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Improved calibration procedures for the EM27/SUN spectrometers of the COllaborative Carbon Column Observing Network (COCCON)
No full textInternational audienceAbstract. In this study, an extension on the previously reported status of the COllaborative Carbon Column Observing Network's (COCCON) calibration procedures incorporating refined methods is presented. COCCON is a global network of portable Bruker EM27/SUN FTIR spectrometers for deriving column-averaged atmospheric abundances of greenhouse gases. The original laboratory open-path lamp measurements for deriving the instrumental line shape (ILS) of the spectrometer from water vapour lines have been refined and extended to the secondary detector channel incorporated in the EM27/SUN spectrometer for detection of carbon monoxide (CO). The refinements encompass improved spectroscopic line lists for the relevant water lines and a revision of the laboratory pressure measurements used for the analysis of the spectra. The new results are found to be in good agreement with those reported by Frey et al. (2019) and discussed in detail. In addition, a new calibration cell for ILS measurements was designed, constructed and put into service. Spectrometers calibrated since January 2020 were tested using both methods for ILS characterization, open-path (OP) and cell measurements. We demonstrate that both methods can detect the small variations in ILS characteristics between different spectrometers, but the results of the cell method indicate a systematic bias of the OP method. Finally, a revision and extension of the COCCON network instrument-to-instrument calibration factors for XCO2, XCO and XCH4 is presented, incorporating 47 new spectrometers (of 83 in total by now). This calibration is based on the reference EM27/SUN spectrometer operated by the Karlsruhe Institute of Technology (KIT) and spectra collected by the collocated TCCON station Karlsruhe. Variations in the instrumental characteristics of the reference EM27/SUN from 2014 to 2017 were detected, probably arising from realignment and the dual-channel upgrade performed in early 2018. These variations are considered in the evaluation of the instrument-specific calibration factors in order to keep all tabulated calibration results consistent
Discovery of X-shaped morphology of the giant radio galaxy 0503-286
No full textInternational audienceThe high surface-brightness sensitivity of the galactic and extragalactic all-sky mwa survey (GLEAM) image of the giant radio galaxy (GRG) 0503-28 at 70–230 MHz has revealed an inversion-symmetric bending of its two lobes, while maintaining a ∼200 kpc wide strip-like radio emission gap between their bent portions. This lends the source the appearance of a mega-sized X-shaped radio galaxy. Identifying the emission gap with the presence of a gaseous layer, probably a WHIM-filled sheet in the cosmic web, we suggest that the layer is the most likely cause of the inversion-symmetric bending of the two radio lobes. Multiple observational manifestations of such gaseous layers are noted. The two lobes of this GRG, known to extend very asymmetrically from the host galaxy, are remarkably symmetric about the emission gap, confirming a curious trend noted earlier for double radio sources of normal dimensions. The anomalous radio spectral gradient reported for the northern lobe of this GRG is not substantiated
Systèmes sémiotiques spécifiques de la chimie et leur apprentissage
No full textInternational audienceCe chapitre expose une approche sémiotique unifiée inspirée du système triadique de Peirce pour mettre en évidence les enjeux d’apprentissage spécifiques de certains signes utilisés en chimie. Deux études portant chacune sur un aspect différent du système triadique montrent la difficile conceptualisation des signes élémentaires de la chimie et des formules spatiales par des élèves après enseignement
La BnF et les services à la recherche à l’heure des humanités numériques
No full textInternational audienc
On possible trypsin‐induced biases in peptides analysis with aerolysin nanopore
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Electrochemical preparation of monodisperse Pt nanoparticles on a grafted 4-aminothiophenol supporting layer for improving the MOR reaction
No full textInternational audienceWell-dispersed Pt nanoparticles for MOR reaction
Séminaire ouvert "Taxinomies du bonheur"
No full textseminaire de recherche réunissantChristian Budex "Eduquer à la fraternité par la pratique de la philosophie avec les enfants à l'école (primaire et collège) : enjeux et conditions de possibilité".- Marie- Pierre Bidal "La bientraitance pédagogique : une relation de confiance partagée, une attention ajustée"- Bernard Mazard "L’apprentissage de la dégustation du vin via une pédagogie eudémonique, les apports de la pleine conscience et de la méthode esthétique : des émotions au capital émotionnel.
