74 results match your criteria: "Centre de Saclay[Affiliation]"

N=16 Magicity Revealed at the Proton Drip Line through the Study of ^{35}Ca.

Phys Rev Lett

September 2023

Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France.

The last proton bound calcium isotope ^{35}Ca has been studied for the first time, using the ^{37}Ca(p,t)^{35}Ca two neutron transfer reaction. The radioactive ^{37}Ca nuclei, produced by the LISE spectrometer at GANIL, interacted with the protons of the liquid hydrogen target CRYPTA, to produce tritons t that were detected in the MUST2 detector array, in coincidence with the heavy residues Ca or Ar. The atomic mass of ^{35}Ca and the energy of its first 3/2^{+} state are reported.

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Structure of ^{36}Ca under the Coulomb Magnifying Glass.

Phys Rev Lett

September 2022

Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen, France.

Detailed spectroscopy of the neutron-deficient nucleus ^{36}Ca was obtained up to 9 MeV using the ^{37}Ca(p,d)^{36}Ca and the ^{38}Ca(p,t)^{36}Ca transfer reactions. The radioactive nuclei, produced by the LISE spectrometer at GANIL, interacted with the protons of the liquid hydrogen target CRYPTA, to produce light ejectiles (the deuteron d or triton t) that were detected in the MUST2 detector array, in coincidence with the heavy residues identified by a zero-degree detection system. Our main findings are (i) a similar shift in energy for the 1_{1}^{+} and 2_{1}^{+} states by about -250  keV, as compared with the mirror nucleus ^{36}S; (ii) the discovery of an intruder 0_{2}^{+} state at 2.

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Neuroimaging evidence for structural correlates in adolescents resilient to polysubstance use: A five-year follow-up study.

Eur Neuropsychopharmacol

August 2021

INSERM U1299 Developmental Trajectories & Psychiatry, Ecole Normale Supérieure Paris-Saclay, Université Paris-Saclay, CNRS, Centre Borelli, Digiteo Labs, Avenue des Sciences, Bâtiment 660 Claude Shannon, Gif-sur-Yvette, France; Centre de Neuro-Imagerie de Recherche, Institut du Cerveau et de la Moëlle épinière, University Hospital Pitié-Salpêtrière, Paris, France. Electronic address:

Early initiation of polysubstance use (PSU) is a strong predictor of subsequent addiction, however scarce individuals present resilience capacity. This neuroimaging study aimed to investigate structural correlates associated with cessation or reduction of PSU and determine the extent to which brain structural features accounted for this resilient outcome. Participants from a European community-based cohort self-reported their alcohol, tobacco and cannabis use frequency at ages 14, 16 and 19 and had neuroimaging sessions at ages 14 and 19.

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This paper presents the use of a kernel-based machine learning strategy targeting classification and regression tasks in view of automatic flaw(s) detection, localization and characterization. The studied use-case is a structural health monitoring configuration with an array of piezoelectric sensors integrated on aluminium panels affected by flaws of various positions and dimensions. The measured guided wave signals are post processed with a guided wave imaging algorithm in order to obtain an image representing the health of each specimen.

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CALCULATION OF CONVERSION COEFFICIENTS FOR VOXELIZED PHANTOMS FOR CRITICALITY ACCIDENT DOSIMETRY.

Radiat Prot Dosimetry

November 2020

Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 17, 31 avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France.

In the event of a criticality accident, not only the maximal doses received by the victims must be determined but it is also crucial to evaluate the doses to the different organs. With a neutron component, morphology is a key parameter in the organ dose calculation. As the simulation tools can be time consuming to proceed, especially if morphology is taken into account, for all the victims, it may be very useful to have a database of conversion coefficients that allow to obtain the organ doses from the dose measured in the dosemeter for different kinds of morphology.

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Ponds are important for their ecological value and for the ecosystem services they provide to human societies, but they are strongly affected by human activities. Peri-urban development, currently one of the most pervasive processes of land use change in Europe, exposes ponds to both urban and agricultural contaminants, causing a potential combination of adverse effects. This study, focused on 12 ponds located in a peri-urban area, has two main objectives: (1) to link the physico-chemical characteristics of the waters and the nature of their contaminants, either organic or mineral, with the human activities around ponds, and (2) to estimate the environmental risk caused by these contaminants.

