Congruences De Sommes De Chiffres De Valeurs Polynomiales

Let m, g, q N with q 2 and (m, q – 1) = 1. For n N,denote by s_n(n) the sum of digits of n in the q-ary digitalexpansion. Given a polynomial f with integer coefficients, degreed 1, and such that f(N) N, it is shown that there exists C= C(f, m, q) > 0 such that for any g Z, and all large N, In the special case m = q = 2 and f(n)= n², the value C = 1/20 is admissible. 2000 Mathematics SubjectClassification 11B85 (primary), 11N37, 11N69 (secondary).     

Tetravinylallene

The first chemical synthesis of tetravinylallene (3,5‐divinylhepta‐1,3,4,6‐tetraene) is reported. The final, key step of the synthesis involves a palladium‐catalyzed, Negishi‐type cross‐coupling involving 1,5‐transposition of a penta‐2‐en‐4‐yn‐1‐ol methanesulfonate. The unprecedented fundamental hydrocarbon is sufficiently stable to be purified by flash chromatography. A similar synthetic pathway grants access to the first substituted tetravinylallenes, which provide insights into the influence of substitution upon stability and reactivity. Tetravinylallenes are shown to break new ground in swift structural complexity creation, with three novel sequences reported.     

Mesh adaptation for large‐eddy simulations in complex geometries

Large‐eddy simulation (LES) consists in explicitly simulating the large scales of the fluid motion and in modeling the influence of the smallest scales. Thanks to the steady growth of computational resources, LES can now be used to simulate realistic systems with complex geometries. However, when LES is used in such complex geometries, an adequate mesh has to be determined to perform valid LES. In this work, a strategy is proposed to assess the quality of a given mesh and to adapt it locally. Two different criteria are used as mesh adaptation criteria. The first criterion is defined to ensure a correct discretization of the mean field, whereas the second criterion is defined to ensure enough explicit resolution of turbulent scales motions. The use of both criteria is shown in canonical flow cases. As a second part of this work, a numerical strategy for mesh adaptation in high‐performance computing context is proposed by coupling the flow solver, YALES2, and the remeshing library, MMG3D, for massively parallel computations. This coupling enables an efficient and parallel remeshing of grids alleviating any memory or performance issues encountered in sequential tools. This strategy is finally applied to the simulation of the isothermal flow in a complex meso‐combustor to demonstrate the applicability of the adaptation methodology to complex turbulent flows. Copyright © 2015 John Wiley & Sons, Ltd.     

Experimental evaluation of different precision criteria applicable to microbiological counting methods

The dispersion of microbiological counting measurements, when repeating the analysis on the same material both within a laboratory (repeatability) and between laboratories (reproducibility) can be characterized by the organization of interlaboratory studies, where several sets of identical test materials are sent to several laboratories. Using the example of data generated by an interlaboratory study on enumeration of Listeria monocytogenes in foods by the standardized reference method (colony-count technique), 2 types of robust estimators of reproducibility standard deviations, based on the median, were examined, in comparison with the classical estimators, based on the mean. Experimental evaluation indicated that the 3 approaches gave consistent results for most of the combinations. The usual log10 transformation of the enumeration results was also questioned before these calculations were conducted.     

Isolation of cytotoxic chondropsins, macrolide lactams from the New-Caledonian marine sponge Psammoclemma sp. and electrospray ion trap multiple stage MS study of these macrolides

Psammoclemma sp. (Phoriospongiidae) was selected for study through biological screening carried out in New Caledonia. The crude extract of Psammoclemma sp. was highly active on KB cells and its fractionation led to the isolation of two macrolides chondropsin A 1 and 73-deoxychondropsin A 2. The complex structures were elucidated by a combination of spectroscopic methods (NMR, ESI-MS/MS). These known compounds were evaluated for their cytotoxic activity towards several tumor cell lines and exhibited an IC50 of approximately 10(-10) M. Flow-cytometric analysis revealed that chondropsin A 1 and 73-deoxychondropsin A 2 blocked the entry of HL 60 and KB cells into G2/M phase, leading to cell death by apoptosis.     

Quantum falling charges

Résumé Relativité restreinte et relativité générale se réfèrent essentiellement à la géométrie différentielle hyperbolique. Or c'est la notion d'espace fibre différentiable qui domine depuis 1940 toute la géométrie différentielle. C'est pourquoi mathématiciens et physiciens ont pris conscience, depuis longtemps déjà, du fait que les espaces fibrés constituent un cadre de pensée fondamental pour la relativité, comme ils le font d'ailleurs aussi pour la mécanique analytique classique. Les identifications, parfois abusives, à laquelle se prête la relativité restreinte ne doivent pas masquer cette réalité.En introduction au séminaire, le but de cette conférence est seulement de rappeler les éléments principaux de ce cadre, sans viser à l'originalité sauf sur quelques points.Read on 15 May 1970 at the Gwatt Seminar on the Bearings of Topology upon General Relativity     

Facile reduction of malonate derivatives using NaBH4/Br2: an efficient route to 1,3-diols

Borane-dimethoxyethane generated from sodium borohydride-bromine mixtures efficiently reduces a wide range of malonate derivatives to the corresponding 1,3-diols. This new reagent system represents a milder alternative to current methods available, providing the requisite 1,3-diols in higher yields over shorter reaction times.