26 research outputs found

    Eubacterium maltosivorans sp nov., a novel human intestinal acetogenic and butyrogenic bacterium with a versatile metabolism

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    A novel anaerobic, non-spore-forming bacterium was isolated from a faecal sample of a healthy adult. The isolate, designated strain YIT, was cultured in a basal liquid medium under a gas phase of H-2/CO2 supplemented with yeast extract (0.1 g l(-1)). Cells of strain YIT were short rods (0.4-0.7 x 2.0-2.5 mu m), appearing singly or in pairs, and stained Gram-positive. Catalase activity and gelatin hydrolysis were positive while oxidase activity, indole formation, urease activity and aesculin hydrolysis were negative. Growth was observed within a temperature range of 20-45 degrees C (optimum, 35-37 degrees C), and a pH range of 5.0-8.0 (optimum pH 7.0-7.5). Doubling time was 2.3 h when grown with glucose at pH 7.2 and 37 degrees C. Besides acetogenic growth, the isolate was able to ferment a large range of monomeric sugars with acetate and butyrate as the main end products. Strain YIT did not show respiratory growth with sulfate, sulfite, thiosulfate or nitrate as electron acceptors. The major cellular fatty acids of the isolate were C-16:0 and C-18:0. The genomic DNA G+C content was 47.8 mol%. Strain YIT is affiliated to the genus Eubacterium, sharing highest levels of 16S rRNA gene similarity with Eubacterium limosum ATCC 8486(T) (97.3 %), Eubacterium callanderi DSM 3662(T) (97.5 %), Eubacterium aggregans DSM 12183(T) (94.4 %) and Eubacterium barkeri DSM 1223(T) (94.8 %). Considering its physiological and phylogenetic characteristics, strain YIT represents a novel species within the genus Eubacterium, for which the name Eubacterium maltosivorans sp. nov. is proposed. The type strain is YIT (= DSM 105863(T) = JCM 32297(T)).Peer reviewe

    Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a search for events with one top-quark and large missing transverse momentum in the final state. Data collected during 2015 and 2016 by the ATLAS experiment from 13 TeV proton–proton collisions at the LHC corresponding to an integrated luminosity of 36.1 fb−1 are used. Two channels are considered, depending on the leptonic or the hadronic decays of the W boson from the top quark. The obtained results are interpreted in the context of simplified models for dark-matter production and for the single production of a vector-like T quark. In the absence of significant deviations from the Standard Model background expectation, 95% confidence-level upper limits on the corresponding production cross-sections are obtained and these limits are translated into constraints on the parameter space of the models considered

    Measurement of the inclusive and differential Higgs boson production cross sections in the leptonic WW decay mode at p root s=13 TeV

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    Measurements of the fiducial inclusive and differential production cross sections of the Higgs boson in proton-proton collisions at root s = 13 TeV are performed using events where the Higgs boson decays into a pair of W bosons that subsequently decay into a final state with an electron, a muon, and a pair of neutrinos. The analysis is based on data collected with the CMS detector at the LHC during 2016-2018, corresponding to an integrated luminosity of 137 fb(-1). Production cross sections are measured as a function of the transverse momentum of the Higgs boson and the associated jet multiplicity. The Higgs boson signal is extracted and simultaneously unfolded to correct for selection efficiency and resolution effects using maximum-likelihood fits to the observed distributions in data. The integrated fiducial cross section is measured to be 86.5 +/- 9.5 fb, consistent with the Standard Model expectation of 82.5 +/- 4.2 fb. No significant deviation from the Standard Model expectations is observed in the differential measurements.Peer reviewe

    Search for heavy resonances decaying into a W or Z boson and a Higgs boson in final states with leptons and b-jets in 36 fb(-1) of root s=13 TeV pp collisions with the ATLAS detector

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    A search is conducted for new resonances decaying into a W or Z boson and a 125 GeV Higgs boson in the νν¯¯¯bb¯¯, ℓ±νbb¯¯, and ℓ+ℓ−bb¯¯ final states, where ℓ± = e± or μ±, in pp collisions at s√=13 TeV. The data used correspond to a total integrated luminosity of 36.1 fb−1 collected with the ATLAS detector at the Large Hadron Collider during the 2015 and 2016 data-taking periods. The search is conducted by examining the reconstructed invariant or transverse mass distributions of W h and Zh candidates for evidence of a localised excess in the mass range of 220 GeV up to 5 TeV. No significant excess is observed and the results are interpreted in terms of constraints on the production cross-section times branching fraction of heavy W ′ and Z′ resonances in heavy-vector-triplet models and the CP-odd scalar boson A in two-Higgs-doublet models. Upper limits are placed at the 95% confidence level and range between 9.0 × 10−4 pb and 7.3 × 10−1 pb depending on the model and mass of the resonance

    Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at s√=13 TeV with the ATLAS detector

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    This paper describes a search for events with one top-quark and large missing transverse momentum in the final state. Data collected during 2015 and 2016 by the ATLAS experiment from 13 TeV proton–proton collisions at the LHC corresponding to an integrated luminosity of 36.1 fb−1 are used. Two channels are considered, depending on the leptonic or the hadronic decays of the W boson from the top quark. The obtained results are interpreted in the context of simplified models for dark-matter production and for the single production of a vector-like T quark. In the absence of significant deviations from the Standard Model background expectation, 95% confidence-level upper limits on the corresponding production cross-sections are obtained and these limits are translated into constraints on the parameter space of the models considered

    Rapid and Brief Communication High training set size reduction by space partitioning and prototype abstraction

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    Abstract Instance-based learning methods like the nearest neighbour classiÿer generally su er from the indiscriminate storage of all training instances, resulting in large memory requirements and slow execution speed. In this paper, new training set size reduction methods based on prototype generation and space partitioning are proposed. Experimental results show that the new algorithms achieve a very high reduction rate with still an important classiÿcation accuracy

    Red Quasars Not So Dusty

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    . Webster et al (1995) claimed that up to 80% of QSOs may be obscured by dust. They inferred the presence of this dust from the remarkably broad range of B \GammaK optical-infrared colours of a sample of flat-spectrum PKS radio QSOs. If such dust is typical of QSOs, it will have rendered invisible most of those which would otherwise been have detected by optical surveys. We used the William Herschel Telescope to image 54 B3 radio QSOs in K, and we find that although several have very red optical-infrared colours, most of these can be attributed to an excess of light in K rather than a dust-induced deficit in B. We present evidence that the infrared excess comes from the light of stars in the host galaxy, or from synchrotron radiation associated with flat-spectrum radio sources. Thus, either the Webster et al QSOs are atypical in having large extinctions, or their reddening is not due to dust. Either way, there is no evidence that a large fraction of QSOs has been missed by optical sur..
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