Poisson approximation for search of rare words in DNA sequences
| dc.creator | Vergne, Nicolas | |
| dc.creator | Abadi, Miguel | |
| dc.date | 2007-11-15 | |
| dc.date.accessioned | 2026-07-07T08:43:05Z | |
| dc.date.available | 2026-07-07T08:43:05Z | |
| dc.description | Using recent results on the occurrence times of a string of symbols in a stochastic process with mixing properties, we present a new method for the search of rare words in biological sequences generally modelled by a Markov chain. We obtain a bound on the error between the distribution of the number of occurrences of a word in a sequence (under a Markov model) and its Poisson approximation. A global bound is already given by a Chen-Stein method. Our approach, the psi-mixing method, gives local bounds. Since we only need the error in the tails of distribution, the global uniform bound of Chen-Stein is too large and it is a better way to consider local bounds. We search for two thresholds on the number of occurrences from which we can regard the studied word as an over-represented or an under-represented one. A biological role is suggested for these over- or under-represented words. Our method gives such thresholds for a panel of words much broader than the Chen-Stein method. Comparing the methods, we observe a better accuracy for the psi-mixing method for the bound of the tails of distribution. We also present the software PANOW (available at http://stat.genopole.cnrs.fr/software/panowdir/) dedicated to the computation of the error term and the thresholds for a studied word. | |
| dc.description | 29 pages, 0 figures | |
| dc.identifier | https://arxiv.org/abs/0711.2382 | |
| dc.identifier | http://arxiv.org/abs/0711.2382 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/142193 | |
| dc.subject | Probability | |
| dc.subject | Statistics Theory | |
| dc.subject | Applications | |
| dc.subject | 60F05, 60G10, 92D20 (Primary); 60-04 (Secondary) | |
| dc.title | Poisson approximation for search of rare words in DNA sequences | |
| dc.type | text |