An edge-on translucent dust disk around the nearest AGB star L2 Puppis - VLT/NACO spectro-imaging from 1.04 to 4.05 microns and VLTI interferometry

As the nearest known AGB star (d=64pc) and one of the brightest (mK-2), L2 Pup is a particularly interesting benchmark object to monitor the final stages of stellar evolution. We report new lucky imaging observations of this star with the VLT/NACO adaptive optics system in twelve narrow band filters covering the 1.0-4.0 microns wavelength range. These diffraction limited images reveal an extended circumstellar dust lane in front of the star, that exhibits a high opacity in the J band and becomes translucent in the H and K bands. In the L band, extended thermal emission from the dust is detected. We reproduce these observations using Monte-Carlo radiative transfer modeling of a dust disk with the RADMC-3D code. We also present new interferometric observations with the VLTI/VINCI and MIDI instruments. We measure in the K band an upper limit to the limb-darkened angular diameter of theta_LD = 17.9 +/- 1.6 mas, converting to a maximum linear radius of R = 123 +/- 14 Rsun. Considering the geometry of the extended K band emission in the NACO images, this upper limit is probably close to the actual angular diameter of the star. The position of L2 Pup in the Herzsprung-Russell diagram indicates that this star has a mass around 2 Msun and is probably experiencing an early stage of the asymptotic giant branch. We do not detect any stellar companion of L2 Pup in our adaptive optics and interferometric observations, and we attribute its apparent astrometric wobble in the Hipparcos data to variable lighting effects on its circumstellar material. We however do not exclude the presence of a binary companion, as the large loop structure extending to more than 10 AU to the North-East of the disk in our L band images may be the result of interaction between the stellar wind of L2 Pup and a hidden secondary object. The geometric configuration that we propose, with a large dust disk seen almost edge-on, appears particularly favorable to test and develop our understanding of the formation of bipolar nebulae.Comment: 16 pages, 15 figure

Le traçage anonyme, dangereux oxymore: Analyse de risques à destination des non-spécialistes

Dans le but affiché de ralentir la progression de l'épidémie COVID-19, la France envisage de mettre en place un système de traçage des contacts des maladesà l'aide d'une application mobile. Les concepteurs de ce type d'applications assurent qu'elles sont respectueuses de la vie privée. Cependant cette notion reste vague. Nous souhaitons donc contribuer au débat public en apportant unéclairage sur ce que pourrait et ne pourrait pas garantir une application de traçage, afin que chacun puisse se forger une opinion sur l'opportunité de son déploiement

The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge

Operation and performance of the ATLAS Tile Calorimeter in Run 1

The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report

Changing geographical patterns and trends in cancer incidence in children and adolescents in Europe, 1991–2010 (Automated Childhood Cancer Information System): a population-based study

Background: A deceleration in the increase in cancer incidence in children and adolescents has been reported in several national and regional studies in Europe. Based on a large database representing 1·3 billion person-years over the period 1991–2010, we provide a consolidated report on cancer incidence trends at ages 0–19 years. Methods: We invited all population-based cancer registries operating in European countries to participate in this population-based registry study. We requested a listing of individual records of cancer cases, including sex, age, date of birth, date of cancer diagnosis, tumour sequence number, primary site, morphology, behaviour, and the most valid basis of diagnosis. We also requested population counts in each calendar year by sex and age for the registration area, from official national sources, and specific information about the covered area and registration practices. An eligible registry could become a contributor if it provided quality data for all complete calendar years in the period 1991–2010. Incidence rates and the average annual percentage change with 95% CIs were reported for all cancers and major diagnostic groups, by region and overall, separately for children (age 0–14 years) and adolescents (age 15–19 years). We examined and quantified the stability of the trends with joinpoint analyses. Findings: For the years 1991–2010, 53 registries in 19 countries contributed a total of 180 335 unique cases. We excluded 15 162 (8·4%) of 180 335 cases due to differing practices of registration, and considered the quality indicators for the 165 173 cases included to be satisfactory. The average annual age-standardised incidence was 137·5 (95% CI 136·7–138·3) per million person-years and incidence increased significantly by 0·54% (0·44–0·65) per year in children (age 0–14 years) with no change in trend. In adolescents, the combined European incidence was 176·2 (174·4–178·0) per million person-years based on all 35 138 eligible cases and increased significantly by 0·96% (0·73–1·19) per year, although recent changes in rates among adolescents suggest a deceleration in this increasing trend. We observed temporal variations in trends by age group, geographical region, and diagnostic group. The combined age-standardised incidence of leukaemia based on 48 458 cases in children was 46·9 (46·5–47·3) per million person-years and increased significantly by 0·66% (0·48–0·84) per year. The average overall incidence of leukaemia in adolescents was 23·6 (22·9–24·3) per million person-years, based on 4702 cases, and the average annual change was 0·93% (0·49–1·37). We also observed increasing incidence of lymphoma in adolescents (average annual change 1·04% [0·65–1·44], malignant CNS tumours in children (average annual change 0·49% [0·20–0·77]), and other tumours in both children (average annual change 0·56 [0·40–0·72]) and adolescents (average annual change 1·17 [0·82–1·53]). Interpretation: Improvements in the diagnosis and registration of cancers over time could partly explain the observed increase in incidence, although some changes in underlying putative risk factors cannot be excluded. Cancer incidence trends in this young population require continued monitoring at an international level. Funding: Federal Ministry of Health of the Federal German Government, the European Union's Seventh Framework Programme, and International Agency for Research on Cancer

