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International audience; The ability of mid-infrared spectroscopy (MIR) to predict indicators (1) of diet composition in dairy herds and (2) for the authentication of the cow feeding restrictions included in the specification of 2 Protected Designation of Origin (PDO) cheeses (Cantal and Laguiole) was tested on 7,607 bulk milk spectra from 1,355 farms located in the Massif Central area of France. For each milk sample, the corresponding cow diet composition data were obtained through on-farm surveys. The cow diet compositions varied largely (i.e., from full grazing for extensive farming systems to corn silage-based diets, which are typical of more intensive farming systems). Partial least square regression and discriminant analysis were used to predict the proportion of different feedstuff's in the cows' diets and to authenticate the cow feeding restrictions for the PDO cheese specifications, respectively. The groups for the discriminant analysis were created by dividing the data set according to the threshold of a specific feedstuff. They were issued based on the specifications of the restriction of the PDO cheese. The pasture proportion in the cows' diets was predicted by MIR with an coefficient of determination in external validation ((RV)-V-2) 0.81 and a standard error of prediction of 11.7% dry matter. Pasture + hay, corn silage, conserved herbage, fermented forage, and total herbage proportion in the cows' diets were predicted with a (RV)-V-2 >0.61 and a standard error of prediction = 50%, and pasture >= 57% in the cows' diets achieved an accuracy and specificity >= 90%. A sensitivity and precision >= 85% were also observed for the pasture proportion discrimination models, but both of these indexes decreased at increasing thresholds from 0 to 50, and 57% pasture in the cows' diets. An accuracy >= 80% was also observed for pasture + hay >= 72%, herbage >= 50%, pasture hay >= 25%, absence of fermented herbage, absence of corn silage, and corn silage 90%. Both the regression and discriminant MIR models for bulk milk can provide useful indicators of cow diet composition and PDO cheese specifications to producers and consumers (farmers, dairy plants).

International audience; There are time-tested assessments for the environmental and economic aspects of sustainability. Its societal aspect has mainly been approached through the assessment of animal welfare. However, the intrinsic quality of milk is seldom taken into account. We developed a participatory construction method for the overall assessment of intrinsic milk quality in its different dimensions (sensory, technological, nutritional and health), according to the fate of the raw milk. Two assessment models were developed, for semiskimmed standardized ultra-high temperature (UHT) milk and for pressed uncooked non-standardized raw milk cheese. They were constructed by a participatory approach involving experts in the dairy sectorwith the aim to obtain a diagnostic tool that could be used in the field to help farmers to manage the quality of their milk (by prioritizing improvements on major problems). They were shaped from prerequisite specifications (limited costs and time of application, desire to obtain a transparent tool with all the steps kept visible) and current technical and scientific knowledge. They were based on indicators obtained from raw bulk tank milk analyses (30 for UHT milk and 50 for cheese assessments), which were then aggregated into criteria, principles, dimensions and overall intrinsic quality at farm level. The assessment models had parts in common, for example, same four dimensions, common indicators for health andnutritional dimensions. They also had process-specific features: units chosen, criteria, indicators and weightings in relation to the final product specifications. For instance, sensory and technological dimensions are more complex and preponderant in the cheese assessment (three principles for cheese vs one for UHT milk in both dimensions). Another example is the lack of microbial pathogens (as potential health risk for consumer) in the UHT milk assessment because of pasteurization. The assessment models then underwent a sensitivity analysis and an application in 30 farms in indoor and grazing periods to finally obtain overall UHT milk and cheese quality scores at a 1-year level. The tool was found to be applicableat farm level. However, we observed low overall quality scores with a narrow dispersion, characteristic of a severe evaluation. Even so, the assessment models showed up seasonal differences of the UHT milk and cheese quality at both overall and dimensional levels. In the light of new scientific knowledge and future quality objectives, these are adaptable to other dairy products allowing for their specific features.

