bluuebunny/crossref_metadata_2025 huggingface dataset:
Transport, Destruction, and Growth of Pebbles in the Gas Envelope of a Protoplanet
Authors: Johansen Anders , Nordlund Åke
Published: November 2020

We analyze the size evolution of pebbles accreted into the gaseous envelope of a protoplanet growing in a protoplanetary disk, taking into account collisions driven by the relative sedimentation speed as well as the convective gas motion. Using a simple estimate of the convective gas speed based on the pebble accretion luminosity, we find that the speed of the convective gas is higher than the sedimentation speed for all particles smaller than 1 mm. This implies that both pebbles and pebble fragments are strongly affected by the convective gas motion and will be transported by large-scale convection cells both toward and away from the protoplanet’s surface. We present a simple scheme for evolving the characteristic size of the pebbles, taking into account the effects of erosion, mass transfer, and fragmentation. Including the downwards motion of convective cells for the transport of pebbles with an initial radius of 1 mm, we find pebble sizes between 100 μm and 1 mm near the surface of the protoplanet. These sizes are generally amenable to accretion at the base of the convection flow. Small protoplanets far from the star (>30 au) nevertheless erode their pebbles to sizes below 10 μm; future hydrodynamical simulations will be needed to determine whether such small fragments can detach from the convection flow and become accreted by the protoplanet.
A Model of Rotating Convection in Stellar and Planetary Interiors. II. Gravito-inertial Wave Generation
Authors: Augustson K. C. , Mathis S. , Astoul A.
Published: November 2020

Gravito-inertial waves are excited at the interface of convective and radiative regions and by the Reynolds stresses in the bulk of the convection zones of rotating stars and planets. Such waves have notable asteroseismic signatures in the frequency spectra of rotating stars, particularly among rapidly rotating early-type stars, which provides a means of probing their internal structure and dynamics. They can also transport angular momentum, chemical species, and energy from the excitation region to where they dissipate in radiative regions. To estimate the excitation and convective parameter dependence of the amplitude of those waves, a monomodal model for stellar and planetary convection as described in Paper I is employed, which provides the magnitude of the rms convective velocity as a function of rotation rate. With this convection model, two channels for wave driving are considered: excitation at a boundary between convectively stable and unstable regions and excitation due to Reynolds stresses. Parameter regimes are found where the sub-inertial waves may carry a significant energy flux, depending upon the convective Rossby number, the interface stiffness, and the wave frequency. The super-inertial waves can also be enhanced, but only for convective Rossby numbers near unity. Interfacially excited waves have a peak energy flux near the lower cutoff frequency when the convective Rossby number of the flows that excite them are below a critical Rossby number that depends upon the stiffness of the interface, whereas that flux decreases when the convective Rossby number is larger than this critical Rossby number.
Galactopause Formation and Gas Precipitation during Strong Galactic Outflows
Authors: Shull J. Michael , Moss Jacob A.
Published: November 2020

Using X-ray constrained β-models for the radial distribution of gas in the outskirts of galaxies, we analyze the termination of galactic winds and the formation and evolution of halo clouds by thermal instability. At low mass-loss rates (

) galactic winds are trapped within the halo, but they burst into the intergalactic medium during intermittent strong outflows with

. We develop analytic models of halo clouds as they cool radiatively over condensation timescales

for hydrogen number densities

, gas temperatures T ≈ (106 K)T
6, and metallicities (Z/Z
⊙). Halo gas can form kiloparsec-scale clouds out to galactocentric distances r ≈ 30–65 kpc, where efficient radiative cooling from 106 K down to T ≈ 104–5 K occurs at Z ≥ 0.3 Z
⊙ on timescales less than 1 Gyr. After condensing to column densities N
H ≥ 4 × 1016 cm−2, these clouds lose hydrostatic pressure support and fall inward on dynamical timescales of ∼200 Myr. Our baseline analysis will be followed by numerical calculations to understand the governing principles of halo cloud formation and transport of gas to the galactic disk.
Blue Large-amplitude Pulsators: The Possible Surviving Companions of Type Ia Supernovae
Authors: Meng Xiang-Cun , Han Zhan-Wen , Podsiadlowski Philipp , Li Jiao
Published: November 2020

The single degenerate (SD) model, one of the leading models for the progenitors of Type Ia supernovae (SNe Ia), predicts that there should be binary companions that survive the supernova explosion, which, in principle, should be detectable in the Galaxy. The discovery of such surviving companions could therefore provide conclusive support for the SD model. Several years ago, a new type of mysterious variable was discovered, the so-called blue large-amplitude pulsators (BLAPs). Here we show that all the properties of BLAPs can be reasonably well reproduced if they are indeed such surviving companions, in contrast to other proposed channels. This suggests that BLAPs could potentially be the long-sought surviving companions of SNe Ia. Our model also predicts a new channel for forming single hot subdwarf stars, consistent with a small group in the present sample of hot subdwarf stars.
Prediction and Understanding of Soft-proton Contamination in XMM-Newton: A Machine Learning Approach
Authors: Kronberg Elena A. , Gastaldello Fabio , Haaland Stein , Smirnov Artem , Berrendorf Max , Ghizzardi Simona , Kuntz K. D. , Sivadas Nithin , Allen Robert C. , Tiengo Andrea , Ilie Raluca , Huang Yu , Kistler Lynn
Published: November 2020

