Étude d’une matrice agile rayonnante à pixels élaborés en métamatériaux maitrise de concepts, réalisation de prototypes et caractérisation

This PhD thesis is dedicated to the study and the development of a novel agile antenna system called ‘Agile Radiating Matrix with Metamaterials Pixels’. This system is formed by a planar matrix which is composed by an association of jointed electromagnetic pixels. The pixel design is inspired from the electromagnetic band gap antenna and it is surrounded by metallic walls. These pixels are fed by means of several beam forming networks.The intensive theoretical study made on the matrix antenna, showed several electromagnetic performances concerning the low mutual coupling, the great beam steering for high scanning angles and the elimination of grating lobes. Three manufactured prototypes are presented in order to experimentally validate the matrix performances and to respond to some application requirements.Ce mémoire est consacré à l’étude et au développement d’un nouveau système antennaire agile en rayonnement appelé MARPEM (Matrice Agile Rayonnante à Pixels Elaborés en Métamatériaux). Ce système est formé d’une matrice planaire formée par un agencement jointif de pixels électromagnétiques. Le concept du pixel est inspiré de l’antenne à Bande Interdite Electromagnétique et entouré par une enceinte murale. Ces pixels sont alimentés par des circuits de formation de faisceaux.Des études théoriques approfondies ont montré des performances électromagnétiques de MARPEM concernant le faible couplage mutuel, les forts pointages électroniques et l’élimination de lobes de réseau. Trois prototypes ont été étudiés et réalisés afin de valider expérimentalement les performances de MARPEM et de répondre aux exigences de différentes applications

Drug-induced hallucination: A case/non case study in the French Pharmacovigilance Database

ABSTRACT -Background and Objectives: Hallucinations are sensory perceptions which occur without external stimuli. There are associated with psychiatric disease but also can be related to organic disease and drug or toxic exposure. The purpose of our study was to investigate the association between exposure to medications and the reporting of hallucinations using data from the spontaneous-reporting French Pharmacovigilance Database (FPVD). Methods: We used the case/noncase method in the FPVD. Cases were all the observations of hallucination with the LLT term "perception disturbances", registered into the FPVD from January 1985 to Jan 2013. Data were expressed as odds ratio (OR) with their 95% confidence intervals. Results: Among the 469,181 reports of adverse effects recorded between 1985 and 2013, 4,086 are hallucinations. For about 50% of these hallucinations were experimented by patient older than 65 years old. A statistically significant OR was found with several medications included rasagiline ]), zolpidem , methylphenidate ) and baclofene ). An increased risk of hallucinations was also observed with non central nervous system drugs, including ertapenem .5]), voriconazole ) and valacyclovir ]). Conclusions: This pharmacoepidemiological study describes an association between drugs and hallucinations. This relationship involves not only some already suspected drugs but also other drugs less known to induce such an adverse reaction. Despite the mandatory limits of this kind of study, these data should lead to special precautions in patient at risk

New Circularly Polarized Matrix Antenna For Space Applications

International audiencethis paper presents a new electromagnetic approach of matrix antenna, specialized for circularly polarized space applications. The design of the proposed antenna matrix is based on small pixels which generate circular polarization field. The concept of the pixels is well demonstrated as a patent and verified for the use in antenna arrays. The design will be used for several space applications with directive and wide angle beams. Index Terms—antenna array, axial ratio, beam forming, Isoflux, Electromagnetic band gap material EBG, Frequency selective surface FSS

An agile electronically scanned EBG matrix antenna for monitoring target activity

International audienceTelecommunications, civil and military radars, RFID (Radio Frequency IDentification) and all the radiating systems are evolving towards the spatial agility that associates « range » and « coverage ». In this context, this article describes and demonstrates an experimental prototype to show the reliability and efficiency of the EBG matrix antenna theoretical aspect, for beam forming and beam steering applications

Kontinuierlicher Wandel: Organisation und Anwerbungspraxis der salafistischen Bewegung

"Die salafistische Bewegung in Deutschland wandelt sich kontinuierlich. Dabei besteht sie aus unterschiedlichen Strömungen und einer Vielfalt an Organisationsformen. Die Methoden, um neue Anhänger zu gewinnen, unterscheiden sich jedoch kaum voneinander: Orientiert an unterschiedlichen Zielgruppen nutzen Salafisten Anwerbungspraktiken wie persönliche Ansprachen, Infostände und Islam-Seminare sowie Propaganda in den sozialen Medien, in Internetblogs und auf Video-Plattformen. Der vorliegende Report klärt über die Organisation und Anwerbungspraktiken des Salafismus in Deutschland auf." (Autorenreferat

