711 research outputs found

    Transcriptomic analysis identifies lactoferrin-induced quiescent circuits in neonatal macrophages

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    IntroductionUpon birth, a hitherto naĂŻve immune system is confronted with a plethora of microbial antigens due to intestinal bacterial colonization. To prevent excessive inflammation and disruption of the epithelial barrier, physiological mechanisms must promote immune-anergy within the neonatal gut. As high concentrations of human lactoferrin (hLF), a transferrin glycoprotein shown to modulate macrophage function, are frequently encountered in colostrum, its direct interaction with intestinal macrophages may satisfy this physiological need. Thus, the primary objective of this study was to investigate transcriptional changes induced by human lactoferrin in neonatal monocyte-derived macrophages.MethodsCord blood-derived monocytes were differentiated with M-CSF in presence or absence of 500 ”g/mL hLF for 7 days and afterwards stimulated with 1 ng/mL LPS or left untreated. RNA was then isolated and subjected to microarray analysis.ResultsDifferentiation of cord blood-derived monocytes in presence of hLF induced a distinct transcriptional program defined by cell cycle arrest in the G2/M phase, induction of IL-4/IL-13-like signaling, altered extracellular matrix interaction, and enhanced propensity for cell-cell interaction. Moreover, near-complete abrogation of transcriptional changes induced by TLR4 engagement with LPS was observed in hLF-treated samples.DiscussionThe global transition towards an M2-like homeostatic phenotype and the acquisition of quiescence elegantly demonstrate the ontogenetical relevance of hLF in attenuating pro-inflammatory signaling within the developing neonatal intestine. The marked anergy towards proinflammatory stimuli such as LPS further underlines the glycoprotein’s potential therapeutic relevance

    Theoretical Studies of Spectroscopy and Dynamics of Hydrated Electrons.

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    Vertical distribution of zooplankton in a shallow peatland pond: the limiting role of dissolved oxygen

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    We investigated the diel vertical distribution patterns of microcrustacean zooplankton (Cladocera, Copepoda) in a shallow pond (max. depth: 70 cm) of the Öreg-turján peatland (Ócsa, Central Hungary) during three 24-h periods in July (19–20th), August (17–18th) and September (11–12th) 2011. Environmental variables showed remarkable vertical stratification. Oxygen concentration was close to zero in the entire water column from night until sunrise, while the lower strata (from 20 cm below the surface) were close to anoxic during all three diel cycles. It proved to be the main determinant of the vertical distribution of microcrustaceans. Accordingly, the highest proportion of individuals was present in the surface layer. Chlorophyll-a concentration and phytoplankton biomass were inversely distributed compared to zooplankton. Microcrustaceans (mainly Daphnia curvirostris) migrated to the middle layer only in August, which could be explained by a trade-off between food resources, dissolved oxygen (DO) and competition with littoral zooplankters. The diurnal density patterns of microcrustaceans suggested horizontal migration into the aquatic macrophytes during night, which could be a strategy to avoid Chaoborus predation. Our results show that strong vertical gradients of abiotic and biotic factors occur even in such shallow waterbodies. Among them, DO can maintain constant vertical aggregation of zooplankters by limiting their occurrence to the surface layers

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +cÂŻÂŻ)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−sÂŻÂŻÂŻ quark asymmetry
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