108 research outputs found
Unit-cell for dual-circular polarisation reflectarrays
International audienceâA new unit-cell composed of two layers for dual-CP reflectarrays is proposed for the first time with the unique capability to reflect independently and simultaneously the two incident circular polarisations at the same frequency. The experimental results demonstrate that this unit-cell exhibits a 3.8% bandwidth around 8.4 GHz for a phase resolution better than 1.92 bits in LHCP and in RHCP. As a first step towards a reflectarray in dual-CP, this innovative unit-cell is studied in an array configuration. To increase the value of the maximum incidence angle up to 30°, a matching dielectric layer is placed over the cell
« Art Follows Empire » : un Ă©tat des lieux des connaissances sur lâhistoire de lâart amĂ©ricain Ă ses dĂ©buts
Introduction | Wendy Bellion Les essais suivants prĂ©sentĂ©s dans cette Ă©tude collaborative sur lâart amĂ©ricain Ă ses dĂ©buts sont tirĂ©s dâune sĂ©ance de travail qui a eu lieu lors de la confĂ©rence « London and the Americas, 1492-1812 ». Celle-ci avait Ă©tĂ© organisĂ©e par la Society of Early Americanists (SEA) Ă Kingston University, au Royaume-Uni, en juillet 2014. Pour cette table ronde intitulĂ©e « Art Follows Empire », jâavais invitĂ© tous les participants Ă prĂ©senter un objet de leur choix. Avec ..
Application de la borne de Cramer-Rao dans le cas de systÚmes antennaires complexes de goniométrie
GĂ©nĂ©ralement, la borne de Cramer-Rao des directions d'arrivĂ©e de signaux sur un rĂ©seau de capteurs est calculĂ©e de façon thĂ©orique [1] [2] [3]. Or dĂšs que l'on dĂ©sire effectuer une application numĂ©rique de la borne de Cramer-Rao pour un systĂšme donnĂ©, on est souvent amenĂ© Ă effectuer des suppositions et/ou des simplifications. En effet, il est souvent trĂšs difficile de tenir compte et de modĂ©liser l'environnement et les diffĂ©rents phĂ©nomĂšnes pouvant perturber le rĂ©seau de capteurs, comme le couplage entre antennes, l'influence d'un porteur (mat ou vĂ©hicule) en termes de diffraction, de rĂ©flexion ou mĂȘme la prĂ©sence d'un sol. Dans ce travail, nous utilisons un logiciel de simulation Ă©lectromagnĂ©tique pour estimer l'impact de l'environnement rĂ©el sur le vecteur direction d'un systĂšme antennaire complexe de goniomĂ©trie. La borne de Cramer-Rao dĂ©terministe des directions d'arrivĂ©e de signaux est ensuite dĂ©terminĂ©e pour le rĂ©seau de capteurs de goniomĂ©trie soumis Ă des perturbations. Les rĂ©sultats montrent que la prĂ©cision dĂ©pend fortement de la prise en compte des couplages et perturbations du systĂšme antennaire. On montre ainsi que l'environnement a un impact non nĂ©gligeable et que l'on peut calculer une borne de Cramer Rao des directions d'arrivĂ©e plus rĂ©aliste et ainsi optimiser dans certains cas le systĂšme antennaire de goniomĂ©trie en fonction de son environnement
Art Follows Empire: new scholarship in Early American art history
Wendy Bellion â Introduction The following essays presented in this collaborative study of early American art developed from a session at the conference, âLondon and the Americas, 1492-1812,â organized by the Society of Early Americanists (SEA) at Kingston University, United Kingdom, in July 2014. For a roundtable entitled âArt Follows Empire,â I invited participants to discuss an object of their choice. The caveat: speakers had to identify a single object that epitomized or problematized the..
Computer Simulation of Cellular Patterning Within the Drosophila Pupal Eye
We present a computer simulation and associated experimental validation of assembly of glial-like support cells into the interweaving hexagonal lattice that spans the Drosophila pupal eye. This process of cell movements organizes the ommatidial array into a functional pattern. Unlike earlier simulations that focused on the arrangements of cells within individual ommatidia, here we examine the local movements that lead to large-scale organization of the emerging eye field. Simulations based on our experimental observations of cell adhesion, cell death, and cell movement successfully patterned a tracing of an emerging wild-type pupal eye. Surprisingly, altering cell adhesion had only a mild effect on patterning, contradicting our previous hypothesis that the patterning was primarily the result of preferential adhesion between IRM-class surface proteins. Instead, our simulations highlighted the importance of programmed cell death (PCD) as well as a previously unappreciated variable: the expansion of cells' apical surface areas, which promoted rearrangement of neighboring cells. We tested this prediction experimentally by preventing expansion in the apical area of individual cells: patterning was disrupted in a manner predicted by our simulations. Our work demonstrates the value of combining computer simulation with in vivo experiments to uncover novel mechanisms that are perpetuated throughout the eye field. It also demonstrates the utility of the GlazierâGranerâHogeweg model (GGH) for modeling the links between local cellular interactions and emergent properties of developing epithelia as well as predicting unanticipated results in vivo
TolerĂąncia de fungos ectomicorrĂzicos e plantas associadas a nĂveis tĂłxicos de metais
In silico toxicology protocols
The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information
De l'Odyssee a l'Iliade: stratagemes et competences pratiques en ethnomarketing
International audienceEthnomarketing approach represents an interesting renewal for consumer research. Methodological and epistemological particularities of ethnomarketing, associated with the Consumer Culture Theory (CCT), can constrain researchers to mobilize stratagems and bring them to deploy ingenious efforts to get into, practice and restore the ground atmosphere. Although those means account for the âtricksâ of this grounded approach, they are rarely highlighted. Pursuing a pedagogic goal, this paper exposes for marketing researchers willing to explore this approach, a large number of cases and solutions allowing them to avoid some obstacles.La dĂ©marche ethnomarketing constitue un renouvellement intĂ©ressant dans lâĂ©tude du comportement du consommateur. Les particularitĂ©s mĂ©thodologiques et Ă©pistĂ©mologiques de cette dĂ©marche, relevant de la Consumer Culture Theory (CCT), peuvent contraindre les chercheurs Ă recourir Ă des stratagĂšmes et les amener Ă dĂ©ployer des efforts dâingĂ©niositĂ© pour accĂ©der, pratiquer et restituer le terrain. Rarement mis en transparence, mais constituant pourtant les « ficelles » de cette mĂ©thode de terrain, ces recours sont exposĂ©s ici dans une visĂ©e pĂ©dagogique pour les chercheurs en marketing souhaitant investir cette approche, en leur proposant des solutions leur permettant de contourner certains obstacles
NADP-dependent glutamate dehydrogenase from a facultative methylotroph, Pseudomonas sp. strain AM1
- âŠ