Metabolic profile of patients with isolated systolic hypertension

PURPOSE/OBJECTIVE

While hypertension is an important contributor to cardiovascular disease (CVD) and its treatment has well-established mortality benefits, there is uncertainty as regards the management of isolated systolic hypertension (ISH). Furthermore, the association of ISH with CVD and mortality has been established, but the metabolic characteristics of the affected population have not as yet been adequately described. The aim of this study was to describe the metabolic profiles of patients with ISH.

METHODS

An observational study of patients attending the Hypertension Unit of the University Hospital of Heraklion, Crete, Greece, was performed.

RESULTS

In total, 809 hypertensive patients not on any antihypertensive treatment were identified. Among them, 44.7% were men, aged 55.6 ± 12.5 years, while 29.7% of both men and women were smokers. Systolic blood pressure was 161.3 ± 15.8 mmHg and diastolic blood pressure was 96.1 ± 11.3 mmHg. Body mass index (BMI) was 31 ± 5.3 kg/m², while 9.6% had type 2 diabetes (T2D). A comparison of patients with ISH with those with hypertension, but not ISH, revealed that patients with ISH were older and had lower SBP and higher pulse pressure, while they also had lower total cholesterol and LDL and were more likely to have T2D, albeit they had a slightly lower BMI. On the other hand, they did not have any difference in terms of gender, smoking status, HDL, triglycerides, liver biochemistry, uric acid, or prevalence of impaired fasting glucose.

CONCLUSION

Patients with ISH were older, with lower SBP, total cholesterol, and LDL and higher pulse pressure and higher prevalence of diabetes.

A glycine substitution in the collagenous domain of Col4a3 in mice recapitulates late onset Alport syndrome

Alport syndrome (AS) is a severe inherited glomerulopathy caused by mutations in the genes encoding the α-chains of type-IV collagen, the most abundant component of the extracellular glomerular basement membrane (GBM). Currently most AS mouse models are knockout models for one of the collagen-IV genes. In contrast, about half of AS patients have missense mutations, with single aminoacid substitutions of glycine being the most common. The only mouse model for AS with a homozygous knockin missense mutation, Col4a3-p.Gly1332Glu, was partly described before by our group. Here, a detailed in-depth description of the same mouse is presented, along with another compound heterozygous mouse that carries the glycine substitution in trans with a knockout allele. Both mice recapitulate essential features of AS, including shorten lifespan by 30–35%, increased proteinuria, increased serum urea and creatinine, pathognomonic alternate GBM thinning and thickening, and podocyte foot process effacement. Notably, glomeruli and tubuli respond differently to mutant collagen-IV protomers, with reduced expression in tubules but apparently normal in glomeruli. However, equally important is the fact that in the glomeruli the mutant α3-chain as well as the normal α4/α5 chains seem to undergo a cleavage at, or near the point of the mutation, possibly by the metalloproteinase MMP-9, producing a 35 kDa C-terminal fragment. These mouse models represent a good tool for better understanding the spectrum of molecular mechanisms governing collagen-IV nephropathies and could be used for pre-clinical studies aimed at better treatments for AS.

•

Two mouse models were generated that recapitulate essential features of AS patients.

•

Glomeruli and tubuli respond differently to mutant collagen IV protomers.

•

The mutant colIV protomers in glomeruli probably undergo a cleavage process by MMP9.

•

The two AS mouse models represent a good tool for studying collagen-IV nephropathies.

•

These models could be used for pre-clinical studies aimed at better treatments.

5 Improving Diagnosis and Management of Urinary Tract Infections for Elderly Patients

Introduction

Diagnosis of urinary tract infection (UTI) in the elderly population is challenging as they commonly present with atypical signs and symptoms. Prevalence of asymptomatic bacteriuria in the elderly population is high. Hence, urine dipstick and urine culture are no longer diagnostic tests. UTI is over-diagnosed and overtreated in the elderly, resulting in poor antimicrobial stewardship. This project was carried out to assess and improve the current practices in the diagnosis and treatment of UTI in the Department of Medicine of the Elderly.

Methods

We reviewed current Scottish Intercollegiate Guidelines Network (SIGN) and National Institute for health and Care Excellence (NICE) guidelines on management of UTI and defined indications for performing urine dipstick and sending urine culture. We then collected and assessed data on all urine dipsticks performed, urine cultures sent, and use of antibiotics in treating UTI and asymptomatic bacteriuria in three Medicine of the Elderly wards in Aberdeen Royal Infirmary.

We carried out intervention by means of presenting and discussing findings of Plan-Do-Study-Act (PDSA) cycles in departmental multi-disciplinary Quality Improvement (QI) meetings followed by educational sessions.

