Abundance of Delta Resonances in 58Ni+58Ni Collisions between 1 and 2 AGeV

Charged pion spectra measured in 58Ni-58Ni collisions at 1.06, 1.45 and 1.93 AGeV are interpreted in terms of a thermal model including the decay of Delta resonances. The transverse momentum spectra of pions are well reproduced by adding the pions originating from the Delta-resonance decay to the component of thermal pions, deduced from the high transverse momentum part of the pion spectra. About 10 and 18% of the nucleons are excited to Delta states at freeze-out for beam energies of 1 and 2 AGeV, respectively.Comment: 14 pages, LaTeX with 3 included figures; submitted to Physics Letters

Stopping and Radial Flow in Central 58Ni + 58Ni Collisions between 1 and 2 AGeV

The production of charged pions, protons and deuterons has been studied in central collisions of 58Ni on 58Ni at incident beam energies of 1.06, 1.45 and 1.93 AGeV. The dependence of transverse-momentum and rapidity spectra on the beam energy and on the centrality of the collison is presented. It is shown that the scaling of the mean rapidity shift of protons established for AGS and SPS energies is valid down to 1 AGeV. The degree of nuclear stopping is discussed; the IQMD transport model reproduces the measured proton rapidity spectra for the most central events reasonably well, but does not show any sensitivity between the soft and the hard equation of state (EoS). A radial flow analysis, using the midrapidity transverse-momentum spectra, delivers freeze-out temperatures T and radial flow velocities beta_r which increase with beam energy up to 2 AGeV; in comparison to existing data of Au on Au over a large range of energies only beta_r shows a system size dependence

K^+ production in the reaction 58Ni+58Ni^{58}Ni+^{58}Ni at incident energies from 1 to 2 AGeV

Semi-inclusive triple differential multiplicity distributions of positively charged kaons have been measured over a wide range in rapidity and transverse mass for central collisions of $^{58}$Ni with $^{58}$Ni nuclei. The transverse mass ($m_t$) spectra have been studied as a function of rapidity at a beam energy 1.93 AGeV. The $m_t$ distributions of K^+ mesons are well described by a single Boltzmann-type function. The spectral slopes are similar to that of the protons indicating that rescattering plays a significant role in the propagation of the kaon. Multiplicity densities have been obtained as a function of rapidity by extrapolating the Boltzmann-type fits to the measured distributions over the remaining phase space. The total K^+ meson yield has been determined at beam energies of 1.06, 1.45, and 1.93 AGeV, and is presented in comparison to existing data. The low total yield indicates that the K^+ meson can not be explained within a hadro-chemical equilibrium scenario, therefore indicating that the yield does remain sensitive to effects related to its production processes such as the equation of state of nuclear matter and/or modifications to the K^+ dispersion relation.Comment: 24 pages Latex (elsart) 7 PS figures to be submitted to Nucl. Phys

Charged pions from Ni on Ni collisions between 1 and 2 AGeV

Charged pions from Ni + Ni reactions at 1.05, 1.45 and 1.93 AGeV are measured with the FOPI detector. The mean $\pi^{\pm}$ multiplicities per mean number of participants increase with beam energy, in accordance with earlier studies of the Ar + KCl and La + La systems. The pion kinetic energy spectra have concave shape and are fitted by the superposition of two Boltzmann distributions with different temperatures. These apparent temperatures depend only weakly on bombarding energy. The pion angular distributions show a forward/backward enhancement at all energies, but not the $\Theta = 90^0$ enhancement which was observed in case of the Au + Au system. These features also determine the rapidity distributions which are therefore in disagreement with the hypothesis of one thermal source. The importance of the Coulomb interaction and of the pion rescattering by spectator matter in producing these phenomena is discussed

Central Collisions of Au on Au at 150, 250 and 400 A MeV

Collisions of Au on Au at incident energies of 150, 250 and 400 A MeV were studied with the FOPI-facility at GSI Darmstadt. Nuclear charge (Z < 16) and velocity of the products were detected with full azimuthal acceptance at laboratory angles of 1-30 degrees. Isotope separated light charged particles were measured with movable multiple telescopes in an angular range of 6-90 degrees. Central collisions representing about 1 % of the reaction cross section were selected by requiring high total transverse energy, but vanishing sideflow. The velocity space distributions and yields of the emitted fragments are reported. The data are analysed in terms of a thermal model including radial flow. A comparison with predictions of the Quantum Molecular Model is presented.Comment: LateX text 62 pages, plus six Postscript files with a total of 34 figures, accepted by Nucl.Phys.

