Measurement of ϕs\phi_s at LHCb

The study of CP violation in $B_s^0$ oscillations is one of the key goals of the LHCb experiment. Effects are predicted to be very small in the Standard Model but can be significantly enhanced in many models of new physics. We present the world's best measurement of the CP-violating phase $\phi_s$ using $B_s^0\to J/\psi KK$ and $B_s^0\to J/\psi\pi\pi$ decays.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society Division of Particles and Fields, Santa Cruz, California, August 13-17, 201

Prospects for CP violation in B0s → J/ψφ from first LHCb data

The determination of the CP-violating phase in B0s → J/ψφ decays is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model but can be significantly enhanced in many models of New Physics. The steps towards a precise determination of this phase with a flavour-tagged, time-dependent angular analysis of the decay B0s → J/ψφ are reviewed and first studies performed with data collected in 2010 at LHC in pp collisions at 7 TeV center-of-mass energy are presented for the first time. In particular, we report the first LHCb measurements of lifetime in the channels B+ → J/ψK+, B0 → J/ψK∗0, B0 → J/ψK0S, B0s → J/ψφ, Λb → J/ψΛ; the polarization amplitudes in B0 → J/ψK∗0 and B0s → J/ψφ; the width and mass differences of the B0s mass eigenstates, ΔΓs and Δms. The data sample used corresponds to an integrated luminosity of 36pb−1

Arboreal ants use the "Velcro® principle" to capture very large prey

Plant-ants live in a mutualistic association with host plants known as "myrmecophytes" that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural VelcroH that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker

Summary of WG4: 'Lifetime, Mixing and Weak Mixing Phase in Charm and Beauty, Including Direct Determination of V_tx

We present the summary of the Working Group on lifetimes, mixing and weak mixing phases in charm and beauty mesons at the CKM 2010 workshop. In the past year or so good progress was achieved on both experimental and theoretical sides. While this yields improvement in our understanding of neutral meson mixing, further work is necessary to achieve the highest possible precision in order to investigate current hints for deviations between experiment and standard model predictions. With the recent LHC startup we see bright prospects for the near term future for huge improvements

Uplift and strength evolution of passive margins inferred from 2D conductive modelling

International audiencePost-breakup vertical motions of passive margins are seen here as a result of the post-rift 2-D thermal evolution. A 2-D finite element numerical model is performed to evaluate both the vertical and horizontal conduction that drive the thermal evolution of continental passive margins, from breakup to post-breakup states. Initial temperature configurations corresponding to non-volcanic and volcanic margins are tested, and lead to different thermal evolution of the lithosphere. For both margins, a thermal thickening is observed in the stretched lithosphere, whereas the unstretched lithosphere undergoes first (0­80 Ma) a thermal thinning and secondly (after 80 Ma) a thermal thickening. In comparison with non-volcanic margins, volcanic margins show a slower thermal thickening and a greater thermal thinning in stretched and unstretched lithosphere, respectively. The variations with time of lithosphere thickness are then translated into isostatic vertical movements and reveal 'seaward' thermal induced subsidence and 'landward' thermal induced uplift. The estimated uplift reaches up to 250 m in volcanic margins and 120 m in non-volcanic margins. The modelled timing and amount of uplift in both margins are consistent with present-day topography of volcanic passive margins that stand two to three times higher than non-volcanic margins. Using these thermal models, we finally show that the 2-D strength of the margins drastically evolves with time from a seeward dominant strength (0­80 Ma) toward a landward dominant strength (time larger than 80 Ma). These lateral strength evolution could have strong effect on the flexural response of the margin through time

Un flou adaptatif en fonction du point de focalisation pour réduire la fatigue visuelle en vision stéréoscopique

National audienceDepuis quelques années, de plus en plus de contenus stéréoscopiques sont disponibles au grand public. Si l'impression de relief est remarquable, il n'en reste pas moins que la vision artificielle stéréoscopique demeure fatigante. Une cause de cette fatigue est le conflit accommodation convergence. Dans cet article, nous proposons d'ajouter un flou dans la vision périphérique (le point de focalisation étant déterminé avec un eye-tracking) pour limiter ce conflit et donc limiter la fatigue visuelle

Comparison of albicans vs. non-albicans candidemia in French intensive care units