Results

Our baseline data showed 77% of urine dipsticks were performed without clinical indication and 18% of patients had urine cultures sent without clinical indication. After presenting our initial findings and carrying out an educational intervention session, 25% of patients had urine dipstick done without clinical indication, and 0% of patients had urine cultures sent without clinical indication. However, over the course of four subsequent PDSA cycles, practices in investigation of UTI fluctuated but were overall consistently better than the initial practice with further interventions. In all PDSA cycles, no patients were treated for asymptomatic bacteriuria.

Conclusions

Multidisciplinary team involvement in discussion of this QI project findings and educational sessions proved to be an effective form of intervention for improving current practice.

Erratum to: Measurement of the W boson polarisation in t t ¯ events from pp collisions at s = 8 TeV in the lepton + jets channel with ATLAS

[This corrects the article DOI: 10.1140/epjc/s10052-017-4819-4.].

Search for electroweak production of supersymmetric particles in final states with two or three leptons at s = 13 TeV with the ATLAS detector

A search for the electroweak production of charginos, neutralinos and sleptons decaying into final states involving two or three electrons or muons is presented. The analysis is based on 36.1 fb- 1 ofs = 13  TeV proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider. Several scenarios based on simplified models are considered. These include the associated production of the next-to-lightest neutralino and the lightest chargino, followed by their decays into final states with leptons and the lightest neutralino via either sleptons or Standard Model gauge bosons; direct production of chargino pairs, which in turn decay into leptons and the lightest neutralino via intermediate sleptons; and slepton pair production, where each slepton decays directly into the lightest neutralino and a lepton. No significant deviations from the Standard Model expectation are observed and stringent limits at 95% confidence level are placed on the masses of relevant supersymmetric particles in each of these scenarios. For a massless lightest neutralino, masses up to 580 GeV are excluded for the associated production of the next-to-lightest neutralino and the lightest chargino, assuming gauge-boson mediated decays, whereas for slepton-pair production masses up to 500 GeV are excluded assuming three generations of mass-degenerate sleptons.

Performance of missing transverse momentum reconstruction with the ATLAS detector using proton-proton collisions at s = 13 TeV

The performance of the missing transverse momentum ( E T miss ) reconstruction with the ATLAS detector is evaluated using data collected in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV in 2015. To reconstruct E T miss , fully calibrated electrons, muons, photons, hadronically decaying τ -leptons , and jets reconstructed from calorimeter energy deposits and charged-particle tracks are used. These are combined with the soft hadronic activity measured by reconstructed charged-particle tracks not associated with the hard objects. Possible double counting of contributions from reconstructed charged-particle tracks from the inner detector, energy deposits in the calorimeter, and reconstructed muons from the muon spectrometer is avoided by applying a signal ambiguity resolution procedure which rejects already used signals when combining the various E T miss contributions. The individual terms as well as the overall reconstructed E T miss are evaluated with various performance metrics for scale (linearity), resolution, and sensitivity to the data-taking conditions. The method developed to determine the systematic uncertainties of the E T miss scale and resolution is discussed. Results are shown based on the full 2015 data sample corresponding to an integrated luminosity of 3.2 fb - 1 .

Measurement of the Soft-Drop Jet Mass in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

Jet substructure observables have significantly extended the search program for physics beyond the standard model at the Large Hadron Collider. The state-of-the-art tools have been motivated by theoretical calculations, but there has never been a direct comparison between data and calculations of jet substructure observables that are accurate beyond leading-logarithm approximation. Such observables are significant not only for probing the collinear regime of QCD that is largely unexplored at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider. This Letter documents a measurement of the first jet substructure quantity at a hadron collider to be calculated at next-to-next-to-leading-logarithm accuracy. The normalized, differential cross section is measured as a function of log_{10}ρ^{2}, where ρ is the ratio of the soft-drop mass to the ungroomed jet transverse momentum. This quantity is measured in dijet events from 32.9  fb^{-1} of sqrt[s]=13  TeV proton-proton collisions recorded by the ATLAS detector. The data are unfolded to correct for detector effects and compared to precise QCD calculations and leading-logarithm particle-level Monte Carlo simulations.

Measurement of the inclusive and fiducial t t ¯ production cross-sections in the lepton+jets channel in pp collisions at s = 8 TeV with the ATLAS detector

The inclusive and fiducial t t ¯ production cross-sections are measured in the lepton+jets channel using 20.2 fb - 1 of proton-proton collision data at a centre-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC. Major systematic uncertainties due to the modelling of the jet energy scale and b-tagging efficiency are constrained by separating selected events into three disjoint regions. In order to reduce systematic uncertainties in the most important background, the W +\,jets process is modelled using Z + jets events in a data-driven approach. The inclusive t t ¯ cross-section is measured with a precision of 5.7% to beσ inc ( t t ¯ ) = 248.3 ± 0.7 ( stat . ) ± 13.4 ( syst . ) ± 4.7 ( lumi . ) pb , assuming a top-quark mass of 172.5 GeV. The result is in agreement with the Standard Model prediction. The cross-section is also measured in a phase space close to that of the selected data. The fiducial cross-section isσ fid ( t t ¯ ) = 48.8 ± 0.1 ( stat . ) ± 2.0 ( syst . ) ± 0.9 ( lumi . ) pb with a precision of 4.5%.