International audience; The ability of mid-infrared spectroscopy (MIR) to predict indicators (i) of diet composition in dairy herds and (ii) forthe authentication of the cow-feeding restrictions included in the specification of two Protected Designation ofOrigin (PDO) cheeses (Cantal and Laguiole) was tested on 7607 bulk milk spectra from 1355 farms located in theFrench Massif Central. For each milk sample, the corresponding cow diet composition was obtained through onfarm surveys between April 2018 and March 2019. Cow diet composition varied largely (from full grazing forextensive farming systems to corn silage-based diets). The database was divided into a calibration (n = 6107) andvalidation (n = 1500) sets. Partial least square regression and discriminant analysis were used to predict theproportion of different feedstuffs in the cows’ diets and to authenticate the cow-feeding restrictions for the PDOcheese specifications, respectively. The pasture proportion in the cows’ diets was predicted by MIR with an R2 inexternal validation (R2V) = 0.81 and a standard error of prediction (SEP) of 11.7% dry matter. Pasture + hay, cornsilage, conserved herbage, fermented forage and total herbage proportions were predicted with a R2V > 0.61 and aSEP < 14.8%. The discrimination models for pasture presence, pasture ≥ 50% and pasture ≥ 57% in the cows’diets achieved an accuracy and specificity ≥ 90%. A sensitivity and precision > 80% were observed for all modelsincluding pasture proportion in cow diet. An accuracy ≥ 80% was also observed for pasture + hay ≥ 72%, herbage≥ 50%, pasture + hay ≥ 25%, absence of fermented herbage, absence of corn silage and corn silage ≤ 30% in thecows’ diets, but for several models, either the sensitivity or precision was lower than the accuracy. Models built withrespect to all the criteria of the feeding restrictions of PDO cheese specifications achieved an accuracy, specificity,sensitivity and precision > 90%. Both the regression and discriminant MIR models for bulk milk can provide usefulindicators of cow diet composition and PDO cheese specifications to producers and consumers; L’aptitude de la spectroscopie dans le moyen infrarouge (MIR) appliquée sur des laits de mélange pour 1) prédirela composition de la ration des troupeaux laitiers et 2) authentifier des pratiques des cahiers des charges desfromages AOP Cantal et Laguiole, a été testée. Les spectres MIR de 7607 laits de mélange AOP et non AOP de larégion ont été associés aux données d’enquêtes sur l’alimentation correspondantes (obtenues entre avril 2018 etmars 2019), afin de constituer la base des données. La composition de la ration était très variable, allant de rations100% pâturage, à des rations à base d’ensilage de maïs (jusqu’à 74%). La base de données a été divisée en deuxpour l’étalonnage (n = 6107) et la validation (n = 1500). Des modèles de régression « partial least squares » et desanalyses discriminantes ont été utilisés pour prédire la composition de la ration en pourcentage de matière sèche(MS) et pour authentifier les critères d’alimentation inclus dans les cahiers des charges des deux AOP,respectivement. La proportion d’herbe pâturée dans la ration a été prédite avec un modèle caractérisé par uncoefficient de détermination en validation externe (R2V) de 0,81 et une erreur standard de prédiction (SEP) de 11,7%. Les proportions de pâturage + foin, d’ensilage de maïs, d’herbe conservée, de fourrages fermentés et d’herbetotale ont été prédites par des modèles ayant des R2V > 0,61 et SEP < 14,8%. Les modèles d’analysesdiscriminantes pour la présence du pâturage, la proportion de pâturage ≥ 50% et ≥ 57% ont montré des valeursd’exactitude et de spécificité ≥ 90%. Des valeurs de sensibilité et de précision ≥ 80% ont été observées pour tousles modèles discriminants concernant la proportion du pâturage dans la ration. Les modèles discriminants pour laproportion de pâturage + foin ≥ 72%, herbe totale (fraiche et conservée) ≥ 50%, le pâturage + foin ≥ 25%, absenced’herbe fermentée, absence d’ensilage de maïs et ensilage de maïs ≤ 30% dans la ration ont montré des valeursd’exactitude ≥ 80%, mais pour ces modèles soit la sensibilité, soit la précision ont été moins performantes. Lesmodèles construits pour tester le respect de l’ensemble des critères des cahiers des charges de chaque AOP ontmontré des valeurs d’exactitude, spécificité, sensibilité et précision > 90%. Les modèles pour la prédiction du %des aliments dans la ration tout comme les modèles discriminants peuvent permettre de fournir, via la MIR, desindicateurs sur la composition de la ration des troupeaux laitiers utiles aux éleveurs, filières et aux consommateurs.

Background Treatment of superficial venous reflux in addition to compression therapy accelerates venous leg ulcer healing and reduces ulcer recurrence. The aim of this study was to evaluate the costs and cost-effectiveness of early versus delayed endovenous treatment of patients with venous leg ulcers. Methods This was a within-trial cost-utility analysis with a 1-year time horizon using data from the EVRA (Early Venous Reflux Ablation) trial. The study compared early versus deferred endovenous ablation for superficial venous truncal reflux in patients with a venous leg ulcer. The outcome measure was the cost per quality-adjusted life-year (QALY) over 1 year. Sensitivity analyses were conducted with alternative methods of handling missing data, alternative preference weights for health-related quality of life, and per protocol. Results After early intervention, the mean(s.e.m.) cost was higher (difference in cost per patient £163(318) (€184(358))) and early intervention was associated with more QALYs at 1 year (mean(s.e.m.) difference 0·041(0·017)). The incremental cost-effectiveness ratio (ICER) was £3976 (€4482) per QALY. There was an 89 per cent probability that early venous intervention is cost-effective at a threshold of £20 000 (€22 546)/QALY. Sensitivity analyses produced similar results, confirming that early treatment of superficial reflux is highly likely to be cost-effective. Conclusion Early treatment of superficial reflux is highly likely to be cost-effective in patients with venous leg ulcers over 1 year. Registration number: ISRCTN02335796 (http://www.isrctn.com).

