Estándares para e-Learning Adaptativo y Accesible

En la actualidad existe un gran número de estándares que tratan sobre la accesibilidad de los sistemas de e-Learning, desde diversos puntos de vista, como los modelos de usuario, los escenarios de aprendizaje, las preferencias de interacción, las capacidades de los dispositivos y metadatos para especificar cómo entregar cualquier recurso de acuerdo a las necesidades de los usuarios. También existen otros estándares relevantes en el campo de la accesibilidad y la usabilidad del software. Cada uno de estos estándares representa un punto de vista diferente con su propio conjunto de objetivos y alcance, lo que dificulta comprender las relaciones que existen entre todos ellos. Esté artículo presentará una recopilación actualizada de los principales estándares relacionados con la accesibilidad, usabilidad y adaptabilidad de los sistemas de e-learning en el contexto del proyecto de investigación A2UN@, que está centrado en atender las necesidades de accesibilidad y adaptación de todos, en la Educación Superior

Accesibilidad Web: tendencias de futuro

Artículo que presenta una monografía de la revista Novática sobre accesibilidad de la web para personas con discapacidad. En él se introduce la temática de la accesibilidad web, y se presentan los artículos de la monografí

Development of a TiNbTaMoZr-Based High Entropy Alloy with Low Young´s Modulus by Mechanical Alloying Route

In this work, an equiatomic TiNbTaMoZr-based high-entropy alloy (HEA) has been developed by a powder metallurgy route, which consists of a process of combined one-step low-temperature mechanical milling starting from the transition metals as raw materials and a subsequent pressureless sintering. In this way, the optimized synthesized specimen, after 10 h of milling time, showed two di erent body-centered cubic (bcc) TiNbTaMoZr alloys, which, after sintering at 1450 C, 1 h of dwell time and a heating and cooling rate of 5 C min1, it remained formed as two bcc TiNbTaMoZr-based HEAs. This material, with micrometric and equiaxed particles, and with homogeneously distributed phases, presented a Young’s modulus that was significantly higher (5.8 GPa) and lower (62.1 GPa) than that of the usual commercially pure (cp) Ti and Ti6Al4V alloy used for bone-replacement implants. It also presented similar values to those of the HEAs developed for the same purpose. These interesting properties would enable this TiNbTaMoZr-based HEA to be used as a potential biomaterial for bulk or porous bone implants with high hardness and low Young´s modulus, thereby preventing the appearance of stress-shielding phenomena

Standards and specifications to manage accessibility issues in e-learning

Despite the acknowledged need of providing a personalized and adaptive learning process for all, current learning management systems do not properly cover personalization and accessibility issues and they are still struggling to support the reusability requirements coming from the pervasive usage of standards. There is a lack of frameworks for providing layered-based infrastructure covering the interoperability required to manage the whole range of standards, applications and services needed to meet accessibility and adaptations needs of lifelong learning services

Status and trends in Arctic vegetation: Evidence from experimental warming and long-term monitoring

Changes in Arctic vegetation can have important implications for trophic interactions and ecosystem functioning leading to climate feedbacks. Plot-based vegetation surveys provide detailed insight into vegetation changes at sites around the Arctic and improve our ability to predict the impacts of environmental change on tundra ecosystems. Here, we review studies of changes in plant community composition and phenology from both long-term monitoring and warming experiments in Arctic environments. We find that Arctic plant communities and species are generally sensitive to warming, but trends over a period of time are heterogeneous and complex and do not always mirror expectations based on responses to experimental manipulations. Our findings highlight the need for more geographically widespread, integrated, and comprehensive monitoring efforts that can better resolve the interacting effects of warming and other local and regional ecological factors

El sílex en la cuenca vasco-cantábrica y el Pirineo occidental: materia prima lítica en la Prehistoria

The existence of thick sedimentary series in the Basque-Cantabrian Basin and the Western Pyrenees helps the outcropping of many and vary geological formations with important silicifications. The study of their different types and their host rocks allows knowing which the disponibility of this important mineral resource was in Prehistoric times. The petrological characterization also allows identifying the geological origin of the lithic remains from the archaeological sites. It has been possible to differentiate 5 Groups of flint depending on the formation environment, 14 Classes if the geological age is considered and more than 20 Types or geological formations. According to the ways rocks are used in prehistoric sites, in turn, they can be classified into: Not used, Local, Regional, Tracer and Super-Tracer flints. Since Neolithic periods a new type of flint appears: the Evaporítico del Ebro (Super-Tracer), with outcrops and workshops outside the geological environment under this study.La existencia de potentes series sedimentarias en la Cuenca Vasco-Cantábrica y Pirineo occidental favorece la aparición de multitud y variadas formaciones geológicas con importantes silicificaciones. El estudio de sus diferentes tipos y de sus rocas encajantes, permite conocer cuál ha sido la disponibilidad de este importante recurso mineral en la Prehistoria. La caracterización petrológica permite también conocer la procedencia geológica de los restos líticos encontrados en los yacimientos arqueológicos. Se ha conseguido diferenciar 5 Grupos de sílex en función de su ambiente de formación, 14 Clases si los cruzamos con su edad geológica y más de 20 Tipos o formaciones geológicas con silicificaciones. En función de su modo de gestión en los yacimientos prehistóricos, a su vez, se clasifican en: sílex No utilizados, Locales (próximos y lejanos), Regionales (próximos y lejanos), Trazadores y Súper-Trazadores. A partir del Neolítico aparece otro nuevo tipo: el Evaporítico del Ebro (Súper-Trazador), con afloramientos y talleres fuera del ámbito geológico objeto del trabajo

