Functional macroscopic behavior of weighted random ball model

We consider a generalization of the weighted random ball model. The model is driven by a random Poisson measure with a product heavy tailed intensity measure. Such a model typically represents the transmission of a network of stations with a fading effect. In a previous article, the authors proved the convergence of the finite-dimensional distributions of related generalized random fields under various scalings and in the particular case when the fading function is the indicator function of the unit ball. In this paper, tightness and functional convergence are investigated. Using suitable moment estimates, we prove functional convergences for some parametric classes of configurations under the so-called large ball scaling and intermediate ball scaling. Convergence in the space of distributions is also discussed

The merging cluster of galaxies Abell 3376: an optical view

Abell 3376 is a merging cluster of galaxies at redshift z=0.046, famous mostly for its giant radio arcs, and shows an elongated and highly substructured X-ray emission, but has not been analysed in detail at optical wavelengths. We have obtained wide field images of Abell 3376 in the B band and derive the GLF applying a statistical subtraction of the background in three regions: a circle of 0.29 deg radius (1.5 Mpc) encompassing the whole cluster, and two circles centered on each of the two brightest galaxies (BCG2, northeast, coinciding with the peak of X-ray emission, and BCG1, southwest) of radii 0.15 deg (0.775 Mpc). We also compute the GLF in the zone around BCG1, which is covered by the WINGS survey in the B and V bands, by selecting cluster members in the red sequence in a (B-V) versus V diagram. Finally, we discuss the dynamical characteristics of the cluster implied by a Serna & Gerbal analysis. The GLFs are not well fit by a single Schechter function, but satisfactory fits are obtained by summing a Gaussian and a Schechter function. The GLF computed by selecting galaxies in the red sequence in the region surrounding BCG1 can also be fit by a Gaussian plus a Schechter function. An excess of galaxies in the brightest bins is detected in the BCG1 and BCG2 regions. The dynamical analysis based on the Serna & Gerbal method shows the existence of a main structure of 82 galaxies which can be subdivided into two main substructures of 25 and 6 galaxies. A smaller structure of 6 galaxies is also detected. The B band GLFs of Abell 3376 are clearly perturbed, as already found in other merging clusters. The dynamical properties are consistent with the existence of several substructures, in agreement with a previously published X-ray analysis.Comment: 11 pages, 12 figures, accepted for publication in A&

A Wave to Wire model of the SEAREV Wave Energy Converter

International audienceThis paper describes a numerical wave-to-wire model of the second-generation wave energy converter called SEAREV. Governing equations are given in the time domain for the motion of the masses involved in the device and for the hydraulic power take-off (PTO) used to convert the motion into electricity. The hydrodynamic forces are derived using the standard linear potential theory. The memory term in the radiation force is replaced by additional states using the Prony method in order to change the equation of motion into the ordinary differential equation form. The PTO is composed of hydraulic rams, an accumulator, and a hydraulic generator, which delivers electricity when there is enough energy stored in the accumulator.Using the MATLAB Simulink tool, the equation of motion is solved to simulate the full device (including the power take-off) from the incident wave to the electricity delivered to the grid. Simulation results are presented in the paper and comparisons are made with a simpler PTO: a linear damper. They show that the torque applied to the hydraulic PTO must exceed a threshold to start absorbing energy, unlike the linear damping model. They also show that the power production can be very discontinuous, depending on the level of the incident wave power. This is due to the fact that the generator considered can transform the energy stored in the accumulator faster than the energy transmitted by the rams into the accumulator. It could therefore be interesting to use several generators to adapt the electrical energy production to the level of incident wave power, or a generator that could work efficiently at part load in order to achieve continuous energy production

ÉTALEMENT URBAIN, DYNAMIQUES AGRICOLES ET POLITIQUES PERIURBAINES UNE ANALYSE SPATIALE DU LANGUEDOC-ROUSSILLON ET DU PORTUGAL

N° ISBN - 978-2-7380-1284-5International audienceFor almost 40 years cities' peripheries and the coastal areas of Languedoc-Roussillon in France and of Portugal have been known important urban dynamics that affect natural spaces, and most particularly the agricultural areas. These dynamics are due to periurbanization, i.e. the increase of urban sprawl and of spatial fragmentation, thus contributing to important decline of the agriculture land. These dynamics are nowadays considered in spatial policies and planning at different scales by developing, among others, the role of agriculture as a way to deal with urban sprawl. This paper is developed in three steps: a) the spatial analysis of the urban dynamics, specially the mutations of the agriculture lands of Languedoc-Roussillon and of Portugal; b) the analysis of spatial policies and planning at different scales, and of how they are dealing with urban dynamics; c) the analysis of two different local projects – one in Languedoc-Roussillon (Lunel) and the other one in Portugal (Guimarães) – that are trying to enhance the periurban agriculture as a way to combat urban sprawl, thus promoting a more urban and periurban sustainable development