One of the major and unfortunately unforeseen sources of background for the current generation of X-ray telescopes are few tens to hundreds of keV (soft) protons concentrated by the mirrors. One such telescope is the European Space Agency’s (ESA) X-ray Multi-Mirror Mission (XMM-Newton). Its observing time lost due to background contamination is about 40%. This loss of observing time affects all the major broad science goals of this observatory, ranging from cosmology to astrophysics of neutron stars and black holes. The soft-proton background could dramatically impact future large X-ray missions such as the ESA planned Athena mission (http://www.the-athena-x-ray-observatory.eu/). Physical processes that trigger this background are still poorly understood. We use a machine learning (ML) approach to delineate related important parameters and to develop a model to predict the background contamination using 12 yr of XMM-Newton observations. As predictors we use the location of the satellite and solar and geomagnetic activity parameters. We revealed that the contamination is most strongly related to the distance in the southern direction, Z (XMM-Newton observations were in the southern hemisphere), the solar wind radial velocity, and the location on the magnetospheric magnetic field lines. We derived simple empirical models for the first two individual predictors and an ML model that utilizes an ensemble of the predictors (Extra-Trees Regressor) and gives better performance. Based on our analysis, future missions should minimize observations during times associated with high solar wind speed and avoid closed magnetic field lines, especially at the dusk flank region in the southern hemisphere.
Stellar Spins in the Open Cluster NGC 2516
Authors: Healy Brian F. , McCullough P. R.
Published: November 2020

Measuring the distribution of stellar spin axis orientations in a coeval group of stars probes the physical processes underlying the stars’ formation. In this paper, we use spectrophotometric observations of the open cluster NGC 2516 to determine the degree of spin alignment among its stars. We combine TESS light curves, ground-based spectroscopy from the Gaia-ESO and GALAH surveys, broadband stellar magnitudes from several surveys, and Gaia astrometry to measure 33 stellar inclinations and quantify overall cluster rotation. Our measurements suggest that stellar spins in this cluster are isotropically oriented, while allowing for the possibility that they are moderately aligned. An isotropic distribution of NGC 2516 spins would imply a star-forming environment in which turbulence dominated ordered motion, while a moderately aligned distribution would suggest a more substantial contribution from rotation. We also perform a three-dimensional analysis of the cluster’s internal kinematics, finding no significant signatures of overall rotation. Stemming from this analysis, we identify evidence of cluster contraction, suggesting possible ongoing mass segregation in NGC 2516.
Delivery of Pebbles from the Protoplanetary Disk into Circumplanetary Disks
Authors: Homma Toru , Ohtsuki Keiji , Maeda Natsuho , Suetsugu Ryo , Machida Masahiro N. , Tanigawa Takayuki
Published: November 2020

Small bodies likely existed in the late stage of planet formation either as remnants of the planetesimal formation stage or as fragments of larger planetesimals. Recent studies suggest that they may have played an important role in the formation of regular satellites of giant planets, but their delivery process into the circumplanetary disk has been poorly understood. Using orbital integration that incorporates the gas flow around the planet obtained by hydrodynamic simulation, we examine delivery of small bodies in the protoplanetary disk into circumplanetary disks. We find that large bodies can be captured when they experience strong gas drag near the midplane of the circumplanetary disk, while particles with Stokes number near unity tend to settle toward the midplane of the protoplanetary disk and can be captured near the outer edge of the circumplanetary disk. On the other hand, small particles coupled to the gas can be delivered into the circumplanetary disk with the vertically accreting gas and are captured near the surface of the circumplanetary disk over a wide radial region, if they are sufficiently stirred off the midplane of the protoplanetary disk. However, if the turbulence in the protoplanetary disk is not sufficiently strong, delivery of small particles by such a mechanism would not be efficient. Also, gas depletion in the vicinity of the planet’s orbit reduces the efficiency of the delivery. In these cases, larger bodies directly captured by gas drag from the circumplanetary disk would be the major building blocks of regular satellites.
Cosmological Insights into the Early Accretion of r-process-enhanced Stars. I. A Comprehensive Chemodynamical Analysis of LAMOST J1109+0754
Authors: Mardini Mohammad K. , Placco Vinicius M. , Meiron Yohai , Ishchenko Marina , Avramov Branislav , Mazzarini Matteo , Berczik Peter , Sedda Manuel Arca , Beers Timothy C. , Frebel Anna , Taani Ali , Donnari Martina , Al-Wardat Mashhoor A. , Zhao Gang
Published: November 2020

This study presents a comprehensive chemodynamical analysis of LAMOST J1109+0754, a bright (V = 12.8), extremely metal-poor ([Fe/H] = −3.17) star, with a strong r-process enhancement ([Eu/Fe] = +0.94 ± 0.12). Our results are based on the 7D measurements supplied by Gaia and the chemical composition derived from a high-resolution (R ∼ 110,000), high signal-to-noise ratio (

optical spectrum obtained by the 2.4 m Automated Planet Finder Telescope at Lick Observatory. We obtain chemical abundances of 31 elements (from lithium to thorium). The abundance ratios ([X/Fe]) of the light elements (Z ≤ 30) suggest a massive Population III progenitor in the 13.4–29.5 M
⊙ mass range. The heavy-element (30 < Z ≤ 90) abundance pattern of J1109+075 agrees extremely well with the scaled-solar r-process signature. We have developed a novel approach to trace the kinematic history and orbital evolution of J1109+0754 with a cOsmologically deRIved timE-varyiNg Galactic poTential (the ORIENT) constructed from snapshots of a simulated Milky Way analog taken from the Illustris-TNG simulation. The orbital evolution within this Milky Way–like galaxy, along with the chemical abundance pattern, implies that J1109+0754 likely originated in a low-mass dwarf galaxy located ∼60 kpc from the center of the Galaxy, which was accreted ∼6–7 Gyr ago, and that the star now belongs to the outer-halo population.
On the Presence of a Universal Acceleration Scale in Elliptical Galaxies
Authors: Chae Kyu-Hyun , Bernardi Mariangela , Sánchez Helena Domínguez , Sheth Ravi K.
Published: November 2020

