An early increase in outbreaks of norovirus gastroenteritis characterised at the French National Reference Centre occurred this winter season. They were concurrent with an unusual pattern of ...circulating strains, with three predominant genotypes: the re-emergent variant GII.P4 2009-GII.4 2012 found in 28% of norovirus outbreaks and two new emergent recombinant strains GII.P16-GII.4 2012 and GII.P16-GII.2 never before observed in France, found in 24% and 14% of norovirus outbreaks, respectively.
Group A rotavirus is a major cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up in France to investigate rotavirus infections and to detect ...the emergence of potentially epidemic strains.
From 2014 to 2017, rotavirus-positive stool samples were collected from 2394 children under 5 years old attending the paediatric emergency units of 13 large hospitals. Rotaviruses were genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7.
Genotyping of 2421 rotaviruses showed that after a marked increase in G9P8 (32.1%) during the 2014–2015 season, G9P8 became the predominant genotype during the 2015–2016 and 2016–2017 seasons with detection rates of 64.1% and 77.3%, respectively, whereas G1P8 were detected at low rates of 16.8% and 6.6%, respectively. Phylogenetic analysis of the partial rotavirus VP7 and VP4 coding genes revealed that all of these G9P 8 strains belonged to the lineage III and the P 8-3 lineage, respectively, and shared the same genetic background (G9-P8-I1-R1-C1-M1-A1-N1-T1-E1-H1) as did most of previously detected G9P8 strains and particularly the emerging G9P8 strains from the 2004–2005 season in France.
G9P8 rotaviruses have become the predominant circulating genotype for the first time since their emergence a decade ago. In the absence of rotavirus immunization programmes in France, our data give an insight into the natural fluctuation of rotavirus genotypes in a non-vaccinated population and provide a base line for a better interpretation of data in European countries with routine rotavirus vaccination.
Aichi virus has been proposed as a causative agent of gastroenteritis. A total of 457 stool specimens from children hospitalized with acute diarrhea and 566 stool specimens from adults and children ...involved in 110 gastroenteritis outbreaks were screened for the presence of Aichi virus by reverse transcription-PCR (RT-PCR) amplification of the genomic region of the 3C and 3D (3CD) nonstructural proteins. Our results show a low incidence of Aichi virus in pediatric samples and the existence of mixed infections with other microbiological agents in some cases. From the outbreak survey, it appears that the presence of Aichi virus is an indicator of mixed infections causing gastroenteritis outbreaks and that it could be involved in half of the oyster-associated outbreaks. A second RT-PCR was developed to amplify a part of the VP1 gene. The phylogenetic analysis showed a good correlation between the two classifications based on 3CD and VP1 gene sequences and revealed the prevalence of genotype A in France. It also allowed us to partially describe an Aichi virus strain that could represent a new genotype, thus suggesting the existence of a certain diversity.
TDCpix pixel detector ASIC with 100 ps time stamping Rinella, G. Aglieri; Bonacini, S.; Jarron, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2023, Letnik:
1053
Journal Article
Recenzirano
Odprti dostop
The TDCpix pixel read-out ASIC contains 1800 pixels arranged in 40 columns and 45 rows with the dimension of 300μm x 300μm. Each pixel contains a preamplifier and shaper circuit with a dynamic range ...of 0.8 to 10 fC and a rise time of 5 ns, followed by a Leading-Edge discriminator with Time-over-Threshold correction. The discriminator outputs of each pixel are connected to time-to-digital converters (TDC) measuring the time when the input signal has exceeded the threshold and the pulse width with a binning of 97 ps. The electronics noise of pre-amplifier/shaper is 170 e− or 2.7 mV rms with a gain of 65 mV/fC. The jitter of the entire processing chain for an electrical input signal of 2.4 fC is lower than 60 ps rms. The ASIC has been designed to work in radiated environments of 6 * 104 Gray per year and 2 x 1014 1 MeV neutron equivalent cm−2.
This manuscript describes the optimization of the front-end readout electronics for high granularity hybrid pixel detectors. The theoretical study aims at minimizing the noise and jitter. The model ...presented here is validated with both circuit post layout simulations and measurements on the Timepix4 Application Specific Integrated Circuit (ASIC). The analog front-end circuit and the procedure to optimize the dimensions of the main transistors are described with detail.
The Timepix4 is the most recent ASIC designed in the framework of the Medipix4 Collaboration. It was manufactured in 65nm CMOS process, and consists of a four side buttable matrix of 448 × 512 pixels with 55µm pitch. The analog front-end has a gain of ∼36mV/ke- when configured in High Gain Mode, and ∼20mV/ke- when configured in Low Gain Mode. The Equivalent Noise Charge (ENC) is ∼68e-rms and ∼80e-rms in High Gain Mode and in Low Gain Mode respectively. In event driven mode the incoming hits can be time stamped within a ∼ 200ps time bin and the chip can deal with a maximum flux of ∼ 3.6MHzmm−2s−1. In photon counting mode, the chip can deal with up to ∼ 5GHzmm−2s−1.
The routine designed to optimize the Timepix4 front-end is then used to analyze the performance limits in terms of jitter and noise for Charge Sensitive Amplifiers in pixel detectors.
