bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral Variability of Two Rapidly Rotating Brown Dwarfs: 2MASS J08354256-0819237 and 2MASS J18212815+1414010
Authors: Schlawin E. , Burgasser Adam J. , Karalidi T. , Gizis J. E. , Teske J.
Published: November 2017

L dwarfs exhibit low-level, rotationally modulated photometric variability generally associated with heterogeneous, cloud-covered atmospheres. The spectral character of these variations yields insight into the particle sizes and vertical structure of the clouds. Here, we present the results of a high-precision, ground-based, near-infrared, spectral monitoring study of two mid-type L dwarfs that have variability reported in the literature, 2MASS J08354256−0819237 and 2MASS J18212815+1414010, using the SpeX instrument on the Infrared Telescope Facility. By simultaneously observing a nearby reference star, we achieve

per-band sensitivity in relative brightness changes across the 0.9–2.4 μm bandwidth. We find that 2MASS J0835−0819 exhibits marginal (≲0.5% per band) variability with no clear spectral dependence, while 2MASS J1821+1414 varies by up to ±1.5% at 0.9 μm, with the variability amplitude declining toward longer wavelengths. The latter result extends the variability trend observed in prior HST/WFC3 spectral monitoring of 2MASS J1821+1414, and we show that the full 0.9–2.4 μm variability amplitude spectrum can be reproduced by Mie extinction from dust particles with a log-normal particle size distribution with a median radius of 0.24 μm. We do not detect statistically significant phase variations with wavelength. The different variability behavior of 2MASS J0835−0819 and 2MASS J1821+1414 suggests dependencies on viewing angle and/or overall cloud content, underlying factors that can be examined through a broader survey.
Variational Estimation of the Large-scale Time-dependent Meridional Circulation in the Sun: Proofs of Concept with a Solar Mean Field Dynamo Model
Authors: Hung Ching Pui , Brun Allan Sacha , Fournier Alexandre , Jouve Laurène , Talagrand Olivier , Zakari Mustapha
Published: November 2017

We present in this work the development of a solar data assimilation method based on an axisymmetric mean field dynamo model and magnetic surface data. Our midterm goal is to predict quasi-cyclic solar activity. Here we focus on the ability of our algorithm to constrain the deep meridional circulation of the Sun based on solar magnetic observations. To that end, we develop a variational data assimilation technique. Within a given assimilation window, the assimilation procedure minimizes the differences between the data and the forecast from the model by finding an optimal meridional circulation in the convection zone and an optimal initial magnetic field via a quasi-Newton algorithm. We demonstrate the capability of the technique to estimate the meridional flow through a closed-loop experiment involving 40 years of synthetic, solar-like data. By assimilating the synthetic magnetic proxies, we are able to reconstruct a (stochastic) time-varying meridional circulation that is also slightly equatorially asymmetric. We show that the method is robust in estimating a flow whose level of fluctuation can reach 30% about the average, and that the horizon of predictive capability of the method is of the order of one cycle length.
Dynamical Effects of the Scale Invariance of the Empty Space: The Fall of Dark Matter?
Authors: Maeder Andre
Published: November 2017

The hypothesis of the scale invariance of the macroscopic empty space, which intervenes through the cosmological constant, has led to new cosmological models. They show an accelerated cosmic expansion after the initial stages and satisfy several major cosmological tests. No unknown particles are needed. Developing the weak-field approximation, we find that the here-derived equation of motion corresponding to Newton’s equation also contains a small outward acceleration term. Its order of magnitude is about

Newton’s gravity (ϱ being the mean density of the system and

the usual critical density). The new term is thus particularly significant for very low density systems. A modified virial theorem is derived and applied to clusters of galaxies. For the Coma Cluster and Abell 2029, the dynamical masses are about a factor of 5–10 smaller than in the standard case. This tends to leave no room for dark matter in these clusters. Then, the two-body problem is studied and an equation corresponding to the Binet equation is obtained. It implies some secular variations of the orbital parameters. The results are applied to the rotation curve of the outer layers of the Milky Way. Starting backward from the present rotation curve, we calculate the past evolution of the Galactic rotation and find that, in the early stages, it was steep and Keplerian. Thus, the flat rotation curves of galaxies appear as an age effect, a result consistent with recent observations of distant galaxies by Genzel et al. and Lang et al. Finally, in an appendix we also study the long-standing problem of the increase with age of the vertical velocity dispersion in the Galaxy. The observed increase appears to result from the new small acceleration term in the equation of the harmonic oscillator describing stellar motions around the Galactic plane. Thus, we tend to conclude that neither dark energy nor dark matter seems to be needed in the proposed theoretical context.
Multiwavelength Stellar Polarimetry of the Filamentary Cloud IC5146. I. Dust Properties
Authors: Wang Jia-Wei , Lai Shih-Ping , Eswaraiah Chakali , Clemens Dan P. , Chen Wen-Ping , Pandey Anil K.
Published: November 2017

We present optical and near-infrared stellar polarization observations toward the dark filamentary clouds associated with IC5146. The data allow us to investigate the dust properties (this paper) and the magnetic field structure (Paper II). A total of 2022 background stars were detected in the R

c
,

, H, and/or K bands to

mag. The ratio of the polarization percentage at different wavelengths provides an estimate of

