7,243 research outputs found
Measurement of , K, p transverse momentum spectra with ALICE in proton-proton collisions at 0.9 and 7 TeV
Results of the measurement of the , K, p transverse momentum
() spectra at mid-rapidity in proton-proton collisions at
TeV are presented. Particle identification was performed using
the energy loss signal in the Inner Tracking System (ITS) and the Time
Projection Chamber (TPC), while information from the Time-of-Flight (TOF)
detector was used to identify particles at higher transverse momentum. From the
spectra at TeV the mean transverse momentum ()
and particle ratios were extracted and compared to results obtained for
collisions at TeV and lower energies.Comment: Quark Matter 2011 proceeding
Parallel Working-Set Search Structures
In this paper we present two versions of a parallel working-set map on p
processors that supports searches, insertions and deletions. In both versions,
the total work of all operations when the map has size at least p is bounded by
the working-set bound, i.e., the cost of an item depends on how recently it was
accessed (for some linearization): accessing an item in the map with recency r
takes O(1+log r) work. In the simpler version each map operation has O((log
p)^2+log n) span (where n is the maximum size of the map). In the pipelined
version each map operation on an item with recency r has O((log p)^2+log r)
span. (Operations in parallel may have overlapping span; span is additive only
for operations in sequence.)
Both data structures are designed to be used by a dynamic multithreading
parallel program that at each step executes a unit-time instruction or makes a
data structure call. To achieve the stated bounds, the pipelined data structure
requires a weak-priority scheduler, which supports a limited form of 2-level
prioritization. At the end we explain how the results translate to practical
implementations using work-stealing schedulers.
To the best of our knowledge, this is the first parallel implementation of a
self-adjusting search structure where the cost of an operation adapts to the
access sequence. A corollary of the working-set bound is that it achieves work
static optimality: the total work is bounded by the access costs in an optimal
static search tree.Comment: Authors' version of a paper accepted to SPAA 201
The role of vibrationally excited nitrogen and oxygen in the ionosphere over Millstone Hill during 16-23 March, 1990
International audienceWe present a comparison of the observed behavior of the F region ionosphere over Millstone Hill during the geomagnetically quiet and storm period on 16-23 March, 1990, with numerical model calculations from the time-dependent mathematical model of the Earth's ionosphere and plasmasphere. The effects of vibrationally excited N2(v) and O2(v) on the electron density and temperature are studied using the N2(v) and O2(v) Boltzmann and non-Boltzmann distribution assumptions. The deviations from the Boltzmann distribution for the first five vibrational levels of N2(v) and O2(v) were calculated. The present study suggests that these deviations are not significant at vibrational levels v = 1 and 2, and the calculated distributions of N2(v) and O2(v) are highly non-Boltzmann at vibrational levels v > 2. The N2(v) and O2(v) non-Boltzmann distribution assumption leads to the decrease of the calculated daytime NmF2 up to a factor of 1.44 (maximum value) in comparison with the N2(v) and O2(v) Boltzmann distribution assumption. The resulting effects of N2(v > 0) and O2(v > 0) on the NmF2 is the decrease of the calculated daytime NmF2 up to a factor of 2.8 (maximum value) for Boltzmann populations of N2(v) and O2(v) and up to a factor of 3.5 (maximum value) for non-Boltzmann populations of N2(v) and O2(v) . This decrease in electron density results in the increase of the calculated daytime electron temperature up to about 1040-1410 K (maximum value) at the F2 peak altitude giving closer agreement between the measured and modeled electron temperatures. Both the daytime and nighttime densities are not reproduced by the model without N2(v > 0) and O2(v > 0) , and inclusion of vibrationally excited N2 and O2 brings the model and data into better agreement. The effects of vibrationally excited O2 and N2 on the electron density and temperature are most pronounced during daytime
Differentiation of Cardiac from Noncardiac Pleural Effusions in Cats using Second-Generation Quantitative and Point-of-Care NT-proBNP Measurements
BACKGROUND: Pleural effusion is a common cause of dyspnea in cats. Nâterminal proâBâtype natriuretic peptide (NTâproBNP) measurement, using a firstâgeneration quantitative ELISA, in plasma and pleural fluid differentiates cardiac from noncardiac causes of pleural effusion. HYPOTHESIS/OBJECTIVES: To determine whether NTâproBNP measurements using secondâgeneration quantitative ELISA and pointâofâcare (POC) tests in plasma and pleural fluid distinguish cardiac from noncardiac pleural effusions and how results compare to the firstâgeneration ELISA. ANIMALS: Thirtyâeight cats (US cohort) and 40 cats (UK cohort) presenting with cardiogenic or noncardiogenic pleural effusion. METHODS: Prospective cohort study. Twentyâone and 17 cats in the US cohort, and 22 and 18 cats in the UK cohort were classified as having cardiac or noncardiac pleural effusion, respectively. NTâproBNP concentrations in paired plasma and pleural fluid samples were measured using secondâgeneration ELISA and POC assays. RESULTS: The secondâgeneration ELISA differentiated cardiac from noncardiac pleural effusion with good diagnostic accuracy (plasma: sensitivity, 95.2%, specificity, 82.4%; pleural fluid: sensitivity, 100%, specificity, 76.5%). NTâproBNP concentrations were greater in pleural fluid (719 pmol/L (134â1500)) than plasma (678 pmol/L (61â1500), P = 0.003), resulting in different cutâoff values depending on the sample type. The POC test had good sensitivity (95.2%) and specificity (87.5%) when using plasma samples. In pleural fluid samples, the POC test had good sensitivity (100%) but low specificity (64.7%). Diagnostic accuracy was similar between firstâ and secondâgeneration ELISA assays. CONCLUSIONS AND CLINICAL IMPORTANCE: Measurement of NTâproBNP using a quantitative ELISA in plasma and pleural fluid or POC test in plasma, but not pleural fluid, distinguishes cardiac from noncardiac causes of pleural effusion in cats
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