A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tt events under typical 2011 pileup conditions, the average trackreconstruction efficiency for promptly-produced charged particles with transverse momenta of p T > 0.9 GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of p T = 100 GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in p T , and respectively, 10 µm and 30 µm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10-12 µm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.
Several techniques have been employed to incise the temporalis muscle for the pterional craniotomy. The authors describe a method which provides the advantage of a free bone flap, yet allows anatomical reapproximation of the temporalis muscle to its bone attachment.
A search is performed for the production of heavy resonances decaying into topantitop quark pairs in proton-proton collisions at √ s = 8 TeV. Data used for the analyses were collected with the CMS detector and correspond to an integrated luminosity of 19.7 fb −1 . The search is performed using events with three different final states, defined by the number of leptons (electrons and muons) from the tt → WbWb decay. The analyses are optimized for reconstruction of top quarks with high Lorentz boosts, where jet substructure techniques are used to enhance the sensitivity. Results are presented for all channels and a combination is performed. No significant excess of events relative to the expected yield from standard model processes is observed. Upper limits on the production cross section of heavy resonances decaying to tt are calculated. A narrow leptophobic topcolor Z resonance with a mass below 2.4 TeV is excluded at 95% confidence level. Limits are also derived for a broad Z resonance with a 10% width relative to the resonance mass, and a Kaluza-Klein excitation of the gluon in the Randall-Sundrum model. These are the most stringent limits to date on heavy resonances decaying into top-antitop quark pairs.
Published in Physical Review D asThe CMS experiment uses a particle-flow (PF) based event reconstruction [37,38], which aggregates input from all subdetectors. This information includes charged-particle tracks from the tracking system and deposited energy from the electromagnetic and hadronic calorimeters, taking advantage of excellent granularity of the sub-systems. Particles are classified as electrons, muons, photons, charged hadrons, and neutral hadrons. Primary vertices are reconstructed using a deterministic annealing filter algorithm [39]. The vertex with the largest squared sum of the associated track p T values is taken to be the primary event vertex.Electrons are reconstructed in the pseudorapidity range |η| < 2.5, by combining tracking information with energy deposits in the electromagnetic calorimeter [40,41]. Electron candidates are required to originate from the primary event vertex. Electrons are identified using infor-6 5 Reconstruction of tt events B The CMS Collaboration
An examination of oxygen and hydrogen isotopic compositions of precipitation in NE Asia from the IAEA/WMO data set reveals that many sites have a distinct winter-summer seasonal pattern in deuterium excess (d-) values that appears to reflect different climatic conditions. To further understand this pattern, stable isotopic data were obtained for individual rainfall events over a 2 yr period at Jeju Island, Korea. The δ 18 O-and δD-values of precipitation at Jeju Island are not dependent upon temperature. However, the deuterium excess values, which range from 3.0 to 40.6 ‰, show a distinct seasonal variation with higher d-values in winter (>~15 ‰) and lower values in summer (~10 ‰). Such a seasonal variation is closely related to different air masses affecting the island during different seasons: a cold-dry continental polar air mass in winter and a hot-humid maritime tropical air mass in summer.
High-dosage, tocolytic magnesium sulfate (MgSO 4 ) administered to pregnant women during preterm labor can be toxic, and sometimes lethal, for their newborns (Cochrane Database of Systematic Reviews (relative mortality risk 2.82, 95% confidence interval 1.2-6.6)). Based on the results of the Magnesium and Neurologic Endpoints Trial and the work of many others, a unifying triangular concept is proposed to account for the increased prevalence of brain lesions, with their likely resultant mortality, in neonates and infants exposed to high-dose MgSO 4 in the context of preterm labor. We review the evidence that: (1) elevated circulating levels of serum ionized magnesium occurring in mothers, and therefore in their babies, at the time of delivery are associated with subsequent neonatal intraventricular hemorrhage (IVH); (2) neonatal IVH is strongly associated with lenticulostriate vasculopathy (LSV), an unusual mineralizing lesion involving the thalami and basal ganglia of the neonate; and, (3) exposure to 50 g or more of tocolytic MgSO 4 during preterm labor is associated with the development of LSV.
Three forms of non-injurious ischemic preconditioning were tested for their effects on endogenous antioxidant activity and subsequent ischemic injury. Test ischemia alone, consisting of 1 h occlusion of both carotid arteries (BCAs) and one middle cerebral artery (MCA), elicited an average volume of cerebral infarction of 143.4 +/- 15.0 mm3 (mean +/- s.e.m.). Twenty minutes occlusion of the MCA only or MCA and BCAs (but not BCAs only) 24 h before test ischemia significantly increased the activity of the antioxidant enzyme superoxide dismutase and significantly reduced the cerebral infarction volume. These findings demonstrate that brief focal ischemia can attenuate the injurious impact of subsequent ischemia and that an upregulation of endogenous antioxidant activity may play a key role in this neuroprotective effect.
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