Magnetic fields produced by the interaction of intense laser beams on the surface of flat solid targets have been characterized. Laser probe polarimetry diagnosed the spatial and temporal evolution of the magnetic field by measuring the changes in the probe beam polarization due to Cotton-Mouton and Faraday effects at different times with respect to a pump laser pulse. The results show that 1 ps after the interaction of the pump laser with the target, a magnetic field of the order of a few MG is already present over a region ≈150 μm in diameter centered around the interaction spot. From the spatial and temporal evolutions of the magnetic field, we infer information on the resistivity of the material, showing evidence of a strongly magnetized resistivity.Magnetic fields produced by the interaction of intense laser beams on the surface of flat solid targets have been characterized. Laser probe polarimetry diagnosed the spatial and temporal evolution of the magnetic field by measuring the changes in the probe beam polarization due to Cotton-Mouton and Faraday effects at different times with respect to a pump laser pulse. The results show that 1 ps after the interaction of the pump laser with the target, a magnetic field of the order of a few MG is already present over a region ≈150 μm in diameter centered around the interaction spot. From the spatial and temporal evolutions of the magnetic field, we infer information on the resistivity of the material, showing evidence of a strongly magnetized resistivity.

A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.

Intense lasers interacting with dense targets accelerate relativistic electron beams, which transport part of the laser energy into the target depth. However, the overall laser-to-target energy coupling efficiency is impaired by the large divergence of the electron beam, intrinsic to the laser–plasma interaction. Here we demonstrate that an efficient guiding of MeV electrons with about 30 MA current in solid matter is obtained by imposing a laser-driven longitudinal magnetostatic field of 600 T. In the magnetized conditions the transported energy density and the peak background electron temperature at the 60-μm-thick target's rear surface rise by about a factor of five, as unfolded from benchmarked simulations. Such an improvement of energy-density flux through dense matter paves the ground for advances in laser-driven intense sources of energetic particles and radiation, driving matter to extreme temperatures, reaching states relevant for planetary or stellar science as yet inaccessible at the laboratory scale and achieving high-gain laser-driven thermonuclear fusion., Efficient energy transport by laser-driven relativistic electron beams is crucial in many applications including inertial confinement fusion, and particle acceleration. Here the authors demonstrate relativistic electron beam guiding in dense plasma with an externally imposed high magnetic field.

The targets that are used to produce high-energy protons with ultra-high intensity lasers generate a strong electromagnetic pulse (EMP). To mitigate that undesired side effect, we developed and tested a concept called the "birdhouse." It consists in confining the EMP field in a finite volume and in dissipating the trapped electromagnetic energy with an electric resistor. A prototype was tested at a 10 TW 50 fs laser facility. The recorded average EMP mitigation ratio is about 20 for frequencies from 100 MHz to 6 GHz. The EMP mitigation ratio attains the level of 50 in the frequency range of 1-2 GHz where microwave emission is maximal. We measured the intensity of proton emission in two directions: along the laser propagation direction and along the edge of the proton beam. We observed that the "birdhouse" induces a two-fold increase of the intensity in the center of the proton beam and a two-fold reduction of the intensity on its edge. We did not observe any modification of the proton beam normalized spectrum.

The SEPAGE spectrometer (Spectrometre Electrons Protons A Grandes Energies) was realized within the PETAL+ project funded by the French ANR (French National Agency for Research). This plasma diagnostic, installed on the LMJ-PETAL laser facility, is dedicated to the measurement of charged particle energy spectra generated by experiments using PETAL (PETawatt Aquitaine Laser). SEPAGE is inserted inside the 10-meter diameter LMJ experimental chamber with a SID (Diagnostic Insertion System) in order to be close enough to the target. It is composed of two Thomson Parabola measuring ion spectra and more particularly proton spectra ranging from 0.1 to 20 MeV and from 8 to 200 MeV for the low and high energy channels respectively. The electron spectrum is also measured with an energy range between 0.1 and 150 MeV. The front part of the diagnostic carries a film stack that can be placed as close as 100 mm from the target center chamber. This stack allows a spatial and spectral characterization of the entire proton beam. It can also be used to realize proton radiographies.

International audience; The effects of packaging on the biochemical and sensory characteristics of industrial blue-veined cheese (pieces of cheeses pre-packaged in materials of different permeability and whole cheeses traditionally wrapped in aluminium foil) were evaluated over 43 days of storage. In cheese pieces in reduced-O-2 packaging, less ammonia production and lower proteolysis were observed. Packaged cheese pieces were distinguished from controls by higher levels of (a) methyl ketones and their corresponding alcohols and acids, (b) methyl acids derived from branched chain amino acids and (c) esters. This may be due to less oxidation. Packaged cheese pieces were also more acid, with more pungency, creaminess and milky odour and less bitterness than the control cheeses. They have high moisture content, owing to the low water vapour permeability of the films. Fourme d'Ambert cheese pieces wrapped in permeable film behaved similarly to the corresponding control throughout storage.

International audience; The aim of this study was to run challenge tests to investigate the behaviour of Listeria monocytogenes in raw milk Cantal type uncooked pressed cheeses throughout the cheese process and during storage in different packagings (stretch film, vacuum packs and kraft paper) at 6 degrees C during two-thirds of the storage period, then at 10 degrees C; for kraft paper the last five days were at 15 degrees C. Whatever the weight of the cheese (10 or 40 kg), L. monocytogenes only increased during the first 24 h of cheese making and decreased significantly in both cores and rinds during ripening at 9 degrees C from day 45 to day 360. In cores, decay rate can depend on milk properties and in our experiment were associated with high levels of lactate and acetate during ripening. The decrease continued significantly in the cores during storage in all three packagings, more rapidly than during ripening. The populations of the pathogen were usually similar whatever the packaging. In rind, L monocytogenes decreased most significantly during storage in kraft paper; after 45 days of storage the counts were significantly lower in kraft paper than under vacuum whereas Gram positive non lactic acid bacteria and yeasts were at hither counts. The low a(w) (

International audience; We experimentally investigate the fast ($\atop\sim}$10 ps into a $\approx$ 140 Mbar blast wave, according to hydrodynamic simulations, consistent with our measurements. These experimental and numerical findings pave the way to a short-pulse-laser-based platform dedicated to high-energy-density physics studies.

International audience; The goal of this paper is twofold: first, we demonstrate shock generation with ultra-short (24 fs) and low-energy (J) laser pulse, following the energy deposition in the target by fast electrons; second, we show that such shocks can be used to provide information on compressed matter. For a target with 50 mu m thickness we have clearly inferred the formation of a shock wave with pressure >= 100 Mbar. We have also measured the color temperature of the emitting target rear side at breakout time (T approximate to 0.6 eV), which is in good agreement with predictions from equation-of-state models (SESAME tables) and hydrodynamic simulations.

Collimated transport of ultrahigh intensity electron current was observed in cold and in laser-shocked vitreous carbon, in agreement with simulation predictions. The fast electron beams were created by coupling high-intensity and high-contrast laser pulses onto copper-coated cones drilled into the carbon samples. The guiding mechanism---observed only for times before the shock breakout at the inner cone tip---is due to self-generated resistive magnetic fields of $\ensuremath{\sim}0.5--1\text{ }\text{ }\mathrm{kT}$ arising from the intense currents of fast electrons in vitreous carbon, by virtue of its specific high resistivity over the range of explored background temperatures. The spatial distribution of the electron beams, injected through the samples at different stages of compression, was characterized by side-on imaging of hard x-ray fluorescence.

We studied D + D fusion reactions at the CELIA/ECLIPSE laser facility. These reactions were triggered by focusing the ECLIPSE laser (up to 100 mJ on target, pulse duration of 40 fs and focal spot of FWHM) on a solid C2 D4 target. By detecting the 2.5 MeV neutrons, produced in the D + D fusion reaction, using C6 D6 scintillators in a time-of-flight experimental set-up, we measured a rate of a few hundred fusions per shot. At the same time, we detected also energetic ions (up to a few 100 keV) using time-of-flight diamond detectors. The experimental set-up will be presented and the results discussed and compared with dedicated simulations.

Fast-electron beam stopping mechanisms in media ranging from solid to warm dense matter have been investigated experimentally and numerically. Laser-driven fast electrons have been transported through solid Al targets and shock-compressed Al and plastic foam targets. Their propagation has been diagnosed via rear-side optical self-emission and Kα X-rays from tracer layers. Comparison between measurements and simulations shows that the transition from collision-dominated to resistive field-dominated energy loss occurs for a fast-electron current density ~5 × 1011 A cm−2. The respective increases in the stopping power with target density and resistivity have been detected in each regime. Self-guided propagation over 200μm has been observed in radially compressed targets due to ~1kT magnetic fields generated by resistivity gradients at the converging shock front.

International audience; The knowledge of the absolute energy distributions of the particles emitted from a clinical accelerator is important for the evaluation of Monte Carlo simulations developed for treatment planning. In this paper, an original approach is presented which allows to measure the absolute energy distribution of the electron beam delivered by a Varian 21Ex medical accelerator. The electron beam was characterized at the isocenter with calibrated image plates covering the exit window of a magnetic spectrometer. The characteristics of the electron beam emitted from an effective source have been inferred from the measurements using the Geant4 Monte Carlo code. The contribution of direct electrons to the absolute depth-dose curve in a water phantom is estimated.

Imaging Plates (IP) are diagnostic devices which contain a photostimulable phosphor layer that stores the incident radiation dose as a latent image. The image is read with a scanner which stimulates the decay of electrons, previously excited by the incident radiation, by exposition to a laser beam. This results in emitted light, which is detected by photomultiplier tubes; so the latent image is reconstructed. IPs have the interesting feature that can be reused many times, after erasing stored information. Algorithms to convert signals stored in the detector to Photostimulated luminescence (PSL) counts depend on the scanner and are not available on every model. A comparative cross-calibration of the IP scanner Dürr CR35 BIO, used in ABC laboratory, was performed, using the Fujifilm FLA 7000 scanner as a reference, to find the equivalence between grey-scale values given by the Dürr scanner to PSL counts. Using an IP and a 55Fe β-source, we produced pairs of samples with the same exposition times, which were analysed by both scanners, placing particular attention to fading times of the image stored on IPs. Data analysis led us to the determine a conversion formula which can be used to compare data of experiments obtained in different laboratories and to use IP calibrations available, till now, only for Fujifilm scanners. © 2016 ENEA.

