Research-grade CMOS image sensors for remote sensing applications

Imaging detectors are key elements for optical instruments and sensors on board space missions dedicated to Earth observation (high resolution imaging, atmosphere spectroscopy...), Solar System exploration (micro cameras, guidance for autonomous vehicle...) and Universe observation (space telescope focal planes, guiding sensors...). This market has been dominated by CCD technology for long. Since the mid-90s, CMOS Image Sensors (CIS) have been competing with CCDs for consumer domains (webcams, cell phones, digital cameras...). Featuring significant advantages over CCD sensors for space applications (lower power consumption, smaller system size, better radiations behaviour...), CMOS technology is also expanding in this field, justifying specific R&D and development programs funded by national and European space agencies (mainly CNES, DGA and ESA). All along the 90s and thanks to their increasingly improving performances, CIS have started to be successfully used for more and more demanding space applications, from vision and control functions requiring low-level performances to guidance applications requiring medium-level performances. Recent technology improvements have made possible the manufacturing of research-grade CIS that are able to compete with CCDs in the high-performances arena. After an introduction outlining the growing interest of optical instruments designers for CMOS image sensors, this paper will present the existing and foreseen ways to reach high-level electro-optics performances for CIS. The developments and performances of CIS prototypes built using an imaging CMOS process will be presented in the corresponding section

Cosavirus, Salivirus and Bufavirus in Diarrheal Tunisian Infants

International audienceThree newly discovered viruses have been recently described in diarrheal patients: Cosa-virus (CosV) and Salivirus (SalV), two picornaviruses, and Bufavirus (BuV), a parvovirus. The detection rate and the role of these viruses remain to be established in acute gastroen-teritis (AGE) in diarrheal Tunisian infants. From October 2010 through March 2012, stool samples were collected from 203 children <5 years-old suffering from AGE and attending the Children's Hospital in Monastir, Tunisia. All samples were screened for CosV, SalV and BuV as well as for norovirus (NoV) and group A rotavirus (RVA) by molecular biology. Positive samples for the three screened viruses were also tested for astrovirus, sapovirus, ade-novirus, and Aichi virus, then genotyped when technically feasible. During the study period, 11 (5.4%) samples were positive for one of the three investigated viruses: 2 (1.0%) CosV-A10, 7 (3.5%) SalV-A1 and 2 (1.0%) BuV-1, whereas 71 (35.0%) children were infected with NoV and 50 (24.6%) with RVA. No mixed infections involving the three viruses were found, but multiple infections with up to 4 classic enteric viruses were found in all cases. Although these viruses are suspected to be responsible for AGE in children, our data showed that this association was uncertain since all infected children also presented infections with several enteric viruses, suggesting here potential water-borne transmission. Therefore, further studies with large cohorts of healthy and diarrheal children will be needed to evaluate their clinical role in AGE

Human Astrovirus Gastroenteritis in Children, Madagascar, 2004–2005

We report data regarding the molecular epidemiology of human astrovirus (HAstV) infections among children in Madagascar. In a 13-month study, 5 HAstV isolates were detected in fecal samples from 237 children (2.1%) by reverse transcription–PCR. Phylogenetic analysis showed the cocirculation of usual and unusual HAstVs

Rôle des antigènes tissulaires de groupes sanguins humains A, B, H et Lewis dans l'évolution des Norovirus GII.4

Les norovirus sont l'une des causes principales de gastroentérite. Depuis 2002, des variants de norovirus GII.4 successifs ont circulé dans la population par cycle de 2-3 ans, ce qui suscite des interrogations quant au rôle de leurs ligands, les antigènes tissulaires de groupes sanguins (HBGA), dans leur évolution. Nous avons analysé l'interaction entre des variants de GII.4 représentatifs et des HBGA, et déterminé le rôle d acides aminés (aa) clés. Par mutagénèse dirigée, nous avons montré qu une configuration stricte des aa directement impliqués dans l accroche est indispensable. La suppression de la thréonine 395, caractéristique des variants après 2002, confère la capacité de se lier à Lex et Si-Lex, démontrant que les aa en dehors du site de liaison peuvent modifier les propriétés d attachement. L'analyse de l'accroche de VLP de 6 variants isolés de 1987 à 2007 à des échantillons de salive phénotypés et des HBGA synthétiques montre que tous les variants sont capables de s attacher à la salive des sécréteurs indépendamment du phénotype ABO et aux oligosaccharides propres au phénotype sécréteur. Deux variants récents ont pu également s accrocher aux sucres présents dans la salive des nonsécréteurs Le(+). Nos données suggèrent que la capacité de se lier à Lex et Si-Lex serait une conséquence de la variation génétique des aa situés à proximité du site de liaison. L'analyse des propriétés d attachement par résonance plasmonique de surface a montré que seuls les variants après 2002 présentent une affinité forte pour les antigènes A et B, suggérant que l accélération évolutive des GII.4 pourrait être liée à une affinité accrue des variants pour les HBGA après 2002.Noroviruses are one of the leading causes of gastroenteritis worldwide. Since 2002 successive GII.4 variants have circulated in the population before being replaced every 2-3 years, which raises questions about the role of their histo-blood group antigen (HBGAs) receptors in their evolution. We analyzed the interaction between representative GII.4 variants and HBGAs and determined the role of selected amino acids (aa) in the binding profiles. By mutagenesis, we showed that there was a strict structural requirement for the aa directly implicated in HBGA bindings. The ablation of the threonine 395 residue, an epidemiological feature of the post 2002 variants, allowed to gain the capacity to bind to the Lewis x and sialyl-Lewis x antigens, demonstrating that aa residues outside the HBGA binding site can modify the binding properties. The analysis of the attachment of VLPs from 6 variants isolated from 1987 to 2007 to phenotyped saliva samples and synthetic HBGAs shows that all variants could attach to saliva of secretors irrespective of the ABO phenotype and to oligosaccharides characteristic of the secretor phenotype. Interestingly, two recent variants additionally bound to carbohydrates present in the saliva of Lewis-positive non-secretors. Our data suggest that GII.4 binding to Lex and Si-Lex antigens might be a by-product of the genetic variation of the aa located in the vicinity of the binding site. Analysis of the binding properties by surface plasmon resonance showed that only post 2002 variants presented a strong affinity for A and B antigens, suggesting that the GII.4 evolution could be related to an increased affinity for HBGAs for the post 2002 variants.DIJON-BU Doc.électronique (212319901) / SudocSudocFranceF