, the wavelength of the peak polarization, which is an indicator of the small-size cutoff of the grain size distribution. The grain size distribution seems to significantly change at

mag, where both the average and dispersion of

decrease. In addition, we found

μm for

mag, which is larger than the ∼0.55 μm in the general interstellar medium (ISM), suggesting that grain growth has already started in low-A

V
regions. Our data also reveal that polarization efficiency (

) decreases with A

V
as a power law in the R

c
,

, and K bands with indices of −0.71 ± 0.10, −1.23 ± 0.10, and −0.53 ± 0.09. However, H-band data show a power index change; the PE varies with A

V
steeply (index of −0.95 ± 0.30) when

mag, but softly (index of −0.25 ± 0.06) for greater A

V
values. The soft decay of PE in high-A

V
regions is consistent with the radiative alignment torque model, suggesting that our data trace the magnetic field to

mag. Furthermore, the breakpoint found in the H band is similar to that for A

V
, where we found the

dispersion significantly decreased. Therefore, the flat PE–A

V
in high-A

V
regions implies that the power-index changes result from additional grain growth.
Constraints on the Evolution of the Galaxy Stellar Mass Function. II. The Quenching Timescale of Galaxies and Its Implication for Their Star Formation Rates
Authors: Contini E. , Kang X. , Romeo A. D. , Xia Q. , Yi S. K.
Published: November 2017

We study the connection between the observed star formation rate–stellar mass (SFR–M
*) relation and the evolution of the stellar mass function (SMF) by means of a subhalo abundance matching technique coupled to merger trees extracted from an N-body simulation. Our approach consists of forcing the model to match the observed SMF at redshift

, and letting it evolve down to

according to a τ model, an exponentially declining functional form that describes the star formation rate decay of both satellite and central galaxies. In this study, we use three different sets of SMFs: ZFOURGE data from Tomczak et al., UltraVISTA data from Ilbert et al., and COSMOS data from Davidzon et al. We also build a mock survey combining UltraVISTA with ZFOURGE. Our modeling of quenching timescales is consistent with the evolution of the SMF down to

, with different accuracy depending on the particular survey used for calibration. We tested our model against the observed SMFs at low redshift, and it predicts residuals (observation versus model) within

observed scatter along most of the stellar mass range investigated, and with mean residuals below 0.1 dex in the range

. We then compare the SFR–M
* relation predicted by the model with the observed one at different redshifts. The predicted SFR–M
* relation underpredicts the median SFR at fixed stellar mass relative to observations at all redshifts. Nevertheless, the shapes are consistent with the observed relations up to intermediate-mass galaxies, followed by a rapid decline for massive galaxies.
Wikipedia in higher education: Changes in perceived value through content contribution
Authors: Soler-Adillon Joan , Pavlovic Dragana , Freixa Pere
Published: November 2017

Wikipedia is a widely used resource by university students, but it is not necessarily regarded as being reliable and trustworthy by them, nor is it seen as a context in which to make content contributions. This paper presents a teaching and research project that consisted in having students edit or create Wikipedia articles and testing whether or not this experience changed their perceived value of the platform. We conducted our experience at Universitat Pompeu Fabra (Barcelona, Spain) and University of Niš (Niš, Serbia) with a total number of 240 students. These students edited articles and answered two questionnaires, one before and one after the exercise. We compared the pre and post experience answers to the questionnaires with a series of paired samples ttests, through which our data showed that students did significantly change their perception of reliability and usefulness, and of likeliness of finding false information on Wikipedia. Their appreciation of the task of writing Wikipedia articles, in terms of it being interesting and challenge also increased. They did not significantly change, however, their judgement on the social value of the platform, neither in the university nor in the general context. In addition, the open questions and informal feedback allowed us to gather valuable insights towards the evaluation of the overall experience

Wikipedia es un recurso muy utilizado por estudiantes universitarios, pero no está necesariamente bien valorado en términos de fiabilidad, ni tampoco es visto como un entorno en el que hacer aportaciones de contenido. Este artículo presenta un proyecto de docencia e investigación que consiste en proponer que los estudiantes editen o creen artículos para la Wikipedia, y en comprobar si la experiencia modifica su valoración de la misma. Se realizó la experiencia en la Universidad Pompeu Fabra (España) y la Universidad de Niš (Serbia) con un total de 240 alumnos. Editaron artículos y respondieron dos cuestionarios, uno antes y otro después de la experiencia. Se compararon las respuestas mediante una serie de pruebas T para muestras emparejadas, a partir de las cuales pudimos comprobar que los datos mostraban un cambio significativo en su percepción sobre la fiabilidad y la utilidad de la Wikipedia y sobre la probabilidad de encontrar información falsa en ella. También cambió su apreciación de la tarea de editar artículos, que se valoró como interesante y representó un reto. En cambio, su valoración del prestigio social de la Wikipedia, tanto en el contexto universitario como el general, no varió significativamente. Adicionalmente, las preguntas abiertas y el feedback informal permitieron recoger informaciones muy valiosas respecto a la valoración del conjunto de la experiencia
Teen videos on YouTube: Features and digital vulnerabilities
Authors: Montes-Vozmediano Manuel , García-Jiménez Antonio , Menor-Sendra Juan
Published: November 2017

As a mechanism for social participation and integration and for the purpose of building their identity, teens make and share videos on platforms such as YouTube of which they are also content consumers. The vulnerability conditions that occur and the risks to which adolescents are exposed, both as creators and consumers of videos, are the focus of this study. The methodology used is content analysis, applied to 400 videos. This research has worked with manifest variables (such as the scene) and latent variables (such as genre or structure). The results show that there are notable differences in style among the videos according to the producer of the message, and indicate that the most consumed videos are located around four thematic axes (sex, bullying, pregnancy and drugs) and that the referents as audiovisual content creators are the YouTubers. Everything points to problems in using the same language, including audiovisual language, as adolescents. This paper provides evidences of the convenience of using their codes so that this sector of the population see risks and conditions of vulnerability that they seem not to perceive according to their audiovisual creations in which they do not protect their identity, among other features.