Search for a new heavy gauge-boson resonance decaying into a lepton and missing transverse momentum in 36 fb - 1 of pp collisions at s = 13 TeV with the ATLAS experiment

The results of a search for new heavy W ' bosons decaying to an electron or muon and a neutrino using proton-proton collision data at a centre-of-mass energy ofs = 13  TeV are presented. The dataset was collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 36.1 fb - 1 . As no excess of events above the Standard Model prediction is observed, the results are used to set upper limits on the W ' boson cross-section times branching ratio to an electron or muon and a neutrino as a function of the W ' mass. Assuming a W ' boson with the same couplings as the Standard Model W boson, W ' masses below 5.1 TeV are excluded at the 95% confidence level.

Search for a Structure in the B_{s}^{0}π^{±} Invariant Mass Spectrum with the ATLAS Experiment

A search for the narrow structure, X(5568), reported by the D0 Collaboration in the decay sequence X→B_{s}^{0}π^{±}, B_{s}^{0}→J/ψϕ, is presented. The analysis is based on a data sample recorded with the ATLAS detector at the LHC corresponding to 4.9  fb^{-1} of pp collisions at 7 TeV and 19.5  fb^{-1} at 8 TeV. No significant signal was found. Upper limits on the number of signal events, with properties corresponding to those reported by D0, and on the X production rate relative to B_{s}^{0} mesons, ρ_{X}, were determined at 95% confidence level. The results are N(X)<382 and ρ_{X}<0.015 for B_{s}^{0} mesons with transverse momenta above 10 GeV, and N(X)<356 and ρ_{X}<0.016 for transverse momenta above 15 GeV. Limits are also set for potential B_{s}^{0}π^{±} resonances in the mass range 5550 to 5700 MeV.

Search for heavy ZZ resonances in the ℓ + ℓ - ℓ + ℓ - and ℓ + ℓ - ν ν ¯ final states using proton-proton collisions at s = 13 TeV with the ATLAS detector

A search for heavy resonances decaying into a pair of Z bosons leading toℓ + ℓ - ℓ + ℓ - andℓ + ℓ - ν ν ¯ final states, where ℓ stands for either an electron or a muon, is presented. The search uses proton-proton collision data at a centre-of-mass energy of 13  TeV corresponding to an integrated luminosity of 36.1  fb - 1 collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 and 2000  GeV . The results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, while those for the spin-2 resonance are used to constrain the Randall-Sundrum model with an extra dimension giving rise to spin-2 graviton excitations.

A search for pair-produced resonances in four-jet final states at s = 13 TeV with the ATLAS detector

A search for massive coloured resonances which are pair-produced and decay into two jets is presented. The analysis uses 36.7 fb- 1 of s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the background prediction is observed. Results are interpreted in a SUSY simplified model where the lightest supersymmetric particle is the top squark, t ~ , which decays promptly into two quarks through R-parity-violating couplings. Top squarks with masses in the range 100 GeV < m t ~ < 410   GeV are excluded at 95% confidence level. If the decay is into a b-quark and a light quark, a dedicated selection requiring two b-tags is used to exclude masses in the ranges 100 GeV < m t ~ < 470   GeV and 480 GeV < m t ~ < 610   GeV . Additional limits are set on the pair-production of massive colour-octet resonances.

Search for doubly charged Higgs boson production in multi-lepton final states with the ATLAS detector using proton-proton collisions at s = 13 TeV

A search for doubly charged Higgs bosons with pairs of prompt, isolated, highly energetic leptons with the same electric charge is presented. The search uses a proton-proton collision data sample at a centre-of-mass energy of 13 TeV corresponding to 36.1 fb - 1 of integrated luminosity recorded in 2015 and 2016 by the ATLAS detector at the LHC. This analysis focuses on the decaysH ± ± → e ± e ± ,H ± ± → e ± μ ± andH ± ± → μ ± μ ± , fitting the dilepton mass spectra in several exclusive signal regions. No significant evidence of a signal is observed and corresponding limits on the production cross-section and consequently a lower limit on m ( H ± ± ) are derived at 95% confidence level. Withℓ ± ℓ ± = e ± e ± / μ ± μ ± / e ± μ ± , the observed lower limit on the mass of a doubly charged Higgs boson only coupling to left-handed leptons varies from 770 to 870 GeV (850 GeV expected) for B ( H ± ± → ℓ ± ℓ ± ) = 100 % and both the expected and observed mass limits are above 450 GeV for B ( H ± ± → ℓ ± ℓ ± ) = 10 % and any combination of partial branching ratios.

