Observation of CR Anisotropy with ARGO-YBJ

The measurement of the anisotropies of cosmic ray arrival direction provides important informations on the propagation mechanisms and on the identification of their sources. In this paper we report the observation of anisotropy regions at different angular scales. In particular, the observation of a possible anisotropy on scales between $\sim$ 10 $^{\circ}$ and $\sim$ 30 $^{\circ}$ suggests the presence of unknown features of the magnetic fields the charged cosmic rays propagate through, as well as potential contributions of nearby sources to the total flux of cosmic rays. Evidence of new weaker few-degree excesses throughout the sky region $195^{\circ}\leq$ R.A. $\leq 315^{\circ}$ is reported for the first time.Comment: Talk given at 12th TAUP Conference 2011, 5-9 September 2011, Munich, German

Analisi dei modelli organizzativi di risposta al COVID-19 in Italia: evidenze da 2 anni di ISTANT REPORT Altems

Sistematizzazione e pubblicazione settimanalmente un report per analizzare in modo sistemico e comparativo i modelli di risposta adottati dalle Regioni in risposta all'emergenza da COVID- 1

Conceptual Design of a Soft X‐ray SASE‐FEL Source

FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R&D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR‐ENEA‐INFN‐University of Roma "Tor Vergata" study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, bringing to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S‐band normal conducting linac with high brightness photoinjector integrated in a RF compressor

Simulations of coherent synchrotron radiation effects in electron machines

Coherent synchrotron radiation (CSR) generated by high intensity electron beams can be a source of undesirable effects limiting the performance of storage rings. The complexity of the physical mechanisms underlying the interplay between the electron beam and the CSR demands for reliable simulation codes. In the past, codes based on Lie algebraic techniques have been very efficient to treat transport problems in accelerators. The extension of these methods to the non linear case is ideally suited to treat wakefields - beam interaction. In this paper we report on the development of a numerical code, based on the solution of the Vlasov equation, which includes the non linear contribution due to wakefields. The proposed solution method exploits an algebraic technique that uses the exponential operators. We show that, in the case of CSR wakefields, the integration procedure is capable of reproducing the onset of an instability which leads to microbunching of the beam thus increasing the CSR at short wavelengths. In addition, considerations on the threshold of the instability for Gaussian bunches is also reported

A vlasov solver for collective effects in particle accelerators

Integration techniques based on Lie algebraic methods have been successfully used in beam transport codes for particle accelerators. Generally these methods have been applied to problems of single-particle beam dynamics. Here we present an application of Lie algebraic techniques to the development of a Vlasov solver suitable for problems of beam transport in the presence of non-negligible particle self-fields. The solver we discuss is suitable for modelling a variety of collective effects that may arise at high current. In particular, we consider the case of coherent synchrotron radiation effects in magnetic bunch compressors which can cause instabilities limiting performance of high current accelerators

A four-dimensional Vlasov solver for microbunching instability in the injection system for X-ray FELs

The micro-bunching instability (MBI) is seeded by small charge-density fluctuations in the electron bunches, and is successively amplified by the combined effect of space charge and coherent synchrotron radiation, as the beam travels through magnetic compressors. The quantitative understanding of this effect demands for accurate numerical simulations. Here we report on the progress of an upgrading of a 2D Vlasov solver code toward a 4D grid-based Vlasov solver, including also the transversedynamics. The goal is to provide an accurate characterization of the MBI seeded by random noise present in the bunch distribution. We also comment on the advantages of our procedure with respect to other approaches, e.g. macroparticle simulations

Design and synthesis of Alpha-v-beta-3 and Alpha-5-beta-1 integrin ligands as delivery systems for fluorescent molecules

The design, synthesis and biol. evaluation of integrin ligands is an important goal for their potential application as diagnostic and therapeutic tools in cancer research. We have synthesized isoxazoline-contg. peptidomimetics, that showed great affinity towards avb3 and a5b1 integrins. These receptors are involved in tumor angiogenesis and the obtained ligands may be thus conjugated to fluoresacent mols. to provide potential diagnostic tools

Dehydro-beta-proline Containing Alpha-4-beta-1 Integrin Antagonists: Stereochemical Recognition in Ligand-Receptor Interplay

A novel class of dehydro-b-proline-contg. peptidomimetics, designed to be effective as a4b1 integrin ligands, has been developed on the basis of the fundamental requirements for the interactions of these transmembrane receptors with bioactive ligands. Dehydro-b-proline ring has been synthesized through an original pathway, involving ring closing metathesis of a diallylamino deriv. The synthesized products showed to be effective and selective as a4b1 integrin antagonists and displayed IC50 values in the nanomolar range in cell adhesion inhibition assays and in VCAM-1-induced phosphorylation of extracellular-signal-regulated kinases. Significant activity was obsd. also toward the homologous integrin a4b7, while they did not display any activity toward selected members of b1, b2, and b3 families. A strong dependence on the stereochem. of the heterocyclic central core could be obsd. The great importance of a4b1 integrin in chronic inflammatory and autoimmune diseases suggests a possible exploitation of these ligands as lead compds. for therapeutic tools development