Effets de l'environnement sur la plasticité des neurones olfactifs durant le développement (étude anatomique, moléculaire, physiologique et comportementale)

Dans le but d évaluer l impact d une exposition postnatale sur une population spécifique de neurones olfactifs, nous avons exposé au Lyral des souris transgéniques dont les neurones récepteurs olfactifs MOR23 expriment la protéine fluorescente, GFP. Nous avons évalué l impact d une exposition précoce sur la population des neurones MOR23, en utilisant plusieurs méthodes. Par des observations anatomiques, nous montrons que le nombre de neurones olfactifs exprimant MOR23 diminue chez les sujets traités. Cette baisse concerne principalement les neurones matures. Ensuite, des analyses en qPCR quantitatives sur de petits échantillons de cellules isolées indiquent que les neurones MOR23 des souris exposées expriment davantage de récepteurs, de canaux couplés aux nucléotides cycliques (CNGA2) et de phosphodiestérase (PDE1C). La surexpression du récepteur MOR23 par neurone est transitoire. Enfin, cette surexpression est corrélée avec les propriétés électriques des neurones en réponse au ligand du récepteur MOR23 étudiées en patch-clamp. Afin d écarter tout effet aspécifique inhérent à une éventuelle toxicité du Lyral, nous avons réalisé des enregistrements d électroolfactogramme (EOG), une étude transcriptomique (41 gènes) et une étude d immunohistochimie sur la muqueuse olfactive montrant que l EO reste intact après exposition de trois semaines au Lyral. Nous montrons également que l effet est dépendant du couple ligand-récepteur. Enfin, par des observations comportementales, nous montrons que les souris exposées développent une préférence pour le Lyral et passent plus de temps à l explorer.Ensemble, ces résultats suggèrent que les neurones olfactifs font preuve d une certaine plasticité et sont capables de s adapter à l environnementIn order to investigate the consequences of postnatal odorant exposure on a specific population of olfactory sensory neurons (OSNs), we have taken the following experimental approach. MOR23-GFP mice were daily exposed to Lyral for 21 days starting at birth and three lines of investigations were carried out. Using anatomical analysis we observe that the density of OSNs expressing MOR23 decreases after odorant exposure. This decrease concerns primarily matures OSN (MOR23-OMP+). In order to study molecular changes within individual OSNs, mRNA levels for olfactory signaling pathway components were quantitatively analyzed using qPCR on GFP-labeled neurons (7 per mouse). mRNAs for CNGA2, PDE1C and MOR23 olfactory receptor were up-regulated in exposed mice, whereas ACIII transcript levels remained stable. This effect is not permanent: we observed an anatomical and a molecular recovery. Patch-clamp recordings on MOR23 dendritic knobs correlate with qPCR datas. To exclude any aspecific effect due to a possible Lyral toxicity we performed EOG, immunohistochemistry and qPCR on total olfactory epithelium (OE). These experiments show that 3 weeks of Lyral exposure does not damage the OE. Then qPCR on isolated cells reveals that the effect is couple ligand-receptor dependant: M71 neurons are not affected by acetophenone exposure. Finally, we performed behavioral experiments on mice from both groups. Exposed mice favored their exposure odor in olfactory preference test and spend more time exploring Lyral than non-exposed mice. These observations suggest that the environment can induce plasticity in olfactory sensory neuronsDIJON-BU Doc.électronique (212319901) / SudocSudocFranceF

Deep Self-Taught Learning for Handwritten Character Recognition

Recent theoretical and empirical work in statistical machine learning has demonstrated the importance of learning algorithms for deep architectures, i.e., function classes obtained by composing multiple non-linear transformations. Self-taught learning (exploiting unlabeled examples or examples from other distributions) has already been applied to deep learners, but mostly to show the advantage of unlabeled examples. Here we explore the advantage brought by {\em out-of-distribution examples}. For this purpose we developed a powerful generator of stochastic variations and noise processes for character images, including not only affine transformations but also slant, local elastic deformations, changes in thickness, background images, grey level changes, contrast, occlusion, and various types of noise. The out-of-distribution examples are obtained from these highly distorted images or by including examples of object classes different from those in the target test set. We show that {\em deep learners benefit more from out-of-distribution examples than a corresponding shallow learner}, at least in the area of handwritten character recognition. In fact, we show that they beat previously published results and reach human-level performance on both handwritten digit classification and 62-class handwritten character recognition

Study of the correlation between columnar aerosol burden, suspended matter at ground and chemical components in a background European environment

