637 research outputs found

    Location, function, and nucleotide sequence of a promoter for bacteriophage T3 RNA polymerase

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    The major promoters for bacteriophage T3 RNA polymerase on the T3 genome have been mapped by DNA.RNA filter hybridization. One promoter is located in a 300-base-pair Hpa I restriction fragment near the genetic "left" end of T3 DNA. The sequence in the vicinity of the major initiation site of transcription in this region has been determined. A part of the (-)strand sequence is 5' T-A-T-T-T-A-C-C-C-T-C-A-C-T-A-A-A-G-+1 G-G-A-A-U 3'. Comparison of this sequence with the prototype 23-base-pair promoter sequence for bacteriophage T7 RNA polymerase shows a striking pattern of homology and divergence. Between positions -9 and +4, the sequences are virtually identical, whereas between positions -17 and -10, the sequences are quite different. It is postulated that these sequence subsets may perform different functions in transcription initiation by the phage RNA polymerases

    Reply to Wassmann et al.: More data at high sampling intensity from medium- and intense-intermittently flooded rice farms is crucial

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    This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Here, we briefly respond to critique of our study (1) by Wassmann et al. (2). A detailed response to their letter is available online (edf.org/riceN2O)

    Measurement of D-0, D+, D+* and D-s(+) production in pp collisions at root s=5.02 TeV with ALICE

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    The measurements of the production of prompt D0, D+, D+, and Ds+ mesons in proton-proton (pp) collisions at TeV with the ALICE detector at the Large Hadron Collider (LHC) are reported. D mesons were reconstructed at mid-rapidity (|y|<0.5) via their hadronic decay channels D0K-+, D+K-++, D+D0+K-++, Ds+phi+K+K-+, and their charge conjugates. The production cross sections were measured in the transverse momentum interval 0<36 for D0, 1<36 for D+ and D+, and in 2<24 for Ds+ mesons. Thanks to the higher integrated luminosity, an analysis in finer pT bins with respect to the previous measurements at sTeV was performed, allowing for a more detailed description of the cross-section pT shape. The measured pT-differential production cross sections are compared to the results at s=7TeV and to four different perturbative QCD calculations. Its rapidity dependence is also tested combining the ALICE and LHCb measurements in pp collisions at s=5.02 TeV. This measurement will allow for a more accurate determination of the nuclear modification factor in p-Pb and Pb-Pb collisions performed at the same nucleon-nucleon centre-of-mass energy

    Charged-particle pseudorapidity density at mid-rapidity in p–Pb collisions at √sNN = 8.16 TeV

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    The pseudorapidity density of charged particles, dN(ch)/d eta, in p-Pb collisions has been measured at a centre of-mass energy per nucleon-nucleon pair of root S-NN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, vertical bar eta vertical bar /2 is 4.73 +/- 0.20, where is the average number of participating nucleons, is 9.5% higher than the corresponding value for p-Pb collisions at root S-NN = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the dN(ch)/d eta distribution. Saturation-based models reproduce the distributions well for eta > -1.3. The dN(ch)/d eta is also measured for different centrality estimators, based both on the charged particle multiplicity and on the energy deposited in the Zero Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p-Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity

    Jet fragmentation transverse momentum measurements from di-hadron correlations in √s=7 TeV pp and √sNN=5.02 TeV p–Pb collisions

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    The transverse structure of jets was studied via jet fragmentation transverse momentum (j(T)) distributions, obtained using two-particle correlations in proton-proton and proton-lead collisions, measured with the ALICE experiment at the LHC. The highest transverse momentum particle in each event is used as the trigger particle and the region 3 < p(Tt) < 15GeV/c is explored in this study. The measured distributions show a clear narrow Gaussian component and a wide non-Gaussian one. Based on Pythia simulations, the narrow component can be related to non-perturbative hadronization and the wide component to quantum chromodynamical splitting. The width of the narrow component shows a weak dependence on the transverse momentum of the trigger particle, in agreement with the expectation of universality of the hadronization process. On the other hand, the width of the wide component shows a rising trend suggesting increased branching for higher transverse momentum. The results obtained in pp collisions at root s TeV and in p-Pb collisions at root sNN=5.02 TeV are compatible within uncertainties and hence no significant cold nuclear matter effects are observed. The results are compared to previous measurements from CCOR and PHENIX as well as to Pythia 8 and Herwig 7 simulations

    Measurement of the production of charm jets tagged with D0^{0} mesons in pp collisions at s\sqrt{s}= 7 TeV