Measurement of differential cross-sections of a single top quark produced in association with a W boson at s = 13 TeV with ATLAS

The differential cross-section for the production of a W boson in association with a top quark is measured for several particle-level observables. The measurements are performed using36.1 fb - 1 of pp collision data collected with the ATLAS detector at the LHC in 2015 and 2016. Differential cross-sections are measured in a fiducial phase space defined by the presence of two charged leptons and exactly one jet matched to a b-hadron, and are normalised with the fiducial cross-section. Results are found to be in good agreement with predictions from several Monte Carlo event generators.

Measurement of quarkonium production in proton-lead and proton-proton collisions at 5.02 TeV with the ATLAS detector

The modification of the production of J / ψ , ψ ( 2 S ) , and Υ ( n S ) ( n = 1 , 2 , 3 ) in p+Pb collisions with respect to their production in pp collisions has been studied. The p+Pb and pp datasets used in this paper correspond to integrated luminosities of 28 nb - 1 and 25 pb - 1 respectively, collected in 2013 and 2015 by the ATLAS detector at the LHC, both at a centre-of-mass energy per nucleon pair of 5.02 TeV. The quarkonium states are reconstructed in the dimuon decay channel. The yields of J / ψ and ψ ( 2 S ) are separated into prompt and non-prompt sources. The measured quarkonium differential cross sections are presented as a function of rapidity and transverse momentum, as is the nuclear modification factor, R p Pb for J / ψ and Υ ( n S ) . No significant modification of the J / ψ production is observed while Υ ( n S ) production is found to be suppressed at low transverse momentum in p+Pb collisions relative to pp collisions. The production of excited charmonium and bottomonium states is found to be suppressed relative to that of the ground states in central p+Pb collisions.

Measurement of τ polarisation in Z / γ ∗ → τ τ decays in proton-proton collisions at s = 8 TeV with the ATLAS detector

This paper presents a measurement of the polarisation of τ leptons produced in Z / γ ∗ → τ τ decays which is performed with a dataset of proton-proton collisions ats = 8 TeV, corresponding to an integrated luminosity of 20.2 fb- 1 recorded with the ATLAS detector at the LHC in 2012. The Z / γ ∗ → τ τ decays are reconstructed from a hadronically decaying τ lepton with a single charged particle in the final state, accompanied by a τ lepton that decays leptonically. The τ polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic τ decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The τ polarisation extracted over the full phase space within the Z / γ ∗ mass range of 66 < m Z / γ ∗ < 116 GeV is found to beP τ = - 0.14 ± 0.02 ( stat ) ± 0.04 ( syst ) . It is in agreement with the Standard Model prediction ofP τ = - 0.1517 ± 0.0019 , which is obtained from the ALPGEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA τ decay library.

Search for the direct production of charginos and neutralinos in final states with tau leptons in s = 13 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1 fb- 1 , recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios of pair production and of and production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of theτ ~ L state is set to be halfway between the masses of the and the . Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of for a massless . Common and masses up to 760 GeV are excluded in the case of production of and assuming a massless . Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the and the are also studied by varying theτ ~ L mass between the masses of the and the .

Measurement of longitudinal flow decorrelations in Pb+Pb collisions at s NN = 2.76 and 5.02 TeV with the ATLAS detector

Measurements of longitudinal flow correlations are presented for charged particles in the pseudorapidity range | η | < 2.4 using 7 and 470 μ b - 1 of Pb+Pb collisions ats NN = 2.76 and 5.02 TeV, respectively, recorded by the ATLAS detector at the LHC. It is found that the correlation between the harmonic flow coefficients v n measured in two separated η intervals does not factorise into the product of single-particle coefficients, and this breaking of factorisation, or flow decorrelation, increases linearly with the η separation between the intervals. The flow decorrelation is stronger at 2.76 TeV than at 5.02 TeV. Higher-order moments of the correlations are also measured, and the corresponding linear coefficients for the k th -moment of the v n are found to be proportional to k for v 3 , but not for v 2 . The decorrelation effect is separated into contributions from the magnitude of v n and the event-plane orientation, each as a function of η . These two contributions are found to be comparable. The longitudinal flow correlations are also measured between v n of different order in n. The decorrelations of v 2 and v 3 are found to be independent of each other, while the decorrelations of v 4 and v 5 are found to be driven by the nonlinear contribution from v 2 2 andv 2 v 3 , respectively.

