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Bio-medical Ontologies Maintenance and Change Management

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Classifying Patterns in <strong>Bio</strong>informatics<br />

Databases by Using Alpha-Beta Associative<br />

Memories<br />

Israel Román Godínez, Itzamá López-Yáñez, <strong>and</strong> Cornelio Yáñez-Márquez<br />

Center for Computer Research, National Polytechnic Institute<br />

iromanb05@sagitario.cic.ipn.mx<br />

Summary. One of the most important genomic tasks is the identification of promoters<br />

<strong>and</strong> splice-junction zone, which are essential on deciding whether there is a<br />

gene or not in a genome sequence. This problem could be seen as a classification<br />

problem, therefore the use of computational algorithms for both, pattern recognition<br />

<strong>and</strong> classification are a natural option to face it. In this chapter we develop<br />

a pattern classifier algorithm that works notably with bioinformatics databases.<br />

The associative memories model on which the classifier is based is the Alpha-Beta<br />

model. In order to achieve a good classification performance it was necessary to<br />

develop a new heteroassociative memories algorithm that let us recall the complete<br />

fundamental set. The heteroassociative memories property of recalling all the<br />

fundamental patterns is not so common; actually, no previous model of heteroassociative<br />

memory can guarantee this property. Thus, creating such a model is an<br />

important contribution. In addition, an heteroasociative Alpha-Beta multimemory<br />

is created, as a fundamental base for the proposed classifier.<br />

1 Introduction<br />

In the later decades, very important scientific advances in the field of molecular<br />

biology have been achieved. Thanks to the enormous amounts of information<br />

derived from these advances, there has arisen a need to process such<br />

information in a faster way <strong>and</strong> just as effectively, or more, than by an expert.<br />

This gives birth to a new branch of science, known as <strong>Bio</strong>informatics:<br />

a multidisciplinary field which combines, among others, two important fields<br />

of science, molecular biology <strong>and</strong> computer sciences [1].<br />

Among the first <strong>and</strong> foremost problems boarded by <strong>Bio</strong>informatics are:<br />

the development of databases, protein sequence alignment, DNA string<br />

sequencing, protein structure prediction, protein structure classification, promoter<br />

identification, splice-junction zone localization, <strong>and</strong> phylogenetic relationships<br />

determining [2], [3].<br />

The solutions to some of these problems are based on the search <strong>and</strong><br />

localization of patterns in certain sequences, in order to classify them. As<br />

an example, we can mention promoter identification <strong>and</strong> splice-junction zone<br />

A.S. Sidhu et al. (Eds.): <strong>Bio</strong><strong>medical</strong> Data <strong>and</strong> Applications, SCI 224, pp. 187–210.<br />

springerlink.com c○ Springer-Verlag Berlin Heidelberg 2009

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