the complexes of mn(oac)3 and/or mn(acac)3 with nucleic bases and nucleosides (adenine, guanine, xanthine, adenosine and guanosine) have been synthesized in nonaqueous solution. polarographic and spectroscopic (ir and visible) methods have been used to establish the active site(s) on the imidazole and pyrimidine rings in the nucleic bases and nucleosides for the interaction with the mn(iii) com...

We study a natural generalization of the noncrossing relation between pairs of elements in [n] to k-tuples in [n]. We show that the flag simplicial complex on ( [n] k ) induced by this relation is a regular, unimodular and flag triangulation of the order polytope of the poset given by the product [k]× [n− k] of two chains, and it is the join of a simplex and a sphere (that is, it is a Gorenstei...

We prove the hyperbolicity of the complement of five lines in general position in an almost complex projective plane, answering a question by S. Ivashkovich.

Résumé. Cet article présente une méthode complexe pour la caractérisation et l’indexation d’images graphiques de documents anciens. A partir d’un bref état de l’art, une méthode pour décrire ces images en tenant compte de leur complexité est proposée. Trois étapes principales de ce traitement sont détaillées dont une méthode novatrice d’analyse, de segmentation et de description des traits. Les...