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We report the observation of the rare charm decay D^{0}→K^{-}π^{+}e^{+}e^{-}, based on 468  fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the center-of-mass energy of the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We find the branching fraction in the invariant mass range 0.675 View Article and Find Full Text PDF

Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in ϒ→SΛ[over ¯]Λ[over ¯] decays based on a sample of 90×10^{6}ϒ(2S) and 110×10^{6}ϒ(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined ϒ(2S,3S)→SΛ[over ¯]Λ[over ¯] branching fraction in the range (1.

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We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B^{0}→D^{(*)}h^{0} with D→K_{S}^{0}π^{+}π^{-} decays, where h^{0}∈{π^{0},η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6}BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6}BB[over ¯] pairs recorded by the Belle detector.

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Haemonchus contortus, one of the most economically important parasites of small ruminants, has become resistant to the anthelmintic ivermectin. Deciphering the role of P-glycoproteins in ivermectin resistance is desirable for understanding and overcoming this resistance. In the model nematode, Caenorhabditis elegans, P-glycoprotein-13 is expressed in the amphids, important neuronal structures for ivermectin activity.

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Tritium and radiocarbon levels in the Rhône river delta and along the French Mediterranean coastline.

J Environ Radioact

July 2018

EDF-R&D, Laboratoire National Hydraulique et Environnement, 6 Quai Wattier, 78401, Chatou, France.

The Rhône is characterised by a heavy concentration of nuclear-based industries including nuclear power stations and nuclear sites housing civilian and military facilities. Here, we report the results of a four-year survey (2010-2013) of tritium and radiocarbon levels in a variety of matrices within the Rhône delta and along the French Mediterranean coastline. The aim of the study is to create a spatial reference framework of environmental levels of these two radionuclides, which are the most prevalent in radioactive effluents from nuclear power stations.

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We search for single-photon events in 53  fb^{-1} of e^{+}e^{-} collision data collected with the BABAR detector at the PEP-II B-Factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A^{'} through the process e^{+}e^{-}→γA^{'}; A^{'}→invisible. Such particles, referred to as "dark photons," are motivated by theories applying a U(1) gauge symmetry to dark matter.

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We measure the mass difference, Δm_{+}, between the D^{*}(2010)^{+} and the D^{+} using the decay chain D^{*}(2010)^{+}→D^{+}π^{0} with D^{+}→K^{-}π^{+}π^{+}. The data were recorded with the BABAR detector at center-of-mass energies at and near the ϒ(4S) resonance, and correspond to an integrated luminosity of approximately 468  fb^{-1}. We measure Δm_{+}=(140 601.

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Influence of Water on the Oxidation of Dimethyl Sulfide by the OH Radical.

J Phys Chem B

October 2017

UPMC Université Paris 06, CNRS UMR 7616, Laboratoire de Chimie Théorique , Case Courrier 137, 4 Place Jussieu, 75252 Paris, France.

Oxidative stress of sulfur-containing biological molecules in aqueous environments may lead to the formation of adduct intermediates that are too short-lived to be experimentally detectable. In this study we have modeled the simplest of such oxidative reactions: the attack of dimethyl sulfide (DMS) by a hydroxyl radical (OH) to form a radical adduct, whose subsequent heterolytic dissociation leads to a radical cation (DMS) that is important for further reactions. We have modeled the aqueous environment with a limited number of discrete water molecules, selected after an original multistep procedure, and further embedded in a polarizable continuum model, to observe the impact of the water configuration on the heterolytic dissociation of the radical adduct.

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Involvement of oxidative stress and calcium signaling in airborne particulate matter - induced damages in human pulmonary artery endothelial cells.

Toxicol In Vitro

December 2017

Université de Bordeaux, 146, rue Léo Saignat, Bordeaux F-33076, France; Inserm U1045, Centre de Recherche Cardio-Thoracique de Bordeaux, 146, rue Léo Saignat, Bordeaux F-33076, France. Electronic address:

Recent studies have revealed that particulate matter (PM) exert deleterious effects on vascular function. Pulmonary artery endothelial cells (HPAEC), which are involved in the vasomotricity regulation, can be a direct target of inhaled particles. Modifications in calcium homeostasis and oxidative stress are critical events involved in the physiopathology of vascular diseases.