Direct top-quark decay width measurement in the t t ¯ lepton+jets channel at s = 8 TeV with the ATLAS experiment

This paper presents a direct measurement of the decay width of the top quark using t t ¯ events in the lepton+jets final state. The data sample was collected by the ATLAS detector at the LHC in proton-proton collisions at a centre-of-mass energy of 8 TeV and corresponds to an integrated luminosity of 20.2 fb- 1 . The decay width of the top quark is measured using a template fit to distributions of kinematic observables associated with the hadronically and semileptonically decaying top quarks. The result,Γ t = 1.76 ± 0.33 ( stat. ) - 0.68 + 0.79 ( syst. ) GeV for a top-quark mass of 172.5 GeV, is consistent with the prediction of the Standard Model.

Measurement of the W-boson mass in pp collisions at s = 7 TeV with the ATLAS detector

A measurement of the mass of the W boson is presented based on proton-proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb - 1 of integrated luminosity. The selected data sample consists of 7.8 × 10 6 candidates in the W → μ ν channel and 5.9 × 10 6 candidates in the W → e ν channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding m W = 80370 ± 7 ( stat. ) ± 11 ( exp. syst. ) ± 14 ( mod. syst. ) MeV = 80370 ± 19 MeV , where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W + and W - bosons yields m W + - m W - = - 29 ± 28  MeV.

Measurement of the W-boson mass in pp collisions at s = 7 TeV with the ATLAS detector

A measurement of the mass of the W boson is presented based on proton-proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb - 1 of integrated luminosity. The selected data sample consists of 7.8 × 10 6 candidates in the W → μ ν channel and 5.9 × 10 6 candidates in the W → e ν channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yieldingm W = 80370 ± 7 ( stat. ) ± 11 ( exp. syst. ) ± 14 ( mod. syst. ) MeV = 80370 ± 19 MeV , where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W + and W - bosons yieldsm W + - m W - = - 29 ± 28  MeV.

Search for new phenomena in high-mass final states with a photon and a jet from pp collisions at s = 13 TeV with the ATLAS detector

A search is performed for new phenomena in events having a photon with high transverse momentum and a jet collected in 36.7 fb - 1 of proton-proton collisions at a centre-of-mass energy of s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The invariant mass distribution of the leading photon and jet is examined to look for the resonant production of new particles or the presence of new high-mass states beyond the Standard Model. No significant deviation from the background-only hypothesis is observed and cross-section limits for generic Gaussian-shaped resonances are extracted. Excited quarks hypothesized in quark compositeness models and high-mass states predicted in quantum black hole models with extra dimensions are also examined in the analysis. The observed data exclude, at 95% confidence level, the mass range below 5.3 TeV for excited quarks and 7.1 TeV (4.4 TeV) for quantum black holes in the Arkani-Hamed-Dimopoulos-Dvali (Randall-Sundrum) model with six (one) extra dimensions.

Search for heavy resonances decaying into WW in the e ν μ ν final state in pp collisions at s = 13 TeV with the ATLAS detector

A search for neutral heavy resonances is performed in the W W → e ν μ ν decay channel using pp collision data corresponding to an integrated luminosity of 36.1 fb - 1 , collected at a centre-of-mass energy of 13TeV by the ATLAS detector at the Large Hadron Collider. No evidence of such heavy resonances is found. In the search for production via the quark-antiquark annihilation or gluon-gluon fusion process, upper limits onσ X × B ( X → W W ) as a function of the resonance mass are obtained in the mass range between 200GeV and up to 5TeV for various benchmark models: a Higgs-like scalar in different width scenarios, a two-Higgs-doublet model, a heavy vector triplet model, and a warped extra dimensions model. In the vector-boson fusion process, constraints are also obtained on these resonances, as well as on a Higgs boson in the Georgi-Machacek model and a heavy tensor particle coupling only to gauge bosons.

Search for dark matter produced in association with bottom or top quarks in s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive dark-matter particles produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and missing transverse momentum are considered. The analysis uses 36.1 fb - 1 of proton-proton collision data recorded by the ATLAS experiment ats = 13  TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are interpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour-neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross-section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour-charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV , mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements.

Gram-negative bacteria as emerging pathogens affecting mortality in skin and soft tissue infections

INTRODUCTION

Skin and soft tissue infections (SSTIs) are commonly encountered in clinical practice and mainly caused by gram-positive cocci such as S.aureus and β-hemolytic streptococci. Complicated SSTIs involving deeper tissues often necessitate surgical intervention and occur in patients with significant comorbidities such as diabetes or immunocompromising conditions.

METHODS

In this study, we retrospectively reviewed the epidemiology, clinical characteristics, microbiology, and treatment of patients admitted with SSTI during a five-year period in the Internal Medicine Department of a tertiary hospital.

