Mellora da propagación in vitro de Vaccinium corymbosum e avaliación da actividade antioxidante en froitos comerciais

Traballo fin de mestrado (UDC.CIE). Bioloxía molecular, celular e xenética. Curso 2015/201

Integrating intelligent methodological and tutoring assistance in a CASE platform: The PANDORA experience

Database Design discipline involves so different aspects as conceptual and logical modelling knowledge or domain understanding. That implies a great effort to carry out the real world abstraction task and represent it through a data model. CASE tools emerge in order to automating the database development process. These platforms try to help to the database designer in different database design phases. Nevertheless, this tools are frequently mere diagrammers and do not carry completely out the design methodology that they are supposed to support; furthermore, they do not offer intelligent methodological advice to novice designers. This paper introduces the PANDORA tool (acronym of Platform for Database Development and Learning via Internet) that is being developed in a research project which tries to mitigate some of the deficiencies observed in several CASE tools, defining methods and techniques for database development which are useful for students and practitioners. Specifically, this work is focused on two PANDORA components: Conceptual Modelling and Learning Support subsystems

Educational experiences detecting, using, and representing ternary relationships in database design

Conceptual models are applied as the first step in software design methodologies for collecting the semantics involved in the universe of discourse. Nevertheless, the abstraction process creates some misunderstandings for novice designers, such as difficulties in modeling some constructs and in understanding the semantics that they represent. This paper presents a thorough study of errors detected among Database Design students in Computer Science Engineering when they apply the abstraction process to generate a conceptual schema using a specific model. Specifically, the paper focuses on errors made in the design of ternary relationships. Some heuristics are proposed in order to help novice designers avoid these common errors, and an experimental study is presented to compare the number of errors made by the students before and after applying these heuristics. (Contains 10 figures, 2 tables, and 3 footnotes.)This work was supported in part by the Software Process Management platform project Modeling, Reuse and Measurement (TIN2004/07083), by the Spanish Ministry of Science and Innovation, and by the Universidad Carlos III de Madrid, which supports the APEINTA research and innovation project.Publicad

Learning to teach database design by trial and error

Proceedings of: 4th International Conference on Enterprise Information Systems (ICEIS 2002), Ciudad Real, Spain, April 3-6, 2002The definition of effective pedagogical strategies for coaching and tutoring students according to their needs in each moment is a high handicap in ITS design. In this paper we propose the use of a Reinforcement Learning (RL) model, that allows the system to learn how to teach to each student individually, only based on the acquired experience with other learners with similar characteristics, like a human tutor does. This technique avoids to define the teaching strategies by learning action policies that define what, when and how to teach. The model is applied to a database design ITS system, used as an example to illustrate all the concepts managed in the model

Validación de un cuestionario para evaluar el funcionamiento de las bibliotecas escolares

The school library has acquired a new prominence in recent years, becoming a fundamental learning space for the teaching of different areas and subjects and the promotion of skills in students.The objective of this work is to validate a questionnaire designed ad hoc to evaluate the functioning and the forms of use and incorporation of the school library to the daily pedagogical activity. To this purpose, the questionnaire was applied to a random sampling of 4,177 students from 358 centers of Primary, Secondary and Post-Compulsory Education, reliability was calculated using the Cronbach's Alpha test and an exploratory factor analysis was carried out. The results show that the Students Questionnaire to Evaluate the Operation of the School Library has acceptable levels of reliability and validity, so that it offers guarantees enough to evaluate the functioning of the school library

Calidad de vida en niños pequeños portadores de un implante coclear

ResumenEn este artículo se presenta una investigación desarrollada durante un curso escolar en la Comunidad Autónoma de Andalucía (2010-2011). El tema central del estudio es analizar la influencia del implante coclear en la mejora de la calidad de vida de niños que lo han recibido en sus primeros años de vida. No es el propósito de este trabajo describir íntegramente la investigación, sino que de forma selectiva se hace un recorrido por el diseño metodológico y los resultados de la investigación, que nos lleva a plantear una serie de reflexiones finales acerca de la mejora de la forma de vida y del desarrollo personal de niños que padecen hipoacusia y son portadores de un implante coclear.AbstractThis article describes a study conducted in an Andalusia Community school (year 2010-2011). It studied the influence of cochlear implantation on improving the quality of life of the children who received implants during their early years. The methodological design and results of the study are also presented, in order to find a better solution to improve the life conditions and personal development of children suffering hearing loss, and having a cochlear implant

Esquemas 2D de alto orden basados en reconstrucciones de estado, para sistemas hiperbólicos no conservativos. Aplicación a problemas de transporte de sedimentos