The AmarCand Study Group (ICU physicians): Drs. Allaouchiche (Lyon), Amigues (Montpellier), Ausseur (Saint Herblain), Azoulay (Paris), Badet (Lyon), Baldesi (Aix-en-Provence), Bastien (Bron), Baudin (Paris), Bayle (Lyon), Bazin (Clermont-Ferrand), Benayoun (Clichy), Blondeau (Roubaix), Bodin (Paris), Bollaert (Nancy), Bonadona (La Tronche), Bonnaire (Aulnay Sous Bois), Bonnivard (Montauban), Borne (Paris), Brabet (Montpellier), Branche (Lyon), Braud (Rouen), Bret (Lyon), Bretonnière (Nantes), Brocas (Evry), Brun (Bron), Bruneel (Versailles), Canevet (Armentières), Cantais (Toulon Armées), Carlet (Paris), Charbonneau (Caen), Charles (Dijon), Chastagner (Chamberry), Corne (Montpellier), Courte (Saint-Brieuc), Cousson (Reims), Cren (Morlaix), Diconne (Saint Etienne), Drouet (Saint-Denis), Dube (Angers), Duguet (Paris), Dulbecco (Antibes), Dumenil (Clamart), Dupont (Amiens), Durand (Grenoble), Durand-Gasselin (Toulon), Durocher (Lille), Fangio (Poissy), Fattouh (Mulhouse), Favier (Metz Armées), Fieux (Paris), Fleureau (Pessac), Freys (Strasbourg), Fulgencio (Paris), Gally (Mulhouse), Garnaud (Orléans), Garot (Tours), Gilhodes (Créteil), Girault (Rouen), Gouin (Marseille), Gouin (Rouen), Guidon (Marseille), Hérault (Grenoble), Hyvernat (Nice), Jobard (Monaco), Jospe (Saint Etienne), Kaidomar (Fréjus), Karoubi (Bobigny), Kherchache (Agen), Lacherade (Poissy), Lakermi (Paris), Lambiotte (Maubeuge), Lamia (Le Kremlin-Bicêtre), Lasocki (Paris), Launoy (Strasbourg), Le Guillou (Paris), Lefort (Saint-Denis), Lefrant (Nîmes), Lemaire (Roubaix), Lepape (Pierre-Bénite), Lepoutre (Lomme), Leroy (Lille), Leroy (Tourcoing), Loriferne (Bry-sur-Marne), Mahe (Nantes), Mandin (Gap), Marighy (Saint- Denis), Mathieu (Lille), Mathonnet (Paris), Megarbane (Paris), Mercat (Angers), Michel (Saint Herblain), Michelet (Marseille), Mimoz (Poitiers), Mohammedi (Lyon), Mouquet (Paris), Mourvillier (Paris), Navellou (Besançon), Novara (Paris), Obadia (Montreuil), Perrigault (Montpellier), Perrin (Marseille), Petit (Valence), Poussel (Metz), Rahmani (Strasbourg), Renard (La Roche sur Yon), Robert (Poitiers), Robert (Lyon), Saliba (Villejuif ), Sannini (Marseille), Santré (Annecy), Seguin (Rennes), Souweine (Clermont-Ferrand), Trouillet (Paris), Valentin (Besançon), Volatron (Rennes), Voltz (Vandoeuvre les Nancy), Winer (Saint Pierre), and Winnock (Bordeaux).International audienceINTRODUCTION: Candidemia raises numerous therapeutic issues for intensive care physicians. Epidemiological data that could guide the choice of initial therapy are still required. This analysis sought to compare the characteristics of intensive care unit (ICU) patients with candidemia due to non-albicans Candida species with those of ICU patients with candidemia due to Candida albicans. METHODS: A prospective, observational, multicenter, French study was conducted from October 2005 to May 2006. Patients exhibiting candidemia developed during ICU stay and exclusively due either to one or more non-albicans Candida species or to C. albicans were selected. The data collected included patient characteristics on ICU admission and at the onset of candidemia. RESULTS: Among the 136 patients analyzed, 78 (57.4%) had candidemia caused by C. albicans. These patients had earlier onset of infection (11.1 +/- 14.2 days after ICU admission vs. 17.4 +/- 17.7, p = 0.02), higher severity scores on ICU admission (SOFA: 10.4 +/- 4.7 vs. 8.6 +/- 4.6, p = 0.03; SAPS II: 57.4 +/- 22.8 vs. 48.7 +/- 15.5, P = 0.015), and were less often neutropenic (2.6% vs. 12%, p = 0.04) than patients with candidemia due to non-albicans Candida species. CONCLUSIONS: Although patients infected with Candida albicans differed from patients infected with non-albicans Candida species for a few characteristics, no clinical factor appeared pertinent enough to guide the choice of empirical antifungal therapy in ICU

Multiple scattering of an ultrasonic shock wave in bubbly media

International audienceThis experimental study deals with the propagation of an ultrasonic shock wave in a random heterogeneous medium, constituted of identical 75-µm radius bubbles, trapped in a yield-stress fluid. The fundamental frequency of the incident wave (in the MHz range) was much larger than the resonance frequency of bubbles (38 kHz). A well expanded coda, resulting from the multiple scattering of the incident shock wave through the heterogeneous medium, was experimentally measured in transmission. Despite the significant amplitude of the shock wave (90 kPa), no sign of nonlinear response of the bubbles was detected. Both the coherent and incoherent fields were successfully described by linear theories. Using a shock wave presents the advantage of characterizing the medium over a large frequency range (1.5-15 MHz)