Extended core and choosability of a graph

A graph $G$ is $(a,b)$-choosable if for any color list of size $a$ associated with each vertices, one can choose a subset of $b$ colors such that adjacent vertices are colored with disjoint color sets. This paper shows an equivalence between the $(a,b)$-choosability of a graph and the $(a,b)$-choosability of one of its subgraphs called the extended core. As an application, this result allows to prove the $(5,2)$-choosability and $(7,3)$-colorability of triangle-free induced subgraphs of the triangular lattice.Comment: 10 page

Vectorial solutions to list multicoloring problems on graphs

For a graph $G$ with a given list assignment $L$ on the vertices, we give an algebraical description of the set of all weights $w$ such that $G$ is $(L,w)$-colorable, called permissible weights. Moreover, for a graph $G$ with a given list $L$ and a given permissible weight $w$, we describe the set of all $(L,w)$-colorings of $G$. By the way, we solve the {\sl channel assignment problem}. Furthermore, we describe the set of solutions to the {\sl on call problem}: when $w$ is not a permissible weight, we find all the nearest permissible weights $w'$. Finally, we give a solution to the non-recoloring problem keeping a given subcoloring.Comment: 10 page

Choosability of a weighted path and free-choosability of a cycle

A graph $G$ with a list of colors $L(v)$ and weight $w(v)$ for each vertex $v$ is $(L,w)$-colorable if one can choose a subset of $w(v)$ colors from $L(v)$ for each vertex $v$, such that adjacent vertices receive disjoint color sets. In this paper, we give necessary and sufficient conditions for a weighted path to be $(L,w)$-colorable for some list assignments $L$. Furthermore, we solve the problem of the free-choosability of a cycle.Comment: 9 page

Degradation of organic compounds and production of activated species in Dielectric Barrier Discharges and Glidarc reactors

Major sterilization mechanisms are related to atoms and radicals, charged parti-cles, excited molecules, ozone, and UV radiation. The ROS (Reactive Oxygen Species) are well known as evildoers. These species are easily created in ambient air and water and they live long enough to reach the cell and attack the organic matter. Test molecules conversion in dry and wet air is studied using Dielectric Barrier Discharge (DBD) and Gliding Arc Reactors (GAR). The effects of tem-perature and energy deposition into the media on the active species production and then on the organic compounds degradation are presented for two non thermal plasma reactors: DBD and GAR. Main production species investigated are OH, O3, NOx, CO and CxHyOz by-products. It is shown from experiment analysis that the reactive species production is quite different from one reactor to another. GAR and pulsed DBD are two chemical processing ways in which the temperature of heavy species in ionized gas is determinant. By reviewing the species production obtained from both reactors, a discussion is open about plasma decontamination.Comment: NATO-AdvancedStudy Institute on Plasma Assisted Decontamination of biological and Chemical Agents, Cesme-Izmir : Turquie (2007

Correction of megavoltage cone-beam CT images of the pelvic region based on phantom measurements for dose calculation purposes.

Megavoltage cone-beam CT (MVCBCT) is an imaging technology that provides a 3D representation of the patient in treatment position. Because it is a form of x-ray tomography, MVCBCT images give information about the attenuation coefficients of the imaged tissues, and thus could be used for dose calculation. However, the cupping and missing data artifacts seen on MVCBCT images can cause inaccuracies in dose calculations. To eliminate these inaccuracies, a correction method specific to pelvis imaging and based on phantom measurements has been devised. Pelvis-shaped water phantoms of three different sizes were designed and imaged with MVCBCT. Three sets of correction factors were created from the artifacts observed in these MVCBCT images by dividing the measured CT number by the predefined CT number for water. Linear interpolation is performed between the sets of correction factors to take into account the varying size of different patients. To compensate for the missing anatomy due to the limited field of view of the MVCBCT system, the MVCBCT image is complemented with the kilovoltage CT (kVCT) image acquired for treatment planning.When the correction method is applied to an anthropomorphic pelvis phantom, the standard deviation between dose calculations performed with kVCT and MVCBCT images is 0.6%, with 98% of the dose points agreeing within +/- 3%.With uncorrected MVCBCT images this percentage falls to 75%. An example of dose calculation performed with a corrected clinicalMVCBCT image of a prostate cancer patient shows that changes in anatomy of normal tissues result in variation of the dose distribution received by these tissues.This correction method enablesMVCBCT images to be used for the verification of the daily dose distribution for patients treated in the pelvis region

Every triangle-free induced subgraph of the triangular lattice is (5m,2m)(5m,2m)-choosable

International audienceA graph $G$ is $(a,b)$-choosable if for any color list of size $a$ associated with each vertex, one can choose a subset of $b$ colors such that adjacent vertices are colored with disjoint color sets. This paper proves that for any integer $m\ge 1$, every finite triangle-free induced subgraph of the triangular lattice is $(5m,2m)$-choosable

Lutte attracticide et lâchers inondatifs de trichogrammes contre le carpocapse de la pomme, cydia pomonella (lepidoptera : tortricidae)

