732 research outputs found

    Automatic Configuration of Opaque Network Functions in CMS

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    Cloud Management Systems (CMS) such as OpenStack are commonly used to manage IT resources such as computing and storage in large datacenters. Recently, CMS are starting to offer customers also the possibility to customize their network infrastructure, allowing each tenant to build his virtual network made of elementary blocks such as traffic monitors, switches, routers, firewalls, and more. However, tenants have to choose those network services among the list of services made available by the CMS and have no possibilities to customize the applications they want. This paper examines some of the modifications required in CMS to support a tenant-centric network service model, in which each tenant can install and configure their preferred network functions, without being limited to use only the list provided by the CMS. A prototype implementation validates the proposed approach and demonstrates the extent of the modifications in terms of languages and software components

    Survey of Low Birthweight and Extremely Low Birthweight Events in a High Environmental Risk Area of Apulia, Italy

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    The association between environmental conditions and pregnancy outcome has been under investigation for a long time, but results appear to be inconclusive regarding damage to either the newborn or the mother. The aim of this study was to evaluate the distribution of hospitalization of newborns with low birthweight (< 2500 g) and extremely low birthweight (< 1000 g) in the geographical area of Taranto, Italy, which is characterized by high environmental risk because of industrial pollution. We analyzed the database of hospital discharge forms for the years 2001–2013 regarding hospital admission of newborns in the region of Apulia. The relative risk (RR) of hospitalization, adjusted for the deprivation index, was estimated using the Besag–York–MolliĂš Bayesian model. The city of Taranto, which has the highest environmental risk, had the highest RR for newborns with low birthweight (1.47, 95% uncertainty interval 1.38–1.56). Other geographical areas with high environmental pollution had higher RRs for low birth weight compared with the regional average. We found no geographical distribution pattern of extremely low birthweight that would suggest an association with environmental pollution

    First measurement of Ξc0\Xi_{\rm c}^0 production in pp collisions at s\mathbf{\sqrt{s}} = 7 TeV

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    The production of the charm-strange baryon Ξc0\Xi_{\rm c}^0 is measured for the first time at the LHC via its semileptonic decay into e+Ξ−Μe^+\Xi^-\nu_{\rm e} in pp collisions at s=7\sqrt{s}=7 TeV with the ALICE detector. The transverse momentum (pTp_{\rm T}) differential cross section multiplied by the branching ratio is presented in the interval 1 << pTp_{\rm T} << 8 GeV/cc at mid-rapidity, ∣y∣|y| << 0.5. The transverse momentum dependence of the Ξc0\Xi_{\rm c}^0 baryon production relative to the D0^0 meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.Comment: 22 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/412

    Constraining the magnitude of the Chiral Magnetic Effect with Event Shape Engineering in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76$ TeV

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    In ultrarelativistic heavy-ion collisions, the event-by-event variation of the elliptic flow v2v_2 reflects fluctuations in the shape of the initial state of the system. This allows to select events with the same centrality but different initial geometry. This selection technique, Event Shape Engineering, has been used in the analysis of charge-dependent two- and three-particle correlations in Pb-Pb collisions at sNN=2.76\sqrt{s_{_{\rm NN}}} =2.76 TeV. The two-particle correlator ⟹cos⁥(φα−φÎČ)⟩\langle \cos(\varphi_\alpha - \varphi_\beta) \rangle, calculated for different combinations of charges α\alpha and ÎČ\beta, is almost independent of v2v_2 (for a given centrality), while the three-particle correlator ⟹cos⁥(φα+φÎČ−2Κ2)⟩\langle \cos(\varphi_\alpha + \varphi_\beta - 2\Psi_2) \rangle scales almost linearly both with the event v2v_2 and charged-particle pseudorapidity density. The charge dependence of the three-particle correlator is often interpreted as evidence for the Chiral Magnetic Effect (CME), a parity violating effect of the strong interaction. However, its measured dependence on v2v_2 points to a large non-CME contribution to the correlator. Comparing the results with Monte Carlo calculations including a magnetic field due to the spectators, the upper limit of the CME signal contribution to the three-particle correlator in the 10-50% centrality interval is found to be 26-33% at 95% confidence level.Comment: 20 pages, 6 captioned figures, 1 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/382

    Measurement of pion, kaon and proton production in proton-proton collisions at s=7\sqrt{s}=7 TeV