RESULTS

During the study period, 317 patients were recorded, with a mean age of 72.1 years. The most common underlying medical conditions were diabetes mellitus, chronic kidney disease, and heart failure. Cultures were positive in 23.3 % of cases, 62.2 % of which were polymicrobial. The most frequently isolated microorganisms were Enterococci, Escherichia coli, and Pseudomonas aeruginosa. Significant antimicrobial resistance rates were noted, in particular for gram-negative microorganisms. Mortality was higher than described in the literature and associated with age, comorbidities, and infection by gram-negative microorganisms.

CONCLUSION

This study denotes the role of gram-negative bacteria in SSTI epidemiology. Therapeutic protocols regarding the empiric treatment of SSTIs should necessarily take into account the local epidemiology of isolated pathogens and antimicrobial resistance. HIPPOKRATIA 2018, 22(1): 23-28.

Search for direct top squark pair production in final states with two leptons in s = 13 TeV pp collisions with the ATLAS detector

The results of a search for direct pair production of top squarks in events with two opposite-charge leptons (electrons or muons) are reported, using 36.1 fb - 1 of integrated luminosity from proton-proton collisions ats = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. To cover a range of mass differences between the top squark t ~ and lighter supersymmetric particles, four possible decay modes of the top squark are targeted with dedicated selections: the decayt ~ → b χ ~ 1 ± into a b-quark and the lightest chargino withχ ~ 1 ± → W χ ~ 1 0 , the decayt ~ → t χ ~ 1 0 into an on-shell top quark and the lightest neutralino, the three-body decayt ~ → b W χ ~ 1 0 and the four-body decayt ~ → b ℓ ν χ ~ 1 0 . No significant excess of events is observed above the Standard Model background for any selection, and limits on top squarks are set as a function of the t ~ andχ ~ 1 0 masses. The results exclude at 95% confidence level t ~ masses up to about 720 GeV, extending the exclusion region of supersymmetric parameter space covered by previous searches.

Determination of the strong coupling constant α s from transverse energy-energy correlations in multijet events at s = 8 TeV using the ATLAS detector

Measurements of transverse energy-energy correlations and their associated asymmetries in multi-jet events using the ATLAS detector at the LHC are presented. The data used correspond tos = 8 TeV proton-proton collisions with an integrated luminosity of 20.2fb - 1 . The results are presented in bins of the scalar sum of the transverse momenta of the two leading jets, unfolded to the particle level and compared to the predictions from Monte Carlo simulations. A comparison with next-to-leading-order perturbative QCD is also performed, showing excellent agreement within the uncertainties. From this comparison, the value of the strong coupling constant is extracted for different energy regimes, thus testing the running ofα s ( μ ) predicted in QCD up to scales over 1 TeV . A global fit to the transverse energy-energy correlation distributions yieldsα s ( m Z ) = 0.1162 ± 0.0011 (exp.) - 0.0070 + 0.0084 (theo.) , while a global fit to the asymmetry distributions yields a value ofα s ( m Z ) = 0.1196 ± 0.0013 (exp.) - 0.0045 + 0.0075 (theo.) .

Measurement of lepton differential distributions and the top quark mass in t t ¯ production in pp collisions at s = 8 TeV with the ATLAS detector

This paper presents single lepton and dilepton kinematic distributions measured in dileptonic t t ¯ events produced in 20.2 fb - 1 ofs = 8  TeV pp collisions recorded by the ATLAS experiment at the LHC. Both absolute and normalised differential cross-sections are measured, using events with an opposite-charge e μ pair and one or two b-tagged jets. The cross-sections are measured in a fiducial region corresponding to the detector acceptance for leptons, and are compared to the predictions from a variety of Monte Carlo event generators, as well as fixed-order QCD calculations, exploring the sensitivity of the cross-sections to the gluon parton distribution function. Some of the distributions are also sensitive to the top quark pole mass; a combined fit of NLO fixed-order predictions to all the measured distributions yields a top quark mass value ofm t pole = 173.2 ± 0.9 ± 0.8 ± 1.2  GeV, where the three uncertainties arise from data statistics, experimental systematics, and theoretical sources.

Measurement of detector-corrected observables sensitive to the anomalous production of events with jets and large missing transverse momentum in p p collisions at s = 13 TeV using the ATLAS detector

Observables sensitive to the anomalous production of events containing hadronic jets and missing momentum in the plane transverse to the proton beams at the Large Hadron Collider are presented. The observables are defined as a ratio of cross sections, for events containing jets and large missing transverse momentum to events containing jets and a pair of charged leptons from the decay of a Z / γ ∗ boson. This definition minimises experimental and theoretical systematic uncertainties in the measurements. This ratio is measured differentially with respect to a number of kinematic properties of the hadronic system in two phase-space regions; one inclusive single-jet region and one region sensitive to vector-boson-fusion topologies. The data are found to be in agreement with the Standard Model predictions and used to constrain a variety of theoretical models for dark-matter production, including simplified models, effective field theory models, and invisible decays of the Higgs boson. The measurements use 3.2 fb- 1 of proton-proton collision data recorded by the ATLAS experiment at a centre-of-mass energy of 13  TeV and are fully corrected for detector effects, meaning that the data can be used to constrain new-physics models beyond those shown in this paper.