Dark matter phenomena in rotationally supported galaxies exhibit a characteristic acceleration scale of g
† ≈ 1.2 × 10−10 m s−2. Whether this acceleration is a manifestation of a universal scale, or merely an emergent property with an intrinsic scatter, has been debated in the literature. Here we investigate whether a universal acceleration scale exists in dispersion-supported galaxies using two uniform sets of integral field spectroscopy (IFS) data from SDSS-IV MaNGA and ATLAS3D. We apply the spherical Jeans equation to 15 MaNGA and 4 ATLAS3D slow-rotator E0 (i.e., nearly spherical) galaxies. Velocity dispersion profiles for these galaxies are well determined with observational errors under control. Bayesian inference indicates that all 19 galaxies are consistent with a universal acceleration of

 m s−2. Moreover, all 387 data points from the radial bins of the velocity dispersion profiles are consistent with a universal relation between the radial acceleration traced by dynamics and that predicted by the observed distribution of baryons. This universality remains if we include 12 additional non-E0 slow-rotator elliptical galaxies from ATLAS

. Finally, the universal acceleration from MaNGA and ATLAS3D is consistent with that for rotationally supported galaxies, so our results support the view that dark matter phenomenology in galaxies involves a universal acceleration scale.
ALMA Observations of Io Going into and Coming out of Eclipse
Authors: Pater Imke de , Luszcz-Cook Statia , Rojo Patricio , Redwing Erin , Kleer Katherine de , Moullet Arielle
Published: November 2020

We present 1 mm observations constructed from Atacama Large (sub)Millimeter Array (ALMA) data of SO2, SO, and KCl when Io went from sunlight into eclipse (2018 March 20) and vice versa (2018 September 2 and 11). There is clear evidence of volcanic plumes on March 20 and September 2. The plumes distort the line profiles, causing high-velocity (≳500 m s−1) wings and red-/blueshifted shoulders in the line profiles. During eclipse ingress, the SO2 flux density dropped exponentially, and the atmosphere re-formed in a linear fashion when reemerging in sunlight, with a “post-eclipse brightening” after ∼10 minutes. While both the in-eclipse decrease and in-sunlight increase in SO was more gradual than for SO2, the fact that SO decreased at all is evidence that self-reactions at the surface are important and fast, and that in-sunlight photolysis of SO2 is the dominant source of SO. Disk-integrated SO2 in-sunlight flux densities are ∼2–3 times higher than in eclipse, indicative of a roughly 30%–50% contribution from volcanic sources to the atmosphere. Typical column densities and temperatures are N ≈ (1.5 ± 0.3) × 1016 cm−2 and T ≈ 220–320 K both in sunlight and in eclipse, while the fractional coverage of the gas is two to three times lower in eclipse than in sunlight. The low-level SO2 emissions present during eclipse may be sourced by stealth volcanism or be evidence of a layer of noncondensible gases preventing complete collapse of the SO2 atmosphere. The melt in magma chambers at different volcanoes must differ in composition to explain the absence of SO and SO2, but simultaneous presence of KCl over Ulgen Patera.
First record of the ant-loving cricket Myrmecophilus crenatus Gorochov, 1986 (Orthoptera, Myrmecophilidae) in Kazakhstan
Authors: Temreshev Izbasar I.
Published: November 2020

The ant-loving cricket Myrmecophilus crenatus Gorochov, 1986 was found in the Turkestan oblast of southern Kazakhstan. This is the first species record for this area. Thus, the current fauna of ant-loving crickets in Kazakhstan includes three species – Myrmecophilus crenatus, M. acervorum (Panzer, 1799) and Bothriophylax semenovi (Miram, 1930).
Living plant collections policy of the Finnish Museum of Natural History
Authors: Hyvärinen Marko-Tapio , Lindholm Mikael , Fitzgerald Heli , Miranto Mari , Anttila Aino , Pakkanen Outi , Pulkkinen Merja , Pehkonen Pertti , Väre Henry , Sihvonen Pasi , Kuusijärvi Anniina , Myllys Leena , Kröger Björn , Heikkinen Mikko , Juslén Aino , Oinonen Markku , Schulman Leif
Published: November 2020

The collections policy of the Finnish Museum of Natural History Luomus is hierarchically structured. The general collections policy defines the overall principles and guidelines. The sub-collections policies, such as the Living collections policy, comply with and apply the general collections policy and specify its guidelines and instructions, taking the special nature of the sub-collections into account. The living plant collections policy guides the care of the collections in the botanic gardens and the seed bank, excluding DNA and tissue samples which are covered by a separate genomic resources policy. The purpose of the collections policy is to help guide the care of the garden collections and the processing of information relating to the collections, thereby providing the basis for developing the botanic gardens.
On some new species of Stenheliinae Brady, 1880 (Copepoda, Harpacticoida, Miraciidae) from north-western Mexico, with the proposal of Lonchoeidestenhelia gen. nov.
Authors: Gómez Samuel
Published: November 2020