Como un mecanismo de participación e integración social y con el propósito de construir su identidad, los adolescentes realizan y comparten vídeos en plataformas como YouTube, de la que también son consumidores de contenido. Las condiciones de vulnerabilidad que tienen lugar y los riesgos a los que se exponen los adolescentes, tanto como creadores como consumidores de vídeos, son el objeto central de este estudio. La metodología utilizada es el análisis de contenido, aplicado a 400 vídeos. Se ha trabajado con variables manifiestas (como el escenario) y latentes (como el género o la estructura). Los resultados muestran unas notables diferencias de estilo entre los vídeos a tenor del productor del mensaje e indican que los vídeos más consumidos se sitúan alrededor de cuatro ejes temáticos (sexo, acoso, embarazo y drogas) y que los referentes como creadores de contenido audiovisual son los «youtubers». Todo apunta a la existencia de problemas a la hora de utilizar el lenguaje, también audiovisual, de los adolescentes. Este trabajo proporciona evidencias de la conveniencia de emplear sus códigos para que este sector de la población se percate de los riesgos y de las condiciones de vulnerabilidad que parecen no percibir según sus creaciones audiovisuales, en las que, entre otras características, no protegen su identidad.
Strategies for the communication and collaborative online work by university students
Authors: Gutiérrez-Porlán Isabel , Román-García Marimar , Sánchez-Vera Maria-del-Mar
Published: November 2017

The impact that Information and Communications Technologies have in the way today’s young people communicate and interact is unquestionable. This impact also affects the educational field, which is required to respond to the needs of twenty first century students by training them in acquiring new skills and strategies to deal with a changing and uncertain future. In this study, which involved 2,054 university students from all Spanish Universities, it delved into the knowledge of networking strategies and tools used by these students for the effective development of communication processes and the implementation of strategies for collaboration and communication. It has been developed a nonexperimental quantitative methodology and the technique used for collecting information was a questionnaire. The results show that all of them use the Internet to communicate and they have a great use of basic tools to collaborate and interact, but they prefer social networks for being in contact with their peers and establishing relationships. It has been found that students do not have the idea of the Internet as a place to learn. This fact implies new challenges to be solved by Universities, to optimize the possibilities of the networks and institutional platforms as an environment to learn collaboratively.

El impacto que las tecnologías de la comunicación tienen en la forma en la que los más jóvenes de hoy en día se comunican y relacionan es incuestionable. Dicho impacto afecta también al campo educativo, al que se le exige que dé respuesta a las necesidades de los estudiantes del siglo XXI, formándoles en la adquisición de habilidades y estrategias para afrontar un futuro cambiante y lleno de incertidumbre. En este estudio, en el que han participado 2.054 estudiantes universitarios de todas las universidades españolas, se profundiza en el conocimiento de las estrategias y herramientas en red empleadas por estos estudiantes para el desarrollo efectivo de los procesos comunicativos y colaborativos. Se ha realizado un diseño de investigación no experimental, de tipo exploratorio basado en el uso del cuestionario como instrumento de recogida de información. Los resultados muestran un mayor uso por parte del alumnado de herramientas básicas de Internet para el trabajo colaborativo mientras que para estar en contacto con sus compañeros y establecer relaciones prefieren las redes sociales. Se ha encontrado que no existe por parte de los estudiantes una concepción de la Red como espacio de aprendizaje, por lo que se plantean nuevos retos a resolver por parte de la institución universitaria de cara a que sus estudiantes optimicen las posibilidades de la Red como lugar en el que aprender colaborativamente.
The ameliorative effect ofAspergillus awamori on aflatoxin B1-induced hepatic damage in rabbits
Authors: Abdelhady D.H. , El-Abasy M.A. , Abou-Asa S.S.E. , Elbialy Z.I. , Shukry M. , Hussein A.H. , Saleh A.A. , El-Magd M.A.
Published: November 2017