En este trabajo se aborda la aproximación numérica del problema de arrastre de sedimentos causada por la evolución del agua. Para la componente hidrodinámica se consideran las ecuaciones de aguas poco profundas. La componente morfodinámica se define mediante una ecuación de continuidad, dada en función del caudal sólido. Ambas componentes constituyen un sistema acoplado que puede reescribirse como un sistema hiperbólico no conservativo (ver [4] A.M. Ferreiro Ferreiro. Desarrollo de técnicas de post-proceso de flujos hidrodinámicos, modelización de problemas de transporte de sedimentos y simulación numérica mediante técnicas de volúmenes finitos. Tesis Doctoral. Universidad de Sevilla. 2006). Se propone un esquema 2D generalizado de Roe con reconstrucciones de estado para sistemas hiperbólicos no conservativos (ver [4]), mediante esquemas de volúmenes finitos y el método de líneas (ver [5] J.A. García Rodríguez. Paralelización de esquemas de vol´umenes finitos: aplicación a la resolución de sistemas de tipo aguas someras. Tesis Doctoral. Universidad de Málaga. 2005), extendiendo los esquemas de alto orden para el caso 1D propuesto en [2] M.J. Castro, J.M. Gallardo and C. Parés. High order finite volume schemes based on reconstruction of states for solving hyperbolic systems with nonconservative products. Applications to shallow water systems. Math. Comp., 75: 1103-1134. 2006. La reconstrucción de estado empleada es de tipo MUSCL (ver [1] B. Van Leer. MUSCL. A new approach to numerical gas dynamics. Computing in plasma physics and astrophysics, Max-Planck-Institut fur plama physik.. Carchung, Germany, April 1976), que proporciona orden dos para mallas no estructuradas de volúmenes finitos de tipo arista. Finalmente se presenta un test num´erico en el que se estudia la evolución del ángulo de expansi´on de una monta˜na de arena (ver [4])

Sediment transport models in Shallow Water equations and numerical approach by high order finite volume methods.

This paper is concerned with the numerical approximation of bedload sediment transport due to water evolution. For the hydrodynamical component we consider Shallow Water equations. The morphodynamical component is defined by a continuity equation, which is defined in function of the solid transport discharge. We present several deterministic models, such as Meyer-Peter & Müller, Van Rijn or Grass model. We also present an unified definition for the solid transport discharge, and we compare with Grass model. Both components define a coupled system of equations that can be rewrite as a non-conservative hyperbolic system. To discretize it, we consider finite volume methods with or without flux limiters and high order state reconstructions. Finally we present several tests, where we observe numerically the order of the numerical schemes. Comparisons with analytical solutions and experimental data are also presented

Do one‐step mechanisms always involve simultaneous evolution of electron density? QTAIM/IQA analysis of the Curtius rearrangement

The Curtius rearrangement reaction is studied by using quantum theory of atoms in molecules (QTAIM) analysis of the electron density and the interacting quantum atoms (IQA) formalism. Although the rearrangements take place in one stage, two phases are distinguished when the rearranged atom is H: the first one corresponds to the separation of N2, and the second one to the N‐H/C‐H bond rearrangement. The transition state (TS) for the reaction does not represent an intermediate between reagent and product for the migration but for the isolation of the N2 molecule. When the migration is undergone by a fluorine atom, no electronic phases can be distinguished and the process is really concerted. As the migration happens closer to the TS, the TS is more similar to the product. The IQA analysis reveals different electron density evolutions for H and F migrations, and the scarce relevance (in terms of energy) of the point where BCPs appear or disappear.Xunta de Galicia | Ref. ED431C 2019/2

Microstructure–hardness–corrosion performance of 17–4 precipitation hardening stainless steels processed by selective laser melting in comparison with commercial alloy

Producción CientíficaThe 17–4 Precipitation Hardening Stainless Steel (PH SS) manufactured by Selective Laser Melting (SLM) has wide appli- cation perspectives, but they are limited due to defects and anisotropy. The selection of the appropriate process variables plays a fundamental part in the microstructure and in the determination of the final mechanical and corrosion properties. The main purpose of this study is to analyze the corrosion behavior, hardness and microstructure of 17–4 PH SS manufac- tured by SLM in comparison to the commercial counterparts. The anisotropic behavior was investigated by analyzing the microstructure–hardness and corrosion interrelationship, both in the surface of the construction platform and in the growth direction of the element. The corrosion behavior of the SLM 17–4PH SS in its natural state was investigated in relation to that of the 17–4 PH SS heat treated in a 0.1 M NaCl + 0.5 M H 2 SO 4 solution, using three electrochemical techniques. The results confirmed that the corrosion resistance of SLM 17–4 PH SS was considerably better than that of the forging, even after 60 days of immersion in the test solution. This was attributed to the absence of important manufacturing defects, to the fine microstructure with an important amount of austenite produced by SLM, and to a small amount of non-metallic inclusions precipitated as a result of the fast cooling and the high speed of solidification associated with the SLM process.Ministerio de Ciencia, Innovación y Universidades (grant RTI2018-097990-B-I00)Junta de Castilla y León (VA275P18) y (VA044G19)Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL