Joseph-Diez Gergonne (1771-1859), professeur et recteur d'Académie à Montpellier. Éditeur du premier grand journal de l'histoire des mathématiques et de leur enseignement: les Annales de Gergonne (1810-1831)

International audienceJoseph-Diez Gergonne est surtout connu pour ses Annales de mathématiques pures et appliquées, journal qui a marqué l'histoire de la communication entre les mathématiciens de toutes catégories : enseignants et élèves du secondaire et des universités, académiciens, anciens polytechniciens, militaires, etc. Ce mensuel, édité pendant près de vingt-deux années, a en effet inauguré la forme actuelle de la communication entre chercheurs et/ou pédagogues de cette science, au plan national comme international, et a participé à l'entrée des mathématiques dans leur champ de spécialité séparé des disciplines dont elles dépendaient jusqu'alors, la philosophie au premier rang d'entre elles. Mais le personnage est intéressant sur de nombreux autres aspects du fait de son implication pédagogique (professeur dans les établissements secondaires puis universitaires), académiques et enfin institutionnelles puisque sa carrière de recteur d'académie à Montpellier est un témoignage de premier plan sur le fonctionnement des institutions de l'époque (la Monarchie de Juillet) et sur la difficulté du métier de recteur.</p

The effects of the covid-19 pandemic on the mass market retailing of wine in Italy

The purpose of this study was to provide a detailed framework of wine purchases in supermarkets during the COVID-19 pandemic. The unexpected diffusion of the virus and the restrictions imposed in Italy to prevent its spread have significantly affected the food purchasing habits of consumers. By analyzing the scanner data of the wine sales in the Italian mass market retail channel, this study was intended to show whether and how the dynamics triggered by the pandemic have modified the overall value and type of wine purchases, focusing on prices, formats, and promotional sales. In particular, this study explores sales in two separate periods, namely March–April (the “lockdown”, with general compulsory closing and severe restrictions) and June–July 2020 (the “post-lockdown”, in which some limitations were no longer effective). The analysis of wine sales during lockdown and post-lockdown and the study of the variations compared to the sales of the previous years showed some significant changes in purchase behavior. The results could provide managers, researchers, and policy makers with extensive insights into the purchasing patterns of consumers during this unprecedented time and reveal trends that may characterize the structure of the future wine demand

Common-mode resonances in ultra wide band connected arrays of dipoles : measurements from the demonstrator and exit strategy

A 6-9 GHz prototype array of dual-polarized connected dipoles has been manufactured. The array is composed by two orthogonal sets of 8×8 elements for each polarization (128), arranged in an egg-crate configuration. Preliminary measurements highlighted the presence of unpredicted common-mode resonances excited in the vertical feeding lines. An analysis of the common-mode excitation is carried out and exit strategies for a design of a resonance-free connected array are presented. © 2009 IEEE

Individualised and health-related quality of life of persons with spinal cord injury

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Storie aliene

Secondo la definizione fornita dalla IUCN (Unione internazionale per la conservazione della natura): le specie aliene (o alloctone, introdotte, esotiche, non-indigene, non-native) sono specie animali o vegetali che si trovano al di fuori della loro area di origine naturale in seguito ad un’azione diretta volontaria o accidentale da parte dell’uomo. L’introduzione di specie alloctone da parte dell’uomo è un fenomeno con radici molto antiche e non comporta di per sé un danno agli ecosistemi ospitanti. Alcune specie trasportate non riescono ad adattarsi alle nuove condizioni e non sopravvivono, altre si stabilizzano in aree confinate trovandovi delle condizioni microclimatiche favorevoli, altre ancora invece non solo si stabilizzano nel nuovo areale, ma diventano “invasive”. In letteratura scientifica non vi è una definizione univoca di specie invasiva, per questo, per chiarezza, userò nuovamente la dicitura fornita dalla IUCN: “le specie aliene invasive sono quelle specie aliene che minacciano la biodiversità e i servizi ecosistemici collegati, con effetti negativi su di modificandoli, e che causano impatti negativi sulla salute umana e sulle attività economiche”. Il podcast si prefigge come obiettivo di portare a conoscenza degli ascoltatori alcune storie di invasioni biologiche che hanno avuto un impatto notevole sugli ecosistemi e le comunità umane che vi abitavano. Negli episodi verranno ascoltate ricercatori/trici, commercianti e/o persone che in qualche modo sono state interessate dal fenomeno oggetto della puntata stessa per ricostruire la storia dell’invasione, la situazione attuale e le prospettive future

Reflection confocal nanoscopy using a super-oscillatory lens

A Superoscillatory lens (SOL) is known to produce a sub-diffraction hotspot which is useful for high-resolution imaging. However, high-energy rings called sidelobes coexist with the central hotspot. Additionally, SOLs have not yet been directly used to image reflective objects due to low efficiency and poor imaging properties. We propose a novel reflection confocal nanoscope which mitigates these issues by relaying the SOL intensity pattern onto the object and use conventional optics for detection. We experimentally demonstrate super-resolution by imaging double bars with 330 nm separation using a 632.8 nm excitation and a 0.95 NA objective. We also discuss the enhanced contrast properties of the SOL nanoscope against a laser confocal microscope, and the degradation of performance while imaging large objects.Comment: 17 pages, 15 figures, supplementary include

Leaky-wave slot array antenna fed by a dual reflector system

This work proposes a leaky-wave slot array antenna fed by a dual offset Gregorian reflector system realized by pins in a parallel plate waveguide. The radiating part of the antenna is composed by parallel slots etched on one side of the same parallel plate waveguide. The dual offset Gregorian reflector system is fed by an arrangement constituted by two vias and a grid, also constituted by pins. A prototype of the antenna has been designed, manufactured and successfully tested. The low profile, low cost and high efficiency of the antenna render it suited for a variety of radar or telecom applications

Christophe Genin, Le street art au tournant. Reconnaissance d’un genre

L’ouvrage occupe une place originale dans le paysage de plus en plus fourni de l’édition classique ou numérique de textes et d’autres contenus – images, vidéos, sites dédiés – sur ce que l’on classe souvent de façon très approximative sous l’appellation street art. On découvre chez Christophe Genin, professeur et chercheur en philosophie de l’art à la Sorbonne, une passion évidente pour tout ce qui a trait à ce « nouveau monde d’images [qui] a envahi l’espace de nos villes et de leurs abords..

Natahlie Heinich, La Sociologie à l’épreuve de l’art. Entretiens avec Julien Ténédos

L’ouvrage de Nathalie Heinich est une compilation actualisée de deux courts livres parus en 2006 et 2007 dans une petite maison d’édition aujourd’hui disparue et dont le créateur, Julien Tédénos, s’est prêté au jeu de cette actualisation. En fait, le rôle de ce dernier est assez secondaire dans l’ouvrage, ses questions semblant n’être là que pour introduire les moments du récit d’une vie comme d’une œuvre et les développements théoriques de la sociologue de l’art reconnue et en même temps aty..