77 research outputs found

    Hypoxic-Ischaemic Encephalopathy and the Blood-Brain Barrier in Neonates

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    This is the peer-reviewed but unedited manuscript version of the following article: Lee, W. L. A., et al. (2017). "Hypoxic-Ischaemic Encephalopathy and the Blood-Brain Barrier in Neonates." Developmental Neuroscience 39(1-4): 49-58. (DOI:10.1159/000467392). The final, published version is available at https://www.karger.com/DOI:10.1159/00046739

    Comparative Pathogenesis of an Avian H5N2 and a Swine H1N1 Influenza Virus in Pigs

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    Pigs are considered intermediate hosts for the transmission of avian influenza viruses (AIVs) to humans but the basic organ pathogenesis of AIVs in pigs has been barely studied. We have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal) to compare the pathogenesis of a low pathogenic (LP) H5N2 AIV with that of an H1N1 swine influenza virus. The respiratory tract and selected extra-respiratory tissues were examined for virus replication by titration, immunofluorescence and RT-PCR throughout the course of infection. Both viruses caused a productive infection of the entire respiratory tract and epithelial cells in the lungs were the major target. Compared to the swine virus, the AIV produced lower virus titers and fewer antigen positive cells at all levels of the respiratory tract. The respiratory part of the nasal mucosa in particular showed only rare AIV positive cells and this was associated with reduced nasal shedding of the avian compared to the swine virus. The titers and distribution of the AIV varied extremely between individual pigs and were strongly affected by the route of inoculation. Gross lung lesions and clinical signs were milder with the avian than with the swine virus, corresponding with lower viral loads in the lungs. The brainstem was the single extra-respiratory tissue found positive for virus and viral RNA with both viruses. Our data do not reject the theory of the pig as an intermediate host for AIVs, but they suggest that AIVs need to undergo genetic changes to establish full replication potential in pigs. From a biomedical perspective, experimental LP H5 AIV infection of pigs may be useful to examine heterologous protection provided by H5 vaccines or other immunization strategies, as well as for further studies on the molecular pathogenesis and neurotropism of AIVs in mammals

    Luminosity determination using Z boson production at the CMS experiment

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    Data Availability Statement - This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preser vation of data used by the CMS Collaboration as the basis for publi cations is guidedbytheCMSpolicyasstatedinhttps://cms-docdb.cern. ch/cgibin/PublicDocDB/RetrieveFile?docid=6032&filename=CMSD ataPolicyV1.2.pdf&version=2. CMS data preservation,re-use and open access policy.]The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton–proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13 TeV . Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same data set, in small intervals of 20 pb-1 of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity.SCOAP

    Search for ZZ and ZH production in the bb̅bb̅ final state using proton-proton collisions at √s = 13TeV

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    A preprint version of the article is available at arXiv - https://arxiv.org/abs/2403.20241A search for ZZ and ZH production in the bb̅bb̅ final state is presented, where H is the standard model (SM) Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133fb−1 collected at a center-of-mass energy of 13TeV with the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating a multi-dimensional background model based on control samples in data. A multiclass multivariate classifier customized for the bb̅bb̅ final state is developed to derive the background model and extract the signal. The data are found to be consistent, within uncertainties, with the SM predictions. The observed (expected) upper limits at 95% confidence level are found to be 3.8 (3.8) and 5.0 (2.9) times the SM prediction for the ZZ and ZH production cross sections, respectively.SCOAP

    Search for dark matter produced in association with a Higgs boson decaying to a pair of bottom quarks in proton-proton collisions at root s=13TeV

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    A search for dark matter produced in association with a Higgs boson decaying to a pair of bottom quarks is performed in proton-proton collisions at a center-of-mass energy of 13 TeV collected with the CMS detector at the LHC. The analyzed data sample corresponds to an integrated luminosity of 35.9 fb(-1). The signal is characterized by a large missing transverse momentum recoiling against a bottom quark-antiquark system that has a large Lorentz boost. The number of events observed in the data is consistent with the standard model background prediction. Results are interpreted in terms of limits both on parameters of the type-2 two-Higgs doublet model extended by an additional light pseudoscalar boson a (2HDM+a) and on parameters of a baryonic Z simplified model. The 2HDM+a model is tested experimentally for the first time. For the baryonic Z model, the presented results constitute the most stringent constraints to date.Peer reviewe