Quarterly sampling campaigns during 2019 to study the diversity of meiofauna in a polluted estuary in northwestern Mexico revealed the subfamily Stenheliinae Brady, 1880 as one of the most important contributors to the diversity of benthic harpacticoids. Two new stenheliin species are described here. One of them was assigned to the, so far, monotypic genus Lonchoeidestenheliagen. nov. defined by the autapomorphic modified proximal outer spinules on the sigmoid process of the male P2ENP2. The other species was assigned to Willenstenhelia Karanovic and Kim, 2014. Lonchoeidestenheliagen. nov. shares the armature formula of the P1 EXP2 with Stenhelia, Anisostenhelia, and Beatricella, but seems to bear a sister-group relationship with the former two genera by the loss of one inner seta on the P2–P3 EXP3, the presence of two outer spine-like elements on the male P5EXP, and the displacement of the outer spine and medial and inner distal setae of P2ENP3, to an apical and subapical inner position, respectively, but is more closely related to Anisostenhelia by the overall shape of the male P2ENP2. Willenstenhelia reductasp. nov. is attributed to a group of species composed of Wi. minuta, Wi. urania, and Wi. terpsichore characterized by the strongly reduced inner seta of the female P5 baseoendopod, but differs in the discrete female P5 baseoendopods and in the presence of one outer seta only on that segment. Willenstenhelia reductasp. nov. is defined here by the autapomorphic loss of the outermost seta of the female P5 baseoendopod.
L’économie informelle à Mayotte en contexte de départementalisation
Authors: Hochet Antoine , Bianchini Victor
Published: November 2020

Cet article appréhende les dynamiques de l’économie informelle mahoraise au regard de la récente « départementalisation » du territoire, fruit d’un long processus de convergence vers les standards institutionnels métropolitains ayant débuté dès les années 1970. Après avoir montré l’intérêt du recours au concept d’économie morale pour esquisser les contours de l’économie informelle mahoraise, cet article interroge la permanence d’une éthique de subsistance qui structure une économie dont les changements institutionnels impactent les sphères d’échanges. Il analyse ensuite l’évolution de la gouvernance du foncier au cours des trois dernières décennies et ses effets sur l’économie informelle, notamment dans les secteurs de l’agriculture et de la construction. Une telle approche permet enfin de souligner le rôle compensatoire de l’économie informelle face aux incertitudes provoquées par une départementalisation mal préparée.
An adaptive total variational despeckling model based on gray level indicator frame
Authors: Zhang Yu , Li Songsong , Guo Zhichang , Wu Boying
Published: November 2020

For the characteristics of the degraded images with multiplicative noise, the gray level indicators for constructing adaptive total variation are proposed. Based on the new regularization term, we propose the new convex adaptive variational model. Then, considering the existence, uniqueness and comparison principle of the minimizer of the functional. The finite difference method with rescaling technique and the primal-dual method with adaptive step size are used to solve the minimization problem. The paper ends with a report on numerical tests for the denoising of images subject to multiplicative noise, the comparison with other methods is provided as well.
Adaptación de la demanda de esquí y del comportamiento de los esquiadores a las condiciones meteorológicas, de nieve y al cambio climático en los Pirineos centrales
Authors: Gilaberte-Búrdalo María , López-Moreno Juan Ignacio
Published: November 2020

Se ha realizado un estudio mediante encuestas para determinar cómo los esquiadores perciben el clima y el cambio climático, así como su comportamiento con respecto a la práctica del esquí en el Pirineo Central. Se utilizó un sistema mixto para recopilar las encuestas; in situ y en línea (n = 205). Las preferencias climáticas muestran que el 80% de los esquiadores no fueron a esquiar en un día lluvioso, el 58.5% en un día de viento excesivo, el 46% con poca visibilidad y el 41% no esquió en condiciones de nieve marginal. El 91% de los encuestados informó haber sido afectado por la escasez de nieve durante una temporada de esquí. Con respecto a las medidas de adaptación al cambio climático, el 49% de los encuestados continuaría esquiando con menos frecuencia en su lugar habitual, el 21% esquiaría de la manera habitual incluso con malas condiciones de nieve, el 10% reemplazaría al esquí por otra actividad de montaña, el 10% viajaría más lejos para encontrar buenas condiciones de nieve, y el 8% dejaría de esquiar durante esa temporada. Un total de 77% de los encuestados cree que el cambio climático tiene un impacto medio o alto en las condiciones de nieve, pero el 76% considera que este es un problema al que se enfrentará en el futuro.
Effets d’un dispositif de type coteaching sur le développement professionnel des enseignants novices : études de cas en formation universitaire
Authors: Michel Laurent , Bertone Stefano
Published: November 2020

Cette recherche vise à étudier les effets de deux dispositifs de type coteaching sur le développement professionnel de l’enseignant stagiaire en éducation physique et sportive (EPS), dans le cadre de sa formation initiale. Par l’étude des effets d’une action conjointe d’enseignement entre un formateur universitaire et un enseignant stagiaire, et à partir d’un postulat théorique emprunté à l’action collective (Wittgenstein, 2004), ce travail de recherche montre que ce format a permis au formateur de dresser de manière ostensive et ostensible la signification des règles de métier et a encouragé la prise de risque par les enseignants novices en situation de classe. Ce dispositif a ainsi constitué un artefact fécond pour stimuler le développement professionnel de professeurs stagiaires, offrant des perspectives nouvelles de compréhension de l’apprentissage du métier enseignant en formation initiale par l’alternance.
L’altruisme, une condition de l’autorité éducative émancipatrice ?
Authors: Terraz Tommy
Published: November 2020

