Reconstruction of missing daily streamflow data using dynamic regression models

International audienceRiver discharge is one of the most important quantities in hydrology. It provides fundamentalrecords for water resources management and climate change monitoring. Even very short data-gaps in thisinformation can cause extremely different analysis outputs. Therefore, reconstructing missing data ofincomplete data sets is an important step regarding the performance of the environmental models, engineering,and research applications, thus it presents a great challenge. The objective of this paper is to introducean effective technique for reconstructing missing daily discharge data when one has access to onlydaily streamflow data. The proposed procedure uses a combination of regression and autoregressive integratedmoving average models (ARIMA) called dynamic regression model. This model uses the linear relationshipbetween neighbor and correlated stations and then adjusts the residual term by fitting an ARIMAstructure. Application of the model to eight daily streamflow data for the Durance river watershed showedthat the model yields reliable estimates for the missing data in the time series. Simulation studies were alsoconducted to evaluate the performance of the procedure

Fluorescence studies on the 30 S ribosome assembly process

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Fusion multimodale image/texte par réseaux de neurones profonds pour la classification de documents imprimés

International audienceDocument classification is an important task in the analysis and processing of digital collections as it is mainly used for input pipeline of such systems. To extract features allowing algorithms to categorize the elements, text and pictures are used.We present in this paper different approaches for document classification using textual datas and pictures, as well as a classification model using both of this datas in single model of convolution neural network.La classification de documents imprimés est une tâche réalisée en entrée de multiples chaînes de traitement et d'analyse d'archives numériques, ce qui en fait un point critique dans de tel systèmes. Afin d'extraire des éléments caractéristiques de chaque catégorie parmi les-quels ces pièces doivent être classés, des données textuelles ou des images sont utilisés. Nous présentons dans cet article une analyse de différentes approches pour la catégorisation de documents exploitant des données textuelles ou des images en entrée, ainsi qu'un système de classification utilisant l'information du texte et de l'image de façon jointe en un modèle de réseau de neurone convolutionnel

Détection d'erreurs dans des transcriptions OCR de documents historiques par réseaux de neurones récurrents multi-niveau

International audienceCombining character level and word level RNNs for post-OCR error detection Post-OCR processing, consist in detecting errors first, then correcting them when possible. In this context the ICDAR-2017 Competition on Post-OCR Text Correction was organized to compare approaches on these two tasks. This paper presents an OCR error detection system based on a 2-pass RNN model combining character level and word level representations. This system was ranked 2nd on three datasets among 11 participants at the ICDAR-2017 Competition.Le traitement à posteriori de transcriptions OCR cherche à détecter les erreurs dans les sorties d'OCR pour tenter de les corriger, deux tâches évaluées par la compétition ICDAR-2017 Post-OCR Text Correction. Nous présenterons dans ce papier un système de détection d'erreurs basé sur un modèle à réseaux récurrents combinant une analyse du texte au niveau des mots et des caractères en deux temps. Ce système a été classé second dans trois catégories évaluées parmi 11 candidats lors de la compétition.MOTS-CLÉS : OCR, detection d'erreurs, réseaux de neurones récurrents

Versatility of Stenotrophomonas maltophilia: Ecological roles of RND efflux pumps

S. maltophilia is a widely distributed bacterium found in natural, anthropized and clinical environments. The genome of this opportunistic pathogen of environmental origin includes a large number of genes encoding RND efflux pumps independently of the clinical or environmental origin of the strains. These pumps have been historically associated with the uptake of antibiotics and clinically relevant molecules because they confer resistance to many antibiotics. However, considering the environmental origin of S. maltophilia, the ecological role of these pumps needs to be clarified. RND efflux systems are highly conserved within bacteria and encountered both in pathogenic and non-pathogenic species. Moreover, their evolutionary origin, conservation and multiple copies in bacterial genomes suggest a primordial role in cellular functions and environmental adaptation. This review is aimed at elucidating the ecological role of S. maltophilia RND efflux pumps in the environmental context and providing an exhaustive description of the environmental niches of S. maltophilia. By looking at the substrates and functions of the pumps, we propose different involvements and roles according to the adaptation of the bacterium to various niches. We highlight that i°) regulatory mechanisms and inducer molecules help to understand the conditions leading to their expression, and ii°) association and functional redundancy of RND pumps and other efflux systems demonstrate their complex role within S. maltophilia cells. These observations emphasize that RND efflux pumps play a role in the versatility of S. maltophilia

Peut-on reconstituer de longues séries de crues par modélisation pluie-débit à partir d’une réanalyse atmosphérique globale ? Application au Fier et à l’Arve

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Large scale genotype comparison of human papillomavirus E2-host interaction networks provides new insights for e2 molecular functions.