This study was conducted to investigate the effect of dietary supplementation ofAspergillus awamorion aflatoxin B1(AFB1)-induced liver damage in rabbits. Administration of AFB1(0.3 mg/kg diet) led to a significant reduction in body weight, body weight gain, total feed intake, total serum proteins, albumin, high density lipoprotein-cholesterol, phagocytic activity, phagocytic index, and the antioxidant enzyme, glutathione peroxidase (GPx). Moreover, AFB1administration was associated with a significant increase in feed conversion ratio, lipid peroxidation and serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase and total bilirubin. In addition, livers of AFB1-supplemented animals showed fatty degeneration with vacuolisation, focal areas of necrosis, mononuclear cells infiltration hyperplasia of bile ducts and sinusoids. A significant increase in the hepatic expression of the biotransformation gene (Cyp3A6), stress-sensitive genes (HO1andSOD1), and inflammation-related genes (IL6, TNFa, NF-kB,andCox2) was also observed. Supplementation of the diets with 0.05, 0.1 or 0.15%A. awamoriameliorated all AFB1deleterious effects with the best improvement observed at the lowest concentration. This is the first investigation to report that supplementation of rabbit diets withA. awamorihas an ameliorative effect against AFB1-induced liver damage possibly through preventing hepatic oxidative stress, promoting the antioxidant defence systems, and inhibiting expression ofCyp3A6,HO1,SOD1,IL6, TNFa, NF-kB,andCox2. Therefore,A. awamoricould be used as a potential preventive or therapeutic agent for aflatoxicosis.
IgG1 Is Required for Optimal Protection after Immunization with the Purified Porin OmpD from Salmonella Typhimurium
Authors: Zhang Yang , Dominguez-Medina Coral , Cumley Nicola J. , Heath Jennifer N. , Essex Sarah J. , Bobat Saeeda , Schager Anna , Goodall Margaret , Kracker Sven , Buckley Christopher D. , May Robin C. , Kingsley Robert A. , MacLennan Calman A. , López-Macías Constantino , Cunningham Adam F. , Toellner Kai-Michael
Published: November 2017

In mice, the IgG subclass induced after Ag encounter can reflect the nature of the Ag. Th2 Ags such as alum-precipitated proteins and helminths induce IgG1, whereas Th1 Ags, such as Salmonella Typhimurium, predominantly induce IgG2a. The contribution of different IgG isotypes to protection against bacteria such as S. Typhimurium is unclear, although as IgG2a is induced by natural infection, it is assumed this isotype is important. Previously, we have shown that purified S. Typhimurium porins including outer membrane protein OmpD, which induce both IgG1 and IgG2a in mice, provide protection to S. Typhimurium infection via Ab. In this study we report the unexpected finding that mice lacking IgG1, but not IgG2a, are substantially less protected after porin immunization than wild-type controls. IgG1-deficient mice produce more porin-specific IgG2a, resulting in total IgG levels that are similar to wild-type mice. The decreased protection in IgG1-deficient mice correlates with less efficient bacterial opsonization and uptake by macrophages, and this reflects the low binding of outer membrane protein OmpD–specific IgG2a to the bacterial surface. Thus, the Th2-associated isotype IgG1 can play a role in protection against Th1-associated organisms such as S. Typhimurium. Therefore, individual IgG subclasses to a single Ag can provide different levels of protection and the IgG isotype induced may need to be a consideration when designing vaccines and immunization strategies.
Regnase-1 and Roquin Nonredundantly Regulate Th1 Differentiation Causing Cardiac Inflammation and Fibrosis
Authors: Cui Xiaotong , Mino Takashi , Yoshinaga Masanori , Nakatsuka Yoshinari , Hia Fabian , Yamasoba Daichi , Tsujimura Tohru , Tomonaga Keizo , Suzuki Yutaka , Uehata Takuya , Takeuchi Osamu
Published: November 2017

Regnase-1 and Roquin are RNA binding proteins that are essential for degradation of inflammatory mRNAs and maintenance of immune homeostasis. Although deficiency of either of the proteins leads to enhanced T cell activation, their functional relationship in T cells has yet to be clarified because of lethality upon mutation of both Regnase-1 and Roquin. By using a Regnase-1 conditional allele, we show that mutations of both Regnase-1 and Roquin in T cells leads to massive lymphocyte activation. In contrast, mutation of either Regnase-1 or Roquin affected T cell activation to a lesser extent than the double mutation, indicating that Regnase-1 and Roquin function nonredundantly in T cells. Interestingly, Regnase-1 and Roquin double-mutant mice suffered from severe inflammation and early formation of fibrosis, especially in the heart, along with the increased expression of Ifng, but not Il4 or Il17a. Consistently, mutation of both Regnase-1 and Roquin leads to a huge increase in the Th1, but not the Th2 or Th17, population in spleens compared with T cells with a single Regnase-1 or Roquin deficiency. Regnase-1 and Roquin are capable of repressing the expression of a group of mRNAs encoding factors involved in Th1 differentiation, such as Furin and Il12rb1, via their 3′ untranslated regions. Moreover, Regnase-1 is capable of repressing Roquin mRNA. This cross-regulation may contribute to the synergistic control of T cell activation/polarization. Collectively, our results demonstrate that Regnase-1 and Roquin maintain T cell immune homeostasis and regulate Th1 polarization synergistically.
Optimal stretching for lattice points under convex curves
Authors: Ariturk Sinan , Laugesen Richard S.
Published: November 2017

Suppose we count the positive integer lattice points beneath a convex decreasing curve in the first quadrant having equal intercepts. Then stretch in the coordinate directions so as to preserve the area under the curve, and again count lattice points. Which choice of stretch factor will maximize the lattice point count? We show the optimal stretch factor approaches

1

as the area approaches infinity. In particular, when

0 < p < 1

, among

p

-ellipses

|sx|^p+|s^{-1}y|^p=r^p

with

s > 0

, the one enclosing the most first-quadrant lattice points approaches a

p

-circle (

s=1

) as

r \to \infty

.

