620 research outputs found
The membrane protein MiRP3 regulates Kv4.2 channels in a KChIP‐dependent manner
No full textMiRP3, the single-span membrane protein encoded by KCNE4, is localized by immunofluorescence microscopy to the transverse tubules of murine cardiac myocytes. MiRP3 is found to co-localize with Kv4.2 subunits that contribute to cardiac transient outward potassium currents (I(to)). Whole-cell, voltage-clamp recordings of human MiRP3 and Kv4.2 expressed in a clonal cell line (tsA201) reveal MiRP3 to modulate Kv4.2 current activation, inactivation and recovery from inactivation. MiRP3 shifts the half-maximal voltage for activation (V(1/2)) approximately 20 mV and slows time to peak approximately 100%. In addition, MiRP3 slows inactivation approximately 100%, speeds recovery from inactivation approximately 30%, and enhances restored currents so they 'overshoot' baseline levels. The cytoplasmic accessory subunit KChIP2 also assembles with Kv4.2 in tsA201 cells to increase peak current, shift V(1/2) approximately 5 mV, slow time to peak approximately 10%, slow inactivation approximately 100%, and speed recovery from inactivation approximately 250% without overshoot. Simultaneous expression of all three subunits yields a biophysical profile unlike either accessory subunit alone, abolishes MiRP3-induced overshoot, and allows biochemical isolation of the ternary complex. Thus, regional heterogeneity in cardiac expression of MiRP3, Kv4.2 and KChIP2 in health and disease may establish the local attributes and magnitude of cardiac I(to)
Search for a new heavy scalar particle decaying into a Higgs boson and a new scalar singlet in final states with one or two light leptons and a pair of -leptons with the ATLAS detector
No full textA search for a new heavy scalar particle decaying into a Standard Model
(SM) Higgs boson and a new singlet scalar particle is presented. The search
uses a proton-proton () collision data sample with an integrated luminosity
of 140 fb recorded at a centre-of-mass energy of TeV
with the ATLAS detector at the Large Hadron Collider. The most sensitive mass
parameter space is explored in mass ranging from 500 to 1500 GeV, with the
corresponding mass in the range 200-500 GeV. The search selects events with
two hadronically decaying -lepton candidates from
decays and one or two light leptons () from () decays while the remaining boson decays hadronically or to
neutrinos. A multivariate discriminant based on event kinematics is used to
separate the signal from the background. No excess is observed beyond the
expected SM background and 95% confidence level upper limits between 72 fb and
542 fb are derived on the cross-section assuming the
same SM-Higgs boson-like decay branching ratios for the decay. Upper
limits on the visible cross-sections and
are also set in the ranges 3-26 fb and
6-33 fb, respectively.Comment: 46 pages in total, author list starting page 28, 5 figures, 5 tables,
published in JHEP. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2022-4
Probing Charm Quark Dynamics via Multiparticle Correlations in Pb-Pb Collisions at √sNN=5.02 TeV
No full textMultiparticle azimuthal correlations of prompt D-0 mesons arc measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of root s(NN) = 5.02 TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v(2)) of D-0 mesons as a function of event centrality and the D-0 transverse momentum. The ratios of the four-particle v(2) values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data
Search for Higgs Boson Pair Production in the Four b Quark Final State in Proton-Proton Collisions at √s=13 TeV
No full textA search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138 fb^{-1}. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, κ_{λ}, and of the coupling of two Higgs bosons to two vector bosons, κ_{2 V}. The observed (expected) allowed intervals at the 95% confidence level are -2.3<9.4 (-5.0<12.0) and -0.1<2.2 (-0.4<2.5). These are the most stringent observed constraints to date on the HH production cross section and on the κ_{2 V } coupling
Distributions of C-reactive protein measured by high- sensitivity assays in apparently healthy men and women from different populations in Europe
No full textNo abstract available
Sex differences in incidence, mortality, and survival in individuals with stroke in Scotland, 1986 to 2005
No full text<p><b>Background and Purpose:</b> The aim of this study was to examine the effect of sex across different age groups and over time for stroke incidence, 30-day case-fatality, and mortality.</p>
<p><b>Methods:</b> All first hospitalizations for stroke in Scotland (1986 to 2005) were identified using linked morbidity and mortality data. Age-specific rate ratios (RRs) for comparing women with men for both incidence and mortality were modeled with adjustment for study year and socioeconomic deprivation. Logistic regression was used to model 30-day case-fatality.</p>