Le carpocapse de la pomme est un ravageur majeur en vergers de pommiers à l'échelle du globe. La lutte chimique est généralement utilisée pour réprimer cet insecte à l'origine de dommages à l'intérieur des pommes. Il existe d'autres moyens de lutte contre le carpocapse à risques réduits pour l'Homme et l'environnement, dont la lutte attracticide et la lutte biologique à l'aide de parasitoïdes. La lutte attracticide est une combinaison d'un leurre sémiochimique attractif qui attire les mâles et d'un produit insecticide qui les tue. La population est ainsi réduite par l'absence d'accouplements. La lutte biologique par lâchers inondatifs consistent en l'introduction de milliers de parasitoïdes dans le but d'augmenter le taux de parasitisme d'un ravageur ciblé afin de prévenir les dommages économiques. L'objectif du premier chapitre est d'évaluer si la lutte attracticide est un outil efficace pour lutter contre le carpocapse de la pomme dans les vergers de pommiers du Québec et si ce type de lutte est compatible avec la lutte biologique lors de l'utilisation de parasitoïdes trichogrammes. Lors de nos expérimentations, la lutte attracticide contre le carpocapse de la pomme a été peu efficace, alors que couplée à la lutte biologique à l'aide de lâchers de trichogrammes, elle semble être une meilleure méthode pour contrôler ce ravageur. L'utilisation d'un parasitoïde généraliste nécessite de bien comprendre son comportement dans le système étudié. Le parasitoïde oophage Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae) est généraliste et s'attaque généralement aux lépidoptères ravageurs. Le carpocapse de la pomme, Cydia pomonella L. (Lepidoptera: Tortricidae) et la tordeuse à bandes obliques (TBO) Choristoneura rosaceana Harris (Lepidoptera: Tortricidae) sont deux hôtes de T. minutum dont les sites de ponte et les stratégies d'oviposition sont très différents. L'objectif du deuxième chapitre était d'étudier les facteurs déterminant le parasitisme de T. minutum face à deux hôtes qui exploitent des sites de pontes différents et qui possèdent une stratégie de ponte très différente. Nos résultats ont montré qu'une femelle T. minutum va se déplacer dans un pommier indépendamment du site de ponte du carpocapse ou de la TBO. Elle va ensuite pondre dans tous les hôtes acceptables qu'elle va rencontrer. Mais, il sera plus profitable pour elle de pondre dans des oeufs de carpocapse plutôt que dans des oeufs de TBO. Pendant les lâchers inondatifs, les parasitoïdes T. minutum ont été relâchés sous forme de pupes à l'intérieur d'hôtes jusqu'à émergence. L'objectif du troisième chapitre était d'évaluer la susceptibilité à la prédation d'oeufs parasités par T. minutum utilisés lors des lâchers inondatifs dans un verger de pommiers. La perte d'oeufs parasités sur les trichocartes utilisées lors d'un lâcher inondatif est relativement importante (prédation, facteurs abiotiques, mortalité). Il serait intéressant d'améliorer les techniques de lâchers inondatifs afin de minimiser ces pertes. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Cydia pomonella, Attracticide, Parasitoïdes, Trichogramma minutum, Choristoneura rosaceana, Vergers de pommiers

Combination of non-thermal plasma and hetergeneous catalysis for paracetamol degradation in water

International audienceMany researches for the abatement of aqueous pharmaceutical pollutants in water by Advanced Oxidation Processes (AOPs), including electrical discharge plasmas, have been performed in the last decade. In the present study, non-thermal plasma coupled to catalyst was used for the degradation of paracetamol in water. The plasma was produced in a reactor consisting in a multiple needle-to-plate DBD discharge configuration, while catalyst is a metal oxide based catalyst. In order to investigate the influence of the oxide nature, various home-made catalysts (iron or manganese-based), prepared by wet impregnating method, were tested. Comparisons of the results with or without catalyst on the paracetamol degradation and the physico-chemistry of the treated liquids were done, and they showed that the iron-based catalyst presented better results in terms of conversion and mineralization. Concretely, coupling this catalyst to non-thermal plasma, after 30 min of treatment, the paracetamol conversion is 78 % with 45 % mineralization, against 51% and 3% respectively with plasma alone. The paracetamol degradation as a function of the treatment duration was investigated with this catalyst

What was your fracture risk evaluated by FRAX® the day before your osteoporotic fracture?

Osteoporotic fracture (OF) is one of the major causes of morbidity and mortality in industrialized countries. Switzerland is among the countries with the greatest risk. Our aim was (1) to calculate the FRAX® in a selected Swiss population the day before the occurrence of an OF and (2) to compare the results with the proposed Swiss FRAX® thresholds. The Swiss Association Against Osteoporosis proposed guidelines for the treatment of osteoporosis based on age-dependent thresholds. To identify a population at a very high risk of osteoporotic fracture, we included all consecutive patients in the active OF pathway cohort from the Lausanne University Hospital, Switzerland. FRAX® was calculated with the available data the day before the actual OF. People with a FRAX® body mass index (BMI) or a FRAX® (bone mineral density) BMD lower than the Swiss thresholds were not considered at high risk. Two-hundred thirty-seven patients were included with a mean age of 77.2years, and 80% were female. Major types of fracture included hip (58%) and proximal humerus (25%) fractures. Mean FRAX® BMI values were 28.0, 10.0, 13.0, 26.0, and 37.0% for age groups 50-59, 60-69, 70-79, and 80-89years old, respectively. Fifty percent of the population was not considered at high risk by the FRAX® BMI. FRAX® BMD was available for 95 patients, and 45% had a T score < −2.5 standard deviation. Only 30% of patients with a normal or osteopenic BMD were classified at high risk by FRAX® BMD. The current proposed Swiss thresholds were not able to classify at high risk in 50 to 70% of the studied population the day before a major O