    A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer

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    Data availability statement: This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by theCMSpolicy as stated in https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032filename=CMSDataPolicyV1.2.pdfversion=2 CMS data preservation, re-use and open access policy.]Copyright © CERN for the benefit of the CMS and TOTEM collaborations 2023. A generic search is presented for the associated production of a Z boson or a photon with an additional unspecified massive particle X, pp→pp+Z/γ+X, in proton-tagged events from proton–proton collisions at s√=13TeV, recorded in 2017 with the CMS detector and the CMS-TOTEM precision proton spectrometer. The missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant excess in data with respect to the background predictions has been observed. Model-independent upper limits on the visible production cross section of pp→pp+Z/γ+X are set.Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development

    Measurement of the top quark mass using a profile likelihood approach with the lepton + jets final states in proton–proton collisions at √s = 13 TeV

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    Data Availability Statement This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in “https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032 &filename=CMSDataPolicyV1.2.pdf &version=2 CMS data preservation, re-use and open access policy”].A preprint version of the article is available at arXiv, arXiv:2302.01967 [hep-ex]. It was replaced with the published version. All the figures and tables can be found at: https://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-20-008 (CMS Public Pages).Report number: CMS-TOP-20-008, CERN-EP-2022-245.Copyright © CERN for the benefit of the CMS collaboration 2023. The mass of the top quark is measured in 36.3 fb-1 of LHC proton–proton collision data collected with the CMS detector at √s = 13 TeV . The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to four observables per event to extract the top quark mass. The top quark mass is measured to be 171.77 ± 0.37 GeV. This approach significantly improves the precision over previous measurements.SCOAP3

    Azimuthal correlations in Z +jets events in proton–proton collisions at √s = 13 TeV

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    Data Availibility Statement: This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032 &filename=CMSDataPolicyV1.2.pdf &version=2. CMS data preservation, re-use and open access policy.]A preprint version of the article was made available at arXiv, arXiv:2210.16139 [hep-ex] It was replaced with the published version. All the figures and tables can be found at: https://cms-results.web.cern.ch/cms-results/public-results/publications/SMP-21-003 (CMS Public Pages).Report number: CMS-SMP-21-003, CERN-EP-2022-178.Copyright © CERN for the benefit of the CMS Collaboration 2023. The production of Z bosons associated with jets is measured in pp collisions at √s = 13 TeV with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3 fb-1 . The multiplicity of jets with transverse momentum pT>30GeV is measured for different regions of the Z boson’s pT(Z) , from lower than 10 GeV to higher than 100 GeV . The azimuthal correlation Δϕ between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of pT(Z) . The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low pT(Z) regions.SCOAP3

    Measurement of the production cross section for a W boson in association with a charm quark in proton–proton collisions at √s=13TeV

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    Data Availability: This manuscript has no associated data or the data will not be deposited. [Authors’ comment: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032 &filename=CMSDataPolicyV1.2.pdf &version=2. CMS data preservation, re-use and open access policy].A preprint version of the article is available at arXiv: https://arxiv.org/abs/2308.02285 .The strange quark content of the proton is probed through the measurement of the production cross section for a W boson and a charm (c) quark in proton–proton collisions at a center-of-mass energy of 13 TeV . The analysis uses a data sample corresponding to a total integrated luminosity of 138 fb-1 collected with the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm jets are tagged using the presence of a muon or a secondary vertex inside the jet. The W + c production cross section and the cross section ratio Rc±=σ(W++c¯)/σ(W-+c) are measured inclusively and differentially as functions of the transverse momentum and the pseudorapidity of the lepton originating from the W boson decay. The precision of the measurements is improved with respect to previous studies, reaching 1% in Rc±=0.950±0.005(stat)±0.010(syst) . The measurements are compared with theoretical predictions up to next-to-next-to-leading order in perturbative quantum chromodynamics.SCOAP
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