FM-AFM with hanging fiber probe for the study of liquid / liquid interfaces

This article describes how an FM-AFM using a hanging fiber force probe made from a quartz tuning fork provides local measurements on liquid-liquid interfaces. After detailing the manufacture and calibration of the force probe, we provide evidence that this AFM is suitable for quantitative measurements at the interface between two liquids. The repeatability of the measurements allows a PDMS / water moving interface to be monitored over several hours : the evaporation of a water droplet immersed in PDMS is observed, and its interfacial tension evolution over time is measured. Deformation of the interface is also observed. These capabilities, and preliminary results on the interface between two immiscible liquids, pave the way for interface manipulation and study of complex fluid-fluid interfaces

Evaluation and Selection of the MEUST Submarine Site

http://meust.cnrs.fr/MEUST_site_choice_report.pdfThis report summarizes the results of the investiga tions performed to select the MEUST submarine site. Measurement campaigns have been conducted during 2012 on several locations off shore of Toulon. During this period the most distant site has s hown a higher sensitivity to bioluminescence seasonal variations, whereas the more coastal sites had simila r conditions as Antares. This observation combined with logistic constraints leads to select a site located at similar latitude as Antares but more western on the other side of the CC5 telecommunication cable to Cors ica. The route of the MEUST Main Electro-Optical Cable has been defined accordingly, with some flexib ility to allow fine tuning of its end point as function of the outcome of the final site characterizations scheduled in 2013

Trends in SAVR with biological vs. mechanical valves in middle-aged patients: results from a French large multi-centric survey

Background/introductionCurrently, despite continued issues with durability ( 1), biological prosthetic valves are increasingly chosen over mechanical valves for surgical aortic valve replacement (SAVR) in adult patients of all ages, at least in Western countries. For younger patients, this choice means assuming the risks associated with a redo SAVR or valve-in-valve procedure.PurposeTo assess the use of mechanical vs. biological valve prostheses for SAVR relative to patient's age and implant time in a large population extracted from the French National Database EPICARD.MethodsPatients in EPICARD undergoing SAVR from 2007 to 2022 were included from 22 participating public or private centers chosen to represent a balanced representation of centre sizes and geographical discrepancies. Patients with associated pathology of the aorta (aneurysm or dissection) and requiring a vascular aortic prosthesis were excluded. Comparisons were made amongst centers, valve choice, implant date range, and patient age.ResultsWe considered 101,070 valvular heart disease patients and included 72,375 SAVR (mean age 71.4 ± 12.2 years). We observed a mechanical vs. biological prosthesis ratio (MBPR) of 0.14 for the overall population. Before 50 years old (y-o), MBPR was >1.3 (p < 0.001) while patients above 60 years-old received principally biological SAVR (p < 0.0001). Concerning patients between 50 and 60 years-old patients, MPVR was 1.04 (p = 0.03). Patients 50–60 years-old from the first and second study duration quartile (before August 2015) received preferentially mechanical SAVR (p < 0.001). We observed a shift towards more biological SAVR (p < 0.001) for patients from the third and fourth quartile to reach a MBPR at 0.43 during the last years of the series. Incidentally, simultaneous mitral valve replacement were more common in case of mechanical SAVR (p < 0.0001), while associated CABGs were more frequent in case of biological SAVR (p < 0.0001).ConclusionIn a large contemporary French patient population, real world practice showed a recent shift towards a lower age-threshold for biological SAVR as compared to what would suggest contemporary guidelines

Recherche de productions simples non résonantes de sneutrinos avec violation de la R-parité au sein du détecteur ALEPH au LEP

AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSTRASBOURG-Bib.Central Recherche (674822133) / SudocSudocFranceF

Antares Neutrino telescope and Deap Sea Observatory,

International audienceThe ANTARES detector consists of a multidisciplinary undersea observatory associated with a neutrino telescope. The neutrino telescope, with 12 mooring lines holding light detectors, was completed in May 2008 and is destined for research in the field of astroparticle physics, in particular in neutrino astronomy

Deep sediment resuspension and thick nepheloid layer generation by open-ocean convection

The ANTARES collaborationInternational audienceThe Gulf of Lions in the northwestern Mediterranean is one of the few sites around the world ocean exhibiting deep open-ocean convection. Based on 6-year long (2009-2015) time series from a mooring in the convection region, shipborne measurements from repeated cruises, from 2012 to 2015, and glider measurements, we report evidence of bottom thick nepheloid layer formation, which is coincident with deep sediment resuspension induced by bottom-reaching convection events. This bottom nepheloid layer, which presents a maximum thickness of around 2000 m in the center of the convection region, probably results from the action of cyclonic eddies that are formed during the convection period and can persist within their core while they travel through the basin. The residence time of this bottom nepheloid layer appears to be less than a year. In-situ measurements of suspended particle size further indicate that the bottom nepheloid layer is primarily composed of aggregates between 100 and 1000 µm in diameter, probably constituted of fine silts. Bottom-reaching open ocean convection, as well as deep dense shelf water cascading that occurred concurrently some years, lead to recurring deep sediments resuspension episodes. They are key mechanisms that control the concentration and characteristics of the suspended particulate matter in the basin, and in turn affect the bathypelagic biological activit

Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as “open-sea convection”. It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts

Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface

<p>The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.</p>

The ANTARES Telescope Neutrino Alert System

17 pages, 9 figures submitted to Astroparticle PhysicsThe ANTARES telescope has the capability to detect neutrinos produced in astrophysical transient sources. Potential sources include gamma-ray bursts, core collapse supernovae, and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. A fast online muon track reconstruction is used to trigger a network of small automatic optical telescopes. Such alerts are generated for special events, such as two or more neutrinos, coincident in time and direction, or single neutrinos of very high energy

Search for Cosmic Neutrino Point Sources with four Years of Data from the ANTARES Telescope

In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by the ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on the neutrino flux have been obtained. Assuming an E –2 ν spectrum, these flux limits are at 1-10 ×10–8 GeV cm–2 s–1 for declinations ranging from –90° to 40°. Limits for specific models of RX J1713.7–3946 and Vela X, which include information on the source morphology and spectrum, are also given