Although routinely monitored by ground based air quality networks, the particulate matter distribution could be eventually better described with remote sensing techniques. However, valid relationships between ground level and columnar ground based quantities should be known beforehand. In this study we have performed a comparison between particulate matter measurements at ground level at different cut sizes (10, 2.5 and 1.0 mm), and the aerosol optical depth obtained by means of a ground based sunphotometer during a multiinstrumental field campaign held in El Arenosillo (Huelva, Spain) from 28 June to 4 July 2006. All the PM fractions were very well correlated with AOD with correlation coefficients that ranged from 0.71 to 0.81 for PM10, PM2.5 and PM1. Furthermore, the influence of the mixing layer height in the correlations was explored. The improvement in the correlation when the vertical distribution is taken into account was significant for days with a homogeneous mixing layer. Moreover, the chemical analysis of the individual size fractions allowed us to study the origin of the particulate matter. Secondary components were the most abundant and also well correlated in the three size fractions; but for PM10 fraction, chemical species related to marine origin were best correlated. Finally, we obtained a relationship between MODIS L3 AOD from collection 5.1 and the three PM cut sizes. In spite of being a relatively clean environment, all the techniques were able to capture similar day to day variations during this field campaign.Peer ReviewedPostprint (published version

Spanish activities in the framework of the CHARMEX project since 2009: a summary

The ChArMEx (Chemistry-Aerosol Mediterranean Experiment) project is a French initiative aiming at developing and coordinating regional research actions for a scientific assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The target of ChArMEx is short-lived particulate and gaseous tropospheric trace species. In 2009 the project gained internationalization with the organization of the first international workshop held in Toulouse, France. Spain was the most represented country (after France) with 7 groups and 10 researchers. Up to date, the Spanish groups involved in ChArMEx have conducted research in several fields. Among them it is worth noting: a 3-year (2010 – 2012) in-situ study over a regional background environment in Mallorca plus 3 intensive measurement campaigns in that period; the installation in Mallorca and in the Sierra Nevada of two autonomous total deposition samplers performing weekly dust deposition on a network basis; and intensive in-situ and remote sensing measurements in Barcelona in thesummer 2012 ChArMEx pre-campaign to give support to airborne observations. The paper gives a summary of all the activities led by Spanish researchers in the framework of ChArMEx. Preliminary results of the 3-year in-situ study in Mallorca and of the summer 2012 pre-campaign, as well as a brief description of the summer 2013 main campaign are presented.Peer ReviewedPostprint (published version

Climatological assessment of the vertically resolved optical and microphysical aerosol properties by lidar measurements, sun photometer, and in situ observations over 17 years at Universitat Politècnica de Catalunya (UPC) Barcelona

Aerosols are one of the most important pollutants in the atmosphere and have been monitored for the past few decades by remote sensing and in situ observation platforms to assess the effectiveness of government-managed reduction emission policies and assess their impact on the radiative budget of the Earth's atmosphere. In fact, aerosols can directly modulate incoming short-wave solar radiation and outgoing long-wave radiation and indirectly influence cloud formation, lifetime, and precipitation. In this study, we quantitatively evaluated long-term temporal trends and seasonal variability from a climatological point of view of the optical and microphysical properties of atmospheric particulate matter at the Universitat Politècnica de Catalunya (UPC), Barcelona, Spain, over the past 17 years, through a synergy of lidar, sun photometer, and in situ concentration measurements. Interannual temporal changes in aerosol optical and microphysical properties are evaluated through the seasonal Mann–Kendall test. Long-term trends in the optical depth of the recovered aerosol; the Ångström exponent (AE); and the concentrations of PM10, PM2.5, and PM1 reveal that emission reduction policies implemented in the past decades were effective in improving air quality, with consistent drops in PM concentrations and optical depth of aerosols. The seasonal analysis of the 17-year average vertically resolved aerosol profiles obtained from lidar observations shows that during summer the aerosol layer can be found up to an altitude of 5 km, after a sharp decay in the first kilometer. In contrast, during the other seasons, the backscatter profiles fit a pronounced exponential decay well with a well-defined scale height. Long-range transport, especially dust outbreaks from the Sahara, is likely to occur throughout the year. During winter, the dust aerosol layers are floating above the boundary layer, while during the other seasons they can penetrate the layer. The analysis also revealed that intense, short-duration pollution events during winter, associated with dust outbreaks, have become more frequent and intense since 2016. This study sheds some light on the meteorological processes and conditions that can lead to the formation of haze and helps decision makers adopt mitigation strategies to preserve large metropolitan areas in the Mediterranean basin.This research has been supported by the European Union through NextgenerationEU funds and by the following projects along the years: FP5 EARLINET project (grant no. ID EVR1-CT-1999-40003), FP6 EARLINET-ASOS (ID: 25991), FP7 ACTRIS (ID: 262254), H2020 ACTRIS-2 (ID: 654109), ACTRIS-PPP (ID: 739530), ACTRIS IMP (ID: 871115) and ATMO-ACCESS (ID: 101008004), projects of the Spanish National Research programs (grant nos. TIC 431/93, AMB96-1144-C02-01, REN2000-1907-CE, REN2000-1754- C02-02/CLI, REN2003-09753-C02-C02/CLI, REN2003-09753- C02-C CGL2008-01330-E/CLI 02/CLI, REN2002-12784-E, CGL2005-5131-E, CGL2006-27108-E/CLI, CGL2006-26149- E/CLI, CGL2007-28871-/CLI, CTM2006-27154-E/TECNO, TEC2006-07850/TCM, TEC2009-09106, TEC2012-34575, TEC2015-63832-P and PID2019-103886RB-I00), the project of the Catalan Regional Government IMMPACTE, and the ESA project (grant no. 21487/08/NL/HE)Peer ReviewedPostprint (published version