International audience; The aim of this study was to evaluate the effects of packaging on the microbiota of blue veined cheeses. The microbial dynamics of portions of industrial cheeses packaged under vacuum in different films and whole cheeses in aluminium foil was compared using culture-dependant and metagenomic approaches. There was no oxygen in the packaging and CO2 concentrations were between 5 and 12%. The composition of the lactic acid bacteria population did not change significantly during storage; it varied more according to factory of origin. Vacuum packaging hampered the growth of aerobic bacteria (Brevibacterium, Arthrobacter, Brachybacterium) and Gram-negative bacteria more than did stretch film. In vacuum-packed cheese portions, Staphylococcus and/or Brevibacterium and Arthrobacter were the dominant Gram-positive catalase-positive populations, depending on the factory of origin. Cheese packaged under vacuum had a lower pH than cheese in aluminium foil or stretch film.

Thanks to their high dynamic range and ability to withstand electromagnetic pulse, imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. In the framework of the development of the diagnostics for the Petawatt Aquitaine Laser facility, we present an absolute calibration and spatial resolution study of five different available types of IP (namely, MS-SR-TR-MP-ND) performed by using laser-induced K-shell X-rays emitted by a solid silver target irradiated by the laser ECLIPSE at CEntre Lasers Intenses et Applications. In addition, IP sensitivity measurements were performed with a 160 kV X-ray generator at CEA DAM DIF, where the absolute response of IP SR and TR has been calibrated to X-rays in the energy range 8-75 keV with uncertainties of about 15%. Finally, the response functions have been modeled in Monte Carlo GEANT4 simulations in order to reproduce experimental data. Simulations enable extrapolation of the IP response functions to photon energies from 1 keV to 1 GeV, of interest, e.g., for laser-driven radiography. © 2016 AIP Publishing LLC.

Results are reported of an experiment performed at the Eclipse laser facility in CELIA, Bordeaux, on the generation of strong electromagnetic pulses. Measurements were performed of the target neutralization current, the total target charge and the tangential component of the magnetic field for the laser energies ranging from 45 mJ to 92 mJ with the pulse duration approximately 40 fs, and for the pulse durations ranging from 39 fs to 1000 fs, with the laser energy approximately 90 mJ. It was found that the values obtained for thick (mm scale) Cu targets are visibly higher than values reported in previous experiments, which is argued to be a manifestation of a strong dependence of the target electric polarization process on the laser contrast and hence on the amount of preplasma. It was also found that values obtained for thin (micrometer scale) Al foils were visibly higher than values for thick Cu targets, especially for pulse durations longer than 100 fs. The correlations between the total target charge versus the maximum value of the target neutralization current, and the maximum value of the tangential component of the magnetic field versus the total target charge were analysed. They were found to be in very good agreement with correlations seen in data from previous experiments, which provides a good consistency check on our experimental procedures., Comment: Presented at the International Conference on Research and Application of Plasmas Plasma 2017, Warsaw, Poland, September 18-22, 2017

Quasi-static magnetic-fields up to $800\,$T are generated in the interaction of intense laser pulses ($500\,$J, $1\,$ns, $10^{17}\,$W/cm$^2$) with capacitor-coil targets of different materials. The reproducible magnetic-field peak and rise-time, consistent with the laser pulse duration, were accurately inferred from measurements with GHz-bandwidth inductor pickup coils (B-dot probes). Results from Faraday rotation of polarized optical laser light and deflectometry of energetic proton beams are consistent with the B-dot probe measurements at the early stages of the target charging, up to $t\approx 0.35\,$ns, and then are disturbed by radiation and plasma effects. The field has a dipole-like distribution over a characteristic volume of $1\,$mm$^3$, which is coherent with theoretical expectations. These results demonstrate a very efficient conversion of the laser energy into magnetic fields, thus establishing a robust laser-driven platform for reproducible, well characterized, generation of quasi-static magnetic fields at the kT-level, as well as for magnetization and accurate probing of high-energy-density samples driven by secondary powerful laser or particle beams., 16 pages, 7 figures

A model providing an accurate estimate of the charge accumulation on the surface of a metallic target irradiated by a high-intensity laser pulse of fs-ps duration is proposed. The model is confirmed by detailed comparisons with specially designed experiments. Such a model is useful for understanding the electromagnetic pulse emission and the quasistatic magnetic field generation in laser-plasma interaction experiments.

Resume Objectif. – La principale complication de l'hemodilution en chirurgie cardiaque pediatrique est l'anemie. L'inefficacite de l'apport substitutif de fer oral nous a conduit a etudier l'effet de l'injection de complexe hydroxyde ferrique–saccharose : Venofer®. Type d'etude. – Ouverte, randomisee. Patients et methodes. – Quatre-vingt-treize operes en hemodilution ont ete repartis en deux series de 44 malades exploitables. Le premier groupe ne recevait pas de fer et le second une injection de 5 mg/kg de Venofer® le matin suivant l'intervention. Les parametres de l'etude etaient l'hemoglobine, la ferritine et le pourcentage de reticulocytes mesures en postoperatoire a j1 et j5. La comparaison des deux series a ete faite par le test statistique t de Student. Resultats. – Les deux series etaient analogues en âge, poids, hemoglobine, ferritine et reticulocytes a j1 (aucune difference significative). A j5 la ferritine etait superieure dans le groupe traite 215 ± 87 vs 101 ± 55 μg/l dans le groupe non traite (p Conclusion. – L'inflammation postoperatoire peut expliquer l'echec du fer oral. L'apport intraveineux pourrait traiter une carence en fer fonctionnelle et/ou favoriser la synthese d'erythropoietine endogene. La reversibilite plus rapide de l'anemie lors de l'injection de fer ameliore la qualite des suites operatoires.

In laser fusion, the coupling and the propagation of the laser beams in the plasma surrounding the pellet must be well controlled for to succeed in producing a high energy level. To achieve thermonuclear ignition and high gain, the coupling efficiency must be as high as possible, the uniformity of the energy deposition must be very good and the fast electron generation must be minimized. This implies a deep understanding of the laser–plasma interaction mechanisms to keep the nonlinear processes at a low level. Important advances in laser–plasma interaction physics have been achieved thanks to the converging efforts of the experimental and theoretical approaches.Among the different studies of the last few years, we will report results on three themes which are important for future fusion experiments. The first concerns the ability of plasmas to induce temporal and spatial incoherence to the laser beams during their propagation. Beam smoothing, beam spraying and increased incoherence may in turn reduce the level of backscattering instabilities.In laser fusion, multiple beams are used to irradiate the target. The effect of the overlap of the laser beams on parametric instabilities may complicate the problem. Not only is there the interplay between instabilities driven by one beam, but also the interplay between instabilities driven by different beams. In the Laboratoire pour l'Utilisation des Lasers Intenses (LULI) experiment, although the overall stimulated Brillouin scattering (SBS) reflectivity was reduced, a well-defined resonance of the amplitude of ion acoustic waves (IAWs) associated with SBS has been observed for waves propagating along the bisecting direction between two laser beams. Energy transfer between two identical laser beams has been observed and correlated with plasma induced incoherence.The nonlinear saturation of stimulated scattering instabilities is a fundamental ingredient of the understanding of the observed and future reflectivity levels. Using Thomson scattering, the decay of the primary IAWs associated with SBS in secondary IAWs has been observed and correlated with the saturation of SBS.The experiments were performed with the six-beam laser facility of the LULI at Ecole Polytechnique, using one or two 1.053 µm interaction beams in the nanosecond regime and a well-characterized preformed plasma. Multiple diagnostics, including Thomson scattering of a probe beam with spatial, temporal and spectral resolution, were used. The comparison between the experimental results and numerical simulations is used to improve the physics included in the codes.

Le Groupe des Applications Plasma (GAP) du CEA a Saclay participe au projet national PREUVE du Reseau Micro- et Nano-Technologies. Ce projet a ete lance fin 1999 pour reunir et developper les competences en France sur la lithographie dans l'extreme ultraviolet (LEUV). Au sein de PREUVE, notre objectif a ete le developpement d'une source plasma laser dans l'EUV autour de 13nm afin de contribuer a la realisation d'un premier banc d'essai pour la lithographie (BEL) en Europe. Afin de realiser cette source, nous utilisons un plasma emetteur qui est produit par l'interaction d'un laser de type Nd :YAG sur un jet de gouttelettes de xenon. A la fin du projet PREUVE, cette source satisfait les principales specifications et repond en particulier aux besoins en flux de photons EUV pour realiser des tests d'insolation EUV avec le banc d'essai. Suite a ces resultats prometteurs, nous demarrons actuellement un projet industriel EXULITE avec nos partenaires du CEA, d'Alcatel et de Thales sur le developpement d'une source EUV de puissance pour des machines de lithographie de production. Ce projet se terminera en 2005.

A portable (200 � 100 � 100 mm 3 ), high-luminosity, spherically bent crystal spectrometer was designed to measure very low emissivity X-ray spectra of different elements with spatial resolution in a wide spectral range (1.2� 19.6 ( A). A large (50 � 15 mm 2 ) open aperture mica spherically bent crystal with R ¼ 150 mm was used as dispersive and focusing element. This spectrometer was associated with a large sensitive area (f ¼ 40 mm) micro-channel plates assembly. This apparatus provides simultaneously high spectral (l=dlB1800) and spatial (100–200mm) resolutions. Its large tunability allowed, without any adjustment of the spectrometer set-up, to record spectra in the 1.38–17.5 ( A wavelength range. We used the X-ray emission of femtosecond laser-produced plasmas from different materials ((CF2)n, CaF2, Cu, Al) to test the spectrometer. Thanks to the high sensitivity (high collection efficiency) of the system, high quality space-resolved X-ray spectra of Fluorine and Aluminum plasmas were obtained on a single laser shot. r 2001 Elsevier Science B.V. All rights reserved.

By means of spatially resolved high-resolution X-ray spectroscopy, we have investigated the generation of fast ions at various laser installations with different flux densities and laser wavelengths. It is demonstrated that the fast ion generation in laser-produced plasma can be achieved for a very low level of the averaged laser intensity on the target. The time-of-flight mass spectrometry ion diagnostics and X-ray spectrographs give very close results for the energy distribution of the thermal ion component. For higher energies, however, we found significant differences: the spatially resolved high-resolution spectrographs expose the presence of suprathermal ions, while the time-of-flight method does not. Suprathermal ion energies Eion plotted as a function of the qλ2 parameter show a large scatter far above the experimental errors. The cause of these large scatters is attributed to a strong nonuniformity of the laser intensity distribution in the focal spot. The analysis by means of hydrodynamics and spectral simulations show that the X-ray emission spectrum is a complex convolution from different parts of the plasma with strongly different electron density and temperature. It is shown that the highly resolved Li-like satellite spectrum near Heαcontains significant distortions even for very low hot electron fractions. Non-Maxwellian spectroscopy allows determination of both the hot electron fraction and the bulk electron temperature.

Transmission crystal spectrometers (TCS) are used on many laser facilities to record hard X-ray spectra. During experiments, signal recorded on imaging plates is often degraded by a background noise. Monte-Carlo simulations made with the code GEANT4 show that this background noise is mainly generated by diffusion of MeV electrons and very hard X-rays. An experiment, carried out at LULI2000, confirmed that the use of magnets in front of the diagnostic, that bent the electron trajectories, reduces significantly this background. The new spectrometer SPECTIX (Spectrometre PETAL a Cristal en TransmIssion X), built for the LMJ/PETAL facility, will include this optimized shielding.

Energy loss in the transport of a beam of relativistic electrons in warm dense aluminum is measured in the regime of ultrahigh electron beam current density over 2×10^{11} A/cm^{2} (time averaged). The samples are heated by shock compression. Comparing to undriven cold solid targets, the roles of the different initial resistivity and of the transient resistivity (upon target heating during electron transport) are directly observable in the experimental data, and are reproduced by a comprehensive set of simulations describing the hydrodynamics of the shock compression and electron beam generation and transport. We measured a 19% increase in electron resistive energy loss in warm dense compared to cold solid samples of identical areal mass.

We present results on laser-driven relativistic electron beam propagation through aluminum samples, which are either solid and cold or compressed and heated by laser-induced shock. A full numerical description of fast electron generation and transport is found to reproduce the experimental absolute K-alpha yield and spot size measurements for varying target thicknesses, and to sequentially quantify the collisional and resistive electron stopping powers. The results demonstrate that both stopping mechanisms are enhanced in compressed Al samples and are attributed to the increase in the medium density and resistivity, respectively. For the achieved time-and space-averaged electronic current density, < j(h)> similar to 8 x 10(10) A/cm(2) in the samples, the collisional and resistive stopping powers in warm and compressed Al are estimated to be 1.5 keV/mu m and 0.8 keV/mu m, respectively. By contrast, for cold and solid Al, the corresponding estimated values are 1.1 keV/mu m and 0.6 keV/mu m. Prospective numerical simulations involving higher j(h) show that the resistive stopping power can reach the same level as the collisional one. In addition to the effects of compression, the effect of the transient behavior of the resistivity of Al during relativistic electron beam transport becomes progressively more dominant, and for a significantly high current density, j(h) similar to 10(12) A/cm(2), cancels the difference in the electron resistive stopping power (or the total stopping power in units of areal density) between solid and compressed samples. Analytical calculations extend the analysis up to j(h) = 10(14) A/cm(2) (representative of the full-scale fast ignition scenario of inertial confinement fusion), where a very rapid transition to the Spitzer resistivity regime saturates the resistive stopping power, averaged over the electron beam duration, to values of similar to 1 keV/mu m. (C) 2014 AIP Publishing LLC.

We describe an experiment performed at the LULI laser facility using an advanced radiographic technique that allowed obtaining 2D, spatially resolved images of a shocked buried-code-target. The technique is suitable for applications on Fast Ignition as well as Warm Dense Matter research. In our experiment, it allowed to show cone survival up to Mbar pressures and to measure the shock front velocity and the fluid velocity associated to the laser-generated shock. This allowed obtaining one point on the shock polar of porous carbon.

Atomic argon clusters were created using various types of nozzles and gas jet backing pressures. High temperature plasmas were created by irradiating the clusters with high intensity 35 fs laser pulses. The data obtained from these experiments were compared with each other as well as an experiment using a longer pulse ( 60 fs ) higher flux density laser. Detailed spectroscopic analysis of high resolution X-ray data near the Heα,Heβ, and Lyα lines of Ar was consistent with a two-temperature collisional-radiative model incorporating the effects of highly energetic electrons. Each variation has an effect on the rate of cluster expansion; therefore, results of the analysis provide useful insight into the behavior of such plasmas over short time scales. It was demonstrated for the first time, that by using sufficiently large clusters, hydrogen-like ions of Ar with an ionization potential of approximately 4120 eV could be obtained with a 35 fs laser pulse with a relatively low flux density of 1×10 17 W/cm 2 .

The generation of fast particles (both ions and electrons) in a femtosecond laser-produced plasma has been studied experimentally and the possibility of applying particle-in-cell (PIC) codes to the description of the experimental results has been investigated. The energy distribution function of fast ions has been measured directly by means of X-ray spectroscopy. It is shown that this diagnostic can also be used as an indirect method to measure fast electrons inside the plasma. The hot electron distribution in the 0:1–2 MeV energy range was measured directly using a standard electron magnetic spectrometer. The comparison of the experimental results with the numerical simulations show: (1) the electromagnetic PIC-FC code can be successfully applied for simulating plasmas created by the interaction of femtosecond-laser pulses with solid targets and (2) the existence of a transient population of hot electrons with a non-Maxwellian distribution typical of interaction experiments with short-pulse lasers. ? 2001 Elsevier Science Ltd. All rights reserved.

