Laboratoire de Physique Corpusculaire de Caen

We develop an efficient, general-purpose, blind/noreference image quality assessment (NR-IQA) algorithm using a natural scene statistics (NSS) model of discrete cosine transform (DCT) coefficients. The algorithm is computationally appealing, given the availability of platforms optimized for DCT computation. The approach relies on a simple Bayesian inference model to predict image quality scores given certain extracted features. The features are based on an NSS model of the image DCT coefficients. The estimated parameters of the model are utilized to form features that are indicative of perceptual quality. These features are used in a simple Bayesian inference approach to predict quality scores. The resulting algorithm, which we name BLIINDS-II, requires minimal training and adopts a simple probabilistic model for score prediction. Given the extracted features from a test image, the quality score that maximizes the probability of the empirically determined inference model is chosen as the predicted quality score of that image. When tested on the LIVE IQA database, BLIINDS-II is shown to correlate highly with human judgments of quality, at a level that is competitive with the popular SSIM index.

We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a ^{199}Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{n}=(0.0±1.1_{stat}±0.2_{sys})×10^{-26} e.cm.

Crystalline microporous solids are an important class of inorganic materials with uses in different areas impacting our everyday lives, namely as catalysts, adsorbents, and ion exchangers. Advancements in synthesis have been invaluable in expanding the classical aluminosilicate zeolites to new unique framework types and compositions, motivating innovative developments. However, the inexhaustible post-synthetic options to tailor zeolite properties have been and will continue to be indispensable to realize emerging and to improve conventional applications. Starting from the routine drying and template removal processes that every zeolite must experience prior to use, a wide spectrum of treatments exists to alter individual or collective characteristics of these materials for optimal performance. This review documents the toolbox of post-synthetic strategies available to tune the properties of zeolitic materials for specific functions. The categorisation is based on the scale at which the alteration is aimed at, including the atomic structure (e.g. the introduction, dislodgment, or replacement of framework atoms), the micropore level (e.g. template removal and functionalisation by inorganic and organic species), and the crystal and particle levels (e.g. the introduction of auxiliary porosity). Through examples in the recent literature, it is shown that the combination of post-synthetic methods enables rational zeolite design, extending the characteristics of these materials way beyond those imposed by the synthesis conditions.

We present for the first time a detailed and comprehensive analysis of the experimental results that set the current world sensitivity limit on the magnitude of the electric dipole moment (EDM) of the neutron. We have extended and enhanced our earlier analysis to include recent developments in the understanding of the effects of gravity in depolarizing ultracold neutrons; an improved calculation of the spectrum of the neutrons; and conservative estimates of other possible systematic errors, which are also shown to be consistent with more recent measurements undertaken with the apparatus. We obtain a net result of ${d}_{\mathrm{n}}=\ensuremath{-}0.21\ifmmode\pm\else\textpm\fi{}1.82\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}26}\text{ }\text{ }e\text{ }\mathrm{cm}$, which may be interpreted as a slightly revised upper limit on the magnitude of the EDM of $3.0\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}26}\text{ }\text{ }e\text{ }\mathrm{cm}$ (90% C.L.) or $3.6\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}26}\text{ }\text{ }e\text{ }\mathrm{cm}$ (95% C.L.).

Oxide electronic materials provide a plethora of possible applications and offer ample opportunity for scientists to probe into some of the exciting and intriguing phenomena exhibited by oxide systems and oxide interfaces. In addition to the already diverse spectrum of properties, the nanoscale form of oxides provides a new dimension of hitherto unknown phenomena due to the increased surface-to-volume ratio.

The current status of precision measurements in allowed nuclear beta decay is reviewed, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. Experimental results are interpreted in the framework of phenomenological model-independent descriptions of nuclear beta decay as well as in some specific extensions of the standard model. The values of the standard couplings and the constraints on the exotic couplings of the general beta decay Hamiltonian are updated. The ratio between the axial and vector couplings obtained is ${C}_{A}∕{C}_{V}=\ensuremath{-}1.269\phantom{\rule{0.2em}{0ex}}92(69)$ under standard model assumptions. Particular attention is devoted to the discussion of the sensitivity and complementarity of different precision experiments in direct beta decay. The prospects and impact of recent developments of precision tools and of high intensity low-energy beams are also addressed.

Abstract The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org . The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.

Controlling Zeolite Nucleation Small zeolite crystals are of increasing interest as catalysts and for membrane separations because they allow the high selectivity of their cages to be exploited while minimizing the kinetic limitations caused by diffusion. Ng et al. (p. 70 , published online 8 December) synthesized ultrasmall crystals (6 to 15 nanometers) of the EMT zeolite, which has a low framework density and good catalytic properties for hydrocarbon “cracking” (conversion of a large hydrocarbon to smaller ones). The synthesis of EMT has normally required expensive organic templates that limit its industrial use. Careful control of the synthesis conditions, such as ratios of reactants and short bursts of microwave heating, allowed small EMT crystals to nucleate and avoid formation of zeolites with closely related structures.

