325 research outputs found
Intertwining Symmetry Algebras of Quantum Superintegrable Systems
We present an algebraic study of a kind of quantum systems belonging to a
family of superintegrable Hamiltonian systems in terms of shape-invariant
intertwinig operators, that span pairs of Lie algebras like or
. The eigenstates of the associated Hamiltonian
hierarchies belong to unitary representations of these algebras. It is shown
that these intertwining operators, related with separable coordinates for the
system, are very useful to determine eigenvalues and eigenfunctions of the
Hamiltonians in the hierarchy. An study of the corresponding superintegrable
classical systems is also included for the sake of completness
The Semantic and Syntactic Model of Metadata
As more information becomes “born digital”, metadata creation is increasingly becoming part of the information creation process. Current metadata schemes inherit much of the library cataloging tradition, which has shown limitations on representing “born digital” type of resources. Through analysis of issues of metadata schemes and review of metadata research and projects, the authors propose an ontology-based approach to building a modular metadata model in which semantics and syntax may be integrated to suit the needs for representing “born digital” resources. The authors use an learning object ontology as an example to demonstrate how the semantics and syntax may be built into a modular model for metadata
Partial coherent states in graphene
Producción CientíficaWe employ a symmetric gauge to describe the interaction of electrons in graphene
with a magnetic field which is orthogonal to the layer surface and to build the so-called partial
and bidimensional coherent states for this system in the Barut-Girardello sense. We also evaluate
the corresponding probability and current densities as well as the mean energy value.Junta de Castilla y León (projects
VA137G18 and BU229P18)Ministerio de Economía, Industria y Competitividad (project MTM2014-57129-C2-1-P
Mapping the axiology of European wellfare
While welfare research on historical and institutional trajectories has been carried out extensively in recent decades, less attention has been paid to citizens preferences for social policies. On analysing welfare provision the self-interest and neo-institutionalist theories have often placed incentives and resources at the core of their explanations. But values can also play a very important role in the support and shaping of welfare arrangements. This article explores how values are present in European populations and to what extent variation can be related to the geographical distribution of the different types of welfare regimes. A classification of values associated with social categories, and an overview of the main axiological differences across Europe is therefore put forward.Peer reviewe
15 años de alfabetización en información: investigación internacional recogida en LISA, ERIC y SSCI entre 1990 y 2005
Se presenta el alcance de la investigación internacional en Alfabetización en Información (ALFIN)entre los años 1990 y 2005 a partir del análisis de las publicaciones recogidas en tres de las principales bases de datos internacionales que cubren el tema: LISA, ERIC y SSCI. Se ha analizado la actividad investigadora del periodo, la tipología documental, idioma, autores más productivos y revistas más
utilizadas. Por otro lado, y a través de una metodología de análisis de contenido, se han categorizado los trabajos de los diez autores más productivos, encontrando en ellos la progresión temática lógica
de un área en desarrollo. Otros resultados indican el predominio de trabajos anglosajones así como el incremento exponencial de la producción a lo largo del periodo estudiadoPublicad
Incorporating Data Literacy into Information Literacy Programs: Core Competencies and Contents
The growing importance of data in society in general and scientific domains in particular, mirrored in the Open Data initiative and in the advent of eScience, requires public, school and academic libraries to contribute to both data and information literacy, as part of their mission to further knowledge and innovation in their respective fields of action. No specific library standards have been proposed to date, however, and most research studies conducted adopt a partial view of data literacy, stressing only the components needed in any given context. The present paper aims to contribute to the advancement of data literacy with the proposal of a set of core competencies and contents that can serve as a framework of reference for its inclusion in libraries' information literacy programs. The various definitions of data literacy are discussed, the coverage of the competencies listed in information literacy standards is described, and the competencies considered in the experiments conducted to date in education and libraries are identified. The conclusion drawn is that the model proposed can favour the development of data literacy support resources and services. Topics for further research are also specified
Desarrollo de una herramienta de creación de videojuegos de rol táctico para escenarios isométricos compuestos por bloques
Gracias al avance de la tecnología y a una mayor disponibilidad de las herramientas, en estos últimos años hemos visto aparecer un gran número de proyectos de videojuegos desarrollados por estudios independientes. Algunos géneros tradicionales, como los juegos de plataformas o los de disparos en primera persona, cuentan con entornos de desarrollo específicos y muy potentes, que permiten prototipar ideas en cuestión de horas. Sin embargo, otros géneros de mayor variabilidad, como el de los juegos de rol, no cuentan con herramientas tan maduras y estables dentro de los motores de videojuegos de última generación.
