How Do Young Adult Drinkers React to Varied Alcohol Warning Formats and Contents? An Exploratory Study in France

Research on alcohol warnings has increased in the last decade, providing key evidence to governments on warning format and contents. The bulk of this research, however, has been conducted in Anglosphere countries, whereas fewer studies have focused on other countries which have high per capita alcohol consumption, and where the high social acceptability of drinking is liable to affect how people accept and react to prevention measures. Since France has one of the highest per capita alcohol consumption rates in the world according to the World Health Organization (WHO), we therefore explore how young adults in France react to warnings on alcoholic beverage advertisements. We conducted 25 in-depth interviews, in 2017, with 18–25-year-old drinkers in France. Respondents were asked open-ended questions on the perceived impact of various warning contents (i.e., on health risk, social-cost risk, and on short- vs. long-term risk) and formats (text only vs. larger text combined with colored pictograms). Warnings that targeted youth-relevant risks (i.e., road accidents or sexual assault) were considered to be the most meaningful and credible, although warnings communicating longer term risks (i.e., brain, cancer) were also thought to be influential. Less familiar risks, such as marketing manipulation and calorie intake, elicited the most negative reactions. Larger text-and-pictogram warnings were considered to be the most effective format in capturing attention and increasing awareness. Regardless of format and content, however, these warnings were not perceived as effective for decreasing alcohol consumption

Two-cross-polarized-frequency VECSEL at 852nm for CPT-based Cs clocks (poster)

International audienceWe demonstrate a tunable high-purity microwave signal generation from a cross- polarized dual-frequency diode-pumped vertical external-cavity semiconductor laser operating at 852 nm for the coherent population trapping of cesium atoms in compact atomic frequency references

High-purity microwave signal from a dual-frequency semiconductor laser for CPT atomic clocks (poster)

Coherent population trapping (CPT) of metal-alkali atoms is an interesting technique for the development of compact atomic frequency references; it relies on the excitation of the atoms by two phase-coherent laser fields. We describe the design and operation of an innovating dual-frequency laser source dedicated to Cs CPT atomic clocks, based on the direct dual-frequency and dual-polarization operation of an optically-pumped semiconductor laser at 852 nm. The phase noise of beatnote generated by the laser source is at maximum of -90 dBrad²/Hz with active stabilization, and the relative intensity noise (RIN) has been measured at -115 dB/Hz. It would potentially results in a clock frequency stability of 1.6 .10^-12 at 1 second, limited by the laser RIN. With proper adjustments in the laser and clock set-up, we target a stability of 3.10^-13 at 1 second

Enabling planetary science across light-years. Ariel Definition Study Report

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

Analyse modale expérimentale de systèmes vibroacoustiques : application aux modes A0 et T1 de la guitare et de la harpe

Les instruments à cordes sont généralement composés d'un ensemble de cordes, d'une table d'harmonie et d'une caisse de résonance munie d'évents. Le rôle de cette dernière est généralement d'augmenter le niveau de pression rayonné par l'instrument en basses fréquences en tirant partie de la première résonance acoustique de la cavité. A basse fréquence, deux modes particuliers liés au couplage entre la résonance de Helmholtz de la cavité et la première résonance mécanique de la table d'harmonie jouent un rôle particulier. Les déformées modales de ces modes mettent en jeu des mouvements couplés de flexion de la table d'une part et d'oscillation des pistons d'air localisés au niveau des évents. Ces deux modes, associés à l'effet bass-reflex de la cavité sont appelés AO et Tl en référence aux cas de la guitare et du violon pour lesquels ils sont identifiés clairement. L'existence de tels modes ont également été identifiés récemment dans le cas de la harpe. Les modes complexes associés à Tl et AO d'un tel système peuvent être identifiés grâce à une méthode de lissage. La forme particulière de ces modes rend difficile le calcul direct des matrices masse (M), raideur (K), amortissement (B) équivalentes au système à 2 degrés de liberté. Néanmoins, il est possible d'obtenir les modes réels associés aux modes complexes au moyen d'une méthode d'appropriation par le calcul et donc d'identifier les matrices M, K et B. Cette procédure d'identification est testée pour trois cas différents : un système discret simulé, une guitare et une harpe

Démodulation optique harmonique non-résonante

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Class-A semiconductor lasers for the transport and generation of optically carried RF analog signals

International audienceClass-A operation of VECSELs is obtained. Such shot noise limited sources are used for the transport of RF signals and the generation of radar local oscillators via two-frequency operation. © 2010 Optical Society of America

Stabilisation de puissance optique d'un VECSEL bifréquence pour une horloge CPT compacte

National audienc

High finesse external cavity VCSELs: from very low noise lasers to dual frequency lasers

International audienceLow noise-level optical sources are required for numerous applications such as microwave photonics, fiber-optic sensing and time/frequency references distribution. In this paper, we demonstrate how inserting a SC active medium into a centimetric high-Q external cavity is a simple way to obtain a shot-noise-limited laser source over a very wide frequency bandwidth. This approach ensures, with a compact design, a sufficiently long photon lifetime to reach the oscillation-relaxation- free class-A regime. This concept has been illustrated by inserting a 1/2-VCSEL in an external cavity including an etalon filter. A -156dB/Hz relative intensity noise level is obtained over the 100 MHz to 18 GHz bandwidth of interest. This is several orders of magnitude better than the noise, previously observed in VCSELs, belonging to the class-B regime. The optimization, in terms of noise, is shown to be a trade-off between the cavity length and the laser mode filtering. The transition between the class-B and class-A dynamical behaviors is directly observed by continuously controlling the photon lifetime is a sub-millimetric to a centimetric cavity length. It's proven that the transition occurs progressively, without any discontinuity. Based on the same laser architecture, tunable dual-frequency oscillation is demonstrated by reducing the polarized eigenstates overlap in the gain medium. The class-A dynamics of such a laser, free of relaxation oscillations, enables to suppress the electrical phase noise in excess, usually observed in the vicinity of the beat note. An original technique for jitter reduction in mode-locked VECSELs is also investigated. Such lasers are needed for photonic analog to digital converters

Parametric study on the phase noise of an optoelectronic oscillator submitted to vibrations

International audienc