2,030 research outputs found
Structural and functional studies of an IRF-7-like gene from Atlantic salmon
No full textInterferon regulatory factor 7 (IRF-7) plays a crucial role in virus-induced activation of interferon-?/? transcription in mammals. This work describes a structural and functional homologue of mammalian IRF-7 from Atlantic salmon. The cloned gene encodes a putative protein of 415 amino acids (aa), which groups with mammalian IRF-7 and other fish IRF-7-like proteins in a phylogenetic analysis of vertebrate IRFs. Using an IFN promoter-luciferase assay we showed that salmon IRF-7 gave increased promoter activity after poly I:C stimulation. Transcript levels of IRF-7 were measured by real-time RT-PCR and compared to those of signal transducer and activator of transcription 1 (STAT1), which is important for transcriptional activation of IFN stimulated genes. Recombinant salmon IFN-?1 and poly I:C proved to be potent inducers of IRF-7 in Atlantic salmon TO cells, and poly I:C also induced the gene in head kidney and liver of Atlantic salmon. STAT1 was also induced by IFN, but was only weakly induced by poly I:C stimulation in vitro. Differences in transcription kinetics between IRF-7 and STAT1 thus indicate that the genes are regulated through different pathways. Finally, infection of TO cells with infectious salmon anemia virus (ISAV) induced early synthesis of STAT1 mRNA, whereas IRF-7 transcripts were up-regulated much later. This indicates that ISAV has mechanisms to antagonize IRF-7 transcription and thus also the IFN system in Atlantic salmon.Accession Number: 20093050505. Publication Type: Journal Article. Language: English. Number of References: 67 ref. Subject Subsets: Animal Breeding; Agricultural Biotechnology; Veterinary Science; Veterinary Scienc
Lightest MSSM Higgs Boson production and its two-photon decay at the LHC
No full textWe present an analysis of the production and two-photon decay of the lightest CP-even Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC). A rather general model is considered, without supergravity constraints. All parameters of the model are taken into account, we especially study the dependence of the cross section on the squark masses, on the bilinear parameter μ and the trilinear supersymmetry breaking parameter Å . Non-zero values of these parameters lead to significant mixing in the squark sector, and, thus, affect the masses of Higgs bosons through radiative corrections, as well as their couplings to squarks. The cross section times the two-photon branching ratio of h0 is of the order of 15--25~fb in much of the parameter space that remains after imposing the present experimental constraints on the parameters
Production and two-photon decay of the MSSM scalar Higgs bosons at the LHC
No full textWe consider the production and two-photon decay of the CP-even Higgs bosons (h0 and H0) of the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider. We study in detail the dependence of the cross section on various parameters of the MSSM, especially the dependence on the mixing effects in the squark sector due to the Higgs bilinear parameter μ and the soft supersymmetry breaking parameter A. We find that the cross section for the production of these Higgs bosons has a significant dependence on the parameters which determine the chiral mixing in the squark sector. The cross section times the two-photon branching ratio of h0is of the order of 15-25~fb in much of the parameter space that remains after imposing the present experimental constraints. For the H0 the two-photon branching ratio is only significant if the H0 is light, but then the cross section times the branching ratio may exceed 200~fb. The QCD corrections due to quark loop contributions are known to increase the cross section by 50%. We find the dependence of the cross section on the gluon distribution function used to be rather insignificant
Lightest MSSM Higgs Boson production and its two-photon decay at the LHC
No full textWe present an analysis of the production and two-photon decay of the lightest CP-even Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC). A rather general model is considered, without supergravity constraints. All parameters of the model are taken into account, we especially study the dependence of the cross section on the squark masses, on the bilinear parameter μ and the trilinear supersymmetry breaking parameter Å . Non-zero values of these parameters lead to significant mixing in the squark sector, and, thus, affect the masses of Higgs bosons through radiative corrections, as well as their couplings to squarks. The cross section times the two-photon branching ratio of h0 is of the order of 15--25~fb in much of the parameter space that remains after imposing the present experimental constraints on the parameters
Intracellular interferons in fish : a unique means to combat viral infection
