Counting non-isomorphic maximal independent sets of the n-cycle graph

The number of maximal independent sets of the n-cycle graph C_n is known to be the nth term of the Perrin sequence. The action of the automorphism group of C_n on the family of these maximal independent sets partitions this family into disjoint orbits, which represent the non-isomorphic (i.e., defined up to a rotation and a reflection) maximal independent sets. We provide exact formulas for the total number of orbits and the number of orbits having a given number of isomorphic representatives. We also provide exact formulas for the total number of unlabeled (i.e., defined up to a rotation) maximal independent sets and the number of unlabeled maximal independent sets having a given number of isomorphic representatives. It turns out that these formulas involve both Perrin and Padovan sequences.Comment: Revised versio

La rigidité générique des graphes biparti-complets dans Rd

Dans un article déjà commenté dans Topologie structurale, E.D. Bolkeret B. Roth ((Bolker 1980), (Whiteley 1979)) amorçaient une classification générique des graphes biparti-complets dans R2 et dans R3. Leur raisonnement était basé sur le calcul de la dimension de l’espace des autocontraintes (stress) pour une réalisation d’un graphe biparti-complet dans un espace donné. La classification qu’ils établissaient se limitait à R2 et A R3. Le texte qui suit se veut une généralisation de leurs résultats à des espaces de dimension supérieure. Nous pourrons établir la classification générique des structures construites sur des graphes biparti-complets en regard de leur comportement rigide dans un espace ambiant fixé de dimension supérieure ou égale à 2.In an article reviewed earlier in Structural Topology, E.D. Bolker and B. Roth ((Bolker 1980), (Whiteley 1979)) put together a generic classification of complete bipartite graphs in R2 and R’. Their reasoning was based on calculating the dimension of the space of stresses for a realization of a complete bipartite graph in a given space. The classification which they established applies only to R2 and R3. The text which follows is a generalization of their results to spaces of higher dimension. We can establish the generic classification of structures built over complete bipartite graphs with regard to their rigid behavior in a fixed ambient space of dimension greater than or equal to 2.Peer Reviewe

An Efficient and Transparent Thread Migration Scheme in the PM2 Runtime System

International audienceThis paper describes a new iso-address approach to the dynamic allocation of data in a multithreaded runtime system with thread migration capability. The system guarantees that the migrated threads and their associated static data are relocated exactly at the same virtual address on the destination nodes, so that no post-migration processing is needed to keep pointers valid. In the experiments reported, a thread can be migrated in less than 75μs

Multivariate Analysis of Dietary Patterns in 939 Swiss Adults: Sociodemographic Parameters and Alcohol Consumption Profiles

A dietary survey of 939 Swiss adults, randomly selected from the population of Geneva and its surrounding communities, was performed according to the history method. A factor analysis, using average weekly intakes for 33 food variables, reveals three principal components of the diet: satiating capacity, healthfulness and culinary complexity. These characteristics, together with the energy content of the diet, were analysed for differences according to sex, age, relative weight index, birthplace, marital status and occupation. All of these sociodemographic variables influence some dimension of dietary habits. Alcohol consumption is positively associated with satiating, protein rich diets, but energy intake from foods does not significatively differ between various groups of abstainers and drinkers. Although the energy contribution of alcoholic beverages is globally additive, we suggest that cultural and societal norms may modulate the relationship of alcohol and die

Multiplexed holographic transmission gratings recorded in holographic polymer-dispersed liquid crystals: static and dynamic studies

The optimization of the experimental parameters of two multiplexed holographic transmission gratings recorded in holographic polymer-dispersed liquid crystals is investigated. Two methods are used to record the holograms: simultaneous and sequential multiplexing. These two processes are optimized to produce two multiplexed Bragg gratings that have the same and the highest possible diffraction efficiencies in the first order. The two methods show similar results when suitable recording parameters are used. The parameters of the recorded gratings (mainly the refractive-index modulation) are retrieved by use of an extension of the rigorous coupled-wave theory to multiplexed gratings. Finally, the response of the holograms to an electric field is studied. We demonstrate few coupling effects between the behavior of both gratings, and we expect a possibility of switching from one grating to the other