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    The production of charm jets in proton-proton collisions at a center-of-mass energy of s=7\sqrt{s}=7 TeV was measured with the ALICE detector at the CERN Large Hadron Collider. The measurement is based on a data sample corresponding to a total integrated luminosity of 6.236.23 nb−1{\rm nb}^{-1}, collected using a minimum-bias trigger. Charm jets are identified by the presence of a D0^0 meson among their constituents. The D0^0 mesons are reconstructed from their hadronic decay D0→^0\rightarrowK−π+^{-}\pi^{+}. The D0^0-meson tagged jets are reconstructed using tracks of charged particles (track-based jets) with the anti-kTk_{\mathrm{T}} algorithm in the jet transverse momentum range 5<pT,jetch<305<p_{\rm{T,jet}}^{\mathrm{ch}}<30 GeV/c{\rm GeV/}c and pseudorapidity ∣ηjet∣<0.5|\eta_{\rm jet}|<0.5. The fraction of charged jets containing a D0^0-meson increases with pT,jetchp_{\rm{T,jet}}^{\rm{ch}} from 0.042±0.004 (stat)±0.006 (syst)0.042 \pm 0.004\, \mathrm{(stat)} \pm 0.006\, \mathrm{(syst)} to 0.080±0.009 (stat)±0.008 (syst)0.080 \pm 0.009\, \rm{(stat)} \pm 0.008\, \rm{(syst)}. The distribution of D0^0-meson tagged jets as a function of the jet momentum fraction carried by the D0^0 meson in the direction of the jet axis (z∣∣chz_{||}^{\mathrm{ch}}) is reported for two ranges of jet transverse momenta, 5<pT,jetch<155<p_{\rm{T,jet}}^{\rm{ch}}<15 GeV/c{\rm GeV/}c and 15<pT,jetch<3015<p_{\rm{T,jet}}^{\rm{ch}}<30 GeV/c{\rm GeV/}c in the intervals 0.2<z∣∣ch<1.00.2<z_{||}^{\rm{ch}}<1.0 and 0.4<z∣∣ch<1.00.4<z_{||}^{\rm{ch}}<1.0, respectively. The data are compared with results from Monte Carlo event generators (PYTHIA 6, PYTHIA 8 and Herwig 7) and with a Next-to-Leading-Order perturbative Quantum Chromodynamics calculation, obtained with the POWHEG method and interfaced with PYTHIA 6 for the generation of the parton shower, fragmentation, hadronisation and underlying event.Comment: 29 pages, 8 captioned figures, 3 tables, authors from page 24, published version, figures at http://alice-publications.web.cern.ch/node/525

    Thermal leptogenesis in a model with mass varying neutrinos

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    In this paper we consider the possibility of neutrino mass varying during the evolution of the Universe and study its implications on leptogenesis. Specifically, we take the minimal seesaw model of neutrino masses and introduce a coupling between the right-handed neutrinos and the dark energy scalar field, the Quintessence. In our model, the right-handed neutrino masses change as the Quintessence scalar evolves. We then examine in detail the parameter space of this model allowed by the observed baryon number asymmetry. Our results show that it is possible to lower the reheating temperature in this scenario in comparison with the case that the neutrino masses are unchanged, which helps solve the gravitino problem. Furthermore, a degenerate neutrino mass patten with mim_i larger than the upper limit given in the minimal leptogenesis scenario is permitted.Comment: 18 pages, 7 figures, version to appear in PR

    A multicenter prospective randomized controlled trial of cardiac resynchronization therapy guided by invasive dP/dt

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    Background: No periprocedural metric has demonstrated improved cardiac resynchronization therapy (CRT) outcomes in a multicenter setting. Objective: We sought to determine if left ventricular (LV) lead placement targeted to the coronary sinus (CS) branch generating the best acute hemodynamic response (AHR) results in improved outcomes at 6 months. Methods: In this multicenter randomized controlled trial, patients were randomized to guided CRT or conventional CRT. Patients in the guided arm had LV dP/dtmax measured during biventricular (BIV) pacing. Target CS branches were identified and the final LV lead position was the branch with the best AHR and acceptable threshold values. The primary endpoint was the proportion of patients with a reduction in LV end-systolic volume (LVESV) of ≥15% at 6 months. Results: A total of 281 patients were recruited across 12 centers. Mean age was 70.8 ± 10.9 years and 54% had ischemic etiology. Seventy-three percent of patients in the guided arm demonstrated a reduction in LVESV of ≥15% at 6 months vs 60% in the conventional arm (P = .02). Patients with AHR ≥ 10% were more likely to demonstrate a reduction of ESV ≥ 15% (84% of patients with an AHR ≥10% vs 28% with an AHR <10%; P < 0.001). Procedure duration and fluoroscopy times were longer in the pressure wire-guided arm (104 ± 39 minutes vs 142 ± 39 minutes; P < .001 and 20 ±16 minutes vs 28 ± 15 minutes; P = .002). Conclusions: AHR determined by invasively measuring LV dP/dtmax during BIV pacing predicts reverse remodeling 6 months after CRT. Patients in whom LV dP/dtmax was used to guide LV lead placement demonstrated better rates of reverse remodeling
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