Most existing XML stream processing systems adopt full structured query languages, such as XPath or XQuery, but they are difficult for ordinary users to learn and use. Keyword search is a user-friendly information discovery technique that has been extensively studied for text documents. This paper presents an XML stream filter system called XKFilter, which is the first system for supporting key...

We investigate through numerical simulations the effect of selection on two summary statistics for nucleotide variation in a sample of two genes from a population of N asexually reproducing haploid individuals. One is the mean time since two individuals had their most recent common ancestor (Ts), and the other is the mean number of nucleotide differences between two genes in the sample (ds). In...

We consider a large population of asexually reproducing individuals in absence of selective pressure. The population size is maintained constant by the environment. We find out that distances between individuals (time from the last common ancestor) exhibit highly non trivial properties. In particular their distribution in a single population is random even in the thermodynamical limit. As a res...

We derive a Poisson random field model for population site polymorphisms differences within and between two species that share a relatively recent common ancestor. The model can be either equilibrium or time inhomogeneous. We first consider a random field of Markov chains that describes the fate of a set of individual mutations. This field is approximated by a Poisson random field from which we...

Several indices that measure the degree of balance of a rooted phylogenetic tree have been proposed so far in the literature. In this work we define and study a new index of this kind, which we call the total cophenetic index: the sum, over all pairs of different leaves, of the depth of their lowest common ancestor. This index makes sense for arbitrary trees, can be computed in linear time and ...

Various approaches to alignment-free sequence comparison are based on the length of exact or inexact word matches between two input sequences. Haubold et al. (2009) showed how the average number of substitutions between two DNA sequences can be estimated based on the average length of exact common substrings. In this paper, we study the length distribution of k-mismatch common substrings betwee...

We present a new model for seed banks, where direct ancestors of individuals may have lived in the near as well as the very far past. The classical Wright-Fisher model, as well as a seed bank model with bounded age distribution considered by Kaj, Krone and Lascoux (2001) are special cases of our model. We discern three parameter regimes of the seed bank age distribution, which lead to substanti...

We propose a recursive multi-resolution collaborative architecture (MRCA), based on multi-agent coordination mechanisms as a solid foundation for the development of web-centric cooperative applications in global manufacturing. The architecture consists of three layers: a low-level internetworking communication-support layer; a coordination layer ± managing inter-agent cooperation through intell...