour le Luxembourg. Parallèlement aux regards bienveillants des visiteurs de passage, les Luxembourgeois prennent conscience de leur patrimoine et de sa valorisation. Soucieux de montrer les beautés d’un pays qui, au niveau politique, intellectuel, culturel et économique, s’émancipe au XIXe siècle, quelques pionniers dont l’hôtelier Alexis Heck s’engagent dans le destination management du Luxembourg. Aidés par les nouvelles technologies de la mobilité, les protagonistes du tourisme donnent l’exemple aux autorités publiques qui suivent très vite l’initiative privée pour transfigurer les préoccupations touristiques en une « industrie nationale ». La promotion du pays, qui inclut le tourisme collectif et récréatif, va de pair avec l’affirmation de l’indépendance du Luxembourg.
Machine Learning for Risk Analysis
Authors: Jain Parita , Aggarwal Puneet Kumar , Makar Kshirja , Garg Riya , Mehta Jaya , Chaudhary Poorvi
Published: April 2022

Evolution of technology summons risks. With the use of complex prototypes and methods, not only the decision-making propensity of the machines increases but also the risk assessment reduces and frauds increased. Machine learning (ML) is considered an appropriate solution for the management of risks as it can produce the desired solution with less human effort. So, to minimize the possibility of risks, certain methods are adopted that benefited through ML. The chapter provides an insight into various applications of ML techniques in the field of risk analysis. The application of ML in this sector has led to a fact that these methods can be used to analyze huge amounts of data with efficient predictive analysis. Moreover, the future of machine learning in risk analysis and management is presented bringing out the positive picture. As a conclusion, one can just say that humans will be seeing an era which will make even complex problems easy to solve with efficiency. The chapter concludes with some limitations which need to be fixed for better risk management.
A Blended Learning Approach
Authors: Yong Su Ting , Tiong Kung Ming
Published: April 2022

This study explored students’ motivation and difficulties in learning programming in a blended learning environment. The face-to-face classroom instructions were blended with digital learning instructions. The study adopted a convergent parallel design mixed methods research and involved 209 pre-university students. The findings were as follows: (i) Looping was hard. Students faced difficulties in program design, problem-solving, and debugging of repetition structures. (ii) Students with prior programming experience were more motivated to learn by innate psychological needs: autonomy and competence. (iii) Competence motivated students performed better in programming, but no significant findings for autonomy and relatedness motivated students. A blended learning environment must be structured around the nature of the subject to satisfy students’ innate psychological needs. Digital learning materials can support understanding of certain programming concepts, but teaching instructors play an important role in providing academic, mental, and emotional support.
Modulation of Operating Cut-Off Frequency by Spin Pinned of Fe/Ni81Fe19/ Fe Heterogenous Multilayer Films with Different Fe Thicknesses
Authors: He Zong Sheng , Wu Chuan Jian , Wang Yi Fan , Jiang Xiao Na , Yu Zhong , Lan Zhong Wen , Sun Ke
Published: April 2022

Multilayer films exhibit high saturation magnetization, high permeability, and high cutoff frequency fr, applying to magnetic inductors that satisfy both high frequency, miniaturization, and integration. In this work, we fabricate Fe/Ni81Fe19/Fe (t/100/t nm) multilayer films on Si (100) using electron beam evaporation, and investigate the Fe thickness dependence of surface morphology, saturation magnetization, coercivity, and ferromagnetic resonance fr. The results demonstrate that Fe/Ni81Fe19/Fe (4/100/4 nm) multilayer film possess relatively high saturation magnetization (12.1 kGs), low coercivity (3.1 Oe), and high ferromagnetic resonance fr (1.93 GHz).
Design and Performance of Polystyrene Modular Composite Dismantling-Free Formwork
Authors: Zhang Ju Song , Sun An Zhao , Zeng Qian Ling
Published: April 2022

A new type of no-demolition insulation formwork was designed with EPS foam concrete as the frost and fire resistant protection layer and polystyrene board as the insulation layer. Tests were conducted on foam concrete to analyze the flexural performance and safety of the formwork. The results show that EPS foam concrete has excellent performance, and when EPS foam concrete with density grade A08 is used as the protective layer, the mechanical properties of the formwork meet the requirements of "Thermalinsulation free from demolition template for buildings" JC/T 2493-2018, which provides a reference basis for its application in the construction field.