QAnswer: Towards Question Answering Search over Websites

Question Answering (QA) is increasingly used by search engines to provide results to their end-users, yet very few websites currently use QA technologies for their search functionality. To illustrate the potential of QA technologies for the website search practitioner, we demonstrate web searches that combine QA over knowledge graphs and QA over free text -- each being usually tackled separately. We also discuss the different benefits and drawbacks of both approaches for web site searches. We use the case studies made of websites hosted by the Wikimedia Foundation (namely Wikipedia and Wikidata). Differently from a search engine (e.g. Google, Bing, etc), the data are indexed integrally, i.e. we do not index only a subset, and they are indexed exclusively, i.e. we index only data available on the corresponding website

Optical properties of single diatom frustules revealed by confocal microspectroscopy

Optical properties of single diatom frustule valves from two different Coscinodiscus species (C. wailesii and C. centralis) are studied by transmission confocal hyperspectral imaging and numerical calculations. Light convergence, concentration, and trapping effects are observed and depend on both the wavelength and the valve orientation. These effects seem to occur independently of the incident light angle. From our results, a wavelength-dependent multifocal lens behavior can be explained by light diffraction related to the radial symmetry of the multiscaled 3D nanostructure.acceptedVersionThis is the authors' accepted and refereed manuscript to the article. Non-commercial

Utilisation de grilles de calcul pour la génomique comparative

International audienceLarge scale phylogenomics and comparative genomics require complex computational methods (parsimony, maximum likelihood, bayesian methods, MCMC, etc.) associated with massively distributed calculation. In this respect, grid computing plays a crucial role. Here we present how we processed exhaustive similarity searches on several millions of sequences with BLAST, using two different grids (TIDRA and GRISBI)

Etude de la synthèse du resvératrol et de ses dérivés (viniférines) par des suspensions de cellules de vigne et optimisation de la production en bioréacteur

Le travail effectué au cours de cette thèse a permis une avancée importante dans la connaissance de l élicitation des cellules de vigne. Nous avons étudié les effets de deux éliciteurs, le méthyljasmonate et la méthyl-b-cyclodextrine, employés seuls et en élicitation croisée sur des suspensions de cellules de vigne (porte-greffe 41B et Vitis labrusca), pour la production de stilbènes (resvératrol et viniférines). Ceci a permis d atteindre des concentrations de resvératrol très élevées pour un métabolite secondaire et les relations entre la concentration d éliciteur, la biomasse à l inoculum et la durée de l élicitation ont été étudiées. D autre part, le travail a également porté sur le changement d échelle quant à la culture cellulaire et son élicitation et sur le suivi de plusieurs phénomènes et paramètres (croissance cellulaire, consommation des sucres, production du resvératrol, suivi du taux d oxygène dissous et du pH). Des essais en bioréacteur clos de 5L ont ainsi abouti à une production significative de resvératrol à cette échelle et ont permis l élaboration de modèles cinétiques rendant compte de la croissance de la biomasse et de la production du resvératrol. Un autre aspect de l étude s est intéressé à la localisation intracellulaire de la synthèse du resvératrol. Les résultats obtenus par microscopie confocale ont confirmé que le resvératrol s accumulait majoritairement dans la paroi de la cellule et dans des vésicules cytoplasmiques (organites sphériques présents à proximité de la paroi), avant d être excrété dans le milieu de culture. Enfin, une démarche a été initiée en vue de la production d autres métabolites à partir du resvératrol notamment l -viniférine.The work presented here addressed two main subjects, namely that of grapevine cells elicitation for the production of stilbenes (resveratrol and viniferins) and the scale up of such culture in bioreactors. Shake-flask cultures of grapevine (rootstock 41B and Vitis labrusca) were elicited with methyl jasmonate or methyl-b-cyclodextrin, alone or in combination. This resulted in a significant accumulation of resveratrol in the medium. The relationship between the production of resveratrol and factors such as the elicitor concentration, inoculation rate and the duration of elicitation phase were studied. The second part of this work was concerned with scale up of the culture from shake-flask to 5 L bioreactor. Several parameters were monitored such as cell growth, sugars consumption, resveratrol production, dissolved oxygen concentration and pH. Kinetic models explaining growth and resveratrol production were developed using the results from three bioreactor batches. Preliminary work was performed to initiate the study of metabolites related to resveratrol such as -viniferin. The study also completed previous work that looked at the localisation of resveratrol synthesis within the cells using confocal microscopy. The results confirmed that resveratrol was accumulated mainly in the cell wall and in the cytoplasmic vesicles before being excreted/secreted into the culture medium.CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

Model of collective fish behavior with hydrodynamic interactions

Fish schooling is often modeled with self-propelled particles subject to phenomenological behavioral rules. Although fish are known to sense and exploit flow features, these models usually neglect hydrodynamics. Here, we propose a novel model that couples behavioral rules with far-field hydrodynamic interactions. We show that (1) a new "collective turning" phase emerges, (2) on average, individuals swim faster thanks to the fluid, and (3) the flow enhances behavioral noise. The results of this model suggest that hydrodynamic effects should be considered to fully understand the collective dynamics of fish