Particle Identification Studies with an ALICE Test TPC

Using a test TPC, consisting of the ALICE TPC field cage prototype in combination with the final ALICE TPC readout and electronics, the energy loss distribution and resolution were measured for identified protons. The measurements were compared to theoretical calculations and good quantitative agreement was found when detector effects were taken into account. The implications for particle identification are discussed.Comment: 6 pages, 4 figures, Quark Matter 06 poster proceedin

Discovery of TUG-770: a highly potent free fatty acid receptor 1 (FFA1/GPR40) agonist for treatment of type 2 diabetes

Free fatty acid receptor 1 (FFA1 or GPR40) enhances glucose-stimulated insulin secretion from pancreatic β-cells and currently attracts high interest as a new target for the treatment of type 2 diabetes. We here report the discovery of a highly potent FFA1 agonist with favorable physicochemical and pharmacokinetic properties. The compound efficiently normalizes glucose tolerance in diet-induced obese mice, an effect that is fully sustained after 29 days of chronic dosing

Curvature-induced symmetry breaking in nonlinear Schrodinger models

We consider a curved chain of nonlinear oscillators and show that the interplay of curvature and nonlinearity leads to a symmetry breaking when an asymmetric stationary state becomes energetically more favorable than a symmetric stationary state. We show that the energy of localized states decreases with increasing curvature, i.e. bending is a trap for nonlinear excitations. A violation of the Vakhitov-Kolokolov stability criterium is found in the case where the instability is due to the softening of the Peierls internal mode.Comment: 4 pages (LaTex) with 6 figures (EPS

Particle Identification at High Transverse Momenta with the ALICE TPC

The ALICE TPC particle identification capabilities have been studied with test beam data and found to be in agreement with theoretical predictions from a photo absorption ionization model calculation of the charged particle energy loss in the gas when detector effects – exponential gas gain variations and diffusion – are taken into account

Lattice stretching bistability and dynamic heterogeneity

A simple one-dimensional lattice model is suggested to describe the experimentally observed plateau in force-stretching diagrams for some macromolecules. This chain model involves the nearest-neighbor interaction of a Morse-like potential (required to have a saturation branch) and an harmonic second-neighbor coupling. Under an external stretching applied t o the chain ends, the intersite Morse-like potential results in the appearance of a double-well potential within each chain monomer, whereas the interaction between the second neighbors provide s a homogeneous bistable (degenerate) ground state, at least within a certain part of the chain. As a result, different conformational changes occur in the chain under the external forcing. The transition regions between these conformations are described as topological solitons. With a strong second-neighbor interaction, the solitons describe the transition between the bistable ground states. However, the key point of the model is the appearance of a heterogenous structure, when the second-neighbor coupling is sufficiently weak. In this case, a part of the chain has short bonds with a single-well potential, whereas the complementary part admits strongly stretched bonds with a double-well potential. This case allows us to explain the existence of a plateau in the force-stretching diagram for DNA and alpha-helix protein. Finally, the soliton dynamics are studied in detail.Comment: Submitted to Phys. Rev. E, 13 figure

The RD53 Collaboration's SystemVerilog-UVM Simulation Framework and its General Applicability to Design of Advanced Pixel Readout Chips

The foreseen Phase 2 pixel upgrades at the LHC have very challenging requirements for the design of hybrid pixel readout chips. A versatile pixel simulation platform is as an essential development tool for the design, verification and optimization of both the system architecture and the pixel chip building blocks (Intellectual Properties, IPs). This work is focused on the implemented simulation and verification environment named VEPIX53, built using the SystemVerilog language and the Universal Verification Methodology (UVM) class library in the framework of the RD53 Collaboration. The environment supports pixel chips at different levels of description: its reusable components feature the generation of different classes of parameterized input hits to the pixel matrix, monitoring of pixel chip inputs and outputs, conformity checks between predicted and actual outputs and collection of statistics on system performance. The environment has been tested performing a study of shared architectures of the trigger latency buffering section of pixel chips. A fully shared architecture and a distributed one have been described at behavioral level and simulated; the resulting memory occupancy statistics and hit loss rates have subsequently been compared.Comment: 15 pages, 10 figures (11 figure files), submitted to Journal of Instrumentatio