The near real-time (NRT) high resolution water vapour distribution models can be constructed based on GNSS observations delivered from Ground Base Augmentation Systems (GBAS) and ground ...meteorological data. Since 2008 in the territory of Poland, a GBAS system called ASG-EUPOS (Active Geodetic Network) has been operating. This paper addresses the problems concerning construction of the NRT model of water vapour distribution in the troposphere near Poland. The first section presents all available GNSS and ground meteorological stations in the area of Poland and neighbouring countries. In this section, data feeding scheme is discussed, together with timeline and time resolution. The high consistency between measured and interpolated temperature value is shown, whereas some discrepancy in the pressure is observed. In the second section, the NRT GNSS data processing strategy of ASG-EUPOS network is discussed. Preliminary results show fine alignment of the obtained Zenith Troposphere Delays (ZTDs) with reference data from European Permanent Network (EPN) processing center. The validation of NRT troposphere products against daily solution shows 15 mm standard deviation of obtained ZTD differences. The last section presents the first results of 2-D water vapour distribution above the GNSS network and application of the tomographic model to 3-D distribution of water vapour in the atmosphere. The GNSS tomography model, working on the simulated data from numerical forecast model, shows high consistency with the reference data (by means of standard deviation 4 mm km−1 or 4 ppm), however, noise analysis shows high solution sensitivity to errors in observations. The discrepancy for real data preliminary solution (measured as a mean standard deviation) between reference NWP data and tomography data was on the level of 9 mm km−1 (or 9 ppm) in terms of wet refractivity.
We present the development of a front end amplifier and discriminator circuit implemented in two successive nodes of commercial CMOS process, namely 90 nm and 130 nm. The aim of this work is ...two-fold, firstly to examine new technology features such as increased transconductance and transit frequency f_{t} resulting in higher speed at lower power consumption, and secondly to prototype a novel front end architecture developed to maintain high dynamic range and open loop gain in the presence of the degradation of intrinsic transistor gain and low supply voltage accompanying the scaling of CMOS processes. The circuits are intended to work with silicon strip detectors of moderate length. Although both versions are optimized for 5 pF input capacitance, the input stage of 130 nm front end can be biased with a current allowing for readout of detectors with capacitances of the order of 10 pF. Special attention has been given to the comparison of noise performance and matching of the channel gain and discriminator offsets. Although both versions show good basic analog performance in terms of speed and gain, an appreciable difference in the channel-to-channel matching and the noise figures is measured. The ENC performance of 130 nm version of the amplifier follows theoretical predictions confirming no excess noise for the devices used, whilst the noise performance of the 90 nm version is noticeably worse. Looking at the difference in noise performance between the two designs, the 130 nm process is better understood and is thus a more appropriate choice for the current upgrade project. As a consequence, the presented 130 nm design will form the core of the ABC130 chip for the ATLAS SCT upgrade.
AIMS: To ascertain the viral load, the distribution of G and P types of group A rotaviruses (RV‐A) in sewage samples and to compare strains in clinical, animal and environmental samples. METHODS AND ...RESULTS: During our study from April 2007 to April 2010, 518 samples of raw and treated sewage were collected from two biological sewage treatment plants (STPs) located in the Monastir region, Tunisia. RV‐A was detected by real‐time RT‐PCR in 375 (72·4%) sewage samples. According to the quantification results of RV‐A, it appears that the viral load in raw and treated sewage of the two STPs was quite similar (P = 0·735). The genotyping of RV‐A strains detected in sewage samples showed a great diversity with 10 G types and 8 P types. Most of them were described as common in humans, but we also detected genotypes commonly found in animals. All the genotypes detected in two previous studies performed in our laboratory on clinical and bovine samples were also found in environmental samples. However, some genotypes commonly found in animal were only found in sewage samples. CONCLUSION: The comparison of environmental, clinical and animal data suggests that STPs may convey not only human sewage but also animal wastes, both of them contaminated with numerous RV‐A strains which are not efficiently eliminated by the sewage treatment process and may spread to surface waters. SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrates the potential release of human and animal RV‐A into water sources, representing a public health risk, by inducing gastroenteritis in population, but also by increasing the risk of zoonotic transmission and formation of reassortant viruses which could get a higher infectious potential. Our findings also suggest that monitoring of sewage may provide an additional tool to determine the epidemiology of RV‐A circulating in a given community.
Épidémies parisiennes de gastro-entérites à norovirus Lecarpentier, T.; Benezit, A.; Marostica, A. ...
Archives de pédiatrie : organe officiel de la Société française de pédiatrie,
November 2010, Letnik:
17, Številka:
11
Journal Article
Recenzirano
La fréquence des gastro-entérites présumées virales sans rotavirus identifié chez les enfants hospitalisés à Paris au cours de 2 automnes successifs nous a conduit à rechercher les calicivirus dans ...cette population. Pendant la période du 1er octobre au 1er décembre des années 2006 à 2008, un norovirus a été isolé chez 14 patients (aucun sapovirus). Parmi ces norovirus, 9 appartenaient à la souche GGII4 et les patients porteurs étaient hospitalisés avec des symptômes sévères. Cette souche était présente uniquement en 2007 et 2008 et absente en 2006. Décrite précédemment chez l’adulte âgé en Europe, elle semble s’implanter chez l’enfant en région parisienne avec des gastro-entérites souvent sévères.
During the months of October and November 2006–2008, norovirus was detected in the stools of 14 children hospitalized with acute diarrhea (no sapovirus). Nine of these noroviruses belonged to a unique GGII4 strain, which produced severe clinical symptoms, present only in 2007 and 2008 and absent in 2006. This strain, identified in Europe mainly in the elderly, seems to be on the rise in children in the Paris area over the past few years.
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![Predominance of G9P[8] rota...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1198-743X/small "Predominance of G9P[8] rotavirus strains throughout France, 2014–2017")