The case

p=2

was established by Antunes and Freitas, with generalization to

1< p <\infty

by Laugesen and Liu. The case

p=1

remains open, where the question is: which right triangles in the first quadrant with two sides along the axes will enclose the most lattice points, as the area tends to infinity?
Approximation rates for regularized level set power mean curvature flow
Authors: Kröner Heiko
Published: November 2017

In [11] the evolution of hypersurfaces in

\mathbb{R}^{n+1}

with normal speed equal to a power

k > 1

of the mean curvature is considered and the level set solution

u

of the flow is obtained as the

C^0

-limit of a sequence

u^{\epsilon}

of smooth functions solving the regularized level set equations. We prove a rate for this convergence.
Corrigendum to ‘‘Positive integers divisible by the product of their nonzero digits’’, Portugaliae Math. 64 (2007), 1: 75–85
Authors: De Koninck Jean-Marie , Luca Florian
Published: November 2017

In this paper, we correct a numerical error from [1].
Una Experiencia Internacional con eRúbricas: una aproximación a la evaluación formativa en dos cursos en la carrera de Educación Infantil.
Authors: Bergman Maria Elena
Published: November 2017

El proyecto que presentamos consistió en una experimentación y evaluación de la herramienta eRubrica[1,2] dentro del programa de formación de docentes de Educación Infantil. eRubrica es una herramienta pero tambien un método para formación didáctica y evaluación formativa. Como principios posee la creación de ambientes de aprendizaje colaborativo, facilitar la consciencia en los estudiantes sobre su propio proceso de aprendizaje y la participación activa en los cursos para asegurar su calidad. Los métodos planteados se entrelazaron con la herramienta y los grupos de control inmersos en la plataforma institucional de la Universidad de Estocolmo. En una perspectiva transnacional se coopera activamente con la universidad de Málaga a través del grupo Gtea[3]. El proyecto se inicia en el curso año académico 2012 y se planificó en tres fases: Implementación, desarrollo y evaluación. Los resultados muestran ventajas pedagógicas de la herramienta en lo que respecta a la reflexión del profesor sobre las competencias y evidencias de aprendizaje, la participación activa del estudiante en sus tareas y el feedback con sus compañeros; al tiempo que se vislumbran resistencias en el docente a la hora de implementar e innovar con la herramienta y su metodología. Por su parte, los estudiantes también realizan un proceso de reflexión y aprendizaje colaborativo obteniendo resultados positivos, mostrando dificultades y limitaciones.

 
Competencias para el aprendizaje ético en estudiantes universitarios de enfermería y pedagogía
Authors: Tey Teijón Amelia , Vilà Baños Ruth , Martín Martín Miquel
Published: November 2017

El artículo presenta los resultados obtenidos en un estudio realizado con estudiantes de las facultades de Pedagogía y Enfermería de la Universidad de Barcelona. Se centra en el análisis de las competencias que pueden favorecer un mayor aprendizaje ético de los estudiantes universitarios. Para ello, busca conocer la percepción de los estudiantes en relación con las dimensiones de la construcción del yo, la reflexión y la convivencialidad. Posteriormente en el estudio se compara ambas muestras y se apunta elementos diferenciales relevantes, que aparecerían si se dibujara el perfil ético de los estudiantes. El diseño de la investigación es mixto. La primera parte, de corte excelentivo,
se centra en entrevistas a profesorado universitario y en grupos de discusión; la segunda parte, más cuantitativa, se lleva a cabo a partir de un estudio por encuesta. En este trabajo se expone los resultados obtenidos a partir de la interpretación de la encuesta. El instrumento, que se administró a los estudiantes de primer y último curso de las Facultades de Pedagogía y Enfermería identifica conductas observables que los estudiantes universitarios pueden considerar propias. En el presente artículo se describe los resultados obtenidos y las principales conclusiones. Entre ellas destaca el notable nivel general de competencias ético-ciudadanas que presentan los estudiantes de la muestra, aunque aparecen también diferencias en los perfiles de los estudiantes, tanto en cuanto la facultad en la que estudian como el curso en el que están.
Compromiso del estudiante y percepción del proceso evaluador basado en rúbricas
Authors: Gallego-Arrufat Maria-Jesus , Raposo-Rivas Manuela
Published: November 2017

En el marco del Proyecto I+D EDU2010-15432 el objetivo del estudio que aquí se presenta está centrado en el conocimiento de las opiniones de los estudiantes universitarios con experiencia en el empleo de rúbricas. Se obtiene una visión de la evaluación usando rúbricas agrupada bajo dos efectos que son investigados: el compromiso del estudiante y la percepción del proceso evaluador. El uso de rúbricas conforma una opinión fundamentada en el estudiante, que se presenta a través de la recopilación y análisis de datos de un cuestionario diseñado para tal fin. Se decide centrar el estudio en dos contextos reales, con similitudes curriculares y académicas bien definidas, realizando un único diseño empírico en la Universidad de Granada y la Universidad de Vigo. Los resultados se organizan en torno a las características de la rúbrica, la modalidad de evaluación, el proceso/procedimiento de evaluación y la repercusión para el aprendizaje. La valoración general de la experimentación con rúbrica incluye la opinión de los estudiantes en cinco variables: el grado en que le motiva, le anima a participar más, le hace más responsable, realiza trabajo cooperativo en grupo y reconoce falta de honestidad en la autoevaluación. Además mediante las variables interés, utilidad y grado de acuerdo también se ofrecen resultados acerca de la percepción del proceso evaluador. Las principales conclusiones residen en la similitud de tendencias de opinión de los estudiantes de ambas universidades, con ligeras diferencias porcentuales.
Criptored y las redes temáticas orientadas a la educación global
Authors: Muñoz Muñoz Alfonso , Ramió Aguirre Jorge
Published: November 2017