A New Agile Radiating System Called Electromagnetic Band Gap Matrix Antenna

Civil and military applications are increasingly in need for agile antenna devices which respond to wireless telecommunications, radars, and electronic warfare requirements. The objective of this paper is to design a new agile antenna system called electromagnetic band gap (EBG) matrix. The working principle of this antenna is based on the radiating aperture theory and constitutes the subject of an accepted CNRS patent. In order to highlight the interest and the originality of this antenna, we present a comparison between it and a classical patch array only for the (one-dimensional) 1D configuration by using a rigorous full wave simulation (CST Microwave software). In addition, EBG matrix antenna can be controlled by specific synthesis algorithms. These algorithms use inside their; optimization loop an analysis procedure to evaluate the radiation pattern. The analysis procedure is described and validated at the end of this paper

Brückennarrative - verbindende Elemente für die Radikalisierung von Gruppen

Ra­di­ka­le Grup­pen stel­len nicht nur die Sicher­heits­be­hörd­en, son­dern die ge­samte Gesel­lschaft vor en­orme Heraus­for­der­ungen. Die­ser Re­port ar­beit­et aus der be­steh­enden For­schung heraus, wie Ra­dikalisierungs­prozesse inner­halb und zwischen Grup­pen ab­laufen und welche Rol­le der­artige Grup­pen­pro­zesse im ge­samt­gesell­schaft­lichen Kontext spielen. Er fokus­siert ins­be­sondere auf die Schnitt­mengen be­stimmt­er ideol­ogischer Ele­mente unter­schied­licher radikaler Gruppen. Diese Gemein­sam­keiten werden im Re­port als Brücken­narrative be­zeichnet. Das erste dieser Na­rrative um­fasst Anti-Imperial­ismus, Anti-Modern­ismus und Anti-Universalis­mus und hat als ge­mein­samen Flucht­punkt den Anti­semitis­mus. Im zweiten Brücken­narrativ, dem Anti­feminis­mus, treffen sich völk­ische Nationalisten, christ­liche und islam­ische Funda­mental­isten und islam­istische Dschi­had­isten. Das drit­te Brücken­narrativ bildet die Vor­stellung, im (legi­timen) Wider­stand zu han­deln und da­durch Ge­walt zu recht­fertigen. Der Re­port legt dar, wie wichtig es ist, diese Na­rrative in der Prä­ventions­arbeit zu be­rück­sichtigen, das heißt, Maß­nahmen zu entwickeln, die das ge­meinsame ideo­logische Must­er ver­schieden­er ra­dikaler Grup­pen an­spre­chen

Systematic review on the prevalence, frequency and comparative value of adverse events data in social media

Aim: The aim of this review was to summarize the prevalence, frequency and comparative value of information on the adverse events of healthcare interventions from user comments and videos in social media. Methods: A systematic review of assessments of the prevalence or type of information on adverse events in social media was undertaken. Sixteen databases and two internet search engines were searched in addition to handsearching, reference checking and contacting experts. The results were sifted independently by two researchers. Data extraction and quality assessment were carried out by one researcher and checked by a second. The quality assessment tool was devised in-house and a narrative synthesis of the results followed. Results: From 3064 records, 51 studies met the inclusion criteria. The studies assessed over 174 social media sites with discussion forums (71%) being the most popular. The overall prevalence of adverse events reports in social media varied from 0.2% to 8% of posts. Twenty-nine studies compared the results from searching social media with using other data sources to identify adverse events. There was general agreement that a higher frequency of adverse events was found in social media and that this was particularly true for ‘symptom’ related and ‘mild’ adverse events. Those adverse events that were under-represented in social media were laboratory-based and serious adverse events. Conclusions: Reports of adverse events are identifiable within social media. However, there is considerable heterogeneity in the frequency and type of events reported, and the reliability or validity of the data has not been thoroughly evaluated

Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort.

BACKGROUND: The interplay between COVID-19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID-19 pandemic on childhood asthma outcomes. METHODS: The PeARL multinational cohort included 1,054 children with asthma and 505 non-asthmatic children aged between 4-18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID-19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control. RESULTS: During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks and hospitalizations due to asthma, in comparison to the preceding year. Sixty-six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre-bronchodilatation FEV1 and peak expiratory flow rate were improved during the pandemic. When compared to non-asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits or hospitalizations during the pandemic. However, an increased risk of URTIs emerged. CONCLUSION: Childhood asthma outcomes, including control, were improved during the first wave of the COVID-19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID-19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent