An integrated method to analyze farm vulnerability to climatic and economic variability according to farm configurations and farmers' adaptations

The need to adapt to decrease farm vulnerability to adverse contextual events has been extensively discussed on a theoretical basis. We developed an integrated and operational method to assess farm vulnerability to multiple and interacting contextual changes and explain how this vulnerability can best be reduced according to farm configurations and farmers' technical adaptations over time. Our method considers farm vulnerability as a function of the raw measurements of vulnerability variables (e.g., economic efficiency of production), the slope of the linear regression of these measurements over time, and the residuals of this linear regression. The last two are extracted from linear mixed models considering a random regression coefficient (an intercept common to all farms), a global trend (a slope common to all farms), a random deviation from the general mean for each farm, and a random deviation from the general trend for each farm. Among all possible combinations, the lowest farm vulnerability is obtained through a combination of high values of measurements, a stable or increasing trend and low variability for all vulnerability variables considered. Our method enables relating the measurements, trends and residuals of vulnerability variables to explanatory variables that illustrate farm exposure to climatic and economic variability, initial farm configurations and farmers' technical adaptations over time. We applied our method to 19 cattle (beef, dairy, and mixed) farms over the period 20082013. Selected vulnerability variables, i.e., farm productivity and economic efficiency, varied greatly among cattle farms and across years, with means ranging from 43.0 to 270.0 kg protein/ha and 29.4-66.0% efficiency, respectively. No farm had a high level, stable or increasing trend and low residuals for both farm productivity and economic efficiency of production. Thus, the least vulnerable farms represented a compromise among measurement value, trend, and variability of both performances. No specific combination of farmers' practices emerged for reducing cattle farm vulnerability to climatic and economic variability. In the least vulnerable farms, the practices implemented (stocking rate, input use ...) were more consistent with the objective of developing the properties targeted (efficiency, robustness ...). Our method can be used to support farmers with sector-specific and local insights about most promising farm adaptations

A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats

Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months) were subjected to unilateral hindlimb casting for 8 days (10-18) and then permitted to recover for 10 to 40 days (R10-R40). They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX) (10 to 18), AOX and leucine (AOX + LEU) (18 to R15) and LEU alone (R15 to R40). Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP) and post absorptive (PA) states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37%) in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40) due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40) without difference in trypsin-and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states) and could be a promising strategy to be tested during recovery from bed rest in humans

Le détecteur pixélisé de grande acceptance: contrôle balistique en ligne en hadronthérapie

International audienceL'hadronthérapie est basée sur l'utilisation de protons ou d'ions carbone. Dotées de propriétés balistiques très intéressantes, dues au pic de Bragg, ces particules viennent compléter l'arsenal de la radiothérapie. Le contrôle du positionnement de ce pic de Bragg est essentiel pour un plan de traitement optimal.Il résulte de nombreuses interactions des ions dans la matière, la production de particules secondaires, parmi lesquelles des noyaux radioactifs émetteurs de B+. La concentration en noyaux de ce type s'avère être un bon marqueur du rendement en profondeur des hadrons donc du picc de Bragg

Construction and first tests of a PET-like detector for hadrontherapy beam ballistic control

