Unified Abstract Mechanism to Model Language Learning Activities

Language learning applications define exercises that are pedagogical tools to introduce new language concepts. The development of this type of applications is complex due to the diversity of language learning methodologies, the variety of execution environments and the number of different technologies that can be used. This article proposes a conceptual model to develop the activities of language learning applications. It defines a new abstraction mechanism to model these activities as part of a model-driven approach to develop applications supporting different language learning processes running on different hardware and software platforms. We define a metamodel that describes the entities and relationships representing language learning activities as well as a series of examples that use the proposed abstraction mechanism to represent different language learning activities. The modelling process is simplified using a common representation that does not affect neither the visual presentation, nor the interaction of each activity. The article includes an evaluation that analyses the product correctness, robustness, extensibility, and reusability of the obtained code. These results conclude that the code generated using the proposed approach overcomes the code generated following a traditional approach

Supporting New Ways of Interaction in Cultural Environments

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Assessing racial and ethnic disparities using a COVID-19 outcomes continuum for New York State

Purpose Heightened COVID-19 mortality among Black non-Hispanic and Hispanic communities (relative to white non-Hispanic) is well established. This study aims to estimate the relative contributions to fatality disparities in terms of differences in SARS-CoV-2 infections, diagnoses, and disease severity. Methods We constructed COVID-19 outcome continua (similar to the HIV care continuum) for white non-Hispanic, Black non-Hispanic, and Hispanic adults in New York State. For each stage in the COVID-19 outcome continua (population, infection experience, diagnosis, hospitalization, fatality), we synthesized the most recent publicly available data. We described each continuum using overall percentages, fatality rates, and relative changes between stages, with comparisons between race and ethnicity using risk ratios. Results Estimated per-population COVID-19 fatality rates were 0.03%, 0.18%, and 0.12% for white non-Hispanic, Black non-Hispanic, and Hispanic adults, respectively. The 3.48-fold disparity for Hispanic, relative to white, communities was explained by differences in infection experience, whereas the 5.38-fold disparity for non-Hispanic Black, relative to white, communities was primarily driven by differences in both infection experience and in the need for hospitalization, given infection. Conclusions These findings suggest the most impactful stages on which to intervene with programs and policies to build COVID-19 health equity

Mashups: A Journey from Concepts and Models to the Quality of Applications

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Transformation architecture for multi-layered WebApp source code generation

The evolution of Web technologies leads to software premature obsolescence requiring technology-independent representations to increase the reuse rates during the development process. They also require integration into service-oriented architectures to exchange information with different Web systems supporting runtime interoperability. Web Applications (WebApps) run on devices with different capabilities and limitations increasing the complexity of the development process. To address these challenges, different proposals have emerged to facilitate the development of WebApps, which is still an open research field with many challenges to address. This paper presents a model transformation architecture based on software standards to automatically generate full stack multi-layered WebApps covering Persistence, Service, and Presentation layers. This transformation architecture also generates the set of test cases to test WebApp business logic. The proposed transformation architecture only requires a UML platform-independent class model as an input to generate fully functional Web applications in a three-tier architecture including the three layers, while most proposals focus on the generation of the Presentation layer. In addition, this architecture employs software industry standards to enable an easy integration into third-party tools and development environments. The transformation Architecture proposed has been empirically validated on the case study of a fully functional travel management WebApp that is generated using a UML class diagram employing a third-party tool integrated into the same integrated development environment

Arsenite sorption and co-precipitation with calcite

Sorption of As(III) by calcite was investigated as a function of As(III) concentration, time and pH. The sorption isotherm, i.e. the log As(III) vs. log [As(OH)3 degrees / Assat] plot is S-shaped and has been modelled on an extended version of the surface precipitation model. At low concentrations, As(OH)3 degrees is adsorbed by complexation to surface Ca surface sites, as previously described by the X-ray standing wave technique. The inflexion point of the isotherm, where As(OH)3 degrees is limited by the amount of surface sites (ST), yields 6 sites nm-2 in good agreement with crystallographic data. Beyond this value, the amount of sorbed arsenic increases linearly with solution concentration, up to the saturation of arsenic with respect to the precipitation of CaHAsO3(s). The solid solutions formed in this concentration range were examined by X-ray and neutron diffraction. The doped calcite lattice parameters increase with arsenic content while c/a ratio remains constant. Our results made on bulk calcite on the atomic displacement of As atoms along [0001] direction extend those published by Cheng et al., (1999) on calcite surface. This study provides a molecular-level explanation for why As(III) is trapped by calcite in industrial treatments.Comment: 9 page