311 research outputs found
Chorioamnionitis induces hepatic inflammation and time-dependent changes of the enterohepatic circulation in the ovine fetus
Chorioamnionitis, inflammation of fetal membranes, is an important cause of preterm birth and a risk factor for the development of adverse neonatal outcomes including sepsis and intestinal pathologies. Intestinal bile acids (BAs) accumulation and hepatic cytokine production are involved in adverse intestinal outcomes. These findings triggered us to study the liver and enterohepatic circulation (EHC) following intra-amniotic (IA) lipopolysaccharide (LPS) exposure. An ovine chorioamnionitis model was used in which circulatory cytokines and outcomes of the liver and EHC of preterm lambs were longitudinally assessed following IA administration of 10 mg LPS at 5, 12 or 24h or 2, 4, 8 or 15d before preterm birth. Hepatic inflammation was observed, characterized by increased hepatic cytokine mRNA levels (5h â 2d post IA LPS exposure) and increased erythropoietic clusters (at 8 and 15 days post IA LPS exposure). Besides, 12h after IA LPS exposure, plasma BA levels were increased, whereas gene expression levels of several hepatic BA transporters were decreased. Initial EHC alterations normalized over time. Concluding, IA LPS exposure induces significant time-dependent changes in the fetal liver and EHC. These chorioamnionitis induced changes have potential postnatal consequences and the duration of IA LPS exposure might be essential herein
Volumetric texture description and discriminant feature selection for MRI
This paper considers the problem of classification of Magnetic Resonance Images using 2D and 3D texture measures. Joint statistics such as co-occurrence matrices are common for analysing texture in 2D since they are simple and effective to implement. However, the computational complexity can be prohibitive especially in 3D. In this work, we develop a texture classification strategy by a sub-band filtering technique that can be extended to 3D. We further propose a feature selection technique based on the Bhattacharyya distance measure that reduces the number of features required for the classification by selecting a set of discriminant features conditioned on a set training texture samples. We describe and illustrate the methodology by quantitatively analysing a series of images: 2D synthetic phantom, 2D natural textures, and MRI of human knees
Magnetization steps in a diluted Heisenberg antiferromagnetic chain: Theory and experiments on TMMC:Cd
A theory for the equilibrium low-temperature magnetization M of a diluted
Heisenberg antiferromagnetic chain is presented. The magnetization curve, M
versus B, is calculated using the exact contributions of finite chains with 1
to 5 spins, and the "rise and ramp approximation" for longer chains. Some
non-equilibrium effects that occur in a rapidly changing B, are also
considered. Specific non-equilibrium models based on earlier treatments of the
phonon bottleneck, and of spin flips associated with cross relaxation and with
level crossings, are discussed. Magnetization data on powders of TMMC diluted
with cadmium [i.e., (CH_3)_4NMn_xCd_(1-x)Cl_3, with 0.16<=x<=0.50 were measured
at 0.55 K in 18 T superconducting magnets. The field B_1 at the first MST from
pairs is used to determine the NN exchange constant, J, which changes from -5.9
K to -6.5 K as x increases from 0.16 to 0.50. The magnetization curves obtained
in the superconducting magnets are compared with simulations based on the
equilibrium theory. Data for the differential susceptibility, dM/dB, were taken
in pulsed magnetic fields (7.4 ms duration) up to 50 T, with the powder samples
in a 1.5 K liquid-helium bath. Non-equilibrium effects, which became more
severe as x decreased, were observed. The non-equilibrium effects are
tentatively interpreted using the "Inadequate Heat Flow Scenario," or to
cross-relaxation, and crossings of energy levels, including those of excited
states.Comment: 16 pages, 14 figure
Measurement of a small atmospheric ratio
From an exposure of 25.5~kiloton-years of the Super-Kamiokande detector, 900
muon-like and 983 electron-like single-ring atmospheric neutrino interactions
were detected with momentum MeV/, MeV/, and
with visible energy less than 1.33 GeV. Using a detailed Monte Carlo
simulation, the ratio was measured to be , consistent with previous results from the
Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from
theoretical models of atmospheric neutrino production.Comment: 14 pages with 5 figure
Why don't some men with banked sperm respond to letters about their stored samples?