Estándares para e-learning adaptativo y accesible

Currently there are many standards that deal with accessibility issues regarding users’ models, learning scenarios, interaction preferences, device capabilities, metadata for specifying the delivery of any resource to meet users’ needs, and software accessibility and usability. It is difficult to understand the existing relationships between these standards, as each one represents a different viewpoint and thus has its own sets of goals and scope. This article gives an overview on existing standards regarding accessibility, usability and adaptation issues in e-learning, and discusses their application to cope with the objectives of the A2UN@ project, which focuses on attending the accessibility and adaptation needs for all in Higher Education.En la actualidad existe un gran número de estándares que tratan sobre la accesibilidad de los sistemas de e-Learning, desde diversos puntos de vista, como los modelos de usuario, los escenarios de aprendizaje, las preferencias de interacción, las capacidades de los dispositivos y metadatos para especificar cómo entregar cualquier recurso de acuerdo a las necesidades de los usuarios. También existen otros estándares relevantes en el campo de la accesibilidad y la usabilidad del software. Cada uno de estos estándares representa un punto de vista diferente con su propio conjunto de objetivos y alcance, lo que dificulta comprender las relaciones que existen entre todos ellos. Este artículo presentará una recopilación actualizada de los principales estándares relacionados con la accesibilidad, usabilidad y adaptabilidad de los sistemas de e-Learning en el contexto del proyecto de investigación A2UN@, que está centrado en atender las necesidades de accesibilidad y adaptación de todos, en la Educación Superior

Plant traits poorly predict winner and loser shrub species in a warming tundra biome

Climate change is leading to species redistributions. In the tundra biome, shrubs are generally expanding, but not all tundra shrub species will benefit from warming. Winner and loser species, and the characteristics that may determine success or failure, have not yet been fully identified. Here, we investigate whether past abundance changes, current range sizes and projected range shifts derived from species distribution models are related to plant trait values and intraspecific trait variation. We combined 17,921 trait records with observed past and modelled future distributions from 62 tundra shrub species across three continents. We found that species with greater variation in seed mass and specific leaf area had larger projected range shifts, and projected winner species had greater seed mass values. However, trait values and variation were not consistently related to current and projected ranges, nor to past abundance change. Overall, our findings indicate that abundance change and range shifts will not lead to directional modifications in shrub trait composition, since winner and loser species share relatively similar trait spaces

A molecular analysis by gene expression profiling reveals Bik/NBK overexpression in sporadic breast tumor samples of Mexican females

BACKGROUND: Breast cancer is one of the most frequent causes of death in Mexican women over 35 years of age. At molecular level, changes in many genetic networks have been reported as associated with this neoplasia. To analyze these changes, we determined gene expression profiles of tumors from Mexican women with breast cancer at different stages and compared these with those of normal breast tissue samples. METHODS: (32)P-radiolabeled cDNA was synthesized by reverse transcription of mRNA from fresh sporadic breast tumor biopsies, as well as normal breast tissue. cDNA probes were hybridized to microarrays and expression levels registered using a phosphorimager. Expression levels of some genes were validated by real time RT-PCR and immunohistochemical assays. RESULTS: We identified two subgroups of tumors according to their expression profiles, probably related with cancer progression. Ten genes, unexpressed in normal tissue, were turned on in some tumors. We found consistent high expression of Bik gene in 14/15 tumors with predominant cytoplasmic distribution. CONCLUSION: Recently, the product of the Bik gene has been associated with tumoral reversion in different neoplasic cell lines, and was proposed as therapy to induce apoptosis in cancers, including breast tumors. Even though a relationship among genes, for example those from a particular pathway, can be observed through microarrays, this relationship might not be sufficient to assign a definitive role to Bik in development and progression of the neoplasia. The findings herein reported deserve further investigation

Scaling of species distribution models across spatial resolutions and extents along a biogeographic gradient. The case of the Iberian mole Talpa occidentalis

P. 279-292Scaling is a key process in modelling approaches since it allows for translating information from one scale to another. However, the success of this procedure may depend on ‘source’ and ‘target’ scales, but also on the biogeographic/ecological context of the study area. We aimed to quantify the performance and success of scaling species distribution model (SDM) predictions across spatial resolution and extent along a biogeographic gradient using the Iberian mole as study case. We ran separate MaxEnt models at two extents (national and regional) using independent datasets (species locations and environmental predictors) collected at 10 km and 50 m resolutions respectively. Model performance and success of scaling SDMs were quantified on the basis of accuracy measures and spatial predictions. Complementarily, we calculated marginality and tolerance as indicators of habitat availability and niche truncation along the biogeographic gradient. Model performance increased with resolution and extent, as well as from north to south (mainly for high resolution models). When regional models were validated at different scales, their performance reduced severely, particularly in the case of coarse resolution models (some of them performed worse than random). However, when the 10 km‐national model was downscaled within regions, it performed better (AUCtest: 0.82, 0.85 and 0.55 respectively for Galicia, Madrid and Granada) than models specifically calibrated within each region at 10 km (0.47, 0.65, 0.44). Indeed, it also had a better accuracy when projected at 50 m (0.77, 0.91, 0.79) than models fitted at that resolution (0.62, 0.83, 0.96) in two of the three cases. The success of scaling model predictions decreased along the biogeographic gradient, being these differences associated to niche truncation. Models representing non‐truncated niches were more successfully scaled across resolutions and extents (particularly in areas not offering all possible habitats for species), which has important implications for SDM applications.S