802 research outputs found

    Importance of structural history in the summit area of Stromboli during the 2002–2003 eruptive crisis inferred from temperature, soil CO2, self-potential, and electrical resistivity tomography

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    International audienceThe 2002-2003 eruptive crisis of Stromboli volcano in the Aeolian Islands raised the question of how to assess the stability of the flanks of this volcanic edifice during such a crisis. To provide a response to this question, we analyzed a detailed fluid flow mapping plus the reiteration of a profile located in the vicinity of the active vents using the self-potential method, temperature data, soil-gas (CO2) measurements, and electric resistivity tomography. Coupling the interpretation of these methods that are sensitive to the flow of gas and water in the ground indicates the position of areas of mechanical weakness. In addition, they can be used to monitor the change in the discharge of fluids associated with these features before and during the 2002-2003 eruptive crisis. Our results emphasize the importance of old structural boundaries, such as the Large Fossa crater, in the development of the new set of fractures observed during the 2002-2003 eruptive crisis. Between October 2002 and January 2003, the use of CO2 soil-gas technique evidenced an increase in the discharge of CO2 outside the Large Fossa crater boundaries, along the failure boundary of the southern Sciara del Fuoco area. Self-potential and temperature measurements made before the 2002-2003 eruptive crisis reveal significant changes along the main structural boundaries of the Fossa area. The development of these anomalies is interpreted as an increase of the permeability of the structure from May 2000 to May 2002. Between January 2003 and March 2003 the reiteration of self-potential, temperature, and CO2 measurements shows an increase of fluid discharge along weakness planes located inside the Large Fossa crater boundary. They evidence no change outside this structural boundary. The importance of the Large Fossa crater boundary in controlling the deformation and fluid flow from January to March 2003 has been attested by the development of the fractures inside the Large Fossa crater boundary, and also with a network of electrooptical distance measurement stations located inside and outside this ancient crater. This multidisciplinary approach to fluid flow assessment before and during an eruptive crisis is complementary to geodetic measurements of the deformation of the edifice. It demonstrates for the first time the powerful potential of combining electrical resistivity tomography, self-potential, temperature, and soil CO2 measurements in assessing the position of the planes of mechanical weakness in a volcanic edifice

    Towards Transiently Secure Updates in Asynchronous SDNs

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    © ACM 2016. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Proceedings of the 2016 Conference on ACM SIGCOMM 2016 Conference - SIGCOMM ’16, http://dx.doi.org/10.1145/2934872.2959083.Software-Defined Networks (SDNs) promise to overcome the often complex and error-prone operation of tradi- tional computer networks, by enabling programmabil- ity, automation and verifiability. Yet, SDNs also in- troduce new challenges, for example due to the asyn- chronous communication channel between the logically centralized control platform and the switches in the data plane. In particular, the asynchronous commu- nication of network update commands (e.g., OpenFlow FlowMod messages) may lead to transient inconsisten- cies, such as loops or bypassed waypoints (e.g., fire- walls). One approach to ensure transient consistency even in asynchronous environments is to employ smart scheduling algorithms: algorithms which update subsets of switches in each communication round only, where each subset in itself guarantees consistency. In this demo, we show how to change routing policies in a transiently consistent manner. We demonstrate two al- gorithms, namely, Wayup [5] and Peacock [4], which partition the network updates sent from SDN controller towards OpenFlow software switches into multiple rounds as per respective algorithms. Later, the barrier mes- sages are utilized to ensure reliable network updates.EC/FP7/619609/EU/Unifying Cloud and Carrier Networks/UNIF

    Exposure of Portuguese children to the novel non-phthalate plasticizer di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH)

