Development of a diagnostic algorithm in periodontal disease and identification of genetic expression patterns: A preliminary report

AbstractBackground/purposeTo identify genetic expression patterns that can be used to define an appropriate diagnostic algorithm of clinical use in periodontal disease.Materials and methodsTotal RNA was extracted from 13 samples corresponding to normal human gingiva (NHG) and human gingiva affected by periodontal disease (PDHG). A comprehensive gene expression analysis was carried out by microarray analysis using Affymetrix Human Genome U133 plus 2.0 oligonucleotide arrays.ResultsSixty-six probe sets (genes and expressed sequence tags – EST) overexpressed in all samples of one of the comparison groups, were used for the diagnostic algorithm. All samples, including an independent test sample, were correctly classified as normal or periodontally affected using the diagnostic algorithm. In addition, 2596 genes/EST were upregulated and 1542 genes/EST were downregulated in PDHG, with numerous gene functions impaired in PDHG, especially those related to the immune response, cell-cell junctions, and extracellular matrix remodeling.ConclusionOur study reveals differential gene expression profiles in NHG and PDHG. The proposed diagnostic algorithm could have clinical usefulness for differential diagnosis in periodontal disease

Search for extra dimensions using diphoton events in 7 TeV proton–proton collisions with the ATLAS detector

Using data recorded in 2011 with the ATLAS detector at the Large Hadron Collider, a search for evidence of extra spatial dimensions has been performed through an analysis of the diphoton final state. The analysis uses data corresponding to an integrated luminosity of 2.12 fb^-1 of sqrt(s) = 7 TeV proton-proton collisions. The diphoton invariant mass spectrum is observed to be in good agreement with the expected Standard Model background. In the large extra dimension scenario of Arkani-Hamed, Dimopoulos and Dvali, the results provide 95% CL lower limits on the fundamental Planck scale between 2.27 and 3.53 TeV, depending on the number of extra dimensions and the theoretical formalism used. The results also set 95% CL lower limits on the lightest Randall-Sundrum graviton mass of between 0.79 and 1.85 TeV, for values of the dimensionless coupling k/\bar{M}_{Pl} varying from 0.01 to 0.1. Combining with previously published ATLAS results from the dielectron and dimuon final states, the 95% CL lower limit on the Randall-Sundrum graviton mass for k/\bar{M}_{Pl} = 0.01 (0.1) is 0.80 (1.95) TeV.Peer Reviewe

Search for events with large missing transverse momentum, jets, and at least two tau leptons in 7 TeV proton–proton collision data with the ATLAS detector

A search for events with large missing transverse momentum, jets, and at least two tau leptons has been performed using 2 fb^-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95% CL visible cross section upper limit for new phenomena is set. A 95% CL lower limit of 32 TeV is set on the GMSB breaking scale Lambda independent of tan(beta). These limits provide the most stringent tests to date in a large part of the considered parameter space.Peer Reviewe

Measurement of D∗+/−D^{*+/-} meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Peer Reviewe

Searches for supersymmetry with the ATLAS detector using final states with two leptons and missing transverse momentum in s=7\sqrt{s}=7 TeV proton-proton collisions

Results of three searches are presented for the production of supersymmetric particles decaying into final states with missing transverse momentum and exactly two isolated leptons, e or mu. The analysis uses a data sample collected during the first half of 2011 that corresponds to a total integrated luminosity of 1 fb^-1 of sqrt{s} = 7 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider. Opposite-sign and same-sign dilepton events are separately studied, with no deviations from the Standard Model expectation observed. Additionally, in opposite- sign events, a search is made for an excess of same-flavour over different-flavour lepton pairs. Effective production cross sections in excess of 9.9 fb for opposite-sign events containing supersymmetric particles with missing transverse momentum greater than 250 GeV are excluded at 95% CL. For same-sign events containing supersymmetric particles with missing transverse momentum greater than 100 GeV, effective production cross sections in excess of 14.8 fb are excluded at 95% CL. The latter limit is interpreted in a simplified weak gaugino production model excluding chargino masses up to 200 GeV.Peer Reviewe

