Prompt K_short production in pp collisions at sqrt(s)=0.9 TeV

The production of K_short mesons in pp collisions at a centre-of-mass energy of 0.9 TeV is studied with the LHCb detector at the Large Hadron Collider. The luminosity of the analysed sample is determined using a novel technique, involving measurements of the beam currents, sizes and positions, and is found to be 6.8 +/- 1.0 microbarn^-1. The differential prompt K_short production cross-section is measured as a function of the K_short transverse momentum and rapidity in the region 0 < pT < 1.6 GeV/c and 2.5 < y < 4.0. The data are found to be in reasonable agreement with previous measurements and generator expectations.Comment: 6+18 pages, 6 figures, updated author lis

Glycosylation of immunoglobulin G is regulated by a large network of genes pleiotropic with inflammatory diseases

Effector functions of immunoglobulin G (IgG) are regulated by the composition of a glycan moiety, thus affecting activity of the immune system. Aberrant glycosylation of IgG has been observed in many diseases, but little is understood about the underlying mechanisms. We performed a genome-wide association study of IgG N-glycosylation (N = 8090) and, using a data-driven network approach, suggested how associated loci form a functional network. We confirmed in vitro that knockdown of IKZF1 decreases the expression of fucosyltransferase FUT8, resulting in increased levels of fucosylated glycans, and suggest that RUNX1 and RUNX3, together with SMARCB1, regulate expression of glycosyltransferase MGAT3. We also show that variants affecting the expression of genes involved in the regulation of glycoenzymes colocalize with variants affecting risk for inflammatory diseases. This study provides new evidence that variation in key transcription factors coupled with regulatory variation in glycogenes modifies IgG glycosylation and has influence on inflammatory diseases.Molecular Epidemiolog

Modified glycine nitrate procedure (MGNP) for the synthesis of SOFC nanopowders

Nanopowders with perovskite type crystal structure were synthesized by modified glycine nitrate procedure. Modification of the procedure was performed by partial replacement of nitrates by acetates, in order to control the burn-up reaction. The obtained nanopowders, according to XRD results are single phase, independent of number of dopants. The yield of powder in all cases was very close to the theoretical one. Many different powders with perovskite type crystal structure were produced, with cation dopants on A as well as on B sites or both. Properties of the synthesized powders together with sintering tests are discussed. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved

A performance comparison of robust adaptive controllers: linear systems

We consider robust adaptive control designs for relative degree one, minimum phase linear systems of known high frequency gain. The designs are based on the dead-zone and projection modifications, and we compare their performance w.r.t. a worst case transient cost functional with a penalty on the L∞ norm of the output, control and control derivative. We establish two qualitative results. If a bound on the L∞ norm of the disturbance is known and the known a priori bound on the uncertainty level is sufficiently conservative, then it is shown that a dead-zone controller outperforms a projection controller. The complementary result shows that the projection controller is superior to the dead-zone controller when the a priori information on the disturbance level is sufficiently conservative

Refining and testing 12,000 km of scintillating plastic fibre for the LHCb SciFi tracker

The LHCb Collaboration is constructing a large scintillating fibre tracker for a major upgrade of the experiment during the LHC long shutdown LS2 scheduled for 2019–2020. The detector is based on blue emitting Kuraray SCSF-78MJ fibres of 0.25 mm diameter, read out by linear 128-channel Hamamatsu SiPM arrays. Over a period of about 2 years the full supply of 12,000 km of fibres underwent a systematic and rigorous quality assurance program, including geometrical refinement to deal with rare punctual imperfections. The measurements comprised attenuation length, ionisation light yield, diameter, cladding integrity and radiation tolerance to X-rays. The supply was found to be timely and of very high quality and stability, which led to negligible rejection rates. A small but systematic degradation of the attenuation length by about 1.4% per year is interpreted as natural aging due to oxidation of the polystyrene fibre core and is subject of further investigations

Measurement of sigma (pp -> bbX) at √s=7 TeV in the forward region

Decays of b hadrons into final states containing a D-0 meson and a muon are used to measure the bb; production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. In the pseudorapidity interval 2 < eta < 6 and integrated over all transverse momenta we find that the average cross-section to produce b-flavoured or b-flavoured hadrons is (75.3 +/- 5.4 +/- 13.0) mu b