Substitution box (S-box) is an important component of block ciphers for providing confusion into the cryptosystems. The functions used as S-boxes should have low differential uniformity, high nonlinearity and high algebraic degree. Due to the lack of knowledge on the existence of APN permutations over F22k , which have the lowest differential uniformity, when k > 3, they are often constructed f...

We prove that every commutative differential graded algebra whose cohomology is a simply-connected Poincaré duality algebra is quasi-isomorphic to one whose underlying algebra is simply-connected and satisfies Poincaré du-ality in the same dimension. This has application in particular to the study of CDGA models of configuration spaces on a closed manifold.

Mathematical methods of analysis of microarray hybridizations deal with gene expression profiles as elementary units. However, some of these profiles do not reflect a biologically relevant transcriptional response, but rather stem from technical artifacts. Here, we describe two technically independent but rationally interconnected methods for identification of such artifactual profiles. Our dia...

AIM To study the value of serum holo-transcobalamin II (holo-TCII) measurements in the differential diagnosis of macrocytosis. METHODS Holo-TCII concentrations were measured in serum samples from 50 healthy non-vegetarian subjects and 30 patients with macrocytosis, using a technique based on the adsorption of holo-TCII with amorphous, precipitated silica. Deoxyuridine (dU) suppression tests w...

Let X be a (d × N)-matrix. We consider the variable polytope ΠX(u) = {w ≥ 0 : Xw = u}. It is known that the function TX that assigns to a parameter u ∈ R the volume of the polytope ΠX(u) is piecewise polynomial. Formulas of Khovanskii-Pukhlikov and Brion-Vergne imply that the number of lattice points in ΠX(u) can be obtained by applying a certain differential operator to the function TX . In th...

Block ciphers use Substitution boxes (S-boxes) to create confusion into the cryptosystems. Functions used as S-boxes should have low differential uniformity, high nonlinearity and algebraic degree larger than 3 (preferably strictly larger). They should be fastly computable; from this viewpoint, it is better when they are in even number of variables. In addition, the functions should be bijectio...

cet article s’intéresse aux titres littéraires et aux problèmes de leur traduction.  les stratégies de traduction sont plus nombreuses que ce que l’on croit; mais l’objectif de toute traduction est la restitution du sens. or à travers cette recherche, nous avons tenté de démontrer que la restitution du sens du titre original ne suffit absolument pas. en effet, le travail sur les mots d’un titre...

Background: Non-steroidal anti-inflammatory drug (NSAID) use and H pylori infection are two major causes of peptic ulcers. This study investigates the effect of H pylori infection and NSAIDs on gastroduodenal damages and bleeding (GIB). Methods: 104 patients with acute gastrointestinal bleeding (GIB) and 102 patients with dyspepsia without bleeding were studied. Duodenal (DU) and gastric ulcers...