Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at √s=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1 fb−1 of proton-proton collision data at s√ = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t¯ →tχ¯01 or t¯ →bχ¯±1 →bW(∗)χ¯01, where χ¯01 (χ¯±1) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t¯ →tχ¯01. For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ¯01 masses below 30 GeV. For a branching fraction of 50% to either t¯ →tχ¯01 or t¯ →bχ¯±1, and assuming the χ¯±1 mass to be twice the χ¯01 mass, top squark masses in the range 250–550 GeV are excluded for χ¯01 masses below 60 GeV

Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb−1 of √s = 8 TeV proton-proton collision data with the ATLAS detector

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3fb−1 of proton-proton collision data at √s = 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale Λ below 63 TeV are excluded, independently of tan β. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded

Effect of somatic mutation on DNA binding properties of anti-DNA autoantibodies

Autoantibodies that bind DNA are a hallmark of systemic lupus erythematosus. A subset of autoantibody•DNA complexes localize to kidney tissue and lead to damage and even death. 11F8, 9F11, and 15B10 are clonally related anti-DNA autoantibodies isolated from an autoimmune mouse. 11F8 binds ssDNA in a sequence-specific manner and causes tissue damage, while 9F11 and 15B10 bind ssDNA non-specifically and are benign. Among these antibodies, DNA binding properties are mediated by five amino acid differences in primary sequence. Thermodynamic and kinetic parameters associated with recognition of structurally different DNA sequences were determined for each antibody to provide insight toward recognition strategies, and to explore a link between binding properties and disease pathogenesis. A model of 11F8 bound to its high affinity consensus sequence provides a foundation for understanding the differences in thermodynamic and kinetic parameters between the three mAbs. Our data suggest that 11F8 utilizes the proposed ssDNA recognition motif including Y32 V L , a hydrogen bonding residue at 91 V L , and an aromatic residue at the tip of the third heavy chain complementarity determining region. Interestingly, a somatic mutation to arginine at 31 V H in 11F8 may afford additional binding site contacts including R31 V H , R96 V H , and R98 V H that could determine specificity. © 2007 Wiley Periodicals, Inc. Biopolymers 85: 471–480, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at [email protected] Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55984/1/20691_ftp.pd

'Birthing a Better Future': A mixed-methods evaluation of an exhibition on the early years of life

BACKGROUND: Our study aimed to evaluate to what extent Zero2 Expo's 'Birthing a Better Future', a co-created multimedia exhibition, was effective in raising awareness on the importance of the first 1001 days of life and explore what refinements would help to optimize the impact of future exhibitions. METHODS: We conducted a mixed-methods evaluation of the exhibition delivered in the John Radcliffe Hospital, Oxford. Through convenience sampling, 14 participants were selected to participate in 12 structured interviews and 19 participants completed a questionnaire. Interviews were thematically analysed alongside quantitative analysis of questionnaire responses through Likert scales. RESULTS: The majority (78.6%, n = 11/14) of participants who completed the questionnaire either agreed or strongly agreed that the exhibition raised their awareness about the first 1001 days of life. This was supported by the analysis of interviews. The use of art was found to provoke an emotional engagement from participants. Participants felt that the length of the written pieces and location of the exhibition were important factors for designers to consider in future exhibitions. CONCLUSION: This study demonstrated that multimedia exhibitions, combining science with art, may be an effective way to raise awareness of public health messages. Engaging with key stakeholders will be an essential step in order to improve future public health exhibitions. PUBLIC CONTRIBUTION: When designing the study, the public reviewed the study tools, which were refined based on their feedback. At every phase of the study, members of the public who are artists co-created the exhibition content

Search for heavy lepton resonances decaying to a Z boson and a lepton in pp collisions at s=8 TeV with the ATLAS detector

A search for heavy leptons decaying to a Z boson and an electron or a muon is presented. The search is based on pp collision data taken at s=8 TeV by the ATLAS experiment at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 20.3 fb−1. Three high-transverse-momentum electrons or muons are selected, with two of them required to be consistent with originating from a Z boson decay. No significant excess above Standard Model background predictions is observed, and 95% confidence level limits on the production cross section of high-mass trilepton resonances are derived. The results are interpreted in the context of vector-like lepton and type-III seesaw models. For the vector-like lepton model, most heavy lepton mass values in the range 114–176 GeV are excluded. For the type-III seesaw model, most mass values in the range 100–468 GeV are excluded

Measurement of charged-particle spectra in Pb+Pb collisions at sNN=2.76 TeV with the ATLAS detector at the LHC

Charged-particle spectra obtained in Pb+Pb interactions at sNN=2.76 TeV and pp interactions at sNN=2.76 TeV with the ATLAS detector at the LHC are presented, using data with integrated luminosities of 0.15 nb−1 and 4.2 pb−1, respectively, in a wide transverse momentum (0.5 < pT< 150 GeV) and pseudorapidity (|η| < 2) range. For Pb+Pb collisions, the spectra are presented as a function of collision centrality, which is determined by the response of the forward calorimeters located on both sides of the interaction point. The nuclear modification factors RAA and RCP are presented in detail as a function of centrality, pT and η. They show a distinct pT-dependence with a pronounced minimum at about 7 GeV. Above 60 GeV, RAA is consistent with a plateau at a centrality-dependent value, within the uncertainties. The value is 0.55 ± 0.01(stat.) ± 0.04(syst.) in the most central collisions. The RAA distribution is consistent with flat |η| dependence over the whole transverse momentum range in all centrality classes

