545 research outputs found
Influence of breed on reactivity of sheep to humans
International audienc
Comparaison du comportement maternel en bergerie à la parturition chez des brebis primipares ou multipares de race Romanov, Préalpes du Sud et Ile-de-France
International audienc
Status and performances of the FAZIA project
FAZIA is designed for detailed studies of the isospin degree of freedom,
extending to the limits the isotopic identification of charged products from
nuclear collisions when using silicon detectors and CsI(Tl) scintillators. We
show that the FAZIA telescopes give isotopic identification up to Z25
with a E-E technique. Digital Pulse Shape Analysis makes possible
elemental identification up to Z=55 and isotopic identification for Z=1-10 when
using the response of a single silicon detector. The project is now in the
phase of building a demonstrator comprising about 200 telescopes
Liquid-gas phase transition in hot nuclei studied with INDRA
Thanks to the high detection quality of the INDRA array, signatures related
to the dynamics (spinodal decomposition) and thermodynamics (negative
microcanonical heat capacity) of a liquid-gas phase transition have been
simultaneously studied in multifragmentation events in the Fermi energy domain.
The correlation between both types of signals strongly supports the existence
of a first order phase transition for hot nuclei.Comment: 9 pages, 2 figures, Invited talk to Nucleus-nucleus 2003 Moscow June
200
Cluster emission and phase transition behaviours in nuclear disassembly
The features of the emissions of light particles (LP), charged particles
(CP), intermediate mass fragments (IMF) and the largest fragment (MAX) are
investigated for as functions of temperature and 'freeze-out'
density in the frameworks of the isospin-dependent lattice gas model and the
classical molecular dynamics model. Definite turning points for the slopes of
average multiplicity of LP, CP and IMF, and of the mean mass of the largest
fragment () are shown around a liquid-gas phase transition temperature
and while the largest variances of the distributions of LP, CP, IMF and MAX
appear there. It indicates that the cluster emission rate can be taken as a
probe of nuclear liquid--gas phase transition. Furthermore, the largest
fluctuation is simultaneously accompanied at the point of the phase transition
as can be noted by investigating both the variances of their cluster
multiplicity or mass distributions and the Campi scatter plots within the
lattice gas model and the molecular dynamics model, which is consistent with
the result of the traditional thermodynamical theory when a phase transition
occurs.Comment: replace nucl-th/0103009 due to the technique problem to access old
versio
Thermodynamical features of multifragmentation in peripheral Au + Au Collisions at 35 A.MeV
The distribution of fragments produced in events involving the
multifragmentation of excited sources is studied for peripheral Au + Au
reactions at 35 A.MeV.
The Quasi-Projectile has been reconstructed from its de-excitation products.
An isotropic emission in its rest frame has been observed, indicating that an
equilibrated system has been formed. The excitation energy of the
Quasi-Projectile has been determined via calorimetry.
A new event by event effective thermometer is proposed based on the energy
balance. A peak in the energy fluctuations is observed related to the heat
capacity, suggesting that the system undergoes a liquid-gas type phase
transition at an excitation energy about 5 A.MeV and a temperature 4 - 6 MeV,
dependent on the freeze-out hypothesis. By analyzing different regions of the
Campi-plot, the events associated with the liquid and gas phases as well as the
critical region are thermodynamically characterized.
The critical exponents, tau, beta,gamma, extracted from the high moments of
the charge distribution are consistent with a liquid-gas type phase transition.Comment: 44 pages, 16 Postscript figures, Fig14_nucl-ex.eps in colors, to be
published in Nucl.Phys.A (1999
Minimising pain in farm animals: the 3S approach - ‘Suppress, Substitute, Soothe'
Recently, the French National Institute for Agricultural Research appointed an expert committee to review the issue of pain in food-producing farm animals. To minimise pain, the authors developed a ‘3S' approach accounting for ‘Suppress, Substitute and Soothe' by analogy with the ‘3Rs' approach of ‘Reduction, Refinement and Replacement' applied in the context of animal experimentation. Thus, when addressing the matter of pain, the following steps and solutions could be assessed, in the light of their feasibility (technical constraints, logistics and regulations), acceptability (societal and financial aspects) and availability. The first solution is to suppress any source of pain that brings no obvious advantage to the animals or the producers, as well as sources of pain for which potential benefits are largely exceeded by the negative effects. For instance, tail docking of cattle has recently been eliminated. Genetic selection on the basis of resistance criteria (as e.g. for lameness in cattle and poultry) or reduction of undesirable traits (e.g. boar taint in pigs) may also reduce painful conditions or procedures. The second solution is to substitute a technique causing pain by another less-painful method. For example, if dehorning cattle is unavoidable, it is preferable to perform it at a very young age, cauterising the horn bud. Animal management and constraint systems should be designed to reduce the risk for injury and bruising. Lastly, in situations where pain is known to be present, because of animal management procedures such as dehorning or castration, or because of pathology, for example lameness, systemic or local pharmacological treatments should be used to soothe pain. These treatments should take into account the duration of pain, which, in the case of some management procedures or diseases, may persist for longer periods. The administration of pain medication may require the intervention of veterinarians, but exemptions exist where breeders are allowed to use local anaesthesia (e.g. castration and dehorning in Switzerland). Extension of such exemptions, national or European legislation on pain management, or the introduction of animal welfare codes by retailers into their meat products may help further developments. In addition, veterinarians and farmers should be given the necessary tools and information to take into account animal pain in their management decision
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