Con el objetivo de ayudar a estos creadores independientes que desean desarrollar videojuegos de este género, se ha extendido una herramienta preexistente llamada IsoUnity, pensada para crear escenarios isométricos compuestos por bloques. Este proyecto amplía su funcionalidad, tanto a nivel de código como de herramientas de edición, para que se puedan crear con facilidad juegos de rol táctico con movimiento, combate por turnos y vista en perspectiva isométrica, al estilo de clásicos como Final Fantasy Tactics.
Con el objetivo de ofrecer a los usuarios una herramienta actual y versátil, se han estudiado y analizado un conjunto representativo de juegos del sector y en base a ese estudio se ha desarrollado el proyecto tratando de incorporar la mayoría de elementos comunes a todos, siguiendo una metodología clásica de análisis, diseño, implementación y prueba que ha dado lugar a un prototipo plenamente funcional que ilustra las posibilidades de esta herramienta. Actualmente el prototipo está en su primera versión (v 1.0), pero se estudia y ofrece la continua mejora de éste.
Este prototipo en su primera versión oficial ofrece las características más destacadas del conjunto de juegos estudiados haciendo hincapié en el sistema de turnos, la creación de personajes y habilidades y el movimiento de personajes basado en celdas desarrollado en IsoUnity
Avanzar en el aprendizaje autónomo y social: integración de autoevaluación y evaluación por pares como herramientas de evaluación formativa
Dialoging about data with the iSchools: exploring curricula trends
Pre-Referee Version. Candidate Paper for the Journal of Information ScienceOur rapidly growing data driven culture is motivating curriculum change in nearly every discipline, including information science. This paper explores this change specifically within the iSchool community, where information science is a major unifying discipline. A cross-institutional analysis of data related curricula was conducted across 65 iSchools. Results show that a majority of iSchools examined (37 out of 65, 56.9%) currently offer some data related education, particularly at the master's level, and that approximately 15% of the formalized degree offerings have a data focus. Overall, iSchools show a greater emphasis in data science and big data analytics, with only a few select programs providing focused curricula in the area of digital curation. Recommendation are also made for iSchools to leverage the interdisciplinary of information science, publish curriculum, and track graduate success so that iSchools may excel in educating information professionals in the data area. Future data education in iSchools may benefit from more interdisciplinary data education, including data curation curricula.Enviad
Inactivation of Salmonella Enteritidis in Chicken Breast Fillets by Single-Cycle and Multiple-Cycle High Pressure Treatments
The effect of single-cycle and multiple-cycle high hydrostatic pressure (HHP) treatments on the survival of three Salmonella Enteritidis strains in chicken breast fillets was investigated. The surface of fillets was inoculated with a cocktail of three Salmonella strains at approximately 107 colony-forming units (CFU)/g, and held at 4°C for 20 hours before HHP treatments. Reduction of Salmonella counts on tryptic soy agar (TSA) by single-cycle treatments at 300 MPa and 12°C ranged from 0.58 log CFU/g for a 0-minute (no dwell time) cycle to 3.35 log CFU/g for a 20-minute cycle, whereas with 400 MPa treatments the decline ranged from 0.93 log CFU/g to more than 5 log CFU/g, respectively. The 4.8 log unit reduction in Salmonella counts on TSA achieved by a 15-minute treatment at 400 MPa should suffice to eliminate the pathogen naturally present in contaminated chicken meat. When plated on Salmonella Shigella agar (SSA), the reduction of Salmonella counts by single-cycle treatments at 300 MPa and 12°C ranged from 0.69 log CFU/g for a 0-minute cycle to 4.21 log CFU/g for a 20-minute cycle, and with 400 MPa treatments from 1.25 log CFU/g to more than 5 log CFU/g, respectively. From the comparison of Salmonella counts on SSA and TSA it was concluded that not only the lethality but also the proportion of injured Salmonella cells increased with the length of HHP treatments. The use of multiple-cycle treatments instead of single-cycle treatments of the same HHP time for the inactivation of Salmonella Enteritidis inoculated on chicken breast fillets showed to be more advantageous at 400 MPa than at 300 MPa. No recovery of injured Salmonella cells was observed when fillets treated at 300 or 400 MPa for 5 minutes were held for 72 hours at 4°C.Financial support from projects CPE03-012-C3-1 (INIA),
S-0505=AGR=0314 (Comunidad de Madrid), and CSD 07-
00016 (Carnisenusa—Consolider program) is acknowledged.Peer reviewe
- …