La presente investigación recoge una experiencia de innovación educativa de 13 años de duración que analiza las bondades e inconvenientes de utilizar redes temáticas orientadas a la educación de la ciudadanía. Esta experiencia se centra en la red temática Criptored fundada en 1999 en la Universidad Politécnica de Madrid. La experiencia publicada en este trabajo demuestra que una red temática puede ser no sólo un buen medio para difundir conocimiento de calidad entre especialistas, sino un buen generador de ideas y proyectos derivados con implicaciones formativas directas de la ciudadanía a través de Internet. Esta demostración se fundamenta en una serie de diferentes decisiones en la evolución de este proyecto, como son una estructuración docente de la información publicada, gestión de la calidad de los contenidos, definición de un esquema de difusión y compartición de información, generación de nuevo contenido basado en interacciones de miembros y no miembros de la red, etc., lo que facilita la apertura de una red temática a un público heterogéneo sin perder calidad ni excelencia. El impacto y la difusión de esta red en diversos sectores quedan retratados por los resultados. La red refleja un impacto significativo en universidades, centros de investigación, empresas TIC en España e Iberoamérica y en la sociedad en general: 243 universidades, centros de investigación y asociaciones de 22 países representados, 925 miembros de la red, 448 documentos para libre descarga, 14 libros electrónicos, 102 vídeos y más de 2.500.000 documentos servidos en 13 años.
PRESENTACIÓN: Evaluación formativa con e-rúbrica: aproximación al estado del arte
Authors: Cebrián de la Serna Manuel , Bergman María Elena
Published: November 2017

Actualmente no hay tanta duda, como existía en otros momentos, sobre las bondades de las tecnologías para la enseñanza universitaria. Especialmente en su capacidad para la socialización del conocimiento, la comunicación y la colaboración, entre otras funciones importantes. Sin duda, representan cada vez más unos equipamientos y servicios imprescindibles para la labor docente. Sin embargo, y a pesar del impacto que vivimos actualmente con el desarrollo de las tecnologías en general, en ciertos ámbitos importantes del proceso de enseñanza -como es la evaluación de los aprendizajes-, no pueden suplantar totalmente al docente -como es el caso de la evaluación de textos-. Prevalece, por tanto, la importancia del docente para crear ambientes de aprendizajes de calidad, que junto con el compromiso de los estudiantes en todos los procesos de enseñanza y aprendizaje, sepan y quieran obtener el máximo potencial de las tecnologías. Este monográfico surge para promover el uso de las tecnologías en la evaluación en general, y plantea como objetivo específico compartir las prácticas exitosas e investigaciones sobre el uso de las erúbricas (o rúbricas electrónicas) para la evaluación formativa de los aprendizajes universitarios. Todo ello, con la idea y la necesidad de fortalecer estas competencias entre docentes y estudiantes; a la vez que, consolidar las comunidades de prácticas sobre su uso...
La evaluación del aprendizaje en red mediante blogs y rúbricas: ¿complementos o suplementos?
Authors: Bartolomé Antonio , Martínez-Figueira Esther , Tellado-González Fernando
Published: November 2017

Este artículo está relacionado con el uso de blogs y rúbricas como recursos en la evaluación del aprendizaje en red con el fin de valorar si estas herramientas pueden actuar como complementos o suplementos en dicho proceso. Se trabaja con 118 estudiantes que en el curso 2011-12 cursan “Didáctica y Currículum” del Grado Pedagogía de la Universidad de Barcelona; y “Nuevas Tecnologías Aplicadas a la Educación Infantil” del Grado Infantil y “Nuevas Tecnologías Aplicadas a la Educación Primaria” del Grado Primaria, ambas de la Universidad de Vigo. El diseño metodológico responde al seguido en el Proyecto I+D EDU2010-15432, que han adpermitido
estudiar a dos grupos de estudiantes: caso 1 constituido por aquellos que han confeccionado sus diarios personales en formato blog, como elemento favorecedor de la estructuración, síntesis, autoanálisis y reflexión de y sobre sus aprendizajes; y caso 2 formado por aquellos estudiantes que, utilizando también blogs, han empleado las rúbricas de autoevaluación como complemento o suplemento a los mismos. Se pretende constatar la influencia que las rúbricas han ejercido tanto en el dominio de contenidos como en el desarrollo de competencias e implicar al alumnado en el proceso de evaluación cuando emplean blogs en la evaluación. Los resultados manifiestan que la utilización de rúbricas como elemento complementario a los blogs, intensifica los beneficios de estos a la hora de trabajar por competencias.
Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar
Authors: Hildebrand Jens , Baumgarten Gerd , Fiedler Jens , Lübken Franz-Josef
Published: November 2017

