Seeded excitation avalanches in off-resonantly driven Rydberg gases

We report an experimental investigation of the facilitated excitation dynamics in off-resonantly driven Rydberg gases by separating the initial off-resonant excitation phase from the facilitation phase, in which successive facilitation events lead to excitation avalanches. We achieve this by creating a controlled number of initial seed excitations. Greater insight into the avalanche mechanism is obtained from an analysis of the full counting distributions. We also present simple mathematical models and numerical simulations of the excitation avalanches that agree well with our experimental results.Comment: 13 pages, 6 figure

Clean Colon Software Program (CCSP), Proposal of a standardized Method to quantify Colon Cleansing During Colonoscopy: Preliminary Results

Background and study aims: Neoplastic lesions can be missed during colonoscopy, especially when cleansing is inadequate. Bowel preparation scales have significant limitations and no objective and standardized method currently exists to establish colon cleanliness during colonoscopy. The aims of our study are to create a software algorithm that is able to analyze bowel cleansing during colonoscopies and to compare it to a validate bowel preparation scale. Patients and methods: A software application (the Clean Colon Software Program, CCSP) was developed. Fifty colonoscopies were carried out and video-recorded. Each video was divided into 3 segments: cecum-hepatic flexure (1st Segment), hepatic flexure-descending colon (2nd Segment) and rectosigmoid segment (3rd Segment). Each segment was recorded twice, both before and after careful cleansing of the intestinal wall. A score from 0 (dirty) to 3 (clean) was then assigned by CCSP. All the videos were also viewed by four endoscopists and colon cleansing was established using the Boston Bowel Preparation Scale. Interclass correlation coefficient was then calculated between the endoscopists and the software. Results: The cleansing score of the prelavage colonoscopies was 1.56\ub10.52 and the postlavage one was 2,08\ub10,59 (P<0.001) showing an approximate 33.3% improvement in cleansing after lavage. Right colon segment prelavage (0.99\ub10.69) was dirtier than left colon segment prelavage (2.07\ub10.71). The overall interobserver agreement between the average cleansing score for the 4 endoscopists and the software pre-cleansing was 0.87 (95% CI, 0.84\u20130.90) and post-cleansing was 0.86 (95% CI, 0.83\u20130.89). Conclusions: The software is able to discriminate clean from non-clean colon tracts with high significance and is comparable to endoscopist evaluation

SELF-EXPANDABLE METAL STENT PLACEMENT FOR CLOSURE OF A LEAK AFTER TOTAL GASTRECTOMY FOR GASTRIC CANCER: REPORT ON THREE CASES AND REVIEW OF THE LITERATURE

consequently the management of this problem has become more critically focused than was previously possible. We report here three cases of placement of a partially silicone-coated SEMS (Evolution Controlled Release Esophageal Stent System, CookMedical, Winston-Salem, NC, USA) in patients who underwent total gastrectomy with Roux-en-Y end-to-side esophagojejunostomy for a gastric adenocarcinoma. The promising results of our report, despite the small number of patients, suggest that early stenting (through a partially silicone-coated SEMS) is a feasible alternative to surgical treatment in this subset of patients. In fact, in the treatment of leakage after total gastrectomy, plastic stents and totally covered metallic stents may not adhere sufficiently to the esophagojejunal walls and, as a result, migrate beyond the anastomosis. However, prospective studies with a larger number of patients might assess the real effectiveness and safety of this procedure

Geoffroy de Lagasnerie, Logique de la création

Les universitaires ont raison d’être inquiets. La société ignore ce qu’ils sont et ce qu’ils font. Le journalisme véhicule les pires poncifs à leur sujet. Quant à leur institution, elle vient de traverser la pire crise de son histoire et ce n’est pas fini. Plusieurs électrochocs récents, souvent aux allures burlesques, ont secoué la vieille maison qui se voit poussée à la réflexivité : une blessure narcissique, suite à la publication en 2003 du classement dit de Shanghai qui reléguait les éta..

Results from CHIPIX-FE0, a Small Scale Prototype of a New Generation Pixel Readout ASIC in 65nm CMOS for HL-LHC