Measurement of jet fragmentation in Pb+Pb and pp collisions at √sNN = 2.76 TeV with the ATLAS detector at the LHC

The distributions of transverse momentum and longitudinal momentum fraction of charged particles in jets are measured in Pb+Pb and pp collisions with the ATLAS detector at the LHC. The distributions are measured as a function of jet transverse momentum and rapidity. The analysis utilises an integrated luminosity of 0.14 nb-1 of Pb+Pb data and 4.0 pb-1 of pp data collected in 2011 and 2013, respectively, at the same centre-of-mass energy of 2.76 TeV per colliding nucleon pair. The distributions measured in pp collisions are used as a reference for those measured in Pb+Pb collisions in order to evaluate the impact on the internal structure of jets from the jet energy loss of fast partons propagating through the hot, dense medium created in heavy-ion collisions. Modest but significant centrality-dependent modifications of fragmentation functions in Pb+Pb collisions with respect to those in pp collisions are seen. No significant dependence of modifications on jet pT and rapidity selections is observed except for the fragments with the highest transverse momenta for which some reduction of yields is observed for more forward jets

Effectiveness of a quality improvement collaborative in reducing time to surgery for patients requiring emergency cholecystectomy.

Background:Acute gallstone disease is a high-volume emergency general surgery presentation with wide variations in the quality of care provided across the UK. This controlled cohort evaluation assessed whether participation in a quality improvement collaborative approach reduced time to surgery for patients with acute gallstone disease to fewer than 8 days from presentation, in line with national guidance. Methods:Patients admitted to hospital with acute biliary conditions in England and Wales between 1 April 2014 and 31 December 2017 were identified from Hospital Episode Statistics data. Time series of quarterly activity were produced for the Cholecystectomy Quality Improvement Collaborative (Chole-QuIC) and all other acute National Health Service hospitals (control group). A negative binomial regression model was used to compare the proportion of patients having surgery within 8 days in the baseline and intervention periods. Results:Of 13 sites invited to join Chole-QuIC, 12 participated throughout the collaborative, which ran from October 2016 to January 2018. Of 7944 admissions, 1160 patients had a cholecystectomy within 8 days of admission, a significant improvement (P < 0·050) from baseline performance. This represented a relative change of 1·56 (95 per cent c.i. 1·38 to 1·75), compared with 1·08 for the control group. At the individual site level, eight of the 12 Chole-QuIC sites showed a significant improvement (P < 0·050), with four sites increasing their 8-day surgery rate to over 20 per cent of all emergency admissions, well above the mean of 15·3 per cent for control hospitals. Conclusion:A surgeon-led quality improvement collaborative approach improved care for patients requiring emergency cholecystectomy

Searches for the Zγ decay mode of the Higgs boson and for new high-mass resonances in pp collisions at s=13 TeV with the ATLAS detector

AbstractThis article presents searches for the Zγ decay of the Higgs boson and for narrow high-mass resonances decaying to Zγ, exploiting Z boson decays to pairs of electrons or muons. The data analysis uses 36.1 fb−1 of pp collisions at s=13 recorded by the ATLAS detector at the CERN Large Hadron Collider. The data are found to be consistent with the expected Standard Model background. The observed (expected — assuming Standard Model pp → H → Zγ production and decay) upper limit on the production cross section times the branching ratio for pp → H → Zγ is 6.6. (5.2) times the Standard Model prediction at the 95% confidence level for a Higgs boson mass of 125.09 GeV. In addition, upper limits are set on the production cross section times the branching ratio as a function of the mass of a narrow resonance between 250 GeV and 2.4 TeV, assuming spin-0 resonances produced via gluon-gluon fusion, and spin-2 resonances produced via gluon-gluon or quark-antiquark initial states. For high-mass spin-0 resonances, the observed (expected) limits vary between 88 fb (61 fb) and 2.8 fb (2.7 fb) for the mass range from 250 GeV to 2.4 TeV at the 95% confidence level

Precision measurement and interpretation of inclusive W+, W- and Z/γ∗ production cross sections with the ATLAS detector

High-precision measurements by the ATLAS Collaboration are presented of inclusive W+→ℓ+ν, W-→ℓ-ν¯ and Z/γ∗→ℓℓ (ℓ=e,μ) Drell–Yan production cross sections at the LHC. The data were collected in proton–proton collisions at s=7TeV with an integrated luminosity of 4.6fb-1. Differential W+ and W- cross sections are measured in a lepton pseudorapidity range |ηℓ|<2.5. Differential Z/γ∗ cross sections are measured as a function of the absolute dilepton rapidity, for |yℓℓ|<3.6, for three intervals of dilepton mass, mℓℓ, extending from 46 to 150GeV. The integrated and differential electron- and muon-channel cross sections are combined and compared to theoretical predictions using recent sets of parton distribution functions. The data, together with the final inclusive e±p scattering cross-section data from H1 and ZEUS, are interpreted in a next-to-next-to-leading-order QCD analysis, and a new set of parton distribution functions, ATLAS-epWZ16, is obtained. The ratio of strange-to-light sea-quark densities in the proton is determined more accurately than in previous determinations based on collider data only, and is established to be close to unity in the sensitivity range of the data. A new measurement of the CKM matrix element |Vcs| is also provided