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    The measurement of primary π±\pi^{\pm}, K±^{\pm}, p and p‟\overline{p} production at mid-rapidity (∣y∣<|y| < 0.5) in proton-proton collisions at s=7\sqrt{s} = 7 TeV performed with ALICE (A Large Ion Collider Experiment) at the Large Hadron Collider (LHC) is reported. Particle identification is performed using the specific ionization energy loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/cc for pions, from 0.2 up to 6 GeV/cc for kaons and from 0.3 up to 6 GeV/cc for protons. The measured spectra and particle ratios are compared with QCD-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.Comment: 33 pages, 19 captioned figures, 3 tables, authors from page 28, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/156

    Measurement of an excess in the yield of J/ψ\psi at very low pTp_{\rm T} in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    We report on the first measurement of an excess in the yield of J/ψ\psi at very low transverse momentum (pT<0.3p_{\rm T}< 0.3 GeV/cc) in peripheral hadronic Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J/ψ\psi in the rapidity range 2.5<y<42.5<y<4 reaches about 7 (2) in the pTp_{\rm T} range 0-0.3 GeV/cc in the 70-90% (50-70%) centrality class. The J/ψ\psi production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J/ψ\psi is the underlying physics mechanism. If confirmed, the observation of J/ψ\psi coherent photoproduction in Pb-Pb collisions at impact parameters smaller than twice the nuclear radius opens new theoretical and experimental challenges and opportunities. In particular, coherent photoproduction accompanying hadronic collisions may provide insight into the dynamics of photoproduction and nuclear reactions, as well as become a novel probe of the Quark-Gluon Plasma.Comment: 18 pages, 3 captioned figures, 1 table, authors from page 13, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/191

    HEAVY METALS CONTAMINATION IN FISH OF THE LIGURIAN SEA

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    Aim of this investigation was to evaluate heavy metals contamination (mercury, cadmium and lead) in fish and shellfish from Ligurian Sea. 58 muscle samples (45 fish and 13 shellfish) were collected and analyzed. 20 samples exceeded the maximum residue limits (MRLs) set by regulation for mercury (16 fish and 4 shellfish samples), while only one fish sample was not consistent with the MRL for lead. Therefore, 35,8% of Ligurian fishing turned out to be not adequate and potentially harmful for consumers. In order to estimate the real risk for human health it is necessary to enforce this study, correlating the results with fish species and with the effective fish consumption

    Industrial air pollution and mortality in the Taranto area, Southern Italy: A difference-in-differences approach.

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    Background: A large steel plant close to the urban area of Taranto (Italy) has been operating since the sixties. Several studies conducted in the past reported an excess of mortality and morbidity from various diseases at the town level, possibly due to air pollution from the plant. However, the relationship between air pollutants emitted from the industry and adverse health outcomes has been controversial. We applied a variant of the "difference-in-differences" (DID) approach to examine the relationship between temporal changes in exposure to industrial PM10 from the plant and changes in cause-specific mortality rates at area unit level. Methods: We examined a dynamic cohort of all subjects (321,356 individuals) resident in the Taranto area in 1998–2010 and followed them up for mortality till 2014. In this work, we included only deaths occurring on 2008–2014. We observed a total of 15,303 natural deaths in the cohort and age-specific annual death rates were computed for each area unit (11 areas in total). PM10 and NO2 concentrations measured at air quality monitoring stations and the results of a dispersion model were used to estimate annual average population weighted exposures to PM10 of industrial origin for each year, area unit and age class. Changes in exposures and in mortality were analyzed using Poisson regression. Results: We estimated an increased risk in natural mortality (1.86%, 95% confidence interval [CI]: −0.06, 3.83%) per 1â€ŻÎŒg/m3 annual change of industrial PM10, mainly driven by respiratory causes (8.74%, 95% CI: 1.50, 16.51%). The associations were statistically significant only in the elderly (65+ years). Conclusions: The DID approach is intuitively simple and reduces confounding by design. Under the multiple assumptions of this approach, the study indicates an effect of industrial PM10 on natural mortality, especially in the elderly population. Keywords: Air pollution, Mortality, PM10, Steel industry, Confounding, Difference-in-difference

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range ∣η∣<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

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    Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a âˆŁÎ”Î·âˆŁ|\Delta \eta| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4}v_{2}\{4\} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4}≃v2{6}≠0v_{2}\{4\} \simeq v_{2}\{6\}\neq 0 which is indicative of a Bessel-Gaussian function for the v2v_{2} distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a âˆŁÎ”Î·âˆŁ>1.4|\Delta\eta| > 1.4 gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
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