CHIPIX65-FE0 is a readout ASIC in CMOS 65nm designed by the CHIPIX65 project for a pixel detector at the HL-LHC, consisting of a matrix of 64x64 pixels of dimension 50x50 μm2. It is fully functional, can work at low thresholds down to 250e− and satisfies all the specifications. Results confirm low-noise, fast performance of both the synchronous and asynchronous front-end in a complex digital chip. CHIPIX65-FE0 has been irradiated up to 600 Mrad and is only marginally affected on analog performance. Further irradiation to 1 Grad will be performed. Bump bonding to silicon sensors is now on going and detailed measurements will be presented. The HL-LHC accelerator will constitute a new frontier for particle physics after year 2024. One major experimental challenge resides in the inner tracking detectors, measuring particle position: here the dimension of the sensitive area (pixel) has to be scaled down with respect to LHC detectors. This paper describes the results obtained by CHIPIX65-FE0, a readout ASIC in CMOS 65nm designed by the CHIPIX65 project as small-scale demonstrator for a pixel detector at the HL-LHC. It consists of a matrix of 64x64 pixels of dimension 50x50 um2 pixels and contains several pieces that are included in RD53A, a large scale ASIC designed by the RD53 Collaboration: two out of three front-ends (a synchronous and an asynchronous architecture); several building blocks; a (4x4) pixel region digital architecture with central local buffer storage, complying with a 3 GHz/cm2 hit rate and a 1 MHz trigger rate maintaining a very high efficiency (above 99%). The chip is 100% functional, either running in triggered or trigger-less mode. All building-blocks (DAC, ADC, Band Gap, SER, sLVS-TX/RX) and very front ends are working as expected. Analog performance shows a remarkably low ENC of 90e-, a fast-rise time below 25ns and low-power consumption (about 4μA/pixel) in both synchronous and asynchronous front-ends; a very linear behavior of CSA and discriminator. No significant cross talk from digital electronics has been measured, achieving a low threshold of 250e-. Signal digitization is obtained with a 5b-Time over Threshold technique and is shown to be fairly linear, working well either at 80 MHz or with higher frequencies of 300 MHz obtained with a tunable local oscillator. Irradiation results up to 600 Mrad at low temperature (-20°C) show that the chip is still fully functional and analog performance is only marginally degraded. Further irradiation will be performed up to 1 Grad either at low or room temperature, to further understand the level of radiation hardness of CHIPIX65-FE0. We are now in the process of bump bonding CHIPIX65-FE0 to 3D and possibly planar silicon sensors during spring. Detailed results will be presented in the conference paper

POLARIX: a small mission of x-ray polarimetry

X-Ray Polarimetry can be now performed by using a Micro Pattern Gas Chamber in the focus of a telescope. It requires large area optics for most important scientific targets. But since the technique is additive a dedicated mission with a cluster of small telescopes can perform many important measurements and bridge the 40 year gap between OSO-8 data and future big telescopes such as XEUS. POLARIX has been conceived as such a pathfinder. It is a Small Satellite based on the optics of JET-X. Two telescopes are available in flight configuration and three more can be easily produced starting from the available superpolished mandrels. We show the capabilities of such a cluster of telescopes each equipped with a focal plane photoelectric polarimeter and discuss a few alternative solutions.Comment: 9 pages, 5 figure

First Measurements of a Prototype of a New Generation Pixel Readout ASIC in 65 nm CMOS for Extreme Rate HEP Detectors at HL-LHC

A first prototype of a readout ASIC in CMOS 65nm for a pixel detector at High Luminosity LHC is described. The pixel cell area is 50x50 um2 and the matrix consists of 64x64 pixels. The chip was designed to guarantee high efficiency at extreme data rates for very low signals and with low power consumption. Two different analogue front-end designs, one synchronous and one asynchronous, were implemented, both occupying an area of 35x35 um2. ENC value is below 100e- for an input capacitance of 50 fF and in-time threshold below 1000e-. Leakage current compensation up to 50 nA with power consumption below 5 uW. A ToT technique is used to perform charge digitization with 5-bit precision using either a 40 MHz clock or a local Fast Oscillator up to 800 MHz. Internal 10-bit DAC's are used for biasing, while monitoring is provided by a 12-bit ADC. A novel digital architecture has been developed to ensure above 99.5% hit efficiency at pixel hit rates up to 3 GHz/cm2, trigger rates up to 1 MHz and trigger latency of 12.5 us. The total power consumption per pixel is below 5uW. Analogue dead-time is below 1%. Data are sent via a serializer connected to a CMOS-to-SLVS transmitter working at 320 MHz. All IP-blocks and front-ends used are silicon-proven and tested after exposure to ionizing radiation levels of 500-800 Mrad. The chip was designed as part of the Italian INFN CHIPIX65 project and in close synergy with the international CERN RD53 and was submitted in July 2016 for production. Early test results for both front-ends regarding minimum threshold, auto-zeroing and low-noise performance are high encouraging and will be presented in this paper

The AGILE Mission

AGILE is an Italian Space Agency mission dedicated to observing the gamma-ray Universe. The AGILE's very innovative instrumentation for the first time combines a gamma-ray imager (sensitive in the energy range 30 MeV-50 GeV), a hard X-ray imager (sensitive in the range 18-60 keV), a calorimeter (sensitive in the range 350 keV-100 MeV), and an anticoincidence system. AGILE was successfully launched on 2007 April 23 from the Indian base of Sriharikota and was inserted in an equatorial orbit with very low particle background. Aims. AGILE provides crucial data for the study of active galactic nuclei, gamma-ray bursts, pulsars, unidentified gamma-ray sources, galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. Methods. An optimal sky angular positioning (reaching 0.1 degrees in gamma- rays and 1-2 arcmin in hard X-rays) and very large fields of view (2.5 sr and 1 sr, respectively) are obtained by the use of Silicon detectors integrated in a very compact instrument. Results. AGILE surveyed the gamma- ray sky and detected many Galactic and extragalactic sources during the first months of observations. Particular emphasis is given to multifrequency observation programs of extragalactic and galactic objects. Conclusions. AGILE is a successful high-energy gamma-ray mission that reached its nominal scientific performance. The AGILE Cycle-1 pointing program started on 2007 December 1, and is open to the international community through a Guest Observer Program