3,820 research outputs found
Signal reconstruction in the EM end-cap calorimeter and check with cosmic data in the region 0< eta <3.2
In 2007, the electromagnetic end-cap calorimeter joined the ATLAS commissioning effort. Since then, calibration and cosmic muon runs are taken regularly, allowing to set-up, debug and test in situ the signal reconstruction. These are the first data in the 1.4500 MeV) have been used to perform a systematic and quantitative comparison between data and predicted physics pulse shapes in a coherent way over the entire calorimeter coverage, 0< eta <3.2. This represents the first attempt to unify barrel and end-cap in situ data in a common analysis. Results are similar in the barrel and the end-cap, only slightly worse for the latter as expected from its more complex geometry. This is the first proof of the quality of an ATLAS-like signal reconstruction in the end-caps, despite its challenging aspect, and gives confidence that the energy reconstruction is in good control over the complete electromagnetic calorimeter coverage 0< eta <3.2
The effect of paricalcitolon dialysate protein loss in peritoneal dialysis patients
Ever since peritoneal dialysis (PD) has been used in the treatment of chronic kidney disease (CKD), high peritoneal protein loss has been observed on each PD exchange. In adult patients, the loss has been estimated at 6 to 13 g daily. Paricalcitol, a selective activator of vitamin D receptors (VDR), is successfully used as a treatment of hyperparathyroidism secondary to CKD. In addition, it has been proposed for reducing proteinuria in patients with CKD. Nonetheless, little is known about its effect on peritoneal protein loss (PPL) in patients on PD, namely after the identification of VDRon the peritoneal membrane. The aim of this study wasto examine the effect of paricalcitol on PPL in PD patients
The ZEUS Forward Plug Calorimeter with Lead-Scintillator Plates and WLS Fiber Readout
A Forward Plug Calorimeter (FPC) for the ZEUS detector at HERA has been built
as a shashlik lead-scintillator calorimeter with wave length shifter fiber
readout. Before installation it was tested and calibrated using the X5 test
beam facility of the SPS accelerator at CERN. Electron, muon and pion beams in
the momentum range of 10 to 100 GeV/c were used. Results of these measurements
are presented as well as a calibration monitoring system based on a Co
source.Comment: 38 pages (Latex); 26 figures (ps
Morgagni hernia in incremental peritoneal dialysis: Is it possible to continue with the technique?
info:eu-repo/semantics/publishedVersio
Vitamin D effects on human colon normal and tumour organoids
Trabajo presentado en FEBS Open Bio, celebrado en Lisboa (Portugal) del 09 al 14 de julio de 2022.Many studies indicate an association between vitamin D deficiency and increased colorectal cancer risk and, specially, mortality. Accordingly, the active vitamin D metabolite 1a,25-dihydroxyvitamin D3 (calcitriol) inhibits the proliferation and promotes the differentiation of colon carcinoma cells and of other tumour cell types, and also has antitumour effects in animal models of colon cancer. These results prompted us to analyse the effects of calcitriol on human colon normal and cancer stem cells. To this end, we established a living biobank of patient-derived colon organoids generated from the tumour mass and from the adjacent healthy tissue obtained from surgical biopsies. Organoids are a three-dimensional culture system of normal or cancer stem cells and their progeny with a self-organized multicellular structure. By immunohistochemistry and RNAscope in situ hybridization, we found that vitamin D receptor is expressed in LGR5+ colon stem cells in human tissue and in normal and tumour organoid cultures. RNA-sequencing assays showed that both organoid types respond differentially to calcitriol with profound and contrasting changes in their transcriptomic profiles. This was confirmed in an independent series of patient-derived organoids by RT-qPCR assays. In normal organoids, calcitriol upregulates stemness-related genes and inhibits cell proliferation. In contrast, in tumour organoids calcitriol has little effect on stemnessrelated genes, while it induces differentiation-associated genes, and variably reduces cell proliferation. Concordantly, electron microscopy analyses showed that calcitriol does not affect the blastic cell phenotype in normal organoids, but it induces a series of differentiated features in tumour organoids. These results indicate that calcitriol maintains the undifferentiated phenotype of human normal colon stem cells (homeostatic action), while it promotes the differentiation of colon cancer stem cells (anticancer action).
Position resolution and particle identification with the ATLAS EM calorimeter
In the years between 2000 and 2002 several pre-series and series modules of
the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon
and pion beams. The performance of the calorimeter with respect to its finely
segmented first sampling has been studied. The polar angle resolution has been
found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection
has been measured to be about 3.5 for 90% photon selection efficiency at pT=50
GeV/c. Electron-pion separation studies have indicated that a pion fake rate of
(0.07-0.5)% can be achieved while maintaining 90% electron identification
efficiency for energies up to 40 GeV.Comment: 32 pages, 22 figures, to be published in NIM
Energy Linearity and Resolution of the ATLAS Electromagnetic Barrel Calorimeter in an Electron Test-Beam
A module of the ATLAS electromagnetic barrel liquid argon calorimeter was
exposed to the CERN electron test-beam at the H8 beam line upgraded for
precision momentum measurement. The available energies of the electron beam
ranged from 10 to 245 GeV. The electron beam impinged at one point
corresponding to a pseudo-rapidity of eta=0.687 and an azimuthal angle of
phi=0.28 in the ATLAS coordinate system. A detailed study of several effects
biasing the electron energy measurement allowed an energy reconstruction
procedure to be developed that ensures a good linearity and a good resolution.
Use is made of detailed Monte Carlo simulations based on Geant which describe
the longitudinal and transverse shower profiles as well as the energy
distributions. For electron energies between 15 GeV and 180 GeV the deviation
of the measured incident electron energy over the beam energy is within 0.1%.
The systematic uncertainty of the measurement is about 0.1% at low energies and
negligible at high energies. The energy resolution is found to be about 10%
sqrt(E) for the sampling term and about 0.2% for the local constant term
Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method
This paper discusses hadron energy reconstruction for the ATLAS barrel
prototype combined calorimeter (consisting of a lead-liquid argon
electromagnetic part and an iron-scintillator hadronic part) in the framework
of the non-parametrical method. The non-parametrical method utilizes only the
known ratios and the electron calibration constants and does not require
the determination of any parameters by a minimization technique. Thus, this
technique lends itself to an easy use in a first level trigger. The
reconstructed mean values of the hadron energies are within of the
true values and the fractional energy resolution is . The value of the ratio
obtained for the electromagnetic compartment of the combined calorimeter is
and agrees with the prediction that for this
electromagnetic calorimeter. Results of a study of the longitudinal hadronic
shower development are also presented. The data have been taken in the H8 beam
line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM
An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment
The ZEUS inclusive differential cross-section data from HERA, for charged and
neutral current processes taken with e+ and e- beams, together with
differential cross-section data on inclusive jet production in e+ p scattering
and dijet production in \gamma p scattering, have been used in a new NLO QCD
analysis to extract the parton distribution functions of the proton. The input
of jet data constrains the gluon and allows an accurate extraction of
\alpha_s(M_Z) at NLO;
\alpha_s(M_Z) = 0.1183 \pm 0.0028(exp.) \pm 0.0008(model)
An additional uncertainty from the choice of scales is estimated as \pm
0.005. This is the first extraction of \alpha_s(M_Z) from HERA data alone.Comment: 37 pages, 14 figures, to be submitted to EPJC. PDFs available at
http://durpdg.dur.ac.uk/hepdata in LHAPDFv
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