Endoscopic Papillary Balloon Dilation and Extraction of Bile Duct Stone

AbstractEndoscopic therapy is the first-line treatment for patients with common bile duct stones. Removing bile duct stones by endoscopic retrograde cholangiopancreaticography (ERCP) requires enlarging the papillary opening, either by cutting the biliary sphincter with an endoscopic sphincterotomy or by endoscopic papillary balloon dilation. Dilation has the advantage of sphincter preservation and a lower risk of hemorrhage, but carries an increased risk of post-ERCP pancreatitis. Although popular in Asia, in the Western world this technique is therefore reserved for patients with a major risk of bleeding or difficult anatomy. Here the technique of balloon dilation of the papillary sphincter is demonstrated in a patient with cholangiosepsis and septic coagulopathy. This article is part of an expert video encyclopedia

Évaluation de l’efficacité à long terme d’un programme de réinsertion sociale

Cette recherche évalue l'impact d'un programme de réinsertion sociale développé à l'unité 304 de l'hôpital Louis-H. Lafontaine pour préparer et suivre les patients psychiatriques de longue durée dans leur réinsertion dans la communauté. Trois ans après leur sortie de l'hôpital, les patients ayant participé au programme ont été comparés à des patients-contrôle appariés sortant d'autres unités. Les résultats indiquent que la participation au programme, couplée à un milieu résidentiel supervisé par du personnel professionnel, favorise une meilleure réinsertion des patients de longue durée.This study evaluates the impact of a rehabilitation program developed by a specific unit (304) of Louis H. Lafontaine Hospital to prepare severely disabled long-term psychiatric inpatients for discharge. Patients who participated in the program were evaluated three years after their discharge and compared to control patients paired to them by age, sex and years of hospitalization and discharged from other units of the hospital. The results suggest that the rehabilitation program, if coupled with an adequately staffed residential environment giving patients continuous care, offers a better outcome, at least in the case of the severely disabled long-term psychiatric inpatients

Effort fiscal comparé : le Québec et les autres provinces canadiennes

This study compares Quebec’s tax effort with that of the other Canadian provinces. The results show that the tax effort is higher in Quebec than in any other Canadian province. In the first section, the authors expose the global situation that currently prevails in Quebec. In the second section, an analysis of the tax effort for six tax bases is carried out. Those six bases are equally divided between individuals and corporations. The analysis makes it possible to identify the tax bases where the gaps are the largest. This in turn lets us identify achievable adjustments within Quebec’s current tax structure in order to attain a comparable structure with the other provinces, if such is the wish of the present government. L’étude compare l’effort fiscal du Québec à celui des autres provinces canadiennes. On y constate que l’effort fiscal est effectivement supérieur au Québec relativement aux autres provinces canadiennes. Dans la première partie de l’étude, les auteurs dressent le portrait de la situation fiscale qui prévaut au Québec. Dans la deuxième partie, une analyse de l’effort fiscal pour six assiettes fiscales est réalisée. Cette analyse s’effectue en deux temps, soit la situation des particuliers et celle des sociétés. Elle permet d’identifier les assiettes où les écarts sont les plus grands et d’envisager certains déplacements possibles au sein de la structure fiscale québécoise afin de la rendre davantage comparable à celles des autres provinces, si tel est le souhait du gouvernement.: personal taxes, corporate taxes, income tax, property tax, corporate income tax, tax on capital, payroll tax, consumption tax, tax effort, tax bases, comparison, Quebec, canadian provinces, impôts sur les particuliers, impôts sur les sociétés, impôt sur le revenu, impôt foncier, impôt sur les bénéfices, taxe sur le capital, taxe sur la masse salariale, taxe à la consommation, effort fiscal, assiettes fiscales, comparaison, Québec, provinces canadiennes