Search for Heavy Higgs Bosons A/H Decaying to a Top Quark Pair in pp Collisions at sqrt[s]=8 TeV with the ATLAS Detector

A search for heavy pseudoscalar (A) and scalar (H) Higgs bosons decaying into a top quark pair (tt[over ¯]) has been performed with 20.3  fb^{-1} of proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider at a center-of-mass energy sqrt[s]=8  TeV. Interference effects between the signal process and standard model tt[over ¯] production, which are expected to distort the signal shape from a single peak to a peak-dip structure, are taken into account. No significant deviation from the standard model prediction is observed in the tt[over ¯] invariant mass spectrum in final states with an electron or muon, large missing transverse momentum, and at least four jets. The results are interpreted within the context of a type-II two-Higgs-doublet model. Exclusion limits on the signal strength are derived as a function of the mass m_{A/H} and the ratio of the vacuum expectation values of the two Higgs fields, tanβ, for m_{A/H}>500  GeV.

Search for Dark Matter Produced in Association with a Higgs Boson Decaying to bb[over ¯] Using 36 fb^{-1} of pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

Several extensions of the standard model predict associated production of dark-matter particles with a Higgs boson. Such processes are searched for in final states with missing transverse momentum and a Higgs boson decaying to a bb[over ¯] pair with the ATLAS detector using 36.1  fb^{-1} of pp collisions at a center-of-mass energy of 13 TeV at the LHC. The observed data are in agreement with the standard model predictions and limits are placed on the associated production of dark-matter particles and a Higgs boson.

Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2

With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 [Formula: see text] for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb[Formula: see text] of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 [Formula: see text]. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 [Formula: see text] is quantified using a novel, data-driven, method. The method uses the energy loss, [Formula: see text], to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is [Formula: see text] and [Formula: see text] for jet transverse momenta of 200-400 [Formula: see text] and 1400-1600 [Formula: see text], respectively.

Frequent COL4 mutations in familial microhematuria accompanied by later-onset Alport nephropathy due to focal segmental glomerulosclerosis

Familial microscopic hematuria (FMH) is associated with a genetically heterogeneous group of conditions including the collagen-IV nephropathies, the heritable C3/CFHR5 nephropathy and the glomerulopathy with fibronectin deposits. The clinical course varies widely, ranging from isolated benign familial hematuria to end-stage renal disease (ESRD) later in life. We investigated 24 families using next generation sequencing (NGS) for 5 genes: COL4A3, COL4A4, COL4A5, CFHR5 and FN1. In 17 families (71%), we found 15 pathogenic mutations in COL4A3/A4/A5, 9 of them novel. In 5 families patients inherited classical AS with hemizygous X-linked COL4A5 mutations. Even more patients developed later-onset Alport-related nephropathy having inherited heterozygous COL4A3/A4 mutations that cause thin basement membranes. Amongst 62 heterozygous or hemizygous patients, 8 (13%) reached ESRD, while 25% of patients with heterozygous COL4A3/A4 mutations, aged >50-years, reached ESRD. In conclusion, COL4A mutations comprise a frequent cause of FMH. Heterozygous COL4A3/A4 mutations predispose to renal function impairment, supporting that thin basement membrane nephropathy is not always benign. The molecular diagnosis is essential for differentiating the X-linked from the autosomal recessive and dominant inheritance. Finally, NGS technology is established as the gold standard for the diagnosis of FMH and associated collagen-IV glomerulopathies, frequently averting the need for invasive renal biopsies.

Study of W W γ and W Z γ production in p p collisions at s = 8 TeV and search for anomalous quartic gauge couplings with the ATLAS experiment

This paper presents a study of W W γ and W Z γ triboson production using events from proton-proton collisions at a centre-of-mass energy ofs = 8 TeV recorded with the ATLAS detector at the LHC and corresponding to an integrated luminosity of 20.2 fb- 1 . The W W γ production cross-section is determined using a final state containing an electron, a muon, a photon, and neutrinos ( e ν μ ν γ ). Upper limits on the production cross-section of the e ν μ ν γ final state and the W W γ and W Z γ final states containing an electron or a muon, two jets, a photon, and a neutrino ( e ν j j γ or μ ν j j γ ) are also derived. The results are compared to the cross-sections predicted by the Standard Model at next-to-leading order in the strong-coupling constant. In addition, upper limits on the production cross-sections are derived in a fiducial region optimised for a search for new physics beyond the Standard Model. The results are interpreted in the context of anomalous quartic gauge couplings using an effective field theory. Confidence intervals at 95% confidence level are derived for the 14 coupling coefficients to which W W γ and W Z γ production are sensitive.