The isomerization of o-xylene, a prototypical example of shape-selective catalysis by zeolites, was investigated on hierarchical porous ZSM-5. Extensive intracrystalline mesoporosity in ZSM-5 was introduced by controlled silicon leaching with NaOH. In addition to the development of secondary porosity, the treatment also induced substantial aluminum redistribution, increasing the density of Lewis acid sites located at the external surface of the crystals. However, the strength of the remaining Brønsted sites was not changed. The mesoporous zeolite displayed a higher o-xylene conversion than its parent, owing to the reduced diffusion limitations. However, the selectivity to p-xylene decreased, and fast deactivation due to coking occurred. This is mainly due to the deleterious effect of acidity at the substantially increased external surface and near the pore mouths. A consecutive mild HCl washing of the hierarchical zeolite proved effective to increase the p-xylene selectivity and reduce the deactivation rate. The HCl-washed hierarchical ZSM-5 displayed an approximately twofold increase in p-xylene yield compared to the purely microporous zeolite. The reaction was followed by operando infrared spectroscopy to simultaneously monitor the catalytic performance and the buildup of carbonaceous deposits on the surface. Our results show that the interplay between activity, selectivity, and stability in modified zeolites can be optimized by relatively simple post-synthesis treatments, such as base leaching (introduction of mesoporosity) and acid washing (surface acidity modification).

Resistance to erythromycin in Streptococcus pneumoniae was first detected in 1967 in the United States and subsequently worldwide (11, 20). The corresponding mechanism was rapidly identified as ribosomal methylation, which had been primarily reported as being responsible for erythromycin resistance in staphylococci (44). Further spread of resistance was then noted in a few countries, such as France, where hospitals observed a sharp increase in the proportion of resistant pneumococci, which reached approximately 20% in 1984 (16). This trend was observed several years before the emergence and spread of penicillin resistance in pneumococci in France. Recently, an increasing number of countries have noted changes in the evolution of macrolide resistance. In some of them, such as the United States, increased incidence has been correlated with the emergence of a new mechanism of erythromycin resistance—efflux (39). This review is devoted to the mechanisms responsible for resistance to macrolides and related antibiotics in pneumococci.

The neutron-rich ${}^{66,68}\mathrm{Ni}$ have been produced at GANIL via interactions of a $65.9A\mathrm{MeV}$ ${}^{70}\mathrm{Zn}$ beam with a ${}^{58}\mathrm{Ni}$ target. Their reduced transition probability $B({E2;0}_{1}^{+}\ensuremath{\rightarrow}{2}^{+})$ has been measured for the first time by Coulomb excitation in a ${}^{208}\mathrm{Pb}$ target at intermediate energy. The $B(E2)$ value for ${}^{68}{\mathrm{Ni}}_{40}$ is unexpectedly small. An analysis in terms of large scale shell model calculations stresses the importance of proton core excitations to reproduce the $B(E2)$ values and indicates the erosion of the $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}40$ harmonic-oscillator subshell by neutron-pair scattering.

The cross sections for single-neutron removal from the very neutron-rich nucleus $^{31}\mathrm{Ne}$ on Pb and C targets have been measured at $230\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$ using the RIBF facility at RIKEN. The deduced large Coulomb breakup cross section of 540(70) mb is indicative of a soft $E1$ excitation. Comparison with direct-breakup model calculations suggests that the valence neutron of $^{31}\mathrm{Ne}$ occupies a low-$\ensuremath{\ell}$ orbital (most probably $2{p}_{3/2}$) with a small separation energy (${S}_{n}\ensuremath{\lesssim}0.8\text{ }\text{ }\mathrm{MeV}$), instead of being predominantly in the $1{f}_{7/2}$ orbital as expected from the conventional shell ordering. These findings suggest that $^{31}\mathrm{Ne}$ is the heaviest halo system known.

The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double β decay experiment SuperNEMO is discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double β decay by measuring the decay half-life and the electron angular and energy distributions.

In-beam $\ensuremath{\gamma}$-ray spectroscopy using fragmentation reactions of both stable and radioactive beams has been performed in order to study the structure of excited states in neutron-rich oxygen isotopes with masses ranging from $A=20$ to 24. For the produced fragments, $\ensuremath{\gamma}$-ray energies, intensities, and $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidences have been measured. Based on this information new level schemes are proposed for $^{21,22}\mathrm{O}$ up to the neutron separation energy. The nonobservation of any $\ensuremath{\gamma}$-decay branch from $^{23}\mathrm{O}$ and $^{24}\mathrm{O}$ suggests that their excited states lie above the neutron decay thresholds. From this, as well as from the level schemes proposed for $^{21}\mathrm{O}$ and $^{22}\mathrm{O}$, the size of the $N=14$ and 16 shell gaps in oxygen isotopes is discussed in the light of shell-model calculations.

Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size and fragility make them unsuitable for use during patient treatment. In collaboration with a French center for cancer treatment in Caen, we describe the development and testing of a low-cost radiotherapy dosimeter (SDM) based on scintillating fibers and signal processing to reduce the effect of Cerenkov radiation background. The employment of photodiodes for light collection reduces the cost relative to systems using photomultipliers (PMTs). However, we have also developed a highly sensitive system that uses PMTs for very low-dose deposition for Brachytherapy. Comparison with standard ionization chambers shows about a 1% difference over a range of 6- to 25-MV photons. This dosimeter is 1 mm in diameter and can be placed where ever required including inside the body. Its small size and flexibility make it useful for delimiting critical regions, where organs may be very radiation sensitive.

Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.

ABSTRACT The English Channel and its Western Approaches constitute a 700 km long epicontinental sea located in a temperate environment and in a tectonic setting where subsidence is minimal. A sedimentological survey of this region reveals quite distinct provinces: a central sector (Western Channel) where predominantly bioclastic sediments are widely represented, bounded by two mainly terrigenous‐rich zones, the outer terrace of the Celtic Sea and the Eastern Channel. Lateral sedimentary variations of decreasing grain size are interpreted in terms of current velocity patterns. The various types of such sequences may relate to the degree of mixing of older lithoclastic sediments with the Holocene bioclastic supply. A scenario for the evolution of the recent sedimentation of this epicontinental sea is presented. Starting from a permanent marine zone—at least since the Würm period—that bounds the Bay of Biscay, the Holocene transgression progressed over the English Channel. In the Western Channel earlier terrigenous deposits were gradually overlapped by bioclastic sediments that originated on the pre‐Mesozoic rocky substratum and which were particularly extensive off the Armorican Massif. In the subsequently submerged Eastern Channel the pre‐Holocene clastic source has undergone comparatively less modification and still crops out in most of the area. With the opening of the Straits of Dover, at about 9000 yr BP, submersion was complete and new hydrodynamic conditions developed as the eustatic level stabilized. The present sediment distribution is in harmony with the hydrodynamic setting except on the southern rise of the Celtic Sea where both morphology and sedimentary patterns still largely reflect pre‐Holocene conditions.

BACKGROUND: Reverse seroconversion to hepatitis B virus (HBV), i.e., HBV reactivation in patients with pretransplant antibodies to hepatitis B surface antigen (anti-HBs) and to hepatitis B core antigen (anti-HBc), is rarely re-ported after allogeneic bone marrow transplantation. METHODS: To determine this risk, we studied clinical outcome and serological changes in 37 patients with pretransplant anti-HBs and anti-HBc. RESULTS: In 33 cases, no change in HBV markers was observed in the posttransplant period. In four cases, anti-HBs and anti-HBc were lost, and hepatitis B surface antigen, hepatitis B e antigen, and HBV DNA emerged together with acute hepatitis, after cessation of immunosuppression. The actuarial risk of reactivation in the 37 patients was 20.5% (median follow-up 20 months). No reactivation occurred in patients with anti-HBs-positive donors. CONCLUSION: Although few cases of postallogeneic bone marrow transplantation reverse seroconversion to HBV have been reported, this study demonstrates that the actuarial risk is relatively high and suggests that donor vaccination might be proposed prophylactically or that HBs-specific immunoglobulin infusions might be warranted.

Two-particle correlations at small relative momenta provide information about the space-time extent and the excitation energy density of the emitting system. Detailed measurements of two-particle correlations were performed for $^{40}\mathrm{induced}$ reactions on $^{197}\mathrm{Au}$ at E/A=60 MeV. In general, more pronounced correlations are measured for particles of higher outgoing energy. From the relative populations of excited states, a mean emission temperature of T\ensuremath{\approxeq}5.5 MeV is extracted. Within the framework of the quantum statistical model, our findings are consistent with an expanding nuclear system which disintegrates at low temperature (T\ensuremath{\approxeq}5.5 MeV) and rather low density (\ensuremath{\rho}\ensuremath{\le}0.1${\ensuremath{\rho}}_{0}$).

This paper deals with the experimental validation of a Matlab-Simulink simulation tool of marine current turbine (MCT) systems. The developed simulator is intended to be used as a sizing and site evaluation tool for MCT installations. For that purpose, the simulator is evaluated within the context of speed control of a permanent magnet synchronous generator-based (PMSG) MCT. To increase the generated power, and therefore the efficiency of an MCT, a nonlinear controller has been proposed. PMSG has been already considered for similar applications, particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Moreover, PMSG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely second-order sliding mode control, is proposed. The proposed control strategy is inserted in the simulator that accounts for the resource and the marine turbine models. Simulations using tidal current data from Raz de Sein (Brittany, France) and experiments on a 7.5-kW real-time simulator are carried out for the validation of the simulator.