Long-term storage of banked sperm, especially when it is not needed, for reproductive purposes, is costly and poses practical problems for sperm banks. For sperm banks to function efficiently, men must understand the implications of unnecessary storage, and make timely decisions about disposal of their own samples. Men who bank sperm prior to cancer treatment are routinely offered follow-up consultations to test their fertility, update consent and, where necessary, expedite referral for Assisted Conception. Yet sperm banks report that men do not respond to letters, suggesting samples are stored needlessly. We conducted semi-structured interviews with six men with a history of not responding to letters, to document reasons for non-response. Interviews were transcribed and analysed using Interpretive Phenomenological Analysis. Men's reasons for not responding are a complex interplay between past, present and future perspectives. In terms of their past, information is important on diagnosis, because men must understand that fertility can change after treatment. Present and future concerns focus on fears of being told fertility has not recovered and being pressured to dispose of banked sperm. The challenge is to devise invitation letters that address men's concerns while offering them tangible benefits and peace of mind
The southern photometric local universe survey (S-PLUS): Improved SEDs, morphologies, and redshifts with 12 optical filters
The Southern Photometric Local Universe Survey (S-PLUS) is imaging ~9300 deg2 of the celestial sphere in 12 optical bands using a dedicated 0.8mrobotic telescope, the T80-South, at the Cerro Tololo Inter-american Observatory, Chile. The telescope is equipped with a 9.2k Ă 9.2k e2v detector with 10 ÎŒm pixels, resulting in a field of view of 2 deg2 with a plate scale of 0.55 arcsec pixel-1. The survey consists of four main subfields, which include two non-contiguous fields at high Galactic latitudes (|b| > 30° , 8000 deg2) and two areas of the Galactic Disc and Bulge (for an additional 1300 deg2). S-PLUS uses the Javalambre 12-band magnitude system, which includes the 5 ugriz broad-band filters and 7 narrow-band filters centred on prominent stellar spectral features: the Balmer jump/[OII], Ca H + K, Hd, G band, Mg b triplet, Hα, and the Ca triplet. S-PLUS delivers accurate photometric redshifts (ÎŽz/(1 + z) = 0.02 or better) for galaxies with r < 19.7 AB mag and z < 0.4, thus producing a 3D map of the local Universe over a volume of more than 1 (Gpc/h)3. The final S-PLUS catalogue will also enable the study of star formation and stellar populations in and around the Milky Way and nearby galaxies, as well as searches for quasars, variable sources, and low-metallicity stars. In this paper we introduce the main characteristics of the survey, illustrated with science verification data highlighting the unique capabilities of S-PLUS. We also present the first public data release of ~336 deg2 of the Stripe 82 area, in 12 bands, to a limiting magnitude of r = 21, available at datalab.noao.edu/splus.Fil: De Oliveira, C. Mendes. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Ribeiro, T.. Universidade Federal de Sergipe; Brasil. National Optical Astronomy Observatory; Estados UnidosFil: Schoenell, W.. Universidade Federal do Rio Grande do Sul; BrasilFil: Kanaan, A.. Universidade Federal de Santa Catarina; BrasilFil: Overzier, R.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; Brasil. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; BrasilFil: Molino, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Sampedro, L.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Coelho, P.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Barbosa, C.E.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Cortesi, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Costa Duarte, M.V.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Herpich, F.R.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal de Santa Catarina; BrasilFil: Hernandez Jimenez, J.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Placco, V.M.. University of Notre Dame; Estados Unidos. JINA Center for the Evolution of the Elements ; Estados UnidosFil: Xavier, H.S.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Abramo, L.R.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Saito, R.K.. Universidade Federal de Santa Catarina; BrasilFil: Chies Santos, A.L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Ederoclite, A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; Brasil. Centro de Estudios de FĂsica del Cosmo de Aragon; EspañaFil: De Oliveira, R. Lopes. Universidade Federal de Sergipe; Brasil. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; Brasil. University of Maryland; Estados UnidosFil: Goncalves, D.R.. Universidade Federal do Rio de Janeiro; BrasilFil: Akras, S.. MinistĂ©rio da CiĂȘncia, Tecnologia, Inovação e ComunicaçÔes. ObservatĂłrio Nacional; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Almeida, L.A.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal do Rio Grande do Norte; BrasilFil: Almeida Fernandes, F.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Beers, T.C.. University of Notre Dame; Estados Unidos. JINA Center for the Evolution of the Elements ; Estados UnidosFil: Bonatto, C.. Universidade Federal do Rio Grande do Sul; BrasilFil: Bonoli, S.. Centro de Estudios de FĂsica del Cosmo de Aragon; EspañaFil: Cypriano, E.S.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Vinicius Lima, E.. Universidade do Sao Paulo. Instituto de Astronomia, GeofĂsica e CiĂȘncias AtmosfĂ©ricas; BrasilFil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de AstrofĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias AstronĂłmicas y GeofĂsicas. Instituto de AstrofĂsica La Plata; Argentin
Measurement of the cross section for isolated-photon plus jet production in pp collisions at âs=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in protonâproton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fbâ1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photonâjet invariant mass and the scattering angle in the photonâjet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
Measurement of the branching ratio Î(Îbâ° â Ï(2S)Î0)/Î(Îbâ° â J/ÏÎ0) with the ATLAS detector
An observation of the decay and
a comparison of its branching fraction with that of the decay has been made with the ATLAS detector in
proton--proton collisions at TeV at the LHC using an integrated
luminosity of fb. The and mesons are
reconstructed in their decays to a muon pair, while the decay is exploited for the baryon reconstruction. The
baryons are reconstructed with transverse momentum GeV and pseudorapidity . The measured branching ratio of
the and decays is , lower than the expectation from the
covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table,
published on Physics Letters B 751 (2015) 63-80. All figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08
Measurement of the View the tt production cross-section using eÎŒ events with b-tagged jets in pp collisions at âs = 13 TeV with the ATLAS detector
This paper describes a measurement of the inclusive top quark pair production cross-section (ÏttÂŻ) with a data sample of 3.2 fbâ1 of protonâproton collisions at a centre-of-mass energy of âs = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electronâmuon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously ÏttÂŻ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be:
ÏttÂŻ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb,
where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
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