No full textPeer reviewe
Beauty production in pp collisions at root s=2.76 TeV measured via semi-electronic decays
No full textThe ALICE Collaboration at the LHC reports measurement of the inclusive production cross section of electrons from semi-leptonic decays of beauty hadrons with rapidity |y| e) = 3.47 +/- 0.40(stat)(+1.12)(-1.33)(sys) +/- 0.07(norm) mu b, was extrapolated to full phase space using Fixed Order plus Next-to-Leading Log (FONLL) calculations to obtain the total b (b) over bar production cross section, sigma(b (b) over bar) = 130 +/- 15.1(stat)(+42.1)(-49.8)(sys)(+3.4)(-3.1)(extr) +/- 2.5(norm) +/- 4.4(BR) mu b. (C) 2014 The Authors. Published by Elsevier B.V
Measurement of inclusive charged-particle b-jet production in pp and p-Pb collisions at √sNN = 5.02 TeV
No full textA measurement of the inclusive b-jet production cross section is presented in pp and p-Pb collisions at sNN = 5.02 TeV, using data collected with the ALICE detector at the LHC. The jets were reconstructed in the central rapidity region |η| T algorithm with resolution parameter R = 0.4. Identification of b jets exploits the long lifetime of b hadrons, using the properties of secondary vertices and impact parameter distributions. The pT-differential inclusive production cross section of b jets, as well as the corresponding inclusive b-jet fraction, are reported for pp and p-Pb collisions in the jet transverse momentum range 10 ≤ pT,ch jet≤ 100 GeV/c, together with the nuclear modification factor, RpPbb−jet. The analysis thus extends the lower pT limit of b-jet measurements at the LHC. The nuclear modification factor is found to be consistent with unity, indicating that the production of b jets in p-Pb at sNN = 5.02 TeV is not affected by cold nuclear matter effects within the current precision. The measurements are well reproduced by POWHEG NLO pQCD calculations with PYTHIA fragmentation. [Figure not available: see fulltext.]
Measurement of inclusive charged-particle b-jet production in pp and p-Pb collisions at √sNN = 5.02 TeV
No full textA measurement of the inclusive b-jet production cross section is presented in pp and p-Pb collisions at sNN = 5.02 TeV, using data collected with the ALICE detector at the LHC. The jets were reconstructed in the central rapidity region |η| < 0.5 from charged particles using the anti-kT algorithm with resolution parameter R = 0.4. Identification of b jets exploits the long lifetime of b hadrons, using the properties of secondary vertices and impact parameter distributions. The pT-differential inclusive production cross section of b jets, as well as the corresponding inclusive b-jet fraction, are reported for pp and p-Pb collisions in the jet transverse momentum range 10 ≤ pT,ch jet≤ 100 GeV/c, together with the nuclear modification factor, RpPbb−jet. The analysis thus extends the lower pT limit of b-jet measurements at the LHC. The nuclear modification factor is found to be consistent with unity, indicating that the production of b jets in p-Pb at sNN = 5.02 TeV is not affected by cold nuclear matter effects within the current precision. The measurements are well reproduced by POWHEG NLO pQCD calculations with PYTHIA fragmentation. [Figure not available: see fulltext.]
Investigating the role of strangeness in baryon–antibaryon annihilation at the LHC
No full textAnnihilation dynamics plays a fundamental role in the baryon–antibaryon interaction (B–B ̅) at low-energy and its strength and range are crucial in the assessment of possible baryonic bound states. Experimental data on annihilation cross sections are available for the p–p ̅ system but not in the low relative momentum region. Data regarding the B–B ̅ interaction with strange degrees of freedom are extremely scarce, hence the modeling of the annihilation contributions is mainly based on nucleon–antinucleon (N–N ̅) results, when available. In this letter we present a measurement of the p–p ̅, p–Λ ̅⊕p ̅–Λ and Λ–Λ ̅ interaction using correlation functions in the relative momentum space in high-multiplicity triggered pp collisions at s=13 TeV recorded by ALICE at the LHC. In the p–p ̅ system the couplings to the mesonic channels in different partial waves are extracted by adopting a coupled-channel approach with recent χEFT potentials. The inclusion of these inelastic channels provides good agreement with the data, showing a significant presence of the annihilation term down to zero momentum. Predictions obtained using the Lednický–Lyuboshits formula and scattering parameters obtained from heavy-ion collisions, hence mainly sensitive to elastic processes, are compared with the experimental p–Λ ̅⊕p ̅–Λ and Λ–Λ ̅ correlations. The model describes the Λ–Λ ̅ data and underestimates the p–Λ ̅⊕p ̅–Λ data in the region of momenta below 200 MeV/c. The observed deviation indicates a different contribution of annihilation channels to the two systems containing strange hadrons
- …