L’épineuse question de l'autorité dans le champ éducatif n’est pas nouvelle, et elle fait plus que jamais débat. Une certaine « érosion » (Prairat, 2012) de l’autorité en éducation semble communément admise, toutefois la notion d’autorité est accueillie de manière hétérogène. Autorité et autoritarisme sont souvent confondus, ce qui amène d’un côté au rejet radical de l’idée même d’autorité éducative, et de l’autre côté à la volonté nostalgique de réhabiliter sous certaines formes perverties une autorité traditionnelle dure. Au sens de « auctoritas », l'autorité n'est pourtant ni domination, ni manipulation, ni conditionnement ; elle semble même nécessaire car elle autorise l'éducateur à éduquer, elle est librement reconnue comme légitime par le sujet éduqué : elle ne vise pas la soumission de l'autre mais autorise son émancipation. Reste à mettre en évidence les principales conditions d’une autorité éducative émancipatrice capable de déjouer les pièges de l’autoritarisme et de la totale permissivité : viser l’émancipation de la « personne » ; respecter tout être humain sans exception en tant que « Personne » de manière inconditionnelle et interdire toute forme de nuisance et de violence à son égard ; permettre la reconnaissance mutuelle et libre ; intégrer le tiers personnel et symbolique ; favoriser la co-construction des savoirs et la transmission de l’héritage culturel de l’humanité ; permettre la sortie des pièges du désir mimétique ; considérer l’asymétrie de la relation éducative comme temporaire et potentiellement réversible. À partir d’une approche en philosophie de l’éducation, nous travaillons l’hypothèse selon laquelle une éthique éducative de l’altruisme permet d’accéder à une autorité éducative émancipatrice, puis de favoriser sa juste et bonne mise en application dans la singularité des situations.
Identité enseignante et collège inclusif : quels remaniements face à un environnement de travail en mutation ?
Authors: Piroux Benoit
Published: November 2020

La Loi 2005-102 dite « Loi pour l’égalité des chances, la participation et la citoyenneté des personnes handicapées », a rendu poreuse la frontière entre l’univers de l’éducation spécialisée et le milieu scolaire ordinaire. Cette volonté politique, ajoutée à une société se tournant vers les marqueurs de l’hypermodernité2, a induit une mutation dans le métier d’enseignant de collège situé aujourd’hui entre une institution difficilement lisible et des « usagers » de plus en plus hétérogènes. Notre recherche, basée sur une méthode compréhensive, propose d’étudier les remaniements identitaires des enseignants de collège. Entre regard des autrui significatifs, demande de l’institution, et représentation d’un métier en mutation, le professionnel se situant dans un espace d’expression nouveau, s’appuiera sur une expérience et des capacités personnelles afin de répondre à un besoin de cohérence identitaire.
Les ATSEM, les activités manuelles et la raison graphique
Authors: Montmasson-Michel Fabienne
Published: November 2020

Les Agentes Territoriales des Écoles Maternelles (ATSEM) ont conquis une place indispensable auprès des enseignants. Longtemps contenues en marge des activités éducatives, elles sont entrées dans les classes dans les dernières décennies du XXe siècle, et y ont acquis des compétences pédagogiques. Dans l’école maternelle massifiée, le langage est devenu prioritaire : les enfants doivent entrer dans la raison graphique et construire une culture écrite, réclamées par la scolarité longue. Une division sociale du travail pédagogique s’est dessinée : aux enseignants les domaines les plus légitimes (langagiers, conceptuels, esthétiques), et aux ATSEM la préparation matérielle, le classement, la conduite « d’activités manuelles ». Une enquête ethnographique étudiant la socialisation langagière des jeunes enfants a pu saisir leur travail pédagogique et montrer sa contribution à l’acculturation scolaire. Les ATSEM mettent en ordre les corps et les objets. Dans les activités, elles accompagnent corporellement les enfants en objectivant les concepts graphiques et scripturaux dans leurs paroles. Elles véhiculent ainsi une culture scolaire bien présente dans l’ordinaire des classes. Cette manière de faire a pourtant peu de légitimité dans le champ de la prescription, qui privilégie les procédés réflexifs, secondarisés, et présuppose une autonomie déjà là.
Vers une démocratisation de l’éducation et de la formation par les MOOC ? Étude des caractéristiques des utilisateurs de la plateforme France Université Numérique
Authors: Vrillon Éléonore
Published: November 2020

Le développement mondial, riche et diversifié des Massive Open Online Courses (MOOC) a été marqué par un engouement fort et l’espoir d’une démocratisation de l’accès à l’enseignement supérieur, l’éducation et la formation. Néanmoins les premiers travaux consacrés aux plateformes américaines ont montré la spécificité du public qui y recourt (Christensen et al., 2013 ; Ho et al., 2014, 2015). Dans quelle mesure peut-on encore parler de démocratisation concernant le phénomène MOOC ? Ce travail propose d’analyser le cas français grâce à une enquête par questionnaire ad hoc diffusée auprès d’utilisateurs de douze MOOC (n =5709) de la plateforme nationale France Université Numérique (FUN). Les résultats montrent que si le profil moyen d’utilisateur se distingue de celui des plateformes américaines, la composition sociale du public reste fortement favorisée et ces caractéristiques (professionnelles et niveau de diplôme) influent sur le recours au MOOC. Si l’on peut évoquer une potentielle « démocratisation ségrégative » (Merle, 2000), en l’état de la recherche, il parait préférable de parler d’une massification. En effet, en dépit de leur ouverture, qu’ils soient utilisés dans un registre de loisir culturel ou comme une ressource de formation, le recrutement social d’un public favorisé laisse à penser que les MOOC reproduisent des inégalités déjà existantes de ces champs et profitent ainsi à ceux qui sont déjà les mieux dotés.
Reducing Uncertainty in Dynamic Stall Measurements Through Data-Driven Clustering of Cycle-To-Cycle Variations
Authors: Ramasamy Manikandan , Sanayei Armaun , Wilson Jacob S. , Martin Preston B. , Harms Tanner , Nikoueeyan Pourya , Naughton Jonathan
Published: November 2020