Jet energy measurement with the ATLAS detector in proton-proton collisions at s=7\sqrt{s}=7 TeV

The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of sqrt(s) = 7 TeV corresponding to an integrated luminosity of 38 inverse pb. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0.4 or R=0.6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pt > 20 GeV and pseudorapidities eta 50 GeV after a dedicated correction for this effect. The JES is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pt, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pt jets recoiling against a high-pt jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, providing an improved jet energy resolution and a reduced flavour dependence of the jet response. The JES systematic uncertainty determined from a combination of in situ techniques are consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pt jets.Peer Reviewe

Search for pair production of a heavy up-type quark decaying to a W boson and a b quark in the lepton+jets channel with the ATLAS detector

A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t't'bar -> W+b W-bbar. The search is based on 1.04 fb^-1 of proton-proton collisions at sqrt(s) = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit is set at m(t') > 404 GeV.Peer Reviewe

Combined search for the Standard Model Higgs boson using up to 4.9 fb−1^{-1} of pppp collision data at s=7\sqrt{s}=7 TeV with the ATLAS detector at the LHC

A combined search for the Standard Model Higgs boson with the ATLAS experiment at the LHC using datasets corresponding to integrated luminosities from 1.04 fb-1 to 4.9 fb-1 of pp collisions collected at sqrt(s) = 7 TeV is presented. The Higgs boson mass ranges 112.9-115.5 GeV, 131-238 GeV and 251-466 GeV are excluded at the 95% confidence level (CL), while the range 124-519 GeV is expected to be excluded in the absence of a signal. An excess of events is observed around mH ~ 126 GeV with a local significance of 3.5 standard deviations (sigma). The local significance of H -> gamma gamma, H -> ZZ(*) -> lll'l' and H -> WW(*) -> lvl'v, the three most sensitive channels in this mass range, are 2.8 sigma, 2.1 sigma and 1.4 sigma, respectively. The global probability for the background to produce such a fluctuation anywhere in the explored Higgs boson mass range 110-600 GeV is estimated to be ~1.4% or, equivalently 2.2 sigma.Peer Reviewe

Measurement of the tt-channel single top-quark production cross section in pppp collisions at s=7\sqrt{s}=7 TeV with the ATLAS detector

We report a measurement of the cross section of single top-quark production in the t-channel using 1.04 fb^-1 of pp collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC. Selected events feature one electron or muon, missing transverse momentum, and two or three jets, exactly one of them identified as originating from a b quark. The cross section is measured by fitting the distribution of a multivariate discriminant constructed with a neural network, yielding sigma(t)= 83 +/- 4 (stat.) +20 -19 (syst) pb which is in good agreement with the prediction of the Standard Model. Using the ratio of the measured to the theoretically predicted cross section and assuming that the top-quark-related CKM matrix elements obey the relation |V(tb)| >> |V(ts)|, |V(td)|, the coupling strength at the W-t-b vertex is determined to be |V(tb)| = 1.13 +0.14 -0.13. If it is assumed that |V(tb)| 0.75 is obtained at the 95% confidence level.Peer Reviewe

Measurement of the cross section for the production of a WW boson in association with b−b^- jets in pppp collisions at s=7\sqrt{s}=7 TeV with the ATLAS detector

A measurement is presented of the cross section for the production of a W boson with one or two jets, of which at least one must be a b-jet, in pp collisions at sqrt(s)=7 TeV. Production via top decay is not included in the signal definition. The measurement is based on 35 pb^-1 of data collected with the ATLAS detector at the LHC. The W+b-jet cross section is defined for jets reconstructed with the anti-kt clustering algorithm with transverse momentum above 25 GeV and rapidity within +/-2.1. The b-jets are identified by reconstructing secondary vertices. The fiducial cross section is measured both for the electron and muon decay channel of the W boson and is found to be 10.2 +/- 1.9 (stat) +/- 2.6 (syst) pb for one lepton flavour. The results are compared with next-to-leading order QCD calculations, which predict a cross section smaller than, though consistent with, the measured value.Peer Reviewe