2,075 research outputs found

    Percussion Ensemble Spring Concert

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    Kennesaw State University School of Music presents Percussion Ensemble Spring Concert.https://digitalcommons.kennesaw.edu/musicprograms/1406/thumbnail.jp

    Perfluoropolyethers: Development of an All-Atom Force Field for Molecular Simulations and Validation with New Experimental Vapor Pressures and Liquid Densities

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    A force field for perfluoropolyethers (PFPEs) based on the general optimized potentials for liquid simulations all-atom (OPLS-AA) force field has been derived in conjunction with experiments and ab initio quantum mechanical calculations. Vapor pressures and densities of two liquid PFPEs, perfluorodiglyme (CF3−O−(CF2−CF2−O)2−CF3) and perfluorotriglyme (CF3−O−(CF2−CF2−O)3−CF3), have been measured experimentally to validate the force field and increase our understanding of the physical properties of PFPEs. Force field parameters build upon those for related molecules (e.g., ethers and perfluoroalkanes) in the OPLS-AA force field, with new parameters introduced for interactions specific to PFPEs. Molecular dynamics simulations using the new force field demonstrate excellent agreement with ab initio calculations at the RHF/6-31G* level for gas-phase torsional energies (<0.5 kcal mol−1 error) and molecular structures for several PFPEs, and also accurately reproduce experimentally determined densities (<0.02 g cm−3 error) and enthalpies of vaporization derived from experimental vapor pressures (<0.3 kcal mol−1). Additional comparisons between experiment and simulation show that polyethers demonstrate a significant decrease in enthalpy of vaporization upon fluorination unlike related molecules (e.g., alkanes and alcohols). Simulation suggests this phenomenon is a result of reduced cohesion in liquid PFPEs due to a reduction in localized associations between backbone oxygen atoms and neighboring molecules

    Cell type-specific regulation of CCN2 protein expression by PI3K–AKT–FoxO signaling

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    The biological activity of connective tissue growth factor (CTGF, CCN2) is regulated at the level of intracellular signaling leading to gene expression, and by its extracellular interaction partners which determine the functional outcome of CCN2 action. In this overview, we summarize the data which provide evidence that one of the major signaling pathways, phosphatidylinositol-3 kinase (PI3K)–AKT signaling, shows a remarkable cell type-dependence in terms of regulation of CCN2 expression. In smooth muscle cells, fibroblasts, and epithelial cells, inhibition of this pathway either reduced CCN2 expression or was not involved in CCN2 gene expression depending on the stimulus used. In microvascular endothelial cells by contrast, activation of PI3K–AKT signaling was inversely related to CCN2 expression. Upregulation of CCN2 upon inhibition of PI3K–AKT was also observed in primary cultures of human endothelial cells (HUVEC) exposed to laminar flow in an in vitro flow-through system. In different types of endothelial cells, FoxO transcription factors, which are negatively regulated by AKT, were identified as potent activators of CCN2 gene expression. In HUVEC, we observed a correlation between enhanced nuclear localization of FoxO1 and increased synthesis of CCN2 protein in areas of non-uniform shear stress. These data indicate that FoxO proteins are key regulators of CCN2 gene expression which determine the effect of PI3K–AKT activation in terms of CCN2 regulation. Short summary Phosphatidylinositol-3 kinase (PI3K)–AKT signaling shows a remarkable cell type-dependence in terms of regulation of CCN2 expression. In endothelial cells activation of PI3K - AKT signaling was inversely related to CCN2 expression. FoxO transcription factors, which are negatively regulated by AKT, were identified as potent activators of CCN2 gene expression

    Nitrogen Inventory in the Nooksack-Fraser Transboundary Watershed

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    The Nooksack-Fraser transboundary area (2639 km2) is home to communities with a strong base in farming, fisheries and outdoor recreation. Water quality issues impact parts of this area, where sewage effluent and animal waste are potential sources of both fecal coliform bacteria (FCB) and nitrogen (N) in the environment. Excessive nitrogen loading can lead to eutrophication in coastal areas, and nitrate contamination of groundwater. The Nooksack-Fraser Transboundary Nitrogen (NFT-N) project was developed to determine the sources and fates of N in the watershed using data on energy use, transportation, fertilization, wastewater treatment plants, livestock operations, wildlife and more. This project brings together stakeholders, agencies, and scientists on both sides of the international border to achieve a first characterization of N inventories and fluxes across the watershed. A comprehensive N assessment can benefit N management by providing key information on source distribution. Focusing on agricultural activities first, we estimate using crop-specific fertilizer recommendations that the requirements for synthetic fertilizer N on the US side of the watershed ranges between 1855 and 3184 metric tons (MT). Application of livestock manure to crops is equal to, or perhaps more than, fertilizer requirements, ranging between 1926 and 3963 MT N per year. The combined septic and sewage input of N falls between 71 and 84 MT per year, while atmospheric deposition contributes 527 MT N per year. Preliminary results for the US side demonstrate the importance of N inputs from agriculture. Results will be refined by updating values, adding other components, integrating with the existing Canadian budget, and understanding connections between inputs and N fates in ground and surface water. The budget will be used to examine the impacts of N policy and management across the boundary (US-Canada), and to support future efforts in developing sustainable N use and management plans in the region

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  Όb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∌0) correlation that grows rapidly with increasing ÎŁETPb. A long-range “away-side” (Δϕ∌π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ÎŁETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁥2Δϕ modulation for all ÎŁETPb ranges and particle pT

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ÏˆÎł (with J/ψ → ÎŒ + ÎŒ −) where photons are reconstructed from Îł → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

    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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