Reconstructing the transmission history of infectious diseases in the absence of medical or epidemiological records often relies on the evolutionary analysis of pathogen genetic sequences. The precision of evolutionary estimates of epidemic history can be increased by the inclusion of sequences derived from 'archived' samples that are genetically distinct from contemporary strains. Historical s...

Based on constant term evaluation, we present a new method to compute a closed form of the summation ∑n−1 k=0 ∏r j=1 Fj(ajn+bjk+cj), where {Fj(k)} are C-finite sequences and aj and aj+bj are nonnegative integers. Our algorithm is much faster than that of Greene and Wilf. Résumé. En s’appuyant sur l’évaluation de termes constants, nous présentons une nouvelle méthode pour calculer une forme clos...

Suppose c ≥ 2 and d ≥ 2 are integers, and let S be the set of integers ⌊ c/d ⌋ , where j and k range over the nonnegative integers. Assume that c and d are multiplicatively independent; that is, if p and q are integers for which c = d, then p = q = 0. The numbers in S form interspersions in various ways. Related fractal sequences and permutations of the set of nonnegative integers are also disc...

This article presents a methodology to extract principal components of large set of data, considering the existence of possible nonlinear relations among them, called C-NLPCA (Cascaded nonlinear principal component analysis), and evaluates its use in the extraction of main human movements in image series, aiming for the development of methodologies and techniques for skill transfer from humans ...

We present accurate UBV(RI)C photometric sequences around 20 symbiotic stars. The sequences extend over wide brightness and color ranges, and are suited to cover quiescence as well as outburst phases. The sequences are intended to assist both present time photometry as well as measurement of photographic plates from historical archives.