PET/CT imaging of the human bradykinin 1 receptor using radiolabeled peptides for cancer detection

Many compounds mimicking endogenous molecules have been used as a starting point to develop targeted diagnostic and therapeutic radiotracers. In particular, radiolabeled peptidomimetics, in association with positron emission tomography combined with computed tomography (PET/CT), are powerful tools to detect cancer with high sensitivity. Peptide-based radiotracers have the advantage of combining favorable pharmacokinetics that allow the use of short-lived isotopes, with a flexible modular design that offers a high versatility for functionalization, making them optimal for developing targeted imaging probes. The bradykinin receptors, which are powerful mediators of inflammation, have been shown to be highly expressed in many common cancers, notably breast and prostate cancers. The purpose of this project was to evaluate the human Bradykinin Receptor 1 (hB1R) as a potential target for cancer imaging and radionuclide therapy. Analogs of [des-Arg¹⁰] Kallidin (KD) were synthesized and labeled with ⁶⁸Ga or ¹⁸F. Following determination of their affinity for hB1R, selected tracers were evaluated in vitro and in vivo using hB1R expressing cells to select optimal radiotracers to imaging by positron emission tomography. The replacement of key amino acids at peptidase cleavage points by unnatural aminoacids improved the stability of the radiolabeled [des-Arg¹⁰]KD analogs in vitro and in vivo. Such peptides were used successfully for h1BR imaging by PET/CT in preclinical models. The use of hydrophilic and in particular cationic linker significantly improved tumour accumulation of various bradykinin analogues. Tracers combining the most favorable features gave high tumour to normal tissue contrast, by combining specific and high tumour uptake with low background and rapid clearance. The accumulation of agonist and antagonist radiotracers in tumours was also compared. In summary, we developed several promising bradykinin receptor ligands, as radiolabeled probes for cancer imaging.Medicine, Department ofGraduat

Etude de l'analyse automatique des règles de conception des systèmes multitâches temps réel

Les travaux présentés dans cette thèse ont pour objectif de proposer une méthode permettant l analyse de l application de règles de conception à partir du code source d une application. Les règles de conception permettent de garantir des propriétés intéressantes sur le programme final. Aussi, vérifier leur application permet-il de garantir la présence de ces propriétés. Au contraire, si la règle ne se trouve pas appliquée dans le programme final, alors il n est pas possible d émettre un avis quant à la qualité du code source, mais le fait que le développeur ait ignoré la règle est significatif. Les vérifications s intéressent particulièrement aux problèmes liés aux systèmes multitâches. L introduction d un ordonnancement non-déterministe entre les tâches rend les analyses par les méthodes classiques de preuve de programme peu ou pas efficaces. C est pourquoi une technique de décomposition de programme est proposée, ainsi que des méthodes de vérification à plusieurs niveaux. La technique développée se base sur l étude du code source seul. Les analyses doivent n être possibles qu à partir de cet élément, en l absence de tout autre élément de conception.The works presented in this thesis propose a novel method to verify the application of design rules based on the analysis of the source code. Design rules allow to guarantee the presence of sound properties on the final program. Therefore, verifying their presence allows to guarantee the presence of the associated properties. On the opposite, if a particular rule is not found to be applied upon the final program, no judgment may be given regarding the quality of the source code, but the fact that the developer didn t follow the rule is significant in itself. The verifications are particularly aimed towards the problems specific to multitask systems. The introduction of a dynamic non-deterministic scheduling between the tasks renders the analyses by classical proof of programs inefficient or even useless. This led us to propose a new program analysis technique, based on multiple levels analysis and program slicing. The technique proposed is based on the study of the source code only. The analyses must be performed on this element only, if no other element regarding the system s design is available.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Specifications and Design of Graphical Interface for Hierarchical Finite State Machines

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