2,373 research outputs found
Electron muon identification by atmospheric shower and electron beam in a new concept of an EAS detector
We present results demonstrating the time resolution and /e separation
capabilities with a new concept of an EAS detector capable for measurements of
cosmic rays arriving with large zenith angles. This kind of detector has been
designed to be a part of a large area (several square kilometers) surface array
designed to measure Ultra High Energy (10-200 PeV) neutrinos using the
Earth-skimming technique. A criteria to identify electron-gammas is also shown
and the particle identification capability is tested by measurements in
coincidence with the KASKADE-GRANDE experiment in Karlsruhe, Germany.Comment: accepted by Astrophysical Journal on January 12 2015, 16 pages 3
Figure
Performance of the Prototype of the Charged-Particle Veto System of the PADME Experiment
The PADME experiment will search for the e+ e- →γ A′ process in a positron-on-target experiment, assuming a decay of the A′ into invisible particles of the hidden sector. The 550-MeV positron beam of the DApdblNE beam-test facility (BTF), at Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, will be used. The suppression of the background, due to bremsstrahlung emission from the beam positrons, requires highly efficient charged-particle detectors with optimized geometry. A fine-grained plastic scintillator veto composed of three stations operating in vacuum is proposed. Two stations, placed inside a dipole magnet with 0.6-T magnetic field, will also provide momentum measurement at the percent level. Different prototypes for the design of the detector elements, the photosensor, and the front-end electronics were studied with single electron beam at the DApdblNE BTF to choose the optimal technologies and construction solutions. PADME is currently under construction, and it is planned to begin data collection in 2018. The design of the charged-particle vetoes and the test beam performance of the prototypes are reviewed
Performance of the PADME calorimeter prototype at the DANE BTF
The PADME experiment at the DANE Beam-Test Facility (BTF) aims at
searching for invisible decays of the dark photon by measuring the final state
missing mass in the process , with undetected. The
measurement requires the determination of the 4-momentum of the recoil photon,
performed using a homogeneous, highly segmented BGO crystals calorimeter. We
report the results of the test of a 55 crystals prototype performed
with an electron beam at the BTF in July 2016
Measurements and tests on FBK silicon sensors with an optimized electronic design for a CTA camera
In October 2013, the Italian Ministry approved the funding of a Research &
Development (R&D) study, within the "Progetto Premiale TElescopi CHErenkov made
in Italy (TECHE)", devoted to the development of a demonstrator for a camera
for the Cherenkov Telescope Array (CTA) consortium. The demonstrator consists
of a sensor plane based on the Silicon Photomultiplier (SiPM) technology and on
an electronics designed for signal sampling. Preliminary tests on a matrix of
sensors produced by the Fondazione Bruno Kessler (FBK-Trento, Italy) and on
electronic prototypes produced by SITAEL S.p.A. will be presented. In
particular, we used different designs of the electronics in order to optimize
the output signals in terms of tail cancellation. This is crucial for
applications where a high background is expected, as for the CTA experiment.Comment: 5 pages, 6 figures; Proceedings of the 10th Workshop on Science with
the New Generation of High-Energy Gamma-ray experiments (SciNeGHE) -
PoS(Scineghe2014)00
SiPM application for a detector for UHE neutrinos tested at Sphinx Station
We present the preliminary test results of the prototype detector working at Sphinx Observatory Center Jungfraujoch (similar to 3800 m a.s.l.) HFSJG Switzerland. This prototype detector is designed to measure large zenith angle showers produced by high energy neutrino interactions in the Earth crust. This station provides us an opportunity to understand if the prototype detector works safely (or not) under hard environmental conditions (the air temperature changes between 25 degrees C and 5 degrees C). The detector prototype is using silicon photomultiplier (SiPM) produced by SensL and DRS4 chip as read out part. Measurements at different temperature at fixed bias voltage (similar to 29.5 V) were performed to reconstruct tracks by Time Of Flight. (C) 2014 Elsevier B.V. All rights reserved
Characterization and Performance of PADME's Cherenkov-Based Small-Angle Calorimeter
The PADME experiment, at the Laboratori Nazionali di Frascati (LNF), in
Italy, will search for invisible decays of the hypothetical dark photon via the
process , where the escapes detection. The
dark photon mass range sensitivity in a first phase will be 1 to 24 MeV. We