Abstract. We present an extensive data set of simultaneous temperature and wind measurements in the Arctic middle atmosphere. It consists of more than 300 h of Doppler Rayleigh lidar observations obtained during three January seasons (2012, 2014, and 2015) and covers the altitude range from 30 km up to about 85 km. The data set reveals large year-to-year variations in monthly mean temperatures and winds, which in 2012 are affected by a sudden stratospheric warming. The temporal evolution of winds and temperatures after that warming are studied over a period of 2 weeks, showing an elevated stratopause and the reformation of the polar vortex. The monthly mean temperatures and winds are compared to data extracted from the Integrated Forecast System of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Horizontal Wind Model (HWM07). Lidar and ECMWF data show good agreement of mean zonal and meridional winds below  ≈ 55 km altitude, but we also find mean temperature, zonal wind, and meridional wind differences of up to 20 K, 20 m s−1, and 5 m s−1, respectively. Differences between lidar observations and HWM07 data are up to 30 m s−1. From the fluctuations of temperatures and winds within single nights we extract the potential and kinetic gravity wave energy density (GWED) per unit mass. It shows that the kinetic GWED is typically 5 to 10 times larger than the potential GWED, the total GWED increases with altitude with a scale height of  ≈ 16 km. Since temporal fluctuations of winds and temperatures are underestimated in ECMWF, the total GWED is underestimated as well by a factor of 3–10 above 50 km altitude. Similarly, we estimate the energy density per unit mass for large-scale waves (LWED) from the fluctuations of nightly mean temperatures and winds. The total LWED is roughly constant with altitude. The ratio of kinetic to potential LWED varies with altitude over 2 orders of magnitude. LWEDs from ECMWF data show results similar to the lidar data. From the comparison of GWED and LWED, it follows that large-scale waves carry about 2 to 5 times more energy than gravity waves.
Technical Note: Evaluation of simultaneous measurements of mesospheric OH, HO2, and O3 under photochemical equilibrium assumption: Statistical approach
Authors: Kulikov Mikhail Yu. , Nechaev Anton A. , Belikovich Mikhail V. , Ermakova Tatiana S. , Feigin Alexander M.
Published: November 2017

Abstract. The Technical Note presents a statistically correct approach to evaluating simultaneous measurements of several atmospheric components under the assumption of photochemical equilibrium. We consider simultaneous measurements of OH, HO2, and O3 at the altitudes of the mesosphere as a specific example and their daytime photochemical equilibrium as an evaluating relationship. A simplified algebraic equation relating local concentrations of these components in the 50–100 km altitude range has been derived. The parameters of the equation are air temperature, air concentration, local zenith angle, and the rates of 9 reactions. We have performed one-year simulation of the mesosphere and lower thermosphere using a 3D chemical-transport model. The simulation shows that the discrepancy between the calculated evolution of the components and the equilibrium value given by the equation does not exceed 3–4 % in the full range of altitudes independent of season or latitude. We have developed the technique of statistic Bayesian evaluation of simultaneous measurements of OH, HO2 and O3 based on the equilibrium equation taking into account the measurement error. The first results of application of the technique to MLS/Aura data are presented in this Technical Note. It has been found that the satellite data of HO2 distribution regularly demonstrates essentially lower altitudes of mesospheric maximum of this component. This has also been confirmed by offline retrieval of HO2 from the MLS primary data.
Unusual behavior of quiet-time zonal and vertical plasma drift velocities over Jicamarca during the recent extended solar minimum of 2008
Authors: Santos Ângela M. , Abdu Mangalathayil A. , Souza Jonas R. , Batista Inez S. , Sobral José H. A.
Published: November 2017

Abstract. The influence of the recent deep and prolonged solar minimum on the daytime zonal and vertical plasma drift velocities during quiet time is investigated in this work. Analyzing the data obtained from incoherent scatter radar from Jicamarca (11.95° S, 76.87° W) we observe an anomalous behavior of the zonal plasma drift during June 2008 characterized by lower than usual daytime westward drift and its early afternoon reversal to eastward. As a case study the zonal drift observed on 24 June 2008 is modeled using a realistic low-latitude ionosphere simulated by the Sheffield University Plasmasphere-Ionosphere Model-INPE (SUPIM-INPE). The results show that an anomalously low zonal wind was mainly responsible for the observed anomalous behavior in the zonal drift. A comparative study of the vertical plasma drifts obtained from magnetometer data for some periods of maximum (2000–2002) and minimum solar activity (1998, 2008, 2010) phases reveal a considerable decrease on the E-region conductivity and the dynamo electric field during 2008. However, we believe that the contribution of these characteristics to the unusual behavior of the zonal plasma drift is significantly smaller than that arising from the anomalously low zonal wind. The SUPIM-INPE result of the critical frequency of the F layer (foF2) over Jicamarca suggested a lower radiation flux than that predicted by solar irradiance model (SOLAR2000) for June 2008.
Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations
Authors: Palm Stephen P. , Kayetha Vinay , Yang Yuekui , Pauly Rebecca
Published: November 2017