Pitching airfoil measurements are known to exhibit significant scatter near stall angles of attack that can make meaningful correlation with modeling or simulation difficult. Application of data-driven clustering algorithms to dynamic stall experiments, conducted at two different research
facilities, revealed the presence of furcation within the data scatter. Such furcation render the statistical mean and standard deviation as inadequate to represent the observed cycle-to-cycle variations. After ruling out facility effects, an alternative approach to conventional statistical
analysis is developed through the use of cluster averages, associated variances, and group probability. Several existing clustering techniques are tested; however, their shortcomings led to the development of two new data-driven algorithms that use proper orthogonal decomposition to cluster
data based on flow phenomena that contribute the most energy to flow variations. Several test cases are used to show the physical mechanisms leading to cycle-to-cycle variations, such as differences in separation location, boundary layer reattachment, occurrence of leading-edge/trailing-edge
stall, and presence of a dynamic stall vortex (or vortices). In all cases, these physical processes and their effects are obscured by conventional phase-averaging. Further analyses on the effects of the Mach number, reduced frequency, mean angle, and amplitude of oscillation reveal trends
in the probability of a given flow behavior. An initial step towards using these results for advanced semiempirical models using Markov analysis is discussed.
The NAD83 Project - background and status
Authors: Henderson J P , Pinch M C , Junkins D R
Published: November 2020

The last general recomputation or readjustment of North American geodetic networks was done during the period 1927-1932 and was designated North American Datum of 1927 (NAD27). By 1972, the need for another general readjustment of North American networks had been
recognized, and strengthening of the network by means of additional electronic distance measurements and satellite Doppler positioning began. Discussions among the national survey organizations of North America and Denmark (for Greenland) led to the recomputation and new datum definition known as
the North American Datum of 1983 (NAD83).
The availability and accuracy of modern satellite positioning techniques, and the high probability of their more widespread use in the future for ail types of surveying and navigation, together with the rapid development of computerized geographic information systems, made it desirable to adopt a
compatible geocentric reference system for the recomputation project. The NAD83 Earth-centered system is significantly different from NAD27 and many existing land-related information databases will require conversion to NAD83.
This paper outlines the steps leading up to the redefinition, describes the method of network adjustment, presents the status of the integration of secondary and primary networks, and outlines user support that will be available from the Geodetic Survey Division.
Neuropathic Pain in Guillain-Barre Syndrome
Authors: Swami Tripti , Khanna Meeka , Gupta Anupam , Prakash Navin B.
Published: November 2020

Background:

Neuropathic pain contributes significantly to the morbidity and affects the quality of life adversely in Guillain-Barre syndrome (GBS).

Objective:

To study neuropathic pain profile in GBS and association with rehabilitation outcomes and effect on the quality of life.

Methods:

Observational study conducted in rehabilitation setting of a tertiary care hospital among adult GBS patients of less than 3 months duration. Assessment was done at the time of admission and discharge with Pain-detect questionnaire (PD-Q), Neuropathic pain scale (NPS), SF 36 survey, Medical Research Council (MRC) score, INCAT sensory sum score (ISS), Overall Disability sum-score (ODSS), Hughes disability score (HDS), Hospital Anxiety and Depression scale (HADS), and Fatigue Severity scale (FSS). Neuropathic pain was managed as per routine protocol and rehabilitation program was individualized.

Results:

32 participants (26 males) with median age of 34.50 years were included. Eighteen (56.25%) patients had neuropathic pain on PD-Q at admission. The median intensity of pain on NPS scale was 47 at admission which decreased significantly to 14 at discharge. Pain group showed significant association with sensory impairment, CSF protein, and emotional domains of QOL while no association with disability.

Conclusion:

Neuropathic pain is associated with sensory impairment in GBS and markedly affects the quality of life, especially emotional, family, and social activities.
EXTRACTION AND CHARACTERIZATION OF CELLULOSE AND MICROCRYSTALLINE CELLULOSE (MCC) FROM Marantochloa cuspidata LEAVES
Authors: Udo E. R , Onuegbu T. U. , Onuegbu T. U. , Akpabio U. D.
Published: November 2020

Microcrystalline cellulose (MCC) from Marantochloa cuspidata leaves were isolated and characterized. The physicochemical properties of the leaves were investigated. The functional groups analyses were carried out using Fourier Transform Infrared (FTIR) Spectroscopy and the crystalline structure were investigated using X-ray Diffraction (XRD). The morphology and thermal stabilities were investigated using Scanning Electron Microscope (SEM) and Thermo Gravimetric Analysis (TGA) respectively. The moisture content of the leaves was 7.16± 0.12%. From FTIR, the spectra showed that the hemicelluloses and lignin were removed from the extracted cellulose. The peaks at 1733cm in the spectra of M. cuspidata leaves which were attributed to C = O stretching and C–O out-of plane stretching vibration of the hemicelluloses and lignin disappeared in the spectra of cellulose and MCC. XRD showed that the MCC produced is cellulose I polymorph. The SEM structures showed the microfibrils of the extracts to be crystallites. Cellulose and MCC were shown to have good thermal stability with a degradation temperature of 250oC and 260oC respectively. Keywords: Microcrystalline cellulose, Marantochloa cuspidata, physicochemical properties FTIR, XRD, SEM, TGA.
Peran Fibrinogen Serum sebagai Prediktor Perforasi pada Pasien Apendisitis Akut di RSUP Dr. Hasan Sadikin Bandung 2018
Authors: Suprayitno Joko , Budiman Reno , Ruchimat Tommy
Published: November 2020