report here on measurement and simulation studies of the performance of the
Small-Angle Calorimeter, a component of PADME's detector dedicated to rejecting
2- and 3-gamma backgrounds. The crucial requirement is a timing resolution of
less than 200 ps, which is satisfied by the choice of PbF crystals and the
newly released Hamamatsu R13478UV photomultiplier tubes (PMTs). We find a
timing resolution of 81 ps (with double-peak separation resolution of 1.8 ns)
and a single-crystal energy resolution of 5.7%/ with light yield of
2.07 photo-electrons per MeV, using 100 to 400 MeV electrons at the Beam Test
Facility of LNF. We also propose the investigation of a two-PMT solution
coupled to a single PbF crystal for higher-energy applications, which has
potentially attractive features.Comment: 12 pages, 19 figures. v2: added section on radiation damage studie
INFN Camera demonstrator for the Cherenkov Telescope Array
The Cherenkov Telescope Array is a world-wide project for a new generation of
ground-based Cherenkov telescopes of the Imaging class with the aim of
exploring the highest energy region of the electromagnetic spectrum. With two
planned arrays, one for each hemisphere, it will guarantee a good sky coverage
in the energy range from a few tens of GeV to hundreds of TeV, with improved
angular resolution and a sensitivity in the TeV energy region better by one
order of magnitude than the currently operating arrays. In order to cover this
wide energy range, three different telescope types are envisaged, with
different mirror sizes and focal plane features. In particular, for the highest
energies a possible design is a dual-mirror Schwarzschild-Couder optical
scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based
camera is being proposed as a solution to match the dimensions of the pixel
(angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made
by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the
focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near
UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a
Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer,
self-trigger and on-demand digitization capabilities specifically developed for
this purpose. The pixel dimensions of mm lead to a very compact
design with challenging problems of thermal dissipation. A modular structure,
made by copper frames hosting one PSM and the corresponding FEE, has been
conceived, with a water cooling system to keep the required working
temperature. The actual design, the adopted technical solutions and the
achieved results for this demonstrator are presented and discussed.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Comprehensive molecular characterization of adenoid cystic carcinoma reveals tumor suppressors as novel drivers and prognostic biomarkers
© 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Adenoid cystic carcinoma (ACC) is a MYB-driven head and neck malignancy with high rates of local recurrence and distant metastasis and poor long-term survival. New effective targeted therapies and clinically useful biomarkers for patient stratification are needed to improve ACC patient survival. Here, we present an integrated copy number and transcriptomic analysis of ACC to identify novel driver genes and prognostic biomarkers. A total of 598 ACCs were studied. Clinical follow-up was available from 366 patients, the largest cohort analyzed to date. Copy number losses of 1p36 (70/492; 14%) and of the tumor suppressor gene PARK2 (6q26) (85/343; 25%) were prognostic biomarkers; patients with concurrent losses (n = 20) had significantly shorter overall survival (OS) than those with one or no deletions (p < 0.0001). Deletion of 1p36 independently predicted short OS in multivariate analysis (p = 0.02). Two pro-apoptotic genes, TP73 and KIF1B, were identified as putative 1p36 tumor suppressor genes whose reduced expression was associated with poor survival and increased resistance to apoptosis. PARK2 expression was markedly reduced in tumors with 6q deletions, and PARK2 knockdown increased spherogenesis and decreased apoptosis, indicating that PARK2 is a tumor suppressor in ACC. Moreover, analysis of the global gene expression pattern in 30 ACCs revealed a transcriptomic signature associated with short OS, multiple copy number alterations including 1p36 deletions, and reduced expression of TP73. Taken together, the results indicate that TP73 and PARK2 are novel putative tumor suppressor genes and potential prognostic biomarkers in ACC. Our studies provide new important insights into the pathogenesis of ACC. The results have important implications for biomarker-driven stratification of patients in clinical trials. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.info:eu-repo/semantics/publishedVersio
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