Multiobjective Evolutionary Induction of Subgroup Discovery Fuzzy Rules: A Case Study in Marketing

This paper presents a multiobjective genetic algorithm which obtains fuzzy rules for subgroup discovery in disjunctive normal form. This kind of fuzzy rules lets us represent knowledge about patterns of interest in an explanatory and understandable form which can be used by the expert. The evolutionary algorithm follows a multiobjective approach in order to optimize in a suitable way the different quality measures used in this kind of problems. Experimental evaluation of the algorithm, applying it to a market problem studied in the University of Mondragón (Spain), shows the validity of the proposal. The application of the proposal to this problem allows us to obtain novel and valuable knowledge for the experts.Spanish Ministry of Science and TechnologyFEDER TIC-2005-08386-C05-01 and TIC-2005- 08386-C05-03TIN2004-20061-E and TIN2004-21343-

Towards eLearning 2.0 University

The editorial introduction to the special issue: Towards eLearning 2.0 University. Interactive Learning Environment

A Proposal to Define Adaptive Learning Designs

Abstract. This paper outlines a framework to describe adaptive learning designs where definitions as the instructional design method, the type of tests, the learning style approach, and the adaptive rules are not prescribed. Standardized metadata based on IMS is used to guarantee the reusability and interoperability of the elements. The framework proposes, also, to adjust the learning design taking into account the student knowledge and the learning style of both the learner and the learning activities by means of adaptive rule definitions. These rules are defined using a set of elements (based on IMS LD) and they describe adaptive statements, techniques and students’ stereotypes

Regulation of glutamine synthetase activity in the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 by the nitrogen source: Effect of ammonium

Glutamine synthetase activity from Synechocystis sp. strain PCC 6803 is regulated as a function of the nitrogen source available in the medium. Addition of 0.25 mM NH4Cl to nitrate-grown cells promotes a clear short-term inactivation of glutamine synthetase, whose enzyme activity decreases to 5 to 10% of the initial value in 25 min. The intracellular levels of glutamine, determined under various conditions, taken together with the results obtained with azaserine (an inhibitor of transamidases), rule out the possibility that glutamine per se is responsible for glutamine synthetase inactivation. Nitrogen starvation attenuates the ammonium-mediated glutamine synthetase inactivation, indicating that glutamine synthetase regulation is modulated through the internal balance between carbon-nitrogen compounds and carbon compounds. The parallelism observed between the glutamine synthetase activity and the internal concentration of α-ketoglutarate suggests that this metabolite could play a role as a positive effector of glutamine synthetase activity in Synechocystis sp. Despite the similarities of this physiological system to that described for enterobacteria, the lack of in vivo 32P labeling of glutamine synthetase during the inactivation process excludes the existence of an adenylylation-deadenylylation system in this cyanobacterium.Dirección General de Investigación Científica y Técnica PB 88-002

A Genetic-Programming-Based Approach for the Learning of Compact Fuzzy Rule-Based Classification Systems

In the design of an interpretable fuzzy rule-based classification system (FRBCS) the precision as much as the simplicity of the extracted knowledge must be considered as objectives. In any inductive learning algorithm, when we deal with problems with a large number of features, the exponential growth of the fuzzy rule search space makes the learning process more difficult. Moreover it leads to an FRBCS with a rule base with a high cardinality. In this paper, we propose a genetic-programming-based method for the learning of an FRBCS, where disjunctive normal form (DNF) rules compete and cooperate among themselves in order to obtain an understandable and compact set of fuzzy rules, which presents a good classification performance with high dimensionality problems. This proposal uses a token competition mechanism to maintain the diversity of the population. The good results obtained with several classification problems support our proposal.Spanish Ministry of Science and Technology TIN-2005-08386-C05-03 and TIN-2005-08386-C05-0

Los trastornos inducidos por sustancias y la conducción: el ejemplo del Interferón

Con el objetivo de condensar los últimos avances de la investigación en la interacción de los psicofármacos en las habilidades implicadas en la conducción se realizó una búsqueda en PubMed y PsycINFO con las palabras clave benzodiazepines, antidepressants, neuroleptics AND drive, driving y drivers. En el trabajo se revisaron todos los artículos publicados desde enero del 2006 hasta octubre de 2010.In order to condense the latest developments in research into the interaction of psychoactive drugs in the skills involved in driving, a search in PubMed and PsycINFO was made, using keywords benzodiazepines, antidepressants, neuroleptics AND drive, driving and drivers. In the paper all articles published from January 2006 until October 2010 were reviewed

Purification and Properties of Glutamine Synthetases from the Cyanobacteria Synechocystis sp. Strain PCC 6803 and Calothrix sp. Strain PCC 7601

Glutamine synthetases (GSs) from two cyanobacteria, one unicellular (Synechocystis sp. strain PCC 6803) and the other filamentous (Calothrix sp. strain PCC 7601 [Fremyella diplosiphon]), were purified to homogeneity. The biosynthetic activities of both enzymes were strongly inhibited by ADP, indicating that the energy charge of the cell might regulate the GS activity. Both cyanobacteria exhibited an ammonium-mediated repression of GS synthesis. In addition, the Synechocystis sp. showed an inactivation of GS promoted by ammonium that had not been demonstrated previously in cyanobacteria.Comisión Asesora de Investigación Científica y Técnica 45/85 85-047