Computational Measures of Deceptive Language: Prospects and Issues
No full textInternational audienceIn this article, we wish to foster a dialogue between theory-based and classificationoriented stylometric approaches regarding deception detection. To do so, we review how cue-based and model-based stylometric systems are used to detect deceit. Baseline methods, common cues, recent methods, and field studies are presented. After reviewing how computational stylometric tools have been used for deception detection purposes, we show that the he stylometric methods and tools cannot be applied to deception detection problems on the field in their current state. We then identify important advantages and issues of stylometric tools. Advantages encompass quickness of extraction and robustness, allowing for best interviewing practices. Issues are discussed in terms of oral data transcription issues and automation bias emergence. We finally establish future research proposals: We emphasize the importance of baseline assessment and the need for transcription methods, and the concern of ethical standards regarding the applicability of stylometry for deception detection purposes in practical settings, while encouraging the cooperation between linguists, psychologists, engineers, and practitioners requiring deception detection methods
Caractérisation protéomique et structurale d'endosulfatases humaines Hsulfs modulant la sulfatation de l'héparane sulfate et biomarqueur de progression tumorale
No full textThe Human endosulfatase HSulf-2 catalyzes the 6-O-desulfation of heparan sulfate (HS) glycosaminoglycan present on proteoglycan at the surface of cells. The interaction properties of HS are thus finely regulated by its sulfation profile. HSulf-2 is synthesized as a pro-protein which matures after cleavage by furin. It has a molecular organization made up of two chains probably linked by disulfide bridges. A hydrophilic domain (HD) overflowing on the two chains and specific to these endosulfatases constitutes a recognition structure of the substrate HS. The organization of HSulf-2 resulting from a folding of the two chains remains to be determined. The objectives of this work aim both to characterize the structure, and to determine its influence on HSulf-2 catalytic activity. By biochemical and biophysical approaches such as mass spectrometry and NMR we have identified for the first time the positions and structures of post-translational modifications present on HSulf-2. Thus, 5 N-glycans have been characterized and 10 cysteines involved in disulfide bridges between the two chains have been identified. We further characterized a unique post-translational modification, which is a chondroitin sulfate-type glycosaminoglycan chain. We have also studied the role of this chain by spectroscopy that seems to act like an activity regulator for HSulf-2. The results obtained should increase the comprehension of this important mechanism for regulating HS interraction and activity. In addition, they should establish the structural bases for the development of new therapeutic approaches targeting HSulfs, that are biomarkers of tumoral progression, in particular by the design of specific inhibitors.L’endosulfatase humaine HSulf-2 catalyse la 6-O-désulfatation du glycosaminoglycane héparane sulfate (HS) présent à la surface cellulaire. Les propriétés d'interaction de HS sont ainsi finement régulée par son profil de sulfatation. HSulf-2 est synthétisée sous forme d'une protéine qui devient mature après clivage par la furine. Elle présente une organisation moléculaire constituée de deux chaînes reliées vraisemblablement par des ponts disulfures. Un domaine hydrophile (HD) débordant sur les deux chaînes et propre à ces endosulfatases constitue une structure de reconnaissance du substrat. L'organisation de HSulf-2 résultant d'un repliement des deux chaînes reste à déterminer. Les objectifs de ce travail visent à la fois à caractériser la structure, et à déterminer son influence sur l'activité catalytique de HSulf-2. Par des approches biochimiques et biophysiques telles que la spectrométrie de masse et la RMN, nous avons identifié pour la première fois les positions et structures des modifications post-traductionnelles présentes sur HSulf-2. Ainsi 5 N-glycanes ont été caractérisés et 10 cystéines impliquées dans des ponts disulfure ont été identifiées. Nous avons en outre caractérisé une modification post- traductionnelle unique qui est une chaîne de glycosaminoglycane de type chondroïtine sulfate. Nous avons également étudié le rôle de cette chaine qui semble réguler l’activité de HSulf-2. Les résultats obtenus ouvrent des voies de compréhension sur cet important mécanisme de régulation de l'activité de HS. Par ailleurs, ils devraient établir les bases structurales pour le développement de nouvelles approches thérapeutiques ciblant les HSulfs, notamment par la conception d'inhibiteurs spécifiques