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Supplementation with 80,000 IU vitamin D3/month between November and April corrects vitamin D insufficiency without overdosing: Effect on serum 25-hydroxyvitamin D serum concentrations.

Presse Med

March 2017

Assistance publique des Hôpitaux de Paris (AP-HP), hôpital Necker-Enfants-Malades, service des explorations fonctionnelles, 149, rue de Sèvres, 75015 Paris, France. Electronic address:

Introduction: Vitamin D insufficiency, defined by a 25-hydroxyvitamin D (25OHD) serum concentration<20ng/mL, is highly frequent in the French general population, especially between November and April. The aim of this study was to evaluate whether 80,000 IU vitamin D3 every month during this period of the year was able to maintain a 25OHD level between 20 and 60ng/mL in apparently healthy subjects whatever their basal vitamin D status.

Methods: Ninety-eight subjects volunteered to receive an 80,000 IU vitamin D3 dose every month between November 2014 and April 2015.

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One aim of modern astronomy is to detect temperate, Earth-like exoplanets that are well suited for atmospheric characterization. Recently, three Earth-sized planets were detected that transit (that is, pass in front of) a star with a mass just eight per cent that of the Sun, located 12 parsecs away. The transiting configuration of these planets, combined with the Jupiter-like size of their host star-named TRAPPIST-1-makes possible in-depth studies of their atmospheric properties with present-day and future astronomical facilities.

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We search for the rare flavor-changing neutral current process B^{+}→K^{+}τ^{+}τ^{-} using data from the BABAR experiment. The data sample, collected at the center-of-mass energy of the ϒ(4S) resonance, corresponds to a total integrated luminosity of 424  fb^{-1} and to 471×10^{6}  BB[over ¯] pairs. We reconstruct one B meson, produced in the ϒ(4S)→B^{+}B^{-} decay, in one of many hadronic decay modes and search for activity compatible with a B^{+}→K^{+}τ^{+}τ^{-} decay in the rest of the event.

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Stability of metal-organic frameworks under gamma irradiation.

Chem Commun (Camb)

October 2016

Unité de Catalyse et Chimie du Solide (UCCS) - UMR CNRS 8181, Université de Lille, ENSCL, Bat C7, BP 90108, 59652 Villeneuve d'Ascq, France.

We report the study of the resistance of archetypal MOFs (MILs, HKUST-1, UiO-66, and ZIF-8) under gamma irradiation. The different porous solids were irradiated with doses up to 1.75 MGy.

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An absolute radon 222 activity measurement system at LNE-LNHB.

Appl Radiat Isot

December 2016

CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Centre de Saclay, 91191 Gif-sur-Yvette, France.

A good metrological traceability of radon and progenies is necessary to accurately measure the radon concentration. In 1995, at the LNE-LNHB, J.L.

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Radii and Binding Energies in Oxygen Isotopes: A Challenge for Nuclear Forces.

Phys Rev Lett

July 2016

TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3.

We present a systematic study of both nuclear radii and binding energies in (even) oxygen isotopes from the valley of stability to the neutron drip line. Both charge and matter radii are compared to state-of-the-art ab initio calculations along with binding energy systematics. Experimental matter radii are obtained through a complete evaluation of the available elastic proton scattering data of oxygen isotopes.

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We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯→D^(*)π^(+)π^(-)ℓ^(-)ν¯, where D^(*) represents a D or D^(*) meson and ℓ^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]→D^{(*)}π^{+}π^{-}ℓ^{-}ν[over ¯])/B(B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed.

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A significant part of the intrinsic brightness variations in cool stars of low and intermediate mass arises from surface convection (seen as granulation) and acoustic oscillations (p-mode pulsations). The characteristics of these phenomena are largely determined by the stars' surface gravity (g). Detailed photometric measurements of either signal can yield an accurate value of g.

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Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars.

Nature

January 2016

Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus, Denmark.

A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation. The technique of 'gyrochronology' uses the rotation period of a star to calculate its age.

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A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars.

Nature

January 2016

Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.

Magnetic fields play a part in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10 per cent exhibit strong surface fields that are presumed to be residuals from the star formation process.

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