Comment in: Human papillomavirus E2 protein: a potential key regulator of viral cell pathogenesis. [Pathog Glob Health. 2012]International audienceHuman Papillomaviruses (HPV) cause widespread infections in humans, resulting in latent infections or diseases ranging from benign hyperplasia to cancers. HPV-induced pathologies result from complex interplays between viral proteins and the host proteome. Given the major public health concern due to HPV-associated cancers, most studies have focused on the early proteins expressed by HPV genotypes with high oncogenic potential (designated high-risk HPV or HR-HPV). To advance the global understanding of HPV pathogenesis, we mapped the virus/host interaction networks of the E2 regulatory protein from 12 genotypes representative of the range of HPV pathogenicity. Large-scale identification of E2-interaction partners was performed by yeast two-hybrid screenings of a HaCaT cDNA library. Based on a high-confidence scoring scheme, a subset of these partners was then validated for pair-wise interaction in mammalian cells with the whole range of the 12 E2 proteins, allowing a comparative interaction analysis. Hierarchical clustering of E2-host interaction profiles mostly recapitulated HPV phylogeny and provides clues to the involvement of E2 in HPV infection. A set of cellular proteins could thus be identified discriminating, among the mucosal HPV, E2 proteins of HR-HPV 16 or 18 from the non-oncogenic genital HPV. The study of the interaction networks revealed a preferential hijacking of highly connected cellular proteins and the targeting of several functional families. These include transcription regulation, regulation of apoptosis, RNA processing, ubiquitination and intracellular trafficking. The present work provides an overview of E2 biological functions across multiple HPV genotypes

Regulation of Monocytes/Macrophages by the Renin–Angiotensin System in Diabetic Nephropathy: State of the Art and Results of a Pilot Study

Diabetic nephropathy (DN) is characterized by albuminuria, loss of renal function, renal fibrosis and infiltration of macrophages originating from peripheral monocytes inside kidneys. DN is also associated with intrarenal overactivation of the renin–angiotensin system (RAS), an enzymatic cascade which is expressed and controlled at the cell and/or tissue levels. All members of the RAS are present in the kidneys and most of them are also expressed in monocytes/macrophages. This review focuses on the control of monocyte recruitment and the modulation of macrophage polarization by the RAS in the context of DN. The local RAS favors the adhesion of monocytes on renal endothelial cells and increases the production of monocyte chemotactic protein-1 and of osteopontin in tubular cells, driving monocytes into the kidneys. There, proinflammatory cytokines and the RAS promote the differentiation of macrophages into the M1 proinflammatory phenotype, largely contributing to renal lesions of DN. Finally, resolution of the inflammatory process is associated with a phenotype switch of macrophages into the M2 anti-inflammatory subset, which protects against DN. The pharmacologic interruption of the RAS reduces albuminuria, improves the trajectory of the renal function, decreases macrophage infiltration in the kidneys and promotes the switch of the macrophage phenotype from M1 to M2

Exploring the toxicity of the new emerging toxicant 6PPD-Quinone to environmental microorganisms.

International audienceThis study examines the toxicity of the newly discovered molecule 6PPD-Quinone (6PPD-Q) to selected environmental microorganisms. After decades of intense research, this molecule, derived from a very common antioxidant (6PPD) used as a car tyre protector, has recently been identified as the main cause of the death of Coho salmon in the north-western United States, and is suspected to be a common toxicant worldwide through tyre treading. 6PPD-Q is produced by the ozone oxidation of 6PPD during the ageing of tyre particles after deposition on roads. The 6PPD-Q produced in this way at low concentrations can accumulate in surface waters after storm water runoff, resulting in acute mortality of salmon migrating to urban streams. In this context, we assessed the toxicity of a wide range of 6PPD-Q concentrations through its intrinsic oxidative potential, and through the response of single-cell microorganisms commonly found in the environment (3 bacterial species, a yeast, an algal strain and an amoeba) by cell tracking with various modern techniques. To assess the mechanisms involved in 6PPD-Q toxicity, particular attention was paid to model bacteria and their capacity for resistance (role of efflux pumps in the response to the toxicant) and degradation of the molecule, monitored by LC-MS/MS. Overall, our results showed that 6PPD-quinone had no or limited impact on all microorganisms tested, at the realistic concentrations tested. For some bacteria and yeasts, a slight inhibition of growth was observed with some concentrations, while other organisms were not impacted at all or were even stimulated by the presence of 6PPD-quinone, probably used as a carbon source by these organisms. Further investigations are needed to assess the potential chronic effects of 6PPD-Q on microbial communities in natural waters and on their ecosystem services

Exploring the toxicity of the new emerging toxicant 6PPD-Quinone to environmental microorganisms.

International audienceThis study examines the toxicity of the newly discovered molecule 6PPD-Quinone (6PPD-Q) to selected environmental microorganisms. After decades of intense research, this molecule, derived from a very common antioxidant (6PPD) used as a car tyre protector, has recently been identified as the main cause of the death of Coho salmon in the north-western United States, and is suspected to be a common toxicant worldwide through tyre treading. 6PPD-Q is produced by the ozone oxidation of 6PPD during the ageing of tyre particles after deposition on roads. The 6PPD-Q produced in this way at low concentrations can accumulate in surface waters after storm water runoff, resulting in acute mortality of salmon migrating to urban streams. In this context, we assessed the toxicity of a wide range of 6PPD-Q concentrations through its intrinsic oxidative potential, and through the response of single-cell microorganisms commonly found in the environment (3 bacterial species, a yeast, an algal strain and an amoeba) by cell tracking with various modern techniques. To assess the mechanisms involved in 6PPD-Q toxicity, particular attention was paid to model bacteria and their capacity for resistance (role of efflux pumps in the response to the toxicant) and degradation of the molecule, monitored by LC-MS/MS. Overall, our results showed that 6PPD-quinone had no or limited impact on all microorganisms tested, at the realistic concentrations tested. For some bacteria and yeasts, a slight inhibition of growth was observed with some concentrations, while other organisms were not impacted at all or were even stimulated by the presence of 6PPD-quinone, probably used as a carbon source by these organisms. Further investigations are needed to assess the potential chronic effects of 6PPD-Q on microbial communities in natural waters and on their ecosystem services