Neutrinos and Non-proliferation in Europe

International audienceTriggered by the demand of the IAEA, neutrino physicists in Europe involved with the Double Chooz experiment are studying the potential of neutrino detection to monitor nuclear reactors. In particular a new set of experiments at the ILL is planned to improve the knowledge of the neutrino spectrum emitted in the fission of 235U and 239Pu

Reanalysis of the GALLEX solar neutrino flux and source experiments

After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX}: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is (73.4 +7.1 -7.3) SNU. This is 5.3% below the old value of (77.5 + 7.5 -7.8) SNU (PLB 447 (1999) 127-133) with a substantially reduced error. A similar reduction is obtained from the reanalysis of the 51Cr neutrino source experiments of 1994/1995.Comment: Accepted by Physics Letters B January 13, 201

Remark on the studies of the muon-induced neutron background in the liquid scintillator detectors

This article gives a point of view on the studies of the muon-induced background for the underground experiments using a liquid scintillator detectors. The results obtained are in good agreement with the data, especially for the neutron yield production. This is the first time, when a study of this kind successes to get the same neutron yield as the one obtained from the experiment.Comment: 5 pages, 2 figures, 1 tabl

Observation of beta decay of In-115 to the first excited level of Sn-115

In the context of the LENS R&D solar neutrino project, the gamma spectrum of a sample of metallic indium was measured using a single experimental setup of 4 HP-Ge detectors located underground at the Gran Sasso National Laboratories (LNGS), Italy. A gamma line at the energy (497.48 +/- 0.21) keV was found that is not present in the background spectrum and that can be identified as a gamma quantum following the beta decay of In-115 to the first excited state of Sn-115 (9/2+ --> 3/2+). This decay channel of In-115, which is reported here for the first time, has an extremely low Q-value, Q = (2 +/- 4) keV, and has a much lower probability than the well-known ground state-ground state transition, being the branching ratio b = (1.18 +/- 0.31) 10^-6. This could be the beta decay with the lowest known Q-value. The limit on charge non-conserving beta decay of In-115 is set at 90% C.L. as tau > 4.1 10^20 y.Comment: 19 pages, 5 figures, 2 table

A proposed search for a fourth neutrino with a PBq antineutrino source

Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV^2. We show that this hypothesis can be tested with a PBq (ten kilocurie scale) 144Ce or 106Ru antineutrino beta-source deployed at the center of a large low background liquid scintillator detector. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unabiguously determine neutrino mass differences and mixing angles.Comment: 4 pages ; 1 table ; 4 figures - Add energy spectrum shape only analysis + referee comments/suggestion

Chimie et neutrinos

Cet article illustre la synergie qui existe entre la chimie et la détection des neutrinos, ces particules élémentaires dont l'existence fut confirmée grâce à l'invention des détecteurs à liquide scintillant par des chimistes. Les progrès de ces détecteurs sont issus des recherches des chimistes. La résolution de l'énigme des neutrinos solaires fut rendue possible entre autres par l'obtention d'une extrême pureté radiochimique des différentes cibles utilisées

Myologie de l'aile chez la buse variable (Buteo buteo Linné)

Ce travail présente les muscles du membre thoracique de la buse variable, Buteo buteo Linné. La première partie est un rappel d'ostéologie indispensable à la compréhension de la situation, des rapports, des insertions, et du rôle des différents muscles, dont l'étude fait l'objet de la deuxième partie.La dernière partie récapitule les groupes musculaires considérés sur les plans fonctionnels et topographiques

Amphiphilic Macromolecules on Cell Membranes: From Protective Layers to Controlled Permeabilization.

International audienceAntimicrobial and cell-penetrating peptides have inspired developments of abiotic membrane-active polymers that can coat, penetrate, or break lipid bilayers in model systems. Application to cell cultures is more recent, but remarkable bioactivities are already reported. Synthetic polymer chains were tailored to achieve (i) high biocide efficiencies, and selectivity for bacteria (Gram-positive/Gram-negative or bacterial/mammalian membranes), (ii) stable and mild encapsulation of viable isolated cells to escape immune systems, (iii) pH-, temperature-, or light-triggered interaction with cells. This review illustrates these recent achievements highlighting the use of abiotic polymers, and compares the major structural determinants that control efficiency of polymers and peptides. Charge density, sp. of cationic and guanidinium side groups, and hydrophobicity (including polarity of stimuli-responsive moieties) guide the design of new copolymers for the handling of cell membranes. While polycationic chains are generally used as biocidal or hemolytic agents, anionic amphiphilic polymers, including Amphipols, are particularly prone to mild permeabilization and/or intracell delivery