Identification and rejection of pile-up jets at high pseudorapidity with the ATLAS detector

The rejection of forward jets originating from additional proton-proton interactions (pile-up) is crucial for a variety of physics analyses at the LHC, including Standard Model measurements and searches for physics beyond the Standard Model. The identification of such jets is challenging due to the lack of track and vertex information in the pseudorapidity range | η | > 2.5 . This paper presents a novel strategy for forward pile-up jet tagging that exploits jet shapes and topological jet correlations in pile-up interactions. Measurements of the per-jet tagging efficiency are presented using a data set of 3.2 fb- 1 of proton-proton collisions at a centre-of-mass energy of 13TeV collected with the ATLAS detector. The fraction of pile-up jets rejected in the range 2.5 < | η | < 4.5 is estimated in simulated events with an average of 22 interactions per bunch-crossing. It increases with jet transverse momentum and, for jets with transverse momentum between 20 and 50 GeV, it ranges between 49% and 67% with an efficiency of 85% for selecting hard-scatter jets. A case study is performed in Higgs boson production via the vector-boson fusion process, showing that these techniques mitigate the background growth due to additional proton-proton interactions, thus enhancing the reach for such signatures.

Measurement of W W / W Z → ℓ ν q q ' production with the hadronically decaying boson reconstructed as one or two jets in pp collisions at s = 8 TeV with ATLAS, and constraints on anomalous gauge couplings

This paper presents a study of the production of WW or WZ boson pairs, with one W boson decaying to e ν or μ ν and one W or Z boson decaying hadronically. The analysis uses 20.2 fb - 1 ofs = 8 TeV pp collision data, collected by the ATLAS detector at the Large Hadron Collider. Cross-sections for WW / WZ production are measured in high- p T fiducial regions defined close to the experimental event selection. The cross-section is measured for the case where the hadronically decaying boson is reconstructed as two resolved jets, and the case where it is reconstructed as a single jet. The transverse momentum distribution of the hadronically decaying boson is used to search for new physics. Observations are consistent with the Standard Model predictions, and 95% confidence intervals are calculated for parameters describing anomalous triple gauge-boson couplings.

Fiducial, total and differential cross-section measurements of t-channel single top-quark production in pp collisions at 8 TeV using data collected by the ATLAS detector

Detailed measurements of t-channel single top-quark production are presented. They use 20.2 fb[Formula: see text] of data collected by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of 8 TeV at the LHC. Total, fiducial and differential cross-sections are measured for both top-quark and top-antiquark production. The fiducial cross-section is measured with a precision of 5.8% (top quark) and 7.8% (top antiquark), respectively. The total cross-sections are measured to be [Formula: see text] for top-quark production and [Formula: see text] for top-antiquark production, in agreement with the Standard Model prediction. In addition, the ratio of top-quark to top-antiquark production cross-sections is determined to be [Formula: see text]. The differential cross-sections as a function of the transverse momentum and rapidity of both the top quark and the top antiquark are measured at both the parton and particle levels. The transverse momentum and rapidity differential cross-sections of the accompanying jet from the t-channel scattering are measured at particle level. All measurements are compared to various Monte Carlo predictions as well as to fixed-order QCD calculations where available.

Search for the Dimuon Decay of the Higgs Boson in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

A search for the dimuon decay of the Higgs boson was performed using data corresponding to an integrated luminosity of 36.1  fb^{-1} collected with the ATLAS detector in pp collisions at sqrt[s]=13  TeV at the Large Hadron Collider. No significant excess is observed above the expected background. The observed (expected) upper limit on the cross section times branching ratio is 3.0 (3.1) times the Standard Model prediction at the 95% confidence level for a Higgs boson mass of 125 GeV. When combined with the pp collision data at sqrt[s]=7  TeV and sqrt[s]=8  TeV, the observed (expected) upper limit is 2.8 (2.9) times the Standard Model prediction.

Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1

The reconstruction of the signal from hadrons and jets emerging from the proton-proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In this, the clustering algorithm implicitly performs a topological noise suppression by removing cells with insignificant signals which are not in close proximity to cells with significant signals. The resulting topological cell clusters have shape and location information, which is exploited to apply a local energy calibration and corrections depending on the nature of the cluster. Topological cell clustering is established as a well-performing calorimeter signal definition for jet and missing transverse momentum reconstruction in ATLAS.