The aim of this work was to develop a vocabulary to describe the odors of selected distilled beverages in 12 panel hours, by monitoring the performance of each assessor and of the panel throughout vocabulary development. Sixteen assessors initially produced a vocabulary of 30 odor terms during group discussion. This list was modified to 20 attributes, and panel agreement on its definition was monitored, over three sessions of descriptive analyses of eight samples which could represent the diversity of odors to be encountered in future use of the vocabulary. The data from each descriptive analysis was analyzed by Principal Component Analysis, Analysis of Variance, Spearman correlation and Kendall W Test. Results obtained after each descriptive analysis were shown to the assessors and discussed. Results obtained over the three sessions showed sufficient improvement in the assessor's performance to deem the panel competent for descriptive analysis of the distilled beverages studied.

A study on the interaction of a 10 TW, 60 fs, Ti–Sapphire laser with a high-density long-scale pulsed nitrogen gas jet is reported. Experimental data on the laser propagation are analyzed with the help of a ray-tracing model. The plasma dynamics is investigated by means of time-resolved shadowgraphy and time-integrated high-resolution x-ray spectroscopy. Shadowgrams show that the plasma does not expand during the first 55 ps, while x-ray spectra exhibit an unusual continuum-like structure attributed to hollow atoms produced by charge exchange process between bare nuclei expelled from the plasma and molecules of the surrounding gas. The interpretation of the results is supported by particle-in-cell simulations. The question of x-ray lasing is also examined using a hydrodynamic code to simulate the long lasting regime of recombination.

The odor and flavor characteristics of 15 commercial Cheddar-flavored enzyme-modified cheeses (EMC) and 3 natural Cheddar cheeses were determined and compared using descriptive sensory analysis. These sensory characteristics of Cheddar EMC were significantly different from those defined for natural Cheddar cheeses. EMC provided a range of “vomit,”“bitter,”“astringent,”“chemical,” and “eggy/sulphur” flavors, whereas the natural Cheddar cheeses were characterized by “sweet,”“caramel,”“creamy,”“nutty,” and “buttery” flavors. Relationships between the composition of EMC and their sensory attributes showed significant correlation. The flavor attributes “pungent,”“vomit,”“astringent,” and “eggy/sulphur” were strongly related to a high fat content and low pH. These relationships were discussed and compared to those observed for natural Cheddar cheeses.

The interaction of a 60-fs laser pulse with argon clusters was experimentally studied. It is shown that cluster heating by an intense femtosecond pulse preceded by a picosecond prepulse can produce plasma whose ionization state is determined by the prepulse properties, while the mean energy of hot electrons is determined by the main pulse intensity. A simple model of cluster plasma evolution is suggested, allowing an adequate description of its X-ray emission.

An x-ray laser scheme based on the recombination of a fully stripped nitrogen plasma is presented. Plasma is assumed to be created by the optical-field ionization of a nitrogen gas jet of 10(19) cm-3 atomic density by an ultrashort (60 fs), high-intensity (3 x 10(19) W/cm2) Ti:sapphire laser. Results of two-dimensional particle-in-cell simulations, modeling laser-plasma interaction, parametric heating, and ponderomotive effects are presented. Hydrodynamic and kinetics calculations are performed and predict important local gain for H-like nitrogen transitions at 25 and 134 A, following fast collisional recombination for specific plasma conditions.

New types of space resolved X-ray spectra produced in light matter experiments with high intensity lasers have been investigated experimentally and theoretically. This type of spectra is characterised by the disappearance of distinct resonance line emission and the appearance of very broad emission structures due to the dielectronic satellite transitions associated to the resonance lines. Atomic data calculations have shown, that rather exotic states with K-shell vacancies are involved. For quantitative spectra interpretation we developed a model for dielectronic satellite accumulation (DSA-model) in cold dense optically thick plasmas which are tested by rigorous comparison with space resolved spectra from ns-lasers. In experiments with laser intensities up to 10 19 W/cm 2 focused into nitrogen gas targets, hollow ion configurations are observed by means of soft X-ray spectroscopy. It is shown that transitions in hollow ions can be used for plasma diagnostic. The determination of the electron temperature in the long lasting recombining regime is demonstrated. In Light-matter interaction experiments with extremely high contrast (up to 10 10 ) short pulse (400 fs) lasers electron densities of n e ≈3×10 23 cm −3 at temperatures between kT e =200–300 eV have been determined by means of spectral simulations developed previously for ns-laser produced plasmas. Expansion velocities are determined analysing asymmetric optically thick line emission. Further, the results are checked by observing the spectral windows involving the region about the He α -line and the region from the He β -line to the He-like continuum. Finally, plasmas of solid density are characteristic in experiments with heavy ion beams heating massive targets. We report the first spectroscopic investigations in plasmas of this type with results on solid neon heated by Ar-ions. A spectroscopic method for the determination of the electron temperature in extreme optically thick plasmas is developed.