Information Quantique par Passage Adiabatique : Portes Quantiques et Décohérence

The first part of this thesis is about adiabatic quantum processes designed for the implementation of quantum logic gates, the elementary components of quantumcomputers, by the interaction of pulsed laser fields with atoms. The adiabaticmethods allow robust processes, i.e. which are not sensitive to the fluctuationsof experimental parameters. The processes described in this thesis only requireaccurate control of the polarisations and the relative static phases of thelaser fields. These processes allow the implementation of a universal set ofquantum gates, which make possible the implementation of all the other quantumgates by combinations.The second part of this thesis concerns the effects of dephasing decoherence inadiabatic passage. The transition probability formula of a two level system withdephasing is established. This formula is valid in all regimes, from diabatic toadiabatic, and can be used to derive the parameters of elliptic trajectoriesthat optimise the population transfer.La première partie de cette thèse est consacrée à l'élaboration théorique deprocessus adiabatiques permettant l'implémentation de portes logiquesquantiques, les constituants élémentaires des ordinateurs quantiques, parl'interaction de champs laser impulsionnels avec des atomes. L'utilisation detechniques adiabatiques permet des implémentations robustes, i.e. insensiblesaux fluctuations des paramètres expérimentaux. Les processus décrits dans cettethèse ne nécessitent que le contrôle précis des polarisations et des phasesrelatives des champs lasers. Ces processus permettent l'implémentation d'unensemble universel de portes quantiques, autorisant l'implémentation de touteautre porte quantique par combinaisons.La seconde partie de cette thèse concerne les effets de la décohérence pardéphasage sur le passage adiabatique. La formule de probabilité de transitiond'un système à deux niveaux tenant compte de ces effets décohérents est établie.Cette formule est valable dans les différents régimes, diabatique etadiabatique, et permet d'établir les paramètres de trajectoires elliptiquesoptimisant le transfert de population

LA PARTENELLE, TANACETUM PARTHENIUM (L.) SCHULTZ BIP.

BESANCON-BU Médecine pharmacie (250562102) / SudocSudocFranceF

Optimization of adiabatic passage with dephasing

International audienc

Information quantique par passage adiabatique (portes quantiques et décohérence)

La première partie de cette thèse est consacrée à l'élaboration théorique de processus adiabatiques permettant l'implémentation de portes logiques quantiques, les constituants élémentaires des ordinateurs quantiques, par l'interaction de champs laser impulsionnels avec des atomes. L'utilisation de techniques adiabatiques permet des implémentations robustes, i.e. insensibles aux fluctuations des paramètres expérimentaux. Les processus décrits dans cette thèse ne nécessitent que le contrôle précis des polarisations et des phases relatives des champs lasers. Ces processus permettent l'implémentation d'un ensemble universel de portes quantiques, autorisant l'implémentation de toute autre porte quantique par combinaisons. La seconde partie de cette thèse concerne les effets de la décohérence par déphasage sur le passage adiabatique. La formule de probabilité de transition d'un système à deux niveaux tenant compte de ces effets décohérents est établie. Cette formule est valable dans les différents régimes, diabatique et adiabatique, et permet d'établir les paramètres de trajectoires elliptiques optimisant le transfert de population.The first part of this thesis is about adiabatic quantum processes designed for the implementation of quantum logic gates, the elementary components of quantum computers, by the interaction of pulsed laser fields with atoms. The adiabatic methods allow robust processes, i.e. which are not sensitive to the fluctuations of experimental parameters. The processes described in this thesis only require accurate control of the polarisations and the relative static phases of the laser fields. These processes allow the implementation of a universal set of quantum gates, which make possible the implementation of all the other quantum gates by combinations. The second part of this thesis concerns the effects of dephasing decoherence in adiabatic passage. The transition probability formula of a two level system with dephasing is established. This formula is valid in all regimes, from diabatic to adiabatic, and can be used to derive the parameters of elliptic trajectories that optimise the population transfer.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Relevant factors affecting microbial surface decontamination by pulsed light.

International audiencePulsed Light (PL) uses intense flashes of white light rich in ultraviolet (UV) light for decontamination. A log-reduction higher than 5 was obtained in one flash and at fluences lower than 1.8 J/cm 2 on spores of a range of spore-forming bacteria, of vegetative cells of non-spore-forming bacteria and on yeasts spread on agar media. Vegetative cells were more sensitive than spores. The inactivation by PL of Bacillus subtilis, B. atrophaeus, B. cereus, Geobacillus stearothermophilus, and Aspergillus niger spores sprayed on polystyrene was similar. The inactivation by PL of B. subtilis and A. niger spores sprayed on glass was slightly lower than on polystyrene. No alteration of the spore structures was detected by scanning electron microscopy for both PL treated B. subtilis and A. niger spores. The inactivation of spores of B. subtilis, B. atrophaeus, B. cereus and B. pumilus by PL or by continuous UV–C at identical fluences was not different, and was much higher by PL for A. niger spores. The increase in the input voltage of the lamps (which also increases the UV–C %) resulted in a higher inactivation. There was no correlation between the resistance to heat and the resistance to PL. The relative effect of UV–C radiations and light thermal energy on PL inactivation was discussed