<p><b>Results:</b> Women had a lower incidence of first hospitalization than men and size of effect varied with age (55 to 64 years, RR=0.65, 95% CI 0.63 to 0.66; 85 years, RR=0.94, 95% CI 0.91 to 0.96). Women aged 55 to 84 years had lower mortality than men and again size of effect varied with age (65 to 74 years, RR=0.79, 95% CI 0.76 to 0.81); 75 to 84 years, RR=0.94, 95% CI 0.92 to 0.95). Conversely, women aged 85 years had 15% higher stroke mortality than men (RR=1.15, 95% CI 1.12 to 1.18). Adjusted risk of death within 30 days was significantly higher in women than men, and this difference increased over the 20-year period in all age groups (adjusted OR in 55 to 64 year olds 1.23, 95% CI 1.14 to 1.33 in 1986 and 1.51, 95% CI 1.39 to 1.63 in 2005).</p>
<p><b>Conclusions:</b> We observed lower rates of incidence and mortality in younger women than men. However, higher numbers of older women in the population mean that the absolute burden of stroke is greater in women. Short-term case-fatality is greater in women of all ages and, worryingly, these differences have increased from 1986 to 2005.</p>
Measurement of the Effective Lifetime with the ATLAS Detector
No full textThis paper reports the first ATLAS measurement of the
effective lifetime. The measurement is based on the data collected in
2015-2016, amounting to 26.3 fb of 13 TeV LHC proton-proton collisions.
The proper decay-time distribution of background-subtracted signal
candidates is fit with simulated signal templates parameterised as a function
of the effective lifetime, with statistical uncertainties extracted
through a Neyman construction. The resulting effective measurement of the
lifetime is and it is found to be consistent with the
Standard Model.Comment: 32 pages in total, author list starting page 14, 4 figures and 1
table. All figures/tables (including auxiliary ones), are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2020-07
Combined searches for the production of supersymmetric top quark partners in proton–proton collisions at
No full textInternational audienceA combination of searches for top squark pair production using proton–proton collision data at a center-of-mass energy of 13 at the CERN LHC, corresponding to an integrated luminosity of 137 collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on the model, the combined result excludes a top squark mass up to 1325 for a massless neutralino, and a neutralino mass up to 700 for a top squark mass of 1150. Top squarks with masses from 145 to 295, for neutralino masses from 0 to 100, with a mass difference between the top squark and the neutralino in a window of 30 around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420
Measurement of the cross-sections of the electroweak and total production of a pair in association with two jets in collisions at = 13 TeV with the ATLAS detector
No full textThis Letter presents the measurement of the fiducial and differential
cross-sections of the electroweak production of a pair in
association with two jets. The analysis uses 140 fb of LHC proton-proton
collision data taken at =13 TeV recorded by the ATLAS detector during
the years 2015-2018. Events with a boson candidate decaying into either an
or pair, a photon and two jets are selected. The
electroweak component is extracted by requiring a large dijet invariant mass
and a large rapidity gap between the two jets and is measured with an observed
and expected significance well above five standard deviations. The fiducial cross-section for the electroweak production is
measured to be 3.6 0.5 fb. The total fiducial cross-section that also
includes contributions where the jets arise from strong interactions is
measured to be fb. The results are consistent with the
Standard Model predictions. Differential cross-sections are also measured using
the same events and are compared with parton-shower Monte Carlo simulations.
Good agreement is observed between data and predictions.Comment: 44 pages in total, author list starting page 27, 6 figures, 3 tables,
submitted to PLB. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2018-36
Search for flavor-changing neutral interactions with in collisions at = 13 TeV using the ATLAS detector
No full textA search for flavour-changing neutral interactions involving the top quark,
the Higgs boson and an up-type quark () is presented. The
proton-proton collision data set used, with an integrated luminosity of 139
fb, was collected at \~TeV by the ATLAS experiment at the
Large Hadron Collider. Both the decay process and the production
process , with the Higgs boson decaying into two photons, are
investigated. No significant excess is observed and upper limits are set on the
and the branching ratios of and , respectively, at the 95% confidence level,
while the expected limits in the absence of signal are and
. Combining this search with ATLAS searches in the and final states yields observed (expected)
upper limits on the branching ratio of at the 95% confidence level. The corresponding observed (expected)
upper limit on the branching ratio is $4.0 \times 10^{-4}\
(2.4 \times 10^{-4})$Comment: 51 pages in total, author list starting page 34, 11 figures, 6
tables, published by JHEP. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2019-0
- …