International audienceWe present the first results obtained with a detector, called Large Area Pixelized Detector (LAPD), dedicated to the beam ballistic control in the context of hadrontherapy. The purpose is to control the ballistics of the beam delivered to the patient by in-beam and real time detection of secondary particles, emitted during its irradiation. These particles could be high energy photons (prompt γ), or charged particles like protons, or 511 keV γ from the annihilation of a positron issued from the β+ emitters induced in the patient tissues along the beam path. These methods require being able to detect with a huge efficiency, and with a minimum dead time, these secondary particles emitted when the beam hits the patient. The LAPD is similar to a conventional Positron Emission Tomography camera. The 511keV γ are detected and the reconstructed line of responses allow to measure the β+ activity distribution. Nevertheless, when trying to use γ from positron annihilations for the ballistic control in hadrontherapy, the large γ prompt background should be taken into account and properly rejected. This detector is made of two half-rings of 120 channels each. Each channel consists of a 13*13*15 mm3 LYSO crystal glued to a PMT. The PMT signal is sent to an Analog Sampling Module (ASM board). ThisVME 6U board is based on the DRS4 chip technology (Switch Capacitor Array) from the Paul Sherrer Institute and was specially designed for the LAPD detector. This board receives up to 24 differential analog input signals, with maximum amplitude of 600 mV, digitized by 12 bits - 33 MHz ADC. The sampling rate varies between 1 and 5 GHz, for a maximum buffer size of 1024 samples. The first part of the talk is devoted to the description of the detector and its electronics. Then, we describe the various trigger strategy, and the on-going upgrade of the VME-based acquisition system to a μTCA-based technology. The selection of the coincident 511 keV γ is also discussed, and the reconstruction using aniterative MLEM algorithm is presented. In the last part of the talk, few results from an experiment with one third of the detector, using proton and carbon ion beams at the Heidelberg Ion-Beam Therapy Center in 2014, are also described, and the Coincidence Resolution Time and energy resolution are given. First reconstruction results, obtained with a phantom filled with a high intensity FDG source at the cancer research center of Clermont-Ferrand in 2015 are also shown. This detector is now characterized, and will be installed at the Lacassagne hadrontherapy center (Nice, France), on the 65 MeV line (Medicyc) in December 2015 first, and on the future 230 MeV line (S2C2 from IBA) in 2016. The capability of this detector and its associated electronics to measure the ballistic of the proton beam in real clinical conditions with a sufficient precision will be evaluated

In-beam tests of a PET demonstrator (LAPD) for hadrontherapy beam ballistic control: data comparison to Geant4 Monte-Carlo predictions

This paper describes a small prototype of an in beam PET like detector, named ”Large Acceptance Pixelized Detector” (LAPD), developed to test technical concepts for the ion range control in the context of cancer treatments using proton or ion beams. The mechanical characteristics of this detector together with the read-out electronics are first presented. Then, results of a first experiment, performed on a 65 MeV proton beamline, are reported. Finally, we discuss the ability of Geant4 Monte-Carlo to reproduce the experimental data

In-beam tests of a PET demonstrator (LAPD) for hadrontherapy beam ballistic control: data comparison to Geant4 Monte-Carlo predictions

International audienceThis paper describes a small prototype of an in beam PET like detector, named ”Large Acceptance Pixelized Detector” (LAPD), developed to test technical concepts for the ion range control in the context of cancer treatments using proton or ion beams. The mechanical characteristics of this detector together with the read-out electronics are first presented. Then, results of a first experiment, performed on a 65 MeV proton beamline, are reported. Finally, we discuss the ability of Geant4 Monte-Carlo to reproduce the experimental data

A diagnosis of progressive myoclonic ataxia guided by blood biomarkers

International audienceNo abstract availabl

In beam PET acquisition on 75 MeV/u carbon beam using sampling-Based Read-out Electronics

International audiencePositron Emission Tomography (PET) dedicated to the ion range verification in the context of hadrontherapy treatments, requires a very selective experimental device able to discriminate the two gamma from + decay from prompt particles due to the interactions of the beam with the matter. Prompt particles are a background noise in the context of induced + activity measurement. A significant part of this background noise is produced by the prompt emitted during beam spill. Therefore a precise knowledge of beam time structure is crucial to control the quality of data of in-beam PET acquisitions. In other words, beam time structure determines the number of primary ions per bunch and the nuclear induced background. An experiment was performed at the National Large Heavy Ion Accelerator (GANIL) in Caen (France) using a 75 A.MeV carbon beam in order to test the use of sampling-based read-out electronics to provide a very accurate time stamping of the detected particles. The experimental set-up is constituted by a small acceptance dual head detector positioned on each side of the beam centered on target. For this cyclotron beam, the cycle is 12 MHz with a beam spill of 10 ns. If acquisition takes into account only events occurring outside the spill, we demonstrate that the energy spectrum of events is equivalent to target radiative decay spectrum obtained just after stopping the beam. For this experiment, the technique of sampling signal was chosen, allowing to provide an accurate time measurements and adjust optimal time and energy cuts on the recorded data. With the time structure of the beam spill at GANIL, taking into account all the events, including those acquired during the spill, the measured background-to-signal event ratio is 10

Une supplémentation séquentielle en antioxydants et leucine durant et après immobilisation par plâtrage permet d’accélérer la récupération de masse protéique musculaire

National audienc

A dietary supplementation in antioxidants and leucine during and after immobilization allows an accelerated recovery of muscle mass in adult rats

International audienc