Abstract. Blowing snow processes commonly occur over the earth's ice sheets when the 10 m wind speed exceeds a threshold value. These processes play a key role in the sublimation and redistribution of snow thereby influencing the surface mass balance. Prior field studies and modeling results have shown the importance of blowing snow sublimation and transport on the surface mass budget and hydrological cycle of high-latitude regions. For the first time, we present continent-wide estimates of blowing snow sublimation and transport over Antarctica for the period 2006–2016 based on direct observation of blowing snow events. We use an improved version of the blowing snow detection algorithm developed for previous work that uses atmospheric backscatter measurements obtained from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite. The blowing snow events identified by CALIPSO and meteorological fields from MERRA-2 are used to compute the blowing snow sublimation and transport rates. Our results show that maximum sublimation occurs along and slightly inland of the coastline. This is contrary to the observed maximum blowing snow frequency which occurs over the interior. The associated temperature and moisture reanalysis fields likely contribute to the spatial distribution of the maximum sublimation values. However, the spatial pattern of the sublimation rate over Antarctica is consistent with modeling studies and precipitation estimates. Overall, our results show that the 2006–2016 Antarctica average integrated blowing snow sublimation is about 393 ± 196 Gt yr−1, which is considerably larger than previous model-derived estimates. We find maximum blowing snow transport amount of 5 Mt km−1 yr−1 over parts of East Antarctica and estimate that the average snow transport from continent to ocean is about 3.7 Gt yr−1. These continent-wide estimates are the first of their kind and can be used to help model and constrain the surface mass budget over Antarctica.
Philosophy and Enlightenment: The Role of Epistemology in the Education of Citizens
Authors: Hartoonian Michael
Published: November 2017

This essay addresses the nature of philosophy and its role in the education of citizens and their critical discussions about public issues. Because philosophical study develops perspectives and critiques of fundamental human values and behaviors it can help us stop fragmenting our knowledge and cultural resources. When we fail to use these resources, our investigations fall into the quicksand of simple-minded answers to complex problems. In truth, can issues like war and peace, abortion, trade, environmental pollution, genetic engineering, and space exploration be critically discussed without some awareness of how knowledge is created and contested?
Opting Out as Democratic Engagement? The Public Dimensions and Challenges of Education Activism
Authors: Wilson Terri S. , Hastings Matthew , Moses Michele S.
Published: November 2017

In recent years, widespread efforts to “opt out” of state tests have pressured school districts, states, and the federal government to reconsider the extent and limits of state assessments. This activism raises a number of questions about the relationship between democratic participation and public institutions. What is the relationship between state authority, expertise, and public opinion? In what ways should citizens be engaged in the public policy process? Are there times in which the state—in subverting the will of citizens—might be reshaped through public activism? We draw on Dewey's concept of “the public” to explore the democratic qualities and consequences of this activism. We highlight two conceptual resources from Dewey's 1927 The Public and its Problems: how publics are formed when they share consequences, and the role of public expertise in addressing social problems. Through these resources, we argue that the opt out movement might be understood as an overlapping set of publics promoting democratic engagement in education. At the same time, Dewey's understanding of the public poses critical questions about the democratic qualities and broader consequences of this emerging movement.
The theory and syntactic representation of control structures: An analysis from Amharic
Authors: Leung Tommi , Halefom Girma
Published: November 2017

This paper conducts a detailed syntactic analysis of control structures in Amharic and sheds light on the current approaches to their syntactic representation and the operation thereof. Amharic control structures consist of the following components: (i) they are marked by the specific clause marker (CM) lɨ-; (ii) the control clause always contains an imperfective verb; (iii) the control predicate is fully inflected by phi-features which are coindexical to the matrix subject; (iv) the subject of the control clause is a PRO; and (v) only exhaustive subject control is licensed. Amharic control poses a challenge to Landau (2014)’s proposal that the control possibility stems from particular combinations of tense and agreement features of the control predicate. Instead we claim that Amharic data fit better in the analysis of future infinitives (Wurmbrand 2014) and prospective aspect (Kratzer 2011; Matthewson 2012). In addition, the PRO-analysis of Amharic control also entails that the Movement Theory of Control (MTC) is disfavored.
S. S. Stevens’s Invariant Legacy: Scale Types and the Power Law
Authors: Ward Lawrence M.
Published: November 2017

S. S. Stevens was one of a number of prominent psychologists who published seminal articles in The American Journal of Psychology (AJP). Indeed, the first or, arguably, most important articles in several of his research strands were published there. In this brief treatment of his monumental work, I review these articles and some of their sequelae, both in Stevens’s own work and in that of others, in an attempt to sketch out how Stevens’s contributions in AJP helped form the development of experimental sensory and perceptual psychology throughout the 20th century. I focus on his work in psychophysical scaling, because in my opinion that has been his most important legacy. Indeed, the article that probably generated the flurry of work in psychophysical scaling that persisted into the 1990s was a brilliant work published in 1956 in AJP. In that article Stevens not only demonstrated the validity and reliability of direct scaling (in this case magnitude estimation and production) but also investigated a range of factors that could affect its results, anchoring the later work that led to its adoption as the fundamental and most popular approach to psychophysical scaling still in use today. In this section I also expand on a few of the modern directions in which this work has gone. Stevens also published in AJP classic articles on the localization of sound, the dimensions of sound, the relation of volume to intensity, and the neural quantum in pitch and loudness discrimination. He even contributed an article on scaling coffee odor. His work is a stellar example of how AJP has influenced psychological science then and now.