Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Assessing the Exceptionality of Coloured Motifs in Networks | Hindawi Publishing Corporation EURASIP Journal on Bioinformatics and Systems Biology Volume 2009 Article ID 616234 9 pages doi 2009 616234 Research Article Assessing the Exceptionality of Coloured Motifs in Networks Sophie Schbath 1 Vincent Lacroix 2 and Marie-France Sagot3 4 5 1Institut National de la Recherche Agronomique INRA UR1077 Unite Mathematique Informatique et Genome 78352 Jouy-en-Josas France 2 Centre for Genomic Regulation CRG Genome Bioinformatics Group Universitat Pompeu Fabra Dr. Aiguader 88 08003 Barcelona Spain 3 Universite de Lyon 69000 Lyon France 4Laboratoire de Biometrie et Biologie Evolutive Universite Claude Bernard Lyon 1 CNRS UMR 5558 69622 Villeurbanne France 5Projet BAMBOO Institut National de Recherche Informatique eten Automatique INRIA Rhône-Alpes 655 avenue de l Europe 38330 Montbonnot Saint-Martin France Correspondence should be addressed to Sophie Schbath Received 1 June 2008 Revised 29 August 2008 Accepted 11 October 2008 Recommended by Dirk Repsilber Various methods have been recently employed to characterise the structure of biological networks. In particular the concept of network motif and the related one of coloured motif have proven useful to model the notion of a functional evolutionary building block. However algorithms that enumerate all the motifs of a network may produce a very large output and methods to decide which motifs should be selected for downstream analysis are needed. A widely used method is to assess if the motif is exceptional that is over- or under-represented with respect to a null hypothesis. Much effort has been put in the last thirty years to derive P-values for the frequencies of topological motifs that is fixed subgraphs. They rely either on compound Poisson and Gaussian approximations for the motif count distribution in Erdos-Renyi random graphs or on simulations in other models. We focus on a different definition of graph motifs that corresponds to coloured .