Latar Belakang. Insidensi apendisitis perforasi di dunia mencapai 2 per 10.000 kelahiran hidup, untuk proporsi apendisitis perforasi sekitar 25%. Kasus apendisitis di Indonesia berdasarkan data Kementerian Kesehatan RI pada tahun 2009 sebesar 596.132 kasus dengan persentase 3.36% dan meningkat pada tahun 2010 menjadi 621.435 kasus dengan persentase 3.53%. Sedangkan insidensi  di RS Hasan Sadikin  pada tahun 2017 mencapai 83% pasien yang datang dengan keluhan apendisitis telah mengalami perforasi. Pemeriksaan radiologik seperti computed tomography scan (CT), magnetic resonance imaging (MRI) ataupun ultrasonography (USG) memiliki sensitifitas dan spesifitas yang tinggi untuk mendiagnosis perforasi apendisitis, tetapi alat–alat ini tidak selalu tersedia di institusi–institusi kesehatan negara berkembang. Fibrinogen sebagai  faktor koagulasi yang pertama kali ditemukan dalam beberapa penelitian berpotensi digunakan sebagai prediktor perforasi pada pasien apendisitis, pemeriksaan fibrinogen dapat dilakukan sewaktu-waktu, memberikan hasil yang lebih cepat dengan harga yang lebih murah dibandingkan dengan pemeriksaan penunjang lain.

Metode. Penelitian observasional analitik dengan pendekatan cross-sectional. Subjek pasien apendisitis periode 1 April 2018 – 31 Desember 2018 yang datang ke Installasi Gawat Darurat RSUP Dr. Hasan Sadikin Bandung dan bersedia mengikuti penelitian. Pasien yang didiagnosis kerja awal sebagai apendisitis akut atau pasien dengan appendisits perforasi dengan gejala peritonitis lokal atau peritonitis difus setelah dilakukan pemeriksaan klinis dan laboratorium. Pasien dilakukan  pemeriksaan fibrinogen serum preoperatif, lalu dilakukan operasi dan dicatat hasil temuan operasi yaitu yang mengalami perforasi dan yang tidak mengalami perforasi. Dilakukan pengelompokkan data setelah jumlah subyek penelitian terpenuhi.

Hasil. Sebanyak 40 pasien (25 laki-laki, 15 perempuan) terdiagnosis apendisitis berdasarkan Alvarado Score, yang terdiri dari 20 pasien apendisitis akut dan 20 pasien apendisitis perforasi. Akurasi kadar fibrinogen serum dalam memprediksi terjadinya perforasi sebesar 85%. Nilai sensitivitas 90%, nilai spesifisitas 80%. Berdasarkan analisis kurva ROC diperoleh nilai Area Under Curve (AUC) sebesar 0,865 (p = 0,001). Menunjukkan bahwa kadar fibrinogen serum memiliki kemampuan diskriminasi yang tinggi dalam memprediksi terjadinya perforasi pada pasien apendisitis.

Kesimpulan. Kadar fibrinogen serum yang meningkat dapat digunakan sebagai prediktor terjadinya perforasi pada pasien apendisitis.

Kata kunci. Apendisitis perforasi, fibrinogen, prediktor

(ISSN 2723-7494 J Bedah Indonesia. 2020;48:3-14)
KÜRESEL ISINMA VE İKLİM DEĞİŞİKLİĞİ: BİLİMSEL UZLAŞMADAN POLİTİK AYRIŞMAYA
Authors: DOGAN Seyhun , DOĞAN Ebru , TÜZER Mutlu
Published: November 2020

İklim bilimi literatüründe, önde gelen iklim bilimciler arasında iklim değişikliği üzerindeki bilimsel uzlaşmayı gözlemlemek mümkündür. Bilimsel alandaki uzlaşmaya ek olarak insan kaynaklı iklim değişikliğinin diğer bir tanımlayıcı niteliği, politik alandaki ayrışmadır. Politik alanda yalnızca iklim değişikliğinin negatif sonuçlarının değil, azaltım politikalarının maliyetlerinin de toplumdaki farklı kesimler tarafından yüklenileceği ve paylaşılacağı aynı derecede açıktır. İklim değişikliği, iki önemli değer arasında kalan modern dünya için büyük bir zorluk teşkil etmektedir. Bir yanda, insan kaynaklı iklim değişikliğinin yaşanmakta olduğunu ve gerekli tedbirlerin ivedilikle alınması gerektiğini işaret eden bilim bulunmaktadır. Diğer yanda ise, demokratik ilkeleri idealize eden ve varlığı ekonomik refahın sürekli olarak yükselmesine dayalı olan modern politik sistem bulunmaktadır.
Family cohesion and depression in adolescents: a mediating role of self-confidence
Authors: Sayyeda Taskeen Zahra  , Sadia Saleem  , Admin
Published: November 2020

Abstract

Objective: To identify the mediating role of self-confidence in family cohesion and depression in adolescents.