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    Di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH) is used as substitute for high molecular weight phthalate plasticizers such as di-(2-ethylhexyl) phthalate (DEHP) and di-(iso-nonyl) phthalate (DINP). Due to a rapid substitution process we have to assume omnipresent and increasing DINCH exposures. The aim of this study was to evaluate DINCH exposure in 112 children (4-18years old) from Portugal, divided in two groups: 1) normal-/underweight following the usual diet; and 2) obese/overweight but under strict nutritional guidance. First morning urine samples were collected during the years 2014 and 2015. Oxidized DINCH metabolites (OH-MINCH, oxo-MINCH, cx-MINCH) were analyzed after enzymatic hydrolysis via on-line HPLC-MS/MS with isotope dilution quantification. We detected DINCH metabolites in all analyzed samples. Urinary median (95th percentile) concentrations were 2.14μg/L (15.91) for OH-MINCH, followed by 1.10μg/L (7.54) for oxo-MINCH and 1.08μg/L (7.33) for cx-MINCH. We observed no significant differences between the two child-groups; only after creatinine adjustment, we found higher metabolite concentrations in the younger compared to the older children. Median (95th percentile) daily DINCH intakes were in the range of 0.37 to 0.76 (2.52 to 5.61) μg/kg body weight/day depending on calculation model and subpopulation. Body weight related daily intakes were somewhat higher in Group 1 compared to Group 2, irrespective of the calculation model. However, in terms of absolute amounts (μg/day), DINCH intakes were higher in Group 2 compared to Group 1. In regard to age, we calculated higher intakes for the younger children compared to older children, but only with the creatinine-based model. This new data for southern European, Portuguese children adds information to the scarce knowledge on DINCH, confirming omnipresent exposure and suggesting higher exposures in children than adults. Significant sources and routes of exposure have yet to be unveiled. For now, all calculated daily intakes are far below established health benchmark levels (TDI, RfD). However, rapidly increasing exposures have to be expected over the next years.info:eu-repo/semantics/publishedVersio

    Glot500: Scaling Multilingual Corpora and Language Models to 500 Languages

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    The NLP community has mainly focused on scaling Large Language Models (LLMs) vertically, i.e., making them better for about 100 languages. We instead scale LLMs horizontally: we create, through continued pretraining, Glot500-m, an LLM that covers 511 predominantly low-resource languages. An important part of this effort is to collect and clean Glot500-c, a corpus that covers these 511 languages and allows us to train Glot500-m. We evaluate Glot500-m on five diverse tasks across these languages. We observe large improvements for both high-resource and low-resource languages compared to an XLM-R baseline. Our analysis shows that no single factor explains the quality of multilingual LLM representations. Rather, a combination of factors determines quality including corpus size, script, “help” from related languages and the total capacity of the model. Our work addresses an important goal of NLP research: we should notlimit NLP to a small fraction of the world’s languages and instead strive to support as many languages as possible to bring the benefits of NLP technology to all languages and cultures. Code, data and models are available at https://github.com/cisnlp/Glot500

    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Bose-Einstein correlations of charged hadrons in proton-proton collisions at s\sqrt s = 13 TeV

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    Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at s \sqrt{s} = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at s \sqrt{s} = 7 TeV, as well as with theoretical predictions.[graphic not available: see fulltext]Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at s=\sqrt{s} = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at s=\sqrt{s} = 7 TeV, as well as with theoretical predictions

    Search for dark matter in events with a leptoquark and missing transverse momentum in proton-proton collisions at 13 TeV

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    A search is presented for dark matter in proton-proton collisions at a center-of-mass energy of root s= 13 TeV using events with at least one high transverse momentum (p(T)) muon, at least one high-p(T) jet, and large missing transverse momentum. The data were collected with the CMS detector at the CERN LHC in 2016 and 2017, and correspond to an integrated luminosity of 77.4 fb(-1). In the examined scenario, a pair of scalar leptoquarks is assumed to be produced. One leptoquark decays to a muon and a jet while the other decays to dark matter and low-p(T) standard model particles. The signature for signal events would be significant missing transverse momentum from the dark matter in conjunction with a peak at the leptoquark mass in the invariant mass distribution of the highest p(T) muon and jet. The data are observed to be consistent with the background predicted by the standard model. For the first benchmark scenario considered, dark matter masses up to 500 GeV are excluded for leptoquark masses m(LQ) approximate to 1400 GeV, and up to 300 GeV for m(LQ) approximate to 1500 GeV. For the second benchmark scenario, dark matter masses up to 600 GeV are excluded for m(LQ) approximate to 1400 GeV. (C) 2019 The Author(s). Published by Elsevier B.V.Peer reviewe
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