Actividades españolas en el marco del proyecto CHARMEX desde 2009: un resumen

El proyecto ChArMEx (Chemistry-Aerosol Mediterranean Experiment) es una iniciativa francesa cuyo objetivo es desarrollar y coordinar las acciones de investigación regionales para una evaluación científica de la situación actual y el futuro del medio ambiente atmosférico en la cuenca mediterránea. Los grupos españoles que participan en ChArMEx llevan a cabo investigaciones en varios campos. Entre ellos cabe señalar: un estudio in-situ de 3 años (2010-2012) en un entorno regional de fondo en Mallorca; la instalación en Mallorca y Granada de dos nuevos colectores de deposición autónomos que colectan la deposición de polvo semanalmente; mediciones intensivas in situ y de teledetección en Barcelona en el verano 2012 durante la pre-campaña ChArMEx; y mediciones de teledetección intensivos en Barcelona y Granada en el verano de 2013 durante la campaña ChArMEx / ADRIMED. Este manuscrito da un resumen de todas las actividades conducidas por investigadores españoles hasta ahora en el marco de ChArMEx. Se presentan resultados preliminares del estudio in-situ de 3 años en Mallorca y parte de las campañas de verano de 2012 y 2013.Peer ReviewedPostprint (published version

An Original Method for the Measurement of the Radiated Susceptibility of an Electronic System Using Induced Electromagnetic Non-linear Effects

International audienceThe objective of this paper is to propose an improved approach based on a novel non-intrusive method for easily assess the high frequency CW EM radiated susceptibility of an electronic system by characterizing its non-linear electromagnetic-effects. For this purpose, we have developed a specific harmonic frequency detection system coupled with a mode stirrer reverberating chamber. We describe the principles of the method, and we study a generic device board which is representative of a real electronic system. We evaluate the EM susceptibility of a micro controller in full functional mode and the data exchanges with two types of external 8 Mb SRAM memories. We observe the EM radiated susceptibility of this device by a functional EMC analysis method; then we measure the harmonic frequency content and make a correlation with the EM susceptibility results. We obtain significant differences between the two memory devices, as a consequence of their different management of internal voltage over stress. We are well aware that this method is currently not validated in industrial environments EMC. In this paper, we only wanted to show that the appearance of the highest harmonic level occurs only when that DUT has the highest functional failure

Air pollution and climate change threats to plant ecosystems

The organizers are thankful to all the attendees for active participation and fruitful discussions. The conference was made possible with support from the European project AIRFRESH (LIFE19 ENV/FR/000086), ARCHES Conseils, France, and the Deputy Ministry of Tourism of Cyprus and the Cyprus Convention Bureau. The physical involvement of E.A. to the conference was supported by the Foreign Young Talents Fund (No. 31950410547) of the National Ministry of Science and Technology, China. E.A. also acknowledges support from the National Natural Science Foundation of China (NSFC) (No. 4210070867), The Startup Foundation for Introducing Talent (No. 003080) of Nanjing University of Information Science & Technology (NUIST), Nanjing, China, and the Jiangsu Distinguished Professor program of the People's Government of Jiangsu Province, China.Peer reviewe