137 research outputs found
Maui-VIA: a user-friendly software for visual identification, alignment, correction, and quantification of gas chromatography-mass spectrometry data
A current bottleneck in GC-MS metabolomics is the processing of raw machine data into a final datamatrix that contains the quantities of identified metabolites in each sample. While there are many bioinformatics tools available to aid the initial steps of the process, their use requires both significant technical expertise and a subsequent manual validation of identifications and alignments if high data quality is desired. The manual validation is tedious and time consuming, becoming prohibitively so as sample numbers increase. We have, therefore, developed Maui-VIA, a solution based on a visual interface that allows experts and non-experts to simultaneously and quickly process, inspect, and correct large numbers of GC-MS samples. It allows for the visual inspection of identifications and alignments, facilitating a unique and, due to its visualization and keyboard shortcuts, very fast interaction with the data. Therefore, Maui-Via fills an important niche by (1) providing functionality that optimizes the component of data processing that is currently most labor intensive to save time and (2) lowering the threshold of expertise required to process GC-MS data. Maui-VIA projects are initiated with baseline-corrected raw data, peaklists, and a database of metabolite spectra and retention indices used for identification. It provides functionality for retention index calculation, a targeted library search, the visual annotation, alignment, correction interface, and metabolite quantification, as well as the export of the final datamatrix. The high quality of data produced by Maui-VIA is illustrated by its comparison to data attained manually by an expert using vendor software on a previously published dataset concerning the response of Chlamydomonas reinhardtii to salt stress. In conclusion, Maui-VIA provides the opportunity for fast, confident, and high-quality data processing validation of large numbers of GC-MS samples by non-experts
Algebraic Systems and Pushdown Automata
The theory of algebraic power series in noncommuting variables, as we un-derstand it today, was initiated in [2] and developed in its early stages by the French school. The main motivation was the interconnection with context-free grammars: the defining equations were made to correspond to context-fre
Measurements of , , , and proton production in proton-carbon interactions at 31 GeV/ with the NA61/SHINE spectrometer at the CERN SPS
Measurements of hadron production in p+C interactions at 31 GeV/c are
performed using the NA61/ SHINE spectrometer at the CERN SPS. The analysis is
based on the full set of data collected in 2009 using a graphite target with a
thickness of 4% of a nuclear interaction length. Inelastic and production cross
sections as well as spectra of , , p, and are
measured with high precision. These measurements are essential for improved
calculations of the initial neutrino fluxes in the T2K long-baseline neutrino
oscillation experiment in Japan. A comparison of the NA61/SHINE measurements
with predictions of several hadroproduction models is presented.Comment: v1 corresponds to the preprint CERN-PH-EP-2015-278; v2 matches the
final published versio
Multiplicity and transverse momentum fluctuations in inelastic proton-proton interactions at the CERN Super Proton Synchrotron
Measurements of multiplicity and transverse momentum fluctuations of charged
particles were performed in inelastic p+p interactions at 20, 31, 40, 80 and
158 GeV/c beam momentum. Results for the scaled variance of the multiplicity
distribution and for three strongly intensive measures of multiplicity and
transverse momentum fluctuations \$\Delta[P_{T},N]\$, \$\Sigma[P_{T},N]\$ and
\$\Phi_{p_T}\$ are presented. For the first time the results on fluctuations
are fully corrected for experimental biases. The results on multiplicity and
transverse momentum fluctuations significantly deviate from expectations for
the independent particle production. They also depend on charges of selected
hadrons. The string-resonance Monte Carlo models EPOS and UrQMD do not describe
the data. The scaled variance of multiplicity fluctuations is significantly
higher in inelastic p+p interactions than in central Pb+Pb collisions measured
by NA49 at the same energy per nucleon. This is in qualitative disagreement
with the predictions of the Wounded Nucleon Model. Within the statistical
framework the enhanced multiplicity fluctuations in inelastic p+p interactions
can be interpreted as due to event-by-event fluctuations of the fireball energy
and/or volume.Comment: 18 pages, 12 figure
Measurements of , K, p and spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS
Measurements of inclusive spectra and mean multiplicities of ,
K, p and produced in inelastic p+p interactions at
incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ( 6.3,
7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super
Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer.
Spectra are presented as function of rapidity and transverse momentum and are
compared to predictions of current models. The measurements serve as the
baseline in the NA61/SHINE study of the properties of the onset of
deconfinement and search for the critical point of strongly interacting matter
Measurements of K, Λ , and production in 120 GeV / c p + C interactions
This paper presents multiplicity measurements of K0S, Λ, and ¯Λ produced in 120 GeV/c proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different periods. Decays of these neutral hadrons impact the measured π+, π−, p and ¯p multiplicities in the 120 GeV/c proton-carbon reaction, which are crucial inputs for long-baseline neutrino experiment predictions of neutrino beam flux. The double-differential multiplicities presented here will be used to more precisely measure charged-hadron multiplicities in this reaction, and to reweight neutral hadron production in neutrino beam Monte Carlo simulations
meson production in inelastic p+p interactions at 40 and 80 beam momenta measured by NA61/SHINE at the CERN SPS
Measurements of K∗(892)0 resonance production via its K+π− decay mode in inelastic p+p collisions at beam momenta 40 and 80 GeV /c (sNN−−−−√=8.8 and 12.3 GeV ) are presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The template method was used to extract the K∗(892)0 signal. Transverse momentum and rapidity spectra were obtained. The mean multiplicities of K∗(892)0 mesons were found to be (35.1±1.3(stat)±3.6(sys))⋅10−3 at 40 GeV /c and (58.3±1.9(stat)±4.9(sys))⋅10−3 at 80 GeV /c. The NA61/SHINE results are compared with the Epos1.99 and Hadron Resonance Gas models as well as with world data. The transverse mass spectra of K∗(892)0 mesons and other particles previously reported by NA61/SHINE were fitted within the Blast-Wave model. The transverse flow velocities are close to 0.1–0.2 of the speed of light and are significantly smaller than the ones determined in heavy nucleus-nucleus interactions at the same beam momenta
Measurement of Hadron Production in -C Interactions at 158 and 350 GeV/c with NA61/SHINE at the CERN SPS
We present a measurement of the momentum spectra of , K,
p, , and K produced in interactions of
negatively charged pions with carbon nuclei at beam momenta of 158 and 350
GeV/c. The total production cross sections are measured as well. The data were
collected with the large-acceptance spectrometer of the fixed target experiment
NA61/SHINE at the CERN SPS. The obtained double-differential - spectra
provide a unique reference data set with unprecedented precision and large
phase-space coverage to tune models used for the simulation of particle
production in extensive air showers in which pions are the most numerous
projectiles
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