Methods: The cross-sectional research design was used and study was conducted in the mainstream government schools of Lahore. A sample of 394 adolescents (boys = 54%, girls = 46%), aged 12-19 years (M = 14.76; SD = 1.39) recruited through multistage sampling strategy. Family Cohesion Scale, Self-confidence Scale and Depression Scale for Adolescents were used to measure family cohesion, self-confidence and depression respectively.

Results: A significant positive association between family cohesion and self-confidence (p < .001), and a significant negative association of family cohesion (p < .001) and self-confidence (p < .01) with depression was found. Moreover, mediation analysis revealed that self-confidence partially mediates the relationship between family cohesion and depression (p = .01).

Conclusion: Early and timely identification of risk factors can prevent from serious consequences of depression in adolescents.

Keywords: Family cohesion, self-confidence, depression, adolescents.
Images as Mediated Realities: Vilém Flusser and Harun Farocki in Meta-dialogue
Authors: Hisayasu Louise
Published: November 2020

A critical gaze and an investigative guise are necessary in a time where the uneven boundaries between “the real” and the phantasmagoric are blurred into our conceptions of reality. We are surrounded by interfaces, screens, virtual spaces and infinite networks. Technologic advancements departing from the photographic medium have the potential to change our relations to our surroundings and our conceptions of ourselves through images. We are no longer merely receivers of images, we are active producers of them; In the 1980’s, philosopher Vilém Flusser and filmmaker Harun Farocki were already engaged in questions aimed at understanding our relationship to images and our responsibility towards the production images. Both urged their readers and spectators to engage in dialogue, to understand the phenomenon of photography and its direct correlations to mass communication structures.

Keywords: codes, communication theory, reality, responsibility, technical image
Augumenting The Physiognomic Gaze Across Space and Time: A Conversation with onformative
Authors: Schiller Devon , Kiefer Cedric
Published: November 2020

Augmented photography can be used in the digital arts to over-code upon real-world environments with computer-generated data, in order to translate stimuli across sensory modalities, and thereby extent or increase our faculties for perceiving spatial and temporal relations. Because of this media-specific affordance, the augmentation of the photographic medium may have especial application for the “physiognomic gaze,” a way of doing “form interpretation” or “nature knowing” based on the physical behaviors and psychological phenomena of the human face, head and body. The innovativeness of such technological prosthetics becomes manifest how new ways are generated to both perceive and to know those experiences that were previously unseeable or otherwise unsensable. Here, I converse with Cedric Kiefer (co-founder and creative lead) of the onformative studio for digital art and design in Germany about their works Meandering River (2017), Pathfinder (2014) and Google Faces (2013). And we explore how onformative uses the augmented photograph in their digital artworks to extend the physiognomic gaze, bringing data not visible to the naked eye into the senseable sphere, to offer the audience different perspectives about space and time.

Keywords: augmented photography, computer-generated data, digital art and science, onformative, physiognomic gaze
Efectividad biológica de carbamatos para el control de (Meloidogyne sp.) en tomate y zanahoria en Morelos
Authors: Acosta Ramos M. , García Munguía C. A , García Munguía A. M , E. Soni Guillermo , Vázquez Sánchez E. , García Munguía A. , Franco Sánchez M. , González De Jesús H.
Published: November 2020

El jitomate y la zanahoria son dos hortalizas muy susceptibles a nematodos agalladores como Meloidogyne spp. En zanahoria ocasionan serias reducciones en los rendimientos y pueden incluso llegar a la pérdida total del cultivo, cuando se presenta en zanahoria hay una deformación de las raíces adventicias y por tanto una deformación en la raíz principal, esto hace que se pierda la presentación y calidad de fruto. En tomate el comportamiento es similar, con la formación de agallas en las raíces impidiendo una buen absorción de agua y nutrientes. En este experimento se evaluaron dos productos del grupo químico de los carbamatos, más utilizados para el control de nematodo agallador para visualizar posibles efectos de resistencia a este grupo químico. Los resultados en zanahoria muestran que carbofuran en dosis de 2500 g. ha-1 es quien mejor eficacia tiene para el control de Meloidogyne, mientras que la dosis baja es la que menos control tiene. En el caso del tomate el Oaxamil en su dosis de 4.7 L.ha-1 es la que mejor controla la población de nematodos agalladores y por lo tanto aumenta el rendimiento en la producción.
Greenfield Steel Projects in India - Special Case Study - Social Cost Benefit Analysis of POSCO
Authors: Mohanty Malay Kumar , Tripathy Chandan Kumar
Published: November 2020

India’s efforts to maintain it’s rapid economic growth rate will depend largely on it’s Greenfield projects. The rising demand for steel in domestic markets as well as in the International markets have made the steel prices soar up in recent years. The Indian steel industry is receiving huge domestic and foreign investments in Greenfield projects in the steel sector. However, other than the already planned steel plant projects, most of the proposed steel Greenfield Projects in the country continue to struggle to see any progress . Development of Greenfield steel projects in India has virtually come to a standstill. Many of these projects have stagnated due to issues like land acquisition, rehabilitation and political interference. Projects should either be rejected or, if approved, implemented with speed. We do need to boost Greenfield capacity addition in steel with holistic, coordinated policy design, and actualise long-pending investment proposals. This paper discusses the special case of POSCO and it’s Greenfield steelworks in Orissa. To catapult India into a steel superpower, POSCO would contribute 12 mtpa from its Greenfield project. There have been no progress in POSCO project since 2005 due to the land acquisition and environmental clearances problems. A special Social Cost Benefit Analysis study have been conducted to prove the economic benefits of the POSCO project for the people of Orissa and the employment and GDP growth it will bring along with it.