Immobilization of murine noroviruses in a cultivated phaeozem soil and its reversibility

Immobilization of murine noroviruses in a cultivated phaeozem soil and its reversibility. Environmental Microbiology & Microbial Ecolog

[Norovirus infections: an overview]

National audienceNoroviruses belong to the Caliciviridae family. They are a major cause of sporadic cases and outbreaks of gastroenteritis in all age groups, and are responsible for a considerable disease burden in industrialized countries. Noroviruses are single-stranded RNA viruses, and show great genetic diversity making their detection difficult. Noroviruses can be divided into 5 genogroups, which themselves are subdivided into genotypes. Besides chance mutations that occur during viral replication, the great heterogeneity observed among noroviruses is also due to intra and inter-genotypic recombination events between strains. Some of these new variants or new recombinants are frequently associated with new epidemic waves of gastroenteritis. Finally, it is worth pointing out that the discovery of mechanisms involved in NoV infections through blood antigen-related receptors and cultivation of the first norovirus, a murine norovirus, are milestones in research on this virus. These advances open new promising avenues of research that will help to the understanding of the -pathogenicity of this important pathogen

Vomiting symptom of acute gastroenteritis estimated from epidemiological data can help predict river contamination by human pathogenic enteric viruses

International audienceContamination of fresh water bodies by human enteric viruses from wastewater discharge is a well-established phenomenon. Here we propose a model of viral contamination of rivers based on acute gastroenteritis epidemiology and assess how well it can simulate in situ experimental monitoring. Noroviruses, rotaviruses, enteroviruses, adenoviruses and hepatitis A viruses were quantified by molecular methods after water concentration. Water flows were obtained from the Hydro databank and wastewater treatment plant (WWTP) data. Acute gastroenteritis cases based on medical prescriptions were recorded by the French public health agency. We estimated the total number of daily viral acute gastroenteritis cases and modeled virus shedding and fate in WWTPs and rivers. Simulated virus concentrations were compared to the weighted sum of measured concentrations. Seasonal variations in viral acute gastroenteritis were predicted from vomiting occurrence. All viruses except hepatitis A virus were widely detected in wastewaters and river, in concentrations reaching 10+6 genome copies·L-1 for adenoviruses in the Artiere River. We were able to predict virus load in raw wastewater and in the Artiere River. Estimated weighting coefficients showed the high impact of noroviruses GII. This model can thus serve to compare water treatment, discharge and reuse scenarios.Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved

Actualités sur les norovirus

Les norovirus appartiennent au genre Norovirus de la famille des Caliciviridae. Ils sont l’un des principaux agents des gastroentérites aiguës sporadiques et épidémiques quelles que soient les tranches d’âge. Ces virus à ARN simple brin présentent une grande diversité, on distingue 5 génogroupes eux-mêmes classifiés en génotypes. À cette diversité s’ajoutent des souches recombinantes et des variants par mutation expliquant la très grande évolutivité génétique de ces virus. Ainsi, ces nouvelles souches seraient responsables des vagues épidémiques régulièrement constatées. La biologie de ces virus connaît actuellement d’importants développements avec d’une part la description de leurs récepteurs glycanes liés aux antigènes des groupes sanguins tissulaires et d’autre part, la découverte d’un norovirus murin cultivable et pouvant servir de modèle

Use of Murine Norovirus as a Surrogate To Evaluate Resistance of Human Norovirus to Disinfectants▿

Murine norovirus (MNV) was used as a surrogate to study resistance of human norovirus to disinfectants used in hospitals. MNV was sensitive to alcohol, alcohol hand rubs, bleach, and povidone iodine-based disinfectant. Real-time reverse transcription-PCR results indicated that the presence of viral RNA did not correlate with the presence of infectious virus

HS-AFM and SERS Analysis of Murine Norovirus Infection: Involvement of the Lipid Rafts

International audienceStudies on human norovirus are severely hampered by the absence of a cellculture system until the discovery of murine norovirus (MNV). The cell membranedomains called lipid rafts have been defined as a port of entry for viruses. Thisstudy is conducted to investigate murine norovirus binding on the mouse leukemicmonocyte macrophage cell line. Lipid raft related structures are extracted from cellsby detergent treatment resulting detergent-resistant membrane (DRMs) domains. Thereal-time polymerase chain reaction technique is performed to detect the viral genome,thereby the MNV binding on the DRMs. The interactions between MNV and DRMsare investigated by high-speed atomic force microscopy (HS-AFM) combined withsurface-enhanced Raman spectroscopy (SERS). The inoculation of the virus ontocells results in the aggregations of detergent-resistant membrane domains significantly.The characteristic Raman band of MNV is found in inoculated samples. To be surethat these results are originated from specific interactions between DRM and MNV,methyl-β-cyclo-dextrin (MβCD) is applied to disrupt lipid rafts. The MNV bindingon DRMs is precluded by the MβCD treatment. The cholesterols chains are defined asa key factor in the interactions between norovirus and DRMs. The authors concludethat the MNV binding involves the presence of DRMs and cholesterol dependent